CFG.cpp revision 6f42b62b6194f53bcbc349f5d17388e1936535d7
1//===--- CFG.cpp - 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#include "clang/Analysis/Support/SaveAndRestore.h" 16#include "clang/Analysis/CFG.h" 17#include "clang/AST/DeclCXX.h" 18#include "clang/AST/StmtVisitor.h" 19#include "clang/AST/PrettyPrinter.h" 20#include "clang/AST/CharUnits.h" 21#include "llvm/Support/GraphWriter.h" 22#include "llvm/Support/Allocator.h" 23#include "llvm/Support/Format.h" 24#include "llvm/ADT/DenseMap.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/OwningPtr.h" 27 28using namespace clang; 29 30namespace { 31 32static SourceLocation GetEndLoc(Decl *D) { 33 if (VarDecl *VD = dyn_cast<VarDecl>(D)) 34 if (Expr *Ex = VD->getInit()) 35 return Ex->getSourceRange().getEnd(); 36 return D->getLocation(); 37} 38 39class CFGBuilder; 40 41/// The CFG builder uses a recursive algorithm to build the CFG. When 42/// we process an expression, sometimes we know that we must add the 43/// subexpressions as block-level expressions. For example: 44/// 45/// exp1 || exp2 46/// 47/// When processing the '||' expression, we know that exp1 and exp2 48/// need to be added as block-level expressions, even though they 49/// might not normally need to be. AddStmtChoice records this 50/// contextual information. If AddStmtChoice is 'NotAlwaysAdd', then 51/// the builder has an option not to add a subexpression as a 52/// block-level expression. 53/// 54class AddStmtChoice { 55public: 56 enum Kind { NotAlwaysAdd = 0, AlwaysAdd = 1 }; 57 58 AddStmtChoice(Kind a_kind = NotAlwaysAdd) : kind(a_kind) {} 59 60 bool alwaysAdd(CFGBuilder &builder, 61 const Stmt *stmt) const; 62 63 /// Return a copy of this object, except with the 'always-add' bit 64 /// set as specified. 65 AddStmtChoice withAlwaysAdd(bool alwaysAdd) const { 66 return AddStmtChoice(alwaysAdd ? AlwaysAdd : NotAlwaysAdd); 67 } 68 69private: 70 Kind kind; 71}; 72 73/// LocalScope - Node in tree of local scopes created for C++ implicit 74/// destructor calls generation. It contains list of automatic variables 75/// declared in the scope and link to position in previous scope this scope 76/// began in. 77/// 78/// The process of creating local scopes is as follows: 79/// - Init CFGBuilder::ScopePos with invalid position (equivalent for null), 80/// - Before processing statements in scope (e.g. CompoundStmt) create 81/// LocalScope object using CFGBuilder::ScopePos as link to previous scope 82/// and set CFGBuilder::ScopePos to the end of new scope, 83/// - On every occurrence of VarDecl increase CFGBuilder::ScopePos if it points 84/// at this VarDecl, 85/// - For every normal (without jump) end of scope add to CFGBlock destructors 86/// for objects in the current scope, 87/// - For every jump add to CFGBlock destructors for objects 88/// between CFGBuilder::ScopePos and local scope position saved for jump 89/// target. Thanks to C++ restrictions on goto jumps we can be sure that 90/// jump target position will be on the path to root from CFGBuilder::ScopePos 91/// (adding any variable that doesn't need constructor to be called to 92/// LocalScope can break this assumption), 93/// 94class LocalScope { 95public: 96 typedef BumpVector<VarDecl*> AutomaticVarsTy; 97 98 /// const_iterator - Iterates local scope backwards and jumps to previous 99 /// scope on reaching the beginning of currently iterated scope. 100 class const_iterator { 101 const LocalScope* Scope; 102 103 /// VarIter is guaranteed to be greater then 0 for every valid iterator. 104 /// Invalid iterator (with null Scope) has VarIter equal to 0. 105 unsigned VarIter; 106 107 public: 108 /// Create invalid iterator. Dereferencing invalid iterator is not allowed. 109 /// Incrementing invalid iterator is allowed and will result in invalid 110 /// iterator. 111 const_iterator() 112 : Scope(NULL), VarIter(0) {} 113 114 /// Create valid iterator. In case when S.Prev is an invalid iterator and 115 /// I is equal to 0, this will create invalid iterator. 116 const_iterator(const LocalScope& S, unsigned I) 117 : Scope(&S), VarIter(I) { 118 // Iterator to "end" of scope is not allowed. Handle it by going up 119 // in scopes tree possibly up to invalid iterator in the root. 120 if (VarIter == 0 && Scope) 121 *this = Scope->Prev; 122 } 123 124 VarDecl *const* operator->() const { 125 assert (Scope && "Dereferencing invalid iterator is not allowed"); 126 assert (VarIter != 0 && "Iterator has invalid value of VarIter member"); 127 return &Scope->Vars[VarIter - 1]; 128 } 129 VarDecl *operator*() const { 130 return *this->operator->(); 131 } 132 133 const_iterator &operator++() { 134 if (!Scope) 135 return *this; 136 137 assert (VarIter != 0 && "Iterator has invalid value of VarIter member"); 138 --VarIter; 139 if (VarIter == 0) 140 *this = Scope->Prev; 141 return *this; 142 } 143 const_iterator operator++(int) { 144 const_iterator P = *this; 145 ++*this; 146 return P; 147 } 148 149 bool operator==(const const_iterator &rhs) const { 150 return Scope == rhs.Scope && VarIter == rhs.VarIter; 151 } 152 bool operator!=(const const_iterator &rhs) const { 153 return !(*this == rhs); 154 } 155 156 operator bool() const { 157 return *this != const_iterator(); 158 } 159 160 int distance(const_iterator L); 161 }; 162 163 friend class const_iterator; 164 165private: 166 BumpVectorContext ctx; 167 168 /// Automatic variables in order of declaration. 169 AutomaticVarsTy Vars; 170 /// Iterator to variable in previous scope that was declared just before 171 /// begin of this scope. 172 const_iterator Prev; 173 174public: 175 /// Constructs empty scope linked to previous scope in specified place. 176 LocalScope(BumpVectorContext &ctx, const_iterator P) 177 : ctx(ctx), Vars(ctx, 4), Prev(P) {} 178 179 /// Begin of scope in direction of CFG building (backwards). 180 const_iterator begin() const { return const_iterator(*this, Vars.size()); } 181 182 void addVar(VarDecl *VD) { 183 Vars.push_back(VD, ctx); 184 } 185}; 186 187/// distance - Calculates distance from this to L. L must be reachable from this 188/// (with use of ++ operator). Cost of calculating the distance is linear w.r.t. 189/// number of scopes between this and L. 190int LocalScope::const_iterator::distance(LocalScope::const_iterator L) { 191 int D = 0; 192 const_iterator F = *this; 193 while (F.Scope != L.Scope) { 194 assert (F != const_iterator() 195 && "L iterator is not reachable from F iterator."); 196 D += F.VarIter; 197 F = F.Scope->Prev; 198 } 199 D += F.VarIter - L.VarIter; 200 return D; 201} 202 203/// BlockScopePosPair - Structure for specifying position in CFG during its 204/// build process. It consists of CFGBlock that specifies position in CFG graph 205/// and LocalScope::const_iterator that specifies position in LocalScope graph. 206struct BlockScopePosPair { 207 BlockScopePosPair() : block(0) {} 208 BlockScopePosPair(CFGBlock *b, LocalScope::const_iterator scopePos) 209 : block(b), scopePosition(scopePos) {} 210 211 CFGBlock *block; 212 LocalScope::const_iterator scopePosition; 213}; 214 215/// TryResult - a class representing a variant over the values 216/// 'true', 'false', or 'unknown'. This is returned by tryEvaluateBool, 217/// and is used by the CFGBuilder to decide if a branch condition 218/// can be decided up front during CFG construction. 219class TryResult { 220 int X; 221public: 222 TryResult(bool b) : X(b ? 1 : 0) {} 223 TryResult() : X(-1) {} 224 225 bool isTrue() const { return X == 1; } 226 bool isFalse() const { return X == 0; } 227 bool isKnown() const { return X >= 0; } 228 void negate() { 229 assert(isKnown()); 230 X ^= 0x1; 231 } 232}; 233 234/// CFGBuilder - This class implements CFG construction from an AST. 235/// The builder is stateful: an instance of the builder should be used to only 236/// construct a single CFG. 237/// 238/// Example usage: 239/// 240/// CFGBuilder builder; 241/// CFG* cfg = builder.BuildAST(stmt1); 242/// 243/// CFG construction is done via a recursive walk of an AST. We actually parse 244/// the AST in reverse order so that the successor of a basic block is 245/// constructed prior to its predecessor. This allows us to nicely capture 246/// implicit fall-throughs without extra basic blocks. 247/// 248class CFGBuilder { 249 typedef BlockScopePosPair JumpTarget; 250 typedef BlockScopePosPair JumpSource; 251 252 ASTContext *Context; 253 OwningPtr<CFG> cfg; 254 255 CFGBlock *Block; 256 CFGBlock *Succ; 257 JumpTarget ContinueJumpTarget; 258 JumpTarget BreakJumpTarget; 259 CFGBlock *SwitchTerminatedBlock; 260 CFGBlock *DefaultCaseBlock; 261 CFGBlock *TryTerminatedBlock; 262 263 // Current position in local scope. 264 LocalScope::const_iterator ScopePos; 265 266 // LabelMap records the mapping from Label expressions to their jump targets. 267 typedef llvm::DenseMap<LabelDecl*, JumpTarget> LabelMapTy; 268 LabelMapTy LabelMap; 269 270 // A list of blocks that end with a "goto" that must be backpatched to their 271 // resolved targets upon completion of CFG construction. 272 typedef std::vector<JumpSource> BackpatchBlocksTy; 273 BackpatchBlocksTy BackpatchBlocks; 274 275 // A list of labels whose address has been taken (for indirect gotos). 276 typedef llvm::SmallPtrSet<LabelDecl*, 5> LabelSetTy; 277 LabelSetTy AddressTakenLabels; 278 279 bool badCFG; 280 const CFG::BuildOptions &BuildOpts; 281 282 // State to track for building switch statements. 283 bool switchExclusivelyCovered; 284 Expr::EvalResult *switchCond; 285 286 CFG::BuildOptions::ForcedBlkExprs::value_type *cachedEntry; 287 const Stmt *lastLookup; 288 289public: 290 explicit CFGBuilder(ASTContext *astContext, 291 const CFG::BuildOptions &buildOpts) 292 : Context(astContext), cfg(new CFG()), // crew a new CFG 293 Block(NULL), Succ(NULL), 294 SwitchTerminatedBlock(NULL), DefaultCaseBlock(NULL), 295 TryTerminatedBlock(NULL), badCFG(false), BuildOpts(buildOpts), 296 switchExclusivelyCovered(false), switchCond(0), 297 cachedEntry(0), lastLookup(0) {} 298 299 // buildCFG - Used by external clients to construct the CFG. 300 CFG* buildCFG(const Decl *D, Stmt *Statement); 301 302 bool alwaysAdd(const Stmt *stmt); 303 304private: 305 // Visitors to walk an AST and construct the CFG. 306 CFGBlock *VisitAddrLabelExpr(AddrLabelExpr *A, AddStmtChoice asc); 307 CFGBlock *VisitBinaryOperator(BinaryOperator *B, AddStmtChoice asc); 308 CFGBlock *VisitBlockExpr(BlockExpr *E, AddStmtChoice asc); 309 CFGBlock *VisitBreakStmt(BreakStmt *B); 310 CFGBlock *VisitCXXCatchStmt(CXXCatchStmt *S); 311 CFGBlock *VisitExprWithCleanups(ExprWithCleanups *E, 312 AddStmtChoice asc); 313 CFGBlock *VisitCXXThrowExpr(CXXThrowExpr *T); 314 CFGBlock *VisitCXXTryStmt(CXXTryStmt *S); 315 CFGBlock *VisitCXXForRangeStmt(CXXForRangeStmt *S); 316 CFGBlock *VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E, 317 AddStmtChoice asc); 318 CFGBlock *VisitCXXConstructExpr(CXXConstructExpr *C, AddStmtChoice asc); 319 CFGBlock *VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E, 320 AddStmtChoice asc); 321 CFGBlock *VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C, 322 AddStmtChoice asc); 323 CFGBlock *VisitCallExpr(CallExpr *C, AddStmtChoice asc); 324 CFGBlock *VisitCaseStmt(CaseStmt *C); 325 CFGBlock *VisitChooseExpr(ChooseExpr *C, AddStmtChoice asc); 326 CFGBlock *VisitCompoundStmt(CompoundStmt *C); 327 CFGBlock *VisitConditionalOperator(AbstractConditionalOperator *C, 328 AddStmtChoice asc); 329 CFGBlock *VisitContinueStmt(ContinueStmt *C); 330 CFGBlock *VisitDeclStmt(DeclStmt *DS); 331 CFGBlock *VisitDeclSubExpr(DeclStmt *DS); 332 CFGBlock *VisitDefaultStmt(DefaultStmt *D); 333 CFGBlock *VisitDoStmt(DoStmt *D); 334 CFGBlock *VisitForStmt(ForStmt *F); 335 CFGBlock *VisitGotoStmt(GotoStmt *G); 336 CFGBlock *VisitIfStmt(IfStmt *I); 337 CFGBlock *VisitImplicitCastExpr(ImplicitCastExpr *E, AddStmtChoice asc); 338 CFGBlock *VisitIndirectGotoStmt(IndirectGotoStmt *I); 339 CFGBlock *VisitLabelStmt(LabelStmt *L); 340 CFGBlock *VisitMemberExpr(MemberExpr *M, AddStmtChoice asc); 341 CFGBlock *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S); 342 CFGBlock *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S); 343 CFGBlock *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S); 344 CFGBlock *VisitObjCAtTryStmt(ObjCAtTryStmt *S); 345 CFGBlock *VisitObjCForCollectionStmt(ObjCForCollectionStmt *S); 346 CFGBlock *VisitReturnStmt(ReturnStmt *R); 347 CFGBlock *VisitPseudoObjectExpr(PseudoObjectExpr *E); 348 CFGBlock *VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E, 349 AddStmtChoice asc); 350 CFGBlock *VisitStmtExpr(StmtExpr *S, AddStmtChoice asc); 351 CFGBlock *VisitSwitchStmt(SwitchStmt *S); 352 CFGBlock *VisitUnaryOperator(UnaryOperator *U, AddStmtChoice asc); 353 CFGBlock *VisitWhileStmt(WhileStmt *W); 354 355 CFGBlock *Visit(Stmt *S, AddStmtChoice asc = AddStmtChoice::NotAlwaysAdd); 356 CFGBlock *VisitStmt(Stmt *S, AddStmtChoice asc); 357 CFGBlock *VisitChildren(Stmt *S); 358 359 // Visitors to walk an AST and generate destructors of temporaries in 360 // full expression. 361 CFGBlock *VisitForTemporaryDtors(Stmt *E, bool BindToTemporary = false); 362 CFGBlock *VisitChildrenForTemporaryDtors(Stmt *E); 363 CFGBlock *VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E); 364 CFGBlock *VisitCXXBindTemporaryExprForTemporaryDtors(CXXBindTemporaryExpr *E, 365 bool BindToTemporary); 366 CFGBlock * 367 VisitConditionalOperatorForTemporaryDtors(AbstractConditionalOperator *E, 368 bool BindToTemporary); 369 370 // NYS == Not Yet Supported 371 CFGBlock *NYS() { 372 badCFG = true; 373 return Block; 374 } 375 376 void autoCreateBlock() { if (!Block) Block = createBlock(); } 377 CFGBlock *createBlock(bool add_successor = true); 378 CFGBlock *createNoReturnBlock(); 379 380 CFGBlock *addStmt(Stmt *S) { 381 return Visit(S, AddStmtChoice::AlwaysAdd); 382 } 383 CFGBlock *addInitializer(CXXCtorInitializer *I); 384 void addAutomaticObjDtors(LocalScope::const_iterator B, 385 LocalScope::const_iterator E, Stmt *S); 386 void addImplicitDtorsForDestructor(const CXXDestructorDecl *DD); 387 388 // Local scopes creation. 389 LocalScope* createOrReuseLocalScope(LocalScope* Scope); 390 391 void addLocalScopeForStmt(Stmt *S); 392 LocalScope* addLocalScopeForDeclStmt(DeclStmt *DS, LocalScope* Scope = NULL); 393 LocalScope* addLocalScopeForVarDecl(VarDecl *VD, LocalScope* Scope = NULL); 394 395 void addLocalScopeAndDtors(Stmt *S); 396 397 // Interface to CFGBlock - adding CFGElements. 398 void appendStmt(CFGBlock *B, const Stmt *S) { 399 if (alwaysAdd(S) && cachedEntry) 400 cachedEntry->second = B; 401 402 // All block-level expressions should have already been IgnoreParens()ed. 403 assert(!isa<Expr>(S) || cast<Expr>(S)->IgnoreParens() == S); 404 B->appendStmt(const_cast<Stmt*>(S), cfg->getBumpVectorContext()); 405 } 406 void appendInitializer(CFGBlock *B, CXXCtorInitializer *I) { 407 B->appendInitializer(I, cfg->getBumpVectorContext()); 408 } 409 void appendBaseDtor(CFGBlock *B, const CXXBaseSpecifier *BS) { 410 B->appendBaseDtor(BS, cfg->getBumpVectorContext()); 411 } 412 void appendMemberDtor(CFGBlock *B, FieldDecl *FD) { 413 B->appendMemberDtor(FD, cfg->getBumpVectorContext()); 414 } 415 void appendTemporaryDtor(CFGBlock *B, CXXBindTemporaryExpr *E) { 416 B->appendTemporaryDtor(E, cfg->getBumpVectorContext()); 417 } 418 void appendAutomaticObjDtor(CFGBlock *B, VarDecl *VD, Stmt *S) { 419 B->appendAutomaticObjDtor(VD, S, cfg->getBumpVectorContext()); 420 } 421 422 void prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk, 423 LocalScope::const_iterator B, LocalScope::const_iterator E); 424 425 void addSuccessor(CFGBlock *B, CFGBlock *S) { 426 B->addSuccessor(S, cfg->getBumpVectorContext()); 427 } 428 429 /// Try and evaluate an expression to an integer constant. 430 bool tryEvaluate(Expr *S, Expr::EvalResult &outResult) { 431 if (!BuildOpts.PruneTriviallyFalseEdges) 432 return false; 433 return !S->isTypeDependent() && 434 !S->isValueDependent() && 435 S->EvaluateAsRValue(outResult, *Context); 436 } 437 438 /// tryEvaluateBool - Try and evaluate the Stmt and return 0 or 1 439 /// if we can evaluate to a known value, otherwise return -1. 