| //===--- CFG.cpp - Classes for representing and building CFGs----*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the CFG and CFGBuilder classes for representing and |
| // building Control-Flow Graphs (CFGs) from ASTs. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Analysis/CFG.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Attr.h" |
| #include "clang/AST/CharUnits.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/PrettyPrinter.h" |
| #include "clang/AST/StmtVisitor.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/OwningPtr.h" |
| #include "llvm/ADT/SmallPtrSet.h" |
| #include "llvm/Support/Allocator.h" |
| #include "llvm/Support/Format.h" |
| #include "llvm/Support/GraphWriter.h" |
| #include "llvm/Support/SaveAndRestore.h" |
| |
| using namespace clang; |
| |
| namespace { |
| |
| static SourceLocation GetEndLoc(Decl *D) { |
| if (VarDecl *VD = dyn_cast<VarDecl>(D)) |
| if (Expr *Ex = VD->getInit()) |
| return Ex->getSourceRange().getEnd(); |
| return D->getLocation(); |
| } |
| |
| class CFGBuilder; |
| |
| /// The CFG builder uses a recursive algorithm to build the CFG. When |
| /// we process an expression, sometimes we know that we must add the |
| /// subexpressions as block-level expressions. For example: |
| /// |
| /// exp1 || exp2 |
| /// |
| /// When processing the '||' expression, we know that exp1 and exp2 |
| /// need to be added as block-level expressions, even though they |
| /// might not normally need to be. AddStmtChoice records this |
| /// contextual information. If AddStmtChoice is 'NotAlwaysAdd', then |
| /// the builder has an option not to add a subexpression as a |
| /// block-level expression. |
| /// |
| class AddStmtChoice { |
| public: |
| enum Kind { NotAlwaysAdd = 0, AlwaysAdd = 1 }; |
| |
| AddStmtChoice(Kind a_kind = NotAlwaysAdd) : kind(a_kind) {} |
| |
| bool alwaysAdd(CFGBuilder &builder, |
| const Stmt *stmt) const; |
| |
| /// Return a copy of this object, except with the 'always-add' bit |
| /// set as specified. |
| AddStmtChoice withAlwaysAdd(bool alwaysAdd) const { |
| return AddStmtChoice(alwaysAdd ? AlwaysAdd : NotAlwaysAdd); |
| } |
| |
| private: |
| Kind kind; |
| }; |
| |
| /// LocalScope - Node in tree of local scopes created for C++ implicit |
| /// destructor calls generation. It contains list of automatic variables |
| /// declared in the scope and link to position in previous scope this scope |
| /// began in. |
| /// |
| /// The process of creating local scopes is as follows: |
| /// - Init CFGBuilder::ScopePos with invalid position (equivalent for null), |
| /// - Before processing statements in scope (e.g. CompoundStmt) create |
| /// LocalScope object using CFGBuilder::ScopePos as link to previous scope |
| /// and set CFGBuilder::ScopePos to the end of new scope, |
| /// - On every occurrence of VarDecl increase CFGBuilder::ScopePos if it points |
| /// at this VarDecl, |
| /// - For every normal (without jump) end of scope add to CFGBlock destructors |
| /// for objects in the current scope, |
| /// - For every jump add to CFGBlock destructors for objects |
| /// between CFGBuilder::ScopePos and local scope position saved for jump |
| /// target. Thanks to C++ restrictions on goto jumps we can be sure that |
| /// jump target position will be on the path to root from CFGBuilder::ScopePos |
| /// (adding any variable that doesn't need constructor to be called to |
| /// LocalScope can break this assumption), |
| /// |
| class LocalScope { |
| public: |
| typedef BumpVector<VarDecl*> AutomaticVarsTy; |
| |
| /// const_iterator - Iterates local scope backwards and jumps to previous |
| /// scope on reaching the beginning of currently iterated scope. |
| class const_iterator { |
| const LocalScope* Scope; |
| |
| /// VarIter is guaranteed to be greater then 0 for every valid iterator. |
| /// Invalid iterator (with null Scope) has VarIter equal to 0. |
| unsigned VarIter; |
| |
| public: |
| /// Create invalid iterator. Dereferencing invalid iterator is not allowed. |
| /// Incrementing invalid iterator is allowed and will result in invalid |
| /// iterator. |
| const_iterator() |
| : Scope(NULL), VarIter(0) {} |
| |
| /// Create valid iterator. In case when S.Prev is an invalid iterator and |
| /// I is equal to 0, this will create invalid iterator. |
| const_iterator(const LocalScope& S, unsigned I) |
| : Scope(&S), VarIter(I) { |
| // Iterator to "end" of scope is not allowed. Handle it by going up |
| // in scopes tree possibly up to invalid iterator in the root. |
| if (VarIter == 0 && Scope) |
| *this = Scope->Prev; |
| } |
| |
| VarDecl *const* operator->() const { |
| assert (Scope && "Dereferencing invalid iterator is not allowed"); |
| assert (VarIter != 0 && "Iterator has invalid value of VarIter member"); |
| return &Scope->Vars[VarIter - 1]; |
| } |
| VarDecl *operator*() const { |
| return *this->operator->(); |
| } |
| |
| const_iterator &operator++() { |
| if (!Scope) |
| return *this; |
| |
| assert (VarIter != 0 && "Iterator has invalid value of VarIter member"); |
| --VarIter; |
| if (VarIter == 0) |
| *this = Scope->Prev; |
| return *this; |
| } |
| const_iterator operator++(int) { |
| const_iterator P = *this; |
| ++*this; |
| return P; |
| } |
| |
| bool operator==(const const_iterator &rhs) const { |
| return Scope == rhs.Scope && VarIter == rhs.VarIter; |
| } |
| bool operator!=(const const_iterator &rhs) const { |
