1 //===--- CFG.h - 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 #ifndef LLVM_CLANG_ANALYSIS_CFG_H
16 #define LLVM_CLANG_ANALYSIS_CFG_H
18 #include "clang/AST/Stmt.h"
19 #include "clang/Analysis/Support/BumpVector.h"
20 #include "clang/Basic/SourceLocation.h"
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/ADT/GraphTraits.h"
23 #include "llvm/ADT/Optional.h"
24 #include "llvm/ADT/PointerIntPair.h"
25 #include "llvm/ADT/iterator_range.h"
26 #include "llvm/Support/Allocator.h"
27 #include "llvm/Support/Casting.h"
28 #include "llvm/Support/raw_ostream.h"
35 class CXXDestructorDecl;
41 class CXXCtorInitializer;
42 class CXXBaseSpecifier;
43 class CXXBindTemporaryExpr;
53 /// CFGElement - Represents a top-level expression in a basic block.
67 DTOR_BEGIN = AutomaticObjectDtor,
68 DTOR_END = TemporaryDtor
72 // The int bits are used to mark the kind.
73 llvm::PointerIntPair<void *, 2> Data1;
74 llvm::PointerIntPair<void *, 2> Data2;
76 CFGElement(Kind kind, const void *Ptr1, const void *Ptr2 = nullptr)
77 : Data1(const_cast<void*>(Ptr1), ((unsigned) kind) & 0x3),
78 Data2(const_cast<void*>(Ptr2), (((unsigned) kind) >> 2) & 0x3) {
79 assert(getKind() == kind);
85 /// \brief Convert to the specified CFGElement type, asserting that this
86 /// CFGElement is of the desired type.
89 assert(T::isKind(*this));
96 /// \brief Convert to the specified CFGElement type, returning None if this
97 /// CFGElement is not of the desired type.
99 Optional<T> getAs() const {
100 if (!T::isKind(*this))
108 Kind getKind() const {
109 unsigned x = Data2.getInt();
116 class CFGStmt : public CFGElement {
118 CFGStmt(Stmt *S) : CFGElement(Statement, S) {}
120 const Stmt *getStmt() const {
121 return static_cast<const Stmt *>(Data1.getPointer());
125 friend class CFGElement;
127 static bool isKind(const CFGElement &E) {
128 return E.getKind() == Statement;
132 /// CFGInitializer - Represents C++ base or member initializer from
133 /// constructor's initialization list.
134 class CFGInitializer : public CFGElement {
136 CFGInitializer(CXXCtorInitializer *initializer)
137 : CFGElement(Initializer, initializer) {}
139 CXXCtorInitializer* getInitializer() const {
140 return static_cast<CXXCtorInitializer*>(Data1.getPointer());
144 friend class CFGElement;
146 static bool isKind(const CFGElement &E) {
147 return E.getKind() == Initializer;
151 /// CFGNewAllocator - Represents C++ allocator call.
152 class CFGNewAllocator : public CFGElement {
154 explicit CFGNewAllocator(const CXXNewExpr *S)
155 : CFGElement(NewAllocator, S) {}
157 // Get the new expression.
158 const CXXNewExpr *getAllocatorExpr() const {
159 return static_cast<CXXNewExpr *>(Data1.getPointer());
163 friend class CFGElement;
165 static bool isKind(const CFGElement &elem) {
166 return elem.getKind() == NewAllocator;
170 /// CFGImplicitDtor - Represents C++ object destructor implicitly generated
171 /// by compiler on various occasions.
172 class CFGImplicitDtor : public CFGElement {
175 CFGImplicitDtor(Kind kind, const void *data1, const void *data2 = nullptr)
176 : CFGElement(kind, data1, data2) {
177 assert(kind >= DTOR_BEGIN && kind <= DTOR_END);
181 const CXXDestructorDecl *getDestructorDecl(ASTContext &astContext) const;
182 bool isNoReturn(ASTContext &astContext) const;
185 friend class CFGElement;
186 static bool isKind(const CFGElement &E) {
187 Kind kind = E.getKind();
188 return kind >= DTOR_BEGIN && kind <= DTOR_END;
192 /// CFGAutomaticObjDtor - Represents C++ object destructor implicitly generated
193 /// for automatic object or temporary bound to const reference at the point
194 /// of leaving its local scope.
195 class CFGAutomaticObjDtor: public CFGImplicitDtor {
197 CFGAutomaticObjDtor(const VarDecl *var, const Stmt *stmt)
198 : CFGImplicitDtor(AutomaticObjectDtor, var, stmt) {}
200 const VarDecl *getVarDecl() const {
201 return static_cast<VarDecl*>(Data1.getPointer());
204 // Get statement end of which triggered the destructor call.
