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_CFG_H
16 #define LLVM_CLANG_CFG_H
18 #include "llvm/ADT/PointerIntPair.h"
19 #include "llvm/ADT/GraphTraits.h"
20 #include "llvm/Support/Allocator.h"
21 #include "llvm/Support/Casting.h"
22 #include "llvm/ADT/OwningPtr.h"
23 #include "llvm/ADT/DenseMap.h"
24 #include "clang/AST/Stmt.h"
25 #include "clang/Analysis/Support/BumpVector.h"
26 #include "clang/Basic/SourceLocation.h"
32 class CXXDestructorDecl;
38 class CXXCtorInitializer;
39 class CXXBaseSpecifier;
40 class CXXBindTemporaryExpr;
46 /// CFGElement - Represents a top-level expression in a basic block.
59 DTOR_BEGIN = AutomaticObjectDtor,
60 DTOR_END = TemporaryDtor
64 // The int bits are used to mark the kind.
65 llvm::PointerIntPair<void *, 2> Data1;
66 llvm::PointerIntPair<void *, 2> Data2;
68 CFGElement(Kind kind, const void *Ptr1, const void *Ptr2 = 0)
69 : Data1(const_cast<void*>(Ptr1), ((unsigned) kind) & 0x3),
70 Data2(const_cast<void*>(Ptr2), (((unsigned) kind) >> 2) & 0x3) {}
75 Kind getKind() const {
76 unsigned x = Data2.getInt();
82 bool isValid() const { return getKind() != Invalid; }
84 operator bool() const { return isValid(); }
86 template<class ElemTy> const ElemTy *getAs() const {
87 if (llvm::isa<ElemTy>(this))
88 return static_cast<const ElemTy*>(this);
92 static bool classof(const CFGElement *E) { return true; }
95 class CFGStmt : public CFGElement {
97 CFGStmt(Stmt *S) : CFGElement(Statement, S) {}
99 const Stmt *getStmt() const {
100 return static_cast<const Stmt *>(Data1.getPointer());
103 static bool classof(const CFGElement *E) {
104 return E->getKind() == Statement;
108 /// CFGInitializer - Represents C++ base or member initializer from
109 /// constructor's initialization list.
110 class CFGInitializer : public CFGElement {
112 CFGInitializer(CXXCtorInitializer *initializer)
113 : CFGElement(Initializer, initializer) {}
115 CXXCtorInitializer* getInitializer() const {
116 return static_cast<CXXCtorInitializer*>(Data1.getPointer());
119 static bool classof(const CFGElement *E) {
120 return E->getKind() == Initializer;
124 /// CFGImplicitDtor - Represents C++ object destructor implicitly generated
125 /// by compiler on various occasions.
126 class CFGImplicitDtor : public CFGElement {
128 CFGImplicitDtor(Kind kind, const void *data1, const void *data2 = 0)
129 : CFGElement(kind, data1, data2) {
130 assert(kind >= DTOR_BEGIN && kind <= DTOR_END);
134 const CXXDestructorDecl *getDestructorDecl(ASTContext &astContext) const;
135 bool isNoReturn(ASTContext &astContext) const;
137 static bool classof(const CFGElement *E) {
138 Kind kind = E->getKind();
139 return kind >= DTOR_BEGIN && kind <= DTOR_END;
143 /// CFGAutomaticObjDtor - Represents C++ object destructor implicitly generated
144 /// for automatic object or temporary bound to const reference at the point
145 /// of leaving its local scope.
146 class CFGAutomaticObjDtor: public CFGImplicitDtor {
148 CFGAutomaticObjDtor(const VarDecl *var, const Stmt *stmt)
149 : CFGImplicitDtor(AutomaticObjectDtor, var, stmt) {}
151 const VarDecl *getVarDecl() const {
152 return static_cast<VarDecl*>(Data1.getPointer());
155 // Get statement end of which triggered the destructor call.
156 const Stmt *getTriggerStmt() const {
157 return static_cast<Stmt*>(Data2.getPointer());
160 static bool classof(const CFGElement *elem) {
161 return elem->getKind() == AutomaticObjectDtor;
165 /// CFGBaseDtor - Represents C++ object destructor implicitly generated for
166 /// base object in destructor.
