CFG.h revision 9c378f705405d37f49795d5e915989de774fe11f
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 Stmt *getStmt() const { return static_cast<Stmt *>(Data1.getPointer()); } 100 101 static bool classof(const CFGElement *E) { 102 return E->getKind() == Statement; 103 } 104}; 105 106/// CFGInitializer - Represents C++ base or member initializer from 107/// constructor's initialization list. 108class CFGInitializer : public CFGElement { 109public: 110 CFGInitializer(CXXCtorInitializer *initializer) 111 : CFGElement(Initializer, initializer) {} 112 113 CXXCtorInitializer* getInitializer() const { 114 return static_cast<CXXCtorInitializer*>(Data1.getPointer()); 115 } 116 117 static bool classof(const CFGElement *E) { 118 return E->getKind() == Initializer; 119 } 120}; 121 122/// CFGImplicitDtor - Represents C++ object destructor implicitly generated 123/// by compiler on various occasions. 124class CFGImplicitDtor : public CFGElement { 125protected: 126 CFGImplicitDtor(Kind kind, const void *data1, const void *data2 = 0) 127 : CFGElement(kind, data1, data2) { 128 assert(kind >= DTOR_BEGIN && kind <= DTOR_END); 129 } 130 131public: 132 const CXXDestructorDecl *getDestructorDecl(ASTContext &astContext) const; 133 bool isNoReturn(ASTContext &astContext) const; 134 135 static bool classof(const CFGElement *E) { 136 Kind kind = E->getKind(); 137 return kind >= DTOR_BEGIN && kind <= DTOR_END; 138 } 139}; 140 141/// CFGAutomaticObjDtor - Represents C++ object destructor implicitly generated 142/// for automatic object or temporary bound to const reference at the point 143/// of leaving its local scope. 144class CFGAutomaticObjDtor: public CFGImplicitDtor { 145public: 146 CFGAutomaticObjDtor(const VarDecl *var, const Stmt *stmt) 147 : CFGImplicitDtor(AutomaticObjectDtor, var, stmt) {} 148 149 const VarDecl *getVarDecl() const { 150 return static_cast<VarDecl*>(Data1.getPointer()); 151 } 152 153 // Get statement end of which triggered the destructor call. 154 const Stmt *getTriggerStmt() const { 155 return static_cast<Stmt*>(Data2.getPointer()); 156 } 157 158 static bool classof(const CFGElement *elem) { 159 return elem->getKind() == AutomaticObjectDtor; 160 } 161}; 162 163/// CFGBaseDtor - Represents C++ object destructor implicitly generated for 164/// base object in destructor. 165class CFGBaseDtor : public CFGImplicitDtor { 166public: 167 CFGBaseDtor(const CXXBaseSpecifier *base) 168 : CFGImplicitDtor(BaseDtor, base) {} 169 170 const CXXBaseSpecifier *getBaseSpecifier() const { 171 return static_cast<const CXXBaseSpecifier*>(Data1.getPointer()); 172 } 173 174 static bool classof(const CFGElement *E) { 175 return E->getKind() == BaseDtor; 176 } 177}; 178 179/// CFGMemberDtor - Represents C++ object destructor implicitly generated for 180/// member object in destructor. 181class CFGMemberDtor : public CFGImplicitDtor { 182public: 183 CFGMemberDtor(const FieldDecl *field) 184 : CFGImplicitDtor(MemberDtor, field, 0) {} 185 186 const FieldDecl *getFieldDecl() const { 187 return static_cast<const FieldDecl*>(Data1.getPointer()); 188 } 189 190 static bool classof(const CFGElement *E) { 191 return E->getKind() == MemberDtor; 192 } 193}; 194 195/// CFGTemporaryDtor - Represents C++ object destructor implicitly generated 196/// at the end of full expression for temporary object. 197class CFGTemporaryDtor : public CFGImplicitDtor { 198public: 199 CFGTemporaryDtor(CXXBindTemporaryExpr *expr) 200 : CFGImplicitDtor(TemporaryDtor, expr, 0) {} 201 202 const CXXBindTemporaryExpr *getBindTemporaryExpr() const { 203 return static_cast<const CXXBindTemporaryExpr *>(Data1.getPointer()); 204 } 205 206 static bool classof(const CFGElement *E) { 207 return E->getKind() == TemporaryDtor; 208 } 209}; 210 211/// CFGTerminator - Represents CFGBlock terminator statement. 