1 //===--- CFG.cpp - Classes for representing and building CFGs----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the CFG and CFGBuilder classes for representing and
11 // building Control-Flow Graphs (CFGs) from ASTs.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Support/SaveAndRestore.h"
16 #include "clang/Analysis/CFG.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/StmtVisitor.h"
20 #include "clang/AST/PrettyPrinter.h"
21 #include "clang/AST/CharUnits.h"
22 #include "clang/Basic/AttrKinds.h"
23 #include "llvm/Support/GraphWriter.h"
24 #include "llvm/Support/Allocator.h"
25 #include "llvm/Support/Format.h"
26 #include "llvm/ADT/DenseMap.h"
27 #include "llvm/ADT/SmallPtrSet.h"
28 #include "llvm/ADT/OwningPtr.h"
30 using namespace clang;
34 static SourceLocation GetEndLoc(Decl *D) {
35 if (VarDecl *VD = dyn_cast<VarDecl>(D))
36 if (Expr *Ex = VD->getInit())
37 return Ex->getSourceRange().getEnd();
38 return D->getLocation();
43 /// The CFG builder uses a recursive algorithm to build the CFG. When
44 /// we process an expression, sometimes we know that we must add the
45 /// subexpressions as block-level expressions. For example:
49 /// When processing the '||' expression, we know that exp1 and exp2
50 /// need to be added as block-level expressions, even though they
51 /// might not normally need to be. AddStmtChoice records this
52 /// contextual information. If AddStmtChoice is 'NotAlwaysAdd', then
53 /// the builder has an option not to add a subexpression as a
54 /// block-level expression.
58 enum Kind { NotAlwaysAdd = 0, AlwaysAdd = 1 };
60 AddStmtChoice(Kind a_kind = NotAlwaysAdd) : kind(a_kind) {}
62 bool alwaysAdd(CFGBuilder &builder,
63 const Stmt *stmt) const;
65 /// Return a copy of this object, except with the 'always-add' bit
67 AddStmtChoice withAlwaysAdd(bool alwaysAdd) const {
68 return AddStmtChoice(alwaysAdd ? AlwaysAdd : NotAlwaysAdd);
75 /// LocalScope - Node in tree of local scopes created for C++ implicit
76 /// destructor calls generation. It contains list of automatic variables
77 /// declared in the scope and link to position in previous scope this scope
80 /// The process of creating local scopes is as follows:
81 /// - Init CFGBuilder::ScopePos with invalid position (equivalent for null),
82 /// - Before processing statements in scope (e.g. CompoundStmt) create
83 /// LocalScope object using CFGBuilder::ScopePos as link to previous scope
84 /// and set CFGBuilder::ScopePos to the end of new scope,
85 /// - On every occurrence of VarDecl increase CFGBuilder::ScopePos if it points
87 /// - For every normal (without jump) end of scope add to CFGBlock destructors
88 /// for objects in the current scope,
89 /// - For every jump add to CFGBlock destructors for objects
90 /// between CFGBuilder::ScopePos and local scope position saved for jump
91 /// target. Thanks to C++ restrictions on goto jumps we can be sure that
92 /// jump target position will be on the path to root from CFGBuilder::ScopePos
93 /// (adding any variable that doesn't need constructor to be called to
94 /// LocalScope can break this assumption),
98 typedef BumpVector<VarDecl*> AutomaticVarsTy;
100 /// const_iterator - Iterates local scope backwards and jumps to previous
101 /// scope on reaching the beginning of currently iterated scope.
102 class const_iterator {
103 const LocalScope* Scope;
105 /// VarIter is guaranteed to be greater then 0 for every valid iterator.
106 /// Invalid iterator (with null Scope) has VarIter equal to 0.
110 /// Create invalid iterator. Dereferencing invalid iterator is not allowed.
111 /// Incrementing invalid iterator is allowed and will result in invalid
114 : Scope(NULL), VarIter(0) {}
116 /// Create valid iterator. In case when S.Prev is an invalid iterator and
117 /// I is equal to 0, this will create invalid iterator.
118 const_iterator(const LocalScope& S, unsigned I)
119 : Scope(&S), VarIter(I) {
120 // Iterator to "end" of scope is not allowed. Handle it by going up
121 // in scopes tree possibly up to invalid iterator in the root.
122 if (VarIter == 0 && Scope)
126 VarDecl *const* operator->() const {
127 assert (Scope && "Dereferencing invalid iterator is not allowed");
128 assert (VarIter != 0 && "Iterator has invalid value of VarIter member");
129 return &Scope->Vars[VarIter - 1];
131 VarDecl *operator*() const {
132 return *this->operator->();
135 const_iterator &operator++() {
139 assert (VarIter != 0 && "Iterator has invalid value of VarIter member");
145 const_iterator operator++(int) {
146 const_iterator P = *this;
151 bool operator==(const const_iterator &rhs) const {
152 return Scope == rhs.Scope && VarIter == rhs.VarIter;
154 bool operator!=(const const_iterator &rhs) const {
155 return !(*this == rhs);
158 operator bool() const {
159 return *this != const_iterator();
162 int distance(const_iterator L);
165 friend class const_iterator;
168 BumpVectorContext ctx;
170 /// Automatic variables in order of declaration.
171 AutomaticVarsTy Vars;
172 /// Iterator to variable in previous scope that was declared just before
173 /// begin of this scope.
177 /// Constructs empty scope linked to previous scope in specified place.
178 LocalScope(BumpVectorContext &ctx, const_iterator P)
179 : ctx(ctx), Vars(ctx, 4), Prev(P) {}
181 /// Begin of scope in direction of CFG building (backwards).
182 const_iterator begin() const { return const_iterator(*this, Vars.size()); }
184 void addVar(VarDecl *VD) {
185 Vars.push_back(VD, ctx);
189 /// distance - Calculates distance from this to L. L must be reachable from this
190 /// (with use of ++ operator). Cost of calculating the distance is linear w.r.t.
191 /// number of scopes between this and L.
192 int LocalScope::const_iterator::distance(LocalScope::const_iterator L) {
194 const_iterator F = *this;
195 while (F.Scope != L.Scope) {
196 assert (F != const_iterator()
197 && "L iterator is not reachable from F iterator.");
201 D += F.VarIter - L.VarIter;
205 /// BlockScopePosPair - Structure for specifying position in CFG during its
206 /// build process. It consists of CFGBlock that specifies position in CFG graph
207 /// and LocalScope::const_iterator that specifies position in LocalScope graph.
208 struct BlockScopePosPair {
209 BlockScopePosPair() : block(0) {}
210 BlockScopePosPair(CFGBlock *b, LocalScope::const_iterator scopePos)
211 : block(b), scopePosition(scopePos) {}
214 LocalScope::const_iterator scopePosition;
217 /// TryResult - a class representing a variant over the values
218 /// 'true', 'false', or 'unknown'. This is returned by tryEvaluateBool,
219 /// and is used by the CFGBuilder to decide if a branch condition
220 /// can be decided up front during CFG construction.
224 TryResult(bool b) : X(b ? 1 : 0) {}
225 TryResult() : X(-1) {}
227 bool isTrue() const { return X == 1; }
228 bool isFalse() const { return X == 0; }
229 bool isKnown() const { return X >= 0; }
236 /// CFGBuilder - This class implements CFG construction from an AST.
237 /// The builder is stateful: an instance of the builder should be used to only
238 /// construct a single CFG.
242 /// CFGBuilder builder;
243 /// CFG* cfg = builder.BuildAST(stmt1);
245 /// CFG construction is done via a recursive walk of an AST. We actually parse
246 /// the AST in reverse order so that the successor of a basic block is
247 /// constructed prior to its predecessor. This allows us to nicely capture
248 /// implicit fall-throughs without extra basic blocks.
251 typedef BlockScopePosPair JumpTarget;
252 typedef BlockScopePosPair JumpSource;
259 JumpTarget ContinueJumpTarget;
260 JumpTarget BreakJumpTarget;
261 CFGBlock *SwitchTerminatedBlock;
262 CFGBlock *DefaultCaseBlock;
263 CFGBlock *TryTerminatedBlock;
265 // Current position in local scope.
266 LocalScope::const_iterator ScopePos;
268 // LabelMap records the mapping from Label expressions to their jump targets.
269 typedef llvm::DenseMap<LabelDecl*, JumpTarget> LabelMapTy;
272 // A list of blocks that end with a "goto" that must be backpatched to their
273 // resolved targets upon completion of CFG construction.
274 typedef std::vector<JumpSource> BackpatchBlocksTy;
275 BackpatchBlocksTy BackpatchBlocks;
277 // A list of labels whose address has been taken (for indirect gotos).
278 typedef llvm::SmallPtrSet<LabelDecl*, 5> LabelSetTy;
279 LabelSetTy AddressTakenLabels;
282 const CFG::BuildOptions &BuildOpts;
284 // State to track for building switch statements.
285 bool switchExclusivelyCovered;
286 Expr::EvalResult *switchCond;
288 CFG::BuildOptions::ForcedBlkExprs::value_type *cachedEntry;
289 const Stmt *lastLookup;
291 // Caches boolean evaluations of expressions to avoid multiple re-evaluations
292 // during construction of branches for chained logical operators.
293 typedef llvm::DenseMap<Expr *, TryResult> CachedBoolEvalsTy;
294 CachedBoolEvalsTy CachedBoolEvals;
297 explicit CFGBuilder(ASTContext *astContext,
298 const CFG::BuildOptions &buildOpts)
299 : Context(astContext), cfg(new CFG()), // crew a new CFG
300 Block(NULL), Succ(NULL),
301 SwitchTerminatedBlock(NULL), DefaultCaseBlock(NULL),
302 TryTerminatedBlock(NULL), badCFG(false), BuildOpts(buildOpts),
303 switchExclusivelyCovered(false), switchCond(0),
304 cachedEntry(0), lastLookup(0) {}
306 // buildCFG - Used by external clients to construct the CFG.
307 CFG* buildCFG(const Decl *D, Stmt *Statement);
309 bool alwaysAdd(const Stmt *stmt);
312 // Visitors to walk an AST and construct the CFG.
313 CFGBlock *VisitAddrLabelExpr(AddrLabelExpr *A, AddStmtChoice asc);
314 CFGBlock *VisitBinaryOperator(BinaryOperator *B, AddStmtChoice asc);
315 CFGBlock *VisitBreakStmt(BreakStmt *B);
316 CFGBlock *VisitCallExpr(CallExpr *C, AddStmtChoice asc);
317 CFGBlock *VisitCaseStmt(CaseStmt *C);
318 CFGBlock *VisitChooseExpr(ChooseExpr *C, AddStmtChoice asc);
319 CFGBlock *VisitCompoundStmt(CompoundStmt *C);
320 CFGBlock *VisitConditionalOperator(AbstractConditionalOperator *C,
322 CFGBlock *VisitContinueStmt(ContinueStmt *C);
323 CFGBlock *VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E,
325 CFGBlock *VisitCXXCatchStmt(CXXCatchStmt *S);
326 CFGBlock *VisitCXXConstructExpr(CXXConstructExpr *C, AddStmtChoice asc);
327 CFGBlock *VisitCXXForRangeStmt(CXXForRangeStmt *S);
328 CFGBlock *VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E,
330 CFGBlock *VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C,
332 CFGBlock *VisitCXXThrowExpr(CXXThrowExpr *T);
333 CFGBlock *VisitCXXTryStmt(CXXTryStmt *S);
334 CFGBlock *VisitDeclStmt(DeclStmt *DS);
335 CFGBlock *VisitDeclSubExpr(DeclStmt *DS);
336 CFGBlock *VisitDefaultStmt(DefaultStmt *D);
337 CFGBlock *VisitDoStmt(DoStmt *D);
338 CFGBlock *VisitExprWithCleanups(ExprWithCleanups *E, AddStmtChoice asc);
339 CFGBlock *VisitForStmt(ForStmt *F);
340 CFGBlock *VisitGotoStmt(GotoStmt *G);
341 CFGBlock *VisitIfStmt(IfStmt *I);
342 CFGBlock *VisitImplicitCastExpr(ImplicitCastExpr *E, AddStmtChoice asc);
343 CFGBlock *VisitIndirectGotoStmt(IndirectGotoStmt *I);
344 CFGBlock *VisitLabelStmt(LabelStmt *L);
345 CFGBlock *VisitLambdaExpr(LambdaExpr *E, AddStmtChoice asc);
346 CFGBlock *VisitLogicalOperator(BinaryOperator *B);
347 std::pair<CFGBlock *, CFGBlock *> VisitLogicalOperator(BinaryOperator *B,
350 CFGBlock *FalseBlock);
351 CFGBlock *VisitMemberExpr(MemberExpr *M, AddStmtChoice asc);
352 CFGBlock *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S);
353 CFGBlock *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S);
354 CFGBlock *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S);
355 CFGBlock *VisitObjCAtTryStmt(ObjCAtTryStmt *S);
356 CFGBlock *VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S);
357 CFGBlock *VisitObjCForCollectionStmt(ObjCForCollectionStmt *S);
358 CFGBlock *VisitPseudoObjectExpr(PseudoObjectExpr *E);
359 CFGBlock *VisitReturnStmt(ReturnStmt *R);
360 CFGBlock *VisitStmtExpr(StmtExpr *S, AddStmtChoice asc);
361 CFGBlock *VisitSwitchStmt(SwitchStmt *S);
362 CFGBlock *VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E,
364 CFGBlock *VisitUnaryOperator(UnaryOperator *U, AddStmtChoice asc);
365 CFGBlock *VisitWhileStmt(WhileStmt *W);
367 CFGBlock *Visit(Stmt *S, AddStmtChoice asc = AddStmtChoice::NotAlwaysAdd);
368 CFGBlock *VisitStmt(Stmt *S, AddStmtChoice asc);
369 CFGBlock *VisitChildren(Stmt *S);
370 CFGBlock *VisitNoRecurse(Expr *E, AddStmtChoice asc);
372 // Visitors to walk an AST and generate destructors of temporaries in
374 CFGBlock *VisitForTemporaryDtors(Stmt *E, bool BindToTemporary = false);
375 CFGBlock *VisitChildrenForTemporaryDtors(Stmt *E);
376 CFGBlock *VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E);
377 CFGBlock *VisitCXXBindTemporaryExprForTemporaryDtors(CXXBindTemporaryExpr *E,
378 bool BindToTemporary);
380 VisitConditionalOperatorForTemporaryDtors(AbstractConditionalOperator *E,
381 bool BindToTemporary);
383 // NYS == Not Yet Supported
389 void autoCreateBlock() { if (!Block) Block = createBlock(); }
390 CFGBlock *createBlock(bool add_successor = true);
391 CFGBlock *createNoReturnBlock();
393 CFGBlock *addStmt(Stmt *S) {
394 return Visit(S, AddStmtChoice::AlwaysAdd);
396 CFGBlock *addInitializer(CXXCtorInitializer *I);
397 void addAutomaticObjDtors(LocalScope::const_iterator B,
398 LocalScope::const_iterator E, Stmt *S);
399 void addImplicitDtorsForDestructor(const CXXDestructorDecl *DD);
401 // Local scopes creation.
402 LocalScope* createOrReuseLocalScope(LocalScope* Scope);
404 void addLocalScopeForStmt(Stmt *S);
405 LocalScope* addLocalScopeForDeclStmt(DeclStmt *DS, LocalScope* Scope = NULL);
406 LocalScope* addLocalScopeForVarDecl(VarDecl *VD, LocalScope* Scope = NULL);
408 void addLocalScopeAndDtors(Stmt *S);
410 // Interface to CFGBlock - adding CFGElements.
411 void appendStmt(CFGBlock *B, const Stmt *S) {
412 if (alwaysAdd(S) && cachedEntry)
413 cachedEntry->second = B;
415 // All block-level expressions should have already been IgnoreParens()ed.