| return !(*this == rhs); |
| } |
| |
| operator bool() const { |
| return *this != const_iterator(); |
| } |
| |
| int distance(const_iterator L); |
| }; |
| |
| friend class const_iterator; |
| |
| private: |
| BumpVectorContext ctx; |
| |
| /// Automatic variables in order of declaration. |
| AutomaticVarsTy Vars; |
| /// Iterator to variable in previous scope that was declared just before |
| /// begin of this scope. |
| const_iterator Prev; |
| |
| public: |
| /// Constructs empty scope linked to previous scope in specified place. |
| LocalScope(BumpVectorContext &ctx, const_iterator P) |
| : ctx(ctx), Vars(ctx, 4), Prev(P) {} |
| |
| /// Begin of scope in direction of CFG building (backwards). |
| const_iterator begin() const { return const_iterator(*this, Vars.size()); } |
| |
| void addVar(VarDecl *VD) { |
| Vars.push_back(VD, ctx); |
| } |
| }; |
| |
| /// distance - Calculates distance from this to L. L must be reachable from this |
| /// (with use of ++ operator). Cost of calculating the distance is linear w.r.t. |
| /// number of scopes between this and L. |
| int LocalScope::const_iterator::distance(LocalScope::const_iterator L) { |
| int D = 0; |
| const_iterator F = *this; |
| while (F.Scope != L.Scope) { |
| assert (F != const_iterator() |
| && "L iterator is not reachable from F iterator."); |
| D += F.VarIter; |
| F = F.Scope->Prev; |
| } |
| D += F.VarIter - L.VarIter; |
| return D; |
| } |
| |
| /// BlockScopePosPair - Structure for specifying position in CFG during its |
| /// build process. It consists of CFGBlock that specifies position in CFG graph |
| /// and LocalScope::const_iterator that specifies position in LocalScope graph. |
| struct BlockScopePosPair { |
| BlockScopePosPair() : block(0) {} |
| BlockScopePosPair(CFGBlock *b, LocalScope::const_iterator scopePos) |
| : block(b), scopePosition(scopePos) {} |
| |
| CFGBlock *block; |
| LocalScope::const_iterator scopePosition; |
| }; |
| |
| /// TryResult - a class representing a variant over the values |
| /// 'true', 'false', or 'unknown'. This is returned by tryEvaluateBool, |
| /// and is used by the CFGBuilder to decide if a branch condition |
| /// can be decided up front during CFG construction. |
| class TryResult { |
| int X; |
| public: |
| TryResult(bool b) : X(b ? 1 : 0) {} |
| TryResult() : X(-1) {} |
| |
| bool isTrue() const { return X == 1; } |
| bool isFalse() const { return X == 0; } |
| bool isKnown() const { return X >= 0; } |
| void negate() { |
| assert(isKnown()); |
| X ^= 0x1; |
| } |
| }; |
| |
| /// CFGBuilder - This class implements CFG construction from an AST. |
| /// The builder is stateful: an instance of the builder should be used to only |
| /// construct a single CFG. |
| /// |
| /// Example usage: |
| /// |
| /// CFGBuilder builder; |
| /// CFG* cfg = builder.BuildAST(stmt1); |
| /// |
| /// CFG construction is done via a recursive walk of an AST. We actually parse |
| /// the AST in reverse order so that the successor of a basic block is |
| /// constructed prior to its predecessor. This allows us to nicely capture |
| /// implicit fall-throughs without extra basic blocks. |
| /// |
| class CFGBuilder { |
| typedef BlockScopePosPair JumpTarget; |
| typedef BlockScopePosPair JumpSource; |
| |
| ASTContext *Context; |
| OwningPtr<CFG> cfg; |
| |
| CFGBlock *Block; |
| CFGBlock *Succ; |
| JumpTarget ContinueJumpTarget; |
| JumpTarget BreakJumpTarget; |
| CFGBlock *SwitchTerminatedBlock; |
| CFGBlock *DefaultCaseBlock; |
| CFGBlock *TryTerminatedBlock; |
| |
| // Current position in local scope. |
| LocalScope::const_iterator ScopePos; |
| |
| // LabelMap records the mapping from Label expressions to their jump targets. |
| typedef llvm::DenseMap<LabelDecl*, JumpTarget> LabelMapTy; |
| LabelMapTy LabelMap; |
| |
| // A list of blocks that end with a "goto" that must be backpatched to their |
| // resolved targets upon completion of CFG construction. |
| typedef std::vector<JumpSource> BackpatchBlocksTy; |
| BackpatchBlocksTy BackpatchBlocks; |
| |
| // A list of labels whose address has been taken (for indirect gotos). |
| typedef llvm::SmallPtrSet<LabelDecl*, 5> LabelSetTy; |
| LabelSetTy AddressTakenLabels; |
| |
| bool badCFG; |
| const CFG::BuildOptions &BuildOpts; |
| |
| // State to track for building switch statements. |
| bool switchExclusivelyCovered; |
| Expr::EvalResult *switchCond; |
| |
| CFG::BuildOptions::ForcedBlkExprs::value_type *cachedEntry; |
| const Stmt *lastLookup; |
| |
| // Caches boolean evaluations of expressions to avoid multiple re-evaluations |
| // during construction of branches for chained logical operators. |
| typedef llvm::DenseMap<Expr *, TryResult> CachedBoolEvalsTy; |
| CachedBoolEvalsTy CachedBoolEvals; |
| |
| public: |
| explicit CFGBuilder(ASTContext *astContext, |
| const CFG::BuildOptions &buildOpts) |
| : Context(astContext), cfg(new CFG()), // crew a new CFG |
| Block(NULL), Succ(NULL), |
| SwitchTerminatedBlock(NULL), DefaultCaseBlock(NULL), |
| TryTerminatedBlock(NULL), badCFG(false), BuildOpts(buildOpts), |
| switchExclusivelyCovered(false), switchCond(0), |
| cachedEntry(0), lastLookup(0) {} |
| |
| // buildCFG - Used by external clients to construct the CFG. |
| CFG* buildCFG(const Decl *D, Stmt *Statement); |
| |
| bool alwaysAdd(const Stmt *stmt); |
| |
| private: |
| // Visitors to walk an AST and construct the CFG. |
| CFGBlock *VisitAddrLabelExpr(AddrLabelExpr *A, AddStmtChoice asc); |
