1 //===--- CFG.h - Classes for representing and building CFGs------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines the CFG and CFGBuilder classes for representing and 11 // building Control-Flow Graphs (CFGs) from ASTs. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_CFG_H 16 #define LLVM_CLANG_CFG_H 17 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 "llvm/ADT/BitVector.h" 25 #include "clang/AST/Stmt.h" 26 #include "clang/Analysis/Support/BumpVector.h" 27 #include "clang/Basic/SourceLocation.h" 28 #include <cassert> 29 #include <iterator> 30 31 namespace clang { 32 class CXXDestructorDecl; 33 class Decl; 34 class Stmt; 35 class Expr; 36 class FieldDecl; 37 class VarDecl; 38 class CXXCtorInitializer; 39 class CXXBaseSpecifier; 40 class CXXBindTemporaryExpr; 41 class CFG; 42 class PrinterHelper; 43 class LangOptions; 44 class ASTContext; 45 46 /// CFGElement - Represents a top-level expression in a basic block. 47 class CFGElement { 48 public: 49 enum Kind { 50 // main kind 51 Invalid, 52 Statement, 53 Initializer, 54 // dtor kind 55 AutomaticObjectDtor, 56 BaseDtor, 57 MemberDtor, 58 TemporaryDtor, 59 DTOR_BEGIN = AutomaticObjectDtor, 60 DTOR_END = TemporaryDtor 61 }; 62 63 protected: 64 // The int bits are used to mark the kind. 65 llvm::PointerIntPair<void *, 2> Data1; 66 llvm::PointerIntPair<void *, 2> Data2; 67 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) {} 71 72 public: 73 CFGElement() {} 74 75 Kind getKind() const { 76 unsigned x = Data2.getInt(); 77 x <<= 2; 78 x |= Data1.getInt(); 79 return (Kind) x; 80 } 81 82 bool isValid() const { return getKind() != Invalid; } 83 84 operator bool() const { return isValid(); } 85 86 template<class ElemTy> const ElemTy *getAs() const { 87 if (llvm::isa<ElemTy>(this)) 88 return static_cast<const ElemTy*>(this); 89 return 0; 90 } 91 92 static bool classof(const CFGElement *E) { return true; } 93 }; 94 95 class CFGStmt : public CFGElement { 96 public: 97 CFGStmt(Stmt *S) : CFGElement(Statement, S) {} 98 99 const Stmt *getStmt() const { 100 return static_cast<const Stmt *>(Data1.getPointer()); 101 } 102 103 static bool classof(const CFGElement *E) { 104 return E->getKind() == Statement; 105 } 106 }; 107 108 /// CFGInitializer - Represents C++ base or member initializer from 109 /// constructor's initialization list. 110 class CFGInitializer : public CFGElement { 111 public: 112 CFGInitializer(CXXCtorInitializer *initializer) 113 : CFGElement(Initializer, initializer) {} 114 115 CXXCtorInitializer* getInitializer() const { 116 return static_cast<CXXCtorInitializer*>(Data1.getPointer()); 117 } 118 119 static bool classof(const CFGElement *E) { 120 return E->getKind() == Initializer; 121 } 122 }; 123 124 /// CFGImplicitDtor - Represents C++ object destructor implicitly generated 125 /// by compiler on various occasions. 126 class CFGImplicitDtor : public CFGElement { 127 protected: 128 CFGImplicitDtor(Kind kind, const void *data1, const void *data2 = 0) 129 : CFGElement(kind, data1, data2) { 130 assert(kind >= DTOR_BEGIN && kind <= DTOR_END); 131 } 132 133 public: 134 const CXXDestructorDecl *getDestructorDecl(ASTContext &astContext) const; 135 bool isNoReturn(ASTContext &astContext) const; 136 137 static bool classof(const CFGElement *E) { 138 Kind kind = E->getKind(); 139 return kind >= DTOR_BEGIN && kind <= DTOR_END; 140 } 141 }; 142 143 /// 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 { 147 public: 148 CFGAutomaticObjDtor(const VarDecl *var, const Stmt *stmt) 149 : CFGImplicitDtor(AutomaticObjectDtor, var, stmt) {} 150 151 const VarDecl *getVarDecl() const { 152 return static_cast<VarDecl*>(Data1.getPointer()); 153 } 154 155 // Get statement end of which triggered the destructor call. 156 const Stmt *getTriggerStmt() const { 157 return static_cast<Stmt*>(Data2.getPointer()); 158 } 159 160 static bool classof(const CFGElement *elem) { 161 return elem->getKind() == AutomaticObjectDtor; 162 } 163 }; 164 165 /// CFGBaseDtor - Represents C++ object destructor implicitly generated for 166 /// base object in destructor. 167 class CFGBaseDtor : public CFGImplicitDtor { 168 public: 169 CFGBaseDtor(const CXXBaseSpecifier *base) 170 : CFGImplicitDtor(BaseDtor, base) {} 171 172 const CXXBaseSpecifier *getBaseSpecifier() const { 173 return static_cast<const CXXBaseSpecifier*>(Data1.getPointer()); 174 } 175 176 static bool classof(const CFGElement *E) { 177 return E->getKind() == BaseDtor; 178 } 179 }; 180 181 /// CFGMemberDtor - Represents C++ object destructor implicitly generated for 182 /// member object in destructor. 183 class CFGMemberDtor : public CFGImplicitDtor { 184 public: 185 CFGMemberDtor(const FieldDecl *field) 186 : CFGImplicitDtor(MemberDtor, field, 0) {} 187 188 const FieldDecl *getFieldDecl() const { 189 return static_cast<const FieldDecl*>(Data1.getPointer()); 190 } 191 192 static bool classof(const CFGElement *E) { 193 return E->getKind() == MemberDtor; 194 } 195 }; 196 197 /// CFGTemporaryDtor - Represents C++ object destructor implicitly generated 198 /// at the end of full expression for temporary object. 199 class CFGTemporaryDtor : public CFGImplicitDtor { 200 public: 201 CFGTemporaryDtor(CXXBindTemporaryExpr *expr) 202 : CFGImplicitDtor(TemporaryDtor, expr, 0) {} 203 204 const CXXBindTemporaryExpr *getBindTemporaryExpr() const { 205 return static_cast<const CXXBindTemporaryExpr *>(Data1.getPointer()); 206 } 207 208 static bool classof(const CFGElement *E) { 209 return E->getKind() == TemporaryDtor; 210 } 211 }; 212 213 /// CFGTerminator - Represents CFGBlock terminator statement. 214 /// 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; 221 public: 222 CFGTerminator() {} 223 CFGTerminator(Stmt *S, bool TemporaryDtorsBranch = false) 224 : Data(S, TemporaryDtorsBranch) {} 225 226 Stmt *getStmt() { return Data.getPointer(); } 227 const Stmt *getStmt() const { return Data.getPointer(); } 228 229 bool isTemporaryDtorsBranch() const { return Data.getInt(); } 230 231 operator Stmt *() { return getStmt(); } 232 operator const Stmt *() const { return getStmt(); } 233 234 Stmt *operator->() { return getStmt(); } 235 const Stmt *operator->() const { return getStmt(); } 236 237 Stmt &operator*() { return *getStmt(); } 238 const Stmt &operator*() const { return *getStmt(); } 239 240 operator bool() const { return getStmt(); } 241 }; 242 243 /// CFGBlock - Represents a single basic block in a source-level CFG. 244 /// It consists of: 245 /// 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. 249 /// 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). 255 /// 256 /// Predecessors: the order in the set of predecessors is arbitrary. 257 /// 258 /// Successors: the order in the set of successors is NOT arbitrary. We 259 /// currently have the following orderings based on the terminator: 260 /// 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 266 /// 267 /// But note that any of that may be NULL in case of optimized-out edges. 