212/// 213/// TemporaryDtorsBranch bit is set to true if the terminator marks a branch 214/// in control flow of destructors of temporaries. In this case terminator 215/// statement is the same statement that branches control flow in evaluation 216/// of matching full expression. 217class CFGTerminator { 218 llvm::PointerIntPair<Stmt *, 1> Data; 219public: 220 CFGTerminator() {} 221 CFGTerminator(Stmt *S, bool TemporaryDtorsBranch = false) 222 : Data(S, TemporaryDtorsBranch) {} 223 224 Stmt *getStmt() { return Data.getPointer(); } 225 const Stmt *getStmt() const { return Data.getPointer(); } 226 227 bool isTemporaryDtorsBranch() const { return Data.getInt(); } 228 229 operator Stmt *() { return getStmt(); } 230 operator const Stmt *() const { return getStmt(); } 231 232 Stmt *operator->() { return getStmt(); } 233 const Stmt *operator->() const { return getStmt(); } 234 235 Stmt &operator*() { return *getStmt(); } 236 const Stmt &operator*() const { return *getStmt(); } 237 238 operator bool() const { return getStmt(); } 239}; 240 241/// CFGBlock - Represents a single basic block in a source-level CFG. 242/// It consists of: 243/// 244/// (1) A set of statements/expressions (which may contain subexpressions). 245/// (2) A "terminator" statement (not in the set of statements). 246/// (3) A list of successors and predecessors. 247/// 248/// Terminator: The terminator represents the type of control-flow that occurs 249/// at the end of the basic block. The terminator is a Stmt* referring to an 250/// AST node that has control-flow: if-statements, breaks, loops, etc. 251/// If the control-flow is conditional, the condition expression will appear 252/// within the set of statements in the block (usually the last statement). 253/// 254/// Predecessors: the order in the set of predecessors is arbitrary. 255/// 256/// Successors: the order in the set of successors is NOT arbitrary. We 257/// currently have the following orderings based on the terminator: 258/// 259/// Terminator Successor Ordering 260/// ----------------------------------------------------- 261/// if Then Block; Else Block 262/// ? operator LHS expression; RHS expression 263/// &&, || expression that uses result of && or ||, RHS 264/// 265/// But note that any of that may be NULL in case of optimized-out edges. 266/// 267class CFGBlock { 268 class ElementList { 269 typedef BumpVector<CFGElement> ImplTy; 270 ImplTy Impl; 271 public: 272 ElementList(BumpVectorContext &C) : Impl(C, 4) {} 273 274 typedef std::reverse_iterator<ImplTy::iterator> iterator; 275 typedef std::reverse_iterator<ImplTy::const_iterator> const_iterator; 276 typedef ImplTy::iterator reverse_iterator; 277 typedef ImplTy::const_iterator const_reverse_iterator; 278 279 void push_back(CFGElement e, BumpVectorContext &C) { Impl.push_back(e, C); } 280 reverse_iterator insert(reverse_iterator I, size_t Cnt, CFGElement E, 281 BumpVectorContext &C) { 282 return Impl.insert(I, Cnt, E, C); 283 } 284 285 CFGElement front() const { return Impl.back(); } 286 CFGElement back() const { return Impl.front(); } 287 288 iterator begin() { return Impl.rbegin(); } 289 iterator end() { return Impl.rend(); } 290 const_iterator begin() const { return Impl.rbegin(); } 291 const_iterator end() const { return Impl.rend(); } 292 reverse_iterator rbegin() { return Impl.begin(); } 293 reverse_iterator rend() { return Impl.end(); } 294 const_reverse_iterator rbegin() const { return Impl.begin(); } 295 const_reverse_iterator rend() const { return Impl.end(); } 296 297 CFGElement operator[](size_t i) const { 298 assert(i < Impl.size()); 299 return Impl[Impl.size() - 1 - i]; 300 } 301 302 size_t size() const { return Impl.size(); } 303 bool empty() const { return Impl.empty(); } 304 }; 305 306 /// Stmts - The set of statements in the basic block. 