CFG.h revision f0e71aede7ccf3e311feac6a414c431f7a0fc3c8
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 31namespace 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. 47class CFGElement { 48public: 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 63protected: 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 72public: 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 95class CFGStmt : public CFGElement { 96public: 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. 110class CFGInitializer : public CFGElement { 111public: 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. 126class CFGImplicitDtor : public CFGElement { 127protected: 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 133public: 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. 146class CFGAutomaticObjDtor: public CFGImplicitDtor { 147public: 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. 167class CFGBaseDtor : public CFGImplicitDtor { 168public: 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. 183class CFGMemberDtor : public CFGImplicitDtor { 184public: 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. 199class CFGTemporaryDtor : public CFGImplicitDtor { 200public: 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. 219class CFGTerminator { 220 llvm::PointerIntPair<Stmt *, 1> Data; 221public: 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/// 269class 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 336public: 337 explicit CFGBlock(unsigned blockid, BumpVectorContext &C) 338 : Elements(C), Label(NULL), Terminator(NULL), LoopTarget(NULL), 339 BlockID(blockid), Preds(C, 1), Succs(C, 1) {} 340 ~CFGBlock() {} 341 342 // Statement iterators 343 typedef ElementList::iterator iterator; 344 typedef ElementList::const_iterator const_iterator; 345 typedef ElementList::reverse_iterator reverse_iterator; 346 typedef ElementList::const_reverse_iterator const_reverse_iterator; 347 348 CFGElement front() const { return Elements.front(); } 349 CFGElement back() const { return Elements.back(); } 350 351 iterator begin() { return Elements.begin(); } 352 iterator end() { return Elements.end(); } 353 const_iterator begin() const { return Elements.begin(); } 354 const_iterator end() const { return Elements.end(); } 355 356 reverse_iterator rbegin() { return Elements.rbegin(); } 357 reverse_iterator rend() { return Elements.rend(); } 358 const_reverse_iterator rbegin() const { return Elements.rbegin(); } 359 const_reverse_iterator rend() const { return Elements.rend(); } 360 361 unsigned size() const { return Elements.size(); } 362 bool empty() const { return Elements.empty(); } 363 364 CFGElement operator[](size_t i) const { return Elements[i]; } 365 366 // CFG iterators 367 typedef AdjacentBlocks::iterator pred_iterator; 368 typedef AdjacentBlocks::const_iterator const_pred_iterator; 369 typedef AdjacentBlocks::reverse_iterator pred_reverse_iterator; 370 typedef AdjacentBlocks::const_reverse_iterator const_pred_reverse_iterator; 371 372 typedef AdjacentBlocks::iterator succ_iterator; 373 typedef AdjacentBlocks::const_iterator const_succ_iterator; 374 typedef AdjacentBlocks::reverse_iterator succ_reverse_iterator; 375 typedef AdjacentBlocks::const_reverse_iterator const_succ_reverse_iterator; 376 377 pred_iterator pred_begin() { return Preds.begin(); } 378 pred_iterator pred_end() { return Preds.end(); } 379 const_pred_iterator pred_begin() const { return Preds.begin(); } 380 const_pred_iterator pred_end() const { return Preds.end(); } 381 382 pred_reverse_iterator pred_rbegin() { return Preds.rbegin(); } 383 pred_reverse_iterator pred_rend() { return Preds.rend(); } 384 const_pred_reverse_iterator pred_rbegin() const { return Preds.rbegin(); } 385 const_pred_reverse_iterator pred_rend() const { return Preds.rend(); } 386 387 succ_iterator succ_begin() { return Succs.begin(); } 388 