440 TryResult tryEvaluateBool(Expr *S) { 441 bool Result; 442 if (!BuildOpts.PruneTriviallyFalseEdges || 443 S->isTypeDependent() || S->isValueDependent() || 444 !S->EvaluateAsBooleanCondition(Result, *Context)) 445 return TryResult(); 446 return Result; 447 } 448 449}; 450 451inline bool AddStmtChoice::alwaysAdd(CFGBuilder &builder, 452 const Stmt *stmt) const { 453 return builder.alwaysAdd(stmt) || kind == AlwaysAdd; 454} 455 456bool CFGBuilder::alwaysAdd(const Stmt *stmt) { 457 bool shouldAdd = BuildOpts.alwaysAdd(stmt); 458 459 if (!BuildOpts.forcedBlkExprs) 460 return shouldAdd; 461 462 if (lastLookup == stmt) { 463 if (cachedEntry) { 464 assert(cachedEntry->first == stmt); 465 return true; 466 } 467 return shouldAdd; 468 } 469 470 lastLookup = stmt; 471 472 // Perform the lookup! 473 CFG::BuildOptions::ForcedBlkExprs *fb = *BuildOpts.forcedBlkExprs; 474 475 if (!fb) { 476 // No need to update 'cachedEntry', since it will always be null. 477 assert(cachedEntry == 0); 478 return shouldAdd; 479 } 480 481 CFG::BuildOptions::ForcedBlkExprs::iterator itr = fb->find(stmt); 482 if (itr == fb->end()) { 483 cachedEntry = 0; 484 return shouldAdd; 485 } 486 487 cachedEntry = &*itr; 488 return true; 489} 490 491// FIXME: Add support for dependent-sized array types in C++? 492// Does it even make sense to build a CFG for an uninstantiated template? 493static const VariableArrayType *FindVA(const Type *t) { 494 while (const ArrayType *vt = dyn_cast<ArrayType>(t)) { 495 if (const VariableArrayType *vat = dyn_cast<VariableArrayType>(vt)) 496 if (vat->getSizeExpr()) 497 return vat; 498 499 t = vt->getElementType().getTypePtr(); 500 } 501 502 return 0; 503} 504 505/// BuildCFG - Constructs a CFG from an AST (a Stmt*). The AST can represent an 506/// arbitrary statement. Examples include a single expression or a function 507/// body (compound statement). The ownership of the returned CFG is 508/// transferred to the caller. If CFG construction fails, this method returns 509/// NULL. 510CFG* CFGBuilder::buildCFG(const Decl *D, Stmt *Statement) { 511 assert(cfg.get()); 512 if (!Statement) 513 return NULL; 514 515 // Create an empty block that will serve as the exit block for the CFG. Since 516 // this is the first block added to the CFG, it will be implicitly registered 517 // as the exit block. 518 Succ = createBlock(); 519 assert(Succ == &cfg->getExit()); 520 Block = NULL; // the EXIT block is empty. Create all other blocks lazily. 521 522 if (BuildOpts.AddImplicitDtors) 523 if (const CXXDestructorDecl *DD = dyn_cast_or_null<CXXDestructorDecl>(D)) 524 addImplicitDtorsForDestructor(DD); 525 526 // Visit the statements and create the CFG. 527 CFGBlock *B = addStmt(Statement); 528 529 if (badCFG) 530 return NULL; 531 532 // For C++ constructor add initializers to CFG. 533 if (const CXXConstructorDecl *CD = dyn_cast_or_null<CXXConstructorDecl>(D)) { 534 for (CXXConstructorDecl::init_const_reverse_iterator I = CD->init_rbegin(), 535 E = CD->init_rend(); I != E; ++I) { 536 B = addInitializer(*I); 537 if (badCFG) 538 return NULL; 539 } 540 } 541 542 if (B) 543 Succ = B; 544 545 // Backpatch the gotos whose label -> block mappings we didn't know when we 546 // encountered them. 547 for (BackpatchBlocksTy::iterator I = BackpatchBlocks.begin(), 548 E = BackpatchBlocks.end(); I != E; ++I ) { 549 550 CFGBlock *B = I->block; 551 GotoStmt *G = cast<GotoStmt>(B->getTerminator()); 552 LabelMapTy::iterator LI = LabelMap.find(G->getLabel()); 553 554 // If there is no target for the goto, then we are looking at an 555 // incomplete AST. Handle this by not registering a successor. 556 if (LI == LabelMap.end()) continue; 557 558 JumpTarget JT = LI->second; 559 prependAutomaticObjDtorsWithTerminator(B, I->scopePosition, 560 JT.scopePosition); 561 addSuccessor(B, JT.block); 562 } 563 564 // Add successors to the Indirect Goto Dispatch block (if we have one). 565 if (CFGBlock *B = cfg->getIndirectGotoBlock()) 566 for (LabelSetTy::iterator I = AddressTakenLabels.begin(), 567 E = AddressTakenLabels.end(); I != E; ++I ) { 568 569 // Lookup the target block. 570 LabelMapTy::iterator LI = LabelMap.find(*I); 571 572 // If there is no target block that contains label, then we are looking 573 // at an incomplete AST. Handle this by not registering a successor. 574 if (LI == LabelMap.end()) continue; 575 576 addSuccessor(B, LI->second.block); 577 } 578 579 // Create an empty entry block that has no predecessors. 580 cfg->setEntry(createBlock()); 581 582 return cfg.take(); 583} 584 585/// createBlock - Used to lazily create blocks that are connected 586/// to the current (global) succcessor. 587CFGBlock *CFGBuilder::createBlock(bool add_successor) { 588 CFGBlock *B = cfg->createBlock(); 589 if (add_successor && Succ) 590 addSuccessor(B, Succ); 591 return B; 592} 593 594/// createNoReturnBlock - Used to create a block is a 'noreturn' point in the 595/// CFG. It is *not* connected to the current (global) successor, and instead 596/// directly tied to the exit block in order to be reachable. 597CFGBlock *CFGBuilder::createNoReturnBlock() { 598 CFGBlock *B = createBlock(false); 599 B->setHasNoReturnElement(); 600 addSuccessor(B, &cfg->getExit()); 601 return B; 602} 603 604/// addInitializer - Add C++ base or member initializer element to CFG. 605CFGBlock *CFGBuilder::addInitializer(CXXCtorInitializer *I) { 606 if (!BuildOpts.AddInitializers) 607 return Block; 608 609 bool IsReference = false; 610 bool HasTemporaries = false; 611 612 // Destructors of temporaries in initialization expression should be called 613 // after initialization finishes. 614 Expr *Init = I->getInit(); 615 if (Init) { 616 if (FieldDecl *FD = I->getAnyMember()) 617 IsReference = FD->getType()->isReferenceType(); 618 HasTemporaries = isa<ExprWithCleanups>(Init); 619 620 if (BuildOpts.AddImplicitDtors && HasTemporaries) { 621 // Generate destructors for temporaries in initialization expression. 622 VisitForTemporaryDtors(cast<ExprWithCleanups>(Init)->getSubExpr(), 623 IsReference); 624 } 625 } 626 627 autoCreateBlock(); 628 appendInitializer(Block, I); 629 630 if (Init) { 631 if (HasTemporaries) { 632 // For expression with temporaries go directly to subexpression to omit 633 // generating destructors for the second time. 634 return Visit(cast<ExprWithCleanups>(Init)->getSubExpr()); 635 } 636 return Visit(Init); 637 } 638 639 return Block; 640} 641 642/// \brief Retrieve the type of the temporary object whose lifetime was 643/// extended by a local reference with the given initializer. 644static QualType getReferenceInitTemporaryType(ASTContext &Context, 645 const Expr *Init) { 646 while (true) { 647 // Skip parentheses. 648 Init = Init->IgnoreParens(); 649 650 // Skip through cleanups. 651 if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Init)) { 652 Init = EWC->getSubExpr(); 653 continue; 654 } 655 656 // Skip through the temporary-materialization expression. 657 if (const MaterializeTemporaryExpr *MTE 658 = dyn_cast<MaterializeTemporaryExpr>(Init)) { 659 Init = MTE->GetTemporaryExpr(); 660 continue; 661 } 662 663 // Skip derived-to-base and no-op casts. 664 if (const CastExpr *CE = dyn_cast<CastExpr>(Init)) { 665 if ((CE->getCastKind() == CK_DerivedToBase || 666 CE->getCastKind() == CK_UncheckedDerivedToBase || 667 CE->getCastKind() == CK_NoOp) && 668 Init->getType()->isRecordType()) { 669 Init = CE->getSubExpr(); 670 continue; 671 } 672 } 673 674 // Skip member accesses into rvalues. 675 if (const MemberExpr *ME = dyn_cast<MemberExpr>(Init)) { 676 if (!ME->isArrow() && ME->getBase()->isRValue()) { 677 Init = ME->getBase(); 678 continue; 679 } 680 } 681 682 break; 683 } 684 685 return Init->getType(); 686} 687 688/// addAutomaticObjDtors - Add to current block automatic objects destructors 689/// for objects in range of local scope positions. Use S as trigger statement 690/// for destructors. 691void CFGBuilder::addAutomaticObjDtors(LocalScope::const_iterator B, 692 LocalScope::const_iterator E, Stmt *S) { 693 if (!BuildOpts.AddImplicitDtors) 694 return; 695 696 if (B == E) 697 return; 698 699 // We need to append the destructors in reverse order, but any one of them 700 // may be a no-return destructor which changes the CFG. As a result, buffer 701 // this sequence up and replay them in reverse order when appending onto the 702 // CFGBlock(s). 703 SmallVector<VarDecl*, 10> Decls; 704 Decls.reserve(B.distance(E)); 705 for (LocalScope::const_iterator I = B; I != E; ++I) 706 Decls.push_back(*I); 707 708 for (SmallVectorImpl<VarDecl*>::reverse_iterator I = Decls.rbegin(), 709 E = Decls.rend(); 710 I != E; ++I) { 711 // If this destructor is marked as a no-return destructor, we need to 712 // create a new block for the destructor which does not have as a successor 713 // anything built thus far: control won't flow out of this block. 714 QualType Ty; 715 if ((*I)->getType()->isReferenceType()) { 716 Ty = getReferenceInitTemporaryType(*Context, (*I)->getInit()); 717 } else { 718 Ty = Context->getBaseElementType((*I)->getType()); 719 } 720 721 const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor(); 722 if (cast<FunctionType>(Dtor->getType())->getNoReturnAttr()) 723 Block = createNoReturnBlock(); 724 else 725 autoCreateBlock(); 726 727 appendAutomaticObjDtor(Block, *I, S); 728 } 729} 730 731/// addImplicitDtorsForDestructor - Add implicit destructors generated for 732/// base and member objects in destructor. 733void CFGBuilder::addImplicitDtorsForDestructor(const CXXDestructorDecl *DD) { 734 assert (BuildOpts.AddImplicitDtors 735 && "Can be called only when dtors should be added"); 736 const CXXRecordDecl *RD = DD->getParent(); 737 738 // At the end destroy virtual base objects. 739 for (CXXRecordDecl::base_class_const_iterator VI = RD->vbases_begin(), 740 VE = RD->vbases_end(); VI != VE; ++VI) { 741 const CXXRecordDecl *CD = VI->getType()->getAsCXXRecordDecl(); 742 if (!CD->hasTrivialDestructor()) { 743 autoCreateBlock(); 744 appendBaseDtor(Block, VI); 745 } 746 } 747 748 // Before virtual bases destroy direct base objects. 749 for (CXXRecordDecl::base_class_const_iterator BI = RD->bases_begin(), 750 BE = RD->bases_end(); BI != BE; ++BI) { 751 if (!BI->isVirtual()) { 752 const CXXRecordDecl *CD = BI->getType()->getAsCXXRecordDecl(); 753 if (!CD->hasTrivialDestructor()) { 754 autoCreateBlock(); 755 appendBaseDtor(Block, BI); 756 } 757 } 758 } 759 760 // First destroy member objects. 761 for (CXXRecordDecl::field_iterator FI = RD->field_begin(), 762 FE = RD->field_end(); FI != FE; ++FI) { 763 // Check for constant size array. Set type to array element type. 764 QualType QT = FI->getType(); 765 if (const ConstantArrayType *AT = Context->getAsConstantArrayType(QT)) { 766 if (AT->getSize() == 0) 767 continue; 768 QT = AT->getElementType(); 769 } 770 771 if (const CXXRecordDecl *CD = QT->getAsCXXRecordDecl()) 772 if (!CD->hasTrivialDestructor()) { 773 autoCreateBlock(); 774 appendMemberDtor(Block, *FI); 775 } 776 } 777} 778 779/// createOrReuseLocalScope - If Scope is NULL create new LocalScope. Either 780/// way return valid LocalScope object. 781LocalScope* CFGBuilder::createOrReuseLocalScope(LocalScope* Scope) { 782 if (!Scope) { 783 llvm::BumpPtrAllocator &alloc = cfg->getAllocator(); 784 Scope = alloc.Allocate<LocalScope>(); 785 BumpVectorContext ctx(alloc); 786 new (Scope) LocalScope(ctx, ScopePos); 787 } 788 return Scope; 789} 790 791/// addLocalScopeForStmt - Add LocalScope to local scopes tree for statement 792/// that should create implicit scope (e.g. if/else substatements). 793void CFGBuilder::addLocalScopeForStmt(Stmt *S) { 794 if (!BuildOpts.AddImplicitDtors) 795 return; 796 797 LocalScope *Scope = 0; 798 799 // For compound statement we will be creating explicit scope. 800 if (CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) { 801 for (CompoundStmt::body_iterator BI = CS->body_begin(), BE = CS->body_end() 802 ; BI != BE; ++BI) { 803 Stmt *SI = (*BI)->stripLabelLikeStatements(); 804 if (DeclStmt *DS = dyn_cast<DeclStmt>(SI)) 805 Scope = addLocalScopeForDeclStmt(DS, Scope); 806 } 807 return; 808 } 809 810 // For any other statement scope will be implicit and as such will be 811 // interesting only for DeclStmt. 812 if (DeclStmt *DS = dyn_cast<DeclStmt>(S->stripLabelLikeStatements())) 813 addLocalScopeForDeclStmt(DS); 814} 815 816/// addLocalScopeForDeclStmt - Add LocalScope for declaration statement. Will 817/// reuse Scope if not NULL. 818LocalScope* CFGBuilder::addLocalScopeForDeclStmt(DeclStmt *DS, 819 LocalScope* Scope) { 820 if (!BuildOpts.AddImplicitDtors) 821 return Scope; 822 823 for (DeclStmt::decl_iterator DI = DS->decl_begin(), DE = DS->decl_end() 824 ; DI != DE; ++DI) { 825 if (VarDecl *VD = dyn_cast<VarDecl>(*DI)) 826 Scope = addLocalScopeForVarDecl(VD, Scope); 827 } 828 return Scope; 829} 830 831/// addLocalScopeForVarDecl - Add LocalScope for variable declaration. It will 832/// create add scope for automatic objects and temporary objects bound to 833/// const reference. Will reuse Scope if not NULL. 834LocalScope* CFGBuilder::addLocalScopeForVarDecl(VarDecl *VD, 835 LocalScope* Scope) { 836 if (!BuildOpts.AddImplicitDtors) 837 return Scope; 838 839 // Check if variable is local. 840 switch (VD->getStorageClass()) { 841 case SC_None: 842 case SC_Auto: 843 case SC_Register: 844 break; 845 default: return Scope; 846 } 847 848 // Check for const references bound to temporary. Set type to pointee. 849 QualType QT = VD->getType(); 850 if (QT.getTypePtr()->isReferenceType()) { 851 if (!VD->extendsLifetimeOfTemporary()) 852 return Scope; 853 854 QT = getReferenceInitTemporaryType(*Context, VD->getInit()); 855 } 856 857 // Check for constant size array. Set type to array element type. 858 while (const ConstantArrayType *AT = Context->getAsConstantArrayType(QT)) { 859 if (AT->getSize() == 0) 860 return Scope; 861 QT = AT->getElementType(); 862 } 863 864 // Check if type is a C++ class with non-trivial destructor. 865 if (const CXXRecordDecl *CD = QT->getAsCXXRecordDecl()) 866 if (!CD->hasTrivialDestructor()) { 867 // Add the variable to scope 868 Scope = createOrReuseLocalScope(Scope); 869 Scope->addVar(VD); 870 ScopePos = Scope->begin(); 871 } 872 return Scope; 873} 874 875/// addLocalScopeAndDtors - For given statement add local scope for it and 876/// add destructors that will cleanup the scope. Will reuse Scope if not NULL. 877void CFGBuilder::addLocalScopeAndDtors(Stmt *S) { 878 if (!BuildOpts.AddImplicitDtors) 879 return; 880 881 LocalScope::const_iterator scopeBeginPos = ScopePos; 882 addLocalScopeForStmt(S); 883 addAutomaticObjDtors(ScopePos, scopeBeginPos, S); 884} 885 886/// prependAutomaticObjDtorsWithTerminator - Prepend destructor CFGElements for 887/// variables with automatic storage duration to CFGBlock's elements vector. 888/// Elements will be prepended to physical beginning of the vector which 889/// happens to be logical end. Use blocks terminator as statement that specifies 890/// destructors call site. 891/// FIXME: This mechanism for adding automatic destructors doesn't handle 892/// no-return destructors properly. 893void CFGBuilder::prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk, 894 LocalScope::const_iterator B, LocalScope::const_iterator E) { 895 BumpVectorContext &C = cfg->getBumpVectorContext(); 896 CFGBlock::iterator InsertPos 897 = Blk->beginAutomaticObjDtorsInsert(Blk->end(), B.distance(E), C); 898 for (LocalScope::const_iterator I = B; I != E; ++I) 899 InsertPos = Blk->insertAutomaticObjDtor(InsertPos, *I, 900 Blk->getTerminator()); 901} 902 903/// Visit - Walk the subtree of a statement and add extra 904/// blocks for ternary operators, &&, and ||. We also process "," and 905/// DeclStmts (which may contain nested control-flow). 