167 class CFGBaseDtor : public CFGImplicitDtor {
169 CFGBaseDtor(const CXXBaseSpecifier *base)
170 : CFGImplicitDtor(BaseDtor, base) {}
172 const CXXBaseSpecifier *getBaseSpecifier() const {
173 return static_cast<const CXXBaseSpecifier*>(Data1.getPointer());
176 static bool classof(const CFGElement *E) {
177 return E->getKind() == BaseDtor;
181 /// CFGMemberDtor - Represents C++ object destructor implicitly generated for
182 /// member object in destructor.
183 class CFGMemberDtor : public CFGImplicitDtor {
185 CFGMemberDtor(const FieldDecl *field)
186 : CFGImplicitDtor(MemberDtor, field, 0) {}
188 const FieldDecl *getFieldDecl() const {
189 return static_cast<const FieldDecl*>(Data1.getPointer());
192 static bool classof(const CFGElement *E) {
193 return E->getKind() == MemberDtor;
197 /// CFGTemporaryDtor - Represents C++ object destructor implicitly generated
198 /// at the end of full expression for temporary object.
199 class CFGTemporaryDtor : public CFGImplicitDtor {
201 CFGTemporaryDtor(CXXBindTemporaryExpr *expr)
202 : CFGImplicitDtor(TemporaryDtor, expr, 0) {}
204 const CXXBindTemporaryExpr *getBindTemporaryExpr() const {
205 return static_cast<const CXXBindTemporaryExpr *>(Data1.getPointer());
208 static bool classof(const CFGElement *E) {
209 return E->getKind() == TemporaryDtor;
213 /// CFGTerminator - Represents CFGBlock terminator statement.
215 /// TemporaryDtorsBranch bit is set to true if the terminator marks a branch
216 /// in control flow of destructors of temporaries. In this case terminator
217 /// statement is the same statement that branches control flow in evaluation
218 /// of matching full expression.
219 class CFGTerminator {
220 llvm::PointerIntPair<Stmt *, 1> Data;
223 CFGTerminator(Stmt *S, bool TemporaryDtorsBranch = false)
224 : Data(S, TemporaryDtorsBranch) {}
226 Stmt *getStmt() { return Data.getPointer(); }
227 const Stmt *getStmt() const { return Data.getPointer(); }
229 bool isTemporaryDtorsBranch() const { return Data.getInt(); }
231 operator Stmt *() { return getStmt(); }
232 operator const Stmt *() const { return getStmt(); }
234 Stmt *operator->() { return getStmt(); }
235 const Stmt *operator->() const { return getStmt(); }
237 Stmt &operator*() { return *getStmt(); }
238 const Stmt &operator*() const { return *getStmt(); }
240 operator bool() const { return getStmt(); }
243 /// CFGBlock - Represents a single basic block in a source-level CFG.
246 /// (1) A set of statements/expressions (which may contain subexpressions).
247 /// (2) A "terminator" statement (not in the set of statements).
248 /// (3) A list of successors and predecessors.
250 /// Terminator: The terminator represents the type of control-flow that occurs
251 /// at the end of the basic block. The terminator is a Stmt* referring to an
252 /// AST node that has control-flow: if-statements, breaks, loops, etc.
253 /// If the control-flow is conditional, the condition expression will appear
254 /// within the set of statements in the block (usually the last statement).
256 /// Predecessors: the order in the set of predecessors is arbitrary.
258 /// Successors: the order in the set of successors is NOT arbitrary. We
259 /// currently have the following orderings based on the terminator:
261 /// Terminator Successor Ordering
262 /// -----------------------------------------------------
263 /// if Then Block; Else Block
264 /// ? operator LHS expression; RHS expression
265 /// &&, || expression that uses result of && or ||, RHS
267 /// But note that any of that may be NULL in case of optimized-out edges.