268 /// 269 class CFGBlock { 270 class ElementList { 271 typedef BumpVector<CFGElement> ImplTy; 272 ImplTy Impl; 273 public: 274 ElementList(BumpVectorContext &C) : Impl(C, 4) {} 275 276 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; 280 281 void push_back(CFGElement e, BumpVectorContext &C) { Impl.push_back(e, C); } 282 reverse_iterator insert(reverse_iterator I, size_t Cnt, CFGElement E, 283 BumpVectorContext &C) { 284 return Impl.insert(I, Cnt, E, C); 285 } 286 287 CFGElement front() const { return Impl.back(); } 288 CFGElement back() const { return Impl.front(); } 289 290 iterator begin() { return Impl.rbegin(); } 291 iterator end() { return Impl.rend(); } 292 const_iterator begin() const { return Impl.rbegin(); } 293 const_iterator end() const { return Impl.rend(); } 294 reverse_iterator rbegin() { return Impl.begin(); } 295 reverse_iterator rend() { return Impl.end(); } 296 const_reverse_iterator rbegin() const { return Impl.begin(); } 297 const_reverse_iterator rend() const { return Impl.end(); } 298 299 CFGElement operator[](size_t i) const { 300 assert(i < Impl.size()); 301 return Impl[Impl.size() - 1 - i]; 302 } 303 304 size_t size() const { return Impl.size(); } 305 bool empty() const { return Impl.empty(); } 306 }; 307 308 /// Stmts - The set of statements in the basic block. 309 ElementList Elements; 310 311 /// Label - An (optional) label that prefixes the executable 312 /// statements in the block. When this variable is non-NULL, it is 313 /// either an instance of LabelStmt, SwitchCase or CXXCatchStmt. 314 Stmt *Label; 315 316 /// Terminator - The terminator for a basic block that 317 /// indicates the type of control-flow that occurs between a block 318 /// and its successors. 319 CFGTerminator Terminator; 320 321 /// LoopTarget - Some blocks are used to represent the "loop edge" to 322 /// the start of a loop from within the loop body. This Stmt* will be 323 /// refer to the loop statement for such blocks (and be null otherwise). 324 const Stmt *LoopTarget; 325 326 /// BlockID - A numerical ID assigned to a CFGBlock during construction 327 /// of the CFG. 328 unsigned BlockID; 329 330 /// Predecessors/Successors - Keep track of the predecessor / successor 331 /// CFG blocks. 332 typedef BumpVector<CFGBlock*> AdjacentBlocks; 333 AdjacentBlocks Preds; 334 AdjacentBlocks Succs; 335 336 /// NoReturn - This bit is set when the basic block contains a function call 337 /// or implicit destructor that is attributed as 'noreturn'. In that case, 338 /// control cannot technically ever proceed past this block. All such blocks 339 /// will have a single immediate successor: the exit block. This allows them 340 /// to be easily reached from the exit block and using this bit quickly 341 /// recognized without scanning the contents of the block. 342 /// 343 /// Optimization Note: This bit could be profitably folded with Terminator's 344 /// storage if the memory usage of CFGBlock becomes an issue. 345 unsigned HasNoReturnElement : 1; 346 347 public: 348 explicit CFGBlock(unsigned blockid, BumpVectorContext &C) 349 : Elements(C), Label(NULL), Terminator(NULL), LoopTarget(NULL), 350 BlockID(blockid), Preds(C, 1), Succs(C, 1), HasNoReturnElement(false) {} 351 ~CFGBlock() {} 352 353 // Statement iterators 354 typedef ElementList::iterator iterator; 355 typedef ElementList::const_iterator const_iterator; 356 typedef ElementList::reverse_iterator reverse_iterator; 357 typedef ElementList::const_reverse_iterator const_reverse_iterator; 358 359 CFGElement front() const { return Elements.front(); } 360 CFGElement back() const { return Elements.back(); } 