forked from OSchip/llvm-project
4481 lines
143 KiB
C++
4481 lines
143 KiB
C++
//===--- CFG.cpp - Classes for representing and building CFGs----*- C++ -*-===//
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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 defines the CFG and CFGBuilder classes for representing and
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// building Control-Flow Graphs (CFGs) from ASTs.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Analysis/CFG.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/Attr.h"
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#include "clang/AST/CharUnits.h"
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#include "clang/AST/DeclCXX.h"
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#include "clang/AST/PrettyPrinter.h"
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#include "clang/AST/StmtVisitor.h"
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#include "clang/Basic/Builtins.h"
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#include "llvm/ADT/DenseMap.h"
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#include <memory>
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/Support/Allocator.h"
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#include "llvm/Support/Format.h"
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#include "llvm/Support/GraphWriter.h"
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#include "llvm/Support/SaveAndRestore.h"
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using namespace clang;
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namespace {
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static SourceLocation GetEndLoc(Decl *D) {
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if (VarDecl *VD = dyn_cast<VarDecl>(D))
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if (Expr *Ex = VD->getInit())
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return Ex->getSourceRange().getEnd();
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return D->getLocation();
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}
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class CFGBuilder;
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/// The CFG builder uses a recursive algorithm to build the CFG. When
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/// we process an expression, sometimes we know that we must add the
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/// subexpressions as block-level expressions. For example:
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///
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/// exp1 || exp2
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///
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/// When processing the '||' expression, we know that exp1 and exp2
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/// need to be added as block-level expressions, even though they
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/// might not normally need to be. AddStmtChoice records this
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/// contextual information. If AddStmtChoice is 'NotAlwaysAdd', then
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/// the builder has an option not to add a subexpression as a
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/// block-level expression.
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///
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class AddStmtChoice {
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public:
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enum Kind { NotAlwaysAdd = 0, AlwaysAdd = 1 };
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AddStmtChoice(Kind a_kind = NotAlwaysAdd) : kind(a_kind) {}
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bool alwaysAdd(CFGBuilder &builder,
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const Stmt *stmt) const;
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/// Return a copy of this object, except with the 'always-add' bit
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/// set as specified.
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AddStmtChoice withAlwaysAdd(bool alwaysAdd) const {
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return AddStmtChoice(alwaysAdd ? AlwaysAdd : NotAlwaysAdd);
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}
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private:
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Kind kind;
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};
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/// LocalScope - Node in tree of local scopes created for C++ implicit
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/// destructor calls generation. It contains list of automatic variables
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/// declared in the scope and link to position in previous scope this scope
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/// began in.
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///
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/// The process of creating local scopes is as follows:
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/// - Init CFGBuilder::ScopePos with invalid position (equivalent for null),
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/// - Before processing statements in scope (e.g. CompoundStmt) create
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/// LocalScope object using CFGBuilder::ScopePos as link to previous scope
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/// and set CFGBuilder::ScopePos to the end of new scope,
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/// - On every occurrence of VarDecl increase CFGBuilder::ScopePos if it points
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/// at this VarDecl,
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/// - For every normal (without jump) end of scope add to CFGBlock destructors
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/// for objects in the current scope,
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/// - For every jump add to CFGBlock destructors for objects
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/// between CFGBuilder::ScopePos and local scope position saved for jump
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/// target. Thanks to C++ restrictions on goto jumps we can be sure that
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/// jump target position will be on the path to root from CFGBuilder::ScopePos
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/// (adding any variable that doesn't need constructor to be called to
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/// LocalScope can break this assumption),
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///
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class LocalScope {
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public:
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typedef BumpVector<VarDecl*> AutomaticVarsTy;
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/// const_iterator - Iterates local scope backwards and jumps to previous
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/// scope on reaching the beginning of currently iterated scope.
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class const_iterator {
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const LocalScope* Scope;
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/// VarIter is guaranteed to be greater then 0 for every valid iterator.
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/// Invalid iterator (with null Scope) has VarIter equal to 0.
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unsigned VarIter;
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public:
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/// Create invalid iterator. Dereferencing invalid iterator is not allowed.
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/// Incrementing invalid iterator is allowed and will result in invalid
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/// iterator.
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const_iterator()
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: Scope(nullptr), VarIter(0) {}
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/// Create valid iterator. In case when S.Prev is an invalid iterator and
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/// I is equal to 0, this will create invalid iterator.
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const_iterator(const LocalScope& S, unsigned I)
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: Scope(&S), VarIter(I) {
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// Iterator to "end" of scope is not allowed. Handle it by going up
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// in scopes tree possibly up to invalid iterator in the root.
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if (VarIter == 0 && Scope)
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*this = Scope->Prev;
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}
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VarDecl *const* operator->() const {
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assert (Scope && "Dereferencing invalid iterator is not allowed");
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assert (VarIter != 0 && "Iterator has invalid value of VarIter member");
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return &Scope->Vars[VarIter - 1];
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}
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VarDecl *operator*() const {
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return *this->operator->();
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}
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const_iterator &operator++() {
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if (!Scope)
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return *this;
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assert (VarIter != 0 && "Iterator has invalid value of VarIter member");
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--VarIter;
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if (VarIter == 0)
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*this = Scope->Prev;
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return *this;
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}
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const_iterator operator++(int) {
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const_iterator P = *this;
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++*this;
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return P;
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}
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bool operator==(const const_iterator &rhs) const {
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return Scope == rhs.Scope && VarIter == rhs.VarIter;
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}
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bool operator!=(const const_iterator &rhs) const {
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return !(*this == rhs);
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}
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LLVM_EXPLICIT operator bool() const {
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return *this != const_iterator();
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}
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int distance(const_iterator L);
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};
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friend class const_iterator;
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private:
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BumpVectorContext ctx;
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/// Automatic variables in order of declaration.
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AutomaticVarsTy Vars;
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/// Iterator to variable in previous scope that was declared just before
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/// begin of this scope.
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const_iterator Prev;
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public:
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/// Constructs empty scope linked to previous scope in specified place.
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LocalScope(BumpVectorContext &ctx, const_iterator P)
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: ctx(ctx), Vars(ctx, 4), Prev(P) {}
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/// Begin of scope in direction of CFG building (backwards).
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const_iterator begin() const { return const_iterator(*this, Vars.size()); }
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void addVar(VarDecl *VD) {
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Vars.push_back(VD, ctx);
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}
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};
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/// distance - Calculates distance from this to L. L must be reachable from this
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/// (with use of ++ operator). Cost of calculating the distance is linear w.r.t.
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/// number of scopes between this and L.
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int LocalScope::const_iterator::distance(LocalScope::const_iterator L) {
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int D = 0;
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const_iterator F = *this;
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while (F.Scope != L.Scope) {
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assert (F != const_iterator()
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&& "L iterator is not reachable from F iterator.");
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D += F.VarIter;
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F = F.Scope->Prev;
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}
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D += F.VarIter - L.VarIter;
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return D;
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}
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/// BlockScopePosPair - Structure for specifying position in CFG during its
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/// build process. It consists of CFGBlock that specifies position in CFG graph
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/// and LocalScope::const_iterator that specifies position in LocalScope graph.
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struct BlockScopePosPair {
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BlockScopePosPair() : block(nullptr) {}
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BlockScopePosPair(CFGBlock *b, LocalScope::const_iterator scopePos)
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: block(b), scopePosition(scopePos) {}
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CFGBlock *block;
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LocalScope::const_iterator scopePosition;
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};
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/// TryResult - a class representing a variant over the values
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/// 'true', 'false', or 'unknown'. This is returned by tryEvaluateBool,
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/// and is used by the CFGBuilder to decide if a branch condition
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/// can be decided up front during CFG construction.
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class TryResult {
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int X;
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public:
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TryResult(bool b) : X(b ? 1 : 0) {}
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TryResult() : X(-1) {}
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bool isTrue() const { return X == 1; }
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bool isFalse() const { return X == 0; }
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bool isKnown() const { return X >= 0; }
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void negate() {
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assert(isKnown());
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X ^= 0x1;
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}
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};
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class reverse_children {
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llvm::SmallVector<Stmt *, 12> childrenBuf;
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ArrayRef<Stmt*> children;
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public:
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reverse_children(Stmt *S);
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typedef ArrayRef<Stmt*>::reverse_iterator iterator;
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iterator begin() const { return children.rbegin(); }
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iterator end() const { return children.rend(); }
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};
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reverse_children::reverse_children(Stmt *S) {
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if (CallExpr *CE = dyn_cast<CallExpr>(S)) {
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children = CE->getRawSubExprs();
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return;
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}
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switch (S->getStmtClass()) {
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// Note: Fill in this switch with more cases we want to optimize.
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case Stmt::InitListExprClass: {
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InitListExpr *IE = cast<InitListExpr>(S);
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children = llvm::makeArrayRef(reinterpret_cast<Stmt**>(IE->getInits()),
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IE->getNumInits());
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return;
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}
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default:
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break;
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}
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// Default case for all other statements.
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for (Stmt::child_range I = S->children(); I; ++I) {
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childrenBuf.push_back(*I);
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}
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// This needs to be done *after* childrenBuf has been populated.
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children = childrenBuf;
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}
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/// CFGBuilder - This class implements CFG construction from an AST.
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/// The builder is stateful: an instance of the builder should be used to only
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/// construct a single CFG.
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///
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/// Example usage:
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///
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/// CFGBuilder builder;
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/// CFG* cfg = builder.BuildAST(stmt1);
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///
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/// CFG construction is done via a recursive walk of an AST. We actually parse
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/// the AST in reverse order so that the successor of a basic block is
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/// constructed prior to its predecessor. This allows us to nicely capture
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/// implicit fall-throughs without extra basic blocks.
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///
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class CFGBuilder {
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typedef BlockScopePosPair JumpTarget;
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typedef BlockScopePosPair JumpSource;
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ASTContext *Context;
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std::unique_ptr<CFG> cfg;
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CFGBlock *Block;
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CFGBlock *Succ;
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JumpTarget ContinueJumpTarget;
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JumpTarget BreakJumpTarget;
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CFGBlock *SwitchTerminatedBlock;
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CFGBlock *DefaultCaseBlock;
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CFGBlock *TryTerminatedBlock;
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// Current position in local scope.
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LocalScope::const_iterator ScopePos;
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// LabelMap records the mapping from Label expressions to their jump targets.
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typedef llvm::DenseMap<LabelDecl*, JumpTarget> LabelMapTy;
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LabelMapTy LabelMap;
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// A list of blocks that end with a "goto" that must be backpatched to their
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// resolved targets upon completion of CFG construction.
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typedef std::vector<JumpSource> BackpatchBlocksTy;
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BackpatchBlocksTy BackpatchBlocks;
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// A list of labels whose address has been taken (for indirect gotos).
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typedef llvm::SmallPtrSet<LabelDecl*, 5> LabelSetTy;
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LabelSetTy AddressTakenLabels;
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bool badCFG;
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const CFG::BuildOptions &BuildOpts;
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// State to track for building switch statements.
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bool switchExclusivelyCovered;
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Expr::EvalResult *switchCond;
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CFG::BuildOptions::ForcedBlkExprs::value_type *cachedEntry;
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const Stmt *lastLookup;
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// Caches boolean evaluations of expressions to avoid multiple re-evaluations
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// during construction of branches for chained logical operators.
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typedef llvm::DenseMap<Expr *, TryResult> CachedBoolEvalsTy;
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CachedBoolEvalsTy CachedBoolEvals;
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public:
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explicit CFGBuilder(ASTContext *astContext,
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const CFG::BuildOptions &buildOpts)
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: Context(astContext), cfg(new CFG()), // crew a new CFG
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Block(nullptr), Succ(nullptr),
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SwitchTerminatedBlock(nullptr), DefaultCaseBlock(nullptr),
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TryTerminatedBlock(nullptr), badCFG(false), BuildOpts(buildOpts),
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switchExclusivelyCovered(false), switchCond(nullptr),
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cachedEntry(nullptr), lastLookup(nullptr) {}
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// buildCFG - Used by external clients to construct the CFG.
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CFG* buildCFG(const Decl *D, Stmt *Statement);
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bool alwaysAdd(const Stmt *stmt);
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private:
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// Visitors to walk an AST and construct the CFG.
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CFGBlock *VisitAddrLabelExpr(AddrLabelExpr *A, AddStmtChoice asc);
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CFGBlock *VisitBinaryOperator(BinaryOperator *B, AddStmtChoice asc);
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CFGBlock *VisitBreakStmt(BreakStmt *B);
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CFGBlock *VisitCallExpr(CallExpr *C, AddStmtChoice asc);
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CFGBlock *VisitCaseStmt(CaseStmt *C);
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CFGBlock *VisitChooseExpr(ChooseExpr *C, AddStmtChoice asc);
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CFGBlock *VisitCompoundStmt(CompoundStmt *C);
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CFGBlock *VisitConditionalOperator(AbstractConditionalOperator *C,
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AddStmtChoice asc);
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CFGBlock *VisitContinueStmt(ContinueStmt *C);
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CFGBlock *VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E,
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AddStmtChoice asc);
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CFGBlock *VisitCXXCatchStmt(CXXCatchStmt *S);
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CFGBlock *VisitCXXConstructExpr(CXXConstructExpr *C, AddStmtChoice asc);
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CFGBlock *VisitCXXNewExpr(CXXNewExpr *DE, AddStmtChoice asc);
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CFGBlock *VisitCXXDeleteExpr(CXXDeleteExpr *DE, AddStmtChoice asc);
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CFGBlock *VisitCXXForRangeStmt(CXXForRangeStmt *S);
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CFGBlock *VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E,
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AddStmtChoice asc);
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CFGBlock *VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C,
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AddStmtChoice asc);
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CFGBlock *VisitCXXThrowExpr(CXXThrowExpr *T);
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CFGBlock *VisitCXXTryStmt(CXXTryStmt *S);
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CFGBlock *VisitDeclStmt(DeclStmt *DS);
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CFGBlock *VisitDeclSubExpr(DeclStmt *DS);
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CFGBlock *VisitDefaultStmt(DefaultStmt *D);
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CFGBlock *VisitDoStmt(DoStmt *D);
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CFGBlock *VisitExprWithCleanups(ExprWithCleanups *E, AddStmtChoice asc);
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CFGBlock *VisitForStmt(ForStmt *F);
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CFGBlock *VisitGotoStmt(GotoStmt *G);
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CFGBlock *VisitIfStmt(IfStmt *I);
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CFGBlock *VisitImplicitCastExpr(ImplicitCastExpr *E, AddStmtChoice asc);
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CFGBlock *VisitIndirectGotoStmt(IndirectGotoStmt *I);
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CFGBlock *VisitLabelStmt(LabelStmt *L);
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CFGBlock *VisitLambdaExpr(LambdaExpr *E, AddStmtChoice asc);
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CFGBlock *VisitLogicalOperator(BinaryOperator *B);
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std::pair<CFGBlock *, CFGBlock *> VisitLogicalOperator(BinaryOperator *B,
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Stmt *Term,
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CFGBlock *TrueBlock,
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CFGBlock *FalseBlock);
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CFGBlock *VisitMemberExpr(MemberExpr *M, AddStmtChoice asc);
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CFGBlock *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S);
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CFGBlock *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S);
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CFGBlock *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S);
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CFGBlock *VisitObjCAtTryStmt(ObjCAtTryStmt *S);
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CFGBlock *VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S);
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CFGBlock *VisitObjCForCollectionStmt(ObjCForCollectionStmt *S);
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CFGBlock *VisitPseudoObjectExpr(PseudoObjectExpr *E);
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CFGBlock *VisitReturnStmt(ReturnStmt *R);
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CFGBlock *VisitStmtExpr(StmtExpr *S, AddStmtChoice asc);
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CFGBlock *VisitSwitchStmt(SwitchStmt *S);
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CFGBlock *VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E,
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AddStmtChoice asc);
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CFGBlock *VisitUnaryOperator(UnaryOperator *U, AddStmtChoice asc);
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CFGBlock *VisitWhileStmt(WhileStmt *W);
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CFGBlock *Visit(Stmt *S, AddStmtChoice asc = AddStmtChoice::NotAlwaysAdd);
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CFGBlock *VisitStmt(Stmt *S, AddStmtChoice asc);
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CFGBlock *VisitChildren(Stmt *S);
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CFGBlock *VisitNoRecurse(Expr *E, AddStmtChoice asc);
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// Visitors to walk an AST and generate destructors of temporaries in
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// full expression.
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CFGBlock *VisitForTemporaryDtors(Stmt *E, bool BindToTemporary = false);
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CFGBlock *VisitChildrenForTemporaryDtors(Stmt *E);
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CFGBlock *VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E);
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CFGBlock *VisitCXXBindTemporaryExprForTemporaryDtors(CXXBindTemporaryExpr *E,
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bool BindToTemporary);
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CFGBlock *
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VisitConditionalOperatorForTemporaryDtors(AbstractConditionalOperator *E,
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bool BindToTemporary);
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// NYS == Not Yet Supported
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CFGBlock *NYS() {
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badCFG = true;
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return Block;
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}
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void autoCreateBlock() { if (!Block) Block = createBlock(); }
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CFGBlock *createBlock(bool add_successor = true);
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CFGBlock *createNoReturnBlock();
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CFGBlock *addStmt(Stmt *S) {
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return Visit(S, AddStmtChoice::AlwaysAdd);
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}
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CFGBlock *addInitializer(CXXCtorInitializer *I);
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void addAutomaticObjDtors(LocalScope::const_iterator B,
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LocalScope::const_iterator E, Stmt *S);
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void addImplicitDtorsForDestructor(const CXXDestructorDecl *DD);
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// Local scopes creation.
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LocalScope* createOrReuseLocalScope(LocalScope* Scope);
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void addLocalScopeForStmt(Stmt *S);
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LocalScope* addLocalScopeForDeclStmt(DeclStmt *DS,
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LocalScope* Scope = nullptr);
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LocalScope* addLocalScopeForVarDecl(VarDecl *VD, LocalScope* Scope = nullptr);
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void addLocalScopeAndDtors(Stmt *S);
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// Interface to CFGBlock - adding CFGElements.
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void appendStmt(CFGBlock *B, const Stmt *S) {
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if (alwaysAdd(S) && cachedEntry)
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cachedEntry->second = B;
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// All block-level expressions should have already been IgnoreParens()ed.
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assert(!isa<Expr>(S) || cast<Expr>(S)->IgnoreParens() == S);
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B->appendStmt(const_cast<Stmt*>(S), cfg->getBumpVectorContext());
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}
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void appendInitializer(CFGBlock *B, CXXCtorInitializer *I) {
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B->appendInitializer(I, cfg->getBumpVectorContext());
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}
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void appendNewAllocator(CFGBlock *B, CXXNewExpr *NE) {
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B->appendNewAllocator(NE, cfg->getBumpVectorContext());
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}
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void appendBaseDtor(CFGBlock *B, const CXXBaseSpecifier *BS) {
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B->appendBaseDtor(BS, cfg->getBumpVectorContext());
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}
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void appendMemberDtor(CFGBlock *B, FieldDecl *FD) {
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|
B->appendMemberDtor(FD, cfg->getBumpVectorContext());
|
|
}
|
|
void appendTemporaryDtor(CFGBlock *B, CXXBindTemporaryExpr *E) {
|
|
B->appendTemporaryDtor(E, cfg->getBumpVectorContext());
|
|
}
|
|
void appendAutomaticObjDtor(CFGBlock *B, VarDecl *VD, Stmt *S) {
|
|
B->appendAutomaticObjDtor(VD, S, cfg->getBumpVectorContext());
|
|
}
|
|
|
|
void appendDeleteDtor(CFGBlock *B, CXXRecordDecl *RD, CXXDeleteExpr *DE) {
|
|
B->appendDeleteDtor(RD, DE, cfg->getBumpVectorContext());
|
|
}
|
|
|
|
void prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk,
|
|
LocalScope::const_iterator B, LocalScope::const_iterator E);
|
|
|
|
void addSuccessor(CFGBlock *B, CFGBlock *S, bool IsReachable = true) {
|
|
B->addSuccessor(CFGBlock::AdjacentBlock(S, IsReachable),
|
|
cfg->getBumpVectorContext());
|
|
}
|
|
|
|
/// Add a reachable successor to a block, with the alternate variant that is
|
|
/// unreachable.
|
|
void addSuccessor(CFGBlock *B, CFGBlock *ReachableBlock, CFGBlock *AltBlock) {
|
|
B->addSuccessor(CFGBlock::AdjacentBlock(ReachableBlock, AltBlock),
|
|
cfg->getBumpVectorContext());
|
|
}
|
|
|
|
/// \brief Find a relational comparison with an expression evaluating to a
|
|
/// boolean and a constant other than 0 and 1.
|
|
/// e.g. if ((x < y) == 10)
|
|
TryResult checkIncorrectRelationalOperator(const BinaryOperator *B) {
|
|
const Expr *LHSExpr = B->getLHS()->IgnoreParens();
|
|
const Expr *RHSExpr = B->getRHS()->IgnoreParens();
|
|
|
|
const IntegerLiteral *IntLiteral = dyn_cast<IntegerLiteral>(LHSExpr);
|
|
const Expr *BoolExpr = RHSExpr;
|
|
bool IntFirst = true;
|
|
if (!IntLiteral) {
|
|
IntLiteral = dyn_cast<IntegerLiteral>(RHSExpr);
|
|
BoolExpr = LHSExpr;
|
|
IntFirst = false;
|
|
}
|
|
|
|
if (!IntLiteral || !BoolExpr->isKnownToHaveBooleanValue())
|
|
return TryResult();
|
|
|
|
llvm::APInt IntValue = IntLiteral->getValue();
|
|
if ((IntValue == 1) || (IntValue == 0))
|
|
return TryResult();
|
|
|
|
bool IntLarger = IntLiteral->getType()->isUnsignedIntegerType() ||
|
|
!IntValue.isNegative();
|
|
|
|
BinaryOperatorKind Bok = B->getOpcode();
|
|
if (Bok == BO_GT || Bok == BO_GE) {
|
|
// Always true for 10 > bool and bool > -1
|
|
// Always false for -1 > bool and bool > 10
|
|
return TryResult(IntFirst == IntLarger);
|
|
} else {
|
|
// Always true for -1 < bool and bool < 10
|
|
// Always false for 10 < bool and bool < -1
|
|
return TryResult(IntFirst != IntLarger);
|
|
}
|
|
}
|
|
|
|
/// Find an incorrect equality comparison. Either with an expression
|
|
/// evaluating to a boolean and a constant other than 0 and 1.