307 ElementList Elements; 308 309 /// Label - An (optional) label that prefixes the executable 310 /// statements in the block. When this variable is non-NULL, it is 311 /// either an instance of LabelStmt, SwitchCase or CXXCatchStmt. 312 Stmt *Label; 313 314 /// Terminator - The terminator for a basic block that 315 /// indicates the type of control-flow that occurs between a block 316 /// and its successors. 317 CFGTerminator Terminator; 318 319 /// LoopTarget - Some blocks are used to represent the "loop edge" to 320 /// the start of a loop from within the loop body. This Stmt* will be 321 /// refer to the loop statement for such blocks (and be null otherwise). 322 const Stmt *LoopTarget; 323 324 /// BlockID - A numerical ID assigned to a CFGBlock during construction 325 /// of the CFG. 326 unsigned BlockID; 327 328 /// Predecessors/Successors - Keep track of the predecessor / successor 329 /// CFG blocks. 330 typedef BumpVector<CFGBlock*> AdjacentBlocks; 331 AdjacentBlocks Preds; 332 AdjacentBlocks Succs; 333 334public: 335 explicit CFGBlock(unsigned blockid, BumpVectorContext &C) 336 : Elements(C), Label(NULL), Terminator(NULL), LoopTarget(NULL), 337 BlockID(blockid), Preds(C, 1), Succs(C, 1) {} 338 ~CFGBlock() {} 339 340 // Statement iterators 341 typedef ElementList::iterator iterator; 342 typedef ElementList::const_iterator const_iterator; 343 typedef ElementList::reverse_iterator reverse_iterator; 344 typedef ElementList::const_reverse_iterator const_reverse_iterator; 345 346 CFGElement front() const { return Elements.front(); } 347 CFGElement back() const { return Elements.back(); } 348 349 iterator begin() { return Elements.begin(); } 350 iterator end() { return Elements.end(); } 351 const_iterator begin() const { return Elements.begin(); } 352 const_iterator end() const { return Elements.end(); } 353 354 reverse_iterator rbegin() { return Elements.rbegin(); } 355 reverse_iterator rend() { return Elements.rend(); } 356 const_reverse_iterator rbegin() const { return Elements.rbegin(); } 357 const_reverse_iterator rend() const { return Elements.rend(); } 358 359 unsigned size() const { return Elements.size(); } 360 bool empty() const { return Elements.empty(); } 361 362 CFGElement operator[](size_t i) const { return Elements[i]; } 363 364 // CFG iterators 365 typedef AdjacentBlocks::iterator pred_iterator; 366 typedef AdjacentBlocks::const_iterator const_pred_iterator; 367 typedef AdjacentBlocks::reverse_iterator pred_reverse_iterator; 368 typedef AdjacentBlocks::const_reverse_iterator const_pred_reverse_iterator; 369 370 typedef AdjacentBlocks::iterator succ_iterator; 371 typedef AdjacentBlocks::const_iterator const_succ_iterator; 372 typedef AdjacentBlocks::reverse_iterator succ_reverse_iterator; 373 typedef AdjacentBlocks::const_reverse_iterator const_succ_reverse_iterator; 374 375 pred_iterator pred_begin() { return Preds.begin(); } 376 pred_iterator pred_end() { return Preds.end(); } 377 const_pred_iterator pred_begin() const { return Preds.begin(); } 378 const_pred_iterator pred_end() const { return Preds.end(); } 379 380 pred_reverse_iterator pred_rbegin() { return Preds.rbegin(); } 381 pred_reverse_iterator pred_rend() { return Preds.rend(); } 382 const_pred_reverse_iterator pred_rbegin() const { return Preds.rbegin(); } 383 const_pred_reverse_iterator pred_rend() const { return Preds.rend(); } 384 385 succ_iterator succ_begin() { return Succs.begin(); } 386 succ_iterator succ_end() { return Succs.end(); } 387 const_succ_iterator