361 362 iterator begin() { return Elements.begin(); } 363 iterator end() { return Elements.end(); } 364 const_iterator begin() const { return Elements.begin(); } 365 const_iterator end() const { return Elements.end(); } 366 367 reverse_iterator rbegin() { return Elements.rbegin(); } 368 reverse_iterator rend() { return Elements.rend(); } 369 const_reverse_iterator rbegin() const { return Elements.rbegin(); } 370 const_reverse_iterator rend() const { return Elements.rend(); } 371 372 unsigned size() const { return Elements.size(); } 373 bool empty() const { return Elements.empty(); } 374 375 CFGElement operator[](size_t i) const { return Elements[i]; } 376 377 // CFG iterators 378 typedef AdjacentBlocks::iterator pred_iterator; 379 typedef AdjacentBlocks::const_iterator const_pred_iterator; 380 typedef AdjacentBlocks::reverse_iterator pred_reverse_iterator; 381 typedef AdjacentBlocks::const_reverse_iterator const_pred_reverse_iterator; 382 383 typedef AdjacentBlocks::iterator succ_iterator; 384 typedef AdjacentBlocks::const_iterator const_succ_iterator; 385 typedef AdjacentBlocks::reverse_iterator succ_reverse_iterator; 386 typedef AdjacentBlocks::const_reverse_iterator const_succ_reverse_iterator; 387 388 pred_iterator pred_begin() { return Preds.begin(); } 389 pred_iterator pred_end() { return Preds.end(); } 390 const_pred_iterator pred_begin() const { return Preds.begin(); } 391 const_pred_iterator pred_end() const { return Preds.end(); } 392 393 pred_reverse_iterator pred_rbegin() { return Preds.rbegin(); } 394 pred_reverse_iterator pred_rend() { return Preds.rend(); } 395 const_pred_reverse_iterator pred_rbegin() const { return Preds.rbegin(); } 396 const_pred_reverse_iterator pred_rend() const { return Preds.rend(); } 397 398 succ_iterator succ_begin() { return Succs.begin(); } 399 succ_iterator succ_end() { return Succs.end(); } 400 const_succ_iterator succ_begin() const { return Succs.begin(); } 401 const_succ_iterator succ_end() const { return Succs.end(); } 402 403 succ_reverse_iterator succ_rbegin() { return Succs.rbegin(); } 404 succ_reverse_iterator succ_rend() { return Succs.rend(); } 405 const_succ_reverse_iterator succ_rbegin() const { return Succs.rbegin(); } 406 const_succ_reverse_iterator succ_rend() const { return Succs.rend(); } 407 408 unsigned succ_size() const { return Succs.size(); } 409 bool succ_empty() const { return Succs.empty(); } 410 411 unsigned pred_size() const { return Preds.size(); } 412 bool pred_empty() const { return Preds.empty(); } 413 414 415 class FilterOptions { 416 public: 417 FilterOptions() { 418 IgnoreDefaultsWithCoveredEnums = 0; 419 } 420 421 unsigned IgnoreDefaultsWithCoveredEnums : 1; 422 }; 423 424 static bool FilterEdge(const FilterOptions &F, const CFGBlock *Src, 425 const CFGBlock *Dst); 426 427 template <typename IMPL, bool IsPred> 428 class FilteredCFGBlockIterator { 429 private: 430 IMPL I, E; 431 const FilterOptions F; 432 const CFGBlock *From; 433 public: 434 explicit FilteredCFGBlockIterator(const IMPL &i, const IMPL &e, 435 const CFGBlock *from, 436 const FilterOptions &f) 437 : I(i), E(e), F(f), From(from) {} 438 439 bool hasMore() const { return I != E; } 440 441 FilteredCFGBlockIterator &operator++() { 442 do { ++I; } while (hasMore() && Filter(*I)); 443 return *this; 444 } 445 446 const CFGBlock *operator*() const { return *I; } 447 private: 448 bool Filter(const CFGBlock *To) { 449 return IsPred ? FilterEdge(F, To, From) : FilterEdge(F, From, To); 450 } 451 }; 452 453 typedef