205 const Stmt *getTriggerStmt() const {
206 return static_cast<Stmt*>(Data2.getPointer());
210 friend class CFGElement;
211 CFGAutomaticObjDtor() {}
212 static bool isKind(const CFGElement &elem) {
213 return elem.getKind() == AutomaticObjectDtor;
217 /// CFGDeleteDtor - Represents C++ object destructor generated
218 /// from a call to delete.
219 class CFGDeleteDtor : public CFGImplicitDtor {
221 CFGDeleteDtor(const CXXRecordDecl *RD, const CXXDeleteExpr *DE)
222 : CFGImplicitDtor(DeleteDtor, RD, DE) {}
224 const CXXRecordDecl *getCXXRecordDecl() const {
225 return static_cast<CXXRecordDecl*>(Data1.getPointer());
228 // Get Delete expression which triggered the destructor call.
229 const CXXDeleteExpr *getDeleteExpr() const {
230 return static_cast<CXXDeleteExpr *>(Data2.getPointer());
234 friend class CFGElement;
236 static bool isKind(const CFGElement &elem) {
237 return elem.getKind() == DeleteDtor;
241 /// CFGBaseDtor - Represents C++ object destructor implicitly generated for
242 /// base object in destructor.
243 class CFGBaseDtor : public CFGImplicitDtor {
245 CFGBaseDtor(const CXXBaseSpecifier *base)
246 : CFGImplicitDtor(BaseDtor, base) {}
248 const CXXBaseSpecifier *getBaseSpecifier() const {
249 return static_cast<const CXXBaseSpecifier*>(Data1.getPointer());
253 friend class CFGElement;
255 static bool isKind(const CFGElement &E) {
256 return E.getKind() == BaseDtor;
260 /// CFGMemberDtor - Represents C++ object destructor implicitly generated for
261 /// member object in destructor.
262 class CFGMemberDtor : public CFGImplicitDtor {
264 CFGMemberDtor(const FieldDecl *field)
265 : CFGImplicitDtor(MemberDtor, field, nullptr) {}
267 const FieldDecl *getFieldDecl() const {
268 return static_cast<const FieldDecl*>(Data1.getPointer());
272 friend class CFGElement;
274 static bool isKind(const CFGElement &E) {
275 return E.getKind() == MemberDtor;
279 /// CFGTemporaryDtor - Represents C++ object destructor implicitly generated
280 /// at the end of full expression for temporary object.
281 class CFGTemporaryDtor : public CFGImplicitDtor {
283 CFGTemporaryDtor(CXXBindTemporaryExpr *expr)
284 : CFGImplicitDtor(TemporaryDtor, expr, nullptr) {}
286 const CXXBindTemporaryExpr *getBindTemporaryExpr() const {
287 return static_cast<const CXXBindTemporaryExpr *>(Data1.getPointer());
291 friend class CFGElement;
292 CFGTemporaryDtor() {}
293 static bool isKind(const CFGElement &E) {
294 return E.getKind() == TemporaryDtor;
298 /// CFGTerminator - Represents CFGBlock terminator statement.
300 /// TemporaryDtorsBranch bit is set to true if the terminator marks a branch
301 /// in control flow of destructors of temporaries. In this case terminator
302 /// statement is the same statement that branches control flow in evaluation
303 /// of matching full expression.
304 class CFGTerminator {
305 llvm::PointerIntPair<Stmt *, 1> Data;
308 CFGTerminator(Stmt *S, bool TemporaryDtorsBranch = false)
309 : Data(S, TemporaryDtorsBranch) {}
311 Stmt *getStmt() { return Data.getPointer(); }
312 const Stmt *getStmt() const { return Data.getPointer(); }
314 bool isTemporaryDtorsBranch() const { return Data.getInt(); }
316 operator Stmt *() { return getStmt(); }
317 operator const Stmt *() const { return getStmt(); }
319 Stmt *operator->() { return getStmt(); }
320 const Stmt *operator->() const { return getStmt(); }
322 Stmt &operator*() { return *getStmt(); }
323 const Stmt &operator*() const { return *getStmt(); }
325 explicit operator bool() const { return getStmt(); }
328 /// CFGBlock - Represents a single basic block in a source-level CFG.
331 /// (1) A set of statements/expressions (which may contain subexpressions).
332 /// (2) A "terminator" statement (not in the set of statements).
333 /// (3) A list of successors and predecessors.
335 /// Terminator: The terminator represents the type of control-flow that occurs
336 /// at the end of the basic block. The terminator is a Stmt* referring to an
337 /// AST node that has control-flow: if-statements, breaks, loops, etc.
338 /// If the control-flow is conditional, the condition expression will appear
339 /// within the set of statements in the block (usually the last statement).
341 /// Predecessors: the order in the set of predecessors is arbitrary.