906CFGBlock *CFGBuilder::Visit(Stmt * S, AddStmtChoice asc) { 907 if (!S) { 908 badCFG = true; 909 return 0; 910 } 911 912 if (Expr *E = dyn_cast<Expr>(S)) 913 S = E->IgnoreParens(); 914 915 switch (S->getStmtClass()) { 916 default: 917 return VisitStmt(S, asc); 918 919 case Stmt::AddrLabelExprClass: 920 return VisitAddrLabelExpr(cast<AddrLabelExpr>(S), asc); 921 922 case Stmt::BinaryConditionalOperatorClass: 923 return VisitConditionalOperator(cast<BinaryConditionalOperator>(S), asc); 924 925 case Stmt::BinaryOperatorClass: 926 return VisitBinaryOperator(cast<BinaryOperator>(S), asc); 927 928 case Stmt::BlockExprClass: 929 return VisitBlockExpr(cast<BlockExpr>(S), asc); 930 931 case Stmt::BreakStmtClass: 932 return VisitBreakStmt(cast<BreakStmt>(S)); 933 934 case Stmt::CallExprClass: 935 case Stmt::CXXOperatorCallExprClass: 936 case Stmt::CXXMemberCallExprClass: 937 return VisitCallExpr(cast<CallExpr>(S), asc); 938 939 case Stmt::CaseStmtClass: 940 return VisitCaseStmt(cast<CaseStmt>(S)); 941 942 case Stmt::ChooseExprClass: 943 return VisitChooseExpr(cast<ChooseExpr>(S), asc); 944 945 case Stmt::CompoundStmtClass: 946 return VisitCompoundStmt(cast<CompoundStmt>(S)); 947 948 case Stmt::ConditionalOperatorClass: 949 return VisitConditionalOperator(cast<ConditionalOperator>(S), asc); 950 951 case Stmt::ContinueStmtClass: 952 return VisitContinueStmt(cast<ContinueStmt>(S)); 953 954 case Stmt::CXXCatchStmtClass: 955 return VisitCXXCatchStmt(cast<CXXCatchStmt>(S)); 956 957 case Stmt::ExprWithCleanupsClass: 958 return VisitExprWithCleanups(cast<ExprWithCleanups>(S), asc); 959 960 case Stmt::CXXBindTemporaryExprClass: 961 return VisitCXXBindTemporaryExpr(cast<CXXBindTemporaryExpr>(S), asc); 962 963 case Stmt::CXXConstructExprClass: 964 return VisitCXXConstructExpr(cast<CXXConstructExpr>(S), asc); 965 966 case Stmt::CXXFunctionalCastExprClass: 967 return VisitCXXFunctionalCastExpr(cast<CXXFunctionalCastExpr>(S), asc); 968 969 case Stmt::CXXTemporaryObjectExprClass: 970 return VisitCXXTemporaryObjectExpr(cast<CXXTemporaryObjectExpr>(S), asc); 971 972 case Stmt::CXXThrowExprClass: 973 return VisitCXXThrowExpr(cast<CXXThrowExpr>(S)); 974 975 case Stmt::CXXTryStmtClass: 976 return VisitCXXTryStmt(cast<CXXTryStmt>(S)); 977 978 case Stmt::CXXForRangeStmtClass: 979 return VisitCXXForRangeStmt(cast<CXXForRangeStmt>(S)); 980 981 case Stmt::DeclStmtClass: 982 return VisitDeclStmt(cast<DeclStmt>(S)); 983 984 case Stmt::DefaultStmtClass: 985 return VisitDefaultStmt(cast<DefaultStmt>(S)); 986 987 case Stmt::DoStmtClass: 988 return VisitDoStmt(cast<DoStmt>(S)); 989 990 case Stmt::ForStmtClass: 991 return VisitForStmt(cast<ForStmt>(S)); 992 993 case Stmt::GotoStmtClass: 994 return VisitGotoStmt(cast<GotoStmt>(S)); 995 996 case Stmt::IfStmtClass: 997 return VisitIfStmt(cast<IfStmt>(S)); 998 999 case Stmt::ImplicitCastExprClass: 1000 return VisitImplicitCastExpr(cast<ImplicitCastExpr>(S), asc); 1001 1002 case Stmt::IndirectGotoStmtClass: 1003 return VisitIndirectGotoStmt(cast<IndirectGotoStmt>(S)); 1004 1005 case Stmt::LabelStmtClass: 1006 return VisitLabelStmt(cast<LabelStmt>(S)); 1007 1008 case Stmt::MemberExprClass: 1009 return VisitMemberExpr(cast<MemberExpr>(S), asc); 1010 1011 case Stmt::NullStmtClass: 1012 return Block; 1013 1014 case Stmt::ObjCAtCatchStmtClass: 1015 return VisitObjCAtCatchStmt(cast<ObjCAtCatchStmt>(S)); 1016 1017 case Stmt::ObjCAtSynchronizedStmtClass: 1018 return VisitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(S)); 1019 1020 case Stmt::ObjCAtThrowStmtClass: 1021 return VisitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(S)); 1022 1023 case Stmt::ObjCAtTryStmtClass: 1024 return VisitObjCAtTryStmt(cast<ObjCAtTryStmt>(S)); 1025 1026 case Stmt::ObjCForCollectionStmtClass: 1027 return VisitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(S)); 1028 1029 case Stmt::OpaqueValueExprClass: 1030 return Block; 1031 1032 case Stmt::PseudoObjectExprClass: 1033 return VisitPseudoObjectExpr(cast<PseudoObjectExpr>(S)); 1034 1035 case Stmt::ReturnStmtClass: 1036 return VisitReturnStmt(cast<ReturnStmt>(S)); 1037 1038 case Stmt::UnaryExprOrTypeTraitExprClass: 1039 return VisitUnaryExprOrTypeTraitExpr(cast<UnaryExprOrTypeTraitExpr>(S), 1040 asc); 1041 1042 case Stmt::StmtExprClass: 1043 return VisitStmtExpr(cast<StmtExpr>(S), asc); 1044 1045 case Stmt::SwitchStmtClass: 1046 return VisitSwitchStmt(cast<SwitchStmt>(S)); 1047 1048 case Stmt::UnaryOperatorClass: 1049 return VisitUnaryOperator(cast<UnaryOperator>(S), asc); 1050 1051 case Stmt::WhileStmtClass: 1052 return VisitWhileStmt(cast<WhileStmt>(S)); 1053 } 1054} 1055 1056CFGBlock *CFGBuilder::VisitStmt(Stmt *S, AddStmtChoice asc) { 1057 if (asc.alwaysAdd(*this, S)) { 1058 autoCreateBlock(); 1059 appendStmt(Block, S); 1060 } 1061 1062 return VisitChildren(S); 1063} 1064 1065/// VisitChildren - Visit the children of a Stmt. 1066CFGBlock *CFGBuilder::VisitChildren(Stmt *Terminator) { 1067 CFGBlock *lastBlock = Block; 1068 for (Stmt::child_range I = Terminator->children(); I; ++I) 1069 if (Stmt *child = *I) 1070 if (CFGBlock *b = Visit(child)) 1071 lastBlock = b; 1072 1073 return lastBlock; 1074} 1075 1076CFGBlock *CFGBuilder::VisitAddrLabelExpr(AddrLabelExpr *A, 1077 AddStmtChoice asc) { 1078 AddressTakenLabels.insert(A->getLabel()); 1079 1080 if (asc.alwaysAdd(*this, A)) { 1081 autoCreateBlock(); 1082 appendStmt(Block, A); 1083 } 1084 1085 return Block; 1086} 1087 1088CFGBlock *CFGBuilder::VisitUnaryOperator(UnaryOperator *U, 1089 AddStmtChoice asc) { 1090 if (asc.alwaysAdd(*this, U)) { 1091 autoCreateBlock(); 1092 appendStmt(Block, U); 1093 } 1094 1095 return Visit(U->getSubExpr(), AddStmtChoice()); 1096} 1097 1098CFGBlock *CFGBuilder::VisitBinaryOperator(BinaryOperator *B, 1099 AddStmtChoice asc) { 1100 if (B->isLogicalOp()) { // && or || 1101 CFGBlock *ConfluenceBlock = Block ? Block : createBlock(); 1102 appendStmt(ConfluenceBlock, B); 1103 1104 if (badCFG) 1105 return 0; 1106 1107 // create the block evaluating the LHS 1108 CFGBlock *LHSBlock = createBlock(false); 1109 LHSBlock->setTerminator(B); 1110 1111 // create the block evaluating the RHS 1112 Succ = ConfluenceBlock; 1113 Block = NULL; 1114 CFGBlock *RHSBlock = addStmt(B->getRHS()); 1115 1116 if (RHSBlock) { 1117 if (badCFG) 1118 return 0; 1119 } else { 1120 // Create an empty block for cases where the RHS doesn't require 1121 // any explicit statements in the CFG. 1122 RHSBlock = createBlock(); 1123 } 1124 1125 // See if this is a known constant. 1126 TryResult KnownVal = tryEvaluateBool(B->getLHS()); 1127 if (KnownVal.isKnown() && (B->getOpcode() == BO_LOr)) 1128 KnownVal.negate(); 1129 1130 // Now link the LHSBlock with RHSBlock. 1131 if (B->getOpcode() == BO_LOr) { 1132 addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock); 1133 addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock); 1134 } else { 1135 assert(B->getOpcode() == BO_LAnd); 1136 addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock); 1137 addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock); 1138 } 1139 1140 // Generate the blocks for evaluating the LHS. 1141 Block = LHSBlock; 1142 return addStmt(B->getLHS()); 1143 } 1144 1145 if (B->getOpcode() == BO_Comma) { // , 1146 autoCreateBlock(); 1147 appendStmt(Block, B); 1148 addStmt(B->getRHS()); 1149 return addStmt(B->getLHS()); 1150 } 1151 1152 if (B->isAssignmentOp()) { 1153 if (asc.alwaysAdd(*this, B)) { 1154 autoCreateBlock(); 1155 appendStmt(Block, B); 1156 } 1157 Visit(B->getLHS()); 1158 return Visit(B->getRHS()); 1159 } 1160 1161 if (asc.alwaysAdd(*this, B)) { 1162 autoCreateBlock(); 1163 appendStmt(Block, B); 1164 } 1165 1166 CFGBlock *RBlock = Visit(B->getRHS()); 1167 CFGBlock *LBlock = Visit(B->getLHS()); 1168 // If visiting RHS causes us to finish 'Block', e.g. the RHS is a StmtExpr 1169 // containing a DoStmt, and the LHS doesn't create a new block, then we should 1170 // return RBlock. Otherwise we'll incorrectly return NULL. 1171 return (LBlock ? LBlock : RBlock); 1172} 1173 1174CFGBlock *CFGBuilder::VisitBlockExpr(BlockExpr *E, AddStmtChoice asc) { 1175 if (asc.alwaysAdd(*this, E)) { 1176 autoCreateBlock(); 1177 appendStmt(Block, E); 1178 } 1179 return Block; 1180} 1181 1182CFGBlock *CFGBuilder::VisitBreakStmt(BreakStmt *B) { 1183 // "break" is a control-flow statement. Thus we stop processing the current 1184 // block. 1185 if (badCFG) 1186 return 0; 1187 1188 // Now create a new block that ends with the break statement. 1189 Block = createBlock(false); 1190 Block->setTerminator(B); 1191 1192 // If there is no target for the break, then we are looking at an incomplete 1193 // AST. This means that the CFG cannot be constructed. 1194 if (BreakJumpTarget.block) { 1195 addAutomaticObjDtors(ScopePos, BreakJumpTarget.scopePosition, B); 1196 addSuccessor(Block, BreakJumpTarget.block); 1197 } else 1198 badCFG = true; 1199 1200 1201 return Block; 1202} 1203 1204static bool CanThrow(Expr *E, ASTContext &Ctx) { 1205 QualType Ty = E->getType(); 1206 if (Ty->isFunctionPointerType()) 1207 Ty = Ty->getAs<PointerType>()->getPointeeType(); 1208 else if (Ty->isBlockPointerType()) 1209 Ty = Ty->getAs<BlockPointerType>()->getPointeeType(); 1210 1211 const FunctionType *FT = Ty->getAs<FunctionType>(); 1212 if (FT) { 1213 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) 1214 if (Proto->isNothrow(Ctx)) 1215 return false; 1216 } 1217 return true; 1218} 1219 1220CFGBlock *CFGBuilder::VisitCallExpr(CallExpr *C, AddStmtChoice asc) { 1221 // Compute the callee type. 1222 QualType calleeType = C->getCallee()->getType(); 1223 if (calleeType == Context->BoundMemberTy) { 1224 QualType boundType = Expr::findBoundMemberType(C->getCallee()); 1225 1226 // We should only get a null bound type if processing a dependent 1227 // CFG. Recover by assuming nothing. 1228 if (!boundType.isNull()) calleeType = boundType; 1229 } 1230 1231 // If this is a call to a no-return function, this stops the block here. 1232 bool NoReturn = getFunctionExtInfo(*calleeType).getNoReturn(); 1233 1234 bool AddEHEdge = false; 1235 1236 // Languages without exceptions are assumed to not throw. 1237 if (Context->getLangOptions().Exceptions) { 1238 if (BuildOpts.AddEHEdges) 1239 AddEHEdge = true; 1240 } 1241 1242 if (FunctionDecl *FD = C->getDirectCallee()) { 1243 if (FD->hasAttr<NoReturnAttr>()) 1244 NoReturn = true; 1245 if (FD->hasAttr<NoThrowAttr>()) 1246 AddEHEdge = false; 1247 } 1248 1249 if (!CanThrow(C->getCallee(), *Context)) 1250 AddEHEdge = false; 1251 1252 if (!NoReturn && !AddEHEdge) 1253 return VisitStmt(C, asc.withAlwaysAdd(true)); 1254 1255 if (Block) { 1256 Succ = Block; 1257 if (badCFG) 1258 return 0; 1259 } 1260 1261 if (NoReturn) 1262 Block = createNoReturnBlock(); 1263 else 1264 Block = createBlock(); 1265 1266 appendStmt(Block, C); 1267 1268 if (AddEHEdge) { 1269 // Add exceptional edges. 1270 if (TryTerminatedBlock) 1271 addSuccessor(Block, TryTerminatedBlock); 1272 else 1273 addSuccessor(Block, &cfg->getExit()); 1274 } 1275 1276 return VisitChildren(C); 1277} 1278 1279CFGBlock *CFGBuilder::VisitChooseExpr(ChooseExpr *C, 1280 AddStmtChoice asc) { 1281 CFGBlock *ConfluenceBlock = Block ? Block : createBlock(); 1282 appendStmt(ConfluenceBlock, C); 1283 if (badCFG) 1284 return 0; 1285 1286 AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true); 1287 Succ = ConfluenceBlock; 1288 Block = NULL; 1289 CFGBlock *LHSBlock = Visit(C->getLHS(), alwaysAdd); 1290 if (badCFG) 1291 return 0; 1292 1293 Succ = ConfluenceBlock; 1294 Block = NULL; 1295 CFGBlock *RHSBlock = Visit(C->getRHS(), alwaysAdd); 1296 if (badCFG) 1297 return 0; 1298 1299 Block = createBlock(false); 1300 // See if this is a known constant. 1301 const TryResult& KnownVal = tryEvaluateBool(C->getCond()); 1302 addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock); 1303 addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock); 1304 Block->setTerminator(C); 1305 return addStmt(C->getCond()); 1306} 1307 1308 1309CFGBlock *CFGBuilder::VisitCompoundStmt(CompoundStmt *C) { 1310 addLocalScopeAndDtors(C); 1311 CFGBlock *LastBlock = Block; 1312 1313 for (CompoundStmt::reverse_body_iterator I=C->body_rbegin(), E=C->body_rend(); 1314 I != E; ++I ) { 1315 // If we hit a segment of code just containing ';' (NullStmts), we can 1316 // get a null block back. In such cases, just use the LastBlock 1317 if (CFGBlock *newBlock = addStmt(*I)) 1318 LastBlock = newBlock; 1319 1320 if (badCFG) 1321 return NULL; 1322 } 1323 1324 return LastBlock; 1325} 1326 1327CFGBlock *CFGBuilder::VisitConditionalOperator(AbstractConditionalOperator *C, 1328 AddStmtChoice asc) { 1329 const BinaryConditionalOperator *BCO = dyn_cast<BinaryConditionalOperator>(C); 1330 const OpaqueValueExpr *opaqueValue = (BCO ? BCO->getOpaqueValue() : NULL); 1331 1332 // Create the confluence block that will "merge" the results of the ternary 1333 // expression. 1334 CFGBlock *ConfluenceBlock = Block ? Block : createBlock(); 1335 appendStmt(ConfluenceBlock, C); 1336 if (badCFG) 1337 return 0; 1338 1339 AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true); 1340 1341 // Create a block for the LHS expression if there is an LHS expression. A 1342 // GCC extension allows LHS to be NULL, causing the condition to be the 1343 // value that is returned instead. 1344 // e.g: x ?: y is shorthand for: x ? x : y; 1345 Succ = ConfluenceBlock; 1346 Block = NULL; 1347 CFGBlock *LHSBlock = 0; 1348 const Expr *trueExpr = C->getTrueExpr(); 1349 if (trueExpr != opaqueValue) { 1350 LHSBlock = Visit(C->getTrueExpr(), alwaysAdd); 1351 if (badCFG) 1352 return 0; 1353 Block = NULL; 1354 } 1355 else 1356 LHSBlock = ConfluenceBlock; 1357 1358 // Create the block for the RHS expression. 1359 Succ = ConfluenceBlock; 1360 CFGBlock *RHSBlock = Visit(C->getFalseExpr(), alwaysAdd); 1361 if (badCFG) 1362 return 0; 1363 1364 // Create the block that will contain the condition. 1365 Block = createBlock(false); 1366 1367 // See if this is a known constant. 1368 const TryResult& KnownVal = tryEvaluateBool(C->getCond()); 1369 addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock); 1370 addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock); 1371 Block->setTerminator(C); 1372 Expr *condExpr = C->getCond(); 1373 1374 if (opaqueValue) { 1375 // Run the condition expression if it's not trivially expressed in 1376 // terms of the opaque value (or if there is no opaque value). 1377 if (condExpr != opaqueValue) 1378 addStmt(condExpr); 1379 1380 // Before that, run the common subexpression if there was one. 1381 // At least one of this or the above will be run. 1382 return addStmt(BCO->getCommon()); 1383 } 1384 1385 return addStmt(condExpr); 1386} 1387 1388CFGBlock *CFGBuilder::VisitDeclStmt(DeclStmt *DS) { 1389 // Check if the Decl is for an __label__. If so, elide it from the 1390 // CFG entirely. 1391 if (isa<LabelDecl>(*DS->decl_begin())) 1392 return Block; 1393 1394 // This case also handles static_asserts. 1395 if (DS->isSingleDecl()) 1396 return VisitDeclSubExpr(DS); 1397 1398 CFGBlock *B = 0; 1399 1400 // FIXME: Add a reverse iterator for DeclStmt to avoid this extra copy. 1401 typedef SmallVector<Decl*,10> BufTy; 1402 BufTy Buf(DS->decl_begin(), DS->decl_end()); 1403 1404 for (BufTy::reverse_iterator I = Buf.rbegin(), E = Buf.rend(); I != E; ++I) { 1405 // Get the alignment of the new DeclStmt, padding out to >=8 bytes. 1406 unsigned A = llvm::AlignOf<DeclStmt>::Alignment < 8 1407 ? 8 : llvm::AlignOf<DeclStmt>::Alignment; 1408 1409 // Allocate the DeclStmt using the BumpPtrAllocator. It will get 1410 // automatically freed with the CFG. 1411 DeclGroupRef DG(*I); 1412 Decl *D = *I; 1413 void *Mem = cfg->getAllocator().Allocate(sizeof(DeclStmt), A); 1414 DeclStmt *DSNew = new (Mem) DeclStmt(DG, D->getLocation(), GetEndLoc(D)); 1415 1416 // Append the fake DeclStmt to block. 