| CFGBlock *VisitBinaryOperator(BinaryOperator *B, AddStmtChoice asc); |
| CFGBlock *VisitBreakStmt(BreakStmt *B); |
| CFGBlock *VisitCallExpr(CallExpr *C, AddStmtChoice asc); |
| CFGBlock *VisitCaseStmt(CaseStmt *C); |
| CFGBlock *VisitChooseExpr(ChooseExpr *C, AddStmtChoice asc); |
| CFGBlock *VisitCompoundStmt(CompoundStmt *C); |
| CFGBlock *VisitConditionalOperator(AbstractConditionalOperator *C, |
| AddStmtChoice asc); |
| CFGBlock *VisitContinueStmt(ContinueStmt *C); |
| CFGBlock *VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E, |
| AddStmtChoice asc); |
| CFGBlock *VisitCXXCatchStmt(CXXCatchStmt *S); |
| CFGBlock *VisitCXXConstructExpr(CXXConstructExpr *C, AddStmtChoice asc); |
| CFGBlock *VisitCXXForRangeStmt(CXXForRangeStmt *S); |
| CFGBlock *VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E, |
| AddStmtChoice asc); |
| CFGBlock *VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C, |
| AddStmtChoice asc); |
| CFGBlock *VisitCXXThrowExpr(CXXThrowExpr *T); |
| CFGBlock *VisitCXXTryStmt(CXXTryStmt *S); |
| CFGBlock *VisitDeclStmt(DeclStmt *DS); |
| CFGBlock *VisitDeclSubExpr(DeclStmt *DS); |
| CFGBlock *VisitDefaultStmt(DefaultStmt *D); |
| CFGBlock *VisitDoStmt(DoStmt *D); |
| CFGBlock *VisitExprWithCleanups(ExprWithCleanups *E, AddStmtChoice asc); |
| CFGBlock *VisitForStmt(ForStmt *F); |
| CFGBlock *VisitGotoStmt(GotoStmt *G); |
| CFGBlock *VisitIfStmt(IfStmt *I); |
| CFGBlock *VisitImplicitCastExpr(ImplicitCastExpr *E, AddStmtChoice asc); |
| CFGBlock *VisitIndirectGotoStmt(IndirectGotoStmt *I); |
| CFGBlock *VisitLabelStmt(LabelStmt *L); |
| CFGBlock *VisitLambdaExpr(LambdaExpr *E, AddStmtChoice asc); |
| CFGBlock *VisitLogicalOperator(BinaryOperator *B); |
| std::pair<CFGBlock *, CFGBlock *> VisitLogicalOperator(BinaryOperator *B, |
| Stmt *Term, |
| CFGBlock *TrueBlock, |
| CFGBlock *FalseBlock); |
| CFGBlock *VisitMemberExpr(MemberExpr *M, AddStmtChoice asc); |
| CFGBlock *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S); |
| CFGBlock *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S); |
| CFGBlock *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S); |
| CFGBlock *VisitObjCAtTryStmt(ObjCAtTryStmt *S); |
| CFGBlock *VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S); |
| CFGBlock *VisitObjCForCollectionStmt(ObjCForCollectionStmt *S); |
| CFGBlock *VisitPseudoObjectExpr(PseudoObjectExpr *E); |
| CFGBlock *VisitReturnStmt(ReturnStmt *R); |
| CFGBlock *VisitStmtExpr(StmtExpr *S, AddStmtChoice asc); |
| CFGBlock *VisitSwitchStmt(SwitchStmt *S); |
| CFGBlock *VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E, |
| AddStmtChoice asc); |
| CFGBlock *VisitUnaryOperator(UnaryOperator *U, AddStmtChoice asc); |
| CFGBlock *VisitWhileStmt(WhileStmt *W); |
| |
| CFGBlock *Visit(Stmt *S, AddStmtChoice asc = AddStmtChoice::NotAlwaysAdd); |
| CFGBlock *VisitStmt(Stmt *S, AddStmtChoice asc); |
| CFGBlock *VisitChildren(Stmt *S); |
| CFGBlock *VisitNoRecurse(Expr *E, AddStmtChoice asc); |
| |
| // Visitors to walk an AST and generate destructors of temporaries in |
| // full expression. |
| CFGBlock *VisitForTemporaryDtors(Stmt *E, bool BindToTemporary = false); |
| CFGBlock *VisitChildrenForTemporaryDtors(Stmt *E); |
| CFGBlock *VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E); |
| CFGBlock *VisitCXXBindTemporaryExprForTemporaryDtors(CXXBindTemporaryExpr *E, |
| bool BindToTemporary); |
| CFGBlock * |
| VisitConditionalOperatorForTemporaryDtors(AbstractConditionalOperator *E, |
| bool BindToTemporary); |
| |
| // NYS == Not Yet Supported |
| CFGBlock *NYS() { |
| badCFG = true; |
| return Block; |
| } |
| |
| void autoCreateBlock() { if (!Block) Block = createBlock(); } |
| CFGBlock *createBlock(bool add_successor = true); |
| CFGBlock *createNoReturnBlock(); |
| |
| CFGBlock *addStmt(Stmt *S) { |
| return Visit(S, AddStmtChoice::AlwaysAdd); |
| } |
| CFGBlock *addInitializer(CXXCtorInitializer *I); |
| void addAutomaticObjDtors(LocalScope::const_iterator B, |
| LocalScope::const_iterator E, Stmt *S); |
| void addImplicitDtorsForDestructor(const CXXDestructorDecl *DD); |
| |
| // Local scopes creation. |
| LocalScope* createOrReuseLocalScope(LocalScope* Scope); |
| |
| void addLocalScopeForStmt(Stmt *S); |
| LocalScope* addLocalScopeForDeclStmt(DeclStmt *DS, LocalScope* Scope = NULL); |
| LocalScope* addLocalScopeForVarDecl(VarDecl *VD, LocalScope* Scope = NULL); |
| |
| void addLocalScopeAndDtors(Stmt *S); |
| |
| // Interface to CFGBlock - adding CFGElements. |
| void appendStmt(CFGBlock *B, const Stmt *S) { |
| if (alwaysAdd(S) && cachedEntry) |
| cachedEntry->second = B; |
| |
| // All block-level expressions should have already been IgnoreParens()ed. |
| assert(!isa<Expr>(S) || cast<Expr>(S)->IgnoreParens() == S); |
| B->appendStmt(const_cast<Stmt*>(S), cfg->getBumpVectorContext()); |
| } |
| void appendInitializer(CFGBlock *B, CXXCtorInitializer *I) { |
| B->appendInitializer(I, cfg->getBumpVectorContext()); |
| } |
| void appendBaseDtor(CFGBlock *B, const CXXBaseSpecifier *BS) { |
| B->appendBaseDtor(BS, cfg->getBumpVectorContext()); |
| } |
| void appendMemberDtor(CFGBlock *B, FieldDecl *FD) { |
| 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 prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk, |
| LocalScope::const_iterator B, LocalScope::const_iterator E); |
| |
| void addSuccessor(CFGBlock *B, CFGBlock *S) { |