succ_begin() const { return Succs.begin(); } 388 const_succ_iterator succ_end() const { return Succs.end(); } 389 390 succ_reverse_iterator succ_rbegin() { return Succs.rbegin(); } 391 succ_reverse_iterator succ_rend() { return Succs.rend(); } 392 const_succ_reverse_iterator succ_rbegin() const { return Succs.rbegin(); } 393 const_succ_reverse_iterator succ_rend() const { return Succs.rend(); } 394 395 unsigned succ_size() const { return Succs.size(); } 396 bool succ_empty() const { return Succs.empty(); } 397 398 unsigned pred_size() const { return Preds.size(); } 399 bool pred_empty() const { return Preds.empty(); } 400 401 402 class FilterOptions { 403 public: 404 FilterOptions() { 405 IgnoreDefaultsWithCoveredEnums = 0; 406 } 407 408 unsigned IgnoreDefaultsWithCoveredEnums : 1; 409 }; 410 411 static bool FilterEdge(const FilterOptions &F, const CFGBlock *Src, 412 const CFGBlock *Dst); 413 414 template <typename IMPL, bool IsPred> 415 class FilteredCFGBlockIterator { 416 private: 417 IMPL I, E; 418 const FilterOptions F; 419 const CFGBlock *From; 420 public: 421 explicit FilteredCFGBlockIterator(const IMPL &i, const IMPL &e, 422 const CFGBlock *from, 423 const FilterOptions &f) 424 : I(i), E(e), F(f), From(from) {} 425 426 bool hasMore() const { return I != E; } 427 428 FilteredCFGBlockIterator &operator++() { 429 do { ++I; } while (hasMore() && Filter(*I)); 430 return *this; 431 } 432 433 const CFGBlock *operator*() const { return *I; } 434 private: 435 bool Filter(const CFGBlock *To) { 436 return IsPred ? FilterEdge(F, To, From) : FilterEdge(F, From, To); 437 } 438 }; 439 440 typedef FilteredCFGBlockIterator<const_pred_iterator, true> 441 filtered_pred_iterator; 442 443 typedef FilteredCFGBlockIterator<const_succ_iterator, false> 444 filtered_succ_iterator; 445 446 filtered_pred_iterator filtered_pred_start_end(const FilterOptions &f) const { 447 return filtered_pred_iterator(pred_begin(), pred_end(), this, f); 448 } 449 450 filtered_succ_iterator filtered_succ_start_end(const FilterOptions &f) const { 451 return filtered_succ_iterator(succ_begin(), succ_end(), this, f); 452 } 453 454 // Manipulation of block contents 455 456 void setTerminator(Stmt *Statement) { Terminator = Statement; } 457 void setLabel(Stmt *Statement) { Label = Statement; } 458 void setLoopTarget(const Stmt *loopTarget) { LoopTarget = loopTarget; } 459 460 CFGTerminator getTerminator() { return Terminator; } 461 const CFGTerminator getTerminator() const { return Terminator; } 462 463 Stmt *getTerminatorCondition(); 464 465 const Stmt *getTerminatorCondition() const { 466 return const_cast<CFGBlock*>(this)->getTerminatorCondition(); 467 } 468 469 const Stmt *getLoopTarget() const { return LoopTarget; } 470 471 Stmt *getLabel() { return Label; } 472 const Stmt *getLabel() const { return Label; } 473 474 unsigned getBlockID() const { return BlockID; } 475 476 void dump(const CFG *cfg, const LangOptions &LO) const; 477 void print(raw_ostream &OS, const CFG* cfg, const LangOptions &LO) const; 478 void printTerminator(raw_ostream &OS, const LangOptions &LO) const; 479 480 void addSuccessor(CFGBlock *Block, BumpVectorContext &C) { 481 if (Block) 482 Block->Preds.push_back(this, C); 483 Succs.push_back(Block, C); 484 } 485 486 void appendStmt(Stmt *statement, BumpVectorContext &C) { 487 Elements.push_back(CFGStmt(statement), C); 488 } 489 490 void appendInitializer(CXXCtorInitializer *initializer, 491 BumpVectorContext &C) { 492 Elements.push_back(CFGInitializer(initializer), C); 493 } 494 495 void appendBaseDtor(const CXXBaseSpecifier *BS, BumpVectorContext &C) { 496 Elements.push_back(CFGBaseDtor(BS), C); 497 } 498 499 void appendMemberDtor(FieldDecl *FD, BumpVectorContext &C) { 500 Elements.push_back(CFGMemberDtor(FD), C); 501 } 502 503 void appendTemporaryDtor(CXXBindTemporaryExpr *E, BumpVectorContext &C) { 504 Elements.push_back(CFGTemporaryDtor(E), C); 505 } 506 507 // Destructors must be inserted in reversed order. So insertion is in two 508 // steps. First we prepare space for some number of elements, then we insert 509 // the elements beginning at the last position in prepared space. 