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/Support/Allocator.h"
26 #include "llvm/Support/Casting.h"
27 #include "llvm/Support/raw_ostream.h"
34 class CXXDestructorDecl;
40 class CXXCtorInitializer;
41 class CXXBaseSpecifier;
42 class CXXBindTemporaryExpr;
52 /// CFGElement - Represents a top-level expression in a basic block.
66 DTOR_BEGIN = AutomaticObjectDtor,
67 DTOR_END = TemporaryDtor
71 // The int bits are used to mark the kind.
72 llvm::PointerIntPair<void *, 2> Data1;
73 llvm::PointerIntPair<void *, 2> Data2;
75 CFGElement(Kind kind, const void *Ptr1, const void *Ptr2 = nullptr)
76 : Data1(const_cast<void*>(Ptr1), ((unsigned) kind) & 0x3),
77 Data2(const_cast<void*>(Ptr2), (((unsigned) kind) >> 2) & 0x3) {
78 assert(getKind() == kind);
84 /// \brief Convert to the specified CFGElement type, asserting that this
85 /// CFGElement is of the desired type.
88 assert(T::isKind(*this));
95 /// \brief Convert to the specified CFGElement type, returning None if this
96 /// CFGElement is not of the desired type.
98 Optional<T> getAs() const {
99 if (!T::isKind(*this))
107 Kind getKind() const {
108 unsigned x = Data2.getInt();
115 class CFGStmt : public CFGElement {
117 CFGStmt(Stmt *S) : CFGElement(Statement, S) {}
119 const Stmt *getStmt() const {
120 return static_cast<const Stmt *>(Data1.getPointer());
124 friend class CFGElement;
126 static bool isKind(const CFGElement &E) {
127 return E.getKind() == Statement;
131 /// CFGInitializer - Represents C++ base or member initializer from
132 /// constructor's initialization list.
133 class CFGInitializer : public CFGElement {
135 CFGInitializer(CXXCtorInitializer *initializer)
136 : CFGElement(Initializer, initializer) {}
138 CXXCtorInitializer* getInitializer() const {
139 return static_cast<CXXCtorInitializer*>(Data1.getPointer());
143 friend class CFGElement;
145 static bool isKind(const CFGElement &E) {
146 return E.getKind() == Initializer;
150 /// CFGNewAllocator - Represents C++ allocator call.
151 class CFGNewAllocator : public CFGElement {
153 explicit CFGNewAllocator(const CXXNewExpr *S)
154 : CFGElement(NewAllocator, S) {}
156 // Get the new expression.
157 const CXXNewExpr *getAllocatorExpr() const {
158 return static_cast<CXXNewExpr *>(Data1.getPointer());
162 friend class CFGElement;
164 static bool isKind(const CFGElement &elem) {
165 return elem.getKind() == NewAllocator;
169 /// CFGImplicitDtor - Represents C++ object destructor implicitly generated
170 /// by compiler on various occasions.
171 class CFGImplicitDtor : public CFGElement {
174 CFGImplicitDtor(Kind kind, const void *data1, const void *data2 = nullptr)
175 : CFGElement(kind, data1, data2) {
176 assert(kind >= DTOR_BEGIN && kind <= DTOR_END);
180 const CXXDestructorDecl *getDestructorDecl(ASTContext &astContext) const;
181 bool isNoReturn(ASTContext &astContext) const;
184 friend class CFGElement;
185 static bool isKind(const CFGElement &E) {
186 Kind kind = E.getKind();
187 return kind >= DTOR_BEGIN && kind <= DTOR_END;
191 /// CFGAutomaticObjDtor - Represents C++ object destructor implicitly generated
192 /// for automatic object or temporary bound to const reference at the point
193 /// of leaving its local scope.
194 class CFGAutomaticObjDtor: public CFGImplicitDtor {
196 CFGAutomaticObjDtor(const VarDecl *var, const Stmt *stmt)
197 : CFGImplicitDtor(AutomaticObjectDtor, var, stmt) {}
199 const VarDecl *getVarDecl() const {
200 return static_cast<VarDecl*>(Data1.getPointer());
203 // Get statement end of which triggered the destructor call.