343 /// Successors: the order in the set of successors is NOT arbitrary. We
344 /// currently have the following orderings based on the terminator:
346 /// Terminator Successor Ordering
347 /// -----------------------------------------------------
348 /// if Then Block; Else Block
349 /// ? operator LHS expression; RHS expression
350 /// &&, || expression that uses result of && or ||, RHS
352 /// But note that any of that may be NULL in case of optimized-out edges.
356 typedef BumpVector<CFGElement> ImplTy;
359 ElementList(BumpVectorContext &C) : Impl(C, 4) {}
361 typedef std::reverse_iterator<ImplTy::iterator> iterator;
362 typedef std::reverse_iterator<ImplTy::const_iterator> const_iterator;
363 typedef ImplTy::iterator reverse_iterator;
364 typedef ImplTy::const_iterator const_reverse_iterator;
365 typedef ImplTy::const_reference const_reference;
367 void push_back(CFGElement e, BumpVectorContext &C) { Impl.push_back(e, C); }
368 reverse_iterator insert(reverse_iterator I, size_t Cnt, CFGElement E,
369 BumpVectorContext &C) {
370 return Impl.insert(I, Cnt, E, C);
373 const_reference front() const { return Impl.back(); }
374 const_reference back() const { return Impl.front(); }
376 iterator begin() { return Impl.rbegin(); }
377 iterator end() { return Impl.rend(); }
378 const_iterator begin() const { return Impl.rbegin(); }
379 const_iterator end() const { return Impl.rend(); }
380 reverse_iterator rbegin() { return Impl.begin(); }
381 reverse_iterator rend() { return Impl.end(); }
382 const_reverse_iterator rbegin() const { return Impl.begin(); }
383 const_reverse_iterator rend() const { return Impl.end(); }
385 CFGElement operator[](size_t i) const {
386 assert(i < Impl.size());
387 return Impl[Impl.size() - 1 - i];
390 size_t size() const { return Impl.size(); }
391 bool empty() const { return Impl.empty(); }
394 /// Stmts - The set of statements in the basic block.
395 ElementList Elements;
397 /// Label - An (optional) label that prefixes the executable
398 /// statements in the block. When this variable is non-NULL, it is
399 /// either an instance of LabelStmt, SwitchCase or CXXCatchStmt.
402 /// Terminator - The terminator for a basic block that
403 /// indicates the type of control-flow that occurs between a block
404 /// and its successors.
405 CFGTerminator Terminator;
407 /// LoopTarget - Some blocks are used to represent the "loop edge" to
408 /// the start of a loop from within the loop body. This Stmt* will be
409 /// refer to the loop statement for such blocks (and be null otherwise).
410 const Stmt *LoopTarget;
412 /// BlockID - A numerical ID assigned to a CFGBlock during construction
417 /// This class represents a potential adjacent block in the CFG. It encodes
418 /// whether or not the block is actually reachable, or can be proved to be
419 /// trivially unreachable. For some cases it allows one to encode scenarios
420 /// where a block was substituted because the original (now alternate) block
422 class AdjacentBlock {
429 CFGBlock *ReachableBlock;
430 llvm::PointerIntPair<CFGBlock*, 2> UnreachableBlock;
433 /// Construct an AdjacentBlock with a possibly unreachable block.
434 AdjacentBlock(CFGBlock *B, bool IsReachable);
436 /// Construct an AdjacentBlock with a reachable block and an alternate
437 /// unreachable block.
438 AdjacentBlock(CFGBlock *B, CFGBlock *AlternateBlock);
440 /// Get the reachable block, if one exists.
441 CFGBlock *getReachableBlock() const {
442 return ReachableBlock;
445 /// Get the potentially unreachable block.
446 CFGBlock *getPossiblyUnreachableBlock() const {
447 return UnreachableBlock.getPointer();
450 /// Provide an implicit conversion to CFGBlock* so that
451 /// AdjacentBlock can be substituted for CFGBlock*.
452 operator CFGBlock*() const {
453 return getReachableBlock();
456 CFGBlock& operator *() const {
457 return *getReachableBlock();
460 CFGBlock* operator ->() const {
461 return getReachableBlock();
464 bool isReachable() const {
465 Kind K = (Kind) UnreachableBlock.getInt();
466 return K == AB_Normal || K == AB_Alternate;
471 /// Predecessors/Successors - Keep track of the predecessor / successor
473 typedef BumpVector<AdjacentBlock> AdjacentBlocks;
474 AdjacentBlocks Preds;
475 AdjacentBlocks Succs;
477 /// NoReturn - This bit is set when the basic block contains a function call
478 /// or implicit destructor that is attributed as 'noreturn'. In that case,
479 /// control cannot technically ever proceed past this block. All such blocks
480 /// will have a single immediate successor: the exit block. This allows them
481 /// to be easily reached from the exit block and using this bit quickly
482 /// recognized without scanning the contents of the block.
