forked from OSchip/llvm-project
11736 lines
416 KiB
C++
11736 lines
416 KiB
C++
//===--- ExprConstant.cpp - Expression Constant Evaluator -----------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the Expr constant evaluator.
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//
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// Constant expression evaluation produces four main results:
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//
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// * A success/failure flag indicating whether constant folding was successful.
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// This is the 'bool' return value used by most of the code in this file. A
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// 'false' return value indicates that constant folding has failed, and any
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// appropriate diagnostic has already been produced.
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//
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// * An evaluated result, valid only if constant folding has not failed.
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//
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// * A flag indicating if evaluation encountered (unevaluated) side-effects.
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// These arise in cases such as (sideEffect(), 0) and (sideEffect() || 1),
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// where it is possible to determine the evaluated result regardless.
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//
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// * A set of notes indicating why the evaluation was not a constant expression
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// (under the C++11 / C++1y rules only, at the moment), or, if folding failed
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// too, why the expression could not be folded.
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//
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// If we are checking for a potential constant expression, failure to constant
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// fold a potential constant sub-expression will be indicated by a 'false'
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// return value (the expression could not be folded) and no diagnostic (the
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// expression is not necessarily non-constant).
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//
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//===----------------------------------------------------------------------===//
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#include "clang/AST/APValue.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/ASTDiagnostic.h"
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#include "clang/AST/ASTLambda.h"
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#include "clang/AST/CharUnits.h"
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#include "clang/AST/Expr.h"
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#include "clang/AST/OSLog.h"
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#include "clang/AST/RecordLayout.h"
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#include "clang/AST/StmtVisitor.h"
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#include "clang/AST/TypeLoc.h"
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#include "clang/Basic/Builtins.h"
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#include "clang/Basic/TargetInfo.h"
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#include "llvm/Support/SaveAndRestore.h"
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#include "llvm/Support/raw_ostream.h"
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#include <cstring>
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#include <functional>
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#define DEBUG_TYPE "exprconstant"
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using namespace clang;
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using llvm::APSInt;
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using llvm::APFloat;
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static bool IsGlobalLValue(APValue::LValueBase B);
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namespace {
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struct LValue;
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struct CallStackFrame;
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struct EvalInfo;
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static QualType getType(APValue::LValueBase B) {
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if (!B) return QualType();
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if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
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// FIXME: It's unclear where we're supposed to take the type from, and
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// this actually matters for arrays of unknown bound. Eg:
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//
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// extern int arr[]; void f() { extern int arr[3]; };
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// constexpr int *p = &arr[1]; // valid?
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//
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// For now, we take the array bound from the most recent declaration.
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for (auto *Redecl = cast<ValueDecl>(D->getMostRecentDecl()); Redecl;
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Redecl = cast_or_null<ValueDecl>(Redecl->getPreviousDecl())) {
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QualType T = Redecl->getType();
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if (!T->isIncompleteArrayType())
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return T;
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}
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return D->getType();
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}
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const Expr *Base = B.get<const Expr*>();
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// For a materialized temporary, the type of the temporary we materialized
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// may not be the type of the expression.
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if (const MaterializeTemporaryExpr *MTE =
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dyn_cast<MaterializeTemporaryExpr>(Base)) {
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SmallVector<const Expr *, 2> CommaLHSs;
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SmallVector<SubobjectAdjustment, 2> Adjustments;
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const Expr *Temp = MTE->GetTemporaryExpr();
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const Expr *Inner = Temp->skipRValueSubobjectAdjustments(CommaLHSs,
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Adjustments);
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// Keep any cv-qualifiers from the reference if we generated a temporary
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// for it directly. Otherwise use the type after adjustment.
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if (!Adjustments.empty())
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return Inner->getType();
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}
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return Base->getType();
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}
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/// Get an LValue path entry, which is known to not be an array index, as a
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/// field or base class.
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static
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APValue::BaseOrMemberType getAsBaseOrMember(APValue::LValuePathEntry E) {
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APValue::BaseOrMemberType Value;
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Value.setFromOpaqueValue(E.BaseOrMember);
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return Value;
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}
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/// Get an LValue path entry, which is known to not be an array index, as a
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/// field declaration.
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static const FieldDecl *getAsField(APValue::LValuePathEntry E) {
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return dyn_cast<FieldDecl>(getAsBaseOrMember(E).getPointer());
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}
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/// Get an LValue path entry, which is known to not be an array index, as a
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/// base class declaration.
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static const CXXRecordDecl *getAsBaseClass(APValue::LValuePathEntry E) {
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return dyn_cast<CXXRecordDecl>(getAsBaseOrMember(E).getPointer());
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}
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/// Determine whether this LValue path entry for a base class names a virtual
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/// base class.
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static bool isVirtualBaseClass(APValue::LValuePathEntry E) {
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return getAsBaseOrMember(E).getInt();
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}
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/// Given a CallExpr, try to get the alloc_size attribute. May return null.
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static const AllocSizeAttr *getAllocSizeAttr(const CallExpr *CE) {
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const FunctionDecl *Callee = CE->getDirectCallee();
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return Callee ? Callee->getAttr<AllocSizeAttr>() : nullptr;
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}
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/// Attempts to unwrap a CallExpr (with an alloc_size attribute) from an Expr.
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/// This will look through a single cast.
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///
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/// Returns null if we couldn't unwrap a function with alloc_size.
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static const CallExpr *tryUnwrapAllocSizeCall(const Expr *E) {
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if (!E->getType()->isPointerType())
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return nullptr;
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E = E->IgnoreParens();
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// If we're doing a variable assignment from e.g. malloc(N), there will
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// probably be a cast of some kind. In exotic cases, we might also see a
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// top-level ExprWithCleanups. Ignore them either way.
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if (const auto *FE = dyn_cast<FullExpr>(E))
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E = FE->getSubExpr()->IgnoreParens();
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if (const auto *Cast = dyn_cast<CastExpr>(E))
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E = Cast->getSubExpr()->IgnoreParens();
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if (const auto *CE = dyn_cast<CallExpr>(E))
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return getAllocSizeAttr(CE) ? CE : nullptr;
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return nullptr;
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}
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/// Determines whether or not the given Base contains a call to a function
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/// with the alloc_size attribute.
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static bool isBaseAnAllocSizeCall(APValue::LValueBase Base) {
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const auto *E = Base.dyn_cast<const Expr *>();
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return E && E->getType()->isPointerType() && tryUnwrapAllocSizeCall(E);
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}
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/// The bound to claim that an array of unknown bound has.
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/// The value in MostDerivedArraySize is undefined in this case. So, set it
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/// to an arbitrary value that's likely to loudly break things if it's used.
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static const uint64_t AssumedSizeForUnsizedArray =
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std::numeric_limits<uint64_t>::max() / 2;
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/// Determines if an LValue with the given LValueBase will have an unsized
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/// array in its designator.
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/// Find the path length and type of the most-derived subobject in the given
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/// path, and find the size of the containing array, if any.
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static unsigned
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findMostDerivedSubobject(ASTContext &Ctx, APValue::LValueBase Base,
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ArrayRef<APValue::LValuePathEntry> Path,
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uint64_t &ArraySize, QualType &Type, bool &IsArray,
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bool &FirstEntryIsUnsizedArray) {
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// This only accepts LValueBases from APValues, and APValues don't support
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// arrays that lack size info.
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assert(!isBaseAnAllocSizeCall(Base) &&
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"Unsized arrays shouldn't appear here");
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unsigned MostDerivedLength = 0;
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Type = getType(Base);
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for (unsigned I = 0, N = Path.size(); I != N; ++I) {
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if (Type->isArrayType()) {
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const ArrayType *AT = Ctx.getAsArrayType(Type);
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Type = AT->getElementType();
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MostDerivedLength = I + 1;
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IsArray = true;
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if (auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
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ArraySize = CAT->getSize().getZExtValue();
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} else {
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assert(I == 0 && "unexpected unsized array designator");
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FirstEntryIsUnsizedArray = true;
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ArraySize = AssumedSizeForUnsizedArray;
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}
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} else if (Type->isAnyComplexType()) {
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const ComplexType *CT = Type->castAs<ComplexType>();
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Type = CT->getElementType();
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ArraySize = 2;
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MostDerivedLength = I + 1;
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IsArray = true;
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} else if (const FieldDecl *FD = getAsField(Path[I])) {
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Type = FD->getType();
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ArraySize = 0;
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MostDerivedLength = I + 1;
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IsArray = false;
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} else {
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// Path[I] describes a base class.
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ArraySize = 0;
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IsArray = false;
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}
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}
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return MostDerivedLength;
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}
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// The order of this enum is important for diagnostics.
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enum CheckSubobjectKind {
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CSK_Base, CSK_Derived, CSK_Field, CSK_ArrayToPointer, CSK_ArrayIndex,
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CSK_This, CSK_Real, CSK_Imag
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};
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/// A path from a glvalue to a subobject of that glvalue.
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struct SubobjectDesignator {
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/// True if the subobject was named in a manner not supported by C++11. Such
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/// lvalues can still be folded, but they are not core constant expressions
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/// and we cannot perform lvalue-to-rvalue conversions on them.
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unsigned Invalid : 1;
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/// Is this a pointer one past the end of an object?
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unsigned IsOnePastTheEnd : 1;
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/// Indicator of whether the first entry is an unsized array.
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unsigned FirstEntryIsAnUnsizedArray : 1;
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/// Indicator of whether the most-derived object is an array element.
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unsigned MostDerivedIsArrayElement : 1;
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/// The length of the path to the most-derived object of which this is a
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/// subobject.
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unsigned MostDerivedPathLength : 28;
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/// The size of the array of which the most-derived object is an element.
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/// This will always be 0 if the most-derived object is not an array
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/// element. 0 is not an indicator of whether or not the most-derived object
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/// is an array, however, because 0-length arrays are allowed.
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///
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/// If the current array is an unsized array, the value of this is
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/// undefined.
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uint64_t MostDerivedArraySize;
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/// The type of the most derived object referred to by this address.
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QualType MostDerivedType;
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typedef APValue::LValuePathEntry PathEntry;
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/// The entries on the path from the glvalue to the designated subobject.
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SmallVector<PathEntry, 8> Entries;
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SubobjectDesignator() : Invalid(true) {}
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explicit SubobjectDesignator(QualType T)
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: Invalid(false), IsOnePastTheEnd(false),
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FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
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MostDerivedPathLength(0), MostDerivedArraySize(0),
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MostDerivedType(T) {}
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SubobjectDesignator(ASTContext &Ctx, const APValue &V)
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: Invalid(!V.isLValue() || !V.hasLValuePath()), IsOnePastTheEnd(false),
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FirstEntryIsAnUnsizedArray(false), MostDerivedIsArrayElement(false),
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MostDerivedPathLength(0), MostDerivedArraySize(0) {
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assert(V.isLValue() && "Non-LValue used to make an LValue designator?");
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if (!Invalid) {
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IsOnePastTheEnd = V.isLValueOnePastTheEnd();
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ArrayRef<PathEntry> VEntries = V.getLValuePath();
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Entries.insert(Entries.end(), VEntries.begin(), VEntries.end());
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if (V.getLValueBase()) {
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bool IsArray = false;
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bool FirstIsUnsizedArray = false;
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MostDerivedPathLength = findMostDerivedSubobject(
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Ctx, V.getLValueBase(), V.getLValuePath(), MostDerivedArraySize,
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MostDerivedType, IsArray, FirstIsUnsizedArray);
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MostDerivedIsArrayElement = IsArray;
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FirstEntryIsAnUnsizedArray = FirstIsUnsizedArray;
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}
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}
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}
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void setInvalid() {
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Invalid = true;
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Entries.clear();
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}
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/// Determine whether the most derived subobject is an array without a
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/// known bound.
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bool isMostDerivedAnUnsizedArray() const {
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assert(!Invalid && "Calling this makes no sense on invalid designators");
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return Entries.size() == 1 && FirstEntryIsAnUnsizedArray;
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}
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/// Determine what the most derived array's size is. Results in an assertion
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/// failure if the most derived array lacks a size.
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uint64_t getMostDerivedArraySize() const {
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assert(!isMostDerivedAnUnsizedArray() && "Unsized array has no size");
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return MostDerivedArraySize;
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}
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/// Determine whether this is a one-past-the-end pointer.
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bool isOnePastTheEnd() const {
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assert(!Invalid);
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if (IsOnePastTheEnd)
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return true;
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if (!isMostDerivedAnUnsizedArray() && MostDerivedIsArrayElement &&
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Entries[MostDerivedPathLength - 1].ArrayIndex == MostDerivedArraySize)
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return true;
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return false;
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}
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/// Get the range of valid index adjustments in the form
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/// {maximum value that can be subtracted from this pointer,
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/// maximum value that can be added to this pointer}
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std::pair<uint64_t, uint64_t> validIndexAdjustments() {
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if (Invalid || isMostDerivedAnUnsizedArray())
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return {0, 0};
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// [expr.add]p4: For the purposes of these operators, a pointer to a
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// nonarray object behaves the same as a pointer to the first element of
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// an array of length one with the type of the object as its element type.
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bool IsArray = MostDerivedPathLength == Entries.size() &&
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MostDerivedIsArrayElement;
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uint64_t ArrayIndex =
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IsArray ? Entries.back().ArrayIndex : (uint64_t)IsOnePastTheEnd;
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uint64_t ArraySize =
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IsArray ? getMostDerivedArraySize() : (uint64_t)1;
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return {ArrayIndex, ArraySize - ArrayIndex};
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}
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/// Check that this refers to a valid subobject.
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bool isValidSubobject() const {
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if (Invalid)
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return false;
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return !isOnePastTheEnd();
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}
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/// Check that this refers to a valid subobject, and if not, produce a
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/// relevant diagnostic and set the designator as invalid.
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bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK);
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/// Get the type of the designated object.
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QualType getType(ASTContext &Ctx) const {
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assert(!Invalid && "invalid designator has no subobject type");
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return MostDerivedPathLength == Entries.size()
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? MostDerivedType
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: Ctx.getRecordType(getAsBaseClass(Entries.back()));
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}
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/// Update this designator to refer to the first element within this array.
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void addArrayUnchecked(const ConstantArrayType *CAT) {
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PathEntry Entry;
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Entry.ArrayIndex = 0;
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Entries.push_back(Entry);
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// This is a most-derived object.
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MostDerivedType = CAT->getElementType();
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MostDerivedIsArrayElement = true;
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MostDerivedArraySize = CAT->getSize().getZExtValue();
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MostDerivedPathLength = Entries.size();
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}
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/// Update this designator to refer to the first element within the array of
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/// elements of type T. This is an array of unknown size.
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void addUnsizedArrayUnchecked(QualType ElemTy) {
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PathEntry Entry;
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Entry.ArrayIndex = 0;
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Entries.push_back(Entry);
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MostDerivedType = ElemTy;
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MostDerivedIsArrayElement = true;
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// The value in MostDerivedArraySize is undefined in this case. So, set it
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// to an arbitrary value that's likely to loudly break things if it's
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// used.
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MostDerivedArraySize = AssumedSizeForUnsizedArray;
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MostDerivedPathLength = Entries.size();
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}
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/// Update this designator to refer to the given base or member of this
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/// object.
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void addDeclUnchecked(const Decl *D, bool Virtual = false) {
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PathEntry Entry;
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APValue::BaseOrMemberType Value(D, Virtual);
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Entry.BaseOrMember = Value.getOpaqueValue();
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Entries.push_back(Entry);
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// If this isn't a base class, it's a new most-derived object.
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if (const FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
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MostDerivedType = FD->getType();
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MostDerivedIsArrayElement = false;
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MostDerivedArraySize = 0;
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MostDerivedPathLength = Entries.size();
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}
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}
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/// Update this designator to refer to the given complex component.
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void addComplexUnchecked(QualType EltTy, bool Imag) {
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PathEntry Entry;
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Entry.ArrayIndex = Imag;
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Entries.push_back(Entry);
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// This is technically a most-derived object, though in practice this
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// is unlikely to matter.
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MostDerivedType = EltTy;
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MostDerivedIsArrayElement = true;
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MostDerivedArraySize = 2;
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MostDerivedPathLength = Entries.size();
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}
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void diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info, const Expr *E);
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void diagnosePointerArithmetic(EvalInfo &Info, const Expr *E,
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const APSInt &N);
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/// Add N to the address of this subobject.
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void adjustIndex(EvalInfo &Info, const Expr *E, APSInt N) {
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if (Invalid || !N) return;
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uint64_t TruncatedN = N.extOrTrunc(64).getZExtValue();
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if (isMostDerivedAnUnsizedArray()) {
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diagnoseUnsizedArrayPointerArithmetic(Info, E);
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// Can't verify -- trust that the user is doing the right thing (or if
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// not, trust that the caller will catch the bad behavior).
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// FIXME: Should we reject if this overflows, at least?
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Entries.back().ArrayIndex += TruncatedN;
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return;
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}
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// [expr.add]p4: For the purposes of these operators, a pointer to a
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// nonarray object behaves the same as a pointer to the first element of
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// an array of length one with the type of the object as its element type.
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bool IsArray = MostDerivedPathLength == Entries.size() &&
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MostDerivedIsArrayElement;
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uint64_t ArrayIndex =
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IsArray ? Entries.back().ArrayIndex : (uint64_t)IsOnePastTheEnd;
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uint64_t ArraySize =
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IsArray ? getMostDerivedArraySize() : (uint64_t)1;
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if (N < -(int64_t)ArrayIndex || N > ArraySize - ArrayIndex) {
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// Calculate the actual index in a wide enough type, so we can include
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// it in the note.
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N = N.extend(std::max<unsigned>(N.getBitWidth() + 1, 65));
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(llvm::APInt&)N += ArrayIndex;
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assert(N.ugt(ArraySize) && "bounds check failed for in-bounds index");
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diagnosePointerArithmetic(Info, E, N);
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setInvalid();
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return;
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}
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ArrayIndex += TruncatedN;
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assert(ArrayIndex <= ArraySize &&
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"bounds check succeeded for out-of-bounds index");
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if (IsArray)
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Entries.back().ArrayIndex = ArrayIndex;
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else
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IsOnePastTheEnd = (ArrayIndex != 0);
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}
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};
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/// A stack frame in the constexpr call stack.
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struct CallStackFrame {
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EvalInfo &Info;
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/// Parent - The caller of this stack frame.
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CallStackFrame *Caller;
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/// Callee - The function which was called.
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const FunctionDecl *Callee;
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/// This - The binding for the this pointer in this call, if any.
|
|
const LValue *This;
|
|
|
|
/// Arguments - Parameter bindings for this function call, indexed by
|
|
/// parameters' function scope indices.
|
|
APValue *Arguments;
|
|
|
|
// Note that we intentionally use std::map here so that references to
|
|
// values are stable.
|
|
typedef std::pair<const void *, unsigned> MapKeyTy;
|
|
typedef std::map<MapKeyTy, APValue> MapTy;
|
|
/// Temporaries - Temporary lvalues materialized within this stack frame.
|
|
MapTy Temporaries;
|
|
|
|
/// CallLoc - The location of the call expression for this call.
|
|
SourceLocation CallLoc;
|
|
|
|
/// Index - The call index of this call.
|
|
unsigned Index;
|
|
|
|
/// The stack of integers for tracking version numbers for temporaries.
|
|
SmallVector<unsigned, 2> TempVersionStack = {1};
|
|
unsigned CurTempVersion = TempVersionStack.back();
|
|
|
|
unsigned getTempVersion() const { return TempVersionStack.back(); }
|
|
|
|
void pushTempVersion() {
|
|
TempVersionStack.push_back(++CurTempVersion);
|
|
}
|
|
|
|
void popTempVersion() {
|
|
TempVersionStack.pop_back();
|
|
}
|
|
|
|
// FIXME: Adding this to every 'CallStackFrame' may have a nontrivial impact
|
|
// on the overall stack usage of deeply-recursing constexpr evaluations.
|
|
// (We should cache this map rather than recomputing it repeatedly.)
|
|
// But let's try this and see how it goes; we can look into caching the map
|
|
// as a later change.
|
|
|
|
/// LambdaCaptureFields - Mapping from captured variables/this to
|
|
/// corresponding data members in the closure class.
|
|
llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
|
|
FieldDecl *LambdaThisCaptureField;
|
|
|
|
CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
|
|
const FunctionDecl *Callee, const LValue *This,
|
|
APValue *Arguments);
|
|
~CallStackFrame();
|
|
|
|
// Return the temporary for Key whose version number is Version.
|
|
APValue *getTemporary(const void *Key, unsigned Version) {
|
|
MapKeyTy KV(Key, Version);
|
|
auto LB = Temporaries.lower_bound(KV);
|
|
if (LB != Temporaries.end() && LB->first == KV)
|
|
return &LB->second;
|
|
// Pair (Key,Version) wasn't found in the map. Check that no elements
|
|
// in the map have 'Key' as their key.
|
|
assert((LB == Temporaries.end() || LB->first.first != Key) &&
|
|
(LB == Temporaries.begin() || std::prev(LB)->first.first != Key) &&
|
|
"Element with key 'Key' found in map");
|
|
return nullptr;
|
|
}
|
|
|
|
// Return the current temporary for Key in the map.
|
|
APValue *getCurrentTemporary(const void *Key) {
|
|
auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX));
|
|
if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
|
|
return &std::prev(UB)->second;
|
|
return nullptr;
|
|
}
|
|
|
|
// Return the version number of the current temporary for Key.
|
|
unsigned getCurrentTemporaryVersion(const void *Key) const {
|
|
auto UB = Temporaries.upper_bound(MapKeyTy(Key, UINT_MAX));
|
|
if (UB != Temporaries.begin() && std::prev(UB)->first.first == Key)
|
|
return std::prev(UB)->first.second;
|
|
return 0;
|
|
}
|
|
|
|
APValue &createTemporary(const void *Key, bool IsLifetimeExtended);
|
|
};
|
|
|
|
/// Temporarily override 'this'.
|
|
class ThisOverrideRAII {
|
|
public:
|
|
ThisOverrideRAII(CallStackFrame &Frame, const LValue *NewThis, bool Enable)
|
|
: Frame(Frame), OldThis(Frame.This) {
|
|
if (Enable)
|
|
Frame.This = NewThis;
|
|
}
|
|
~ThisOverrideRAII() {
|
|
Frame.This = OldThis;
|
|
}
|
|
private:
|
|
CallStackFrame &Frame;
|
|
const LValue *OldThis;
|
|
};
|
|
|
|
/// A partial diagnostic which we might know in advance that we are not going
|
|
/// to emit.
|
|
class OptionalDiagnostic {
|
|
PartialDiagnostic *Diag;
|
|
|
|
public:
|
|
explicit OptionalDiagnostic(PartialDiagnostic *Diag = nullptr)
|
|
: Diag(Diag) {}
|
|
|
|
template<typename T>
|
|
OptionalDiagnostic &operator<<(const T &v) {
|
|
if (Diag)
|
|
*Diag << v;
|
|
return *this;
|
|
}
|
|
|
|
OptionalDiagnostic &operator<<(const APSInt &I) {
|
|
if (Diag) {
|
|
SmallVector<char, 32> Buffer;
|
|
I.toString(Buffer);
|
|
*Diag << StringRef(Buffer.data(), Buffer.size());
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
OptionalDiagnostic &operator<<(const APFloat &F) {
|
|
if (Diag) {
|
|
// FIXME: Force the precision of the source value down so we don't
|
|
// print digits which are usually useless (we don't really care here if
|
|
// we truncate a digit by accident in edge cases). Ideally,
|
|
// APFloat::toString would automatically print the shortest
|
|
// representation which rounds to the correct value, but it's a bit
|
|
// tricky to implement.
|
|
unsigned precision =
|
|
llvm::APFloat::semanticsPrecision(F.getSemantics());
|
|
precision = (precision * 59 + 195) / 196;
|
|
SmallVector<char, 32> Buffer;
|
|
F.toString(Buffer, precision);
|
|
*Diag << StringRef(Buffer.data(), Buffer.size());
|
|
}
|
|
return *this;
|
|
}
|
|
};
|
|
|
|
/// A cleanup, and a flag indicating whether it is lifetime-extended.
|
|
class Cleanup {
|
|
llvm::PointerIntPair<APValue*, 1, bool> Value;
|
|
|
|
public:
|
|
Cleanup(APValue *Val, bool IsLifetimeExtended)
|
|
: Value(Val, IsLifetimeExtended) {}
|
|
|
|
bool isLifetimeExtended() const { return Value.getInt(); }
|
|
void endLifetime() {
|
|
*Value.getPointer() = APValue();
|
|
}
|
|
};
|
|
|
|
/// EvalInfo - This is a private struct used by the evaluator to capture
|
|
/// information about a subexpression as it is folded. It retains information
|
|
/// about the AST context, but also maintains information about the folded
|
|
/// expression.
|
|
///
|
|
/// If an expression could be evaluated, it is still possible it is not a C
|
|
/// "integer constant expression" or constant expression. If not, this struct
|
|
/// captures information about how and why not.
|
|
///
|
|
/// One bit of information passed *into* the request for constant folding
|
|
/// indicates whether the subexpression is "evaluated" or not according to C
|
|
/// rules. For example, the RHS of (0 && foo()) is not evaluated. We can
|
|
/// evaluate the expression regardless of what the RHS is, but C only allows
|
|
/// certain things in certain situations.
|
|
struct EvalInfo {
|
|
ASTContext &Ctx;
|
|
|
|
/// EvalStatus - Contains information about the evaluation.
|
|
Expr::EvalStatus &EvalStatus;
|
|
|
|
/// CurrentCall - The top of the constexpr call stack.
|
|
CallStackFrame *CurrentCall;
|
|
|
|
/// CallStackDepth - The number of calls in the call stack right now.
|
|
unsigned CallStackDepth;
|
|
|
|
/// NextCallIndex - The next call index to assign.
|
|
unsigned NextCallIndex;
|
|
|
|
/// StepsLeft - The remaining number of evaluation steps we're permitted
|
|
/// to perform. This is essentially a limit for the number of statements
|
|
/// we will evaluate.
|
|
unsigned StepsLeft;
|
|
|
|
/// BottomFrame - The frame in which evaluation started. This must be
|
|
/// initialized after CurrentCall and CallStackDepth.
|
|
CallStackFrame BottomFrame;
|
|
|
|
/// A stack of values whose lifetimes end at the end of some surrounding
|
|
/// evaluation frame.
|
|
llvm::SmallVector<Cleanup, 16> CleanupStack;
|
|
|
|
/// EvaluatingDecl - This is the declaration whose initializer is being
|
|
/// evaluated, if any.
|
|
APValue::LValueBase EvaluatingDecl;
|
|
|
|
/// EvaluatingDeclValue - This is the value being constructed for the
|
|
/// declaration whose initializer is being evaluated, if any.
|
|
APValue *EvaluatingDeclValue;
|
|
|
|
/// EvaluatingObject - Pair of the AST node that an lvalue represents and
|
|
/// the call index that that lvalue was allocated in.
|
|
typedef std::pair<APValue::LValueBase, std::pair<unsigned, unsigned>>
|
|
EvaluatingObject;
|
|
|
|
/// EvaluatingConstructors - Set of objects that are currently being
|
|
/// constructed.
|
|
llvm::DenseSet<EvaluatingObject> EvaluatingConstructors;
|
|
|
|
struct EvaluatingConstructorRAII {
|
|
EvalInfo &EI;
|
|
EvaluatingObject Object;
|
|
bool DidInsert;
|
|
EvaluatingConstructorRAII(EvalInfo &EI, EvaluatingObject Object)
|
|
: EI(EI), Object(Object) {
|
|
DidInsert = EI.EvaluatingConstructors.insert(Object).second;
|
|
}
|
|
~EvaluatingConstructorRAII() {
|
|
if (DidInsert) EI.EvaluatingConstructors.erase(Object);
|
|
}
|
|
};
|
|
|
|
bool isEvaluatingConstructor(APValue::LValueBase Decl, unsigned CallIndex,
|
|
unsigned Version) {
|
|
return EvaluatingConstructors.count(
|
|
EvaluatingObject(Decl, {CallIndex, Version}));
|
|
}
|
|
|
|
/// The current array initialization index, if we're performing array
|
|
/// initialization.
|
|
uint64_t ArrayInitIndex = -1;
|
|
|
|
/// HasActiveDiagnostic - Was the previous diagnostic stored? If so, further
|
|
/// notes attached to it will also be stored, otherwise they will not be.
|
|
bool HasActiveDiagnostic;
|
|
|
|
/// Have we emitted a diagnostic explaining why we couldn't constant
|
|
/// fold (not just why it's not strictly a constant expression)?
|
|
bool HasFoldFailureDiagnostic;
|
|
|
|
/// Whether or not we're currently speculatively evaluating.
|
|
bool IsSpeculativelyEvaluating;
|
|
|
|
/// Whether or not we're in a context where the front end requires a
|
|
/// constant value.
|
|
bool InConstantContext;
|
|
|
|
enum EvaluationMode {
|
|
/// Evaluate as a constant expression. Stop if we find that the expression
|
|
/// is not a constant expression.
|
|
EM_ConstantExpression,
|
|
|
|
/// Evaluate as a potential constant expression. Keep going if we hit a
|
|
/// construct that we can't evaluate yet (because we don't yet know the
|
|
/// value of something) but stop if we hit something that could never be
|
|
/// a constant expression.
|
|
EM_PotentialConstantExpression,
|
|
|
|
/// Fold the expression to a constant. Stop if we hit a side-effect that
|
|
/// we can't model.
|
|
EM_ConstantFold,
|
|
|
|
/// Evaluate the expression looking for integer overflow and similar
|
|
/// issues. Don't worry about side-effects, and try to visit all
|
|
/// subexpressions.
|
|
EM_EvaluateForOverflow,
|
|
|
|
/// Evaluate in any way we know how. Don't worry about side-effects that
|
|
/// can't be modeled.
|
|
EM_IgnoreSideEffects,
|
|
|
|
/// Evaluate as a constant expression. Stop if we find that the expression
|
|
/// is not a constant expression. Some expressions can be retried in the
|
|
/// optimizer if we don't constant fold them here, but in an unevaluated
|
|
/// context we try to fold them immediately since the optimizer never
|
|
/// gets a chance to look at it.
|
|
EM_ConstantExpressionUnevaluated,
|
|
|
|
/// Evaluate as a potential constant expression. Keep going if we hit a
|
|
/// construct that we can't evaluate yet (because we don't yet know the
|
|
/// value of something) but stop if we hit something that could never be
|
|
/// a constant expression. Some expressions can be retried in the
|
|
/// optimizer if we don't constant fold them here, but in an unevaluated
|
|
/// context we try to fold them immediately since the optimizer never
|
|
/// gets a chance to look at it.
|
|
EM_PotentialConstantExpressionUnevaluated,
|
|
} EvalMode;
|
|
|
|
/// Are we checking whether the expression is a potential constant
|
|
/// expression?
|
|
bool checkingPotentialConstantExpression() const {
|
|
return EvalMode == EM_PotentialConstantExpression ||
|
|
EvalMode == EM_PotentialConstantExpressionUnevaluated;
|
|
}
|
|
|
|
/// Are we checking an expression for overflow?
|
|
// FIXME: We should check for any kind of undefined or suspicious behavior
|
|
// in such constructs, not just overflow.
|
|
bool checkingForOverflow() { return EvalMode == EM_EvaluateForOverflow; }
|
|
|
|
EvalInfo(const ASTContext &C, Expr::EvalStatus &S, EvaluationMode Mode)
|
|
: Ctx(const_cast<ASTContext &>(C)), EvalStatus(S), CurrentCall(nullptr),
|
|
CallStackDepth(0), NextCallIndex(1),
|
|
StepsLeft(getLangOpts().ConstexprStepLimit),
|
|
BottomFrame(*this, SourceLocation(), nullptr, nullptr, nullptr),
|
|
EvaluatingDecl((const ValueDecl *)nullptr),
|
|
EvaluatingDeclValue(nullptr), HasActiveDiagnostic(false),
|
|
HasFoldFailureDiagnostic(false), IsSpeculativelyEvaluating(false),
|
|
InConstantContext(false), EvalMode(Mode) {}
|
|
|
|
void setEvaluatingDecl(APValue::LValueBase Base, APValue &Value) {
|
|
EvaluatingDecl = Base;
|
|
EvaluatingDeclValue = &Value;
|
|
EvaluatingConstructors.insert({Base, {0, 0}});
|
|
}
|
|
|
|
const LangOptions &getLangOpts() const { return Ctx.getLangOpts(); }
|
|
|
|
bool CheckCallLimit(SourceLocation Loc) {
|
|
// Don't perform any constexpr calls (other than the call we're checking)
|
|
// when checking a potential constant expression.
|
|
if (checkingPotentialConstantExpression() && CallStackDepth > 1)
|
|
return false;
|
|
if (NextCallIndex == 0) {
|
|
// NextCallIndex has wrapped around.
|
|
FFDiag(Loc, diag::note_constexpr_call_limit_exceeded);
|
|
return false;
|
|
}
|
|
if (CallStackDepth <= getLangOpts().ConstexprCallDepth)
|
|
return true;
|
|
FFDiag(Loc, diag::note_constexpr_depth_limit_exceeded)
|
|
<< getLangOpts().ConstexprCallDepth;
|
|
return false;
|
|
}
|
|
|
|
CallStackFrame *getCallFrame(unsigned CallIndex) {
|
|
assert(CallIndex && "no call index in getCallFrame");
|
|
// We will eventually hit BottomFrame, which has Index 1, so Frame can't
|
|
// be null in this loop.
|
|
CallStackFrame *Frame = CurrentCall;
|
|
while (Frame->Index > CallIndex)
|
|
Frame = Frame->Caller;
|
|
return (Frame->Index == CallIndex) ? Frame : nullptr;
|
|
}
|
|
|
|
bool nextStep(const Stmt *S) {
|
|
if (!StepsLeft) {
|
|
FFDiag(S->getBeginLoc(), diag::note_constexpr_step_limit_exceeded);
|
|
return false;
|
|
}
|
|
--StepsLeft;
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
/// Add a diagnostic to the diagnostics list.
|
|
PartialDiagnostic &addDiag(SourceLocation Loc, diag::kind DiagId) {
|
|
PartialDiagnostic PD(DiagId, Ctx.getDiagAllocator());
|
|
EvalStatus.Diag->push_back(std::make_pair(Loc, PD));
|
|
return EvalStatus.Diag->back().second;
|
|
}
|
|
|
|
/// Add notes containing a call stack to the current point of evaluation.
|
|
void addCallStack(unsigned Limit);
|
|
|
|
private:
|
|
OptionalDiagnostic Diag(SourceLocation Loc, diag::kind DiagId,
|
|
unsigned ExtraNotes, bool IsCCEDiag) {
|
|
|
|
if (EvalStatus.Diag) {
|
|
// If we have a prior diagnostic, it will be noting that the expression
|
|
// isn't a constant expression. This diagnostic is more important,
|
|
// unless we require this evaluation to produce a constant expression.
|
|
//
|
|
// FIXME: We might want to show both diagnostics to the user in
|
|
// EM_ConstantFold mode.
|
|
if (!EvalStatus.Diag->empty()) {
|
|
switch (EvalMode) {
|
|
case EM_ConstantFold:
|
|
case EM_IgnoreSideEffects:
|
|
case EM_EvaluateForOverflow:
|
|
if (!HasFoldFailureDiagnostic)
|
|
break;
|
|
// We've already failed to fold something. Keep that diagnostic.
|
|
LLVM_FALLTHROUGH;
|
|
case EM_ConstantExpression:
|
|
case EM_PotentialConstantExpression:
|
|
case EM_ConstantExpressionUnevaluated:
|
|
case EM_PotentialConstantExpressionUnevaluated:
|
|
HasActiveDiagnostic = false;
|
|
return OptionalDiagnostic();
|
|
}
|
|
}
|
|
|
|
unsigned CallStackNotes = CallStackDepth - 1;
|
|
unsigned Limit = Ctx.getDiagnostics().getConstexprBacktraceLimit();
|
|
if (Limit)
|
|
CallStackNotes = std::min(CallStackNotes, Limit + 1);
|
|
if (checkingPotentialConstantExpression())
|
|
CallStackNotes = 0;
|
|
|
|
HasActiveDiagnostic = true;
|
|
HasFoldFailureDiagnostic = !IsCCEDiag;
|
|
EvalStatus.Diag->clear();
|
|
EvalStatus.Diag->reserve(1 + ExtraNotes + CallStackNotes);
|
|
addDiag(Loc, DiagId);
|
|
if (!checkingPotentialConstantExpression())
|
|
addCallStack(Limit);
|
|
return OptionalDiagnostic(&(*EvalStatus.Diag)[0].second);
|
|
}
|
|
HasActiveDiagnostic = false;
|
|
return OptionalDiagnostic();
|
|
}
|
|
public:
|
|
// Diagnose that the evaluation could not be folded (FF => FoldFailure)
|
|
OptionalDiagnostic
|
|
FFDiag(SourceLocation Loc,
|
|
diag::kind DiagId = diag::note_invalid_subexpr_in_const_expr,
|
|
unsigned ExtraNotes = 0) {
|
|
return Diag(Loc, DiagId, ExtraNotes, false);
|
|
}
|
|
|
|
OptionalDiagnostic FFDiag(const Expr *E, diag::kind DiagId
|
|
= diag::note_invalid_subexpr_in_const_expr,
|
|
unsigned ExtraNotes = 0) {
|
|
if (EvalStatus.Diag)
|
|
return Diag(E->getExprLoc(), DiagId, ExtraNotes, /*IsCCEDiag*/false);
|
|
HasActiveDiagnostic = false;
|
|
return OptionalDiagnostic();
|
|
}
|
|
|
|
/// Diagnose that the evaluation does not produce a C++11 core constant
|
|
/// expression.
|
|
///
|
|
/// FIXME: Stop evaluating if we're in EM_ConstantExpression or
|
|
/// EM_PotentialConstantExpression mode and we produce one of these.
|
|
OptionalDiagnostic CCEDiag(SourceLocation Loc, diag::kind DiagId
|
|
= diag::note_invalid_subexpr_in_const_expr,
|
|
unsigned ExtraNotes = 0) {
|
|
// Don't override a previous diagnostic. Don't bother collecting
|
|
// diagnostics if we're evaluating for overflow.
|
|
if (!EvalStatus.Diag || !EvalStatus.Diag->empty()) {
|
|
HasActiveDiagnostic = false;
|
|
return OptionalDiagnostic();
|
|
}
|
|
return Diag(Loc, DiagId, ExtraNotes, true);
|
|
}
|
|
OptionalDiagnostic CCEDiag(const Expr *E, diag::kind DiagId
|
|
= diag::note_invalid_subexpr_in_const_expr,
|
|
unsigned ExtraNotes = 0) {
|
|
return CCEDiag(E->getExprLoc(), DiagId, ExtraNotes);
|
|
}
|
|
/// Add a note to a prior diagnostic.
|
|
OptionalDiagnostic Note(SourceLocation Loc, diag::kind DiagId) {
|
|
if (!HasActiveDiagnostic)
|
|
return OptionalDiagnostic();
|
|
return OptionalDiagnostic(&addDiag(Loc, DiagId));
|
|
}
|
|
|
|
/// Add a stack of notes to a prior diagnostic.
|
|
void addNotes(ArrayRef<PartialDiagnosticAt> Diags) {
|
|
if (HasActiveDiagnostic) {
|
|
EvalStatus.Diag->insert(EvalStatus.Diag->end(),
|
|
Diags.begin(), Diags.end());
|
|
}
|
|
}
|
|
|
|
/// Should we continue evaluation after encountering a side-effect that we
|
|
/// couldn't model?
|
|
bool keepEvaluatingAfterSideEffect() {
|
|
switch (EvalMode) {
|
|
case EM_PotentialConstantExpression:
|
|
case EM_PotentialConstantExpressionUnevaluated:
|
|
case EM_EvaluateForOverflow:
|
|
case EM_IgnoreSideEffects:
|
|
return true;
|
|
|
|
case EM_ConstantExpression:
|
|
case EM_ConstantExpressionUnevaluated:
|
|
case EM_ConstantFold:
|
|
return false;
|
|
}
|
|
llvm_unreachable("Missed EvalMode case");
|
|
}
|
|
|
|
/// Note that we have had a side-effect, and determine whether we should
|
|
/// keep evaluating.
|
|
bool noteSideEffect() {
|
|
EvalStatus.HasSideEffects = true;
|
|
return keepEvaluatingAfterSideEffect();
|
|
}
|
|
|
|
/// Should we continue evaluation after encountering undefined behavior?
|
|
bool keepEvaluatingAfterUndefinedBehavior() {
|
|
switch (EvalMode) {
|
|
case EM_EvaluateForOverflow:
|
|
case EM_IgnoreSideEffects:
|
|
case EM_ConstantFold:
|
|
return true;
|
|
|
|
case EM_PotentialConstantExpression:
|
|
case EM_PotentialConstantExpressionUnevaluated:
|
|
case EM_ConstantExpression:
|
|
case EM_ConstantExpressionUnevaluated:
|
|
return false;
|
|
}
|
|
llvm_unreachable("Missed EvalMode case");
|
|
}
|
|
|
|
/// Note that we hit something that was technically undefined behavior, but
|
|
/// that we can evaluate past it (such as signed overflow or floating-point
|
|
/// division by zero.)
|
|
bool noteUndefinedBehavior() {
|
|
EvalStatus.HasUndefinedBehavior = true;
|
|
return keepEvaluatingAfterUndefinedBehavior();
|
|
}
|
|
|
|
/// Should we continue evaluation as much as possible after encountering a
|
|
/// construct which can't be reduced to a value?
|
|
bool keepEvaluatingAfterFailure() {
|
|
if (!StepsLeft)
|
|
return false;
|
|
|
|
switch (EvalMode) {
|
|
case EM_PotentialConstantExpression:
|
|
case EM_PotentialConstantExpressionUnevaluated:
|
|
case EM_EvaluateForOverflow:
|
|
return true;
|
|
|
|
case EM_ConstantExpression:
|
|
case EM_ConstantExpressionUnevaluated:
|
|
case EM_ConstantFold:
|
|
case EM_IgnoreSideEffects:
|
|
return false;
|
|
}
|
|
llvm_unreachable("Missed EvalMode case");
|
|
}
|
|
|
|
/// Notes that we failed to evaluate an expression that other expressions
|
|
/// directly depend on, and determine if we should keep evaluating. This
|
|
/// should only be called if we actually intend to keep evaluating.
|
|
///
|
|
/// Call noteSideEffect() instead if we may be able to ignore the value that
|
|
/// we failed to evaluate, e.g. if we failed to evaluate Foo() in:
|
|
///
|
|
/// (Foo(), 1) // use noteSideEffect
|
|
/// (Foo() || true) // use noteSideEffect
|
|
/// Foo() + 1 // use noteFailure
|
|
LLVM_NODISCARD bool noteFailure() {
|
|
// Failure when evaluating some expression often means there is some
|
|
// subexpression whose evaluation was skipped. Therefore, (because we
|
|
// don't track whether we skipped an expression when unwinding after an
|
|
// evaluation failure) every evaluation failure that bubbles up from a
|
|
// subexpression implies that a side-effect has potentially happened. We
|
|
// skip setting the HasSideEffects flag to true until we decide to
|
|
// continue evaluating after that point, which happens here.
|
|
bool KeepGoing = keepEvaluatingAfterFailure();
|
|
EvalStatus.HasSideEffects |= KeepGoing;
|
|
return KeepGoing;
|
|
}
|
|
|
|
class ArrayInitLoopIndex {
|
|
EvalInfo &Info;
|
|
uint64_t OuterIndex;
|
|
|
|
public:
|
|
ArrayInitLoopIndex(EvalInfo &Info)
|
|
: Info(Info), OuterIndex(Info.ArrayInitIndex) {
|
|
Info.ArrayInitIndex = 0;
|
|
}
|
|
~ArrayInitLoopIndex() { Info.ArrayInitIndex = OuterIndex; }
|
|
|
|
operator uint64_t&() { return Info.ArrayInitIndex; }
|
|
};
|
|
};
|
|
|
|
/// Object used to treat all foldable expressions as constant expressions.
|
|
struct FoldConstant {
|
|
EvalInfo &Info;
|
|
bool Enabled;
|
|
bool HadNoPriorDiags;
|
|
EvalInfo::EvaluationMode OldMode;
|
|
|
|
explicit FoldConstant(EvalInfo &Info, bool Enabled)
|
|
: Info(Info),
|
|
Enabled(Enabled),
|
|
HadNoPriorDiags(Info.EvalStatus.Diag &&
|
|
Info.EvalStatus.Diag->empty() &&
|
|
!Info.EvalStatus.HasSideEffects),
|
|
OldMode(Info.EvalMode) {
|
|
if (Enabled &&
|
|
(Info.EvalMode == EvalInfo::EM_ConstantExpression ||
|
|
Info.EvalMode == EvalInfo::EM_ConstantExpressionUnevaluated))
|
|
Info.EvalMode = EvalInfo::EM_ConstantFold;
|
|
}
|
|
void keepDiagnostics() { Enabled = false; }
|
|
~FoldConstant() {
|
|
if (Enabled && HadNoPriorDiags && !Info.EvalStatus.Diag->empty() &&
|
|
!Info.EvalStatus.HasSideEffects)
|
|
Info.EvalStatus.Diag->clear();
|
|
Info.EvalMode = OldMode;
|
|
}
|
|
};
|
|
|
|
/// RAII object used to set the current evaluation mode to ignore
|
|
/// side-effects.
|
|
struct IgnoreSideEffectsRAII {
|
|
EvalInfo &Info;
|
|
EvalInfo::EvaluationMode OldMode;
|
|
explicit IgnoreSideEffectsRAII(EvalInfo &Info)
|
|
: Info(Info), OldMode(Info.EvalMode) {
|
|
if (!Info.checkingPotentialConstantExpression())
|
|
Info.EvalMode = EvalInfo::EM_IgnoreSideEffects;
|
|
}
|
|
|
|
~IgnoreSideEffectsRAII() { Info.EvalMode = OldMode; }
|
|
};
|
|
|
|
/// RAII object used to optionally suppress diagnostics and side-effects from
|
|
/// a speculative evaluation.
|
|
class SpeculativeEvaluationRAII {
|
|
EvalInfo *Info = nullptr;
|
|
Expr::EvalStatus OldStatus;
|
|
bool OldIsSpeculativelyEvaluating;
|
|
|
|
void moveFromAndCancel(SpeculativeEvaluationRAII &&Other) {
|
|
Info = Other.Info;
|
|
OldStatus = Other.OldStatus;
|
|
OldIsSpeculativelyEvaluating = Other.OldIsSpeculativelyEvaluating;
|
|
Other.Info = nullptr;
|
|
}
|
|
|
|
void maybeRestoreState() {
|
|
if (!Info)
|
|
return;
|
|
|
|
Info->EvalStatus = OldStatus;
|
|
Info->IsSpeculativelyEvaluating = OldIsSpeculativelyEvaluating;
|
|
}
|
|
|
|
public:
|
|
SpeculativeEvaluationRAII() = default;
|
|
|
|
SpeculativeEvaluationRAII(
|
|
EvalInfo &Info, SmallVectorImpl<PartialDiagnosticAt> *NewDiag = nullptr)
|
|
: Info(&Info), OldStatus(Info.EvalStatus),
|
|
OldIsSpeculativelyEvaluating(Info.IsSpeculativelyEvaluating) {
|
|
Info.EvalStatus.Diag = NewDiag;
|
|
Info.IsSpeculativelyEvaluating = true;
|
|
}
|
|
|
|
SpeculativeEvaluationRAII(const SpeculativeEvaluationRAII &Other) = delete;
|
|
SpeculativeEvaluationRAII(SpeculativeEvaluationRAII &&Other) {
|
|
moveFromAndCancel(std::move(Other));
|
|
}
|
|
|
|
SpeculativeEvaluationRAII &operator=(SpeculativeEvaluationRAII &&Other) {
|
|
maybeRestoreState();
|
|
moveFromAndCancel(std::move(Other));
|
|
return *this;
|
|
}
|
|
|
|
~SpeculativeEvaluationRAII() { maybeRestoreState(); }
|
|
};
|
|
|
|
/// RAII object wrapping a full-expression or block scope, and handling
|
|
/// the ending of the lifetime of temporaries created within it.
|
|
template<bool IsFullExpression>
|
|
class ScopeRAII {
|
|
EvalInfo &Info;
|
|
unsigned OldStackSize;
|
|
public:
|
|
ScopeRAII(EvalInfo &Info)
|
|
: Info(Info), OldStackSize(Info.CleanupStack.size()) {
|
|
// Push a new temporary version. This is needed to distinguish between
|
|
// temporaries created in different iterations of a loop.
|
|
Info.CurrentCall->pushTempVersion();
|
|
}
|
|
~ScopeRAII() {
|
|
// Body moved to a static method to encourage the compiler to inline away
|
|
// instances of this class.
|
|
cleanup(Info, OldStackSize);
|
|
Info.CurrentCall->popTempVersion();
|
|
}
|
|
private:
|
|
static void cleanup(EvalInfo &Info, unsigned OldStackSize) {
|
|
unsigned NewEnd = OldStackSize;
|
|
for (unsigned I = OldStackSize, N = Info.CleanupStack.size();
|
|
I != N; ++I) {
|
|
if (IsFullExpression && Info.CleanupStack[I].isLifetimeExtended()) {
|
|
// Full-expression cleanup of a lifetime-extended temporary: nothing
|
|
// to do, just move this cleanup to the right place in the stack.
|
|
std::swap(Info.CleanupStack[I], Info.CleanupStack[NewEnd]);
|
|
++NewEnd;
|
|
} else {
|
|
// End the lifetime of the object.
|
|
Info.CleanupStack[I].endLifetime();
|
|
}
|
|
}
|
|
Info.CleanupStack.erase(Info.CleanupStack.begin() + NewEnd,
|
|
Info.CleanupStack.end());
|
|
}
|
|
};
|
|
typedef ScopeRAII<false> BlockScopeRAII;
|
|
typedef ScopeRAII<true> FullExpressionRAII;
|
|
}
|
|
|
|
bool SubobjectDesignator::checkSubobject(EvalInfo &Info, const Expr *E,
|
|
CheckSubobjectKind CSK) {
|
|
if (Invalid)
|
|
return false;
|
|
if (isOnePastTheEnd()) {
|
|
Info.CCEDiag(E, diag::note_constexpr_past_end_subobject)
|
|
<< CSK;
|
|
setInvalid();
|
|
return false;
|
|
}
|
|
// Note, we do not diagnose if isMostDerivedAnUnsizedArray(), because there
|
|
// must actually be at least one array element; even a VLA cannot have a
|
|
// bound of zero. And if our index is nonzero, we already had a CCEDiag.
|
|
return true;
|
|
}
|
|
|
|
void SubobjectDesignator::diagnoseUnsizedArrayPointerArithmetic(EvalInfo &Info,
|
|
const Expr *E) {
|
|
Info.CCEDiag(E, diag::note_constexpr_unsized_array_indexed);
|
|
// Do not set the designator as invalid: we can represent this situation,
|
|
// and correct handling of __builtin_object_size requires us to do so.
|
|
}
|
|
|
|
void SubobjectDesignator::diagnosePointerArithmetic(EvalInfo &Info,
|
|
const Expr *E,
|
|
const APSInt &N) {
|
|
// If we're complaining, we must be able to statically determine the size of
|
|
// the most derived array.
|
|
if (MostDerivedPathLength == Entries.size() && MostDerivedIsArrayElement)
|
|
Info.CCEDiag(E, diag::note_constexpr_array_index)
|
|
<< N << /*array*/ 0
|
|
<< static_cast<unsigned>(getMostDerivedArraySize());
|
|
else
|
|
Info.CCEDiag(E, diag::note_constexpr_array_index)
|
|
<< N << /*non-array*/ 1;
|
|
setInvalid();
|
|
}
|
|
|
|
CallStackFrame::CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
|
|
const FunctionDecl *Callee, const LValue *This,
|
|
APValue *Arguments)
|
|
: Info(Info), Caller(Info.CurrentCall), Callee(Callee), This(This),
|
|
Arguments(Arguments), CallLoc(CallLoc), Index(Info.NextCallIndex++) {
|
|
Info.CurrentCall = this;
|
|
++Info.CallStackDepth;
|
|
}
|
|
|
|
CallStackFrame::~CallStackFrame() {
|
|
assert(Info.CurrentCall == this && "calls retired out of order");
|
|
--Info.CallStackDepth;
|
|
Info.CurrentCall = Caller;
|
|
}
|
|
|
|
APValue &CallStackFrame::createTemporary(const void *Key,
|
|
bool IsLifetimeExtended) {
|
|
unsigned Version = Info.CurrentCall->getTempVersion();
|
|
APValue &Result = Temporaries[MapKeyTy(Key, Version)];
|
|
assert(Result.isUninit() && "temporary created multiple times");
|
|
Info.CleanupStack.push_back(Cleanup(&Result, IsLifetimeExtended));
|
|
return Result;
|
|
}
|
|
|
|
static void describeCall(CallStackFrame *Frame, raw_ostream &Out);
|
|
|
|
void EvalInfo::addCallStack(unsigned Limit) {
|
|
// Determine which calls to skip, if any.
|
|
unsigned ActiveCalls = CallStackDepth - 1;
|
|
unsigned SkipStart = ActiveCalls, SkipEnd = SkipStart;
|
|
if (Limit && Limit < ActiveCalls) {
|
|
SkipStart = Limit / 2 + Limit % 2;
|
|
SkipEnd = ActiveCalls - Limit / 2;
|
|
}
|
|
|
|
// Walk the call stack and add the diagnostics.
|
|
unsigned CallIdx = 0;
|
|
for (CallStackFrame *Frame = CurrentCall; Frame != &BottomFrame;
|
|
Frame = Frame->Caller, ++CallIdx) {
|
|
// Skip this call?
|
|
if (CallIdx >= SkipStart && CallIdx < SkipEnd) {
|
|
if (CallIdx == SkipStart) {
|
|
// Note that we're skipping calls.
|
|
addDiag(Frame->CallLoc, diag::note_constexpr_calls_suppressed)
|
|
<< unsigned(ActiveCalls - Limit);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
// Use a different note for an inheriting constructor, because from the
|
|
// user's perspective it's not really a function at all.
|
|
if (auto *CD = dyn_cast_or_null<CXXConstructorDecl>(Frame->Callee)) {
|
|
if (CD->isInheritingConstructor()) {
|
|
addDiag(Frame->CallLoc, diag::note_constexpr_inherited_ctor_call_here)
|
|
<< CD->getParent();
|
|
continue;
|
|
}
|
|
}
|
|
|
|
SmallVector<char, 128> Buffer;
|
|
llvm::raw_svector_ostream Out(Buffer);
|
|
describeCall(Frame, Out);
|
|
addDiag(Frame->CallLoc, diag::note_constexpr_call_here) << Out.str();
|
|
}
|
|
}
|
|
|
|
/// Kinds of access we can perform on an object, for diagnostics.
|
|
enum AccessKinds {
|
|
AK_Read,
|
|
AK_Assign,
|
|
AK_Increment,
|
|
AK_Decrement
|
|
};
|
|
|
|
namespace {
|
|
struct ComplexValue {
|
|
private:
|
|
bool IsInt;
|
|
|
|
public:
|
|
APSInt IntReal, IntImag;
|
|
APFloat FloatReal, FloatImag;
|
|
|
|
ComplexValue() : FloatReal(APFloat::Bogus()), FloatImag(APFloat::Bogus()) {}
|
|
|
|
void makeComplexFloat() { IsInt = false; }
|
|
bool isComplexFloat() const { return !IsInt; }
|
|
APFloat &getComplexFloatReal() { return FloatReal; }
|
|
APFloat &getComplexFloatImag() { return FloatImag; }
|
|
|
|
void makeComplexInt() { IsInt = true; }
|
|
bool isComplexInt() const { return IsInt; }
|
|
APSInt &getComplexIntReal() { return IntReal; }
|
|
APSInt &getComplexIntImag() { return IntImag; }
|
|
|
|
void moveInto(APValue &v) const {
|
|
if (isComplexFloat())
|
|
v = APValue(FloatReal, FloatImag);
|
|
else
|
|
v = APValue(IntReal, IntImag);
|
|
}
|
|
void setFrom(const APValue &v) {
|
|
assert(v.isComplexFloat() || v.isComplexInt());
|
|
if (v.isComplexFloat()) {
|
|
makeComplexFloat();
|
|
FloatReal = v.getComplexFloatReal();
|
|
FloatImag = v.getComplexFloatImag();
|
|
} else {
|
|
makeComplexInt();
|
|
IntReal = v.getComplexIntReal();
|
|
IntImag = v.getComplexIntImag();
|
|
}
|
|
}
|
|
};
|
|
|
|
struct LValue {
|
|
APValue::LValueBase Base;
|
|
CharUnits Offset;
|
|
SubobjectDesignator Designator;
|
|
bool IsNullPtr : 1;
|
|
bool InvalidBase : 1;
|
|
|
|
const APValue::LValueBase getLValueBase() const { return Base; }
|
|
CharUnits &getLValueOffset() { return Offset; }
|
|
const CharUnits &getLValueOffset() const { return Offset; }
|
|
SubobjectDesignator &getLValueDesignator() { return Designator; }
|
|
const SubobjectDesignator &getLValueDesignator() const { return Designator;}
|
|
bool isNullPointer() const { return IsNullPtr;}
|
|
|
|
unsigned getLValueCallIndex() const { return Base.getCallIndex(); }
|
|
unsigned getLValueVersion() const { return Base.getVersion(); }
|
|
|
|
void moveInto(APValue &V) const {
|
|
if (Designator.Invalid)
|
|
V = APValue(Base, Offset, APValue::NoLValuePath(), IsNullPtr);
|
|
else {
|
|
assert(!InvalidBase && "APValues can't handle invalid LValue bases");
|
|
V = APValue(Base, Offset, Designator.Entries,
|
|
Designator.IsOnePastTheEnd, IsNullPtr);
|
|
}
|
|
}
|
|
void setFrom(ASTContext &Ctx, const APValue &V) {
|
|
assert(V.isLValue() && "Setting LValue from a non-LValue?");
|
|
Base = V.getLValueBase();
|
|
Offset = V.getLValueOffset();
|
|
InvalidBase = false;
|
|
Designator = SubobjectDesignator(Ctx, V);
|
|
IsNullPtr = V.isNullPointer();
|
|
}
|
|
|
|
void set(APValue::LValueBase B, bool BInvalid = false) {
|
|
#ifndef NDEBUG
|
|
// We only allow a few types of invalid bases. Enforce that here.
|
|
if (BInvalid) {
|
|
const auto *E = B.get<const Expr *>();
|
|
assert((isa<MemberExpr>(E) || tryUnwrapAllocSizeCall(E)) &&
|
|
"Unexpected type of invalid base");
|
|
}
|
|
#endif
|
|
|
|
Base = B;
|
|
Offset = CharUnits::fromQuantity(0);
|
|
InvalidBase = BInvalid;
|
|
Designator = SubobjectDesignator(getType(B));
|
|
IsNullPtr = false;
|
|
}
|
|
|
|
void setNull(QualType PointerTy, uint64_t TargetVal) {
|
|
Base = (Expr *)nullptr;
|
|
Offset = CharUnits::fromQuantity(TargetVal);
|
|
InvalidBase = false;
|
|
Designator = SubobjectDesignator(PointerTy->getPointeeType());
|
|
IsNullPtr = true;
|
|
}
|
|
|
|
void setInvalid(APValue::LValueBase B, unsigned I = 0) {
|
|
set(B, true);
|
|
}
|
|
|
|
private:
|
|
// Check that this LValue is not based on a null pointer. If it is, produce
|
|
// a diagnostic and mark the designator as invalid.
|
|
template <typename GenDiagType>
|
|
bool checkNullPointerDiagnosingWith(const GenDiagType &GenDiag) {
|
|
if (Designator.Invalid)
|
|
return false;
|
|
if (IsNullPtr) {
|
|
GenDiag();
|
|
Designator.setInvalid();
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
public:
|
|
bool checkNullPointer(EvalInfo &Info, const Expr *E,
|
|
CheckSubobjectKind CSK) {
|
|
return checkNullPointerDiagnosingWith([&Info, E, CSK] {
|
|
Info.CCEDiag(E, diag::note_constexpr_null_subobject) << CSK;
|
|
});
|
|
}
|
|
|
|
bool checkNullPointerForFoldAccess(EvalInfo &Info, const Expr *E,
|
|
AccessKinds AK) {
|
|
return checkNullPointerDiagnosingWith([&Info, E, AK] {
|
|
Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
|
|
});
|
|
}
|
|
|
|
// Check this LValue refers to an object. If not, set the designator to be
|
|
// invalid and emit a diagnostic.