204 const Stmt *getTriggerStmt() const {
205 return static_cast<Stmt*>(Data2.getPointer());
209 friend class CFGElement;
210 CFGAutomaticObjDtor() {}
211 static bool isKind(const CFGElement &elem) {
212 return elem.getKind() == AutomaticObjectDtor;
216 /// CFGDeleteDtor - Represents C++ object destructor generated
217 /// from a call to delete.
218 class CFGDeleteDtor : public CFGImplicitDtor {
220 CFGDeleteDtor(const CXXRecordDecl *RD, const CXXDeleteExpr *DE)
221 : CFGImplicitDtor(DeleteDtor, RD, DE) {}
223 const CXXRecordDecl *getCXXRecordDecl() const {
224 return static_cast<CXXRecordDecl*>(Data1.getPointer());
227 // Get Delete expression which triggered the destructor call.
228 const CXXDeleteExpr *getDeleteExpr() const {
229 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;
527 typedef AdjacentBlocks::iterator succ_iterator;
528 typedef AdjacentBlocks::const_iterator const_succ_iterator;
529 typedef AdjacentBlocks::reverse_iterator succ_reverse_iterator;
530 typedef AdjacentBlocks::const_reverse_iterator const_succ_reverse_iterator;
532 pred_iterator pred_begin() { return Preds.begin(); }
533 pred_iterator pred_end() { return Preds.end(); }
534 const_pred_iterator pred_begin() const { return Preds.begin(); }
535 const_pred_iterator pred_end() const { return Preds.end(); }
537 pred_reverse_iterator pred_rbegin() { return Preds.rbegin(); }
538 pred_reverse_iterator pred_rend() { return Preds.rend(); }
539 const_pred_reverse_iterator pred_rbegin() const { return Preds.rbegin(); }
540 const_pred_reverse_iterator pred_rend() const { return Preds.rend(); }
542 succ_iterator succ_begin() { return Succs.begin(); }
543 succ_iterator succ_end() { return Succs.end(); }
544 const_succ_iterator succ_begin() const { return Succs.begin(); }
545 const_succ_iterator succ_end() const { return Succs.end(); }
547 succ_reverse_iterator succ_rbegin() { return Succs.rbegin(); }
548 succ_reverse_iterator succ_rend() { return Succs.rend(); }
549 const_succ_reverse_iterator succ_rbegin() const { return Succs.rbegin(); }
550 const_succ_reverse_iterator succ_rend() const { return Succs.rend(); }
552 unsigned succ_size() const { return Succs.size(); }
553 bool succ_empty() const { return Succs.empty(); }
555 unsigned pred_size() const { return Preds.size(); }
556 bool pred_empty() const { return Preds.empty(); }
559 class FilterOptions {
562 IgnoreNullPredecessors = 1;
563 IgnoreDefaultsWithCoveredEnums = 0;
566 unsigned IgnoreNullPredecessors : 1;
567 unsigned IgnoreDefaultsWithCoveredEnums : 1;
570 static bool FilterEdge(const FilterOptions &F, const CFGBlock *Src,
571 const CFGBlock *Dst);
573 template <typename IMPL, bool IsPred>
574 class FilteredCFGBlockIterator {
577 const FilterOptions F;
578 const CFGBlock *From;
580 explicit FilteredCFGBlockIterator(const IMPL &i, const IMPL &e,
581 const CFGBlock *from,
582 const FilterOptions &f)
583 : I(i), E(e), F(f), From(from) {
584 while (hasMore() && Filter(*I))
588 bool hasMore() const { return I != E; }
590 FilteredCFGBlockIterator &operator++() {
591 do { ++I; } while (hasMore() && Filter(*I));
595 const CFGBlock *operator*() const { return *I; }
597 bool Filter(const CFGBlock *To) {