1417 B = VisitDeclSubExpr(DSNew); 1418 } 1419 1420 return B; 1421} 1422 1423/// VisitDeclSubExpr - Utility method to add block-level expressions for 1424/// DeclStmts and initializers in them. 1425CFGBlock *CFGBuilder::VisitDeclSubExpr(DeclStmt *DS) { 1426 assert(DS->isSingleDecl() && "Can handle single declarations only."); 1427 Decl *D = DS->getSingleDecl(); 1428 1429 if (isa<StaticAssertDecl>(D)) { 1430 // static_asserts aren't added to the CFG because they do not impact 1431 // runtime semantics. 1432 return Block; 1433 } 1434 1435 VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl()); 1436 1437 if (!VD) { 1438 autoCreateBlock(); 1439 appendStmt(Block, DS); 1440 return Block; 1441 } 1442 1443 bool IsReference = false; 1444 bool HasTemporaries = false; 1445 1446 // Destructors of temporaries in initialization expression should be called 1447 // after initialization finishes. 1448 Expr *Init = VD->getInit(); 1449 if (Init) { 1450 IsReference = VD->getType()->isReferenceType(); 1451 HasTemporaries = isa<ExprWithCleanups>(Init); 1452 1453 if (BuildOpts.AddImplicitDtors && HasTemporaries) { 1454 // Generate destructors for temporaries in initialization expression. 1455 VisitForTemporaryDtors(cast<ExprWithCleanups>(Init)->getSubExpr(), 1456 IsReference); 1457 } 1458 } 1459 1460 autoCreateBlock(); 1461 appendStmt(Block, DS); 1462 1463 if (Init) { 1464 if (HasTemporaries) 1465 // For expression with temporaries go directly to subexpression to omit 1466 // generating destructors for the second time. 1467 Visit(cast<ExprWithCleanups>(Init)->getSubExpr()); 1468 else 1469 Visit(Init); 1470 } 1471 1472 // If the type of VD is a VLA, then we must process its size expressions. 1473 for (const VariableArrayType* VA = FindVA(VD->getType().getTypePtr()); 1474 VA != 0; VA = FindVA(VA->getElementType().getTypePtr())) 1475 Block = addStmt(VA->getSizeExpr()); 1476 1477 // Remove variable from local scope. 1478 if (ScopePos && VD == *ScopePos) 1479 ++ScopePos; 1480 1481 return Block; 1482} 1483 1484CFGBlock *CFGBuilder::VisitIfStmt(IfStmt *I) { 1485 // We may see an if statement in the middle of a basic block, or it may be the 1486 // first statement we are processing. In either case, we create a new basic 1487 // block. First, we create the blocks for the then...else statements, and 1488 // then we create the block containing the if statement. If we were in the 1489 // middle of a block, we stop processing that block. That block is then the 1490 // implicit successor for the "then" and "else" clauses. 1491 1492 // Save local scope position because in case of condition variable ScopePos 1493 // won't be restored when traversing AST. 1494 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos); 1495 1496 // Create local scope for possible condition variable. 1497 // Store scope position. Add implicit destructor. 1498 if (VarDecl *VD = I->getConditionVariable()) { 1499 LocalScope::const_iterator BeginScopePos = ScopePos; 1500 addLocalScopeForVarDecl(VD); 1501 addAutomaticObjDtors(ScopePos, BeginScopePos, I); 1502 } 1503 1504 // The block we were processing is now finished. Make it the successor 1505 // block. 1506 if (Block) { 1507 Succ = Block; 1508 if (badCFG) 1509 return 0; 1510 } 1511 1512 // Process the false branch. 1513 CFGBlock *ElseBlock = Succ; 1514 1515 if (Stmt *Else = I->getElse()) { 1516 SaveAndRestore<CFGBlock*> sv(Succ); 1517 1518 // NULL out Block so that the recursive call to Visit will 1519 // create a new basic block. 1520 Block = NULL; 1521 1522 // If branch is not a compound statement create implicit scope 1523 // and add destructors. 1524 if (!isa<CompoundStmt>(Else)) 1525 addLocalScopeAndDtors(Else); 1526 1527 ElseBlock = addStmt(Else); 1528 1529 if (!ElseBlock) // Can occur when the Else body has all NullStmts. 1530 ElseBlock = sv.get(); 1531 else if (Block) { 1532 if (badCFG) 1533 return 0; 1534 } 1535 } 1536 1537 // Process the true branch. 1538 CFGBlock *ThenBlock; 1539 { 1540 Stmt *Then = I->getThen(); 1541 assert(Then); 1542 SaveAndRestore<CFGBlock*> sv(Succ); 1543 Block = NULL; 1544 1545 // If branch is not a compound statement create implicit scope 1546 // and add destructors. 1547 if (!isa<CompoundStmt>(Then)) 1548 addLocalScopeAndDtors(Then); 1549 1550 ThenBlock = addStmt(Then); 1551 1552 if (!ThenBlock) { 1553 // We can reach here if the "then" body has all NullStmts. 1554 // Create an empty block so we can distinguish between true and false 1555 // branches in path-sensitive analyses. 1556 ThenBlock = createBlock(false); 1557 addSuccessor(ThenBlock, sv.get()); 1558 } else if (Block) { 1559 if (badCFG) 1560 return 0; 1561 } 1562 } 1563 1564 // Now create a new block containing the if statement. 1565 Block = createBlock(false); 1566 1567 // Set the terminator of the new block to the If statement. 1568 Block->setTerminator(I); 1569 1570 // See if this is a known constant. 1571 const TryResult &KnownVal = tryEvaluateBool(I->getCond()); 1572 1573 // Now add the successors. 1574 addSuccessor(Block, KnownVal.isFalse() ? NULL : ThenBlock); 1575 addSuccessor(Block, KnownVal.isTrue()? NULL : ElseBlock); 1576 1577 // Add the condition as the last statement in the new block. This may create 1578 // new blocks as the condition may contain control-flow. Any newly created 1579 // blocks will be pointed to be "Block". 1580 Block = addStmt(I->getCond()); 1581 1582 // Finally, if the IfStmt contains a condition variable, add both the IfStmt 1583 // and the condition variable initialization to the CFG. 1584 if (VarDecl *VD = I->getConditionVariable()) { 1585 if (Expr *Init = VD->getInit()) { 1586 autoCreateBlock(); 1587 appendStmt(Block, I->getConditionVariableDeclStmt()); 1588 addStmt(Init); 1589 } 1590 } 1591 1592 return Block; 1593} 1594 1595 1596CFGBlock *CFGBuilder::VisitReturnStmt(ReturnStmt *R) { 1597 // If we were in the middle of a block we stop processing that block. 1598 // 1599 // NOTE: If a "return" appears in the middle of a block, this means that the 1600 // code afterwards is DEAD (unreachable). We still keep a basic block 1601 // for that code; a simple "mark-and-sweep" from the entry block will be 1602 // able to report such dead blocks. 1603 1604 // Create the new block. 1605 Block = createBlock(false); 1606 1607 // The Exit block is the only successor. 1608 addAutomaticObjDtors(ScopePos, LocalScope::const_iterator(), R); 1609 addSuccessor(Block, &cfg->getExit()); 1610 1611 // Add the return statement to the block. This may create new blocks if R 1612 // contains control-flow (short-circuit operations). 1613 return VisitStmt(R, AddStmtChoice::AlwaysAdd); 1614} 1615 1616CFGBlock *CFGBuilder::VisitLabelStmt(LabelStmt *L) { 1617 // Get the block of the labeled statement. Add it to our map. 1618 addStmt(L->getSubStmt()); 1619 CFGBlock *LabelBlock = Block; 1620 1621 if (!LabelBlock) // This can happen when the body is empty, i.e. 1622 LabelBlock = createBlock(); // scopes that only contains NullStmts. 1623 1624 assert(LabelMap.find(L->getDecl()) == LabelMap.end() && 1625 "label already in map"); 1626 LabelMap[L->getDecl()] = JumpTarget(LabelBlock, ScopePos); 1627 1628 // Labels partition blocks, so this is the end of the basic block we were 1629 // processing (L is the block's label). Because this is label (and we have 1630 // already processed the substatement) there is no extra control-flow to worry 1631 // about. 1632 LabelBlock->setLabel(L); 1633 if (badCFG) 1634 return 0; 1635 1636 // We set Block to NULL to allow lazy creation of a new block (if necessary); 1637 Block = NULL; 1638 1639 // This block is now the implicit successor of other blocks. 1640 Succ = LabelBlock; 1641 1642 return LabelBlock; 1643} 1644 1645CFGBlock *CFGBuilder::VisitGotoStmt(GotoStmt *G) { 1646 // Goto is a control-flow statement. Thus we stop processing the current 1647 // block and create a new one. 1648 1649 Block = createBlock(false); 1650 Block->setTerminator(G); 1651 1652 // If we already know the mapping to the label block add the successor now. 1653 LabelMapTy::iterator I = LabelMap.find(G->getLabel()); 1654 1655 if (I == LabelMap.end()) 1656 // We will need to backpatch this block later. 1657 BackpatchBlocks.push_back(JumpSource(Block, ScopePos)); 1658 else { 1659 JumpTarget JT = I->second; 1660 addAutomaticObjDtors(ScopePos, JT.scopePosition, G); 1661 addSuccessor(Block, JT.block); 1662 } 1663 1664 return Block; 1665} 1666 1667CFGBlock *CFGBuilder::VisitForStmt(ForStmt *F) { 1668 CFGBlock *LoopSuccessor = NULL; 1669 1670 // Save local scope position because in case of condition variable ScopePos 1671 // won't be restored when traversing AST. 1672 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos); 1673 1674 // Create local scope for init statement and possible condition variable. 1675 // Add destructor for init statement and condition variable. 1676 // Store scope position for continue statement. 1677 if (Stmt *Init = F->getInit()) 1678 addLocalScopeForStmt(Init); 1679 LocalScope::const_iterator LoopBeginScopePos = ScopePos; 1680 1681 if (VarDecl *VD = F->getConditionVariable()) 1682 addLocalScopeForVarDecl(VD); 1683 LocalScope::const_iterator ContinueScopePos = ScopePos; 1684 1685 addAutomaticObjDtors(ScopePos, save_scope_pos.get(), F); 1686 1687 // "for" is a control-flow statement. Thus we stop processing the current 1688 // block. 1689 if (Block) { 1690 if (badCFG) 1691 return 0; 1692 LoopSuccessor = Block; 1693 } else 1694 LoopSuccessor = Succ; 1695 1696 // Save the current value for the break targets. 1697 // All breaks should go to the code following the loop. 1698 SaveAndRestore<JumpTarget> save_break(BreakJumpTarget); 1699 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos); 1700 1701 // Because of short-circuit evaluation, the condition of the loop can span 1702 // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that 1703 // evaluate the condition. 1704 CFGBlock *ExitConditionBlock = createBlock(false); 1705 CFGBlock *EntryConditionBlock = ExitConditionBlock; 1706 1707 // Set the terminator for the "exit" condition block. 1708 ExitConditionBlock->setTerminator(F); 1709 1710 // Now add the actual condition to the condition block. Because the condition 1711 // itself may contain control-flow, new blocks may be created. 1712 if (Stmt *C = F->getCond()) { 1713 Block = ExitConditionBlock; 1714 EntryConditionBlock = addStmt(C); 1715 if (badCFG) 1716 return 0; 1717 assert(Block == EntryConditionBlock || 1718 (Block == 0 && EntryConditionBlock == Succ)); 1719 1720 // If this block contains a condition variable, add both the condition 1721 // variable and initializer to the CFG. 1722 if (VarDecl *VD = F->getConditionVariable()) { 1723 if (Expr *Init = VD->getInit()) { 1724 autoCreateBlock(); 1725 appendStmt(Block, F->getConditionVariableDeclStmt()); 1726 EntryConditionBlock = addStmt(Init); 1727 assert(Block == EntryConditionBlock); 1728 } 1729 } 1730 1731 if (Block) { 1732 if (badCFG) 1733 return 0; 1734 } 1735 } 1736 1737 // The condition block is the implicit successor for the loop body as well as 1738 // any code above the loop. 1739 Succ = EntryConditionBlock; 1740 1741 // See if this is a known constant. 1742 TryResult KnownVal(true); 1743 1744 if (F->getCond()) 1745 KnownVal = tryEvaluateBool(F->getCond()); 1746 1747 // Now create the loop body. 1748 { 1749 assert(F->getBody()); 1750 1751 // Save the current values for Block, Succ, and continue targets. 1752 SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ); 1753 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget); 1754 1755 // Create a new block to contain the (bottom) of the loop body. 1756 Block = NULL; 1757 1758 // Loop body should end with destructor of Condition variable (if any). 1759 addAutomaticObjDtors(ScopePos, LoopBeginScopePos, F); 1760 1761 if (Stmt *I = F->getInc()) { 1762 // Generate increment code in its own basic block. This is the target of 1763 // continue statements. 1764 Succ = addStmt(I); 1765 } else { 1766 // No increment code. Create a special, empty, block that is used as the 1767 // target block for "looping back" to the start of the loop. 1768 assert(Succ == EntryConditionBlock); 1769 Succ = Block ? Block : createBlock(); 1770 } 1771 1772 // Finish up the increment (or empty) block if it hasn't been already. 1773 if (Block) { 1774 assert(Block == Succ); 1775 if (badCFG) 1776 return 0; 1777 Block = 0; 1778 } 1779 1780 ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos); 1781 1782 // The starting block for the loop increment is the block that should 1783 // represent the 'loop target' for looping back to the start of the loop. 1784 ContinueJumpTarget.block->setLoopTarget(F); 1785 1786 // If body is not a compound statement create implicit scope 1787 // and add destructors. 1788 if (!isa<CompoundStmt>(F->getBody())) 1789 addLocalScopeAndDtors(F->getBody()); 1790 1791 // Now populate the body block, and in the process create new blocks as we 1792 // walk the body of the loop. 1793 CFGBlock *BodyBlock = addStmt(F->getBody()); 1794 1795 if (!BodyBlock) 1796 BodyBlock = ContinueJumpTarget.block;//can happen for "for (...;...;...);" 1797 else if (badCFG) 1798 return 0; 1799 1800 // This new body block is a successor to our "exit" condition block. 1801 addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock); 1802 } 1803 1804 // Link up the condition block with the code that follows the loop. (the 1805 // false branch). 1806 addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor); 1807 1808 // If the loop contains initialization, create a new block for those 1809 // statements. This block can also contain statements that precede the loop. 1810 if (Stmt *I = F->getInit()) { 1811 Block = createBlock(); 1812 return addStmt(I); 1813 } 1814 1815 // There is no loop initialization. We are thus basically a while loop. 1816 // NULL out Block to force lazy block construction. 1817 Block = NULL; 1818 Succ = EntryConditionBlock; 1819 return EntryConditionBlock; 1820} 1821 1822CFGBlock *CFGBuilder::VisitMemberExpr(MemberExpr *M, AddStmtChoice asc) { 1823 if (asc.alwaysAdd(*this, M)) { 1824 autoCreateBlock(); 1825 appendStmt(Block, M); 1826 } 1827 return Visit(M->getBase()); 1828} 1829 1830CFGBlock *CFGBuilder::VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) { 1831 // Objective-C fast enumeration 'for' statements: 1832 // http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC 1833 // 1834 // for ( Type newVariable in collection_expression ) { statements } 1835 // 1836 // becomes: 1837 // 1838 // prologue: 1839 // 1. collection_expression 1840 // T. jump to loop_entry 1841 // loop_entry: 1842 // 1. side-effects of element expression 1843 // 1. ObjCForCollectionStmt [performs binding to newVariable] 1844 // T. ObjCForCollectionStmt TB, FB [jumps to TB if newVariable != nil] 1845 // TB: 1846 // statements 1847 // T. jump to loop_entry 1848 // FB: 1849 // what comes after 1850 // 1851 // and 1852 // 1853 // Type existingItem; 1854 // for ( existingItem in expression ) { statements } 1855 // 1856 // becomes: 1857 // 1858 // the same with newVariable replaced with existingItem; the binding works 1859 // the same except that for one ObjCForCollectionStmt::getElement() returns 1860 // a DeclStmt and the other returns a DeclRefExpr. 1861 // 1862 1863 CFGBlock *LoopSuccessor = 0; 1864 1865 if (Block) { 1866 if (badCFG) 1867 return 0; 1868 LoopSuccessor = Block; 1869 Block = 0; 1870 } else 1871 LoopSuccessor = Succ; 1872 1873 // Build the condition blocks. 1874 CFGBlock *ExitConditionBlock = createBlock(false); 1875 1876 // Set the terminator for the "exit" condition block. 1877 ExitConditionBlock->setTerminator(S); 1878 1879 // The last statement in the block should be the ObjCForCollectionStmt, which 1880 // performs the actual binding to 'element' and determines if there are any 1881 // more items in the collection. 