|
|
bool checkSubobject(EvalInfo &Info, const Expr *E, CheckSubobjectKind CSK) {
|
|
return (CSK == CSK_ArrayToPointer || checkNullPointer(Info, E, CSK)) &&
|
|
Designator.checkSubobject(Info, E, CSK);
|
|
}
|
|
|
|
void addDecl(EvalInfo &Info, const Expr *E,
|
|
const Decl *D, bool Virtual = false) {
|
|
if (checkSubobject(Info, E, isa<FieldDecl>(D) ? CSK_Field : CSK_Base))
|
|
Designator.addDeclUnchecked(D, Virtual);
|
|
}
|
|
void addUnsizedArray(EvalInfo &Info, const Expr *E, QualType ElemTy) {
|
|
if (!Designator.Entries.empty()) {
|
|
Info.CCEDiag(E, diag::note_constexpr_unsupported_unsized_array);
|
|
Designator.setInvalid();
|
|
return;
|
|
}
|
|
if (checkSubobject(Info, E, CSK_ArrayToPointer)) {
|
|
assert(getType(Base)->isPointerType() || getType(Base)->isArrayType());
|
|
Designator.FirstEntryIsAnUnsizedArray = true;
|
|
Designator.addUnsizedArrayUnchecked(ElemTy);
|
|
}
|
|
}
|
|
void addArray(EvalInfo &Info, const Expr *E, const ConstantArrayType *CAT) {
|
|
if (checkSubobject(Info, E, CSK_ArrayToPointer))
|
|
Designator.addArrayUnchecked(CAT);
|
|
}
|
|
void addComplex(EvalInfo &Info, const Expr *E, QualType EltTy, bool Imag) {
|
|
if (checkSubobject(Info, E, Imag ? CSK_Imag : CSK_Real))
|
|
Designator.addComplexUnchecked(EltTy, Imag);
|
|
}
|
|
void clearIsNullPointer() {
|
|
IsNullPtr = false;
|
|
}
|
|
void adjustOffsetAndIndex(EvalInfo &Info, const Expr *E,
|
|
const APSInt &Index, CharUnits ElementSize) {
|
|
// An index of 0 has no effect. (In C, adding 0 to a null pointer is UB,
|
|
// but we're not required to diagnose it and it's valid in C++.)
|
|
if (!Index)
|
|
return;
|
|
|
|
// Compute the new offset in the appropriate width, wrapping at 64 bits.
|
|
// FIXME: When compiling for a 32-bit target, we should use 32-bit
|
|
// offsets.
|
|
uint64_t Offset64 = Offset.getQuantity();
|
|
uint64_t ElemSize64 = ElementSize.getQuantity();
|
|
uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
|
|
Offset = CharUnits::fromQuantity(Offset64 + ElemSize64 * Index64);
|
|
|
|
if (checkNullPointer(Info, E, CSK_ArrayIndex))
|
|
Designator.adjustIndex(Info, E, Index);
|
|
clearIsNullPointer();
|
|
}
|
|
void adjustOffset(CharUnits N) {
|
|
Offset += N;
|
|
if (N.getQuantity())
|
|
clearIsNullPointer();
|
|
}
|
|
};
|
|
|
|
struct MemberPtr {
|
|
MemberPtr() {}
|
|
explicit MemberPtr(const ValueDecl *Decl) :
|
|
DeclAndIsDerivedMember(Decl, false), Path() {}
|
|
|
|
/// The member or (direct or indirect) field referred to by this member
|
|
/// pointer, or 0 if this is a null member pointer.
|
|
const ValueDecl *getDecl() const {
|
|
return DeclAndIsDerivedMember.getPointer();
|
|
}
|
|
/// Is this actually a member of some type derived from the relevant class?
|
|
bool isDerivedMember() const {
|
|
return DeclAndIsDerivedMember.getInt();
|
|
}
|
|
/// Get the class which the declaration actually lives in.
|
|
const CXXRecordDecl *getContainingRecord() const {
|
|
return cast<CXXRecordDecl>(
|
|
DeclAndIsDerivedMember.getPointer()->getDeclContext());
|
|
}
|
|
|
|
void moveInto(APValue &V) const {
|
|
V = APValue(getDecl(), isDerivedMember(), Path);
|
|
}
|
|
void setFrom(const APValue &V) {
|
|
assert(V.isMemberPointer());
|
|
DeclAndIsDerivedMember.setPointer(V.getMemberPointerDecl());
|
|
DeclAndIsDerivedMember.setInt(V.isMemberPointerToDerivedMember());
|
|
Path.clear();
|
|
ArrayRef<const CXXRecordDecl*> P = V.getMemberPointerPath();
|
|
Path.insert(Path.end(), P.begin(), P.end());
|
|
}
|
|
|
|
/// DeclAndIsDerivedMember - The member declaration, and a flag indicating
|
|
/// whether the member is a member of some class derived from the class type
|
|
/// of the member pointer.
|
|
llvm::PointerIntPair<const ValueDecl*, 1, bool> DeclAndIsDerivedMember;
|
|
/// Path - The path of base/derived classes from the member declaration's
|
|
/// class (exclusive) to the class type of the member pointer (inclusive).
|
|
SmallVector<const CXXRecordDecl*, 4> Path;
|
|
|
|
/// Perform a cast towards the class of the Decl (either up or down the
|
|
/// hierarchy).
|
|
bool castBack(const CXXRecordDecl *Class) {
|
|
assert(!Path.empty());
|
|
const CXXRecordDecl *Expected;
|
|
if (Path.size() >= 2)
|
|
Expected = Path[Path.size() - 2];
|
|
else
|
|
Expected = getContainingRecord();
|
|
if (Expected->getCanonicalDecl() != Class->getCanonicalDecl()) {
|
|
// C++11 [expr.static.cast]p12: In a conversion from (D::*) to (B::*),
|
|
// if B does not contain the original member and is not a base or
|
|
// derived class of the class containing the original member, the result
|
|
// of the cast is undefined.
|
|
// C++11 [conv.mem]p2 does not cover this case for a cast from (B::*) to
|
|
// (D::*). We consider that to be a language defect.
|
|
return false;
|
|
}
|
|
Path.pop_back();
|
|
return true;
|
|
}
|
|
/// Perform a base-to-derived member pointer cast.
|
|
bool castToDerived(const CXXRecordDecl *Derived) {
|
|
if (!getDecl())
|
|
return true;
|
|
if (!isDerivedMember()) {
|
|
Path.push_back(Derived);
|
|
return true;
|
|
}
|
|
if (!castBack(Derived))
|
|
return false;
|
|
if (Path.empty())
|
|
DeclAndIsDerivedMember.setInt(false);
|
|
return true;
|
|
}
|
|
/// Perform a derived-to-base member pointer cast.
|
|
bool castToBase(const CXXRecordDecl *Base) {
|
|
if (!getDecl())
|
|
return true;
|
|
if (Path.empty())
|
|
DeclAndIsDerivedMember.setInt(true);
|
|
if (isDerivedMember()) {
|
|
Path.push_back(Base);
|
|
return true;
|
|
}
|
|
return castBack(Base);
|
|
}
|
|
};
|
|
|
|
/// Compare two member pointers, which are assumed to be of the same type.
|
|
static bool operator==(const MemberPtr &LHS, const MemberPtr &RHS) {
|
|
if (!LHS.getDecl() || !RHS.getDecl())
|
|
return !LHS.getDecl() && !RHS.getDecl();
|
|
if (LHS.getDecl()->getCanonicalDecl() != RHS.getDecl()->getCanonicalDecl())
|
|
return false;
|
|
return LHS.Path == RHS.Path;
|
|
}
|
|
}
|
|
|
|
static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E);
|
|
static bool EvaluateInPlace(APValue &Result, EvalInfo &Info,
|
|
const LValue &This, const Expr *E,
|
|
bool AllowNonLiteralTypes = false);
|
|
static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
|
|
bool InvalidBaseOK = false);
|
|
static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info,
|
|
bool InvalidBaseOK = false);
|
|
static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
|
|
EvalInfo &Info);
|
|
static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info);
|
|
static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info);
|
|
static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
|
|
EvalInfo &Info);
|
|
static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info);
|
|
static bool EvaluateComplex(const Expr *E, ComplexValue &Res, EvalInfo &Info);
|
|
static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
|
|
EvalInfo &Info);
|
|
static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result);
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Misc utilities
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// A helper function to create a temporary and set an LValue.
|
|
template <class KeyTy>
|
|
static APValue &createTemporary(const KeyTy *Key, bool IsLifetimeExtended,
|
|
LValue &LV, CallStackFrame &Frame) {
|
|
LV.set({Key, Frame.Info.CurrentCall->Index,
|
|
Frame.Info.CurrentCall->getTempVersion()});
|
|
return Frame.createTemporary(Key, IsLifetimeExtended);
|
|
}
|
|
|
|
/// Negate an APSInt in place, converting it to a signed form if necessary, and
|
|
/// preserving its value (by extending by up to one bit as needed).
|
|
static void negateAsSigned(APSInt &Int) {
|
|
if (Int.isUnsigned() || Int.isMinSignedValue()) {
|
|
Int = Int.extend(Int.getBitWidth() + 1);
|
|
Int.setIsSigned(true);
|
|
}
|
|
Int = -Int;
|
|
}
|
|
|
|
/// Produce a string describing the given constexpr call.
|
|
static void describeCall(CallStackFrame *Frame, raw_ostream &Out) {
|
|
unsigned ArgIndex = 0;
|
|
bool IsMemberCall = isa<CXXMethodDecl>(Frame->Callee) &&
|
|
!isa<CXXConstructorDecl>(Frame->Callee) &&
|
|
cast<CXXMethodDecl>(Frame->Callee)->isInstance();
|
|
|
|
if (!IsMemberCall)
|
|
Out << *Frame->Callee << '(';
|
|
|
|
if (Frame->This && IsMemberCall) {
|
|
APValue Val;
|
|
Frame->This->moveInto(Val);
|
|
Val.printPretty(Out, Frame->Info.Ctx,
|
|
Frame->This->Designator.MostDerivedType);
|
|
// FIXME: Add parens around Val if needed.
|
|
Out << "->" << *Frame->Callee << '(';
|
|
IsMemberCall = false;
|
|
}
|
|
|
|
for (FunctionDecl::param_const_iterator I = Frame->Callee->param_begin(),
|
|
E = Frame->Callee->param_end(); I != E; ++I, ++ArgIndex) {
|
|
if (ArgIndex > (unsigned)IsMemberCall)
|
|
Out << ", ";
|
|
|
|
const ParmVarDecl *Param = *I;
|
|
const APValue &Arg = Frame->Arguments[ArgIndex];
|
|
Arg.printPretty(Out, Frame->Info.Ctx, Param->getType());
|
|
|
|
if (ArgIndex == 0 && IsMemberCall)
|
|
Out << "->" << *Frame->Callee << '(';
|
|
}
|
|
|
|
Out << ')';
|
|
}
|
|
|
|
/// Evaluate an expression to see if it had side-effects, and discard its
|
|
/// result.
|
|
/// \return \c true if the caller should keep evaluating.
|
|
static bool EvaluateIgnoredValue(EvalInfo &Info, const Expr *E) {
|
|
APValue Scratch;
|
|
if (!Evaluate(Scratch, Info, E))
|
|
// We don't need the value, but we might have skipped a side effect here.
|
|
return Info.noteSideEffect();
|
|
return true;
|
|
}
|
|
|
|
/// Should this call expression be treated as a string literal?
|
|
static bool IsStringLiteralCall(const CallExpr *E) {
|
|
unsigned Builtin = E->getBuiltinCallee();
|
|
return (Builtin == Builtin::BI__builtin___CFStringMakeConstantString ||
|
|
Builtin == Builtin::BI__builtin___NSStringMakeConstantString);
|
|
}
|
|
|
|
static bool IsGlobalLValue(APValue::LValueBase B) {
|
|
// C++11 [expr.const]p3 An address constant expression is a prvalue core
|
|
// constant expression of pointer type that evaluates to...
|
|
|
|
// ... a null pointer value, or a prvalue core constant expression of type
|
|
// std::nullptr_t.
|
|
if (!B) return true;
|
|
|
|
if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
|
|
// ... the address of an object with static storage duration,
|
|
if (const VarDecl *VD = dyn_cast<VarDecl>(D))
|
|
return VD->hasGlobalStorage();
|
|
// ... the address of a function,
|
|
return isa<FunctionDecl>(D);
|
|
}
|
|
|
|
const Expr *E = B.get<const Expr*>();
|
|
switch (E->getStmtClass()) {
|
|
default:
|
|
return false;
|
|
case Expr::CompoundLiteralExprClass: {
|
|
const CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E);
|
|
return CLE->isFileScope() && CLE->isLValue();
|
|
}
|
|
case Expr::MaterializeTemporaryExprClass:
|
|
// A materialized temporary might have been lifetime-extended to static
|
|
// storage duration.
|
|
return cast<MaterializeTemporaryExpr>(E)->getStorageDuration() == SD_Static;
|
|
// A string literal has static storage duration.
|
|
case Expr::StringLiteralClass:
|
|
case Expr::PredefinedExprClass:
|
|
case Expr::ObjCStringLiteralClass:
|
|
case Expr::ObjCEncodeExprClass:
|
|
case Expr::CXXTypeidExprClass:
|
|
case Expr::CXXUuidofExprClass:
|
|
return true;
|
|
case Expr::CallExprClass:
|
|
return IsStringLiteralCall(cast<CallExpr>(E));
|
|
// For GCC compatibility, &&label has static storage duration.
|
|
case Expr::AddrLabelExprClass:
|
|
return true;
|
|
// A Block literal expression may be used as the initialization value for
|
|
// Block variables at global or local static scope.
|
|
case Expr::BlockExprClass:
|
|
return !cast<BlockExpr>(E)->getBlockDecl()->hasCaptures();
|
|
case Expr::ImplicitValueInitExprClass:
|
|
// FIXME:
|
|
// We can never form an lvalue with an implicit value initialization as its
|
|
// base through expression evaluation, so these only appear in one case: the
|
|
// implicit variable declaration we invent when checking whether a constexpr
|
|
// constructor can produce a constant expression. We must assume that such
|
|
// an expression might be a global lvalue.
|
|
return true;
|
|
}
|
|
}
|
|
|
|
static const ValueDecl *GetLValueBaseDecl(const LValue &LVal) {
|
|
return LVal.Base.dyn_cast<const ValueDecl*>();
|
|
}
|
|
|
|
static bool IsLiteralLValue(const LValue &Value) {
|
|
if (Value.getLValueCallIndex())
|
|
return false;
|
|
const Expr *E = Value.Base.dyn_cast<const Expr*>();
|
|
return E && !isa<MaterializeTemporaryExpr>(E);
|
|
}
|
|
|
|
static bool IsWeakLValue(const LValue &Value) {
|
|
const ValueDecl *Decl = GetLValueBaseDecl(Value);
|
|
return Decl && Decl->isWeak();
|
|
}
|
|
|
|
static bool isZeroSized(const LValue &Value) {
|
|
const ValueDecl *Decl = GetLValueBaseDecl(Value);
|
|
if (Decl && isa<VarDecl>(Decl)) {
|
|
QualType Ty = Decl->getType();
|
|
if (Ty->isArrayType())
|
|
return Ty->isIncompleteType() ||
|
|
Decl->getASTContext().getTypeSize(Ty) == 0;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool HasSameBase(const LValue &A, const LValue &B) {
|
|
if (!A.getLValueBase())
|
|
return !B.getLValueBase();
|
|
if (!B.getLValueBase())
|
|
return false;
|
|
|
|
if (A.getLValueBase().getOpaqueValue() !=
|
|
B.getLValueBase().getOpaqueValue()) {
|
|
const Decl *ADecl = GetLValueBaseDecl(A);
|
|
if (!ADecl)
|
|
return false;
|
|
const Decl *BDecl = GetLValueBaseDecl(B);
|
|
if (!BDecl || ADecl->getCanonicalDecl() != BDecl->getCanonicalDecl())
|
|
return false;
|
|
}
|
|
|
|
return IsGlobalLValue(A.getLValueBase()) ||
|
|
(A.getLValueCallIndex() == B.getLValueCallIndex() &&
|
|
A.getLValueVersion() == B.getLValueVersion());
|
|
}
|
|
|
|
static void NoteLValueLocation(EvalInfo &Info, APValue::LValueBase Base) {
|
|
assert(Base && "no location for a null lvalue");
|
|
const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
|
|
if (VD)
|
|
Info.Note(VD->getLocation(), diag::note_declared_at);
|
|
else
|
|
Info.Note(Base.get<const Expr*>()->getExprLoc(),
|
|
diag::note_constexpr_temporary_here);
|
|
}
|
|
|
|
/// Check that this reference or pointer core constant expression is a valid
|
|
/// value for an address or reference constant expression. Return true if we
|
|
/// can fold this expression, whether or not it's a constant expression.
|
|
static bool CheckLValueConstantExpression(EvalInfo &Info, SourceLocation Loc,
|
|
QualType Type, const LValue &LVal,
|
|
Expr::ConstExprUsage Usage) {
|
|
bool IsReferenceType = Type->isReferenceType();
|
|
|
|
APValue::LValueBase Base = LVal.getLValueBase();
|
|
const SubobjectDesignator &Designator = LVal.getLValueDesignator();
|
|
|
|
// Check that the object is a global. Note that the fake 'this' object we
|
|
// manufacture when checking potential constant expressions is conservatively
|
|
// assumed to be global here.
|
|
if (!IsGlobalLValue(Base)) {
|
|
if (Info.getLangOpts().CPlusPlus11) {
|
|
const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
|
|
Info.FFDiag(Loc, diag::note_constexpr_non_global, 1)
|
|
<< IsReferenceType << !Designator.Entries.empty()
|
|
<< !!VD << VD;
|
|
NoteLValueLocation(Info, Base);
|
|
} else {
|
|
Info.FFDiag(Loc);
|
|
}
|
|
// Don't allow references to temporaries to escape.
|
|
return false;
|
|
}
|
|
assert((Info.checkingPotentialConstantExpression() ||
|
|
LVal.getLValueCallIndex() == 0) &&
|
|
"have call index for global lvalue");
|
|
|
|
if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
|
|
if (const VarDecl *Var = dyn_cast<const VarDecl>(VD)) {
|
|
// Check if this is a thread-local variable.
|
|
if (Var->getTLSKind())
|
|
return false;
|
|
|
|
// A dllimport variable never acts like a constant.
|
|
if (Usage == Expr::EvaluateForCodeGen && Var->hasAttr<DLLImportAttr>())
|
|
return false;
|
|
}
|
|
if (const auto *FD = dyn_cast<const FunctionDecl>(VD)) {
|
|
// __declspec(dllimport) must be handled very carefully:
|
|
// We must never initialize an expression with the thunk in C++.
|
|
// Doing otherwise would allow the same id-expression to yield
|
|
// different addresses for the same function in different translation
|
|
// units. However, this means that we must dynamically initialize the
|
|
// expression with the contents of the import address table at runtime.
|
|
//
|
|
// The C language has no notion of ODR; furthermore, it has no notion of
|
|
// dynamic initialization. This means that we are permitted to
|
|
// perform initialization with the address of the thunk.
|
|
if (Info.getLangOpts().CPlusPlus && Usage == Expr::EvaluateForCodeGen &&
|
|
FD->hasAttr<DLLImportAttr>())
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Allow address constant expressions to be past-the-end pointers. This is
|
|
// an extension: the standard requires them to point to an object.
|
|
if (!IsReferenceType)
|
|
return true;
|
|
|
|
// A reference constant expression must refer to an object.
|
|
if (!Base) {
|
|
// FIXME: diagnostic
|
|
Info.CCEDiag(Loc);
|
|
return true;
|
|
}
|
|
|
|
// Does this refer one past the end of some object?
|
|
if (!Designator.Invalid && Designator.isOnePastTheEnd()) {
|
|
const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
|
|
Info.FFDiag(Loc, diag::note_constexpr_past_end, 1)
|
|
<< !Designator.Entries.empty() << !!VD << VD;
|
|
NoteLValueLocation(Info, Base);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/// Member pointers are constant expressions unless they point to a
|
|
/// non-virtual dllimport member function.
|
|
static bool CheckMemberPointerConstantExpression(EvalInfo &Info,
|
|
SourceLocation Loc,
|
|
QualType Type,
|
|
const APValue &Value,
|
|
Expr::ConstExprUsage Usage) {
|
|
const ValueDecl *Member = Value.getMemberPointerDecl();
|
|
const auto *FD = dyn_cast_or_null<CXXMethodDecl>(Member);
|
|
if (!FD)
|
|
return true;
|
|
return Usage == Expr::EvaluateForMangling || FD->isVirtual() ||
|
|
!FD->hasAttr<DLLImportAttr>();
|
|
}
|
|
|
|
/// Check that this core constant expression is of literal type, and if not,
|
|
/// produce an appropriate diagnostic.
|
|
static bool CheckLiteralType(EvalInfo &Info, const Expr *E,
|
|
const LValue *This = nullptr) {
|
|
if (!E->isRValue() || E->getType()->isLiteralType(Info.Ctx))
|
|
return true;
|
|
|
|
// C++1y: A constant initializer for an object o [...] may also invoke
|
|
// constexpr constructors for o and its subobjects even if those objects
|
|
// are of non-literal class types.
|
|
//
|
|
// C++11 missed this detail for aggregates, so classes like this:
|
|
// struct foo_t { union { int i; volatile int j; } u; };
|
|
// are not (obviously) initializable like so:
|
|
// __attribute__((__require_constant_initialization__))
|
|
// static const foo_t x = {{0}};
|
|
// because "i" is a subobject with non-literal initialization (due to the
|
|
// volatile member of the union). See:
|
|
// http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1677
|
|
// Therefore, we use the C++1y behavior.
|
|
if (This && Info.EvaluatingDecl == This->getLValueBase())
|
|
return true;
|
|
|
|
// Prvalue constant expressions must be of literal types.
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.FFDiag(E, diag::note_constexpr_nonliteral)
|
|
<< E->getType();
|
|
else
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
|
|
/// Check that this core constant expression value is a valid value for a
|
|
/// constant expression. If not, report an appropriate diagnostic. Does not
|
|
/// check that the expression is of literal type.
|
|
static bool
|
|
CheckConstantExpression(EvalInfo &Info, SourceLocation DiagLoc, QualType Type,
|
|
const APValue &Value,
|
|
Expr::ConstExprUsage Usage = Expr::EvaluateForCodeGen) {
|
|
if (Value.isUninit()) {
|
|
Info.FFDiag(DiagLoc, diag::note_constexpr_uninitialized)
|
|
<< true << Type;
|
|
return false;
|
|
}
|
|
|
|
// We allow _Atomic(T) to be initialized from anything that T can be
|
|
// initialized from.
|
|
if (const AtomicType *AT = Type->getAs<AtomicType>())
|
|
Type = AT->getValueType();
|
|
|
|
// Core issue 1454: For a literal constant expression of array or class type,
|
|
// each subobject of its value shall have been initialized by a constant
|
|
// expression.
|
|
if (Value.isArray()) {
|
|
QualType EltTy = Type->castAsArrayTypeUnsafe()->getElementType();
|
|
for (unsigned I = 0, N = Value.getArrayInitializedElts(); I != N; ++I) {
|
|
if (!CheckConstantExpression(Info, DiagLoc, EltTy,
|
|
Value.getArrayInitializedElt(I), Usage))
|
|
return false;
|
|
}
|
|
if (!Value.hasArrayFiller())
|
|
return true;
|
|
return CheckConstantExpression(Info, DiagLoc, EltTy, Value.getArrayFiller(),
|
|
Usage);
|
|
}
|
|
if (Value.isUnion() && Value.getUnionField()) {
|
|
return CheckConstantExpression(Info, DiagLoc,
|
|
Value.getUnionField()->getType(),
|
|
Value.getUnionValue(), Usage);
|
|
}
|
|
if (Value.isStruct()) {
|
|
RecordDecl *RD = Type->castAs<RecordType>()->getDecl();
|
|
if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
|
|
unsigned BaseIndex = 0;
|
|
for (const CXXBaseSpecifier &BS : CD->bases()) {
|
|
if (!CheckConstantExpression(Info, DiagLoc, BS.getType(),
|
|
Value.getStructBase(BaseIndex), Usage))
|
|
return false;
|
|
++BaseIndex;
|
|
}
|
|
}
|
|
for (const auto *I : RD->fields()) {
|
|
if (I->isUnnamedBitfield())
|
|
continue;
|
|
|
|
if (!CheckConstantExpression(Info, DiagLoc, I->getType(),
|
|
Value.getStructField(I->getFieldIndex()),
|
|
Usage))
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if (Value.isLValue()) {
|
|
LValue LVal;
|
|
LVal.setFrom(Info.Ctx, Value);
|
|
return CheckLValueConstantExpression(Info, DiagLoc, Type, LVal, Usage);
|
|
}
|
|
|
|
if (Value.isMemberPointer())
|
|
return CheckMemberPointerConstantExpression(Info, DiagLoc, Type, Value, Usage);
|
|
|
|
// Everything else is fine.
|
|
return true;
|
|
}
|
|
|
|
static bool EvalPointerValueAsBool(const APValue &Value, bool &Result) {
|
|
// A null base expression indicates a null pointer. These are always
|
|
// evaluatable, and they are false unless the offset is zero.
|
|
if (!Value.getLValueBase()) {
|
|
Result = !Value.getLValueOffset().isZero();
|
|
return true;
|
|
}
|
|
|
|
// We have a non-null base. These are generally known to be true, but if it's
|
|
// a weak declaration it can be null at runtime.
|
|
Result = true;
|
|
const ValueDecl *Decl = Value.getLValueBase().dyn_cast<const ValueDecl*>();
|
|
return !Decl || !Decl->isWeak();
|
|
}
|
|
|
|
static bool HandleConversionToBool(const APValue &Val, bool &Result) {
|
|
switch (Val.getKind()) {
|
|
case APValue::Uninitialized:
|
|
return false;
|
|
case APValue::Int:
|
|
Result = Val.getInt().getBoolValue();
|
|
return true;
|
|
case APValue::Float:
|
|
Result = !Val.getFloat().isZero();
|
|
return true;
|
|
case APValue::ComplexInt:
|
|
Result = Val.getComplexIntReal().getBoolValue() ||
|
|
Val.getComplexIntImag().getBoolValue();
|
|
return true;
|
|
case APValue::ComplexFloat:
|
|
Result = !Val.getComplexFloatReal().isZero() ||
|
|
!Val.getComplexFloatImag().isZero();
|
|
return true;
|
|
case APValue::LValue:
|
|
return EvalPointerValueAsBool(Val, Result);
|
|
case APValue::MemberPointer:
|
|
Result = Val.getMemberPointerDecl();
|
|
return true;
|
|
case APValue::Vector:
|
|
case APValue::Array:
|
|
case APValue::Struct:
|
|
case APValue::Union:
|
|
case APValue::AddrLabelDiff:
|
|
return false;
|
|
}
|
|
|
|
llvm_unreachable("unknown APValue kind");
|
|
}
|
|
|
|
static bool EvaluateAsBooleanCondition(const Expr *E, bool &Result,
|
|
EvalInfo &Info) {
|
|
assert(E->isRValue() && "missing lvalue-to-rvalue conv in bool condition");
|
|
APValue Val;
|
|
if (!Evaluate(Val, Info, E))
|
|
return false;
|
|
return HandleConversionToBool(Val, Result);
|
|
}
|
|
|
|
template<typename T>
|
|
static bool HandleOverflow(EvalInfo &Info, const Expr *E,
|
|
const T &SrcValue, QualType DestType) {
|
|
Info.CCEDiag(E, diag::note_constexpr_overflow)
|
|
<< SrcValue << DestType;
|
|
return Info.noteUndefinedBehavior();
|
|
}
|
|
|
|
static bool HandleFloatToIntCast(EvalInfo &Info, const Expr *E,
|
|
QualType SrcType, const APFloat &Value,
|
|
QualType DestType, APSInt &Result) {
|
|
unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
|
|
// Determine whether we are converting to unsigned or signed.
|
|
bool DestSigned = DestType->isSignedIntegerOrEnumerationType();
|
|
|
|
Result = APSInt(DestWidth, !DestSigned);
|
|
bool ignored;
|
|
if (Value.convertToInteger(Result, llvm::APFloat::rmTowardZero, &ignored)
|
|
& APFloat::opInvalidOp)
|
|
return HandleOverflow(Info, E, Value, DestType);
|
|
return true;
|
|
}
|
|
|
|
static bool HandleFloatToFloatCast(EvalInfo &Info, const Expr *E,
|
|
QualType SrcType, QualType DestType,
|
|
APFloat &Result) {
|
|
APFloat Value = Result;
|
|
bool ignored;
|
|
if (Result.convert(Info.Ctx.getFloatTypeSemantics(DestType),
|
|
APFloat::rmNearestTiesToEven, &ignored)
|
|
& APFloat::opOverflow)
|
|
return HandleOverflow(Info, E, Value, DestType);
|
|
return true;
|
|
}
|
|
|
|
static APSInt HandleIntToIntCast(EvalInfo &Info, const Expr *E,
|
|
QualType DestType, QualType SrcType,
|
|
const APSInt &Value) {
|
|
unsigned DestWidth = Info.Ctx.getIntWidth(DestType);
|
|
// Figure out if this is a truncate, extend or noop cast.
|
|
// If the input is signed, do a sign extend, noop, or truncate.
|
|
APSInt Result = Value.extOrTrunc(DestWidth);
|
|
Result.setIsUnsigned(DestType->isUnsignedIntegerOrEnumerationType());
|
|
if (DestType->isBooleanType())
|
|
Result = Value.getBoolValue();
|
|
return Result;
|
|
}
|
|
|
|
static bool HandleIntToFloatCast(EvalInfo &Info, const Expr *E,
|
|
QualType SrcType, const APSInt &Value,
|
|
QualType DestType, APFloat &Result) {
|
|
Result = APFloat(Info.Ctx.getFloatTypeSemantics(DestType), 1);
|
|
if (Result.convertFromAPInt(Value, Value.isSigned(),
|
|
APFloat::rmNearestTiesToEven)
|
|
& APFloat::opOverflow)
|
|
return HandleOverflow(Info, E, Value, DestType);
|
|
return true;
|
|
}
|
|
|
|
static bool truncateBitfieldValue(EvalInfo &Info, const Expr *E,
|
|
APValue &Value, const FieldDecl *FD) {
|
|
assert(FD->isBitField() && "truncateBitfieldValue on non-bitfield");
|
|
|
|
if (!Value.isInt()) {
|
|
// Trying to store a pointer-cast-to-integer into a bitfield.
|
|
// FIXME: In this case, we should provide the diagnostic for casting
|
|
// a pointer to an integer.
|
|
assert(Value.isLValue() && "integral value neither int nor lvalue?");
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
|
|
APSInt &Int = Value.getInt();
|
|
unsigned OldBitWidth = Int.getBitWidth();
|
|
unsigned NewBitWidth = FD->getBitWidthValue(Info.Ctx);
|
|
if (NewBitWidth < OldBitWidth)
|
|
Int = Int.trunc(NewBitWidth).extend(OldBitWidth);
|
|
return true;
|
|
}
|
|
|
|
static bool EvalAndBitcastToAPInt(EvalInfo &Info, const Expr *E,
|
|
llvm::APInt &Res) {
|
|
APValue SVal;
|
|
if (!Evaluate(SVal, Info, E))
|
|
return false;
|
|
if (SVal.isInt()) {
|
|
Res = SVal.getInt();
|
|
return true;
|
|
}
|
|
if (SVal.isFloat()) {
|
|
Res = SVal.getFloat().bitcastToAPInt();
|
|
return true;
|
|
}
|
|
if (SVal.isVector()) {
|
|
QualType VecTy = E->getType();
|
|
unsigned VecSize = Info.Ctx.getTypeSize(VecTy);
|
|
QualType EltTy = VecTy->castAs<VectorType>()->getElementType();
|
|
unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
|
|
bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
|
|
Res = llvm::APInt::getNullValue(VecSize);
|
|
for (unsigned i = 0; i < SVal.getVectorLength(); i++) {
|
|
APValue &Elt = SVal.getVectorElt(i);
|
|
llvm::APInt EltAsInt;
|
|
if (Elt.isInt()) {
|
|
EltAsInt = Elt.getInt();
|
|
} else if (Elt.isFloat()) {
|
|
EltAsInt = Elt.getFloat().bitcastToAPInt();
|
|
} else {
|
|
// Don't try to handle vectors of anything other than int or float
|
|
// (not sure if it's possible to hit this case).
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
unsigned BaseEltSize = EltAsInt.getBitWidth();
|
|
if (BigEndian)
|
|
Res |= EltAsInt.zextOrTrunc(VecSize).rotr(i*EltSize+BaseEltSize);
|
|
else
|
|
Res |= EltAsInt.zextOrTrunc(VecSize).rotl(i*EltSize);
|
|
}
|
|
return true;
|
|
}
|
|
// Give up if the input isn't an int, float, or vector. For example, we
|
|
// reject "(v4i16)(intptr_t)&a".
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
|
|
/// Perform the given integer operation, which is known to need at most BitWidth
|
|
/// bits, and check for overflow in the original type (if that type was not an
|
|
/// unsigned type).
|
|
template<typename Operation>
|
|
static bool CheckedIntArithmetic(EvalInfo &Info, const Expr *E,
|
|
const APSInt &LHS, const APSInt &RHS,
|
|
unsigned BitWidth, Operation Op,
|
|
APSInt &Result) {
|
|
if (LHS.isUnsigned()) {
|
|
Result = Op(LHS, RHS);
|
|
return true;
|
|
}
|
|
|
|
APSInt Value(Op(LHS.extend(BitWidth), RHS.extend(BitWidth)), false);
|
|
Result = Value.trunc(LHS.getBitWidth());
|
|
if (Result.extend(BitWidth) != Value) {
|
|
if (Info.checkingForOverflow())
|
|
Info.Ctx.getDiagnostics().Report(E->getExprLoc(),
|
|
diag::warn_integer_constant_overflow)
|
|
<< Result.toString(10) << E->getType();
|
|
else
|
|
return HandleOverflow(Info, E, Value, E->getType());
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// Perform the given binary integer operation.
|
|
static bool handleIntIntBinOp(EvalInfo &Info, const Expr *E, const APSInt &LHS,
|
|
BinaryOperatorKind Opcode, APSInt RHS,
|
|
APSInt &Result) {
|
|
switch (Opcode) {
|
|
default:
|
|
Info.FFDiag(E);
|
|
return false;
|
|
case BO_Mul:
|
|
return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() * 2,
|
|
std::multiplies<APSInt>(), Result);
|
|
case BO_Add:
|
|
return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
|
|
std::plus<APSInt>(), Result);
|
|
case BO_Sub:
|
|
return CheckedIntArithmetic(Info, E, LHS, RHS, LHS.getBitWidth() + 1,
|
|
std::minus<APSInt>(), Result);
|
|
case BO_And: Result = LHS & RHS; return true;
|
|
case BO_Xor: Result = LHS ^ RHS; return true;
|
|
case BO_Or: Result = LHS | RHS; return true;
|
|
case BO_Div:
|
|
case BO_Rem:
|
|
if (RHS == 0) {
|
|
Info.FFDiag(E, diag::note_expr_divide_by_zero);
|
|
return false;
|
|
}
|
|
Result = (Opcode == BO_Rem ? LHS % RHS : LHS / RHS);
|
|
// Check for overflow case: INT_MIN / -1 or INT_MIN % -1. APSInt supports
|
|
// this operation and gives the two's complement result.
|
|
if (RHS.isNegative() && RHS.isAllOnesValue() &&
|
|
LHS.isSigned() && LHS.isMinSignedValue())
|
|
return HandleOverflow(Info, E, -LHS.extend(LHS.getBitWidth() + 1),
|
|
E->getType());
|
|
return true;
|
|
case BO_Shl: {
|
|
if (Info.getLangOpts().OpenCL)
|
|
// OpenCL 6.3j: shift values are effectively % word size of LHS.
|
|
RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
|
|
static_cast<uint64_t>(LHS.getBitWidth() - 1)),
|
|
RHS.isUnsigned());
|
|
else if (RHS.isSigned() && RHS.isNegative()) {
|
|
// During constant-folding, a negative shift is an opposite shift. Such
|
|
// a shift is not a constant expression.
|
|
Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
|
|
RHS = -RHS;
|
|
goto shift_right;
|
|
}
|
|
shift_left:
|
|
// C++11 [expr.shift]p1: Shift width must be less than the bit width of
|
|
// the shifted type.
|
|
unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
|
|
if (SA != RHS) {
|
|
Info.CCEDiag(E, diag::note_constexpr_large_shift)
|
|
<< RHS << E->getType() << LHS.getBitWidth();
|
|
} else if (LHS.isSigned()) {
|
|
// C++11 [expr.shift]p2: A signed left shift must have a non-negative
|
|
// operand, and must not overflow the corresponding unsigned type.
|
|
if (LHS.isNegative())
|
|
Info.CCEDiag(E, diag::note_constexpr_lshift_of_negative) << LHS;
|
|
else if (LHS.countLeadingZeros() < SA)
|
|
Info.CCEDiag(E, diag::note_constexpr_lshift_discards);
|
|
}
|
|
Result = LHS << SA;
|
|
return true;
|
|
}
|
|
case BO_Shr: {
|
|
if (Info.getLangOpts().OpenCL)
|
|
// OpenCL 6.3j: shift values are effectively % word size of LHS.
|
|
RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
|
|
static_cast<uint64_t>(LHS.getBitWidth() - 1)),
|
|
RHS.isUnsigned());
|
|
else if (RHS.isSigned() && RHS.isNegative()) {
|
|
// During constant-folding, a negative shift is an opposite shift. Such a
|
|
// shift is not a constant expression.
|
|
Info.CCEDiag(E, diag::note_constexpr_negative_shift) << RHS;
|
|
RHS = -RHS;
|
|
goto shift_left;
|
|
}
|
|
shift_right:
|
|
// C++11 [expr.shift]p1: Shift width must be less than the bit width of the
|
|
// shifted type.
|
|
unsigned SA = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1);
|
|
if (SA != RHS)
|
|
Info.CCEDiag(E, diag::note_constexpr_large_shift)
|
|
<< RHS << E->getType() << LHS.getBitWidth();
|
|
Result = LHS >> SA;
|
|
return true;
|
|
}
|
|
|
|
case BO_LT: Result = LHS < RHS; return true;
|
|
case BO_GT: Result = LHS > RHS; return true;
|
|
case BO_LE: Result = LHS <= RHS; return true;
|
|
case BO_GE: Result = LHS >= RHS; return true;
|
|
case BO_EQ: Result = LHS == RHS; return true;
|
|
case BO_NE: Result = LHS != RHS; return true;
|
|
case BO_Cmp:
|
|
llvm_unreachable("BO_Cmp should be handled elsewhere");
|
|
}
|
|
}
|
|
|
|
/// Perform the given binary floating-point operation, in-place, on LHS.
|
|
static bool handleFloatFloatBinOp(EvalInfo &Info, const Expr *E,
|
|
APFloat &LHS, BinaryOperatorKind Opcode,
|
|
const APFloat &RHS) {
|
|
switch (Opcode) {
|
|
default:
|
|
Info.FFDiag(E);
|
|
return false;
|
|
case BO_Mul:
|
|
LHS.multiply(RHS, APFloat::rmNearestTiesToEven);
|
|
break;
|
|
case BO_Add:
|
|
LHS.add(RHS, APFloat::rmNearestTiesToEven);
|
|
break;
|
|
case BO_Sub:
|
|
LHS.subtract(RHS, APFloat::rmNearestTiesToEven);
|
|
break;
|
|
case BO_Div:
|
|
LHS.divide(RHS, APFloat::rmNearestTiesToEven);
|
|
break;
|
|
}
|
|
|
|
if (LHS.isInfinity() || LHS.isNaN()) {
|
|
Info.CCEDiag(E, diag::note_constexpr_float_arithmetic) << LHS.isNaN();
|
|
return Info.noteUndefinedBehavior();
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// Cast an lvalue referring to a base subobject to a derived class, by
|
|
/// truncating the lvalue's path to the given length.
|
|
static bool CastToDerivedClass(EvalInfo &Info, const Expr *E, LValue &Result,
|
|
const RecordDecl *TruncatedType,
|
|
unsigned TruncatedElements) {
|
|
SubobjectDesignator &D = Result.Designator;
|
|
|
|
// Check we actually point to a derived class object.
|
|
if (TruncatedElements == D.Entries.size())
|
|
return true;
|
|
assert(TruncatedElements >= D.MostDerivedPathLength &&
|
|
"not casting to a derived class");
|
|
if (!Result.checkSubobject(Info, E, CSK_Derived))
|
|
return false;
|
|
|
|
// Truncate the path to the subobject, and remove any derived-to-base offsets.
|
|
const RecordDecl *RD = TruncatedType;
|
|
for (unsigned I = TruncatedElements, N = D.Entries.size(); I != N; ++I) {
|
|
if (RD->isInvalidDecl()) return false;
|
|
const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
|
|
const CXXRecordDecl *Base = getAsBaseClass(D.Entries[I]);
|
|
if (isVirtualBaseClass(D.Entries[I]))
|
|
Result.Offset -= Layout.getVBaseClassOffset(Base);
|
|
else
|
|
Result.Offset -= Layout.getBaseClassOffset(Base);
|
|
RD = Base;
|
|
}
|
|
D.Entries.resize(TruncatedElements);
|
|
return true;
|
|
}
|
|
|
|
static bool HandleLValueDirectBase(EvalInfo &Info, const Expr *E, LValue &Obj,
|
|
const CXXRecordDecl *Derived,
|
|
const CXXRecordDecl *Base,
|
|
const ASTRecordLayout *RL = nullptr) {
|
|
if (!RL) {
|
|
if (Derived->isInvalidDecl()) return false;
|
|
RL = &Info.Ctx.getASTRecordLayout(Derived);
|
|
}
|
|
|
|
Obj.getLValueOffset() += RL->getBaseClassOffset(Base);
|
|
Obj.addDecl(Info, E, Base, /*Virtual*/ false);
|
|
return true;
|
|
}
|
|
|
|
static bool HandleLValueBase(EvalInfo &Info, const Expr *E, LValue &Obj,
|
|
const CXXRecordDecl *DerivedDecl,
|
|
const CXXBaseSpecifier *Base) {
|
|
const CXXRecordDecl *BaseDecl = Base->getType()->getAsCXXRecordDecl();
|
|
|
|
if (!Base->isVirtual())
|
|
return HandleLValueDirectBase(Info, E, Obj, DerivedDecl, BaseDecl);
|
|
|
|
SubobjectDesignator &D = Obj.Designator;
|
|
if (D.Invalid)
|
|
return false;
|
|
|
|
// Extract most-derived object and corresponding type.
|
|
DerivedDecl = D.MostDerivedType->getAsCXXRecordDecl();
|
|
if (!CastToDerivedClass(Info, E, Obj, DerivedDecl, D.MostDerivedPathLength))
|
|
return false;
|
|
|
|
// Find the virtual base class.
|
|
if (DerivedDecl->isInvalidDecl()) return false;
|
|
const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(DerivedDecl);
|
|
Obj.getLValueOffset() += Layout.getVBaseClassOffset(BaseDecl);
|
|
Obj.addDecl(Info, E, BaseDecl, /*Virtual*/ true);
|
|
return true;
|
|
}
|
|
|
|
static bool HandleLValueBasePath(EvalInfo &Info, const CastExpr *E,
|
|
QualType Type, LValue &Result) {
|
|
for (CastExpr::path_const_iterator PathI = E->path_begin(),
|
|
PathE = E->path_end();
|
|
PathI != PathE; ++PathI) {
|
|
if (!HandleLValueBase(Info, E, Result, Type->getAsCXXRecordDecl(),
|
|
*PathI))
|
|
return false;
|
|
Type = (*PathI)->getType();
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// Update LVal to refer to the given field, which must be a member of the type
|
|
/// currently described by LVal.
|
|
static bool HandleLValueMember(EvalInfo &Info, const Expr *E, LValue &LVal,
|
|
const FieldDecl *FD,
|
|
const ASTRecordLayout *RL = nullptr) {
|
|
if (!RL) {
|
|
if (FD->getParent()->isInvalidDecl()) return false;
|
|
RL = &Info.Ctx.getASTRecordLayout(FD->getParent());
|
|
}
|
|
|
|
unsigned I = FD->getFieldIndex();
|
|
LVal.adjustOffset(Info.Ctx.toCharUnitsFromBits(RL->getFieldOffset(I)));
|
|
LVal.addDecl(Info, E, FD);
|
|
return true;
|
|
}
|
|
|
|
/// Update LVal to refer to the given indirect field.
|
|
static bool HandleLValueIndirectMember(EvalInfo &Info, const Expr *E,
|
|
LValue &LVal,
|
|
const IndirectFieldDecl *IFD) {
|
|
for (const auto *C : IFD->chain())
|
|
if (!HandleLValueMember(Info, E, LVal, cast<FieldDecl>(C)))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
/// Get the size of the given type in char units.
|
|
static bool HandleSizeof(EvalInfo &Info, SourceLocation Loc,
|
|
QualType Type, CharUnits &Size) {
|
|
// sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc
|
|
// extension.
|
|
if (Type->isVoidType() || Type->isFunctionType()) {
|
|
Size = CharUnits::One();
|
|
return true;
|
|
}
|
|
|
|
if (Type->isDependentType()) {
|
|
Info.FFDiag(Loc);
|
|
return false;
|
|
}
|
|
|
|
if (!Type->isConstantSizeType()) {
|
|
// sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
|
|
// FIXME: Better diagnostic.
|
|
Info.FFDiag(Loc);
|
|
return false;
|
|
}
|
|
|
|
Size = Info.Ctx.getTypeSizeInChars(Type);
|
|
return true;
|
|
}
|
|
|
|
/// Update a pointer value to model pointer arithmetic.
|
|
/// \param Info - Information about the ongoing evaluation.
|
|
/// \param E - The expression being evaluated, for diagnostic purposes.
|
|
/// \param LVal - The pointer value to be updated.
|
|
/// \param EltTy - The pointee type represented by LVal.
|
|
/// \param Adjustment - The adjustment, in objects of type EltTy, to add.
|
|
static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
|
|
LValue &LVal, QualType EltTy,
|
|
APSInt Adjustment) {
|
|
CharUnits SizeOfPointee;
|
|
if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfPointee))
|
|
return false;
|
|
|
|
LVal.adjustOffsetAndIndex(Info, E, Adjustment, SizeOfPointee);
|
|
return true;
|
|
}
|
|
|
|
static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E,
|
|
LValue &LVal, QualType EltTy,
|
|
int64_t Adjustment) {
|
|
return HandleLValueArrayAdjustment(Info, E, LVal, EltTy,
|
|
APSInt::get(Adjustment));
|
|
}
|
|
|
|
/// Update an lvalue to refer to a component of a complex number.
|
|
/// \param Info - Information about the ongoing evaluation.
|
|
/// \param LVal - The lvalue to be updated.
|
|
/// \param EltTy - The complex number's component type.
|
|
/// \param Imag - False for the real component, true for the imaginary.
|
|
static bool HandleLValueComplexElement(EvalInfo &Info, const Expr *E,
|
|
LValue &LVal, QualType EltTy,
|
|
bool Imag) {
|
|
if (Imag) {
|
|
CharUnits SizeOfComponent;
|
|
if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfComponent))
|
|
return false;
|
|
LVal.Offset += SizeOfComponent;
|
|
}
|
|
LVal.addComplex(Info, E, EltTy, Imag);
|
|
return true;
|
|
}
|
|
|
|
static bool handleLValueToRValueConversion(EvalInfo &Info, const Expr *Conv,
|
|
QualType Type, const LValue &LVal,
|
|
APValue &RVal);
|
|
|
|
/// Try to evaluate the initializer for a variable declaration.
|
|
///
|
|
/// \param Info Information about the ongoing evaluation.
|
|
/// \param E An expression to be used when printing diagnostics.
|
|
/// \param VD The variable whose initializer should be obtained.
|
|
/// \param Frame The frame in which the variable was created. Must be null
|
|
/// if this variable is not local to the evaluation.
|
|
/// \param Result Filled in with a pointer to the value of the variable.
|
|
static bool evaluateVarDeclInit(EvalInfo &Info, const Expr *E,
|
|
const VarDecl *VD, CallStackFrame *Frame,
|
|
APValue *&Result, const LValue *LVal) {
|
|
|
|
// If this is a parameter to an active constexpr function call, perform
|
|
// argument substitution.
|
|
if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(VD)) {
|
|
// Assume arguments of a potential constant expression are unknown
|
|
// constant expressions.
|
|
if (Info.checkingPotentialConstantExpression())
|
|
return false;
|
|
if (!Frame || !Frame->Arguments) {
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
Result = &Frame->Arguments[PVD->getFunctionScopeIndex()];
|
|
return true;
|
|
}
|
|
|
|
// If this is a local variable, dig out its value.
|
|
if (Frame) {
|
|
Result = LVal ? Frame->getTemporary(VD, LVal->getLValueVersion())
|
|
: Frame->getCurrentTemporary(VD);
|
|
if (!Result) {
|
|
// Assume variables referenced within a lambda's call operator that were
|
|
// not declared within the call operator are captures and during checking
|
|
// of a potential constant expression, assume they are unknown constant
|
|
// expressions.
|
|
assert(isLambdaCallOperator(Frame->Callee) &&
|
|
(VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) &&
|
|
"missing value for local variable");
|
|
if (Info.checkingPotentialConstantExpression())
|
|
return false;
|
|
// FIXME: implement capture evaluation during constant expr evaluation.
|
|
Info.FFDiag(E->getBeginLoc(),
|
|
diag::note_unimplemented_constexpr_lambda_feature_ast)
|
|
<< "captures not currently allowed";
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Dig out the initializer, and use the declaration which it's attached to.
|
|
const Expr *Init = VD->getAnyInitializer(VD);
|
|
if (!Init || Init->isValueDependent()) {
|
|
// If we're checking a potential constant expression, the variable could be
|
|
// initialized later.
|
|
if (!Info.checkingPotentialConstantExpression())
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
|
|
// If we're currently evaluating the initializer of this declaration, use that
|
|
// in-flight value.
|
|
if (Info.EvaluatingDecl.dyn_cast<const ValueDecl*>() == VD) {
|
|
Result = Info.EvaluatingDeclValue;
|
|
return true;
|
|
}
|
|
|
|
// Never evaluate the initializer of a weak variable. We can't be sure that
|
|
// this is the definition which will be used.
|
|
if (VD->isWeak()) {
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
|
|
// Check that we can fold the initializer. In C++, we will have already done
|
|
// this in the cases where it matters for conformance.
|
|
SmallVector<PartialDiagnosticAt, 8> Notes;
|
|
if (!VD->evaluateValue(Notes)) {
|
|
Info.FFDiag(E, diag::note_constexpr_var_init_non_constant,
|
|
Notes.size() + 1) << VD;
|
|
Info.Note(VD->getLocation(), diag::note_declared_at);
|
|
Info.addNotes(Notes);
|
|
return false;
|
|
} else if (!VD->checkInitIsICE()) {
|
|
Info.CCEDiag(E, diag::note_constexpr_var_init_non_constant,
|
|
Notes.size() + 1) << VD;
|
|
Info.Note(VD->getLocation(), diag::note_declared_at);
|
|
Info.addNotes(Notes);
|
|
}
|
|
|
|
Result = VD->getEvaluatedValue();
|
|
return true;
|
|
}
|
|
|
|
static bool IsConstNonVolatile(QualType T) {
|
|
Qualifiers Quals = T.getQualifiers();
|
|
return Quals.hasConst() && !Quals.hasVolatile();
|
|
}
|
|
|
|
/// Get the base index of the given base class within an APValue representing
|
|
/// the given derived class.
|
|
static unsigned getBaseIndex(const CXXRecordDecl *Derived,
|
|
const CXXRecordDecl *Base) {
|
|
Base = Base->getCanonicalDecl();
|
|
unsigned Index = 0;
|
|
for (CXXRecordDecl::base_class_const_iterator I = Derived->bases_begin(),
|
|
E = Derived->bases_end(); I != E; ++I, ++Index) {
|
|
if (I->getType()->getAsCXXRecordDecl()->getCanonicalDecl() == Base)
|
|
return Index;
|
|
}
|
|
|
|
llvm_unreachable("base class missing from derived class's bases list");
|
|
}
|
|
|
|
/// Extract the value of a character from a string literal.
|
|
static APSInt extractStringLiteralCharacter(EvalInfo &Info, const Expr *Lit,
|
|
uint64_t Index) {
|
|
// FIXME: Support MakeStringConstant
|
|
if (const auto *ObjCEnc = dyn_cast<ObjCEncodeExpr>(Lit)) {
|
|
std::string Str;
|
|
Info.Ctx.getObjCEncodingForType(ObjCEnc->getEncodedType(), Str);
|
|
assert(Index <= Str.size() && "Index too large");
|
|
return APSInt::getUnsigned(Str.c_str()[Index]);
|
|
}
|
|
|
|
if (auto PE = dyn_cast<PredefinedExpr>(Lit))
|
|
Lit = PE->getFunctionName();
|
|
const StringLiteral *S = cast<StringLiteral>(Lit);
|
|
const ConstantArrayType *CAT =
|
|
Info.Ctx.getAsConstantArrayType(S->getType());
|
|
assert(CAT && "string literal isn't an array");
|
|
QualType CharType = CAT->getElementType();
|
|
assert(CharType->isIntegerType() && "unexpected character type");
|
|
|
|
APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
|
|
CharType->isUnsignedIntegerType());
|
|
if (Index < S->getLength())
|
|
Value = S->getCodeUnit(Index);
|
|
return Value;
|
|
}
|
|
|
|
// Expand a string literal into an array of characters.
|
|
static void expandStringLiteral(EvalInfo &Info, const Expr *Lit,
|
|
APValue &Result) {
|
|
const StringLiteral *S = cast<StringLiteral>(Lit);
|
|
const ConstantArrayType *CAT =
|
|
Info.Ctx.getAsConstantArrayType(S->getType());
|
|
assert(CAT && "string literal isn't an array");
|
|
QualType CharType = CAT->getElementType();
|
|
assert(CharType->isIntegerType() && "unexpected character type");
|
|
|
|
unsigned Elts = CAT->getSize().getZExtValue();
|
|
Result = APValue(APValue::UninitArray(),
|
|
std::min(S->getLength(), Elts), Elts);
|
|
APSInt Value(S->getCharByteWidth() * Info.Ctx.getCharWidth(),
|
|
CharType->isUnsignedIntegerType());
|
|
if (Result.hasArrayFiller())
|
|
Result.getArrayFiller() = APValue(Value);
|
|
for (unsigned I = 0, N = Result.getArrayInitializedElts(); I != N; ++I) {
|
|
Value = S->getCodeUnit(I);
|
|
Result.getArrayInitializedElt(I) = APValue(Value);
|
|
}
|
|
}
|
|
|
|
// Expand an array so that it has more than Index filled elements.
|
|
static void expandArray(APValue &Array, unsigned Index) {
|
|
unsigned Size = Array.getArraySize();
|
|
assert(Index < Size);
|
|
|
|
// Always at least double the number of elements for which we store a value.
|
|
unsigned OldElts = Array.getArrayInitializedElts();
|
|
unsigned NewElts = std::max(Index+1, OldElts * 2);
|
|
NewElts = std::min(Size, std::max(NewElts, 8u));
|
|
|
|
// Copy the data across.
|
|
APValue NewValue(APValue::UninitArray(), NewElts, Size);
|
|
for (unsigned I = 0; I != OldElts; ++I)
|
|
NewValue.getArrayInitializedElt(I).swap(Array.getArrayInitializedElt(I));
|
|
for (unsigned I = OldElts; I != NewElts; ++I)
|
|
NewValue.getArrayInitializedElt(I) = Array.getArrayFiller();
|
|
if (NewValue.hasArrayFiller())
|
|
NewValue.getArrayFiller() = Array.getArrayFiller();
|
|
Array.swap(NewValue);
|
|
}
|
|
|
|
/// Determine whether a type would actually be read by an lvalue-to-rvalue
|
|
/// conversion. If it's of class type, we may assume that the copy operation
|
|
/// is trivial. Note that this is never true for a union type with fields
|
|
/// (because the copy always "reads" the active member) and always true for
|
|
/// a non-class type.
|
|
static bool isReadByLvalueToRvalueConversion(QualType T) {
|
|
CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
|
|
if (!RD || (RD->isUnion() && !RD->field_empty()))
|
|
return true;
|
|
if (RD->isEmpty())
|
|
return false;
|
|
|
|
for (auto *Field : RD->fields())
|
|
if (isReadByLvalueToRvalueConversion(Field->getType()))
|
|
return true;
|
|
|
|
for (auto &BaseSpec : RD->bases())
|
|
if (isReadByLvalueToRvalueConversion(BaseSpec.getType()))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/// Diagnose an attempt to read from any unreadable field within the specified
|
|
/// type, which might be a class type.
|
|
static bool diagnoseUnreadableFields(EvalInfo &Info, const Expr *E,
|
|
QualType T) {
|
|
CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
|
|
if (!RD)
|
|
return false;
|
|
|
|
if (!RD->hasMutableFields())
|
|
return false;
|
|
|
|
for (auto *Field : RD->fields()) {
|
|
// If we're actually going to read this field in some way, then it can't
|
|
// be mutable. If we're in a union, then assigning to a mutable field
|
|
// (even an empty one) can change the active member, so that's not OK.
|
|
// FIXME: Add core issue number for the union case.
|
|
if (Field->isMutable() &&
|
|
(RD->isUnion() || isReadByLvalueToRvalueConversion(Field->getType()))) {
|
|
Info.FFDiag(E, diag::note_constexpr_ltor_mutable, 1) << Field;
|
|
Info.Note(Field->getLocation(), diag::note_declared_at);
|
|
return true;
|
|
}
|
|
|
|
if (diagnoseUnreadableFields(Info, E, Field->getType()))
|
|
return true;
|
|
}
|
|
|
|
for (auto &BaseSpec : RD->bases())
|
|
if (diagnoseUnreadableFields(Info, E, BaseSpec.getType()))
|
|
return true;
|
|
|
|
// All mutable fields were empty, and thus not actually read.
|
|
return false;
|
|
}
|
|
|
|
namespace {
|
|
/// A handle to a complete object (an object that is not a subobject of
|
|
/// another object).
|
|
struct CompleteObject {
|
|
/// The value of the complete object.
|
|
APValue *Value;
|
|
/// The type of the complete object.
|
|
QualType Type;
|
|
bool LifetimeStartedInEvaluation;
|
|
|
|
CompleteObject() : Value(nullptr) {}
|
|
CompleteObject(APValue *Value, QualType Type,
|
|
bool LifetimeStartedInEvaluation)
|
|
: Value(Value), Type(Type),
|
|
LifetimeStartedInEvaluation(LifetimeStartedInEvaluation) {
|
|
assert(Value && "missing value for complete object");
|
|
}
|
|
|
|
explicit operator bool() const { return Value; }
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
/// Find the designated sub-object of an rvalue.
|
|
template<typename SubobjectHandler>
|
|
typename SubobjectHandler::result_type
|
|
findSubobject(EvalInfo &Info, const Expr *E, const CompleteObject &Obj,
|
|
const SubobjectDesignator &Sub, SubobjectHandler &handler) {
|
|
if (Sub.Invalid)
|
|
// A diagnostic will have already been produced.
|
|
return handler.failed();
|
|
if (Sub.isOnePastTheEnd() || Sub.isMostDerivedAnUnsizedArray()) {
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.FFDiag(E, Sub.isOnePastTheEnd()
|
|
? diag::note_constexpr_access_past_end
|
|
: diag::note_constexpr_access_unsized_array)
|
|
<< handler.AccessKind;
|
|
else
|
|
Info.FFDiag(E);
|
|
return handler.failed();
|
|
}
|
|
|
|
APValue *O = Obj.Value;
|
|
QualType ObjType = Obj.Type;
|
|
const FieldDecl *LastField = nullptr;
|
|
const bool MayReadMutableMembers =
|
|
Obj.LifetimeStartedInEvaluation && Info.getLangOpts().CPlusPlus14;
|
|
|
|
// Walk the designator's path to find the subobject.
|
|
for (unsigned I = 0, N = Sub.Entries.size(); /**/; ++I) {
|
|
if (O->isUninit()) {
|
|
if (!Info.checkingPotentialConstantExpression())
|
|
Info.FFDiag(E, diag::note_constexpr_access_uninit) << handler.AccessKind;
|
|
return handler.failed();
|
|
}
|
|
|
|
if (I == N) {
|
|
// If we are reading an object of class type, there may still be more
|
|
// things we need to check: if there are any mutable subobjects, we
|
|
// cannot perform this read. (This only happens when performing a trivial
|
|
// copy or assignment.)
|
|
if (ObjType->isRecordType() && handler.AccessKind == AK_Read &&
|
|
!MayReadMutableMembers && diagnoseUnreadableFields(Info, E, ObjType))
|
|
return handler.failed();
|
|
|
|
if (!handler.found(*O, ObjType))
|
|
return false;
|
|
|
|
// If we modified a bit-field, truncate it to the right width.
|
|
if (handler.AccessKind != AK_Read &&
|
|
LastField && LastField->isBitField() &&
|
|
!truncateBitfieldValue(Info, E, *O, LastField))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
LastField = nullptr;
|
|
if (ObjType->isArrayType()) {
|
|
// Next subobject is an array element.
|
|
const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(ObjType);
|
|
assert(CAT && "vla in literal type?");
|
|
uint64_t Index = Sub.Entries[I].ArrayIndex;
|
|
if (CAT->getSize().ule(Index)) {
|
|
// Note, it should not be possible to form a pointer with a valid
|
|
// designator which points more than one past the end of the array.