| B->addSuccessor(S, cfg->getBumpVectorContext()); |
| } |
| |
| /// 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(); |
| } |
| } |
| |
| return TryResult(); |
| } |
| } |
| |
| 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 == 0); |
| return shouldAdd; |
| } |
| |
| CFG::BuildOptions::ForcedBlkExprs::iterator itr = fb->find(stmt); |
| if (itr == fb->end()) { |
| cachedEntry = 0; |
| 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 0; |
| } |
| |
| /// 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 NULL; |
| |
| // 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 = NULL; // 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 NULL; |
| |
| // 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 NULL; |
| } |
| } |
| |
| 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; |
| 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.take(); |
| } |
| |
| /// 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()); |
| 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 (cast<FunctionType>(Dtor->getType())->getNoReturnAttr()) |
| 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 (CXXRecordDecl::base_class_const_iterator VI = RD->vbases_begin(), |
| VE = RD->vbases_end(); VI != VE; ++VI) { |
| const CXXRecordDecl *CD = VI->getType()->getAsCXXRecordDecl(); |
| if (!CD->hasTrivialDestructor()) { |
| autoCreateBlock(); |
| appendBaseDtor(Block, VI); |
| } |
| } |
| |
| // Before virtual bases destroy direct base objects. |
| for (CXXRecordDecl::base_class_const_iterator BI = RD->bases_begin(), |
| BE = RD->bases_end(); BI != BE; ++BI) { |
| if (!BI->isVirtual()) { |
| const CXXRecordDecl *CD = BI->getType()->getAsCXXRecordDecl(); |
| if (!CD->hasTrivialDestructor()) { |
| autoCreateBlock(); |
| appendBaseDtor(Block, BI); |
| } |
| } |
| } |
| |
| // First destroy member objects. |
| for (CXXRecordDecl::field_iterator FI = RD->field_begin(), |
| FE = RD->field_end(); FI != FE; ++FI) { |
| // 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 = 0; |
| |
| // For compound statement we will be creating explicit scope. |
| if (CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) { |
| for (CompoundStmt::body_iterator BI = CS->body_begin(), BE = CS->body_end() |
| ; BI != BE; ++BI) { |
| 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 (DeclStmt::decl_iterator DI = DS->decl_begin(), DE = DS->decl_end() |
| ; DI != DE; ++DI) { |
| 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()) { |
| if (!VD->extendsLifetimeOfTemporary()) |
| return Scope; |
| |
| QT = getReferenceInitTemporaryType(*Context, VD->getInit()); |
| } |
| |
| // 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 0; |
| } |
| |
| 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: |
| // 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> |
| return VisitStmt(S, asc); |
| |
| case Stmt::CXXBindTemporaryExprClass: |
| return VisitCXXBindTemporaryExpr(cast<CXXBindTemporaryExpr>(S), asc); |
| |
| case Stmt::CXXConstructExprClass: |
| return VisitCXXConstructExpr(cast<CXXConstructExpr>(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 *Terminator) { |
| CFGBlock *lastBlock = Block; |
| for (Stmt::child_range I = Terminator->children(); I; ++I) |
| if (Stmt *child = *I) |
| if (CFGBlock *b = Visit(child)) |
| lastBlock = b; |
| |
| return lastBlock; |
| } |
| |
| 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 0; |
| |
| return VisitLogicalOperator(B, 0, 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()) { |
| llvm::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); |
| addSuccessor(RHSBlock, KnownVal.isFalse() ? NULL : TrueBlock); |
| addSuccessor(RHSBlock, KnownVal.isTrue() ? NULL : FalseBlock); |
| } |
| |
| Block = RHSBlock; |
| RHSBlock = addStmt(RHS); |
| } |
| while (false); |
| |
| if (badCFG) |
| return std::make_pair((CFGBlock*)0, (CFGBlock*)0); |
| |
| // 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((CFGBlock*)0, (CFGBlock*)0); |
| |
| // See if this is a known constant. |
| TryResult KnownVal = tryEvaluateBool(LHS); |
| |
| // Now link the LHSBlock with RHSBlock. |
| if (B->getOpcode() == BO_LOr) { |
| addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : TrueBlock); |
| addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : RHSBlock); |
| } else { |
| assert(B->getOpcode() == BO_LAnd); |
| addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock); |
| addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : FalseBlock); |
| } |
| |
| 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 0; |
| |
| // 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 (FunctionDecl *FD = C->getDirectCallee()) { |
| if (FD->hasAttr<NoReturnAttr>()) |
| NoReturn = true; |
| if (FD->hasAttr<NoThrowAttr>()) |
| AddEHEdge = false; |
| } |
| |
| if (!CanThrow(C->getCallee(), *Context)) |
| AddEHEdge = false; |
| |
| if (!NoReturn && !AddEHEdge) |
| return VisitStmt(C, asc.withAlwaysAdd(true)); |
| |
| if (Block) { |
| Succ = Block; |
| if (badCFG) |
| return 0; |
| } |
| |
| 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 0; |
| |
| AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true); |
| Succ = ConfluenceBlock; |
| Block = NULL; |
| CFGBlock *LHSBlock = Visit(C->getLHS(), alwaysAdd); |
| if (badCFG) |
| return 0; |
| |
| Succ = ConfluenceBlock; |
| Block = NULL; |
| CFGBlock *RHSBlock = Visit(C->getRHS(), alwaysAdd); |
| if (badCFG) |
| return 0; |
| |
| Block = createBlock(false); |