FilteredCFGBlockIterator<const_pred_iterator, true> 454 filtered_pred_iterator; 455 456 typedef FilteredCFGBlockIterator<const_succ_iterator, false> 457 filtered_succ_iterator; 458 459 filtered_pred_iterator filtered_pred_start_end(const FilterOptions &f) const { 460 return filtered_pred_iterator(pred_begin(), pred_end(), this, f); 461 } 462 463 filtered_succ_iterator filtered_succ_start_end(const FilterOptions &f) const { 464 return filtered_succ_iterator(succ_begin(), succ_end(), this, f); 465 } 466 467 // Manipulation of block contents 468 469 void setTerminator(Stmt *Statement) { Terminator = Statement; } 470 void setLabel(Stmt *Statement) { Label = Statement; } 471 void setLoopTarget(const Stmt *loopTarget) { LoopTarget = loopTarget; } 472 void setHasNoReturnElement() { HasNoReturnElement = true; } 473 474 CFGTerminator getTerminator() { return Terminator; } 475 const CFGTerminator getTerminator() const { return Terminator; } 476 477 Stmt *getTerminatorCondition(); 478 479 const Stmt *getTerminatorCondition() const { 480 return const_cast<CFGBlock*>(this)->getTerminatorCondition(); 481 } 482 483 const Stmt *getLoopTarget() const { return LoopTarget; } 484 485 Stmt *getLabel() { return Label; } 486 const Stmt *getLabel() const { return Label; } 487 488 bool hasNoReturnElement() const { return HasNoReturnElement; } 489 490 unsigned getBlockID() const { return BlockID; } 491 492 void dump(const CFG *cfg, const LangOptions &LO) const; 493 void print(raw_ostream &OS, const CFG* cfg, const LangOptions &LO) const; 494 void printTerminator(raw_ostream &OS, const LangOptions &LO) const; 495 496 void addSuccessor(CFGBlock *Block, BumpVectorContext &C) { 497 if (Block) 498 Block->Preds.push_back(this, C); 499 Succs.push_back(Block, C); 500 } 501 502 void appendStmt(Stmt *statement, BumpVectorContext &C) { 503 Elements.push_back(CFGStmt(statement), C); 504 } 505 506 void appendInitializer(CXXCtorInitializer *initializer, 507 BumpVectorContext &C) { 508 Elements.push_back(CFGInitializer(initializer), C); 509 } 510 511 void appendBaseDtor(const CXXBaseSpecifier *BS, BumpVectorContext &C) { 512 Elements.push_back(CFGBaseDtor(BS), C); 513 } 514 515 void appendMemberDtor(FieldDecl *FD, BumpVectorContext &C) { 516 Elements.push_back(CFGMemberDtor(FD), C); 517 } 518 519 void appendTemporaryDtor(CXXBindTemporaryExpr *E, BumpVectorContext &C) { 520 Elements.push_back(CFGTemporaryDtor(E), C); 521 } 522 523 void appendAutomaticObjDtor(VarDecl *VD, Stmt *S, BumpVectorContext &C) { 524 Elements.push_back(CFGAutomaticObjDtor(VD, S), C); 525 } 526 527 // Destructors must be inserted in reversed order. So insertion is in two 528 // steps. First we prepare space for some number of elements, then we insert 529 // the elements beginning at the last position in prepared space. 530 iterator beginAutomaticObjDtorsInsert(iterator I, size_t Cnt, 531 BumpVectorContext &C) { 532 return iterator(Elements.insert(I.base(), Cnt, CFGElement(), C)); 533 } 534 iterator insertAutomaticObjDtor(iterator I, VarDecl *VD, Stmt *S) { 535 *I = CFGAutomaticObjDtor(VD, S); 536 return ++I; 537 } 538 }; 539 540 /// CFG - Represents a source-level, intra-procedural CFG that represents the 541 /// control-flow of a Stmt. The Stmt can represent an entire function body, 542 /// or a single expression. A CFG will always contain one empty block that 543 /// represents the Exit point of the CFG. A CFG will also contain a designated 544 /// Entry block. The CFG solely represents control-flow; it consists of 545 /// CFGBlocks which are simply containers of Stmt*'s in the AST the CFG 546 /// was constructed from. 547 class CFG { 548 public: 549 //===--------------------------------------------------------------------===// 550 // CFG Construction & Manipulation. 