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.FFDiag(E, diag::note_constexpr_access_past_end)
|
|
<< handler.AccessKind;
|
|
else
|
|
Info.FFDiag(E);
|
|
return handler.failed();
|
|
}
|
|
|
|
ObjType = CAT->getElementType();
|
|
|
|
// An array object is represented as either an Array APValue or as an
|
|
// LValue which refers to a string literal.
|
|
if (O->isLValue()) {
|
|
assert(I == N - 1 && "extracting subobject of character?");
|
|
assert(!O->hasLValuePath() || O->getLValuePath().empty());
|
|
if (handler.AccessKind != AK_Read)
|
|
expandStringLiteral(Info, O->getLValueBase().get<const Expr *>(),
|
|
*O);
|
|
else
|
|
return handler.foundString(*O, ObjType, Index);
|
|
}
|
|
|
|
if (O->getArrayInitializedElts() > Index)
|
|
O = &O->getArrayInitializedElt(Index);
|
|
else if (handler.AccessKind != AK_Read) {
|
|
expandArray(*O, Index);
|
|
O = &O->getArrayInitializedElt(Index);
|
|
} else
|
|
O = &O->getArrayFiller();
|
|
} else if (ObjType->isAnyComplexType()) {
|
|
// Next subobject is a complex number.
|
|
uint64_t Index = Sub.Entries[I].ArrayIndex;
|
|
if (Index > 1) {
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.FFDiag(E, diag::note_constexpr_access_past_end)
|
|
<< handler.AccessKind;
|
|
else
|
|
Info.FFDiag(E);
|
|
return handler.failed();
|
|
}
|
|
|
|
bool WasConstQualified = ObjType.isConstQualified();
|
|
ObjType = ObjType->castAs<ComplexType>()->getElementType();
|
|
if (WasConstQualified)
|
|
ObjType.addConst();
|
|
|
|
assert(I == N - 1 && "extracting subobject of scalar?");
|
|
if (O->isComplexInt()) {
|
|
return handler.found(Index ? O->getComplexIntImag()
|
|
: O->getComplexIntReal(), ObjType);
|
|
} else {
|
|
assert(O->isComplexFloat());
|
|
return handler.found(Index ? O->getComplexFloatImag()
|
|
: O->getComplexFloatReal(), ObjType);
|
|
}
|
|
} else if (const FieldDecl *Field = getAsField(Sub.Entries[I])) {
|
|
// In C++14 onwards, it is permitted to read a mutable member whose
|
|
// lifetime began within the evaluation.
|
|
// FIXME: Should we also allow this in C++11?
|
|
if (Field->isMutable() && handler.AccessKind == AK_Read &&
|
|
!MayReadMutableMembers) {
|
|
Info.FFDiag(E, diag::note_constexpr_ltor_mutable, 1)
|
|
<< Field;
|
|
Info.Note(Field->getLocation(), diag::note_declared_at);
|
|
return handler.failed();
|
|
}
|
|
|
|
// Next subobject is a class, struct or union field.
|
|
RecordDecl *RD = ObjType->castAs<RecordType>()->getDecl();
|
|
if (RD->isUnion()) {
|
|
const FieldDecl *UnionField = O->getUnionField();
|
|
if (!UnionField ||
|
|
UnionField->getCanonicalDecl() != Field->getCanonicalDecl()) {
|
|
Info.FFDiag(E, diag::note_constexpr_access_inactive_union_member)
|
|
<< handler.AccessKind << Field << !UnionField << UnionField;
|
|
return handler.failed();
|
|
}
|
|
O = &O->getUnionValue();
|
|
} else
|
|
O = &O->getStructField(Field->getFieldIndex());
|
|
|
|
bool WasConstQualified = ObjType.isConstQualified();
|
|
ObjType = Field->getType();
|
|
if (WasConstQualified && !Field->isMutable())
|
|
ObjType.addConst();
|
|
|
|
if (ObjType.isVolatileQualified()) {
|
|
if (Info.getLangOpts().CPlusPlus) {
|
|
// FIXME: Include a description of the path to the volatile subobject.
|
|
Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
|
|
<< handler.AccessKind << 2 << Field;
|
|
Info.Note(Field->getLocation(), diag::note_declared_at);
|
|
} else {
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
}
|
|
return handler.failed();
|
|
}
|
|
|
|
LastField = Field;
|
|
} else {
|
|
// Next subobject is a base class.
|
|
const CXXRecordDecl *Derived = ObjType->getAsCXXRecordDecl();
|
|
const CXXRecordDecl *Base = getAsBaseClass(Sub.Entries[I]);
|
|
O = &O->getStructBase(getBaseIndex(Derived, Base));
|
|
|
|
bool WasConstQualified = ObjType.isConstQualified();
|
|
ObjType = Info.Ctx.getRecordType(Base);
|
|
if (WasConstQualified)
|
|
ObjType.addConst();
|
|
}
|
|
}
|
|
}
|
|
|
|
namespace {
|
|
struct ExtractSubobjectHandler {
|
|
EvalInfo &Info;
|
|
APValue &Result;
|
|
|
|
static const AccessKinds AccessKind = AK_Read;
|
|
|
|
typedef bool result_type;
|
|
bool failed() { return false; }
|
|
bool found(APValue &Subobj, QualType SubobjType) {
|
|
Result = Subobj;
|
|
return true;
|
|
}
|
|
bool found(APSInt &Value, QualType SubobjType) {
|
|
Result = APValue(Value);
|
|
return true;
|
|
}
|
|
bool found(APFloat &Value, QualType SubobjType) {
|
|
Result = APValue(Value);
|
|
return true;
|
|
}
|
|
bool foundString(APValue &Subobj, QualType SubobjType, uint64_t Character) {
|
|
Result = APValue(extractStringLiteralCharacter(
|
|
Info, Subobj.getLValueBase().get<const Expr *>(), Character));
|
|
return true;
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
const AccessKinds ExtractSubobjectHandler::AccessKind;
|
|
|
|
/// Extract the designated sub-object of an rvalue.
|
|
static bool extractSubobject(EvalInfo &Info, const Expr *E,
|
|
const CompleteObject &Obj,
|
|
const SubobjectDesignator &Sub,
|
|
APValue &Result) {
|
|
ExtractSubobjectHandler Handler = { Info, Result };
|
|
return findSubobject(Info, E, Obj, Sub, Handler);
|
|
}
|
|
|
|
namespace {
|
|
struct ModifySubobjectHandler {
|
|
EvalInfo &Info;
|
|
APValue &NewVal;
|
|
const Expr *E;
|
|
|
|
typedef bool result_type;
|
|
static const AccessKinds AccessKind = AK_Assign;
|
|
|
|
bool checkConst(QualType QT) {
|
|
// Assigning to a const object has undefined behavior.
|
|
if (QT.isConstQualified()) {
|
|
Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool failed() { return false; }
|
|
bool found(APValue &Subobj, QualType SubobjType) {
|
|
if (!checkConst(SubobjType))
|
|
return false;
|
|
// We've been given ownership of NewVal, so just swap it in.
|
|
Subobj.swap(NewVal);
|
|
return true;
|
|
}
|
|
bool found(APSInt &Value, QualType SubobjType) {
|
|
if (!checkConst(SubobjType))
|
|
return false;
|
|
if (!NewVal.isInt()) {
|
|
// Maybe trying to write a cast pointer value into a complex?
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
Value = NewVal.getInt();
|
|
return true;
|
|
}
|
|
bool found(APFloat &Value, QualType SubobjType) {
|
|
if (!checkConst(SubobjType))
|
|
return false;
|
|
Value = NewVal.getFloat();
|
|
return true;
|
|
}
|
|
bool foundString(APValue &Subobj, QualType SubobjType, uint64_t Character) {
|
|
llvm_unreachable("shouldn't encounter string elements with ExpandArrays");
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
const AccessKinds ModifySubobjectHandler::AccessKind;
|
|
|
|
/// Update the designated sub-object of an rvalue to the given value.
|
|
static bool modifySubobject(EvalInfo &Info, const Expr *E,
|
|
const CompleteObject &Obj,
|
|
const SubobjectDesignator &Sub,
|
|
APValue &NewVal) {
|
|
ModifySubobjectHandler Handler = { Info, NewVal, E };
|
|
return findSubobject(Info, E, Obj, Sub, Handler);
|
|
}
|
|
|
|
/// Find the position where two subobject designators diverge, or equivalently
|
|
/// the length of the common initial subsequence.
|
|
static unsigned FindDesignatorMismatch(QualType ObjType,
|
|
const SubobjectDesignator &A,
|
|
const SubobjectDesignator &B,
|
|
bool &WasArrayIndex) {
|
|
unsigned I = 0, N = std::min(A.Entries.size(), B.Entries.size());
|
|
for (/**/; I != N; ++I) {
|
|
if (!ObjType.isNull() &&
|
|
(ObjType->isArrayType() || ObjType->isAnyComplexType())) {
|
|
// Next subobject is an array element.
|
|
if (A.Entries[I].ArrayIndex != B.Entries[I].ArrayIndex) {
|
|
WasArrayIndex = true;
|
|
return I;
|
|
}
|
|
if (ObjType->isAnyComplexType())
|
|
ObjType = ObjType->castAs<ComplexType>()->getElementType();
|
|
else
|
|
ObjType = ObjType->castAsArrayTypeUnsafe()->getElementType();
|
|
} else {
|
|
if (A.Entries[I].BaseOrMember != B.Entries[I].BaseOrMember) {
|
|
WasArrayIndex = false;
|
|
return I;
|
|
}
|
|
if (const FieldDecl *FD = getAsField(A.Entries[I]))
|
|
// Next subobject is a field.
|
|
ObjType = FD->getType();
|
|
else
|
|
// Next subobject is a base class.
|
|
ObjType = QualType();
|
|
}
|
|
}
|
|
WasArrayIndex = false;
|
|
return I;
|
|
}
|
|
|
|
/// Determine whether the given subobject designators refer to elements of the
|
|
/// same array object.
|
|
static bool AreElementsOfSameArray(QualType ObjType,
|
|
const SubobjectDesignator &A,
|
|
const SubobjectDesignator &B) {
|
|
if (A.Entries.size() != B.Entries.size())
|
|
return false;
|
|
|
|
bool IsArray = A.MostDerivedIsArrayElement;
|
|
if (IsArray && A.MostDerivedPathLength != A.Entries.size())
|
|
// A is a subobject of the array element.
|
|
return false;
|
|
|
|
// If A (and B) designates an array element, the last entry will be the array
|
|
// index. That doesn't have to match. Otherwise, we're in the 'implicit array
|
|
// of length 1' case, and the entire path must match.
|
|
bool WasArrayIndex;
|
|
unsigned CommonLength = FindDesignatorMismatch(ObjType, A, B, WasArrayIndex);
|
|
return CommonLength >= A.Entries.size() - IsArray;
|
|
}
|
|
|
|
/// Find the complete object to which an LValue refers.
|
|
static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
|
|
AccessKinds AK, const LValue &LVal,
|
|
QualType LValType) {
|
|
if (!LVal.Base) {
|
|
Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
|
|
return CompleteObject();
|
|
}
|
|
|
|
CallStackFrame *Frame = nullptr;
|
|
if (LVal.getLValueCallIndex()) {
|
|
Frame = Info.getCallFrame(LVal.getLValueCallIndex());
|
|
if (!Frame) {
|
|
Info.FFDiag(E, diag::note_constexpr_lifetime_ended, 1)
|
|
<< AK << LVal.Base.is<const ValueDecl*>();
|
|
NoteLValueLocation(Info, LVal.Base);
|
|
return CompleteObject();
|
|
}
|
|
}
|
|
|
|
// C++11 DR1311: An lvalue-to-rvalue conversion on a volatile-qualified type
|
|
// is not a constant expression (even if the object is non-volatile). We also
|
|
// apply this rule to C++98, in order to conform to the expected 'volatile'
|
|
// semantics.
|
|
if (LValType.isVolatileQualified()) {
|
|
if (Info.getLangOpts().CPlusPlus)
|
|
Info.FFDiag(E, diag::note_constexpr_access_volatile_type)
|
|
<< AK << LValType;
|
|
else
|
|
Info.FFDiag(E);
|
|
return CompleteObject();
|
|
}
|
|
|
|
// Compute value storage location and type of base object.
|
|
APValue *BaseVal = nullptr;
|
|
QualType BaseType = getType(LVal.Base);
|
|
bool LifetimeStartedInEvaluation = Frame;
|
|
|
|
if (const ValueDecl *D = LVal.Base.dyn_cast<const ValueDecl*>()) {
|
|
// In C++98, const, non-volatile integers initialized with ICEs are ICEs.
|
|
// In C++11, constexpr, non-volatile variables initialized with constant
|
|
// expressions are constant expressions too. Inside constexpr functions,
|
|
// parameters are constant expressions even if they're non-const.
|
|
// In C++1y, objects local to a constant expression (those with a Frame) are
|
|
// both readable and writable inside constant expressions.
|
|
// In C, such things can also be folded, although they are not ICEs.
|
|
const VarDecl *VD = dyn_cast<VarDecl>(D);
|
|
if (VD) {
|
|
if (const VarDecl *VDef = VD->getDefinition(Info.Ctx))
|
|
VD = VDef;
|
|
}
|
|
if (!VD || VD->isInvalidDecl()) {
|
|
Info.FFDiag(E);
|
|
return CompleteObject();
|
|
}
|
|
|
|
// Accesses of volatile-qualified objects are not allowed.
|
|
if (BaseType.isVolatileQualified()) {
|
|
if (Info.getLangOpts().CPlusPlus) {
|
|
Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
|
|
<< AK << 1 << VD;
|
|
Info.Note(VD->getLocation(), diag::note_declared_at);
|
|
} else {
|
|
Info.FFDiag(E);
|
|
}
|
|
return CompleteObject();
|
|
}
|
|
|
|
// Unless we're looking at a local variable or argument in a constexpr call,
|
|
// the variable we're reading must be const.
|
|
if (!Frame) {
|
|
if (Info.getLangOpts().CPlusPlus14 &&
|
|
VD == Info.EvaluatingDecl.dyn_cast<const ValueDecl *>()) {
|
|
// OK, we can read and modify an object if we're in the process of
|
|
// evaluating its initializer, because its lifetime began in this
|
|
// evaluation.
|
|
} else if (AK != AK_Read) {
|
|
// All the remaining cases only permit reading.
|
|
Info.FFDiag(E, diag::note_constexpr_modify_global);
|
|
return CompleteObject();
|
|
} else if (VD->isConstexpr()) {
|
|
// OK, we can read this variable.
|
|
} else if (BaseType->isIntegralOrEnumerationType()) {
|
|
// In OpenCL if a variable is in constant address space it is a const value.
|
|
if (!(BaseType.isConstQualified() ||
|
|
(Info.getLangOpts().OpenCL &&
|
|
BaseType.getAddressSpace() == LangAS::opencl_constant))) {
|
|
if (Info.getLangOpts().CPlusPlus) {
|
|
Info.FFDiag(E, diag::note_constexpr_ltor_non_const_int, 1) << VD;
|
|
Info.Note(VD->getLocation(), diag::note_declared_at);
|
|
} else {
|
|
Info.FFDiag(E);
|
|
}
|
|
return CompleteObject();
|
|
}
|
|
} else if (BaseType->isFloatingType() && BaseType.isConstQualified()) {
|
|
// We support folding of const floating-point types, in order to make
|
|
// static const data members of such types (supported as an extension)
|
|
// more useful.
|
|
if (Info.getLangOpts().CPlusPlus11) {
|
|
Info.CCEDiag(E, diag::note_constexpr_ltor_non_constexpr, 1) << VD;
|
|
Info.Note(VD->getLocation(), diag::note_declared_at);
|
|
} else {
|
|
Info.CCEDiag(E);
|
|
}
|
|
} else if (BaseType.isConstQualified() && VD->hasDefinition(Info.Ctx)) {
|
|
Info.CCEDiag(E, diag::note_constexpr_ltor_non_constexpr) << VD;
|
|
// Keep evaluating to see what we can do.
|
|
} else {
|
|
// FIXME: Allow folding of values of any literal type in all languages.
|
|
if (Info.checkingPotentialConstantExpression() &&
|
|
VD->getType().isConstQualified() && !VD->hasDefinition(Info.Ctx)) {
|
|
// The definition of this variable could be constexpr. We can't
|
|
// access it right now, but may be able to in future.
|
|
} else if (Info.getLangOpts().CPlusPlus11) {
|
|
Info.FFDiag(E, diag::note_constexpr_ltor_non_constexpr, 1) << VD;
|
|
Info.Note(VD->getLocation(), diag::note_declared_at);
|
|
} else {
|
|
Info.FFDiag(E);
|
|
}
|
|
return CompleteObject();
|
|
}
|
|
}
|
|
|
|
if (!evaluateVarDeclInit(Info, E, VD, Frame, BaseVal, &LVal))
|
|
return CompleteObject();
|
|
} else {
|
|
const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
|
|
|
|
if (!Frame) {
|
|
if (const MaterializeTemporaryExpr *MTE =
|
|
dyn_cast<MaterializeTemporaryExpr>(Base)) {
|
|
assert(MTE->getStorageDuration() == SD_Static &&
|
|
"should have a frame for a non-global materialized temporary");
|
|
|
|
// Per C++1y [expr.const]p2:
|
|
// an lvalue-to-rvalue conversion [is not allowed unless it applies to]
|
|
// - a [...] glvalue of integral or enumeration type that refers to
|
|
// a non-volatile const object [...]
|
|
// [...]
|
|
// - a [...] glvalue of literal type that refers to a non-volatile
|
|
// object whose lifetime began within the evaluation of e.
|
|
//
|
|
// C++11 misses the 'began within the evaluation of e' check and
|
|
// instead allows all temporaries, including things like:
|
|
// int &&r = 1;
|
|
// int x = ++r;
|
|
// constexpr int k = r;
|
|
// Therefore we use the C++14 rules in C++11 too.
|
|
const ValueDecl *VD = Info.EvaluatingDecl.dyn_cast<const ValueDecl*>();
|
|
const ValueDecl *ED = MTE->getExtendingDecl();
|
|
if (!(BaseType.isConstQualified() &&
|
|
BaseType->isIntegralOrEnumerationType()) &&
|
|
!(VD && VD->getCanonicalDecl() == ED->getCanonicalDecl())) {
|
|
Info.FFDiag(E, diag::note_constexpr_access_static_temporary, 1) << AK;
|
|
Info.Note(MTE->getExprLoc(), diag::note_constexpr_temporary_here);
|
|
return CompleteObject();
|
|
}
|
|
|
|
BaseVal = Info.Ctx.getMaterializedTemporaryValue(MTE, false);
|
|
assert(BaseVal && "got reference to unevaluated temporary");
|
|
LifetimeStartedInEvaluation = true;
|
|
} else {
|
|
Info.FFDiag(E);
|
|
return CompleteObject();
|
|
}
|
|
} else {
|
|
BaseVal = Frame->getTemporary(Base, LVal.Base.getVersion());
|
|
assert(BaseVal && "missing value for temporary");
|
|
}
|
|
|
|
// Volatile temporary objects cannot be accessed in constant expressions.
|
|
if (BaseType.isVolatileQualified()) {
|
|
if (Info.getLangOpts().CPlusPlus) {
|
|
Info.FFDiag(E, diag::note_constexpr_access_volatile_obj, 1)
|
|
<< AK << 0;
|
|
Info.Note(Base->getExprLoc(), diag::note_constexpr_temporary_here);
|
|
} else {
|
|
Info.FFDiag(E);
|
|
}
|
|
return CompleteObject();
|
|
}
|
|
}
|
|
|
|
// During the construction of an object, it is not yet 'const'.
|
|
// FIXME: This doesn't do quite the right thing for const subobjects of the
|
|
// object under construction.
|
|
if (Info.isEvaluatingConstructor(LVal.getLValueBase(),
|
|
LVal.getLValueCallIndex(),
|
|
LVal.getLValueVersion())) {
|
|
BaseType = Info.Ctx.getCanonicalType(BaseType);
|
|
BaseType.removeLocalConst();
|
|
LifetimeStartedInEvaluation = true;
|
|
}
|
|
|
|
// In C++14, we can't safely access any mutable state when we might be
|
|
// evaluating after an unmodeled side effect.
|
|
//
|
|
// FIXME: Not all local state is mutable. Allow local constant subobjects
|
|
// to be read here (but take care with 'mutable' fields).
|
|
if ((Frame && Info.getLangOpts().CPlusPlus14 &&
|
|
Info.EvalStatus.HasSideEffects) ||
|
|
(AK != AK_Read && Info.IsSpeculativelyEvaluating))
|
|
return CompleteObject();
|
|
|
|
return CompleteObject(BaseVal, BaseType, LifetimeStartedInEvaluation);
|
|
}
|
|
|
|
/// Perform an lvalue-to-rvalue conversion on the given glvalue. This
|
|
/// can also be used for 'lvalue-to-lvalue' conversions for looking up the
|
|
/// glvalue referred to by an entity of reference type.
|
|
///
|
|
/// \param Info - Information about the ongoing evaluation.
|
|
/// \param Conv - The expression for which we are performing the conversion.
|
|
/// Used for diagnostics.
|
|
/// \param Type - The type of the glvalue (before stripping cv-qualifiers in the
|
|
/// case of a non-class type).
|
|
/// \param LVal - The glvalue on which we are attempting to perform this action.
|
|
/// \param RVal - The produced value will be placed here.
|
|
static bool handleLValueToRValueConversion(EvalInfo &Info, const Expr *Conv,
|
|
QualType Type,
|
|
const LValue &LVal, APValue &RVal) {
|
|
if (LVal.Designator.Invalid)
|
|
return false;
|
|
|
|
// Check for special cases where there is no existing APValue to look at.
|
|
const Expr *Base = LVal.Base.dyn_cast<const Expr*>();
|
|
if (Base && !LVal.getLValueCallIndex() && !Type.isVolatileQualified()) {
|
|
if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(Base)) {
|
|
// In C99, a CompoundLiteralExpr is an lvalue, and we defer evaluating the
|
|
// initializer until now for such expressions. Such an expression can't be
|
|
// an ICE in C, so this only matters for fold.
|
|
if (Type.isVolatileQualified()) {
|
|
Info.FFDiag(Conv);
|
|
return false;
|
|
}
|
|
APValue Lit;
|
|
if (!Evaluate(Lit, Info, CLE->getInitializer()))
|
|
return false;
|
|
CompleteObject LitObj(&Lit, Base->getType(), false);
|
|
return extractSubobject(Info, Conv, LitObj, LVal.Designator, RVal);
|
|
} else if (isa<StringLiteral>(Base) || isa<PredefinedExpr>(Base)) {
|
|
// We represent a string literal array as an lvalue pointing at the
|
|
// corresponding expression, rather than building an array of chars.
|
|
// FIXME: Support ObjCEncodeExpr, MakeStringConstant
|
|
APValue Str(Base, CharUnits::Zero(), APValue::NoLValuePath(), 0);
|
|
CompleteObject StrObj(&Str, Base->getType(), false);
|
|
return extractSubobject(Info, Conv, StrObj, LVal.Designator, RVal);
|
|
}
|
|
}
|
|
|
|
CompleteObject Obj = findCompleteObject(Info, Conv, AK_Read, LVal, Type);
|
|
return Obj && extractSubobject(Info, Conv, Obj, LVal.Designator, RVal);
|
|
}
|
|
|
|
/// Perform an assignment of Val to LVal. Takes ownership of Val.
|
|
static bool handleAssignment(EvalInfo &Info, const Expr *E, const LValue &LVal,
|
|
QualType LValType, APValue &Val) {
|
|
if (LVal.Designator.Invalid)
|
|
return false;
|
|
|
|
if (!Info.getLangOpts().CPlusPlus14) {
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
|
|
CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
|
|
return Obj && modifySubobject(Info, E, Obj, LVal.Designator, Val);
|
|
}
|
|
|
|
namespace {
|
|
struct CompoundAssignSubobjectHandler {
|
|
EvalInfo &Info;
|
|
const Expr *E;
|
|
QualType PromotedLHSType;
|
|
BinaryOperatorKind Opcode;
|
|
const APValue &RHS;
|
|
|
|
static const AccessKinds AccessKind = AK_Assign;
|
|
|
|
typedef bool result_type;
|
|
|
|
bool checkConst(QualType QT) {
|
|
// Assigning to a const object has undefined behavior.
|
|
if (QT.isConstQualified()) {
|
|
Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool failed() { return false; }
|
|
bool found(APValue &Subobj, QualType SubobjType) {
|
|
switch (Subobj.getKind()) {
|
|
case APValue::Int:
|
|
return found(Subobj.getInt(), SubobjType);
|
|
case APValue::Float:
|
|
return found(Subobj.getFloat(), SubobjType);
|
|
case APValue::ComplexInt:
|
|
case APValue::ComplexFloat:
|
|
// FIXME: Implement complex compound assignment.
|
|
Info.FFDiag(E);
|
|
return false;
|
|
case APValue::LValue:
|
|
return foundPointer(Subobj, SubobjType);
|
|
default:
|
|
// FIXME: can this happen?
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
}
|
|
bool found(APSInt &Value, QualType SubobjType) {
|
|
if (!checkConst(SubobjType))
|
|
return false;
|
|
|
|
if (!SubobjType->isIntegerType()) {
|
|
// We don't support compound assignment on integer-cast-to-pointer
|
|
// values.
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
|
|
if (RHS.isInt()) {
|
|
APSInt LHS =
|
|
HandleIntToIntCast(Info, E, PromotedLHSType, SubobjType, Value);
|
|
if (!handleIntIntBinOp(Info, E, LHS, Opcode, RHS.getInt(), LHS))
|
|
return false;
|
|
Value = HandleIntToIntCast(Info, E, SubobjType, PromotedLHSType, LHS);
|
|
return true;
|
|
} else if (RHS.isFloat()) {
|
|
APFloat FValue(0.0);
|
|
return HandleIntToFloatCast(Info, E, SubobjType, Value, PromotedLHSType,
|
|
FValue) &&
|
|
handleFloatFloatBinOp(Info, E, FValue, Opcode, RHS.getFloat()) &&
|
|
HandleFloatToIntCast(Info, E, PromotedLHSType, FValue, SubobjType,
|
|
Value);
|
|
}
|
|
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
bool found(APFloat &Value, QualType SubobjType) {
|
|
return checkConst(SubobjType) &&
|
|
HandleFloatToFloatCast(Info, E, SubobjType, PromotedLHSType,
|
|
Value) &&
|
|
handleFloatFloatBinOp(Info, E, Value, Opcode, RHS.getFloat()) &&
|
|
HandleFloatToFloatCast(Info, E, PromotedLHSType, SubobjType, Value);
|
|
}
|
|
bool foundPointer(APValue &Subobj, QualType SubobjType) {
|
|
if (!checkConst(SubobjType))
|
|
return false;
|
|
|
|
QualType PointeeType;
|
|
if (const PointerType *PT = SubobjType->getAs<PointerType>())
|
|
PointeeType = PT->getPointeeType();
|
|
|
|
if (PointeeType.isNull() || !RHS.isInt() ||
|
|
(Opcode != BO_Add && Opcode != BO_Sub)) {
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
|
|
APSInt Offset = RHS.getInt();
|
|
if (Opcode == BO_Sub)
|
|
negateAsSigned(Offset);
|
|
|
|
LValue LVal;
|
|
LVal.setFrom(Info.Ctx, Subobj);
|
|
if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType, Offset))
|
|
return false;
|
|
LVal.moveInto(Subobj);
|
|
return true;
|
|
}
|
|
bool foundString(APValue &Subobj, QualType SubobjType, uint64_t Character) {
|
|
llvm_unreachable("shouldn't encounter string elements here");
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
const AccessKinds CompoundAssignSubobjectHandler::AccessKind;
|
|
|
|
/// Perform a compound assignment of LVal <op>= RVal.
|
|
static bool handleCompoundAssignment(
|
|
EvalInfo &Info, const Expr *E,
|
|
const LValue &LVal, QualType LValType, QualType PromotedLValType,
|
|
BinaryOperatorKind Opcode, const APValue &RVal) {
|
|
if (LVal.Designator.Invalid)
|
|
return false;
|
|
|
|
if (!Info.getLangOpts().CPlusPlus14) {
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
|
|
CompleteObject Obj = findCompleteObject(Info, E, AK_Assign, LVal, LValType);
|
|
CompoundAssignSubobjectHandler Handler = { Info, E, PromotedLValType, Opcode,
|
|
RVal };
|
|
return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
|
|
}
|
|
|
|
namespace {
|
|
struct IncDecSubobjectHandler {
|
|
EvalInfo &Info;
|
|
const UnaryOperator *E;
|
|
AccessKinds AccessKind;
|
|
APValue *Old;
|
|
|
|
typedef bool result_type;
|
|
|
|
bool checkConst(QualType QT) {
|
|
// Assigning to a const object has undefined behavior.
|
|
if (QT.isConstQualified()) {
|
|
Info.FFDiag(E, diag::note_constexpr_modify_const_type) << QT;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool failed() { return false; }
|
|
bool found(APValue &Subobj, QualType SubobjType) {
|
|
// Stash the old value. Also clear Old, so we don't clobber it later
|
|
// if we're post-incrementing a complex.
|
|
if (Old) {
|
|
*Old = Subobj;
|
|
Old = nullptr;
|
|
}
|
|
|
|
switch (Subobj.getKind()) {
|
|
case APValue::Int:
|
|
return found(Subobj.getInt(), SubobjType);
|
|
case APValue::Float:
|
|
return found(Subobj.getFloat(), SubobjType);
|
|
case APValue::ComplexInt:
|
|
return found(Subobj.getComplexIntReal(),
|
|
SubobjType->castAs<ComplexType>()->getElementType()
|
|
.withCVRQualifiers(SubobjType.getCVRQualifiers()));
|
|
case APValue::ComplexFloat:
|
|
return found(Subobj.getComplexFloatReal(),
|
|
SubobjType->castAs<ComplexType>()->getElementType()
|
|
.withCVRQualifiers(SubobjType.getCVRQualifiers()));
|
|
case APValue::LValue:
|
|
return foundPointer(Subobj, SubobjType);
|
|
default:
|
|
// FIXME: can this happen?
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
}
|
|
bool found(APSInt &Value, QualType SubobjType) {
|
|
if (!checkConst(SubobjType))
|
|
return false;
|
|
|
|
if (!SubobjType->isIntegerType()) {
|
|
// We don't support increment / decrement on integer-cast-to-pointer
|
|
// values.
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
|
|
if (Old) *Old = APValue(Value);
|
|
|
|
// bool arithmetic promotes to int, and the conversion back to bool
|
|
// doesn't reduce mod 2^n, so special-case it.
|
|
if (SubobjType->isBooleanType()) {
|
|
if (AccessKind == AK_Increment)
|
|
Value = 1;
|
|
else
|
|
Value = !Value;
|
|
return true;
|
|
}
|
|
|
|
bool WasNegative = Value.isNegative();
|
|
if (AccessKind == AK_Increment) {
|
|
++Value;
|
|
|
|
if (!WasNegative && Value.isNegative() && E->canOverflow()) {
|
|
APSInt ActualValue(Value, /*IsUnsigned*/true);
|
|
return HandleOverflow(Info, E, ActualValue, SubobjType);
|
|
}
|
|
} else {
|
|
--Value;
|
|
|
|
if (WasNegative && !Value.isNegative() && E->canOverflow()) {
|
|
unsigned BitWidth = Value.getBitWidth();
|
|
APSInt ActualValue(Value.sext(BitWidth + 1), /*IsUnsigned*/false);
|
|
ActualValue.setBit(BitWidth);
|
|
return HandleOverflow(Info, E, ActualValue, SubobjType);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
bool found(APFloat &Value, QualType SubobjType) {
|
|
if (!checkConst(SubobjType))
|
|
return false;
|
|
|
|
if (Old) *Old = APValue(Value);
|
|
|
|
APFloat One(Value.getSemantics(), 1);
|
|
if (AccessKind == AK_Increment)
|
|
Value.add(One, APFloat::rmNearestTiesToEven);
|
|
else
|
|
Value.subtract(One, APFloat::rmNearestTiesToEven);
|
|
return true;
|
|
}
|
|
bool foundPointer(APValue &Subobj, QualType SubobjType) {
|
|
if (!checkConst(SubobjType))
|
|
return false;
|
|
|
|
QualType PointeeType;
|
|
if (const PointerType *PT = SubobjType->getAs<PointerType>())
|
|
PointeeType = PT->getPointeeType();
|
|
else {
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
|
|
LValue LVal;
|
|
LVal.setFrom(Info.Ctx, Subobj);
|
|
if (!HandleLValueArrayAdjustment(Info, E, LVal, PointeeType,
|
|
AccessKind == AK_Increment ? 1 : -1))
|
|
return false;
|
|
LVal.moveInto(Subobj);
|
|
return true;
|
|
}
|
|
bool foundString(APValue &Subobj, QualType SubobjType, uint64_t Character) {
|
|
llvm_unreachable("shouldn't encounter string elements here");
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
/// Perform an increment or decrement on LVal.
|
|
static bool handleIncDec(EvalInfo &Info, const Expr *E, const LValue &LVal,
|
|
QualType LValType, bool IsIncrement, APValue *Old) {
|
|
if (LVal.Designator.Invalid)
|
|
return false;
|
|
|
|
if (!Info.getLangOpts().CPlusPlus14) {
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
|
|
AccessKinds AK = IsIncrement ? AK_Increment : AK_Decrement;
|
|
CompleteObject Obj = findCompleteObject(Info, E, AK, LVal, LValType);
|
|
IncDecSubobjectHandler Handler = {Info, cast<UnaryOperator>(E), AK, Old};
|
|
return Obj && findSubobject(Info, E, Obj, LVal.Designator, Handler);
|
|
}
|
|
|
|
/// Build an lvalue for the object argument of a member function call.
|
|
static bool EvaluateObjectArgument(EvalInfo &Info, const Expr *Object,
|
|
LValue &This) {
|
|
if (Object->getType()->isPointerType())
|
|
return EvaluatePointer(Object, This, Info);
|
|
|
|
if (Object->isGLValue())
|
|
return EvaluateLValue(Object, This, Info);
|
|
|
|
if (Object->getType()->isLiteralType(Info.Ctx))
|
|
return EvaluateTemporary(Object, This, Info);
|
|
|
|
Info.FFDiag(Object, diag::note_constexpr_nonliteral) << Object->getType();
|
|
return false;
|
|
}
|
|
|
|
/// HandleMemberPointerAccess - Evaluate a member access operation and build an
|
|
/// lvalue referring to the result.
|
|
///
|
|
/// \param Info - Information about the ongoing evaluation.
|
|
/// \param LV - An lvalue referring to the base of the member pointer.
|
|
/// \param RHS - The member pointer expression.
|
|
/// \param IncludeMember - Specifies whether the member itself is included in
|
|
/// the resulting LValue subobject designator. This is not possible when
|
|
/// creating a bound member function.
|
|
/// \return The field or method declaration to which the member pointer refers,
|
|
/// or 0 if evaluation fails.
|
|
static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
|
|
QualType LVType,
|
|
LValue &LV,
|
|
const Expr *RHS,
|
|
bool IncludeMember = true) {
|
|
MemberPtr MemPtr;
|
|
if (!EvaluateMemberPointer(RHS, MemPtr, Info))
|
|
return nullptr;
|
|
|
|
// C++11 [expr.mptr.oper]p6: If the second operand is the null pointer to
|
|
// member value, the behavior is undefined.
|
|
if (!MemPtr.getDecl()) {
|
|
// FIXME: Specific diagnostic.
|
|
Info.FFDiag(RHS);
|
|
return nullptr;
|
|
}
|
|
|
|
if (MemPtr.isDerivedMember()) {
|
|
// This is a member of some derived class. Truncate LV appropriately.
|
|
// The end of the derived-to-base path for the base object must match the
|
|
// derived-to-base path for the member pointer.
|
|
if (LV.Designator.MostDerivedPathLength + MemPtr.Path.size() >
|
|
LV.Designator.Entries.size()) {
|
|
Info.FFDiag(RHS);
|
|
return nullptr;
|
|
}
|
|
unsigned PathLengthToMember =
|
|
LV.Designator.Entries.size() - MemPtr.Path.size();
|
|
for (unsigned I = 0, N = MemPtr.Path.size(); I != N; ++I) {
|
|
const CXXRecordDecl *LVDecl = getAsBaseClass(
|
|
LV.Designator.Entries[PathLengthToMember + I]);
|
|
const CXXRecordDecl *MPDecl = MemPtr.Path[I];
|
|
if (LVDecl->getCanonicalDecl() != MPDecl->getCanonicalDecl()) {
|
|
Info.FFDiag(RHS);
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
// Truncate the lvalue to the appropriate derived class.
|
|
if (!CastToDerivedClass(Info, RHS, LV, MemPtr.getContainingRecord(),
|
|
PathLengthToMember))
|
|
return nullptr;
|
|
} else if (!MemPtr.Path.empty()) {
|
|
// Extend the LValue path with the member pointer's path.
|
|
LV.Designator.Entries.reserve(LV.Designator.Entries.size() +
|
|
MemPtr.Path.size() + IncludeMember);
|
|
|
|
// Walk down to the appropriate base class.
|
|
if (const PointerType *PT = LVType->getAs<PointerType>())
|
|
LVType = PT->getPointeeType();
|
|
const CXXRecordDecl *RD = LVType->getAsCXXRecordDecl();
|
|
assert(RD && "member pointer access on non-class-type expression");
|
|
// The first class in the path is that of the lvalue.
|
|
for (unsigned I = 1, N = MemPtr.Path.size(); I != N; ++I) {
|
|
const CXXRecordDecl *Base = MemPtr.Path[N - I - 1];
|
|
if (!HandleLValueDirectBase(Info, RHS, LV, RD, Base))
|
|
return nullptr;
|
|
RD = Base;
|
|
}
|
|
// Finally cast to the class containing the member.
|
|
if (!HandleLValueDirectBase(Info, RHS, LV, RD,
|
|
MemPtr.getContainingRecord()))
|
|
return nullptr;
|
|
}
|
|
|
|
// Add the member. Note that we cannot build bound member functions here.
|
|
if (IncludeMember) {
|
|
if (const FieldDecl *FD = dyn_cast<FieldDecl>(MemPtr.getDecl())) {
|
|
if (!HandleLValueMember(Info, RHS, LV, FD))
|
|
return nullptr;
|
|
} else if (const IndirectFieldDecl *IFD =
|
|
dyn_cast<IndirectFieldDecl>(MemPtr.getDecl())) {
|
|
if (!HandleLValueIndirectMember(Info, RHS, LV, IFD))
|
|
return nullptr;
|
|
} else {
|
|
llvm_unreachable("can't construct reference to bound member function");
|
|
}
|
|
}
|
|
|
|
return MemPtr.getDecl();
|
|
}
|
|
|
|
static const ValueDecl *HandleMemberPointerAccess(EvalInfo &Info,
|
|
const BinaryOperator *BO,
|
|
LValue &LV,
|
|
bool IncludeMember = true) {
|
|
assert(BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI);
|
|
|
|
if (!EvaluateObjectArgument(Info, BO->getLHS(), LV)) {
|
|
if (Info.noteFailure()) {
|
|
MemberPtr MemPtr;
|
|
EvaluateMemberPointer(BO->getRHS(), MemPtr, Info);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
return HandleMemberPointerAccess(Info, BO->getLHS()->getType(), LV,
|
|
BO->getRHS(), IncludeMember);
|
|
}
|
|
|
|
/// HandleBaseToDerivedCast - Apply the given base-to-derived cast operation on
|
|
/// the provided lvalue, which currently refers to the base object.
|
|
static bool HandleBaseToDerivedCast(EvalInfo &Info, const CastExpr *E,
|
|
LValue &Result) {
|
|
SubobjectDesignator &D = Result.Designator;
|
|
if (D.Invalid || !Result.checkNullPointer(Info, E, CSK_Derived))
|
|
return false;
|
|
|
|
QualType TargetQT = E->getType();
|
|
if (const PointerType *PT = TargetQT->getAs<PointerType>())
|
|
TargetQT = PT->getPointeeType();
|
|
|
|
// Check this cast lands within the final derived-to-base subobject path.
|
|
if (D.MostDerivedPathLength + E->path_size() > D.Entries.size()) {
|
|
Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
|
|
<< D.MostDerivedType << TargetQT;
|
|
return false;
|
|
}
|
|
|
|
// Check the type of the final cast. We don't need to check the path,
|
|
// since a cast can only be formed if the path is unique.
|
|
unsigned NewEntriesSize = D.Entries.size() - E->path_size();
|
|
const CXXRecordDecl *TargetType = TargetQT->getAsCXXRecordDecl();
|
|
const CXXRecordDecl *FinalType;
|
|
if (NewEntriesSize == D.MostDerivedPathLength)
|
|
FinalType = D.MostDerivedType->getAsCXXRecordDecl();
|
|
else
|
|
FinalType = getAsBaseClass(D.Entries[NewEntriesSize - 1]);
|
|
if (FinalType->getCanonicalDecl() != TargetType->getCanonicalDecl()) {
|
|
Info.CCEDiag(E, diag::note_constexpr_invalid_downcast)
|
|
<< D.MostDerivedType << TargetQT;
|
|
return false;
|
|
}
|
|
|
|
// Truncate the lvalue to the appropriate derived class.
|
|
return CastToDerivedClass(Info, E, Result, TargetType, NewEntriesSize);
|
|
}
|
|
|
|
namespace {
|
|
enum EvalStmtResult {
|
|
/// Evaluation failed.
|
|
ESR_Failed,
|
|
/// Hit a 'return' statement.
|
|
ESR_Returned,
|
|
/// Evaluation succeeded.
|
|
ESR_Succeeded,
|
|
/// Hit a 'continue' statement.
|
|
ESR_Continue,
|
|
/// Hit a 'break' statement.
|
|
ESR_Break,
|
|
/// Still scanning for 'case' or 'default' statement.
|
|
ESR_CaseNotFound
|
|
};
|
|
}
|
|
|
|
static bool EvaluateVarDecl(EvalInfo &Info, const VarDecl *VD) {
|
|
// We don't need to evaluate the initializer for a static local.
|
|
if (!VD->hasLocalStorage())
|
|
return true;
|
|
|
|
LValue Result;
|
|
APValue &Val = createTemporary(VD, true, Result, *Info.CurrentCall);
|
|
|
|
const Expr *InitE = VD->getInit();
|
|
if (!InitE) {
|
|
Info.FFDiag(VD->getBeginLoc(), diag::note_constexpr_uninitialized)
|
|
<< false << VD->getType();
|
|
Val = APValue();
|
|
return false;
|
|
}
|
|
|
|
if (InitE->isValueDependent())
|
|
return false;
|
|
|
|
if (!EvaluateInPlace(Val, Info, Result, InitE)) {
|
|
// Wipe out any partially-computed value, to allow tracking that this
|
|
// evaluation failed.
|
|
Val = APValue();
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool EvaluateDecl(EvalInfo &Info, const Decl *D) {
|
|
bool OK = true;
|
|
|
|
if (const VarDecl *VD = dyn_cast<VarDecl>(D))
|
|
OK &= EvaluateVarDecl(Info, VD);
|
|
|
|
if (const DecompositionDecl *DD = dyn_cast<DecompositionDecl>(D))
|
|
for (auto *BD : DD->bindings())
|
|
if (auto *VD = BD->getHoldingVar())
|
|
OK &= EvaluateDecl(Info, VD);
|
|
|
|
return OK;
|
|
}
|
|
|
|
|
|
/// Evaluate a condition (either a variable declaration or an expression).
|
|
static bool EvaluateCond(EvalInfo &Info, const VarDecl *CondDecl,
|
|
const Expr *Cond, bool &Result) {
|
|
FullExpressionRAII Scope(Info);
|
|
if (CondDecl && !EvaluateDecl(Info, CondDecl))
|
|
return false;
|
|
return EvaluateAsBooleanCondition(Cond, Result, Info);
|
|
}
|
|
|
|
namespace {
|
|
/// A location where the result (returned value) of evaluating a
|
|
/// statement should be stored.
|
|
struct StmtResult {
|
|
/// The APValue that should be filled in with the returned value.
|
|
APValue &Value;
|
|
/// The location containing the result, if any (used to support RVO).
|
|
const LValue *Slot;
|
|
};
|
|
|
|
struct TempVersionRAII {
|
|
CallStackFrame &Frame;
|
|
|
|
TempVersionRAII(CallStackFrame &Frame) : Frame(Frame) {
|
|
Frame.pushTempVersion();
|
|
}
|
|
|
|
~TempVersionRAII() {
|
|
Frame.popTempVersion();
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
|
|
const Stmt *S,
|
|
const SwitchCase *SC = nullptr);
|
|
|
|
/// Evaluate the body of a loop, and translate the result as appropriate.
|
|
static EvalStmtResult EvaluateLoopBody(StmtResult &Result, EvalInfo &Info,
|
|
const Stmt *Body,
|
|
const SwitchCase *Case = nullptr) {
|
|
BlockScopeRAII Scope(Info);
|
|
switch (EvalStmtResult ESR = EvaluateStmt(Result, Info, Body, Case)) {
|
|
case ESR_Break:
|
|
return ESR_Succeeded;
|
|
case ESR_Succeeded:
|
|
case ESR_Continue:
|
|
return ESR_Continue;
|
|
case ESR_Failed:
|
|
case ESR_Returned:
|
|
case ESR_CaseNotFound:
|
|
return ESR;
|
|
}
|
|
llvm_unreachable("Invalid EvalStmtResult!");
|
|
}
|
|
|
|
/// Evaluate a switch statement.
|
|
static EvalStmtResult EvaluateSwitch(StmtResult &Result, EvalInfo &Info,
|
|
const SwitchStmt *SS) {
|
|
BlockScopeRAII Scope(Info);
|
|
|
|
// Evaluate the switch condition.
|
|
APSInt Value;
|
|
{
|
|
FullExpressionRAII Scope(Info);
|
|
if (const Stmt *Init = SS->getInit()) {
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
}
|
|
if (SS->getConditionVariable() &&
|
|
!EvaluateDecl(Info, SS->getConditionVariable()))
|
|
return ESR_Failed;
|
|
if (!EvaluateInteger(SS->getCond(), Value, Info))
|
|
return ESR_Failed;
|
|
}
|
|
|
|
// Find the switch case corresponding to the value of the condition.
|
|
// FIXME: Cache this lookup.
|
|
const SwitchCase *Found = nullptr;
|
|
for (const SwitchCase *SC = SS->getSwitchCaseList(); SC;
|
|
SC = SC->getNextSwitchCase()) {
|
|
if (isa<DefaultStmt>(SC)) {
|
|
Found = SC;
|
|
continue;
|
|
}
|
|
|
|
const CaseStmt *CS = cast<CaseStmt>(SC);
|
|
APSInt LHS = CS->getLHS()->EvaluateKnownConstInt(Info.Ctx);
|
|
APSInt RHS = CS->getRHS() ? CS->getRHS()->EvaluateKnownConstInt(Info.Ctx)
|
|
: LHS;
|
|
if (LHS <= Value && Value <= RHS) {
|
|
Found = SC;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!Found)
|
|
return ESR_Succeeded;
|
|
|
|
// Search the switch body for the switch case and evaluate it from there.
|
|
switch (EvalStmtResult ESR = EvaluateStmt(Result, Info, SS->getBody(), Found)) {
|
|
case ESR_Break:
|
|
return ESR_Succeeded;
|
|
case ESR_Succeeded:
|
|
case ESR_Continue:
|
|
case ESR_Failed:
|
|
case ESR_Returned:
|
|
return ESR;
|
|
case ESR_CaseNotFound:
|
|
// This can only happen if the switch case is nested within a statement
|
|
// expression. We have no intention of supporting that.
|
|
Info.FFDiag(Found->getBeginLoc(),
|
|
diag::note_constexpr_stmt_expr_unsupported);
|
|
return ESR_Failed;
|
|
}
|
|
llvm_unreachable("Invalid EvalStmtResult!");
|
|
}
|
|
|
|
// Evaluate a statement.
|
|
static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
|
|
const Stmt *S, const SwitchCase *Case) {
|
|
if (!Info.nextStep(S))
|
|
return ESR_Failed;
|
|
|
|
// If we're hunting down a 'case' or 'default' label, recurse through
|
|
// substatements until we hit the label.
|
|
if (Case) {
|
|
// FIXME: We don't start the lifetime of objects whose initialization we
|
|
// jump over. However, such objects must be of class type with a trivial
|
|
// default constructor that initialize all subobjects, so must be empty,
|
|
// so this almost never matters.
|
|
switch (S->getStmtClass()) {
|
|
case Stmt::CompoundStmtClass:
|
|
// FIXME: Precompute which substatement of a compound statement we
|
|
// would jump to, and go straight there rather than performing a
|
|
// linear scan each time.
|
|
case Stmt::LabelStmtClass:
|
|
case Stmt::AttributedStmtClass:
|
|
case Stmt::DoStmtClass:
|
|
break;
|
|
|
|
case Stmt::CaseStmtClass:
|
|
case Stmt::DefaultStmtClass:
|
|
if (Case == S)
|
|
Case = nullptr;
|
|
break;
|
|
|
|
case Stmt::IfStmtClass: {
|
|
// FIXME: Precompute which side of an 'if' we would jump to, and go
|
|
// straight there rather than scanning both sides.
|
|
const IfStmt *IS = cast<IfStmt>(S);
|
|
|
|
// Wrap the evaluation in a block scope, in case it's a DeclStmt
|
|
// preceded by our switch label.
|
|
BlockScopeRAII Scope(Info);
|
|
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, IS->getThen(), Case);
|
|
if (ESR != ESR_CaseNotFound || !IS->getElse())
|
|
return ESR;
|
|
return EvaluateStmt(Result, Info, IS->getElse(), Case);
|
|
}
|
|
|
|
case Stmt::WhileStmtClass: {
|
|
EvalStmtResult ESR =
|
|
EvaluateLoopBody(Result, Info, cast<WhileStmt>(S)->getBody(), Case);
|
|
if (ESR != ESR_Continue)
|
|
return ESR;
|
|
break;
|
|
}
|
|
|
|
case Stmt::ForStmtClass: {
|
|
const ForStmt *FS = cast<ForStmt>(S);
|
|
EvalStmtResult ESR =
|
|
EvaluateLoopBody(Result, Info, FS->getBody(), Case);
|
|
if (ESR != ESR_Continue)
|
|
return ESR;
|
|
if (FS->getInc()) {
|
|
FullExpressionRAII IncScope(Info);
|
|
if (!EvaluateIgnoredValue(Info, FS->getInc()))
|
|
return ESR_Failed;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case Stmt::DeclStmtClass:
|
|
// FIXME: If the variable has initialization that can't be jumped over,
|
|
// bail out of any immediately-surrounding compound-statement too.
|
|
default:
|
|
return ESR_CaseNotFound;
|
|
}
|
|
}
|
|
|
|
switch (S->getStmtClass()) {
|
|
default:
|
|
if (const Expr *E = dyn_cast<Expr>(S)) {
|
|
// Don't bother evaluating beyond an expression-statement which couldn't
|
|
// be evaluated.
|
|
FullExpressionRAII Scope(Info);
|
|
if (!EvaluateIgnoredValue(Info, E))
|
|
return ESR_Failed;
|
|
return ESR_Succeeded;
|
|
}
|
|
|
|
Info.FFDiag(S->getBeginLoc());
|
|
return ESR_Failed;
|
|
|
|
case Stmt::NullStmtClass:
|
|
return ESR_Succeeded;
|
|
|
|
case Stmt::DeclStmtClass: {
|
|
const DeclStmt *DS = cast<DeclStmt>(S);
|
|
for (const auto *DclIt : DS->decls()) {
|
|
// Each declaration initialization is its own full-expression.
|
|
// FIXME: This isn't quite right; if we're performing aggregate
|
|
// initialization, each braced subexpression is its own full-expression.
|
|
FullExpressionRAII Scope(Info);
|
|
if (!EvaluateDecl(Info, DclIt) && !Info.noteFailure())
|
|
return ESR_Failed;
|
|
}
|
|
return ESR_Succeeded;
|
|
}
|
|
|
|
case Stmt::ReturnStmtClass: {
|
|
const Expr *RetExpr = cast<ReturnStmt>(S)->getRetValue();
|
|
FullExpressionRAII Scope(Info);
|
|
if (RetExpr &&
|
|
!(Result.Slot
|
|
? EvaluateInPlace(Result.Value, Info, *Result.Slot, RetExpr)
|
|
: Evaluate(Result.Value, Info, RetExpr)))
|
|
return ESR_Failed;
|
|
return ESR_Returned;
|
|
}
|
|
|
|
case Stmt::CompoundStmtClass: {
|
|
BlockScopeRAII Scope(Info);
|
|
|
|
const CompoundStmt *CS = cast<CompoundStmt>(S);
|
|
for (const auto *BI : CS->body()) {
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, BI, Case);
|
|
if (ESR == ESR_Succeeded)
|
|
Case = nullptr;
|
|
else if (ESR != ESR_CaseNotFound)
|
|
return ESR;
|
|
}
|
|
return Case ? ESR_CaseNotFound : ESR_Succeeded;
|
|
}
|
|
|
|
case Stmt::IfStmtClass: {
|
|
const IfStmt *IS = cast<IfStmt>(S);
|
|
|
|
// Evaluate the condition, as either a var decl or as an expression.
|
|
BlockScopeRAII Scope(Info);
|
|
if (const Stmt *Init = IS->getInit()) {
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, Init);
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
}
|
|
bool Cond;
|
|
if (!EvaluateCond(Info, IS->getConditionVariable(), IS->getCond(), Cond))
|
|
return ESR_Failed;
|
|
|
|
if (const Stmt *SubStmt = Cond ? IS->getThen() : IS->getElse()) {
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, SubStmt);
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
}
|
|
return ESR_Succeeded;
|
|
}
|
|
|
|
case Stmt::WhileStmtClass: {
|
|
const WhileStmt *WS = cast<WhileStmt>(S);
|
|
while (true) {
|
|
BlockScopeRAII Scope(Info);
|
|
bool Continue;
|
|
if (!EvaluateCond(Info, WS->getConditionVariable(), WS->getCond(),
|
|
Continue))
|
|
return ESR_Failed;
|
|
if (!Continue)
|
|
break;
|
|
|
|
EvalStmtResult ESR = EvaluateLoopBody(Result, Info, WS->getBody());
|
|
if (ESR != ESR_Continue)
|
|
return ESR;
|
|
}
|
|
return ESR_Succeeded;
|
|
}
|
|
|
|
case Stmt::DoStmtClass: {
|
|
const DoStmt *DS = cast<DoStmt>(S);
|
|
bool Continue;
|
|
do {
|
|
EvalStmtResult ESR = EvaluateLoopBody(Result, Info, DS->getBody(), Case);
|
|
if (ESR != ESR_Continue)
|
|
return ESR;
|
|
Case = nullptr;
|
|
|
|
FullExpressionRAII CondScope(Info);
|
|
if (!EvaluateAsBooleanCondition(DS->getCond(), Continue, Info))
|
|
return ESR_Failed;
|
|
} while (Continue);
|
|
return ESR_Succeeded;
|
|
}
|
|
|
|
case Stmt::ForStmtClass: {
|
|
const ForStmt *FS = cast<ForStmt>(S);
|
|
BlockScopeRAII Scope(Info);
|
|
if (FS->getInit()) {
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
}
|
|
while (true) {
|
|
BlockScopeRAII Scope(Info);
|
|
bool Continue = true;
|
|
if (FS->getCond() && !EvaluateCond(Info, FS->getConditionVariable(),
|
|
FS->getCond(), Continue))
|
|
return ESR_Failed;
|
|
if (!Continue)
|
|
break;
|
|
|
|
EvalStmtResult ESR = EvaluateLoopBody(Result, Info, FS->getBody());
|
|
if (ESR != ESR_Continue)
|
|
return ESR;
|
|
|
|
if (FS->getInc()) {
|
|
FullExpressionRAII IncScope(Info);
|
|
if (!EvaluateIgnoredValue(Info, FS->getInc()))
|
|
return ESR_Failed;
|
|
}
|
|
}
|
|
return ESR_Succeeded;
|
|
}
|
|
|
|
case Stmt::CXXForRangeStmtClass: {
|
|
const CXXForRangeStmt *FS = cast<CXXForRangeStmt>(S);
|
|
BlockScopeRAII Scope(Info);
|
|
|
|
// Evaluate the init-statement if present.
|
|
if (FS->getInit()) {
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getInit());
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
}
|
|
|
|
// Initialize the __range variable.