1882 appendStmt(ExitConditionBlock, S); 1883 Block = ExitConditionBlock; 1884 1885 // Walk the 'element' expression to see if there are any side-effects. We 1886 // generate new blocks as necessary. We DON'T add the statement by default to 1887 // the CFG unless it contains control-flow. 1888 CFGBlock *EntryConditionBlock = Visit(S->getElement(), 1889 AddStmtChoice::NotAlwaysAdd); 1890 if (Block) { 1891 if (badCFG) 1892 return 0; 1893 Block = 0; 1894 } 1895 1896 // The condition block is the implicit successor for the loop body as well as 1897 // any code above the loop. 1898 Succ = EntryConditionBlock; 1899 1900 // Now create the true branch. 1901 { 1902 // Save the current values for Succ, continue and break targets. 1903 SaveAndRestore<CFGBlock*> save_Succ(Succ); 1904 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget), 1905 save_break(BreakJumpTarget); 1906 1907 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos); 1908 ContinueJumpTarget = JumpTarget(EntryConditionBlock, ScopePos); 1909 1910 CFGBlock *BodyBlock = addStmt(S->getBody()); 1911 1912 if (!BodyBlock) 1913 BodyBlock = EntryConditionBlock; // can happen for "for (X in Y) ;" 1914 else if (Block) { 1915 if (badCFG) 1916 return 0; 1917 } 1918 1919 // This new body block is a successor to our "exit" condition block. 1920 addSuccessor(ExitConditionBlock, BodyBlock); 1921 } 1922 1923 // Link up the condition block with the code that follows the loop. 1924 // (the false branch). 1925 addSuccessor(ExitConditionBlock, LoopSuccessor); 1926 1927 // Now create a prologue block to contain the collection expression. 1928 Block = createBlock(); 1929 return addStmt(S->getCollection()); 1930} 1931 1932CFGBlock *CFGBuilder::VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S) { 1933 // FIXME: Add locking 'primitives' to CFG for @synchronized. 1934 1935 // Inline the body. 1936 CFGBlock *SyncBlock = addStmt(S->getSynchBody()); 1937 1938 // The sync body starts its own basic block. This makes it a little easier 1939 // for diagnostic clients. 1940 if (SyncBlock) { 1941 if (badCFG) 1942 return 0; 1943 1944 Block = 0; 1945 Succ = SyncBlock; 1946 } 1947 1948 // Add the @synchronized to the CFG. 1949 autoCreateBlock(); 1950 appendStmt(Block, S); 1951 1952 // Inline the sync expression. 1953 return addStmt(S->getSynchExpr()); 1954} 1955 1956CFGBlock *CFGBuilder::VisitObjCAtTryStmt(ObjCAtTryStmt *S) { 1957 // FIXME 1958 return NYS(); 1959} 1960 1961CFGBlock *CFGBuilder::VisitPseudoObjectExpr(PseudoObjectExpr *E) { 1962 autoCreateBlock(); 1963 1964 // Add the PseudoObject as the last thing. 1965 appendStmt(Block, E); 1966 1967 CFGBlock *lastBlock = Block; 1968 1969 // Before that, evaluate all of the semantics in order. In 1970 // CFG-land, that means appending them in reverse order. 1971 for (unsigned i = E->getNumSemanticExprs(); i != 0; ) { 1972 Expr *Semantic = E->getSemanticExpr(--i); 1973 1974 // If the semantic is an opaque value, we're being asked to bind 1975 // it to its source expression. 1976 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic)) 1977 Semantic = OVE->getSourceExpr(); 1978 1979 if (CFGBlock *B = Visit(Semantic)) 1980 lastBlock = B; 1981 } 1982 1983 return lastBlock; 1984} 1985 1986CFGBlock *CFGBuilder::VisitWhileStmt(WhileStmt *W) { 1987 CFGBlock *LoopSuccessor = NULL; 1988 1989 // Save local scope position because in case of condition variable ScopePos 1990 // won't be restored when traversing AST. 1991 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos); 1992 1993 // Create local scope for possible condition variable. 1994 // Store scope position for continue statement. 1995 LocalScope::const_iterator LoopBeginScopePos = ScopePos; 1996 if (VarDecl *VD = W->getConditionVariable()) { 1997 addLocalScopeForVarDecl(VD); 1998 addAutomaticObjDtors(ScopePos, LoopBeginScopePos, W); 1999 } 2000 2001 // "while" is a control-flow statement. Thus we stop processing the current 2002 // block. 2003 if (Block) { 2004 if (badCFG) 2005 return 0; 2006 LoopSuccessor = Block; 2007 Block = 0; 2008 } else 2009 LoopSuccessor = Succ; 2010 2011 // Because of short-circuit evaluation, the condition of the loop can span 2012 // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that 2013 // evaluate the condition. 2014 CFGBlock *ExitConditionBlock = createBlock(false); 2015 CFGBlock *EntryConditionBlock = ExitConditionBlock; 2016 2017 // Set the terminator for the "exit" condition block. 2018 ExitConditionBlock->setTerminator(W); 2019 2020 // Now add the actual condition to the condition block. Because the condition 2021 // itself may contain control-flow, new blocks may be created. Thus we update 2022 // "Succ" after adding the condition. 2023 if (Stmt *C = W->getCond()) { 2024 Block = ExitConditionBlock; 2025 EntryConditionBlock = addStmt(C); 2026 // The condition might finish the current 'Block'. 2027 Block = EntryConditionBlock; 2028 2029 // If this block contains a condition variable, add both the condition 2030 // variable and initializer to the CFG. 2031 if (VarDecl *VD = W->getConditionVariable()) { 2032 if (Expr *Init = VD->getInit()) { 2033 autoCreateBlock(); 2034 appendStmt(Block, W->getConditionVariableDeclStmt()); 2035 EntryConditionBlock = addStmt(Init); 2036 assert(Block == EntryConditionBlock); 2037 } 2038 } 2039 2040 if (Block) { 2041 if (badCFG) 2042 return 0; 2043 } 2044 } 2045 2046 // The condition block is the implicit successor for the loop body as well as 2047 // any code above the loop. 2048 Succ = EntryConditionBlock; 2049 2050 // See if this is a known constant. 2051 const TryResult& KnownVal = tryEvaluateBool(W->getCond()); 2052 2053 // Process the loop body. 2054 { 2055 assert(W->getBody()); 2056 2057 // Save the current values for Block, Succ, and continue and break targets 2058 SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ); 2059 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget), 2060 save_break(BreakJumpTarget); 2061 2062 // Create an empty block to represent the transition block for looping back 2063 // to the head of the loop. 2064 Block = 0; 2065 assert(Succ == EntryConditionBlock); 2066 Succ = createBlock(); 2067 Succ->setLoopTarget(W); 2068 ContinueJumpTarget = JumpTarget(Succ, LoopBeginScopePos); 2069 2070 // All breaks should go to the code following the loop. 2071 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos); 2072 2073 // NULL out Block to force lazy instantiation of blocks for the body. 2074 Block = NULL; 2075 2076 // Loop body should end with destructor of Condition variable (if any). 2077 addAutomaticObjDtors(ScopePos, LoopBeginScopePos, W); 2078 2079 // If body is not a compound statement create implicit scope 2080 // and add destructors. 2081 if (!isa<CompoundStmt>(W->getBody())) 2082 addLocalScopeAndDtors(W->getBody()); 2083 2084 // Create the body. The returned block is the entry to the loop body. 2085 CFGBlock *BodyBlock = addStmt(W->getBody()); 2086 2087 if (!BodyBlock) 2088 BodyBlock = ContinueJumpTarget.block; // can happen for "while(...) ;" 2089 else if (Block) { 2090 if (badCFG) 2091 return 0; 2092 } 2093 2094 // Add the loop body entry as a successor to the condition. 2095 addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock); 2096 } 2097 2098 // Link up the condition block with the code that follows the loop. (the 2099 // false branch). 2100 addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor); 2101 2102 // There can be no more statements in the condition block since we loop back 2103 // to this block. NULL out Block to force lazy creation of another block. 2104 Block = NULL; 2105 2106 // Return the condition block, which is the dominating block for the loop. 2107 Succ = EntryConditionBlock; 2108 return EntryConditionBlock; 2109} 2110 2111 2112CFGBlock *CFGBuilder::VisitObjCAtCatchStmt(ObjCAtCatchStmt *S) { 2113 // FIXME: For now we pretend that @catch and the code it contains does not 2114 // exit. 2115 return Block; 2116} 2117 2118CFGBlock *CFGBuilder::VisitObjCAtThrowStmt(ObjCAtThrowStmt *S) { 2119 // FIXME: This isn't complete. We basically treat @throw like a return 2120 // statement. 2121 2122 // If we were in the middle of a block we stop processing that block. 2123 if (badCFG) 2124 return 0; 2125 2126 // Create the new block. 2127 Block = createBlock(false); 2128 2129 // The Exit block is the only successor. 2130 addSuccessor(Block, &cfg->getExit()); 2131 2132 // Add the statement to the block. This may create new blocks if S contains 2133 // control-flow (short-circuit operations). 2134 return VisitStmt(S, AddStmtChoice::AlwaysAdd); 2135} 2136 2137CFGBlock *CFGBuilder::VisitCXXThrowExpr(CXXThrowExpr *T) { 2138 // If we were in the middle of a block we stop processing that block. 2139 if (badCFG) 2140 return 0; 2141 2142 // Create the new block. 2143 Block = createBlock(false); 2144 2145 if (TryTerminatedBlock) 2146 // The current try statement is the only successor. 2147 addSuccessor(Block, TryTerminatedBlock); 2148 else 2149 // otherwise the Exit block is the only successor. 2150 addSuccessor(Block, &cfg->getExit()); 2151 2152 // Add the statement to the block. This may create new blocks if S contains 2153 // control-flow (short-circuit operations). 2154 return VisitStmt(T, AddStmtChoice::AlwaysAdd); 2155} 2156 2157CFGBlock *CFGBuilder::VisitDoStmt(DoStmt *D) { 2158 CFGBlock *LoopSuccessor = NULL; 2159 2160 // "do...while" is a control-flow statement. Thus we stop processing the 2161 // current block. 2162 if (Block) { 2163 if (badCFG) 2164 return 0; 2165 LoopSuccessor = Block; 2166 } else 2167 LoopSuccessor = Succ; 2168 2169 // Because of short-circuit evaluation, the condition of the loop can span 2170 // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that 2171 // evaluate the condition. 2172 CFGBlock *ExitConditionBlock = createBlock(false); 2173 CFGBlock *EntryConditionBlock = ExitConditionBlock; 2174 2175 // Set the terminator for the "exit" condition block. 2176 ExitConditionBlock->setTerminator(D); 2177 2178 // Now add the actual condition to the condition block. Because the condition 2179 // itself may contain control-flow, new blocks may be created. 2180 if (Stmt *C = D->getCond()) { 2181 Block = ExitConditionBlock; 2182 EntryConditionBlock = addStmt(C); 2183 if (Block) { 2184 if (badCFG) 2185 return 0; 2186 } 2187 } 2188 2189 // The condition block is the implicit successor for the loop body. 2190 Succ = EntryConditionBlock; 2191 2192 // See if this is a known constant. 2193 const TryResult &KnownVal = tryEvaluateBool(D->getCond()); 2194 2195 // Process the loop body. 2196 CFGBlock *BodyBlock = NULL; 2197 { 2198 assert(D->getBody()); 2199 2200 // Save the current values for Block, Succ, and continue and break targets 2201 SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ); 2202 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget), 2203 save_break(BreakJumpTarget); 2204 2205 // All continues within this loop should go to the condition block 2206 ContinueJumpTarget = JumpTarget(EntryConditionBlock, ScopePos); 2207 2208 // All breaks should go to the code following the loop. 2209 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos); 2210 2211 // NULL out Block to force lazy instantiation of blocks for the body. 2212 Block = NULL; 2213 2214 // If body is not a compound statement create implicit scope 2215 // and add destructors. 2216 if (!isa<CompoundStmt>(D->getBody())) 2217 addLocalScopeAndDtors(D->getBody()); 2218 2219 // Create the body. The returned block is the entry to the loop body. 2220 BodyBlock = addStmt(D->getBody()); 2221 2222 if (!BodyBlock) 2223 BodyBlock = EntryConditionBlock; // can happen for "do ; while(...)" 2224 else if (Block) { 2225 if (badCFG) 2226 return 0; 2227 } 2228 2229 if (!KnownVal.isFalse()) { 2230 // Add an intermediate block between the BodyBlock and the 2231 // ExitConditionBlock to represent the "loop back" transition. Create an 2232 // empty block to represent the transition block for looping back to the 2233 // head of the loop. 2234 // FIXME: Can we do this more efficiently without adding another block? 2235 Block = NULL; 2236 Succ = BodyBlock; 2237 CFGBlock *LoopBackBlock = createBlock(); 2238 LoopBackBlock->setLoopTarget(D); 2239 2240 // Add the loop body entry as a successor to the condition. 2241 addSuccessor(ExitConditionBlock, LoopBackBlock); 2242 } 2243 else 2244 addSuccessor(ExitConditionBlock, NULL); 2245 } 2246 2247 // Link up the condition block with the code that follows the loop. 2248 // (the false branch). 2249 addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor); 2250 2251 // There can be no more statements in the body block(s) since we loop back to 2252 // the body. NULL out Block to force lazy creation of another block. 2253 Block = NULL; 2254 2255 // Return the loop body, which is the dominating block for the loop. 2256 Succ = BodyBlock; 2257 return BodyBlock; 2258} 2259 2260CFGBlock *CFGBuilder::VisitContinueStmt(ContinueStmt *C) { 2261 // "continue" is a control-flow statement. Thus we stop processing the 2262 // current block. 2263 if (badCFG) 2264 return 0; 2265 2266 // Now create a new block that ends with the continue statement. 2267 Block = createBlock(false); 2268 Block->setTerminator(C); 2269 2270 // If there is no target for the continue, then we are looking at an 2271 // incomplete AST. This means the CFG cannot be constructed. 2272 if (ContinueJumpTarget.block) { 2273 addAutomaticObjDtors(ScopePos, ContinueJumpTarget.scopePosition, C); 2274 addSuccessor(Block, ContinueJumpTarget.block); 2275 } else 2276 badCFG = true; 2277 2278 return Block; 2279} 2280 2281CFGBlock *CFGBuilder::VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E, 2282 AddStmtChoice asc) { 2283 2284 if (asc.alwaysAdd(*this, E)) { 2285 autoCreateBlock(); 2286 appendStmt(Block, E); 2287 } 2288 2289 // VLA types have expressions that must be evaluated. 2290 CFGBlock *lastBlock = Block; 2291 2292 if (E->isArgumentType()) { 2293 for (const VariableArrayType *VA =FindVA(E->getArgumentType().getTypePtr()); 2294 VA != 0; VA = FindVA(VA->getElementType().getTypePtr())) 2295 lastBlock = addStmt(VA->getSizeExpr()); 2296 } 2297 return lastBlock; 2298} 2299 2300/// VisitStmtExpr - Utility method to handle (nested) statement 2301/// expressions (a GCC extension). 2302CFGBlock *CFGBuilder::VisitStmtExpr(StmtExpr *SE, AddStmtChoice asc) { 2303 if (asc.alwaysAdd(*this, SE)) { 2304 autoCreateBlock(); 2305 appendStmt(Block, SE); 2306 } 2307 return VisitCompoundStmt(SE->getSubStmt()); 2308} 2309 2310CFGBlock *CFGBuilder::VisitSwitchStmt(SwitchStmt *Terminator) { 2311 // "switch" is a control-flow statement. Thus we stop processing the current 2312 // block. 2313 CFGBlock *SwitchSuccessor = NULL; 2314 2315 // Save local scope position because in case of condition variable ScopePos 2316 // won't be restored when traversing AST. 2317 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos); 2318 2319 // Create local scope for possible condition variable. 2320 // Store scope position. Add implicit destructor. 2321 if (VarDecl *VD = Terminator->getConditionVariable()) { 2322 LocalScope::const_iterator SwitchBeginScopePos = ScopePos; 2323 addLocalScopeForVarDecl(VD); 2324 addAutomaticObjDtors(ScopePos, SwitchBeginScopePos, Terminator); 2325 } 2326 2327 if (Block) { 2328 if (badCFG) 2329 return 0; 2330 SwitchSuccessor = Block; 2331 } else SwitchSuccessor = Succ; 2332 2333 // Save the current "switch" context. 2334 SaveAndRestore<CFGBlock*> save_switch(SwitchTerminatedBlock), 2335 save_default(DefaultCaseBlock); 2336 SaveAndRestore<JumpTarget> save_break(BreakJumpTarget); 2337 2338 // Set the "default" case to be the block after the switch statement. If the 2339 // switch statement contains a "default:", this value will be overwritten with 2340 // the block for that code. 2341 DefaultCaseBlock = SwitchSuccessor; 2342 2343 // Create a new block that will contain the switch statement. 2344 SwitchTerminatedBlock = createBlock(false); 2345 2346 // Now process the switch body. The code after the switch is the implicit 2347 // successor. 2348 Succ = SwitchSuccessor; 2349 BreakJumpTarget = JumpTarget(SwitchSuccessor, ScopePos); 2350 2351 // When visiting the body, the case statements should automatically get linked 2352 // up to the switch. We also don't keep a pointer to the body, since all 2353 // control-flow from the switch goes to case/default statements. 