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llvm-project/clang/lib/AST/ExprConstant.cpp

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//===--- ExprConstant.cpp - Expression Constant Evaluator -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Expr constant evaluator.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/APValue.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/ASTDiagnostic.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/Support/Compiler.h"
using namespace clang;
using llvm::APSInt;
using llvm::APFloat;
/// 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;
/// EvalResult - Contains information about the evaluation.
Expr::EvalResult &EvalResult;
/// ShortCircuit - will be greater than zero if the current subexpression has
/// will not be evaluated because it's short-circuited (according to C rules).
unsigned ShortCircuit;
EvalInfo(ASTContext &ctx, Expr::EvalResult& evalresult) : Ctx(ctx),
EvalResult(evalresult), ShortCircuit(0) {}
};
static bool EvaluateLValue(const Expr *E, APValue &Result, EvalInfo &Info);
static bool EvaluatePointer(const Expr *E, APValue &Result, EvalInfo &Info);
static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info);
static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info);
static bool EvaluateComplex(const Expr *E, APValue &Result, EvalInfo &Info);
//===----------------------------------------------------------------------===//
// Misc utilities
//===----------------------------------------------------------------------===//
static bool HandleConversionToBool(Expr* E, bool& Result, EvalInfo &Info) {
if (E->getType()->isIntegralType()) {
APSInt IntResult;
if (!EvaluateInteger(E, IntResult, Info))
return false;
Result = IntResult != 0;
return true;
} else if (E->getType()->isRealFloatingType()) {
APFloat FloatResult(0.0);
if (!EvaluateFloat(E, FloatResult, Info))
return false;
Result = !FloatResult.isZero();
return true;
} else if (E->getType()->isPointerType()) {
APValue PointerResult;
if (!EvaluatePointer(E, PointerResult, Info))
return false;
// FIXME: Is this accurate for all kinds of bases? If not, what would
// the check look like?
Result = PointerResult.getLValueBase() || PointerResult.getLValueOffset();
return true;
}
return false;
}
static APSInt HandleFloatToIntCast(QualType DestType, QualType SrcType,
APFloat &Value, ASTContext &Ctx) {
unsigned DestWidth = Ctx.getIntWidth(DestType);
// Determine whether we are converting to unsigned or signed.
bool DestSigned = DestType->isSignedIntegerType();
// FIXME: Warning for overflow.
uint64_t Space[4];
bool ignored;
(void)Value.convertToInteger(Space, DestWidth, DestSigned,
llvm::APFloat::rmTowardZero, &ignored);
return APSInt(llvm::APInt(DestWidth, 4, Space), !DestSigned);
}
static APFloat HandleFloatToFloatCast(QualType DestType, QualType SrcType,
APFloat &Value, ASTContext &Ctx) {
bool ignored;
APFloat Result = Value;
Result.convert(Ctx.getFloatTypeSemantics(DestType),
APFloat::rmNearestTiesToEven, &ignored);
return Result;
}
static APSInt HandleIntToIntCast(QualType DestType, QualType SrcType,
APSInt &Value, ASTContext &Ctx) {
unsigned DestWidth = Ctx.getIntWidth(DestType);
APSInt Result = Value;
// Figure out if this is a truncate, extend or noop cast.
// If the input is signed, do a sign extend, noop, or truncate.
Result.extOrTrunc(DestWidth);
Result.setIsUnsigned(DestType->isUnsignedIntegerType());
return Result;
}
static APFloat HandleIntToFloatCast(QualType DestType, QualType SrcType,
APSInt &Value, ASTContext &Ctx) {
APFloat Result(Ctx.getFloatTypeSemantics(DestType), 1);
Result.convertFromAPInt(Value, Value.isSigned(),
APFloat::rmNearestTiesToEven);
return Result;
}
//===----------------------------------------------------------------------===//
// LValue Evaluation
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN LValueExprEvaluator
: public StmtVisitor<LValueExprEvaluator, APValue> {
EvalInfo &Info;
public:
LValueExprEvaluator(EvalInfo &info) : Info(info) {}
APValue VisitStmt(Stmt *S) {
#if 0
// FIXME: Remove this when we support more expressions.
printf("Unhandled pointer statement\n");
S->dump();
#endif
return APValue();
}
APValue VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); }
APValue VisitDeclRefExpr(DeclRefExpr *E);
APValue VisitPredefinedExpr(PredefinedExpr *E) { return APValue(E, 0); }
APValue VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
APValue VisitMemberExpr(MemberExpr *E);
APValue VisitStringLiteral(StringLiteral *E) { return APValue(E, 0); }
APValue VisitArraySubscriptExpr(ArraySubscriptExpr *E);
};
} // end anonymous namespace
static bool EvaluateLValue(const Expr* E, APValue& Result, EvalInfo &Info) {
Result = LValueExprEvaluator(Info).Visit(const_cast<Expr*>(E));
return Result.isLValue();
}
APValue LValueExprEvaluator::VisitDeclRefExpr(DeclRefExpr *E)
{
if (!E->hasGlobalStorage())
return APValue();
return APValue(E, 0);
}
APValue LValueExprEvaluator::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
if (E->isFileScope())
return APValue(E, 0);
return APValue();
}
APValue LValueExprEvaluator::VisitMemberExpr(MemberExpr *E) {
APValue result;
QualType Ty;
if (E->isArrow()) {
if (!EvaluatePointer(E->getBase(), result, Info))
return APValue();
Ty = E->getBase()->getType()->getAsPointerType()->getPointeeType();
} else {
result = Visit(E->getBase());
if (result.isUninit())
return APValue();
Ty = E->getBase()->getType();
}
RecordDecl *RD = Ty->getAsRecordType()->getDecl();
const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl());
if (!FD) // FIXME: deal with other kinds of member expressions
return APValue();
// FIXME: This is linear time.