271 typedef BumpVector<CFGElement> ImplTy;
274 ElementList(BumpVectorContext &C) : Impl(C, 4) {}
276 typedef std::reverse_iterator<ImplTy::iterator> iterator;
277 typedef std::reverse_iterator<ImplTy::const_iterator> const_iterator;
278 typedef ImplTy::iterator reverse_iterator;
279 typedef ImplTy::const_iterator const_reverse_iterator;
280 typedef ImplTy::const_reference const_reference;
282 void push_back(CFGElement e, BumpVectorContext &C) { Impl.push_back(e, C); }
283 reverse_iterator insert(reverse_iterator I, size_t Cnt, CFGElement E,
284 BumpVectorContext &C) {
285 return Impl.insert(I, Cnt, E, C);
288 const_reference front() const { return Impl.back(); }
289 const_reference back() const { return Impl.front(); }
291 iterator begin() { return Impl.rbegin(); }
292 iterator end() { return Impl.rend(); }
293 const_iterator begin() const { return Impl.rbegin(); }
294 const_iterator end() const { return Impl.rend(); }
295 reverse_iterator rbegin() { return Impl.begin(); }
296 reverse_iterator rend() { return Impl.end(); }
297 const_reverse_iterator rbegin() const { return Impl.begin(); }
298 const_reverse_iterator rend() const { return Impl.end(); }
300 CFGElement operator[](size_t i) const {
301 assert(i < Impl.size());
302 return Impl[Impl.size() - 1 - i];
305 size_t size() const { return Impl.size(); }
306 bool empty() const { return Impl.empty(); }
309 /// Stmts - The set of statements in the basic block.
310 ElementList Elements;
312 /// Label - An (optional) label that prefixes the executable
313 /// statements in the block. When this variable is non-NULL, it is
314 /// either an instance of LabelStmt, SwitchCase or CXXCatchStmt.
317 /// Terminator - The terminator for a basic block that
318 /// indicates the type of control-flow that occurs between a block
319 /// and its successors.
320 CFGTerminator Terminator;
322 /// LoopTarget - Some blocks are used to represent the "loop edge" to
323 /// the start of a loop from within the loop body. This Stmt* will be
324 /// refer to the loop statement for such blocks (and be null otherwise).
325 const Stmt *LoopTarget;
327 /// BlockID - A numerical ID assigned to a CFGBlock during construction
331 /// Predecessors/Successors - Keep track of the predecessor / successor
333 typedef BumpVector<CFGBlock*> AdjacentBlocks;
334 AdjacentBlocks Preds;
335 AdjacentBlocks Succs;
337 /// NoReturn - This bit is set when the basic block contains a function call
338 /// or implicit destructor that is attributed as 'noreturn'. In that case,
339 /// control cannot technically ever proceed past this block. All such blocks
340 /// will have a single immediate successor: the exit block. This allows them
341 /// to be easily reached from the exit block and using this bit quickly
342 /// recognized without scanning the contents of the block.
344 /// Optimization Note: This bit could be profitably folded with Terminator's
345 /// storage if the memory usage of CFGBlock becomes an issue.
346 unsigned HasNoReturnElement : 1;
348 /// Parent - The parent CFG that owns this CFGBlock.
352 explicit CFGBlock(unsigned blockid, BumpVectorContext &C, CFG *parent)
353 : Elements(C), Label(NULL), Terminator(NULL), LoopTarget(NULL),
354 BlockID(blockid), Preds(C, 1), Succs(C, 1), HasNoReturnElement(false),
358 // Statement iterators
359 typedef ElementList::iterator iterator;
360 typedef ElementList::const_iterator const_iterator;
361 typedef ElementList::reverse_iterator reverse_iterator;
362 typedef ElementList::const_reverse_iterator const_reverse_iterator;
364 CFGElement front() const { return Elements.front(); }
365 CFGElement back() const { return Elements.back(); }
367 iterator begin() { return Elements.begin(); }
368 iterator end() { return Elements.end(); }
369 const_iterator begin() const { return Elements.begin(); }