416 assert(!isa<Expr>(S) || cast<Expr>(S)->IgnoreParens() == S);
417 B->appendStmt(const_cast<Stmt*>(S), cfg->getBumpVectorContext());
419 void appendInitializer(CFGBlock *B, CXXCtorInitializer *I) {
420 B->appendInitializer(I, cfg->getBumpVectorContext());
422 void appendBaseDtor(CFGBlock *B, const CXXBaseSpecifier *BS) {
423 B->appendBaseDtor(BS, cfg->getBumpVectorContext());
425 void appendMemberDtor(CFGBlock *B, FieldDecl *FD) {
426 B->appendMemberDtor(FD, cfg->getBumpVectorContext());
428 void appendTemporaryDtor(CFGBlock *B, CXXBindTemporaryExpr *E) {
429 B->appendTemporaryDtor(E, cfg->getBumpVectorContext());
431 void appendAutomaticObjDtor(CFGBlock *B, VarDecl *VD, Stmt *S) {
432 B->appendAutomaticObjDtor(VD, S, cfg->getBumpVectorContext());
435 void prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk,
436 LocalScope::const_iterator B, LocalScope::const_iterator E);
438 void addSuccessor(CFGBlock *B, CFGBlock *S) {
439 B->addSuccessor(S, cfg->getBumpVectorContext());
442 /// Try and evaluate an expression to an integer constant.
443 bool tryEvaluate(Expr *S, Expr::EvalResult &outResult) {
444 if (!BuildOpts.PruneTriviallyFalseEdges)
446 return !S->isTypeDependent() &&
447 !S->isValueDependent() &&
448 S->EvaluateAsRValue(outResult, *Context);
451 /// tryEvaluateBool - Try and evaluate the Stmt and return 0 or 1
452 /// if we can evaluate to a known value, otherwise return -1.
453 TryResult tryEvaluateBool(Expr *S) {
454 if (!BuildOpts.PruneTriviallyFalseEdges ||
455 S->isTypeDependent() || S->isValueDependent())
458 if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(S)) {
459 if (Bop->isLogicalOp()) {
460 // Check the cache first.
461 CachedBoolEvalsTy::iterator I = CachedBoolEvals.find(S);
462 if (I != CachedBoolEvals.end())
463 return I->second; // already in map;
465 // Retrieve result at first, or the map might be updated.
466 TryResult Result = evaluateAsBooleanConditionNoCache(S);
467 CachedBoolEvals[S] = Result; // update or insert
472 return evaluateAsBooleanConditionNoCache(S);
475 /// \brief Evaluate as boolean \param E without using the cache.
476 TryResult evaluateAsBooleanConditionNoCache(Expr *E) {
477 if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(E)) {
478 if (Bop->isLogicalOp()) {
479 TryResult LHS = tryEvaluateBool(Bop->getLHS());
481 // We were able to evaluate the LHS, see if we can get away with not
482 // evaluating the RHS: 0 && X -> 0, 1 || X -> 1
483 if (LHS.isTrue() == (Bop->getOpcode() == BO_LOr))
486 TryResult RHS = tryEvaluateBool(Bop->getRHS());
488 if (Bop->getOpcode() == BO_LOr)
489 return LHS.isTrue() || RHS.isTrue();
491 return LHS.isTrue() && RHS.isTrue();
494 TryResult RHS = tryEvaluateBool(Bop->getRHS());
496 // We can't evaluate the LHS; however, sometimes the result
497 // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
498 if (RHS.isTrue() == (Bop->getOpcode() == BO_LOr))
508 if (E->EvaluateAsBooleanCondition(Result, *Context))
516 inline bool AddStmtChoice::alwaysAdd(CFGBuilder &builder,
517 const Stmt *stmt) const {
518 return builder.alwaysAdd(stmt) || kind == AlwaysAdd;
521 bool CFGBuilder::alwaysAdd(const Stmt *stmt) {
522 bool shouldAdd = BuildOpts.alwaysAdd(stmt);
524 if (!BuildOpts.forcedBlkExprs)
527 if (lastLookup == stmt) {
529 assert(cachedEntry->first == stmt);
537 // Perform the lookup!
538 CFG::BuildOptions::ForcedBlkExprs *fb = *BuildOpts.forcedBlkExprs;
541 // No need to update 'cachedEntry', since it will always be null.
542 assert(cachedEntry == 0);
546 CFG::BuildOptions::ForcedBlkExprs::iterator itr = fb->find(stmt);
547 if (itr == fb->end()) {
556 // FIXME: Add support for dependent-sized array types in C++?
557 // Does it even make sense to build a CFG for an uninstantiated template?
558 static const VariableArrayType *FindVA(const Type *t) {
559 while (const ArrayType *vt = dyn_cast<ArrayType>(t)) {
560 if (const VariableArrayType *vat = dyn_cast<VariableArrayType>(vt))
561 if (vat->getSizeExpr())
564 t = vt->getElementType().getTypePtr();
570 /// BuildCFG - Constructs a CFG from an AST (a Stmt*). The AST can represent an
571 /// arbitrary statement. Examples include a single expression or a function
572 /// body (compound statement). The ownership of the returned CFG is
573 /// transferred to the caller. If CFG construction fails, this method returns
575 CFG* CFGBuilder::buildCFG(const Decl *D, Stmt *Statement) {
580 // Create an empty block that will serve as the exit block for the CFG. Since
581 // this is the first block added to the CFG, it will be implicitly registered
582 // as the exit block.
583 Succ = createBlock();
584 assert(Succ == &cfg->getExit());
585 Block = NULL; // the EXIT block is empty. Create all other blocks lazily.
587 if (BuildOpts.AddImplicitDtors)
588 if (const CXXDestructorDecl *DD = dyn_cast_or_null<CXXDestructorDecl>(D))
589 addImplicitDtorsForDestructor(DD);
591 // Visit the statements and create the CFG.
592 CFGBlock *B = addStmt(Statement);
597 // For C++ constructor add initializers to CFG.
598 if (const CXXConstructorDecl *CD = dyn_cast_or_null<CXXConstructorDecl>(D)) {
599 for (CXXConstructorDecl::init_const_reverse_iterator I = CD->init_rbegin(),
600 E = CD->init_rend(); I != E; ++I) {
601 B = addInitializer(*I);
610 // Backpatch the gotos whose label -> block mappings we didn't know when we
612 for (BackpatchBlocksTy::iterator I = BackpatchBlocks.begin(),
613 E = BackpatchBlocks.end(); I != E; ++I ) {
615 CFGBlock *B = I->block;
616 GotoStmt *G = cast<GotoStmt>(B->getTerminator());
617 LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
619 // If there is no target for the goto, then we are looking at an
620 // incomplete AST. Handle this by not registering a successor.
621 if (LI == LabelMap.end()) continue;
623 JumpTarget JT = LI->second;
624 prependAutomaticObjDtorsWithTerminator(B, I->scopePosition,
626 addSuccessor(B, JT.block);
629 // Add successors to the Indirect Goto Dispatch block (if we have one).
630 if (CFGBlock *B = cfg->getIndirectGotoBlock())
631 for (LabelSetTy::iterator I = AddressTakenLabels.begin(),
632 E = AddressTakenLabels.end(); I != E; ++I ) {
634 // Lookup the target block.
635 LabelMapTy::iterator LI = LabelMap.find(*I);
637 // If there is no target block that contains label, then we are looking
638 // at an incomplete AST. Handle this by not registering a successor.
639 if (LI == LabelMap.end()) continue;
641 addSuccessor(B, LI->second.block);
644 // Create an empty entry block that has no predecessors.
645 cfg->setEntry(createBlock());
650 /// createBlock - Used to lazily create blocks that are connected
651 /// to the current (global) succcessor.
652 CFGBlock *CFGBuilder::createBlock(bool add_successor) {
653 CFGBlock *B = cfg->createBlock();
654 if (add_successor && Succ)
655 addSuccessor(B, Succ);
659 /// createNoReturnBlock - Used to create a block is a 'noreturn' point in the
660 /// CFG. It is *not* connected to the current (global) successor, and instead
661 /// directly tied to the exit block in order to be reachable.
662 CFGBlock *CFGBuilder::createNoReturnBlock() {
663 CFGBlock *B = createBlock(false);
664 B->setHasNoReturnElement();
665 addSuccessor(B, &cfg->getExit());
669 /// addInitializer - Add C++ base or member initializer element to CFG.
670 CFGBlock *CFGBuilder::addInitializer(CXXCtorInitializer *I) {
671 if (!BuildOpts.AddInitializers)
674 bool IsReference = false;
675 bool HasTemporaries = false;
677 // Destructors of temporaries in initialization expression should be called
678 // after initialization finishes.
679 Expr *Init = I->getInit();
681 if (FieldDecl *FD = I->getAnyMember())
682 IsReference = FD->getType()->isReferenceType();
683 HasTemporaries = isa<ExprWithCleanups>(Init);
685 if (BuildOpts.AddImplicitDtors && HasTemporaries) {
686 // Generate destructors for temporaries in initialization expression.
687 VisitForTemporaryDtors(cast<ExprWithCleanups>(Init)->getSubExpr(),
693 appendInitializer(Block, I);
696 if (HasTemporaries) {
697 // For expression with temporaries go directly to subexpression to omit
698 // generating destructors for the second time.
699 return Visit(cast<ExprWithCleanups>(Init)->getSubExpr());
707 /// \brief Retrieve the type of the temporary object whose lifetime was
708 /// extended by a local reference with the given initializer.
709 static QualType getReferenceInitTemporaryType(ASTContext &Context,
713 Init = Init->IgnoreParens();
715 // Skip through cleanups.
716 if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Init)) {
717 Init = EWC->getSubExpr();
721 // Skip through the temporary-materialization expression.
722 if (const MaterializeTemporaryExpr *MTE
723 = dyn_cast<MaterializeTemporaryExpr>(Init)) {
724 Init = MTE->GetTemporaryExpr();
728 // Skip derived-to-base and no-op casts.
729 if (const CastExpr *CE = dyn_cast<CastExpr>(Init)) {
730 if ((CE->getCastKind() == CK_DerivedToBase ||
731 CE->getCastKind() == CK_UncheckedDerivedToBase ||
732 CE->getCastKind() == CK_NoOp) &&
733 Init->getType()->isRecordType()) {
734 Init = CE->getSubExpr();
739 // Skip member accesses into rvalues.
740 if (const MemberExpr *ME = dyn_cast<MemberExpr>(Init)) {
741 if (!ME->isArrow() && ME->getBase()->isRValue()) {
742 Init = ME->getBase();
750 return Init->getType();
753 /// addAutomaticObjDtors - Add to current block automatic objects destructors
754 /// for objects in range of local scope positions. Use S as trigger statement
756 void CFGBuilder::addAutomaticObjDtors(LocalScope::const_iterator B,
757 LocalScope::const_iterator E, Stmt *S) {
758 if (!BuildOpts.AddImplicitDtors)
764 // We need to append the destructors in reverse order, but any one of them
765 // may be a no-return destructor which changes the CFG. As a result, buffer
766 // this sequence up and replay them in reverse order when appending onto the
768 SmallVector<VarDecl*, 10> Decls;
769 Decls.reserve(B.distance(E));
770 for (LocalScope::const_iterator I = B; I != E; ++I)
773 for (SmallVectorImpl<VarDecl*>::reverse_iterator I = Decls.rbegin(),
776 // If this destructor is marked as a no-return destructor, we need to
777 // create a new block for the destructor which does not have as a successor
778 // anything built thus far: control won't flow out of this block.
779 QualType Ty = (*I)->getType();
780 if (Ty->isReferenceType()) {
781 Ty = getReferenceInitTemporaryType(*Context, (*I)->getInit());
783 Ty = Context->getBaseElementType(Ty);
785 const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor();
786 if (cast<FunctionType>(Dtor->getType())->getNoReturnAttr())
787 Block = createNoReturnBlock();
791 appendAutomaticObjDtor(Block, *I, S);
795 /// addImplicitDtorsForDestructor - Add implicit destructors generated for
796 /// base and member objects in destructor.
797 void CFGBuilder::addImplicitDtorsForDestructor(const CXXDestructorDecl *DD) {
798 assert (BuildOpts.AddImplicitDtors
799 && "Can be called only when dtors should be added");
800 const CXXRecordDecl *RD = DD->getParent();
802 // At the end destroy virtual base objects.
803 for (CXXRecordDecl::base_class_const_iterator VI = RD->vbases_begin(),
804 VE = RD->vbases_end(); VI != VE; ++VI) {
805 const CXXRecordDecl *CD = VI->getType()->getAsCXXRecordDecl();
806 if (!CD->hasTrivialDestructor()) {
808 appendBaseDtor(Block, VI);
812 // Before virtual bases destroy direct base objects.
813 for (CXXRecordDecl::base_class_const_iterator BI = RD->bases_begin(),
814 BE = RD->bases_end(); BI != BE; ++BI) {
815 if (!BI->isVirtual()) {
816 const CXXRecordDecl *CD = BI->getType()->getAsCXXRecordDecl();
817 if (!CD->hasTrivialDestructor()) {
819 appendBaseDtor(Block, BI);
824 // First destroy member objects.
825 for (CXXRecordDecl::field_iterator FI = RD->field_begin(),
826 FE = RD->field_end(); FI != FE; ++FI) {
827 // Check for constant size array. Set type to array element type.
828 QualType QT = FI->getType();
829 if (const ConstantArrayType *AT = Context->getAsConstantArrayType(QT)) {
830 if (AT->getSize() == 0)
832 QT = AT->getElementType();
835 if (const CXXRecordDecl *CD = QT->getAsCXXRecordDecl())
836 if (!CD->hasTrivialDestructor()) {
838 appendMemberDtor(Block, *FI);
843 /// createOrReuseLocalScope - If Scope is NULL create new LocalScope. Either
844 /// way return valid LocalScope object.
845 LocalScope* CFGBuilder::createOrReuseLocalScope(LocalScope* Scope) {
847 llvm::BumpPtrAllocator &alloc = cfg->getAllocator();
848 Scope = alloc.Allocate<LocalScope>();
849 BumpVectorContext ctx(alloc);
850 new (Scope) LocalScope(ctx, ScopePos);
855 /// addLocalScopeForStmt - Add LocalScope to local scopes tree for statement
856 /// that should create implicit scope (e.g. if/else substatements).
857 void CFGBuilder::addLocalScopeForStmt(Stmt *S) {
858 if (!BuildOpts.AddImplicitDtors)
861 LocalScope *Scope = 0;
863 // For compound statement we will be creating explicit scope.
864 if (CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) {
865 for (CompoundStmt::body_iterator BI = CS->body_begin(), BE = CS->body_end()
867 Stmt *SI = (*BI)->stripLabelLikeStatements();
868 if (DeclStmt *DS = dyn_cast<DeclStmt>(SI))
869 Scope = addLocalScopeForDeclStmt(DS, Scope);
874 // For any other statement scope will be implicit and as such will be
875 // interesting only for DeclStmt.
876 if (DeclStmt *DS = dyn_cast<DeclStmt>(S->stripLabelLikeStatements()))
877 addLocalScopeForDeclStmt(DS);
880 /// addLocalScopeForDeclStmt - Add LocalScope for declaration statement. Will
881 /// reuse Scope if not NULL.
882 LocalScope* CFGBuilder::addLocalScopeForDeclStmt(DeclStmt *DS,
884 if (!BuildOpts.AddImplicitDtors)
887 for (DeclStmt::decl_iterator DI = DS->decl_begin(), DE = DS->decl_end()
889 if (VarDecl *VD = dyn_cast<VarDecl>(*DI))
890 Scope = addLocalScopeForVarDecl(VD, Scope);
895 /// addLocalScopeForVarDecl - Add LocalScope for variable declaration. It will
896 /// create add scope for automatic objects and temporary objects bound to
897 /// const reference. Will reuse Scope if not NULL.
898 LocalScope* CFGBuilder::addLocalScopeForVarDecl(VarDecl *VD,
900 if (!BuildOpts.AddImplicitDtors)
903 // Check if variable is local.
904 switch (VD->getStorageClass()) {
909 default: return Scope;
912 // Check for const references bound to temporary. Set type to pointee.
913 QualType QT = VD->getType();
914 if (QT.getTypePtr()->isReferenceType()) {
915 if (!VD->extendsLifetimeOfTemporary())
918 QT = getReferenceInitTemporaryType(*Context, VD->getInit());
921 // Check for constant size array. Set type to array element type.
922 while (const ConstantArrayType *AT = Context->getAsConstantArrayType(QT)) {
923 if (AT->getSize() == 0)
925 QT = AT->getElementType();
928 // Check if type is a C++ class with non-trivial destructor.