unsigned i = 0;
for (RecordDecl::field_iterator Field = RD->field_begin(),
FieldEnd = RD->field_end();
Field != FieldEnd; (void)++Field, ++i) {
if (*Field == FD)
break;
}
result.setLValue(result.getLValueBase(),
result.getLValueOffset() + RL.getFieldOffset(i) / 8);
return result;
}
APValue LValueExprEvaluator::VisitArraySubscriptExpr(ArraySubscriptExpr *E)
{
APValue Result;
if (!EvaluatePointer(E->getBase(), Result, Info))
return APValue();
APSInt Index;
if (!EvaluateInteger(E->getIdx(), Index, Info))
return APValue();
uint64_t ElementSize = Info.Ctx.getTypeSize(E->getType()) / 8;
uint64_t Offset = Index.getSExtValue() * ElementSize;
Result.setLValue(Result.getLValueBase(),
Result.getLValueOffset() + Offset);
return Result;
}
//===----------------------------------------------------------------------===//
// Pointer Evaluation
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN PointerExprEvaluator
: public StmtVisitor<PointerExprEvaluator, APValue> {
EvalInfo &Info;
public:
PointerExprEvaluator(EvalInfo &info) : Info(info) {}
APValue VisitStmt(Stmt *S) {
return APValue();
}
APValue VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); }
APValue VisitBinaryOperator(const BinaryOperator *E);
APValue VisitCastExpr(const CastExpr* E);
APValue VisitUnaryOperator(const UnaryOperator *E);
APValue VisitObjCStringLiteral(ObjCStringLiteral *E)
{ return APValue(E, 0); }
APValue VisitAddrLabelExpr(AddrLabelExpr *E)
{ return APValue(E, 0); }
APValue VisitCallExpr(CallExpr *E);
APValue VisitConditionalOperator(ConditionalOperator *E);
};
} // end anonymous namespace
static bool EvaluatePointer(const Expr* E, APValue& Result, EvalInfo &Info) {
if (!E->getType()->isPointerType())
return false;
Result = PointerExprEvaluator(Info).Visit(const_cast<Expr*>(E));
return Result.isLValue();
}
APValue PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
if (E->getOpcode() != BinaryOperator::Add &&
E->getOpcode() != BinaryOperator::Sub)
return APValue();
const Expr *PExp = E->getLHS();
const Expr *IExp = E->getRHS();
if (IExp->getType()->isPointerType())
std::swap(PExp, IExp);
APValue ResultLValue;
if (!EvaluatePointer(PExp, ResultLValue, Info))
return APValue();
llvm::APSInt AdditionalOffset(32);
if (!EvaluateInteger(IExp, AdditionalOffset, Info))
return APValue();
QualType PointeeType = PExp->getType()->getAsPointerType()->getPointeeType();
uint64_t SizeOfPointee = Info.Ctx.getTypeSize(PointeeType) / 8;
uint64_t Offset = ResultLValue.getLValueOffset();
if (E->getOpcode() == BinaryOperator::Add)
Offset += AdditionalOffset.getLimitedValue() * SizeOfPointee;
else
Offset -= AdditionalOffset.getLimitedValue() * SizeOfPointee;
return APValue(ResultLValue.getLValueBase(), Offset);
}
APValue PointerExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
if (E->getOpcode() == UnaryOperator::Extension) {
// FIXME: Deal with warnings?
return Visit(E->getSubExpr());
}
if (E->getOpcode() == UnaryOperator::AddrOf) {
APValue result;
if (EvaluateLValue(E->getSubExpr(), result, Info))
return result;
}
return APValue();
}
APValue PointerExprEvaluator::VisitCastExpr(const CastExpr* E) {
const Expr* SubExpr = E->getSubExpr();
// Check for pointer->pointer cast
if (SubExpr->getType()->isPointerType()) {
APValue Result;
if (EvaluatePointer(SubExpr, Result, Info))
return Result;
return APValue();
}
if (SubExpr->getType()->isIntegralType()) {
llvm::APSInt Result(32);
if (EvaluateInteger(SubExpr, Result, Info)) {
Result.extOrTrunc((unsigned)Info.Ctx.getTypeSize(E->getType()));
return APValue(0, Result.getZExtValue());
}
}
if (SubExpr->getType()->isFunctionType() ||
SubExpr->getType()->isArrayType()) {
APValue Result;
if (EvaluateLValue(SubExpr, Result, Info))
return Result;
return APValue();
}
//assert(0 && "Unhandled cast");
return APValue();
}
APValue PointerExprEvaluator::VisitCallExpr(CallExpr *E) {
if (E->isBuiltinCall() == Builtin::BI__builtin___CFStringMakeConstantString)
return APValue(E, 0);
return APValue();
}
APValue PointerExprEvaluator::VisitConditionalOperator(ConditionalOperator *E) {
bool BoolResult;
if (!HandleConversionToBool(E->getCond(), BoolResult, Info))
return APValue();
Expr* EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr();
APValue Result;
if (EvaluatePointer(EvalExpr, Result, Info))
return Result;
return APValue();
}
//===----------------------------------------------------------------------===//
// Vector Evaluation
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN VectorExprEvaluator
: public StmtVisitor<VectorExprEvaluator, APValue> {
EvalInfo &Info;
public:
VectorExprEvaluator(EvalInfo &info) : Info(info) {}
APValue VisitStmt(Stmt *S) {
return APValue();
}
APValue VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); }
APValue VisitCastExpr(const CastExpr* E);
APValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
APValue VisitInitListExpr(const InitListExpr *E);
};
} // end anonymous namespace
static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) {
if (!E->getType()->isVectorType())
return false;
Result = VectorExprEvaluator(Info).Visit(const_cast<Expr*>(E));
return !Result.isUninit();
}
APValue VectorExprEvaluator::VisitCastExpr(const CastExpr* E) {
const Expr* SE = E->getSubExpr();
// Check for vector->vector bitcast.