succ_iterator succ_end() { return Succs.end(); } 389 const_succ_iterator succ_begin() const { return Succs.begin(); } 390 const_succ_iterator succ_end() const { return Succs.end(); } 391 392 succ_reverse_iterator succ_rbegin() { return Succs.rbegin(); } 393 succ_reverse_iterator succ_rend() { return Succs.rend(); } 394 const_succ_reverse_iterator succ_rbegin() const { return Succs.rbegin(); } 395 const_succ_reverse_iterator succ_rend() const { return Succs.rend(); } 396 397 unsigned succ_size() const { return Succs.size(); } 398 bool succ_empty() const { return Succs.empty(); } 399 400 unsigned pred_size() const { return Preds.size(); } 401 bool pred_empty() const { return Preds.empty(); } 402 403 404 class FilterOptions { 405 public: 406 FilterOptions() { 407 IgnoreDefaultsWithCoveredEnums = 0; 408 } 409 410 unsigned IgnoreDefaultsWithCoveredEnums : 1; 411 }; 412 413 static bool FilterEdge(const FilterOptions &F, const CFGBlock *Src, 414 const CFGBlock *Dst); 415 416 template <typename IMPL, bool IsPred> 417 class FilteredCFGBlockIterator { 418 private: 419 IMPL I, E; 420 const FilterOptions F; 421 const CFGBlock *From; 422 public: 423 explicit FilteredCFGBlockIterator(const IMPL &i, const IMPL &e, 424 const CFGBlock *from, 425 const FilterOptions &f) 426 : I(i), E(e), F(f), From(from) {} 427 428 bool hasMore() const { return I != E; } 429 430 FilteredCFGBlockIterator &operator++() { 431 do { ++I; } while (hasMore() && Filter(*I)); 432 return *this; 433 } 434 435 const CFGBlock *operator*() const { return *I; } 436 private: 437 bool Filter(const CFGBlock *To) { 438 return IsPred ? FilterEdge(F, To, From) : FilterEdge(F, From, To); 439 } 440 }; 441 442 typedef FilteredCFGBlockIterator<const_pred_iterator, true> 443 filtered_pred_iterator; 444 445 typedef FilteredCFGBlockIterator<const_succ_iterator, false> 446 filtered_succ_iterator; 447 448 filtered_pred_iterator filtered_pred_start_end(const FilterOptions &f) const { 449 return filtered_pred_iterator(pred_begin(), pred_end(), this, f); 450 } 451 452 filtered_succ_iterator filtered_succ_start_end(const FilterOptions &f) const { 453 return filtered_succ_iterator(succ_begin(), succ_end(), this, f); 454 } 455 456 // Manipulation of block contents 457 458 void setTerminator(Stmt *Statement) { Terminator = Statement; } 459 void setLabel(Stmt *Statement) { Label = Statement; } 460 void setLoopTarget(const Stmt *loopTarget) { LoopTarget = loopTarget; } 461 462 CFGTerminator getTerminator() { return Terminator; } 463 const CFGTerminator getTerminator() const { return Terminator; } 464 465 Stmt *getTerminatorCondition(); 466 467 const Stmt *getTerminatorCondition() const { 468 return const_cast<CFGBlock*>(this)->getTerminatorCondition(); 469 } 470 471 const Stmt *getLoopTarget() const { return LoopTarget; } 472 473 Stmt *getLabel() { return Label; } 474 const Stmt *getLabel() const { return Label; } 475 476 unsigned getBlockID() const { return BlockID; } 477 478 void dump(const CFG *cfg, const LangOptions &LO) const; 479 void print(raw_ostream &OS, const CFG* cfg, const LangOptions &LO) const; 480 void printTerminator(raw_ostream &OS, const LangOptions &LO) const; 481 482 void addSuccessor(CFGBlock *Block, BumpVectorContext &C) { 483 if (Block) 484 Block->Preds.push_back(this, C); 485 Succs.push_back(Block, C); 486 } 487 488 void appendStmt(Stmt *statement, BumpVectorContext &C) { 489 Elements.push_back(CFGStmt(statement), C); 490 } 491 492 void appendInitializer(CXXCtorInitializer *initializer, 493 BumpVectorContext &C) { 494 Elements.push_back(CFGInitializer(initializer), C); 495 } 496 497 void appendBaseDtor(const CXXBaseSpecifier *BS, BumpVectorContext &C) { 498 Elements.push_back(CFGBaseDtor(BS), C); 499 } 500 501 void appendMemberDtor(FieldDecl *FD, BumpVectorContext &C) { 502 Elements.push_back(CFGMemberDtor(FD), C); 503 } 504 505 void appendTemporaryDtor(CXXBindTemporaryExpr *E, BumpVectorContext &C) { 506 Elements.push_back(CFGTemporaryDtor(E), C); 507 } 508 509 // Destructors must be inserted in reversed order. So insertion is in two 510 // steps. First we prepare space for some number of elements, then we insert 511 // the elements beginning at the last position in prepared space. 