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, FS->getRangeStmt());
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
|
|
// Create the __begin and __end iterators.
|
|
ESR = EvaluateStmt(Result, Info, FS->getBeginStmt());
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
ESR = EvaluateStmt(Result, Info, FS->getEndStmt());
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
|
|
while (true) {
|
|
// Condition: __begin != __end.
|
|
{
|
|
bool Continue = true;
|
|
FullExpressionRAII CondExpr(Info);
|
|
if (!EvaluateAsBooleanCondition(FS->getCond(), Continue, Info))
|
|
return ESR_Failed;
|
|
if (!Continue)
|
|
break;
|
|
}
|
|
|
|
// User's variable declaration, initialized by *__begin.
|
|
BlockScopeRAII InnerScope(Info);
|
|
ESR = EvaluateStmt(Result, Info, FS->getLoopVarStmt());
|
|
if (ESR != ESR_Succeeded)
|
|
return ESR;
|
|
|
|
// Loop body.
|
|
ESR = EvaluateLoopBody(Result, Info, FS->getBody());
|
|
if (ESR != ESR_Continue)
|
|
return ESR;
|
|
|
|
// Increment: ++__begin
|
|
if (!EvaluateIgnoredValue(Info, FS->getInc()))
|
|
return ESR_Failed;
|
|
}
|
|
|
|
return ESR_Succeeded;
|
|
}
|
|
|
|
case Stmt::SwitchStmtClass:
|
|
return EvaluateSwitch(Result, Info, cast<SwitchStmt>(S));
|
|
|
|
case Stmt::ContinueStmtClass:
|
|
return ESR_Continue;
|
|
|
|
case Stmt::BreakStmtClass:
|
|
return ESR_Break;
|
|
|
|
case Stmt::LabelStmtClass:
|
|
return EvaluateStmt(Result, Info, cast<LabelStmt>(S)->getSubStmt(), Case);
|
|
|
|
case Stmt::AttributedStmtClass:
|
|
// As a general principle, C++11 attributes can be ignored without
|
|
// any semantic impact.
|
|
return EvaluateStmt(Result, Info, cast<AttributedStmt>(S)->getSubStmt(),
|
|
Case);
|
|
|
|
case Stmt::CaseStmtClass:
|
|
case Stmt::DefaultStmtClass:
|
|
return EvaluateStmt(Result, Info, cast<SwitchCase>(S)->getSubStmt(), Case);
|
|
case Stmt::CXXTryStmtClass:
|
|
// Evaluate try blocks by evaluating all sub statements.
|
|
return EvaluateStmt(Result, Info, cast<CXXTryStmt>(S)->getTryBlock(), Case);
|
|
}
|
|
}
|
|
|
|
/// CheckTrivialDefaultConstructor - Check whether a constructor is a trivial
|
|
/// default constructor. If so, we'll fold it whether or not it's marked as
|
|
/// constexpr. If it is marked as constexpr, we will never implicitly define it,
|
|
/// so we need special handling.
|
|
static bool CheckTrivialDefaultConstructor(EvalInfo &Info, SourceLocation Loc,
|
|
const CXXConstructorDecl *CD,
|
|
bool IsValueInitialization) {
|
|
if (!CD->isTrivial() || !CD->isDefaultConstructor())
|
|
return false;
|
|
|
|
// Value-initialization does not call a trivial default constructor, so such a
|
|
// call is a core constant expression whether or not the constructor is
|
|
// constexpr.
|
|
if (!CD->isConstexpr() && !IsValueInitialization) {
|
|
if (Info.getLangOpts().CPlusPlus11) {
|
|
// FIXME: If DiagDecl is an implicitly-declared special member function,
|
|
// we should be much more explicit about why it's not constexpr.
|
|
Info.CCEDiag(Loc, diag::note_constexpr_invalid_function, 1)
|
|
<< /*IsConstexpr*/0 << /*IsConstructor*/1 << CD;
|
|
Info.Note(CD->getLocation(), diag::note_declared_at);
|
|
} else {
|
|
Info.CCEDiag(Loc, diag::note_invalid_subexpr_in_const_expr);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// CheckConstexprFunction - Check that a function can be called in a constant
|
|
/// expression.
|
|
static bool CheckConstexprFunction(EvalInfo &Info, SourceLocation CallLoc,
|
|
const FunctionDecl *Declaration,
|
|
const FunctionDecl *Definition,
|
|
const Stmt *Body) {
|
|
// Potential constant expressions can contain calls to declared, but not yet
|
|
// defined, constexpr functions.
|
|
if (Info.checkingPotentialConstantExpression() && !Definition &&
|
|
Declaration->isConstexpr())
|
|
return false;
|
|
|
|
// Bail out if the function declaration itself is invalid. We will
|
|
// have produced a relevant diagnostic while parsing it, so just
|
|
// note the problematic sub-expression.
|
|
if (Declaration->isInvalidDecl()) {
|
|
Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
|
|
// Can we evaluate this function call?
|
|
if (Definition && Definition->isConstexpr() &&
|
|
!Definition->isInvalidDecl() && Body)
|
|
return true;
|
|
|
|
if (Info.getLangOpts().CPlusPlus11) {
|
|
const FunctionDecl *DiagDecl = Definition ? Definition : Declaration;
|
|
|
|
// If this function is not constexpr because it is an inherited
|
|
// non-constexpr constructor, diagnose that directly.
|
|
auto *CD = dyn_cast<CXXConstructorDecl>(DiagDecl);
|
|
if (CD && CD->isInheritingConstructor()) {
|
|
auto *Inherited = CD->getInheritedConstructor().getConstructor();
|
|
if (!Inherited->isConstexpr())
|
|
DiagDecl = CD = Inherited;
|
|
}
|
|
|
|
// FIXME: If DiagDecl is an implicitly-declared special member function
|
|
// or an inheriting constructor, we should be much more explicit about why
|
|
// it's not constexpr.
|
|
if (CD && CD->isInheritingConstructor())
|
|
Info.FFDiag(CallLoc, diag::note_constexpr_invalid_inhctor, 1)
|
|
<< CD->getInheritedConstructor().getConstructor()->getParent();
|
|
else
|
|
Info.FFDiag(CallLoc, diag::note_constexpr_invalid_function, 1)
|
|
<< DiagDecl->isConstexpr() << (bool)CD << DiagDecl;
|
|
Info.Note(DiagDecl->getLocation(), diag::note_declared_at);
|
|
} else {
|
|
Info.FFDiag(CallLoc, diag::note_invalid_subexpr_in_const_expr);
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/// Determine if a class has any fields that might need to be copied by a
|
|
/// trivial copy or move operation.
|
|
static bool hasFields(const CXXRecordDecl *RD) {
|
|
if (!RD || RD->isEmpty())
|
|
return false;
|
|
for (auto *FD : RD->fields()) {
|
|
if (FD->isUnnamedBitfield())
|
|
continue;
|
|
return true;
|
|
}
|
|
for (auto &Base : RD->bases())
|
|
if (hasFields(Base.getType()->getAsCXXRecordDecl()))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
namespace {
|
|
typedef SmallVector<APValue, 8> ArgVector;
|
|
}
|
|
|
|
/// EvaluateArgs - Evaluate the arguments to a function call.
|
|
static bool EvaluateArgs(ArrayRef<const Expr*> Args, ArgVector &ArgValues,
|
|
EvalInfo &Info) {
|
|
bool Success = true;
|
|
for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
|
|
I != E; ++I) {
|
|
if (!Evaluate(ArgValues[I - Args.begin()], Info, *I)) {
|
|
// If we're checking for a potential constant expression, evaluate all
|
|
// initializers even if some of them fail.
|
|
if (!Info.noteFailure())
|
|
return false;
|
|
Success = false;
|
|
}
|
|
}
|
|
return Success;
|
|
}
|
|
|
|
/// Evaluate a function call.
|
|
static bool HandleFunctionCall(SourceLocation CallLoc,
|
|
const FunctionDecl *Callee, const LValue *This,
|
|
ArrayRef<const Expr*> Args, const Stmt *Body,
|
|
EvalInfo &Info, APValue &Result,
|
|
const LValue *ResultSlot) {
|
|
ArgVector ArgValues(Args.size());
|
|
if (!EvaluateArgs(Args, ArgValues, Info))
|
|
return false;
|
|
|
|
if (!Info.CheckCallLimit(CallLoc))
|
|
return false;
|
|
|
|
CallStackFrame Frame(Info, CallLoc, Callee, This, ArgValues.data());
|
|
|
|
// For a trivial copy or move assignment, perform an APValue copy. This is
|
|
// essential for unions, where the operations performed by the assignment
|
|
// operator cannot be represented as statements.
|
|
//
|
|
// Skip this for non-union classes with no fields; in that case, the defaulted
|
|
// copy/move does not actually read the object.
|
|
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Callee);
|
|
if (MD && MD->isDefaulted() &&
|
|
(MD->getParent()->isUnion() ||
|
|
(MD->isTrivial() && hasFields(MD->getParent())))) {
|
|
assert(This &&
|
|
(MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()));
|
|
LValue RHS;
|
|
RHS.setFrom(Info.Ctx, ArgValues[0]);
|
|
APValue RHSValue;
|
|
if (!handleLValueToRValueConversion(Info, Args[0], Args[0]->getType(),
|
|
RHS, RHSValue))
|
|
return false;
|
|
if (!handleAssignment(Info, Args[0], *This, MD->getThisType(),
|
|
RHSValue))
|
|
return false;
|
|
This->moveInto(Result);
|
|
return true;
|
|
} else if (MD && isLambdaCallOperator(MD)) {
|
|
// We're in a lambda; determine the lambda capture field maps unless we're
|
|
// just constexpr checking a lambda's call operator. constexpr checking is
|
|
// done before the captures have been added to the closure object (unless
|
|
// we're inferring constexpr-ness), so we don't have access to them in this
|
|
// case. But since we don't need the captures to constexpr check, we can
|
|
// just ignore them.
|
|
if (!Info.checkingPotentialConstantExpression())
|
|
MD->getParent()->getCaptureFields(Frame.LambdaCaptureFields,
|
|
Frame.LambdaThisCaptureField);
|
|
}
|
|
|
|
StmtResult Ret = {Result, ResultSlot};
|
|
EvalStmtResult ESR = EvaluateStmt(Ret, Info, Body);
|
|
if (ESR == ESR_Succeeded) {
|
|
if (Callee->getReturnType()->isVoidType())
|
|
return true;
|
|
Info.FFDiag(Callee->getEndLoc(), diag::note_constexpr_no_return);
|
|
}
|
|
return ESR == ESR_Returned;
|
|
}
|
|
|
|
/// Evaluate a constructor call.
|
|
static bool HandleConstructorCall(const Expr *E, const LValue &This,
|
|
APValue *ArgValues,
|
|
const CXXConstructorDecl *Definition,
|
|
EvalInfo &Info, APValue &Result) {
|
|
SourceLocation CallLoc = E->getExprLoc();
|
|
if (!Info.CheckCallLimit(CallLoc))
|
|
return false;
|
|
|
|
const CXXRecordDecl *RD = Definition->getParent();
|
|
if (RD->getNumVBases()) {
|
|
Info.FFDiag(CallLoc, diag::note_constexpr_virtual_base) << RD;
|
|
return false;
|
|
}
|
|
|
|
EvalInfo::EvaluatingConstructorRAII EvalObj(
|
|
Info, {This.getLValueBase(),
|
|
{This.getLValueCallIndex(), This.getLValueVersion()}});
|
|
CallStackFrame Frame(Info, CallLoc, Definition, &This, ArgValues);
|
|
|
|
// FIXME: Creating an APValue just to hold a nonexistent return value is
|
|
// wasteful.
|
|
APValue RetVal;
|
|
StmtResult Ret = {RetVal, nullptr};
|
|
|
|
// If it's a delegating constructor, delegate.
|
|
if (Definition->isDelegatingConstructor()) {
|
|
CXXConstructorDecl::init_const_iterator I = Definition->init_begin();
|
|
{
|
|
FullExpressionRAII InitScope(Info);
|
|
if (!EvaluateInPlace(Result, Info, This, (*I)->getInit()))
|
|
return false;
|
|
}
|
|
return EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed;
|
|
}
|
|
|
|
// For a trivial copy or move constructor, perform an APValue copy. This is
|
|
// essential for unions (or classes with anonymous union members), where the
|
|
// operations performed by the constructor cannot be represented by
|
|
// ctor-initializers.
|
|
//
|
|
// Skip this for empty non-union classes; we should not perform an
|
|
// lvalue-to-rvalue conversion on them because their copy constructor does not
|
|
// actually read them.
|
|
if (Definition->isDefaulted() && Definition->isCopyOrMoveConstructor() &&
|
|
(Definition->getParent()->isUnion() ||
|
|
(Definition->isTrivial() && hasFields(Definition->getParent())))) {
|
|
LValue RHS;
|
|
RHS.setFrom(Info.Ctx, ArgValues[0]);
|
|
return handleLValueToRValueConversion(
|
|
Info, E, Definition->getParamDecl(0)->getType().getNonReferenceType(),
|
|
RHS, Result);
|
|
}
|
|
|
|
// Reserve space for the struct members.
|
|
if (!RD->isUnion() && Result.isUninit())
|
|
Result = APValue(APValue::UninitStruct(), RD->getNumBases(),
|
|
std::distance(RD->field_begin(), RD->field_end()));
|
|
|
|
if (RD->isInvalidDecl()) return false;
|
|
const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
|
|
|
|
// A scope for temporaries lifetime-extended by reference members.
|
|
BlockScopeRAII LifetimeExtendedScope(Info);
|
|
|
|
bool Success = true;
|
|
unsigned BasesSeen = 0;
|
|
#ifndef NDEBUG
|
|
CXXRecordDecl::base_class_const_iterator BaseIt = RD->bases_begin();
|
|
#endif
|
|
for (const auto *I : Definition->inits()) {
|
|
LValue Subobject = This;
|
|
LValue SubobjectParent = This;
|
|
APValue *Value = &Result;
|
|
|
|
// Determine the subobject to initialize.
|
|
FieldDecl *FD = nullptr;
|
|
if (I->isBaseInitializer()) {
|
|
QualType BaseType(I->getBaseClass(), 0);
|
|
#ifndef NDEBUG
|
|
// Non-virtual base classes are initialized in the order in the class
|
|
// definition. We have already checked for virtual base classes.
|
|
assert(!BaseIt->isVirtual() && "virtual base for literal type");
|
|
assert(Info.Ctx.hasSameType(BaseIt->getType(), BaseType) &&
|
|
"base class initializers not in expected order");
|
|
++BaseIt;
|
|
#endif
|
|
if (!HandleLValueDirectBase(Info, I->getInit(), Subobject, RD,
|
|
BaseType->getAsCXXRecordDecl(), &Layout))
|
|
return false;
|
|
Value = &Result.getStructBase(BasesSeen++);
|
|
} else if ((FD = I->getMember())) {
|
|
if (!HandleLValueMember(Info, I->getInit(), Subobject, FD, &Layout))
|
|
return false;
|
|
if (RD->isUnion()) {
|
|
Result = APValue(FD);
|
|
Value = &Result.getUnionValue();
|
|
} else {
|
|
Value = &Result.getStructField(FD->getFieldIndex());
|
|
}
|
|
} else if (IndirectFieldDecl *IFD = I->getIndirectMember()) {
|
|
// Walk the indirect field decl's chain to find the object to initialize,
|
|
// and make sure we've initialized every step along it.
|
|
auto IndirectFieldChain = IFD->chain();
|
|
for (auto *C : IndirectFieldChain) {
|
|
FD = cast<FieldDecl>(C);
|
|
CXXRecordDecl *CD = cast<CXXRecordDecl>(FD->getParent());
|
|
// Switch the union field if it differs. This happens if we had
|
|
// preceding zero-initialization, and we're now initializing a union
|
|
// subobject other than the first.
|
|
// FIXME: In this case, the values of the other subobjects are
|
|
// specified, since zero-initialization sets all padding bits to zero.
|
|
if (Value->isUninit() ||
|
|
(Value->isUnion() && Value->getUnionField() != FD)) {
|
|
if (CD->isUnion())
|
|
*Value = APValue(FD);
|
|
else
|
|
*Value = APValue(APValue::UninitStruct(), CD->getNumBases(),
|
|
std::distance(CD->field_begin(), CD->field_end()));
|
|
}
|
|
// Store Subobject as its parent before updating it for the last element
|
|
// in the chain.
|
|
if (C == IndirectFieldChain.back())
|
|
SubobjectParent = Subobject;
|
|
if (!HandleLValueMember(Info, I->getInit(), Subobject, FD))
|
|
return false;
|
|
if (CD->isUnion())
|
|
Value = &Value->getUnionValue();
|
|
else
|
|
Value = &Value->getStructField(FD->getFieldIndex());
|
|
}
|
|
} else {
|
|
llvm_unreachable("unknown base initializer kind");
|
|
}
|
|
|
|
// Need to override This for implicit field initializers as in this case
|
|
// This refers to innermost anonymous struct/union containing initializer,
|
|
// not to currently constructed class.
|
|
const Expr *Init = I->getInit();
|
|
ThisOverrideRAII ThisOverride(*Info.CurrentCall, &SubobjectParent,
|
|
isa<CXXDefaultInitExpr>(Init));
|
|
FullExpressionRAII InitScope(Info);
|
|
if (!EvaluateInPlace(*Value, Info, Subobject, Init) ||
|
|
(FD && FD->isBitField() &&
|
|
!truncateBitfieldValue(Info, Init, *Value, FD))) {
|
|
// If we're checking for a potential constant expression, evaluate all
|
|
// initializers even if some of them fail.
|
|
if (!Info.noteFailure())
|
|
return false;
|
|
Success = false;
|
|
}
|
|
}
|
|
|
|
return Success &&
|
|
EvaluateStmt(Ret, Info, Definition->getBody()) != ESR_Failed;
|
|
}
|
|
|
|
static bool HandleConstructorCall(const Expr *E, const LValue &This,
|
|
ArrayRef<const Expr*> Args,
|
|
const CXXConstructorDecl *Definition,
|
|
EvalInfo &Info, APValue &Result) {
|
|
ArgVector ArgValues(Args.size());
|
|
if (!EvaluateArgs(Args, ArgValues, Info))
|
|
return false;
|
|
|
|
return HandleConstructorCall(E, This, ArgValues.data(), Definition,
|
|
Info, Result);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Generic Evaluation
|
|
//===----------------------------------------------------------------------===//
|
|
namespace {
|
|
|
|
template <class Derived>
|
|
class ExprEvaluatorBase
|
|
: public ConstStmtVisitor<Derived, bool> {
|
|
private:
|
|
Derived &getDerived() { return static_cast<Derived&>(*this); }
|
|
bool DerivedSuccess(const APValue &V, const Expr *E) {
|
|
return getDerived().Success(V, E);
|
|
}
|
|
bool DerivedZeroInitialization(const Expr *E) {
|
|
return getDerived().ZeroInitialization(E);
|
|
}
|
|
|
|
// Check whether a conditional operator with a non-constant condition is a
|
|
// potential constant expression. If neither arm is a potential constant
|
|
// expression, then the conditional operator is not either.
|
|
template<typename ConditionalOperator>
|
|
void CheckPotentialConstantConditional(const ConditionalOperator *E) {
|
|
assert(Info.checkingPotentialConstantExpression());
|
|
|
|
// Speculatively evaluate both arms.
|
|
SmallVector<PartialDiagnosticAt, 8> Diag;
|
|
{
|
|
SpeculativeEvaluationRAII Speculate(Info, &Diag);
|
|
StmtVisitorTy::Visit(E->getFalseExpr());
|
|
if (Diag.empty())
|
|
return;
|
|
}
|
|
|
|
{
|
|
SpeculativeEvaluationRAII Speculate(Info, &Diag);
|
|
Diag.clear();
|
|
StmtVisitorTy::Visit(E->getTrueExpr());
|
|
if (Diag.empty())
|
|
return;
|
|
}
|
|
|
|
Error(E, diag::note_constexpr_conditional_never_const);
|
|
}
|
|
|
|
|
|
template<typename ConditionalOperator>
|
|
bool HandleConditionalOperator(const ConditionalOperator *E) {
|
|
bool BoolResult;
|
|
if (!EvaluateAsBooleanCondition(E->getCond(), BoolResult, Info)) {
|
|
if (Info.checkingPotentialConstantExpression() && Info.noteFailure()) {
|
|
CheckPotentialConstantConditional(E);
|
|
return false;
|
|
}
|
|
if (Info.noteFailure()) {
|
|
StmtVisitorTy::Visit(E->getTrueExpr());
|
|
StmtVisitorTy::Visit(E->getFalseExpr());
|
|
}
|
|
return false;
|
|
}
|
|
|
|
Expr *EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr();
|
|
return StmtVisitorTy::Visit(EvalExpr);
|
|
}
|
|
|
|
protected:
|
|
EvalInfo &Info;
|
|
typedef ConstStmtVisitor<Derived, bool> StmtVisitorTy;
|
|
typedef ExprEvaluatorBase ExprEvaluatorBaseTy;
|
|
|
|
OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
|
|
return Info.CCEDiag(E, D);
|
|
}
|
|
|
|
bool ZeroInitialization(const Expr *E) { return Error(E); }
|
|
|
|
public:
|
|
ExprEvaluatorBase(EvalInfo &Info) : Info(Info) {}
|
|
|
|
EvalInfo &getEvalInfo() { return Info; }
|
|
|
|
/// Report an evaluation error. This should only be called when an error is
|
|
/// first discovered. When propagating an error, just return false.
|
|
bool Error(const Expr *E, diag::kind D) {
|
|
Info.FFDiag(E, D);
|
|
return false;
|
|
}
|
|
bool Error(const Expr *E) {
|
|
return Error(E, diag::note_invalid_subexpr_in_const_expr);
|
|
}
|
|
|
|
bool VisitStmt(const Stmt *) {
|
|
llvm_unreachable("Expression evaluator should not be called on stmts");
|
|
}
|
|
bool VisitExpr(const Expr *E) {
|
|
return Error(E);
|
|
}
|
|
|
|
bool VisitConstantExpr(const ConstantExpr *E)
|
|
{ return StmtVisitorTy::Visit(E->getSubExpr()); }
|
|
bool VisitParenExpr(const ParenExpr *E)
|
|
{ return StmtVisitorTy::Visit(E->getSubExpr()); }
|
|
bool VisitUnaryExtension(const UnaryOperator *E)
|
|
{ return StmtVisitorTy::Visit(E->getSubExpr()); }
|
|
bool VisitUnaryPlus(const UnaryOperator *E)
|
|
{ return StmtVisitorTy::Visit(E->getSubExpr()); }
|
|
bool VisitChooseExpr(const ChooseExpr *E)
|
|
{ return StmtVisitorTy::Visit(E->getChosenSubExpr()); }
|
|
bool VisitGenericSelectionExpr(const GenericSelectionExpr *E)
|
|
{ return StmtVisitorTy::Visit(E->getResultExpr()); }
|
|
bool VisitSubstNonTypeTemplateParmExpr(const SubstNonTypeTemplateParmExpr *E)
|
|
{ return StmtVisitorTy::Visit(E->getReplacement()); }
|
|
bool VisitCXXDefaultArgExpr(const CXXDefaultArgExpr *E) {
|
|
TempVersionRAII RAII(*Info.CurrentCall);
|
|
return StmtVisitorTy::Visit(E->getExpr());
|
|
}
|
|
bool VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *E) {
|
|
TempVersionRAII RAII(*Info.CurrentCall);
|
|
// The initializer may not have been parsed yet, or might be erroneous.
|
|
if (!E->getExpr())
|
|
return Error(E);
|
|
return StmtVisitorTy::Visit(E->getExpr());
|
|
}
|
|
// We cannot create any objects for which cleanups are required, so there is
|
|
// nothing to do here; all cleanups must come from unevaluated subexpressions.
|
|
bool VisitExprWithCleanups(const ExprWithCleanups *E)
|
|
{ return StmtVisitorTy::Visit(E->getSubExpr()); }
|
|
|
|
bool VisitCXXReinterpretCastExpr(const CXXReinterpretCastExpr *E) {
|
|
CCEDiag(E, diag::note_constexpr_invalid_cast) << 0;
|
|
return static_cast<Derived*>(this)->VisitCastExpr(E);
|
|
}
|
|
bool VisitCXXDynamicCastExpr(const CXXDynamicCastExpr *E) {
|
|
CCEDiag(E, diag::note_constexpr_invalid_cast) << 1;
|
|
return static_cast<Derived*>(this)->VisitCastExpr(E);
|
|
}
|
|
|
|
bool VisitBinaryOperator(const BinaryOperator *E) {
|
|
switch (E->getOpcode()) {
|
|
default:
|
|
return Error(E);
|
|
|
|
case BO_Comma:
|
|
VisitIgnoredValue(E->getLHS());
|
|
return StmtVisitorTy::Visit(E->getRHS());
|
|
|
|
case BO_PtrMemD:
|
|
case BO_PtrMemI: {
|
|
LValue Obj;
|
|
if (!HandleMemberPointerAccess(Info, E, Obj))
|
|
return false;
|
|
APValue Result;
|
|
if (!handleLValueToRValueConversion(Info, E, E->getType(), Obj, Result))
|
|
return false;
|
|
return DerivedSuccess(Result, E);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool VisitBinaryConditionalOperator(const BinaryConditionalOperator *E) {
|
|
// Evaluate and cache the common expression. We treat it as a temporary,
|
|
// even though it's not quite the same thing.
|
|
if (!Evaluate(Info.CurrentCall->createTemporary(E->getOpaqueValue(), false),
|
|
Info, E->getCommon()))
|
|
return false;
|
|
|
|
return HandleConditionalOperator(E);
|
|
}
|
|
|
|
bool VisitConditionalOperator(const ConditionalOperator *E) {
|
|
bool IsBcpCall = false;
|
|
// If the condition (ignoring parens) is a __builtin_constant_p call,
|
|
// the result is a constant expression if it can be folded without
|
|
// side-effects. This is an important GNU extension. See GCC PR38377
|
|
// for discussion.
|
|
if (const CallExpr *CallCE =
|
|
dyn_cast<CallExpr>(E->getCond()->IgnoreParenCasts()))
|
|
if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
|
|
IsBcpCall = true;
|
|
|
|
// Always assume __builtin_constant_p(...) ? ... : ... is a potential
|
|
// constant expression; we can't check whether it's potentially foldable.
|
|
if (Info.checkingPotentialConstantExpression() && IsBcpCall)
|
|
return false;
|
|
|
|
FoldConstant Fold(Info, IsBcpCall);
|
|
if (!HandleConditionalOperator(E)) {
|
|
Fold.keepDiagnostics();
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool VisitOpaqueValueExpr(const OpaqueValueExpr *E) {
|
|
if (APValue *Value = Info.CurrentCall->getCurrentTemporary(E))
|
|
return DerivedSuccess(*Value, E);
|
|
|
|
const Expr *Source = E->getSourceExpr();
|
|
if (!Source)
|
|
return Error(E);
|
|
if (Source == E) { // sanity checking.
|
|
assert(0 && "OpaqueValueExpr recursively refers to itself");
|
|
return Error(E);
|
|
}
|
|
return StmtVisitorTy::Visit(Source);
|
|
}
|
|
|
|
bool VisitCallExpr(const CallExpr *E) {
|
|
APValue Result;
|
|
if (!handleCallExpr(E, Result, nullptr))
|
|
return false;
|
|
return DerivedSuccess(Result, E);
|
|
}
|
|
|
|
bool handleCallExpr(const CallExpr *E, APValue &Result,
|
|
const LValue *ResultSlot) {
|
|
const Expr *Callee = E->getCallee()->IgnoreParens();
|
|
QualType CalleeType = Callee->getType();
|
|
|
|
const FunctionDecl *FD = nullptr;
|
|
LValue *This = nullptr, ThisVal;
|
|
auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
|
|
bool HasQualifier = false;
|
|
|
|
// Extract function decl and 'this' pointer from the callee.
|
|
if (CalleeType->isSpecificBuiltinType(BuiltinType::BoundMember)) {
|
|
const ValueDecl *Member = nullptr;
|
|
if (const MemberExpr *ME = dyn_cast<MemberExpr>(Callee)) {
|
|
// Explicit bound member calls, such as x.f() or p->g();
|
|
if (!EvaluateObjectArgument(Info, ME->getBase(), ThisVal))
|
|
return false;
|
|
Member = ME->getMemberDecl();
|
|
This = &ThisVal;
|
|
HasQualifier = ME->hasQualifier();
|
|
} else if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(Callee)) {
|
|
// Indirect bound member calls ('.*' or '->*').
|
|
Member = HandleMemberPointerAccess(Info, BE, ThisVal, false);
|
|
if (!Member) return false;
|
|
This = &ThisVal;
|
|
} else
|
|
return Error(Callee);
|
|
|
|
FD = dyn_cast<FunctionDecl>(Member);
|
|
if (!FD)
|
|
return Error(Callee);
|
|
} else if (CalleeType->isFunctionPointerType()) {
|
|
LValue Call;
|
|
if (!EvaluatePointer(Callee, Call, Info))
|
|
return false;
|
|
|
|
if (!Call.getLValueOffset().isZero())
|
|
return Error(Callee);
|
|
FD = dyn_cast_or_null<FunctionDecl>(
|
|
Call.getLValueBase().dyn_cast<const ValueDecl*>());
|
|
if (!FD)
|
|
return Error(Callee);
|
|
// Don't call function pointers which have been cast to some other type.
|
|
// Per DR (no number yet), the caller and callee can differ in noexcept.
|
|
if (!Info.Ctx.hasSameFunctionTypeIgnoringExceptionSpec(
|
|
CalleeType->getPointeeType(), FD->getType())) {
|
|
return Error(E);
|
|
}
|
|
|
|
// Overloaded operator calls to member functions are represented as normal
|
|
// calls with '*this' as the first argument.
|
|
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
|
|
if (MD && !MD->isStatic()) {
|
|
// FIXME: When selecting an implicit conversion for an overloaded
|
|
// operator delete, we sometimes try to evaluate calls to conversion
|
|
// operators without a 'this' parameter!
|
|
if (Args.empty())
|
|
return Error(E);
|
|
|
|
if (!EvaluateObjectArgument(Info, Args[0], ThisVal))
|
|
return false;
|
|
This = &ThisVal;
|
|
Args = Args.slice(1);
|
|
} else if (MD && MD->isLambdaStaticInvoker()) {
|
|
// Map the static invoker for the lambda back to the call operator.
|
|
// Conveniently, we don't have to slice out the 'this' argument (as is
|
|
// being done for the non-static case), since a static member function
|
|
// doesn't have an implicit argument passed in.
|
|
const CXXRecordDecl *ClosureClass = MD->getParent();
|
|
assert(
|
|
ClosureClass->captures_begin() == ClosureClass->captures_end() &&
|
|
"Number of captures must be zero for conversion to function-ptr");
|
|
|
|
const CXXMethodDecl *LambdaCallOp =
|
|
ClosureClass->getLambdaCallOperator();
|
|
|
|
// Set 'FD', the function that will be called below, to the call
|
|
// operator. If the closure object represents a generic lambda, find
|
|
// the corresponding specialization of the call operator.
|
|
|
|
if (ClosureClass->isGenericLambda()) {
|
|
assert(MD->isFunctionTemplateSpecialization() &&
|
|
"A generic lambda's static-invoker function must be a "
|
|
"template specialization");
|
|
const TemplateArgumentList *TAL = MD->getTemplateSpecializationArgs();
|
|
FunctionTemplateDecl *CallOpTemplate =
|
|
LambdaCallOp->getDescribedFunctionTemplate();
|
|
void *InsertPos = nullptr;
|
|
FunctionDecl *CorrespondingCallOpSpecialization =
|
|
CallOpTemplate->findSpecialization(TAL->asArray(), InsertPos);
|
|
assert(CorrespondingCallOpSpecialization &&
|
|
"We must always have a function call operator specialization "
|
|
"that corresponds to our static invoker specialization");
|
|
FD = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
|
|
} else
|
|
FD = LambdaCallOp;
|
|
}
|
|
|
|
|
|
} else
|
|
return Error(E);
|
|
|
|
if (This && !This->checkSubobject(Info, E, CSK_This))
|
|
return false;
|
|
|
|
// DR1358 allows virtual constexpr functions in some cases. Don't allow
|
|
// calls to such functions in constant expressions.
|
|
if (This && !HasQualifier &&
|
|
isa<CXXMethodDecl>(FD) && cast<CXXMethodDecl>(FD)->isVirtual())
|
|
return Error(E, diag::note_constexpr_virtual_call);
|
|
|
|
const FunctionDecl *Definition = nullptr;
|
|
Stmt *Body = FD->getBody(Definition);
|
|
|
|
if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body) ||
|
|
!HandleFunctionCall(E->getExprLoc(), Definition, This, Args, Body, Info,
|
|
Result, ResultSlot))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
|
|
return StmtVisitorTy::Visit(E->getInitializer());
|
|
}
|
|
bool VisitInitListExpr(const InitListExpr *E) {
|
|
if (E->getNumInits() == 0)
|
|
return DerivedZeroInitialization(E);
|
|
if (E->getNumInits() == 1)
|
|
return StmtVisitorTy::Visit(E->getInit(0));
|
|
return Error(E);
|
|
}
|
|
bool VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
|
|
return DerivedZeroInitialization(E);
|
|
}
|
|
bool VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
|
|
return DerivedZeroInitialization(E);
|
|
}
|
|
bool VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
|
|
return DerivedZeroInitialization(E);
|
|
}
|
|
|
|
/// A member expression where the object is a prvalue is itself a prvalue.
|
|
bool VisitMemberExpr(const MemberExpr *E) {
|
|
assert(!E->isArrow() && "missing call to bound member function?");
|
|
|
|
APValue Val;
|
|
if (!Evaluate(Val, Info, E->getBase()))
|
|
return false;
|
|
|
|
QualType BaseTy = E->getBase()->getType();
|
|
|
|
const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl());
|
|
if (!FD) return Error(E);
|
|
assert(!FD->getType()->isReferenceType() && "prvalue reference?");
|
|
assert(BaseTy->castAs<RecordType>()->getDecl()->getCanonicalDecl() ==
|
|
FD->getParent()->getCanonicalDecl() && "record / field mismatch");
|
|
|
|
CompleteObject Obj(&Val, BaseTy, true);
|
|
SubobjectDesignator Designator(BaseTy);
|
|
Designator.addDeclUnchecked(FD);
|
|
|
|
APValue Result;
|
|
return extractSubobject(Info, E, Obj, Designator, Result) &&
|
|
DerivedSuccess(Result, E);
|
|
}
|
|
|
|
bool VisitCastExpr(const CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
break;
|
|
|
|
case CK_AtomicToNonAtomic: {
|
|
APValue AtomicVal;
|
|
// This does not need to be done in place even for class/array types:
|
|
// atomic-to-non-atomic conversion implies copying the object
|
|
// representation.
|
|
if (!Evaluate(AtomicVal, Info, E->getSubExpr()))
|
|
return false;
|
|
return DerivedSuccess(AtomicVal, E);
|
|
}
|
|
|
|
case CK_NoOp:
|
|
case CK_UserDefinedConversion:
|
|
return StmtVisitorTy::Visit(E->getSubExpr());
|
|
|
|
case CK_LValueToRValue: {
|
|
LValue LVal;
|
|
if (!EvaluateLValue(E->getSubExpr(), LVal, Info))
|
|
return false;
|
|
APValue RVal;
|
|
// Note, we use the subexpression's type in order to retain cv-qualifiers.
|
|
if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
|
|
LVal, RVal))
|
|
return false;
|
|
return DerivedSuccess(RVal, E);
|
|
}
|
|
}
|
|
|
|
return Error(E);
|
|
}
|
|
|
|
bool VisitUnaryPostInc(const UnaryOperator *UO) {
|
|
return VisitUnaryPostIncDec(UO);
|
|
}
|
|
bool VisitUnaryPostDec(const UnaryOperator *UO) {
|
|
return VisitUnaryPostIncDec(UO);
|
|
}
|
|
bool VisitUnaryPostIncDec(const UnaryOperator *UO) {
|
|
if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
|
|
return Error(UO);
|
|
|
|
LValue LVal;
|
|
if (!EvaluateLValue(UO->getSubExpr(), LVal, Info))
|
|
return false;
|
|
APValue RVal;
|
|
if (!handleIncDec(this->Info, UO, LVal, UO->getSubExpr()->getType(),
|
|
UO->isIncrementOp(), &RVal))
|
|
return false;
|
|
return DerivedSuccess(RVal, UO);
|
|
}
|
|
|
|
bool VisitStmtExpr(const StmtExpr *E) {
|
|
// We will have checked the full-expressions inside the statement expression
|
|
// when they were completed, and don't need to check them again now.
|
|
if (Info.checkingForOverflow())
|
|
return Error(E);
|
|
|
|
BlockScopeRAII Scope(Info);
|
|
const CompoundStmt *CS = E->getSubStmt();
|
|
if (CS->body_empty())
|
|
return true;
|
|
|
|
for (CompoundStmt::const_body_iterator BI = CS->body_begin(),
|
|
BE = CS->body_end();
|
|
/**/; ++BI) {
|
|
if (BI + 1 == BE) {
|
|
const Expr *FinalExpr = dyn_cast<Expr>(*BI);
|
|
if (!FinalExpr) {
|
|
Info.FFDiag((*BI)->getBeginLoc(),
|
|
diag::note_constexpr_stmt_expr_unsupported);
|
|
return false;
|
|
}
|
|
return this->Visit(FinalExpr);
|
|
}
|
|
|
|
APValue ReturnValue;
|
|
StmtResult Result = { ReturnValue, nullptr };
|
|
EvalStmtResult ESR = EvaluateStmt(Result, Info, *BI);
|
|
if (ESR != ESR_Succeeded) {
|
|
// FIXME: If the statement-expression terminated due to 'return',
|
|
// 'break', or 'continue', it would be nice to propagate that to
|
|
// the outer statement evaluation rather than bailing out.
|
|
if (ESR != ESR_Failed)
|
|
Info.FFDiag((*BI)->getBeginLoc(),
|
|
diag::note_constexpr_stmt_expr_unsupported);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
llvm_unreachable("Return from function from the loop above.");
|
|
}
|
|
|
|
/// Visit a value which is evaluated, but whose value is ignored.
|
|
void VisitIgnoredValue(const Expr *E) {
|
|
EvaluateIgnoredValue(Info, E);
|
|
}
|
|
|
|
/// Potentially visit a MemberExpr's base expression.
|
|
void VisitIgnoredBaseExpression(const Expr *E) {
|
|
// While MSVC doesn't evaluate the base expression, it does diagnose the
|
|
// presence of side-effecting behavior.
|
|
if (Info.getLangOpts().MSVCCompat && !E->HasSideEffects(Info.Ctx))
|
|
return;
|
|
VisitIgnoredValue(E);
|
|
}
|
|
};
|
|
|
|
} // namespace
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Common base class for lvalue and temporary evaluation.
|
|
//===----------------------------------------------------------------------===//
|
|
namespace {
|
|
template<class Derived>
|
|
class LValueExprEvaluatorBase
|
|
: public ExprEvaluatorBase<Derived> {
|
|
protected:
|
|
LValue &Result;
|
|
bool InvalidBaseOK;
|
|
typedef LValueExprEvaluatorBase LValueExprEvaluatorBaseTy;
|
|
typedef ExprEvaluatorBase<Derived> ExprEvaluatorBaseTy;
|
|
|
|
bool Success(APValue::LValueBase B) {
|
|
Result.set(B);
|
|
return true;
|
|
}
|
|
|
|
bool evaluatePointer(const Expr *E, LValue &Result) {
|
|
return EvaluatePointer(E, Result, this->Info, InvalidBaseOK);
|
|
}
|
|
|
|
public:
|
|
LValueExprEvaluatorBase(EvalInfo &Info, LValue &Result, bool InvalidBaseOK)
|
|
: ExprEvaluatorBaseTy(Info), Result(Result),
|
|
InvalidBaseOK(InvalidBaseOK) {}
|
|
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
Result.setFrom(this->Info.Ctx, V);
|
|
return true;
|
|
}
|
|
|
|
bool VisitMemberExpr(const MemberExpr *E) {
|
|
// Handle non-static data members.
|
|
QualType BaseTy;
|
|
bool EvalOK;
|
|
if (E->isArrow()) {
|
|
EvalOK = evaluatePointer(E->getBase(), Result);
|
|
BaseTy = E->getBase()->getType()->castAs<PointerType>()->getPointeeType();
|
|
} else if (E->getBase()->isRValue()) {
|
|
assert(E->getBase()->getType()->isRecordType());
|
|
EvalOK = EvaluateTemporary(E->getBase(), Result, this->Info);
|
|
BaseTy = E->getBase()->getType();
|
|
} else {
|
|
EvalOK = this->Visit(E->getBase());
|
|
BaseTy = E->getBase()->getType();
|
|
}
|
|
if (!EvalOK) {
|
|
if (!InvalidBaseOK)
|
|
return false;
|
|
Result.setInvalid(E);
|
|
return true;
|
|
}
|
|
|
|
const ValueDecl *MD = E->getMemberDecl();
|
|
if (const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl())) {
|
|
assert(BaseTy->getAs<RecordType>()->getDecl()->getCanonicalDecl() ==
|
|
FD->getParent()->getCanonicalDecl() && "record / field mismatch");
|
|
(void)BaseTy;
|
|
if (!HandleLValueMember(this->Info, E, Result, FD))
|
|
return false;
|
|
} else if (const IndirectFieldDecl *IFD = dyn_cast<IndirectFieldDecl>(MD)) {
|
|
if (!HandleLValueIndirectMember(this->Info, E, Result, IFD))
|
|
return false;
|
|
} else
|
|
return this->Error(E);
|
|
|
|
if (MD->getType()->isReferenceType()) {
|
|
APValue RefValue;
|
|
if (!handleLValueToRValueConversion(this->Info, E, MD->getType(), Result,
|
|
RefValue))
|
|
return false;
|
|
return Success(RefValue, E);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool VisitBinaryOperator(const BinaryOperator *E) {
|
|
switch (E->getOpcode()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
|
|
|
|
case BO_PtrMemD:
|
|
case BO_PtrMemI:
|
|
return HandleMemberPointerAccess(this->Info, E, Result);
|
|
}
|
|
}
|
|
|
|
bool VisitCastExpr(const CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
|
|
case CK_DerivedToBase:
|
|
case CK_UncheckedDerivedToBase:
|
|
if (!this->Visit(E->getSubExpr()))
|
|
return false;
|
|
|
|
// Now figure out the necessary offset to add to the base LV to get from
|
|
// the derived class to the base class.
|
|
return HandleLValueBasePath(this->Info, E, E->getSubExpr()->getType(),
|
|
Result);
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// LValue Evaluation
|
|
//
|
|
// This is used for evaluating lvalues (in C and C++), xvalues (in C++11),
|
|
// function designators (in C), decl references to void objects (in C), and
|
|
// temporaries (if building with -Wno-address-of-temporary).
|
|
//
|
|
// LValue evaluation produces values comprising a base expression of one of the
|
|
// following types:
|
|
// - Declarations
|
|
// * VarDecl
|
|
// * FunctionDecl
|
|
// - Literals
|
|
// * CompoundLiteralExpr in C (and in global scope in C++)
|
|
// * StringLiteral
|
|
// * CXXTypeidExpr
|
|
// * PredefinedExpr
|
|
// * ObjCStringLiteralExpr
|
|
// * ObjCEncodeExpr
|
|
// * AddrLabelExpr
|
|
// * BlockExpr
|
|
// * CallExpr for a MakeStringConstant builtin
|
|
// - Locals and temporaries
|
|
// * MaterializeTemporaryExpr
|
|
// * Any Expr, with a CallIndex indicating the function in which the temporary
|
|
// was evaluated, for cases where the MaterializeTemporaryExpr is missing
|
|
// from the AST (FIXME).
|
|
// * A MaterializeTemporaryExpr that has static storage duration, with no
|
|
// CallIndex, for a lifetime-extended temporary.
|
|
// plus an offset in bytes.
|
|
//===----------------------------------------------------------------------===//
|
|
namespace {
|
|
class LValueExprEvaluator
|
|
: public LValueExprEvaluatorBase<LValueExprEvaluator> {
|
|
public:
|
|
LValueExprEvaluator(EvalInfo &Info, LValue &Result, bool InvalidBaseOK) :
|
|
LValueExprEvaluatorBaseTy(Info, Result, InvalidBaseOK) {}
|
|
|
|
bool VisitVarDecl(const Expr *E, const VarDecl *VD);
|
|
bool VisitUnaryPreIncDec(const UnaryOperator *UO);
|
|
|
|
bool VisitDeclRefExpr(const DeclRefExpr *E);
|
|
bool VisitPredefinedExpr(const PredefinedExpr *E) { return Success(E); }
|
|
bool VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
|
|
bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
|
|
bool VisitMemberExpr(const MemberExpr *E);
|
|
bool VisitStringLiteral(const StringLiteral *E) { return Success(E); }
|
|
bool VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { return Success(E); }
|
|
bool VisitCXXTypeidExpr(const CXXTypeidExpr *E);
|
|
bool VisitCXXUuidofExpr(const CXXUuidofExpr *E);
|
|
bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E);
|
|
bool VisitUnaryDeref(const UnaryOperator *E);
|
|
bool VisitUnaryReal(const UnaryOperator *E);
|
|
bool VisitUnaryImag(const UnaryOperator *E);
|
|
bool VisitUnaryPreInc(const UnaryOperator *UO) {
|
|
return VisitUnaryPreIncDec(UO);
|
|
}
|
|
bool VisitUnaryPreDec(const UnaryOperator *UO) {
|
|
return VisitUnaryPreIncDec(UO);
|
|
}
|
|
bool VisitBinAssign(const BinaryOperator *BO);
|
|
bool VisitCompoundAssignOperator(const CompoundAssignOperator *CAO);
|
|
|
|
bool VisitCastExpr(const CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
|
|
case CK_LValueBitCast:
|
|
this->CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
Result.Designator.setInvalid();
|
|
return true;
|
|
|
|
case CK_BaseToDerived:
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
return HandleBaseToDerivedCast(Info, E, Result);
|
|
}
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
/// Evaluate an expression as an lvalue. This can be legitimately called on
|
|
/// expressions which are not glvalues, in three cases:
|
|
/// * function designators in C, and
|
|
/// * "extern void" objects
|
|
/// * @selector() expressions in Objective-C
|
|
static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info,
|
|
bool InvalidBaseOK) {
|
|
assert(E->isGLValue() || E->getType()->isFunctionType() ||
|
|
E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E));
|
|
return LValueExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
|
|
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(E->getDecl()))
|
|
return Success(FD);
|
|
if (const VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()))
|
|
return VisitVarDecl(E, VD);
|
|
if (const BindingDecl *BD = dyn_cast<BindingDecl>(E->getDecl()))
|
|
return Visit(BD->getBinding());
|
|
return Error(E);
|
|
}
|
|
|
|
|
|
bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
|
|
|
|
// If we are within a lambda's call operator, check whether the 'VD' referred
|
|
// to within 'E' actually represents a lambda-capture that maps to a
|
|
// data-member/field within the closure object, and if so, evaluate to the
|
|
// field or what the field refers to.
|
|
if (Info.CurrentCall && isLambdaCallOperator(Info.CurrentCall->Callee) &&
|
|
isa<DeclRefExpr>(E) &&
|
|
cast<DeclRefExpr>(E)->refersToEnclosingVariableOrCapture()) {
|
|
// We don't always have a complete capture-map when checking or inferring if
|
|
// the function call operator meets the requirements of a constexpr function
|
|
// - but we don't need to evaluate the captures to determine constexprness
|
|
// (dcl.constexpr C++17).
|
|
if (Info.checkingPotentialConstantExpression())
|
|
return false;
|
|
|
|
if (auto *FD = Info.CurrentCall->LambdaCaptureFields.lookup(VD)) {
|
|
// Start with 'Result' referring to the complete closure object...
|
|
Result = *Info.CurrentCall->This;
|
|
// ... then update it to refer to the field of the closure object
|
|
// that represents the capture.
|
|
if (!HandleLValueMember(Info, E, Result, FD))
|
|
return false;
|
|
// And if the field is of reference type, update 'Result' to refer to what
|
|
// the field refers to.
|
|
if (FD->getType()->isReferenceType()) {
|
|
APValue RVal;
|
|
if (!handleLValueToRValueConversion(Info, E, FD->getType(), Result,
|
|
RVal))
|
|
return false;
|
|
Result.setFrom(Info.Ctx, RVal);
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
CallStackFrame *Frame = nullptr;
|
|
if (VD->hasLocalStorage() && Info.CurrentCall->Index > 1) {
|
|
// Only if a local variable was declared in the function currently being
|
|
// evaluated, do we expect to be able to find its value in the current
|
|
// frame. (Otherwise it was likely declared in an enclosing context and
|
|
// could either have a valid evaluatable value (for e.g. a constexpr
|
|
// variable) or be ill-formed (and trigger an appropriate evaluation
|
|
// diagnostic)).
|
|
if (Info.CurrentCall->Callee &&
|
|
Info.CurrentCall->Callee->Equals(VD->getDeclContext())) {
|
|
Frame = Info.CurrentCall;
|
|
}
|
|
}
|
|
|
|
if (!VD->getType()->isReferenceType()) {
|
|
if (Frame) {
|
|
Result.set({VD, Frame->Index,
|
|
Info.CurrentCall->getCurrentTemporaryVersion(VD)});
|
|
return true;
|
|
}
|
|
return Success(VD);
|
|
}
|
|
|
|
APValue *V;
|
|
if (!evaluateVarDeclInit(Info, E, VD, Frame, V, nullptr))
|
|
return false;
|
|
if (V->isUninit()) {
|
|
if (!Info.checkingPotentialConstantExpression())
|
|
Info.FFDiag(E, diag::note_constexpr_use_uninit_reference);
|
|
return false;
|
|
}
|
|
return Success(*V, E);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitMaterializeTemporaryExpr(
|
|
const MaterializeTemporaryExpr *E) {
|
|
// Walk through the expression to find the materialized temporary itself.
|
|
SmallVector<const Expr *, 2> CommaLHSs;
|
|
SmallVector<SubobjectAdjustment, 2> Adjustments;
|
|
const Expr *Inner = E->GetTemporaryExpr()->
|
|
skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
|
|
|
|
// If we passed any comma operators, evaluate their LHSs.
|
|
for (unsigned I = 0, N = CommaLHSs.size(); I != N; ++I)
|
|
if (!EvaluateIgnoredValue(Info, CommaLHSs[I]))
|
|
return false;
|
|
|
|
// A materialized temporary with static storage duration can appear within the
|
|
// result of a constant expression evaluation, so we need to preserve its
|
|
// value for use outside this evaluation.
|
|
APValue *Value;
|
|
if (E->getStorageDuration() == SD_Static) {
|
|
Value = Info.Ctx.getMaterializedTemporaryValue(E, true);
|
|
*Value = APValue();
|
|
Result.set(E);
|
|
} else {
|
|
Value = &createTemporary(E, E->getStorageDuration() == SD_Automatic, Result,
|
|
*Info.CurrentCall);
|
|
}
|
|
|
|
QualType Type = Inner->getType();
|
|
|
|
// Materialize the temporary itself.
|
|
if (!EvaluateInPlace(*Value, Info, Result, Inner) ||
|
|
(E->getStorageDuration() == SD_Static &&
|
|
!CheckConstantExpression(Info, E->getExprLoc(), Type, *Value))) {
|
|
*Value = APValue();
|
|
return false;
|
|
}
|
|
|
|
// Adjust our lvalue to refer to the desired subobject.
|
|
for (unsigned I = Adjustments.size(); I != 0; /**/) {
|
|
--I;
|
|
switch (Adjustments[I].Kind) {
|
|
case SubobjectAdjustment::DerivedToBaseAdjustment:
|
|
if (!HandleLValueBasePath(Info, Adjustments[I].DerivedToBase.BasePath,
|
|
Type, Result))
|
|
return false;
|
|
Type = Adjustments[I].DerivedToBase.BasePath->getType();
|
|
break;
|
|
|
|
case SubobjectAdjustment::FieldAdjustment:
|
|
if (!HandleLValueMember(Info, E, Result, Adjustments[I].Field))
|
|
return false;
|
|
Type = Adjustments[I].Field->getType();
|
|
break;
|
|
|
|
case SubobjectAdjustment::MemberPointerAdjustment:
|
|
if (!HandleMemberPointerAccess(this->Info, Type, Result,
|
|
Adjustments[I].Ptr.RHS))
|
|
return false;
|
|
Type = Adjustments[I].Ptr.MPT->getPointeeType();
|
|
break;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
LValueExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
|
|
assert((!Info.getLangOpts().CPlusPlus || E->isFileScope()) &&
|
|
"lvalue compound literal in c++?");
|
|
// Defer visiting the literal until the lvalue-to-rvalue conversion. We can
|
|
// only see this when folding in C, so there's no standard to follow here.
|
|
return Success(E);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
|
|
if (!E->isPotentiallyEvaluated())
|
|
return Success(E);
|
|
|
|
Info.FFDiag(E, diag::note_constexpr_typeid_polymorphic)
|
|
<< E->getExprOperand()->getType()
|
|
<< E->getExprOperand()->getSourceRange();
|
|
return false;
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
|
|
return Success(E);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitMemberExpr(const MemberExpr *E) {
|
|
// Handle static data members.
|
|
if (const VarDecl *VD = dyn_cast<VarDecl>(E->getMemberDecl())) {
|
|
VisitIgnoredBaseExpression(E->getBase());
|
|
return VisitVarDecl(E, VD);
|
|
}
|
|
|
|
// Handle static member functions.
|
|
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl())) {
|
|
if (MD->isStatic()) {
|
|
VisitIgnoredBaseExpression(E->getBase());
|
|
return Success(MD);
|
|
}
|
|
}
|
|
|
|
// Handle non-static data members.
|
|
return LValueExprEvaluatorBaseTy::VisitMemberExpr(E);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
|
|
// FIXME: Deal with vectors as array subscript bases.
|
|
if (E->getBase()->getType()->isVectorType())
|
|
return Error(E);
|
|
|
|
bool Success = true;
|
|
if (!evaluatePointer(E->getBase(), Result)) {
|
|
if (!Info.noteFailure())
|
|
return false;
|
|
Success = false;
|
|
}
|
|
|
|
APSInt Index;
|
|
if (!EvaluateInteger(E->getIdx(), Index, Info))
|
|
return false;
|
|
|
|
return Success &&
|
|
HandleLValueArrayAdjustment(Info, E, Result, E->getType(), Index);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitUnaryDeref(const UnaryOperator *E) {
|
|
return evaluatePointer(E->getSubExpr(), Result);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
// __real is a no-op on scalar lvalues.
|
|
if (E->getSubExpr()->getType()->isAnyComplexType())
|
|
HandleLValueComplexElement(Info, E, Result, E->getType(), false);
|
|
return true;
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
|
|
assert(E->getSubExpr()->getType()->isAnyComplexType() &&
|
|
"lvalue __imag__ on scalar?");
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
HandleLValueComplexElement(Info, E, Result, E->getType(), true);
|
|
return true;
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitUnaryPreIncDec(const UnaryOperator *UO) {
|
|
if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
|
|
return Error(UO);
|
|
|
|
if (!this->Visit(UO->getSubExpr()))
|
|
return false;
|
|
|
|
return handleIncDec(
|
|
this->Info, UO, Result, UO->getSubExpr()->getType(),
|
|
UO->isIncrementOp(), nullptr);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitCompoundAssignOperator(
|
|
const CompoundAssignOperator *CAO) {
|
|
if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
|
|
return Error(CAO);
|
|
|
|
APValue RHS;
|
|
|
|
// The overall lvalue result is the result of evaluating the LHS.
|
|
if (!this->Visit(CAO->getLHS())) {
|
|
if (Info.noteFailure())
|
|
Evaluate(RHS, this->Info, CAO->getRHS());
|
|
return false;
|
|
}
|
|
|
|
if (!Evaluate(RHS, this->Info, CAO->getRHS()))
|
|
return false;
|
|
|
|
return handleCompoundAssignment(
|
|
this->Info, CAO,
|
|
Result, CAO->getLHS()->getType(), CAO->getComputationLHSType(),
|
|
CAO->getOpForCompoundAssignment(CAO->getOpcode()), RHS);
|
|
}
|
|
|
|
bool LValueExprEvaluator::VisitBinAssign(const BinaryOperator *E) {
|
|
if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
|
|
return Error(E);
|
|
|
|
APValue NewVal;
|
|
|
|
if (!this->Visit(E->getLHS())) {
|
|
if (Info.noteFailure())
|
|
Evaluate(NewVal, this->Info, E->getRHS());
|
|
return false;
|
|
}
|
|
|
|
if (!Evaluate(NewVal, this->Info, E->getRHS()))
|
|
return false;
|
|
|
|
return handleAssignment(this->Info, E, Result, E->getLHS()->getType(),
|
|
NewVal);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Pointer Evaluation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// Attempts to compute the number of bytes available at the pointer
|
|
/// returned by a function with the alloc_size attribute. Returns true if we
|
|
/// were successful. Places an unsigned number into `Result`.
|
|
///
|
|
/// This expects the given CallExpr to be a call to a function with an
|
|
/// alloc_size attribute.
|
|
static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
|
|
const CallExpr *Call,
|
|
llvm::APInt &Result) {
|
|
const AllocSizeAttr *AllocSize = getAllocSizeAttr(Call);
|
|
|
|
assert(AllocSize && AllocSize->getElemSizeParam().isValid());
|
|
unsigned SizeArgNo = AllocSize->getElemSizeParam().getASTIndex();
|
|
unsigned BitsInSizeT = Ctx.getTypeSize(Ctx.getSizeType());
|
|
if (Call->getNumArgs() <= SizeArgNo)
|
|
return false;
|
|
|
|
auto EvaluateAsSizeT = [&](const Expr *E, APSInt &Into) {
|
|
Expr::EvalResult ExprResult;
|
|
if (!E->EvaluateAsInt(ExprResult, Ctx, Expr::SE_AllowSideEffects))
|
|
return false;
|
|
Into = ExprResult.Val.getInt();
|
|
if (Into.isNegative() || !Into.isIntN(BitsInSizeT))
|
|
return false;
|
|
Into = Into.zextOrSelf(BitsInSizeT);
|
|
return true;
|
|
};
|
|
|
|
APSInt SizeOfElem;
|
|
if (!EvaluateAsSizeT(Call->getArg(SizeArgNo), SizeOfElem))
|
|
return false;
|
|
|
|
if (!AllocSize->getNumElemsParam().isValid()) {
|
|
Result = std::move(SizeOfElem);
|
|
return true;
|
|
}
|
|
|
|
APSInt NumberOfElems;
|
|
unsigned NumArgNo = AllocSize->getNumElemsParam().getASTIndex();
|
|
if (!EvaluateAsSizeT(Call->getArg(NumArgNo), NumberOfElems))
|
|
return false;
|
|
|
|
bool Overflow;
|
|
llvm::APInt BytesAvailable = SizeOfElem.umul_ov(NumberOfElems, Overflow);
|
|
if (Overflow)
|
|
return false;
|
|
|
|
Result = std::move(BytesAvailable);
|
|
return true;
|
|
}
|
|
|
|
/// Convenience function. LVal's base must be a call to an alloc_size
|
|
/// function.
|
|
static bool getBytesReturnedByAllocSizeCall(const ASTContext &Ctx,
|
|
const LValue &LVal,
|
|
llvm::APInt &Result) {
|
|
assert(isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
|
|
"Can't get the size of a non alloc_size function");
|
|
const auto *Base = LVal.getLValueBase().get<const Expr *>();
|
|
const CallExpr *CE = tryUnwrapAllocSizeCall(Base);
|
|
return getBytesReturnedByAllocSizeCall(Ctx, CE, Result);
|
|
}
|
|
|
|
/// Attempts to evaluate the given LValueBase as the result of a call to
|
|
/// a function with the alloc_size attribute. If it was possible to do so, this
|
|
/// function will return true, make Result's Base point to said function call,
|
|
/// and mark Result's Base as invalid.
|
|
static bool evaluateLValueAsAllocSize(EvalInfo &Info, APValue::LValueBase Base,
|
|
LValue &Result) {
|
|
if (Base.isNull())
|
|
return false;
|
|
|
|
// Because we do no form of static analysis, we only support const variables.
|
|
//
|
|
// Additionally, we can't support parameters, nor can we support static
|
|
// variables (in the latter case, use-before-assign isn't UB; in the former,
|
|
// we have no clue what they'll be assigned to).
|
|
const auto *VD =
|
|
dyn_cast_or_null<VarDecl>(Base.dyn_cast<const ValueDecl *>());
|
|
if (!VD || !VD->isLocalVarDecl() || !VD->getType().isConstQualified())
|
|
return false;
|
|
|
|
const Expr *Init = VD->getAnyInitializer();
|
|
if (!Init)
|
|
return false;
|
|
|
|
const Expr *E = Init->IgnoreParens();
|
|
if (!tryUnwrapAllocSizeCall(E))
|
|
return false;
|
|
|
|
// Store E instead of E unwrapped so that the type of the LValue's base is
|
|
// what the user wanted.
|
|
Result.setInvalid(E);
|
|
|
|
QualType Pointee = E->getType()->castAs<PointerType>()->getPointeeType();
|
|
Result.addUnsizedArray(Info, E, Pointee);
|
|
return true;
|
|
}
|
|
|
|
namespace {
|
|
class PointerExprEvaluator
|
|
: public ExprEvaluatorBase<PointerExprEvaluator> {
|
|
LValue &Result;
|
|
bool InvalidBaseOK;
|
|
|
|
bool Success(const Expr *E) {
|
|
Result.set(E);
|
|
return true;
|
|
}
|
|
|
|
bool evaluateLValue(const Expr *E, LValue &Result) {
|
|
return EvaluateLValue(E, Result, Info, InvalidBaseOK);
|
|
}
|
|
|
|
bool evaluatePointer(const Expr *E, LValue &Result) {
|
|
return EvaluatePointer(E, Result, Info, InvalidBaseOK);
|
|
}
|
|
|
|
bool visitNonBuiltinCallExpr(const CallExpr *E);
|
|
public:
|
|
|
|
PointerExprEvaluator(EvalInfo &info, LValue &Result, bool InvalidBaseOK)
|
|
: ExprEvaluatorBaseTy(info), Result(Result),
|
|
InvalidBaseOK(InvalidBaseOK) {}
|
|
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
Result.setFrom(Info.Ctx, V);
|
|
return true;
|
|
}
|
|
bool ZeroInitialization(const Expr *E) {
|
|
auto TargetVal = Info.Ctx.getTargetNullPointerValue(E->getType());
|
|
Result.setNull(E->getType(), TargetVal);
|
|
return true;
|
|
}
|
|
|
|
bool VisitBinaryOperator(const BinaryOperator *E);
|
|
bool VisitCastExpr(const CastExpr* E);
|
|
bool VisitUnaryAddrOf(const UnaryOperator *E);
|
|
bool VisitObjCStringLiteral(const ObjCStringLiteral *E)
|
|
{ return Success(E); }
|
|
bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
|
|
if (Info.noteFailure())
|
|
EvaluateIgnoredValue(Info, E->getSubExpr());
|
|
return Error(E);
|
|
}
|
|
bool VisitAddrLabelExpr(const AddrLabelExpr *E)
|
|
{ return Success(E); }
|
|
bool VisitCallExpr(const CallExpr *E);
|
|
bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
|
|
bool VisitBlockExpr(const BlockExpr *E) {
|
|
if (!E->getBlockDecl()->hasCaptures())
|
|
return Success(E);
|
|
return Error(E);
|
|
}
|
|
bool VisitCXXThisExpr(const CXXThisExpr *E) {
|
|
// Can't look at 'this' when checking a potential constant expression.
|
|
if (Info.checkingPotentialConstantExpression())
|
|
return false;
|
|
if (!Info.CurrentCall->This) {
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.FFDiag(E, diag::note_constexpr_this) << E->isImplicit();
|
|
else
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
Result = *Info.CurrentCall->This;
|
|
// If we are inside a lambda's call operator, the 'this' expression refers
|
|
// to the enclosing '*this' object (either by value or reference) which is
|
|
// either copied into the closure object's field that represents the '*this'
|
|
// or refers to '*this'.
|
|
if (isLambdaCallOperator(Info.CurrentCall->Callee)) {
|
|
// Update 'Result' to refer to the data member/field of the closure object
|
|
// that represents the '*this' capture.
|
|
if (!HandleLValueMember(Info, E, Result,
|
|
Info.CurrentCall->LambdaThisCaptureField))
|
|
return false;
|
|
// If we captured '*this' by reference, replace the field with its referent.
|
|
if (Info.CurrentCall->LambdaThisCaptureField->getType()
|
|
->isPointerType()) {
|
|
APValue RVal;
|
|
if (!handleLValueToRValueConversion(Info, E, E->getType(), Result,
|
|
RVal))
|
|
return false;
|
|
|
|
Result.setFrom(Info.Ctx, RVal);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// FIXME: Missing: @protocol, @selector
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info,
|
|
bool InvalidBaseOK) {
|
|
assert(E->isRValue() && E->getType()->hasPointerRepresentation());
|
|
return PointerExprEvaluator(Info, Result, InvalidBaseOK).Visit(E);
|
|
}
|
|
|
|
bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
|
|
if (E->getOpcode() != BO_Add &&
|
|
E->getOpcode() != BO_Sub)
|
|
return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
|
|
|
|
const Expr *PExp = E->getLHS();
|
|
const Expr *IExp = E->getRHS();
|
|
if (IExp->getType()->isPointerType())
|
|
std::swap(PExp, IExp);
|
|
|
|
bool EvalPtrOK = evaluatePointer(PExp, Result);
|
|
if (!EvalPtrOK && !Info.noteFailure())
|
|
return false;
|
|
|
|
llvm::APSInt Offset;
|
|
if (!EvaluateInteger(IExp, Offset, Info) || !EvalPtrOK)
|
|
return false;
|
|
|
|
if (E->getOpcode() == BO_Sub)
|
|
negateAsSigned(Offset);
|
|
|
|
QualType Pointee = PExp->getType()->castAs<PointerType>()->getPointeeType();
|
|
return HandleLValueArrayAdjustment(Info, E, Result, Pointee, Offset);
|
|
}
|
|
|
|
bool PointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
|
|
return evaluateLValue(E->getSubExpr(), Result);
|
|
}
|
|
|
|
bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
|
|
const Expr *SubExpr = E->getSubExpr();
|
|
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
break;
|
|
|
|
case CK_BitCast:
|
|
case CK_CPointerToObjCPointerCast:
|
|
case CK_BlockPointerToObjCPointerCast:
|
|
case CK_AnyPointerToBlockPointerCast:
|
|
case CK_AddressSpaceConversion:
|
|
if (!Visit(SubExpr))
|
|
return false;
|
|
// Bitcasts to cv void* are static_casts, not reinterpret_casts, so are
|
|
// permitted in constant expressions in C++11. Bitcasts from cv void* are
|
|
// also static_casts, but we disallow them as a resolution to DR1312.