if (SE->getType()->isVectorType())
return this->Visit(const_cast<Expr*>(SE));
return APValue();
}
APValue
VectorExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
return this->Visit(const_cast<Expr*>(E->getInitializer()));
}
APValue
VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
const VectorType *VT = E->getType()->getAsVectorType();
unsigned NumInits = E->getNumInits();
if (!VT || VT->getNumElements() != NumInits)
return APValue();
QualType EltTy = VT->getElementType();
llvm::SmallVector<APValue, 4> Elements;
for (unsigned i = 0; i < NumInits; i++) {
if (EltTy->isIntegerType()) {
llvm::APSInt sInt(32);
if (!EvaluateInteger(E->getInit(i), sInt, Info))
return APValue();
Elements.push_back(APValue(sInt));
} else {
llvm::APFloat f(0.0);
if (!EvaluateFloat(E->getInit(i), f, Info))
return APValue();
Elements.push_back(APValue(f));
}
}
return APValue(&Elements[0], Elements.size());
}
//===----------------------------------------------------------------------===//
// Integer Evaluation
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN IntExprEvaluator
: public StmtVisitor<IntExprEvaluator, bool> {
EvalInfo &Info;
APSInt &Result;
public:
IntExprEvaluator(EvalInfo &info, APSInt &result)
: Info(info), Result(result) {}
unsigned getIntTypeSizeInBits(QualType T) const {
return (unsigned)Info.Ctx.getIntWidth(T);
}
bool Extension(SourceLocation L, diag::kind D, const Expr *E) {
Info.EvalResult.DiagLoc = L;
Info.EvalResult.Diag = D;
Info.EvalResult.DiagExpr = E;
return true; // still a constant.
}
bool Error(SourceLocation L, diag::kind D, const Expr *E) {
// If this is in an unevaluated portion of the subexpression, ignore the
// error.
if (Info.ShortCircuit) {
// If error is ignored because the value isn't evaluated, get the real
// type at least to prevent errors downstream.
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
// Take the first error.
if (Info.EvalResult.Diag == 0) {
Info.EvalResult.DiagLoc = L;
Info.EvalResult.Diag = D;
Info.EvalResult.DiagExpr = E;
}
return false;
}
//===--------------------------------------------------------------------===//
// Visitor Methods
//===--------------------------------------------------------------------===//
bool VisitStmt(Stmt *) {
assert(0 && "This should be called on integers, stmts are not integers");
return false;
}
bool VisitExpr(Expr *E) {
return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
}
bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); }
bool VisitIntegerLiteral(const IntegerLiteral *E) {
Result = E->getValue();
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
bool VisitCharacterLiteral(const CharacterLiteral *E) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result = E->getValue();
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
bool VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
// Per gcc docs "this built-in function ignores top level
// qualifiers". We need to use the canonical version to properly
// be able to strip CRV qualifiers from the type.
QualType T0 = Info.Ctx.getCanonicalType(E->getArgType1());
QualType T1 = Info.Ctx.getCanonicalType(E->getArgType2());
Result = Info.Ctx.typesAreCompatible(T0.getUnqualifiedType(),
T1.getUnqualifiedType());
return true;
}
bool VisitDeclRefExpr(const DeclRefExpr *E);
bool VisitCallExpr(const CallExpr *E);
bool VisitBinaryOperator(const BinaryOperator *E);
bool VisitUnaryOperator(const UnaryOperator *E);
bool VisitConditionalOperator(const ConditionalOperator *E);
bool VisitCastExpr(CastExpr* E);
bool VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E);
bool VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result = E->getValue();
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
bool VisitGNUNullExpr(const GNUNullExpr *E) {
Result = APSInt::getNullValue(getIntTypeSizeInBits(E->getType()));
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
bool VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) {
Result = APSInt::getNullValue(getIntTypeSizeInBits(E->getType()));
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
bool VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result = E->Evaluate();
return true;
}
private:
unsigned GetAlignOfExpr(const Expr *E);
unsigned GetAlignOfType(QualType T);
};
} // end anonymous namespace
static bool EvaluateInteger(const Expr* E, APSInt &Result, EvalInfo &Info) {
return IntExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E));
}
bool IntExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
// Enums are integer constant exprs.
if (const EnumConstantDecl *D = dyn_cast<EnumConstantDecl>(E->getDecl())) {
Result = D->getInitVal();
// FIXME: This is an ugly hack around the fact that enums don't set their
// signedness consistently; see PR3173
Result.setIsUnsigned(!E->getType()->isSignedIntegerType());
return true;
}
// Otherwise, random variable references are not constants.
return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
}
/// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
/// as GCC.
static int EvaluateBuiltinClassifyType(const CallExpr *E) {
// The following enum mimics the values returned by GCC.
enum gcc_type_class {
no_type_class = -1,
void_type_class, integer_type_class, char_type_class,
enumeral_type_class, boolean_type_class,
pointer_type_class, reference_type_class, offset_type_class,
real_type_class, complex_type_class,
function_type_class, method_type_class,
record_type_class, union_type_class,
array_type_class, string_type_class,
lang_type_class
};
// If no argument was supplied, default to "no_type_class". This isn't
// ideal, however it is what gcc does.