| // See if this is a known constant. |
| const TryResult& KnownVal = tryEvaluateBool(C->getCond()); |
| addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock); |
| addSuccessor(Block, KnownVal.isTrue() ? NULL : 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 NULL; |
| } |
| |
| return LastBlock; |
| } |
| |
| CFGBlock *CFGBuilder::VisitConditionalOperator(AbstractConditionalOperator *C, |
| AddStmtChoice asc) { |
| const BinaryConditionalOperator *BCO = dyn_cast<BinaryConditionalOperator>(C); |
| const OpaqueValueExpr *opaqueValue = (BCO ? BCO->getOpaqueValue() : NULL); |
| |
| // Create the confluence block that will "merge" the results of the ternary |
| // expression. |
| CFGBlock *ConfluenceBlock = Block ? Block : createBlock(); |
| appendStmt(ConfluenceBlock, C); |
| if (badCFG) |
| return 0; |
| |
| 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 = NULL; |
| CFGBlock *LHSBlock = 0; |
| const Expr *trueExpr = C->getTrueExpr(); |
| if (trueExpr != opaqueValue) { |
| LHSBlock = Visit(C->getTrueExpr(), alwaysAdd); |
| if (badCFG) |
| return 0; |
| Block = NULL; |
| } |
| else |
| LHSBlock = ConfluenceBlock; |
| |
| // Create the block for the RHS expression. |
| Succ = ConfluenceBlock; |
| CFGBlock *RHSBlock = Visit(C->getFalseExpr(), alwaysAdd); |
| if (badCFG) |
| return 0; |
| |
| // 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, KnownVal.isFalse() ? NULL : LHSBlock); |
| addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock); |
| 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 = 0; |
| |
| // 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)); |
| |
| // 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."); |
| Decl *D = DS->getSingleDecl(); |
| |
| if (isa<StaticAssertDecl>(D)) { |
| // static_asserts aren't added to the CFG because they do not impact |
| // runtime semantics. |
| return Block; |
| } |
| |
| VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl()); |
| |
| if (!VD) { |
| autoCreateBlock(); |
| appendStmt(Block, DS); |
| return Block; |
| } |
| |
| bool IsReference = false; |
| bool HasTemporaries = false; |
| |
| // 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 != 0; VA = FindVA(VA->getElementType().getTypePtr())) { |
| if (CFGBlock *newBlock = addStmt(VA->getSizeExpr())) |
| LastBlock = newBlock; |
| } |
| |
| // Remove variable from local scope. |
| if (ScopePos && VD == *ScopePos) |
| ++ScopePos; |
| |
| return Block ? Block : LastBlock; |
| } |
| |
| 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 0; |
| } |
| |
| // 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 = NULL; |
| |
| // 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 0; |
| } |
| } |
| |
| // Process the true branch. |
| CFGBlock *ThenBlock; |
| { |
| Stmt *Then = I->getThen(); |
| assert(Then); |
| SaveAndRestore<CFGBlock*> sv(Succ); |
| Block = NULL; |
| |
| // 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 0; |
| } |
| } |
| |
| // 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()); |
| |
| // Now add the successors. |
| addSuccessor(Block, KnownVal.isFalse() ? NULL : ThenBlock); |
| addSuccessor(Block, KnownVal.isTrue()? NULL : ElseBlock); |
| |
| // 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 both the IfStmt |
| // and the condition variable initialization to the CFG. |
| if (VarDecl *VD = I->getConditionVariable()) { |
| if (Expr *Init = VD->getInit()) { |
| autoCreateBlock(); |
| appendStmt(Block, I->getConditionVariableDeclStmt()); |
| LastBlock = addStmt(Init); |
| } |
| } |
| |
| 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); |
| |
| // The Exit block is the only successor. |
| addAutomaticObjDtors(ScopePos, LocalScope::const_iterator(), R); |
| 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 0; |
| |
| // We set Block to NULL to allow lazy creation of a new block (if necessary); |
| Block = NULL; |
| |
| // 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 != 0) |
| 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 = NULL; |
| |
| // 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 0; |
| 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 = 0, *TransitionBlock = 0; |
| |
| // 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 0; |
| Block = 0; |
| } |
| |
| // 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 0; |
| } |
| |
| // 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 = 0, *ExitConditionBlock = 0; |
| |
| 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() : 0)) |
| if (Cond->isLogicalOp()) { |
| llvm::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 0; |
| |
| KnownVal = tryEvaluateBool(C); |
| } |
| |
| // Add the loop body entry as a successor to the condition. |
| addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock); |
| // Link up the condition block with the code that follows the loop. (the |
| // false branch). |
| addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : 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 = NULL; |
| 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 = 0; |
| |
| if (Block) { |
| if (badCFG) |
| return 0; |
| LoopSuccessor = Block; |
| Block = 0; |
| } 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 0; |
| Block = 0; |
| } |
| |
| // 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_Succ(Succ); |
| SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget), |
| save_break(BreakJumpTarget); |