370 const_iterator end() const { return Elements.end(); }
372 reverse_iterator rbegin() { return Elements.rbegin(); }
373 reverse_iterator rend() { return Elements.rend(); }
374 const_reverse_iterator rbegin() const { return Elements.rbegin(); }
375 const_reverse_iterator rend() const { return Elements.rend(); }
377 unsigned size() const { return Elements.size(); }
378 bool empty() const { return Elements.empty(); }
380 CFGElement operator[](size_t i) const { return Elements[i]; }
383 typedef AdjacentBlocks::iterator pred_iterator;
384 typedef AdjacentBlocks::const_iterator const_pred_iterator;
385 typedef AdjacentBlocks::reverse_iterator pred_reverse_iterator;
386 typedef AdjacentBlocks::const_reverse_iterator const_pred_reverse_iterator;
388 typedef AdjacentBlocks::iterator succ_iterator;
389 typedef AdjacentBlocks::const_iterator const_succ_iterator;
390 typedef AdjacentBlocks::reverse_iterator succ_reverse_iterator;
391 typedef AdjacentBlocks::const_reverse_iterator const_succ_reverse_iterator;
393 pred_iterator pred_begin() { return Preds.begin(); }
394 pred_iterator pred_end() { return Preds.end(); }
395 const_pred_iterator pred_begin() const { return Preds.begin(); }
396 const_pred_iterator pred_end() const { return Preds.end(); }
398 pred_reverse_iterator pred_rbegin() { return Preds.rbegin(); }
399 pred_reverse_iterator pred_rend() { return Preds.rend(); }
400 const_pred_reverse_iterator pred_rbegin() const { return Preds.rbegin(); }
401 const_pred_reverse_iterator pred_rend() const { return Preds.rend(); }
403 succ_iterator succ_begin() { return Succs.begin(); }
404 succ_iterator succ_end() { return Succs.end(); }
405 const_succ_iterator succ_begin() const { return Succs.begin(); }
406 const_succ_iterator succ_end() const { return Succs.end(); }
408 succ_reverse_iterator succ_rbegin() { return Succs.rbegin(); }
409 succ_reverse_iterator succ_rend() { return Succs.rend(); }
410 const_succ_reverse_iterator succ_rbegin() const { return Succs.rbegin(); }
411 const_succ_reverse_iterator succ_rend() const { return Succs.rend(); }
413 unsigned succ_size() const { return Succs.size(); }
414 bool succ_empty() const { return Succs.empty(); }
416 unsigned pred_size() const { return Preds.size(); }
417 bool pred_empty() const { return Preds.empty(); }
420 class FilterOptions {
423 IgnoreDefaultsWithCoveredEnums = 0;
426 unsigned IgnoreDefaultsWithCoveredEnums : 1;
429 static bool FilterEdge(const FilterOptions &F, const CFGBlock *Src,
430 const CFGBlock *Dst);
432 template <typename IMPL, bool IsPred>
433 class FilteredCFGBlockIterator {
436 const FilterOptions F;
437 const CFGBlock *From;
439 explicit FilteredCFGBlockIterator(const IMPL &i, const IMPL &e,
440 const CFGBlock *from,
441 const FilterOptions &f)
442 : I(i), E(e), F(f), From(from) {}
444 bool hasMore() const { return I != E; }
446 FilteredCFGBlockIterator &operator++() {
447 do { ++I; } while (hasMore() && Filter(*I));
451 const CFGBlock *operator*() const { return *I; }
453 bool Filter(const CFGBlock *To) {
454 return IsPred ? FilterEdge(F, To, From) : FilterEdge(F, From, To);
458 typedef FilteredCFGBlockIterator<const_pred_iterator, true>
459 filtered_pred_iterator;
461 typedef FilteredCFGBlockIterator<const_succ_iterator, false>
462 filtered_succ_iterator;
464 filtered_pred_iterator filtered_pred_start_end(const FilterOptions &f) const {
465 return filtered_pred_iterator(pred_begin(), pred_end(), this, f);
468 filtered_succ_iterator filtered_succ_start_end(const FilterOptions &f) const {
469 return filtered_succ_iterator(succ_begin(), succ_end(), this, f);
472 // Manipulation of block contents
474 void setTerminator(Stmt *Statement) { Terminator = Statement; }
475 void setLabel(Stmt *Statement) { Label = Statement; }
476 void setLoopTarget(const Stmt *loopTarget) { LoopTarget = loopTarget; }