929 if (const CXXRecordDecl *CD = QT->getAsCXXRecordDecl())
930 if (!CD->hasTrivialDestructor()) {
931 // Add the variable to scope
932 Scope = createOrReuseLocalScope(Scope);
934 ScopePos = Scope->begin();
939 /// addLocalScopeAndDtors - For given statement add local scope for it and
940 /// add destructors that will cleanup the scope. Will reuse Scope if not NULL.
941 void CFGBuilder::addLocalScopeAndDtors(Stmt *S) {
942 if (!BuildOpts.AddImplicitDtors)
945 LocalScope::const_iterator scopeBeginPos = ScopePos;
946 addLocalScopeForStmt(S);
947 addAutomaticObjDtors(ScopePos, scopeBeginPos, S);
950 /// prependAutomaticObjDtorsWithTerminator - Prepend destructor CFGElements for
951 /// variables with automatic storage duration to CFGBlock's elements vector.
952 /// Elements will be prepended to physical beginning of the vector which
953 /// happens to be logical end. Use blocks terminator as statement that specifies
954 /// destructors call site.
955 /// FIXME: This mechanism for adding automatic destructors doesn't handle
956 /// no-return destructors properly.
957 void CFGBuilder::prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk,
958 LocalScope::const_iterator B, LocalScope::const_iterator E) {
959 BumpVectorContext &C = cfg->getBumpVectorContext();
960 CFGBlock::iterator InsertPos
961 = Blk->beginAutomaticObjDtorsInsert(Blk->end(), B.distance(E), C);
962 for (LocalScope::const_iterator I = B; I != E; ++I)
963 InsertPos = Blk->insertAutomaticObjDtor(InsertPos, *I,
964 Blk->getTerminator());
967 /// Visit - Walk the subtree of a statement and add extra
968 /// blocks for ternary operators, &&, and ||. We also process "," and
969 /// DeclStmts (which may contain nested control-flow).
970 CFGBlock *CFGBuilder::Visit(Stmt * S, AddStmtChoice asc) {
976 if (Expr *E = dyn_cast<Expr>(S))
977 S = E->IgnoreParens();
979 switch (S->getStmtClass()) {
981 return VisitStmt(S, asc);
983 case Stmt::AddrLabelExprClass:
984 return VisitAddrLabelExpr(cast<AddrLabelExpr>(S), asc);
986 case Stmt::BinaryConditionalOperatorClass:
987 return VisitConditionalOperator(cast<BinaryConditionalOperator>(S), asc);
989 case Stmt::BinaryOperatorClass:
990 return VisitBinaryOperator(cast<BinaryOperator>(S), asc);
992 case Stmt::BlockExprClass:
993 return VisitNoRecurse(cast<Expr>(S), asc);
995 case Stmt::BreakStmtClass:
996 return VisitBreakStmt(cast<BreakStmt>(S));
998 case Stmt::CallExprClass:
999 case Stmt::CXXOperatorCallExprClass:
1000 case Stmt::CXXMemberCallExprClass:
1001 case Stmt::UserDefinedLiteralClass:
1002 return VisitCallExpr(cast<CallExpr>(S), asc);
1004 case Stmt::CaseStmtClass:
1005 return VisitCaseStmt(cast<CaseStmt>(S));
1007 case Stmt::ChooseExprClass:
1008 return VisitChooseExpr(cast<ChooseExpr>(S), asc);
1010 case Stmt::CompoundStmtClass:
1011 return VisitCompoundStmt(cast<CompoundStmt>(S));
1013 case Stmt::ConditionalOperatorClass:
1014 return VisitConditionalOperator(cast<ConditionalOperator>(S), asc);
1016 case Stmt::ContinueStmtClass:
1017 return VisitContinueStmt(cast<ContinueStmt>(S));
1019 case Stmt::CXXCatchStmtClass:
1020 return VisitCXXCatchStmt(cast<CXXCatchStmt>(S));
1022 case Stmt::ExprWithCleanupsClass:
1023 return VisitExprWithCleanups(cast<ExprWithCleanups>(S), asc);
1025 case Stmt::CXXBindTemporaryExprClass:
1026 return VisitCXXBindTemporaryExpr(cast<CXXBindTemporaryExpr>(S), asc);
1028 case Stmt::CXXConstructExprClass:
1029 return VisitCXXConstructExpr(cast<CXXConstructExpr>(S), asc);
1031 case Stmt::CXXFunctionalCastExprClass:
1032 return VisitCXXFunctionalCastExpr(cast<CXXFunctionalCastExpr>(S), asc);
1034 case Stmt::CXXTemporaryObjectExprClass:
1035 return VisitCXXTemporaryObjectExpr(cast<CXXTemporaryObjectExpr>(S), asc);
1037 case Stmt::CXXThrowExprClass:
1038 return VisitCXXThrowExpr(cast<CXXThrowExpr>(S));
1040 case Stmt::CXXTryStmtClass:
1041 return VisitCXXTryStmt(cast<CXXTryStmt>(S));
1043 case Stmt::CXXForRangeStmtClass:
1044 return VisitCXXForRangeStmt(cast<CXXForRangeStmt>(S));
1046 case Stmt::DeclStmtClass:
1047 return VisitDeclStmt(cast<DeclStmt>(S));
1049 case Stmt::DefaultStmtClass:
1050 return VisitDefaultStmt(cast<DefaultStmt>(S));
1052 case Stmt::DoStmtClass:
1053 return VisitDoStmt(cast<DoStmt>(S));
1055 case Stmt::ForStmtClass:
1056 return VisitForStmt(cast<ForStmt>(S));
1058 case Stmt::GotoStmtClass:
1059 return VisitGotoStmt(cast<GotoStmt>(S));
1061 case Stmt::IfStmtClass:
1062 return VisitIfStmt(cast<IfStmt>(S));
1064 case Stmt::ImplicitCastExprClass:
1065 return VisitImplicitCastExpr(cast<ImplicitCastExpr>(S), asc);
1067 case Stmt::IndirectGotoStmtClass:
1068 return VisitIndirectGotoStmt(cast<IndirectGotoStmt>(S));
1070 case Stmt::LabelStmtClass:
1071 return VisitLabelStmt(cast<LabelStmt>(S));
1073 case Stmt::LambdaExprClass:
1074 return VisitLambdaExpr(cast<LambdaExpr>(S), asc);
1076 case Stmt::MemberExprClass:
1077 return VisitMemberExpr(cast<MemberExpr>(S), asc);
1079 case Stmt::NullStmtClass:
1082 case Stmt::ObjCAtCatchStmtClass:
1083 return VisitObjCAtCatchStmt(cast<ObjCAtCatchStmt>(S));
1085 case Stmt::ObjCAutoreleasePoolStmtClass:
1086 return VisitObjCAutoreleasePoolStmt(cast<ObjCAutoreleasePoolStmt>(S));
1088 case Stmt::ObjCAtSynchronizedStmtClass:
1089 return VisitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(S));
1091 case Stmt::ObjCAtThrowStmtClass:
1092 return VisitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(S));
1094 case Stmt::ObjCAtTryStmtClass:
1095 return VisitObjCAtTryStmt(cast<ObjCAtTryStmt>(S));
1097 case Stmt::ObjCForCollectionStmtClass:
1098 return VisitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(S));
1100 case Stmt::OpaqueValueExprClass:
1103 case Stmt::PseudoObjectExprClass:
1104 return VisitPseudoObjectExpr(cast<PseudoObjectExpr>(S));
1106 case Stmt::ReturnStmtClass:
1107 return VisitReturnStmt(cast<ReturnStmt>(S));
1109 case Stmt::UnaryExprOrTypeTraitExprClass:
1110 return VisitUnaryExprOrTypeTraitExpr(cast<UnaryExprOrTypeTraitExpr>(S),
1113 case Stmt::StmtExprClass:
1114 return VisitStmtExpr(cast<StmtExpr>(S), asc);
1116 case Stmt::SwitchStmtClass:
1117 return VisitSwitchStmt(cast<SwitchStmt>(S));
1119 case Stmt::UnaryOperatorClass:
1120 return VisitUnaryOperator(cast<UnaryOperator>(S), asc);
1122 case Stmt::WhileStmtClass:
1123 return VisitWhileStmt(cast<WhileStmt>(S));
1127 CFGBlock *CFGBuilder::VisitStmt(Stmt *S, AddStmtChoice asc) {
1128 if (asc.alwaysAdd(*this, S)) {
1130 appendStmt(Block, S);
1133 return VisitChildren(S);
1136 /// VisitChildren - Visit the children of a Stmt.
1137 CFGBlock *CFGBuilder::VisitChildren(Stmt *Terminator) {
1138 CFGBlock *lastBlock = Block;
1139 for (Stmt::child_range I = Terminator->children(); I; ++I)
1140 if (Stmt *child = *I)
1141 if (CFGBlock *b = Visit(child))
1147 CFGBlock *CFGBuilder::VisitAddrLabelExpr(AddrLabelExpr *A,
1148 AddStmtChoice asc) {
1149 AddressTakenLabels.insert(A->getLabel());
1151 if (asc.alwaysAdd(*this, A)) {
1153 appendStmt(Block, A);
1159 CFGBlock *CFGBuilder::VisitUnaryOperator(UnaryOperator *U,
1160 AddStmtChoice asc) {
1161 if (asc.alwaysAdd(*this, U)) {
1163 appendStmt(Block, U);
1166 return Visit(U->getSubExpr(), AddStmtChoice());
1169 CFGBlock *CFGBuilder::VisitLogicalOperator(BinaryOperator *B) {
1170 CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
1171 appendStmt(ConfluenceBlock, B);
1176 return VisitLogicalOperator(B, 0, ConfluenceBlock, ConfluenceBlock).first;
1179 std::pair<CFGBlock*, CFGBlock*>
1180 CFGBuilder::VisitLogicalOperator(BinaryOperator *B,
1182 CFGBlock *TrueBlock,
1183 CFGBlock *FalseBlock) {
1185 // Introspect the RHS. If it is a nested logical operation, we recursively
1186 // build the CFG using this function. Otherwise, resort to default
1187 // CFG construction behavior.
1188 Expr *RHS = B->getRHS()->IgnoreParens();
1189 CFGBlock *RHSBlock, *ExitBlock;
1192 if (BinaryOperator *B_RHS = dyn_cast<BinaryOperator>(RHS))
1193 if (B_RHS->isLogicalOp()) {
1194 llvm::tie(RHSBlock, ExitBlock) =
1195 VisitLogicalOperator(B_RHS, Term, TrueBlock, FalseBlock);
1199 // The RHS is not a nested logical operation. Don't push the terminator
1200 // down further, but instead visit RHS and construct the respective
1201 // pieces of the CFG, and link up the RHSBlock with the terminator
1202 // we have been provided.
1203 ExitBlock = RHSBlock = createBlock(false);
1206 assert(TrueBlock == FalseBlock);
1207 addSuccessor(RHSBlock, TrueBlock);
1210 RHSBlock->setTerminator(Term);
1211 TryResult KnownVal = tryEvaluateBool(RHS);
1212 addSuccessor(RHSBlock, KnownVal.isFalse() ? NULL : TrueBlock);
1213 addSuccessor(RHSBlock, KnownVal.isTrue() ? NULL : FalseBlock);
1217 RHSBlock = addStmt(RHS);
1222 return std::make_pair((CFGBlock*)0, (CFGBlock*)0);
1224 // Generate the blocks for evaluating the LHS.
1225 Expr *LHS = B->getLHS()->IgnoreParens();
1227 if (BinaryOperator *B_LHS = dyn_cast<BinaryOperator>(LHS))
1228 if (B_LHS->isLogicalOp()) {
1229 if (B->getOpcode() == BO_LOr)
1230 FalseBlock = RHSBlock;
1232 TrueBlock = RHSBlock;
1234 // For the LHS, treat 'B' as the terminator that we want to sink
1235 // into the nested branch. The RHS always gets the top-most
1237 return VisitLogicalOperator(B_LHS, B, TrueBlock, FalseBlock);
1240 // Create the block evaluating the LHS.
1241 // This contains the '&&' or '||' as the terminator.
1242 CFGBlock *LHSBlock = createBlock(false);
1243 LHSBlock->setTerminator(B);
1246 CFGBlock *EntryLHSBlock = addStmt(LHS);
1249 return std::make_pair((CFGBlock*)0, (CFGBlock*)0);
1251 // See if this is a known constant.
1252 TryResult KnownVal = tryEvaluateBool(LHS);
1254 // Now link the LHSBlock with RHSBlock.
1255 if (B->getOpcode() == BO_LOr) {
1256 addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : TrueBlock);
1257 addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : RHSBlock);
1259 assert(B->getOpcode() == BO_LAnd);
1260 addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
1261 addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : FalseBlock);
1264 return std::make_pair(EntryLHSBlock, ExitBlock);
1268 CFGBlock *CFGBuilder::VisitBinaryOperator(BinaryOperator *B,
1269 AddStmtChoice asc) {
1271 if (B->isLogicalOp())
1272 return VisitLogicalOperator(B);
1274 if (B->getOpcode() == BO_Comma) { // ,
1276 appendStmt(Block, B);
1277 addStmt(B->getRHS());
1278 return addStmt(B->getLHS());
1281 if (B->isAssignmentOp()) {
1282 if (asc.alwaysAdd(*this, B)) {
1284 appendStmt(Block, B);
1287 return Visit(B->getRHS());
1290 if (asc.alwaysAdd(*this, B)) {
1292 appendStmt(Block, B);
1295 CFGBlock *RBlock = Visit(B->getRHS());
1296 CFGBlock *LBlock = Visit(B->getLHS());
1297 // If visiting RHS causes us to finish 'Block', e.g. the RHS is a StmtExpr
1298 // containing a DoStmt, and the LHS doesn't create a new block, then we should
1299 // return RBlock. Otherwise we'll incorrectly return NULL.
1300 return (LBlock ? LBlock : RBlock);
1303 CFGBlock *CFGBuilder::VisitNoRecurse(Expr *E, AddStmtChoice asc) {
1304 if (asc.alwaysAdd(*this, E)) {
1306 appendStmt(Block, E);
1311 CFGBlock *CFGBuilder::VisitBreakStmt(BreakStmt *B) {
1312 // "break" is a control-flow statement. Thus we stop processing the current
1317 // Now create a new block that ends with the break statement.
1318 Block = createBlock(false);
1319 Block->setTerminator(B);
1321 // If there is no target for the break, then we are looking at an incomplete
1322 // AST. This means that the CFG cannot be constructed.
1323 if (BreakJumpTarget.block) {
1324 addAutomaticObjDtors(ScopePos, BreakJumpTarget.scopePosition, B);
1325 addSuccessor(Block, BreakJumpTarget.block);
1333 static bool CanThrow(Expr *E, ASTContext &Ctx) {
1334 QualType Ty = E->getType();
1335 if (Ty->isFunctionPointerType())
1336 Ty = Ty->getAs<PointerType>()->getPointeeType();
1337 else if (Ty->isBlockPointerType())
1338 Ty = Ty->getAs<BlockPointerType>()->getPointeeType();
1340 const FunctionType *FT = Ty->getAs<FunctionType>();
1342 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT))
1343 if (!isUnresolvedExceptionSpec(Proto->getExceptionSpecType()) &&
1344 Proto->isNothrow(Ctx))
1350 CFGBlock *CFGBuilder::VisitCallExpr(CallExpr *C, AddStmtChoice asc) {
1351 // Compute the callee type.
1352 QualType calleeType = C->getCallee()->getType();
1353 if (calleeType == Context->BoundMemberTy) {
1354 QualType boundType = Expr::findBoundMemberType(C->getCallee());
1356 // We should only get a null bound type if processing a dependent
1357 // CFG. Recover by assuming nothing.
1358 if (!boundType.isNull()) calleeType = boundType;
1361 // If this is a call to a no-return function, this stops the block here.
1362 bool NoReturn = getFunctionExtInfo(*calleeType).getNoReturn();
1364 bool AddEHEdge = false;
1366 // Languages without exceptions are assumed to not throw.
1367 if (Context->getLangOpts().Exceptions) {
1368 if (BuildOpts.AddEHEdges)
1372 if (FunctionDecl *FD = C->getDirectCallee()) {
1373 if (FD->hasAttr<NoReturnAttr>())
1375 if (FD->hasAttr<NoThrowAttr>())
1379 if (!CanThrow(C->getCallee(), *Context))
1382 if (!NoReturn && !AddEHEdge)
1383 return VisitStmt(C, asc.withAlwaysAdd(true));
1392 Block = createNoReturnBlock();
1394 Block = createBlock();
1396 appendStmt(Block, C);
1399 // Add exceptional edges.