|
|
/// e.g. if (!x == 10) or a bitwise and/or operation that always evaluates to
|
|
/// true/false e.q. (x & 8) == 4.
|
|
TryResult checkIncorrectEqualityOperator(const BinaryOperator *B) {
|
|
const Expr *LHSExpr = B->getLHS()->IgnoreParens();
|
|
const Expr *RHSExpr = B->getRHS()->IgnoreParens();
|
|
|
|
const IntegerLiteral *IntLiteral = dyn_cast<IntegerLiteral>(LHSExpr);
|
|
const Expr *BoolExpr = RHSExpr;
|
|
|
|
if (!IntLiteral) {
|
|
IntLiteral = dyn_cast<IntegerLiteral>(RHSExpr);
|
|
BoolExpr = LHSExpr;
|
|
}
|
|
|
|
if (!IntLiteral)
|
|
return TryResult();
|
|
|
|
const BinaryOperator *BitOp = dyn_cast<BinaryOperator>(BoolExpr);
|
|
if (BitOp && (BitOp->getOpcode() == BO_And ||
|
|
BitOp->getOpcode() == BO_Or)) {
|
|
const Expr *LHSExpr2 = BitOp->getLHS()->IgnoreParens();
|
|
const Expr *RHSExpr2 = BitOp->getRHS()->IgnoreParens();
|
|
|
|
const IntegerLiteral *IntLiteral2 = dyn_cast<IntegerLiteral>(LHSExpr2);
|
|
|
|
if (!IntLiteral2)
|
|
IntLiteral2 = dyn_cast<IntegerLiteral>(RHSExpr2);
|
|
|
|
if (!IntLiteral2)
|
|
return TryResult();
|
|
|
|
llvm::APInt L1 = IntLiteral->getValue();
|
|
llvm::APInt L2 = IntLiteral2->getValue();
|
|
if ((BitOp->getOpcode() == BO_And && (L2 & L1) != L1) ||
|
|
(BitOp->getOpcode() == BO_Or && (L2 | L1) != L1)) {
|
|
if (BuildOpts.Observer)
|
|
BuildOpts.Observer->compareBitwiseEquality(B,
|
|
B->getOpcode() != BO_EQ);
|
|
TryResult(B->getOpcode() != BO_EQ);
|
|
}
|
|
} else if (BoolExpr->isKnownToHaveBooleanValue()) {
|
|
llvm::APInt IntValue = IntLiteral->getValue();
|
|
if ((IntValue == 1) || (IntValue == 0)) {
|
|
return TryResult();
|
|
}
|
|
return TryResult(B->getOpcode() != BO_EQ);
|
|
}
|
|
|
|
return TryResult();
|
|
}
|
|
|
|
TryResult analyzeLogicOperatorCondition(BinaryOperatorKind Relation,
|
|
const llvm::APSInt &Value1,
|
|
const llvm::APSInt &Value2) {
|
|
assert(Value1.isSigned() == Value2.isSigned());
|
|
switch (Relation) {
|
|
default:
|
|
return TryResult();
|
|
case BO_EQ:
|
|
return TryResult(Value1 == Value2);
|
|
case BO_NE:
|
|
return TryResult(Value1 != Value2);
|
|
case BO_LT:
|
|
return TryResult(Value1 < Value2);
|
|
case BO_LE:
|
|
return TryResult(Value1 <= Value2);
|
|
case BO_GT:
|
|
return TryResult(Value1 > Value2);
|
|
case BO_GE:
|
|
return TryResult(Value1 >= Value2);
|
|
}
|
|
}
|
|
|
|
/// \brief Find a pair of comparison expressions with or without parentheses
|
|
/// with a shared variable and constants and a logical operator between them
|
|
/// that always evaluates to either true or false.
|
|
/// e.g. if (x != 3 || x != 4)
|
|
TryResult checkIncorrectLogicOperator(const BinaryOperator *B) {
|
|
assert(B->isLogicalOp());
|
|
const BinaryOperator *LHS =
|
|
dyn_cast<BinaryOperator>(B->getLHS()->IgnoreParens());
|
|
const BinaryOperator *RHS =
|
|
dyn_cast<BinaryOperator>(B->getRHS()->IgnoreParens());
|
|
if (!LHS || !RHS)
|
|
return TryResult();
|
|
|
|
if (!LHS->isComparisonOp() || !RHS->isComparisonOp())
|
|
return TryResult();
|
|
|
|
BinaryOperatorKind BO1 = LHS->getOpcode();
|
|
const DeclRefExpr *Decl1 =
|
|
dyn_cast<DeclRefExpr>(LHS->getLHS()->IgnoreParenImpCasts());
|
|
const IntegerLiteral *Literal1 =
|
|
dyn_cast<IntegerLiteral>(LHS->getRHS()->IgnoreParens());
|
|
if (!Decl1 && !Literal1) {
|
|
if (BO1 == BO_GT)
|
|
BO1 = BO_LT;
|
|
else if (BO1 == BO_GE)
|
|
BO1 = BO_LE;
|
|
else if (BO1 == BO_LT)
|
|
BO1 = BO_GT;
|
|
else if (BO1 == BO_LE)
|
|
BO1 = BO_GE;
|
|
Decl1 = dyn_cast<DeclRefExpr>(LHS->getRHS()->IgnoreParenImpCasts());
|
|
Literal1 = dyn_cast<IntegerLiteral>(LHS->getLHS()->IgnoreParens());
|
|
}
|
|
|
|
if (!Decl1 || !Literal1)
|
|
return TryResult();
|
|
|
|
BinaryOperatorKind BO2 = RHS->getOpcode();
|
|
const DeclRefExpr *Decl2 =
|
|
dyn_cast<DeclRefExpr>(RHS->getLHS()->IgnoreParenImpCasts());
|
|
const IntegerLiteral *Literal2 =
|
|
dyn_cast<IntegerLiteral>(RHS->getRHS()->IgnoreParens());
|
|
if (!Decl2 && !Literal2) {
|
|
if (BO2 == BO_GT)
|
|
BO2 = BO_LT;
|
|
else if (BO2 == BO_GE)
|
|
BO2 = BO_LE;
|
|
else if (BO2 == BO_LT)
|
|
BO2 = BO_GT;
|
|
else if (BO2 == BO_LE)
|
|
BO2 = BO_GE;
|
|
Decl2 = dyn_cast<DeclRefExpr>(RHS->getRHS()->IgnoreParenImpCasts());
|
|
Literal2 = dyn_cast<IntegerLiteral>(RHS->getLHS()->IgnoreParens());
|
|
}
|
|
|
|
if (!Decl2 || !Literal2)
|
|
return TryResult();
|
|
|
|
// Check that it is the same variable on both sides.
|
|
if (Decl1->getDecl() != Decl2->getDecl())
|
|
return TryResult();
|
|
|
|
llvm::APSInt L1, L2;
|
|
|
|
if (!Literal1->EvaluateAsInt(L1, *Context) ||
|
|
!Literal2->EvaluateAsInt(L2, *Context))
|
|
return TryResult();
|
|
|
|
// Can't compare signed with unsigned or with different bit width.
|
|
if (L1.isSigned() != L2.isSigned() || L1.getBitWidth() != L2.getBitWidth())
|
|
return TryResult();
|
|
|
|
// Values that will be used to determine if result of logical
|
|
// operator is always true/false
|
|
const llvm::APSInt Values[] = {
|
|
// Value less than both Value1 and Value2
|
|
llvm::APSInt::getMinValue(L1.getBitWidth(), L1.isUnsigned()),
|
|
// L1
|
|
L1,
|
|
// Value between Value1 and Value2
|
|
((L1 < L2) ? L1 : L2) + llvm::APSInt(llvm::APInt(L1.getBitWidth(), 1),
|
|
L1.isUnsigned()),
|
|
// L2
|
|
L2,
|
|
// Value greater than both Value1 and Value2
|
|
llvm::APSInt::getMaxValue(L1.getBitWidth(), L1.isUnsigned()),
|
|
};
|
|
|
|
// Check whether expression is always true/false by evaluating the following
|
|
// * variable x is less than the smallest literal.
|
|
// * variable x is equal to the smallest literal.
|
|
// * Variable x is between smallest and largest literal.
|
|
// * Variable x is equal to the largest literal.
|
|
// * Variable x is greater than largest literal.
|
|
bool AlwaysTrue = true, AlwaysFalse = true;
|
|
for (unsigned int ValueIndex = 0;
|
|
ValueIndex < sizeof(Values) / sizeof(Values[0]);
|
|
++ValueIndex) {
|
|
llvm::APSInt Value = Values[ValueIndex];
|
|
TryResult Res1, Res2;
|
|
Res1 = analyzeLogicOperatorCondition(BO1, Value, L1);
|
|
Res2 = analyzeLogicOperatorCondition(BO2, Value, L2);
|
|
|
|
if (!Res1.isKnown() || !Res2.isKnown())
|
|
return TryResult();
|
|
|
|
if (B->getOpcode() == BO_LAnd) {
|
|
AlwaysTrue &= (Res1.isTrue() && Res2.isTrue());
|
|
AlwaysFalse &= !(Res1.isTrue() && Res2.isTrue());
|
|
} else {
|
|
AlwaysTrue &= (Res1.isTrue() || Res2.isTrue());
|
|
AlwaysFalse &= !(Res1.isTrue() || Res2.isTrue());
|
|
}
|
|
}
|
|
|
|
if (AlwaysTrue || AlwaysFalse) {
|
|
if (BuildOpts.Observer)
|
|
BuildOpts.Observer->compareAlwaysTrue(B, AlwaysTrue);
|
|
return TryResult(AlwaysTrue);
|
|
}
|
|
return TryResult();
|
|
}
|
|
|
|
/// Try and evaluate an expression to an integer constant.
|
|
bool tryEvaluate(Expr *S, Expr::EvalResult &outResult) {
|
|
if (!BuildOpts.PruneTriviallyFalseEdges)
|
|
return false;
|
|
return !S->isTypeDependent() &&
|
|
!S->isValueDependent() &&
|
|
S->EvaluateAsRValue(outResult, *Context);
|
|
}
|
|
|
|
/// tryEvaluateBool - Try and evaluate the Stmt and return 0 or 1
|
|
/// if we can evaluate to a known value, otherwise return -1.
|
|
TryResult tryEvaluateBool(Expr *S) {
|
|
if (!BuildOpts.PruneTriviallyFalseEdges ||
|
|
S->isTypeDependent() || S->isValueDependent())
|
|
return TryResult();
|
|
|
|
if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(S)) {
|
|
if (Bop->isLogicalOp()) {
|
|
// Check the cache first.
|
|
CachedBoolEvalsTy::iterator I = CachedBoolEvals.find(S);
|
|
if (I != CachedBoolEvals.end())
|
|
return I->second; // already in map;
|
|
|
|
// Retrieve result at first, or the map might be updated.
|
|
TryResult Result = evaluateAsBooleanConditionNoCache(S);
|
|
CachedBoolEvals[S] = Result; // update or insert
|
|
return Result;
|
|
}
|
|
else {
|
|
switch (Bop->getOpcode()) {
|
|
default: break;
|
|
// For 'x & 0' and 'x * 0', we can determine that
|
|
// the value is always false.
|
|
case BO_Mul:
|
|
case BO_And: {
|
|
// If either operand is zero, we know the value
|
|
// must be false.
|
|
llvm::APSInt IntVal;
|
|
if (Bop->getLHS()->EvaluateAsInt(IntVal, *Context)) {
|
|
if (IntVal.getBoolValue() == false) {
|
|
return TryResult(false);
|
|
}
|
|
}
|
|
if (Bop->getRHS()->EvaluateAsInt(IntVal, *Context)) {
|
|
if (IntVal.getBoolValue() == false) {
|
|
return TryResult(false);
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return evaluateAsBooleanConditionNoCache(S);
|
|
}
|
|
|
|
/// \brief Evaluate as boolean \param E without using the cache.
|
|
TryResult evaluateAsBooleanConditionNoCache(Expr *E) {
|
|
if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(E)) {
|
|
if (Bop->isLogicalOp()) {
|
|
TryResult LHS = tryEvaluateBool(Bop->getLHS());
|
|
if (LHS.isKnown()) {
|
|
// 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 (LHS.isTrue() == (Bop->getOpcode() == BO_LOr))
|
|
return LHS.isTrue();
|
|
|
|
TryResult RHS = tryEvaluateBool(Bop->getRHS());
|
|
if (RHS.isKnown()) {
|
|
if (Bop->getOpcode() == BO_LOr)
|
|
return LHS.isTrue() || RHS.isTrue();
|
|
else
|
|
return LHS.isTrue() && RHS.isTrue();
|
|
}
|
|
} else {
|
|
TryResult RHS = tryEvaluateBool(Bop->getRHS());
|
|
if (RHS.isKnown()) {
|
|
// We can't evaluate the LHS; however, sometimes the result
|
|
// is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
|
|
if (RHS.isTrue() == (Bop->getOpcode() == BO_LOr))
|
|
return RHS.isTrue();
|
|
} else {
|
|
TryResult BopRes = checkIncorrectLogicOperator(Bop);
|
|
if (BopRes.isKnown())
|
|
return BopRes.isTrue();
|
|
}
|
|
}
|
|
|
|
return TryResult();
|
|
} else if (Bop->isEqualityOp()) {
|
|
TryResult BopRes = checkIncorrectEqualityOperator(Bop);
|
|
if (BopRes.isKnown())
|
|
return BopRes.isTrue();
|
|
} else if (Bop->isRelationalOp()) {
|
|
TryResult BopRes = checkIncorrectRelationalOperator(Bop);
|
|
if (BopRes.isKnown())
|
|
return BopRes.isTrue();
|
|
}
|
|
}
|
|
|
|
bool Result;
|
|
if (E->EvaluateAsBooleanCondition(Result, *Context))
|
|
return Result;
|
|
|
|
return TryResult();
|
|
}
|
|
|
|
};
|
|
|
|
inline bool AddStmtChoice::alwaysAdd(CFGBuilder &builder,
|
|
const Stmt *stmt) const {
|
|
return builder.alwaysAdd(stmt) || kind == AlwaysAdd;
|
|
}
|
|
|
|
bool CFGBuilder::alwaysAdd(const Stmt *stmt) {
|
|
bool shouldAdd = BuildOpts.alwaysAdd(stmt);
|
|
|
|
if (!BuildOpts.forcedBlkExprs)
|
|
return shouldAdd;
|
|
|
|
if (lastLookup == stmt) {
|
|
if (cachedEntry) {
|
|
assert(cachedEntry->first == stmt);
|
|
return true;
|
|
}
|
|
return shouldAdd;
|
|
}
|
|
|
|
lastLookup = stmt;
|
|
|
|
// Perform the lookup!
|
|
CFG::BuildOptions::ForcedBlkExprs *fb = *BuildOpts.forcedBlkExprs;
|
|
|
|
if (!fb) {
|
|
// No need to update 'cachedEntry', since it will always be null.
|
|
assert(!cachedEntry);
|
|
return shouldAdd;
|
|
}
|
|
|
|
CFG::BuildOptions::ForcedBlkExprs::iterator itr = fb->find(stmt);
|
|
if (itr == fb->end()) {
|
|
cachedEntry = nullptr;
|
|
return shouldAdd;
|
|
}
|
|
|
|
cachedEntry = &*itr;
|
|
return true;
|
|
}
|
|
|
|
// FIXME: Add support for dependent-sized array types in C++?
|
|
// Does it even make sense to build a CFG for an uninstantiated template?
|
|
static const VariableArrayType *FindVA(const Type *t) {
|
|
while (const ArrayType *vt = dyn_cast<ArrayType>(t)) {
|
|
if (const VariableArrayType *vat = dyn_cast<VariableArrayType>(vt))
|
|
if (vat->getSizeExpr())
|
|
return vat;
|
|
|
|
t = vt->getElementType().getTypePtr();
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
/// BuildCFG - Constructs a CFG from an AST (a Stmt*). The AST can represent an
|
|
/// arbitrary statement. Examples include a single expression or a function
|
|
/// body (compound statement). The ownership of the returned CFG is
|
|
/// transferred to the caller. If CFG construction fails, this method returns
|
|
/// NULL.
|
|
CFG* CFGBuilder::buildCFG(const Decl *D, Stmt *Statement) {
|
|
assert(cfg.get());
|
|
if (!Statement)
|
|
return nullptr;
|
|
|
|
// Create an empty block that will serve as the exit block for the CFG. Since
|
|
// this is the first block added to the CFG, it will be implicitly registered
|
|
// as the exit block.
|
|
Succ = createBlock();
|
|
assert(Succ == &cfg->getExit());
|
|
Block = nullptr; // the EXIT block is empty. Create all other blocks lazily.
|
|
|
|
if (BuildOpts.AddImplicitDtors)
|
|
if (const CXXDestructorDecl *DD = dyn_cast_or_null<CXXDestructorDecl>(D))
|
|
addImplicitDtorsForDestructor(DD);
|
|
|
|
// Visit the statements and create the CFG.
|
|
CFGBlock *B = addStmt(Statement);
|
|
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// For C++ constructor add initializers to CFG.
|
|
if (const CXXConstructorDecl *CD = dyn_cast_or_null<CXXConstructorDecl>(D)) {
|
|
for (CXXConstructorDecl::init_const_reverse_iterator I = CD->init_rbegin(),
|
|
E = CD->init_rend(); I != E; ++I) {
|
|
B = addInitializer(*I);
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
if (B)
|
|
Succ = B;
|
|
|
|
// Backpatch the gotos whose label -> block mappings we didn't know when we
|
|
// encountered them.
|
|
for (BackpatchBlocksTy::iterator I = BackpatchBlocks.begin(),
|
|
E = BackpatchBlocks.end(); I != E; ++I ) {
|
|
|
|
CFGBlock *B = I->block;
|
|
const GotoStmt *G = cast<GotoStmt>(B->getTerminator());
|
|
LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
|
|
|
|
// If there is no target for the goto, then we are looking at an
|
|
// incomplete AST. Handle this by not registering a successor.
|
|
if (LI == LabelMap.end()) continue;
|
|
|
|
JumpTarget JT = LI->second;
|
|
prependAutomaticObjDtorsWithTerminator(B, I->scopePosition,
|
|
JT.scopePosition);
|
|
addSuccessor(B, JT.block);
|
|
}
|
|
|
|
// Add successors to the Indirect Goto Dispatch block (if we have one).
|
|
if (CFGBlock *B = cfg->getIndirectGotoBlock())
|
|
for (LabelSetTy::iterator I = AddressTakenLabels.begin(),
|
|
E = AddressTakenLabels.end(); I != E; ++I ) {
|
|
|
|
// Lookup the target block.
|
|
LabelMapTy::iterator LI = LabelMap.find(*I);
|
|
|
|
// If there is no target block that contains label, then we are looking
|
|
// at an incomplete AST. Handle this by not registering a successor.
|
|
if (LI == LabelMap.end()) continue;
|
|
|
|
addSuccessor(B, LI->second.block);
|
|
}
|
|
|
|
// Create an empty entry block that has no predecessors.
|
|
cfg->setEntry(createBlock());
|
|
|
|
return cfg.release();
|
|
}
|
|
|
|
/// createBlock - Used to lazily create blocks that are connected
|
|
/// to the current (global) succcessor.
|
|
CFGBlock *CFGBuilder::createBlock(bool add_successor) {
|
|
CFGBlock *B = cfg->createBlock();
|
|
if (add_successor && Succ)
|
|
addSuccessor(B, Succ);
|
|
return B;
|
|
}
|
|
|
|
/// createNoReturnBlock - Used to create a block is a 'noreturn' point in the
|
|
/// CFG. It is *not* connected to the current (global) successor, and instead
|
|
/// directly tied to the exit block in order to be reachable.
|
|
CFGBlock *CFGBuilder::createNoReturnBlock() {
|
|
CFGBlock *B = createBlock(false);
|
|
B->setHasNoReturnElement();
|
|
addSuccessor(B, &cfg->getExit(), Succ);
|
|
return B;
|
|
}
|
|
|
|
/// addInitializer - Add C++ base or member initializer element to CFG.
|
|
CFGBlock *CFGBuilder::addInitializer(CXXCtorInitializer *I) {
|
|
if (!BuildOpts.AddInitializers)
|
|
return Block;
|
|
|
|
bool IsReference = false;
|
|
bool HasTemporaries = false;
|
|
|
|
// Destructors of temporaries in initialization expression should be called
|
|
// after initialization finishes.
|
|
Expr *Init = I->getInit();
|
|
if (Init) {
|
|
if (FieldDecl *FD = I->getAnyMember())
|
|
IsReference = FD->getType()->isReferenceType();
|
|
HasTemporaries = isa<ExprWithCleanups>(Init);
|
|
|
|
if (BuildOpts.AddTemporaryDtors && HasTemporaries) {
|
|
// Generate destructors for temporaries in initialization expression.
|
|
VisitForTemporaryDtors(cast<ExprWithCleanups>(Init)->getSubExpr(),
|
|
IsReference);
|
|
}
|
|
}
|
|
|
|
autoCreateBlock();
|
|
appendInitializer(Block, I);
|
|
|
|
if (Init) {
|
|
if (HasTemporaries) {
|
|
// For expression with temporaries go directly to subexpression to omit
|
|
// generating destructors for the second time.
|
|
return Visit(cast<ExprWithCleanups>(Init)->getSubExpr());
|
|
}
|
|
return Visit(Init);
|
|
}
|
|
|
|
return Block;
|
|
}
|
|
|
|
/// \brief Retrieve the type of the temporary object whose lifetime was
|
|
/// extended by a local reference with the given initializer.
|
|
static QualType getReferenceInitTemporaryType(ASTContext &Context,
|
|
const Expr *Init) {
|
|
while (true) {
|
|
// Skip parentheses.