| |
| BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos); |
| ContinueJumpTarget = JumpTarget(EntryConditionBlock, ScopePos); |
| |
| CFGBlock *BodyBlock = addStmt(S->getBody()); |
| |
| if (!BodyBlock) |
| BodyBlock = EntryConditionBlock; // can happen for "for (X in Y) ;" |
| else if (Block) { |
| if (badCFG) |
| return 0; |
| } |
| |
| // 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 0; |
| |
| Block = 0; |
| 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 = NULL; |
| |
| // 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 0; |
| LoopSuccessor = Block; |
| Block = 0; |
| } else { |
| LoopSuccessor = Succ; |
| } |
| |
| CFGBlock *BodyBlock = 0, *TransitionBlock = 0; |
| |
| // 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 0; |
| } |
| |
| // 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 = 0, *ExitConditionBlock = 0; |
| |
| 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()) { |
| llvm::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 0; |
| |
| // 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() ? NULL : BodyBlock); |
| // Link up the condition block with the code that follows the loop. (the |
| // false branch). |
| addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : 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 = NULL; |
| |
| // 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 0; |
| |
| // 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 0; |
| |
| // 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 = NULL; |
| |
| // "do...while" is a control-flow statement. Thus we stop processing the |
| // current block. |
| if (Block) { |
| if (badCFG) |
| return 0; |
| 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 0; |
| } |
| } |
| |
| // 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 = NULL; |
| { |
| 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 = NULL; |
| |
| // 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 0; |
| } |
| |
| 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 = NULL; |
| 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, NULL); |
| } |
| |
| // Link up the condition block with the code that follows the loop. |
| // (the false branch). |
| addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : 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 = NULL; |
| |
| // 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 0; |
| |
| // 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 != 0; 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 = NULL; |
| |
| // 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 0; |
| 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 = NULL; |
| |
| // 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 : 0); |
| |
| // 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 0; |
| } |
| |
| // 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). |
| addSuccessor(SwitchTerminatedBlock, |
| switchExclusivelyCovered || Terminator->isAllEnumCasesCovered() |
| ? 0 : DefaultCaseBlock); |
| |
| // 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 = 0, *LastBlock = 0; |
| |
| 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 : 0); |
| |
| 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 0; |
| |
| // Add this block to the list of successors for the block with the switch |
| // statement. |
| assert(SwitchTerminatedBlock); |
| addSuccessor(SwitchTerminatedBlock, |
| shouldAddCase(switchExclusivelyCovered, switchCond, |
| CS, *Context) |
| ? CaseBlock : 0); |
| |
| // We set Block to NULL to allow lazy creation of a new block (if necessary) |
| Block = NULL; |
| |
| 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 0; |
| |
| // 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 = NULL; |
| |
| // 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 = NULL; |
| |
| if (Block) { |
| if (badCFG) |
| return 0; |
| 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() == 0) { |
| HasCatchAll = true; |
| } |
| Block = NULL; |
| CFGBlock *CatchBlock = VisitCXXCatchStmt(CS); |
| if (CatchBlock == 0) |
| return 0; |
| // 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 = NULL; |
| 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 0; |
| |
| // We set Block to NULL to allow lazy creation of a new block (if necessary) |
| Block = NULL; |
| |
| 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 = NULL; |
| if (Block) { |
| if (badCFG) |
| return 0; |
| 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 0; |
| 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 = 0; |
| 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 0; |
| Block = 0; |
| |
| |
| // 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 0; |
| CFGBlock *LoopVarStmtBlock = addStmt(S->getLoopVarStmt()); |
| if (badCFG) |
| return 0; |
| |
| // This new body block is a successor to our condition block. |
| addSuccessor(ConditionBlock, KnownVal.isFalse() ? 0 : LoopVarStmtBlock); |
| } |
| |
| // Link up the condition block with the code that follows the loop (the |
| // false branch). |
| addSuccessor(ConditionBlock, KnownVal.isTrue() ? 0 : 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::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 0; |
| |
| 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 NULL; |
| } |
| 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. Because there's no reverse iterator for children must to reverse |