|
|
if (!E->getType()->isVoidPointerType()) {
|
|
Result.Designator.setInvalid();
|
|
if (SubExpr->getType()->isVoidPointerType())
|
|
CCEDiag(E, diag::note_constexpr_invalid_cast)
|
|
<< 3 << SubExpr->getType();
|
|
else
|
|
CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
|
|
}
|
|
if (E->getCastKind() == CK_AddressSpaceConversion && Result.IsNullPtr)
|
|
ZeroInitialization(E);
|
|
return true;
|
|
|
|
case CK_DerivedToBase:
|
|
case CK_UncheckedDerivedToBase:
|
|
if (!evaluatePointer(E->getSubExpr(), Result))
|
|
return false;
|
|
if (!Result.Base && Result.Offset.isZero())
|
|
return true;
|
|
|
|
// Now figure out the necessary offset to add to the base LV to get from
|
|
// the derived class to the base class.
|
|
return HandleLValueBasePath(Info, E, E->getSubExpr()->getType()->
|
|
castAs<PointerType>()->getPointeeType(),
|
|
Result);
|
|
|
|
case CK_BaseToDerived:
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
if (!Result.Base && Result.Offset.isZero())
|
|
return true;
|
|
return HandleBaseToDerivedCast(Info, E, Result);
|
|
|
|
case CK_NullToPointer:
|
|
VisitIgnoredValue(E->getSubExpr());
|
|
return ZeroInitialization(E);
|
|
|
|
case CK_IntegralToPointer: {
|
|
CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
|
|
|
|
APValue Value;
|
|
if (!EvaluateIntegerOrLValue(SubExpr, Value, Info))
|
|
break;
|
|
|
|
if (Value.isInt()) {
|
|
unsigned Size = Info.Ctx.getTypeSize(E->getType());
|
|
uint64_t N = Value.getInt().extOrTrunc(Size).getZExtValue();
|
|
Result.Base = (Expr*)nullptr;
|
|
Result.InvalidBase = false;
|
|
Result.Offset = CharUnits::fromQuantity(N);
|
|
Result.Designator.setInvalid();
|
|
Result.IsNullPtr = false;
|
|
return true;
|
|
} else {
|
|
// Cast is of an lvalue, no need to change value.
|
|
Result.setFrom(Info.Ctx, Value);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
case CK_ArrayToPointerDecay: {
|
|
if (SubExpr->isGLValue()) {
|
|
if (!evaluateLValue(SubExpr, Result))
|
|
return false;
|
|
} else {
|
|
APValue &Value = createTemporary(SubExpr, false, Result,
|
|
*Info.CurrentCall);
|
|
if (!EvaluateInPlace(Value, Info, Result, SubExpr))
|
|
return false;
|
|
}
|
|
// The result is a pointer to the first element of the array.
|
|
auto *AT = Info.Ctx.getAsArrayType(SubExpr->getType());
|
|
if (auto *CAT = dyn_cast<ConstantArrayType>(AT))
|
|
Result.addArray(Info, E, CAT);
|
|
else
|
|
Result.addUnsizedArray(Info, E, AT->getElementType());
|
|
return true;
|
|
}
|
|
|
|
case CK_FunctionToPointerDecay:
|
|
return evaluateLValue(SubExpr, Result);
|
|
|
|
case CK_LValueToRValue: {
|
|
LValue LVal;
|
|
if (!evaluateLValue(E->getSubExpr(), LVal))
|
|
return false;
|
|
|
|
APValue RVal;
|
|
// Note, we use the subexpression's type in order to retain cv-qualifiers.
|
|
if (!handleLValueToRValueConversion(Info, E, E->getSubExpr()->getType(),
|
|
LVal, RVal))
|
|
return InvalidBaseOK &&
|
|
evaluateLValueAsAllocSize(Info, LVal.Base, Result);
|
|
return Success(RVal, E);
|
|
}
|
|
}
|
|
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
}
|
|
|
|
static CharUnits GetAlignOfType(EvalInfo &Info, QualType T,
|
|
UnaryExprOrTypeTrait ExprKind) {
|
|
// C++ [expr.alignof]p3:
|
|
// When alignof is applied to a reference type, the result is the
|
|
// alignment of the referenced type.
|
|
if (const ReferenceType *Ref = T->getAs<ReferenceType>())
|
|
T = Ref->getPointeeType();
|
|
|
|
if (T.getQualifiers().hasUnaligned())
|
|
return CharUnits::One();
|
|
|
|
const bool AlignOfReturnsPreferred =
|
|
Info.Ctx.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver7;
|
|
|
|
// __alignof is defined to return the preferred alignment.
|
|
// Before 8, clang returned the preferred alignment for alignof and _Alignof
|
|
// as well.
|
|
if (ExprKind == UETT_PreferredAlignOf || AlignOfReturnsPreferred)
|
|
return Info.Ctx.toCharUnitsFromBits(
|
|
Info.Ctx.getPreferredTypeAlign(T.getTypePtr()));
|
|
// alignof and _Alignof are defined to return the ABI alignment.
|
|
else if (ExprKind == UETT_AlignOf)
|
|
return Info.Ctx.getTypeAlignInChars(T.getTypePtr());
|
|
else
|
|
llvm_unreachable("GetAlignOfType on a non-alignment ExprKind");
|
|
}
|
|
|
|
static CharUnits GetAlignOfExpr(EvalInfo &Info, const Expr *E,
|
|
UnaryExprOrTypeTrait ExprKind) {
|
|
E = E->IgnoreParens();
|
|
|
|
// The kinds of expressions that we have special-case logic here for
|
|
// should be kept up to date with the special checks for those
|
|
// expressions in Sema.
|
|
|
|
// alignof decl is always accepted, even if it doesn't make sense: we default
|
|
// to 1 in those cases.
|
|
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
|
|
return Info.Ctx.getDeclAlign(DRE->getDecl(),
|
|
/*RefAsPointee*/true);
|
|
|
|
if (const MemberExpr *ME = dyn_cast<MemberExpr>(E))
|
|
return Info.Ctx.getDeclAlign(ME->getMemberDecl(),
|
|
/*RefAsPointee*/true);
|
|
|
|
return GetAlignOfType(Info, E->getType(), ExprKind);
|
|
}
|
|
|
|
// To be clear: this happily visits unsupported builtins. Better name welcomed.
|
|
bool PointerExprEvaluator::visitNonBuiltinCallExpr(const CallExpr *E) {
|
|
if (ExprEvaluatorBaseTy::VisitCallExpr(E))
|
|
return true;
|
|
|
|
if (!(InvalidBaseOK && getAllocSizeAttr(E)))
|
|
return false;
|
|
|
|
Result.setInvalid(E);
|
|
QualType PointeeTy = E->getType()->castAs<PointerType>()->getPointeeType();
|
|
Result.addUnsizedArray(Info, E, PointeeTy);
|
|
return true;
|
|
}
|
|
|
|
bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) {
|
|
if (IsStringLiteralCall(E))
|
|
return Success(E);
|
|
|
|
if (unsigned BuiltinOp = E->getBuiltinCallee())
|
|
return VisitBuiltinCallExpr(E, BuiltinOp);
|
|
|
|
return visitNonBuiltinCallExpr(E);
|
|
}
|
|
|
|
bool PointerExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
|
|
unsigned BuiltinOp) {
|
|
switch (BuiltinOp) {
|
|
case Builtin::BI__builtin_addressof:
|
|
return evaluateLValue(E->getArg(0), Result);
|
|
case Builtin::BI__builtin_assume_aligned: {
|
|
// We need to be very careful here because: if the pointer does not have the
|
|
// asserted alignment, then the behavior is undefined, and undefined
|
|
// behavior is non-constant.
|
|
if (!evaluatePointer(E->getArg(0), Result))
|
|
return false;
|
|
|
|
LValue OffsetResult(Result);
|
|
APSInt Alignment;
|
|
if (!EvaluateInteger(E->getArg(1), Alignment, Info))
|
|
return false;
|
|
CharUnits Align = CharUnits::fromQuantity(Alignment.getZExtValue());
|
|
|
|
if (E->getNumArgs() > 2) {
|
|
APSInt Offset;
|
|
if (!EvaluateInteger(E->getArg(2), Offset, Info))
|
|
return false;
|
|
|
|
int64_t AdditionalOffset = -Offset.getZExtValue();
|
|
OffsetResult.Offset += CharUnits::fromQuantity(AdditionalOffset);
|
|
}
|
|
|
|
// If there is a base object, then it must have the correct alignment.
|
|
if (OffsetResult.Base) {
|
|
CharUnits BaseAlignment;
|
|
if (const ValueDecl *VD =
|
|
OffsetResult.Base.dyn_cast<const ValueDecl*>()) {
|
|
BaseAlignment = Info.Ctx.getDeclAlign(VD);
|
|
} else {
|
|
BaseAlignment = GetAlignOfExpr(
|
|
Info, OffsetResult.Base.get<const Expr *>(), UETT_AlignOf);
|
|
}
|
|
|
|
if (BaseAlignment < Align) {
|
|
Result.Designator.setInvalid();
|
|
// FIXME: Add support to Diagnostic for long / long long.
|
|
CCEDiag(E->getArg(0),
|
|
diag::note_constexpr_baa_insufficient_alignment) << 0
|
|
<< (unsigned)BaseAlignment.getQuantity()
|
|
<< (unsigned)Align.getQuantity();
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// The offset must also have the correct alignment.
|
|
if (OffsetResult.Offset.alignTo(Align) != OffsetResult.Offset) {
|
|
Result.Designator.setInvalid();
|
|
|
|
(OffsetResult.Base
|
|
? CCEDiag(E->getArg(0),
|
|
diag::note_constexpr_baa_insufficient_alignment) << 1
|
|
: CCEDiag(E->getArg(0),
|
|
diag::note_constexpr_baa_value_insufficient_alignment))
|
|
<< (int)OffsetResult.Offset.getQuantity()
|
|
<< (unsigned)Align.getQuantity();
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
case Builtin::BI__builtin_launder:
|
|
return evaluatePointer(E->getArg(0), Result);
|
|
case Builtin::BIstrchr:
|
|
case Builtin::BIwcschr:
|
|
case Builtin::BImemchr:
|
|
case Builtin::BIwmemchr:
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.CCEDiag(E, diag::note_constexpr_invalid_function)
|
|
<< /*isConstexpr*/0 << /*isConstructor*/0
|
|
<< (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
|
|
else
|
|
Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
LLVM_FALLTHROUGH;
|
|
case Builtin::BI__builtin_strchr:
|
|
case Builtin::BI__builtin_wcschr:
|
|
case Builtin::BI__builtin_memchr:
|
|
case Builtin::BI__builtin_char_memchr:
|
|
case Builtin::BI__builtin_wmemchr: {
|
|
if (!Visit(E->getArg(0)))
|
|
return false;
|
|
APSInt Desired;
|
|
if (!EvaluateInteger(E->getArg(1), Desired, Info))
|
|
return false;
|
|
uint64_t MaxLength = uint64_t(-1);
|
|
if (BuiltinOp != Builtin::BIstrchr &&
|
|
BuiltinOp != Builtin::BIwcschr &&
|
|
BuiltinOp != Builtin::BI__builtin_strchr &&
|
|
BuiltinOp != Builtin::BI__builtin_wcschr) {
|
|
APSInt N;
|
|
if (!EvaluateInteger(E->getArg(2), N, Info))
|
|
return false;
|
|
MaxLength = N.getExtValue();
|
|
}
|
|
// We cannot find the value if there are no candidates to match against.
|
|
if (MaxLength == 0u)
|
|
return ZeroInitialization(E);
|
|
if (!Result.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
|
|
Result.Designator.Invalid)
|
|
return false;
|
|
QualType CharTy = Result.Designator.getType(Info.Ctx);
|
|
bool IsRawByte = BuiltinOp == Builtin::BImemchr ||
|
|
BuiltinOp == Builtin::BI__builtin_memchr;
|
|
assert(IsRawByte ||
|
|
Info.Ctx.hasSameUnqualifiedType(
|
|
CharTy, E->getArg(0)->getType()->getPointeeType()));
|
|
// Pointers to const void may point to objects of incomplete type.
|
|
if (IsRawByte && CharTy->isIncompleteType()) {
|
|
Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy;
|
|
return false;
|
|
}
|
|
// Give up on byte-oriented matching against multibyte elements.
|
|
// FIXME: We can compare the bytes in the correct order.
|
|
if (IsRawByte && Info.Ctx.getTypeSizeInChars(CharTy) != CharUnits::One())
|
|
return false;
|
|
// Figure out what value we're actually looking for (after converting to
|
|
// the corresponding unsigned type if necessary).
|
|
uint64_t DesiredVal;
|
|
bool StopAtNull = false;
|
|
switch (BuiltinOp) {
|
|
case Builtin::BIstrchr:
|
|
case Builtin::BI__builtin_strchr:
|
|
// strchr compares directly to the passed integer, and therefore
|
|
// always fails if given an int that is not a char.
|
|
if (!APSInt::isSameValue(HandleIntToIntCast(Info, E, CharTy,
|
|
E->getArg(1)->getType(),
|
|
Desired),
|
|
Desired))
|
|
return ZeroInitialization(E);
|
|
StopAtNull = true;
|
|
LLVM_FALLTHROUGH;
|
|
case Builtin::BImemchr:
|
|
case Builtin::BI__builtin_memchr:
|
|
case Builtin::BI__builtin_char_memchr:
|
|
// memchr compares by converting both sides to unsigned char. That's also
|
|
// correct for strchr if we get this far (to cope with plain char being
|
|
// unsigned in the strchr case).
|
|
DesiredVal = Desired.trunc(Info.Ctx.getCharWidth()).getZExtValue();
|
|
break;
|
|
|
|
case Builtin::BIwcschr:
|
|
case Builtin::BI__builtin_wcschr:
|
|
StopAtNull = true;
|
|
LLVM_FALLTHROUGH;
|
|
case Builtin::BIwmemchr:
|
|
case Builtin::BI__builtin_wmemchr:
|
|
// wcschr and wmemchr are given a wchar_t to look for. Just use it.
|
|
DesiredVal = Desired.getZExtValue();
|
|
break;
|
|
}
|
|
|
|
for (; MaxLength; --MaxLength) {
|
|
APValue Char;
|
|
if (!handleLValueToRValueConversion(Info, E, CharTy, Result, Char) ||
|
|
!Char.isInt())
|
|
return false;
|
|
if (Char.getInt().getZExtValue() == DesiredVal)
|
|
return true;
|
|
if (StopAtNull && !Char.getInt())
|
|
break;
|
|
if (!HandleLValueArrayAdjustment(Info, E, Result, CharTy, 1))
|
|
return false;
|
|
}
|
|
// Not found: return nullptr.
|
|
return ZeroInitialization(E);
|
|
}
|
|
|
|
case Builtin::BImemcpy:
|
|
case Builtin::BImemmove:
|
|
case Builtin::BIwmemcpy:
|
|
case Builtin::BIwmemmove:
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.CCEDiag(E, diag::note_constexpr_invalid_function)
|
|
<< /*isConstexpr*/0 << /*isConstructor*/0
|
|
<< (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
|
|
else
|
|
Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
LLVM_FALLTHROUGH;
|
|
case Builtin::BI__builtin_memcpy:
|
|
case Builtin::BI__builtin_memmove:
|
|
case Builtin::BI__builtin_wmemcpy:
|
|
case Builtin::BI__builtin_wmemmove: {
|
|
bool WChar = BuiltinOp == Builtin::BIwmemcpy ||
|
|
BuiltinOp == Builtin::BIwmemmove ||
|
|
BuiltinOp == Builtin::BI__builtin_wmemcpy ||
|
|
BuiltinOp == Builtin::BI__builtin_wmemmove;
|
|
bool Move = BuiltinOp == Builtin::BImemmove ||
|
|
BuiltinOp == Builtin::BIwmemmove ||
|
|
BuiltinOp == Builtin::BI__builtin_memmove ||
|
|
BuiltinOp == Builtin::BI__builtin_wmemmove;
|
|
|
|
// The result of mem* is the first argument.
|
|
if (!Visit(E->getArg(0)))
|
|
return false;
|
|
LValue Dest = Result;
|
|
|
|
LValue Src;
|
|
if (!EvaluatePointer(E->getArg(1), Src, Info))
|
|
return false;
|
|
|
|
APSInt N;
|
|
if (!EvaluateInteger(E->getArg(2), N, Info))
|
|
return false;
|
|
assert(!N.isSigned() && "memcpy and friends take an unsigned size");
|
|
|
|
// If the size is zero, we treat this as always being a valid no-op.
|
|
// (Even if one of the src and dest pointers is null.)
|
|
if (!N)
|
|
return true;
|
|
|
|
// Otherwise, if either of the operands is null, we can't proceed. Don't
|
|
// try to determine the type of the copied objects, because there aren't
|
|
// any.
|
|
if (!Src.Base || !Dest.Base) {
|
|
APValue Val;
|
|
(!Src.Base ? Src : Dest).moveInto(Val);
|
|
Info.FFDiag(E, diag::note_constexpr_memcpy_null)
|
|
<< Move << WChar << !!Src.Base
|
|
<< Val.getAsString(Info.Ctx, E->getArg(0)->getType());
|
|
return false;
|
|
}
|
|
if (Src.Designator.Invalid || Dest.Designator.Invalid)
|
|
return false;
|
|
|
|
// We require that Src and Dest are both pointers to arrays of
|
|
// trivially-copyable type. (For the wide version, the designator will be
|
|
// invalid if the designated object is not a wchar_t.)
|
|
QualType T = Dest.Designator.getType(Info.Ctx);
|
|
QualType SrcT = Src.Designator.getType(Info.Ctx);
|
|
if (!Info.Ctx.hasSameUnqualifiedType(T, SrcT)) {
|
|
Info.FFDiag(E, diag::note_constexpr_memcpy_type_pun) << Move << SrcT << T;
|
|
return false;
|
|
}
|
|
if (T->isIncompleteType()) {
|
|
Info.FFDiag(E, diag::note_constexpr_memcpy_incomplete_type) << Move << T;
|
|
return false;
|
|
}
|
|
if (!T.isTriviallyCopyableType(Info.Ctx)) {
|
|
Info.FFDiag(E, diag::note_constexpr_memcpy_nontrivial) << Move << T;
|
|
return false;
|
|
}
|
|
|
|
// Figure out how many T's we're copying.
|
|
uint64_t TSize = Info.Ctx.getTypeSizeInChars(T).getQuantity();
|
|
if (!WChar) {
|
|
uint64_t Remainder;
|
|
llvm::APInt OrigN = N;
|
|
llvm::APInt::udivrem(OrigN, TSize, N, Remainder);
|
|
if (Remainder) {
|
|
Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
|
|
<< Move << WChar << 0 << T << OrigN.toString(10, /*Signed*/false)
|
|
<< (unsigned)TSize;
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Check that the copying will remain within the arrays, just so that we
|
|
// can give a more meaningful diagnostic. This implicitly also checks that
|
|
// N fits into 64 bits.
|
|
uint64_t RemainingSrcSize = Src.Designator.validIndexAdjustments().second;
|
|
uint64_t RemainingDestSize = Dest.Designator.validIndexAdjustments().second;
|
|
if (N.ugt(RemainingSrcSize) || N.ugt(RemainingDestSize)) {
|
|
Info.FFDiag(E, diag::note_constexpr_memcpy_unsupported)
|
|
<< Move << WChar << (N.ugt(RemainingSrcSize) ? 1 : 2) << T
|
|
<< N.toString(10, /*Signed*/false);
|
|
return false;
|
|
}
|
|
uint64_t NElems = N.getZExtValue();
|
|
uint64_t NBytes = NElems * TSize;
|
|
|
|
// Check for overlap.
|
|
int Direction = 1;
|
|
if (HasSameBase(Src, Dest)) {
|
|
uint64_t SrcOffset = Src.getLValueOffset().getQuantity();
|
|
uint64_t DestOffset = Dest.getLValueOffset().getQuantity();
|
|
if (DestOffset >= SrcOffset && DestOffset - SrcOffset < NBytes) {
|
|
// Dest is inside the source region.
|
|
if (!Move) {
|
|
Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
|
|
return false;
|
|
}
|
|
// For memmove and friends, copy backwards.
|
|
if (!HandleLValueArrayAdjustment(Info, E, Src, T, NElems - 1) ||
|
|
!HandleLValueArrayAdjustment(Info, E, Dest, T, NElems - 1))
|
|
return false;
|
|
Direction = -1;
|
|
} else if (!Move && SrcOffset >= DestOffset &&
|
|
SrcOffset - DestOffset < NBytes) {
|
|
// Src is inside the destination region for memcpy: invalid.
|
|
Info.FFDiag(E, diag::note_constexpr_memcpy_overlap) << WChar;
|
|
return false;
|
|
}
|
|
}
|
|
|
|
while (true) {
|
|
APValue Val;
|
|
if (!handleLValueToRValueConversion(Info, E, T, Src, Val) ||
|
|
!handleAssignment(Info, E, Dest, T, Val))
|
|
return false;
|
|
// Do not iterate past the last element; if we're copying backwards, that
|
|
// might take us off the start of the array.
|
|
if (--NElems == 0)
|
|
return true;
|
|
if (!HandleLValueArrayAdjustment(Info, E, Src, T, Direction) ||
|
|
!HandleLValueArrayAdjustment(Info, E, Dest, T, Direction))
|
|
return false;
|
|
}
|
|
}
|
|
|
|
default:
|
|
return visitNonBuiltinCallExpr(E);
|
|
}
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Member Pointer Evaluation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class MemberPointerExprEvaluator
|
|
: public ExprEvaluatorBase<MemberPointerExprEvaluator> {
|
|
MemberPtr &Result;
|
|
|
|
bool Success(const ValueDecl *D) {
|
|
Result = MemberPtr(D);
|
|
return true;
|
|
}
|
|
public:
|
|
|
|
MemberPointerExprEvaluator(EvalInfo &Info, MemberPtr &Result)
|
|
: ExprEvaluatorBaseTy(Info), Result(Result) {}
|
|
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
Result.setFrom(V);
|
|
return true;
|
|
}
|
|
bool ZeroInitialization(const Expr *E) {
|
|
return Success((const ValueDecl*)nullptr);
|
|
}
|
|
|
|
bool VisitCastExpr(const CastExpr *E);
|
|
bool VisitUnaryAddrOf(const UnaryOperator *E);
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool EvaluateMemberPointer(const Expr *E, MemberPtr &Result,
|
|
EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isMemberPointerType());
|
|
return MemberPointerExprEvaluator(Info, Result).Visit(E);
|
|
}
|
|
|
|
bool MemberPointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
|
|
case CK_NullToMemberPointer:
|
|
VisitIgnoredValue(E->getSubExpr());
|
|
return ZeroInitialization(E);
|
|
|
|
case CK_BaseToDerivedMemberPointer: {
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
if (E->path_empty())
|
|
return true;
|
|
// Base-to-derived member pointer casts store the path in derived-to-base
|
|
// order, so iterate backwards. The CXXBaseSpecifier also provides us with
|
|
// the wrong end of the derived->base arc, so stagger the path by one class.
|
|
typedef std::reverse_iterator<CastExpr::path_const_iterator> ReverseIter;
|
|
for (ReverseIter PathI(E->path_end() - 1), PathE(E->path_begin());
|
|
PathI != PathE; ++PathI) {
|
|
assert(!(*PathI)->isVirtual() && "memptr cast through vbase");
|
|
const CXXRecordDecl *Derived = (*PathI)->getType()->getAsCXXRecordDecl();
|
|
if (!Result.castToDerived(Derived))
|
|
return Error(E);
|
|
}
|
|
const Type *FinalTy = E->getType()->castAs<MemberPointerType>()->getClass();
|
|
if (!Result.castToDerived(FinalTy->getAsCXXRecordDecl()))
|
|
return Error(E);
|
|
return true;
|
|
}
|
|
|
|
case CK_DerivedToBaseMemberPointer:
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
for (CastExpr::path_const_iterator PathI = E->path_begin(),
|
|
PathE = E->path_end(); PathI != PathE; ++PathI) {
|
|
assert(!(*PathI)->isVirtual() && "memptr cast through vbase");
|
|
const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
|
|
if (!Result.castToBase(Base))
|
|
return Error(E);
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool MemberPointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
|
|
// C++11 [expr.unary.op]p3 has very strict rules on how the address of a
|
|
// member can be formed.
|
|
return Success(cast<DeclRefExpr>(E->getSubExpr())->getDecl());
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Record Evaluation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class RecordExprEvaluator
|
|
: public ExprEvaluatorBase<RecordExprEvaluator> {
|
|
const LValue &This;
|
|
APValue &Result;
|
|
public:
|
|
|
|
RecordExprEvaluator(EvalInfo &info, const LValue &This, APValue &Result)
|
|
: ExprEvaluatorBaseTy(info), This(This), Result(Result) {}
|
|
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
Result = V;
|
|
return true;
|
|
}
|
|
bool ZeroInitialization(const Expr *E) {
|
|
return ZeroInitialization(E, E->getType());
|
|
}
|
|
bool ZeroInitialization(const Expr *E, QualType T);
|
|
|
|
bool VisitCallExpr(const CallExpr *E) {
|
|
return handleCallExpr(E, Result, &This);
|
|
}
|
|
bool VisitCastExpr(const CastExpr *E);
|
|
bool VisitInitListExpr(const InitListExpr *E);
|
|
bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
|
|
return VisitCXXConstructExpr(E, E->getType());
|
|
}
|
|
bool VisitLambdaExpr(const LambdaExpr *E);
|
|
bool VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
|
|
bool VisitCXXConstructExpr(const CXXConstructExpr *E, QualType T);
|
|
bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E);
|
|
|
|
bool VisitBinCmp(const BinaryOperator *E);
|
|
};
|
|
}
|
|
|
|
/// Perform zero-initialization on an object of non-union class type.
|
|
/// C++11 [dcl.init]p5:
|
|
/// To zero-initialize an object or reference of type T means:
|
|
/// [...]
|
|
/// -- if T is a (possibly cv-qualified) non-union class type,
|
|
/// each non-static data member and each base-class subobject is
|
|
/// zero-initialized
|
|
static bool HandleClassZeroInitialization(EvalInfo &Info, const Expr *E,
|
|
const RecordDecl *RD,
|
|
const LValue &This, APValue &Result) {
|
|
assert(!RD->isUnion() && "Expected non-union class type");
|
|
const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
|
|
Result = APValue(APValue::UninitStruct(), CD ? CD->getNumBases() : 0,
|
|
std::distance(RD->field_begin(), RD->field_end()));
|
|
|
|
if (RD->isInvalidDecl()) return false;
|
|
const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
|
|
|
|
if (CD) {
|
|
unsigned Index = 0;
|
|
for (CXXRecordDecl::base_class_const_iterator I = CD->bases_begin(),
|
|
End = CD->bases_end(); I != End; ++I, ++Index) {
|
|
const CXXRecordDecl *Base = I->getType()->getAsCXXRecordDecl();
|
|
LValue Subobject = This;
|
|
if (!HandleLValueDirectBase(Info, E, Subobject, CD, Base, &Layout))
|
|
return false;
|
|
if (!HandleClassZeroInitialization(Info, E, Base, Subobject,
|
|
Result.getStructBase(Index)))
|
|
return false;
|
|
}
|
|
}
|
|
|
|
for (const auto *I : RD->fields()) {
|
|
// -- if T is a reference type, no initialization is performed.
|
|
if (I->getType()->isReferenceType())
|
|
continue;
|
|
|
|
LValue Subobject = This;
|
|
if (!HandleLValueMember(Info, E, Subobject, I, &Layout))
|
|
return false;
|
|
|
|
ImplicitValueInitExpr VIE(I->getType());
|
|
if (!EvaluateInPlace(
|
|
Result.getStructField(I->getFieldIndex()), Info, Subobject, &VIE))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool RecordExprEvaluator::ZeroInitialization(const Expr *E, QualType T) {
|
|
const RecordDecl *RD = T->castAs<RecordType>()->getDecl();
|
|
if (RD->isInvalidDecl()) return false;
|
|
if (RD->isUnion()) {
|
|
// C++11 [dcl.init]p5: If T is a (possibly cv-qualified) union type, the
|
|
// object's first non-static named data member is zero-initialized
|
|
RecordDecl::field_iterator I = RD->field_begin();
|
|
if (I == RD->field_end()) {
|
|
Result = APValue((const FieldDecl*)nullptr);
|
|
return true;
|
|
}
|
|
|
|
LValue Subobject = This;
|
|
if (!HandleLValueMember(Info, E, Subobject, *I))
|
|
return false;
|
|
Result = APValue(*I);
|
|
ImplicitValueInitExpr VIE(I->getType());
|
|
return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, &VIE);
|
|
}
|
|
|
|
if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->getNumVBases()) {
|
|
Info.FFDiag(E, diag::note_constexpr_virtual_base) << RD;
|
|
return false;
|
|
}
|
|
|
|
return HandleClassZeroInitialization(Info, E, RD, This, Result);
|
|
}
|
|
|
|
bool RecordExprEvaluator::VisitCastExpr(const CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
|
|
case CK_ConstructorConversion:
|
|
return Visit(E->getSubExpr());
|
|
|
|
case CK_DerivedToBase:
|
|
case CK_UncheckedDerivedToBase: {
|
|
APValue DerivedObject;
|
|
if (!Evaluate(DerivedObject, Info, E->getSubExpr()))
|
|
return false;
|
|
if (!DerivedObject.isStruct())
|
|
return Error(E->getSubExpr());
|
|
|
|
// Derived-to-base rvalue conversion: just slice off the derived part.
|
|
APValue *Value = &DerivedObject;
|
|
const CXXRecordDecl *RD = E->getSubExpr()->getType()->getAsCXXRecordDecl();
|
|
for (CastExpr::path_const_iterator PathI = E->path_begin(),
|
|
PathE = E->path_end(); PathI != PathE; ++PathI) {
|
|
assert(!(*PathI)->isVirtual() && "record rvalue with virtual base");
|
|
const CXXRecordDecl *Base = (*PathI)->getType()->getAsCXXRecordDecl();
|
|
Value = &Value->getStructBase(getBaseIndex(RD, Base));
|
|
RD = Base;
|
|
}
|
|
Result = *Value;
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool RecordExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
|
|
if (E->isTransparent())
|
|
return Visit(E->getInit(0));
|
|
|
|
const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
|
|
if (RD->isInvalidDecl()) return false;
|
|
const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
|
|
|
|
if (RD->isUnion()) {
|
|
const FieldDecl *Field = E->getInitializedFieldInUnion();
|
|
Result = APValue(Field);
|
|
if (!Field)
|
|
return true;
|
|
|
|
// If the initializer list for a union does not contain any elements, the
|
|
// first element of the union is value-initialized.
|
|
// FIXME: The element should be initialized from an initializer list.
|
|
// Is this difference ever observable for initializer lists which
|
|
// we don't build?
|
|
ImplicitValueInitExpr VIE(Field->getType());
|
|
const Expr *InitExpr = E->getNumInits() ? E->getInit(0) : &VIE;
|
|
|
|
LValue Subobject = This;
|
|
if (!HandleLValueMember(Info, InitExpr, Subobject, Field, &Layout))
|
|
return false;
|
|
|
|
// Temporarily override This, in case there's a CXXDefaultInitExpr in here.
|
|
ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
|
|
isa<CXXDefaultInitExpr>(InitExpr));
|
|
|
|
return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, InitExpr);
|
|
}
|
|
|
|
auto *CXXRD = dyn_cast<CXXRecordDecl>(RD);
|
|
if (Result.isUninit())
|
|
Result = APValue(APValue::UninitStruct(), CXXRD ? CXXRD->getNumBases() : 0,
|
|
std::distance(RD->field_begin(), RD->field_end()));
|
|
unsigned ElementNo = 0;
|
|
bool Success = true;
|
|
|
|
// Initialize base classes.
|
|
if (CXXRD) {
|
|
for (const auto &Base : CXXRD->bases()) {
|
|
assert(ElementNo < E->getNumInits() && "missing init for base class");
|
|
const Expr *Init = E->getInit(ElementNo);
|
|
|
|
LValue Subobject = This;
|
|
if (!HandleLValueBase(Info, Init, Subobject, CXXRD, &Base))
|
|
return false;
|
|
|
|
APValue &FieldVal = Result.getStructBase(ElementNo);
|
|
if (!EvaluateInPlace(FieldVal, Info, Subobject, Init)) {
|
|
if (!Info.noteFailure())
|
|
return false;
|
|
Success = false;
|
|
}
|
|
++ElementNo;
|
|
}
|
|
}
|
|
|
|
// Initialize members.
|
|
for (const auto *Field : RD->fields()) {
|
|
// Anonymous bit-fields are not considered members of the class for
|
|
// purposes of aggregate initialization.
|
|
if (Field->isUnnamedBitfield())
|
|
continue;
|
|
|
|
LValue Subobject = This;
|
|
|
|
bool HaveInit = ElementNo < E->getNumInits();
|
|
|
|
// FIXME: Diagnostics here should point to the end of the initializer
|
|
// list, not the start.
|
|
if (!HandleLValueMember(Info, HaveInit ? E->getInit(ElementNo) : E,
|
|
Subobject, Field, &Layout))
|
|
return false;
|
|
|
|
// Perform an implicit value-initialization for members beyond the end of
|
|
// the initializer list.
|
|
ImplicitValueInitExpr VIE(HaveInit ? Info.Ctx.IntTy : Field->getType());
|
|
const Expr *Init = HaveInit ? E->getInit(ElementNo++) : &VIE;
|
|
|
|
// Temporarily override This, in case there's a CXXDefaultInitExpr in here.
|
|
ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
|
|
isa<CXXDefaultInitExpr>(Init));
|
|
|
|
APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
|
|
if (!EvaluateInPlace(FieldVal, Info, Subobject, Init) ||
|
|
(Field->isBitField() && !truncateBitfieldValue(Info, Init,
|
|
FieldVal, Field))) {
|
|
if (!Info.noteFailure())
|
|
return false;
|
|
Success = false;
|
|
}
|
|
}
|
|
|
|
return Success;
|
|
}
|
|
|
|
bool RecordExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
|
|
QualType T) {
|
|
// Note that E's type is not necessarily the type of our class here; we might
|
|
// be initializing an array element instead.
|
|
const CXXConstructorDecl *FD = E->getConstructor();
|
|
if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl()) return false;
|
|
|
|
bool ZeroInit = E->requiresZeroInitialization();
|
|
if (CheckTrivialDefaultConstructor(Info, E->getExprLoc(), FD, ZeroInit)) {
|
|
// If we've already performed zero-initialization, we're already done.
|
|
if (!Result.isUninit())
|
|
return true;
|
|
|
|
// We can get here in two different ways:
|
|
// 1) We're performing value-initialization, and should zero-initialize
|
|
// the object, or
|
|
// 2) We're performing default-initialization of an object with a trivial
|
|
// constexpr default constructor, in which case we should start the
|
|
// lifetimes of all the base subobjects (there can be no data member
|
|
// subobjects in this case) per [basic.life]p1.
|
|
// Either way, ZeroInitialization is appropriate.
|
|
return ZeroInitialization(E, T);
|
|
}
|
|
|
|
const FunctionDecl *Definition = nullptr;
|
|
auto Body = FD->getBody(Definition);
|
|
|
|
if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
|
|
return false;
|
|
|
|
// Avoid materializing a temporary for an elidable copy/move constructor.
|
|
if (E->isElidable() && !ZeroInit)
|
|
if (const MaterializeTemporaryExpr *ME
|
|
= dyn_cast<MaterializeTemporaryExpr>(E->getArg(0)))
|
|
return Visit(ME->GetTemporaryExpr());
|
|
|
|
if (ZeroInit && !ZeroInitialization(E, T))
|
|
return false;
|
|
|
|
auto Args = llvm::makeArrayRef(E->getArgs(), E->getNumArgs());
|
|
return HandleConstructorCall(E, This, Args,
|
|
cast<CXXConstructorDecl>(Definition), Info,
|
|
Result);
|
|
}
|
|
|
|
bool RecordExprEvaluator::VisitCXXInheritedCtorInitExpr(
|
|
const CXXInheritedCtorInitExpr *E) {
|
|
if (!Info.CurrentCall) {
|
|
assert(Info.checkingPotentialConstantExpression());
|
|
return false;
|
|
}
|
|
|
|
const CXXConstructorDecl *FD = E->getConstructor();
|
|
if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl())
|
|
return false;
|
|
|
|
const FunctionDecl *Definition = nullptr;
|
|
auto Body = FD->getBody(Definition);
|
|
|
|
if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
|
|
return false;
|
|
|
|
return HandleConstructorCall(E, This, Info.CurrentCall->Arguments,
|
|
cast<CXXConstructorDecl>(Definition), Info,
|
|
Result);
|
|
}
|
|
|
|
bool RecordExprEvaluator::VisitCXXStdInitializerListExpr(
|
|
const CXXStdInitializerListExpr *E) {
|
|
const ConstantArrayType *ArrayType =
|
|
Info.Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
|
|
|
|
LValue Array;
|
|
if (!EvaluateLValue(E->getSubExpr(), Array, Info))
|
|
return false;
|
|
|
|
// Get a pointer to the first element of the array.
|
|
Array.addArray(Info, E, ArrayType);
|
|
|
|
// FIXME: Perform the checks on the field types in SemaInit.
|
|
RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
|
|
RecordDecl::field_iterator Field = Record->field_begin();
|
|
if (Field == Record->field_end())
|
|
return Error(E);
|
|
|
|
// Start pointer.
|
|
if (!Field->getType()->isPointerType() ||
|
|
!Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
|
|
ArrayType->getElementType()))
|
|
return Error(E);
|
|
|
|
// FIXME: What if the initializer_list type has base classes, etc?
|
|
Result = APValue(APValue::UninitStruct(), 0, 2);
|
|
Array.moveInto(Result.getStructField(0));
|
|
|
|
if (++Field == Record->field_end())
|
|
return Error(E);
|
|
|
|
if (Field->getType()->isPointerType() &&
|
|
Info.Ctx.hasSameType(Field->getType()->getPointeeType(),
|
|
ArrayType->getElementType())) {
|
|
// End pointer.
|
|
if (!HandleLValueArrayAdjustment(Info, E, Array,
|
|
ArrayType->getElementType(),
|
|
ArrayType->getSize().getZExtValue()))
|
|
return false;
|
|
Array.moveInto(Result.getStructField(1));
|
|
} else if (Info.Ctx.hasSameType(Field->getType(), Info.Ctx.getSizeType()))
|
|
// Length.
|
|
Result.getStructField(1) = APValue(APSInt(ArrayType->getSize()));
|
|
else
|
|
return Error(E);
|
|
|
|
if (++Field != Record->field_end())
|
|
return Error(E);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool RecordExprEvaluator::VisitLambdaExpr(const LambdaExpr *E) {
|
|
const CXXRecordDecl *ClosureClass = E->getLambdaClass();
|
|
if (ClosureClass->isInvalidDecl()) return false;
|
|
|
|
if (Info.checkingPotentialConstantExpression()) return true;
|
|
|
|
const size_t NumFields =
|
|
std::distance(ClosureClass->field_begin(), ClosureClass->field_end());
|
|
|
|
assert(NumFields == (size_t)std::distance(E->capture_init_begin(),
|
|
E->capture_init_end()) &&
|
|
"The number of lambda capture initializers should equal the number of "
|
|
"fields within the closure type");
|
|
|
|
Result = APValue(APValue::UninitStruct(), /*NumBases*/0, NumFields);
|
|
// Iterate through all the lambda's closure object's fields and initialize
|
|
// them.
|
|
auto *CaptureInitIt = E->capture_init_begin();
|
|
const LambdaCapture *CaptureIt = ClosureClass->captures_begin();
|
|
bool Success = true;
|
|
for (const auto *Field : ClosureClass->fields()) {
|
|
assert(CaptureInitIt != E->capture_init_end());
|
|
// Get the initializer for this field
|
|
Expr *const CurFieldInit = *CaptureInitIt++;
|
|
|
|
// If there is no initializer, either this is a VLA or an error has
|
|
// occurred.
|
|
if (!CurFieldInit)
|
|
return Error(E);
|
|
|
|
APValue &FieldVal = Result.getStructField(Field->getFieldIndex());
|
|
if (!EvaluateInPlace(FieldVal, Info, This, CurFieldInit)) {
|
|
if (!Info.keepEvaluatingAfterFailure())
|
|
return false;
|
|
Success = false;
|
|
}
|
|
++CaptureIt;
|
|
}
|
|
return Success;
|
|
}
|
|
|
|
static bool EvaluateRecord(const Expr *E, const LValue &This,
|
|
APValue &Result, EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isRecordType() &&
|
|
"can't evaluate expression as a record rvalue");
|
|
return RecordExprEvaluator(Info, This, Result).Visit(E);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Temporary Evaluation
|
|
//
|
|
// Temporaries are represented in the AST as rvalues, but generally behave like
|
|
// lvalues. The full-object of which the temporary is a subobject is implicitly
|
|
// materialized so that a reference can bind to it.
|
|
//===----------------------------------------------------------------------===//
|
|
namespace {
|
|
class TemporaryExprEvaluator
|
|
: public LValueExprEvaluatorBase<TemporaryExprEvaluator> {
|
|
public:
|
|
TemporaryExprEvaluator(EvalInfo &Info, LValue &Result) :
|
|
LValueExprEvaluatorBaseTy(Info, Result, false) {}
|
|
|
|
/// Visit an expression which constructs the value of this temporary.
|
|
bool VisitConstructExpr(const Expr *E) {
|
|
APValue &Value = createTemporary(E, false, Result, *Info.CurrentCall);
|
|
return EvaluateInPlace(Value, Info, Result, E);
|
|
}
|
|
|
|
bool VisitCastExpr(const CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
return LValueExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
|
|
case CK_ConstructorConversion:
|
|
return VisitConstructExpr(E->getSubExpr());
|
|
}
|
|
}
|
|
bool VisitInitListExpr(const InitListExpr *E) {
|
|
return VisitConstructExpr(E);
|
|
}
|
|
bool VisitCXXConstructExpr(const CXXConstructExpr *E) {
|
|
return VisitConstructExpr(E);
|
|
}
|
|
bool VisitCallExpr(const CallExpr *E) {
|
|
return VisitConstructExpr(E);
|
|
}
|
|
bool VisitCXXStdInitializerListExpr(const CXXStdInitializerListExpr *E) {
|
|
return VisitConstructExpr(E);
|
|
}
|
|
bool VisitLambdaExpr(const LambdaExpr *E) {
|
|
return VisitConstructExpr(E);
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
/// Evaluate an expression of record type as a temporary.
|
|
static bool EvaluateTemporary(const Expr *E, LValue &Result, EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isRecordType());
|
|
return TemporaryExprEvaluator(Info, Result).Visit(E);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Vector Evaluation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class VectorExprEvaluator
|
|
: public ExprEvaluatorBase<VectorExprEvaluator> {
|
|
APValue &Result;
|
|
public:
|
|
|
|
VectorExprEvaluator(EvalInfo &info, APValue &Result)
|
|
: ExprEvaluatorBaseTy(info), Result(Result) {}
|
|
|
|
bool Success(ArrayRef<APValue> V, const Expr *E) {
|
|
assert(V.size() == E->getType()->castAs<VectorType>()->getNumElements());
|
|
// FIXME: remove this APValue copy.
|
|
Result = APValue(V.data(), V.size());
|
|
return true;
|
|
}
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
assert(V.isVector());
|
|
Result = V;
|
|
return true;
|
|
}
|
|
bool ZeroInitialization(const Expr *E);
|
|
|
|
bool VisitUnaryReal(const UnaryOperator *E)
|
|
{ return Visit(E->getSubExpr()); }
|
|
bool VisitCastExpr(const CastExpr* E);
|
|
bool VisitInitListExpr(const InitListExpr *E);
|
|
bool VisitUnaryImag(const UnaryOperator *E);
|
|
// FIXME: Missing: unary -, unary ~, binary add/sub/mul/div,
|
|
// binary comparisons, binary and/or/xor,
|
|
// shufflevector, ExtVectorElementExpr
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isVectorType() &&"not a vector rvalue");
|
|
return VectorExprEvaluator(Info, Result).Visit(E);
|
|
}
|
|
|
|
bool VectorExprEvaluator::VisitCastExpr(const CastExpr *E) {
|
|
const VectorType *VTy = E->getType()->castAs<VectorType>();
|
|
unsigned NElts = VTy->getNumElements();
|
|
|
|
const Expr *SE = E->getSubExpr();
|
|
QualType SETy = SE->getType();
|
|
|
|
switch (E->getCastKind()) {
|
|
case CK_VectorSplat: {
|
|
APValue Val = APValue();
|
|
if (SETy->isIntegerType()) {
|
|
APSInt IntResult;
|
|
if (!EvaluateInteger(SE, IntResult, Info))
|
|
return false;
|
|
Val = APValue(std::move(IntResult));
|
|
} else if (SETy->isRealFloatingType()) {
|
|
APFloat FloatResult(0.0);
|
|
if (!EvaluateFloat(SE, FloatResult, Info))
|
|
return false;
|
|
Val = APValue(std::move(FloatResult));
|
|
} else {
|
|
return Error(E);
|
|
}
|
|
|
|
// Splat and create vector APValue.
|
|
SmallVector<APValue, 4> Elts(NElts, Val);
|
|
return Success(Elts, E);
|
|
}
|
|
case CK_BitCast: {
|
|
// Evaluate the operand into an APInt we can extract from.
|
|
llvm::APInt SValInt;
|
|
if (!EvalAndBitcastToAPInt(Info, SE, SValInt))
|
|
return false;
|
|
// Extract the elements
|
|
QualType EltTy = VTy->getElementType();
|
|
unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
|
|
bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
|
|
SmallVector<APValue, 4> Elts;
|
|
if (EltTy->isRealFloatingType()) {
|
|
const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(EltTy);
|
|
unsigned FloatEltSize = EltSize;
|
|
if (&Sem == &APFloat::x87DoubleExtended())
|
|
FloatEltSize = 80;
|
|
for (unsigned i = 0; i < NElts; i++) {
|
|
llvm::APInt Elt;
|
|
if (BigEndian)
|
|
Elt = SValInt.rotl(i*EltSize+FloatEltSize).trunc(FloatEltSize);
|
|
else
|
|
Elt = SValInt.rotr(i*EltSize).trunc(FloatEltSize);
|
|
Elts.push_back(APValue(APFloat(Sem, Elt)));
|
|
}
|
|
} else if (EltTy->isIntegerType()) {
|
|
for (unsigned i = 0; i < NElts; i++) {
|
|
llvm::APInt Elt;
|
|
if (BigEndian)
|
|
Elt = SValInt.rotl(i*EltSize+EltSize).zextOrTrunc(EltSize);
|
|
else
|
|
Elt = SValInt.rotr(i*EltSize).zextOrTrunc(EltSize);
|
|
Elts.push_back(APValue(APSInt(Elt, EltTy->isSignedIntegerType())));
|
|
}
|
|
} else {
|
|
return Error(E);
|
|
}
|
|
return Success(Elts, E);
|
|
}
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
}
|
|
}
|
|
|
|
bool
|
|
VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
|
|
const VectorType *VT = E->getType()->castAs<VectorType>();
|
|
unsigned NumInits = E->getNumInits();
|
|
unsigned NumElements = VT->getNumElements();
|
|
|
|
QualType EltTy = VT->getElementType();
|
|
SmallVector<APValue, 4> Elements;
|
|
|
|
// The number of initializers can be less than the number of
|
|
// vector elements. For OpenCL, this can be due to nested vector
|
|
// initialization. For GCC compatibility, missing trailing elements
|
|
// should be initialized with zeroes.
|
|
unsigned CountInits = 0, CountElts = 0;
|
|
while (CountElts < NumElements) {
|
|
// Handle nested vector initialization.
|
|
if (CountInits < NumInits
|
|
&& E->getInit(CountInits)->getType()->isVectorType()) {
|
|
APValue v;
|
|
if (!EvaluateVector(E->getInit(CountInits), v, Info))
|
|
return Error(E);
|
|
unsigned vlen = v.getVectorLength();
|
|
for (unsigned j = 0; j < vlen; j++)
|
|
Elements.push_back(v.getVectorElt(j));
|
|
CountElts += vlen;
|
|
} else if (EltTy->isIntegerType()) {
|
|
llvm::APSInt sInt(32);
|
|
if (CountInits < NumInits) {
|
|
if (!EvaluateInteger(E->getInit(CountInits), sInt, Info))
|
|
return false;
|
|
} else // trailing integer zero.
|
|
sInt = Info.Ctx.MakeIntValue(0, EltTy);
|
|
Elements.push_back(APValue(sInt));
|
|
CountElts++;
|
|
} else {
|
|
llvm::APFloat f(0.0);
|
|
if (CountInits < NumInits) {
|
|
if (!EvaluateFloat(E->getInit(CountInits), f, Info))
|
|
return false;
|
|
} else // trailing float zero.
|
|
f = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy));
|
|
Elements.push_back(APValue(f));
|
|
CountElts++;
|
|
}
|
|
CountInits++;
|
|
}
|
|
return Success(Elements, E);
|
|
}
|
|
|
|
bool
|
|
VectorExprEvaluator::ZeroInitialization(const Expr *E) {
|
|
const VectorType *VT = E->getType()->getAs<VectorType>();
|
|
QualType EltTy = VT->getElementType();
|
|
APValue ZeroElement;
|
|
if (EltTy->isIntegerType())
|
|
ZeroElement = APValue(Info.Ctx.MakeIntValue(0, EltTy));
|
|
else
|
|
ZeroElement =
|
|
APValue(APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy)));
|
|
|
|
SmallVector<APValue, 4> Elements(VT->getNumElements(), ZeroElement);
|
|
return Success(Elements, E);
|
|
}
|
|
|
|
bool VectorExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
|
|
VisitIgnoredValue(E->getSubExpr());
|
|
return ZeroInitialization(E);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Array Evaluation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class ArrayExprEvaluator
|
|
: public ExprEvaluatorBase<ArrayExprEvaluator> {
|
|
const LValue &This;
|
|
APValue &Result;
|
|
public:
|
|
|
|
ArrayExprEvaluator(EvalInfo &Info, const LValue &This, APValue &Result)
|
|
: ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
|
|
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
assert((V.isArray() || V.isLValue()) &&
|
|
"expected array or string literal");
|
|
Result = V;
|
|
return true;
|
|
}
|
|
|
|
bool ZeroInitialization(const Expr *E) {
|
|
const ConstantArrayType *CAT =
|
|
Info.Ctx.getAsConstantArrayType(E->getType());
|
|
if (!CAT)
|
|
return Error(E);
|
|
|
|
Result = APValue(APValue::UninitArray(), 0,
|
|
CAT->getSize().getZExtValue());
|
|
if (!Result.hasArrayFiller()) return true;
|
|
|
|
// Zero-initialize all elements.
|
|
LValue Subobject = This;
|
|
Subobject.addArray(Info, E, CAT);
|
|
ImplicitValueInitExpr VIE(CAT->getElementType());
|
|
return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject, &VIE);
|
|
}
|
|
|
|
bool VisitCallExpr(const CallExpr *E) {
|
|
return handleCallExpr(E, Result, &This);
|
|
}
|
|
bool VisitInitListExpr(const InitListExpr *E);
|
|
bool VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E);
|
|
bool VisitCXXConstructExpr(const CXXConstructExpr *E);
|
|
bool VisitCXXConstructExpr(const CXXConstructExpr *E,
|
|
const LValue &Subobject,
|
|
APValue *Value, QualType Type);
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool EvaluateArray(const Expr *E, const LValue &This,
|
|
APValue &Result, EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isArrayType() && "not an array rvalue");
|
|
return ArrayExprEvaluator(Info, This, Result).Visit(E);
|
|
}
|
|
|
|
// Return true iff the given array filler may depend on the element index.
|
|
static bool MaybeElementDependentArrayFiller(const Expr *FillerExpr) {
|
|
// For now, just whitelist non-class value-initialization and initialization
|
|
// lists comprised of them.
|
|
if (isa<ImplicitValueInitExpr>(FillerExpr))
|
|
return false;
|
|
if (const InitListExpr *ILE = dyn_cast<InitListExpr>(FillerExpr)) {
|
|
for (unsigned I = 0, E = ILE->getNumInits(); I != E; ++I) {
|
|
if (MaybeElementDependentArrayFiller(ILE->getInit(I)))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool ArrayExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
|
|
const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(E->getType());
|
|
if (!CAT)
|
|
return Error(E);
|
|
|
|
// C++11 [dcl.init.string]p1: A char array [...] can be initialized by [...]
|
|
// an appropriately-typed string literal enclosed in braces.
|
|
if (E->isStringLiteralInit()) {
|
|
LValue LV;
|
|
if (!EvaluateLValue(E->getInit(0), LV, Info))
|
|
return false;
|
|
APValue Val;
|
|
LV.moveInto(Val);
|
|
return Success(Val, E);
|
|
}
|
|
|
|
bool Success = true;
|
|
|
|
assert((!Result.isArray() || Result.getArrayInitializedElts() == 0) &&
|
|
"zero-initialized array shouldn't have any initialized elts");
|
|
APValue Filler;
|
|
if (Result.isArray() && Result.hasArrayFiller())
|
|
Filler = Result.getArrayFiller();
|
|
|
|
unsigned NumEltsToInit = E->getNumInits();
|
|
unsigned NumElts = CAT->getSize().getZExtValue();
|
|
const Expr *FillerExpr = E->hasArrayFiller() ? E->getArrayFiller() : nullptr;
|
|
|
|
// If the initializer might depend on the array index, run it for each
|
|
// array element.
|
|
if (NumEltsToInit != NumElts && MaybeElementDependentArrayFiller(FillerExpr))
|
|
NumEltsToInit = NumElts;
|
|
|
|
LLVM_DEBUG(llvm::dbgs() << "The number of elements to initialize: "
|
|
<< NumEltsToInit << ".\n");
|
|
|
|
Result = APValue(APValue::UninitArray(), NumEltsToInit, NumElts);
|
|
|
|
// If the array was previously zero-initialized, preserve the
|
|
// zero-initialized values.
|
|
if (!Filler.isUninit()) {
|
|
for (unsigned I = 0, E = Result.getArrayInitializedElts(); I != E; ++I)
|
|
Result.getArrayInitializedElt(I) = Filler;
|
|
if (Result.hasArrayFiller())
|
|
Result.getArrayFiller() = Filler;
|
|
}
|
|
|
|
LValue Subobject = This;
|
|
Subobject.addArray(Info, E, CAT);
|
|
for (unsigned Index = 0; Index != NumEltsToInit; ++Index) {
|
|
const Expr *Init =
|
|
Index < E->getNumInits() ? E->getInit(Index) : FillerExpr;
|
|
if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
|
|
Info, Subobject, Init) ||
|
|
!HandleLValueArrayAdjustment(Info, Init, Subobject,
|
|
CAT->getElementType(), 1)) {
|
|
if (!Info.noteFailure())
|
|
return false;
|
|
Success = false;
|
|
}
|
|
}
|
|
|
|
if (!Result.hasArrayFiller())
|
|
return Success;
|
|
|
|
// If we get here, we have a trivial filler, which we can just evaluate
|
|
// once and splat over the rest of the array elements.
|
|
assert(FillerExpr && "no array filler for incomplete init list");
|
|
return EvaluateInPlace(Result.getArrayFiller(), Info, Subobject,
|
|
FillerExpr) && Success;
|
|
}
|
|
|
|
bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
|
|
if (E->getCommonExpr() &&
|
|
!Evaluate(Info.CurrentCall->createTemporary(E->getCommonExpr(), false),
|
|
Info, E->getCommonExpr()->getSourceExpr()))
|
|
return false;
|
|
|
|
auto *CAT = cast<ConstantArrayType>(E->getType()->castAsArrayTypeUnsafe());
|
|
|
|
uint64_t Elements = CAT->getSize().getZExtValue();
|
|
Result = APValue(APValue::UninitArray(), Elements, Elements);
|
|
|
|
LValue Subobject = This;
|
|
Subobject.addArray(Info, E, CAT);
|
|
|
|
bool Success = true;
|
|
for (EvalInfo::ArrayInitLoopIndex Index(Info); Index != Elements; ++Index) {
|
|
if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
|
|
Info, Subobject, E->getSubExpr()) ||
|
|
!HandleLValueArrayAdjustment(Info, E, Subobject,
|
|
CAT->getElementType(), 1)) {
|
|
if (!Info.noteFailure())
|
|
return false;
|
|
Success = false;
|
|
}
|
|
}
|
|
|
|
return Success;
|
|
}
|
|
|
|
bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
|
|
return VisitCXXConstructExpr(E, This, &Result, E->getType());
|
|
}
|
|
|
|
bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E,
|
|
const LValue &Subobject,
|
|
APValue *Value,
|
|
QualType Type) {
|
|
bool HadZeroInit = !Value->isUninit();
|
|
|
|
if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(Type)) {
|
|
unsigned N = CAT->getSize().getZExtValue();
|
|
|
|
// Preserve the array filler if we had prior zero-initialization.
|
|
APValue Filler =
|
|
HadZeroInit && Value->hasArrayFiller() ? Value->getArrayFiller()
|
|
: APValue();
|
|
|
|
*Value = APValue(APValue::UninitArray(), N, N);
|
|
|
|
if (HadZeroInit)
|
|
for (unsigned I = 0; I != N; ++I)
|
|
Value->getArrayInitializedElt(I) = Filler;
|
|
|
|
// Initialize the elements.
|
|
LValue ArrayElt = Subobject;
|
|
ArrayElt.addArray(Info, E, CAT);
|
|
for (unsigned I = 0; I != N; ++I)
|
|
if (!VisitCXXConstructExpr(E, ArrayElt, &Value->getArrayInitializedElt(I),
|
|
CAT->getElementType()) ||
|
|
!HandleLValueArrayAdjustment(Info, E, ArrayElt,
|
|
CAT->getElementType(), 1))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
if (!Type->isRecordType())
|
|
return Error(E);
|
|
|
|
return RecordExprEvaluator(Info, Subobject, *Value)
|
|
.VisitCXXConstructExpr(E, Type);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Integer Evaluation
|
|
//
|
|
// As a GNU extension, we support casting pointers to sufficiently-wide integer
|
|
// types and back in constant folding. Integer values are thus represented
|
|
// either as an integer-valued APValue, or as an lvalue-valued APValue.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class IntExprEvaluator
|
|
: public ExprEvaluatorBase<IntExprEvaluator> {
|
|
APValue &Result;
|
|
public:
|
|
IntExprEvaluator(EvalInfo &info, APValue &result)
|
|
: ExprEvaluatorBaseTy(info), Result(result) {}
|
|
|
|
bool Success(const llvm::APSInt &SI, const Expr *E, APValue &Result) {
|
|
assert(E->getType()->isIntegralOrEnumerationType() &&
|
|
"Invalid evaluation result.");
|
|
assert(SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() &&
|
|
"Invalid evaluation result.");
|
|
assert(SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
|
|
"Invalid evaluation result.");
|
|
Result = APValue(SI);
|
|
return true;
|
|
}
|
|
bool Success(const llvm::APSInt &SI, const Expr *E) {
|
|
return Success(SI, E, Result);
|
|
}
|
|
|
|
bool Success(const llvm::APInt &I, const Expr *E, APValue &Result) {
|
|
assert(E->getType()->isIntegralOrEnumerationType() &&
|
|
"Invalid evaluation result.");
|
|
assert(I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
|
|
"Invalid evaluation result.");
|
|
Result = APValue(APSInt(I));
|
|
Result.getInt().setIsUnsigned(
|
|
E->getType()->isUnsignedIntegerOrEnumerationType());
|
|
return true;
|
|
}
|
|
bool Success(const llvm::APInt &I, const Expr *E) {
|
|
return Success(I, E, Result);
|
|
}
|
|
|
|
bool Success(uint64_t Value, const Expr *E, APValue &Result) {
|
|
assert(E->getType()->isIntegralOrEnumerationType() &&
|
|
"Invalid evaluation result.");
|
|
Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType()));
|
|
return true;
|
|
}
|
|
bool Success(uint64_t Value, const Expr *E) {
|
|
return Success(Value, E, Result);
|
|
}
|
|
|
|
bool Success(CharUnits Size, const Expr *E) {
|
|
return Success(Size.getQuantity(), E);
|
|
}
|
|
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
if (V.isLValue() || V.isAddrLabelDiff()) {
|
|
Result = V;
|
|
return true;
|
|
}
|
|
return Success(V.getInt(), E);
|
|
}
|
|
|
|
bool ZeroInitialization(const Expr *E) { return Success(0, E); }
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// Visitor Methods
|
|
//===--------------------------------------------------------------------===//
|
|
|
|
bool VisitConstantExpr(const ConstantExpr *E);
|
|
|
|
bool VisitIntegerLiteral(const IntegerLiteral *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
bool VisitCharacterLiteral(const CharacterLiteral *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
|
|
bool CheckReferencedDecl(const Expr *E, const Decl *D);
|
|
bool VisitDeclRefExpr(const DeclRefExpr *E) {
|
|
if (CheckReferencedDecl(E, E->getDecl()))
|
|
return true;
|
|
|
|
return ExprEvaluatorBaseTy::VisitDeclRefExpr(E);
|
|
}
|
|
bool VisitMemberExpr(const MemberExpr *E) {
|
|
if (CheckReferencedDecl(E, E->getMemberDecl())) {
|
|
VisitIgnoredBaseExpression(E->getBase());
|
|
return true;
|
|
}
|
|
|
|
return ExprEvaluatorBaseTy::VisitMemberExpr(E);
|
|
}
|
|
|
|
bool VisitCallExpr(const CallExpr *E);
|
|
bool VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp);
|
|
bool VisitBinaryOperator(const BinaryOperator *E);
|
|
bool VisitOffsetOfExpr(const OffsetOfExpr *E);
|
|
bool VisitUnaryOperator(const UnaryOperator *E);
|
|
|
|
bool VisitCastExpr(const CastExpr* E);
|
|
bool VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
|
|
|
|
bool VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
|
|
bool VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
|
|
bool VisitArrayInitIndexExpr(const ArrayInitIndexExpr *E) {
|
|
if (Info.ArrayInitIndex == uint64_t(-1)) {
|
|
// We were asked to evaluate this subexpression independent of the
|
|
// enclosing ArrayInitLoopExpr. We can't do that.
|
|
Info.FFDiag(E);
|
|
return false;
|
|
}
|
|
return Success(Info.ArrayInitIndex, E);
|
|
}
|
|
|
|
// Note, GNU defines __null as an integer, not a pointer.
|
|
bool VisitGNUNullExpr(const GNUNullExpr *E) {
|
|
return ZeroInitialization(E);
|
|
}
|
|
|
|
bool VisitTypeTraitExpr(const TypeTraitExpr *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
|
|
bool VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
|
|
bool VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
|
|
bool VisitUnaryReal(const UnaryOperator *E);
|
|
bool VisitUnaryImag(const UnaryOperator *E);
|
|
|
|
bool VisitCXXNoexceptExpr(const CXXNoexceptExpr *E);
|
|
bool VisitSizeOfPackExpr(const SizeOfPackExpr *E);
|
|
|
|
// FIXME: Missing: array subscript of vector, member of vector
|
|
};
|
|
|
|
class FixedPointExprEvaluator
|
|
: public ExprEvaluatorBase<FixedPointExprEvaluator> {
|
|
APValue &Result;
|
|
|
|
public:
|
|
FixedPointExprEvaluator(EvalInfo &info, APValue &result)
|
|
: ExprEvaluatorBaseTy(info), Result(result) {}
|
|
|
|
bool Success(const llvm::APSInt &SI, const Expr *E, APValue &Result) {
|
|
assert(E->getType()->isFixedPointType() && "Invalid evaluation result.");
|
|
assert(SI.isSigned() == E->getType()->isSignedFixedPointType() &&
|
|
"Invalid evaluation result.");
|
|
assert(SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
|
|
"Invalid evaluation result.");
|
|
Result = APValue(SI);
|
|
return true;
|
|
}
|
|
bool Success(const llvm::APSInt &SI, const Expr *E) {
|
|
return Success(SI, E, Result);
|
|
}
|
|
|
|
bool Success(const llvm::APInt &I, const Expr *E, APValue &Result) {
|
|
assert(E->getType()->isFixedPointType() && "Invalid evaluation result.");
|
|
assert(I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
|
|
"Invalid evaluation result.");
|
|
Result = APValue(APSInt(I));
|
|
Result.getInt().setIsUnsigned(E->getType()->isUnsignedFixedPointType());
|
|
return true;
|
|
}
|
|
bool Success(const llvm::APInt &I, const Expr *E) {
|
|
return Success(I, E, Result);
|
|
}
|
|
|
|
bool Success(uint64_t Value, const Expr *E, APValue &Result) {
|
|
assert(E->getType()->isFixedPointType() && "Invalid evaluation result.");
|
|
Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType()));
|
|
return true;
|
|
}
|
|
bool Success(uint64_t Value, const Expr *E) {
|
|
return Success(Value, E, Result);
|
|
}
|
|
|
|
bool Success(CharUnits Size, const Expr *E) {
|
|
return Success(Size.getQuantity(), E);
|
|
}
|
|
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
if (V.isLValue() || V.isAddrLabelDiff()) {
|
|
Result = V;
|
|
return true;
|
|
}
|
|
return Success(V.getInt(), E);
|
|
}
|
|
|
|
bool ZeroInitialization(const Expr *E) { return Success(0, E); }
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// Visitor Methods
|
|
//===--------------------------------------------------------------------===//
|
|
|
|
bool VisitFixedPointLiteral(const FixedPointLiteral *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
|
|
bool VisitUnaryOperator(const UnaryOperator *E);
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
/// EvaluateIntegerOrLValue - Evaluate an rvalue integral-typed expression, and
|
|
/// produce either the integer value or a pointer.
|
|
///
|
|
/// GCC has a heinous extension which folds casts between pointer types and
|
|
/// pointer-sized integral types. We support this by allowing the evaluation of
|
|
/// an integer rvalue to produce a pointer (represented as an lvalue) instead.
|
|
/// Some simple arithmetic on such values is supported (they are treated much
|
|
/// like char*).
|
|
static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
|
|
EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isIntegralOrEnumerationType());
|
|
return IntExprEvaluator(Info, Result).Visit(E);
|
|
}
|
|
|
|
static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info) {
|
|
APValue Val;
|
|
if (!EvaluateIntegerOrLValue(E, Val, Info))
|
|
return false;
|
|
if (!Val.isInt()) {
|
|
// FIXME: It would be better to produce the diagnostic for casting
|
|
// a pointer to an integer.