484 /// Optimization Note: This bit could be profitably folded with Terminator's
485 /// storage if the memory usage of CFGBlock becomes an issue.
486 unsigned HasNoReturnElement : 1;
488 /// Parent - The parent CFG that owns this CFGBlock.
492 explicit CFGBlock(unsigned blockid, BumpVectorContext &C, CFG *parent)
493 : Elements(C), Label(nullptr), Terminator(nullptr), LoopTarget(nullptr),
494 BlockID(blockid), Preds(C, 1), Succs(C, 1), HasNoReturnElement(false),
497 // Statement iterators
498 typedef ElementList::iterator iterator;
499 typedef ElementList::const_iterator const_iterator;
500 typedef ElementList::reverse_iterator reverse_iterator;
501 typedef ElementList::const_reverse_iterator const_reverse_iterator;
503 CFGElement front() const { return Elements.front(); }
504 CFGElement back() const { return Elements.back(); }
506 iterator begin() { return Elements.begin(); }
507 iterator end() { return Elements.end(); }
508 const_iterator begin() const { return Elements.begin(); }
509 const_iterator end() const { return Elements.end(); }
511 reverse_iterator rbegin() { return Elements.rbegin(); }
512 reverse_iterator rend() { return Elements.rend(); }
513 const_reverse_iterator rbegin() const { return Elements.rbegin(); }
514 const_reverse_iterator rend() const { return Elements.rend(); }
516 unsigned size() const { return Elements.size(); }
517 bool empty() const { return Elements.empty(); }
519 CFGElement operator[](size_t i) const { return Elements[i]; }
522 typedef AdjacentBlocks::iterator pred_iterator;
523 typedef AdjacentBlocks::const_iterator const_pred_iterator;
524 typedef AdjacentBlocks::reverse_iterator pred_reverse_iterator;
525 typedef AdjacentBlocks::const_reverse_iterator const_pred_reverse_iterator;
526 typedef llvm::iterator_range<pred_iterator> pred_range;
527 typedef llvm::iterator_range<const_pred_iterator> pred_const_range;
529 typedef AdjacentBlocks::iterator succ_iterator;
530 typedef AdjacentBlocks::const_iterator const_succ_iterator;
531 typedef AdjacentBlocks::reverse_iterator succ_reverse_iterator;
532 typedef AdjacentBlocks::const_reverse_iterator const_succ_reverse_iterator;
533 typedef llvm::iterator_range<succ_iterator> succ_range;
534 typedef llvm::iterator_range<const_succ_iterator> succ_const_range;
536 pred_iterator pred_begin() { return Preds.begin(); }
537 pred_iterator pred_end() { return Preds.end(); }
538 const_pred_iterator pred_begin() const { return Preds.begin(); }
539 const_pred_iterator pred_end() const { return Preds.end(); }
541 pred_reverse_iterator pred_rbegin() { return Preds.rbegin(); }
542 pred_reverse_iterator pred_rend() { return Preds.rend(); }
543 const_pred_reverse_iterator pred_rbegin() const { return Preds.rbegin(); }
544 const_pred_reverse_iterator pred_rend() const { return Preds.rend(); }
547 return pred_range(pred_begin(), pred_end());
549 pred_const_range preds() const {
550 return pred_const_range(pred_begin(), pred_end());
553 succ_iterator succ_begin() { return Succs.begin(); }
554 succ_iterator succ_end() { return Succs.end(); }
555 const_succ_iterator succ_begin() const { return Succs.begin(); }
556 const_succ_iterator succ_end() const { return Succs.end(); }
558 succ_reverse_iterator succ_rbegin() { return Succs.rbegin(); }
559 succ_reverse_iterator succ_rend() { return Succs.rend(); }
560 const_succ_reverse_iterator succ_rbegin() const { return Succs.rbegin(); }
561 const_succ_reverse_iterator succ_rend() const { return Succs.rend(); }
564 return succ_range(succ_begin(), succ_end());
566 succ_const_range succs() const {
567 return succ_const_range(succ_begin(), succ_end());
570 unsigned succ_size() const { return Succs.size(); }
571 bool succ_empty() const { return Succs.empty(); }
573 unsigned pred_size() const { return Preds.size(); }
574 bool pred_empty() const { return Preds.empty(); }
577 class FilterOptions {
580 IgnoreNullPredecessors = 1;
581 IgnoreDefaultsWithCoveredEnums = 0;
584 unsigned IgnoreNullPredecessors : 1;
585 unsigned IgnoreDefaultsWithCoveredEnums : 1;
588 static bool FilterEdge(const FilterOptions &F, const CFGBlock *Src,
589 const CFGBlock *Dst);
591 template <typename IMPL, bool IsPred>