510 iterator beginAutomaticObjDtorsInsert(iterator I, size_t Cnt, 511 BumpVectorContext &C) { 512 return iterator(Elements.insert(I.base(), Cnt, CFGElement(), C)); 513 } 514 iterator insertAutomaticObjDtor(iterator I, VarDecl *VD, Stmt *S) { 515 *I = CFGAutomaticObjDtor(VD, S); 516 return ++I; 517 } 518}; 519 520/// CFG - Represents a source-level, intra-procedural CFG that represents the 521/// control-flow of a Stmt. The Stmt can represent an entire function body, 522/// or a single expression. A CFG will always contain one empty block that 523/// represents the Exit point of the CFG. A CFG will also contain a designated 524/// Entry block. The CFG solely represents control-flow; it consists of 525/// CFGBlocks which are simply containers of Stmt*'s in the AST the CFG 526/// was constructed from. 527class CFG { 528public: 529 //===--------------------------------------------------------------------===// 530 // CFG Construction & Manipulation. 531 //===--------------------------------------------------------------------===// 532 533 class BuildOptions { 534 llvm::BitVector alwaysAddMask; 535 public: 536 typedef llvm::DenseMap<const Stmt *, const CFGBlock*> ForcedBlkExprs; 537 ForcedBlkExprs **forcedBlkExprs; 538 539 bool PruneTriviallyFalseEdges; 540 bool AddEHEdges; 541 bool AddInitializers; 542 bool AddImplicitDtors; 543 544 bool alwaysAdd(const Stmt *stmt) const { 545 return alwaysAddMask[stmt->getStmtClass()]; 546 } 547 548 BuildOptions &setAlwaysAdd(Stmt::StmtClass stmtClass, bool val = true) { 549 alwaysAddMask[stmtClass] = val; 550 return *this; 551 } 552 553 BuildOptions &setAllAlwaysAdd() { 554 alwaysAddMask.set(); 555 return *this; 556 } 557 558 BuildOptions() 559 : alwaysAddMask(Stmt::lastStmtConstant, false) 560 ,forcedBlkExprs(0), PruneTriviallyFalseEdges(true) 561 ,AddEHEdges(false) 562 ,AddInitializers(false) 563 ,AddImplicitDtors(false) {} 564 }; 565 566 /// buildCFG - Builds a CFG from an AST. The responsibility to free the 567 /// constructed CFG belongs to the caller. 568 static CFG* buildCFG(const Decl *D, Stmt *AST, ASTContext *C, 569 const BuildOptions &BO); 570 571 /// createBlock - Create a new block in the CFG. The CFG owns the block; 572 /// the caller should not directly free it. 573 CFGBlock *createBlock(); 574 575 /// setEntry - Set the entry block of the CFG. This is typically used 576 /// only during CFG construction. Most CFG clients expect that the 577 /// entry block has no predecessors and contains no statements. 578 void setEntry(CFGBlock *B) { Entry = B; } 579 580 /// setIndirectGotoBlock - Set the block used for indirect goto jumps. 581 /// This is typically used only during CFG construction. 582 void setIndirectGotoBlock(CFGBlock *B) { IndirectGotoBlock = B; } 583 584 //===--------------------------------------------------------------------===// 585 // Block Iterators 586 //===--------------------------------------------------------------------===// 587 588 typedef BumpVector<CFGBlock*> CFGBlockListTy; 589 typedef CFGBlockListTy::iterator iterator; 590 typedef CFGBlockListTy::const_iterator const_iterator; 591 typedef std::reverse_iterator<iterator> reverse_iterator; 592 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 593 594 CFGBlock & front() { return *Blocks.front(); } 