551 //===--------------------------------------------------------------------===// 552 553 class BuildOptions { 554 llvm::BitVector alwaysAddMask; 555 public: 556 typedef llvm::DenseMap<const Stmt *, const CFGBlock*> ForcedBlkExprs; 557 ForcedBlkExprs **forcedBlkExprs; 558 559 bool PruneTriviallyFalseEdges; 560 bool AddEHEdges; 561 bool AddInitializers; 562 bool AddImplicitDtors; 563 564 bool alwaysAdd(const Stmt *stmt) const { 565 return alwaysAddMask[stmt->getStmtClass()]; 566 } 567 568 BuildOptions &setAlwaysAdd(Stmt::StmtClass stmtClass, bool val = true) { 569 alwaysAddMask[stmtClass] = val; 570 return *this; 571 } 572 573 BuildOptions &setAllAlwaysAdd() { 574 alwaysAddMask.set(); 575 return *this; 576 } 577 578 BuildOptions() 579 : alwaysAddMask(Stmt::lastStmtConstant, false) 580 ,forcedBlkExprs(0), PruneTriviallyFalseEdges(true) 581 ,AddEHEdges(false) 582 ,AddInitializers(false) 583 ,AddImplicitDtors(false) {} 584 }; 585 586 /// buildCFG - Builds a CFG from an AST. The responsibility to free the 587 /// constructed CFG belongs to the caller. 588 static CFG* buildCFG(const Decl *D, Stmt *AST, ASTContext *C, 589 const BuildOptions &BO); 590 591 /// createBlock - Create a new block in the CFG. The CFG owns the block; 592 /// the caller should not directly free it. 593 CFGBlock *createBlock(); 594 595 /// setEntry - Set the entry block of the CFG. This is typically used 596 /// only during CFG construction. Most CFG clients expect that the 597 /// entry block has no predecessors and contains no statements. 598 void setEntry(CFGBlock *B) { Entry = B; } 599 600 /// setIndirectGotoBlock - Set the block used for indirect goto jumps. 601 /// This is typically used only during CFG construction. 602 void setIndirectGotoBlock(CFGBlock *B) { IndirectGotoBlock = B; } 603 604 //===--------------------------------------------------------------------===// 605 // Block Iterators 606 //===--------------------------------------------------------------------===// 607 608 typedef BumpVector<CFGBlock*> CFGBlockListTy; 609 typedef CFGBlockListTy::iterator iterator; 610 typedef CFGBlockListTy::const_iterator const_iterator; 611 typedef std::reverse_iterator<iterator> reverse_iterator; 612 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 613 614 CFGBlock & front() { return *Blocks.front(); } 615 CFGBlock & back() { return *Blocks.back(); } 616 617 iterator begin() { return Blocks.begin(); } 618 iterator end() { return Blocks.end(); } 619 const_iterator begin() const { return Blocks.begin(); } 620 const_iterator end() const { return Blocks.end(); } 621 622 reverse_iterator rbegin() { return Blocks.rbegin(); } 623 reverse_iterator rend() { return Blocks.rend(); } 624 const_reverse_iterator rbegin() const { return Blocks.rbegin(); } 625 const_reverse_iterator rend() const { return Blocks.rend(); } 626 627 CFGBlock & getEntry() { return *Entry; } 628 const CFGBlock & getEntry() const { return *Entry; } 629 CFGBlock & getExit() { return *Exit; } 630 const CFGBlock & getExit() const { return *Exit; } 631 632 CFGBlock * getIndirectGotoBlock() { return IndirectGotoBlock; } 633 const CFGBlock * getIndirectGotoBlock() const { return IndirectGotoBlock; } 634 635 typedef std::vector<const CFGBlock*>::const_iterator try_block_iterator; 636 try_block_iterator