592 class FilteredCFGBlockIterator {
595 const FilterOptions F;
596 const CFGBlock *From;
598 explicit FilteredCFGBlockIterator(const IMPL &i, const IMPL &e,
599 const CFGBlock *from,
600 const FilterOptions &f)
601 : I(i), E(e), F(f), From(from) {
602 while (hasMore() && Filter(*I))
606 bool hasMore() const { return I != E; }
608 FilteredCFGBlockIterator &operator++() {
609 do { ++I; } while (hasMore() && Filter(*I));
613 const CFGBlock *operator*() const { return *I; }
615 bool Filter(const CFGBlock *To) {
616 return IsPred ? FilterEdge(F, To, From) : FilterEdge(F, From, To);
620 typedef FilteredCFGBlockIterator<const_pred_iterator, true>
621 filtered_pred_iterator;
623 typedef FilteredCFGBlockIterator<const_succ_iterator, false>
624 filtered_succ_iterator;
626 filtered_pred_iterator filtered_pred_start_end(const FilterOptions &f) const {
627 return filtered_pred_iterator(pred_begin(), pred_end(), this, f);
630 filtered_succ_iterator filtered_succ_start_end(const FilterOptions &f) const {
631 return filtered_succ_iterator(succ_begin(), succ_end(), this, f);
634 // Manipulation of block contents
636 void setTerminator(CFGTerminator Term) { Terminator = Term; }
637 void setLabel(Stmt *Statement) { Label = Statement; }
638 void setLoopTarget(const Stmt *loopTarget) { LoopTarget = loopTarget; }
639 void setHasNoReturnElement() { HasNoReturnElement = true; }
641 CFGTerminator getTerminator() { return Terminator; }
642 const CFGTerminator getTerminator() const { return Terminator; }
644 Stmt *getTerminatorCondition(bool StripParens = true);
646 const Stmt *getTerminatorCondition(bool StripParens = true) const {
647 return const_cast<CFGBlock*>(this)->getTerminatorCondition(StripParens);
650 const Stmt *getLoopTarget() const { return LoopTarget; }
652 Stmt *getLabel() { return Label; }
653 const Stmt *getLabel() const { return Label; }
655 bool hasNoReturnElement() const { return HasNoReturnElement; }
657 unsigned getBlockID() const { return BlockID; }
659 CFG *getParent() const { return Parent; }
663 void dump(const CFG *cfg, const LangOptions &LO, bool ShowColors = false) const;
664 void print(raw_ostream &OS, const CFG* cfg, const LangOptions &LO,
665 bool ShowColors) const;
666 void printTerminator(raw_ostream &OS, const LangOptions &LO) const;
667 void printAsOperand(raw_ostream &OS, bool /*PrintType*/) {
668 OS << "BB#" << getBlockID();
671 /// Adds a (potentially unreachable) successor block to the current block.
672 void addSuccessor(AdjacentBlock Succ, BumpVectorContext &C);
674 void appendStmt(Stmt *statement, BumpVectorContext &C) {
675 Elements.push_back(CFGStmt(statement), C);
678 void appendInitializer(CXXCtorInitializer *initializer,
679 BumpVectorContext &C) {
680 Elements.push_back(CFGInitializer(initializer), C);
683 void appendNewAllocator(CXXNewExpr *NE,
684 BumpVectorContext &C) {
685 Elements.push_back(CFGNewAllocator(NE), C);
688 void appendBaseDtor(const CXXBaseSpecifier *BS, BumpVectorContext &C) {
689 Elements.push_back(CFGBaseDtor(BS), C);
692 void appendMemberDtor(FieldDecl *FD, BumpVectorContext &C) {
693 Elements.push_back(CFGMemberDtor(FD), C);
696 void appendTemporaryDtor(CXXBindTemporaryExpr *E, BumpVectorContext &C) {
697 Elements.push_back(CFGTemporaryDtor(E), C);
700 void appendAutomaticObjDtor(VarDecl *VD, Stmt *S, BumpVectorContext &C) {
701 Elements.push_back(CFGAutomaticObjDtor(VD, S), C);
704 void appendDeleteDtor(CXXRecordDecl *RD, CXXDeleteExpr *DE, BumpVectorContext &C) {
705 Elements.push_back(CFGDeleteDtor(RD, DE), C);
708 // Destructors must be inserted in reversed order. So insertion is in two
709 // steps. First we prepare space for some number of elements, then we insert
710 // the elements beginning at the last position in prepared space.
711 iterator beginAutomaticObjDtorsInsert(iterator I, size_t Cnt,
712 BumpVectorContext &C) {
713 return iterator(Elements.insert(I.base(), Cnt,
714 CFGAutomaticObjDtor(nullptr, nullptr), C));
716 iterator insertAutomaticObjDtor(iterator I, VarDecl *VD, Stmt *S) {
717 *I = CFGAutomaticObjDtor(VD, S);
722 /// \brief CFGCallback defines methods that should be called when a logical
723 /// operator error is found when building the CFG.