477 void setHasNoReturnElement() { HasNoReturnElement = true; }
479 CFGTerminator getTerminator() { return Terminator; }
480 const CFGTerminator getTerminator() const { return Terminator; }
482 Stmt *getTerminatorCondition();
484 const Stmt *getTerminatorCondition() const {
485 return const_cast<CFGBlock*>(this)->getTerminatorCondition();
488 const Stmt *getLoopTarget() const { return LoopTarget; }
490 Stmt *getLabel() { return Label; }
491 const Stmt *getLabel() const { return Label; }
493 bool hasNoReturnElement() const { return HasNoReturnElement; }
495 unsigned getBlockID() const { return BlockID; }
497 CFG *getParent() const { return Parent; }
499 void dump(const CFG *cfg, const LangOptions &LO, bool ShowColors = false) const;
500 void print(raw_ostream &OS, const CFG* cfg, const LangOptions &LO,
501 bool ShowColors) const;
502 void printTerminator(raw_ostream &OS, const LangOptions &LO) const;
504 void addSuccessor(CFGBlock *Block, BumpVectorContext &C) {
506 Block->Preds.push_back(this, C);
507 Succs.push_back(Block, C);
510 void appendStmt(Stmt *statement, BumpVectorContext &C) {
511 Elements.push_back(CFGStmt(statement), C);
514 void appendInitializer(CXXCtorInitializer *initializer,
515 BumpVectorContext &C) {
516 Elements.push_back(CFGInitializer(initializer), C);
519 void appendBaseDtor(const CXXBaseSpecifier *BS, BumpVectorContext &C) {
520 Elements.push_back(CFGBaseDtor(BS), C);
523 void appendMemberDtor(FieldDecl *FD, BumpVectorContext &C) {
524 Elements.push_back(CFGMemberDtor(FD), C);
527 void appendTemporaryDtor(CXXBindTemporaryExpr *E, BumpVectorContext &C) {
528 Elements.push_back(CFGTemporaryDtor(E), C);
531 void appendAutomaticObjDtor(VarDecl *VD, Stmt *S, BumpVectorContext &C) {
532 Elements.push_back(CFGAutomaticObjDtor(VD, S), C);
535 // Destructors must be inserted in reversed order. So insertion is in two
536 // steps. First we prepare space for some number of elements, then we insert
537 // the elements beginning at the last position in prepared space.
538 iterator beginAutomaticObjDtorsInsert(iterator I, size_t Cnt,
539 BumpVectorContext &C) {
540 return iterator(Elements.insert(I.base(), Cnt, CFGElement(), C));
542 iterator insertAutomaticObjDtor(iterator I, VarDecl *VD, Stmt *S) {
543 *I = CFGAutomaticObjDtor(VD, S);
548 /// CFG - Represents a source-level, intra-procedural CFG that represents the
549 /// control-flow of a Stmt. The Stmt can represent an entire function body,
550 /// or a single expression. A CFG will always contain one empty block that
551 /// represents the Exit point of the CFG. A CFG will also contain a designated
552 /// Entry block. The CFG solely represents control-flow; it consists of
553 /// CFGBlocks which are simply containers of Stmt*'s in the AST the CFG
554 /// was constructed from.
557 //===--------------------------------------------------------------------===//
558 // CFG Construction & Manipulation.
559 //===--------------------------------------------------------------------===//
562 std::bitset<Stmt::lastStmtConstant> alwaysAddMask;
564 typedef llvm::DenseMap<const Stmt *, const CFGBlock*> ForcedBlkExprs;
565 ForcedBlkExprs **forcedBlkExprs;
567 bool PruneTriviallyFalseEdges;
569 bool AddInitializers;
570 bool AddImplicitDtors;
571 bool AddTemporaryDtors;
573 bool alwaysAdd(const Stmt *stmt) const {
574 return alwaysAddMask[stmt->getStmtClass()];
577 BuildOptions &setAlwaysAdd(Stmt::StmtClass stmtClass, bool val = true) {
578 alwaysAddMask[stmtClass] = val;
582 BuildOptions &setAllAlwaysAdd() {
588 : forcedBlkExprs(0), PruneTriviallyFalseEdges(true)
590 ,AddInitializers(false)
591 ,AddImplicitDtors(false)
592 ,AddTemporaryDtors(false) {}
595 /// \brief Provides a custom implementation of the iterator class to have the
596 /// same interface as Function::iterator - iterator returns CFGBlock
597 /// (not a pointer to CFGBlock).