512 iterator beginAutomaticObjDtorsInsert(iterator I, size_t Cnt, 513 BumpVectorContext &C) { 514 return iterator(Elements.insert(I.base(), Cnt, CFGElement(), C)); 515 } 516 iterator insertAutomaticObjDtor(iterator I, VarDecl *VD, Stmt *S) { 517 *I = CFGAutomaticObjDtor(VD, S); 518 return ++I; 519 } 520}; 521 522/// CFG - Represents a source-level, intra-procedural CFG that represents the 523/// control-flow of a Stmt. The Stmt can represent an entire function body, 524/// or a single expression. A CFG will always contain one empty block that 525/// represents the Exit point of the CFG. A CFG will also contain a designated 526/// Entry block. The CFG solely represents control-flow; it consists of 527/// CFGBlocks which are simply containers of Stmt*'s in the AST the CFG 528/// was constructed from. 529class CFG { 530public: 531 //===--------------------------------------------------------------------===// 532 // CFG Construction & Manipulation. 533 //===--------------------------------------------------------------------===// 534 535 class BuildOptions { 536 llvm::BitVector alwaysAddMask; 537 public: 538 typedef llvm::DenseMap<const Stmt *, const CFGBlock*> ForcedBlkExprs; 539 ForcedBlkExprs **forcedBlkExprs; 540 541 bool PruneTriviallyFalseEdges; 542 bool AddEHEdges; 543 bool AddInitializers; 544 bool AddImplicitDtors; 545 546 bool alwaysAdd(const Stmt *stmt) const { 547 return alwaysAddMask[stmt->getStmtClass()]; 548 } 549 550 BuildOptions &setAlwaysAdd(Stmt::StmtClass stmtClass, bool val = true) { 551 alwaysAddMask[stmtClass] = val; 552 return *this; 553 } 554 555 BuildOptions &setAllAlwaysAdd() { 556 alwaysAddMask.set(); 557 return *this; 558 } 559 560 BuildOptions() 561 : alwaysAddMask(Stmt::lastStmtConstant, false) 562 ,forcedBlkExprs(0), PruneTriviallyFalseEdges(true) 563 ,AddEHEdges(false) 564 ,AddInitializers(false) 565 ,AddImplicitDtors(false) {} 566 }; 567 568 /// buildCFG - Builds a CFG from an AST. The responsibility to free the 569 /// constructed CFG belongs to the caller. 570 static CFG* buildCFG(const Decl *D, Stmt *AST, ASTContext *C, 571 const BuildOptions &BO); 572 573 /// createBlock - Create a new block in the CFG. The CFG owns the block; 574 /// the caller should not directly free it. 575 CFGBlock *createBlock(); 576 577 /// setEntry - Set the entry block of the CFG. This is typically used 578 /// only during CFG construction. Most CFG clients expect that the 579 /// entry block has no predecessors and contains no statements. 580 void setEntry(CFGBlock *B) { Entry = B; } 581 582 /// setIndirectGotoBlock - Set the block used for indirect goto jumps. 583 /// This is typically used only during CFG construction. 584 void setIndirectGotoBlock(CFGBlock *B) { IndirectGotoBlock = B; } 585 586 //===--------------------------------------------------------------------===// 587 // Block Iterators 588 //===--------------------------------------------------------------------===// 589 590 typedef BumpVector<CFGBlock*> CFGBlockListTy; 591 typedef CFGBlockListTy::iterator iterator; 592 typedef CFGBlockListTy::const_iterator const_iterator; 593 typedef std::reverse_iterator<iterator> reverse_iterator; 594 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 595 596 CFGBlock & front() { return *Blocks.front(); } 597 CFGBlock & back() { return *Blocks.back(); } 598 599 iterator begin() { return Blocks.begin(); } 600 iterator end() { return Blocks.end(); } 601 const_iterator begin() const { return Blocks.begin(); } 602 const_iterator end() const { return Blocks.end(); } 