if (E->getNumArgs() == 0)
return no_type_class;
QualType ArgTy = E->getArg(0)->getType();
if (ArgTy->isVoidType())
return void_type_class;
else if (ArgTy->isEnumeralType())
return enumeral_type_class;
else if (ArgTy->isBooleanType())
return boolean_type_class;
else if (ArgTy->isCharType())
return string_type_class; // gcc doesn't appear to use char_type_class
else if (ArgTy->isIntegerType())
return integer_type_class;
else if (ArgTy->isPointerType())
return pointer_type_class;
else if (ArgTy->isReferenceType())
return reference_type_class;
else if (ArgTy->isRealType())
return real_type_class;
else if (ArgTy->isComplexType())
return complex_type_class;
else if (ArgTy->isFunctionType())
return function_type_class;
else if (ArgTy->isStructureType())
return record_type_class;
else if (ArgTy->isUnionType())
return union_type_class;
else if (ArgTy->isArrayType())
return array_type_class;
else if (ArgTy->isUnionType())
return union_type_class;
else // FIXME: offset_type_class, method_type_class, & lang_type_class?
assert(0 && "CallExpr::isBuiltinClassifyType(): unimplemented type");
return -1;
}
bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
switch (E->isBuiltinCall()) {
default:
return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
case Builtin::BI__builtin_classify_type:
Result.setIsSigned(true);
Result = EvaluateBuiltinClassifyType(E);
return true;
case Builtin::BI__builtin_constant_p:
// __builtin_constant_p always has one operand: it returns true if that
// operand can be folded, false otherwise.
Result = E->getArg(0)->isEvaluatable(Info.Ctx);
return true;
}
}
bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
if (E->getOpcode() == BinaryOperator::Comma) {
if (!Visit(E->getRHS()))
return false;
if (!Info.ShortCircuit) {
// If we can't evaluate the LHS, it must be because it has
// side effects.
if (!E->getLHS()->isEvaluatable(Info.Ctx))
Info.EvalResult.HasSideEffects = true;
return Extension(E->getOperatorLoc(), diag::note_comma_in_ice, E);
}
return true;
}
if (E->isLogicalOp()) {
// These need to be handled specially because the operands aren't
// necessarily integral
bool lhsResult, rhsResult;
if (HandleConversionToBool(E->getLHS(), lhsResult, Info)) {
// 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 (lhsResult == (E->getOpcode() == BinaryOperator::LOr) ||
!lhsResult == (E->getOpcode() == BinaryOperator::LAnd)) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
Result = lhsResult;
Info.ShortCircuit++;
bool rhsEvaluated = HandleConversionToBool(E->getRHS(), rhsResult, Info);
Info.ShortCircuit--;
if (rhsEvaluated)
return true;
// FIXME: Return an extension warning saying that the RHS could not be
// evaluated.
return true;
}
if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
if (E->getOpcode() == BinaryOperator::LOr)
Result = lhsResult || rhsResult;
else
Result = lhsResult && rhsResult;
return true;
}
} else {
if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) {
// 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() == BinaryOperator::LOr) ||
!rhsResult == (E->getOpcode() == BinaryOperator::LAnd)) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
Result = rhsResult;
// Since we werent able to evaluate the left hand side, it
// must have had side effects.
Info.EvalResult.HasSideEffects = true;
return true;
}
}
}
return false;
}
QualType LHSTy = E->getLHS()->getType();
QualType RHSTy = E->getRHS()->getType();
if (LHSTy->isAnyComplexType()) {
assert(RHSTy->isAnyComplexType() && "Invalid comparison");
APValue LHS, RHS;
if (!EvaluateComplex(E->getLHS(), LHS, Info))
return false;
if (!EvaluateComplex(E->getRHS(), RHS, Info))
return false;
if (LHS.isComplexFloat()) {
APFloat::cmpResult CR_r =
LHS.getComplexFloatReal().compare(RHS.getComplexFloatReal());
APFloat::cmpResult CR_i =
LHS.getComplexFloatImag().compare(RHS.getComplexFloatImag());
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
if (E->getOpcode() == BinaryOperator::EQ)
Result = (CR_r == APFloat::cmpEqual &&
CR_i == APFloat::cmpEqual);
else if (E->getOpcode() == BinaryOperator::NE)
Result = ((CR_r == APFloat::cmpGreaterThan ||
CR_r == APFloat::cmpLessThan) &&
(CR_i == APFloat::cmpGreaterThan ||
CR_i == APFloat::cmpLessThan));
else
assert(0 && "Invalid complex compartison.");
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
} else {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
if (E->getOpcode() == BinaryOperator::EQ)
Result = (LHS.getComplexIntReal() == RHS.getComplexIntReal() &&
LHS.getComplexIntImag() == RHS.getComplexIntImag());
else if (E->getOpcode() == BinaryOperator::NE)
Result = (LHS.getComplexIntReal() != RHS.getComplexIntReal() ||
LHS.getComplexIntImag() != RHS.getComplexIntImag());
else
assert(0 && "Invalid complex compartison.");
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
}
if (LHSTy->isRealFloatingType() &&
RHSTy->isRealFloatingType()) {
APFloat RHS(0.0), LHS(0.0);
if (!EvaluateFloat(E->getRHS(), RHS, Info))
return false;
if (!EvaluateFloat(E->getLHS(), LHS, Info))
return false;
APFloat::cmpResult CR = LHS.compare(RHS);
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
switch (E->getOpcode()) {
default:
assert(0 && "Invalid binary operator!");
case BinaryOperator::LT:
Result = CR == APFloat::cmpLessThan;
break;
case BinaryOperator::GT:
Result = CR == APFloat::cmpGreaterThan;
break;
case BinaryOperator::LE:
Result = CR == APFloat::cmpLessThan || CR == APFloat::cmpEqual;
break;
case BinaryOperator::GE:
Result = CR == APFloat::cmpGreaterThan || CR == APFloat::cmpEqual;
break;
case BinaryOperator::EQ:
Result = CR == APFloat::cmpEqual;
break;
case BinaryOperator::NE:
Result = CR == APFloat::cmpGreaterThan || CR == APFloat::cmpLessThan;
break;
}
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
if (E->getOpcode() == BinaryOperator::Sub) {
if (LHSTy->isPointerType() && RHSTy->isPointerType()) {
APValue LHSValue;
if (!EvaluatePointer(E->getLHS(), LHSValue, Info))
return false;
APValue RHSValue;
if (!EvaluatePointer(E->getRHS(), RHSValue, Info))
return false;
// FIXME: Is this correct? What if only one of the operands has a base?