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
Result = Val.getInt();
|
|
return true;
|
|
}
|
|
|
|
/// Check whether the given declaration can be directly converted to an integral
|
|
/// rvalue. If not, no diagnostic is produced; there are other things we can
|
|
/// try.
|
|
bool IntExprEvaluator::CheckReferencedDecl(const Expr* E, const Decl* D) {
|
|
// Enums are integer constant exprs.
|
|
if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) {
|
|
// Check for signedness/width mismatches between E type and ECD value.
|
|
bool SameSign = (ECD->getInitVal().isSigned()
|
|
== E->getType()->isSignedIntegerOrEnumerationType());
|
|
bool SameWidth = (ECD->getInitVal().getBitWidth()
|
|
== Info.Ctx.getIntWidth(E->getType()));
|
|
if (SameSign && SameWidth)
|
|
return Success(ECD->getInitVal(), E);
|
|
else {
|
|
// Get rid of mismatch (otherwise Success assertions will fail)
|
|
// by computing a new value matching the type of E.
|
|
llvm::APSInt Val = ECD->getInitVal();
|
|
if (!SameSign)
|
|
Val.setIsSigned(!ECD->getInitVal().isSigned());
|
|
if (!SameWidth)
|
|
Val = Val.extOrTrunc(Info.Ctx.getIntWidth(E->getType()));
|
|
return Success(Val, E);
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/// Values returned by __builtin_classify_type, chosen to match the values
|
|
/// produced by GCC's builtin.
|
|
enum class GCCTypeClass {
|
|
None = -1,
|
|
Void = 0,
|
|
Integer = 1,
|
|
// GCC reserves 2 for character types, but instead classifies them as
|
|
// integers.
|
|
Enum = 3,
|
|
Bool = 4,
|
|
Pointer = 5,
|
|
// GCC reserves 6 for references, but appears to never use it (because
|
|
// expressions never have reference type, presumably).
|
|
PointerToDataMember = 7,
|
|
RealFloat = 8,
|
|
Complex = 9,
|
|
// GCC reserves 10 for functions, but does not use it since GCC version 6 due
|
|
// to decay to pointer. (Prior to version 6 it was only used in C++ mode).
|
|
// GCC claims to reserve 11 for pointers to member functions, but *actually*
|
|
// uses 12 for that purpose, same as for a class or struct. Maybe it
|
|
// internally implements a pointer to member as a struct? Who knows.
|
|
PointerToMemberFunction = 12, // Not a bug, see above.
|
|
ClassOrStruct = 12,
|
|
Union = 13,
|
|
// GCC reserves 14 for arrays, but does not use it since GCC version 6 due to
|
|
// decay to pointer. (Prior to version 6 it was only used in C++ mode).
|
|
// GCC reserves 15 for strings, but actually uses 5 (pointer) for string
|
|
// literals.
|
|
};
|
|
|
|
/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
|
|
/// as GCC.
|
|
static GCCTypeClass
|
|
EvaluateBuiltinClassifyType(QualType T, const LangOptions &LangOpts) {
|
|
assert(!T->isDependentType() && "unexpected dependent type");
|
|
|
|
QualType CanTy = T.getCanonicalType();
|
|
const BuiltinType *BT = dyn_cast<BuiltinType>(CanTy);
|
|
|
|
switch (CanTy->getTypeClass()) {
|
|
#define TYPE(ID, BASE)
|
|
#define DEPENDENT_TYPE(ID, BASE) case Type::ID:
|
|
#define NON_CANONICAL_TYPE(ID, BASE) case Type::ID:
|
|
#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(ID, BASE) case Type::ID:
|
|
#include "clang/AST/TypeNodes.def"
|
|
case Type::Auto:
|
|
case Type::DeducedTemplateSpecialization:
|
|
llvm_unreachable("unexpected non-canonical or dependent type");
|
|
|
|
case Type::Builtin:
|
|
switch (BT->getKind()) {
|
|
#define BUILTIN_TYPE(ID, SINGLETON_ID)
|
|
#define SIGNED_TYPE(ID, SINGLETON_ID) \
|
|
case BuiltinType::ID: return GCCTypeClass::Integer;
|
|
#define FLOATING_TYPE(ID, SINGLETON_ID) \
|
|
case BuiltinType::ID: return GCCTypeClass::RealFloat;
|
|
#define PLACEHOLDER_TYPE(ID, SINGLETON_ID) \
|
|
case BuiltinType::ID: break;
|
|
#include "clang/AST/BuiltinTypes.def"
|
|
case BuiltinType::Void:
|
|
return GCCTypeClass::Void;
|
|
|
|
case BuiltinType::Bool:
|
|
return GCCTypeClass::Bool;
|
|
|
|
case BuiltinType::Char_U:
|
|
case BuiltinType::UChar:
|
|
case BuiltinType::WChar_U:
|
|
case BuiltinType::Char8:
|
|
case BuiltinType::Char16:
|
|
case BuiltinType::Char32:
|
|
case BuiltinType::UShort:
|
|
case BuiltinType::UInt:
|
|
case BuiltinType::ULong:
|
|
case BuiltinType::ULongLong:
|
|
case BuiltinType::UInt128:
|
|
return GCCTypeClass::Integer;
|
|
|
|
case BuiltinType::UShortAccum:
|
|
case BuiltinType::UAccum:
|
|
case BuiltinType::ULongAccum:
|
|
case BuiltinType::UShortFract:
|
|
case BuiltinType::UFract:
|
|
case BuiltinType::ULongFract:
|
|
case BuiltinType::SatUShortAccum:
|
|
case BuiltinType::SatUAccum:
|
|
case BuiltinType::SatULongAccum:
|
|
case BuiltinType::SatUShortFract:
|
|
case BuiltinType::SatUFract:
|
|
case BuiltinType::SatULongFract:
|
|
return GCCTypeClass::None;
|
|
|
|
case BuiltinType::NullPtr:
|
|
|
|
case BuiltinType::ObjCId:
|
|
case BuiltinType::ObjCClass:
|
|
case BuiltinType::ObjCSel:
|
|
#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
|
|
case BuiltinType::Id:
|
|
#include "clang/Basic/OpenCLImageTypes.def"
|
|
#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
|
|
case BuiltinType::Id:
|
|
#include "clang/Basic/OpenCLExtensionTypes.def"
|
|
case BuiltinType::OCLSampler:
|
|
case BuiltinType::OCLEvent:
|
|
case BuiltinType::OCLClkEvent:
|
|
case BuiltinType::OCLQueue:
|
|
case BuiltinType::OCLReserveID:
|
|
return GCCTypeClass::None;
|
|
|
|
case BuiltinType::Dependent:
|
|
llvm_unreachable("unexpected dependent type");
|
|
};
|
|
llvm_unreachable("unexpected placeholder type");
|
|
|
|
case Type::Enum:
|
|
return LangOpts.CPlusPlus ? GCCTypeClass::Enum : GCCTypeClass::Integer;
|
|
|
|
case Type::Pointer:
|
|
case Type::ConstantArray:
|
|
case Type::VariableArray:
|
|
case Type::IncompleteArray:
|
|
case Type::FunctionNoProto:
|
|
case Type::FunctionProto:
|
|
return GCCTypeClass::Pointer;
|
|
|
|
case Type::MemberPointer:
|
|
return CanTy->isMemberDataPointerType()
|
|
? GCCTypeClass::PointerToDataMember
|
|
: GCCTypeClass::PointerToMemberFunction;
|
|
|
|
case Type::Complex:
|
|
return GCCTypeClass::Complex;
|
|
|
|
case Type::Record:
|
|
return CanTy->isUnionType() ? GCCTypeClass::Union
|
|
: GCCTypeClass::ClassOrStruct;
|
|
|
|
case Type::Atomic:
|
|
// GCC classifies _Atomic T the same as T.
|
|
return EvaluateBuiltinClassifyType(
|
|
CanTy->castAs<AtomicType>()->getValueType(), LangOpts);
|
|
|
|
case Type::BlockPointer:
|
|
case Type::Vector:
|
|
case Type::ExtVector:
|
|
case Type::ObjCObject:
|
|
case Type::ObjCInterface:
|
|
case Type::ObjCObjectPointer:
|
|
case Type::Pipe:
|
|
// GCC classifies vectors as None. We follow its lead and classify all
|
|
// other types that don't fit into the regular classification the same way.
|
|
return GCCTypeClass::None;
|
|
|
|
case Type::LValueReference:
|
|
case Type::RValueReference:
|
|
llvm_unreachable("invalid type for expression");
|
|
}
|
|
|
|
llvm_unreachable("unexpected type class");
|
|
}
|
|
|
|
/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
|
|
/// as GCC.
|
|
static GCCTypeClass
|
|
EvaluateBuiltinClassifyType(const CallExpr *E, const LangOptions &LangOpts) {
|
|
// If no argument was supplied, default to None. This isn't
|
|
// ideal, however it is what gcc does.
|
|
if (E->getNumArgs() == 0)
|
|
return GCCTypeClass::None;
|
|
|
|
// FIXME: Bizarrely, GCC treats a call with more than one argument as not
|
|
// being an ICE, but still folds it to a constant using the type of the first
|
|
// argument.
|
|
return EvaluateBuiltinClassifyType(E->getArg(0)->getType(), LangOpts);
|
|
}
|
|
|
|
/// EvaluateBuiltinConstantPForLValue - Determine the result of
|
|
/// __builtin_constant_p when applied to the given lvalue.
|
|
///
|
|
/// An lvalue is only "constant" if it is a pointer or reference to the first
|
|
/// character of a string literal.
|
|
template<typename LValue>
|
|
static bool EvaluateBuiltinConstantPForLValue(const LValue &LV) {
|
|
const Expr *E = LV.getLValueBase().template dyn_cast<const Expr*>();
|
|
return E && isa<StringLiteral>(E) && LV.getLValueOffset().isZero();
|
|
}
|
|
|
|
/// EvaluateBuiltinConstantP - Evaluate __builtin_constant_p as similarly to
|
|
/// GCC as we can manage.
|
|
static bool EvaluateBuiltinConstantP(ASTContext &Ctx, const Expr *Arg) {
|
|
QualType ArgType = Arg->getType();
|
|
|
|
// __builtin_constant_p always has one operand. The rules which gcc follows
|
|
// are not precisely documented, but are as follows:
|
|
//
|
|
// - If the operand is of integral, floating, complex or enumeration type,
|
|
// and can be folded to a known value of that type, it returns 1.
|
|
// - If the operand and can be folded to a pointer to the first character
|
|
// of a string literal (or such a pointer cast to an integral type), it
|
|
// returns 1.
|
|
//
|
|
// Otherwise, it returns 0.
|
|
//
|
|
// FIXME: GCC also intends to return 1 for literals of aggregate types, but
|
|
// its support for this does not currently work.
|
|
if (ArgType->isIntegralOrEnumerationType()) {
|
|
Expr::EvalResult Result;
|
|
if (!Arg->EvaluateAsRValue(Result, Ctx) || Result.HasSideEffects)
|
|
return false;
|
|
|
|
APValue &V = Result.Val;
|
|
if (V.getKind() == APValue::Int)
|
|
return true;
|
|
if (V.getKind() == APValue::LValue)
|
|
return EvaluateBuiltinConstantPForLValue(V);
|
|
} else if (ArgType->isFloatingType() || ArgType->isAnyComplexType()) {
|
|
return Arg->isEvaluatable(Ctx);
|
|
} else if (ArgType->isPointerType() || Arg->isGLValue()) {
|
|
LValue LV;
|
|
Expr::EvalStatus Status;
|
|
EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
|
|
if ((Arg->isGLValue() ? EvaluateLValue(Arg, LV, Info)
|
|
: EvaluatePointer(Arg, LV, Info)) &&
|
|
!Status.HasSideEffects)
|
|
return EvaluateBuiltinConstantPForLValue(LV);
|
|
}
|
|
|
|
// Anything else isn't considered to be sufficiently constant.
|
|
return false;
|
|
}
|
|
|
|
/// Retrieves the "underlying object type" of the given expression,
|
|
/// as used by __builtin_object_size.
|
|
static QualType getObjectType(APValue::LValueBase B) {
|
|
if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
|
|
if (const VarDecl *VD = dyn_cast<VarDecl>(D))
|
|
return VD->getType();
|
|
} else if (const Expr *E = B.get<const Expr*>()) {
|
|
if (isa<CompoundLiteralExpr>(E))
|
|
return E->getType();
|
|
}
|
|
|
|
return QualType();
|
|
}
|
|
|
|
/// A more selective version of E->IgnoreParenCasts for
|
|
/// tryEvaluateBuiltinObjectSize. This ignores some casts/parens that serve only
|
|
/// to change the type of E.
|
|
/// Ex. For E = `(short*)((char*)(&foo))`, returns `&foo`
|
|
///
|
|
/// Always returns an RValue with a pointer representation.
|
|
static const Expr *ignorePointerCastsAndParens(const Expr *E) {
|
|
assert(E->isRValue() && E->getType()->hasPointerRepresentation());
|
|
|
|
auto *NoParens = E->IgnoreParens();
|
|
auto *Cast = dyn_cast<CastExpr>(NoParens);
|
|
if (Cast == nullptr)
|
|
return NoParens;
|
|
|
|
// We only conservatively allow a few kinds of casts, because this code is
|
|
// inherently a simple solution that seeks to support the common case.
|
|
auto CastKind = Cast->getCastKind();
|
|
if (CastKind != CK_NoOp && CastKind != CK_BitCast &&
|
|
CastKind != CK_AddressSpaceConversion)
|
|
return NoParens;
|
|
|
|
auto *SubExpr = Cast->getSubExpr();
|
|
if (!SubExpr->getType()->hasPointerRepresentation() || !SubExpr->isRValue())
|
|
return NoParens;
|
|
return ignorePointerCastsAndParens(SubExpr);
|
|
}
|
|
|
|
/// Checks to see if the given LValue's Designator is at the end of the LValue's
|
|
/// record layout. e.g.
|
|
/// struct { struct { int a, b; } fst, snd; } obj;
|
|
/// obj.fst // no
|
|
/// obj.snd // yes
|
|
/// obj.fst.a // no
|
|
/// obj.fst.b // no
|
|
/// obj.snd.a // no
|
|
/// obj.snd.b // yes
|
|
///
|
|
/// Please note: this function is specialized for how __builtin_object_size
|
|
/// views "objects".
|
|
///
|
|
/// If this encounters an invalid RecordDecl or otherwise cannot determine the
|
|
/// correct result, it will always return true.
|
|
static bool isDesignatorAtObjectEnd(const ASTContext &Ctx, const LValue &LVal) {
|
|
assert(!LVal.Designator.Invalid);
|
|
|
|
auto IsLastOrInvalidFieldDecl = [&Ctx](const FieldDecl *FD, bool &Invalid) {
|
|
const RecordDecl *Parent = FD->getParent();
|
|
Invalid = Parent->isInvalidDecl();
|
|
if (Invalid || Parent->isUnion())
|
|
return true;
|
|
const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(Parent);
|
|
return FD->getFieldIndex() + 1 == Layout.getFieldCount();
|
|
};
|
|
|
|
auto &Base = LVal.getLValueBase();
|
|
if (auto *ME = dyn_cast_or_null<MemberExpr>(Base.dyn_cast<const Expr *>())) {
|
|
if (auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
|
|
bool Invalid;
|
|
if (!IsLastOrInvalidFieldDecl(FD, Invalid))
|
|
return Invalid;
|
|
} else if (auto *IFD = dyn_cast<IndirectFieldDecl>(ME->getMemberDecl())) {
|
|
for (auto *FD : IFD->chain()) {
|
|
bool Invalid;
|
|
if (!IsLastOrInvalidFieldDecl(cast<FieldDecl>(FD), Invalid))
|
|
return Invalid;
|
|
}
|
|
}
|
|
}
|
|
|
|
unsigned I = 0;
|
|
QualType BaseType = getType(Base);
|
|
if (LVal.Designator.FirstEntryIsAnUnsizedArray) {
|
|
// If we don't know the array bound, conservatively assume we're looking at
|
|
// the final array element.
|
|
++I;
|
|
if (BaseType->isIncompleteArrayType())
|
|
BaseType = Ctx.getAsArrayType(BaseType)->getElementType();
|
|
else
|
|
BaseType = BaseType->castAs<PointerType>()->getPointeeType();
|
|
}
|
|
|
|
for (unsigned E = LVal.Designator.Entries.size(); I != E; ++I) {
|
|
const auto &Entry = LVal.Designator.Entries[I];
|
|
if (BaseType->isArrayType()) {
|
|
// Because __builtin_object_size treats arrays as objects, we can ignore
|
|
// the index iff this is the last array in the Designator.
|
|
if (I + 1 == E)
|
|
return true;
|
|
const auto *CAT = cast<ConstantArrayType>(Ctx.getAsArrayType(BaseType));
|
|
uint64_t Index = Entry.ArrayIndex;
|
|
if (Index + 1 != CAT->getSize())
|
|
return false;
|
|
BaseType = CAT->getElementType();
|
|
} else if (BaseType->isAnyComplexType()) {
|
|
const auto *CT = BaseType->castAs<ComplexType>();
|
|
uint64_t Index = Entry.ArrayIndex;
|
|
if (Index != 1)
|
|
return false;
|
|
BaseType = CT->getElementType();
|
|
} else if (auto *FD = getAsField(Entry)) {
|
|
bool Invalid;
|
|
if (!IsLastOrInvalidFieldDecl(FD, Invalid))
|
|
return Invalid;
|
|
BaseType = FD->getType();
|
|
} else {
|
|
assert(getAsBaseClass(Entry) && "Expecting cast to a base class");
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// Tests to see if the LValue has a user-specified designator (that isn't
|
|
/// necessarily valid). Note that this always returns 'true' if the LValue has
|
|
/// an unsized array as its first designator entry, because there's currently no
|
|
/// way to tell if the user typed *foo or foo[0].
|
|
static bool refersToCompleteObject(const LValue &LVal) {
|
|
if (LVal.Designator.Invalid)
|
|
return false;
|
|
|
|
if (!LVal.Designator.Entries.empty())
|
|
return LVal.Designator.isMostDerivedAnUnsizedArray();
|
|
|
|
if (!LVal.InvalidBase)
|
|
return true;
|
|
|
|
// If `E` is a MemberExpr, then the first part of the designator is hiding in
|
|
// the LValueBase.
|
|
const auto *E = LVal.Base.dyn_cast<const Expr *>();
|
|
return !E || !isa<MemberExpr>(E);
|
|
}
|
|
|
|
/// Attempts to detect a user writing into a piece of memory that's impossible
|
|
/// to figure out the size of by just using types.
|
|
static bool isUserWritingOffTheEnd(const ASTContext &Ctx, const LValue &LVal) {
|
|
const SubobjectDesignator &Designator = LVal.Designator;
|
|
// Notes:
|
|
// - Users can only write off of the end when we have an invalid base. Invalid
|
|
// bases imply we don't know where the memory came from.
|
|
// - We used to be a bit more aggressive here; we'd only be conservative if
|
|
// the array at the end was flexible, or if it had 0 or 1 elements. This
|
|
// broke some common standard library extensions (PR30346), but was
|
|
// otherwise seemingly fine. It may be useful to reintroduce this behavior
|
|
// with some sort of whitelist. OTOH, it seems that GCC is always
|
|
// conservative with the last element in structs (if it's an array), so our
|
|
// current behavior is more compatible than a whitelisting approach would
|
|
// be.
|
|
return LVal.InvalidBase &&
|
|
Designator.Entries.size() == Designator.MostDerivedPathLength &&
|
|
Designator.MostDerivedIsArrayElement &&
|
|
isDesignatorAtObjectEnd(Ctx, LVal);
|
|
}
|
|
|
|
/// Converts the given APInt to CharUnits, assuming the APInt is unsigned.
|
|
/// Fails if the conversion would cause loss of precision.
|
|
static bool convertUnsignedAPIntToCharUnits(const llvm::APInt &Int,
|
|
CharUnits &Result) {
|
|
auto CharUnitsMax = std::numeric_limits<CharUnits::QuantityType>::max();
|
|
if (Int.ugt(CharUnitsMax))
|
|
return false;
|
|
Result = CharUnits::fromQuantity(Int.getZExtValue());
|
|
return true;
|
|
}
|
|
|
|
/// Helper for tryEvaluateBuiltinObjectSize -- Given an LValue, this will
|
|
/// determine how many bytes exist from the beginning of the object to either
|
|
/// the end of the current subobject, or the end of the object itself, depending
|
|
/// on what the LValue looks like + the value of Type.
|
|
///
|
|
/// If this returns false, the value of Result is undefined.
|
|
static bool determineEndOffset(EvalInfo &Info, SourceLocation ExprLoc,
|
|
unsigned Type, const LValue &LVal,
|
|
CharUnits &EndOffset) {
|
|
bool DetermineForCompleteObject = refersToCompleteObject(LVal);
|
|
|
|
auto CheckedHandleSizeof = [&](QualType Ty, CharUnits &Result) {
|
|
if (Ty.isNull() || Ty->isIncompleteType() || Ty->isFunctionType())
|
|
return false;
|
|
return HandleSizeof(Info, ExprLoc, Ty, Result);
|
|
};
|
|
|
|
// We want to evaluate the size of the entire object. This is a valid fallback
|
|
// for when Type=1 and the designator is invalid, because we're asked for an
|
|
// upper-bound.
|
|
if (!(Type & 1) || LVal.Designator.Invalid || DetermineForCompleteObject) {
|
|
// Type=3 wants a lower bound, so we can't fall back to this.
|
|
if (Type == 3 && !DetermineForCompleteObject)
|
|
return false;
|
|
|
|
llvm::APInt APEndOffset;
|
|
if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
|
|
getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
|
|
return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
|
|
|
|
if (LVal.InvalidBase)
|
|
return false;
|
|
|
|
QualType BaseTy = getObjectType(LVal.getLValueBase());
|
|
return CheckedHandleSizeof(BaseTy, EndOffset);
|
|
}
|
|
|
|
// We want to evaluate the size of a subobject.
|
|
const SubobjectDesignator &Designator = LVal.Designator;
|
|
|
|
// The following is a moderately common idiom in C:
|
|
//
|
|
// struct Foo { int a; char c[1]; };
|
|
// struct Foo *F = (struct Foo *)malloc(sizeof(struct Foo) + strlen(Bar));
|
|
// strcpy(&F->c[0], Bar);
|
|
//
|
|
// In order to not break too much legacy code, we need to support it.
|
|
if (isUserWritingOffTheEnd(Info.Ctx, LVal)) {
|
|
// If we can resolve this to an alloc_size call, we can hand that back,
|
|
// because we know for certain how many bytes there are to write to.
|
|
llvm::APInt APEndOffset;
|
|
if (isBaseAnAllocSizeCall(LVal.getLValueBase()) &&
|
|
getBytesReturnedByAllocSizeCall(Info.Ctx, LVal, APEndOffset))
|
|
return convertUnsignedAPIntToCharUnits(APEndOffset, EndOffset);
|
|
|
|
// If we cannot determine the size of the initial allocation, then we can't
|
|
// given an accurate upper-bound. However, we are still able to give
|
|
// conservative lower-bounds for Type=3.
|
|
if (Type == 1)
|
|
return false;
|
|
}
|
|
|
|
CharUnits BytesPerElem;
|
|
if (!CheckedHandleSizeof(Designator.MostDerivedType, BytesPerElem))
|
|
return false;
|
|
|
|
// According to the GCC documentation, we want the size of the subobject
|
|
// denoted by the pointer. But that's not quite right -- what we actually
|
|
// want is the size of the immediately-enclosing array, if there is one.
|
|
int64_t ElemsRemaining;
|
|
if (Designator.MostDerivedIsArrayElement &&
|
|
Designator.Entries.size() == Designator.MostDerivedPathLength) {
|
|
uint64_t ArraySize = Designator.getMostDerivedArraySize();
|
|
uint64_t ArrayIndex = Designator.Entries.back().ArrayIndex;
|
|
ElemsRemaining = ArraySize <= ArrayIndex ? 0 : ArraySize - ArrayIndex;
|
|
} else {
|
|
ElemsRemaining = Designator.isOnePastTheEnd() ? 0 : 1;
|
|
}
|
|
|
|
EndOffset = LVal.getLValueOffset() + BytesPerElem * ElemsRemaining;
|
|
return true;
|
|
}
|
|
|
|
/// Tries to evaluate the __builtin_object_size for @p E. If successful,
|
|
/// returns true and stores the result in @p Size.
|
|
///
|
|
/// If @p WasError is non-null, this will report whether the failure to evaluate
|
|
/// is to be treated as an Error in IntExprEvaluator.
|
|
static bool tryEvaluateBuiltinObjectSize(const Expr *E, unsigned Type,
|
|
EvalInfo &Info, uint64_t &Size) {
|
|
// Determine the denoted object.
|
|
LValue LVal;
|
|
{
|
|
// The operand of __builtin_object_size is never evaluated for side-effects.
|
|
// If there are any, but we can determine the pointed-to object anyway, then
|
|
// ignore the side-effects.
|
|
SpeculativeEvaluationRAII SpeculativeEval(Info);
|
|
IgnoreSideEffectsRAII Fold(Info);
|
|
|
|
if (E->isGLValue()) {
|
|
// It's possible for us to be given GLValues if we're called via
|
|
// Expr::tryEvaluateObjectSize.
|
|
APValue RVal;
|
|
if (!EvaluateAsRValue(Info, E, RVal))
|
|
return false;
|
|
LVal.setFrom(Info.Ctx, RVal);
|
|
} else if (!EvaluatePointer(ignorePointerCastsAndParens(E), LVal, Info,
|
|
/*InvalidBaseOK=*/true))
|
|
return false;
|
|
}
|
|
|
|
// If we point to before the start of the object, there are no accessible
|
|
// bytes.
|
|
if (LVal.getLValueOffset().isNegative()) {
|
|
Size = 0;
|
|
return true;
|
|
}
|
|
|
|
CharUnits EndOffset;
|
|
if (!determineEndOffset(Info, E->getExprLoc(), Type, LVal, EndOffset))
|
|
return false;
|
|
|
|
// If we've fallen outside of the end offset, just pretend there's nothing to
|
|
// write to/read from.
|
|
if (EndOffset <= LVal.getLValueOffset())
|
|
Size = 0;
|
|
else
|
|
Size = (EndOffset - LVal.getLValueOffset()).getQuantity();
|
|
return true;
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitConstantExpr(const ConstantExpr *E) {
|
|
llvm::SaveAndRestore<bool> InConstantContext(Info.InConstantContext, true);
|
|
return ExprEvaluatorBaseTy::VisitConstantExpr(E);
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
|
|
if (unsigned BuiltinOp = E->getBuiltinCallee())
|
|
return VisitBuiltinCallExpr(E, BuiltinOp);
|
|
|
|
return ExprEvaluatorBaseTy::VisitCallExpr(E);
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
|
|
unsigned BuiltinOp) {
|
|
switch (unsigned BuiltinOp = E->getBuiltinCallee()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCallExpr(E);
|
|
|
|
case Builtin::BI__builtin_object_size: {
|
|
// The type was checked when we built the expression.
|
|
unsigned Type =
|
|
E->getArg(1)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
|
|
assert(Type <= 3 && "unexpected type");
|
|
|
|
uint64_t Size;
|
|
if (tryEvaluateBuiltinObjectSize(E->getArg(0), Type, Info, Size))
|
|
return Success(Size, E);
|
|
|
|
if (E->getArg(0)->HasSideEffects(Info.Ctx))
|
|
return Success((Type & 2) ? 0 : -1, E);
|
|
|
|
// Expression had no side effects, but we couldn't statically determine the
|
|
// size of the referenced object.
|
|
switch (Info.EvalMode) {
|
|
case EvalInfo::EM_ConstantExpression:
|
|
case EvalInfo::EM_PotentialConstantExpression:
|
|
case EvalInfo::EM_ConstantFold:
|
|
case EvalInfo::EM_EvaluateForOverflow:
|
|
case EvalInfo::EM_IgnoreSideEffects:
|
|
// Leave it to IR generation.
|
|
return Error(E);
|
|
case EvalInfo::EM_ConstantExpressionUnevaluated:
|
|
case EvalInfo::EM_PotentialConstantExpressionUnevaluated:
|
|
// Reduce it to a constant now.
|
|
return Success((Type & 2) ? 0 : -1, E);
|
|
}
|
|
|
|
llvm_unreachable("unexpected EvalMode");
|
|
}
|
|
|
|
case Builtin::BI__builtin_os_log_format_buffer_size: {
|
|
analyze_os_log::OSLogBufferLayout Layout;
|
|
analyze_os_log::computeOSLogBufferLayout(Info.Ctx, E, Layout);
|
|
return Success(Layout.size().getQuantity(), E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_bswap16:
|
|
case Builtin::BI__builtin_bswap32:
|
|
case Builtin::BI__builtin_bswap64: {
|
|
APSInt Val;
|
|
if (!EvaluateInteger(E->getArg(0), Val, Info))
|
|
return false;
|
|
|
|
return Success(Val.byteSwap(), E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_classify_type:
|
|
return Success((int)EvaluateBuiltinClassifyType(E, Info.getLangOpts()), E);
|
|
|
|
case Builtin::BI__builtin_clrsb:
|
|
case Builtin::BI__builtin_clrsbl:
|
|
case Builtin::BI__builtin_clrsbll: {
|
|
APSInt Val;
|
|
if (!EvaluateInteger(E->getArg(0), Val, Info))
|
|
return false;
|
|
|
|
return Success(Val.getBitWidth() - Val.getMinSignedBits(), E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_clz:
|
|
case Builtin::BI__builtin_clzl:
|
|
case Builtin::BI__builtin_clzll:
|
|
case Builtin::BI__builtin_clzs: {
|
|
APSInt Val;
|
|
if (!EvaluateInteger(E->getArg(0), Val, Info))
|
|
return false;
|
|
if (!Val)
|
|
return Error(E);
|
|
|
|
return Success(Val.countLeadingZeros(), E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_constant_p: {
|
|
auto Arg = E->getArg(0);
|
|
if (EvaluateBuiltinConstantP(Info.Ctx, Arg))
|
|
return Success(true, E);
|
|
auto ArgTy = Arg->IgnoreImplicit()->getType();
|
|
if (!Info.InConstantContext && !Arg->HasSideEffects(Info.Ctx) &&
|
|
!ArgTy->isAggregateType() && !ArgTy->isPointerType()) {
|
|
// We can delay calculation of __builtin_constant_p until after
|
|
// inlining. Note: This diagnostic won't be shown to the user.
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
return Success(false, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_ctz:
|
|
case Builtin::BI__builtin_ctzl:
|
|
case Builtin::BI__builtin_ctzll:
|
|
case Builtin::BI__builtin_ctzs: {
|
|
APSInt Val;
|
|
if (!EvaluateInteger(E->getArg(0), Val, Info))
|
|
return false;
|
|
if (!Val)
|
|
return Error(E);
|
|
|
|
return Success(Val.countTrailingZeros(), E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_eh_return_data_regno: {
|
|
int Operand = E->getArg(0)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
|
|
Operand = Info.Ctx.getTargetInfo().getEHDataRegisterNumber(Operand);
|
|
return Success(Operand, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_expect:
|
|
return Visit(E->getArg(0));
|
|
|
|
case Builtin::BI__builtin_ffs:
|
|
case Builtin::BI__builtin_ffsl:
|
|
case Builtin::BI__builtin_ffsll: {
|
|
APSInt Val;
|
|
if (!EvaluateInteger(E->getArg(0), Val, Info))
|
|
return false;
|
|
|
|
unsigned N = Val.countTrailingZeros();
|
|
return Success(N == Val.getBitWidth() ? 0 : N + 1, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_fpclassify: {
|
|
APFloat Val(0.0);
|
|
if (!EvaluateFloat(E->getArg(5), Val, Info))
|
|
return false;
|
|
unsigned Arg;
|
|
switch (Val.getCategory()) {
|
|
case APFloat::fcNaN: Arg = 0; break;
|
|
case APFloat::fcInfinity: Arg = 1; break;
|
|
case APFloat::fcNormal: Arg = Val.isDenormal() ? 3 : 2; break;
|
|
case APFloat::fcZero: Arg = 4; break;
|
|
}
|
|
return Visit(E->getArg(Arg));
|
|
}
|
|
|
|
case Builtin::BI__builtin_isinf_sign: {
|
|
APFloat Val(0.0);
|
|
return EvaluateFloat(E->getArg(0), Val, Info) &&
|
|
Success(Val.isInfinity() ? (Val.isNegative() ? -1 : 1) : 0, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_isinf: {
|
|
APFloat Val(0.0);
|
|
return EvaluateFloat(E->getArg(0), Val, Info) &&
|
|
Success(Val.isInfinity() ? 1 : 0, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_isfinite: {
|
|
APFloat Val(0.0);
|
|
return EvaluateFloat(E->getArg(0), Val, Info) &&
|
|
Success(Val.isFinite() ? 1 : 0, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_isnan: {
|
|
APFloat Val(0.0);
|
|
return EvaluateFloat(E->getArg(0), Val, Info) &&
|
|
Success(Val.isNaN() ? 1 : 0, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_isnormal: {
|
|
APFloat Val(0.0);
|
|
return EvaluateFloat(E->getArg(0), Val, Info) &&
|
|
Success(Val.isNormal() ? 1 : 0, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_parity:
|
|
case Builtin::BI__builtin_parityl:
|
|
case Builtin::BI__builtin_parityll: {
|
|
APSInt Val;
|
|
if (!EvaluateInteger(E->getArg(0), Val, Info))
|
|
return false;
|
|
|
|
return Success(Val.countPopulation() % 2, E);
|
|
}
|
|
|
|
case Builtin::BI__builtin_popcount:
|
|
case Builtin::BI__builtin_popcountl:
|
|
case Builtin::BI__builtin_popcountll: {
|
|
APSInt Val;
|
|
if (!EvaluateInteger(E->getArg(0), Val, Info))
|
|
return false;
|
|
|
|
return Success(Val.countPopulation(), E);
|
|
}
|
|
|
|
case Builtin::BIstrlen:
|
|
case Builtin::BIwcslen:
|
|
// A call to strlen is not a constant expression.
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.CCEDiag(E, diag::note_constexpr_invalid_function)
|
|
<< /*isConstexpr*/0 << /*isConstructor*/0
|
|
<< (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
|
|
else
|
|
Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
LLVM_FALLTHROUGH;
|
|
case Builtin::BI__builtin_strlen:
|
|
case Builtin::BI__builtin_wcslen: {
|
|
// As an extension, we support __builtin_strlen() as a constant expression,
|
|
// and support folding strlen() to a constant.
|
|
LValue String;
|
|
if (!EvaluatePointer(E->getArg(0), String, Info))
|
|
return false;
|
|
|
|
QualType CharTy = E->getArg(0)->getType()->getPointeeType();
|
|
|
|
// Fast path: if it's a string literal, search the string value.
|
|
if (const StringLiteral *S = dyn_cast_or_null<StringLiteral>(
|
|
String.getLValueBase().dyn_cast<const Expr *>())) {
|
|
// The string literal may have embedded null characters. Find the first
|
|
// one and truncate there.
|
|
StringRef Str = S->getBytes();
|
|
int64_t Off = String.Offset.getQuantity();
|
|
if (Off >= 0 && (uint64_t)Off <= (uint64_t)Str.size() &&
|
|
S->getCharByteWidth() == 1 &&
|
|
// FIXME: Add fast-path for wchar_t too.
|
|
Info.Ctx.hasSameUnqualifiedType(CharTy, Info.Ctx.CharTy)) {
|
|
Str = Str.substr(Off);
|
|
|
|
StringRef::size_type Pos = Str.find(0);
|
|
if (Pos != StringRef::npos)
|
|
Str = Str.substr(0, Pos);
|
|
|
|
return Success(Str.size(), E);
|
|
}
|
|
|
|
// Fall through to slow path to issue appropriate diagnostic.
|
|
}
|
|
|
|
// Slow path: scan the bytes of the string looking for the terminating 0.
|
|
for (uint64_t Strlen = 0; /**/; ++Strlen) {
|
|
APValue Char;
|
|
if (!handleLValueToRValueConversion(Info, E, CharTy, String, Char) ||
|
|
!Char.isInt())
|
|
return false;
|
|
if (!Char.getInt())
|
|
return Success(Strlen, E);
|
|
if (!HandleLValueArrayAdjustment(Info, E, String, CharTy, 1))
|
|
return false;
|
|
}
|
|
}
|
|
|
|
case Builtin::BIstrcmp:
|
|
case Builtin::BIwcscmp:
|
|
case Builtin::BIstrncmp:
|
|
case Builtin::BIwcsncmp:
|
|
case Builtin::BImemcmp:
|
|
case Builtin::BIwmemcmp:
|
|
// A call to strlen is not a constant expression.
|
|
if (Info.getLangOpts().CPlusPlus11)
|
|
Info.CCEDiag(E, diag::note_constexpr_invalid_function)
|
|
<< /*isConstexpr*/0 << /*isConstructor*/0
|
|
<< (std::string("'") + Info.Ctx.BuiltinInfo.getName(BuiltinOp) + "'");
|
|
else
|
|
Info.CCEDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
LLVM_FALLTHROUGH;
|
|
case Builtin::BI__builtin_strcmp:
|
|
case Builtin::BI__builtin_wcscmp:
|
|
case Builtin::BI__builtin_strncmp:
|
|
case Builtin::BI__builtin_wcsncmp:
|
|
case Builtin::BI__builtin_memcmp:
|
|
case Builtin::BI__builtin_wmemcmp: {
|
|
LValue String1, String2;
|
|
if (!EvaluatePointer(E->getArg(0), String1, Info) ||
|
|
!EvaluatePointer(E->getArg(1), String2, Info))
|
|
return false;
|
|
|
|
uint64_t MaxLength = uint64_t(-1);
|
|
if (BuiltinOp != Builtin::BIstrcmp &&
|
|
BuiltinOp != Builtin::BIwcscmp &&
|
|
BuiltinOp != Builtin::BI__builtin_strcmp &&
|
|
BuiltinOp != Builtin::BI__builtin_wcscmp) {
|
|
APSInt N;
|
|
if (!EvaluateInteger(E->getArg(2), N, Info))
|
|
return false;
|
|
MaxLength = N.getExtValue();
|
|
}
|
|
|
|
// Empty substrings compare equal by definition.
|
|
if (MaxLength == 0u)
|
|
return Success(0, E);
|
|
|
|
if (!String1.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
|
|
!String2.checkNullPointerForFoldAccess(Info, E, AK_Read) ||
|
|
String1.Designator.Invalid || String2.Designator.Invalid)
|
|
return false;
|
|
|
|
QualType CharTy1 = String1.Designator.getType(Info.Ctx);
|
|
QualType CharTy2 = String2.Designator.getType(Info.Ctx);
|
|
|
|
bool IsRawByte = BuiltinOp == Builtin::BImemcmp ||
|
|
BuiltinOp == Builtin::BI__builtin_memcmp;
|
|
|
|
assert(IsRawByte ||
|
|
(Info.Ctx.hasSameUnqualifiedType(
|
|
CharTy1, E->getArg(0)->getType()->getPointeeType()) &&
|
|
Info.Ctx.hasSameUnqualifiedType(CharTy1, CharTy2)));
|
|
|
|
const auto &ReadCurElems = [&](APValue &Char1, APValue &Char2) {
|
|
return handleLValueToRValueConversion(Info, E, CharTy1, String1, Char1) &&
|
|
handleLValueToRValueConversion(Info, E, CharTy2, String2, Char2) &&
|
|
Char1.isInt() && Char2.isInt();
|
|
};
|
|
const auto &AdvanceElems = [&] {
|
|
return HandleLValueArrayAdjustment(Info, E, String1, CharTy1, 1) &&
|
|
HandleLValueArrayAdjustment(Info, E, String2, CharTy2, 1);
|
|
};
|
|
|
|
if (IsRawByte) {
|
|
uint64_t BytesRemaining = MaxLength;
|
|
// Pointers to const void may point to objects of incomplete type.
|
|
if (CharTy1->isIncompleteType()) {
|
|
Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy1;
|
|
return false;
|
|
}
|
|
if (CharTy2->isIncompleteType()) {
|
|
Info.FFDiag(E, diag::note_constexpr_ltor_incomplete_type) << CharTy2;
|
|
return false;
|
|
}
|
|
uint64_t CharTy1Width{Info.Ctx.getTypeSize(CharTy1)};
|
|
CharUnits CharTy1Size = Info.Ctx.toCharUnitsFromBits(CharTy1Width);
|
|
// Give up on comparing between elements with disparate widths.
|
|
if (CharTy1Size != Info.Ctx.getTypeSizeInChars(CharTy2))
|
|
return false;
|
|
uint64_t BytesPerElement = CharTy1Size.getQuantity();
|
|
assert(BytesRemaining && "BytesRemaining should not be zero: the "
|
|
"following loop considers at least one element");
|
|
while (true) {
|
|
APValue Char1, Char2;
|
|
if (!ReadCurElems(Char1, Char2))
|
|
return false;
|
|
// We have compatible in-memory widths, but a possible type and
|
|
// (for `bool`) internal representation mismatch.
|
|
// Assuming two's complement representation, including 0 for `false` and
|
|
// 1 for `true`, we can check an appropriate number of elements for
|
|
// equality even if they are not byte-sized.
|
|
APSInt Char1InMem = Char1.getInt().extOrTrunc(CharTy1Width);
|
|
APSInt Char2InMem = Char2.getInt().extOrTrunc(CharTy1Width);
|
|
if (Char1InMem.ne(Char2InMem)) {
|
|
// If the elements are byte-sized, then we can produce a three-way
|
|
// comparison result in a straightforward manner.
|
|
if (BytesPerElement == 1u) {
|
|
// memcmp always compares unsigned chars.
|
|
return Success(Char1InMem.ult(Char2InMem) ? -1 : 1, E);
|
|
}
|
|
// The result is byte-order sensitive, and we have multibyte elements.
|
|
// FIXME: We can compare the remaining bytes in the correct order.
|
|
return false;
|
|
}
|
|
if (!AdvanceElems())
|
|
return false;
|
|
if (BytesRemaining <= BytesPerElement)
|
|
break;
|
|
BytesRemaining -= BytesPerElement;
|
|
}
|
|
// Enough elements are equal to account for the memcmp limit.
|
|
return Success(0, E);
|
|
}
|
|
|
|
bool StopAtNull = (BuiltinOp != Builtin::BImemcmp &&
|
|
BuiltinOp != Builtin::BIwmemcmp &&
|
|
BuiltinOp != Builtin::BI__builtin_memcmp &&
|
|
BuiltinOp != Builtin::BI__builtin_wmemcmp);
|
|
bool IsWide = BuiltinOp == Builtin::BIwcscmp ||
|
|
BuiltinOp == Builtin::BIwcsncmp ||
|
|
BuiltinOp == Builtin::BIwmemcmp ||
|
|
BuiltinOp == Builtin::BI__builtin_wcscmp ||
|
|
BuiltinOp == Builtin::BI__builtin_wcsncmp ||
|
|
BuiltinOp == Builtin::BI__builtin_wmemcmp;
|
|
|
|
for (; MaxLength; --MaxLength) {
|
|
APValue Char1, Char2;
|
|
if (!ReadCurElems(Char1, Char2))
|
|
return false;
|
|
if (Char1.getInt() != Char2.getInt()) {
|
|
if (IsWide) // wmemcmp compares with wchar_t signedness.
|
|
return Success(Char1.getInt() < Char2.getInt() ? -1 : 1, E);
|
|
// memcmp always compares unsigned chars.
|
|
return Success(Char1.getInt().ult(Char2.getInt()) ? -1 : 1, E);
|
|
}
|
|
if (StopAtNull && !Char1.getInt())
|
|
return Success(0, E);
|
|
assert(!(StopAtNull && !Char2.getInt()));
|
|
if (!AdvanceElems())
|
|
return false;
|
|
}
|
|
// We hit the strncmp / memcmp limit.
|
|
return Success(0, E);
|
|
}
|
|
|
|
case Builtin::BI__atomic_always_lock_free:
|
|
case Builtin::BI__atomic_is_lock_free:
|
|
case Builtin::BI__c11_atomic_is_lock_free: {
|
|
APSInt SizeVal;
|
|
if (!EvaluateInteger(E->getArg(0), SizeVal, Info))
|
|
return false;
|
|
|
|
// For __atomic_is_lock_free(sizeof(_Atomic(T))), if the size is a power
|
|
// of two less than the maximum inline atomic width, we know it is
|
|
// lock-free. If the size isn't a power of two, or greater than the
|
|
// maximum alignment where we promote atomics, we know it is not lock-free
|
|
// (at least not in the sense of atomic_is_lock_free). Otherwise,
|
|
// the answer can only be determined at runtime; for example, 16-byte
|
|
// atomics have lock-free implementations on some, but not all,
|
|
// x86-64 processors.
|
|
|
|
// Check power-of-two.
|
|
CharUnits Size = CharUnits::fromQuantity(SizeVal.getZExtValue());
|
|
if (Size.isPowerOfTwo()) {
|
|
// Check against inlining width.
|
|
unsigned InlineWidthBits =
|
|
Info.Ctx.getTargetInfo().getMaxAtomicInlineWidth();
|
|
if (Size <= Info.Ctx.toCharUnitsFromBits(InlineWidthBits)) {
|
|
if (BuiltinOp == Builtin::BI__c11_atomic_is_lock_free ||
|
|
Size == CharUnits::One() ||
|
|
E->getArg(1)->isNullPointerConstant(Info.Ctx,
|
|
Expr::NPC_NeverValueDependent))
|
|
// OK, we will inline appropriately-aligned operations of this size,
|
|
// and _Atomic(T) is appropriately-aligned.
|
|
return Success(1, E);
|
|
|
|
QualType PointeeType = E->getArg(1)->IgnoreImpCasts()->getType()->
|
|
castAs<PointerType>()->getPointeeType();
|
|
if (!PointeeType->isIncompleteType() &&
|
|
Info.Ctx.getTypeAlignInChars(PointeeType) >= Size) {
|
|
// OK, we will inline operations on this object.
|
|
return Success(1, E);
|
|
}
|
|
}
|
|
}
|
|
|
|
return BuiltinOp == Builtin::BI__atomic_always_lock_free ?
|
|
Success(0, E) : Error(E);
|
|
}
|
|
case Builtin::BIomp_is_initial_device:
|
|
// We can decide statically which value the runtime would return if called.
|
|
return Success(Info.getLangOpts().OpenMPIsDevice ? 0 : 1, E);
|
|
case Builtin::BI__builtin_add_overflow:
|
|
case Builtin::BI__builtin_sub_overflow:
|
|
case Builtin::BI__builtin_mul_overflow:
|
|
case Builtin::BI__builtin_sadd_overflow:
|
|
case Builtin::BI__builtin_uadd_overflow:
|
|
case Builtin::BI__builtin_uaddl_overflow:
|
|
case Builtin::BI__builtin_uaddll_overflow:
|
|
case Builtin::BI__builtin_usub_overflow:
|
|
case Builtin::BI__builtin_usubl_overflow:
|
|
case Builtin::BI__builtin_usubll_overflow:
|
|
case Builtin::BI__builtin_umul_overflow:
|
|
case Builtin::BI__builtin_umull_overflow:
|
|
case Builtin::BI__builtin_umulll_overflow:
|
|
case Builtin::BI__builtin_saddl_overflow:
|
|
case Builtin::BI__builtin_saddll_overflow:
|
|
case Builtin::BI__builtin_ssub_overflow:
|
|
case Builtin::BI__builtin_ssubl_overflow:
|
|
case Builtin::BI__builtin_ssubll_overflow:
|
|
case Builtin::BI__builtin_smul_overflow:
|
|
case Builtin::BI__builtin_smull_overflow:
|
|
case Builtin::BI__builtin_smulll_overflow: {
|
|
LValue ResultLValue;
|
|
APSInt LHS, RHS;
|
|
|
|
QualType ResultType = E->getArg(2)->getType()->getPointeeType();
|
|
if (!EvaluateInteger(E->getArg(0), LHS, Info) ||
|
|
!EvaluateInteger(E->getArg(1), RHS, Info) ||
|
|
!EvaluatePointer(E->getArg(2), ResultLValue, Info))
|
|
return false;
|
|
|
|
APSInt Result;
|
|
bool DidOverflow = false;
|
|
|
|
// If the types don't have to match, enlarge all 3 to the largest of them.
|
|
if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
|
|
BuiltinOp == Builtin::BI__builtin_sub_overflow ||
|
|
BuiltinOp == Builtin::BI__builtin_mul_overflow) {
|
|
bool IsSigned = LHS.isSigned() || RHS.isSigned() ||
|
|
ResultType->isSignedIntegerOrEnumerationType();
|
|
bool AllSigned = LHS.isSigned() && RHS.isSigned() &&
|
|
ResultType->isSignedIntegerOrEnumerationType();
|
|
uint64_t LHSSize = LHS.getBitWidth();
|
|
uint64_t RHSSize = RHS.getBitWidth();
|
|
uint64_t ResultSize = Info.Ctx.getTypeSize(ResultType);
|
|
uint64_t MaxBits = std::max(std::max(LHSSize, RHSSize), ResultSize);
|
|
|
|
// Add an additional bit if the signedness isn't uniformly agreed to. We
|
|
// could do this ONLY if there is a signed and an unsigned that both have
|
|
// MaxBits, but the code to check that is pretty nasty. The issue will be
|
|
// caught in the shrink-to-result later anyway.
|
|
if (IsSigned && !AllSigned)
|
|
++MaxBits;
|
|
|
|
LHS = APSInt(IsSigned ? LHS.sextOrSelf(MaxBits) : LHS.zextOrSelf(MaxBits),
|
|
!IsSigned);
|
|
RHS = APSInt(IsSigned ? RHS.sextOrSelf(MaxBits) : RHS.zextOrSelf(MaxBits),
|
|
!IsSigned);
|
|
Result = APSInt(MaxBits, !IsSigned);
|
|
}
|
|
|
|
// Find largest int.
|
|
switch (BuiltinOp) {
|
|
default:
|
|
llvm_unreachable("Invalid value for BuiltinOp");
|
|
case Builtin::BI__builtin_add_overflow:
|
|
case Builtin::BI__builtin_sadd_overflow:
|
|
case Builtin::BI__builtin_saddl_overflow:
|
|
case Builtin::BI__builtin_saddll_overflow:
|
|
case Builtin::BI__builtin_uadd_overflow:
|
|
case Builtin::BI__builtin_uaddl_overflow:
|
|
case Builtin::BI__builtin_uaddll_overflow:
|
|
Result = LHS.isSigned() ? LHS.sadd_ov(RHS, DidOverflow)
|
|
: LHS.uadd_ov(RHS, DidOverflow);
|
|
break;
|
|
case Builtin::BI__builtin_sub_overflow:
|
|
case Builtin::BI__builtin_ssub_overflow:
|
|
case Builtin::BI__builtin_ssubl_overflow:
|
|
case Builtin::BI__builtin_ssubll_overflow:
|
|
case Builtin::BI__builtin_usub_overflow:
|
|
case Builtin::BI__builtin_usubl_overflow:
|
|
case Builtin::BI__builtin_usubll_overflow:
|
|
Result = LHS.isSigned() ? LHS.ssub_ov(RHS, DidOverflow)
|
|
: LHS.usub_ov(RHS, DidOverflow);
|
|
break;
|
|
case Builtin::BI__builtin_mul_overflow:
|
|
case Builtin::BI__builtin_smul_overflow:
|
|
case Builtin::BI__builtin_smull_overflow:
|
|
case Builtin::BI__builtin_smulll_overflow:
|
|
case Builtin::BI__builtin_umul_overflow:
|
|
case Builtin::BI__builtin_umull_overflow:
|
|
case Builtin::BI__builtin_umulll_overflow:
|
|
Result = LHS.isSigned() ? LHS.smul_ov(RHS, DidOverflow)
|
|
: LHS.umul_ov(RHS, DidOverflow);
|
|
break;
|
|
}
|
|
|
|
// In the case where multiple sizes are allowed, truncate and see if
|
|
// the values are the same.
|
|
if (BuiltinOp == Builtin::BI__builtin_add_overflow ||
|
|
BuiltinOp == Builtin::BI__builtin_sub_overflow ||
|
|
BuiltinOp == Builtin::BI__builtin_mul_overflow) {
|
|
// APSInt doesn't have a TruncOrSelf, so we use extOrTrunc instead,
|
|
// since it will give us the behavior of a TruncOrSelf in the case where
|
|
// its parameter <= its size. We previously set Result to be at least the
|
|
// type-size of the result, so getTypeSize(ResultType) <= Result.BitWidth
|
|
// will work exactly like TruncOrSelf.
|
|
APSInt Temp = Result.extOrTrunc(Info.Ctx.getTypeSize(ResultType));
|
|
Temp.setIsSigned(ResultType->isSignedIntegerOrEnumerationType());
|
|
|
|
if (!APSInt::isSameValue(Temp, Result))
|
|
DidOverflow = true;
|
|
Result = Temp;
|
|
}
|
|
|
|
APValue APV{Result};
|
|
if (!handleAssignment(Info, E, ResultLValue, ResultType, APV))
|
|
return false;
|
|
return Success(DidOverflow, E);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Determine whether this is a pointer past the end of the complete
|
|
/// object referred to by the lvalue.
|
|
static bool isOnePastTheEndOfCompleteObject(const ASTContext &Ctx,
|
|
const LValue &LV) {
|
|
// A null pointer can be viewed as being "past the end" but we don't
|
|
// choose to look at it that way here.
|
|
if (!LV.getLValueBase())
|
|
return false;
|
|
|
|
// If the designator is valid and refers to a subobject, we're not pointing
|
|
// past the end.
|
|
if (!LV.getLValueDesignator().Invalid &&
|
|
!LV.getLValueDesignator().isOnePastTheEnd())
|
|
return false;
|
|
|
|
// A pointer to an incomplete type might be past-the-end if the type's size is
|
|
// zero. We cannot tell because the type is incomplete.
|
|
QualType Ty = getType(LV.getLValueBase());
|
|
if (Ty->isIncompleteType())
|
|
return true;
|
|
|
|
// We're a past-the-end pointer if we point to the byte after the object,
|
|
// no matter what our type or path is.
|
|
auto Size = Ctx.getTypeSizeInChars(Ty);
|
|
return LV.getLValueOffset() == Size;
|
|
}
|
|
|
|
namespace {
|
|
|
|
/// Data recursive integer evaluator of certain binary operators.
|
|
///
|
|
/// We use a data recursive algorithm for binary operators so that we are able
|
|
/// to handle extreme cases of chained binary operators without causing stack
|
|
/// overflow.
|
|
class DataRecursiveIntBinOpEvaluator {
|
|
struct EvalResult {
|
|
APValue Val;
|
|
bool Failed;
|
|
|
|
EvalResult() : Failed(false) { }
|
|
|
|
void swap(EvalResult &RHS) {
|
|
Val.swap(RHS.Val);
|
|
Failed = RHS.Failed;
|
|
RHS.Failed = false;
|
|
}
|
|
};
|
|
|
|
struct Job {
|
|
const Expr *E;
|
|
EvalResult LHSResult; // meaningful only for binary operator expression.
|
|
enum { AnyExprKind, BinOpKind, BinOpVisitedLHSKind } Kind;
|
|
|
|
Job() = default;
|
|
Job(Job &&) = default;
|
|
|
|
void startSpeculativeEval(EvalInfo &Info) {
|
|
SpecEvalRAII = SpeculativeEvaluationRAII(Info);
|
|
}
|
|
|
|
private:
|
|
SpeculativeEvaluationRAII SpecEvalRAII;
|
|
};
|
|
|
|
SmallVector<Job, 16> Queue;
|
|
|
|
IntExprEvaluator &IntEval;
|
|
EvalInfo &Info;
|
|
APValue &FinalResult;
|
|
|
|
public:
|
|
DataRecursiveIntBinOpEvaluator(IntExprEvaluator &IntEval, APValue &Result)
|
|
: IntEval(IntEval), Info(IntEval.getEvalInfo()), FinalResult(Result) { }
|
|
|
|
/// True if \param E is a binary operator that we are going to handle
|
|
/// data recursively.