try_blocks_begin() const { 637 return TryDispatchBlocks.begin(); 638 } 639 try_block_iterator try_blocks_end() const { 640 return TryDispatchBlocks.end(); 641 } 642 643 void addTryDispatchBlock(const CFGBlock *block) { 644 TryDispatchBlocks.push_back(block); 645 } 646 647 //===--------------------------------------------------------------------===// 648 // Member templates useful for various batch operations over CFGs. 649 //===--------------------------------------------------------------------===// 650 651 template <typename CALLBACK> 652 void VisitBlockStmts(CALLBACK& O) const { 653 for (const_iterator I=begin(), E=end(); I != E; ++I) 654 for (CFGBlock::const_iterator BI=(*I)->begin(), BE=(*I)->end(); 655 BI != BE; ++BI) { 656 if (const CFGStmt *stmt = BI->getAs<CFGStmt>()) 657 O(const_cast<Stmt*>(stmt->getStmt())); 658 } 659 } 660 661 //===--------------------------------------------------------------------===// 662 // CFG Introspection. 663 //===--------------------------------------------------------------------===// 664 665 struct BlkExprNumTy { 666 const signed Idx; 667 explicit BlkExprNumTy(signed idx) : Idx(idx) {} 668 explicit BlkExprNumTy() : Idx(-1) {} 669 operator bool() const { return Idx >= 0; } 670 operator unsigned() const { assert(Idx >=0); return (unsigned) Idx; } 671 }; 672 673 bool isBlkExpr(const Stmt *S) { return getBlkExprNum(S); } 674 bool isBlkExpr(const Stmt *S) const { 675 return const_cast<CFG*>(this)->isBlkExpr(S); 676 } 677 BlkExprNumTy getBlkExprNum(const Stmt *S); 678 unsigned getNumBlkExprs(); 679 680 /// getNumBlockIDs - Returns the total number of BlockIDs allocated (which 681 /// start at 0). 682 unsigned getNumBlockIDs() const { return NumBlockIDs; } 683 684 //===--------------------------------------------------------------------===// 685 // CFG Debugging: Pretty-Printing and Visualization. 686 //===--------------------------------------------------------------------===// 687 688 void viewCFG(const LangOptions &LO) const; 689 void print(raw_ostream &OS, const LangOptions &LO) const; 690 void dump(const LangOptions &LO) const; 691 692 //===--------------------------------------------------------------------===// 693 // Internal: constructors and data. 694 //===--------------------------------------------------------------------===// 695 696 CFG() : Entry(NULL), Exit(NULL), IndirectGotoBlock(NULL), NumBlockIDs(0), 697 BlkExprMap(NULL), Blocks(BlkBVC, 10) {} 698 699 ~CFG(); 700 701 llvm::BumpPtrAllocator& getAllocator() { 702 return BlkBVC.getAllocator(); 703 } 704 705 BumpVectorContext &getBumpVectorContext() { 706 return BlkBVC; 707 } 708 709 private: 710 CFGBlock *Entry; 711 CFGBlock *Exit; 712 CFGBlock* IndirectGotoBlock; // Special block to contain collective dispatch 713 // for indirect gotos 714 unsigned NumBlockIDs; 715 716 // BlkExprMap - An opaque pointer to prevent inclusion of DenseMap.h. 717 // It represents a map from Expr* to integers to record the set of 718 // block-level expressions and their "statement number" in the CFG. 719 void * BlkExprMap; 720 721 BumpVectorContext BlkBVC; 722 723 CFGBlockListTy Blocks; 724 725 /// C++ 'try' statements are modeled with an indirect dispatch block. 726 /// This is the collection of such blocks present in the CFG. 727 std::vector<const CFGBlock *> TryDispatchBlocks; 728 729 }; 730 } // end namespace clang 731 732 //===----------------------------------------------------------------------===// 733 // GraphTraits specializations for CFG basic block graphs (source-level CFGs) 734 //===----------------------------------------------------------------------===// 735 736 namespace llvm { 737 738 /// Implement simplify_type for CFGTerminator, so that we can dyn_cast from 739 /// CFGTerminator to a specific Stmt class. 