|
|
Init = Init->IgnoreParens();
|
|
|
|
// Skip through cleanups.
|
|
if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Init)) {
|
|
Init = EWC->getSubExpr();
|
|
continue;
|
|
}
|
|
|
|
// Skip through the temporary-materialization expression.
|
|
if (const MaterializeTemporaryExpr *MTE
|
|
= dyn_cast<MaterializeTemporaryExpr>(Init)) {
|
|
Init = MTE->GetTemporaryExpr();
|
|
continue;
|
|
}
|
|
|
|
// Skip derived-to-base and no-op casts.
|
|
if (const CastExpr *CE = dyn_cast<CastExpr>(Init)) {
|
|
if ((CE->getCastKind() == CK_DerivedToBase ||
|
|
CE->getCastKind() == CK_UncheckedDerivedToBase ||
|
|
CE->getCastKind() == CK_NoOp) &&
|
|
Init->getType()->isRecordType()) {
|
|
Init = CE->getSubExpr();
|
|
continue;
|
|
}
|
|
}
|
|
|
|
// Skip member accesses into rvalues.
|
|
if (const MemberExpr *ME = dyn_cast<MemberExpr>(Init)) {
|
|
if (!ME->isArrow() && ME->getBase()->isRValue()) {
|
|
Init = ME->getBase();
|
|
continue;
|
|
}
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
return Init->getType();
|
|
}
|
|
|
|
/// addAutomaticObjDtors - Add to current block automatic objects destructors
|
|
/// for objects in range of local scope positions. Use S as trigger statement
|
|
/// for destructors.
|
|
void CFGBuilder::addAutomaticObjDtors(LocalScope::const_iterator B,
|
|
LocalScope::const_iterator E, Stmt *S) {
|
|
if (!BuildOpts.AddImplicitDtors)
|
|
return;
|
|
|
|
if (B == E)
|
|
return;
|
|
|
|
// We need to append the destructors in reverse order, but any one of them
|
|
// may be a no-return destructor which changes the CFG. As a result, buffer
|
|
// this sequence up and replay them in reverse order when appending onto the
|
|
// CFGBlock(s).
|
|
SmallVector<VarDecl*, 10> Decls;
|
|
Decls.reserve(B.distance(E));
|
|
for (LocalScope::const_iterator I = B; I != E; ++I)
|
|
Decls.push_back(*I);
|
|
|
|
for (SmallVectorImpl<VarDecl*>::reverse_iterator I = Decls.rbegin(),
|
|
E = Decls.rend();
|
|
I != E; ++I) {
|
|
// If this destructor is marked as a no-return destructor, we need to
|
|
// create a new block for the destructor which does not have as a successor
|
|
// anything built thus far: control won't flow out of this block.
|
|
QualType Ty = (*I)->getType();
|
|
if (Ty->isReferenceType()) {
|
|
Ty = getReferenceInitTemporaryType(*Context, (*I)->getInit());
|
|
}
|
|
Ty = Context->getBaseElementType(Ty);
|
|
|
|
const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor();
|
|
if (Dtor->isNoReturn())
|
|
Block = createNoReturnBlock();
|
|
else
|
|
autoCreateBlock();
|
|
|
|
appendAutomaticObjDtor(Block, *I, S);
|
|
}
|
|
}
|
|
|
|
/// addImplicitDtorsForDestructor - Add implicit destructors generated for
|
|
/// base and member objects in destructor.
|
|
void CFGBuilder::addImplicitDtorsForDestructor(const CXXDestructorDecl *DD) {
|
|
assert (BuildOpts.AddImplicitDtors
|
|
&& "Can be called only when dtors should be added");
|
|
const CXXRecordDecl *RD = DD->getParent();
|
|
|
|
// At the end destroy virtual base objects.
|
|
for (const auto &VI : RD->vbases()) {
|
|
const CXXRecordDecl *CD = VI.getType()->getAsCXXRecordDecl();
|
|
if (!CD->hasTrivialDestructor()) {
|
|
autoCreateBlock();
|
|
appendBaseDtor(Block, &VI);
|
|
}
|
|
}
|
|
|
|
// Before virtual bases destroy direct base objects.
|
|
for (const auto &BI : RD->bases()) {
|
|
if (!BI.isVirtual()) {
|
|
const CXXRecordDecl *CD = BI.getType()->getAsCXXRecordDecl();
|
|
if (!CD->hasTrivialDestructor()) {
|
|
autoCreateBlock();
|
|
appendBaseDtor(Block, &BI);
|
|
}
|
|
}
|
|
}
|
|
|
|
// First destroy member objects.
|
|
for (auto *FI : RD->fields()) {
|
|
// Check for constant size array. Set type to array element type.
|
|
QualType QT = FI->getType();
|
|
if (const ConstantArrayType *AT = Context->getAsConstantArrayType(QT)) {
|
|
if (AT->getSize() == 0)
|
|
continue;
|
|
QT = AT->getElementType();
|
|
}
|
|
|
|
if (const CXXRecordDecl *CD = QT->getAsCXXRecordDecl())
|
|
if (!CD->hasTrivialDestructor()) {
|
|
autoCreateBlock();
|
|
appendMemberDtor(Block, FI);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// createOrReuseLocalScope - If Scope is NULL create new LocalScope. Either
|
|
/// way return valid LocalScope object.
|
|
LocalScope* CFGBuilder::createOrReuseLocalScope(LocalScope* Scope) {
|
|
if (!Scope) {
|
|
llvm::BumpPtrAllocator &alloc = cfg->getAllocator();
|
|
Scope = alloc.Allocate<LocalScope>();
|
|
BumpVectorContext ctx(alloc);
|
|
new (Scope) LocalScope(ctx, ScopePos);
|
|
}
|
|
return Scope;
|
|
}
|
|
|
|
/// addLocalScopeForStmt - Add LocalScope to local scopes tree for statement
|
|
/// that should create implicit scope (e.g. if/else substatements).
|
|
void CFGBuilder::addLocalScopeForStmt(Stmt *S) {
|
|
if (!BuildOpts.AddImplicitDtors)
|
|
return;
|
|
|
|
LocalScope *Scope = nullptr;
|
|
|
|
// For compound statement we will be creating explicit scope.
|
|
if (CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) {
|
|
for (auto *BI : CS->body()) {
|
|
Stmt *SI = BI->stripLabelLikeStatements();
|
|
if (DeclStmt *DS = dyn_cast<DeclStmt>(SI))
|
|
Scope = addLocalScopeForDeclStmt(DS, Scope);
|
|
}
|
|
return;
|
|
}
|
|
|
|
// For any other statement scope will be implicit and as such will be
|
|
// interesting only for DeclStmt.
|
|
if (DeclStmt *DS = dyn_cast<DeclStmt>(S->stripLabelLikeStatements()))
|
|
addLocalScopeForDeclStmt(DS);
|
|
}
|
|
|
|
/// addLocalScopeForDeclStmt - Add LocalScope for declaration statement. Will
|
|
/// reuse Scope if not NULL.
|
|
LocalScope* CFGBuilder::addLocalScopeForDeclStmt(DeclStmt *DS,
|
|
LocalScope* Scope) {
|
|
if (!BuildOpts.AddImplicitDtors)
|
|
return Scope;
|
|
|
|
for (auto *DI : DS->decls())
|
|
if (VarDecl *VD = dyn_cast<VarDecl>(DI))
|
|
Scope = addLocalScopeForVarDecl(VD, Scope);
|
|
return Scope;
|
|
}
|
|
|
|
/// addLocalScopeForVarDecl - Add LocalScope for variable declaration. It will
|
|
/// create add scope for automatic objects and temporary objects bound to
|
|
/// const reference. Will reuse Scope if not NULL.
|
|
LocalScope* CFGBuilder::addLocalScopeForVarDecl(VarDecl *VD,
|
|
LocalScope* Scope) {
|
|
if (!BuildOpts.AddImplicitDtors)
|
|
return Scope;
|
|
|
|
// Check if variable is local.
|
|
switch (VD->getStorageClass()) {
|
|
case SC_None:
|
|
case SC_Auto:
|
|
case SC_Register:
|
|
break;
|
|
default: return Scope;
|
|
}
|
|
|
|
// Check for const references bound to temporary. Set type to pointee.
|
|
QualType QT = VD->getType();
|
|
if (QT.getTypePtr()->isReferenceType()) {
|
|
// Attempt to determine whether this declaration lifetime-extends a
|
|
// temporary.
|
|
//
|
|
// FIXME: This is incorrect. Non-reference declarations can lifetime-extend
|
|
// temporaries, and a single declaration can extend multiple temporaries.
|
|
// We should look at the storage duration on each nested
|
|
// MaterializeTemporaryExpr instead.
|
|
const Expr *Init = VD->getInit();
|
|
if (!Init)
|
|
return Scope;
|
|
if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Init))
|
|
Init = EWC->getSubExpr();
|
|
if (!isa<MaterializeTemporaryExpr>(Init))
|
|
return Scope;
|
|
|
|
// Lifetime-extending a temporary.
|
|
QT = getReferenceInitTemporaryType(*Context, Init);
|
|
}
|
|
|
|
// Check for constant size array. Set type to array element type.
|
|
while (const ConstantArrayType *AT = Context->getAsConstantArrayType(QT)) {
|
|
if (AT->getSize() == 0)
|
|
return Scope;
|
|
QT = AT->getElementType();
|
|
}
|
|
|
|
// Check if type is a C++ class with non-trivial destructor.
|
|
if (const CXXRecordDecl *CD = QT->getAsCXXRecordDecl())
|
|
if (!CD->hasTrivialDestructor()) {
|
|
// Add the variable to scope
|
|
Scope = createOrReuseLocalScope(Scope);
|
|
Scope->addVar(VD);
|
|
ScopePos = Scope->begin();
|
|
}
|
|
return Scope;
|
|
}
|
|
|
|
/// addLocalScopeAndDtors - For given statement add local scope for it and
|
|
/// add destructors that will cleanup the scope. Will reuse Scope if not NULL.
|
|
void CFGBuilder::addLocalScopeAndDtors(Stmt *S) {
|
|
if (!BuildOpts.AddImplicitDtors)
|
|
return;
|
|
|
|
LocalScope::const_iterator scopeBeginPos = ScopePos;
|
|
addLocalScopeForStmt(S);
|
|
addAutomaticObjDtors(ScopePos, scopeBeginPos, S);
|
|
}
|
|
|
|
/// prependAutomaticObjDtorsWithTerminator - Prepend destructor CFGElements for
|
|
/// variables with automatic storage duration to CFGBlock's elements vector.
|
|
/// Elements will be prepended to physical beginning of the vector which
|
|
/// happens to be logical end. Use blocks terminator as statement that specifies
|
|
/// destructors call site.
|
|
/// FIXME: This mechanism for adding automatic destructors doesn't handle
|
|
/// no-return destructors properly.
|
|
void CFGBuilder::prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk,
|
|
LocalScope::const_iterator B, LocalScope::const_iterator E) {
|
|
BumpVectorContext &C = cfg->getBumpVectorContext();
|
|
CFGBlock::iterator InsertPos
|
|
= Blk->beginAutomaticObjDtorsInsert(Blk->end(), B.distance(E), C);
|
|
for (LocalScope::const_iterator I = B; I != E; ++I)
|
|
InsertPos = Blk->insertAutomaticObjDtor(InsertPos, *I,
|
|
Blk->getTerminator());
|
|
}
|
|
|
|
/// Visit - Walk the subtree of a statement and add extra
|
|
/// blocks for ternary operators, &&, and ||. We also process "," and
|
|
/// DeclStmts (which may contain nested control-flow).
|
|
CFGBlock *CFGBuilder::Visit(Stmt * S, AddStmtChoice asc) {
|
|
if (!S) {
|
|
badCFG = true;
|
|
return nullptr;
|
|
}
|
|
|
|
if (Expr *E = dyn_cast<Expr>(S))
|
|
S = E->IgnoreParens();
|
|
|
|
switch (S->getStmtClass()) {
|
|
default:
|
|
return VisitStmt(S, asc);
|
|
|
|
case Stmt::AddrLabelExprClass:
|
|
return VisitAddrLabelExpr(cast<AddrLabelExpr>(S), asc);
|
|
|
|
case Stmt::BinaryConditionalOperatorClass:
|
|
return VisitConditionalOperator(cast<BinaryConditionalOperator>(S), asc);
|
|
|
|
case Stmt::BinaryOperatorClass:
|
|
return VisitBinaryOperator(cast<BinaryOperator>(S), asc);
|
|
|
|
case Stmt::BlockExprClass:
|
|
return VisitNoRecurse(cast<Expr>(S), asc);
|
|
|
|
case Stmt::BreakStmtClass:
|
|
return VisitBreakStmt(cast<BreakStmt>(S));
|
|
|
|
case Stmt::CallExprClass:
|
|
case Stmt::CXXOperatorCallExprClass:
|
|
case Stmt::CXXMemberCallExprClass:
|
|
case Stmt::UserDefinedLiteralClass:
|
|
return VisitCallExpr(cast<CallExpr>(S), asc);
|
|
|
|
case Stmt::CaseStmtClass:
|
|
return VisitCaseStmt(cast<CaseStmt>(S));
|
|
|
|
case Stmt::ChooseExprClass:
|
|
return VisitChooseExpr(cast<ChooseExpr>(S), asc);
|
|
|
|
case Stmt::CompoundStmtClass:
|
|
return VisitCompoundStmt(cast<CompoundStmt>(S));
|
|
|
|
case Stmt::ConditionalOperatorClass:
|
|
return VisitConditionalOperator(cast<ConditionalOperator>(S), asc);
|
|
|
|
case Stmt::ContinueStmtClass:
|
|
return VisitContinueStmt(cast<ContinueStmt>(S));
|
|
|
|
case Stmt::CXXCatchStmtClass:
|
|
return VisitCXXCatchStmt(cast<CXXCatchStmt>(S));
|
|
|
|
case Stmt::ExprWithCleanupsClass:
|
|
return VisitExprWithCleanups(cast<ExprWithCleanups>(S), asc);
|
|
|
|
case Stmt::CXXDefaultArgExprClass:
|
|
case Stmt::CXXDefaultInitExprClass:
|
|
// FIXME: The expression inside a CXXDefaultArgExpr is owned by the
|
|
// called function's declaration, not by the caller. If we simply add
|
|
// this expression to the CFG, we could end up with the same Expr
|
|
// appearing multiple times.
|
|
// PR13385 / <rdar://problem/12156507>
|
|
//
|
|
// It's likewise possible for multiple CXXDefaultInitExprs for the same
|
|
// expression to be used in the same function (through aggregate
|
|
// initialization).
|
|
return VisitStmt(S, asc);
|
|
|
|
case Stmt::CXXBindTemporaryExprClass:
|
|
return VisitCXXBindTemporaryExpr(cast<CXXBindTemporaryExpr>(S), asc);
|
|
|
|
case Stmt::CXXConstructExprClass:
|
|
return VisitCXXConstructExpr(cast<CXXConstructExpr>(S), asc);
|
|
|
|
case Stmt::CXXNewExprClass:
|
|
return VisitCXXNewExpr(cast<CXXNewExpr>(S), asc);
|
|
|
|
case Stmt::CXXDeleteExprClass:
|
|
return VisitCXXDeleteExpr(cast<CXXDeleteExpr>(S), asc);
|
|
|
|
case Stmt::CXXFunctionalCastExprClass:
|
|
return VisitCXXFunctionalCastExpr(cast<CXXFunctionalCastExpr>(S), asc);
|
|
|
|
case Stmt::CXXTemporaryObjectExprClass:
|
|
return VisitCXXTemporaryObjectExpr(cast<CXXTemporaryObjectExpr>(S), asc);
|
|
|
|
case Stmt::CXXThrowExprClass:
|
|
return VisitCXXThrowExpr(cast<CXXThrowExpr>(S));
|
|
|
|
case Stmt::CXXTryStmtClass:
|
|
return VisitCXXTryStmt(cast<CXXTryStmt>(S));
|
|
|
|
case Stmt::CXXForRangeStmtClass:
|
|
return VisitCXXForRangeStmt(cast<CXXForRangeStmt>(S));
|
|
|
|
case Stmt::DeclStmtClass:
|
|
return VisitDeclStmt(cast<DeclStmt>(S));
|
|
|
|
case Stmt::DefaultStmtClass:
|
|
return VisitDefaultStmt(cast<DefaultStmt>(S));
|
|
|
|
case Stmt::DoStmtClass:
|
|
return VisitDoStmt(cast<DoStmt>(S));
|
|
|
|
case Stmt::ForStmtClass:
|
|
return VisitForStmt(cast<ForStmt>(S));
|
|
|
|
case Stmt::GotoStmtClass:
|
|
return VisitGotoStmt(cast<GotoStmt>(S));
|
|
|
|
case Stmt::IfStmtClass:
|
|
return VisitIfStmt(cast<IfStmt>(S));
|
|
|
|
case Stmt::ImplicitCastExprClass:
|
|
return VisitImplicitCastExpr(cast<ImplicitCastExpr>(S), asc);
|
|
|
|
case Stmt::IndirectGotoStmtClass:
|
|
return VisitIndirectGotoStmt(cast<IndirectGotoStmt>(S));
|
|
|
|
case Stmt::LabelStmtClass:
|
|
return VisitLabelStmt(cast<LabelStmt>(S));
|
|
|
|
case Stmt::LambdaExprClass:
|
|
return VisitLambdaExpr(cast<LambdaExpr>(S), asc);
|
|
|
|
case Stmt::MemberExprClass:
|
|
return VisitMemberExpr(cast<MemberExpr>(S), asc);
|
|
|
|
case Stmt::NullStmtClass:
|
|
return Block;
|
|
|
|
case Stmt::ObjCAtCatchStmtClass:
|
|
return VisitObjCAtCatchStmt(cast<ObjCAtCatchStmt>(S));
|
|
|
|
case Stmt::ObjCAutoreleasePoolStmtClass:
|
|
return VisitObjCAutoreleasePoolStmt(cast<ObjCAutoreleasePoolStmt>(S));
|
|
|
|
case Stmt::ObjCAtSynchronizedStmtClass:
|
|
return VisitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(S));
|
|
|
|
case Stmt::ObjCAtThrowStmtClass:
|
|
return VisitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(S));
|
|
|
|
case Stmt::ObjCAtTryStmtClass:
|
|
return VisitObjCAtTryStmt(cast<ObjCAtTryStmt>(S));
|
|
|
|
case Stmt::ObjCForCollectionStmtClass:
|
|
return VisitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(S));
|
|
|
|
case Stmt::OpaqueValueExprClass:
|
|
return Block;
|
|
|
|
case Stmt::PseudoObjectExprClass:
|
|
return VisitPseudoObjectExpr(cast<PseudoObjectExpr>(S));
|
|
|
|
case Stmt::ReturnStmtClass:
|
|
return VisitReturnStmt(cast<ReturnStmt>(S));
|
|
|
|
case Stmt::UnaryExprOrTypeTraitExprClass:
|
|
return VisitUnaryExprOrTypeTraitExpr(cast<UnaryExprOrTypeTraitExpr>(S),
|
|
asc);
|
|
|
|
case Stmt::StmtExprClass:
|
|
return VisitStmtExpr(cast<StmtExpr>(S), asc);
|
|
|
|
case Stmt::SwitchStmtClass:
|
|
return VisitSwitchStmt(cast<SwitchStmt>(S));
|
|
|
|
case Stmt::UnaryOperatorClass:
|
|
return VisitUnaryOperator(cast<UnaryOperator>(S), asc);
|
|
|
|
case Stmt::WhileStmtClass:
|
|
return VisitWhileStmt(cast<WhileStmt>(S));
|
|
}
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitStmt(Stmt *S, AddStmtChoice asc) {
|
|
if (asc.alwaysAdd(*this, S)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, S);
|
|
}
|
|
|
|
return VisitChildren(S);
|
|
}
|
|
|
|
/// VisitChildren - Visit the children of a Stmt.
|
|
CFGBlock *CFGBuilder::VisitChildren(Stmt *S) {
|
|
CFGBlock *B = Block;
|
|
|
|
// Visit the children in their reverse order so that they appear in
|
|
// left-to-right (natural) order in the CFG.
|
|
reverse_children RChildren(S);
|
|
for (reverse_children::iterator I = RChildren.begin(), E = RChildren.end();
|
|
I != E; ++I) {
|
|
if (Stmt *Child = *I)
|
|
if (CFGBlock *R = Visit(Child))
|
|
B = R;
|
|
}
|
|
return B;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitAddrLabelExpr(AddrLabelExpr *A,
|
|
AddStmtChoice asc) {
|
|
AddressTakenLabels.insert(A->getLabel());
|
|
|
|
if (asc.alwaysAdd(*this, A)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, A);
|
|
}
|
|
|
|
return Block;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitUnaryOperator(UnaryOperator *U,
|
|
AddStmtChoice asc) {
|
|
if (asc.alwaysAdd(*this, U)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, U);
|
|
}
|
|
|
|
return Visit(U->getSubExpr(), AddStmtChoice());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitLogicalOperator(BinaryOperator *B) {
|
|
CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
|
|
appendStmt(ConfluenceBlock, B);
|
|
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
return VisitLogicalOperator(B, nullptr, ConfluenceBlock,
|
|
ConfluenceBlock).first;
|
|
}
|
|
|
|
std::pair<CFGBlock*, CFGBlock*>
|
|
CFGBuilder::VisitLogicalOperator(BinaryOperator *B,
|
|
Stmt *Term,
|
|
CFGBlock *TrueBlock,
|
|
CFGBlock *FalseBlock) {
|
|
|
|
// Introspect the RHS. If it is a nested logical operation, we recursively
|
|
// build the CFG using this function. Otherwise, resort to default
|
|
// CFG construction behavior.