1400 if (TryTerminatedBlock)
1401 addSuccessor(Block, TryTerminatedBlock);
1403 addSuccessor(Block, &cfg->getExit());
1406 return VisitChildren(C);
1409 CFGBlock *CFGBuilder::VisitChooseExpr(ChooseExpr *C,
1410 AddStmtChoice asc) {
1411 CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
1412 appendStmt(ConfluenceBlock, C);
1416 AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true);
1417 Succ = ConfluenceBlock;
1419 CFGBlock *LHSBlock = Visit(C->getLHS(), alwaysAdd);
1423 Succ = ConfluenceBlock;
1425 CFGBlock *RHSBlock = Visit(C->getRHS(), alwaysAdd);
1429 Block = createBlock(false);
1430 // See if this is a known constant.
1431 const TryResult& KnownVal = tryEvaluateBool(C->getCond());
1432 addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
1433 addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
1434 Block->setTerminator(C);
1435 return addStmt(C->getCond());
1439 CFGBlock *CFGBuilder::VisitCompoundStmt(CompoundStmt *C) {
1440 addLocalScopeAndDtors(C);
1441 CFGBlock *LastBlock = Block;
1443 for (CompoundStmt::reverse_body_iterator I=C->body_rbegin(), E=C->body_rend();
1445 // If we hit a segment of code just containing ';' (NullStmts), we can
1446 // get a null block back. In such cases, just use the LastBlock
1447 if (CFGBlock *newBlock = addStmt(*I))
1448 LastBlock = newBlock;
1457 CFGBlock *CFGBuilder::VisitConditionalOperator(AbstractConditionalOperator *C,
1458 AddStmtChoice asc) {
1459 const BinaryConditionalOperator *BCO = dyn_cast<BinaryConditionalOperator>(C);
1460 const OpaqueValueExpr *opaqueValue = (BCO ? BCO->getOpaqueValue() : NULL);
1462 // Create the confluence block that will "merge" the results of the ternary
1464 CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
1465 appendStmt(ConfluenceBlock, C);
1469 AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true);
1471 // Create a block for the LHS expression if there is an LHS expression. A
1472 // GCC extension allows LHS to be NULL, causing the condition to be the
1473 // value that is returned instead.
1474 // e.g: x ?: y is shorthand for: x ? x : y;
1475 Succ = ConfluenceBlock;
1477 CFGBlock *LHSBlock = 0;
1478 const Expr *trueExpr = C->getTrueExpr();
1479 if (trueExpr != opaqueValue) {
1480 LHSBlock = Visit(C->getTrueExpr(), alwaysAdd);
1486 LHSBlock = ConfluenceBlock;
1488 // Create the block for the RHS expression.
1489 Succ = ConfluenceBlock;
1490 CFGBlock *RHSBlock = Visit(C->getFalseExpr(), alwaysAdd);
1494 // If the condition is a logical '&&' or '||', build a more accurate CFG.
1495 if (BinaryOperator *Cond =
1496 dyn_cast<BinaryOperator>(C->getCond()->IgnoreParens()))
1497 if (Cond->isLogicalOp())
1498 return VisitLogicalOperator(Cond, C, LHSBlock, RHSBlock).first;
1500 // Create the block that will contain the condition.
1501 Block = createBlock(false);
1503 // See if this is a known constant.
1504 const TryResult& KnownVal = tryEvaluateBool(C->getCond());
1505 addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
1506 addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
1507 Block->setTerminator(C);
1508 Expr *condExpr = C->getCond();
1511 // Run the condition expression if it's not trivially expressed in
1512 // terms of the opaque value (or if there is no opaque value).
1513 if (condExpr != opaqueValue)
1516 // Before that, run the common subexpression if there was one.
1517 // At least one of this or the above will be run.
1518 return addStmt(BCO->getCommon());
1521 return addStmt(condExpr);
1524 CFGBlock *CFGBuilder::VisitDeclStmt(DeclStmt *DS) {
1525 // Check if the Decl is for an __label__. If so, elide it from the
1527 if (isa<LabelDecl>(*DS->decl_begin()))
1530 // This case also handles static_asserts.
1531 if (DS->isSingleDecl())
1532 return VisitDeclSubExpr(DS);
1536 // Build an individual DeclStmt for each decl.
1537 for (DeclStmt::reverse_decl_iterator I = DS->decl_rbegin(),
1538 E = DS->decl_rend();
1540 // Get the alignment of the new DeclStmt, padding out to >=8 bytes.
1541 unsigned A = llvm::AlignOf<DeclStmt>::Alignment < 8
1542 ? 8 : llvm::AlignOf<DeclStmt>::Alignment;
1544 // Allocate the DeclStmt using the BumpPtrAllocator. It will get
1545 // automatically freed with the CFG.
1546 DeclGroupRef DG(*I);
1548 void *Mem = cfg->getAllocator().Allocate(sizeof(DeclStmt), A);
1549 DeclStmt *DSNew = new (Mem) DeclStmt(DG, D->getLocation(), GetEndLoc(D));
1551 // Append the fake DeclStmt to block.
1552 B = VisitDeclSubExpr(DSNew);
1558 /// VisitDeclSubExpr - Utility method to add block-level expressions for
1559 /// DeclStmts and initializers in them.
1560 CFGBlock *CFGBuilder::VisitDeclSubExpr(DeclStmt *DS) {
1561 assert(DS->isSingleDecl() && "Can handle single declarations only.");
1562 Decl *D = DS->getSingleDecl();
1564 if (isa<StaticAssertDecl>(D)) {
1565 // static_asserts aren't added to the CFG because they do not impact
1566 // runtime semantics.
1570 VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl());
1574 appendStmt(Block, DS);
1578 bool IsReference = false;
1579 bool HasTemporaries = false;
1581 // Destructors of temporaries in initialization expression should be called
1582 // after initialization finishes.
1583 Expr *Init = VD->getInit();
1585 IsReference = VD->getType()->isReferenceType();
1586 HasTemporaries = isa<ExprWithCleanups>(Init);
1588 if (BuildOpts.AddImplicitDtors && HasTemporaries) {
1589 // Generate destructors for temporaries in initialization expression.
1590 VisitForTemporaryDtors(cast<ExprWithCleanups>(Init)->getSubExpr(),
1596 appendStmt(Block, DS);
1598 // Keep track of the last non-null block, as 'Block' can be nulled out
1599 // if the initializer expression is something like a 'while' in a
1600 // statement-expression.
1601 CFGBlock *LastBlock = Block;
1604 if (HasTemporaries) {
1605 // For expression with temporaries go directly to subexpression to omit
1606 // generating destructors for the second time.
1607 ExprWithCleanups *EC = cast<ExprWithCleanups>(Init);
1608 if (CFGBlock *newBlock = Visit(EC->getSubExpr()))
1609 LastBlock = newBlock;
1612 if (CFGBlock *newBlock = Visit(Init))
1613 LastBlock = newBlock;
1617 // If the type of VD is a VLA, then we must process its size expressions.
1618 for (const VariableArrayType* VA = FindVA(VD->getType().getTypePtr());
1619 VA != 0; VA = FindVA(VA->getElementType().getTypePtr()))
1620 Block = addStmt(VA->getSizeExpr());
1622 // Remove variable from local scope.
1623 if (ScopePos && VD == *ScopePos)
1626 return Block ? Block : LastBlock;
1629 CFGBlock *CFGBuilder::VisitIfStmt(IfStmt *I) {
1630 // We may see an if statement in the middle of a basic block, or it may be the
1631 // first statement we are processing. In either case, we create a new basic
1632 // block. First, we create the blocks for the then...else statements, and
1633 // then we create the block containing the if statement. If we were in the
1634 // middle of a block, we stop processing that block. That block is then the
1635 // implicit successor for the "then" and "else" clauses.
1637 // Save local scope position because in case of condition variable ScopePos
1638 // won't be restored when traversing AST.
1639 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
1641 // Create local scope for possible condition variable.
1642 // Store scope position. Add implicit destructor.
1643 if (VarDecl *VD = I->getConditionVariable()) {
1644 LocalScope::const_iterator BeginScopePos = ScopePos;
1645 addLocalScopeForVarDecl(VD);
1646 addAutomaticObjDtors(ScopePos, BeginScopePos, I);
1649 // The block we were processing is now finished. Make it the successor
1657 // Process the false branch.
1658 CFGBlock *ElseBlock = Succ;
1660 if (Stmt *Else = I->getElse()) {
1661 SaveAndRestore<CFGBlock*> sv(Succ);
1663 // NULL out Block so that the recursive call to Visit will
1664 // create a new basic block.
1667 // If branch is not a compound statement create implicit scope
1668 // and add destructors.
1669 if (!isa<CompoundStmt>(Else))
1670 addLocalScopeAndDtors(Else);
1672 ElseBlock = addStmt(Else);
1674 if (!ElseBlock) // Can occur when the Else body has all NullStmts.
1675 ElseBlock = sv.get();
1682 // Process the true branch.
1683 CFGBlock *ThenBlock;
1685 Stmt *Then = I->getThen();
1687 SaveAndRestore<CFGBlock*> sv(Succ);
1690 // If branch is not a compound statement create implicit scope
1691 // and add destructors.
1692 if (!isa<CompoundStmt>(Then))
1693 addLocalScopeAndDtors(Then);
1695 ThenBlock = addStmt(Then);
1698 // We can reach here if the "then" body has all NullStmts.
1699 // Create an empty block so we can distinguish between true and false
1700 // branches in path-sensitive analyses.
1701 ThenBlock = createBlock(false);
1702 addSuccessor(ThenBlock, sv.get());
1709 // Specially handle "if (expr1 || ...)" and "if (expr1 && ...)" by
1710 // having these handle the actual control-flow jump. Note that
1711 // if we introduce a condition variable, e.g. "if (int x = exp1 || exp2)"
1712 // we resort to the old control-flow behavior. This special handling
1713 // removes infeasible paths from the control-flow graph by having the
1714 // control-flow transfer of '&&' or '||' go directly into the then/else
1716 if (!I->getConditionVariable())
1717 if (BinaryOperator *Cond =
1718 dyn_cast<BinaryOperator>(I->getCond()->IgnoreParens()))
1719 if (Cond->isLogicalOp())
1720 return VisitLogicalOperator(Cond, I, ThenBlock, ElseBlock).first;
1722 // Now create a new block containing the if statement.
1723 Block = createBlock(false);
1725 // Set the terminator of the new block to the If statement.
1726 Block->setTerminator(I);
1728 // See if this is a known constant.
1729 const TryResult &KnownVal = tryEvaluateBool(I->getCond());
1731 // Now add the successors.
1732 addSuccessor(Block, KnownVal.isFalse() ? NULL : ThenBlock);
1733 addSuccessor(Block, KnownVal.isTrue()? NULL : ElseBlock);
1735 // Add the condition as the last statement in the new block. This may create
1736 // new blocks as the condition may contain control-flow. Any newly created
1737 // blocks will be pointed to be "Block".
1738 Block = addStmt(I->getCond());
1740 // Finally, if the IfStmt contains a condition variable, add both the IfStmt
1741 // and the condition variable initialization to the CFG.
1742 if (VarDecl *VD = I->getConditionVariable()) {
1743 if (Expr *Init = VD->getInit()) {
1745 appendStmt(Block, I->getConditionVariableDeclStmt());
1754 CFGBlock *CFGBuilder::VisitReturnStmt(ReturnStmt *R) {
1755 // If we were in the middle of a block we stop processing that block.
1757 // NOTE: If a "return" appears in the middle of a block, this means that the
1758 // code afterwards is DEAD (unreachable). We still keep a basic block
1759 // for that code; a simple "mark-and-sweep" from the entry block will be
1760 // able to report such dead blocks.
1762 // Create the new block.
1763 Block = createBlock(false);
1765 // The Exit block is the only successor.
1766 addAutomaticObjDtors(ScopePos, LocalScope::const_iterator(), R);
1767 addSuccessor(Block, &cfg->getExit());
1769 // Add the return statement to the block. This may create new blocks if R
1770 // contains control-flow (short-circuit operations).
1771 return VisitStmt(R, AddStmtChoice::AlwaysAdd);
1774 CFGBlock *CFGBuilder::VisitLabelStmt(LabelStmt *L) {
1775 // Get the block of the labeled statement. Add it to our map.
1776 addStmt(L->getSubStmt());
1777 CFGBlock *LabelBlock = Block;
1779 if (!LabelBlock) // This can happen when the body is empty, i.e.
1780 LabelBlock = createBlock(); // scopes that only contains NullStmts.
1782 assert(LabelMap.find(L->getDecl()) == LabelMap.end() &&
1783 "label already in map");
1784 LabelMap[L->getDecl()] = JumpTarget(LabelBlock, ScopePos);
1786 // Labels partition blocks, so this is the end of the basic block we were
1787 // processing (L is the block's label). Because this is label (and we have
1788 // already processed the substatement) there is no extra control-flow to worry
1790 LabelBlock->setLabel(L);
1794 // We set Block to NULL to allow lazy creation of a new block (if necessary);
1797 // This block is now the implicit successor of other blocks.
1803 CFGBlock *CFGBuilder::VisitLambdaExpr(LambdaExpr *E, AddStmtChoice asc) {
1804 CFGBlock *LastBlock = VisitNoRecurse(E, asc);
1805 for (LambdaExpr::capture_init_iterator it = E->capture_init_begin(),
1806 et = E->capture_init_end(); it != et; ++it) {
1807 if (Expr *Init = *it) {
1808 CFGBlock *Tmp = Visit(Init);
1816 CFGBlock *CFGBuilder::VisitGotoStmt(GotoStmt *G) {
1817 // Goto is a control-flow statement. Thus we stop processing the current
1818 // block and create a new one.
1820 Block = createBlock(false);
1821 Block->setTerminator(G);
1823 // If we already know the mapping to the label block add the successor now.
1824 LabelMapTy::iterator I = LabelMap.find(G->getLabel());
1826 if (I == LabelMap.end())
1827 // We will need to backpatch this block later.
1828 BackpatchBlocks.push_back(JumpSource(Block, ScopePos));
1830 JumpTarget JT = I->second;
1831 addAutomaticObjDtors(ScopePos, JT.scopePosition, G);
1832 addSuccessor(Block, JT.block);
1838 CFGBlock *CFGBuilder::VisitForStmt(ForStmt *F) {
1839 CFGBlock *LoopSuccessor = NULL;
1841 // Save local scope position because in case of condition variable ScopePos
1842 // won't be restored when traversing AST.
1843 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
1845 // Create local scope for init statement and possible condition variable.
1846 // Add destructor for init statement and condition variable.
1847 // Store scope position for continue statement.
1848 if (Stmt *Init = F->getInit())
1849 addLocalScopeForStmt(Init);
1850 LocalScope::const_iterator LoopBeginScopePos = ScopePos;
1852 if (VarDecl *VD = F->getConditionVariable())
1853 addLocalScopeForVarDecl(VD);
1854 LocalScope::const_iterator ContinueScopePos = ScopePos;
1856 addAutomaticObjDtors(ScopePos, save_scope_pos.get(), F);
1858 // "for" is a control-flow statement. Thus we stop processing the current
1863 LoopSuccessor = Block;
1865 LoopSuccessor = Succ;
1867 // Save the current value for the break targets.
1868 // All breaks should go to the code following the loop.
1869 SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
1870 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
1872 CFGBlock *BodyBlock = 0, *TransitionBlock = 0;
1874 // Now create the loop body.
1876 assert(F->getBody());
1878 // Save the current values for Block, Succ, continue and break targets.
1879 SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
1880 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget);
1882 // Create an empty block to represent the transition block for looping back
1883 // to the head of the loop. If we have increment code, it will
1884 // go in this block as well.
1885 Block = Succ = TransitionBlock = createBlock(false);
1886 TransitionBlock->setLoopTarget(F);
1888 if (Stmt *I = F->getInc()) {
1889 // Generate increment code in its own basic block. This is the target of
1890 // continue statements.
1894 // Finish up the increment (or empty) block if it hasn't been already.
1896 assert(Block == Succ);
1902 // The starting block for the loop increment is the block that should
1903 // represent the 'loop target' for looping back to the start of the loop.