2354 assert(Terminator->getBody() && "switch must contain a non-NULL body"); 2355 Block = NULL; 2356 2357 // For pruning unreachable case statements, save the current state 2358 // for tracking the condition value. 2359 SaveAndRestore<bool> save_switchExclusivelyCovered(switchExclusivelyCovered, 2360 false); 2361 2362 // Determine if the switch condition can be explicitly evaluated. 2363 assert(Terminator->getCond() && "switch condition must be non-NULL"); 2364 Expr::EvalResult result; 2365 bool b = tryEvaluate(Terminator->getCond(), result); 2366 SaveAndRestore<Expr::EvalResult*> save_switchCond(switchCond, 2367 b ? &result : 0); 2368 2369 // If body is not a compound statement create implicit scope 2370 // and add destructors. 2371 if (!isa<CompoundStmt>(Terminator->getBody())) 2372 addLocalScopeAndDtors(Terminator->getBody()); 2373 2374 addStmt(Terminator->getBody()); 2375 if (Block) { 2376 if (badCFG) 2377 return 0; 2378 } 2379 2380 // If we have no "default:" case, the default transition is to the code 2381 // following the switch body. Moreover, take into account if all the 2382 // cases of a switch are covered (e.g., switching on an enum value). 2383 addSuccessor(SwitchTerminatedBlock, 2384 switchExclusivelyCovered || Terminator->isAllEnumCasesCovered() 2385 ? 0 : DefaultCaseBlock); 2386 2387 // Add the terminator and condition in the switch block. 2388 SwitchTerminatedBlock->setTerminator(Terminator); 2389 Block = SwitchTerminatedBlock; 2390 Block = addStmt(Terminator->getCond()); 2391 2392 // Finally, if the SwitchStmt contains a condition variable, add both the 2393 // SwitchStmt and the condition variable initialization to the CFG. 2394 if (VarDecl *VD = Terminator->getConditionVariable()) { 2395 if (Expr *Init = VD->getInit()) { 2396 autoCreateBlock(); 2397 appendStmt(Block, Terminator->getConditionVariableDeclStmt()); 2398 addStmt(Init); 2399 } 2400 } 2401 2402 return Block; 2403} 2404 2405static bool shouldAddCase(bool &switchExclusivelyCovered, 2406 const Expr::EvalResult *switchCond, 2407 const CaseStmt *CS, 2408 ASTContext &Ctx) { 2409 if (!switchCond) 2410 return true; 2411 2412 bool addCase = false; 2413 2414 if (!switchExclusivelyCovered) { 2415 if (switchCond->Val.isInt()) { 2416 // Evaluate the LHS of the case value. 2417 const llvm::APSInt &lhsInt = CS->getLHS()->EvaluateKnownConstInt(Ctx); 2418 const llvm::APSInt &condInt = switchCond->Val.getInt(); 2419 2420 if (condInt == lhsInt) { 2421 addCase = true; 2422 switchExclusivelyCovered = true; 2423 } 2424 else if (condInt < lhsInt) { 2425 if (const Expr *RHS = CS->getRHS()) { 2426 // Evaluate the RHS of the case value. 2427 const llvm::APSInt &V2 = RHS->EvaluateKnownConstInt(Ctx); 2428 if (V2 <= condInt) { 2429 addCase = true; 2430 switchExclusivelyCovered = true; 2431 } 2432 } 2433 } 2434 } 2435 else 2436 addCase = true; 2437 } 2438 return addCase; 2439} 2440 2441CFGBlock *CFGBuilder::VisitCaseStmt(CaseStmt *CS) { 2442 // CaseStmts are essentially labels, so they are the first statement in a 2443 // block. 2444 CFGBlock *TopBlock = 0, *LastBlock = 0; 2445 2446 if (Stmt *Sub = CS->getSubStmt()) { 2447 // For deeply nested chains of CaseStmts, instead of doing a recursion 2448 // (which can blow out the stack), manually unroll and create blocks 2449 // along the way. 2450 while (isa<CaseStmt>(Sub)) { 2451 CFGBlock *currentBlock = createBlock(false); 2452 currentBlock->setLabel(CS); 2453 2454 if (TopBlock) 2455 addSuccessor(LastBlock, currentBlock); 2456 else 2457 TopBlock = currentBlock; 2458 2459 addSuccessor(SwitchTerminatedBlock, 2460 shouldAddCase(switchExclusivelyCovered, switchCond, 2461 CS, *Context) 2462 ? currentBlock : 0); 2463 2464 LastBlock = currentBlock; 2465 CS = cast<CaseStmt>(Sub); 2466 Sub = CS->getSubStmt(); 2467 } 2468 2469 addStmt(Sub); 2470 } 2471 2472 CFGBlock *CaseBlock = Block; 2473 if (!CaseBlock) 2474 CaseBlock = createBlock(); 2475 2476 // Cases statements partition blocks, so this is the top of the basic block we 2477 // were processing (the "case XXX:" is the label). 2478 CaseBlock->setLabel(CS); 2479 2480 if (badCFG) 2481 return 0; 2482 2483 // Add this block to the list of successors for the block with the switch 2484 // statement. 2485 assert(SwitchTerminatedBlock); 2486 addSuccessor(SwitchTerminatedBlock, 2487 shouldAddCase(switchExclusivelyCovered, switchCond, 2488 CS, *Context) 2489 ? CaseBlock : 0); 2490 2491 // We set Block to NULL to allow lazy creation of a new block (if necessary) 2492 Block = NULL; 2493 2494 if (TopBlock) { 2495 addSuccessor(LastBlock, CaseBlock); 2496 Succ = TopBlock; 2497 } else { 2498 // This block is now the implicit successor of other blocks. 2499 Succ = CaseBlock; 2500 } 2501 2502 return Succ; 2503} 2504 2505CFGBlock *CFGBuilder::VisitDefaultStmt(DefaultStmt *Terminator) { 2506 if (Terminator->getSubStmt()) 2507 addStmt(Terminator->getSubStmt()); 2508 2509 DefaultCaseBlock = Block; 2510 2511 if (!DefaultCaseBlock) 2512 DefaultCaseBlock = createBlock(); 2513 2514 // Default statements partition blocks, so this is the top of the basic block 2515 // we were processing (the "default:" is the label). 2516 DefaultCaseBlock->setLabel(Terminator); 2517 2518 if (badCFG) 2519 return 0; 2520 2521 // Unlike case statements, we don't add the default block to the successors 2522 // for the switch statement immediately. This is done when we finish 2523 // processing the switch statement. This allows for the default case 2524 // (including a fall-through to the code after the switch statement) to always 2525 // be the last successor of a switch-terminated block. 2526 2527 // We set Block to NULL to allow lazy creation of a new block (if necessary) 2528 Block = NULL; 2529 2530 // This block is now the implicit successor of other blocks. 2531 Succ = DefaultCaseBlock; 2532 2533 return DefaultCaseBlock; 2534} 2535 2536CFGBlock *CFGBuilder::VisitCXXTryStmt(CXXTryStmt *Terminator) { 2537 // "try"/"catch" is a control-flow statement. Thus we stop processing the 2538 // current block. 2539 CFGBlock *TrySuccessor = NULL; 2540 2541 if (Block) { 2542 if (badCFG) 2543 return 0; 2544 TrySuccessor = Block; 2545 } else TrySuccessor = Succ; 2546 2547 CFGBlock *PrevTryTerminatedBlock = TryTerminatedBlock; 2548 2549 // Create a new block that will contain the try statement. 2550 CFGBlock *NewTryTerminatedBlock = createBlock(false); 2551 // Add the terminator in the try block. 2552 NewTryTerminatedBlock->setTerminator(Terminator); 2553 2554 bool HasCatchAll = false; 2555 for (unsigned h = 0; h <Terminator->getNumHandlers(); ++h) { 2556 // The code after the try is the implicit successor. 2557 Succ = TrySuccessor; 2558 CXXCatchStmt *CS = Terminator->getHandler(h); 2559 if (CS->getExceptionDecl() == 0) { 2560 HasCatchAll = true; 2561 } 2562 Block = NULL; 2563 CFGBlock *CatchBlock = VisitCXXCatchStmt(CS); 2564 if (CatchBlock == 0) 2565 return 0; 2566 // Add this block to the list of successors for the block with the try 2567 // statement. 2568 addSuccessor(NewTryTerminatedBlock, CatchBlock); 2569 } 2570 if (!HasCatchAll) { 2571 if (PrevTryTerminatedBlock) 2572 addSuccessor(NewTryTerminatedBlock, PrevTryTerminatedBlock); 2573 else 2574 addSuccessor(NewTryTerminatedBlock, &cfg->getExit()); 2575 } 2576 2577 // The code after the try is the implicit successor. 2578 Succ = TrySuccessor; 2579 2580 // Save the current "try" context. 2581 SaveAndRestore<CFGBlock*> save_try(TryTerminatedBlock, NewTryTerminatedBlock); 2582 cfg->addTryDispatchBlock(TryTerminatedBlock); 2583 2584 assert(Terminator->getTryBlock() && "try must contain a non-NULL body"); 2585 Block = NULL; 2586 Block = addStmt(Terminator->getTryBlock()); 2587 return Block; 2588} 2589 2590CFGBlock *CFGBuilder::VisitCXXCatchStmt(CXXCatchStmt *CS) { 2591 // CXXCatchStmt are treated like labels, so they are the first statement in a 2592 // block. 2593 2594 // Save local scope position because in case of exception variable ScopePos 2595 // won't be restored when traversing AST. 2596 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos); 2597 2598 // Create local scope for possible exception variable. 2599 // Store scope position. Add implicit destructor. 2600 if (VarDecl *VD = CS->getExceptionDecl()) { 2601 LocalScope::const_iterator BeginScopePos = ScopePos; 2602 addLocalScopeForVarDecl(VD); 2603 addAutomaticObjDtors(ScopePos, BeginScopePos, CS); 2604 } 2605 2606 if (CS->getHandlerBlock()) 2607 addStmt(CS->getHandlerBlock()); 2608 2609 CFGBlock *CatchBlock = Block; 2610 if (!CatchBlock) 2611 CatchBlock = createBlock(); 2612 2613 CatchBlock->setLabel(CS); 2614 2615 if (badCFG) 2616 return 0; 2617 2618 // We set Block to NULL to allow lazy creation of a new block (if necessary) 2619 Block = NULL; 2620 2621 return CatchBlock; 2622} 2623 2624CFGBlock *CFGBuilder::VisitCXXForRangeStmt(CXXForRangeStmt *S) { 2625 // C++0x for-range statements are specified as [stmt.ranged]: 2626 // 2627 // { 2628 // auto && __range = range-init; 2629 // for ( auto __begin = begin-expr, 2630 // __end = end-expr; 2631 // __begin != __end; 2632 // ++__begin ) { 2633 // for-range-declaration = *__begin; 2634 // statement 2635 // } 2636 // } 2637 2638 // Save local scope position before the addition of the implicit variables. 2639 SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos); 2640 2641 // Create local scopes and destructors for range, begin and end variables. 2642 if (Stmt *Range = S->getRangeStmt()) 2643 addLocalScopeForStmt(Range); 2644 if (Stmt *BeginEnd = S->getBeginEndStmt()) 2645 addLocalScopeForStmt(BeginEnd); 2646 addAutomaticObjDtors(ScopePos, save_scope_pos.get(), S); 2647 2648 LocalScope::const_iterator ContinueScopePos = ScopePos; 2649 2650 // "for" is a control-flow statement. Thus we stop processing the current 2651 // block. 2652 CFGBlock *LoopSuccessor = NULL; 2653 if (Block) { 2654 if (badCFG) 2655 return 0; 2656 LoopSuccessor = Block; 2657 } else 2658 LoopSuccessor = Succ; 2659 2660 // Save the current value for the break targets. 2661 // All breaks should go to the code following the loop. 2662 SaveAndRestore<JumpTarget> save_break(BreakJumpTarget); 2663 BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos); 2664 2665 // The block for the __begin != __end expression. 2666 CFGBlock *ConditionBlock = createBlock(false); 2667 ConditionBlock->setTerminator(S); 2668 2669 // Now add the actual condition to the condition block. 2670 if (Expr *C = S->getCond()) { 2671 Block = ConditionBlock; 2672 CFGBlock *BeginConditionBlock = addStmt(C); 2673 if (badCFG) 2674 return 0; 2675 assert(BeginConditionBlock == ConditionBlock && 2676 "condition block in for-range was unexpectedly complex"); 2677 (void)BeginConditionBlock; 2678 } 2679 2680 // The condition block is the implicit successor for the loop body as well as 2681 // any code above the loop. 2682 Succ = ConditionBlock; 2683 2684 // See if this is a known constant. 2685 TryResult KnownVal(true); 2686 2687 if (S->getCond()) 2688 KnownVal = tryEvaluateBool(S->getCond()); 2689 2690 // Now create the loop body. 2691 { 2692 assert(S->getBody()); 2693 2694 // Save the current values for Block, Succ, and continue targets. 2695 SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ); 2696 SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget); 2697 2698 // Generate increment code in its own basic block. This is the target of 2699 // continue statements. 2700 Block = 0; 2701 Succ = addStmt(S->getInc()); 2702 ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos); 2703 2704 // The starting block for the loop increment is the block that should 2705 // represent the 'loop target' for looping back to the start of the loop. 2706 ContinueJumpTarget.block->setLoopTarget(S); 2707 2708 // Finish up the increment block and prepare to start the loop body. 2709 assert(Block); 2710 if (badCFG) 2711 return 0; 2712 Block = 0; 2713 2714 2715 // Add implicit scope and dtors for loop variable. 2716 addLocalScopeAndDtors(S->getLoopVarStmt()); 2717 2718 // Populate a new block to contain the loop body and loop variable. 2719 Block = addStmt(S->getBody()); 2720 if (badCFG) 2721 return 0; 2722 Block = addStmt(S->getLoopVarStmt()); 2723 if (badCFG) 2724 return 0; 2725 2726 // This new body block is a successor to our condition block. 2727 addSuccessor(ConditionBlock, KnownVal.isFalse() ? 0 : Block); 2728 } 2729 2730 // Link up the condition block with the code that follows the loop (the 2731 // false branch). 2732 addSuccessor(ConditionBlock, KnownVal.isTrue() ? 0 : LoopSuccessor); 2733 2734 // Add the initialization statements. 2735 Block = createBlock(); 2736 addStmt(S->getBeginEndStmt()); 2737 return addStmt(S->getRangeStmt()); 2738} 2739 2740CFGBlock *CFGBuilder::VisitExprWithCleanups(ExprWithCleanups *E, 2741 AddStmtChoice asc) { 2742 if (BuildOpts.AddImplicitDtors) { 2743 // If adding implicit destructors visit the full expression for adding 2744 // destructors of temporaries. 2745 VisitForTemporaryDtors(E->getSubExpr()); 2746 2747 // Full expression has to be added as CFGStmt so it will be sequenced 2748 // before destructors of it's temporaries. 2749 asc = asc.withAlwaysAdd(true); 2750 } 2751 return Visit(E->getSubExpr(), asc); 2752} 2753 2754CFGBlock *CFGBuilder::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E, 2755 AddStmtChoice asc) { 2756 if (asc.alwaysAdd(*this, E)) { 2757 autoCreateBlock(); 2758 appendStmt(Block, E); 2759 2760 // We do not want to propagate the AlwaysAdd property. 2761 asc = asc.withAlwaysAdd(false); 2762 } 2763 return Visit(E->getSubExpr(), asc); 2764} 2765 2766CFGBlock *CFGBuilder::VisitCXXConstructExpr(CXXConstructExpr *C, 2767 AddStmtChoice asc) { 2768 autoCreateBlock(); 2769 appendStmt(Block, C); 2770 2771 return VisitChildren(C); 2772} 2773 2774CFGBlock *CFGBuilder::VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E, 2775 AddStmtChoice asc) { 2776 if (asc.alwaysAdd(*this, E)) { 2777 autoCreateBlock(); 2778 appendStmt(Block, E); 2779 // We do not want to propagate the AlwaysAdd property. 2780 asc = asc.withAlwaysAdd(false); 2781 } 2782 return Visit(E->getSubExpr(), asc); 2783} 2784 2785CFGBlock *CFGBuilder::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C, 2786 AddStmtChoice asc) { 2787 autoCreateBlock(); 2788 appendStmt(Block, C); 2789 return VisitChildren(C); 2790} 2791 2792CFGBlock *CFGBuilder::VisitImplicitCastExpr(ImplicitCastExpr *E, 2793 AddStmtChoice asc) { 2794 if (asc.alwaysAdd(*this, E)) { 2795 autoCreateBlock(); 2796 appendStmt(Block, E); 2797 } 2798 return Visit(E->getSubExpr(), AddStmtChoice()); 2799} 2800 2801CFGBlock *CFGBuilder::VisitIndirectGotoStmt(IndirectGotoStmt *I) { 2802 // Lazily create the indirect-goto dispatch block if there isn't one already. 2803 CFGBlock *IBlock = cfg->getIndirectGotoBlock(); 2804 2805 if (!IBlock) { 2806 IBlock = createBlock(false); 2807 cfg->setIndirectGotoBlock(IBlock); 2808 } 2809 2810 // IndirectGoto is a control-flow statement. Thus we stop processing the 2811 // current block and create a new one. 2812 if (badCFG) 2813 return 0; 2814 2815 Block = createBlock(false); 2816 Block->setTerminator(I); 2817 addSuccessor(Block, IBlock); 2818 return addStmt(I->getTarget()); 2819} 2820 2821CFGBlock *CFGBuilder::VisitForTemporaryDtors(Stmt *E, bool BindToTemporary) { 2822tryAgain: 2823 if (!E) { 2824 badCFG = true; 2825 return NULL; 2826 } 2827 switch (E->getStmtClass()) { 2828 default: 2829 return VisitChildrenForTemporaryDtors(E); 2830 2831 case Stmt::BinaryOperatorClass: 2832 return VisitBinaryOperatorForTemporaryDtors(cast<BinaryOperator>(E)); 2833 2834 case Stmt::CXXBindTemporaryExprClass: 2835 return VisitCXXBindTemporaryExprForTemporaryDtors( 2836 cast<CXXBindTemporaryExpr>(E), BindToTemporary); 2837 2838 case Stmt::BinaryConditionalOperatorClass: 2839 case Stmt::ConditionalOperatorClass: 2840 return VisitConditionalOperatorForTemporaryDtors( 2841 cast<AbstractConditionalOperator>(E), BindToTemporary); 2842 2843 case Stmt::ImplicitCastExprClass: 2844 // For implicit cast we want BindToTemporary to be passed further. 