740 template <> struct simplify_type<const ::clang::CFGTerminator> { 741 typedef const ::clang::Stmt *SimpleType; 742 static SimpleType getSimplifiedValue(const ::clang::CFGTerminator &Val) { 743 return Val.getStmt(); 744 } 745 }; 746 747 template <> struct simplify_type< ::clang::CFGTerminator> { 748 typedef ::clang::Stmt *SimpleType; 749 static SimpleType getSimplifiedValue(const ::clang::CFGTerminator &Val) { 750 return const_cast<SimpleType>(Val.getStmt()); 751 } 752 }; 753 754 // Traits for: CFGBlock 755 756 template <> struct GraphTraits< ::clang::CFGBlock *> { 757 typedef ::clang::CFGBlock NodeType; 758 typedef ::clang::CFGBlock::succ_iterator ChildIteratorType; 759 760 static NodeType* getEntryNode(::clang::CFGBlock *BB) 761 { return BB; } 762 763 static inline ChildIteratorType child_begin(NodeType* N) 764 { return N->succ_begin(); } 765 766 static inline ChildIteratorType child_end(NodeType* N) 767 { return N->succ_end(); } 768 }; 769 770 template <> struct GraphTraits< const ::clang::CFGBlock *> { 771 typedef const ::clang::CFGBlock NodeType; 772 typedef ::clang::CFGBlock::const_succ_iterator ChildIteratorType; 773 774 static NodeType* getEntryNode(const clang::CFGBlock *BB) 775 { return BB; } 776 777 static inline ChildIteratorType child_begin(NodeType* N) 778 { return N->succ_begin(); } 779 780 static inline ChildIteratorType child_end(NodeType* N) 781 { return N->succ_end(); } 782 }; 783 784 template <> struct GraphTraits<Inverse<const ::clang::CFGBlock*> > { 785 typedef const ::clang::CFGBlock NodeType; 786 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType; 787 788 static NodeType *getEntryNode(Inverse<const ::clang::CFGBlock*> G) 789 { return G.Graph; } 790 791 static inline ChildIteratorType child_begin(NodeType* N) 792 { return N->pred_begin(); } 793 794 static inline ChildIteratorType child_end(NodeType* N) 795 { return N->pred_end(); } 796 }; 797 798 // Traits for: CFG 799 800 template <> struct GraphTraits< ::clang::CFG* > 801 : public GraphTraits< ::clang::CFGBlock *> { 802 803 typedef ::clang::CFG::iterator nodes_iterator; 804 805 static NodeType *getEntryNode(::clang::CFG* F) { return &F->getEntry(); } 806 static nodes_iterator nodes_begin(::clang::CFG* F) { return F->begin(); } 807 static nodes_iterator nodes_end(::clang::CFG* F) { return F->end(); } 808 }; 809 810 template <> struct GraphTraits<const ::clang::CFG* > 811 : public GraphTraits<const ::clang::CFGBlock *> { 812 813 typedef ::clang::CFG::const_iterator nodes_iterator; 814 815 static NodeType *getEntryNode( const ::clang::CFG* F) { 816 return &F->getEntry(); 817 } 818 static nodes_iterator nodes_begin( const ::clang::CFG* F) { 819 return F->begin(); 820 } 821 static nodes_iterator nodes_end( const ::clang::CFG* F) { 822 return F->end(); 823 } 824 }; 825 826 template <> struct GraphTraits<Inverse<const ::clang::CFG*> > 827 : public GraphTraits<Inverse<const ::clang::CFGBlock*> > { 828 829 typedef ::clang::CFG::const_iterator nodes_iterator; 830 831 static NodeType *getEntryNode(const ::clang::CFG* F) { return &F->getExit(); } 832 static nodes_iterator nodes_begin(const ::clang::CFG* F) { return F->begin();} 833 static nodes_iterator nodes_end(const ::clang::CFG* F) { return F->end(); } 834 }; 835 } // end llvm namespace 836 #endif 837