598 class graph_iterator {
600 typedef const CFGBlock value_type;
601 typedef value_type& reference;
602 typedef value_type* pointer;
603 typedef BumpVector<CFGBlock*>::iterator ImplTy;
605 graph_iterator(const ImplTy &i) : I(i) {}
607 bool operator==(const graph_iterator &X) const { return I == X.I; }
608 bool operator!=(const graph_iterator &X) const { return I != X.I; }
610 reference operator*() const { return **I; }
611 pointer operator->() const { return *I; }
612 operator CFGBlock* () { return *I; }
614 graph_iterator &operator++() { ++I; return *this; }
615 graph_iterator &operator--() { --I; return *this; }
621 class const_graph_iterator {
623 typedef const CFGBlock value_type;
624 typedef value_type& reference;
625 typedef value_type* pointer;
626 typedef BumpVector<CFGBlock*>::const_iterator ImplTy;
628 const_graph_iterator(const ImplTy &i) : I(i) {}
630 bool operator==(const const_graph_iterator &X) const { return I == X.I; }
631 bool operator!=(const const_graph_iterator &X) const { return I != X.I; }
633 reference operator*() const { return **I; }
634 pointer operator->() const { return *I; }
635 operator CFGBlock* () const { return *I; }
637 const_graph_iterator &operator++() { ++I; return *this; }
638 const_graph_iterator &operator--() { --I; return *this; }
644 /// buildCFG - Builds a CFG from an AST. The responsibility to free the
645 /// constructed CFG belongs to the caller.
646 static CFG* buildCFG(const Decl *D, Stmt *AST, ASTContext *C,
647 const BuildOptions &BO);
649 /// createBlock - Create a new block in the CFG. The CFG owns the block;
650 /// the caller should not directly free it.
651 CFGBlock *createBlock();
653 /// setEntry - Set the entry block of the CFG. This is typically used
654 /// only during CFG construction. Most CFG clients expect that the
655 /// entry block has no predecessors and contains no statements.
656 void setEntry(CFGBlock *B) { Entry = B; }
658 /// setIndirectGotoBlock - Set the block used for indirect goto jumps.
659 /// This is typically used only during CFG construction.
660 void setIndirectGotoBlock(CFGBlock *B) { IndirectGotoBlock = B; }
662 //===--------------------------------------------------------------------===//
664 //===--------------------------------------------------------------------===//
666 typedef BumpVector<CFGBlock*> CFGBlockListTy;
667 typedef CFGBlockListTy::iterator iterator;
668 typedef CFGBlockListTy::const_iterator const_iterator;
669 typedef std::reverse_iterator<iterator> reverse_iterator;
670 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
672 CFGBlock & front() { return *Blocks.front(); }
673 CFGBlock & back() { return *Blocks.back(); }
675 iterator begin() { return Blocks.begin(); }
676 iterator end() { return Blocks.end(); }
677 const_iterator begin() const { return Blocks.begin(); }
678 const_iterator end() const { return Blocks.end(); }
680 graph_iterator nodes_begin() { return graph_iterator(Blocks.begin()); }
681 graph_iterator nodes_end() { return graph_iterator(Blocks.end()); }
682 const_graph_iterator nodes_begin() const {
683 return const_graph_iterator(Blocks.begin());
685 const_graph_iterator nodes_end() const {
686 return const_graph_iterator(Blocks.end());
689 reverse_iterator rbegin() { return Blocks.rbegin(); }
690 reverse_iterator rend() { return Blocks.rend(); }
691 const_reverse_iterator rbegin() const { return Blocks.rbegin(); }
692 const_reverse_iterator rend() const { return Blocks.rend(); }
694 CFGBlock & getEntry() { return *Entry; }
695 const CFGBlock & getEntry() const { return *Entry; }
696 CFGBlock & getExit() { return *Exit; }
697 const CFGBlock & getExit() const { return *Exit; }
699 CFGBlock * getIndirectGotoBlock() { return IndirectGotoBlock; }
700 const CFGBlock * getIndirectGotoBlock() const { return IndirectGotoBlock; }
702 typedef std::vector<const CFGBlock*>::const_iterator try_block_iterator;
703 try_block_iterator try_blocks_begin() const {
704 return TryDispatchBlocks.begin();
706 try_block_iterator try_blocks_end() const {
707 return TryDispatchBlocks.end();
710 void addTryDispatchBlock(const CFGBlock *block) {
711 TryDispatchBlocks.push_back(block);
714 //===--------------------------------------------------------------------===//
715 // Member templates useful for various batch operations over CFGs.