if (LHSValue.getLValueBase() || RHSValue.getLValueBase())
return false;
const QualType Type = E->getLHS()->getType();
const QualType ElementType = Type->getAsPointerType()->getPointeeType();
uint64_t D = LHSValue.getLValueOffset() - RHSValue.getLValueOffset();
D /= Info.Ctx.getTypeSize(ElementType) / 8;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result = D;
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
}
if (!LHSTy->isIntegralType() ||
!RHSTy->isIntegralType()) {
// We can't continue from here for non-integral types, and they
// could potentially confuse the following operations.
// FIXME: Deal with EQ and friends.
return false;
}
// The LHS of a constant expr is always evaluated and needed.
llvm::APSInt RHS(32);
if (!Visit(E->getLHS())) {
return false; // error in subexpression.
}
// FIXME Maybe we want to succeed even where we can't evaluate the
// right side of LAnd/LOr?
// For example, see http://llvm.org/bugs/show_bug.cgi?id=2525
if (!EvaluateInteger(E->getRHS(), RHS, Info))
return false;
switch (E->getOpcode()) {
default:
return Error(E->getOperatorLoc(), diag::note_invalid_subexpr_in_ice, E);
case BinaryOperator::Mul: Result *= RHS; return true;
case BinaryOperator::Add: Result += RHS; return true;
case BinaryOperator::Sub: Result -= RHS; return true;
case BinaryOperator::And: Result &= RHS; return true;
case BinaryOperator::Xor: Result ^= RHS; return true;
case BinaryOperator::Or: Result |= RHS; return true;
case BinaryOperator::Div:
if (RHS == 0)
return Error(E->getOperatorLoc(), diag::note_expr_divide_by_zero, E);
Result /= RHS;
break;
case BinaryOperator::Rem:
if (RHS == 0)
return Error(E->getOperatorLoc(), diag::note_expr_divide_by_zero, E);
Result %= RHS;
break;
case BinaryOperator::Shl:
// FIXME: Warn about out of range shift amounts!
Result <<= (unsigned)RHS.getLimitedValue(Result.getBitWidth()-1);
break;
case BinaryOperator::Shr:
Result >>= (unsigned)RHS.getLimitedValue(Result.getBitWidth()-1);
break;
case BinaryOperator::LT:
Result = Result < RHS;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
break;
case BinaryOperator::GT:
Result = Result > RHS;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
break;
case BinaryOperator::LE:
Result = Result <= RHS;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
break;
case BinaryOperator::GE:
Result = Result >= RHS;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
break;
case BinaryOperator::EQ:
Result = Result == RHS;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
break;
case BinaryOperator::NE:
Result = Result != RHS;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
break;
case BinaryOperator::LAnd:
Result = Result != 0 && RHS != 0;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
break;
case BinaryOperator::LOr:
Result = Result != 0 || RHS != 0;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
break;
}
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
bool IntExprEvaluator::VisitConditionalOperator(const ConditionalOperator *E) {
bool Cond;
if (!HandleConversionToBool(E->getCond(), Cond, Info))
return false;
return Visit(Cond ? E->getTrueExpr() : E->getFalseExpr());
}
unsigned IntExprEvaluator::GetAlignOfType(QualType T) {
const Type *Ty = Info.Ctx.getCanonicalType(T).getTypePtr();
// __alignof__(void) = 1 as a gcc extension.
if (Ty->isVoidType())
return 1;
// GCC extension: alignof(function) = 4.
// FIXME: AlignOf shouldn't be unconditionally 4! It should listen to the
// attribute(align) directive.
if (Ty->isFunctionType())
return 4;
if (const ASQualType *ASQT = dyn_cast<ASQualType>(Ty))
return GetAlignOfType(QualType(ASQT->getBaseType(), 0));
// alignof VLA/incomplete array.
if (const ArrayType *VAT = dyn_cast<ArrayType>(Ty))
return GetAlignOfType(VAT->getElementType());
// sizeof (objc class)?
if (isa<ObjCInterfaceType>(Ty))
return 1; // FIXME: This probably isn't right.
// Get information about the alignment.
unsigned CharSize = Info.Ctx.Target.getCharWidth();
return Info.Ctx.getTypeAlign(Ty) / CharSize;
}
unsigned IntExprEvaluator::GetAlignOfExpr(const Expr *E) {
E = E->IgnoreParens();
// 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());
if (const MemberExpr *ME = dyn_cast<MemberExpr>(E))
return Info.Ctx.getDeclAlign(ME->getMemberDecl());
return GetAlignOfType(E->getType());
}
/// VisitSizeAlignOfExpr - Evaluate a sizeof or alignof with a result as the
/// expression's type.
bool IntExprEvaluator::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) {
QualType DstTy = E->getType();
// Return the result in the right width.