595 CFGBlock & back() { return *Blocks.back(); } 596 597 iterator begin() { return Blocks.begin(); } 598 iterator end() { return Blocks.end(); } 599 const_iterator begin() const { return Blocks.begin(); } 600 const_iterator end() const { return Blocks.end(); } 601 602 reverse_iterator rbegin() { return Blocks.rbegin(); } 603 reverse_iterator rend() { return Blocks.rend(); } 604 const_reverse_iterator rbegin() const { return Blocks.rbegin(); } 605 const_reverse_iterator rend() const { return Blocks.rend(); } 606 607 CFGBlock & getEntry() { return *Entry; } 608 const CFGBlock & getEntry() const { return *Entry; } 609 CFGBlock & getExit() { return *Exit; } 610 const CFGBlock & getExit() const { return *Exit; } 611 612 CFGBlock * getIndirectGotoBlock() { return IndirectGotoBlock; } 613 const CFGBlock * getIndirectGotoBlock() const { return IndirectGotoBlock; } 614 615 //===--------------------------------------------------------------------===// 616 // Member templates useful for various batch operations over CFGs. 617 //===--------------------------------------------------------------------===// 618 619 template <typename CALLBACK> 620 void VisitBlockStmts(CALLBACK& O) const { 621 for (const_iterator I=begin(), E=end(); I != E; ++I) 622 for (CFGBlock::const_iterator BI=(*I)->begin(), BE=(*I)->end(); 623 BI != BE; ++BI) { 624 if (const CFGStmt *stmt = BI->getAs<CFGStmt>()) 625 O(stmt->getStmt()); 626 } 627 } 628 629 //===--------------------------------------------------------------------===// 630 // CFG Introspection. 631 //===--------------------------------------------------------------------===// 632 633 struct BlkExprNumTy { 634 const signed Idx; 635 explicit BlkExprNumTy(signed idx) : Idx(idx) {} 636 explicit BlkExprNumTy() : Idx(-1) {} 637 operator bool() const { return Idx >= 0; } 638 operator unsigned() const { assert(Idx >=0); return (unsigned) Idx; } 639 }; 640 641 bool isBlkExpr(const Stmt *S) { return getBlkExprNum(S); } 642 bool isBlkExpr(const Stmt *S) const { 643 return const_cast<CFG*>(this)->isBlkExpr(S); 644 } 645 BlkExprNumTy getBlkExprNum(const Stmt *S); 646 unsigned getNumBlkExprs(); 647 648 /// getNumBlockIDs - Returns the total number of BlockIDs allocated (which 649 /// start at 0). 650 unsigned getNumBlockIDs() const { return NumBlockIDs; } 651 652 //===--------------------------------------------------------------------===// 653 // CFG Debugging: Pretty-Printing and Visualization. 654 //===--------------------------------------------------------------------===// 655 656 void viewCFG(const LangOptions &LO) const; 657 void print(raw_ostream &OS, const LangOptions &LO) const; 658 void dump(const LangOptions &LO) const; 659 660 //===--------------------------------------------------------------------===// 661 // Internal: constructors and data. 662 //===--------------------------------------------------------------------===// 663 664 CFG() : Entry(NULL), Exit(NULL), IndirectGotoBlock(NULL), NumBlockIDs(0), 665 BlkExprMap(NULL), Blocks(BlkBVC, 10) {} 666 667 ~CFG(); 668 669 llvm::BumpPtrAllocator& getAllocator() { 670 return BlkBVC.getAllocator(); 671 } 672 673 BumpVectorContext &getBumpVectorContext() { 674 return BlkBVC; 675 } 676 677private: 678 CFGBlock *Entry; 679 CFGBlock *Exit; 680 CFGBlock* IndirectGotoBlock; // Special block to contain collective dispatch 681 // for indirect gotos 682 unsigned NumBlockIDs; 683 684 // BlkExprMap - An opaque pointer to prevent inclusion of DenseMap.h. 685 // It represents a map from Expr* to integers to record the set of 686 // block-level expressions and their "statement number" in the CFG. 687 void * BlkExprMap; 688 689 BumpVectorContext BlkBVC; 690 691 CFGBlockListTy Blocks; 692 693}; 694} // end namespace clang 695 696//===----------------------------------------------------------------------===// 697// GraphTraits specializations for CFG basic block graphs (source-level CFGs) 698//===----------------------------------------------------------------------===// 699 700namespace llvm { 701 702/// Implement simplify_type for CFGTerminator, so that we can dyn_cast from 703/// CFGTerminator to a specific Stmt class. 