716 //===--------------------------------------------------------------------===//
718 template <typename CALLBACK>
719 void VisitBlockStmts(CALLBACK& O) const {
720 for (const_iterator I=begin(), E=end(); I != E; ++I)
721 for (CFGBlock::const_iterator BI=(*I)->begin(), BE=(*I)->end();
723 if (const CFGStmt *stmt = BI->getAs<CFGStmt>())
724 O(const_cast<Stmt*>(stmt->getStmt()));
728 //===--------------------------------------------------------------------===//
729 // CFG Introspection.
730 //===--------------------------------------------------------------------===//
732 struct BlkExprNumTy {
734 explicit BlkExprNumTy(signed idx) : Idx(idx) {}
735 explicit BlkExprNumTy() : Idx(-1) {}
736 operator bool() const { return Idx >= 0; }
737 operator unsigned() const { assert(Idx >=0); return (unsigned) Idx; }
740 bool isBlkExpr(const Stmt *S) { return getBlkExprNum(S); }
741 bool isBlkExpr(const Stmt *S) const {
742 return const_cast<CFG*>(this)->isBlkExpr(S);
744 BlkExprNumTy getBlkExprNum(const Stmt *S);
745 unsigned getNumBlkExprs();
747 /// getNumBlockIDs - Returns the total number of BlockIDs allocated (which
749 unsigned getNumBlockIDs() const { return NumBlockIDs; }
751 /// size - Return the total number of CFGBlocks within the CFG
752 /// This is simply a renaming of the getNumBlockIDs(). This is necessary
753 /// because the dominator implementation needs such an interface.
754 unsigned size() const { return NumBlockIDs; }
756 //===--------------------------------------------------------------------===//
757 // CFG Debugging: Pretty-Printing and Visualization.
758 //===--------------------------------------------------------------------===//
760 void viewCFG(const LangOptions &LO) const;
761 void print(raw_ostream &OS, const LangOptions &LO, bool ShowColors) const;
762 void dump(const LangOptions &LO, bool ShowColors) const;
764 //===--------------------------------------------------------------------===//
765 // Internal: constructors and data.
766 //===--------------------------------------------------------------------===//
768 CFG() : Entry(NULL), Exit(NULL), IndirectGotoBlock(NULL), NumBlockIDs(0),
769 BlkExprMap(NULL), Blocks(BlkBVC, 10) {}
773 llvm::BumpPtrAllocator& getAllocator() {
774 return BlkBVC.getAllocator();
777 BumpVectorContext &getBumpVectorContext() {
784 CFGBlock* IndirectGotoBlock; // Special block to contain collective dispatch
785 // for indirect gotos
786 unsigned NumBlockIDs;
788 // BlkExprMap - An opaque pointer to prevent inclusion of DenseMap.h.
789 // It represents a map from Expr* to integers to record the set of
790 // block-level expressions and their "statement number" in the CFG.
793 BumpVectorContext BlkBVC;
795 CFGBlockListTy Blocks;
797 /// C++ 'try' statements are modeled with an indirect dispatch block.
798 /// This is the collection of such blocks present in the CFG.
799 std::vector<const CFGBlock *> TryDispatchBlocks;
802 } // end namespace clang
804 //===----------------------------------------------------------------------===//
805 // GraphTraits specializations for CFG basic block graphs (source-level CFGs)
806 //===----------------------------------------------------------------------===//
810 /// Implement simplify_type for CFGTerminator, so that we can dyn_cast from
811 /// CFGTerminator to a specific Stmt class.