727 virtual void compareAlwaysTrue(const BinaryOperator *B, bool isAlwaysTrue) {}
728 virtual void compareBitwiseEquality(const BinaryOperator *B,
729 bool isAlwaysTrue) {}
730 virtual ~CFGCallback() {}
733 /// CFG - Represents a source-level, intra-procedural CFG that represents the
734 /// control-flow of a Stmt. The Stmt can represent an entire function body,
735 /// or a single expression. A CFG will always contain one empty block that
736 /// represents the Exit point of the CFG. A CFG will also contain a designated
737 /// Entry block. The CFG solely represents control-flow; it consists of
738 /// CFGBlocks which are simply containers of Stmt*'s in the AST the CFG
739 /// was constructed from.
742 //===--------------------------------------------------------------------===//
743 // CFG Construction & Manipulation.
744 //===--------------------------------------------------------------------===//
747 std::bitset<Stmt::lastStmtConstant> alwaysAddMask;
749 typedef llvm::DenseMap<const Stmt *, const CFGBlock*> ForcedBlkExprs;
750 ForcedBlkExprs **forcedBlkExprs;
751 CFGCallback *Observer;
752 bool PruneTriviallyFalseEdges;
754 bool AddInitializers;
755 bool AddImplicitDtors;
756 bool AddTemporaryDtors;
757 bool AddStaticInitBranches;
758 bool AddCXXNewAllocator;
759 bool AddCXXDefaultInitExprInCtors;
761 bool alwaysAdd(const Stmt *stmt) const {
762 return alwaysAddMask[stmt->getStmtClass()];
765 BuildOptions &setAlwaysAdd(Stmt::StmtClass stmtClass, bool val = true) {
766 alwaysAddMask[stmtClass] = val;
770 BuildOptions &setAllAlwaysAdd() {
776 : forcedBlkExprs(nullptr), Observer(nullptr),
777 PruneTriviallyFalseEdges(true), AddEHEdges(false),
778 AddInitializers(false), AddImplicitDtors(false),
779 AddTemporaryDtors(false), AddStaticInitBranches(false),
780 AddCXXNewAllocator(false), AddCXXDefaultInitExprInCtors(false) {}
783 /// buildCFG - Builds a CFG from an AST.
784 static std::unique_ptr<CFG> buildCFG(const Decl *D, Stmt *AST, ASTContext *C,
785 const BuildOptions &BO);
787 /// createBlock - Create a new block in the CFG. The CFG owns the block;
788 /// the caller should not directly free it.
789 CFGBlock *createBlock();
791 /// setEntry - Set the entry block of the CFG. This is typically used
792 /// only during CFG construction. Most CFG clients expect that the
793 /// entry block has no predecessors and contains no statements.
794 void setEntry(CFGBlock *B) { Entry = B; }
796 /// setIndirectGotoBlock - Set the block used for indirect goto jumps.
797 /// This is typically used only during CFG construction.
798 void setIndirectGotoBlock(CFGBlock *B) { IndirectGotoBlock = B; }
800 //===--------------------------------------------------------------------===//
802 //===--------------------------------------------------------------------===//
804 typedef BumpVector<CFGBlock*> CFGBlockListTy;
805 typedef CFGBlockListTy::iterator iterator;
806 typedef CFGBlockListTy::const_iterator const_iterator;
807 typedef std::reverse_iterator<iterator> reverse_iterator;
808 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
810 CFGBlock & front() { return *Blocks.front(); }
811 CFGBlock & back() { return *Blocks.back(); }
813 iterator begin() { return Blocks.begin(); }
814 iterator end() { return Blocks.end(); }
815 const_iterator begin() const { return Blocks.begin(); }
816 const_iterator end() const { return Blocks.end(); }
818 iterator nodes_begin() { return iterator(Blocks.begin()); }
819 iterator nodes_end() { return iterator(Blocks.end()); }
820 const_iterator nodes_begin() const { return const_iterator(Blocks.begin()); }
821 const_iterator nodes_end() const { return const_iterator(Blocks.end()); }
823 reverse_iterator rbegin() { return Blocks.rbegin(); }
824 reverse_iterator rend() { return Blocks.rend(); }
825 const_reverse_iterator rbegin() const { return Blocks.rbegin(); }
826 const_reverse_iterator rend() const { return Blocks.rend(); }
828 CFGBlock & getEntry() { return *Entry; }
829 const CFGBlock & getEntry() const { return *Entry; }
830 CFGBlock & getExit() { return *Exit; }
831 const CFGBlock & getExit() const { return *Exit; }
833 CFGBlock * getIndirectGotoBlock() { return IndirectGotoBlock; }
834 const CFGBlock * getIndirectGotoBlock() const { return IndirectGotoBlock; }
836 typedef std::vector<const CFGBlock*>::const_iterator try_block_iterator;
837 try_block_iterator try_blocks_begin() const {
838 return TryDispatchBlocks.begin();
840 try_block_iterator try_blocks_end() const {
841 return TryDispatchBlocks.end();
844 void addTryDispatchBlock(const CFGBlock *block) {
845 TryDispatchBlocks.push_back(block);
848 /// Records a synthetic DeclStmt and the DeclStmt it was constructed from.