598 return IsPred ? FilterEdge(F, To, From) : FilterEdge(F, From, To);
602 typedef FilteredCFGBlockIterator<const_pred_iterator, true>
603 filtered_pred_iterator;
605 typedef FilteredCFGBlockIterator<const_succ_iterator, false>
606 filtered_succ_iterator;
608 filtered_pred_iterator filtered_pred_start_end(const FilterOptions &f) const {
609 return filtered_pred_iterator(pred_begin(), pred_end(), this, f);
612 filtered_succ_iterator filtered_succ_start_end(const FilterOptions &f) const {
613 return filtered_succ_iterator(succ_begin(), succ_end(), this, f);
616 // Manipulation of block contents
618 void setTerminator(CFGTerminator Term) { Terminator = Term; }
619 void setLabel(Stmt *Statement) { Label = Statement; }
620 void setLoopTarget(const Stmt *loopTarget) { LoopTarget = loopTarget; }
621 void setHasNoReturnElement() { HasNoReturnElement = true; }
623 CFGTerminator getTerminator() { return Terminator; }
624 const CFGTerminator getTerminator() const { return Terminator; }
626 Stmt *getTerminatorCondition(bool StripParens = true);
628 const Stmt *getTerminatorCondition(bool StripParens = true) const {
629 return const_cast<CFGBlock*>(this)->getTerminatorCondition(StripParens);
632 const Stmt *getLoopTarget() const { return LoopTarget; }
634 Stmt *getLabel() { return Label; }
635 const Stmt *getLabel() const { return Label; }
637 bool hasNoReturnElement() const { return HasNoReturnElement; }
639 unsigned getBlockID() const { return BlockID; }
641 CFG *getParent() const { return Parent; }
645 void dump(const CFG *cfg, const LangOptions &LO, bool ShowColors = false) const;
646 void print(raw_ostream &OS, const CFG* cfg, const LangOptions &LO,
647 bool ShowColors) const;
648 void printTerminator(raw_ostream &OS, const LangOptions &LO) const;
649 void printAsOperand(raw_ostream &OS, bool /*PrintType*/) {
650 OS << "BB#" << getBlockID();
653 /// Adds a (potentially unreachable) successor block to the current block.
654 void addSuccessor(AdjacentBlock Succ, BumpVectorContext &C);
656 void appendStmt(Stmt *statement, BumpVectorContext &C) {
657 Elements.push_back(CFGStmt(statement), C);
660 void appendInitializer(CXXCtorInitializer *initializer,
661 BumpVectorContext &C) {
662 Elements.push_back(CFGInitializer(initializer), C);
665 void appendNewAllocator(CXXNewExpr *NE,
666 BumpVectorContext &C) {
667 Elements.push_back(CFGNewAllocator(NE), C);
670 void appendBaseDtor(const CXXBaseSpecifier *BS, BumpVectorContext &C) {
671 Elements.push_back(CFGBaseDtor(BS), C);
674 void appendMemberDtor(FieldDecl *FD, BumpVectorContext &C) {
675 Elements.push_back(CFGMemberDtor(FD), C);
678 void appendTemporaryDtor(CXXBindTemporaryExpr *E, BumpVectorContext &C) {
679 Elements.push_back(CFGTemporaryDtor(E), C);
682 void appendAutomaticObjDtor(VarDecl *VD, Stmt *S, BumpVectorContext &C) {
683 Elements.push_back(CFGAutomaticObjDtor(VD, S), C);
686 void appendDeleteDtor(CXXRecordDecl *RD, CXXDeleteExpr *DE, BumpVectorContext &C) {
687 Elements.push_back(CFGDeleteDtor(RD, DE), C);
690 // Destructors must be inserted in reversed order. So insertion is in two
691 // steps. First we prepare space for some number of elements, then we insert
692 // the elements beginning at the last position in prepared space.