812 template <> struct simplify_type<const ::clang::CFGTerminator> {
813 typedef const ::clang::Stmt *SimpleType;
814 static SimpleType getSimplifiedValue(const ::clang::CFGTerminator &Val) {
815 return Val.getStmt();
819 template <> struct simplify_type< ::clang::CFGTerminator> {
820 typedef ::clang::Stmt *SimpleType;
821 static SimpleType getSimplifiedValue(const ::clang::CFGTerminator &Val) {
822 return const_cast<SimpleType>(Val.getStmt());
826 // Traits for: CFGBlock
828 template <> struct GraphTraits< ::clang::CFGBlock *> {
829 typedef ::clang::CFGBlock NodeType;
830 typedef ::clang::CFGBlock::succ_iterator ChildIteratorType;
832 static NodeType* getEntryNode(::clang::CFGBlock *BB)
835 static inline ChildIteratorType child_begin(NodeType* N)
836 { return N->succ_begin(); }
838 static inline ChildIteratorType child_end(NodeType* N)
839 { return N->succ_end(); }
842 template <> struct GraphTraits< const ::clang::CFGBlock *> {
843 typedef const ::clang::CFGBlock NodeType;
844 typedef ::clang::CFGBlock::const_succ_iterator ChildIteratorType;
846 static NodeType* getEntryNode(const clang::CFGBlock *BB)
849 static inline ChildIteratorType child_begin(NodeType* N)
850 { return N->succ_begin(); }
852 static inline ChildIteratorType child_end(NodeType* N)
853 { return N->succ_end(); }
856 template <> struct GraphTraits<Inverse< ::clang::CFGBlock*> > {
857 typedef ::clang::CFGBlock NodeType;
858 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType;
860 static NodeType *getEntryNode(Inverse< ::clang::CFGBlock*> G)
863 static inline ChildIteratorType child_begin(NodeType* N)
864 { return N->pred_begin(); }
866 static inline ChildIteratorType child_end(NodeType* N)
867 { return N->pred_end(); }
870 template <> struct GraphTraits<Inverse<const ::clang::CFGBlock*> > {
871 typedef const ::clang::CFGBlock NodeType;
872 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType;
874 static NodeType *getEntryNode(Inverse<const ::clang::CFGBlock*> G)
877 static inline ChildIteratorType child_begin(NodeType* N)
878 { return N->pred_begin(); }
880 static inline ChildIteratorType child_end(NodeType* N)
881 { return N->pred_end(); }
886 template <> struct GraphTraits< ::clang::CFG* >
887 : public GraphTraits< ::clang::CFGBlock *> {
889 typedef ::clang::CFG::graph_iterator nodes_iterator;
891 static NodeType *getEntryNode(::clang::CFG* F) { return &F->getEntry(); }
892 static nodes_iterator nodes_begin(::clang::CFG* F) { return F->nodes_begin();}
893 static nodes_iterator nodes_end(::clang::CFG* F) { return F->nodes_end(); }
894 static unsigned size(::clang::CFG* F) { return F->size(); }
897 template <> struct GraphTraits<const ::clang::CFG* >
898 : public GraphTraits<const ::clang::CFGBlock *> {
900 typedef ::clang::CFG::const_graph_iterator nodes_iterator;
902 static NodeType *getEntryNode( const ::clang::CFG* F) {
903 return &F->getEntry();
905 static nodes_iterator nodes_begin( const ::clang::CFG* F) {
906 return F->nodes_begin();
908 static nodes_iterator nodes_end( const ::clang::CFG* F) {
909 return F->nodes_end();
911 static unsigned size(const ::clang::CFG* F) {
916 template <> struct GraphTraits<Inverse< ::clang::CFG*> >
917 : public GraphTraits<Inverse< ::clang::CFGBlock*> > {
919 typedef ::clang::CFG::graph_iterator nodes_iterator;
921 static NodeType *getEntryNode( ::clang::CFG* F) { return &F->getExit(); }
922 static nodes_iterator nodes_begin( ::clang::CFG* F) {return F->nodes_begin();}
923 static nodes_iterator nodes_end( ::clang::CFG* F) { return F->nodes_end(); }
926 template <> struct GraphTraits<Inverse<const ::clang::CFG*> >
927 : public GraphTraits<Inverse<const ::clang::CFGBlock*> > {
929 typedef ::clang::CFG::const_graph_iterator nodes_iterator;
931 static NodeType *getEntryNode(const ::clang::CFG* F) { return &F->getExit(); }
932 static nodes_iterator nodes_begin(const ::clang::CFG* F) {
933 return F->nodes_begin();
935 static nodes_iterator nodes_end(const ::clang::CFG* F) {
936 return F->nodes_end();
939 } // end llvm namespace