603 604 reverse_iterator rbegin() { return Blocks.rbegin(); } 605 reverse_iterator rend() { return Blocks.rend(); } 606 const_reverse_iterator rbegin() const { return Blocks.rbegin(); } 607 const_reverse_iterator rend() const { return Blocks.rend(); } 608 609 CFGBlock & getEntry() { return *Entry; } 610 const CFGBlock & getEntry() const { return *Entry; } 611 CFGBlock & getExit() { return *Exit; } 612 const CFGBlock & getExit() const { return *Exit; } 613 614 CFGBlock * getIndirectGotoBlock() { return IndirectGotoBlock; } 615 const CFGBlock * getIndirectGotoBlock() const { return IndirectGotoBlock; } 616 617 typedef std::vector<const CFGBlock*>::const_iterator try_block_iterator; 618 try_block_iterator try_blocks_begin() const { 619 return TryDispatchBlocks.begin(); 620 } 621 try_block_iterator try_blocks_end() const { 622 return TryDispatchBlocks.end(); 623 } 624 625 void addTryDispatchBlock(const CFGBlock *block) { 626 TryDispatchBlocks.push_back(block); 627 } 628 629 //===--------------------------------------------------------------------===// 630 // Member templates useful for various batch operations over CFGs. 631 //===--------------------------------------------------------------------===// 632 633 template <typename CALLBACK> 634 void VisitBlockStmts(CALLBACK& O) const { 635 for (const_iterator I=begin(), E=end(); I != E; ++I) 636 for (CFGBlock::const_iterator BI=(*I)->begin(), BE=(*I)->end(); 637 BI != BE; ++BI) { 638 if (const CFGStmt *stmt = BI->getAs<CFGStmt>()) 639 O(const_cast<Stmt*>(stmt->getStmt())); 640 } 641 } 642 643 //===--------------------------------------------------------------------===// 644 // CFG Introspection. 645 //===--------------------------------------------------------------------===// 646 647 struct BlkExprNumTy { 648 const signed Idx; 649 explicit BlkExprNumTy(signed idx) : Idx(idx) {} 650 explicit BlkExprNumTy() : Idx(-1) {} 651 operator bool() const { return Idx >= 0; } 652 operator unsigned() const { assert(Idx >=0); return (unsigned) Idx; } 653 }; 654 655 bool isBlkExpr(const Stmt *S) { return getBlkExprNum(S); } 656 bool isBlkExpr(const Stmt *S) const { 657 return const_cast<CFG*>(this)->isBlkExpr(S); 658 } 659 BlkExprNumTy getBlkExprNum(const Stmt *S); 660 unsigned getNumBlkExprs(); 661 662 /// getNumBlockIDs - Returns the total number of BlockIDs allocated (which 663 /// start at 0). 664 unsigned getNumBlockIDs() const { return NumBlockIDs; } 665 666 //===--------------------------------------------------------------------===// 667 // CFG Debugging: Pretty-Printing and Visualization. 668 //===--------------------------------------------------------------------===// 669 670 void viewCFG(const LangOptions &LO) const; 671 void print(raw_ostream &OS, const LangOptions &LO) const; 672 void dump(const LangOptions &LO) const; 673 674 //===--------------------------------------------------------------------===// 675 // Internal: constructors and data. 676 //===--------------------------------------------------------------------===// 677 678 CFG() : Entry(NULL), Exit(NULL), IndirectGotoBlock(NULL), NumBlockIDs(0), 679 BlkExprMap(NULL), Blocks(BlkBVC, 10) {} 680 681 ~CFG(); 682 683 llvm::BumpPtrAllocator& getAllocator() { 684 return BlkBVC.getAllocator(); 685 } 686 687 BumpVectorContext &getBumpVectorContext() { 688 return BlkBVC; 689 } 690 691private: 692 CFGBlock *Entry; 693 CFGBlock *Exit; 694 CFGBlock* IndirectGotoBlock; // Special block to contain collective dispatch 695 // for indirect gotos 696 unsigned NumBlockIDs; 697 698 // BlkExprMap - An opaque pointer to prevent inclusion of DenseMap.h. 699 // It represents a map from Expr* to integers to record the set of 700 // block-level expressions and their "statement number" in the CFG. 701 void * BlkExprMap; 702 703 BumpVectorContext BlkBVC; 704 705 CFGBlockListTy Blocks; 706 707 /// C++ 'try' statements are modeled with an indirect dispatch block. 