|
|
Expr *RHS = B->getRHS()->IgnoreParens();
|
|
CFGBlock *RHSBlock, *ExitBlock;
|
|
|
|
do {
|
|
if (BinaryOperator *B_RHS = dyn_cast<BinaryOperator>(RHS))
|
|
if (B_RHS->isLogicalOp()) {
|
|
std::tie(RHSBlock, ExitBlock) =
|
|
VisitLogicalOperator(B_RHS, Term, TrueBlock, FalseBlock);
|
|
break;
|
|
}
|
|
|
|
// The RHS is not a nested logical operation. Don't push the terminator
|
|
// down further, but instead visit RHS and construct the respective
|
|
// pieces of the CFG, and link up the RHSBlock with the terminator
|
|
// we have been provided.
|
|
ExitBlock = RHSBlock = createBlock(false);
|
|
|
|
if (!Term) {
|
|
assert(TrueBlock == FalseBlock);
|
|
addSuccessor(RHSBlock, TrueBlock);
|
|
}
|
|
else {
|
|
RHSBlock->setTerminator(Term);
|
|
TryResult KnownVal = tryEvaluateBool(RHS);
|
|
if (!KnownVal.isKnown())
|
|
KnownVal = tryEvaluateBool(B);
|
|
addSuccessor(RHSBlock, TrueBlock, !KnownVal.isFalse());
|
|
addSuccessor(RHSBlock, FalseBlock, !KnownVal.isTrue());
|
|
}
|
|
|
|
Block = RHSBlock;
|
|
RHSBlock = addStmt(RHS);
|
|
}
|
|
while (false);
|
|
|
|
if (badCFG)
|
|
return std::make_pair(nullptr, nullptr);
|
|
|
|
// Generate the blocks for evaluating the LHS.
|
|
Expr *LHS = B->getLHS()->IgnoreParens();
|
|
|
|
if (BinaryOperator *B_LHS = dyn_cast<BinaryOperator>(LHS))
|
|
if (B_LHS->isLogicalOp()) {
|
|
if (B->getOpcode() == BO_LOr)
|
|
FalseBlock = RHSBlock;
|
|
else
|
|
TrueBlock = RHSBlock;
|
|
|
|
// For the LHS, treat 'B' as the terminator that we want to sink
|
|
// into the nested branch. The RHS always gets the top-most
|
|
// terminator.
|
|
return VisitLogicalOperator(B_LHS, B, TrueBlock, FalseBlock);
|
|
}
|
|
|
|
// Create the block evaluating the LHS.
|
|
// This contains the '&&' or '||' as the terminator.
|
|
CFGBlock *LHSBlock = createBlock(false);
|
|
LHSBlock->setTerminator(B);
|
|
|
|
Block = LHSBlock;
|
|
CFGBlock *EntryLHSBlock = addStmt(LHS);
|
|
|
|
if (badCFG)
|
|
return std::make_pair(nullptr, nullptr);
|
|
|
|
// See if this is a known constant.
|
|
TryResult KnownVal = tryEvaluateBool(LHS);
|
|
|
|
// Now link the LHSBlock with RHSBlock.
|
|
if (B->getOpcode() == BO_LOr) {
|
|
addSuccessor(LHSBlock, TrueBlock, !KnownVal.isFalse());
|
|
addSuccessor(LHSBlock, RHSBlock, !KnownVal.isTrue());
|
|
} else {
|
|
assert(B->getOpcode() == BO_LAnd);
|
|
addSuccessor(LHSBlock, RHSBlock, !KnownVal.isFalse());
|
|
addSuccessor(LHSBlock, FalseBlock, !KnownVal.isTrue());
|
|
}
|
|
|
|
return std::make_pair(EntryLHSBlock, ExitBlock);
|
|
}
|
|
|
|
|
|
CFGBlock *CFGBuilder::VisitBinaryOperator(BinaryOperator *B,
|
|
AddStmtChoice asc) {
|
|
// && or ||
|
|
if (B->isLogicalOp())
|
|
return VisitLogicalOperator(B);
|
|
|
|
if (B->getOpcode() == BO_Comma) { // ,
|
|
autoCreateBlock();
|
|
appendStmt(Block, B);
|
|
addStmt(B->getRHS());
|
|
return addStmt(B->getLHS());
|
|
}
|
|
|
|
if (B->isAssignmentOp()) {
|
|
if (asc.alwaysAdd(*this, B)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, B);
|
|
}
|
|
Visit(B->getLHS());
|
|
return Visit(B->getRHS());
|
|
}
|
|
|
|
if (asc.alwaysAdd(*this, B)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, B);
|
|
}
|
|
|
|
CFGBlock *RBlock = Visit(B->getRHS());
|
|
CFGBlock *LBlock = Visit(B->getLHS());
|
|
// If visiting RHS causes us to finish 'Block', e.g. the RHS is a StmtExpr
|
|
// containing a DoStmt, and the LHS doesn't create a new block, then we should
|
|
// return RBlock. Otherwise we'll incorrectly return NULL.
|
|
return (LBlock ? LBlock : RBlock);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitNoRecurse(Expr *E, AddStmtChoice asc) {
|
|
if (asc.alwaysAdd(*this, E)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, E);
|
|
}
|
|
return Block;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitBreakStmt(BreakStmt *B) {
|
|
// "break" is a control-flow statement. Thus we stop processing the current
|
|
// block.
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// Now create a new block that ends with the break statement.
|
|
Block = createBlock(false);
|
|
Block->setTerminator(B);
|
|
|
|
// If there is no target for the break, then we are looking at an incomplete
|
|
// AST. This means that the CFG cannot be constructed.
|
|
if (BreakJumpTarget.block) {
|
|
addAutomaticObjDtors(ScopePos, BreakJumpTarget.scopePosition, B);
|
|
addSuccessor(Block, BreakJumpTarget.block);
|
|
} else
|
|
badCFG = true;
|
|
|
|
|
|
return Block;
|
|
}
|
|
|
|
static bool CanThrow(Expr *E, ASTContext &Ctx) {
|
|
QualType Ty = E->getType();
|
|
if (Ty->isFunctionPointerType())
|
|
Ty = Ty->getAs<PointerType>()->getPointeeType();
|
|
else if (Ty->isBlockPointerType())
|
|
Ty = Ty->getAs<BlockPointerType>()->getPointeeType();
|
|
|
|
const FunctionType *FT = Ty->getAs<FunctionType>();
|
|
if (FT) {
|
|
if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT))
|
|
if (!isUnresolvedExceptionSpec(Proto->getExceptionSpecType()) &&
|
|
Proto->isNothrow(Ctx))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCallExpr(CallExpr *C, AddStmtChoice asc) {
|
|
// Compute the callee type.
|
|
QualType calleeType = C->getCallee()->getType();
|
|
if (calleeType == Context->BoundMemberTy) {
|
|
QualType boundType = Expr::findBoundMemberType(C->getCallee());
|
|
|
|
// We should only get a null bound type if processing a dependent
|
|
// CFG. Recover by assuming nothing.
|
|
if (!boundType.isNull()) calleeType = boundType;
|
|
}
|
|
|
|
// If this is a call to a no-return function, this stops the block here.
|
|
bool NoReturn = getFunctionExtInfo(*calleeType).getNoReturn();
|
|
|
|
bool AddEHEdge = false;
|
|
|
|
// Languages without exceptions are assumed to not throw.
|
|
if (Context->getLangOpts().Exceptions) {
|
|
if (BuildOpts.AddEHEdges)
|
|
AddEHEdge = true;
|
|
}
|
|
|
|
// If this is a call to a builtin function, it might not actually evaluate
|
|
// its arguments. Don't add them to the CFG if this is the case.
|
|
bool OmitArguments = false;
|
|
|
|
if (FunctionDecl *FD = C->getDirectCallee()) {
|
|
if (FD->isNoReturn())
|
|
NoReturn = true;
|
|
if (FD->hasAttr<NoThrowAttr>())
|
|
AddEHEdge = false;
|
|
if (FD->getBuiltinID() == Builtin::BI__builtin_object_size)
|
|
OmitArguments = true;
|
|
}
|
|
|
|
if (!CanThrow(C->getCallee(), *Context))
|
|
AddEHEdge = false;
|
|
|
|
if (OmitArguments) {
|
|
assert(!NoReturn && "noreturn calls with unevaluated args not implemented");
|
|
assert(!AddEHEdge && "EH calls with unevaluated args not implemented");
|
|
autoCreateBlock();
|
|
appendStmt(Block, C);
|
|
return Visit(C->getCallee());
|
|
}
|
|
|
|
if (!NoReturn && !AddEHEdge) {
|
|
return VisitStmt(C, asc.withAlwaysAdd(true));
|
|
}
|
|
|
|
if (Block) {
|
|
Succ = Block;
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
if (NoReturn)
|
|
Block = createNoReturnBlock();
|
|
else
|
|
Block = createBlock();
|
|
|
|
appendStmt(Block, C);
|
|
|
|
if (AddEHEdge) {
|
|
// Add exceptional edges.
|
|
if (TryTerminatedBlock)
|
|
addSuccessor(Block, TryTerminatedBlock);
|
|
else
|
|
addSuccessor(Block, &cfg->getExit());
|
|
}
|
|
|
|
return VisitChildren(C);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitChooseExpr(ChooseExpr *C,
|
|
AddStmtChoice asc) {
|
|
CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
|
|
appendStmt(ConfluenceBlock, C);
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true);
|
|
Succ = ConfluenceBlock;
|
|
Block = nullptr;
|
|
CFGBlock *LHSBlock = Visit(C->getLHS(), alwaysAdd);
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
Succ = ConfluenceBlock;
|
|
Block = nullptr;
|
|
CFGBlock *RHSBlock = Visit(C->getRHS(), alwaysAdd);
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
Block = createBlock(false);
|
|
// See if this is a known constant.
|
|
const TryResult& KnownVal = tryEvaluateBool(C->getCond());
|
|
addSuccessor(Block, KnownVal.isFalse() ? nullptr : LHSBlock);
|
|
addSuccessor(Block, KnownVal.isTrue() ? nullptr : RHSBlock);
|
|
Block->setTerminator(C);
|
|
return addStmt(C->getCond());
|
|
}
|
|
|
|
|
|
CFGBlock *CFGBuilder::VisitCompoundStmt(CompoundStmt *C) {
|
|
addLocalScopeAndDtors(C);
|
|
CFGBlock *LastBlock = Block;
|
|
|
|
for (CompoundStmt::reverse_body_iterator I=C->body_rbegin(), E=C->body_rend();
|
|
I != E; ++I ) {
|
|
// If we hit a segment of code just containing ';' (NullStmts), we can
|
|
// get a null block back. In such cases, just use the LastBlock
|
|
if (CFGBlock *newBlock = addStmt(*I))
|
|
LastBlock = newBlock;
|
|
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
return LastBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitConditionalOperator(AbstractConditionalOperator *C,
|
|
AddStmtChoice asc) {
|
|
const BinaryConditionalOperator *BCO = dyn_cast<BinaryConditionalOperator>(C);
|
|
const OpaqueValueExpr *opaqueValue = (BCO ? BCO->getOpaqueValue() : nullptr);
|
|
|
|
// Create the confluence block that will "merge" the results of the ternary
|
|
// expression.
|
|
CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
|
|
appendStmt(ConfluenceBlock, C);
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true);
|
|
|
|
// Create a block for the LHS expression if there is an LHS expression. A
|
|
// GCC extension allows LHS to be NULL, causing the condition to be the
|
|
// value that is returned instead.
|
|
// e.g: x ?: y is shorthand for: x ? x : y;
|
|
Succ = ConfluenceBlock;
|
|
Block = nullptr;
|
|
CFGBlock *LHSBlock = nullptr;
|
|
const Expr *trueExpr = C->getTrueExpr();
|
|
if (trueExpr != opaqueValue) {
|
|
LHSBlock = Visit(C->getTrueExpr(), alwaysAdd);
|
|
if (badCFG)
|
|
return nullptr;
|
|
Block = nullptr;
|
|
}
|
|
else
|
|
LHSBlock = ConfluenceBlock;
|
|
|
|
// Create the block for the RHS expression.
|
|
Succ = ConfluenceBlock;
|
|
CFGBlock *RHSBlock = Visit(C->getFalseExpr(), alwaysAdd);
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// If the condition is a logical '&&' or '||', build a more accurate CFG.
|
|
if (BinaryOperator *Cond =
|
|
dyn_cast<BinaryOperator>(C->getCond()->IgnoreParens()))
|
|
if (Cond->isLogicalOp())
|
|
return VisitLogicalOperator(Cond, C, LHSBlock, RHSBlock).first;
|
|
|
|
// Create the block that will contain the condition.
|
|
Block = createBlock(false);
|
|
|
|
// See if this is a known constant.
|
|
const TryResult& KnownVal = tryEvaluateBool(C->getCond());
|
|
addSuccessor(Block, LHSBlock, !KnownVal.isFalse());
|
|
addSuccessor(Block, RHSBlock, !KnownVal.isTrue());
|
|
Block->setTerminator(C);
|
|
Expr *condExpr = C->getCond();
|
|
|
|
if (opaqueValue) {
|
|
// Run the condition expression if it's not trivially expressed in
|
|
// terms of the opaque value (or if there is no opaque value).
|
|
if (condExpr != opaqueValue)
|
|
addStmt(condExpr);
|
|
|
|
// Before that, run the common subexpression if there was one.
|
|
// At least one of this or the above will be run.
|
|
return addStmt(BCO->getCommon());
|
|
}
|
|
|
|
return addStmt(condExpr);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitDeclStmt(DeclStmt *DS) {
|
|
// Check if the Decl is for an __label__. If so, elide it from the
|
|
// CFG entirely.
|
|
if (isa<LabelDecl>(*DS->decl_begin()))
|
|
return Block;
|
|
|
|
// This case also handles static_asserts.
|
|
if (DS->isSingleDecl())
|
|
return VisitDeclSubExpr(DS);
|
|
|
|
CFGBlock *B = nullptr;
|
|
|
|
// Build an individual DeclStmt for each decl.
|
|
for (DeclStmt::reverse_decl_iterator I = DS->decl_rbegin(),
|
|
E = DS->decl_rend();
|
|
I != E; ++I) {
|
|
// Get the alignment of the new DeclStmt, padding out to >=8 bytes.
|
|
unsigned A = llvm::AlignOf<DeclStmt>::Alignment < 8
|
|
? 8 : llvm::AlignOf<DeclStmt>::Alignment;
|
|
|
|
// Allocate the DeclStmt using the BumpPtrAllocator. It will get
|
|
// automatically freed with the CFG.
|
|
DeclGroupRef DG(*I);
|
|
Decl *D = *I;
|
|
void *Mem = cfg->getAllocator().Allocate(sizeof(DeclStmt), A);
|
|
DeclStmt *DSNew = new (Mem) DeclStmt(DG, D->getLocation(), GetEndLoc(D));
|
|
cfg->addSyntheticDeclStmt(DSNew, DS);
|
|
|
|
// Append the fake DeclStmt to block.
|
|
B = VisitDeclSubExpr(DSNew);
|
|
}
|
|
|
|
return B;
|
|
}
|
|
|
|
/// VisitDeclSubExpr - Utility method to add block-level expressions for
|
|
/// DeclStmts and initializers in them.
|
|
CFGBlock *CFGBuilder::VisitDeclSubExpr(DeclStmt *DS) {
|
|
assert(DS->isSingleDecl() && "Can handle single declarations only.");
|
|
VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl());
|
|
|
|
if (!VD) {
|
|
// Of everything that can be declared in a DeclStmt, only VarDecls impact
|
|
// runtime semantics.
|
|
return Block;
|
|
}
|
|
|
|
bool IsReference = false;
|
|
bool HasTemporaries = false;
|
|
|
|
// Guard static initializers under a branch.
|
|
CFGBlock *blockAfterStaticInit = nullptr;
|
|
|
|
if (BuildOpts.AddStaticInitBranches && VD->isStaticLocal()) {
|
|
// For static variables, we need to create a branch to track
|
|
// whether or not they are initialized.
|
|
if (Block) {
|
|
Succ = Block;
|
|
Block = nullptr;
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
blockAfterStaticInit = Succ;
|
|
}
|
|
|
|
// Destructors of temporaries in initialization expression should be called
|
|
// after initialization finishes.
|
|
Expr *Init = VD->getInit();
|
|
if (Init) {
|
|
IsReference = VD->getType()->isReferenceType();
|
|
HasTemporaries = isa<ExprWithCleanups>(Init);
|
|
|
|
if (BuildOpts.AddTemporaryDtors && HasTemporaries) {
|
|
// Generate destructors for temporaries in initialization expression.
|
|
VisitForTemporaryDtors(cast<ExprWithCleanups>(Init)->getSubExpr(),
|
|
IsReference);
|
|
}
|
|
}
|
|
|
|
autoCreateBlock();
|
|
appendStmt(Block, DS);
|
|
|
|
// Keep track of the last non-null block, as 'Block' can be nulled out
|
|
// if the initializer expression is something like a 'while' in a
|
|
// statement-expression.
|
|
CFGBlock *LastBlock = Block;
|
|
|
|
if (Init) {
|
|
if (HasTemporaries) {
|
|
// For expression with temporaries go directly to subexpression to omit
|
|
// generating destructors for the second time.
|
|
ExprWithCleanups *EC = cast<ExprWithCleanups>(Init);
|
|
if (CFGBlock *newBlock = Visit(EC->getSubExpr()))
|
|
LastBlock = newBlock;
|
|
}
|
|
else {
|
|
if (CFGBlock *newBlock = Visit(Init))
|
|
LastBlock = newBlock;
|
|
}
|
|
}
|
|
|
|
// If the type of VD is a VLA, then we must process its size expressions.
|
|
for (const VariableArrayType* VA = FindVA(VD->getType().getTypePtr());
|
|
VA != nullptr; VA = FindVA(VA->getElementType().getTypePtr())) {
|
|
if (CFGBlock *newBlock = addStmt(VA->getSizeExpr()))
|
|
LastBlock = newBlock;
|
|
}
|
|
|
|
// Remove variable from local scope.
|
|
if (ScopePos && VD == *ScopePos)
|
|
++ScopePos;
|
|
|
|
CFGBlock *B = LastBlock;
|
|
if (blockAfterStaticInit) {
|
|
Succ = B;
|
|
Block = createBlock(false);
|
|
Block->setTerminator(DS);
|
|
addSuccessor(Block, blockAfterStaticInit);
|
|
addSuccessor(Block, B);
|
|
B = Block;
|
|
}
|
|
|
|
return B;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitIfStmt(IfStmt *I) {
|
|
// We may see an if statement in the middle of a basic block, or it may be the
|
|
// first statement we are processing. In either case, we create a new basic
|
|
// block. First, we create the blocks for the then...else statements, and
|
|
// then we create the block containing the if statement. If we were in the
|
|
// middle of a block, we stop processing that block. That block is then the
|
|
// implicit successor for the "then" and "else" clauses.
|
|
|
|
// Save local scope position because in case of condition variable ScopePos
|
|
// won't be restored when traversing AST.
|
|
SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
|
|
|
|
// Create local scope for possible condition variable.
|
|
// Store scope position. Add implicit destructor.
|
|
if (VarDecl *VD = I->getConditionVariable()) {
|
|
LocalScope::const_iterator BeginScopePos = ScopePos;
|
|
addLocalScopeForVarDecl(VD);
|
|
addAutomaticObjDtors(ScopePos, BeginScopePos, I);
|
|
}
|
|
|
|
// The block we were processing is now finished. Make it the successor
|
|
// block.
|
|
if (Block) {
|
|
Succ = Block;
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
// Process the false branch.
|
|
CFGBlock *ElseBlock = Succ;
|
|
|
|
if (Stmt *Else = I->getElse()) {
|
|
SaveAndRestore<CFGBlock*> sv(Succ);
|
|
|
|
// NULL out Block so that the recursive call to Visit will
|
|
// create a new basic block.
|
|
Block = nullptr;
|
|
|
|
// If branch is not a compound statement create implicit scope
|
|
// and add destructors.
|
|
if (!isa<CompoundStmt>(Else))
|
|
addLocalScopeAndDtors(Else);
|
|
|
|
ElseBlock = addStmt(Else);
|
|
|
|
if (!ElseBlock) // Can occur when the Else body has all NullStmts.
|
|
ElseBlock = sv.get();
|
|
else if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
// Process the true branch.
|
|
CFGBlock *ThenBlock;
|
|
{
|
|
Stmt *Then = I->getThen();
|
|
assert(Then);
|
|
SaveAndRestore<CFGBlock*> sv(Succ);
|
|
Block = nullptr;
|
|
|
|
// If branch is not a compound statement create implicit scope
|
|
// and add destructors.
|
|
if (!isa<CompoundStmt>(Then))
|
|
addLocalScopeAndDtors(Then);
|
|
|
|
ThenBlock = addStmt(Then);
|
|
|
|
if (!ThenBlock) {
|
|
// We can reach here if the "then" body has all NullStmts.
|
|
// Create an empty block so we can distinguish between true and false
|
|
// branches in path-sensitive analyses.
|
|
ThenBlock = createBlock(false);
|
|
addSuccessor(ThenBlock, sv.get());
|
|
} else if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
// Specially handle "if (expr1 || ...)" and "if (expr1 && ...)" by
|
|
// having these handle the actual control-flow jump. Note that
|
|
// if we introduce a condition variable, e.g. "if (int x = exp1 || exp2)"
|
|
// we resort to the old control-flow behavior. This special handling
|
|
// removes infeasible paths from the control-flow graph by having the
|
|
// control-flow transfer of '&&' or '||' go directly into the then/else
|
|
// blocks directly.
|
|
if (!I->getConditionVariable())
|
|
if (BinaryOperator *Cond =
|
|
dyn_cast<BinaryOperator>(I->getCond()->IgnoreParens()))
|
|
if (Cond->isLogicalOp())
|
|
return VisitLogicalOperator(Cond, I, ThenBlock, ElseBlock).first;
|
|
|
|
// Now create a new block containing the if statement.
|
|
Block = createBlock(false);
|
|
|
|
// Set the terminator of the new block to the If statement.
|
|
Block->setTerminator(I);
|
|
|
|
// See if this is a known constant.
|
|
const TryResult &KnownVal = tryEvaluateBool(I->getCond());
|
|
|
|
// Add the successors. If we know that specific branches are
|
|
// unreachable, inform addSuccessor() of that knowledge.