693 iterator beginAutomaticObjDtorsInsert(iterator I, size_t Cnt,
694 BumpVectorContext &C) {
695 return iterator(Elements.insert(I.base(), Cnt,
696 CFGAutomaticObjDtor(nullptr, 0), C));
698 iterator insertAutomaticObjDtor(iterator I, VarDecl *VD, Stmt *S) {
699 *I = CFGAutomaticObjDtor(VD, S);
704 /// \brief CFGCallback defines methods that should be called when a logical
705 /// operator error is found when building the CFG.
709 virtual void compareAlwaysTrue(const BinaryOperator *B, bool isAlwaysTrue) {}
710 virtual void compareBitwiseEquality(const BinaryOperator *B,
711 bool isAlwaysTrue) {}
712 virtual ~CFGCallback() {}
715 /// CFG - Represents a source-level, intra-procedural CFG that represents the
716 /// control-flow of a Stmt. The Stmt can represent an entire function body,
717 /// or a single expression. A CFG will always contain one empty block that
718 /// represents the Exit point of the CFG. A CFG will also contain a designated
719 /// Entry block. The CFG solely represents control-flow; it consists of
720 /// CFGBlocks which are simply containers of Stmt*'s in the AST the CFG
721 /// was constructed from.
724 //===--------------------------------------------------------------------===//
725 // CFG Construction & Manipulation.
726 //===--------------------------------------------------------------------===//
729 std::bitset<Stmt::lastStmtConstant> alwaysAddMask;
731 typedef llvm::DenseMap<const Stmt *, const CFGBlock*> ForcedBlkExprs;
732 ForcedBlkExprs **forcedBlkExprs;
733 CFGCallback *Observer;
734 bool PruneTriviallyFalseEdges;
736 bool AddInitializers;
737 bool AddImplicitDtors;
738 bool AddTemporaryDtors;
739 bool AddStaticInitBranches;
740 bool AddCXXNewAllocator;
741 bool AddCXXDefaultInitExprInCtors;
743 bool alwaysAdd(const Stmt *stmt) const {
744 return alwaysAddMask[stmt->getStmtClass()];
747 BuildOptions &setAlwaysAdd(Stmt::StmtClass stmtClass, bool val = true) {
748 alwaysAddMask[stmtClass] = val;
752 BuildOptions &setAllAlwaysAdd() {
758 : forcedBlkExprs(nullptr), Observer(nullptr),
759 PruneTriviallyFalseEdges(true), AddEHEdges(false),
760 AddInitializers(false), AddImplicitDtors(false),
761 AddTemporaryDtors(false), AddStaticInitBranches(false),
762 AddCXXNewAllocator(false), AddCXXDefaultInitExprInCtors(false) {}
765 /// \brief Provides a custom implementation of the iterator class to have the
766 /// same interface as Function::iterator - iterator returns CFGBlock
767 /// (not a pointer to CFGBlock).
768 class graph_iterator {
770 typedef const CFGBlock value_type;
771 typedef value_type& reference;
772 typedef value_type* pointer;
773 typedef BumpVector<CFGBlock*>::iterator ImplTy;
775 graph_iterator(const ImplTy &i) : I(i) {}
777 bool operator==(const graph_iterator &X) const { return I == X.I; }
778 bool operator!=(const graph_iterator &X) const { return I != X.I; }
780 reference operator*() const { return **I; }
781 pointer operator->() const { return *I; }
782 operator CFGBlock* () { return *I; }
784 graph_iterator &operator++() { ++I; return *this; }
785 graph_iterator &operator--() { --I; return *this; }
791 class const_graph_iterator {
793 typedef const CFGBlock value_type;
794 typedef value_type& reference;
795 typedef value_type* pointer;
796 typedef BumpVector<CFGBlock*>::const_iterator ImplTy;
798 const_graph_iterator(const ImplTy &i) : I(i) {}
800 bool operator==(const const_graph_iterator &X) const { return I == X.I; }
801 bool operator!=(const const_graph_iterator &X) const { return I != X.I; }
803 reference operator*() const { return **I; }
804 pointer operator->() const { return *I; }
805 operator CFGBlock* () const { return *I; }
807 const_graph_iterator &operator++() { ++I; return *this; }
808 const_graph_iterator &operator--() { --I; return *this; }
814 /// buildCFG - Builds a CFG from an AST.