708 /// This is the collection of such blocks present in the CFG. 709 std::vector<const CFGBlock *> TryDispatchBlocks; 710 711}; 712} // end namespace clang 713 714//===----------------------------------------------------------------------===// 715// GraphTraits specializations for CFG basic block graphs (source-level CFGs) 716//===----------------------------------------------------------------------===// 717 718namespace llvm { 719 720/// Implement simplify_type for CFGTerminator, so that we can dyn_cast from 721/// CFGTerminator to a specific Stmt class. 722template <> struct simplify_type<const ::clang::CFGTerminator> { 723 typedef const ::clang::Stmt *SimpleType; 724 static SimpleType getSimplifiedValue(const ::clang::CFGTerminator &Val) { 725 return Val.getStmt(); 726 } 727}; 728 729template <> struct simplify_type< ::clang::CFGTerminator> { 730 typedef ::clang::Stmt *SimpleType; 731 static SimpleType getSimplifiedValue(const ::clang::CFGTerminator &Val) { 732 return const_cast<SimpleType>(Val.getStmt()); 733 } 734}; 735 736// Traits for: CFGBlock 737 738template <> struct GraphTraits< ::clang::CFGBlock *> { 739 typedef ::clang::CFGBlock NodeType; 740 typedef ::clang::CFGBlock::succ_iterator ChildIteratorType; 741 742 static NodeType* getEntryNode(::clang::CFGBlock *BB) 743 { return BB; } 744 745 static inline ChildIteratorType child_begin(NodeType* N) 746 { return N->succ_begin(); } 747 748 static inline ChildIteratorType child_end(NodeType* N) 749 { return N->succ_end(); } 750}; 751 752template <> struct GraphTraits< const ::clang::CFGBlock *> { 753 typedef const ::clang::CFGBlock NodeType; 754 typedef ::clang::CFGBlock::const_succ_iterator ChildIteratorType; 755 756 static NodeType* getEntryNode(const clang::CFGBlock *BB) 757 { return BB; } 758 759 static inline ChildIteratorType child_begin(NodeType* N) 760 { return N->succ_begin(); } 761 762 static inline ChildIteratorType child_end(NodeType* N) 763 { return N->succ_end(); } 764}; 765 766template <> struct GraphTraits<Inverse<const ::clang::CFGBlock*> > { 767 typedef const ::clang::CFGBlock NodeType; 768 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType; 769 770 static NodeType *getEntryNode(Inverse<const ::clang::CFGBlock*> G) 771 { return G.Graph; } 772 773 static inline ChildIteratorType child_begin(NodeType* N) 774 { return N->pred_begin(); } 775 776 static inline ChildIteratorType child_end(NodeType* N) 777 { return N->pred_end(); } 778}; 779 780// Traits for: CFG 781 782template <> struct GraphTraits< ::clang::CFG* > 783 : public GraphTraits< ::clang::CFGBlock *> { 784 785 typedef ::clang::CFG::iterator nodes_iterator; 786 787 static NodeType *getEntryNode(::clang::CFG* F) { return &F->getEntry(); } 788 static nodes_iterator nodes_begin(::clang::CFG* F) { return F->begin(); } 789 static nodes_iterator nodes_end(::clang::CFG* F) { return F->end(); } 790}; 791 792template <> struct GraphTraits<const ::clang::CFG* > 793 : public GraphTraits<const ::clang::CFGBlock *> { 794 795 typedef ::clang::CFG::const_iterator nodes_iterator; 796 797 static NodeType *getEntryNode( const ::clang::CFG* F) { 798 return &F->getEntry(); 799 } 800 static nodes_iterator nodes_begin( const ::clang::CFG* F) { 801 return F->begin(); 802 } 803 static nodes_iterator nodes_end( const ::clang::CFG* F) { 804 return F->end(); 805 } 806}; 807 808template <> struct GraphTraits<Inverse<const ::clang::CFG*> > 809 : public GraphTraits<Inverse<const ::clang::CFGBlock*> > { 810 811 typedef ::clang::CFG::const_iterator nodes_iterator; 812 813 static NodeType *getEntryNode(const ::clang::CFG* F) { return &F->getExit(); } 814 static nodes_iterator nodes_begin(const ::clang::CFG* F) { return F->begin();} 815 static nodes_iterator nodes_end(const ::clang::CFG* F) { return F->end(); } 816}; 817} // end llvm namespace 818#endif 819