|
|
addSuccessor(Block, ThenBlock, /* isReachable = */ !KnownVal.isFalse());
|
|
addSuccessor(Block, ElseBlock, /* isReachable = */ !KnownVal.isTrue());
|
|
|
|
// Add the condition as the last statement in the new block. This may create
|
|
// new blocks as the condition may contain control-flow. Any newly created
|
|
// blocks will be pointed to be "Block".
|
|
CFGBlock *LastBlock = addStmt(I->getCond());
|
|
|
|
// Finally, if the IfStmt contains a condition variable, add it and its
|
|
// initializer to the CFG.
|
|
if (const DeclStmt* DS = I->getConditionVariableDeclStmt()) {
|
|
autoCreateBlock();
|
|
LastBlock = addStmt(const_cast<DeclStmt *>(DS));
|
|
}
|
|
|
|
return LastBlock;
|
|
}
|
|
|
|
|
|
CFGBlock *CFGBuilder::VisitReturnStmt(ReturnStmt *R) {
|
|
// If we were in the middle of a block we stop processing that block.
|
|
//
|
|
// NOTE: If a "return" appears in the middle of a block, this means that the
|
|
// code afterwards is DEAD (unreachable). We still keep a basic block
|
|
// for that code; a simple "mark-and-sweep" from the entry block will be
|
|
// able to report such dead blocks.
|
|
|
|
// Create the new block.
|
|
Block = createBlock(false);
|
|
|
|
addAutomaticObjDtors(ScopePos, LocalScope::const_iterator(), R);
|
|
|
|
// If the one of the destructors does not return, we already have the Exit
|
|
// block as a successor.
|
|
if (!Block->hasNoReturnElement())
|
|
addSuccessor(Block, &cfg->getExit());
|
|
|
|
// Add the return statement to the block. This may create new blocks if R
|
|
// contains control-flow (short-circuit operations).
|
|
return VisitStmt(R, AddStmtChoice::AlwaysAdd);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitLabelStmt(LabelStmt *L) {
|
|
// Get the block of the labeled statement. Add it to our map.
|
|
addStmt(L->getSubStmt());
|
|
CFGBlock *LabelBlock = Block;
|
|
|
|
if (!LabelBlock) // This can happen when the body is empty, i.e.
|
|
LabelBlock = createBlock(); // scopes that only contains NullStmts.
|
|
|
|
assert(LabelMap.find(L->getDecl()) == LabelMap.end() &&
|
|
"label already in map");
|
|
LabelMap[L->getDecl()] = JumpTarget(LabelBlock, ScopePos);
|
|
|
|
// Labels partition blocks, so this is the end of the basic block we were
|
|
// processing (L is the block's label). Because this is label (and we have
|
|
// already processed the substatement) there is no extra control-flow to worry
|
|
// about.
|
|
LabelBlock->setLabel(L);
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// We set Block to NULL to allow lazy creation of a new block (if necessary);
|
|
Block = nullptr;
|
|
|
|
// This block is now the implicit successor of other blocks.
|
|
Succ = LabelBlock;
|
|
|
|
return LabelBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitLambdaExpr(LambdaExpr *E, AddStmtChoice asc) {
|
|
CFGBlock *LastBlock = VisitNoRecurse(E, asc);
|
|
for (LambdaExpr::capture_init_iterator it = E->capture_init_begin(),
|
|
et = E->capture_init_end(); it != et; ++it) {
|
|
if (Expr *Init = *it) {
|
|
CFGBlock *Tmp = Visit(Init);
|
|
if (Tmp)
|
|
LastBlock = Tmp;
|
|
}
|
|
}
|
|
return LastBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitGotoStmt(GotoStmt *G) {
|
|
// Goto is a control-flow statement. Thus we stop processing the current
|
|
// block and create a new one.
|
|
|
|
Block = createBlock(false);
|
|
Block->setTerminator(G);
|
|
|
|
// If we already know the mapping to the label block add the successor now.
|
|
LabelMapTy::iterator I = LabelMap.find(G->getLabel());
|
|
|
|
if (I == LabelMap.end())
|
|
// We will need to backpatch this block later.
|
|
BackpatchBlocks.push_back(JumpSource(Block, ScopePos));
|
|
else {
|
|
JumpTarget JT = I->second;
|
|
addAutomaticObjDtors(ScopePos, JT.scopePosition, G);
|
|
addSuccessor(Block, JT.block);
|
|
}
|
|
|
|
return Block;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitForStmt(ForStmt *F) {
|
|
CFGBlock *LoopSuccessor = nullptr;
|
|
|
|
// Save local scope position because in case of condition variable ScopePos
|
|
// won't be restored when traversing AST.
|
|
SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
|
|
|
|
// Create local scope for init statement and possible condition variable.
|
|
// Add destructor for init statement and condition variable.
|
|
// Store scope position for continue statement.
|
|
if (Stmt *Init = F->getInit())
|
|
addLocalScopeForStmt(Init);
|
|
LocalScope::const_iterator LoopBeginScopePos = ScopePos;
|
|
|
|
if (VarDecl *VD = F->getConditionVariable())
|
|
addLocalScopeForVarDecl(VD);
|
|
LocalScope::const_iterator ContinueScopePos = ScopePos;
|
|
|
|
addAutomaticObjDtors(ScopePos, save_scope_pos.get(), F);
|
|
|
|
// "for" is a control-flow statement. Thus we stop processing the current
|
|
// block.
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
LoopSuccessor = Block;
|
|
} else
|
|
LoopSuccessor = Succ;
|
|
|
|
// Save the current value for the break targets.
|
|
// All breaks should go to the code following the loop.
|
|
SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
|
|
BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
|
|
|
|
CFGBlock *BodyBlock = nullptr, *TransitionBlock = nullptr;
|
|
|
|
// Now create the loop body.
|
|
{
|
|
assert(F->getBody());
|
|
|
|
// Save the current values for Block, Succ, continue and break targets.
|
|
SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
|
|
SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget);
|
|
|
|
// Create an empty block to represent the transition block for looping back
|
|
// to the head of the loop. If we have increment code, it will
|
|
// go in this block as well.
|
|
Block = Succ = TransitionBlock = createBlock(false);
|
|
TransitionBlock->setLoopTarget(F);
|
|
|
|
if (Stmt *I = F->getInc()) {
|
|
// Generate increment code in its own basic block. This is the target of
|
|
// continue statements.
|
|
Succ = addStmt(I);
|
|
}
|
|
|
|
// Finish up the increment (or empty) block if it hasn't been already.
|
|
if (Block) {
|
|
assert(Block == Succ);
|
|
if (badCFG)
|
|
return nullptr;
|
|
Block = nullptr;
|
|
}
|
|
|
|
// The starting block for the loop increment is the block that should
|
|
// represent the 'loop target' for looping back to the start of the loop.
|
|
ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos);
|
|
ContinueJumpTarget.block->setLoopTarget(F);
|
|
|
|
// Loop body should end with destructor of Condition variable (if any).
|
|
addAutomaticObjDtors(ScopePos, LoopBeginScopePos, F);
|
|
|
|
// If body is not a compound statement create implicit scope
|
|
// and add destructors.
|
|
if (!isa<CompoundStmt>(F->getBody()))
|
|
addLocalScopeAndDtors(F->getBody());
|
|
|
|
// Now populate the body block, and in the process create new blocks as we
|
|
// walk the body of the loop.
|
|
BodyBlock = addStmt(F->getBody());
|
|
|
|
if (!BodyBlock) {
|
|
// In the case of "for (...;...;...);" we can have a null BodyBlock.
|
|
// Use the continue jump target as the proxy for the body.
|
|
BodyBlock = ContinueJumpTarget.block;
|
|
}
|
|
else if (badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
// Because of short-circuit evaluation, the condition of the loop can span
|
|
// multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
|
|
// evaluate the condition.
|
|
CFGBlock *EntryConditionBlock = nullptr, *ExitConditionBlock = nullptr;
|
|
|
|
do {
|
|
Expr *C = F->getCond();
|
|
|
|
// Specially handle logical operators, which have a slightly
|
|
// more optimal CFG representation.
|
|
if (BinaryOperator *Cond =
|
|
dyn_cast_or_null<BinaryOperator>(C ? C->IgnoreParens() : nullptr))
|
|
if (Cond->isLogicalOp()) {
|
|
std::tie(EntryConditionBlock, ExitConditionBlock) =
|
|
VisitLogicalOperator(Cond, F, BodyBlock, LoopSuccessor);
|
|
break;
|
|
}
|
|
|
|
// The default case when not handling logical operators.
|
|
EntryConditionBlock = ExitConditionBlock = createBlock(false);
|
|
ExitConditionBlock->setTerminator(F);
|
|
|
|
// See if this is a known constant.
|
|
TryResult KnownVal(true);
|
|
|
|
if (C) {
|
|
// Now add the actual condition to the condition block.
|
|
// Because the condition itself may contain control-flow, new blocks may
|
|
// be created. Thus we update "Succ" after adding the condition.
|
|
Block = ExitConditionBlock;
|
|
EntryConditionBlock = addStmt(C);
|
|
|
|
// If this block contains a condition variable, add both the condition
|
|
// variable and initializer to the CFG.
|
|
if (VarDecl *VD = F->getConditionVariable()) {
|
|
if (Expr *Init = VD->getInit()) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, F->getConditionVariableDeclStmt());
|
|
EntryConditionBlock = addStmt(Init);
|
|
assert(Block == EntryConditionBlock);
|
|
}
|
|
}
|
|
|
|
if (Block && badCFG)
|
|
return nullptr;
|
|
|
|
KnownVal = tryEvaluateBool(C);
|
|
}
|
|
|
|
// Add the loop body entry as a successor to the condition.
|
|
addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? nullptr : BodyBlock);
|
|
// Link up the condition block with the code that follows the loop. (the
|
|
// false branch).
|
|
addSuccessor(ExitConditionBlock,
|
|
KnownVal.isTrue() ? nullptr : LoopSuccessor);
|
|
|
|
} while (false);
|
|
|
|
// Link up the loop-back block to the entry condition block.
|
|
addSuccessor(TransitionBlock, EntryConditionBlock);
|
|
|
|
// The condition block is the implicit successor for any code above the loop.
|
|
Succ = EntryConditionBlock;
|
|
|
|
// If the loop contains initialization, create a new block for those
|
|
// statements. This block can also contain statements that precede the loop.
|
|
if (Stmt *I = F->getInit()) {
|
|
Block = createBlock();
|
|
return addStmt(I);
|
|
}
|
|
|
|
// There is no loop initialization. We are thus basically a while loop.
|
|
// NULL out Block to force lazy block construction.
|
|
Block = nullptr;
|
|
Succ = EntryConditionBlock;
|
|
return EntryConditionBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitMemberExpr(MemberExpr *M, AddStmtChoice asc) {
|
|
if (asc.alwaysAdd(*this, M)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, M);
|
|
}
|
|
return Visit(M->getBase());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
|
|
// Objective-C fast enumeration 'for' statements:
|
|
// http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC
|
|
//
|
|
// for ( Type newVariable in collection_expression ) { statements }
|
|
//
|
|
// becomes:
|
|
//
|
|
// prologue:
|
|
// 1. collection_expression
|
|
// T. jump to loop_entry
|
|
// loop_entry:
|
|
// 1. side-effects of element expression
|
|
// 1. ObjCForCollectionStmt [performs binding to newVariable]
|
|
// T. ObjCForCollectionStmt TB, FB [jumps to TB if newVariable != nil]
|
|
// TB:
|
|
// statements
|
|
// T. jump to loop_entry
|
|
// FB:
|
|
// what comes after
|
|
//
|
|
// and
|
|
//
|
|
// Type existingItem;
|
|
// for ( existingItem in expression ) { statements }
|
|
//
|
|
// becomes:
|
|
//
|
|
// the same with newVariable replaced with existingItem; the binding works
|
|
// the same except that for one ObjCForCollectionStmt::getElement() returns
|
|
// a DeclStmt and the other returns a DeclRefExpr.
|
|
//
|
|
|
|
CFGBlock *LoopSuccessor = nullptr;
|
|
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
LoopSuccessor = Block;
|
|
Block = nullptr;
|
|
} else
|
|
LoopSuccessor = Succ;
|
|
|
|
// Build the condition blocks.
|
|
CFGBlock *ExitConditionBlock = createBlock(false);
|
|
|
|
// Set the terminator for the "exit" condition block.
|
|
ExitConditionBlock->setTerminator(S);
|
|
|
|
// The last statement in the block should be the ObjCForCollectionStmt, which
|
|
// performs the actual binding to 'element' and determines if there are any
|
|
// more items in the collection.
|
|
appendStmt(ExitConditionBlock, S);
|
|
Block = ExitConditionBlock;
|
|
|
|
// Walk the 'element' expression to see if there are any side-effects. We
|
|
// generate new blocks as necessary. We DON'T add the statement by default to
|
|
// the CFG unless it contains control-flow.
|
|
CFGBlock *EntryConditionBlock = Visit(S->getElement(),
|
|
AddStmtChoice::NotAlwaysAdd);
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
Block = nullptr;
|
|
}
|
|
|
|
// The condition block is the implicit successor for the loop body as well as
|
|
// any code above the loop.
|
|
Succ = EntryConditionBlock;
|
|
|
|
// Now create the true branch.
|
|
{
|
|
// Save the current values for Succ, continue and break targets.
|
|
SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
|
|
SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
|
|
save_break(BreakJumpTarget);
|
|
|
|
// Add an intermediate block between the BodyBlock and the
|
|
// EntryConditionBlock to represent the "loop back" transition, for looping
|
|
// back to the head of the loop.
|
|
CFGBlock *LoopBackBlock = nullptr;
|
|
Succ = LoopBackBlock = createBlock();
|
|
LoopBackBlock->setLoopTarget(S);
|
|
|
|
BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
|
|
ContinueJumpTarget = JumpTarget(Succ, ScopePos);
|
|
|
|
CFGBlock *BodyBlock = addStmt(S->getBody());
|
|
|
|
if (!BodyBlock)
|
|
BodyBlock = ContinueJumpTarget.block; // can happen for "for (X in Y) ;"
|
|
else if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
// This new body block is a successor to our "exit" condition block.
|
|
addSuccessor(ExitConditionBlock, BodyBlock);
|
|
}
|
|
|
|
// Link up the condition block with the code that follows the loop.
|
|
// (the false branch).
|
|
addSuccessor(ExitConditionBlock, LoopSuccessor);
|
|
|
|
// Now create a prologue block to contain the collection expression.
|
|
Block = createBlock();
|
|
return addStmt(S->getCollection());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S) {
|
|
// Inline the body.
|
|
return addStmt(S->getSubStmt());
|
|
// TODO: consider adding cleanups for the end of @autoreleasepool scope.
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S) {
|
|
// FIXME: Add locking 'primitives' to CFG for @synchronized.
|
|
|
|
// Inline the body.
|
|
CFGBlock *SyncBlock = addStmt(S->getSynchBody());
|
|
|
|
// The sync body starts its own basic block. This makes it a little easier
|
|
// for diagnostic clients.
|
|
if (SyncBlock) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
Block = nullptr;
|
|
Succ = SyncBlock;
|
|
}
|
|
|
|
// Add the @synchronized to the CFG.
|
|
autoCreateBlock();
|
|
appendStmt(Block, S);
|
|
|
|
// Inline the sync expression.
|
|
return addStmt(S->getSynchExpr());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitObjCAtTryStmt(ObjCAtTryStmt *S) {
|
|
// FIXME
|
|
return NYS();
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitPseudoObjectExpr(PseudoObjectExpr *E) {
|
|
autoCreateBlock();
|
|
|
|
// Add the PseudoObject as the last thing.
|
|
appendStmt(Block, E);
|
|
|
|
CFGBlock *lastBlock = Block;
|
|
|
|
// Before that, evaluate all of the semantics in order. In
|
|
// CFG-land, that means appending them in reverse order.
|
|
for (unsigned i = E->getNumSemanticExprs(); i != 0; ) {
|
|
Expr *Semantic = E->getSemanticExpr(--i);
|
|
|
|
// If the semantic is an opaque value, we're being asked to bind
|
|
// it to its source expression.
|
|
if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
|
|
Semantic = OVE->getSourceExpr();
|
|
|
|
if (CFGBlock *B = Visit(Semantic))
|
|
lastBlock = B;
|
|
}
|
|
|
|
return lastBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitWhileStmt(WhileStmt *W) {
|
|
CFGBlock *LoopSuccessor = nullptr;
|
|
|
|
// Save local scope position because in case of condition variable ScopePos
|
|
// won't be restored when traversing AST.
|
|
SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
|
|
|
|
// Create local scope for possible condition variable.
|
|
// Store scope position for continue statement.
|
|
LocalScope::const_iterator LoopBeginScopePos = ScopePos;
|
|
if (VarDecl *VD = W->getConditionVariable()) {
|
|
addLocalScopeForVarDecl(VD);
|
|
addAutomaticObjDtors(ScopePos, LoopBeginScopePos, W);
|
|
}
|
|
|
|
// "while" is a control-flow statement. Thus we stop processing the current
|
|
// block.
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
LoopSuccessor = Block;
|
|
Block = nullptr;
|
|
} else {
|
|
LoopSuccessor = Succ;
|
|
}
|
|
|
|
CFGBlock *BodyBlock = nullptr, *TransitionBlock = nullptr;
|
|
|
|
// Process the loop body.
|
|
{
|
|
assert(W->getBody());
|
|
|
|
// Save the current values for Block, Succ, continue and break targets.
|
|
SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
|
|
SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
|
|
save_break(BreakJumpTarget);
|
|
|
|
// Create an empty block to represent the transition block for looping back
|
|
// to the head of the loop.
|
|
Succ = TransitionBlock = createBlock(false);
|
|
TransitionBlock->setLoopTarget(W);
|
|
ContinueJumpTarget = JumpTarget(Succ, LoopBeginScopePos);
|
|
|
|
// All breaks should go to the code following the loop.
|
|
BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
|
|
|
|
// Loop body should end with destructor of Condition variable (if any).
|
|
addAutomaticObjDtors(ScopePos, LoopBeginScopePos, W);
|
|
|
|
// If body is not a compound statement create implicit scope
|
|
// and add destructors.
|
|
if (!isa<CompoundStmt>(W->getBody()))
|
|
addLocalScopeAndDtors(W->getBody());
|
|
|
|
// Create the body. The returned block is the entry to the loop body.
|
|
BodyBlock = addStmt(W->getBody());
|
|
|
|
if (!BodyBlock)
|
|
BodyBlock = ContinueJumpTarget.block; // can happen for "while(...) ;"
|
|
else if (Block && badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
// Because of short-circuit evaluation, the condition of the loop can span
|
|
// multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
|
|
// evaluate the condition.
|
|
CFGBlock *EntryConditionBlock = nullptr, *ExitConditionBlock = nullptr;
|
|
|
|
do {
|
|
Expr *C = W->getCond();
|
|
|
|
// Specially handle logical operators, which have a slightly
|
|
// more optimal CFG representation.
|
|
if (BinaryOperator *Cond = dyn_cast<BinaryOperator>(C->IgnoreParens()))
|
|
if (Cond->isLogicalOp()) {
|
|
std::tie(EntryConditionBlock, ExitConditionBlock) =
|
|
VisitLogicalOperator(Cond, W, BodyBlock, LoopSuccessor);
|
|
break;
|
|
}
|
|
|
|
// The default case when not handling logical operators.
|
|
ExitConditionBlock = createBlock(false);
|
|
ExitConditionBlock->setTerminator(W);
|
|
|
|
// Now add the actual condition to the condition block.
|
|
// Because the condition itself may contain control-flow, new blocks may
|
|
// be created. Thus we update "Succ" after adding the condition.
|
|
Block = ExitConditionBlock;
|
|
Block = EntryConditionBlock = addStmt(C);
|
|
|
|
// If this block contains a condition variable, add both the condition
|
|
// variable and initializer to the CFG.
|
|
if (VarDecl *VD = W->getConditionVariable()) {
|
|
if (Expr *Init = VD->getInit()) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, W->getConditionVariableDeclStmt());
|
|
EntryConditionBlock = addStmt(Init);
|
|
assert(Block == EntryConditionBlock);
|
|
}
|
|
}
|
|
|
|
if (Block && badCFG)
|
|
return nullptr;
|
|
|
|
// See if this is a known constant.
|
|
const TryResult& KnownVal = tryEvaluateBool(C);
|
|
|
|
// Add the loop body entry as a successor to the condition.
|
|
addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? nullptr : BodyBlock);
|
|
// Link up the condition block with the code that follows the loop. (the
|
|
// false branch).
|
|
addSuccessor(ExitConditionBlock,
|
|
KnownVal.isTrue() ? nullptr : LoopSuccessor);
|
|
|
|
} while(false);
|
|
|
|
// Link up the loop-back block to the entry condition block.
|
|
addSuccessor(TransitionBlock, EntryConditionBlock);
|
|
|
|
// There can be no more statements in the condition block since we loop back
|
|
// to this block. NULL out Block to force lazy creation of another block.
|
|
Block = nullptr;
|
|
|
|
// Return the condition block, which is the dominating block for the loop.
|
|
Succ = EntryConditionBlock;
|
|
return EntryConditionBlock;
|
|
}
|
|
|
|
|
|
CFGBlock *CFGBuilder::VisitObjCAtCatchStmt(ObjCAtCatchStmt *S) {
|
|
// FIXME: For now we pretend that @catch and the code it contains does not
|
|
// exit.
|
|
return Block;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitObjCAtThrowStmt(ObjCAtThrowStmt *S) {
|
|
// FIXME: This isn't complete. We basically treat @throw like a return
|
|
// statement.
|
|
|
|
// If we were in the middle of a block we stop processing that block.
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// Create the new block.
|
|
Block = createBlock(false);
|
|
|
|
// The Exit block is the only successor.
|
|
addSuccessor(Block, &cfg->getExit());
|
|
|
|
// Add the statement to the block. This may create new blocks if S contains
|
|
// control-flow (short-circuit operations).
|
|
return VisitStmt(S, AddStmtChoice::AlwaysAdd);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXThrowExpr(CXXThrowExpr *T) {
|
|
// If we were in the middle of a block we stop processing that block.