2845 E = cast<CastExpr>(E)->getSubExpr(); 2846 goto tryAgain; 2847 2848 case Stmt::ParenExprClass: 2849 E = cast<ParenExpr>(E)->getSubExpr(); 2850 goto tryAgain; 2851 2852 case Stmt::MaterializeTemporaryExprClass: 2853 E = cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr(); 2854 goto tryAgain; 2855 } 2856} 2857 2858CFGBlock *CFGBuilder::VisitChildrenForTemporaryDtors(Stmt *E) { 2859 // When visiting children for destructors we want to visit them in reverse 2860 // order. Because there's no reverse iterator for children must to reverse 2861 // them in helper vector. 2862 typedef SmallVector<Stmt *, 4> ChildrenVect; 2863 ChildrenVect ChildrenRev; 2864 for (Stmt::child_range I = E->children(); I; ++I) { 2865 if (*I) ChildrenRev.push_back(*I); 2866 } 2867 2868 CFGBlock *B = Block; 2869 for (ChildrenVect::reverse_iterator I = ChildrenRev.rbegin(), 2870 L = ChildrenRev.rend(); I != L; ++I) { 2871 if (CFGBlock *R = VisitForTemporaryDtors(*I)) 2872 B = R; 2873 } 2874 return B; 2875} 2876 2877CFGBlock *CFGBuilder::VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E) { 2878 if (E->isLogicalOp()) { 2879 // Destructors for temporaries in LHS expression should be called after 2880 // those for RHS expression. Even if this will unnecessarily create a block, 2881 // this block will be used at least by the full expression. 2882 autoCreateBlock(); 2883 CFGBlock *ConfluenceBlock = VisitForTemporaryDtors(E->getLHS()); 2884 if (badCFG) 2885 return NULL; 2886 2887 Succ = ConfluenceBlock; 2888 Block = NULL; 2889 CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS()); 2890 2891 if (RHSBlock) { 2892 if (badCFG) 2893 return NULL; 2894 2895 // If RHS expression did produce destructors we need to connect created 2896 // blocks to CFG in same manner as for binary operator itself. 2897 CFGBlock *LHSBlock = createBlock(false); 2898 LHSBlock->setTerminator(CFGTerminator(E, true)); 2899 2900 // For binary operator LHS block is before RHS in list of predecessors 2901 // of ConfluenceBlock. 2902 std::reverse(ConfluenceBlock->pred_begin(), 2903 ConfluenceBlock->pred_end()); 2904 2905 // See if this is a known constant. 2906 TryResult KnownVal = tryEvaluateBool(E->getLHS()); 2907 if (KnownVal.isKnown() && (E->getOpcode() == BO_LOr)) 2908 KnownVal.negate(); 2909 2910 // Link LHSBlock with RHSBlock exactly the same way as for binary operator 2911 // itself. 2912 if (E->getOpcode() == BO_LOr) { 2913 addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock); 2914 addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock); 2915 } else { 2916 assert (E->getOpcode() == BO_LAnd); 2917 addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock); 2918 addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock); 2919 } 2920 2921 Block = LHSBlock; 2922 return LHSBlock; 2923 } 2924 2925 Block = ConfluenceBlock; 2926 return ConfluenceBlock; 2927 } 2928 2929 if (E->isAssignmentOp()) { 2930 // For assignment operator (=) LHS expression is visited 2931 // before RHS expression. For destructors visit them in reverse order. 2932 CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS()); 2933 CFGBlock *LHSBlock = VisitForTemporaryDtors(E->getLHS()); 2934 return LHSBlock ? LHSBlock : RHSBlock; 2935 } 2936 2937 // For any other binary operator RHS expression is visited before 2938 // LHS expression (order of children). For destructors visit them in reverse 2939 // order. 2940 CFGBlock *LHSBlock = VisitForTemporaryDtors(E->getLHS()); 2941 CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS()); 2942 return RHSBlock ? RHSBlock : LHSBlock; 2943} 2944 2945CFGBlock *CFGBuilder::VisitCXXBindTemporaryExprForTemporaryDtors( 2946 CXXBindTemporaryExpr *E, bool BindToTemporary) { 2947 // First add destructors for temporaries in subexpression. 2948 CFGBlock *B = VisitForTemporaryDtors(E->getSubExpr()); 2949 if (!BindToTemporary) { 2950 // If lifetime of temporary is not prolonged (by assigning to constant 2951 // reference) add destructor for it. 2952 2953 // If the destructor is marked as a no-return destructor, we need to create 2954 // a new block for the destructor which does not have as a successor 2955 // anything built thus far. Control won't flow out of this block. 2956 const CXXDestructorDecl *Dtor = E->getTemporary()->getDestructor(); 2957 if (cast<FunctionType>(Dtor->getType())->getNoReturnAttr()) 2958 Block = createNoReturnBlock(); 2959 else 2960 autoCreateBlock(); 2961 2962 appendTemporaryDtor(Block, E); 2963 B = Block; 2964 } 2965 return B; 2966} 2967 2968CFGBlock *CFGBuilder::VisitConditionalOperatorForTemporaryDtors( 2969 AbstractConditionalOperator *E, bool BindToTemporary) { 2970 // First add destructors for condition expression. Even if this will 2971 // unnecessarily create a block, this block will be used at least by the full 2972 // expression. 2973 autoCreateBlock(); 2974 CFGBlock *ConfluenceBlock = VisitForTemporaryDtors(E->getCond()); 2975 if (badCFG) 2976 return NULL; 2977 if (BinaryConditionalOperator *BCO 2978 = dyn_cast<BinaryConditionalOperator>(E)) { 2979 ConfluenceBlock = VisitForTemporaryDtors(BCO->getCommon()); 2980 if (badCFG) 2981 return NULL; 2982 } 2983 2984 // Try to add block with destructors for LHS expression. 2985 CFGBlock *LHSBlock = NULL; 2986 Succ = ConfluenceBlock; 2987 Block = NULL; 2988 LHSBlock = VisitForTemporaryDtors(E->getTrueExpr(), BindToTemporary); 2989 if (badCFG) 2990 return NULL; 2991 2992 // Try to add block with destructors for RHS expression; 2993 Succ = ConfluenceBlock; 2994 Block = NULL; 2995 CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getFalseExpr(), 2996 BindToTemporary); 2997 if (badCFG) 2998 return NULL; 2999 3000 if (!RHSBlock && !LHSBlock) { 3001 // If neither LHS nor RHS expression had temporaries to destroy don't create 3002 // more blocks. 3003 Block = ConfluenceBlock; 3004 return Block; 3005 } 3006 3007 Block = createBlock(false); 3008 Block->setTerminator(CFGTerminator(E, true)); 3009 3010 // See if this is a known constant. 3011 const TryResult &KnownVal = tryEvaluateBool(E->getCond()); 3012 3013 if (LHSBlock) { 3014 addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock); 3015 } else if (KnownVal.isFalse()) { 3016 addSuccessor(Block, NULL); 3017 } else { 3018 addSuccessor(Block, ConfluenceBlock); 3019 std::reverse(ConfluenceBlock->pred_begin(), ConfluenceBlock->pred_end()); 3020 } 3021 3022 if (!RHSBlock) 3023 RHSBlock = ConfluenceBlock; 3024 addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock); 3025 3026 return Block; 3027} 3028 3029} // end anonymous namespace 3030 3031/// createBlock - Constructs and adds a new CFGBlock to the CFG. The block has 3032/// no successors or predecessors. If this is the first block created in the 3033/// CFG, it is automatically set to be the Entry and Exit of the CFG. 3034CFGBlock *CFG::createBlock() { 3035 bool first_block = begin() == end(); 3036 3037 // Create the block. 3038 CFGBlock *Mem = getAllocator().Allocate<CFGBlock>(); 3039 new (Mem) CFGBlock(NumBlockIDs++, BlkBVC, this); 3040 Blocks.push_back(Mem, BlkBVC); 3041 3042 // If this is the first block, set it as the Entry and Exit. 3043 if (first_block) 3044 Entry = Exit = &back(); 3045 3046 // Return the block. 3047 return &back(); 3048} 3049 3050/// buildCFG - Constructs a CFG from an AST. Ownership of the returned 3051/// CFG is returned to the caller. 3052CFG* CFG::buildCFG(const Decl *D, Stmt *Statement, ASTContext *C, 3053 const BuildOptions &BO) { 3054 CFGBuilder Builder(C, BO); 3055 return Builder.buildCFG(D, Statement); 3056} 3057 3058const CXXDestructorDecl * 3059CFGImplicitDtor::getDestructorDecl(ASTContext &astContext) const { 3060 switch (getKind()) { 3061 case CFGElement::Invalid: 3062 case CFGElement::Statement: 3063 case CFGElement::Initializer: 3064 llvm_unreachable("getDestructorDecl should only be used with " 3065 "ImplicitDtors"); 3066 case CFGElement::AutomaticObjectDtor: { 3067 const VarDecl *var = cast<CFGAutomaticObjDtor>(this)->getVarDecl(); 3068 QualType ty = var->getType(); 3069 ty = ty.getNonReferenceType(); 3070 if (const ArrayType *arrayType = astContext.getAsArrayType(ty)) { 3071 ty = arrayType->getElementType(); 3072 } 3073 const RecordType *recordType = ty->getAs<RecordType>(); 3074 const CXXRecordDecl *classDecl = 3075 cast<CXXRecordDecl>(recordType->getDecl()); 3076 return classDecl->getDestructor(); 3077 } 3078 case CFGElement::TemporaryDtor: { 3079 const CXXBindTemporaryExpr *bindExpr = 3080 cast<CFGTemporaryDtor>(this)->getBindTemporaryExpr(); 3081 const CXXTemporary *temp = bindExpr->getTemporary(); 3082 return temp->getDestructor(); 3083 } 3084 case CFGElement::BaseDtor: 3085 case CFGElement::MemberDtor: 3086 3087 // Not yet supported. 3088 return 0; 3089 } 3090 llvm_unreachable("getKind() returned bogus value"); 3091} 3092 3093bool CFGImplicitDtor::isNoReturn(ASTContext &astContext) const { 3094 if (const CXXDestructorDecl *cdecl = getDestructorDecl(astContext)) { 3095 QualType ty = cdecl->getType(); 3096 return cast<FunctionType>(ty)->getNoReturnAttr(); 3097 } 3098 return false; 3099} 3100 3101//===----------------------------------------------------------------------===// 3102// CFG: Queries for BlkExprs. 3103//===----------------------------------------------------------------------===// 3104 3105namespace { 3106 typedef llvm::DenseMap<const Stmt*,unsigned> BlkExprMapTy; 3107} 3108 3109static void FindSubExprAssignments(const Stmt *S, 3110 llvm::SmallPtrSet<const Expr*,50>& Set) { 3111 if (!S) 3112 return; 3113 3114 for (Stmt::const_child_range I = S->children(); I; ++I) { 3115 const Stmt *child = *I; 3116 if (!child) 3117 continue; 3118 3119 if (const BinaryOperator* B = dyn_cast<BinaryOperator>(child)) 3120 if (B->isAssignmentOp()) Set.insert(B); 3121 3122 FindSubExprAssignments(child, Set); 3123 } 3124} 3125 3126static BlkExprMapTy* PopulateBlkExprMap(CFG& cfg) { 3127 BlkExprMapTy* M = new BlkExprMapTy(); 3128 3129 // Look for assignments that are used as subexpressions. These are the only 3130 // assignments that we want to *possibly* register as a block-level 3131 // expression. Basically, if an assignment occurs both in a subexpression and 3132 // at the block-level, it is a block-level expression. 3133 llvm::SmallPtrSet<const Expr*,50> SubExprAssignments; 3134 3135 for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I) 3136 for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI) 3137 if (const CFGStmt *S = BI->getAs<CFGStmt>()) 3138 FindSubExprAssignments(S->getStmt(), SubExprAssignments); 3139 3140 for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I) { 3141 3142 // Iterate over the statements again on identify the Expr* and Stmt* at the 3143 // block-level that are block-level expressions. 3144 3145 for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI) { 3146 const CFGStmt *CS = BI->getAs<CFGStmt>(); 3147 if (!CS) 3148 continue; 3149 if (const Expr *Exp = dyn_cast<Expr>(CS->getStmt())) { 3150 assert((Exp->IgnoreParens() == Exp) && "No parens on block-level exps"); 3151 3152 if (const BinaryOperator* B = dyn_cast<BinaryOperator>(Exp)) { 3153 // Assignment expressions that are not nested within another 3154 // expression are really "statements" whose value is never used by 3155 // another expression. 3156 if (B->isAssignmentOp() && !SubExprAssignments.count(Exp)) 3157 continue; 3158 } else if (const StmtExpr *SE = dyn_cast<StmtExpr>(Exp)) { 3159 // Special handling for statement expressions. The last statement in 3160 // the statement expression is also a block-level expr. 3161 const CompoundStmt *C = SE->getSubStmt(); 3162 if (!C->body_empty()) { 3163 const Stmt *Last = C->body_back(); 3164 if (const Expr *LastEx = dyn_cast<Expr>(Last)) 3165 Last = LastEx->IgnoreParens(); 3166 unsigned x = M->size(); 3167 (*M)[Last] = x; 3168 } 3169 } 3170 3171 unsigned x = M->size(); 3172 (*M)[Exp] = x; 3173 } 3174 } 3175 3176 // Look at terminators. The condition is a block-level expression. 3177 3178 Stmt *S = (*I)->getTerminatorCondition(); 3179 3180 if (S && M->find(S) == M->end()) { 3181 unsigned x = M->size(); 3182 (*M)[S] = x; 3183 } 3184 } 3185 3186 return M; 3187} 3188 3189CFG::BlkExprNumTy CFG::getBlkExprNum(const Stmt *S) { 3190 assert(S != NULL); 3191 if (!BlkExprMap) { BlkExprMap = (void*) PopulateBlkExprMap(*this); } 3192 3193 BlkExprMapTy* M = reinterpret_cast<BlkExprMapTy*>(BlkExprMap); 3194 BlkExprMapTy::iterator I = M->find(S); 3195 return (I == M->end()) ? CFG::BlkExprNumTy() : CFG::BlkExprNumTy(I->second); 3196} 3197 3198unsigned CFG::getNumBlkExprs() { 3199 if (const BlkExprMapTy* M = reinterpret_cast<const BlkExprMapTy*>(BlkExprMap)) 3200 return M->size(); 3201 3202 // We assume callers interested in the number of BlkExprs will want 3203 // the map constructed if it doesn't already exist. 3204 BlkExprMap = (void*) PopulateBlkExprMap(*this); 3205 return reinterpret_cast<BlkExprMapTy*>(BlkExprMap)->size(); 3206} 3207 3208//===----------------------------------------------------------------------===// 3209// Filtered walking of the CFG. 3210//===----------------------------------------------------------------------===// 3211 3212bool CFGBlock::FilterEdge(const CFGBlock::FilterOptions &F, 3213 const CFGBlock *From, const CFGBlock *To) { 3214 3215 if (To && F.IgnoreDefaultsWithCoveredEnums) { 3216 // If the 'To' has no label or is labeled but the label isn't a 3217 // CaseStmt then filter this edge. 3218 if (const SwitchStmt *S = 3219 dyn_cast_or_null<SwitchStmt>(From->getTerminator().getStmt())) { 3220 if (S->isAllEnumCasesCovered()) { 3221 const Stmt *L = To->getLabel(); 3222 if (!L || !isa<CaseStmt>(L)) 3223 return true; 3224 } 3225 } 3226 } 3227 3228 return false; 3229} 3230 3231//===----------------------------------------------------------------------===// 3232// Cleanup: CFG dstor. 