Result.zextOrTrunc(getIntTypeSizeInBits(DstTy));
Result.setIsUnsigned(DstTy->isUnsignedIntegerType());
// Handle alignof separately.
if (!E->isSizeOf()) {
if (E->isArgumentType())
Result = GetAlignOfType(E->getArgumentType());
else
Result = GetAlignOfExpr(E->getArgumentExpr());
return true;
}
QualType SrcTy = E->getTypeOfArgument();
// sizeof(void) and __alignof__(void) = 1 as a gcc extension.
if (SrcTy->isVoidType()) {
Result = 1;
return true;
}
// sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
if (!SrcTy->isConstantSizeType())
return false;
// GCC extension: sizeof(function) = 1.
if (SrcTy->isFunctionType()) {
Result = 1;
return true;
}
if (SrcTy->isObjCInterfaceType()) {
// Slightly unusual case: the size of an ObjC interface type is the
// size of the class. This code intentionally falls through to the normal
// case.
ObjCInterfaceDecl *OI = SrcTy->getAsObjCInterfaceType()->getDecl();
RecordDecl *RD = const_cast<RecordDecl*>(Info.Ctx.addRecordToClass(OI));
SrcTy = Info.Ctx.getTagDeclType(static_cast<TagDecl*>(RD));
}
// Get information about the size.
unsigned CharSize = Info.Ctx.Target.getCharWidth();
Result = Info.Ctx.getTypeSize(SrcTy) / CharSize;
return true;
}
bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
// Special case unary operators that do not need their subexpression
// evaluated. offsetof/sizeof/alignof are all special.
if (E->isOffsetOfOp()) {
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result = E->evaluateOffsetOf(Info.Ctx);
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
if (E->getOpcode() == UnaryOperator::LNot) {
// LNot's operand isn't necessarily an integer, so we handle it specially.
bool bres;
if (!HandleConversionToBool(E->getSubExpr(), bres, Info))
return false;
Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
Result = !bres;
return true;
}
// Get the operand value into 'Result'.
if (!Visit(E->getSubExpr()))
return false;
switch (E->getOpcode()) {
default:
// Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
// See C99 6.6p3.
return Error(E->getOperatorLoc(), diag::note_invalid_subexpr_in_ice, E);
case UnaryOperator::Extension:
// FIXME: Should extension allow i-c-e extension expressions in its scope?
// If so, we could clear the diagnostic ID.
case UnaryOperator::Plus:
// The result is always just the subexpr.
break;
case UnaryOperator::Minus:
Result = -Result;
break;
case UnaryOperator::Not:
Result = ~Result;
break;
}
Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
return true;
}
/// HandleCast - This is used to evaluate implicit or explicit casts where the
/// result type is integer.
bool IntExprEvaluator::VisitCastExpr(CastExpr *E) {
Expr *SubExpr = E->getSubExpr();
QualType DestType = E->getType();
unsigned DestWidth = getIntTypeSizeInBits(DestType);
if (DestType->isBooleanType()) {
bool BoolResult;
if (!HandleConversionToBool(SubExpr, BoolResult, Info))
return false;
Result.zextOrTrunc(DestWidth);
Result.setIsUnsigned(DestType->isUnsignedIntegerType());
Result = BoolResult;
return true;
}
// Handle simple integer->integer casts.
if (SubExpr->getType()->isIntegralType()) {
if (!Visit(SubExpr))
return false;
Result = HandleIntToIntCast(DestType, SubExpr->getType(), Result, Info.Ctx);
return true;
}
// FIXME: Clean this up!
if (SubExpr->getType()->isPointerType()) {
APValue LV;
if (!EvaluatePointer(SubExpr, LV, Info))
return false;
if (LV.getLValueBase())
return false;
Result.extOrTrunc(DestWidth);
Result = LV.getLValueOffset();
Result.setIsUnsigned(DestType->isUnsignedIntegerType());
return true;
}
if (!SubExpr->getType()->isRealFloatingType())
return Error(E->getExprLoc(), diag::note_invalid_subexpr_in_ice, E);
APFloat F(0.0);
if (!EvaluateFloat(SubExpr, F, Info))
return Error(E->getExprLoc(), diag::note_invalid_subexpr_in_ice, E);
Result = HandleFloatToIntCast(DestType, SubExpr->getType(), F, Info.Ctx);
return true;
}
//===----------------------------------------------------------------------===//
// Float Evaluation
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN FloatExprEvaluator
: public StmtVisitor<FloatExprEvaluator, bool> {
EvalInfo &Info;
APFloat &Result;
public:
FloatExprEvaluator(EvalInfo &info, APFloat &result)
: Info(info), Result(result) {}
bool VisitStmt(Stmt *S) {
return false;
}
bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); }
bool VisitCallExpr(const CallExpr *E);
bool VisitUnaryOperator(const UnaryOperator *E);
bool VisitBinaryOperator(const BinaryOperator *E);
bool VisitFloatingLiteral(const FloatingLiteral *E);
bool VisitCastExpr(CastExpr *E);
bool VisitCXXZeroInitValueExpr(CXXZeroInitValueExpr *E);
};
} // end anonymous namespace
static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) {
return FloatExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E));
}
bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
switch (E->isBuiltinCall()) {
default: return false;
case Builtin::BI__builtin_huge_val:
case Builtin::BI__builtin_huge_valf:
case Builtin::BI__builtin_huge_vall:
case Builtin::BI__builtin_inf:
case Builtin::BI__builtin_inff:
case Builtin::BI__builtin_infl: {
const llvm::fltSemantics &Sem =
Info.Ctx.getFloatTypeSemantics(E->getType());
Result = llvm::APFloat::getInf(Sem);
return true;
}
case Builtin::BI__builtin_nan:
case Builtin::BI__builtin_nanf:
case Builtin::BI__builtin_nanl:
// If this is __builtin_nan("") turn this into a simple nan, otherwise we
// can't constant fold it.
if (const StringLiteral *S =
dyn_cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts())) {
if (!S->isWide() && S->getByteLength() == 0) { // empty string.