850 /// The CFG uses synthetic DeclStmts when a single AST DeclStmt contains
852 void addSyntheticDeclStmt(const DeclStmt *Synthetic,
853 const DeclStmt *Source) {
854 assert(Synthetic->isSingleDecl() && "Can handle single declarations only");
855 assert(Synthetic != Source && "Don't include original DeclStmts in map");
856 assert(!SyntheticDeclStmts.count(Synthetic) && "Already in map");
857 SyntheticDeclStmts[Synthetic] = Source;
860 typedef llvm::DenseMap<const DeclStmt *, const DeclStmt *>::const_iterator
861 synthetic_stmt_iterator;
862 typedef llvm::iterator_range<synthetic_stmt_iterator> synthetic_stmt_range;
864 /// Iterates over synthetic DeclStmts in the CFG.
866 /// Each element is a (synthetic statement, source statement) pair.
868 /// \sa addSyntheticDeclStmt
869 synthetic_stmt_iterator synthetic_stmt_begin() const {
870 return SyntheticDeclStmts.begin();
873 /// \sa synthetic_stmt_begin
874 synthetic_stmt_iterator synthetic_stmt_end() const {
875 return SyntheticDeclStmts.end();
878 /// \sa synthetic_stmt_begin
879 synthetic_stmt_range synthetic_stmts() const {
880 return synthetic_stmt_range(synthetic_stmt_begin(), synthetic_stmt_end());
883 //===--------------------------------------------------------------------===//
884 // Member templates useful for various batch operations over CFGs.
885 //===--------------------------------------------------------------------===//
887 template <typename CALLBACK>
888 void VisitBlockStmts(CALLBACK& O) const {
889 for (const_iterator I=begin(), E=end(); I != E; ++I)
890 for (CFGBlock::const_iterator BI=(*I)->begin(), BE=(*I)->end();
892 if (Optional<CFGStmt> stmt = BI->getAs<CFGStmt>())
893 O(const_cast<Stmt*>(stmt->getStmt()));
897 //===--------------------------------------------------------------------===//
898 // CFG Introspection.
899 //===--------------------------------------------------------------------===//
901 /// getNumBlockIDs - Returns the total number of BlockIDs allocated (which
903 unsigned getNumBlockIDs() const { return NumBlockIDs; }
905 /// size - Return the total number of CFGBlocks within the CFG
906 /// This is simply a renaming of the getNumBlockIDs(). This is necessary
907 /// because the dominator implementation needs such an interface.
908 unsigned size() const { return NumBlockIDs; }
910 //===--------------------------------------------------------------------===//
911 // CFG Debugging: Pretty-Printing and Visualization.
912 //===--------------------------------------------------------------------===//
914 void viewCFG(const LangOptions &LO) const;
915 void print(raw_ostream &OS, const LangOptions &LO, bool ShowColors) const;
916 void dump(const LangOptions &LO, bool ShowColors) const;
918 //===--------------------------------------------------------------------===//
919 // Internal: constructors and data.
920 //===--------------------------------------------------------------------===//
923 : Entry(nullptr), Exit(nullptr), IndirectGotoBlock(nullptr), NumBlockIDs(0),
924 Blocks(BlkBVC, 10) {}
926 llvm::BumpPtrAllocator& getAllocator() {
927 return BlkBVC.getAllocator();
930 BumpVectorContext &getBumpVectorContext() {
937 CFGBlock* IndirectGotoBlock; // Special block to contain collective dispatch
938 // for indirect gotos
939 unsigned NumBlockIDs;
941 BumpVectorContext BlkBVC;
943 CFGBlockListTy Blocks;
945 /// C++ 'try' statements are modeled with an indirect dispatch block.
946 /// This is the collection of such blocks present in the CFG.
947 std::vector<const CFGBlock *> TryDispatchBlocks;
949 /// Collects DeclStmts synthesized for this CFG and maps each one back to its
951 llvm::DenseMap<const DeclStmt *, const DeclStmt *> SyntheticDeclStmts;
953 } // end namespace clang
955 //===----------------------------------------------------------------------===//
956 // GraphTraits specializations for CFG basic block graphs (source-level CFGs)
957 //===----------------------------------------------------------------------===//
961 /// Implement simplify_type for CFGTerminator, so that we can dyn_cast from
962 /// CFGTerminator to a specific Stmt class.