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// Create the new block.
|
|
Block = createBlock(false);
|
|
|
|
if (TryTerminatedBlock)
|
|
// The current try statement is the only successor.
|
|
addSuccessor(Block, TryTerminatedBlock);
|
|
else
|
|
// otherwise the Exit block is the only successor.
|
|
addSuccessor(Block, &cfg->getExit());
|
|
|
|
// Add the statement to the block. This may create new blocks if S contains
|
|
// control-flow (short-circuit operations).
|
|
return VisitStmt(T, AddStmtChoice::AlwaysAdd);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitDoStmt(DoStmt *D) {
|
|
CFGBlock *LoopSuccessor = nullptr;
|
|
|
|
// "do...while" is a control-flow statement. Thus we stop processing the
|
|
// current block.
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
LoopSuccessor = Block;
|
|
} else
|
|
LoopSuccessor = Succ;
|
|
|
|
// Because of short-circuit evaluation, the condition of the loop can span
|
|
// multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
|
|
// evaluate the condition.
|
|
CFGBlock *ExitConditionBlock = createBlock(false);
|
|
CFGBlock *EntryConditionBlock = ExitConditionBlock;
|
|
|
|
// Set the terminator for the "exit" condition block.
|
|
ExitConditionBlock->setTerminator(D);
|
|
|
|
// Now add the actual condition to the condition block. Because the condition
|
|
// itself may contain control-flow, new blocks may be created.
|
|
if (Stmt *C = D->getCond()) {
|
|
Block = ExitConditionBlock;
|
|
EntryConditionBlock = addStmt(C);
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
// The condition block is the implicit successor for the loop body.
|
|
Succ = EntryConditionBlock;
|
|
|
|
// See if this is a known constant.
|
|
const TryResult &KnownVal = tryEvaluateBool(D->getCond());
|
|
|
|
// Process the loop body.
|
|
CFGBlock *BodyBlock = nullptr;
|
|
{
|
|
assert(D->getBody());
|
|
|
|
// Save the current values for Block, Succ, and continue and break targets
|
|
SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
|
|
SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
|
|
save_break(BreakJumpTarget);
|
|
|
|
// All continues within this loop should go to the condition block
|
|
ContinueJumpTarget = JumpTarget(EntryConditionBlock, ScopePos);
|
|
|
|
// All breaks should go to the code following the loop.
|
|
BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
|
|
|
|
// NULL out Block to force lazy instantiation of blocks for the body.
|
|
Block = nullptr;
|
|
|
|
// If body is not a compound statement create implicit scope
|
|
// and add destructors.
|
|
if (!isa<CompoundStmt>(D->getBody()))
|
|
addLocalScopeAndDtors(D->getBody());
|
|
|
|
// Create the body. The returned block is the entry to the loop body.
|
|
BodyBlock = addStmt(D->getBody());
|
|
|
|
if (!BodyBlock)
|
|
BodyBlock = EntryConditionBlock; // can happen for "do ; while(...)"
|
|
else if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
if (!KnownVal.isFalse()) {
|
|
// Add an intermediate block between the BodyBlock and the
|
|
// ExitConditionBlock to represent the "loop back" transition. Create an
|
|
// empty block to represent the transition block for looping back to the
|
|
// head of the loop.
|
|
// FIXME: Can we do this more efficiently without adding another block?
|
|
Block = nullptr;
|
|
Succ = BodyBlock;
|
|
CFGBlock *LoopBackBlock = createBlock();
|
|
LoopBackBlock->setLoopTarget(D);
|
|
|
|
// Add the loop body entry as a successor to the condition.
|
|
addSuccessor(ExitConditionBlock, LoopBackBlock);
|
|
}
|
|
else
|
|
addSuccessor(ExitConditionBlock, nullptr);
|
|
}
|
|
|
|
// Link up the condition block with the code that follows the loop.
|
|
// (the false branch).
|
|
addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? nullptr : LoopSuccessor);
|
|
|
|
// There can be no more statements in the body block(s) since we loop back to
|
|
// the body. NULL out Block to force lazy creation of another block.
|
|
Block = nullptr;
|
|
|
|
// Return the loop body, which is the dominating block for the loop.
|
|
Succ = BodyBlock;
|
|
return BodyBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitContinueStmt(ContinueStmt *C) {
|
|
// "continue" is a control-flow statement. Thus we stop processing the
|
|
// current block.
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// Now create a new block that ends with the continue statement.
|
|
Block = createBlock(false);
|
|
Block->setTerminator(C);
|
|
|
|
// If there is no target for the continue, then we are looking at an
|
|
// incomplete AST. This means the CFG cannot be constructed.
|
|
if (ContinueJumpTarget.block) {
|
|
addAutomaticObjDtors(ScopePos, ContinueJumpTarget.scopePosition, C);
|
|
addSuccessor(Block, ContinueJumpTarget.block);
|
|
} else
|
|
badCFG = true;
|
|
|
|
return Block;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E,
|
|
AddStmtChoice asc) {
|
|
|
|
if (asc.alwaysAdd(*this, E)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, E);
|
|
}
|
|
|
|
// VLA types have expressions that must be evaluated.
|
|
CFGBlock *lastBlock = Block;
|
|
|
|
if (E->isArgumentType()) {
|
|
for (const VariableArrayType *VA =FindVA(E->getArgumentType().getTypePtr());
|
|
VA != nullptr; VA = FindVA(VA->getElementType().getTypePtr()))
|
|
lastBlock = addStmt(VA->getSizeExpr());
|
|
}
|
|
return lastBlock;
|
|
}
|
|
|
|
/// VisitStmtExpr - Utility method to handle (nested) statement
|
|
/// expressions (a GCC extension).
|
|
CFGBlock *CFGBuilder::VisitStmtExpr(StmtExpr *SE, AddStmtChoice asc) {
|
|
if (asc.alwaysAdd(*this, SE)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, SE);
|
|
}
|
|
return VisitCompoundStmt(SE->getSubStmt());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitSwitchStmt(SwitchStmt *Terminator) {
|
|
// "switch" is a control-flow statement. Thus we stop processing the current
|
|
// block.
|
|
CFGBlock *SwitchSuccessor = nullptr;
|
|
|
|
// Save local scope position because in case of condition variable ScopePos
|
|
// won't be restored when traversing AST.
|
|
SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
|
|
|
|
// Create local scope for possible condition variable.
|
|
// Store scope position. Add implicit destructor.
|
|
if (VarDecl *VD = Terminator->getConditionVariable()) {
|
|
LocalScope::const_iterator SwitchBeginScopePos = ScopePos;
|
|
addLocalScopeForVarDecl(VD);
|
|
addAutomaticObjDtors(ScopePos, SwitchBeginScopePos, Terminator);
|
|
}
|
|
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
SwitchSuccessor = Block;
|
|
} else SwitchSuccessor = Succ;
|
|
|
|
// Save the current "switch" context.
|
|
SaveAndRestore<CFGBlock*> save_switch(SwitchTerminatedBlock),
|
|
save_default(DefaultCaseBlock);
|
|
SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
|
|
|
|
// Set the "default" case to be the block after the switch statement. If the
|
|
// switch statement contains a "default:", this value will be overwritten with
|
|
// the block for that code.
|
|
DefaultCaseBlock = SwitchSuccessor;
|
|
|
|
// Create a new block that will contain the switch statement.
|
|
SwitchTerminatedBlock = createBlock(false);
|
|
|
|
// Now process the switch body. The code after the switch is the implicit
|
|
// successor.
|
|
Succ = SwitchSuccessor;
|
|
BreakJumpTarget = JumpTarget(SwitchSuccessor, ScopePos);
|
|
|
|
// When visiting the body, the case statements should automatically get linked
|
|
// up to the switch. We also don't keep a pointer to the body, since all
|
|
// control-flow from the switch goes to case/default statements.
|
|
assert(Terminator->getBody() && "switch must contain a non-NULL body");
|
|
Block = nullptr;
|
|
|
|
// For pruning unreachable case statements, save the current state
|
|
// for tracking the condition value.
|
|
SaveAndRestore<bool> save_switchExclusivelyCovered(switchExclusivelyCovered,
|
|
false);
|
|
|
|
// Determine if the switch condition can be explicitly evaluated.
|
|
assert(Terminator->getCond() && "switch condition must be non-NULL");
|
|
Expr::EvalResult result;
|
|
bool b = tryEvaluate(Terminator->getCond(), result);
|
|
SaveAndRestore<Expr::EvalResult*> save_switchCond(switchCond,
|
|
b ? &result : nullptr);
|
|
|
|
// If body is not a compound statement create implicit scope
|
|
// and add destructors.
|
|
if (!isa<CompoundStmt>(Terminator->getBody()))
|
|
addLocalScopeAndDtors(Terminator->getBody());
|
|
|
|
addStmt(Terminator->getBody());
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
// If we have no "default:" case, the default transition is to the code
|
|
// following the switch body. Moreover, take into account if all the
|
|
// cases of a switch are covered (e.g., switching on an enum value).
|
|
//
|
|
// Note: We add a successor to a switch that is considered covered yet has no
|
|
// case statements if the enumeration has no enumerators.
|
|
bool SwitchAlwaysHasSuccessor = false;
|
|
SwitchAlwaysHasSuccessor |= switchExclusivelyCovered;
|
|
SwitchAlwaysHasSuccessor |= Terminator->isAllEnumCasesCovered() &&
|
|
Terminator->getSwitchCaseList();
|
|
addSuccessor(SwitchTerminatedBlock, DefaultCaseBlock,
|
|
!SwitchAlwaysHasSuccessor);
|
|
|
|
// Add the terminator and condition in the switch block.
|
|
SwitchTerminatedBlock->setTerminator(Terminator);
|
|
Block = SwitchTerminatedBlock;
|
|
CFGBlock *LastBlock = addStmt(Terminator->getCond());
|
|
|
|
// Finally, if the SwitchStmt contains a condition variable, add both the
|
|
// SwitchStmt and the condition variable initialization to the CFG.
|
|
if (VarDecl *VD = Terminator->getConditionVariable()) {
|
|
if (Expr *Init = VD->getInit()) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, Terminator->getConditionVariableDeclStmt());
|
|
LastBlock = addStmt(Init);
|
|
}
|
|
}
|
|
|
|
return LastBlock;
|
|
}
|
|
|
|
static bool shouldAddCase(bool &switchExclusivelyCovered,
|
|
const Expr::EvalResult *switchCond,
|
|
const CaseStmt *CS,
|
|
ASTContext &Ctx) {
|
|
if (!switchCond)
|
|
return true;
|
|
|
|
bool addCase = false;
|
|
|
|
if (!switchExclusivelyCovered) {
|
|
if (switchCond->Val.isInt()) {
|
|
// Evaluate the LHS of the case value.
|
|
const llvm::APSInt &lhsInt = CS->getLHS()->EvaluateKnownConstInt(Ctx);
|
|
const llvm::APSInt &condInt = switchCond->Val.getInt();
|
|
|
|
if (condInt == lhsInt) {
|
|
addCase = true;
|
|
switchExclusivelyCovered = true;
|
|
}
|
|
else if (condInt < lhsInt) {
|
|
if (const Expr *RHS = CS->getRHS()) {
|
|
// Evaluate the RHS of the case value.
|
|
const llvm::APSInt &V2 = RHS->EvaluateKnownConstInt(Ctx);
|
|
if (V2 <= condInt) {
|
|
addCase = true;
|
|
switchExclusivelyCovered = true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else
|
|
addCase = true;
|
|
}
|
|
return addCase;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCaseStmt(CaseStmt *CS) {
|
|
// CaseStmts are essentially labels, so they are the first statement in a
|
|
// block.
|
|
CFGBlock *TopBlock = nullptr, *LastBlock = nullptr;
|
|
|
|
if (Stmt *Sub = CS->getSubStmt()) {
|
|
// For deeply nested chains of CaseStmts, instead of doing a recursion
|
|
// (which can blow out the stack), manually unroll and create blocks
|
|
// along the way.
|
|
while (isa<CaseStmt>(Sub)) {
|
|
CFGBlock *currentBlock = createBlock(false);
|
|
currentBlock->setLabel(CS);
|
|
|
|
if (TopBlock)
|
|
addSuccessor(LastBlock, currentBlock);
|
|
else
|
|
TopBlock = currentBlock;
|
|
|
|
addSuccessor(SwitchTerminatedBlock,
|
|
shouldAddCase(switchExclusivelyCovered, switchCond,
|
|
CS, *Context)
|
|
? currentBlock : nullptr);
|
|
|
|
LastBlock = currentBlock;
|
|
CS = cast<CaseStmt>(Sub);
|
|
Sub = CS->getSubStmt();
|
|
}
|
|
|
|
addStmt(Sub);
|
|
}
|
|
|
|
CFGBlock *CaseBlock = Block;
|
|
if (!CaseBlock)
|
|
CaseBlock = createBlock();
|
|
|
|
// Cases statements partition blocks, so this is the top of the basic block we
|
|
// were processing (the "case XXX:" is the label).
|
|
CaseBlock->setLabel(CS);
|
|
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// Add this block to the list of successors for the block with the switch
|
|
// statement.
|
|
assert(SwitchTerminatedBlock);
|
|
addSuccessor(SwitchTerminatedBlock, CaseBlock,
|
|
shouldAddCase(switchExclusivelyCovered, switchCond,
|
|
CS, *Context));
|
|
|
|
// We set Block to NULL to allow lazy creation of a new block (if necessary)
|
|
Block = nullptr;
|
|
|
|
if (TopBlock) {
|
|
addSuccessor(LastBlock, CaseBlock);
|
|
Succ = TopBlock;
|
|
} else {
|
|
// This block is now the implicit successor of other blocks.
|
|
Succ = CaseBlock;
|
|
}
|
|
|
|
return Succ;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitDefaultStmt(DefaultStmt *Terminator) {
|
|
if (Terminator->getSubStmt())
|
|
addStmt(Terminator->getSubStmt());
|
|
|
|
DefaultCaseBlock = Block;
|
|
|
|
if (!DefaultCaseBlock)
|
|
DefaultCaseBlock = createBlock();
|
|
|
|
// Default statements partition blocks, so this is the top of the basic block
|
|
// we were processing (the "default:" is the label).
|
|
DefaultCaseBlock->setLabel(Terminator);
|
|
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// Unlike case statements, we don't add the default block to the successors
|
|
// for the switch statement immediately. This is done when we finish
|
|
// processing the switch statement. This allows for the default case
|
|
// (including a fall-through to the code after the switch statement) to always
|
|
// be the last successor of a switch-terminated block.
|
|
|
|
// We set Block to NULL to allow lazy creation of a new block (if necessary)
|
|
Block = nullptr;
|
|
|
|
// This block is now the implicit successor of other blocks.
|
|
Succ = DefaultCaseBlock;
|
|
|
|
return DefaultCaseBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXTryStmt(CXXTryStmt *Terminator) {
|
|
// "try"/"catch" is a control-flow statement. Thus we stop processing the
|
|
// current block.
|
|
CFGBlock *TrySuccessor = nullptr;
|
|
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
TrySuccessor = Block;
|
|
} else TrySuccessor = Succ;
|
|
|
|
CFGBlock *PrevTryTerminatedBlock = TryTerminatedBlock;
|
|
|
|
// Create a new block that will contain the try statement.
|
|
CFGBlock *NewTryTerminatedBlock = createBlock(false);
|
|
// Add the terminator in the try block.
|
|
NewTryTerminatedBlock->setTerminator(Terminator);
|
|
|
|
bool HasCatchAll = false;
|
|
for (unsigned h = 0; h <Terminator->getNumHandlers(); ++h) {
|
|
// The code after the try is the implicit successor.
|
|
Succ = TrySuccessor;
|
|
CXXCatchStmt *CS = Terminator->getHandler(h);
|
|
if (CS->getExceptionDecl() == nullptr) {
|
|
HasCatchAll = true;
|
|
}
|
|
Block = nullptr;
|
|
CFGBlock *CatchBlock = VisitCXXCatchStmt(CS);
|
|
if (!CatchBlock)
|
|
return nullptr;
|
|
// Add this block to the list of successors for the block with the try
|
|
// statement.
|
|
addSuccessor(NewTryTerminatedBlock, CatchBlock);
|
|
}
|
|
if (!HasCatchAll) {
|
|
if (PrevTryTerminatedBlock)
|
|
addSuccessor(NewTryTerminatedBlock, PrevTryTerminatedBlock);
|
|
else
|
|
addSuccessor(NewTryTerminatedBlock, &cfg->getExit());
|
|
}
|
|
|
|
// The code after the try is the implicit successor.
|
|
Succ = TrySuccessor;
|
|
|
|
// Save the current "try" context.
|
|
SaveAndRestore<CFGBlock*> save_try(TryTerminatedBlock, NewTryTerminatedBlock);
|
|
cfg->addTryDispatchBlock(TryTerminatedBlock);
|
|
|
|
assert(Terminator->getTryBlock() && "try must contain a non-NULL body");
|
|
Block = nullptr;
|
|
return addStmt(Terminator->getTryBlock());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXCatchStmt(CXXCatchStmt *CS) {
|
|
// CXXCatchStmt are treated like labels, so they are the first statement in a
|
|
// block.
|
|
|
|
// Save local scope position because in case of exception variable ScopePos
|
|
// won't be restored when traversing AST.
|
|
SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
|
|
|
|
// Create local scope for possible exception variable.
|
|
// Store scope position. Add implicit destructor.
|
|
if (VarDecl *VD = CS->getExceptionDecl()) {
|
|
LocalScope::const_iterator BeginScopePos = ScopePos;
|
|
addLocalScopeForVarDecl(VD);
|
|
addAutomaticObjDtors(ScopePos, BeginScopePos, CS);
|
|
}
|
|
|
|
if (CS->getHandlerBlock())
|
|
addStmt(CS->getHandlerBlock());
|
|
|
|
CFGBlock *CatchBlock = Block;
|
|
if (!CatchBlock)
|
|
CatchBlock = createBlock();
|
|
|
|
// CXXCatchStmt is more than just a label. They have semantic meaning
|
|
// as well, as they implicitly "initialize" the catch variable. Add
|
|
// it to the CFG as a CFGElement so that the control-flow of these
|
|
// semantics gets captured.
|
|
appendStmt(CatchBlock, CS);
|
|
|
|
// Also add the CXXCatchStmt as a label, to mirror handling of regular
|
|
// labels.
|
|
CatchBlock->setLabel(CS);
|
|
|
|
// Bail out if the CFG is bad.
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// We set Block to NULL to allow lazy creation of a new block (if necessary)
|
|
Block = nullptr;
|
|
|
|
return CatchBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
|
|
// C++0x for-range statements are specified as [stmt.ranged]:
|
|
//
|
|
// {
|
|
// auto && __range = range-init;
|
|
// for ( auto __begin = begin-expr,
|
|
// __end = end-expr;
|
|
// __begin != __end;
|
|
// ++__begin ) {
|
|
// for-range-declaration = *__begin;
|
|
// statement
|
|
// }
|
|
// }
|
|
|
|
// Save local scope position before the addition of the implicit variables.
|
|
SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
|
|
|
|
// Create local scopes and destructors for range, begin and end variables.
|
|
if (Stmt *Range = S->getRangeStmt())
|
|
addLocalScopeForStmt(Range);
|
|
if (Stmt *BeginEnd = S->getBeginEndStmt())
|
|
addLocalScopeForStmt(BeginEnd);
|
|
addAutomaticObjDtors(ScopePos, save_scope_pos.get(), S);
|
|
|
|
LocalScope::const_iterator ContinueScopePos = ScopePos;
|
|
|
|
// "for" is a control-flow statement. Thus we stop processing the current
|
|
// block.
|
|
CFGBlock *LoopSuccessor = nullptr;
|
|
if (Block) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
LoopSuccessor = Block;
|
|
} else
|
|
LoopSuccessor = Succ;
|
|
|
|
// Save the current value for the break targets.
|
|
// All breaks should go to the code following the loop.
|
|
SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
|
|
BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
|
|
|
|
// The block for the __begin != __end expression.
|
|
CFGBlock *ConditionBlock = createBlock(false);
|
|
ConditionBlock->setTerminator(S);
|
|
|
|
// Now add the actual condition to the condition block.
|
|
if (Expr *C = S->getCond()) {
|
|
Block = ConditionBlock;
|
|
CFGBlock *BeginConditionBlock = addStmt(C);
|
|
if (badCFG)
|
|
return nullptr;
|
|
assert(BeginConditionBlock == ConditionBlock &&
|
|
"condition block in for-range was unexpectedly complex");
|
|
(void)BeginConditionBlock;
|
|
}
|
|
|
|
// The condition block is the implicit successor for the loop body as well as
|
|
// any code above the loop.
|
|
Succ = ConditionBlock;
|
|
|
|
// See if this is a known constant.
|
|
TryResult KnownVal(true);
|
|
|
|
if (S->getCond())
|
|
KnownVal = tryEvaluateBool(S->getCond());
|
|
|
|
// Now create the loop body.
|
|
{
|
|
assert(S->getBody());
|
|
|
|
// Save the current values for Block, Succ, and continue targets.
|
|
SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
|
|
SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget);
|
|
|
|
// Generate increment code in its own basic block. This is the target of
|
|
// continue statements.
|
|
Block = nullptr;
|
|
Succ = addStmt(S->getInc());
|
|
ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos);
|
|
|
|
// The starting block for the loop increment is the block that should
|
|
// represent the 'loop target' for looping back to the start of the loop.
|
|
ContinueJumpTarget.block->setLoopTarget(S);
|
|
|
|
// Finish up the increment block and prepare to start the loop body.
|
|
assert(Block);
|
|
if (badCFG)
|
|
return nullptr;
|
|
Block = nullptr;
|
|
|
|
// Add implicit scope and dtors for loop variable.
|
|
addLocalScopeAndDtors(S->getLoopVarStmt());
|
|
|
|
// Populate a new block to contain the loop body and loop variable.