1904 ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos);
1905 ContinueJumpTarget.block->setLoopTarget(F);
1907 // Loop body should end with destructor of Condition variable (if any).
1908 addAutomaticObjDtors(ScopePos, LoopBeginScopePos, F);
1910 // If body is not a compound statement create implicit scope
1911 // and add destructors.
1912 if (!isa<CompoundStmt>(F->getBody()))
1913 addLocalScopeAndDtors(F->getBody());
1915 // Now populate the body block, and in the process create new blocks as we
1916 // walk the body of the loop.
1917 BodyBlock = addStmt(F->getBody());
1920 // In the case of "for (...;...;...);" we can have a null BodyBlock.
1921 // Use the continue jump target as the proxy for the body.
1922 BodyBlock = ContinueJumpTarget.block;
1928 // Because of short-circuit evaluation, the condition of the loop can span
1929 // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
1930 // evaluate the condition.
1931 CFGBlock *EntryConditionBlock = 0, *ExitConditionBlock = 0;
1934 Expr *C = F->getCond();
1936 // Specially handle logical operators, which have a slightly
1937 // more optimal CFG representation.
1938 if (BinaryOperator *Cond =
1939 dyn_cast_or_null<BinaryOperator>(C ? C->IgnoreParens() : 0))
1940 if (Cond->isLogicalOp()) {
1941 llvm::tie(EntryConditionBlock, ExitConditionBlock) =
1942 VisitLogicalOperator(Cond, F, BodyBlock, LoopSuccessor);
1946 // The default case when not handling logical operators.
1947 EntryConditionBlock = ExitConditionBlock = createBlock(false);
1948 ExitConditionBlock->setTerminator(F);
1950 // See if this is a known constant.
1951 TryResult KnownVal(true);
1954 // Now add the actual condition to the condition block.
1955 // Because the condition itself may contain control-flow, new blocks may
1956 // be created. Thus we update "Succ" after adding the condition.
1957 Block = ExitConditionBlock;
1958 EntryConditionBlock = addStmt(C);
1960 // If this block contains a condition variable, add both the condition
1961 // variable and initializer to the CFG.
1962 if (VarDecl *VD = F->getConditionVariable()) {
1963 if (Expr *Init = VD->getInit()) {
1965 appendStmt(Block, F->getConditionVariableDeclStmt());
1966 EntryConditionBlock = addStmt(Init);
1967 assert(Block == EntryConditionBlock);
1971 if (Block && badCFG)
1974 KnownVal = tryEvaluateBool(C);
1977 // Add the loop body entry as a successor to the condition.
1978 addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock);
1979 // Link up the condition block with the code that follows the loop. (the
1981 addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
1985 // Link up the loop-back block to the entry condition block.
1986 addSuccessor(TransitionBlock, EntryConditionBlock);
1988 // The condition block is the implicit successor for any code above the loop.
1989 Succ = EntryConditionBlock;
1991 // If the loop contains initialization, create a new block for those
1992 // statements. This block can also contain statements that precede the loop.
1993 if (Stmt *I = F->getInit()) {
1994 Block = createBlock();
1998 // There is no loop initialization. We are thus basically a while loop.
1999 // NULL out Block to force lazy block construction.
2001 Succ = EntryConditionBlock;
2002 return EntryConditionBlock;
2005 CFGBlock *CFGBuilder::VisitMemberExpr(MemberExpr *M, AddStmtChoice asc) {
2006 if (asc.alwaysAdd(*this, M)) {
2008 appendStmt(Block, M);
2010 return Visit(M->getBase());
2013 CFGBlock *CFGBuilder::VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
2014 // Objective-C fast enumeration 'for' statements:
2015 // http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC
2017 // for ( Type newVariable in collection_expression ) { statements }
2022 // 1. collection_expression
2023 // T. jump to loop_entry
2025 // 1. side-effects of element expression
2026 // 1. ObjCForCollectionStmt [performs binding to newVariable]
2027 // T. ObjCForCollectionStmt TB, FB [jumps to TB if newVariable != nil]
2030 // T. jump to loop_entry
2036 // Type existingItem;
2037 // for ( existingItem in expression ) { statements }
2041 // the same with newVariable replaced with existingItem; the binding works
2042 // the same except that for one ObjCForCollectionStmt::getElement() returns
2043 // a DeclStmt and the other returns a DeclRefExpr.
2046 CFGBlock *LoopSuccessor = 0;
2051 LoopSuccessor = Block;
2054 LoopSuccessor = Succ;
2056 // Build the condition blocks.
2057 CFGBlock *ExitConditionBlock = createBlock(false);
2059 // Set the terminator for the "exit" condition block.
2060 ExitConditionBlock->setTerminator(S);
2062 // The last statement in the block should be the ObjCForCollectionStmt, which
2063 // performs the actual binding to 'element' and determines if there are any
2064 // more items in the collection.
2065 appendStmt(ExitConditionBlock, S);
2066 Block = ExitConditionBlock;
2068 // Walk the 'element' expression to see if there are any side-effects. We
2069 // generate new blocks as necessary. We DON'T add the statement by default to
2070 // the CFG unless it contains control-flow.
2071 CFGBlock *EntryConditionBlock = Visit(S->getElement(),
2072 AddStmtChoice::NotAlwaysAdd);
2079 // The condition block is the implicit successor for the loop body as well as
2080 // any code above the loop.
2081 Succ = EntryConditionBlock;
2083 // Now create the true branch.
2085 // Save the current values for Succ, continue and break targets.
2086 SaveAndRestore<CFGBlock*> save_Succ(Succ);
2087 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
2088 save_break(BreakJumpTarget);
2090 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
2091 ContinueJumpTarget = JumpTarget(EntryConditionBlock, ScopePos);
2093 CFGBlock *BodyBlock = addStmt(S->getBody());
2096 BodyBlock = EntryConditionBlock; // can happen for "for (X in Y) ;"
2102 // This new body block is a successor to our "exit" condition block.
2103 addSuccessor(ExitConditionBlock, BodyBlock);
2106 // Link up the condition block with the code that follows the loop.
2107 // (the false branch).
2108 addSuccessor(ExitConditionBlock, LoopSuccessor);
2110 // Now create a prologue block to contain the collection expression.
2111 Block = createBlock();
2112 return addStmt(S->getCollection());
2115 CFGBlock *CFGBuilder::VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S) {
2117 return addStmt(S->getSubStmt());
2118 // TODO: consider adding cleanups for the end of @autoreleasepool scope.
2121 CFGBlock *CFGBuilder::VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S) {
2122 // FIXME: Add locking 'primitives' to CFG for @synchronized.
2125 CFGBlock *SyncBlock = addStmt(S->getSynchBody());
2127 // The sync body starts its own basic block. This makes it a little easier
2128 // for diagnostic clients.
2137 // Add the @synchronized to the CFG.
2139 appendStmt(Block, S);
2141 // Inline the sync expression.
2142 return addStmt(S->getSynchExpr());
2145 CFGBlock *CFGBuilder::VisitObjCAtTryStmt(ObjCAtTryStmt *S) {
2150 CFGBlock *CFGBuilder::VisitPseudoObjectExpr(PseudoObjectExpr *E) {
2153 // Add the PseudoObject as the last thing.
2154 appendStmt(Block, E);
2156 CFGBlock *lastBlock = Block;
2158 // Before that, evaluate all of the semantics in order. In
2159 // CFG-land, that means appending them in reverse order.
2160 for (unsigned i = E->getNumSemanticExprs(); i != 0; ) {
2161 Expr *Semantic = E->getSemanticExpr(--i);
2163 // If the semantic is an opaque value, we're being asked to bind
2164 // it to its source expression.
2165 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
2166 Semantic = OVE->getSourceExpr();
2168 if (CFGBlock *B = Visit(Semantic))
2175 CFGBlock *CFGBuilder::VisitWhileStmt(WhileStmt *W) {
2176 CFGBlock *LoopSuccessor = NULL;
2178 // Save local scope position because in case of condition variable ScopePos
2179 // won't be restored when traversing AST.
2180 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
2182 // Create local scope for possible condition variable.
2183 // Store scope position for continue statement.
2184 LocalScope::const_iterator LoopBeginScopePos = ScopePos;
2185 if (VarDecl *VD = W->getConditionVariable()) {
2186 addLocalScopeForVarDecl(VD);
2187 addAutomaticObjDtors(ScopePos, LoopBeginScopePos, W);
2190 // "while" is a control-flow statement. Thus we stop processing the current
2195 LoopSuccessor = Block;
2198 LoopSuccessor = Succ;
2201 CFGBlock *BodyBlock = 0, *TransitionBlock = 0;
2203 // Process the loop body.
2205 assert(W->getBody());
2207 // Save the current values for Block, Succ, continue and break targets.
2208 SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
2209 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
2210 save_break(BreakJumpTarget);
2212 // Create an empty block to represent the transition block for looping back
2213 // to the head of the loop.
2214 Succ = TransitionBlock = createBlock(false);
2215 TransitionBlock->setLoopTarget(W);
2216 ContinueJumpTarget = JumpTarget(Succ, LoopBeginScopePos);
2218 // All breaks should go to the code following the loop.
2219 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
2221 // Loop body should end with destructor of Condition variable (if any).
2222 addAutomaticObjDtors(ScopePos, LoopBeginScopePos, W);
2224 // If body is not a compound statement create implicit scope
2225 // and add destructors.
2226 if (!isa<CompoundStmt>(W->getBody()))
2227 addLocalScopeAndDtors(W->getBody());
2229 // Create the body. The returned block is the entry to the loop body.
2230 BodyBlock = addStmt(W->getBody());
2233 BodyBlock = ContinueJumpTarget.block; // can happen for "while(...) ;"
2234 else if (Block && badCFG)
2238 // Because of short-circuit evaluation, the condition of the loop can span
2239 // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
2240 // evaluate the condition.
2241 CFGBlock *EntryConditionBlock = 0, *ExitConditionBlock = 0;
2244 Expr *C = W->getCond();
2246 // Specially handle logical operators, which have a slightly
2247 // more optimal CFG representation.
2248 if (BinaryOperator *Cond = dyn_cast<BinaryOperator>(C->IgnoreParens()))
2249 if (Cond->isLogicalOp()) {
2250 llvm::tie(EntryConditionBlock, ExitConditionBlock) =
2251 VisitLogicalOperator(Cond, W, BodyBlock,
2256 // The default case when not handling logical operators.
2257 EntryConditionBlock = ExitConditionBlock = createBlock(false);
2258 ExitConditionBlock->setTerminator(W);
2260 // Now add the actual condition to the condition block.
2261 // Because the condition itself may contain control-flow, new blocks may
2262 // be created. Thus we update "Succ" after adding the condition.
2263 Block = ExitConditionBlock;
2264 Block = EntryConditionBlock = addStmt(C);
2266 // If this block contains a condition variable, add both the condition
2267 // variable and initializer to the CFG.
2268 if (VarDecl *VD = W->getConditionVariable()) {
2269 if (Expr *Init = VD->getInit()) {
2271 appendStmt(Block, W->getConditionVariableDeclStmt());
2272 EntryConditionBlock = addStmt(Init);
2273 assert(Block == EntryConditionBlock);
2277 if (Block && badCFG)
2280 // See if this is a known constant.
2281 const TryResult& KnownVal = tryEvaluateBool(C);
2283 // Add the loop body entry as a successor to the condition.
2284 addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock);
2285 // Link up the condition block with the code that follows the loop. (the
2287 addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
2291 // Link up the loop-back block to the entry condition block.
2292 addSuccessor(TransitionBlock, EntryConditionBlock);
2294 // There can be no more statements in the condition block since we loop back
2295 // to this block. NULL out Block to force lazy creation of another block.
2298 // Return the condition block, which is the dominating block for the loop.
2299 Succ = EntryConditionBlock;
2300 return EntryConditionBlock;
2304 CFGBlock *CFGBuilder::VisitObjCAtCatchStmt(ObjCAtCatchStmt *S) {
2305 // FIXME: For now we pretend that @catch and the code it contains does not
2310 CFGBlock *CFGBuilder::VisitObjCAtThrowStmt(ObjCAtThrowStmt *S) {
2311 // FIXME: This isn't complete. We basically treat @throw like a return
2314 // If we were in the middle of a block we stop processing that block.
2318 // Create the new block.
2319 Block = createBlock(false);
2321 // The Exit block is the only successor.
2322 addSuccessor(Block, &cfg->getExit());
2324 // Add the statement to the block. This may create new blocks if S contains
2325 // control-flow (short-circuit operations).
2326 return VisitStmt(S, AddStmtChoice::AlwaysAdd);
2329 CFGBlock *CFGBuilder::VisitCXXThrowExpr(CXXThrowExpr *T) {
2330 // If we were in the middle of a block we stop processing that block.
2334 // Create the new block.
2335 Block = createBlock(false);
2337 if (TryTerminatedBlock)
2338 // The current try statement is the only successor.
2339 addSuccessor(Block, TryTerminatedBlock);
2341 // otherwise the Exit block is the only successor.
2342 addSuccessor(Block, &cfg->getExit());
2344 // Add the statement to the block. This may create new blocks if S contains
2345 // control-flow (short-circuit operations).
2346 return VisitStmt(T, AddStmtChoice::AlwaysAdd);
2349 CFGBlock *CFGBuilder::VisitDoStmt(DoStmt *D) {
2350 CFGBlock *LoopSuccessor = NULL;
2352 // "do...while" is a control-flow statement. Thus we stop processing the
2357 LoopSuccessor = Block;
2359 LoopSuccessor = Succ;
2361 // Because of short-circuit evaluation, the condition of the loop can span
2362 // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
2363 // evaluate the condition.
2364 CFGBlock *ExitConditionBlock = createBlock(false);
2365 CFGBlock *EntryConditionBlock = ExitConditionBlock;
2367 // Set the terminator for the "exit" condition block.
2368 ExitConditionBlock->setTerminator(D);
2370 // Now add the actual condition to the condition block. Because the condition
2371 // itself may contain control-flow, new blocks may be created.
2372 if (Stmt *C = D->getCond()) {
2373 Block = ExitConditionBlock;
2374 EntryConditionBlock = addStmt(C);
2381 // The condition block is the implicit successor for the loop body.
2382 Succ = EntryConditionBlock;
2384 // See if this is a known constant.
2385 const TryResult &KnownVal = tryEvaluateBool(D->getCond());
2387 // Process the loop body.
2388 CFGBlock *BodyBlock = NULL;
2390 assert(D->getBody());
2392 // Save the current values for Block, Succ, and continue and break targets
2393 SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
2394 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
2395 save_break(BreakJumpTarget);
2397 // All continues within this loop should go to the condition block
2398 ContinueJumpTarget = JumpTarget(EntryConditionBlock, ScopePos);
2400 // All breaks should go to the code following the loop.
2401 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
2403 // NULL out Block to force lazy instantiation of blocks for the body.
2406 // If body is not a compound statement create implicit scope
2407 // and add destructors.
2408 if (!isa<CompoundStmt>(D->getBody()))
2409 addLocalScopeAndDtors(D->getBody());
2411 // Create the body. The returned block is the entry to the loop body.
2412 BodyBlock = addStmt(D->getBody());
2415 BodyBlock = EntryConditionBlock; // can happen for "do ; while(...)"
2421 if (!KnownVal.isFalse()) {
2422 // Add an intermediate block between the BodyBlock and the
2423 // ExitConditionBlock to represent the "loop back" transition. Create an
2424 // empty block to represent the transition block for looping back to the
2425 // head of the loop.
2426 // FIXME: Can we do this more efficiently without adding another block?
2429 CFGBlock *LoopBackBlock = createBlock();
2430 LoopBackBlock->setLoopTarget(D);
2432 // Add the loop body entry as a successor to the condition.
2433 addSuccessor(ExitConditionBlock, LoopBackBlock);
2436 addSuccessor(ExitConditionBlock, NULL);
2439 // Link up the condition block with the code that follows the loop.
2440 // (the false branch).
2441 addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
2443 // There can be no more statements in the body block(s) since we loop back to
2444 // the body. NULL out Block to force lazy creation of another block.
2447 // Return the loop body, which is the dominating block for the loop.
2452 CFGBlock *CFGBuilder::VisitContinueStmt(ContinueStmt *C) {
2453 // "continue" is a control-flow statement. Thus we stop processing the
2458 // Now create a new block that ends with the continue statement.