const llvm::fltSemantics &Sem =
Info.Ctx.getFloatTypeSemantics(E->getType());
Result = llvm::APFloat::getNaN(Sem);
return true;
}
}
return false;
case Builtin::BI__builtin_fabs:
case Builtin::BI__builtin_fabsf:
case Builtin::BI__builtin_fabsl:
if (!EvaluateFloat(E->getArg(0), Result, Info))
return false;
if (Result.isNegative())
Result.changeSign();
return true;
case Builtin::BI__builtin_copysign:
case Builtin::BI__builtin_copysignf:
case Builtin::BI__builtin_copysignl: {
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::VisitUnaryOperator(const UnaryOperator *E) {
if (E->getOpcode() == UnaryOperator::Deref)
return false;
if (!EvaluateFloat(E->getSubExpr(), Result, Info))
return false;
switch (E->getOpcode()) {
default: return false;
case UnaryOperator::Plus:
return true;
case UnaryOperator::Minus:
Result.changeSign();
return true;
}
}
bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
// FIXME: Diagnostics? I really don't understand how the warnings
// and errors are supposed to work.
APFloat RHS(0.0);
if (!EvaluateFloat(E->getLHS(), Result, Info))
return false;
if (!EvaluateFloat(E->getRHS(), RHS, Info))
return false;
switch (E->getOpcode()) {
default: return false;
case BinaryOperator::Mul:
Result.multiply(RHS, APFloat::rmNearestTiesToEven);
return true;
case BinaryOperator::Add:
Result.add(RHS, APFloat::rmNearestTiesToEven);
return true;
case BinaryOperator::Sub:
Result.subtract(RHS, APFloat::rmNearestTiesToEven);
return true;
case BinaryOperator::Div:
Result.divide(RHS, APFloat::rmNearestTiesToEven);
return true;
case BinaryOperator::Rem:
Result.mod(RHS, APFloat::rmNearestTiesToEven);
return true;
}
}
bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) {
Result = E->getValue();
return true;
}
bool FloatExprEvaluator::VisitCastExpr(CastExpr *E) {
Expr* SubExpr = E->getSubExpr();
if (SubExpr->getType()->isIntegralType()) {
APSInt IntResult;
if (!EvaluateInteger(E, IntResult, Info))
return false;
Result = HandleIntToFloatCast(E->getType(), SubExpr->getType(),
IntResult, Info.Ctx);
return true;
}
if (SubExpr->getType()->isRealFloatingType()) {
if (!Visit(SubExpr))
return false;
Result = HandleFloatToFloatCast(E->getType(), SubExpr->getType(),
Result, Info.Ctx);
return true;
}
return false;
}
bool FloatExprEvaluator::VisitCXXZeroInitValueExpr(CXXZeroInitValueExpr *E) {
Result = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(E->getType()));
return true;
}
//===----------------------------------------------------------------------===//
// Complex Evaluation (for float and integer)
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN ComplexExprEvaluator
: public StmtVisitor<ComplexExprEvaluator, APValue> {
EvalInfo &Info;
public:
ComplexExprEvaluator(EvalInfo &info) : Info(info) {}
//===--------------------------------------------------------------------===//
// Visitor Methods
//===--------------------------------------------------------------------===//
APValue VisitStmt(Stmt *S) {
return APValue();
}
APValue VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); }
APValue VisitImaginaryLiteral(ImaginaryLiteral *E) {
Expr* SubExpr = E->getSubExpr();
if (SubExpr->getType()->isRealFloatingType()) {
APFloat Result(0.0);
if (!EvaluateFloat(SubExpr, Result, Info))
return APValue();
return APValue(APFloat(Result.getSemantics(), APFloat::fcZero, false),
Result);
} else {
assert(SubExpr->getType()->isIntegerType() &&
"Unexpected imaginary literal.");
llvm::APSInt Result;
if (!EvaluateInteger(SubExpr, Result, Info))
return APValue();
llvm::APSInt Zero(Result.getBitWidth(), !Result.isSigned());
Zero = 0;
return APValue(Zero, Result);
}
}
APValue VisitCastExpr(CastExpr *E) {
Expr* SubExpr = E->getSubExpr();
QualType EltType = E->getType()->getAsComplexType()->getElementType();
QualType SubType = SubExpr->getType();
if (SubType->isRealFloatingType()) {
APFloat Result(0.0);
if (!EvaluateFloat(SubExpr, Result, Info))
return APValue();
// Apply float conversion if necessary.
Result = HandleFloatToFloatCast(EltType, SubType, Result, Info.Ctx);
return APValue(Result,
APFloat(Result.getSemantics(), APFloat::fcZero, false));
} else if (SubType->isIntegerType()) {
APSInt Result;
if (!EvaluateInteger(SubExpr, Result, Info))
return APValue();
// Apply integer conversion if necessary.
Result = HandleIntToIntCast(EltType, SubType, Result, Info.Ctx);
llvm::APSInt Zero(Result.getBitWidth(), !Result.isSigned());
Zero = 0;
return APValue(Result, Zero);
} else if (const ComplexType *CT = SubType->getAsComplexType()) {
APValue Src;
if (!EvaluateComplex(SubExpr, Src, Info))
return APValue();
QualType SrcType = CT->getElementType();
if (Src.isComplexFloat()) {
if (EltType->isRealFloatingType()) {
return APValue(HandleFloatToFloatCast(EltType, SrcType,
Src.getComplexFloatReal(),
Info.Ctx),
HandleFloatToFloatCast(EltType, SrcType,
Src.getComplexFloatImag(),
Info.Ctx));
} else {
return APValue(HandleFloatToIntCast(EltType, SrcType,
Src.getComplexFloatReal(),
Info.Ctx),
HandleFloatToIntCast(EltType, SrcType,
Src.getComplexFloatImag(),
Info.Ctx));
}
} else {
assert(Src.isComplexInt() && "Invalid evaluate result.");
if (EltType->isRealFloatingType()) {
return APValue(HandleIntToFloatCast(EltType, SrcType,
Src.getComplexIntReal(),
Info.Ctx),
HandleIntToFloatCast(EltType, SrcType,
Src.getComplexIntImag(),
Info.Ctx));
} else {
return APValue(HandleIntToIntCast(EltType, SrcType,
Src.getComplexIntReal(),
Info.Ctx),
HandleIntToIntCast(EltType, SrcType,
Src.getComplexIntImag(),
Info.Ctx));
}
}
}
// FIXME: Handle more casts.