|
|
addStmt(S->getBody());
|
|
if (badCFG)
|
|
return nullptr;
|
|
CFGBlock *LoopVarStmtBlock = addStmt(S->getLoopVarStmt());
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// This new body block is a successor to our condition block.
|
|
addSuccessor(ConditionBlock,
|
|
KnownVal.isFalse() ? nullptr : LoopVarStmtBlock);
|
|
}
|
|
|
|
// Link up the condition block with the code that follows the loop (the
|
|
// false branch).
|
|
addSuccessor(ConditionBlock, KnownVal.isTrue() ? nullptr : LoopSuccessor);
|
|
|
|
// Add the initialization statements.
|
|
Block = createBlock();
|
|
addStmt(S->getBeginEndStmt());
|
|
return addStmt(S->getRangeStmt());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitExprWithCleanups(ExprWithCleanups *E,
|
|
AddStmtChoice asc) {
|
|
if (BuildOpts.AddTemporaryDtors) {
|
|
// If adding implicit destructors visit the full expression for adding
|
|
// destructors of temporaries.
|
|
VisitForTemporaryDtors(E->getSubExpr());
|
|
|
|
// Full expression has to be added as CFGStmt so it will be sequenced
|
|
// before destructors of it's temporaries.
|
|
asc = asc.withAlwaysAdd(true);
|
|
}
|
|
return Visit(E->getSubExpr(), asc);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E,
|
|
AddStmtChoice asc) {
|
|
if (asc.alwaysAdd(*this, E)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, E);
|
|
|
|
// We do not want to propagate the AlwaysAdd property.
|
|
asc = asc.withAlwaysAdd(false);
|
|
}
|
|
return Visit(E->getSubExpr(), asc);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXConstructExpr(CXXConstructExpr *C,
|
|
AddStmtChoice asc) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, C);
|
|
|
|
return VisitChildren(C);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXNewExpr(CXXNewExpr *NE,
|
|
AddStmtChoice asc) {
|
|
|
|
autoCreateBlock();
|
|
appendStmt(Block, NE);
|
|
|
|
if (NE->getInitializer())
|
|
Block = Visit(NE->getInitializer());
|
|
if (BuildOpts.AddCXXNewAllocator)
|
|
appendNewAllocator(Block, NE);
|
|
if (NE->isArray())
|
|
Block = Visit(NE->getArraySize());
|
|
for (CXXNewExpr::arg_iterator I = NE->placement_arg_begin(),
|
|
E = NE->placement_arg_end(); I != E; ++I)
|
|
Block = Visit(*I);
|
|
return Block;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXDeleteExpr(CXXDeleteExpr *DE,
|
|
AddStmtChoice asc) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, DE);
|
|
QualType DTy = DE->getDestroyedType();
|
|
DTy = DTy.getNonReferenceType();
|
|
CXXRecordDecl *RD = Context->getBaseElementType(DTy)->getAsCXXRecordDecl();
|
|
if (RD) {
|
|
if (RD->isCompleteDefinition() && !RD->hasTrivialDestructor())
|
|
appendDeleteDtor(Block, RD, DE);
|
|
}
|
|
|
|
return VisitChildren(DE);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E,
|
|
AddStmtChoice asc) {
|
|
if (asc.alwaysAdd(*this, E)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, E);
|
|
// We do not want to propagate the AlwaysAdd property.
|
|
asc = asc.withAlwaysAdd(false);
|
|
}
|
|
return Visit(E->getSubExpr(), asc);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C,
|
|
AddStmtChoice asc) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, C);
|
|
return VisitChildren(C);
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitImplicitCastExpr(ImplicitCastExpr *E,
|
|
AddStmtChoice asc) {
|
|
if (asc.alwaysAdd(*this, E)) {
|
|
autoCreateBlock();
|
|
appendStmt(Block, E);
|
|
}
|
|
return Visit(E->getSubExpr(), AddStmtChoice());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitIndirectGotoStmt(IndirectGotoStmt *I) {
|
|
// Lazily create the indirect-goto dispatch block if there isn't one already.
|
|
CFGBlock *IBlock = cfg->getIndirectGotoBlock();
|
|
|
|
if (!IBlock) {
|
|
IBlock = createBlock(false);
|
|
cfg->setIndirectGotoBlock(IBlock);
|
|
}
|
|
|
|
// IndirectGoto is a control-flow statement. Thus we stop processing the
|
|
// current block and create a new one.
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
Block = createBlock(false);
|
|
Block->setTerminator(I);
|
|
addSuccessor(Block, IBlock);
|
|
return addStmt(I->getTarget());
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitForTemporaryDtors(Stmt *E, bool BindToTemporary) {
|
|
assert(BuildOpts.AddImplicitDtors && BuildOpts.AddTemporaryDtors);
|
|
|
|
tryAgain:
|
|
if (!E) {
|
|
badCFG = true;
|
|
return nullptr;
|
|
}
|
|
switch (E->getStmtClass()) {
|
|
default:
|
|
return VisitChildrenForTemporaryDtors(E);
|
|
|
|
case Stmt::BinaryOperatorClass:
|
|
return VisitBinaryOperatorForTemporaryDtors(cast<BinaryOperator>(E));
|
|
|
|
case Stmt::CXXBindTemporaryExprClass:
|
|
return VisitCXXBindTemporaryExprForTemporaryDtors(
|
|
cast<CXXBindTemporaryExpr>(E), BindToTemporary);
|
|
|
|
case Stmt::BinaryConditionalOperatorClass:
|
|
case Stmt::ConditionalOperatorClass:
|
|
return VisitConditionalOperatorForTemporaryDtors(
|
|
cast<AbstractConditionalOperator>(E), BindToTemporary);
|
|
|
|
case Stmt::ImplicitCastExprClass:
|
|
// For implicit cast we want BindToTemporary to be passed further.
|
|
E = cast<CastExpr>(E)->getSubExpr();
|
|
goto tryAgain;
|
|
|
|
case Stmt::ParenExprClass:
|
|
E = cast<ParenExpr>(E)->getSubExpr();
|
|
goto tryAgain;
|
|
|
|
case Stmt::MaterializeTemporaryExprClass:
|
|
E = cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr();
|
|
goto tryAgain;
|
|
}
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitChildrenForTemporaryDtors(Stmt *E) {
|
|
// When visiting children for destructors we want to visit them in reverse
|
|
// order that they will appear in the CFG. Because the CFG is built
|
|
// bottom-up, this means we visit them in their natural order, which
|
|
// reverses them in the CFG.
|
|
CFGBlock *B = Block;
|
|
for (Stmt::child_range I = E->children(); I; ++I) {
|
|
if (Stmt *Child = *I)
|
|
if (CFGBlock *R = VisitForTemporaryDtors(Child))
|
|
B = R;
|
|
}
|
|
return B;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E) {
|
|
if (E->isLogicalOp()) {
|
|
// Destructors for temporaries in LHS expression should be called after
|
|
// those for RHS expression. Even if this will unnecessarily create a block,
|
|
// this block will be used at least by the full expression.
|
|
autoCreateBlock();
|
|
CFGBlock *ConfluenceBlock = VisitForTemporaryDtors(E->getLHS());
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
Succ = ConfluenceBlock;
|
|
Block = nullptr;
|
|
CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
|
|
|
|
if (RHSBlock) {
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// If RHS expression did produce destructors we need to connect created
|
|
// blocks to CFG in same manner as for binary operator itself.
|
|
CFGBlock *LHSBlock = createBlock(false);
|
|
LHSBlock->setTerminator(CFGTerminator(E, true));
|
|
|
|
// For binary operator LHS block is before RHS in list of predecessors
|
|
// of ConfluenceBlock.
|
|
std::reverse(ConfluenceBlock->pred_begin(),
|
|
ConfluenceBlock->pred_end());
|
|
|
|
// See if this is a known constant.
|
|
TryResult KnownVal = tryEvaluateBool(E->getLHS());
|
|
if (KnownVal.isKnown() && (E->getOpcode() == BO_LOr))
|
|
KnownVal.negate();
|
|
|
|
// Link LHSBlock with RHSBlock exactly the same way as for binary operator
|
|
// itself.
|
|
if (E->getOpcode() == BO_LOr) {
|
|
addSuccessor(LHSBlock, KnownVal.isTrue() ? nullptr : ConfluenceBlock);
|
|
addSuccessor(LHSBlock, KnownVal.isFalse() ? nullptr : RHSBlock);
|
|
} else {
|
|
assert (E->getOpcode() == BO_LAnd);
|
|
addSuccessor(LHSBlock, KnownVal.isFalse() ? nullptr : RHSBlock);
|
|
addSuccessor(LHSBlock, KnownVal.isTrue() ? nullptr : ConfluenceBlock);
|
|
}
|
|
|
|
Block = LHSBlock;
|
|
return LHSBlock;
|
|
}
|
|
|
|
Block = ConfluenceBlock;
|
|
return ConfluenceBlock;
|
|
}
|
|
|
|
if (E->isAssignmentOp()) {
|
|
// For assignment operator (=) LHS expression is visited
|
|
// before RHS expression. For destructors visit them in reverse order.
|
|
CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
|
|
CFGBlock *LHSBlock = VisitForTemporaryDtors(E->getLHS());
|
|
return LHSBlock ? LHSBlock : RHSBlock;
|
|
}
|
|
|
|
// For any other binary operator RHS expression is visited before
|
|
// LHS expression (order of children). For destructors visit them in reverse
|
|
// order.
|
|
CFGBlock *LHSBlock = VisitForTemporaryDtors(E->getLHS());
|
|
CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
|
|
return RHSBlock ? RHSBlock : LHSBlock;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitCXXBindTemporaryExprForTemporaryDtors(
|
|
CXXBindTemporaryExpr *E, bool BindToTemporary) {
|
|
// First add destructors for temporaries in subexpression.
|
|
CFGBlock *B = VisitForTemporaryDtors(E->getSubExpr());
|
|
if (!BindToTemporary) {
|
|
// If lifetime of temporary is not prolonged (by assigning to constant
|
|
// reference) add destructor for it.
|
|
|
|
// If the destructor is marked as a no-return destructor, we need to create
|
|
// a new block for the destructor which does not have as a successor
|
|
// anything built thus far. Control won't flow out of this block.
|
|
const CXXDestructorDecl *Dtor = E->getTemporary()->getDestructor();
|
|
if (Dtor->isNoReturn()) {
|
|
Succ = B;
|
|
Block = createNoReturnBlock();
|
|
} else {
|
|
autoCreateBlock();
|
|
}
|
|
|
|
appendTemporaryDtor(Block, E);
|
|
B = Block;
|
|
}
|
|
return B;
|
|
}
|
|
|
|
CFGBlock *CFGBuilder::VisitConditionalOperatorForTemporaryDtors(
|
|
AbstractConditionalOperator *E, bool BindToTemporary) {
|
|
// First add destructors for condition expression. Even if this will
|
|
// unnecessarily create a block, this block will be used at least by the full
|
|
// expression.
|
|
autoCreateBlock();
|
|
CFGBlock *ConfluenceBlock = VisitForTemporaryDtors(E->getCond());
|
|
if (badCFG)
|
|
return nullptr;
|
|
if (BinaryConditionalOperator *BCO
|
|
= dyn_cast<BinaryConditionalOperator>(E)) {
|
|
ConfluenceBlock = VisitForTemporaryDtors(BCO->getCommon());
|
|
if (badCFG)
|
|
return nullptr;
|
|
}
|
|
|
|
// Try to add block with destructors for LHS expression.
|
|
CFGBlock *LHSBlock = nullptr;
|
|
Succ = ConfluenceBlock;
|
|
Block = nullptr;
|
|
LHSBlock = VisitForTemporaryDtors(E->getTrueExpr(), BindToTemporary);
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
// Try to add block with destructors for RHS expression;
|
|
Succ = ConfluenceBlock;
|
|
Block = nullptr;
|
|
CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getFalseExpr(),
|
|
BindToTemporary);
|
|
if (badCFG)
|
|
return nullptr;
|
|
|
|
if (!RHSBlock && !LHSBlock) {
|
|
// If neither LHS nor RHS expression had temporaries to destroy don't create
|
|
// more blocks.
|
|
Block = ConfluenceBlock;
|
|
return Block;
|
|
}
|
|
|
|
Block = createBlock(false);
|
|
Block->setTerminator(CFGTerminator(E, true));
|
|
assert(Block->getTerminator().isTemporaryDtorsBranch());
|
|
|
|
// See if this is a known constant.
|
|
const TryResult &KnownVal = tryEvaluateBool(E->getCond());
|
|
|
|
if (LHSBlock) {
|
|
addSuccessor(Block, LHSBlock, !KnownVal.isFalse());
|
|
} else if (KnownVal.isFalse()) {
|
|
addSuccessor(Block, nullptr);
|
|
} else {
|
|
addSuccessor(Block, ConfluenceBlock);
|
|
std::reverse(ConfluenceBlock->pred_begin(), ConfluenceBlock->pred_end());
|
|
}
|
|
|
|
if (!RHSBlock)
|
|
RHSBlock = ConfluenceBlock;
|
|
|
|
addSuccessor(Block, RHSBlock, !KnownVal.isTrue());
|
|
|
|
return Block;
|
|
}
|
|
|
|
} // end anonymous namespace
|
|
|
|
/// createBlock - Constructs and adds a new CFGBlock to the CFG. The block has
|
|
/// no successors or predecessors. If this is the first block created in the
|
|
/// CFG, it is automatically set to be the Entry and Exit of the CFG.
|
|
CFGBlock *CFG::createBlock() {
|
|
bool first_block = begin() == end();
|
|
|
|
// Create the block.
|
|
CFGBlock *Mem = getAllocator().Allocate<CFGBlock>();
|
|
new (Mem) CFGBlock(NumBlockIDs++, BlkBVC, this);
|
|
Blocks.push_back(Mem, BlkBVC);
|
|
|
|
// If this is the first block, set it as the Entry and Exit.
|
|
if (first_block)
|
|
Entry = Exit = &back();
|
|
|
|
// Return the block.
|
|
return &back();
|
|
}
|
|
|
|
/// buildCFG - Constructs a CFG from an AST. Ownership of the returned
|
|
/// CFG is returned to the caller.
|
|
CFG* CFG::buildCFG(const Decl *D, Stmt *Statement, ASTContext *C,
|
|
const BuildOptions &BO) {
|
|
CFGBuilder Builder(C, BO);
|
|
return Builder.buildCFG(D, Statement);
|
|
}
|
|
|
|
const CXXDestructorDecl *
|
|
CFGImplicitDtor::getDestructorDecl(ASTContext &astContext) const {
|
|
switch (getKind()) {
|
|
case CFGElement::Statement:
|
|
case CFGElement::Initializer:
|
|
case CFGElement::NewAllocator:
|
|
llvm_unreachable("getDestructorDecl should only be used with "
|
|
"ImplicitDtors");
|
|
case CFGElement::AutomaticObjectDtor: {
|
|
const VarDecl *var = castAs<CFGAutomaticObjDtor>().getVarDecl();
|
|
QualType ty = var->getType();
|
|
ty = ty.getNonReferenceType();
|
|
while (const ArrayType *arrayType = astContext.getAsArrayType(ty)) {
|
|
ty = arrayType->getElementType();
|
|
}
|
|
const RecordType *recordType = ty->getAs<RecordType>();
|
|
const CXXRecordDecl *classDecl =
|
|
cast<CXXRecordDecl>(recordType->getDecl());
|
|
return classDecl->getDestructor();
|
|
}
|
|
case CFGElement::DeleteDtor: {
|
|
const CXXDeleteExpr *DE = castAs<CFGDeleteDtor>().getDeleteExpr();
|
|
QualType DTy = DE->getDestroyedType();
|
|
DTy = DTy.getNonReferenceType();
|
|
const CXXRecordDecl *classDecl =
|
|
astContext.getBaseElementType(DTy)->getAsCXXRecordDecl();
|
|
return classDecl->getDestructor();
|
|
}
|
|
case CFGElement::TemporaryDtor: {
|
|
const CXXBindTemporaryExpr *bindExpr =
|
|
castAs<CFGTemporaryDtor>().getBindTemporaryExpr();
|
|
const CXXTemporary *temp = bindExpr->getTemporary();
|
|
return temp->getDestructor();
|
|
}
|
|
case CFGElement::BaseDtor:
|
|
case CFGElement::MemberDtor:
|
|
|
|
// Not yet supported.
|
|
return nullptr;
|
|
}
|
|
llvm_unreachable("getKind() returned bogus value");
|
|
}
|
|
|
|
bool CFGImplicitDtor::isNoReturn(ASTContext &astContext) const {
|
|
if (const CXXDestructorDecl *DD = getDestructorDecl(astContext))
|
|
return DD->isNoReturn();
|
|
return false;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// CFGBlock operations.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
CFGBlock::AdjacentBlock::AdjacentBlock(CFGBlock *B, bool IsReachable)
|
|
: ReachableBlock(IsReachable ? B : nullptr),
|
|
UnreachableBlock(!IsReachable ? B : nullptr,
|
|
B && IsReachable ? AB_Normal : AB_Unreachable) {}
|
|
|
|
CFGBlock::AdjacentBlock::AdjacentBlock(CFGBlock *B, CFGBlock *AlternateBlock)
|
|
: ReachableBlock(B),
|
|
UnreachableBlock(B == AlternateBlock ? nullptr : AlternateBlock,
|
|
B == AlternateBlock ? AB_Alternate : AB_Normal) {}
|
|
|
|
void CFGBlock::addSuccessor(AdjacentBlock Succ,
|
|
BumpVectorContext &C) {
|
|
if (CFGBlock *B = Succ.getReachableBlock())
|
|
B->Preds.push_back(AdjacentBlock(this, Succ.isReachable()), C);
|
|
|
|
if (CFGBlock *UnreachableB = Succ.getPossiblyUnreachableBlock())
|
|
UnreachableB->Preds.push_back(AdjacentBlock(this, false), C);
|
|
|
|
Succs.push_back(Succ, C);
|
|
}
|
|
|
|
bool CFGBlock::FilterEdge(const CFGBlock::FilterOptions &F,
|
|
const CFGBlock *From, const CFGBlock *To) {
|
|
|
|
if (F.IgnoreNullPredecessors && !From)
|
|
return true;
|
|
|
|
if (To && From && F.IgnoreDefaultsWithCoveredEnums) {
|
|
// If the 'To' has no label or is labeled but the label isn't a
|
|
// CaseStmt then filter this edge.
|
|
if (const SwitchStmt *S =
|
|
dyn_cast_or_null<SwitchStmt>(From->getTerminator().getStmt())) {
|
|
if (S->isAllEnumCasesCovered()) {
|
|
const Stmt *L = To->getLabel();
|
|
if (!L || !isa<CaseStmt>(L))
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// CFG pretty printing
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
|
|
class StmtPrinterHelper : public PrinterHelper {
|
|
typedef llvm::DenseMap<const Stmt*,std::pair<unsigned,unsigned> > StmtMapTy;
|
|
typedef llvm::DenseMap<const Decl*,std::pair<unsigned,unsigned> > DeclMapTy;
|
|
StmtMapTy StmtMap;
|
|
DeclMapTy DeclMap;
|
|
signed currentBlock;
|
|
unsigned currStmt;
|
|
const LangOptions &LangOpts;
|
|
public:
|
|
|
|
StmtPrinterHelper(const CFG* cfg, const LangOptions &LO)
|
|
: currentBlock(0), currStmt(0), LangOpts(LO)
|
|
{
|
|
for (CFG::const_iterator I = cfg->begin(), E = cfg->end(); I != E; ++I ) {
|
|
unsigned j = 1;
|
|
for (CFGBlock::const_iterator BI = (*I)->begin(), BEnd = (*I)->end() ;
|
|
BI != BEnd; ++BI, ++j ) {
|
|
if (Optional<CFGStmt> SE = BI->getAs<CFGStmt>()) {
|
|
const Stmt *stmt= SE->getStmt();
|
|
std::pair<unsigned, unsigned> P((*I)->getBlockID(), j);
|
|
StmtMap[stmt] = P;
|
|
|
|
switch (stmt->getStmtClass()) {
|
|
case Stmt::DeclStmtClass:
|
|
DeclMap[cast<DeclStmt>(stmt)->getSingleDecl()] = P;
|
|
break;
|
|
case Stmt::IfStmtClass: {
|
|
const VarDecl *var = cast<IfStmt>(stmt)->getConditionVariable();
|
|
if (var)
|
|
DeclMap[var] = P;
|
|
break;
|
|
}
|
|
case Stmt::ForStmtClass: {
|
|
const VarDecl *var = cast<ForStmt>(stmt)->getConditionVariable();
|
|
if (var)
|
|
DeclMap[var] = P;
|
|
break;
|
|
}
|
|
case Stmt::WhileStmtClass: {
|
|
const VarDecl *var =
|
|
cast<WhileStmt>(stmt)->getConditionVariable();
|
|
if (var)
|
|
DeclMap[var] = P;
|
|
break;
|
|
}
|
|
case Stmt::SwitchStmtClass: {
|
|
const VarDecl *var =
|
|
cast<SwitchStmt>(stmt)->getConditionVariable();
|
|
if (var)
|
|
DeclMap[var] = P;
|
|
break;
|
|
}
|
|
case Stmt::CXXCatchStmtClass: {
|
|
const VarDecl *var =
|
|
cast<CXXCatchStmt>(stmt)->getExceptionDecl();
|
|
if (var)
|
|
DeclMap[var] = P;
|
|
break;
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
virtual ~StmtPrinterHelper() {}
|
|
|
|
const LangOptions &getLangOpts() const { return LangOpts; }
|
|
void setBlockID(signed i) { currentBlock = i; }
|
|
void setStmtID(unsigned i) { currStmt = i; }
|
|
|
|
bool handledStmt(Stmt *S, raw_ostream &OS) override {
|
|
StmtMapTy::iterator I = StmtMap.find(S);
|
|
|
|
if (I == StmtMap.end())
|
|
return false;
|
|
|
|
if (currentBlock >= 0 && I->second.first == (unsigned) currentBlock
|
|
&& I->second.second == currStmt) {
|
|
return false;
|
|
}
|
|
|
|
OS << "[B" << I->second.first << "." << I->second.second << "]";
|
|
return true;
|
|
}
|
|
|
|
bool handleDecl(const Decl *D, raw_ostream &OS) {
|
|
DeclMapTy::iterator I = DeclMap.find(D);
|
|
|
|
if (I == DeclMap.end())
|
|
return false;
|
|
|
|
if (currentBlock >= 0 && I->second.first == (unsigned) currentBlock
|
|
&& I->second.second == currStmt) {
|
|
return false;
|
|
}
|
|
|
|
OS << "[B" << I->second.first << "." << I->second.second << "]";
|
|
return true;
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
|
|
namespace {
|
|
class CFGBlockTerminatorPrint
|
|
: public StmtVisitor<CFGBlockTerminatorPrint,void> {
|
|
|
|
raw_ostream &OS;
|
|
StmtPrinterHelper* Helper;
|
|
PrintingPolicy Policy;
|
|
public:
|
|
CFGBlockTerminatorPrint(raw_ostream &os, StmtPrinterHelper* helper,
|
|
const PrintingPolicy &Policy)
|
|
: OS(os), Helper(helper), Policy(Policy) {
|
|
this->Policy.IncludeNewlines = false;
|
|
}
|
|
|
|
void VisitIfStmt(IfStmt *I) {
|
|
OS << "if ";
|
|
I->getCond()->printPretty(OS,Helper,Policy);
|
|
}
|
|
|
|
// Default case.