2459 Block = createBlock(false);
2460 Block->setTerminator(C);
2462 // If there is no target for the continue, then we are looking at an
2463 // incomplete AST. This means the CFG cannot be constructed.
2464 if (ContinueJumpTarget.block) {
2465 addAutomaticObjDtors(ScopePos, ContinueJumpTarget.scopePosition, C);
2466 addSuccessor(Block, ContinueJumpTarget.block);
2473 CFGBlock *CFGBuilder::VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E,
2474 AddStmtChoice asc) {
2476 if (asc.alwaysAdd(*this, E)) {
2478 appendStmt(Block, E);
2481 // VLA types have expressions that must be evaluated.
2482 CFGBlock *lastBlock = Block;
2484 if (E->isArgumentType()) {
2485 for (const VariableArrayType *VA =FindVA(E->getArgumentType().getTypePtr());
2486 VA != 0; VA = FindVA(VA->getElementType().getTypePtr()))
2487 lastBlock = addStmt(VA->getSizeExpr());
2492 /// VisitStmtExpr - Utility method to handle (nested) statement
2493 /// expressions (a GCC extension).
2494 CFGBlock *CFGBuilder::VisitStmtExpr(StmtExpr *SE, AddStmtChoice asc) {
2495 if (asc.alwaysAdd(*this, SE)) {
2497 appendStmt(Block, SE);
2499 return VisitCompoundStmt(SE->getSubStmt());
2502 CFGBlock *CFGBuilder::VisitSwitchStmt(SwitchStmt *Terminator) {
2503 // "switch" is a control-flow statement. Thus we stop processing the current
2505 CFGBlock *SwitchSuccessor = NULL;
2507 // Save local scope position because in case of condition variable ScopePos
2508 // won't be restored when traversing AST.
2509 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
2511 // Create local scope for possible condition variable.
2512 // Store scope position. Add implicit destructor.
2513 if (VarDecl *VD = Terminator->getConditionVariable()) {
2514 LocalScope::const_iterator SwitchBeginScopePos = ScopePos;
2515 addLocalScopeForVarDecl(VD);
2516 addAutomaticObjDtors(ScopePos, SwitchBeginScopePos, Terminator);
2522 SwitchSuccessor = Block;
2523 } else SwitchSuccessor = Succ;
2525 // Save the current "switch" context.
2526 SaveAndRestore<CFGBlock*> save_switch(SwitchTerminatedBlock),
2527 save_default(DefaultCaseBlock);
2528 SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
2530 // Set the "default" case to be the block after the switch statement. If the
2531 // switch statement contains a "default:", this value will be overwritten with
2532 // the block for that code.
2533 DefaultCaseBlock = SwitchSuccessor;
2535 // Create a new block that will contain the switch statement.
2536 SwitchTerminatedBlock = createBlock(false);
2538 // Now process the switch body. The code after the switch is the implicit
2540 Succ = SwitchSuccessor;
2541 BreakJumpTarget = JumpTarget(SwitchSuccessor, ScopePos);
2543 // When visiting the body, the case statements should automatically get linked
2544 // up to the switch. We also don't keep a pointer to the body, since all
2545 // control-flow from the switch goes to case/default statements.
2546 assert(Terminator->getBody() && "switch must contain a non-NULL body");
2549 // For pruning unreachable case statements, save the current state
2550 // for tracking the condition value.
2551 SaveAndRestore<bool> save_switchExclusivelyCovered(switchExclusivelyCovered,
2554 // Determine if the switch condition can be explicitly evaluated.
2555 assert(Terminator->getCond() && "switch condition must be non-NULL");
2556 Expr::EvalResult result;
2557 bool b = tryEvaluate(Terminator->getCond(), result);
2558 SaveAndRestore<Expr::EvalResult*> save_switchCond(switchCond,
2561 // If body is not a compound statement create implicit scope
2562 // and add destructors.
2563 if (!isa<CompoundStmt>(Terminator->getBody()))
2564 addLocalScopeAndDtors(Terminator->getBody());
2566 addStmt(Terminator->getBody());
2572 // If we have no "default:" case, the default transition is to the code
2573 // following the switch body. Moreover, take into account if all the
2574 // cases of a switch are covered (e.g., switching on an enum value).
2575 addSuccessor(SwitchTerminatedBlock,
2576 switchExclusivelyCovered || Terminator->isAllEnumCasesCovered()
2577 ? 0 : DefaultCaseBlock);
2579 // Add the terminator and condition in the switch block.
2580 SwitchTerminatedBlock->setTerminator(Terminator);
2581 Block = SwitchTerminatedBlock;
2582 Block = addStmt(Terminator->getCond());
2584 // Finally, if the SwitchStmt contains a condition variable, add both the
2585 // SwitchStmt and the condition variable initialization to the CFG.
2586 if (VarDecl *VD = Terminator->getConditionVariable()) {
2587 if (Expr *Init = VD->getInit()) {
2589 appendStmt(Block, Terminator->getConditionVariableDeclStmt());
2597 static bool shouldAddCase(bool &switchExclusivelyCovered,
2598 const Expr::EvalResult *switchCond,
2604 bool addCase = false;
2606 if (!switchExclusivelyCovered) {
2607 if (switchCond->Val.isInt()) {
2608 // Evaluate the LHS of the case value.
2609 const llvm::APSInt &lhsInt = CS->getLHS()->EvaluateKnownConstInt(Ctx);
2610 const llvm::APSInt &condInt = switchCond->Val.getInt();
2612 if (condInt == lhsInt) {
2614 switchExclusivelyCovered = true;
2616 else if (condInt < lhsInt) {
2617 if (const Expr *RHS = CS->getRHS()) {
2618 // Evaluate the RHS of the case value.
2619 const llvm::APSInt &V2 = RHS->EvaluateKnownConstInt(Ctx);
2620 if (V2 <= condInt) {
2622 switchExclusivelyCovered = true;
2633 CFGBlock *CFGBuilder::VisitCaseStmt(CaseStmt *CS) {
2634 // CaseStmts are essentially labels, so they are the first statement in a
2636 CFGBlock *TopBlock = 0, *LastBlock = 0;
2638 if (Stmt *Sub = CS->getSubStmt()) {
2639 // For deeply nested chains of CaseStmts, instead of doing a recursion
2640 // (which can blow out the stack), manually unroll and create blocks
2642 while (isa<CaseStmt>(Sub)) {
2643 CFGBlock *currentBlock = createBlock(false);
2644 currentBlock->setLabel(CS);
2647 addSuccessor(LastBlock, currentBlock);
2649 TopBlock = currentBlock;
2651 addSuccessor(SwitchTerminatedBlock,
2652 shouldAddCase(switchExclusivelyCovered, switchCond,
2654 ? currentBlock : 0);
2656 LastBlock = currentBlock;
2657 CS = cast<CaseStmt>(Sub);
2658 Sub = CS->getSubStmt();
2664 CFGBlock *CaseBlock = Block;
2666 CaseBlock = createBlock();
2668 // Cases statements partition blocks, so this is the top of the basic block we
2669 // were processing (the "case XXX:" is the label).
2670 CaseBlock->setLabel(CS);
2675 // Add this block to the list of successors for the block with the switch
2677 assert(SwitchTerminatedBlock);
2678 addSuccessor(SwitchTerminatedBlock,
2679 shouldAddCase(switchExclusivelyCovered, switchCond,
2683 // We set Block to NULL to allow lazy creation of a new block (if necessary)
2687 addSuccessor(LastBlock, CaseBlock);
2690 // This block is now the implicit successor of other blocks.
2697 CFGBlock *CFGBuilder::VisitDefaultStmt(DefaultStmt *Terminator) {
2698 if (Terminator->getSubStmt())
2699 addStmt(Terminator->getSubStmt());
2701 DefaultCaseBlock = Block;
2703 if (!DefaultCaseBlock)
2704 DefaultCaseBlock = createBlock();
2706 // Default statements partition blocks, so this is the top of the basic block
2707 // we were processing (the "default:" is the label).
2708 DefaultCaseBlock->setLabel(Terminator);
2713 // Unlike case statements, we don't add the default block to the successors
2714 // for the switch statement immediately. This is done when we finish
2715 // processing the switch statement. This allows for the default case
2716 // (including a fall-through to the code after the switch statement) to always
2717 // be the last successor of a switch-terminated block.
2719 // We set Block to NULL to allow lazy creation of a new block (if necessary)
2722 // This block is now the implicit successor of other blocks.
2723 Succ = DefaultCaseBlock;
2725 return DefaultCaseBlock;
2728 CFGBlock *CFGBuilder::VisitCXXTryStmt(CXXTryStmt *Terminator) {
2729 // "try"/"catch" is a control-flow statement. Thus we stop processing the
2731 CFGBlock *TrySuccessor = NULL;
2736 TrySuccessor = Block;
2737 } else TrySuccessor = Succ;
2739 CFGBlock *PrevTryTerminatedBlock = TryTerminatedBlock;
2741 // Create a new block that will contain the try statement.
2742 CFGBlock *NewTryTerminatedBlock = createBlock(false);
2743 // Add the terminator in the try block.
2744 NewTryTerminatedBlock->setTerminator(Terminator);
2746 bool HasCatchAll = false;
2747 for (unsigned h = 0; h <Terminator->getNumHandlers(); ++h) {
2748 // The code after the try is the implicit successor.
2749 Succ = TrySuccessor;
2750 CXXCatchStmt *CS = Terminator->getHandler(h);
2751 if (CS->getExceptionDecl() == 0) {
2755 CFGBlock *CatchBlock = VisitCXXCatchStmt(CS);
2756 if (CatchBlock == 0)
2758 // Add this block to the list of successors for the block with the try
2760 addSuccessor(NewTryTerminatedBlock, CatchBlock);
2763 if (PrevTryTerminatedBlock)
2764 addSuccessor(NewTryTerminatedBlock, PrevTryTerminatedBlock);
2766 addSuccessor(NewTryTerminatedBlock, &cfg->getExit());
2769 // The code after the try is the implicit successor.
2770 Succ = TrySuccessor;
2772 // Save the current "try" context.
2773 SaveAndRestore<CFGBlock*> save_try(TryTerminatedBlock, NewTryTerminatedBlock);
2774 cfg->addTryDispatchBlock(TryTerminatedBlock);
2776 assert(Terminator->getTryBlock() && "try must contain a non-NULL body");
2778 Block = addStmt(Terminator->getTryBlock());
2782 CFGBlock *CFGBuilder::VisitCXXCatchStmt(CXXCatchStmt *CS) {
2783 // CXXCatchStmt are treated like labels, so they are the first statement in a
2786 // Save local scope position because in case of exception variable ScopePos
2787 // won't be restored when traversing AST.
2788 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
2790 // Create local scope for possible exception variable.
2791 // Store scope position. Add implicit destructor.
2792 if (VarDecl *VD = CS->getExceptionDecl()) {
2793 LocalScope::const_iterator BeginScopePos = ScopePos;
2794 addLocalScopeForVarDecl(VD);
2795 addAutomaticObjDtors(ScopePos, BeginScopePos, CS);
2798 if (CS->getHandlerBlock())
2799 addStmt(CS->getHandlerBlock());
2801 CFGBlock *CatchBlock = Block;
2803 CatchBlock = createBlock();
2805 // CXXCatchStmt is more than just a label. They have semantic meaning
2806 // as well, as they implicitly "initialize" the catch variable. Add
2807 // it to the CFG as a CFGElement so that the control-flow of these
2808 // semantics gets captured.
2809 appendStmt(CatchBlock, CS);
2811 // Also add the CXXCatchStmt as a label, to mirror handling of regular
2813 CatchBlock->setLabel(CS);
2815 // Bail out if the CFG is bad.
2819 // We set Block to NULL to allow lazy creation of a new block (if necessary)
2825 CFGBlock *CFGBuilder::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
2826 // C++0x for-range statements are specified as [stmt.ranged]:
2829 // auto && __range = range-init;
2830 // for ( auto __begin = begin-expr,
2831 // __end = end-expr;
2832 // __begin != __end;
2834 // for-range-declaration = *__begin;
2839 // Save local scope position before the addition of the implicit variables.
2840 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
2842 // Create local scopes and destructors for range, begin and end variables.
2843 if (Stmt *Range = S->getRangeStmt())
2844 addLocalScopeForStmt(Range);
2845 if (Stmt *BeginEnd = S->getBeginEndStmt())
2846 addLocalScopeForStmt(BeginEnd);
2847 addAutomaticObjDtors(ScopePos, save_scope_pos.get(), S);
2849 LocalScope::const_iterator ContinueScopePos = ScopePos;
2851 // "for" is a control-flow statement. Thus we stop processing the current
2853 CFGBlock *LoopSuccessor = NULL;
2857 LoopSuccessor = Block;
2859 LoopSuccessor = Succ;
2861 // Save the current value for the break targets.
2862 // All breaks should go to the code following the loop.
2863 SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
2864 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
2866 // The block for the __begin != __end expression.
2867 CFGBlock *ConditionBlock = createBlock(false);
2868 ConditionBlock->setTerminator(S);
2870 // Now add the actual condition to the condition block.
2871 if (Expr *C = S->getCond()) {
2872 Block = ConditionBlock;
2873 CFGBlock *BeginConditionBlock = addStmt(C);
2876 assert(BeginConditionBlock == ConditionBlock &&
2877 "condition block in for-range was unexpectedly complex");
2878 (void)BeginConditionBlock;
2881 // The condition block is the implicit successor for the loop body as well as
2882 // any code above the loop.
2883 Succ = ConditionBlock;
2885 // See if this is a known constant.
2886 TryResult KnownVal(true);
2889 KnownVal = tryEvaluateBool(S->getCond());
2891 // Now create the loop body.
2893 assert(S->getBody());
2895 // Save the current values for Block, Succ, and continue targets.
2896 SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
2897 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget);
2899 // Generate increment code in its own basic block. This is the target of
2900 // continue statements.
2902 Succ = addStmt(S->getInc());
2903 ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos);
2905 // The starting block for the loop increment is the block that should
2906 // represent the 'loop target' for looping back to the start of the loop.
2907 ContinueJumpTarget.block->setLoopTarget(S);
2909 // Finish up the increment block and prepare to start the loop body.
2916 // Add implicit scope and dtors for loop variable.
2917 addLocalScopeAndDtors(S->getLoopVarStmt());
2919 // Populate a new block to contain the loop body and loop variable.
2920 Block = addStmt(S->getBody());
2923 Block = addStmt(S->getLoopVarStmt());
2927 // This new body block is a successor to our condition block.
2928 addSuccessor(ConditionBlock, KnownVal.isFalse() ? 0 : Block);
2931 // Link up the condition block with the code that follows the loop (the
2933 addSuccessor(ConditionBlock, KnownVal.isTrue() ? 0 : LoopSuccessor);
2935 // Add the initialization statements.
2936 Block = createBlock();
2937 addStmt(S->getBeginEndStmt());
2938 return addStmt(S->getRangeStmt());
2941 CFGBlock *CFGBuilder::VisitExprWithCleanups(ExprWithCleanups *E,
2942 AddStmtChoice asc) {
2943 if (BuildOpts.AddImplicitDtors) {
2944 // If adding implicit destructors visit the full expression for adding
2945 // destructors of temporaries.
2946 VisitForTemporaryDtors(E->getSubExpr());
2948 // Full expression has to be added as CFGStmt so it will be sequenced
2949 // before destructors of it's temporaries.
2950 asc = asc.withAlwaysAdd(true);
2952 return Visit(E->getSubExpr(), asc);
2955 CFGBlock *CFGBuilder::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E,
2956 AddStmtChoice asc) {
2957 if (asc.alwaysAdd(*this, E)) {
2959 appendStmt(Block, E);
2961 // We do not want to propagate the AlwaysAdd property.
2962 asc = asc.withAlwaysAdd(false);
2964 return Visit(E->getSubExpr(), asc);
2967 CFGBlock *CFGBuilder::VisitCXXConstructExpr(CXXConstructExpr *C,
2968 AddStmtChoice asc) {
2970 appendStmt(Block, C);
2972 return VisitChildren(C);
2975 CFGBlock *CFGBuilder::VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E,
2976 AddStmtChoice asc) {
2977 if (asc.alwaysAdd(*this, E)) {
2979 appendStmt(Block, E);
2980 // We do not want to propagate the AlwaysAdd property.