3233//===----------------------------------------------------------------------===// 3234 3235CFG::~CFG() { 3236 delete reinterpret_cast<const BlkExprMapTy*>(BlkExprMap); 3237} 3238 3239//===----------------------------------------------------------------------===// 3240// CFG pretty printing 3241//===----------------------------------------------------------------------===// 3242 3243namespace { 3244 3245class StmtPrinterHelper : public PrinterHelper { 3246 typedef llvm::DenseMap<const Stmt*,std::pair<unsigned,unsigned> > StmtMapTy; 3247 typedef llvm::DenseMap<const Decl*,std::pair<unsigned,unsigned> > DeclMapTy; 3248 StmtMapTy StmtMap; 3249 DeclMapTy DeclMap; 3250 signed currentBlock; 3251 unsigned currentStmt; 3252 const LangOptions &LangOpts; 3253public: 3254 3255 StmtPrinterHelper(const CFG* cfg, const LangOptions &LO) 3256 : currentBlock(0), currentStmt(0), LangOpts(LO) 3257 { 3258 for (CFG::const_iterator I = cfg->begin(), E = cfg->end(); I != E; ++I ) { 3259 unsigned j = 1; 3260 for (CFGBlock::const_iterator BI = (*I)->begin(), BEnd = (*I)->end() ; 3261 BI != BEnd; ++BI, ++j ) { 3262 if (const CFGStmt *SE = BI->getAs<CFGStmt>()) { 3263 const Stmt *stmt= SE->getStmt(); 3264 std::pair<unsigned, unsigned> P((*I)->getBlockID(), j); 3265 StmtMap[stmt] = P; 3266 3267 switch (stmt->getStmtClass()) { 3268 case Stmt::DeclStmtClass: 3269 DeclMap[cast<DeclStmt>(stmt)->getSingleDecl()] = P; 3270 break; 3271 case Stmt::IfStmtClass: { 3272 const VarDecl *var = cast<IfStmt>(stmt)->getConditionVariable(); 3273 if (var) 3274 DeclMap[var] = P; 3275 break; 3276 } 3277 case Stmt::ForStmtClass: { 3278 const VarDecl *var = cast<ForStmt>(stmt)->getConditionVariable(); 3279 if (var) 3280 DeclMap[var] = P; 3281 break; 3282 } 3283 case Stmt::WhileStmtClass: { 3284 const VarDecl *var = 3285 cast<WhileStmt>(stmt)->getConditionVariable(); 3286 if (var) 3287 DeclMap[var] = P; 3288 break; 3289 } 3290 case Stmt::SwitchStmtClass: { 3291 const VarDecl *var = 3292 cast<SwitchStmt>(stmt)->getConditionVariable(); 3293 if (var) 3294 DeclMap[var] = P; 3295 break; 3296 } 3297 case Stmt::CXXCatchStmtClass: { 3298 const VarDecl *var = 3299 cast<CXXCatchStmt>(stmt)->getExceptionDecl(); 3300 if (var) 3301 DeclMap[var] = P; 3302 break; 3303 } 3304 default: 3305 break; 3306 } 3307 } 3308 } 3309 } 3310 } 3311 3312 3313 virtual ~StmtPrinterHelper() {} 3314 3315 const LangOptions &getLangOpts() const { return LangOpts; } 3316 void setBlockID(signed i) { currentBlock = i; } 3317 void setStmtID(unsigned i) { currentStmt = i; } 3318 3319 virtual bool handledStmt(Stmt *S, raw_ostream &OS) { 3320 StmtMapTy::iterator I = StmtMap.find(S); 3321 3322 if (I == StmtMap.end()) 3323 return false; 3324 3325 if (currentBlock >= 0 && I->second.first == (unsigned) currentBlock 3326 && I->second.second == currentStmt) { 3327 return false; 3328 } 3329 3330 OS << "[B" << I->second.first << "." << I->second.second << "]"; 3331 return true; 3332 } 3333 3334 bool handleDecl(const Decl *D, raw_ostream &OS) { 3335 DeclMapTy::iterator I = DeclMap.find(D); 3336 3337 if (I == DeclMap.end()) 3338 return false; 3339 3340 if (currentBlock >= 0 && I->second.first == (unsigned) currentBlock 3341 && I->second.second == currentStmt) { 3342 return false; 3343 } 3344 3345 OS << "[B" << I->second.first << "." << I->second.second << "]"; 3346 return true; 3347 } 3348}; 3349} // end anonymous namespace 3350 3351 3352namespace { 3353class CFGBlockTerminatorPrint 3354 : public StmtVisitor<CFGBlockTerminatorPrint,void> { 3355 3356 raw_ostream &OS; 3357 StmtPrinterHelper* Helper; 3358 PrintingPolicy Policy; 3359public: 3360 CFGBlockTerminatorPrint(raw_ostream &os, StmtPrinterHelper* helper, 3361 const PrintingPolicy &Policy) 3362 : OS(os), Helper(helper), Policy(Policy) {} 3363 3364 void VisitIfStmt(IfStmt *I) { 3365 OS << "if "; 3366 I->getCond()->printPretty(OS,Helper,Policy); 3367 } 3368 3369 // Default case. 3370 void VisitStmt(Stmt *Terminator) { 3371 Terminator->printPretty(OS, Helper, Policy); 3372 } 3373 3374 void VisitForStmt(ForStmt *F) { 3375 OS << "for (" ; 3376 if (F->getInit()) 3377 OS << "..."; 3378 OS << "; "; 3379 if (Stmt *C = F->getCond()) 3380 C->printPretty(OS, Helper, Policy); 3381 OS << "; "; 3382 if (F->getInc()) 3383 OS << "..."; 3384 OS << ")"; 3385 } 3386 3387 void VisitWhileStmt(WhileStmt *W) { 3388 OS << "while " ; 3389 if (Stmt *C = W->getCond()) 3390 C->printPretty(OS, Helper, Policy); 3391 } 3392 3393 void VisitDoStmt(DoStmt *D) { 3394 OS << "do ... while "; 3395 if (Stmt *C = D->getCond()) 3396 C->printPretty(OS, Helper, Policy); 3397 } 3398 3399 void VisitSwitchStmt(SwitchStmt *Terminator) { 3400 OS << "switch "; 3401 Terminator->getCond()->printPretty(OS, Helper, Policy); 3402 } 3403 3404 void VisitCXXTryStmt(CXXTryStmt *CS) { 3405 OS << "try ..."; 3406 } 3407 3408 void VisitAbstractConditionalOperator(AbstractConditionalOperator* C) { 3409 C->getCond()->printPretty(OS, Helper, Policy); 3410 OS << " ? ... : ..."; 3411 } 3412 3413 void VisitChooseExpr(ChooseExpr *C) { 3414 OS << "__builtin_choose_expr( "; 3415 C->getCond()->printPretty(OS, Helper, Policy); 3416 OS << " )"; 3417 } 3418 3419 void VisitIndirectGotoStmt(IndirectGotoStmt *I) { 3420 OS << "goto *"; 3421 I->getTarget()->printPretty(OS, Helper, Policy); 3422 } 3423 3424 void VisitBinaryOperator(BinaryOperator* B) { 3425 if (!B->isLogicalOp()) { 3426 VisitExpr(B); 3427 return; 3428 } 3429 3430 B->getLHS()->printPretty(OS, Helper, Policy); 3431 3432 switch (B->getOpcode()) { 3433 case BO_LOr: 3434 OS << " || ..."; 3435 return; 3436 case BO_LAnd: 3437 OS << " && ..."; 3438 return; 3439 default: 3440 llvm_unreachable("Invalid logical operator."); 3441 } 3442 } 3443 3444 void VisitExpr(Expr *E) { 3445 E->printPretty(OS, Helper, Policy); 3446 } 3447}; 3448} // end anonymous namespace 3449 3450static void print_elem(raw_ostream &OS, StmtPrinterHelper* Helper, 3451 const CFGElement &E) { 3452 if (const CFGStmt *CS = E.getAs<CFGStmt>()) { 3453 const Stmt *S = CS->getStmt(); 3454 3455 if (Helper) { 3456 3457 // special printing for statement-expressions. 3458 if (const StmtExpr *SE = dyn_cast<StmtExpr>(S)) { 3459 const CompoundStmt *Sub = SE->getSubStmt(); 3460 3461 if (Sub->children()) { 3462 OS << "({ ... ; "; 3463 Helper->handledStmt(*SE->getSubStmt()->body_rbegin(),OS); 3464 OS << " })\n"; 3465 return; 3466 } 3467 } 3468 // special printing for comma expressions. 3469 if (const BinaryOperator* B = dyn_cast<BinaryOperator>(S)) { 3470 if (B->getOpcode() == BO_Comma) { 3471 OS << "... , "; 3472 Helper->handledStmt(B->getRHS(),OS); 3473 OS << '\n'; 3474 return; 3475 } 3476 } 3477 } 3478 S->printPretty(OS, Helper, PrintingPolicy(Helper->getLangOpts())); 3479 3480 if (isa<CXXOperatorCallExpr>(S)) { 3481 OS << " (OperatorCall)"; 3482 } 3483 else if (isa<CXXBindTemporaryExpr>(S)) { 3484 OS << " (BindTemporary)"; 3485 } 3486 else if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(S)) { 3487 OS << " (CXXConstructExpr, " << CCE->getType().getAsString() << ")"; 3488 } 3489 else if (const CastExpr *CE = dyn_cast<CastExpr>(S)) { 3490 OS << " (" << CE->getStmtClassName() << ", " 3491 << CE->getCastKindName() 3492 << ", " << CE->getType().getAsString() 3493 << ")"; 3494 } 3495 3496 // Expressions need a newline. 3497 if (isa<Expr>(S)) 3498 OS << '\n'; 3499 3500 } else if (const CFGInitializer *IE = E.getAs<CFGInitializer>()) { 3501 const CXXCtorInitializer *I = IE->getInitializer(); 3502 if (I->isBaseInitializer()) 3503 OS << I->getBaseClass()->getAsCXXRecordDecl()->getName(); 3504 else OS << I->getAnyMember()->getName(); 3505 3506 OS << "("; 3507 if (Expr *IE = I->getInit()) 3508 IE->printPretty(OS, Helper, PrintingPolicy(Helper->getLangOpts())); 3509 OS << ")"; 3510 3511 if (I->isBaseInitializer()) 3512 OS << " (Base initializer)\n"; 3513 else OS << " (Member initializer)\n"; 3514 3515 } else if (const CFGAutomaticObjDtor *DE = E.getAs<CFGAutomaticObjDtor>()){ 3516 const VarDecl *VD = DE->getVarDecl(); 3517 Helper->handleDecl(VD, OS); 3518 3519 const Type* T = VD->getType().getTypePtr(); 3520 if (const ReferenceType* RT = T->getAs<ReferenceType>()) 3521 T = RT->getPointeeType().getTypePtr(); 3522 else if (const Type *ET = T->getArrayElementTypeNoTypeQual()) 3523 T = ET; 3524 3525 OS << ".~" << T->getAsCXXRecordDecl()->getName().str() << "()"; 3526 OS << " (Implicit destructor)\n"; 3527 3528 } else if (const CFGBaseDtor *BE = E.getAs<CFGBaseDtor>()) { 3529 const CXXBaseSpecifier *BS = BE->getBaseSpecifier(); 3530 OS << "~" << BS->getType()->getAsCXXRecordDecl()->getName() << "()"; 3531 OS << " (Base object destructor)\n"; 3532 3533 } else if (const CFGMemberDtor *ME = E.getAs<CFGMemberDtor>()) { 3534 const FieldDecl *FD = ME->getFieldDecl(); 3535 3536 const Type *T = FD->getType().getTypePtr(); 3537 if (const Type *ET = T->getArrayElementTypeNoTypeQual()) 3538 T = ET; 3539 3540 OS << "this->" << FD->getName(); 3541 OS << ".~" << T->getAsCXXRecordDecl()->getName() << "()"; 3542 OS << " (Member object destructor)\n"; 3543 3544 } else if (const CFGTemporaryDtor *TE = E.getAs<CFGTemporaryDtor>()) { 3545 const CXXBindTemporaryExpr *BT = TE->getBindTemporaryExpr(); 3546 OS << "~" << BT->getType()->getAsCXXRecordDecl()->getName() << "()"; 3547 OS << " (Temporary object destructor)\n"; 3548 } 3549} 3550 3551static void print_block(raw_ostream &OS, const CFG* cfg, 3552 const CFGBlock &B, 3553 StmtPrinterHelper* Helper, bool print_edges, 3554 bool ShowColors) { 3555 3556 if (Helper) 3557 Helper->setBlockID(B.getBlockID()); 3558 3559 // Print the header. 3560 if (ShowColors) 3561 OS.changeColor(raw_ostream::YELLOW, true); 3562 3563 OS << "\n [B" << B.getBlockID(); 3564 3565 if (&B == &cfg->getEntry()) 3566 OS << " (ENTRY)]\n"; 3567 else if (&B == &cfg->getExit()) 3568 OS << " (EXIT)]\n"; 3569 else if (&B == cfg->getIndirectGotoBlock()) 3570 OS << " (INDIRECT GOTO DISPATCH)]\n"; 3571 else 3572 OS << "]\n"; 3573 3574 if (ShowColors) 3575 OS.resetColor(); 3576 3577 // Print the label of this block. 3578 if (Stmt *Label = const_cast<Stmt*>(B.getLabel())) { 3579 3580 if (print_edges) 3581 OS << " "; 3582 3583 if (LabelStmt *L = dyn_cast<LabelStmt>(Label)) 3584 OS << L->getName(); 3585 else if (CaseStmt *C = dyn_cast<CaseStmt>(Label)) { 3586 OS << "case "; 3587 C->getLHS()->printPretty(OS, Helper, 3588 PrintingPolicy(Helper->getLangOpts())); 3589 if (C->getRHS()) { 3590 OS << " ... "; 3591 C->getRHS()->printPretty(OS, Helper, 3592 PrintingPolicy(Helper->getLangOpts())); 3593 } 3594 } else if (isa<DefaultStmt>(Label)) 3595 OS << "default"; 3596 else if (CXXCatchStmt *CS = dyn_cast<CXXCatchStmt>(Label)) { 3597 OS << "catch ("; 3598 if (CS->getExceptionDecl()) 3599 CS->getExceptionDecl()->print(OS, PrintingPolicy(Helper->getLangOpts()), 3600 0); 3601 else 3602 OS << "..."; 3603 OS << ")"; 3604 3605 } else 3606 llvm_unreachable("Invalid label statement in CFGBlock."); 3607 3608 OS << ":\n"; 3609 } 3610 3611 // Iterate through the statements in the block and print them. 3612 unsigned j = 1; 3613 3614 for (CFGBlock::const_iterator I = B.begin(), E = B.end() ; 3615 I != E ; ++I, ++j ) { 3616 3617 // Print the statement # in the basic block and the statement itself. 3618 if (print_edges) 3619 OS << " "; 3620 3621 OS << llvm::format("%3d", j) << ": "; 3622 3623 if (Helper) 3624 Helper->setStmtID(j); 3625 3626 print_elem(OS, Helper, *I); 3627 } 3628 3629 // Print the terminator of this block. 3630 if (B.getTerminator()) { 3631 if (ShowColors) 3632 OS.changeColor(raw_ostream::GREEN); 3633 3634 OS << " T: "; 3635 3636 if (Helper) Helper->setBlockID(-1); 3637 3638 CFGBlockTerminatorPrint TPrinter(OS, Helper, 3639 PrintingPolicy(Helper->getLangOpts())); 3640 TPrinter.Visit(const_cast<Stmt*>(B.getTerminator().getStmt())); 3641 OS << '\n'; 3642 3643 if (ShowColors) 3644 OS.resetColor(); 3645 } 3646 3647 if (print_edges) { 3648 // Print the predecessors of this block. 3649 if (!B.pred_empty()) { 3650 const raw_ostream::Colors Color = raw_ostream::BLUE; 3651 if (ShowColors) 3652 OS.changeColor(Color); 3653 OS << " Preds " ; 3654 if (ShowColors) 3655 OS.resetColor(); 3656 OS << '(' << B.pred_size() << "):"; 3657 unsigned i = 0; 3658 3659 if (ShowColors) 3660 OS.changeColor(Color); 3661 3662 for (CFGBlock::const_pred_iterator I = B.pred_begin(), E = B.pred_end(); 3663 I != E; ++I, ++i) { 3664 3665 if (i == 8 || (i-8) == 0) 3666 OS << "\n "; 3667 3668 OS << " B" << (*I)->getBlockID(); 3669 } 3670 3671 if (ShowColors) 3672 OS.resetColor(); 3673 3674 OS << '\n'; 3675 } 3676 3677 // Print the successors of this block. 3678 if (!B.succ_empty()) { 3679 const raw_ostream::Colors Color = raw_ostream::MAGENTA; 3680 if (ShowColors) 3681 OS.changeColor(Color); 3682 OS << " Succs "; 3683 if (ShowColors) 3684 OS.resetColor(); 3685 OS << '(' << B.succ_size() << "):"; 3686 unsigned i = 0; 3687 3688 if (ShowColors) 3689 OS.changeColor(Color); 3690 3691 for (CFGBlock::const_succ_iterator I = B.succ_begin(), E = B.succ_end(); 3692 I != E; ++I, ++i) { 3693 3694 if (i == 8 || (i-8) % 10 == 0) 3695 OS << "\n "; 3696 3697 if (*I) 3698 OS << " B" << (*I)->getBlockID(); 3699 else 3700 OS << " NULL"; 3701 } 3702 3703 if (ShowColors) 3704 OS.resetColor(); 3705 OS << '\n'; 3706 } 3707 } 3708} 3709 3710 3711/// dump - A simple pretty printer of a CFG that outputs to stderr. 3712void CFG::dump(const LangOptions &LO, bool ShowColors) const { 3713 print(llvm::errs(), LO, ShowColors); 3714} 3715 3716/// print - A simple pretty printer of a CFG that outputs to an ostream. 3717void CFG::print(raw_ostream &OS, const LangOptions &LO, bool ShowColors) const { 3718 StmtPrinterHelper Helper(this, LO); 3719 3720 // Print the entry block. 3721 print_block(OS, this, getEntry(), &Helper, true, ShowColors); 3722 3723 // Iterate through the CFGBlocks and print them one by one. 3724 for (const_iterator I = Blocks.begin(), E = Blocks.end() ; I != E ; ++I) { 3725 // Skip the entry block, because we already printed it. 3726 if (&(**I) == &getEntry() || &(**I) == &getExit()) 3727 continue; 3728 3729 print_block(OS, this, **I, &Helper, true, ShowColors); 3730 } 3731 3732 // Print the exit block. 3733 print_block(OS, this, getExit(), &Helper, true, ShowColors); 3734 OS << '\n'; 3735 OS.flush(); 3736} 3737 3738/// dump - A simply pretty printer of a CFGBlock that outputs to stderr. 3739void CFGBlock::dump(const CFG* cfg, const LangOptions &LO, 3740 bool ShowColors) const { 3741 print(llvm::errs(), cfg, LO, ShowColors); 3742} 3743 3744/// print - A simple pretty printer of a CFGBlock that outputs to an ostream. 3745/// Generally this will only be called from CFG::print. 3746void CFGBlock::print(raw_ostream &OS, const CFG* cfg, 3747 const LangOptions &LO, bool ShowColors) const { 3748 StmtPrinterHelper Helper(cfg, LO); 3749 print_block(OS, cfg, *this, &Helper, true, ShowColors); 3750 OS << '\n'; 3751} 3752 3753/// printTerminator - A simple pretty printer of the terminator of a CFGBlock. 3754void CFGBlock::printTerminator(raw_ostream &OS, 3755 const LangOptions &LO) const { 3756 CFGBlockTerminatorPrint TPrinter(OS, NULL, PrintingPolicy(LO)); 3757 TPrinter.Visit(const_cast<Stmt*>(getTerminator().getStmt())); 3758} 3759 3760Stmt *CFGBlock::getTerminatorCondition() { 3761 Stmt *Terminator = this->Terminator; 3762 if (!Terminator) 3763 return NULL; 3764 3765 Expr *E = NULL; 3766 3767 switch (Terminator->getStmtClass()) { 3768 default: 3769 break; 3770 3771 case Stmt::ForStmtClass: 3772 E = cast<ForStmt>(Terminator)->getCond(); 3773 break; 3774 3775 case Stmt::WhileStmtClass: 3776 E = cast<WhileStmt>(Terminator)->getCond(); 3777 break; 3778 3779 case Stmt::DoStmtClass: 3780 E = cast<DoStmt>(Terminator)->getCond(); 3781 break; 3782 3783 case Stmt::IfStmtClass: 3784 E = cast<IfStmt>(Terminator)->getCond(); 3785 break; 3786 3787 case Stmt::ChooseExprClass: 3788 E = cast<ChooseExpr>(Terminator)->getCond(); 3789 break; 3790 3791 case Stmt::IndirectGotoStmtClass: 3792 E = cast<IndirectGotoStmt>(Terminator)->getTarget(); 3793 break; 3794 3795 case Stmt::SwitchStmtClass: 3796 E = cast<SwitchStmt>(Terminator)->getCond(); 3797 break; 3798 3799 case Stmt::BinaryConditionalOperatorClass: 3800 E = cast<BinaryConditionalOperator>(Terminator)->getCond(); 3801 break; 3802 3803 case Stmt::ConditionalOperatorClass: 3804 E = cast<ConditionalOperator>(Terminator)->getCond(); 3805 break; 3806 3807 case Stmt::BinaryOperatorClass: // '&&' and '||' 3808 E = cast<BinaryOperator>(Terminator)->getLHS(); 3809 break; 3810 3811 case Stmt::ObjCForCollectionStmtClass: 3812 return Terminator; 3813 } 3814 3815 return E ? E->IgnoreParens() : NULL; 3816} 3817 3818//===----------------------------------------------------------------------===// 3819// CFG Graphviz Visualization 3820//===----------------------------------------------------------------------===// 3821 3822 3823#ifndef NDEBUG 3824static StmtPrinterHelper* GraphHelper; 3825#endif 3826 3827void CFG::viewCFG(const LangOptions &LO) const { 3828#ifndef NDEBUG 3829 StmtPrinterHelper H(this, LO); 3830 GraphHelper = &H; 3831 llvm::ViewGraph(this,"CFG"); 3832 GraphHelper = NULL; 3833#endif 3834} 3835 3836namespace llvm { 3837template<> 3838struct DOTGraphTraits<const CFG*> : public DefaultDOTGraphTraits { 3839 3840 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {} 3841 3842 static std::string getNodeLabel(const CFGBlock *Node, const CFG* Graph) { 3843 3844#ifndef NDEBUG 3845 std::string OutSStr; 3846 llvm::raw_string_ostream Out(OutSStr); 3847 print_block(Out,Graph, *Node, GraphHelper, false, false); 3848 std::string& OutStr = Out.str(); 3849 3850 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); 3851 3852 // Process string output to make it nicer... 3853 for (unsigned i = 0; i != OutStr.length(); ++i) 3854 if (OutStr[i] == '\n') { // Left justify 3855 OutStr[i] = '\\'; 3856 OutStr.insert(OutStr.begin()+i+1, 'l'); 3857 } 3858 3859 return OutStr; 3860#else 3861 return ""; 3862#endif 3863 } 3864}; 3865} // end namespace llvm 3866