return APValue();
}
APValue VisitBinaryOperator(const BinaryOperator *E);
};
} // end anonymous namespace
static bool EvaluateComplex(const Expr *E, APValue &Result, EvalInfo &Info)
{
Result = ComplexExprEvaluator(Info).Visit(const_cast<Expr*>(E));
assert((!Result.isComplexFloat() ||
(&Result.getComplexFloatReal().getSemantics() ==
&Result.getComplexFloatImag().getSemantics())) &&
"Invalid complex evaluation.");
return Result.isComplexFloat() || Result.isComplexInt();
}
APValue ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E)
{
APValue Result, RHS;
if (!EvaluateComplex(E->getLHS(), Result, Info))
return APValue();
if (!EvaluateComplex(E->getRHS(), RHS, Info))
return APValue();
assert(Result.isComplexFloat() == RHS.isComplexFloat() &&
"Invalid operands to binary operator.");
switch (E->getOpcode()) {
default: return APValue();
case BinaryOperator::Add:
if (Result.isComplexFloat()) {
Result.getComplexFloatReal().add(RHS.getComplexFloatReal(),
APFloat::rmNearestTiesToEven);
Result.getComplexFloatImag().add(RHS.getComplexFloatImag(),
APFloat::rmNearestTiesToEven);
} else {
Result.getComplexIntReal() += RHS.getComplexIntReal();
Result.getComplexIntImag() += RHS.getComplexIntImag();
}
break;
case BinaryOperator::Sub:
if (Result.isComplexFloat()) {
Result.getComplexFloatReal().subtract(RHS.getComplexFloatReal(),
APFloat::rmNearestTiesToEven);
Result.getComplexFloatImag().subtract(RHS.getComplexFloatImag(),
APFloat::rmNearestTiesToEven);
} else {
Result.getComplexIntReal() -= RHS.getComplexIntReal();
Result.getComplexIntImag() -= RHS.getComplexIntImag();
}
break;
case BinaryOperator::Mul:
if (Result.isComplexFloat()) {
APValue LHS = Result;
APFloat &LHS_r = LHS.getComplexFloatReal();
APFloat &LHS_i = LHS.getComplexFloatImag();
APFloat &RHS_r = RHS.getComplexFloatReal();
APFloat &RHS_i = RHS.getComplexFloatImag();
APFloat Tmp = LHS_r;
Tmp.multiply(RHS_r, APFloat::rmNearestTiesToEven);
Result.getComplexFloatReal() = Tmp;
Tmp = LHS_i;
Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven);
Result.getComplexFloatReal().subtract(Tmp, APFloat::rmNearestTiesToEven);
Tmp = LHS_r;
Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven);
Result.getComplexFloatImag() = Tmp;
Tmp = LHS_i;
Tmp.multiply(RHS_r, APFloat::rmNearestTiesToEven);
Result.getComplexFloatImag().add(Tmp, APFloat::rmNearestTiesToEven);
} else {
APValue LHS = Result;
Result.getComplexIntReal() =
(LHS.getComplexIntReal() * RHS.getComplexIntReal() -
LHS.getComplexIntImag() * RHS.getComplexIntImag());
Result.getComplexIntImag() =
(LHS.getComplexIntReal() * RHS.getComplexIntImag() +
LHS.getComplexIntImag() * RHS.getComplexIntReal());
}
break;
}
return Result;
}
//===----------------------------------------------------------------------===//
// Top level Expr::Evaluate method.
//===----------------------------------------------------------------------===//
/// Evaluate - 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.
bool Expr::Evaluate(EvalResult &Result, ASTContext &Ctx) const {
EvalInfo Info(Ctx, Result);
if (getType()->isVectorType()) {
if (!EvaluateVector(this, Result.Val, Info))
return false;
} else if (getType()->isIntegerType()) {
llvm::APSInt sInt(32);
if (!EvaluateInteger(this, sInt, Info))
return false;
Result.Val = APValue(sInt);
} else if (getType()->isPointerType()) {
if (!EvaluatePointer(this, Result.Val, Info))
return false;
} else if (getType()->isRealFloatingType()) {
llvm::APFloat f(0.0);
if (!EvaluateFloat(this, f, Info))
return false;
Result.Val = APValue(f);
} else if (getType()->isAnyComplexType()) {
if (!EvaluateComplex(this, Result.Val, Info))
return false;
} else
return false;
return true;
}
/// isEvaluatable - Call Evaluate to see if this expression can be constant
/// folded, but discard the result.
bool Expr::isEvaluatable(ASTContext &Ctx) const {
EvalResult Result;
return Evaluate(Result, Ctx) && !Result.HasSideEffects;
}
APSInt Expr::EvaluateAsInt(ASTContext &Ctx) const {
EvalResult EvalResult;
bool Result = Evaluate(EvalResult, Ctx);
Result = Result;
assert(Result && "Could not evaluate expression");
assert(EvalResult.Val.isInt() && "Expression did not evaluate to integer");
return EvalResult.Val.getInt();
}
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