| // them in helper vector. |
| typedef SmallVector<Stmt *, 4> ChildrenVect; |
| ChildrenVect ChildrenRev; |
| for (Stmt::child_range I = E->children(); I; ++I) { |
| if (*I) ChildrenRev.push_back(*I); |
| } |
| |
| CFGBlock *B = Block; |
| for (ChildrenVect::reverse_iterator I = ChildrenRev.rbegin(), |
| L = ChildrenRev.rend(); I != L; ++I) { |
| if (CFGBlock *R = VisitForTemporaryDtors(*I)) |
| 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 NULL; |
| |
| Succ = ConfluenceBlock; |
| Block = NULL; |
| CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS()); |
| |
| if (RHSBlock) { |
| if (badCFG) |
| return NULL; |
| |
| // 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() ? NULL : ConfluenceBlock); |
| addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock); |
| } else { |
| assert (E->getOpcode() == BO_LAnd); |
| addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock); |
| addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : 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 (cast<FunctionType>(Dtor->getType())->getNoReturnAttr()) |
| 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 NULL; |
| if (BinaryConditionalOperator *BCO |
| = dyn_cast<BinaryConditionalOperator>(E)) { |
| ConfluenceBlock = VisitForTemporaryDtors(BCO->getCommon()); |
| if (badCFG) |
| return NULL; |
| } |
| |
| // Try to add block with destructors for LHS expression. |
| CFGBlock *LHSBlock = NULL; |
| Succ = ConfluenceBlock; |
| Block = NULL; |
| LHSBlock = VisitForTemporaryDtors(E->getTrueExpr(), BindToTemporary); |
| if (badCFG) |
| return NULL; |
| |
| // Try to add block with destructors for RHS expression; |
| Succ = ConfluenceBlock; |
| Block = NULL; |
| CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getFalseExpr(), |
| BindToTemporary); |
| if (badCFG) |
| return NULL; |
| |
| 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)); |
| |
| // See if this is a known constant. |
| const TryResult &KnownVal = tryEvaluateBool(E->getCond()); |
| |
| if (LHSBlock) { |
| addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock); |
| } else if (KnownVal.isFalse()) { |
| addSuccessor(Block, NULL); |
| } else { |
| addSuccessor(Block, ConfluenceBlock); |
| std::reverse(ConfluenceBlock->pred_begin(), ConfluenceBlock->pred_end()); |
| } |
| |
| if (!RHSBlock) |
| RHSBlock = ConfluenceBlock; |
| addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock); |
| |
| 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::Invalid: |
| case CFGElement::Statement: |
| case CFGElement::Initializer: |
| llvm_unreachable("getDestructorDecl should only be used with " |
| "ImplicitDtors"); |
| case CFGElement::AutomaticObjectDtor: { |
| const VarDecl *var = cast<CFGAutomaticObjDtor>(this)->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::TemporaryDtor: { |
| const CXXBindTemporaryExpr *bindExpr = |
| cast<CFGTemporaryDtor>(this)->getBindTemporaryExpr(); |
| const CXXTemporary *temp = bindExpr->getTemporary(); |
| return temp->getDestructor(); |
| } |
| case CFGElement::BaseDtor: |
| case CFGElement::MemberDtor: |
| |
| // Not yet supported. |
| return 0; |
| } |
| llvm_unreachable("getKind() returned bogus value"); |
| } |
| |
| bool CFGImplicitDtor::isNoReturn(ASTContext &astContext) const { |
| if (const CXXDestructorDecl *decl = getDestructorDecl(astContext)) { |
| QualType ty = decl->getType(); |
| return cast<FunctionType>(ty)->getNoReturnAttr(); |
| } |
| return false; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // CFG: Queries for BlkExprs. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| typedef llvm::DenseMap<const Stmt*,unsigned> BlkExprMapTy; |
| } |
| |
| static void FindSubExprAssignments(const Stmt *S, |
| llvm::SmallPtrSet<const Expr*,50>& Set) { |
| if (!S) |
| return; |
| |
| for (Stmt::const_child_range I = S->children(); I; ++I) { |
| const Stmt *child = *I; |
| if (!child) |
| continue; |
| |
| if (const BinaryOperator* B = dyn_cast<BinaryOperator>(child)) |
| if (B->isAssignmentOp()) Set.insert(B); |
| |
| FindSubExprAssignments(child, Set); |
| } |
| } |
| |
| static BlkExprMapTy* PopulateBlkExprMap(CFG& cfg) { |
| BlkExprMapTy* M = new BlkExprMapTy(); |
| |
| // Look for assignments that are used as subexpressions. These are the only |
| // assignments that we want to *possibly* register as a block-level |
| // expression. Basically, if an assignment occurs both in a subexpression and |
| // at the block-level, it is a block-level expression. |
| llvm::SmallPtrSet<const Expr*,50> SubExprAssignments; |
| |
| for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I) |
| for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI) |
| if (const CFGStmt *S = BI->getAs<CFGStmt>()) |
| FindSubExprAssignments(S->getStmt(), SubExprAssignments); |
| |
| for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I) { |
| |
| // Iterate over the statements again on identify the Expr* and Stmt* at the |
| // block-level that are block-level expressions. |
| |
| for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI) { |
| const CFGStmt *CS = BI->getAs<CFGStmt>(); |
| if (!CS) |
| continue; |
| if (const Expr *Exp = dyn_cast<Expr>(CS->getStmt())) { |
| assert((Exp->IgnoreParens() == Exp) && "No parens on block-level exps"); |
| |
| if (const BinaryOperator* B = dyn_cast<BinaryOperator>(Exp)) { |
| // Assignment expressions that are not nested within another |