|
|
/// We handle binary operators that are comma, logical, or that have operands
|
|
/// with integral or enumeration type.
|
|
static bool shouldEnqueue(const BinaryOperator *E) {
|
|
return E->getOpcode() == BO_Comma || E->isLogicalOp() ||
|
|
(E->isRValue() && E->getType()->isIntegralOrEnumerationType() &&
|
|
E->getLHS()->getType()->isIntegralOrEnumerationType() &&
|
|
E->getRHS()->getType()->isIntegralOrEnumerationType());
|
|
}
|
|
|
|
bool Traverse(const BinaryOperator *E) {
|
|
enqueue(E);
|
|
EvalResult PrevResult;
|
|
while (!Queue.empty())
|
|
process(PrevResult);
|
|
|
|
if (PrevResult.Failed) return false;
|
|
|
|
FinalResult.swap(PrevResult.Val);
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
bool Success(uint64_t Value, const Expr *E, APValue &Result) {
|
|
return IntEval.Success(Value, E, Result);
|
|
}
|
|
bool Success(const APSInt &Value, const Expr *E, APValue &Result) {
|
|
return IntEval.Success(Value, E, Result);
|
|
}
|
|
bool Error(const Expr *E) {
|
|
return IntEval.Error(E);
|
|
}
|
|
bool Error(const Expr *E, diag::kind D) {
|
|
return IntEval.Error(E, D);
|
|
}
|
|
|
|
OptionalDiagnostic CCEDiag(const Expr *E, diag::kind D) {
|
|
return Info.CCEDiag(E, D);
|
|
}
|
|
|
|
// Returns true if visiting the RHS is necessary, false otherwise.
|
|
bool VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
|
|
bool &SuppressRHSDiags);
|
|
|
|
bool VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
|
|
const BinaryOperator *E, APValue &Result);
|
|
|
|
void EvaluateExpr(const Expr *E, EvalResult &Result) {
|
|
Result.Failed = !Evaluate(Result.Val, Info, E);
|
|
if (Result.Failed)
|
|
Result.Val = APValue();
|
|
}
|
|
|
|
void process(EvalResult &Result);
|
|
|
|
void enqueue(const Expr *E) {
|
|
E = E->IgnoreParens();
|
|
Queue.resize(Queue.size()+1);
|
|
Queue.back().E = E;
|
|
Queue.back().Kind = Job::AnyExprKind;
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
bool DataRecursiveIntBinOpEvaluator::
|
|
VisitBinOpLHSOnly(EvalResult &LHSResult, const BinaryOperator *E,
|
|
bool &SuppressRHSDiags) {
|
|
if (E->getOpcode() == BO_Comma) {
|
|
// Ignore LHS but note if we could not evaluate it.
|
|
if (LHSResult.Failed)
|
|
return Info.noteSideEffect();
|
|
return true;
|
|
}
|
|
|
|
if (E->isLogicalOp()) {
|
|
bool LHSAsBool;
|
|
if (!LHSResult.Failed && HandleConversionToBool(LHSResult.Val, LHSAsBool)) {
|
|
// We were able to evaluate the LHS, see if we can get away with not
|
|
// evaluating the RHS: 0 && X -> 0, 1 || X -> 1
|
|
if (LHSAsBool == (E->getOpcode() == BO_LOr)) {
|
|
Success(LHSAsBool, E, LHSResult.Val);
|
|
return false; // Ignore RHS
|
|
}
|
|
} else {
|
|
LHSResult.Failed = true;
|
|
|
|
// Since we weren't able to evaluate the left hand side, it
|
|
// might have had side effects.
|
|
if (!Info.noteSideEffect())
|
|
return false;
|
|
|
|
// We can't evaluate the LHS; however, sometimes the result
|
|
// is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
|
|
// Don't ignore RHS and suppress diagnostics from this arm.
|
|
SuppressRHSDiags = true;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
assert(E->getLHS()->getType()->isIntegralOrEnumerationType() &&
|
|
E->getRHS()->getType()->isIntegralOrEnumerationType());
|
|
|
|
if (LHSResult.Failed && !Info.noteFailure())
|
|
return false; // Ignore RHS;
|
|
|
|
return true;
|
|
}
|
|
|
|
static void addOrSubLValueAsInteger(APValue &LVal, const APSInt &Index,
|
|
bool IsSub) {
|
|
// Compute the new offset in the appropriate width, wrapping at 64 bits.
|
|
// FIXME: When compiling for a 32-bit target, we should use 32-bit
|
|
// offsets.
|
|
assert(!LVal.hasLValuePath() && "have designator for integer lvalue");
|
|
CharUnits &Offset = LVal.getLValueOffset();
|
|
uint64_t Offset64 = Offset.getQuantity();
|
|
uint64_t Index64 = Index.extOrTrunc(64).getZExtValue();
|
|
Offset = CharUnits::fromQuantity(IsSub ? Offset64 - Index64
|
|
: Offset64 + Index64);
|
|
}
|
|
|
|
bool DataRecursiveIntBinOpEvaluator::
|
|
VisitBinOp(const EvalResult &LHSResult, const EvalResult &RHSResult,
|
|
const BinaryOperator *E, APValue &Result) {
|
|
if (E->getOpcode() == BO_Comma) {
|
|
if (RHSResult.Failed)
|
|
return false;
|
|
Result = RHSResult.Val;
|
|
return true;
|
|
}
|
|
|
|
if (E->isLogicalOp()) {
|
|
bool lhsResult, rhsResult;
|
|
bool LHSIsOK = HandleConversionToBool(LHSResult.Val, lhsResult);
|
|
bool RHSIsOK = HandleConversionToBool(RHSResult.Val, rhsResult);
|
|
|
|
if (LHSIsOK) {
|
|
if (RHSIsOK) {
|
|
if (E->getOpcode() == BO_LOr)
|
|
return Success(lhsResult || rhsResult, E, Result);
|
|
else
|
|
return Success(lhsResult && rhsResult, E, Result);
|
|
}
|
|
} else {
|
|
if (RHSIsOK) {
|
|
// We can't evaluate the LHS; however, sometimes the result
|
|
// is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
|
|
if (rhsResult == (E->getOpcode() == BO_LOr))
|
|
return Success(rhsResult, E, Result);
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
assert(E->getLHS()->getType()->isIntegralOrEnumerationType() &&
|
|
E->getRHS()->getType()->isIntegralOrEnumerationType());
|
|
|
|
if (LHSResult.Failed || RHSResult.Failed)
|
|
return false;
|
|
|
|
const APValue &LHSVal = LHSResult.Val;
|
|
const APValue &RHSVal = RHSResult.Val;
|
|
|
|
// Handle cases like (unsigned long)&a + 4.
|
|
if (E->isAdditiveOp() && LHSVal.isLValue() && RHSVal.isInt()) {
|
|
Result = LHSVal;
|
|
addOrSubLValueAsInteger(Result, RHSVal.getInt(), E->getOpcode() == BO_Sub);
|
|
return true;
|
|
}
|
|
|
|
// Handle cases like 4 + (unsigned long)&a
|
|
if (E->getOpcode() == BO_Add &&
|
|
RHSVal.isLValue() && LHSVal.isInt()) {
|
|
Result = RHSVal;
|
|
addOrSubLValueAsInteger(Result, LHSVal.getInt(), /*IsSub*/false);
|
|
return true;
|
|
}
|
|
|
|
if (E->getOpcode() == BO_Sub && LHSVal.isLValue() && RHSVal.isLValue()) {
|
|
// Handle (intptr_t)&&A - (intptr_t)&&B.
|
|
if (!LHSVal.getLValueOffset().isZero() ||
|
|
!RHSVal.getLValueOffset().isZero())
|
|
return false;
|
|
const Expr *LHSExpr = LHSVal.getLValueBase().dyn_cast<const Expr*>();
|
|
const Expr *RHSExpr = RHSVal.getLValueBase().dyn_cast<const Expr*>();
|
|
if (!LHSExpr || !RHSExpr)
|
|
return false;
|
|
const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
|
|
const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
|
|
if (!LHSAddrExpr || !RHSAddrExpr)
|
|
return false;
|
|
// Make sure both labels come from the same function.
|
|
if (LHSAddrExpr->getLabel()->getDeclContext() !=
|
|
RHSAddrExpr->getLabel()->getDeclContext())
|
|
return false;
|
|
Result = APValue(LHSAddrExpr, RHSAddrExpr);
|
|
return true;
|
|
}
|
|
|
|
// All the remaining cases expect both operands to be an integer
|
|
if (!LHSVal.isInt() || !RHSVal.isInt())
|
|
return Error(E);
|
|
|
|
// Set up the width and signedness manually, in case it can't be deduced
|
|
// from the operation we're performing.
|
|
// FIXME: Don't do this in the cases where we can deduce it.
|
|
APSInt Value(Info.Ctx.getIntWidth(E->getType()),
|
|
E->getType()->isUnsignedIntegerOrEnumerationType());
|
|
if (!handleIntIntBinOp(Info, E, LHSVal.getInt(), E->getOpcode(),
|
|
RHSVal.getInt(), Value))
|
|
return false;
|
|
return Success(Value, E, Result);
|
|
}
|
|
|
|
void DataRecursiveIntBinOpEvaluator::process(EvalResult &Result) {
|
|
Job &job = Queue.back();
|
|
|
|
switch (job.Kind) {
|
|
case Job::AnyExprKind: {
|
|
if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(job.E)) {
|
|
if (shouldEnqueue(Bop)) {
|
|
job.Kind = Job::BinOpKind;
|
|
enqueue(Bop->getLHS());
|
|
return;
|
|
}
|
|
}
|
|
|
|
EvaluateExpr(job.E, Result);
|
|
Queue.pop_back();
|
|
return;
|
|
}
|
|
|
|
case Job::BinOpKind: {
|
|
const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
|
|
bool SuppressRHSDiags = false;
|
|
if (!VisitBinOpLHSOnly(Result, Bop, SuppressRHSDiags)) {
|
|
Queue.pop_back();
|
|
return;
|
|
}
|
|
if (SuppressRHSDiags)
|
|
job.startSpeculativeEval(Info);
|
|
job.LHSResult.swap(Result);
|
|
job.Kind = Job::BinOpVisitedLHSKind;
|
|
enqueue(Bop->getRHS());
|
|
return;
|
|
}
|
|
|
|
case Job::BinOpVisitedLHSKind: {
|
|
const BinaryOperator *Bop = cast<BinaryOperator>(job.E);
|
|
EvalResult RHS;
|
|
RHS.swap(Result);
|
|
Result.Failed = !VisitBinOp(job.LHSResult, RHS, Bop, Result.Val);
|
|
Queue.pop_back();
|
|
return;
|
|
}
|
|
}
|
|
|
|
llvm_unreachable("Invalid Job::Kind!");
|
|
}
|
|
|
|
namespace {
|
|
/// Used when we determine that we should fail, but can keep evaluating prior to
|
|
/// noting that we had a failure.
|
|
class DelayedNoteFailureRAII {
|
|
EvalInfo &Info;
|
|
bool NoteFailure;
|
|
|
|
public:
|
|
DelayedNoteFailureRAII(EvalInfo &Info, bool NoteFailure = true)
|
|
: Info(Info), NoteFailure(NoteFailure) {}
|
|
~DelayedNoteFailureRAII() {
|
|
if (NoteFailure) {
|
|
bool ContinueAfterFailure = Info.noteFailure();
|
|
(void)ContinueAfterFailure;
|
|
assert(ContinueAfterFailure &&
|
|
"Shouldn't have kept evaluating on failure.");
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
template <class SuccessCB, class AfterCB>
|
|
static bool
|
|
EvaluateComparisonBinaryOperator(EvalInfo &Info, const BinaryOperator *E,
|
|
SuccessCB &&Success, AfterCB &&DoAfter) {
|
|
assert(E->isComparisonOp() && "expected comparison operator");
|
|
assert((E->getOpcode() == BO_Cmp ||
|
|
E->getType()->isIntegralOrEnumerationType()) &&
|
|
"unsupported binary expression evaluation");
|
|
auto Error = [&](const Expr *E) {
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
};
|
|
|
|
using CCR = ComparisonCategoryResult;
|
|
bool IsRelational = E->isRelationalOp();
|
|
bool IsEquality = E->isEqualityOp();
|
|
if (E->getOpcode() == BO_Cmp) {
|
|
const ComparisonCategoryInfo &CmpInfo =
|
|
Info.Ctx.CompCategories.getInfoForType(E->getType());
|
|
IsRelational = CmpInfo.isOrdered();
|
|
IsEquality = CmpInfo.isEquality();
|
|
}
|
|
|
|
QualType LHSTy = E->getLHS()->getType();
|
|
QualType RHSTy = E->getRHS()->getType();
|
|
|
|
if (LHSTy->isIntegralOrEnumerationType() &&
|
|
RHSTy->isIntegralOrEnumerationType()) {
|
|
APSInt LHS, RHS;
|
|
bool LHSOK = EvaluateInteger(E->getLHS(), LHS, Info);
|
|
if (!LHSOK && !Info.noteFailure())
|
|
return false;
|
|
if (!EvaluateInteger(E->getRHS(), RHS, Info) || !LHSOK)
|
|
return false;
|
|
if (LHS < RHS)
|
|
return Success(CCR::Less, E);
|
|
if (LHS > RHS)
|
|
return Success(CCR::Greater, E);
|
|
return Success(CCR::Equal, E);
|
|
}
|
|
|
|
if (LHSTy->isAnyComplexType() || RHSTy->isAnyComplexType()) {
|
|
ComplexValue LHS, RHS;
|
|
bool LHSOK;
|
|
if (E->isAssignmentOp()) {
|
|
LValue LV;
|
|
EvaluateLValue(E->getLHS(), LV, Info);
|
|
LHSOK = false;
|
|
} else if (LHSTy->isRealFloatingType()) {
|
|
LHSOK = EvaluateFloat(E->getLHS(), LHS.FloatReal, Info);
|
|
if (LHSOK) {
|
|
LHS.makeComplexFloat();
|
|
LHS.FloatImag = APFloat(LHS.FloatReal.getSemantics());
|
|
}
|
|
} else {
|
|
LHSOK = EvaluateComplex(E->getLHS(), LHS, Info);
|
|
}
|
|
if (!LHSOK && !Info.noteFailure())
|
|
return false;
|
|
|
|
if (E->getRHS()->getType()->isRealFloatingType()) {
|
|
if (!EvaluateFloat(E->getRHS(), RHS.FloatReal, Info) || !LHSOK)
|
|
return false;
|
|
RHS.makeComplexFloat();
|
|
RHS.FloatImag = APFloat(RHS.FloatReal.getSemantics());
|
|
} else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
|
|
return false;
|
|
|
|
if (LHS.isComplexFloat()) {
|
|
APFloat::cmpResult CR_r =
|
|
LHS.getComplexFloatReal().compare(RHS.getComplexFloatReal());
|
|
APFloat::cmpResult CR_i =
|
|
LHS.getComplexFloatImag().compare(RHS.getComplexFloatImag());
|
|
bool IsEqual = CR_r == APFloat::cmpEqual && CR_i == APFloat::cmpEqual;
|
|
return Success(IsEqual ? CCR::Equal : CCR::Nonequal, E);
|
|
} else {
|
|
assert(IsEquality && "invalid complex comparison");
|
|
bool IsEqual = LHS.getComplexIntReal() == RHS.getComplexIntReal() &&
|
|
LHS.getComplexIntImag() == RHS.getComplexIntImag();
|
|
return Success(IsEqual ? CCR::Equal : CCR::Nonequal, E);
|
|
}
|
|
}
|
|
|
|
if (LHSTy->isRealFloatingType() &&
|
|
RHSTy->isRealFloatingType()) {
|
|
APFloat RHS(0.0), LHS(0.0);
|
|
|
|
bool LHSOK = EvaluateFloat(E->getRHS(), RHS, Info);
|
|
if (!LHSOK && !Info.noteFailure())
|
|
return false;
|
|
|
|
if (!EvaluateFloat(E->getLHS(), LHS, Info) || !LHSOK)
|
|
return false;
|
|
|
|
assert(E->isComparisonOp() && "Invalid binary operator!");
|
|
auto GetCmpRes = [&]() {
|
|
switch (LHS.compare(RHS)) {
|
|
case APFloat::cmpEqual:
|
|
return CCR::Equal;
|
|
case APFloat::cmpLessThan:
|
|
return CCR::Less;
|
|
case APFloat::cmpGreaterThan:
|
|
return CCR::Greater;
|
|
case APFloat::cmpUnordered:
|
|
return CCR::Unordered;
|
|
}
|
|
llvm_unreachable("Unrecognised APFloat::cmpResult enum");
|
|
};
|
|
return Success(GetCmpRes(), E);
|
|
}
|
|
|
|
if (LHSTy->isPointerType() && RHSTy->isPointerType()) {
|
|
LValue LHSValue, RHSValue;
|
|
|
|
bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
|
|
if (!LHSOK && !Info.noteFailure())
|
|
return false;
|
|
|
|
if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
|
|
return false;
|
|
|
|
// Reject differing bases from the normal codepath; we special-case
|
|
// comparisons to null.
|
|
if (!HasSameBase(LHSValue, RHSValue)) {
|
|
// Inequalities and subtractions between unrelated pointers have
|
|
// unspecified or undefined behavior.
|
|
if (!IsEquality)
|
|
return Error(E);
|
|
// A constant address may compare equal to the address of a symbol.
|
|
// The one exception is that address of an object cannot compare equal
|
|
// to a null pointer constant.
|
|
if ((!LHSValue.Base && !LHSValue.Offset.isZero()) ||
|
|
(!RHSValue.Base && !RHSValue.Offset.isZero()))
|
|
return Error(E);
|
|
// It's implementation-defined whether distinct literals will have
|
|
// distinct addresses. In clang, the result of such a comparison is
|
|
// unspecified, so it is not a constant expression. However, we do know
|
|
// that the address of a literal will be non-null.
|
|
if ((IsLiteralLValue(LHSValue) || IsLiteralLValue(RHSValue)) &&
|
|
LHSValue.Base && RHSValue.Base)
|
|
return Error(E);
|
|
// We can't tell whether weak symbols will end up pointing to the same
|
|
// object.
|
|
if (IsWeakLValue(LHSValue) || IsWeakLValue(RHSValue))
|
|
return Error(E);
|
|
// We can't compare the address of the start of one object with the
|
|
// past-the-end address of another object, per C++ DR1652.
|
|
if ((LHSValue.Base && LHSValue.Offset.isZero() &&
|
|
isOnePastTheEndOfCompleteObject(Info.Ctx, RHSValue)) ||
|
|
(RHSValue.Base && RHSValue.Offset.isZero() &&
|
|
isOnePastTheEndOfCompleteObject(Info.Ctx, LHSValue)))
|
|
return Error(E);
|
|
// We can't tell whether an object is at the same address as another
|
|
// zero sized object.
|
|
if ((RHSValue.Base && isZeroSized(LHSValue)) ||
|
|
(LHSValue.Base && isZeroSized(RHSValue)))
|
|
return Error(E);
|
|
return Success(CCR::Nonequal, E);
|
|
}
|
|
|
|
const CharUnits &LHSOffset = LHSValue.getLValueOffset();
|
|
const CharUnits &RHSOffset = RHSValue.getLValueOffset();
|
|
|
|
SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
|
|
SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
|
|
|
|
// C++11 [expr.rel]p3:
|
|
// Pointers to void (after pointer conversions) can be compared, with a
|
|
// result defined as follows: If both pointers represent the same
|
|
// address or are both the null pointer value, the result is true if the
|
|
// operator is <= or >= and false otherwise; otherwise the result is
|
|
// unspecified.
|
|
// We interpret this as applying to pointers to *cv* void.
|
|
if (LHSTy->isVoidPointerType() && LHSOffset != RHSOffset && IsRelational)
|
|
Info.CCEDiag(E, diag::note_constexpr_void_comparison);
|
|
|
|
// C++11 [expr.rel]p2:
|
|
// - If two pointers point to non-static data members of the same object,
|
|
// or to subobjects or array elements fo such members, recursively, the
|
|
// pointer to the later declared member compares greater provided the
|
|
// two members have the same access control and provided their class is
|
|
// not a union.
|
|
// [...]
|
|
// - Otherwise pointer comparisons are unspecified.
|
|
if (!LHSDesignator.Invalid && !RHSDesignator.Invalid && IsRelational) {
|
|
bool WasArrayIndex;
|
|
unsigned Mismatch = FindDesignatorMismatch(
|
|
getType(LHSValue.Base), LHSDesignator, RHSDesignator, WasArrayIndex);
|
|
// At the point where the designators diverge, the comparison has a
|
|
// specified value if:
|
|
// - we are comparing array indices
|
|
// - we are comparing fields of a union, or fields with the same access
|
|
// Otherwise, the result is unspecified and thus the comparison is not a
|
|
// constant expression.
|
|
if (!WasArrayIndex && Mismatch < LHSDesignator.Entries.size() &&
|
|
Mismatch < RHSDesignator.Entries.size()) {
|
|
const FieldDecl *LF = getAsField(LHSDesignator.Entries[Mismatch]);
|
|
const FieldDecl *RF = getAsField(RHSDesignator.Entries[Mismatch]);
|
|
if (!LF && !RF)
|
|
Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_classes);
|
|
else if (!LF)
|
|
Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
|
|
<< getAsBaseClass(LHSDesignator.Entries[Mismatch])
|
|
<< RF->getParent() << RF;
|
|
else if (!RF)
|
|
Info.CCEDiag(E, diag::note_constexpr_pointer_comparison_base_field)
|
|
<< getAsBaseClass(RHSDesignator.Entries[Mismatch])
|
|
<< LF->getParent() << LF;
|
|
else if (!LF->getParent()->isUnion() &&
|
|
LF->getAccess() != RF->getAccess())
|
|
Info.CCEDiag(E,
|
|
diag::note_constexpr_pointer_comparison_differing_access)
|
|
<< LF << LF->getAccess() << RF << RF->getAccess()
|
|
<< LF->getParent();
|
|
}
|
|
}
|
|
|
|
// The comparison here must be unsigned, and performed with the same
|
|
// width as the pointer.
|
|
unsigned PtrSize = Info.Ctx.getTypeSize(LHSTy);
|
|
uint64_t CompareLHS = LHSOffset.getQuantity();
|
|
uint64_t CompareRHS = RHSOffset.getQuantity();
|
|
assert(PtrSize <= 64 && "Unexpected pointer width");
|
|
uint64_t Mask = ~0ULL >> (64 - PtrSize);
|
|
CompareLHS &= Mask;
|
|
CompareRHS &= Mask;
|
|
|
|
// If there is a base and this is a relational operator, we can only
|
|
// compare pointers within the object in question; otherwise, the result
|
|
// depends on where the object is located in memory.
|
|
if (!LHSValue.Base.isNull() && IsRelational) {
|
|
QualType BaseTy = getType(LHSValue.Base);
|
|
if (BaseTy->isIncompleteType())
|
|
return Error(E);
|
|
CharUnits Size = Info.Ctx.getTypeSizeInChars(BaseTy);
|
|
uint64_t OffsetLimit = Size.getQuantity();
|
|
if (CompareLHS > OffsetLimit || CompareRHS > OffsetLimit)
|
|
return Error(E);
|
|
}
|
|
|
|
if (CompareLHS < CompareRHS)
|
|
return Success(CCR::Less, E);
|
|
if (CompareLHS > CompareRHS)
|
|
return Success(CCR::Greater, E);
|
|
return Success(CCR::Equal, E);
|
|
}
|
|
|
|
if (LHSTy->isMemberPointerType()) {
|
|
assert(IsEquality && "unexpected member pointer operation");
|
|
assert(RHSTy->isMemberPointerType() && "invalid comparison");
|
|
|
|
MemberPtr LHSValue, RHSValue;
|
|
|
|
bool LHSOK = EvaluateMemberPointer(E->getLHS(), LHSValue, Info);
|
|
if (!LHSOK && !Info.noteFailure())
|
|
return false;
|
|
|
|
if (!EvaluateMemberPointer(E->getRHS(), RHSValue, Info) || !LHSOK)
|
|
return false;
|
|
|
|
// C++11 [expr.eq]p2:
|
|
// If both operands are null, they compare equal. Otherwise if only one is
|
|
// null, they compare unequal.
|
|
if (!LHSValue.getDecl() || !RHSValue.getDecl()) {
|
|
bool Equal = !LHSValue.getDecl() && !RHSValue.getDecl();
|
|
return Success(Equal ? CCR::Equal : CCR::Nonequal, E);
|
|
}
|
|
|
|
// Otherwise if either is a pointer to a virtual member function, the
|
|
// result is unspecified.
|
|
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(LHSValue.getDecl()))
|
|
if (MD->isVirtual())
|
|
Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
|
|
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(RHSValue.getDecl()))
|
|
if (MD->isVirtual())
|
|
Info.CCEDiag(E, diag::note_constexpr_compare_virtual_mem_ptr) << MD;
|
|
|
|
// Otherwise they compare equal if and only if they would refer to the
|
|
// same member of the same most derived object or the same subobject if
|
|
// they were dereferenced with a hypothetical object of the associated
|
|
// class type.
|
|
bool Equal = LHSValue == RHSValue;
|
|
return Success(Equal ? CCR::Equal : CCR::Nonequal, E);
|
|
}
|
|
|
|
if (LHSTy->isNullPtrType()) {
|
|
assert(E->isComparisonOp() && "unexpected nullptr operation");
|
|
assert(RHSTy->isNullPtrType() && "missing pointer conversion");
|
|
// C++11 [expr.rel]p4, [expr.eq]p3: If two operands of type std::nullptr_t
|
|
// are compared, the result is true of the operator is <=, >= or ==, and
|
|
// false otherwise.
|
|
return Success(CCR::Equal, E);
|
|
}
|
|
|
|
return DoAfter();
|
|
}
|
|
|
|
bool RecordExprEvaluator::VisitBinCmp(const BinaryOperator *E) {
|
|
if (!CheckLiteralType(Info, E))
|
|
return false;
|
|
|
|
auto OnSuccess = [&](ComparisonCategoryResult ResKind,
|
|
const BinaryOperator *E) {
|
|
// Evaluation succeeded. Lookup the information for the comparison category
|
|
// type and fetch the VarDecl for the result.
|
|
const ComparisonCategoryInfo &CmpInfo =
|
|
Info.Ctx.CompCategories.getInfoForType(E->getType());
|
|
const VarDecl *VD =
|
|
CmpInfo.getValueInfo(CmpInfo.makeWeakResult(ResKind))->VD;
|
|
// Check and evaluate the result as a constant expression.
|
|
LValue LV;
|
|
LV.set(VD);
|
|
if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
|
|
return false;
|
|
return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result);
|
|
};
|
|
return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
|
|
return ExprEvaluatorBaseTy::VisitBinCmp(E);
|
|
});
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
|
|
// We don't call noteFailure immediately because the assignment happens after
|
|
// we evaluate LHS and RHS.
|
|
if (!Info.keepEvaluatingAfterFailure() && E->isAssignmentOp())
|
|
return Error(E);
|
|
|
|
DelayedNoteFailureRAII MaybeNoteFailureLater(Info, E->isAssignmentOp());
|
|
if (DataRecursiveIntBinOpEvaluator::shouldEnqueue(E))
|
|
return DataRecursiveIntBinOpEvaluator(*this, Result).Traverse(E);
|
|
|
|
assert((!E->getLHS()->getType()->isIntegralOrEnumerationType() ||
|
|
!E->getRHS()->getType()->isIntegralOrEnumerationType()) &&
|
|
"DataRecursiveIntBinOpEvaluator should have handled integral types");
|
|
|
|
if (E->isComparisonOp()) {
|
|
// Evaluate builtin binary comparisons by evaluating them as C++2a three-way
|
|
// comparisons and then translating the result.
|
|
auto OnSuccess = [&](ComparisonCategoryResult ResKind,
|
|
const BinaryOperator *E) {
|
|
using CCR = ComparisonCategoryResult;
|
|
bool IsEqual = ResKind == CCR::Equal,
|
|
IsLess = ResKind == CCR::Less,
|
|
IsGreater = ResKind == CCR::Greater;
|
|
auto Op = E->getOpcode();
|
|
switch (Op) {
|
|
default:
|
|
llvm_unreachable("unsupported binary operator");
|
|
case BO_EQ:
|
|
case BO_NE:
|
|
return Success(IsEqual == (Op == BO_EQ), E);
|
|
case BO_LT: return Success(IsLess, E);
|
|
case BO_GT: return Success(IsGreater, E);
|
|
case BO_LE: return Success(IsEqual || IsLess, E);
|
|
case BO_GE: return Success(IsEqual || IsGreater, E);
|
|
}
|
|
};
|
|
return EvaluateComparisonBinaryOperator(Info, E, OnSuccess, [&]() {
|
|
return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
|
|
});
|
|
}
|
|
|
|
QualType LHSTy = E->getLHS()->getType();
|
|
QualType RHSTy = E->getRHS()->getType();
|
|
|
|
if (LHSTy->isPointerType() && RHSTy->isPointerType() &&
|
|
E->getOpcode() == BO_Sub) {
|
|
LValue LHSValue, RHSValue;
|
|
|
|
bool LHSOK = EvaluatePointer(E->getLHS(), LHSValue, Info);
|
|
if (!LHSOK && !Info.noteFailure())
|
|
return false;
|
|
|
|
if (!EvaluatePointer(E->getRHS(), RHSValue, Info) || !LHSOK)
|
|
return false;
|
|
|
|
// Reject differing bases from the normal codepath; we special-case
|
|
// comparisons to null.
|
|
if (!HasSameBase(LHSValue, RHSValue)) {
|
|
// Handle &&A - &&B.
|
|
if (!LHSValue.Offset.isZero() || !RHSValue.Offset.isZero())
|
|
return Error(E);
|
|
const Expr *LHSExpr = LHSValue.Base.dyn_cast<const Expr *>();
|
|
const Expr *RHSExpr = RHSValue.Base.dyn_cast<const Expr *>();
|
|
if (!LHSExpr || !RHSExpr)
|
|
return Error(E);
|
|
const AddrLabelExpr *LHSAddrExpr = dyn_cast<AddrLabelExpr>(LHSExpr);
|
|
const AddrLabelExpr *RHSAddrExpr = dyn_cast<AddrLabelExpr>(RHSExpr);
|
|
if (!LHSAddrExpr || !RHSAddrExpr)
|
|
return Error(E);
|
|
// Make sure both labels come from the same function.
|
|
if (LHSAddrExpr->getLabel()->getDeclContext() !=
|
|
RHSAddrExpr->getLabel()->getDeclContext())
|
|
return Error(E);
|
|
return Success(APValue(LHSAddrExpr, RHSAddrExpr), E);
|
|
}
|
|
const CharUnits &LHSOffset = LHSValue.getLValueOffset();
|
|
const CharUnits &RHSOffset = RHSValue.getLValueOffset();
|
|
|
|
SubobjectDesignator &LHSDesignator = LHSValue.getLValueDesignator();
|
|
SubobjectDesignator &RHSDesignator = RHSValue.getLValueDesignator();
|
|
|
|
// C++11 [expr.add]p6:
|
|
// Unless both pointers point to elements of the same array object, or
|
|
// one past the last element of the array object, the behavior is
|
|
// undefined.
|
|
if (!LHSDesignator.Invalid && !RHSDesignator.Invalid &&
|
|
!AreElementsOfSameArray(getType(LHSValue.Base), LHSDesignator,
|
|
RHSDesignator))
|
|
Info.CCEDiag(E, diag::note_constexpr_pointer_subtraction_not_same_array);
|
|
|
|
QualType Type = E->getLHS()->getType();
|
|
QualType ElementType = Type->getAs<PointerType>()->getPointeeType();
|
|
|
|
CharUnits ElementSize;
|
|
if (!HandleSizeof(Info, E->getExprLoc(), ElementType, ElementSize))
|
|
return false;
|
|
|
|
// As an extension, a type may have zero size (empty struct or union in
|
|
// C, array of zero length). Pointer subtraction in such cases has
|
|
// undefined behavior, so is not constant.
|
|
if (ElementSize.isZero()) {
|
|
Info.FFDiag(E, diag::note_constexpr_pointer_subtraction_zero_size)
|
|
<< ElementType;
|
|
return false;
|
|
}
|
|
|
|
// FIXME: LLVM and GCC both compute LHSOffset - RHSOffset at runtime,
|
|
// and produce incorrect results when it overflows. Such behavior
|
|
// appears to be non-conforming, but is common, so perhaps we should
|
|
// assume the standard intended for such cases to be undefined behavior
|
|
// and check for them.
|
|
|
|
// Compute (LHSOffset - RHSOffset) / Size carefully, checking for
|
|
// overflow in the final conversion to ptrdiff_t.
|
|
APSInt LHS(llvm::APInt(65, (int64_t)LHSOffset.getQuantity(), true), false);
|
|
APSInt RHS(llvm::APInt(65, (int64_t)RHSOffset.getQuantity(), true), false);
|
|
APSInt ElemSize(llvm::APInt(65, (int64_t)ElementSize.getQuantity(), true),
|
|
false);
|
|
APSInt TrueResult = (LHS - RHS) / ElemSize;
|
|
APSInt Result = TrueResult.trunc(Info.Ctx.getIntWidth(E->getType()));
|
|
|
|
if (Result.extend(65) != TrueResult &&
|
|
!HandleOverflow(Info, E, TrueResult, E->getType()))
|
|
return false;
|
|
return Success(Result, E);
|
|
}
|
|
|
|
return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
|
|
}
|
|
|
|
/// VisitUnaryExprOrTypeTraitExpr - Evaluate a sizeof, alignof or vec_step with
|
|
/// a result as the expression's type.
|
|
bool IntExprEvaluator::VisitUnaryExprOrTypeTraitExpr(
|
|
const UnaryExprOrTypeTraitExpr *E) {
|
|
switch(E->getKind()) {
|
|
case UETT_PreferredAlignOf:
|
|
case UETT_AlignOf: {
|
|
if (E->isArgumentType())
|
|
return Success(GetAlignOfType(Info, E->getArgumentType(), E->getKind()),
|
|
E);
|
|
else
|
|
return Success(GetAlignOfExpr(Info, E->getArgumentExpr(), E->getKind()),
|
|
E);
|
|
}
|
|
|
|
case UETT_VecStep: {
|
|
QualType Ty = E->getTypeOfArgument();
|
|
|
|
if (Ty->isVectorType()) {
|
|
unsigned n = Ty->castAs<VectorType>()->getNumElements();
|
|
|
|
// The vec_step built-in functions that take a 3-component
|
|
// vector return 4. (OpenCL 1.1 spec 6.11.12)
|
|
if (n == 3)
|
|
n = 4;
|
|
|
|
return Success(n, E);
|
|
} else
|
|
return Success(1, E);
|
|
}
|
|
|
|
case UETT_SizeOf: {
|
|
QualType SrcTy = E->getTypeOfArgument();
|
|
// C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
|
|
// the result is the size of the referenced type."
|
|
if (const ReferenceType *Ref = SrcTy->getAs<ReferenceType>())
|
|
SrcTy = Ref->getPointeeType();
|
|
|
|
CharUnits Sizeof;
|
|
if (!HandleSizeof(Info, E->getExprLoc(), SrcTy, Sizeof))
|
|
return false;
|
|
return Success(Sizeof, E);
|
|
}
|
|
case UETT_OpenMPRequiredSimdAlign:
|
|
assert(E->isArgumentType());
|
|
return Success(
|
|
Info.Ctx.toCharUnitsFromBits(
|
|
Info.Ctx.getOpenMPDefaultSimdAlign(E->getArgumentType()))
|
|
.getQuantity(),
|
|
E);
|
|
}
|
|
|
|
llvm_unreachable("unknown expr/type trait");
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *OOE) {
|
|
CharUnits Result;
|
|
unsigned n = OOE->getNumComponents();
|
|
if (n == 0)
|
|
return Error(OOE);
|
|
QualType CurrentType = OOE->getTypeSourceInfo()->getType();
|
|
for (unsigned i = 0; i != n; ++i) {
|
|
OffsetOfNode ON = OOE->getComponent(i);
|
|
switch (ON.getKind()) {
|
|
case OffsetOfNode::Array: {
|
|
const Expr *Idx = OOE->getIndexExpr(ON.getArrayExprIndex());
|
|
APSInt IdxResult;
|
|
if (!EvaluateInteger(Idx, IdxResult, Info))
|
|
return false;
|
|
const ArrayType *AT = Info.Ctx.getAsArrayType(CurrentType);
|
|
if (!AT)
|
|
return Error(OOE);
|
|
CurrentType = AT->getElementType();
|
|
CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(CurrentType);
|
|
Result += IdxResult.getSExtValue() * ElementSize;
|
|
break;
|
|
}
|
|
|
|
case OffsetOfNode::Field: {
|
|
FieldDecl *MemberDecl = ON.getField();
|
|
const RecordType *RT = CurrentType->getAs<RecordType>();
|
|
if (!RT)
|
|
return Error(OOE);
|
|
RecordDecl *RD = RT->getDecl();
|
|
if (RD->isInvalidDecl()) return false;
|
|
const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
|
|
unsigned i = MemberDecl->getFieldIndex();
|
|
assert(i < RL.getFieldCount() && "offsetof field in wrong type");
|
|
Result += Info.Ctx.toCharUnitsFromBits(RL.getFieldOffset(i));
|
|
CurrentType = MemberDecl->getType().getNonReferenceType();
|
|
break;
|
|
}
|
|
|
|
case OffsetOfNode::Identifier:
|
|
llvm_unreachable("dependent __builtin_offsetof");
|
|
|
|
case OffsetOfNode::Base: {
|
|
CXXBaseSpecifier *BaseSpec = ON.getBase();
|
|
if (BaseSpec->isVirtual())
|
|
return Error(OOE);
|
|
|
|
// Find the layout of the class whose base we are looking into.
|
|
const RecordType *RT = CurrentType->getAs<RecordType>();
|
|
if (!RT)
|
|
return Error(OOE);
|
|
RecordDecl *RD = RT->getDecl();
|
|
if (RD->isInvalidDecl()) return false;
|
|
const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
|
|
|
|
// Find the base class itself.
|
|
CurrentType = BaseSpec->getType();
|
|
const RecordType *BaseRT = CurrentType->getAs<RecordType>();
|
|
if (!BaseRT)
|
|
return Error(OOE);
|
|
|
|
// Add the offset to the base.
|
|
Result += RL.getBaseClassOffset(cast<CXXRecordDecl>(BaseRT->getDecl()));
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
return Success(Result, OOE);
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
|
|
switch (E->getOpcode()) {
|
|
default:
|
|
// Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
|
|
// See C99 6.6p3.
|
|
return Error(E);
|
|
case UO_Extension:
|
|
// FIXME: Should extension allow i-c-e extension expressions in its scope?
|
|
// If so, we could clear the diagnostic ID.
|
|
return Visit(E->getSubExpr());
|
|
case UO_Plus:
|
|
// The result is just the value.
|
|
return Visit(E->getSubExpr());
|
|
case UO_Minus: {
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
if (!Result.isInt()) return Error(E);
|
|
const APSInt &Value = Result.getInt();
|
|
if (Value.isSigned() && Value.isMinSignedValue() && E->canOverflow() &&
|
|
!HandleOverflow(Info, E, -Value.extend(Value.getBitWidth() + 1),
|
|
E->getType()))
|
|
return false;
|
|
return Success(-Value, E);
|
|
}
|
|
case UO_Not: {
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
if (!Result.isInt()) return Error(E);
|
|
return Success(~Result.getInt(), E);
|
|
}
|
|
case UO_LNot: {
|
|
bool bres;
|
|
if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
|
|
return false;
|
|
return Success(!bres, E);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// HandleCast - This is used to evaluate implicit or explicit casts where the
|
|
/// result type is integer.
|
|
bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
|
|
const Expr *SubExpr = E->getSubExpr();
|
|
QualType DestType = E->getType();
|
|
QualType SrcType = SubExpr->getType();
|
|
|
|
switch (E->getCastKind()) {
|
|
case CK_BaseToDerived:
|
|
case CK_DerivedToBase:
|
|
case CK_UncheckedDerivedToBase:
|
|
case CK_Dynamic:
|
|
case CK_ToUnion:
|
|
case CK_ArrayToPointerDecay:
|
|
case CK_FunctionToPointerDecay:
|
|
case CK_NullToPointer:
|
|
case CK_NullToMemberPointer:
|
|
case CK_BaseToDerivedMemberPointer:
|
|
case CK_DerivedToBaseMemberPointer:
|
|
case CK_ReinterpretMemberPointer:
|
|
case CK_ConstructorConversion:
|
|
case CK_IntegralToPointer:
|
|
case CK_ToVoid:
|
|
case CK_VectorSplat:
|
|
case CK_IntegralToFloating:
|
|
case CK_FloatingCast:
|
|
case CK_CPointerToObjCPointerCast:
|
|
case CK_BlockPointerToObjCPointerCast:
|
|
case CK_AnyPointerToBlockPointerCast:
|
|
case CK_ObjCObjectLValueCast:
|
|
case CK_FloatingRealToComplex:
|
|
case CK_FloatingComplexToReal:
|
|
case CK_FloatingComplexCast:
|
|
case CK_FloatingComplexToIntegralComplex:
|
|
case CK_IntegralRealToComplex:
|
|
case CK_IntegralComplexCast:
|
|
case CK_IntegralComplexToFloatingComplex:
|
|
case CK_BuiltinFnToFnPtr:
|
|
case CK_ZeroToOCLOpaqueType:
|
|
case CK_NonAtomicToAtomic:
|
|
case CK_AddressSpaceConversion:
|
|
case CK_IntToOCLSampler:
|
|
case CK_FixedPointCast:
|
|
llvm_unreachable("invalid cast kind for integral value");
|
|
|
|
case CK_BitCast:
|
|
case CK_Dependent:
|
|
case CK_LValueBitCast:
|
|
case CK_ARCProduceObject:
|
|
case CK_ARCConsumeObject:
|
|
case CK_ARCReclaimReturnedObject:
|
|
case CK_ARCExtendBlockObject:
|
|
case CK_CopyAndAutoreleaseBlockObject:
|
|
return Error(E);
|
|
|
|
case CK_UserDefinedConversion:
|
|
case CK_LValueToRValue:
|
|
case CK_AtomicToNonAtomic:
|
|
case CK_NoOp:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
|
|
case CK_MemberPointerToBoolean:
|
|
case CK_PointerToBoolean:
|
|
case CK_IntegralToBoolean:
|
|
case CK_FloatingToBoolean:
|
|
case CK_BooleanToSignedIntegral:
|
|
case CK_FloatingComplexToBoolean:
|
|
case CK_IntegralComplexToBoolean: {
|
|
bool BoolResult;
|
|
if (!EvaluateAsBooleanCondition(SubExpr, BoolResult, Info))
|
|
return false;
|
|
uint64_t IntResult = BoolResult;
|
|
if (BoolResult && E->getCastKind() == CK_BooleanToSignedIntegral)
|
|
IntResult = (uint64_t)-1;
|
|
return Success(IntResult, E);
|
|
}
|
|
|
|
case CK_FixedPointToBoolean: {
|
|
// Unsigned padding does not affect this.
|
|
APValue Val;
|
|
if (!Evaluate(Val, Info, SubExpr))
|
|
return false;
|
|
return Success(Val.getInt().getBoolValue(), E);
|
|
}
|
|
|
|
case CK_IntegralCast: {
|
|
if (!Visit(SubExpr))
|
|
return false;
|
|
|
|
if (!Result.isInt()) {
|
|
// Allow casts of address-of-label differences if they are no-ops
|
|
// or narrowing. (The narrowing case isn't actually guaranteed to
|
|
// be constant-evaluatable except in some narrow cases which are hard
|
|
// to detect here. We let it through on the assumption the user knows
|
|
// what they are doing.)
|
|
if (Result.isAddrLabelDiff())
|
|
return Info.Ctx.getTypeSize(DestType) <= Info.Ctx.getTypeSize(SrcType);
|
|
// Only allow casts of lvalues if they are lossless.
|
|
return Info.Ctx.getTypeSize(DestType) == Info.Ctx.getTypeSize(SrcType);
|
|
}
|
|
|
|
return Success(HandleIntToIntCast(Info, E, DestType, SrcType,
|
|
Result.getInt()), E);
|
|
}
|
|
|
|
case CK_PointerToIntegral: {
|
|
CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
|
|
|
|
LValue LV;
|
|
if (!EvaluatePointer(SubExpr, LV, Info))
|
|
return false;
|
|
|
|
if (LV.getLValueBase()) {
|
|
// Only allow based lvalue casts if they are lossless.
|
|
// FIXME: Allow a larger integer size than the pointer size, and allow
|
|
// narrowing back down to pointer width in subsequent integral casts.
|
|
// FIXME: Check integer type's active bits, not its type size.
|
|
if (Info.Ctx.getTypeSize(DestType) != Info.Ctx.getTypeSize(SrcType))
|
|
return Error(E);
|
|
|
|
LV.Designator.setInvalid();
|
|
LV.moveInto(Result);
|
|
return true;
|
|
}
|
|
|
|
uint64_t V;
|
|
if (LV.isNullPointer())
|
|
V = Info.Ctx.getTargetNullPointerValue(SrcType);
|
|
else
|
|
V = LV.getLValueOffset().getQuantity();
|
|
|
|
APSInt AsInt = Info.Ctx.MakeIntValue(V, SrcType);
|
|
return Success(HandleIntToIntCast(Info, E, DestType, SrcType, AsInt), E);
|
|
}
|
|
|
|
case CK_IntegralComplexToReal: {
|
|
ComplexValue C;
|
|
if (!EvaluateComplex(SubExpr, C, Info))
|
|
return false;
|
|
return Success(C.getComplexIntReal(), E);
|
|
}
|
|
|
|
case CK_FloatingToIntegral: {
|
|
APFloat F(0.0);
|
|
if (!EvaluateFloat(SubExpr, F, Info))
|
|
return false;
|
|
|
|
APSInt Value;
|
|
if (!HandleFloatToIntCast(Info, E, SrcType, F, DestType, Value))
|
|
return false;
|
|
return Success(Value, E);
|
|
}
|
|
}
|
|
|
|
llvm_unreachable("unknown cast resulting in integral value");
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
|
|
if (E->getSubExpr()->getType()->isAnyComplexType()) {
|
|
ComplexValue LV;
|
|
if (!EvaluateComplex(E->getSubExpr(), LV, Info))
|
|
return false;
|
|
if (!LV.isComplexInt())
|
|
return Error(E);
|
|
return Success(LV.getComplexIntReal(), E);
|
|
}
|
|
|
|
return Visit(E->getSubExpr());
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
|
|
if (E->getSubExpr()->getType()->isComplexIntegerType()) {
|
|
ComplexValue LV;
|
|
if (!EvaluateComplex(E->getSubExpr(), LV, Info))
|
|
return false;
|
|
if (!LV.isComplexInt())
|
|
return Error(E);
|
|
return Success(LV.getComplexIntImag(), E);
|
|
}
|
|
|
|
VisitIgnoredValue(E->getSubExpr());
|
|
return Success(0, E);
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitSizeOfPackExpr(const SizeOfPackExpr *E) {
|
|
return Success(E->getPackLength(), E);
|
|
}
|
|
|
|
bool IntExprEvaluator::VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
|
|
return Success(E->getValue(), E);
|
|
}
|
|
|
|
bool FixedPointExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
|
|
switch (E->getOpcode()) {
|
|
default:
|
|
// Invalid unary operators
|
|
return Error(E);
|
|
case UO_Plus:
|
|
// The result is just the value.
|
|
return Visit(E->getSubExpr());
|
|
case UO_Minus: {
|
|
if (!Visit(E->getSubExpr())) return false;
|
|
if (!Result.isInt()) return Error(E);
|
|
const APSInt &Value = Result.getInt();
|
|
if (Value.isSigned() && Value.isMinSignedValue() && E->canOverflow()) {
|
|
SmallString<64> S;
|
|
FixedPointValueToString(S, Value,
|
|
Info.Ctx.getTypeInfo(E->getType()).Width);
|
|
Info.CCEDiag(E, diag::note_constexpr_overflow) << S << E->getType();
|
|
if (Info.noteUndefinedBehavior()) return false;
|
|
}
|
|
return Success(-Value, E);
|
|
}
|
|
case UO_LNot: {
|
|
bool bres;
|
|
if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info))
|
|
return false;
|
|
return Success(!bres, E);
|
|
}
|
|
}
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Float Evaluation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class FloatExprEvaluator
|
|
: public ExprEvaluatorBase<FloatExprEvaluator> {
|
|
APFloat &Result;
|
|
public:
|
|
FloatExprEvaluator(EvalInfo &info, APFloat &result)
|
|
: ExprEvaluatorBaseTy(info), Result(result) {}
|
|
|
|
bool Success(const APValue &V, const Expr *e) {
|
|
Result = V.getFloat();
|
|
return true;
|
|
}
|
|
|
|
bool ZeroInitialization(const Expr *E) {
|
|
Result = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(E->getType()));
|
|
return true;
|
|
}
|
|
|
|
bool VisitCallExpr(const CallExpr *E);
|
|
|
|
bool VisitUnaryOperator(const UnaryOperator *E);
|
|
bool VisitBinaryOperator(const BinaryOperator *E);
|
|
bool VisitFloatingLiteral(const FloatingLiteral *E);
|
|
bool VisitCastExpr(const CastExpr *E);
|
|
|
|
bool VisitUnaryReal(const UnaryOperator *E);
|
|
bool VisitUnaryImag(const UnaryOperator *E);
|
|
|
|
// FIXME: Missing: array subscript of vector, member of vector
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isRealFloatingType());
|
|
return FloatExprEvaluator(Info, Result).Visit(E);
|
|
}
|
|
|
|
static bool TryEvaluateBuiltinNaN(const ASTContext &Context,
|
|
QualType ResultTy,
|
|
const Expr *Arg,
|
|
bool SNaN,
|
|
llvm::APFloat &Result) {
|
|
const StringLiteral *S = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts());
|
|
if (!S) return false;
|
|
|
|
const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(ResultTy);
|
|
|
|
llvm::APInt fill;
|
|
|
|
// Treat empty strings as if they were zero.
|
|
if (S->getString().empty())
|
|
fill = llvm::APInt(32, 0);
|
|
else if (S->getString().getAsInteger(0, fill))
|
|
return false;
|
|
|
|
if (Context.getTargetInfo().isNan2008()) {
|
|
if (SNaN)
|
|
Result = llvm::APFloat::getSNaN(Sem, false, &fill);
|
|
else
|
|
Result = llvm::APFloat::getQNaN(Sem, false, &fill);
|
|
} else {
|
|
// Prior to IEEE 754-2008, architectures were allowed to choose whether
|
|
// the first bit of their significand was set for qNaN or sNaN. MIPS chose
|
|
// a different encoding to what became a standard in 2008, and for pre-
|
|
// 2008 revisions, MIPS interpreted sNaN-2008 as qNan and qNaN-2008 as
|
|
// sNaN. This is now known as "legacy NaN" encoding.
|
|
if (SNaN)
|
|
Result = llvm::APFloat::getQNaN(Sem, false, &fill);
|
|
else
|
|
Result = llvm::APFloat::getSNaN(Sem, false, &fill);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
|
|
switch (E->getBuiltinCallee()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCallExpr(E);
|
|
|
|
case Builtin::BI__builtin_huge_val:
|
|
case Builtin::BI__builtin_huge_valf:
|
|
case Builtin::BI__builtin_huge_vall:
|
|
case Builtin::BI__builtin_huge_valf128:
|
|
case Builtin::BI__builtin_inf:
|
|
case Builtin::BI__builtin_inff:
|
|
case Builtin::BI__builtin_infl:
|
|
case Builtin::BI__builtin_inff128: {
|
|
const llvm::fltSemantics &Sem =
|
|
Info.Ctx.getFloatTypeSemantics(E->getType());
|
|
Result = llvm::APFloat::getInf(Sem);
|
|
return true;
|
|
}
|
|
|
|
case Builtin::BI__builtin_nans:
|
|
case Builtin::BI__builtin_nansf:
|
|
case Builtin::BI__builtin_nansl:
|
|
case Builtin::BI__builtin_nansf128:
|
|
if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
|
|
true, Result))
|
|
return Error(E);
|
|
return true;
|
|
|
|
case Builtin::BI__builtin_nan:
|
|
case Builtin::BI__builtin_nanf:
|
|
case Builtin::BI__builtin_nanl:
|
|
case Builtin::BI__builtin_nanf128:
|
|
// If this is __builtin_nan() turn this into a nan, otherwise we
|
|
// can't constant fold it.
|
|
if (!TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
|
|
false, Result))
|
|
return Error(E);
|
|
return true;
|
|
|
|
case Builtin::BI__builtin_fabs:
|
|
case Builtin::BI__builtin_fabsf:
|
|
case Builtin::BI__builtin_fabsl:
|
|
case Builtin::BI__builtin_fabsf128:
|
|
if (!EvaluateFloat(E->getArg(0), Result, Info))
|
|
return false;
|
|
|
|
if (Result.isNegative())
|
|
Result.changeSign();
|
|
return true;
|
|
|
|
// FIXME: Builtin::BI__builtin_powi
|
|
// FIXME: Builtin::BI__builtin_powif
|
|
// FIXME: Builtin::BI__builtin_powil
|
|
|
|
case Builtin::BI__builtin_copysign:
|
|
case Builtin::BI__builtin_copysignf:
|
|
case Builtin::BI__builtin_copysignl:
|
|
case Builtin::BI__builtin_copysignf128: {
|
|
APFloat RHS(0.);
|
|
if (!EvaluateFloat(E->getArg(0), Result, Info) ||
|
|
!EvaluateFloat(E->getArg(1), RHS, Info))
|
|
return false;
|
|
Result.copySign(RHS);
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool FloatExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
|
|
if (E->getSubExpr()->getType()->isAnyComplexType()) {
|
|
ComplexValue CV;
|
|
if (!EvaluateComplex(E->getSubExpr(), CV, Info))
|
|
return false;
|
|
Result = CV.FloatReal;
|
|
return true;
|
|
}
|
|
|
|
return Visit(E->getSubExpr());
|
|
}
|
|
|
|
bool FloatExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
|
|
if (E->getSubExpr()->getType()->isAnyComplexType()) {
|
|
ComplexValue CV;
|
|
if (!EvaluateComplex(E->getSubExpr(), CV, Info))
|
|
return false;
|
|
Result = CV.FloatImag;
|
|
return true;
|
|
}
|
|
|
|
VisitIgnoredValue(E->getSubExpr());
|
|
const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(E->getType());
|
|
Result = llvm::APFloat::getZero(Sem);
|
|
return true;
|
|
}
|
|
|
|
bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
|
|
switch (E->getOpcode()) {
|
|
default: return Error(E);
|
|
case UO_Plus:
|
|
return EvaluateFloat(E->getSubExpr(), Result, Info);
|
|
case UO_Minus:
|
|
if (!EvaluateFloat(E->getSubExpr(), Result, Info))
|
|
return false;
|
|
Result.changeSign();
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
|
|
if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
|
|
return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
|
|
|
|
APFloat RHS(0.0);
|
|
bool LHSOK = EvaluateFloat(E->getLHS(), Result, Info);
|
|
if (!LHSOK && !Info.noteFailure())
|
|
return false;
|
|
return EvaluateFloat(E->getRHS(), RHS, Info) && LHSOK &&
|
|
handleFloatFloatBinOp(Info, E, Result, E->getOpcode(), RHS);
|
|
}
|
|
|
|
bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) {
|
|
Result = E->getValue();
|
|
return true;
|
|
}
|
|
|
|
bool FloatExprEvaluator::VisitCastExpr(const CastExpr *E) {
|
|
const Expr* SubExpr = E->getSubExpr();
|
|
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
|
|
case CK_IntegralToFloating: {
|
|
APSInt IntResult;
|
|
return EvaluateInteger(SubExpr, IntResult, Info) &&
|
|
HandleIntToFloatCast(Info, E, SubExpr->getType(), IntResult,
|
|
E->getType(), Result);
|
|
}
|
|
|
|
case CK_FloatingCast: {
|
|
if (!Visit(SubExpr))
|
|
return false;
|
|
return HandleFloatToFloatCast(Info, E, SubExpr->getType(), E->getType(),
|
|
Result);
|
|
}
|
|
|
|
case CK_FloatingComplexToReal: {
|
|
ComplexValue V;
|
|
if (!EvaluateComplex(SubExpr, V, Info))
|
|
return false;
|
|
Result = V.getComplexFloatReal();
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Complex Evaluation (for float and integer)
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class ComplexExprEvaluator
|
|
: public ExprEvaluatorBase<ComplexExprEvaluator> {
|
|
ComplexValue &Result;
|
|
|
|
public:
|
|
ComplexExprEvaluator(EvalInfo &info, ComplexValue &Result)
|
|
: ExprEvaluatorBaseTy(info), Result(Result) {}
|
|
|
|
bool Success(const APValue &V, const Expr *e) {
|
|
Result.setFrom(V);
|
|
return true;
|
|
}
|
|
|
|
bool ZeroInitialization(const Expr *E);
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// Visitor Methods
|
|
//===--------------------------------------------------------------------===//
|
|
|
|
bool VisitImaginaryLiteral(const ImaginaryLiteral *E);
|
|
bool VisitCastExpr(const CastExpr *E);
|
|
bool VisitBinaryOperator(const BinaryOperator *E);
|
|
bool VisitUnaryOperator(const UnaryOperator *E);
|
|
bool VisitInitListExpr(const InitListExpr *E);
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool EvaluateComplex(const Expr *E, ComplexValue &Result,
|
|
EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isAnyComplexType());
|
|
return ComplexExprEvaluator(Info, Result).Visit(E);
|
|
}
|
|
|
|
bool ComplexExprEvaluator::ZeroInitialization(const Expr *E) {
|
|
QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
|
|
if (ElemTy->isRealFloatingType()) {
|
|
Result.makeComplexFloat();
|
|
APFloat Zero = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(ElemTy));
|
|
Result.FloatReal = Zero;
|
|
Result.FloatImag = Zero;
|
|
} else {
|
|
Result.makeComplexInt();
|
|
APSInt Zero = Info.Ctx.MakeIntValue(0, ElemTy);
|
|
Result.IntReal = Zero;
|
|
Result.IntImag = Zero;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool ComplexExprEvaluator::VisitImaginaryLiteral(const ImaginaryLiteral *E) {
|
|
const Expr* SubExpr = E->getSubExpr();
|
|
|
|
if (SubExpr->getType()->isRealFloatingType()) {
|
|
Result.makeComplexFloat();
|
|
APFloat &Imag = Result.FloatImag;
|
|
if (!EvaluateFloat(SubExpr, Imag, Info))
|
|
return false;
|
|
|
|
Result.FloatReal = APFloat(Imag.getSemantics());
|
|
return true;
|
|
} else {
|
|
assert(SubExpr->getType()->isIntegerType() &&
|
|
"Unexpected imaginary literal.");
|
|
|
|
Result.makeComplexInt();
|
|
APSInt &Imag = Result.IntImag;
|
|
if (!EvaluateInteger(SubExpr, Imag, Info))
|
|
return false;
|
|
|
|
Result.IntReal = APSInt(Imag.getBitWidth(), !Imag.isSigned());
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
|
|
|
|
switch (E->getCastKind()) {
|
|
case CK_BitCast:
|
|
case CK_BaseToDerived:
|
|
case CK_DerivedToBase:
|
|
case CK_UncheckedDerivedToBase:
|
|
case CK_Dynamic:
|
|
case CK_ToUnion:
|
|
case CK_ArrayToPointerDecay:
|
|
case CK_FunctionToPointerDecay:
|
|
case CK_NullToPointer:
|
|
case CK_NullToMemberPointer:
|
|
case CK_BaseToDerivedMemberPointer:
|
|
case CK_DerivedToBaseMemberPointer:
|
|
case CK_MemberPointerToBoolean:
|
|
case CK_ReinterpretMemberPointer:
|
|
case CK_ConstructorConversion:
|
|
case CK_IntegralToPointer:
|
|
case CK_PointerToIntegral:
|
|
case CK_PointerToBoolean:
|
|
case CK_ToVoid:
|
|
case CK_VectorSplat:
|
|
case CK_IntegralCast:
|
|
case CK_BooleanToSignedIntegral:
|
|
case CK_IntegralToBoolean:
|
|
case CK_IntegralToFloating:
|
|
case CK_FloatingToIntegral:
|
|
case CK_FloatingToBoolean:
|
|
case CK_FloatingCast:
|
|
case CK_CPointerToObjCPointerCast:
|
|
case CK_BlockPointerToObjCPointerCast:
|
|
case CK_AnyPointerToBlockPointerCast:
|
|
case CK_ObjCObjectLValueCast:
|
|
case CK_FloatingComplexToReal:
|
|
case CK_FloatingComplexToBoolean:
|
|
case CK_IntegralComplexToReal:
|
|
case CK_IntegralComplexToBoolean:
|
|
case CK_ARCProduceObject:
|
|
case CK_ARCConsumeObject:
|
|
case CK_ARCReclaimReturnedObject:
|
|
case CK_ARCExtendBlockObject:
|
|
case CK_CopyAndAutoreleaseBlockObject:
|
|
case CK_BuiltinFnToFnPtr:
|
|
case CK_ZeroToOCLOpaqueType:
|
|
case CK_NonAtomicToAtomic:
|
|
case CK_AddressSpaceConversion:
|
|
case CK_IntToOCLSampler:
|
|
case CK_FixedPointCast:
|
|
case CK_FixedPointToBoolean:
|
|
llvm_unreachable("invalid cast kind for complex value");
|
|
|
|
case CK_LValueToRValue:
|
|
case CK_AtomicToNonAtomic:
|
|
case CK_NoOp:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
|
|
case CK_Dependent:
|
|
case CK_LValueBitCast:
|
|
case CK_UserDefinedConversion:
|
|
return Error(E);
|
|
|
|
case CK_FloatingRealToComplex: {
|
|
APFloat &Real = Result.FloatReal;
|
|
if (!EvaluateFloat(E->getSubExpr(), Real, Info))
|
|
return false;
|
|
|
|
Result.makeComplexFloat();
|
|
Result.FloatImag = APFloat(Real.getSemantics());
|
|
return true;
|
|
}
|
|
|
|
case CK_FloatingComplexCast: {
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
|
|
QualType To = E->getType()->getAs<ComplexType>()->getElementType();
|
|
QualType From
|
|
= E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
|
|
|
|
return HandleFloatToFloatCast(Info, E, From, To, Result.FloatReal) &&
|
|
HandleFloatToFloatCast(Info, E, From, To, Result.FloatImag);
|
|
}
|
|
|
|
case CK_FloatingComplexToIntegralComplex: {
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
|
|
QualType To = E->getType()->getAs<ComplexType>()->getElementType();
|
|
QualType From
|
|
= E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
|
|
Result.makeComplexInt();
|
|
return HandleFloatToIntCast(Info, E, From, Result.FloatReal,
|
|
To, Result.IntReal) &&
|
|
HandleFloatToIntCast(Info, E, From, Result.FloatImag,
|
|
To, Result.IntImag);
|
|
}
|
|
|
|
case CK_IntegralRealToComplex: {
|
|
APSInt &Real = Result.IntReal;
|
|
if (!EvaluateInteger(E->getSubExpr(), Real, Info))
|
|
return false;
|
|
|
|
Result.makeComplexInt();
|
|
Result.IntImag = APSInt(Real.getBitWidth(), !Real.isSigned());
|
|
return true;
|
|
}
|
|
|
|
case CK_IntegralComplexCast: {
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
|
|
QualType To = E->getType()->getAs<ComplexType>()->getElementType();
|
|
QualType From
|
|
= E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
|
|
|
|
Result.IntReal = HandleIntToIntCast(Info, E, To, From, Result.IntReal);
|
|
Result.IntImag = HandleIntToIntCast(Info, E, To, From, Result.IntImag);
|
|
return true;
|
|
}
|
|
|
|
case CK_IntegralComplexToFloatingComplex: {
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
|
|
QualType To = E->getType()->castAs<ComplexType>()->getElementType();
|
|
QualType From
|
|
= E->getSubExpr()->getType()->castAs<ComplexType>()->getElementType();
|
|
Result.makeComplexFloat();
|
|
return HandleIntToFloatCast(Info, E, From, Result.IntReal,
|
|
To, Result.FloatReal) &&
|
|
HandleIntToFloatCast(Info, E, From, Result.IntImag,
|
|
To, Result.FloatImag);
|
|
}
|
|
}
|
|
|
|
llvm_unreachable("unknown cast resulting in complex value");
|
|
}
|
|
|
|
bool ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
|
|
if (E->isPtrMemOp() || E->isAssignmentOp() || E->getOpcode() == BO_Comma)
|
|
return ExprEvaluatorBaseTy::VisitBinaryOperator(E);
|
|
|
|
// Track whether the LHS or RHS is real at the type system level. When this is
|
|
// the case we can simplify our evaluation strategy.