815 static std::unique_ptr<CFG> buildCFG(const Decl *D, Stmt *AST, ASTContext *C,
816 const BuildOptions &BO);
818 /// createBlock - Create a new block in the CFG. The CFG owns the block;
819 /// the caller should not directly free it.
820 CFGBlock *createBlock();
822 /// setEntry - Set the entry block of the CFG. This is typically used
823 /// only during CFG construction. Most CFG clients expect that the
824 /// entry block has no predecessors and contains no statements.
825 void setEntry(CFGBlock *B) { Entry = B; }
827 /// setIndirectGotoBlock - Set the block used for indirect goto jumps.
828 /// This is typically used only during CFG construction.
829 void setIndirectGotoBlock(CFGBlock *B) { IndirectGotoBlock = B; }
831 //===--------------------------------------------------------------------===//
833 //===--------------------------------------------------------------------===//
835 typedef BumpVector<CFGBlock*> CFGBlockListTy;
836 typedef CFGBlockListTy::iterator iterator;
837 typedef CFGBlockListTy::const_iterator const_iterator;
838 typedef std::reverse_iterator<iterator> reverse_iterator;
839 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
841 CFGBlock & front() { return *Blocks.front(); }
842 CFGBlock & back() { return *Blocks.back(); }
844 iterator begin() { return Blocks.begin(); }
845 iterator end() { return Blocks.end(); }
846 const_iterator begin() const { return Blocks.begin(); }
847 const_iterator end() const { return Blocks.end(); }
849 graph_iterator nodes_begin() { return graph_iterator(Blocks.begin()); }
850 graph_iterator nodes_end() { return graph_iterator(Blocks.end()); }
851 const_graph_iterator nodes_begin() const {
852 return const_graph_iterator(Blocks.begin());
854 const_graph_iterator nodes_end() const {
855 return const_graph_iterator(Blocks.end());
858 reverse_iterator rbegin() { return Blocks.rbegin(); }
859 reverse_iterator rend() { return Blocks.rend(); }
860 const_reverse_iterator rbegin() const { return Blocks.rbegin(); }
861 const_reverse_iterator rend() const { return Blocks.rend(); }
863 CFGBlock & getEntry() { return *Entry; }
864 const CFGBlock & getEntry() const { return *Entry; }
865 CFGBlock & getExit() { return *Exit; }
866 const CFGBlock & getExit() const { return *Exit; }
868 CFGBlock * getIndirectGotoBlock() { return IndirectGotoBlock; }
869 const CFGBlock * getIndirectGotoBlock() const { return IndirectGotoBlock; }
871 typedef std::vector<const CFGBlock*>::const_iterator try_block_iterator;
872 try_block_iterator try_blocks_begin() const {
873 return TryDispatchBlocks.begin();
875 try_block_iterator try_blocks_end() const {
876 return TryDispatchBlocks.end();
879 void addTryDispatchBlock(const CFGBlock *block) {
880 TryDispatchBlocks.push_back(block);
883 /// Records a synthetic DeclStmt and the DeclStmt it was constructed from.
885 /// The CFG uses synthetic DeclStmts when a single AST DeclStmt contains
887 void addSyntheticDeclStmt(const DeclStmt *Synthetic,
888 const DeclStmt *Source) {
889 assert(Synthetic->isSingleDecl() && "Can handle single declarations only");
890 assert(Synthetic != Source && "Don't include original DeclStmts in map");
891 assert(!SyntheticDeclStmts.count(Synthetic) && "Already in map");
892 SyntheticDeclStmts[Synthetic] = Source;
895 typedef llvm::DenseMap<const DeclStmt *, const DeclStmt *>::const_iterator
896 synthetic_stmt_iterator;
898 /// Iterates over synthetic DeclStmts in the CFG.