| // expression are really "statements" whose value is never used by |
| // another expression. |
| if (B->isAssignmentOp() && !SubExprAssignments.count(Exp)) |
| continue; |
| } else if (const StmtExpr *SE = dyn_cast<StmtExpr>(Exp)) { |
| // Special handling for statement expressions. The last statement in |
| // the statement expression is also a block-level expr. |
| const CompoundStmt *C = SE->getSubStmt(); |
| if (!C->body_empty()) { |
| const Stmt *Last = C->body_back(); |
| if (const Expr *LastEx = dyn_cast<Expr>(Last)) |
| Last = LastEx->IgnoreParens(); |
| unsigned x = M->size(); |
| (*M)[Last] = x; |
| } |
| } |
| |
| unsigned x = M->size(); |
| (*M)[Exp] = x; |
| } |
| } |
| |
| // Look at terminators. The condition is a block-level expression. |
| |
| Stmt *S = (*I)->getTerminatorCondition(); |
| |
| if (S && M->find(S) == M->end()) { |
| unsigned x = M->size(); |
| (*M)[S] = x; |
| } |
| } |
| |
| return M; |
| } |
| |
| CFG::BlkExprNumTy CFG::getBlkExprNum(const Stmt *S) { |
| assert(S != NULL); |
| if (!BlkExprMap) { BlkExprMap = (void*) PopulateBlkExprMap(*this); } |
| |
| BlkExprMapTy* M = reinterpret_cast<BlkExprMapTy*>(BlkExprMap); |
| BlkExprMapTy::iterator I = M->find(S); |
| return (I == M->end()) ? CFG::BlkExprNumTy() : CFG::BlkExprNumTy(I->second); |
| } |
| |
| unsigned CFG::getNumBlkExprs() { |
| if (const BlkExprMapTy* M = reinterpret_cast<const BlkExprMapTy*>(BlkExprMap)) |
| return M->size(); |
| |
| // We assume callers interested in the number of BlkExprs will want |
| // the map constructed if it doesn't already exist. |
| BlkExprMap = (void*) PopulateBlkExprMap(*this); |
| return reinterpret_cast<BlkExprMapTy*>(BlkExprMap)->size(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Filtered walking of the CFG. |
| //===----------------------------------------------------------------------===// |
| |
| bool CFGBlock::FilterEdge(const CFGBlock::FilterOptions &F, |
| const CFGBlock *From, const CFGBlock *To) { |
| |
| if (To && 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; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Cleanup: CFG dstor. |
| //===----------------------------------------------------------------------===// |
| |
| CFG::~CFG() { |
| delete reinterpret_cast<const BlkExprMapTy*>(BlkExprMap); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // 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 (const 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; } |
| |
| virtual bool handledStmt(Stmt *S, raw_ostream &OS) { |
| 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) {} |
| |
| void VisitIfStmt(IfStmt *I) { |
| OS << "if "; |
| I->getCond()->printPretty(OS,Helper,Policy); |
| } |
| |
| // Default case. |
| void VisitStmt(Stmt *Terminator) { |
| Terminator->printPretty(OS, Helper, Policy); |
| } |
| |
| 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); |
| } |
| }; |
| } // end anonymous namespace |
| |
| static void print_elem(raw_ostream &OS, StmtPrinterHelper* Helper, |
| const CFGElement &E) { |
| if (const CFGStmt *CS = E.getAs<CFGStmt>()) { |
| const Stmt *S = CS->getStmt(); |
| |
| if (Helper) { |
| |
| // 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 (const CFGInitializer *IE = E.getAs<CFGInitializer>()) { |
| const CXXCtorInitializer *I = IE->getInitializer(); |
| if (I->isBaseInitializer()) |
| OS << I->getBaseClass()->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 OS << " (Member initializer)\n"; |
| |
| } else if (const 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 (const CFGBaseDtor *BE = E.getAs<CFGBaseDtor>()) { |
| const CXXBaseSpecifier *BS = BE->getBaseSpecifier(); |
| OS << "~" << BS->getType()->getAsCXXRecordDecl()->getName() << "()"; |
| OS << " (Base object destructor)\n"; |
| |
| } else if (const 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 (const CFGTemporaryDtor *TE = E.getAs<CFGTemporaryDtor>()) { |
| const CXXBindTemporaryExpr *BT = TE->getBindTemporaryExpr(); |
| OS << "~" << BT->getType()->getAsCXXRecordDecl()->getName() << "()"; |
| 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) { |
| |
| if (Helper) |
| 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 |
| 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) << ": "; |
| |
| if (Helper) |
| 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: "; |
| |
| if (Helper) Helper->setBlockID(-1); |
| |
| PrintingPolicy PP(Helper ? Helper->getLangOpts() : LangOptions()); |
| CFGBlockTerminatorPrint TPrinter(OS, Helper, PP); |
| TPrinter.Visit(const_cast<Stmt*>(B.getTerminator().getStmt())); |
| 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 "; |
| |
| OS << " B" << (*I)->getBlockID(); |
| } |
| |
| 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 "; |
| |
| if (*I) |
| OS << " B" << (*I)->getBlockID(); |
| 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, NULL, PrintingPolicy(LO)); |
| TPrinter.Visit(const_cast<Stmt*>(getTerminator().getStmt())); |
| } |
| |
| Stmt *CFGBlock::getTerminatorCondition() { |
| Stmt *Terminator = this->Terminator; |
| if (!Terminator) |
| return NULL; |
| |
| Expr *E = NULL; |
| |
| switch (Terminator->getStmtClass()) { |
| default: |
| 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; |
| } |
| |
| return E ? E->IgnoreParens() : NULL; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // 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 = NULL; |
| #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 |