963 template <> struct simplify_type< ::clang::CFGTerminator> {
964 typedef ::clang::Stmt *SimpleType;
965 static SimpleType getSimplifiedValue(::clang::CFGTerminator Val) {
966 return Val.getStmt();
970 // Traits for: CFGBlock
972 template <> struct GraphTraits< ::clang::CFGBlock *> {
973 typedef ::clang::CFGBlock *NodeRef;
974 typedef ::clang::CFGBlock::succ_iterator ChildIteratorType;
976 static NodeRef getEntryNode(::clang::CFGBlock *BB) { return BB; }
978 static ChildIteratorType child_begin(NodeRef N) { return N->succ_begin(); }
980 static ChildIteratorType child_end(NodeRef N) { return N->succ_end(); }
983 template <> struct GraphTraits< const ::clang::CFGBlock *> {
984 typedef const ::clang::CFGBlock *NodeRef;
985 typedef ::clang::CFGBlock::const_succ_iterator ChildIteratorType;
987 static NodeRef getEntryNode(const clang::CFGBlock *BB) { return BB; }
989 static ChildIteratorType child_begin(NodeRef N) { return N->succ_begin(); }
991 static ChildIteratorType child_end(NodeRef N) { return N->succ_end(); }
994 template <> struct GraphTraits<Inverse< ::clang::CFGBlock*> > {
995 typedef ::clang::CFGBlock *NodeRef;
996 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType;
998 static NodeRef getEntryNode(Inverse<::clang::CFGBlock *> G) {
1002 static ChildIteratorType child_begin(NodeRef N) { return N->pred_begin(); }
1004 static ChildIteratorType child_end(NodeRef N) { return N->pred_end(); }
1007 template <> struct GraphTraits<Inverse<const ::clang::CFGBlock*> > {
1008 typedef const ::clang::CFGBlock *NodeRef;
1009 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType;
1011 static NodeRef getEntryNode(Inverse<const ::clang::CFGBlock *> G) {
1015 static ChildIteratorType child_begin(NodeRef N) { return N->pred_begin(); }
1017 static ChildIteratorType child_end(NodeRef N) { return N->pred_end(); }
1022 template <> struct GraphTraits< ::clang::CFG* >
1023 : public GraphTraits< ::clang::CFGBlock *> {
1025 typedef ::clang::CFG::iterator nodes_iterator;
1027 static NodeRef getEntryNode(::clang::CFG *F) { return &F->getEntry(); }
1028 static nodes_iterator nodes_begin(::clang::CFG* F) { return F->nodes_begin();}
1029 static nodes_iterator nodes_end(::clang::CFG* F) { return F->nodes_end(); }
1030 static unsigned size(::clang::CFG* F) { return F->size(); }
1033 template <> struct GraphTraits<const ::clang::CFG* >
1034 : public GraphTraits<const ::clang::CFGBlock *> {
1036 typedef ::clang::CFG::const_iterator nodes_iterator;
1038 static NodeRef getEntryNode(const ::clang::CFG *F) { return &F->getEntry(); }
1039 static nodes_iterator nodes_begin( const ::clang::CFG* F) {
1040 return F->nodes_begin();
1042 static nodes_iterator nodes_end( const ::clang::CFG* F) {
1043 return F->nodes_end();
1045 static unsigned size(const ::clang::CFG* F) {
1050 template <> struct GraphTraits<Inverse< ::clang::CFG*> >
1051 : public GraphTraits<Inverse< ::clang::CFGBlock*> > {
1053 typedef ::clang::CFG::iterator nodes_iterator;
1055 static NodeRef getEntryNode(::clang::CFG *F) { return &F->getExit(); }
1056 static nodes_iterator nodes_begin( ::clang::CFG* F) {return F->nodes_begin();}
1057 static nodes_iterator nodes_end( ::clang::CFG* F) { return F->nodes_end(); }
1060 template <> struct GraphTraits<Inverse<const ::clang::CFG*> >
1061 : public GraphTraits<Inverse<const ::clang::CFGBlock*> > {
1063 typedef ::clang::CFG::const_iterator nodes_iterator;
1065 static NodeRef getEntryNode(const ::clang::CFG *F) { return &F->getExit(); }
1066 static nodes_iterator nodes_begin(const ::clang::CFG* F) {
1067 return F->nodes_begin();
1069 static nodes_iterator nodes_end(const ::clang::CFG* F) {
1070 return F->nodes_end();
1073 } // end llvm namespace
1075 #endif // LLVM_CLANG_ANALYSIS_CFG_H