900 /// Each element is a (synthetic statement, source statement) pair.
902 /// \sa addSyntheticDeclStmt
903 synthetic_stmt_iterator synthetic_stmt_begin() const {
904 return SyntheticDeclStmts.begin();
907 /// \sa synthetic_stmt_begin
908 synthetic_stmt_iterator synthetic_stmt_end() const {
909 return SyntheticDeclStmts.end();
912 //===--------------------------------------------------------------------===//
913 // Member templates useful for various batch operations over CFGs.
914 //===--------------------------------------------------------------------===//
916 template <typename CALLBACK>
917 void VisitBlockStmts(CALLBACK& O) const {
918 for (const_iterator I=begin(), E=end(); I != E; ++I)
919 for (CFGBlock::const_iterator BI=(*I)->begin(), BE=(*I)->end();
921 if (Optional<CFGStmt> stmt = BI->getAs<CFGStmt>())
922 O(const_cast<Stmt*>(stmt->getStmt()));
926 //===--------------------------------------------------------------------===//
927 // CFG Introspection.
928 //===--------------------------------------------------------------------===//
930 /// getNumBlockIDs - Returns the total number of BlockIDs allocated (which
932 unsigned getNumBlockIDs() const { return NumBlockIDs; }
934 /// size - Return the total number of CFGBlocks within the CFG
935 /// This is simply a renaming of the getNumBlockIDs(). This is necessary
936 /// because the dominator implementation needs such an interface.
937 unsigned size() const { return NumBlockIDs; }
939 //===--------------------------------------------------------------------===//
940 // CFG Debugging: Pretty-Printing and Visualization.
941 //===--------------------------------------------------------------------===//
943 void viewCFG(const LangOptions &LO) const;
944 void print(raw_ostream &OS, const LangOptions &LO, bool ShowColors) const;
945 void dump(const LangOptions &LO, bool ShowColors) const;
947 //===--------------------------------------------------------------------===//
948 // Internal: constructors and data.
949 //===--------------------------------------------------------------------===//
952 : Entry(nullptr), Exit(nullptr), IndirectGotoBlock(nullptr), NumBlockIDs(0),
953 Blocks(BlkBVC, 10) {}
955 llvm::BumpPtrAllocator& getAllocator() {
956 return BlkBVC.getAllocator();
959 BumpVectorContext &getBumpVectorContext() {
966 CFGBlock* IndirectGotoBlock; // Special block to contain collective dispatch
967 // for indirect gotos
968 unsigned NumBlockIDs;
970 BumpVectorContext BlkBVC;
972 CFGBlockListTy Blocks;
974 /// C++ 'try' statements are modeled with an indirect dispatch block.
975 /// This is the collection of such blocks present in the CFG.
976 std::vector<const CFGBlock *> TryDispatchBlocks;
978 /// Collects DeclStmts synthesized for this CFG and maps each one back to its
980 llvm::DenseMap<const DeclStmt *, const DeclStmt *> SyntheticDeclStmts;
982 } // end namespace clang
984 //===----------------------------------------------------------------------===//
985 // GraphTraits specializations for CFG basic block graphs (source-level CFGs)
986 //===----------------------------------------------------------------------===//
990 /// Implement simplify_type for CFGTerminator, so that we can dyn_cast from
991 /// CFGTerminator to a specific Stmt class.