|
|
bool LHSReal = false, RHSReal = false;
|
|
|
|
bool LHSOK;
|
|
if (E->getLHS()->getType()->isRealFloatingType()) {
|
|
LHSReal = true;
|
|
APFloat &Real = Result.FloatReal;
|
|
LHSOK = EvaluateFloat(E->getLHS(), Real, Info);
|
|
if (LHSOK) {
|
|
Result.makeComplexFloat();
|
|
Result.FloatImag = APFloat(Real.getSemantics());
|
|
}
|
|
} else {
|
|
LHSOK = Visit(E->getLHS());
|
|
}
|
|
if (!LHSOK && !Info.noteFailure())
|
|
return false;
|
|
|
|
ComplexValue RHS;
|
|
if (E->getRHS()->getType()->isRealFloatingType()) {
|
|
RHSReal = true;
|
|
APFloat &Real = RHS.FloatReal;
|
|
if (!EvaluateFloat(E->getRHS(), Real, Info) || !LHSOK)
|
|
return false;
|
|
RHS.makeComplexFloat();
|
|
RHS.FloatImag = APFloat(Real.getSemantics());
|
|
} else if (!EvaluateComplex(E->getRHS(), RHS, Info) || !LHSOK)
|
|
return false;
|
|
|
|
assert(!(LHSReal && RHSReal) &&
|
|
"Cannot have both operands of a complex operation be real.");
|
|
switch (E->getOpcode()) {
|
|
default: return Error(E);
|
|
case BO_Add:
|
|
if (Result.isComplexFloat()) {
|
|
Result.getComplexFloatReal().add(RHS.getComplexFloatReal(),
|
|
APFloat::rmNearestTiesToEven);
|
|
if (LHSReal)
|
|
Result.getComplexFloatImag() = RHS.getComplexFloatImag();
|
|
else if (!RHSReal)
|
|
Result.getComplexFloatImag().add(RHS.getComplexFloatImag(),
|
|
APFloat::rmNearestTiesToEven);
|
|
} else {
|
|
Result.getComplexIntReal() += RHS.getComplexIntReal();
|
|
Result.getComplexIntImag() += RHS.getComplexIntImag();
|
|
}
|
|
break;
|
|
case BO_Sub:
|
|
if (Result.isComplexFloat()) {
|
|
Result.getComplexFloatReal().subtract(RHS.getComplexFloatReal(),
|
|
APFloat::rmNearestTiesToEven);
|
|
if (LHSReal) {
|
|
Result.getComplexFloatImag() = RHS.getComplexFloatImag();
|
|
Result.getComplexFloatImag().changeSign();
|
|
} else if (!RHSReal) {
|
|
Result.getComplexFloatImag().subtract(RHS.getComplexFloatImag(),
|
|
APFloat::rmNearestTiesToEven);
|
|
}
|
|
} else {
|
|
Result.getComplexIntReal() -= RHS.getComplexIntReal();
|
|
Result.getComplexIntImag() -= RHS.getComplexIntImag();
|
|
}
|
|
break;
|
|
case BO_Mul:
|
|
if (Result.isComplexFloat()) {
|
|
// This is an implementation of complex multiplication according to the
|
|
// constraints laid out in C11 Annex G. The implementation uses the
|
|
// following naming scheme:
|
|
// (a + ib) * (c + id)
|
|
ComplexValue LHS = Result;
|
|
APFloat &A = LHS.getComplexFloatReal();
|
|
APFloat &B = LHS.getComplexFloatImag();
|
|
APFloat &C = RHS.getComplexFloatReal();
|
|
APFloat &D = RHS.getComplexFloatImag();
|
|
APFloat &ResR = Result.getComplexFloatReal();
|
|
APFloat &ResI = Result.getComplexFloatImag();
|
|
if (LHSReal) {
|
|
assert(!RHSReal && "Cannot have two real operands for a complex op!");
|
|
ResR = A * C;
|
|
ResI = A * D;
|
|
} else if (RHSReal) {
|
|
ResR = C * A;
|
|
ResI = C * B;
|
|
} else {
|
|
// In the fully general case, we need to handle NaNs and infinities
|
|
// robustly.
|
|
APFloat AC = A * C;
|
|
APFloat BD = B * D;
|
|
APFloat AD = A * D;
|
|
APFloat BC = B * C;
|
|
ResR = AC - BD;
|
|
ResI = AD + BC;
|
|
if (ResR.isNaN() && ResI.isNaN()) {
|
|
bool Recalc = false;
|
|
if (A.isInfinity() || B.isInfinity()) {
|
|
A = APFloat::copySign(
|
|
APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
|
|
B = APFloat::copySign(
|
|
APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
|
|
if (C.isNaN())
|
|
C = APFloat::copySign(APFloat(C.getSemantics()), C);
|
|
if (D.isNaN())
|
|
D = APFloat::copySign(APFloat(D.getSemantics()), D);
|
|
Recalc = true;
|
|
}
|
|
if (C.isInfinity() || D.isInfinity()) {
|
|
C = APFloat::copySign(
|
|
APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
|
|
D = APFloat::copySign(
|
|
APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
|
|
if (A.isNaN())
|
|
A = APFloat::copySign(APFloat(A.getSemantics()), A);
|
|
if (B.isNaN())
|
|
B = APFloat::copySign(APFloat(B.getSemantics()), B);
|
|
Recalc = true;
|
|
}
|
|
if (!Recalc && (AC.isInfinity() || BD.isInfinity() ||
|
|
AD.isInfinity() || BC.isInfinity())) {
|
|
if (A.isNaN())
|
|
A = APFloat::copySign(APFloat(A.getSemantics()), A);
|
|
if (B.isNaN())
|
|
B = APFloat::copySign(APFloat(B.getSemantics()), B);
|
|
if (C.isNaN())
|
|
C = APFloat::copySign(APFloat(C.getSemantics()), C);
|
|
if (D.isNaN())
|
|
D = APFloat::copySign(APFloat(D.getSemantics()), D);
|
|
Recalc = true;
|
|
}
|
|
if (Recalc) {
|
|
ResR = APFloat::getInf(A.getSemantics()) * (A * C - B * D);
|
|
ResI = APFloat::getInf(A.getSemantics()) * (A * D + B * C);
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
ComplexValue LHS = Result;
|
|
Result.getComplexIntReal() =
|
|
(LHS.getComplexIntReal() * RHS.getComplexIntReal() -
|
|
LHS.getComplexIntImag() * RHS.getComplexIntImag());
|
|
Result.getComplexIntImag() =
|
|
(LHS.getComplexIntReal() * RHS.getComplexIntImag() +
|
|
LHS.getComplexIntImag() * RHS.getComplexIntReal());
|
|
}
|
|
break;
|
|
case BO_Div:
|
|
if (Result.isComplexFloat()) {
|
|
// This is an implementation of complex division according to the
|
|
// constraints laid out in C11 Annex G. The implementation uses the
|
|
// following naming scheme:
|
|
// (a + ib) / (c + id)
|
|
ComplexValue LHS = Result;
|
|
APFloat &A = LHS.getComplexFloatReal();
|
|
APFloat &B = LHS.getComplexFloatImag();
|
|
APFloat &C = RHS.getComplexFloatReal();
|
|
APFloat &D = RHS.getComplexFloatImag();
|
|
APFloat &ResR = Result.getComplexFloatReal();
|
|
APFloat &ResI = Result.getComplexFloatImag();
|
|
if (RHSReal) {
|
|
ResR = A / C;
|
|
ResI = B / C;
|
|
} else {
|
|
if (LHSReal) {
|
|
// No real optimizations we can do here, stub out with zero.
|
|
B = APFloat::getZero(A.getSemantics());
|
|
}
|
|
int DenomLogB = 0;
|
|
APFloat MaxCD = maxnum(abs(C), abs(D));
|
|
if (MaxCD.isFinite()) {
|
|
DenomLogB = ilogb(MaxCD);
|
|
C = scalbn(C, -DenomLogB, APFloat::rmNearestTiesToEven);
|
|
D = scalbn(D, -DenomLogB, APFloat::rmNearestTiesToEven);
|
|
}
|
|
APFloat Denom = C * C + D * D;
|
|
ResR = scalbn((A * C + B * D) / Denom, -DenomLogB,
|
|
APFloat::rmNearestTiesToEven);
|
|
ResI = scalbn((B * C - A * D) / Denom, -DenomLogB,
|
|
APFloat::rmNearestTiesToEven);
|
|
if (ResR.isNaN() && ResI.isNaN()) {
|
|
if (Denom.isPosZero() && (!A.isNaN() || !B.isNaN())) {
|
|
ResR = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * A;
|
|
ResI = APFloat::getInf(ResR.getSemantics(), C.isNegative()) * B;
|
|
} else if ((A.isInfinity() || B.isInfinity()) && C.isFinite() &&
|
|
D.isFinite()) {
|
|
A = APFloat::copySign(
|
|
APFloat(A.getSemantics(), A.isInfinity() ? 1 : 0), A);
|
|
B = APFloat::copySign(
|
|
APFloat(B.getSemantics(), B.isInfinity() ? 1 : 0), B);
|
|
ResR = APFloat::getInf(ResR.getSemantics()) * (A * C + B * D);
|
|
ResI = APFloat::getInf(ResI.getSemantics()) * (B * C - A * D);
|
|
} else if (MaxCD.isInfinity() && A.isFinite() && B.isFinite()) {
|
|
C = APFloat::copySign(
|
|
APFloat(C.getSemantics(), C.isInfinity() ? 1 : 0), C);
|
|
D = APFloat::copySign(
|
|
APFloat(D.getSemantics(), D.isInfinity() ? 1 : 0), D);
|
|
ResR = APFloat::getZero(ResR.getSemantics()) * (A * C + B * D);
|
|
ResI = APFloat::getZero(ResI.getSemantics()) * (B * C - A * D);
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if (RHS.getComplexIntReal() == 0 && RHS.getComplexIntImag() == 0)
|
|
return Error(E, diag::note_expr_divide_by_zero);
|
|
|
|
ComplexValue LHS = Result;
|
|
APSInt Den = RHS.getComplexIntReal() * RHS.getComplexIntReal() +
|
|
RHS.getComplexIntImag() * RHS.getComplexIntImag();
|
|
Result.getComplexIntReal() =
|
|
(LHS.getComplexIntReal() * RHS.getComplexIntReal() +
|
|
LHS.getComplexIntImag() * RHS.getComplexIntImag()) / Den;
|
|
Result.getComplexIntImag() =
|
|
(LHS.getComplexIntImag() * RHS.getComplexIntReal() -
|
|
LHS.getComplexIntReal() * RHS.getComplexIntImag()) / Den;
|
|
}
|
|
break;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool ComplexExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
|
|
// Get the operand value into 'Result'.
|
|
if (!Visit(E->getSubExpr()))
|
|
return false;
|
|
|
|
switch (E->getOpcode()) {
|
|
default:
|
|
return Error(E);
|
|
case UO_Extension:
|
|
return true;
|
|
case UO_Plus:
|
|
// The result is always just the subexpr.
|
|
return true;
|
|
case UO_Minus:
|
|
if (Result.isComplexFloat()) {
|
|
Result.getComplexFloatReal().changeSign();
|
|
Result.getComplexFloatImag().changeSign();
|
|
}
|
|
else {
|
|
Result.getComplexIntReal() = -Result.getComplexIntReal();
|
|
Result.getComplexIntImag() = -Result.getComplexIntImag();
|
|
}
|
|
return true;
|
|
case UO_Not:
|
|
if (Result.isComplexFloat())
|
|
Result.getComplexFloatImag().changeSign();
|
|
else
|
|
Result.getComplexIntImag() = -Result.getComplexIntImag();
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool ComplexExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
|
|
if (E->getNumInits() == 2) {
|
|
if (E->getType()->isComplexType()) {
|
|
Result.makeComplexFloat();
|
|
if (!EvaluateFloat(E->getInit(0), Result.FloatReal, Info))
|
|
return false;
|
|
if (!EvaluateFloat(E->getInit(1), Result.FloatImag, Info))
|
|
return false;
|
|
} else {
|
|
Result.makeComplexInt();
|
|
if (!EvaluateInteger(E->getInit(0), Result.IntReal, Info))
|
|
return false;
|
|
if (!EvaluateInteger(E->getInit(1), Result.IntImag, Info))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
return ExprEvaluatorBaseTy::VisitInitListExpr(E);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Atomic expression evaluation, essentially just handling the NonAtomicToAtomic
|
|
// implicit conversion.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class AtomicExprEvaluator :
|
|
public ExprEvaluatorBase<AtomicExprEvaluator> {
|
|
const LValue *This;
|
|
APValue &Result;
|
|
public:
|
|
AtomicExprEvaluator(EvalInfo &Info, const LValue *This, APValue &Result)
|
|
: ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
|
|
|
|
bool Success(const APValue &V, const Expr *E) {
|
|
Result = V;
|
|
return true;
|
|
}
|
|
|
|
bool ZeroInitialization(const Expr *E) {
|
|
ImplicitValueInitExpr VIE(
|
|
E->getType()->castAs<AtomicType>()->getValueType());
|
|
// For atomic-qualified class (and array) types in C++, initialize the
|
|
// _Atomic-wrapped subobject directly, in-place.
|
|
return This ? EvaluateInPlace(Result, Info, *This, &VIE)
|
|
: Evaluate(Result, Info, &VIE);
|
|
}
|
|
|
|
bool VisitCastExpr(const CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
case CK_NonAtomicToAtomic:
|
|
return This ? EvaluateInPlace(Result, Info, *This, E->getSubExpr())
|
|
: Evaluate(Result, Info, E->getSubExpr());
|
|
}
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
|
|
EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isAtomicType());
|
|
return AtomicExprEvaluator(Info, This, Result).Visit(E);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Void expression evaluation, primarily for a cast to void on the LHS of a
|
|
// comma operator
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class VoidExprEvaluator
|
|
: public ExprEvaluatorBase<VoidExprEvaluator> {
|
|
public:
|
|
VoidExprEvaluator(EvalInfo &Info) : ExprEvaluatorBaseTy(Info) {}
|
|
|
|
bool Success(const APValue &V, const Expr *e) { return true; }
|
|
|
|
bool ZeroInitialization(const Expr *E) { return true; }
|
|
|
|
bool VisitCastExpr(const CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCastExpr(E);
|
|
case CK_ToVoid:
|
|
VisitIgnoredValue(E->getSubExpr());
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool VisitCallExpr(const CallExpr *E) {
|
|
switch (E->getBuiltinCallee()) {
|
|
default:
|
|
return ExprEvaluatorBaseTy::VisitCallExpr(E);
|
|
case Builtin::BI__assume:
|
|
case Builtin::BI__builtin_assume:
|
|
// The argument is not evaluated!
|
|
return true;
|
|
}
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool EvaluateVoid(const Expr *E, EvalInfo &Info) {
|
|
assert(E->isRValue() && E->getType()->isVoidType());
|
|
return VoidExprEvaluator(Info).Visit(E);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Top level Expr::EvaluateAsRValue method.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) {
|
|
// In C, function designators are not lvalues, but we evaluate them as if they
|
|
// are.
|
|
QualType T = E->getType();
|
|
if (E->isGLValue() || T->isFunctionType()) {
|
|
LValue LV;
|
|
if (!EvaluateLValue(E, LV, Info))
|
|
return false;
|
|
LV.moveInto(Result);
|
|
} else if (T->isVectorType()) {
|
|
if (!EvaluateVector(E, Result, Info))
|
|
return false;
|
|
} else if (T->isIntegralOrEnumerationType()) {
|
|
if (!IntExprEvaluator(Info, Result).Visit(E))
|
|
return false;
|
|
} else if (T->hasPointerRepresentation()) {
|
|
LValue LV;
|
|
if (!EvaluatePointer(E, LV, Info))
|
|
return false;
|
|
LV.moveInto(Result);
|
|
} else if (T->isRealFloatingType()) {
|
|
llvm::APFloat F(0.0);
|
|
if (!EvaluateFloat(E, F, Info))
|
|
return false;
|
|
Result = APValue(F);
|
|
} else if (T->isAnyComplexType()) {
|
|
ComplexValue C;
|
|
if (!EvaluateComplex(E, C, Info))
|
|
return false;
|
|
C.moveInto(Result);
|
|
} else if (T->isFixedPointType()) {
|
|
if (!FixedPointExprEvaluator(Info, Result).Visit(E)) return false;
|
|
} else if (T->isMemberPointerType()) {
|
|
MemberPtr P;
|
|
if (!EvaluateMemberPointer(E, P, Info))
|
|
return false;
|
|
P.moveInto(Result);
|
|
return true;
|
|
} else if (T->isArrayType()) {
|
|
LValue LV;
|
|
APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall);
|
|
if (!EvaluateArray(E, LV, Value, Info))
|
|
return false;
|
|
Result = Value;
|
|
} else if (T->isRecordType()) {
|
|
LValue LV;
|
|
APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall);
|
|
if (!EvaluateRecord(E, LV, Value, Info))
|
|
return false;
|
|
Result = Value;
|
|
} else if (T->isVoidType()) {
|
|
if (!Info.getLangOpts().CPlusPlus11)
|
|
Info.CCEDiag(E, diag::note_constexpr_nonliteral)
|
|
<< E->getType();
|
|
if (!EvaluateVoid(E, Info))
|
|
return false;
|
|
} else if (T->isAtomicType()) {
|
|
QualType Unqual = T.getAtomicUnqualifiedType();
|
|
if (Unqual->isArrayType() || Unqual->isRecordType()) {
|
|
LValue LV;
|
|
APValue &Value = createTemporary(E, false, LV, *Info.CurrentCall);
|
|
if (!EvaluateAtomic(E, &LV, Value, Info))
|
|
return false;
|
|
} else {
|
|
if (!EvaluateAtomic(E, nullptr, Result, Info))
|
|
return false;
|
|
}
|
|
} else if (Info.getLangOpts().CPlusPlus11) {
|
|
Info.FFDiag(E, diag::note_constexpr_nonliteral) << E->getType();
|
|
return false;
|
|
} else {
|
|
Info.FFDiag(E, diag::note_invalid_subexpr_in_const_expr);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/// EvaluateInPlace - Evaluate an expression in-place in an APValue. In some
|
|
/// cases, the in-place evaluation is essential, since later initializers for
|
|
/// an object can indirectly refer to subobjects which were initialized earlier.
|
|
static bool EvaluateInPlace(APValue &Result, EvalInfo &Info, const LValue &This,
|
|
const Expr *E, bool AllowNonLiteralTypes) {
|
|
assert(!E->isValueDependent());
|
|
|
|
if (!AllowNonLiteralTypes && !CheckLiteralType(Info, E, &This))
|
|
return false;
|
|
|
|
if (E->isRValue()) {
|
|
// Evaluate arrays and record types in-place, so that later initializers can
|
|
// refer to earlier-initialized members of the object.
|
|
QualType T = E->getType();
|
|
if (T->isArrayType())
|
|
return EvaluateArray(E, This, Result, Info);
|
|
else if (T->isRecordType())
|
|
return EvaluateRecord(E, This, Result, Info);
|
|
else if (T->isAtomicType()) {
|
|
QualType Unqual = T.getAtomicUnqualifiedType();
|
|
if (Unqual->isArrayType() || Unqual->isRecordType())
|
|
return EvaluateAtomic(E, &This, Result, Info);
|
|
}
|
|
}
|
|
|
|
// For any other type, in-place evaluation is unimportant.
|
|
return Evaluate(Result, Info, E);
|
|
}
|
|
|
|
/// EvaluateAsRValue - Try to evaluate this expression, performing an implicit
|
|
/// lvalue-to-rvalue cast if it is an lvalue.
|
|
static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result) {
|
|
if (E->getType().isNull())
|
|
return false;
|
|
|
|
if (!CheckLiteralType(Info, E))
|
|
return false;
|
|
|
|
if (!::Evaluate(Result, Info, E))
|
|
return false;
|
|
|
|
if (E->isGLValue()) {
|
|
LValue LV;
|
|
LV.setFrom(Info.Ctx, Result);
|
|
if (!handleLValueToRValueConversion(Info, E, E->getType(), LV, Result))
|
|
return false;
|
|
}
|
|
|
|
// Check this core constant expression is a constant expression.
|
|
return CheckConstantExpression(Info, E->getExprLoc(), E->getType(), Result);
|
|
}
|
|
|
|
static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
|
|
const ASTContext &Ctx, bool &IsConst) {
|
|
// Fast-path evaluations of integer literals, since we sometimes see files
|
|
// containing vast quantities of these.
|
|
if (const IntegerLiteral *L = dyn_cast<IntegerLiteral>(Exp)) {
|
|
Result.Val = APValue(APSInt(L->getValue(),
|
|
L->getType()->isUnsignedIntegerType()));
|
|
IsConst = true;
|
|
return true;
|
|
}
|
|
|
|
// This case should be rare, but we need to check it before we check on
|
|
// the type below.
|
|
if (Exp->getType().isNull()) {
|
|
IsConst = false;
|
|
return true;
|
|
}
|
|
|
|
// FIXME: Evaluating values of large array and record types can cause
|
|
// performance problems. Only do so in C++11 for now.
|
|
if (Exp->isRValue() && (Exp->getType()->isArrayType() ||
|
|
Exp->getType()->isRecordType()) &&
|
|
!Ctx.getLangOpts().CPlusPlus11) {
|
|
IsConst = false;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool hasUnacceptableSideEffect(Expr::EvalStatus &Result,
|
|
Expr::SideEffectsKind SEK) {
|
|
return (SEK < Expr::SE_AllowSideEffects && Result.HasSideEffects) ||
|
|
(SEK < Expr::SE_AllowUndefinedBehavior && Result.HasUndefinedBehavior);
|
|
}
|
|
|
|
static bool EvaluateAsRValue(const Expr *E, Expr::EvalResult &Result,
|
|
const ASTContext &Ctx, EvalInfo &Info) {
|
|
bool IsConst;
|
|
if (FastEvaluateAsRValue(E, Result, Ctx, IsConst))
|
|
return IsConst;
|
|
|
|
return EvaluateAsRValue(Info, E, Result.Val);
|
|
}
|
|
|
|
static bool EvaluateAsInt(const Expr *E, Expr::EvalResult &ExprResult,
|
|
const ASTContext &Ctx,
|
|
Expr::SideEffectsKind AllowSideEffects,
|
|
EvalInfo &Info) {
|
|
if (!E->getType()->isIntegralOrEnumerationType())
|
|
return false;
|
|
|
|
if (!::EvaluateAsRValue(E, ExprResult, Ctx, Info) ||
|
|
!ExprResult.Val.isInt() ||
|
|
hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/// EvaluateAsRValue - Return true if this is a constant which we can fold using
|
|
/// any crazy technique (that has nothing to do with language standards) that
|
|
/// we want to. If this function returns true, it returns the folded constant
|
|
/// in Result. If this expression is a glvalue, an lvalue-to-rvalue conversion
|
|
/// will be applied to the result.
|
|
bool Expr::EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx,
|
|
bool InConstantContext) const {
|
|
EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
|
|
Info.InConstantContext = InConstantContext;
|
|
return ::EvaluateAsRValue(this, Result, Ctx, Info);
|
|
}
|
|
|
|
bool Expr::EvaluateAsBooleanCondition(bool &Result,
|
|
const ASTContext &Ctx) const {
|
|
EvalResult Scratch;
|
|
return EvaluateAsRValue(Scratch, Ctx) &&
|
|
HandleConversionToBool(Scratch.Val, Result);
|
|
}
|
|
|
|
bool Expr::EvaluateAsInt(EvalResult &Result, const ASTContext &Ctx,
|
|
SideEffectsKind AllowSideEffects) const {
|
|
EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
|
|
return ::EvaluateAsInt(this, Result, Ctx, AllowSideEffects, Info);
|
|
}
|
|
|
|
bool Expr::EvaluateAsFloat(APFloat &Result, const ASTContext &Ctx,
|
|
SideEffectsKind AllowSideEffects) const {
|
|
if (!getType()->isRealFloatingType())
|
|
return false;
|
|
|
|
EvalResult ExprResult;
|
|
if (!EvaluateAsRValue(ExprResult, Ctx) || !ExprResult.Val.isFloat() ||
|
|
hasUnacceptableSideEffect(ExprResult, AllowSideEffects))
|
|
return false;
|
|
|
|
Result = ExprResult.Val.getFloat();
|
|
return true;
|
|
}
|
|
|
|
bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx) const {
|
|
EvalInfo Info(Ctx, Result, EvalInfo::EM_ConstantFold);
|
|
|
|
LValue LV;
|
|
if (!EvaluateLValue(this, LV, Info) || Result.HasSideEffects ||
|
|
!CheckLValueConstantExpression(Info, getExprLoc(),
|
|
Ctx.getLValueReferenceType(getType()), LV,
|
|
Expr::EvaluateForCodeGen))
|
|
return false;
|
|
|
|
LV.moveInto(Result.Val);
|
|
return true;
|
|
}
|
|
|
|
bool Expr::EvaluateAsConstantExpr(EvalResult &Result, ConstExprUsage Usage,
|
|
const ASTContext &Ctx) const {
|
|
EvalInfo::EvaluationMode EM = EvalInfo::EM_ConstantExpression;
|
|
EvalInfo Info(Ctx, Result, EM);
|
|
if (!::Evaluate(Result.Val, Info, this))
|
|
return false;
|
|
|
|
return CheckConstantExpression(Info, getExprLoc(), getType(), Result.Val,
|
|
Usage);
|
|
}
|
|
|
|
bool Expr::EvaluateAsInitializer(APValue &Value, const ASTContext &Ctx,
|
|
const VarDecl *VD,
|
|
SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
|
|
// FIXME: Evaluating initializers for large array and record types can cause
|
|
// performance problems. Only do so in C++11 for now.
|
|
if (isRValue() && (getType()->isArrayType() || getType()->isRecordType()) &&
|
|
!Ctx.getLangOpts().CPlusPlus11)
|
|
return false;
|
|
|
|
Expr::EvalStatus EStatus;
|
|
EStatus.Diag = &Notes;
|
|
|
|
EvalInfo InitInfo(Ctx, EStatus, VD->isConstexpr()
|
|
? EvalInfo::EM_ConstantExpression
|
|
: EvalInfo::EM_ConstantFold);
|
|
InitInfo.setEvaluatingDecl(VD, Value);
|
|
InitInfo.InConstantContext = true;
|
|
|
|
LValue LVal;
|
|
LVal.set(VD);
|
|
|
|
// C++11 [basic.start.init]p2:
|
|
// Variables with static storage duration or thread storage duration shall be
|
|
// zero-initialized before any other initialization takes place.
|
|
// This behavior is not present in C.
|
|
if (Ctx.getLangOpts().CPlusPlus && !VD->hasLocalStorage() &&
|
|
!VD->getType()->isReferenceType()) {
|
|
ImplicitValueInitExpr VIE(VD->getType());
|
|
if (!EvaluateInPlace(Value, InitInfo, LVal, &VIE,
|
|
/*AllowNonLiteralTypes=*/true))
|
|
return false;
|
|
}
|
|
|
|
if (!EvaluateInPlace(Value, InitInfo, LVal, this,
|
|
/*AllowNonLiteralTypes=*/true) ||
|
|
EStatus.HasSideEffects)
|
|
return false;
|
|
|
|
return CheckConstantExpression(InitInfo, VD->getLocation(), VD->getType(),
|
|
Value);
|
|
}
|
|
|
|
/// isEvaluatable - Call EvaluateAsRValue to see if this expression can be
|
|
/// constant folded, but discard the result.
|
|
bool Expr::isEvaluatable(const ASTContext &Ctx, SideEffectsKind SEK) const {
|
|
EvalResult Result;
|
|
return EvaluateAsRValue(Result, Ctx, /* in constant context */ true) &&
|
|
!hasUnacceptableSideEffect(Result, SEK);
|
|
}
|
|
|
|
APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx,
|
|
SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
|
|
EvalResult EVResult;
|
|
EVResult.Diag = Diag;
|
|
EvalInfo Info(Ctx, EVResult, EvalInfo::EM_IgnoreSideEffects);
|
|
Info.InConstantContext = true;
|
|
|
|
bool Result = ::EvaluateAsRValue(this, EVResult, Ctx, Info);
|
|
(void)Result;
|
|
assert(Result && "Could not evaluate expression");
|
|
assert(EVResult.Val.isInt() && "Expression did not evaluate to integer");
|
|
|
|
return EVResult.Val.getInt();
|
|
}
|
|
|
|
APSInt Expr::EvaluateKnownConstIntCheckOverflow(
|
|
const ASTContext &Ctx, SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
|
|
EvalResult EVResult;
|
|
EVResult.Diag = Diag;
|
|
EvalInfo Info(Ctx, EVResult, EvalInfo::EM_EvaluateForOverflow);
|
|
Info.InConstantContext = true;
|
|
|
|
bool Result = ::EvaluateAsRValue(Info, this, EVResult.Val);
|
|
(void)Result;
|
|
assert(Result && "Could not evaluate expression");
|
|
assert(EVResult.Val.isInt() && "Expression did not evaluate to integer");
|
|
|
|
return EVResult.Val.getInt();
|
|
}
|
|
|
|
void Expr::EvaluateForOverflow(const ASTContext &Ctx) const {
|
|
bool IsConst;
|
|
EvalResult EVResult;
|
|
if (!FastEvaluateAsRValue(this, EVResult, Ctx, IsConst)) {
|
|
EvalInfo Info(Ctx, EVResult, EvalInfo::EM_EvaluateForOverflow);
|
|
(void)::EvaluateAsRValue(Info, this, EVResult.Val);
|
|
}
|
|
}
|
|
|
|
bool Expr::EvalResult::isGlobalLValue() const {
|
|
assert(Val.isLValue());
|
|
return IsGlobalLValue(Val.getLValueBase());
|
|
}
|
|
|
|
|
|
/// isIntegerConstantExpr - this recursive routine will test if an expression is
|
|
/// an integer constant expression.
|
|
|
|
/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
|
|
/// comma, etc
|
|
|
|
// CheckICE - This function does the fundamental ICE checking: the returned
|
|
// ICEDiag contains an ICEKind indicating whether the expression is an ICE,
|
|
// and a (possibly null) SourceLocation indicating the location of the problem.
|
|
//
|
|
// Note that to reduce code duplication, this helper does no evaluation
|
|
// itself; the caller checks whether the expression is evaluatable, and
|
|
// in the rare cases where CheckICE actually cares about the evaluated
|
|
// value, it calls into Evaluate.
|
|
|
|
namespace {
|
|
|
|
enum ICEKind {
|
|
/// This expression is an ICE.
|
|
IK_ICE,
|
|
/// This expression is not an ICE, but if it isn't evaluated, it's
|
|
/// a legal subexpression for an ICE. This return value is used to handle
|
|
/// the comma operator in C99 mode, and non-constant subexpressions.
|
|
IK_ICEIfUnevaluated,
|
|
/// This expression is not an ICE, and is not a legal subexpression for one.
|
|
IK_NotICE
|
|
};
|
|
|
|
struct ICEDiag {
|
|
ICEKind Kind;
|
|
SourceLocation Loc;
|
|
|
|
ICEDiag(ICEKind IK, SourceLocation l) : Kind(IK), Loc(l) {}
|
|
};
|
|
|
|
}
|
|
|
|
static ICEDiag NoDiag() { return ICEDiag(IK_ICE, SourceLocation()); }
|
|
|
|
static ICEDiag Worst(ICEDiag A, ICEDiag B) { return A.Kind >= B.Kind ? A : B; }
|
|
|
|
static ICEDiag CheckEvalInICE(const Expr* E, const ASTContext &Ctx) {
|
|
Expr::EvalResult EVResult;
|
|
Expr::EvalStatus Status;
|
|
EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
|
|
|
|
Info.InConstantContext = true;
|
|
if (!::EvaluateAsRValue(E, EVResult, Ctx, Info) || EVResult.HasSideEffects ||
|
|
!EVResult.Val.isInt())
|
|
return ICEDiag(IK_NotICE, E->getBeginLoc());
|
|
|
|
return NoDiag();
|
|
}
|
|
|
|
static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
|
|
assert(!E->isValueDependent() && "Should not see value dependent exprs!");
|
|
if (!E->getType()->isIntegralOrEnumerationType())
|
|
return ICEDiag(IK_NotICE, E->getBeginLoc());
|
|
|
|
switch (E->getStmtClass()) {
|
|
#define ABSTRACT_STMT(Node)
|
|
#define STMT(Node, Base) case Expr::Node##Class:
|
|
#define EXPR(Node, Base)
|
|
#include "clang/AST/StmtNodes.inc"
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case Expr::PredefinedExprClass:
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case Expr::FloatingLiteralClass:
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case Expr::ImaginaryLiteralClass:
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case Expr::StringLiteralClass:
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case Expr::ArraySubscriptExprClass:
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case Expr::OMPArraySectionExprClass:
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case Expr::MemberExprClass:
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case Expr::CompoundAssignOperatorClass:
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case Expr::CompoundLiteralExprClass:
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case Expr::ExtVectorElementExprClass:
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case Expr::DesignatedInitExprClass:
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case Expr::ArrayInitLoopExprClass:
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case Expr::ArrayInitIndexExprClass:
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case Expr::NoInitExprClass:
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case Expr::DesignatedInitUpdateExprClass:
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case Expr::ImplicitValueInitExprClass:
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case Expr::ParenListExprClass:
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case Expr::VAArgExprClass:
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case Expr::AddrLabelExprClass:
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case Expr::StmtExprClass:
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case Expr::CXXMemberCallExprClass:
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case Expr::CUDAKernelCallExprClass:
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case Expr::CXXDynamicCastExprClass:
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case Expr::CXXTypeidExprClass:
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case Expr::CXXUuidofExprClass:
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case Expr::MSPropertyRefExprClass:
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case Expr::MSPropertySubscriptExprClass:
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case Expr::CXXNullPtrLiteralExprClass:
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case Expr::UserDefinedLiteralClass:
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case Expr::CXXThisExprClass:
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case Expr::CXXThrowExprClass:
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case Expr::CXXNewExprClass:
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case Expr::CXXDeleteExprClass:
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case Expr::CXXPseudoDestructorExprClass:
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case Expr::UnresolvedLookupExprClass:
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case Expr::TypoExprClass:
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case Expr::DependentScopeDeclRefExprClass:
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case Expr::CXXConstructExprClass:
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case Expr::CXXInheritedCtorInitExprClass:
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case Expr::CXXStdInitializerListExprClass:
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case Expr::CXXBindTemporaryExprClass:
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case Expr::ExprWithCleanupsClass:
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case Expr::CXXTemporaryObjectExprClass:
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case Expr::CXXUnresolvedConstructExprClass:
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case Expr::CXXDependentScopeMemberExprClass:
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case Expr::UnresolvedMemberExprClass:
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case Expr::ObjCStringLiteralClass:
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case Expr::ObjCBoxedExprClass:
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case Expr::ObjCArrayLiteralClass:
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case Expr::ObjCDictionaryLiteralClass:
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case Expr::ObjCEncodeExprClass:
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case Expr::ObjCMessageExprClass:
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case Expr::ObjCSelectorExprClass:
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case Expr::ObjCProtocolExprClass:
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case Expr::ObjCIvarRefExprClass:
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case Expr::ObjCPropertyRefExprClass:
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case Expr::ObjCSubscriptRefExprClass:
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case Expr::ObjCIsaExprClass:
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case Expr::ObjCAvailabilityCheckExprClass:
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case Expr::ShuffleVectorExprClass:
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case Expr::ConvertVectorExprClass:
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case Expr::BlockExprClass:
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case Expr::NoStmtClass:
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case Expr::OpaqueValueExprClass:
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case Expr::PackExpansionExprClass:
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case Expr::SubstNonTypeTemplateParmPackExprClass:
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case Expr::FunctionParmPackExprClass:
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case Expr::AsTypeExprClass:
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case Expr::ObjCIndirectCopyRestoreExprClass:
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case Expr::MaterializeTemporaryExprClass:
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case Expr::PseudoObjectExprClass:
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case Expr::AtomicExprClass:
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case Expr::LambdaExprClass:
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case Expr::CXXFoldExprClass:
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case Expr::CoawaitExprClass:
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case Expr::DependentCoawaitExprClass:
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case Expr::CoyieldExprClass:
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return ICEDiag(IK_NotICE, E->getBeginLoc());
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case Expr::InitListExprClass: {
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// C++03 [dcl.init]p13: If T is a scalar type, then a declaration of the
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// form "T x = { a };" is equivalent to "T x = a;".
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// Unless we're initializing a reference, T is a scalar as it is known to be
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// of integral or enumeration type.
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if (E->isRValue())
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if (cast<InitListExpr>(E)->getNumInits() == 1)
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return CheckICE(cast<InitListExpr>(E)->getInit(0), Ctx);
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return ICEDiag(IK_NotICE, E->getBeginLoc());
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}
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case Expr::SizeOfPackExprClass:
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case Expr::GNUNullExprClass:
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// GCC considers the GNU __null value to be an integral constant expression.
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return NoDiag();
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case Expr::SubstNonTypeTemplateParmExprClass:
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return
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CheckICE(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(), Ctx);
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case Expr::ConstantExprClass:
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return CheckICE(cast<ConstantExpr>(E)->getSubExpr(), Ctx);
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case Expr::ParenExprClass:
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return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
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case Expr::GenericSelectionExprClass:
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return CheckICE(cast<GenericSelectionExpr>(E)->getResultExpr(), Ctx);
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case Expr::IntegerLiteralClass:
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case Expr::FixedPointLiteralClass:
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case Expr::CharacterLiteralClass:
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case Expr::ObjCBoolLiteralExprClass:
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case Expr::CXXBoolLiteralExprClass:
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case Expr::CXXScalarValueInitExprClass:
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case Expr::TypeTraitExprClass:
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case Expr::ArrayTypeTraitExprClass:
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case Expr::ExpressionTraitExprClass:
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case Expr::CXXNoexceptExprClass:
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return NoDiag();
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case Expr::CallExprClass:
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case Expr::CXXOperatorCallExprClass: {
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// C99 6.6/3 allows function calls within unevaluated subexpressions of
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// constant expressions, but they can never be ICEs because an ICE cannot
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// contain an operand of (pointer to) function type.
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const CallExpr *CE = cast<CallExpr>(E);
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if (CE->getBuiltinCallee())
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return CheckEvalInICE(E, Ctx);
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return ICEDiag(IK_NotICE, E->getBeginLoc());
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}
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case Expr::DeclRefExprClass: {
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if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
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return NoDiag();
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const ValueDecl *D = cast<DeclRefExpr>(E)->getDecl();
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if (Ctx.getLangOpts().CPlusPlus &&
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D && IsConstNonVolatile(D->getType())) {
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// Parameter variables are never constants. Without this check,
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// getAnyInitializer() can find a default argument, which leads
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// to chaos.
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if (isa<ParmVarDecl>(D))
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return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
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// C++ 7.1.5.1p2
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// A variable of non-volatile const-qualified integral or enumeration
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// type initialized by an ICE can be used in ICEs.
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if (const VarDecl *Dcl = dyn_cast<VarDecl>(D)) {
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if (!Dcl->getType()->isIntegralOrEnumerationType())
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return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
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const VarDecl *VD;
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// Look for a declaration of this variable that has an initializer, and
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// check whether it is an ICE.
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if (Dcl->getAnyInitializer(VD) && VD->checkInitIsICE())
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return NoDiag();
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else
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return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
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}
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}
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return ICEDiag(IK_NotICE, E->getBeginLoc());
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}
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case Expr::UnaryOperatorClass: {
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const UnaryOperator *Exp = cast<UnaryOperator>(E);
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switch (Exp->getOpcode()) {
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case UO_PostInc:
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case UO_PostDec:
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case UO_PreInc:
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case UO_PreDec:
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case UO_AddrOf:
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case UO_Deref:
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case UO_Coawait:
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// C99 6.6/3 allows increment and decrement within unevaluated
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// subexpressions of constant expressions, but they can never be ICEs
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// because an ICE cannot contain an lvalue operand.
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return ICEDiag(IK_NotICE, E->getBeginLoc());
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case UO_Extension:
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case UO_LNot:
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case UO_Plus:
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case UO_Minus:
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case UO_Not:
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case UO_Real:
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case UO_Imag:
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return CheckICE(Exp->getSubExpr(), Ctx);
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}
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llvm_unreachable("invalid unary operator class");
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}
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case Expr::OffsetOfExprClass: {
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// Note that per C99, offsetof must be an ICE. And AFAIK, using
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// EvaluateAsRValue matches the proposed gcc behavior for cases like
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// "offsetof(struct s{int x[4];}, x[1.0])". This doesn't affect
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// compliance: we should warn earlier for offsetof expressions with
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// array subscripts that aren't ICEs, and if the array subscripts
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// are ICEs, the value of the offsetof must be an integer constant.
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return CheckEvalInICE(E, Ctx);
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}
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case Expr::UnaryExprOrTypeTraitExprClass: {
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const UnaryExprOrTypeTraitExpr *Exp = cast<UnaryExprOrTypeTraitExpr>(E);
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if ((Exp->getKind() == UETT_SizeOf) &&
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Exp->getTypeOfArgument()->isVariableArrayType())
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return ICEDiag(IK_NotICE, E->getBeginLoc());
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return NoDiag();
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}
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case Expr::BinaryOperatorClass: {
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const BinaryOperator *Exp = cast<BinaryOperator>(E);
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switch (Exp->getOpcode()) {
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case BO_PtrMemD:
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case BO_PtrMemI:
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case BO_Assign:
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case BO_MulAssign:
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case BO_DivAssign:
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case BO_RemAssign:
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case BO_AddAssign:
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case BO_SubAssign:
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case BO_ShlAssign:
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case BO_ShrAssign:
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case BO_AndAssign:
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case BO_XorAssign:
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case BO_OrAssign:
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// C99 6.6/3 allows assignments within unevaluated subexpressions of
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// constant expressions, but they can never be ICEs because an ICE cannot
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// contain an lvalue operand.
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return ICEDiag(IK_NotICE, E->getBeginLoc());
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case BO_Mul:
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case BO_Div:
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case BO_Rem:
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case BO_Add:
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case BO_Sub:
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case BO_Shl:
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case BO_Shr:
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case BO_LT:
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case BO_GT:
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case BO_LE:
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case BO_GE:
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case BO_EQ:
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case BO_NE:
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case BO_And:
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case BO_Xor:
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case BO_Or:
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case BO_Comma:
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case BO_Cmp: {
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ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
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ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
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|
if (Exp->getOpcode() == BO_Div ||
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Exp->getOpcode() == BO_Rem) {
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// EvaluateAsRValue gives an error for undefined Div/Rem, so make sure
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// we don't evaluate one.
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if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE) {
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llvm::APSInt REval = Exp->getRHS()->EvaluateKnownConstInt(Ctx);
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if (REval == 0)
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return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
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if (REval.isSigned() && REval.isAllOnesValue()) {
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llvm::APSInt LEval = Exp->getLHS()->EvaluateKnownConstInt(Ctx);
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if (LEval.isMinSignedValue())
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return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
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}
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}
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}
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if (Exp->getOpcode() == BO_Comma) {
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if (Ctx.getLangOpts().C99) {
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|
// C99 6.6p3 introduces a strange edge case: comma can be in an ICE
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// if it isn't evaluated.
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if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICE)
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return ICEDiag(IK_ICEIfUnevaluated, E->getBeginLoc());
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} else {
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// In both C89 and C++, commas in ICEs are illegal.
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|
return ICEDiag(IK_NotICE, E->getBeginLoc());
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|
}
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|
}
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|
return Worst(LHSResult, RHSResult);
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|
}
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|
case BO_LAnd:
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case BO_LOr: {
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ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
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ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
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if (LHSResult.Kind == IK_ICE && RHSResult.Kind == IK_ICEIfUnevaluated) {
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|
// Rare case where the RHS has a comma "side-effect"; we need
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|
// to actually check the condition to see whether the side
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|
// with the comma is evaluated.
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|
if ((Exp->getOpcode() == BO_LAnd) !=
|
|
(Exp->getLHS()->EvaluateKnownConstInt(Ctx) == 0))
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|
return RHSResult;
|
|
return NoDiag();
|
|
}
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|
|
|
return Worst(LHSResult, RHSResult);
|
|
}
|
|
}
|
|
llvm_unreachable("invalid binary operator kind");
|
|
}
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|
case Expr::ImplicitCastExprClass:
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|
case Expr::CStyleCastExprClass:
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|
case Expr::CXXFunctionalCastExprClass:
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|
case Expr::CXXStaticCastExprClass:
|
|
case Expr::CXXReinterpretCastExprClass:
|
|
case Expr::CXXConstCastExprClass:
|
|
case Expr::ObjCBridgedCastExprClass: {
|
|
const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr();
|
|
if (isa<ExplicitCastExpr>(E)) {
|
|
if (const FloatingLiteral *FL
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= dyn_cast<FloatingLiteral>(SubExpr->IgnoreParenImpCasts())) {
|
|
unsigned DestWidth = Ctx.getIntWidth(E->getType());
|
|
bool DestSigned = E->getType()->isSignedIntegerOrEnumerationType();
|
|
APSInt IgnoredVal(DestWidth, !DestSigned);
|
|
bool Ignored;
|
|
// If the value does not fit in the destination type, the behavior is
|
|
// undefined, so we are not required to treat it as a constant
|
|
// expression.
|
|
if (FL->getValue().convertToInteger(IgnoredVal,
|
|
llvm::APFloat::rmTowardZero,
|
|
&Ignored) & APFloat::opInvalidOp)
|
|
return ICEDiag(IK_NotICE, E->getBeginLoc());
|
|
return NoDiag();
|
|
}
|
|
}
|
|
switch (cast<CastExpr>(E)->getCastKind()) {
|
|
case CK_LValueToRValue:
|
|
case CK_AtomicToNonAtomic:
|
|
case CK_NonAtomicToAtomic:
|
|
case CK_NoOp:
|
|
case CK_IntegralToBoolean:
|
|
case CK_IntegralCast:
|
|
return CheckICE(SubExpr, Ctx);
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|
default:
|
|
return ICEDiag(IK_NotICE, E->getBeginLoc());
|
|
}
|
|
}
|
|
case Expr::BinaryConditionalOperatorClass: {
|
|
const BinaryConditionalOperator *Exp = cast<BinaryConditionalOperator>(E);
|
|
ICEDiag CommonResult = CheckICE(Exp->getCommon(), Ctx);
|
|
if (CommonResult.Kind == IK_NotICE) return CommonResult;
|
|
ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
|
|
if (FalseResult.Kind == IK_NotICE) return FalseResult;
|
|
if (CommonResult.Kind == IK_ICEIfUnevaluated) return CommonResult;
|
|
if (FalseResult.Kind == IK_ICEIfUnevaluated &&
|
|
Exp->getCommon()->EvaluateKnownConstInt(Ctx) != 0) return NoDiag();
|
|
return FalseResult;
|
|
}
|
|
case Expr::ConditionalOperatorClass: {
|
|
const ConditionalOperator *Exp = cast<ConditionalOperator>(E);
|
|
// If the condition (ignoring parens) is a __builtin_constant_p call,
|
|
// then only the true side is actually considered in an integer constant
|
|
// expression, and it is fully evaluated. This is an important GNU
|
|
// extension. See GCC PR38377 for discussion.
|
|
if (const CallExpr *CallCE
|
|
= dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts()))
|
|
if (CallCE->getBuiltinCallee() == Builtin::BI__builtin_constant_p)
|
|
return CheckEvalInICE(E, Ctx);
|
|
ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
|
|
if (CondResult.Kind == IK_NotICE)
|
|
return CondResult;
|
|
|
|
ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
|
|
ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
|
|
|
|
if (TrueResult.Kind == IK_NotICE)
|
|
return TrueResult;
|
|
if (FalseResult.Kind == IK_NotICE)
|
|
return FalseResult;
|
|
if (CondResult.Kind == IK_ICEIfUnevaluated)
|
|
return CondResult;
|
|
if (TrueResult.Kind == IK_ICE && FalseResult.Kind == IK_ICE)
|
|
return NoDiag();
|
|
// Rare case where the diagnostics depend on which side is evaluated
|
|
// Note that if we get here, CondResult is 0, and at least one of
|
|
// TrueResult and FalseResult is non-zero.
|
|
if (Exp->getCond()->EvaluateKnownConstInt(Ctx) == 0)
|
|
return FalseResult;
|
|
return TrueResult;
|
|
}
|
|
case Expr::CXXDefaultArgExprClass:
|
|
return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx);
|
|
case Expr::CXXDefaultInitExprClass:
|
|
return CheckICE(cast<CXXDefaultInitExpr>(E)->getExpr(), Ctx);
|
|
case Expr::ChooseExprClass: {
|
|
return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(), Ctx);
|
|
}
|
|
}
|
|
|
|
llvm_unreachable("Invalid StmtClass!");
|
|
}
|
|
|
|
/// Evaluate an expression as a C++11 integral constant expression.
|
|
static bool EvaluateCPlusPlus11IntegralConstantExpr(const ASTContext &Ctx,
|
|
const Expr *E,
|
|
llvm::APSInt *Value,
|
|
SourceLocation *Loc) {
|
|
if (!E->getType()->isIntegralOrUnscopedEnumerationType()) {
|
|
if (Loc) *Loc = E->getExprLoc();
|
|
return false;
|
|
}
|
|
|
|
APValue Result;
|
|
if (!E->isCXX11ConstantExpr(Ctx, &Result, Loc))
|
|
return false;
|
|
|
|
if (!Result.isInt()) {
|
|
if (Loc) *Loc = E->getExprLoc();
|
|
return false;
|
|
}
|
|
|
|
if (Value) *Value = Result.getInt();
|
|
return true;
|
|
}
|
|
|
|
bool Expr::isIntegerConstantExpr(const ASTContext &Ctx,
|
|
SourceLocation *Loc) const {
|
|
if (Ctx.getLangOpts().CPlusPlus11)
|
|
return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, nullptr, Loc);
|
|
|
|
ICEDiag D = CheckICE(this, Ctx);
|
|
if (D.Kind != IK_ICE) {
|
|
if (Loc) *Loc = D.Loc;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool Expr::isIntegerConstantExpr(llvm::APSInt &Value, const ASTContext &Ctx,
|
|
SourceLocation *Loc, bool isEvaluated) const {
|
|
if (Ctx.getLangOpts().CPlusPlus11)
|
|
return EvaluateCPlusPlus11IntegralConstantExpr(Ctx, this, &Value, Loc);
|
|
|
|
if (!isIntegerConstantExpr(Ctx, Loc))
|
|
return false;
|
|
|
|
// The only possible side-effects here are due to UB discovered in the
|
|
// evaluation (for instance, INT_MAX + 1). In such a case, we are still
|
|
// required to treat the expression as an ICE, so we produce the folded
|
|
// value.
|
|
EvalResult ExprResult;
|
|
Expr::EvalStatus Status;
|
|
EvalInfo Info(Ctx, Status, EvalInfo::EM_IgnoreSideEffects);
|
|
Info.InConstantContext = true;
|
|
|
|
if (!::EvaluateAsInt(this, ExprResult, Ctx, SE_AllowSideEffects, Info))
|
|
llvm_unreachable("ICE cannot be evaluated!");
|
|
|
|
Value = ExprResult.Val.getInt();
|
|
return true;
|
|
}
|
|
|
|
bool Expr::isCXX98IntegralConstantExpr(const ASTContext &Ctx) const {
|
|
return CheckICE(this, Ctx).Kind == IK_ICE;
|
|
}
|
|
|
|
bool Expr::isCXX11ConstantExpr(const ASTContext &Ctx, APValue *Result,
|
|
SourceLocation *Loc) const {
|
|
// We support this checking in C++98 mode in order to diagnose compatibility
|
|
// issues.
|
|
assert(Ctx.getLangOpts().CPlusPlus);
|
|
|
|
// Build evaluation settings.
|
|
Expr::EvalStatus Status;
|
|
SmallVector<PartialDiagnosticAt, 8> Diags;
|
|
Status.Diag = &Diags;
|
|
EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpression);
|
|
|
|
APValue Scratch;
|
|
bool IsConstExpr = ::EvaluateAsRValue(Info, this, Result ? *Result : Scratch);
|
|
|
|
if (!Diags.empty()) {
|
|
IsConstExpr = false;
|
|
if (Loc) *Loc = Diags[0].first;
|
|
} else if (!IsConstExpr) {
|
|
// FIXME: This shouldn't happen.
|
|
if (Loc) *Loc = getExprLoc();
|
|
}
|
|
|
|
return IsConstExpr;
|
|
}
|
|
|
|
bool Expr::EvaluateWithSubstitution(APValue &Value, ASTContext &Ctx,
|
|
const FunctionDecl *Callee,
|
|
ArrayRef<const Expr*> Args,
|
|
const Expr *This) const {
|
|
Expr::EvalStatus Status;
|
|
EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantExpressionUnevaluated);
|
|
|
|
LValue ThisVal;
|
|
const LValue *ThisPtr = nullptr;
|
|
if (This) {
|
|
#ifndef NDEBUG
|
|
auto *MD = dyn_cast<CXXMethodDecl>(Callee);
|
|
assert(MD && "Don't provide `this` for non-methods.");
|
|
assert(!MD->isStatic() && "Don't provide `this` for static methods.");
|
|
#endif
|
|
if (EvaluateObjectArgument(Info, This, ThisVal))
|
|
ThisPtr = &ThisVal;
|
|
if (Info.EvalStatus.HasSideEffects)
|
|
return false;
|
|
}
|
|
|
|
ArgVector ArgValues(Args.size());
|
|
for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
|
|
I != E; ++I) {
|
|
if ((*I)->isValueDependent() ||
|
|
!Evaluate(ArgValues[I - Args.begin()], Info, *I))
|
|
// If evaluation fails, throw away the argument entirely.
|
|
ArgValues[I - Args.begin()] = APValue();
|
|
if (Info.EvalStatus.HasSideEffects)
|
|
return false;
|
|
}
|
|
|
|
// Build fake call to Callee.
|
|
CallStackFrame Frame(Info, Callee->getLocation(), Callee, ThisPtr,
|
|
ArgValues.data());
|
|
return Evaluate(Value, Info, this) && !Info.EvalStatus.HasSideEffects;
|
|
}
|
|
|
|
bool Expr::isPotentialConstantExpr(const FunctionDecl *FD,
|
|
SmallVectorImpl<
|
|
PartialDiagnosticAt> &Diags) {
|
|
// FIXME: It would be useful to check constexpr function templates, but at the
|
|
// moment the constant expression evaluator cannot cope with the non-rigorous
|
|
// ASTs which we build for dependent expressions.
|
|
if (FD->isDependentContext())
|
|
return true;
|
|
|
|
Expr::EvalStatus Status;
|
|
Status.Diag = &Diags;
|
|
|
|
EvalInfo Info(FD->getASTContext(), Status,
|
|
EvalInfo::EM_PotentialConstantExpression);
|
|
Info.InConstantContext = true;
|
|
|
|
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
|
|
const CXXRecordDecl *RD = MD ? MD->getParent()->getCanonicalDecl() : nullptr;
|
|
|
|
// Fabricate an arbitrary expression on the stack and pretend that it
|
|
// is a temporary being used as the 'this' pointer.
|
|
LValue This;
|
|
ImplicitValueInitExpr VIE(RD ? Info.Ctx.getRecordType(RD) : Info.Ctx.IntTy);
|
|
This.set({&VIE, Info.CurrentCall->Index});
|
|
|
|
ArrayRef<const Expr*> Args;
|
|
|
|
APValue Scratch;
|
|
if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) {
|
|
// Evaluate the call as a constant initializer, to allow the construction
|
|
// of objects of non-literal types.
|
|
Info.setEvaluatingDecl(This.getLValueBase(), Scratch);
|
|
HandleConstructorCall(&VIE, This, Args, CD, Info, Scratch);
|
|
} else {
|
|
SourceLocation Loc = FD->getLocation();
|
|
HandleFunctionCall(Loc, FD, (MD && MD->isInstance()) ? &This : nullptr,
|
|
Args, FD->getBody(), Info, Scratch, nullptr);
|
|
}
|
|
|
|
return Diags.empty();
|
|
}
|
|
|
|
bool Expr::isPotentialConstantExprUnevaluated(Expr *E,
|
|
const FunctionDecl *FD,
|
|
SmallVectorImpl<
|
|
PartialDiagnosticAt> &Diags) {
|
|
Expr::EvalStatus Status;
|
|
Status.Diag = &Diags;
|
|
|
|
EvalInfo Info(FD->getASTContext(), Status,
|
|
EvalInfo::EM_PotentialConstantExpressionUnevaluated);
|
|
|
|
// Fabricate a call stack frame to give the arguments a plausible cover story.
|
|
ArrayRef<const Expr*> Args;
|
|
ArgVector ArgValues(0);
|
|
bool Success = EvaluateArgs(Args, ArgValues, Info);
|
|
(void)Success;
|
|
assert(Success &&
|
|
"Failed to set up arguments for potential constant evaluation");
|
|
CallStackFrame Frame(Info, SourceLocation(), FD, nullptr, ArgValues.data());
|
|
|
|
APValue ResultScratch;
|
|
Evaluate(ResultScratch, Info, E);
|
|
return Diags.empty();
|
|
}
|
|
|
|
bool Expr::tryEvaluateObjectSize(uint64_t &Result, ASTContext &Ctx,
|
|
unsigned Type) const {
|
|
if (!getType()->isPointerType())
|
|
return false;
|
|
|
|
Expr::EvalStatus Status;
|
|
EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold);
|
|
return tryEvaluateBuiltinObjectSize(this, Type, Info, Result);
|
|
}
|