2981 asc = asc.withAlwaysAdd(false);
2983 return Visit(E->getSubExpr(), asc);
2986 CFGBlock *CFGBuilder::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C,
2987 AddStmtChoice asc) {
2989 appendStmt(Block, C);
2990 return VisitChildren(C);
2993 CFGBlock *CFGBuilder::VisitImplicitCastExpr(ImplicitCastExpr *E,
2994 AddStmtChoice asc) {
2995 if (asc.alwaysAdd(*this, E)) {
2997 appendStmt(Block, E);
2999 return Visit(E->getSubExpr(), AddStmtChoice());
3002 CFGBlock *CFGBuilder::VisitIndirectGotoStmt(IndirectGotoStmt *I) {
3003 // Lazily create the indirect-goto dispatch block if there isn't one already.
3004 CFGBlock *IBlock = cfg->getIndirectGotoBlock();
3007 IBlock = createBlock(false);
3008 cfg->setIndirectGotoBlock(IBlock);
3011 // IndirectGoto is a control-flow statement. Thus we stop processing the
3012 // current block and create a new one.
3016 Block = createBlock(false);
3017 Block->setTerminator(I);
3018 addSuccessor(Block, IBlock);
3019 return addStmt(I->getTarget());
3022 CFGBlock *CFGBuilder::VisitForTemporaryDtors(Stmt *E, bool BindToTemporary) {
3028 switch (E->getStmtClass()) {
3030 return VisitChildrenForTemporaryDtors(E);
3032 case Stmt::BinaryOperatorClass:
3033 return VisitBinaryOperatorForTemporaryDtors(cast<BinaryOperator>(E));
3035 case Stmt::CXXBindTemporaryExprClass:
3036 return VisitCXXBindTemporaryExprForTemporaryDtors(
3037 cast<CXXBindTemporaryExpr>(E), BindToTemporary);
3039 case Stmt::BinaryConditionalOperatorClass:
3040 case Stmt::ConditionalOperatorClass:
3041 return VisitConditionalOperatorForTemporaryDtors(
3042 cast<AbstractConditionalOperator>(E), BindToTemporary);
3044 case Stmt::ImplicitCastExprClass:
3045 // For implicit cast we want BindToTemporary to be passed further.
3046 E = cast<CastExpr>(E)->getSubExpr();
3049 case Stmt::ParenExprClass:
3050 E = cast<ParenExpr>(E)->getSubExpr();
3053 case Stmt::MaterializeTemporaryExprClass:
3054 E = cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr();
3059 CFGBlock *CFGBuilder::VisitChildrenForTemporaryDtors(Stmt *E) {
3060 // When visiting children for destructors we want to visit them in reverse
3061 // order. Because there's no reverse iterator for children must to reverse
3062 // them in helper vector.
3063 typedef SmallVector<Stmt *, 4> ChildrenVect;
3064 ChildrenVect ChildrenRev;
3065 for (Stmt::child_range I = E->children(); I; ++I) {
3066 if (*I) ChildrenRev.push_back(*I);
3069 CFGBlock *B = Block;
3070 for (ChildrenVect::reverse_iterator I = ChildrenRev.rbegin(),
3071 L = ChildrenRev.rend(); I != L; ++I) {
3072 if (CFGBlock *R = VisitForTemporaryDtors(*I))
3078 CFGBlock *CFGBuilder::VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E) {
3079 if (E->isLogicalOp()) {
3080 // Destructors for temporaries in LHS expression should be called after
3081 // those for RHS expression. Even if this will unnecessarily create a block,
3082 // this block will be used at least by the full expression.
3084 CFGBlock *ConfluenceBlock = VisitForTemporaryDtors(E->getLHS());
3088 Succ = ConfluenceBlock;
3090 CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
3096 // If RHS expression did produce destructors we need to connect created
3097 // blocks to CFG in same manner as for binary operator itself.
3098 CFGBlock *LHSBlock = createBlock(false);
3099 LHSBlock->setTerminator(CFGTerminator(E, true));
3101 // For binary operator LHS block is before RHS in list of predecessors
3102 // of ConfluenceBlock.
3103 std::reverse(ConfluenceBlock->pred_begin(),
3104 ConfluenceBlock->pred_end());
3106 // See if this is a known constant.
3107 TryResult KnownVal = tryEvaluateBool(E->getLHS());
3108 if (KnownVal.isKnown() && (E->getOpcode() == BO_LOr))
3111 // Link LHSBlock with RHSBlock exactly the same way as for binary operator
3113 if (E->getOpcode() == BO_LOr) {
3114 addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
3115 addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
3117 assert (E->getOpcode() == BO_LAnd);
3118 addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
3119 addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
3126 Block = ConfluenceBlock;
3127 return ConfluenceBlock;
3130 if (E->isAssignmentOp()) {
3131 // For assignment operator (=) LHS expression is visited
3132 // before RHS expression. For destructors visit them in reverse order.
3133 CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
3134 CFGBlock *LHSBlock = VisitForTemporaryDtors(E->getLHS());
3135 return LHSBlock ? LHSBlock : RHSBlock;
3138 // For any other binary operator RHS expression is visited before
3139 // LHS expression (order of children). For destructors visit them in reverse
3141 CFGBlock *LHSBlock = VisitForTemporaryDtors(E->getLHS());
3142 CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
3143 return RHSBlock ? RHSBlock : LHSBlock;
3146 CFGBlock *CFGBuilder::VisitCXXBindTemporaryExprForTemporaryDtors(
3147 CXXBindTemporaryExpr *E, bool BindToTemporary) {
3148 // First add destructors for temporaries in subexpression.
3149 CFGBlock *B = VisitForTemporaryDtors(E->getSubExpr());
3150 if (!BindToTemporary) {
3151 // If lifetime of temporary is not prolonged (by assigning to constant
3152 // reference) add destructor for it.
3154 // If the destructor is marked as a no-return destructor, we need to create
3155 // a new block for the destructor which does not have as a successor
3156 // anything built thus far. Control won't flow out of this block.
3157 const CXXDestructorDecl *Dtor = E->getTemporary()->getDestructor();
3158 if (cast<FunctionType>(Dtor->getType())->getNoReturnAttr())
3159 Block = createNoReturnBlock();
3163 appendTemporaryDtor(Block, E);
3169 CFGBlock *CFGBuilder::VisitConditionalOperatorForTemporaryDtors(
3170 AbstractConditionalOperator *E, bool BindToTemporary) {
3171 // First add destructors for condition expression. Even if this will
3172 // unnecessarily create a block, this block will be used at least by the full
3175 CFGBlock *ConfluenceBlock = VisitForTemporaryDtors(E->getCond());
3178 if (BinaryConditionalOperator *BCO
3179 = dyn_cast<BinaryConditionalOperator>(E)) {
3180 ConfluenceBlock = VisitForTemporaryDtors(BCO->getCommon());
3185 // Try to add block with destructors for LHS expression.
3186 CFGBlock *LHSBlock = NULL;
3187 Succ = ConfluenceBlock;
3189 LHSBlock = VisitForTemporaryDtors(E->getTrueExpr(), BindToTemporary);
3193 // Try to add block with destructors for RHS expression;
3194 Succ = ConfluenceBlock;
3196 CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getFalseExpr(),
3201 if (!RHSBlock && !LHSBlock) {
3202 // If neither LHS nor RHS expression had temporaries to destroy don't create
3204 Block = ConfluenceBlock;
3208 Block = createBlock(false);
3209 Block->setTerminator(CFGTerminator(E, true));
3211 // See if this is a known constant.
3212 const TryResult &KnownVal = tryEvaluateBool(E->getCond());
3215 addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
3216 } else if (KnownVal.isFalse()) {
3217 addSuccessor(Block, NULL);
3219 addSuccessor(Block, ConfluenceBlock);
3220 std::reverse(ConfluenceBlock->pred_begin(), ConfluenceBlock->pred_end());
3224 RHSBlock = ConfluenceBlock;
3225 addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
3230 } // end anonymous namespace
3232 /// createBlock - Constructs and adds a new CFGBlock to the CFG. The block has
3233 /// no successors or predecessors. If this is the first block created in the
3234 /// CFG, it is automatically set to be the Entry and Exit of the CFG.
3235 CFGBlock *CFG::createBlock() {
3236 bool first_block = begin() == end();
3238 // Create the block.
3239 CFGBlock *Mem = getAllocator().Allocate<CFGBlock>();
3240 new (Mem) CFGBlock(NumBlockIDs++, BlkBVC, this);
3241 Blocks.push_back(Mem, BlkBVC);
3243 // If this is the first block, set it as the Entry and Exit.
3245 Entry = Exit = &back();
3247 // Return the block.
3251 /// buildCFG - Constructs a CFG from an AST. Ownership of the returned
3252 /// CFG is returned to the caller.
3253 CFG* CFG::buildCFG(const Decl *D, Stmt *Statement, ASTContext *C,
3254 const BuildOptions &BO) {
3255 CFGBuilder Builder(C, BO);
3256 return Builder.buildCFG(D, Statement);
3259 const CXXDestructorDecl *
3260 CFGImplicitDtor::getDestructorDecl(ASTContext &astContext) const {
3261 switch (getKind()) {
3262 case CFGElement::Invalid:
3263 case CFGElement::Statement:
3264 case CFGElement::Initializer:
3265 llvm_unreachable("getDestructorDecl should only be used with "
3267 case CFGElement::AutomaticObjectDtor: {
3268 const VarDecl *var = cast<CFGAutomaticObjDtor>(this)->getVarDecl();
3269 QualType ty = var->getType();
3270 ty = ty.getNonReferenceType();
3271 while (const ArrayType *arrayType = astContext.getAsArrayType(ty)) {
3272 ty = arrayType->getElementType();
3274 const RecordType *recordType = ty->getAs<RecordType>();
3275 const CXXRecordDecl *classDecl =
3276 cast<CXXRecordDecl>(recordType->getDecl());
3277 return classDecl->getDestructor();
3279 case CFGElement::TemporaryDtor: {
3280 const CXXBindTemporaryExpr *bindExpr =
3281 cast<CFGTemporaryDtor>(this)->getBindTemporaryExpr();
3282 const CXXTemporary *temp = bindExpr->getTemporary();
3283 return temp->getDestructor();
3285 case CFGElement::BaseDtor:
3286 case CFGElement::MemberDtor:
3288 // Not yet supported.
3291 llvm_unreachable("getKind() returned bogus value");
3294 bool CFGImplicitDtor::isNoReturn(ASTContext &astContext) const {
3295 if (const CXXDestructorDecl *decl = getDestructorDecl(astContext)) {
3296 QualType ty = decl->getType();
3297 return cast<FunctionType>(ty)->getNoReturnAttr();
3302 //===----------------------------------------------------------------------===//
3303 // CFG: Queries for BlkExprs.
3304 //===----------------------------------------------------------------------===//
3307 typedef llvm::DenseMap<const Stmt*,unsigned> BlkExprMapTy;
3310 static void FindSubExprAssignments(const Stmt *S,
3311 llvm::SmallPtrSet<const Expr*,50>& Set) {
3315 for (Stmt::const_child_range I = S->children(); I; ++I) {
3316 const Stmt *child = *I;
3320 if (const BinaryOperator* B = dyn_cast<BinaryOperator>(child))
3321 if (B->isAssignmentOp()) Set.insert(B);
3323 FindSubExprAssignments(child, Set);
3327 static BlkExprMapTy* PopulateBlkExprMap(CFG& cfg) {
3328 BlkExprMapTy* M = new BlkExprMapTy();
3330 // Look for assignments that are used as subexpressions. These are the only
3331 // assignments that we want to *possibly* register as a block-level
3332 // expression. Basically, if an assignment occurs both in a subexpression and
3333 // at the block-level, it is a block-level expression.
3334 llvm::SmallPtrSet<const Expr*,50> SubExprAssignments;
3336 for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I)
3337 for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI)
3338 if (const CFGStmt *S = BI->getAs<CFGStmt>())
3339 FindSubExprAssignments(S->getStmt(), SubExprAssignments);
3341 for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I) {
3343 // Iterate over the statements again on identify the Expr* and Stmt* at the
3344 // block-level that are block-level expressions.
3346 for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI) {
3347 const CFGStmt *CS = BI->getAs<CFGStmt>();
3350 if (const Expr *Exp = dyn_cast<Expr>(CS->getStmt())) {
3351 assert((Exp->IgnoreParens() == Exp) && "No parens on block-level exps");
3353 if (const BinaryOperator* B = dyn_cast<BinaryOperator>(Exp)) {
3354 // Assignment expressions that are not nested within another
3355 // expression are really "statements" whose value is never used by
3356 // another expression.
3357 if (B->isAssignmentOp() && !SubExprAssignments.count(Exp))
3359 } else if (const StmtExpr *SE = dyn_cast<StmtExpr>(Exp)) {
3360 // Special handling for statement expressions. The last statement in
3361 // the statement expression is also a block-level expr.
3362 const CompoundStmt *C = SE->getSubStmt();
3363 if (!C->body_empty()) {
3364 const Stmt *Last = C->body_back();
3365 if (const Expr *LastEx = dyn_cast<Expr>(Last))
3366 Last = LastEx->IgnoreParens();
3367 unsigned x = M->size();
3372 unsigned x = M->size();
3377 // Look at terminators. The condition is a block-level expression.
3379 Stmt *S = (*I)->getTerminatorCondition();
3381 if (S && M->find(S) == M->end()) {
3382 unsigned x = M->size();
3390 CFG::BlkExprNumTy CFG::getBlkExprNum(const Stmt *S) {
3392 if (!BlkExprMap) { BlkExprMap = (void*) PopulateBlkExprMap(*this); }
3394 BlkExprMapTy* M = reinterpret_cast<BlkExprMapTy*>(BlkExprMap);
3395 BlkExprMapTy::iterator I = M->find(S);
3396 return (I == M->end()) ? CFG::BlkExprNumTy() : CFG::BlkExprNumTy(I->second);
3399 unsigned CFG::getNumBlkExprs() {
3400 if (const BlkExprMapTy* M = reinterpret_cast<const BlkExprMapTy*>(BlkExprMap))
3403 // We assume callers interested in the number of BlkExprs will want
3404 // the map constructed if it doesn't already exist.
3405 BlkExprMap = (void*) PopulateBlkExprMap(*this);
3406 return reinterpret_cast<BlkExprMapTy*>(BlkExprMap)->size();
3409 //===----------------------------------------------------------------------===//
3410 // Filtered walking of the CFG.
3411 //===----------------------------------------------------------------------===//
3413 bool CFGBlock::FilterEdge(const CFGBlock::FilterOptions &F,
3414 const CFGBlock *From, const CFGBlock *To) {
3416 if (To && F.IgnoreDefaultsWithCoveredEnums) {
3417 // If the 'To' has no label or is labeled but the label isn't a
3418 // CaseStmt then filter this edge.
3419 if (const SwitchStmt *S =
3420 dyn_cast_or_null<SwitchStmt>(From->getTerminator().getStmt())) {
3421 if (S->isAllEnumCasesCovered()) {
3422 const Stmt *L = To->getLabel();
3423 if (!L || !isa<CaseStmt>(L))
3432 //===----------------------------------------------------------------------===//
3433 // Cleanup: CFG dstor.