992 template <> struct simplify_type< ::clang::CFGTerminator> {
993 typedef ::clang::Stmt *SimpleType;
994 static SimpleType getSimplifiedValue(::clang::CFGTerminator Val) {
995 return Val.getStmt();
999 // Traits for: CFGBlock
1001 template <> struct GraphTraits< ::clang::CFGBlock *> {
1002 typedef ::clang::CFGBlock NodeType;
1003 typedef ::clang::CFGBlock::succ_iterator ChildIteratorType;
1005 static NodeType* getEntryNode(::clang::CFGBlock *BB)
1008 static inline ChildIteratorType child_begin(NodeType* N)
1009 { return N->succ_begin(); }
1011 static inline ChildIteratorType child_end(NodeType* N)
1012 { return N->succ_end(); }
1015 template <> struct GraphTraits< const ::clang::CFGBlock *> {
1016 typedef const ::clang::CFGBlock NodeType;
1017 typedef ::clang::CFGBlock::const_succ_iterator ChildIteratorType;
1019 static NodeType* getEntryNode(const clang::CFGBlock *BB)
1022 static inline ChildIteratorType child_begin(NodeType* N)
1023 { return N->succ_begin(); }
1025 static inline ChildIteratorType child_end(NodeType* N)
1026 { return N->succ_end(); }
1029 template <> struct GraphTraits<Inverse< ::clang::CFGBlock*> > {
1030 typedef ::clang::CFGBlock NodeType;
1031 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType;
1033 static NodeType *getEntryNode(Inverse< ::clang::CFGBlock*> G)
1036 static inline ChildIteratorType child_begin(NodeType* N)
1037 { return N->pred_begin(); }
1039 static inline ChildIteratorType child_end(NodeType* N)
1040 { return N->pred_end(); }
1043 template <> struct GraphTraits<Inverse<const ::clang::CFGBlock*> > {
1044 typedef const ::clang::CFGBlock NodeType;
1045 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType;
1047 static NodeType *getEntryNode(Inverse<const ::clang::CFGBlock*> G)
1050 static inline ChildIteratorType child_begin(NodeType* N)
1051 { return N->pred_begin(); }
1053 static inline ChildIteratorType child_end(NodeType* N)
1054 { return N->pred_end(); }
1059 template <> struct GraphTraits< ::clang::CFG* >
1060 : public GraphTraits< ::clang::CFGBlock *> {
1062 typedef ::clang::CFG::graph_iterator nodes_iterator;
1064 static NodeType *getEntryNode(::clang::CFG* F) { return &F->getEntry(); }
1065 static nodes_iterator nodes_begin(::clang::CFG* F) { return F->nodes_begin();}
1066 static nodes_iterator nodes_end(::clang::CFG* F) { return F->nodes_end(); }
1067 static unsigned size(::clang::CFG* F) { return F->size(); }
1070 template <> struct GraphTraits<const ::clang::CFG* >
1071 : public GraphTraits<const ::clang::CFGBlock *> {
1073 typedef ::clang::CFG::const_graph_iterator nodes_iterator;
1075 static NodeType *getEntryNode( const ::clang::CFG* F) {
1076 return &F->getEntry();
1078 static nodes_iterator nodes_begin( const ::clang::CFG* F) {
1079 return F->nodes_begin();
1081 static nodes_iterator nodes_end( const ::clang::CFG* F) {
1082 return F->nodes_end();
1084 static unsigned size(const ::clang::CFG* F) {
1089 template <> struct GraphTraits<Inverse< ::clang::CFG*> >
1090 : public GraphTraits<Inverse< ::clang::CFGBlock*> > {
1092 typedef ::clang::CFG::graph_iterator nodes_iterator;
1094 static NodeType *getEntryNode( ::clang::CFG* F) { return &F->getExit(); }
1095 static nodes_iterator nodes_begin( ::clang::CFG* F) {return F->nodes_begin();}
1096 static nodes_iterator nodes_end( ::clang::CFG* F) { return F->nodes_end(); }
1099 template <> struct GraphTraits<Inverse<const ::clang::CFG*> >
1100 : public GraphTraits<Inverse<const ::clang::CFGBlock*> > {
1102 typedef ::clang::CFG::const_graph_iterator nodes_iterator;
1104 static NodeType *getEntryNode(const ::clang::CFG* F) { return &F->getExit(); }
1105 static nodes_iterator nodes_begin(const ::clang::CFG* F) {
1106 return F->nodes_begin();
1108 static nodes_iterator nodes_end(const ::clang::CFG* F) {
1109 return F->nodes_end();
1112 } // end llvm namespace