|
|
void VisitStmt(Stmt *Terminator) {
|
|
Terminator->printPretty(OS, Helper, Policy);
|
|
}
|
|
|
|
void VisitDeclStmt(DeclStmt *DS) {
|
|
VarDecl *VD = cast<VarDecl>(DS->getSingleDecl());
|
|
OS << "static init " << VD->getName();
|
|
}
|
|
|
|
void VisitForStmt(ForStmt *F) {
|
|
OS << "for (" ;
|
|
if (F->getInit())
|
|
OS << "...";
|
|
OS << "; ";
|
|
if (Stmt *C = F->getCond())
|
|
C->printPretty(OS, Helper, Policy);
|
|
OS << "; ";
|
|
if (F->getInc())
|
|
OS << "...";
|
|
OS << ")";
|
|
}
|
|
|
|
void VisitWhileStmt(WhileStmt *W) {
|
|
OS << "while " ;
|
|
if (Stmt *C = W->getCond())
|
|
C->printPretty(OS, Helper, Policy);
|
|
}
|
|
|
|
void VisitDoStmt(DoStmt *D) {
|
|
OS << "do ... while ";
|
|
if (Stmt *C = D->getCond())
|
|
C->printPretty(OS, Helper, Policy);
|
|
}
|
|
|
|
void VisitSwitchStmt(SwitchStmt *Terminator) {
|
|
OS << "switch ";
|
|
Terminator->getCond()->printPretty(OS, Helper, Policy);
|
|
}
|
|
|
|
void VisitCXXTryStmt(CXXTryStmt *CS) {
|
|
OS << "try ...";
|
|
}
|
|
|
|
void VisitAbstractConditionalOperator(AbstractConditionalOperator* C) {
|
|
C->getCond()->printPretty(OS, Helper, Policy);
|
|
OS << " ? ... : ...";
|
|
}
|
|
|
|
void VisitChooseExpr(ChooseExpr *C) {
|
|
OS << "__builtin_choose_expr( ";
|
|
C->getCond()->printPretty(OS, Helper, Policy);
|
|
OS << " )";
|
|
}
|
|
|
|
void VisitIndirectGotoStmt(IndirectGotoStmt *I) {
|
|
OS << "goto *";
|
|
I->getTarget()->printPretty(OS, Helper, Policy);
|
|
}
|
|
|
|
void VisitBinaryOperator(BinaryOperator* B) {
|
|
if (!B->isLogicalOp()) {
|
|
VisitExpr(B);
|
|
return;
|
|
}
|
|
|
|
B->getLHS()->printPretty(OS, Helper, Policy);
|
|
|
|
switch (B->getOpcode()) {
|
|
case BO_LOr:
|
|
OS << " || ...";
|
|
return;
|
|
case BO_LAnd:
|
|
OS << " && ...";
|
|
return;
|
|
default:
|
|
llvm_unreachable("Invalid logical operator.");
|
|
}
|
|
}
|
|
|
|
void VisitExpr(Expr *E) {
|
|
E->printPretty(OS, Helper, Policy);
|
|
}
|
|
|
|
public:
|
|
void print(CFGTerminator T) {
|
|
if (T.isTemporaryDtorsBranch())
|
|
OS << "(Temp Dtor) ";
|
|
Visit(T.getStmt());
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static void print_elem(raw_ostream &OS, StmtPrinterHelper &Helper,
|
|
const CFGElement &E) {
|
|
if (Optional<CFGStmt> CS = E.getAs<CFGStmt>()) {
|
|
const Stmt *S = CS->getStmt();
|
|
|
|
// special printing for statement-expressions.
|
|
if (const StmtExpr *SE = dyn_cast<StmtExpr>(S)) {
|
|
const CompoundStmt *Sub = SE->getSubStmt();
|
|
|
|
if (Sub->children()) {
|
|
OS << "({ ... ; ";
|
|
Helper.handledStmt(*SE->getSubStmt()->body_rbegin(),OS);
|
|
OS << " })\n";
|
|
return;
|
|
}
|
|
}
|
|
// special printing for comma expressions.
|
|
if (const BinaryOperator* B = dyn_cast<BinaryOperator>(S)) {
|
|
if (B->getOpcode() == BO_Comma) {
|
|
OS << "... , ";
|
|
Helper.handledStmt(B->getRHS(),OS);
|
|
OS << '\n';
|
|
return;
|
|
}
|
|
}
|
|
S->printPretty(OS, &Helper, PrintingPolicy(Helper.getLangOpts()));
|
|
|
|
if (isa<CXXOperatorCallExpr>(S)) {
|
|
OS << " (OperatorCall)";
|
|
}
|
|
else if (isa<CXXBindTemporaryExpr>(S)) {
|
|
OS << " (BindTemporary)";
|
|
}
|
|
else if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(S)) {
|
|
OS << " (CXXConstructExpr, " << CCE->getType().getAsString() << ")";
|
|
}
|
|
else if (const CastExpr *CE = dyn_cast<CastExpr>(S)) {
|
|
OS << " (" << CE->getStmtClassName() << ", "
|
|
<< CE->getCastKindName()
|
|
<< ", " << CE->getType().getAsString()
|
|
<< ")";
|
|
}
|
|
|
|
// Expressions need a newline.
|
|
if (isa<Expr>(S))
|
|
OS << '\n';
|
|
|
|
} else if (Optional<CFGInitializer> IE = E.getAs<CFGInitializer>()) {
|
|
const CXXCtorInitializer *I = IE->getInitializer();
|
|
if (I->isBaseInitializer())
|
|
OS << I->getBaseClass()->getAsCXXRecordDecl()->getName();
|
|
else if (I->isDelegatingInitializer())
|
|
OS << I->getTypeSourceInfo()->getType()->getAsCXXRecordDecl()->getName();
|
|
else OS << I->getAnyMember()->getName();
|
|
|
|
OS << "(";
|
|
if (Expr *IE = I->getInit())
|
|
IE->printPretty(OS, &Helper, PrintingPolicy(Helper.getLangOpts()));
|
|
OS << ")";
|
|
|
|
if (I->isBaseInitializer())
|
|
OS << " (Base initializer)\n";
|
|
else if (I->isDelegatingInitializer())
|
|
OS << " (Delegating initializer)\n";
|
|
else OS << " (Member initializer)\n";
|
|
|
|
} else if (Optional<CFGAutomaticObjDtor> DE =
|
|
E.getAs<CFGAutomaticObjDtor>()) {
|
|
const VarDecl *VD = DE->getVarDecl();
|
|
Helper.handleDecl(VD, OS);
|
|
|
|
const Type* T = VD->getType().getTypePtr();
|
|
if (const ReferenceType* RT = T->getAs<ReferenceType>())
|
|
T = RT->getPointeeType().getTypePtr();
|
|
T = T->getBaseElementTypeUnsafe();
|
|
|
|
OS << ".~" << T->getAsCXXRecordDecl()->getName().str() << "()";
|
|
OS << " (Implicit destructor)\n";
|
|
|
|
} else if (Optional<CFGNewAllocator> NE = E.getAs<CFGNewAllocator>()) {
|
|
OS << "CFGNewAllocator(";
|
|
if (const CXXNewExpr *AllocExpr = NE->getAllocatorExpr())
|
|
AllocExpr->getType().print(OS, PrintingPolicy(Helper.getLangOpts()));
|
|
OS << ")\n";
|
|
} else if (Optional<CFGDeleteDtor> DE = E.getAs<CFGDeleteDtor>()) {
|
|
const CXXRecordDecl *RD = DE->getCXXRecordDecl();
|
|
if (!RD)
|
|
return;
|
|
CXXDeleteExpr *DelExpr =
|
|
const_cast<CXXDeleteExpr*>(DE->getDeleteExpr());
|
|
Helper.handledStmt(cast<Stmt>(DelExpr->getArgument()), OS);
|
|
OS << "->~" << RD->getName().str() << "()";
|
|
OS << " (Implicit destructor)\n";
|
|
} else if (Optional<CFGBaseDtor> BE = E.getAs<CFGBaseDtor>()) {
|
|
const CXXBaseSpecifier *BS = BE->getBaseSpecifier();
|
|
OS << "~" << BS->getType()->getAsCXXRecordDecl()->getName() << "()";
|
|
OS << " (Base object destructor)\n";
|
|
|
|
} else if (Optional<CFGMemberDtor> ME = E.getAs<CFGMemberDtor>()) {
|
|
const FieldDecl *FD = ME->getFieldDecl();
|
|
const Type *T = FD->getType()->getBaseElementTypeUnsafe();
|
|
OS << "this->" << FD->getName();
|
|
OS << ".~" << T->getAsCXXRecordDecl()->getName() << "()";
|
|
OS << " (Member object destructor)\n";
|
|
|
|
} else if (Optional<CFGTemporaryDtor> TE = E.getAs<CFGTemporaryDtor>()) {
|
|
const CXXBindTemporaryExpr *BT = TE->getBindTemporaryExpr();
|
|
OS << "~";
|
|
BT->getType().print(OS, PrintingPolicy(Helper.getLangOpts()));
|
|
OS << "() (Temporary object destructor)\n";
|
|
}
|
|
}
|
|
|
|
static void print_block(raw_ostream &OS, const CFG* cfg,
|
|
const CFGBlock &B,
|
|
StmtPrinterHelper &Helper, bool print_edges,
|
|
bool ShowColors) {
|
|
|
|
Helper.setBlockID(B.getBlockID());
|
|
|
|
// Print the header.
|
|
if (ShowColors)
|
|
OS.changeColor(raw_ostream::YELLOW, true);
|
|
|
|
OS << "\n [B" << B.getBlockID();
|
|
|
|
if (&B == &cfg->getEntry())
|
|
OS << " (ENTRY)]\n";
|
|
else if (&B == &cfg->getExit())
|
|
OS << " (EXIT)]\n";
|
|
else if (&B == cfg->getIndirectGotoBlock())
|
|
OS << " (INDIRECT GOTO DISPATCH)]\n";
|
|
else if (B.hasNoReturnElement())
|
|
OS << " (NORETURN)]\n";
|
|
else
|
|
OS << "]\n";
|
|
|
|
if (ShowColors)
|
|
OS.resetColor();
|
|
|
|
// Print the label of this block.
|
|
if (Stmt *Label = const_cast<Stmt*>(B.getLabel())) {
|
|
|
|
if (print_edges)
|
|
OS << " ";
|
|
|
|
if (LabelStmt *L = dyn_cast<LabelStmt>(Label))
|
|
OS << L->getName();
|
|
else if (CaseStmt *C = dyn_cast<CaseStmt>(Label)) {
|
|
OS << "case ";
|
|
C->getLHS()->printPretty(OS, &Helper,
|
|
PrintingPolicy(Helper.getLangOpts()));
|
|
if (C->getRHS()) {
|
|
OS << " ... ";
|
|
C->getRHS()->printPretty(OS, &Helper,
|
|
PrintingPolicy(Helper.getLangOpts()));
|
|
}
|
|
} else if (isa<DefaultStmt>(Label))
|
|
OS << "default";
|
|
else if (CXXCatchStmt *CS = dyn_cast<CXXCatchStmt>(Label)) {
|
|
OS << "catch (";
|
|
if (CS->getExceptionDecl())
|
|
CS->getExceptionDecl()->print(OS, PrintingPolicy(Helper.getLangOpts()),
|
|
0);
|
|
else
|
|
OS << "...";
|
|
OS << ")";
|
|
|
|
} else
|
|
llvm_unreachable("Invalid label statement in CFGBlock.");
|
|
|
|
OS << ":\n";
|
|
}
|
|
|
|
// Iterate through the statements in the block and print them.
|
|
unsigned j = 1;
|
|
|
|
for (CFGBlock::const_iterator I = B.begin(), E = B.end() ;
|
|
I != E ; ++I, ++j ) {
|
|
|
|
// Print the statement # in the basic block and the statement itself.
|
|
if (print_edges)
|
|
OS << " ";
|
|
|
|
OS << llvm::format("%3d", j) << ": ";
|
|
|
|
Helper.setStmtID(j);
|
|
|
|
print_elem(OS, Helper, *I);
|
|
}
|
|
|
|
// Print the terminator of this block.
|
|
if (B.getTerminator()) {
|
|
if (ShowColors)
|
|
OS.changeColor(raw_ostream::GREEN);
|
|
|
|
OS << " T: ";
|
|
|
|
Helper.setBlockID(-1);
|
|
|
|
PrintingPolicy PP(Helper.getLangOpts());
|
|
CFGBlockTerminatorPrint TPrinter(OS, &Helper, PP);
|
|
TPrinter.print(B.getTerminator());
|
|
OS << '\n';
|
|
|
|
if (ShowColors)
|
|
OS.resetColor();
|
|
}
|
|
|
|
if (print_edges) {
|
|
// Print the predecessors of this block.
|
|
if (!B.pred_empty()) {
|
|
const raw_ostream::Colors Color = raw_ostream::BLUE;
|
|
if (ShowColors)
|
|
OS.changeColor(Color);
|
|
OS << " Preds " ;
|
|
if (ShowColors)
|
|
OS.resetColor();
|
|
OS << '(' << B.pred_size() << "):";
|
|
unsigned i = 0;
|
|
|
|
if (ShowColors)
|
|
OS.changeColor(Color);
|
|
|
|
for (CFGBlock::const_pred_iterator I = B.pred_begin(), E = B.pred_end();
|
|
I != E; ++I, ++i) {
|
|
|
|
if (i % 10 == 8)
|
|
OS << "\n ";
|
|
|
|
CFGBlock *B = *I;
|
|
bool Reachable = true;
|
|
if (!B) {
|
|
Reachable = false;
|
|
B = I->getPossiblyUnreachableBlock();
|
|
}
|
|
|
|
OS << " B" << B->getBlockID();
|
|
if (!Reachable)
|
|
OS << "(Unreachable)";
|
|
}
|
|
|
|
if (ShowColors)
|
|
OS.resetColor();
|
|
|
|
OS << '\n';
|
|
}
|
|
|
|
// Print the successors of this block.
|
|
if (!B.succ_empty()) {
|
|
const raw_ostream::Colors Color = raw_ostream::MAGENTA;
|
|
if (ShowColors)
|
|
OS.changeColor(Color);
|
|
OS << " Succs ";
|
|
if (ShowColors)
|
|
OS.resetColor();
|
|
OS << '(' << B.succ_size() << "):";
|
|
unsigned i = 0;
|
|
|
|
if (ShowColors)
|
|
OS.changeColor(Color);
|
|
|
|
for (CFGBlock::const_succ_iterator I = B.succ_begin(), E = B.succ_end();
|
|
I != E; ++I, ++i) {
|
|
|
|
if (i % 10 == 8)
|
|
OS << "\n ";
|
|
|
|
CFGBlock *B = *I;
|
|
|
|
bool Reachable = true;
|
|
if (!B) {
|
|
Reachable = false;
|
|
B = I->getPossiblyUnreachableBlock();
|
|
}
|
|
|
|
if (B) {
|
|
OS << " B" << B->getBlockID();
|
|
if (!Reachable)
|
|
OS << "(Unreachable)";
|
|
}
|
|
else {
|
|
OS << " NULL";
|
|
}
|
|
}
|
|
|
|
if (ShowColors)
|
|
OS.resetColor();
|
|
OS << '\n';
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/// dump - A simple pretty printer of a CFG that outputs to stderr.
|
|
void CFG::dump(const LangOptions &LO, bool ShowColors) const {
|
|
print(llvm::errs(), LO, ShowColors);
|
|
}
|
|
|
|
/// print - A simple pretty printer of a CFG that outputs to an ostream.
|
|
void CFG::print(raw_ostream &OS, const LangOptions &LO, bool ShowColors) const {
|
|
StmtPrinterHelper Helper(this, LO);
|
|
|
|
// Print the entry block.
|
|
print_block(OS, this, getEntry(), Helper, true, ShowColors);
|
|
|
|
// Iterate through the CFGBlocks and print them one by one.
|
|
for (const_iterator I = Blocks.begin(), E = Blocks.end() ; I != E ; ++I) {
|
|
// Skip the entry block, because we already printed it.
|
|
if (&(**I) == &getEntry() || &(**I) == &getExit())
|
|
continue;
|
|
|
|
print_block(OS, this, **I, Helper, true, ShowColors);
|
|
}
|
|
|
|
// Print the exit block.
|
|
print_block(OS, this, getExit(), Helper, true, ShowColors);
|
|
OS << '\n';
|
|
OS.flush();
|
|
}
|
|
|
|
/// dump - A simply pretty printer of a CFGBlock that outputs to stderr.
|
|
void CFGBlock::dump(const CFG* cfg, const LangOptions &LO,
|
|
bool ShowColors) const {
|
|
print(llvm::errs(), cfg, LO, ShowColors);
|
|
}
|
|
|
|
/// print - A simple pretty printer of a CFGBlock that outputs to an ostream.
|
|
/// Generally this will only be called from CFG::print.
|
|
void CFGBlock::print(raw_ostream &OS, const CFG* cfg,
|
|
const LangOptions &LO, bool ShowColors) const {
|
|
StmtPrinterHelper Helper(cfg, LO);
|
|
print_block(OS, cfg, *this, Helper, true, ShowColors);
|
|
OS << '\n';
|
|
}
|
|
|
|
/// printTerminator - A simple pretty printer of the terminator of a CFGBlock.
|
|
void CFGBlock::printTerminator(raw_ostream &OS,
|
|
const LangOptions &LO) const {
|
|
CFGBlockTerminatorPrint TPrinter(OS, nullptr, PrintingPolicy(LO));
|
|
TPrinter.print(getTerminator());
|
|
}
|
|
|
|
Stmt *CFGBlock::getTerminatorCondition(bool StripParens) {
|
|
Stmt *Terminator = this->Terminator;
|
|
if (!Terminator)
|
|
return nullptr;
|
|
|
|
Expr *E = nullptr;
|
|
|
|
switch (Terminator->getStmtClass()) {
|
|
default:
|
|
break;
|
|
|
|
case Stmt::CXXForRangeStmtClass:
|
|
E = cast<CXXForRangeStmt>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::ForStmtClass:
|
|
E = cast<ForStmt>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::WhileStmtClass:
|
|
E = cast<WhileStmt>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::DoStmtClass:
|
|
E = cast<DoStmt>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::IfStmtClass:
|
|
E = cast<IfStmt>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::ChooseExprClass:
|
|
E = cast<ChooseExpr>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::IndirectGotoStmtClass:
|
|
E = cast<IndirectGotoStmt>(Terminator)->getTarget();
|
|
break;
|
|
|
|
case Stmt::SwitchStmtClass:
|
|
E = cast<SwitchStmt>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::BinaryConditionalOperatorClass:
|
|
E = cast<BinaryConditionalOperator>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::ConditionalOperatorClass:
|
|
E = cast<ConditionalOperator>(Terminator)->getCond();
|
|
break;
|
|
|
|
case Stmt::BinaryOperatorClass: // '&&' and '||'
|
|
E = cast<BinaryOperator>(Terminator)->getLHS();
|
|
break;
|
|
|
|
case Stmt::ObjCForCollectionStmtClass:
|
|
return Terminator;
|
|
}
|
|
|
|
if (!StripParens)
|
|
return E;
|
|
|
|
return E ? E->IgnoreParens() : nullptr;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// CFG Graphviz Visualization
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
|
#ifndef NDEBUG
|
|
static StmtPrinterHelper* GraphHelper;
|
|
#endif
|
|
|
|
void CFG::viewCFG(const LangOptions &LO) const {
|
|
#ifndef NDEBUG
|
|
StmtPrinterHelper H(this, LO);
|
|
GraphHelper = &H;
|
|
llvm::ViewGraph(this,"CFG");
|
|
GraphHelper = nullptr;
|
|
#endif
|
|
}
|
|
|
|
namespace llvm {
|
|
template<>
|
|
struct DOTGraphTraits<const CFG*> : public DefaultDOTGraphTraits {
|
|
|
|
DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
|
|
|
|
static std::string getNodeLabel(const CFGBlock *Node, const CFG* Graph) {
|
|
|
|
#ifndef NDEBUG
|
|
std::string OutSStr;
|
|
llvm::raw_string_ostream Out(OutSStr);
|
|
print_block(Out,Graph, *Node, *GraphHelper, false, false);
|
|
std::string& OutStr = Out.str();
|
|
|
|
if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
|
|
|
|
// Process string output to make it nicer...
|
|
for (unsigned i = 0; i != OutStr.length(); ++i)
|
|
if (OutStr[i] == '\n') { // Left justify
|
|
OutStr[i] = '\\';
|
|
OutStr.insert(OutStr.begin()+i+1, 'l');
|
|
}
|
|
|
|
return OutStr;
|
|
#else
|
|
return "";
|
|
#endif
|
|
}
|
|
};
|
|
} // end namespace llvm
|