3434 //===----------------------------------------------------------------------===//
3437 delete reinterpret_cast<const BlkExprMapTy*>(BlkExprMap);
3440 //===----------------------------------------------------------------------===//
3441 // CFG pretty printing
3442 //===----------------------------------------------------------------------===//
3446 class StmtPrinterHelper : public PrinterHelper {
3447 typedef llvm::DenseMap<const Stmt*,std::pair<unsigned,unsigned> > StmtMapTy;
3448 typedef llvm::DenseMap<const Decl*,std::pair<unsigned,unsigned> > DeclMapTy;
3451 signed currentBlock;
3452 unsigned currentStmt;
3453 const LangOptions &LangOpts;
3456 StmtPrinterHelper(const CFG* cfg, const LangOptions &LO)
3457 : currentBlock(0), currentStmt(0), LangOpts(LO)
3459 for (CFG::const_iterator I = cfg->begin(), E = cfg->end(); I != E; ++I ) {
3461 for (CFGBlock::const_iterator BI = (*I)->begin(), BEnd = (*I)->end() ;
3462 BI != BEnd; ++BI, ++j ) {
3463 if (const CFGStmt *SE = BI->getAs<CFGStmt>()) {
3464 const Stmt *stmt= SE->getStmt();
3465 std::pair<unsigned, unsigned> P((*I)->getBlockID(), j);
3468 switch (stmt->getStmtClass()) {
3469 case Stmt::DeclStmtClass:
3470 DeclMap[cast<DeclStmt>(stmt)->getSingleDecl()] = P;
3472 case Stmt::IfStmtClass: {
3473 const VarDecl *var = cast<IfStmt>(stmt)->getConditionVariable();
3478 case Stmt::ForStmtClass: {
3479 const VarDecl *var = cast<ForStmt>(stmt)->getConditionVariable();
3484 case Stmt::WhileStmtClass: {
3485 const VarDecl *var =
3486 cast<WhileStmt>(stmt)->getConditionVariable();
3491 case Stmt::SwitchStmtClass: {
3492 const VarDecl *var =
3493 cast<SwitchStmt>(stmt)->getConditionVariable();
3498 case Stmt::CXXCatchStmtClass: {
3499 const VarDecl *var =
3500 cast<CXXCatchStmt>(stmt)->getExceptionDecl();
3514 virtual ~StmtPrinterHelper() {}
3516 const LangOptions &getLangOpts() const { return LangOpts; }
3517 void setBlockID(signed i) { currentBlock = i; }
3518 void setStmtID(unsigned i) { currentStmt = i; }
3520 virtual bool handledStmt(Stmt *S, raw_ostream &OS) {
3521 StmtMapTy::iterator I = StmtMap.find(S);
3523 if (I == StmtMap.end())
3526 if (currentBlock >= 0 && I->second.first == (unsigned) currentBlock
3527 && I->second.second == currentStmt) {
3531 OS << "[B" << I->second.first << "." << I->second.second << "]";
3535 bool handleDecl(const Decl *D, raw_ostream &OS) {
3536 DeclMapTy::iterator I = DeclMap.find(D);
3538 if (I == DeclMap.end())
3541 if (currentBlock >= 0 && I->second.first == (unsigned) currentBlock
3542 && I->second.second == currentStmt) {
3546 OS << "[B" << I->second.first << "." << I->second.second << "]";
3550 } // end anonymous namespace
3554 class CFGBlockTerminatorPrint
3555 : public StmtVisitor<CFGBlockTerminatorPrint,void> {
3558 StmtPrinterHelper* Helper;
3559 PrintingPolicy Policy;
3561 CFGBlockTerminatorPrint(raw_ostream &os, StmtPrinterHelper* helper,
3562 const PrintingPolicy &Policy)
3563 : OS(os), Helper(helper), Policy(Policy) {}
3565 void VisitIfStmt(IfStmt *I) {
3567 I->getCond()->printPretty(OS,Helper,Policy);
3571 void VisitStmt(Stmt *Terminator) {
3572 Terminator->printPretty(OS, Helper, Policy);
3575 void VisitForStmt(ForStmt *F) {
3580 if (Stmt *C = F->getCond())
3581 C->printPretty(OS, Helper, Policy);
3588 void VisitWhileStmt(WhileStmt *W) {
3590 if (Stmt *C = W->getCond())
3591 C->printPretty(OS, Helper, Policy);
3594 void VisitDoStmt(DoStmt *D) {
3595 OS << "do ... while ";
3596 if (Stmt *C = D->getCond())
3597 C->printPretty(OS, Helper, Policy);
3600 void VisitSwitchStmt(SwitchStmt *Terminator) {
3602 Terminator->getCond()->printPretty(OS, Helper, Policy);
3605 void VisitCXXTryStmt(CXXTryStmt *CS) {
3609 void VisitAbstractConditionalOperator(AbstractConditionalOperator* C) {
3610 C->getCond()->printPretty(OS, Helper, Policy);
3611 OS << " ? ... : ...";
3614 void VisitChooseExpr(ChooseExpr *C) {
3615 OS << "__builtin_choose_expr( ";
3616 C->getCond()->printPretty(OS, Helper, Policy);
3620 void VisitIndirectGotoStmt(IndirectGotoStmt *I) {
3622 I->getTarget()->printPretty(OS, Helper, Policy);
3625 void VisitBinaryOperator(BinaryOperator* B) {
3626 if (!B->isLogicalOp()) {
3631 B->getLHS()->printPretty(OS, Helper, Policy);
3633 switch (B->getOpcode()) {
3641 llvm_unreachable("Invalid logical operator.");
3645 void VisitExpr(Expr *E) {
3646 E->printPretty(OS, Helper, Policy);
3649 } // end anonymous namespace
3651 static void print_elem(raw_ostream &OS, StmtPrinterHelper* Helper,
3652 const CFGElement &E) {
3653 if (const CFGStmt *CS = E.getAs<CFGStmt>()) {
3654 const Stmt *S = CS->getStmt();
3658 // special printing for statement-expressions.
3659 if (const StmtExpr *SE = dyn_cast<StmtExpr>(S)) {
3660 const CompoundStmt *Sub = SE->getSubStmt();
3662 if (Sub->children()) {
3664 Helper->handledStmt(*SE->getSubStmt()->body_rbegin(),OS);
3669 // special printing for comma expressions.
3670 if (const BinaryOperator* B = dyn_cast<BinaryOperator>(S)) {
3671 if (B->getOpcode() == BO_Comma) {
3673 Helper->handledStmt(B->getRHS(),OS);
3679 S->printPretty(OS, Helper, PrintingPolicy(Helper->getLangOpts()));
3681 if (isa<CXXOperatorCallExpr>(S)) {
3682 OS << " (OperatorCall)";
3684 else if (isa<CXXBindTemporaryExpr>(S)) {
3685 OS << " (BindTemporary)";
3687 else if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(S)) {
3688 OS << " (CXXConstructExpr, " << CCE->getType().getAsString() << ")";
3690 else if (const CastExpr *CE = dyn_cast<CastExpr>(S)) {
3691 OS << " (" << CE->getStmtClassName() << ", "
3692 << CE->getCastKindName()
3693 << ", " << CE->getType().getAsString()
3697 // Expressions need a newline.
3701 } else if (const CFGInitializer *IE = E.getAs<CFGInitializer>()) {
3702 const CXXCtorInitializer *I = IE->getInitializer();
3703 if (I->isBaseInitializer())
3704 OS << I->getBaseClass()->getAsCXXRecordDecl()->getName();
3705 else OS << I->getAnyMember()->getName();
3708 if (Expr *IE = I->getInit())
3709 IE->printPretty(OS, Helper, PrintingPolicy(Helper->getLangOpts()));
3712 if (I->isBaseInitializer())
3713 OS << " (Base initializer)\n";
3714 else OS << " (Member initializer)\n";
3716 } else if (const CFGAutomaticObjDtor *DE = E.getAs<CFGAutomaticObjDtor>()){
3717 const VarDecl *VD = DE->getVarDecl();
3718 Helper->handleDecl(VD, OS);
3720 const Type* T = VD->getType().getTypePtr();
3721 if (const ReferenceType* RT = T->getAs<ReferenceType>())
3722 T = RT->getPointeeType().getTypePtr();
3723 T = T->getBaseElementTypeUnsafe();
3725 OS << ".~" << T->getAsCXXRecordDecl()->getName().str() << "()";
3726 OS << " (Implicit destructor)\n";
3728 } else if (const CFGBaseDtor *BE = E.getAs<CFGBaseDtor>()) {
3729 const CXXBaseSpecifier *BS = BE->getBaseSpecifier();
3730 OS << "~" << BS->getType()->getAsCXXRecordDecl()->getName() << "()";
3731 OS << " (Base object destructor)\n";
3733 } else if (const CFGMemberDtor *ME = E.getAs<CFGMemberDtor>()) {
3734 const FieldDecl *FD = ME->getFieldDecl();
3735 const Type *T = FD->getType()->getBaseElementTypeUnsafe();
3736 OS << "this->" << FD->getName();
3737 OS << ".~" << T->getAsCXXRecordDecl()->getName() << "()";
3738 OS << " (Member object destructor)\n";
3740 } else if (const CFGTemporaryDtor *TE = E.getAs<CFGTemporaryDtor>()) {
3741 const CXXBindTemporaryExpr *BT = TE->getBindTemporaryExpr();
3742 OS << "~" << BT->getType()->getAsCXXRecordDecl()->getName() << "()";
3743 OS << " (Temporary object destructor)\n";
3747 static void print_block(raw_ostream &OS, const CFG* cfg,
3749 StmtPrinterHelper* Helper, bool print_edges,
3753 Helper->setBlockID(B.getBlockID());
3755 // Print the header.
3757 OS.changeColor(raw_ostream::YELLOW, true);
3759 OS << "\n [B" << B.getBlockID();
3761 if (&B == &cfg->getEntry())
3762 OS << " (ENTRY)]\n";
3763 else if (&B == &cfg->getExit())
3765 else if (&B == cfg->getIndirectGotoBlock())
3766 OS << " (INDIRECT GOTO DISPATCH)]\n";
3773 // Print the label of this block.
3774 if (Stmt *Label = const_cast<Stmt*>(B.getLabel())) {
3779 if (LabelStmt *L = dyn_cast<LabelStmt>(Label))
3781 else if (CaseStmt *C = dyn_cast<CaseStmt>(Label)) {
3783 C->getLHS()->printPretty(OS, Helper,
3784 PrintingPolicy(Helper->getLangOpts()));
3787 C->getRHS()->printPretty(OS, Helper,
3788 PrintingPolicy(Helper->getLangOpts()));
3790 } else if (isa<DefaultStmt>(Label))
3792 else if (CXXCatchStmt *CS = dyn_cast<CXXCatchStmt>(Label)) {
3794 if (CS->getExceptionDecl())
3795 CS->getExceptionDecl()->print(OS, PrintingPolicy(Helper->getLangOpts()),
3802 llvm_unreachable("Invalid label statement in CFGBlock.");
3807 // Iterate through the statements in the block and print them.
3810 for (CFGBlock::const_iterator I = B.begin(), E = B.end() ;
3811 I != E ; ++I, ++j ) {
3813 // Print the statement # in the basic block and the statement itself.
3817 OS << llvm::format("%3d", j) << ": ";
3820 Helper->setStmtID(j);
3822 print_elem(OS, Helper, *I);
3825 // Print the terminator of this block.
3826 if (B.getTerminator()) {
3828 OS.changeColor(raw_ostream::GREEN);
3832 if (Helper) Helper->setBlockID(-1);
3834 CFGBlockTerminatorPrint TPrinter(OS, Helper,
3835 PrintingPolicy(Helper->getLangOpts()));
3836 TPrinter.Visit(const_cast<Stmt*>(B.getTerminator().getStmt()));
3844 // Print the predecessors of this block.
3845 if (!B.pred_empty()) {
3846 const raw_ostream::Colors Color = raw_ostream::BLUE;
3848 OS.changeColor(Color);
3852 OS << '(' << B.pred_size() << "):";
3856 OS.changeColor(Color);
3858 for (CFGBlock::const_pred_iterator I = B.pred_begin(), E = B.pred_end();
3861 if (i == 8 || (i-8) == 0)
3864 OS << " B" << (*I)->getBlockID();
3873 // Print the successors of this block.
3874 if (!B.succ_empty()) {
3875 const raw_ostream::Colors Color = raw_ostream::MAGENTA;
3877 OS.changeColor(Color);
3881 OS << '(' << B.succ_size() << "):";
3885 OS.changeColor(Color);
3887 for (CFGBlock::const_succ_iterator I = B.succ_begin(), E = B.succ_end();
3890 if (i == 8 || (i-8) % 10 == 0)
3894 OS << " B" << (*I)->getBlockID();
3907 /// dump - A simple pretty printer of a CFG that outputs to stderr.
3908 void CFG::dump(const LangOptions &LO, bool ShowColors) const {
3909 print(llvm::errs(), LO, ShowColors);
3912 /// print - A simple pretty printer of a CFG that outputs to an ostream.
3913 void CFG::print(raw_ostream &OS, const LangOptions &LO, bool ShowColors) const {
3914 StmtPrinterHelper Helper(this, LO);
3916 // Print the entry block.
3917 print_block(OS, this, getEntry(), &Helper, true, ShowColors);
3919 // Iterate through the CFGBlocks and print them one by one.
3920 for (const_iterator I = Blocks.begin(), E = Blocks.end() ; I != E ; ++I) {
3921 // Skip the entry block, because we already printed it.
3922 if (&(**I) == &getEntry() || &(**I) == &getExit())
3925 print_block(OS, this, **I, &Helper, true, ShowColors);
3928 // Print the exit block.
3929 print_block(OS, this, getExit(), &Helper, true, ShowColors);
3934 /// dump - A simply pretty printer of a CFGBlock that outputs to stderr.
3935 void CFGBlock::dump(const CFG* cfg, const LangOptions &LO,
3936 bool ShowColors) const {
3937 print(llvm::errs(), cfg, LO, ShowColors);
3940 /// print - A simple pretty printer of a CFGBlock that outputs to an ostream.
3941 /// Generally this will only be called from CFG::print.
3942 void CFGBlock::print(raw_ostream &OS, const CFG* cfg,
3943 const LangOptions &LO, bool ShowColors) const {
3944 StmtPrinterHelper Helper(cfg, LO);
3945 print_block(OS, cfg, *this, &Helper, true, ShowColors);
3949 /// printTerminator - A simple pretty printer of the terminator of a CFGBlock.
3950 void CFGBlock::printTerminator(raw_ostream &OS,
3951 const LangOptions &LO) const {
3952 CFGBlockTerminatorPrint TPrinter(OS, NULL, PrintingPolicy(LO));
3953 TPrinter.Visit(const_cast<Stmt*>(getTerminator().getStmt()));
3956 Stmt *CFGBlock::getTerminatorCondition() {
3957 Stmt *Terminator = this->Terminator;
3963 switch (Terminator->getStmtClass()) {
3967 case Stmt::ForStmtClass:
3968 E = cast<ForStmt>(Terminator)->getCond();
3971 case Stmt::WhileStmtClass:
3972 E = cast<WhileStmt>(Terminator)->getCond();
3975 case Stmt::DoStmtClass:
3976 E = cast<DoStmt>(Terminator)->getCond();
3979 case Stmt::IfStmtClass:
3980 E = cast<IfStmt>(Terminator)->getCond();
3983 case Stmt::ChooseExprClass:
3984 E = cast<ChooseExpr>(Terminator)->getCond();
3987 case Stmt::IndirectGotoStmtClass:
3988 E = cast<IndirectGotoStmt>(Terminator)->getTarget();
3991 case Stmt::SwitchStmtClass:
3992 E = cast<SwitchStmt>(Terminator)->getCond();
3995 case Stmt::BinaryConditionalOperatorClass:
3996 E = cast<BinaryConditionalOperator>(Terminator)->getCond();
3999 case Stmt::ConditionalOperatorClass:
4000 E = cast<ConditionalOperator>(Terminator)->getCond();
4003 case Stmt::BinaryOperatorClass: // '&&' and '||'
4004 E = cast<BinaryOperator>(Terminator)->getLHS();
4007 case Stmt::ObjCForCollectionStmtClass:
4011 return E ? E->IgnoreParens() : NULL;
4014 //===----------------------------------------------------------------------===//
4015 // CFG Graphviz Visualization
4016 //===----------------------------------------------------------------------===//
4020 static StmtPrinterHelper* GraphHelper;
4023 void CFG::viewCFG(const LangOptions &LO) const {
4025 StmtPrinterHelper H(this, LO);
4027 llvm::ViewGraph(this,"CFG");
4034 struct DOTGraphTraits<const CFG*> : public DefaultDOTGraphTraits {
4036 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
4038 static std::string getNodeLabel(const CFGBlock *Node, const CFG* Graph) {
4041 std::string OutSStr;
4042 llvm::raw_string_ostream Out(OutSStr);
4043 print_block(Out,Graph, *Node, GraphHelper, false, false);
4044 std::string& OutStr = Out.str();
4046 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
4048 // Process string output to make it nicer...
4049 for (unsigned i = 0; i != OutStr.length(); ++i)
4050 if (OutStr[i] == '\n') { // Left justify
4052 OutStr.insert(OutStr.begin()+i+1, 'l');
4061 } // end namespace llvm