704template <> struct simplify_type<const ::clang::CFGTerminator> { 705 typedef const ::clang::Stmt *SimpleType; 706 static SimpleType getSimplifiedValue(const ::clang::CFGTerminator &Val) { 707 return Val.getStmt(); 708 } 709}; 710 711template <> struct simplify_type< ::clang::CFGTerminator> { 712 typedef ::clang::Stmt *SimpleType; 713 static SimpleType getSimplifiedValue(const ::clang::CFGTerminator &Val) { 714 return const_cast<SimpleType>(Val.getStmt()); 715 } 716}; 717 718// Traits for: CFGBlock 719 720template <> struct GraphTraits< ::clang::CFGBlock *> { 721 typedef ::clang::CFGBlock NodeType; 722 typedef ::clang::CFGBlock::succ_iterator ChildIteratorType; 723 724 static NodeType* getEntryNode(::clang::CFGBlock *BB) 725 { return BB; } 726 727 static inline ChildIteratorType child_begin(NodeType* N) 728 { return N->succ_begin(); } 729 730 static inline ChildIteratorType child_end(NodeType* N) 731 { return N->succ_end(); } 732}; 733 734template <> struct GraphTraits< const ::clang::CFGBlock *> { 735 typedef const ::clang::CFGBlock NodeType; 736 typedef ::clang::CFGBlock::const_succ_iterator ChildIteratorType; 737 738 static NodeType* getEntryNode(const clang::CFGBlock *BB) 739 { return BB; } 740 741 static inline ChildIteratorType child_begin(NodeType* N) 742 { return N->succ_begin(); } 743 744 static inline ChildIteratorType child_end(NodeType* N) 745 { return N->succ_end(); } 746}; 747 748template <> struct GraphTraits<Inverse<const ::clang::CFGBlock*> > { 749 typedef const ::clang::CFGBlock NodeType; 750 typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType; 751 752 static NodeType *getEntryNode(Inverse<const ::clang::CFGBlock*> G) 753 { return G.Graph; } 754 755 static inline ChildIteratorType child_begin(NodeType* N) 756 { return N->pred_begin(); } 757 758 static inline ChildIteratorType child_end(NodeType* N) 759 { return N->pred_end(); } 760}; 761 762// Traits for: CFG 763 764template <> struct GraphTraits< ::clang::CFG* > 765 : public GraphTraits< ::clang::CFGBlock *> { 766 767 typedef ::clang::CFG::iterator nodes_iterator; 768 769 static NodeType *getEntryNode(::clang::CFG* F) { return &F->getEntry(); } 770 static nodes_iterator nodes_begin(::clang::CFG* F) { return F->begin(); } 771 static nodes_iterator nodes_end(::clang::CFG* F) { return F->end(); } 772}; 773 774template <> struct GraphTraits<const ::clang::CFG* > 775 : public GraphTraits<const ::clang::CFGBlock *> { 776 777 typedef ::clang::CFG::const_iterator nodes_iterator; 778 779 static NodeType *getEntryNode( const ::clang::CFG* F) { 780 return &F->getEntry(); 781 } 782 static nodes_iterator nodes_begin( const ::clang::CFG* F) { 783 return F->begin(); 784 } 785 static nodes_iterator nodes_end( const ::clang::CFG* F) { 786 return F->end(); 787 } 788}; 789 790template <> struct GraphTraits<Inverse<const ::clang::CFG*> > 791 : public GraphTraits<Inverse<const ::clang::CFGBlock*> > { 792 793 typedef ::clang::CFG::const_iterator nodes_iterator; 794 795 static NodeType *getEntryNode(const ::clang::CFG* F) { return &F->getExit(); } 796 static nodes_iterator nodes_begin(const ::clang::CFG* F) { return F->begin();} 797 static nodes_iterator nodes_end(const ::clang::CFG* F) { return F->end(); } 798}; 799} // end llvm namespace 800#endif 801