ExprEngineCallAndReturn.cpp revision 6fe4dfbc9e5a7018763b1d898876d9b2b8ec3425
1//=-- ExprEngineCallAndReturn.cpp - Support for call/return -----*- 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 ExprEngine's support for calls and returns. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "ExprEngine" 15 16#include "clang/Analysis/Analyses/LiveVariables.h" 17#include "clang/StaticAnalyzer/Core/CheckerManager.h" 18#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 19#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 20#include "clang/AST/DeclCXX.h" 21#include "clang/AST/ParentMap.h" 22#include "llvm/ADT/SmallSet.h" 23#include "llvm/ADT/Statistic.h" 24#include "llvm/Support/SaveAndRestore.h" 25 26using namespace clang; 27using namespace ento; 28 29STATISTIC(NumOfDynamicDispatchPathSplits, 30 "The # of times we split the path due to imprecise dynamic dispatch info"); 31 32STATISTIC(NumInlinedCalls, 33 "The # of times we inlined a call"); 34 35void ExprEngine::processCallEnter(CallEnter CE, ExplodedNode *Pred) { 36 // Get the entry block in the CFG of the callee. 37 const StackFrameContext *calleeCtx = CE.getCalleeContext(); 38 const CFG *CalleeCFG = calleeCtx->getCFG(); 39 const CFGBlock *Entry = &(CalleeCFG->getEntry()); 40 41 // Validate the CFG. 42 assert(Entry->empty()); 43 assert(Entry->succ_size() == 1); 44 45 // Get the solitary sucessor. 46 const CFGBlock *Succ = *(Entry->succ_begin()); 47 48 // Construct an edge representing the starting location in the callee. 49 BlockEdge Loc(Entry, Succ, calleeCtx); 50 51 ProgramStateRef state = Pred->getState(); 52 53 // Construct a new node and add it to the worklist. 54 bool isNew; 55 ExplodedNode *Node = G.getNode(Loc, state, false, &isNew); 56 Node->addPredecessor(Pred, G); 57 if (isNew) 58 Engine.getWorkList()->enqueue(Node); 59} 60 61// Find the last statement on the path to the exploded node and the 62// corresponding Block. 63static std::pair<const Stmt*, 64 const CFGBlock*> getLastStmt(const ExplodedNode *Node) { 65 const Stmt *S = 0; 66 const StackFrameContext *SF = 67 Node->getLocation().getLocationContext()->getCurrentStackFrame(); 68 69 // Back up through the ExplodedGraph until we reach a statement node. 70 while (Node) { 71 const ProgramPoint &PP = Node->getLocation(); 72 73 if (const StmtPoint *SP = dyn_cast<StmtPoint>(&PP)) { 74 S = SP->getStmt(); 75 break; 76 } else if (const CallExitEnd *CEE = dyn_cast<CallExitEnd>(&PP)) { 77 S = CEE->getCalleeContext()->getCallSite(); 78 if (S) 79 break; 80 // If we have an implicit call, we'll probably end up with a 81 // StmtPoint inside the callee, which is acceptable. 82 // (It's possible a function ONLY contains implicit calls -- such as an 83 // implicitly-generated destructor -- so we shouldn't just skip back to 84 // the CallEnter node and keep going.) 85 } else if (const CallEnter *CE = dyn_cast<CallEnter>(&PP)) { 86 // If we reached the CallEnter for this function, it has no statements. 87 if (CE->getCalleeContext() == SF) 88 break; 89 } 90 91 Node = *Node->pred_begin(); 92 } 93 94 const CFGBlock *Blk = 0; 95 if (S) { 96 // Now, get the enclosing basic block. 97 while (Node && Node->pred_size() >=1 ) { 98 const ProgramPoint &PP = Node->getLocation(); 99 if (isa<BlockEdge>(PP) && 100 (PP.getLocationContext()->getCurrentStackFrame() == SF)) { 101 BlockEdge &EPP = cast<BlockEdge>(PP); 102 Blk = EPP.getDst(); 103 break; 104 } 105 Node = *Node->pred_begin(); 106 } 107 } 108 109 return std::pair<const Stmt*, const CFGBlock*>(S, Blk); 110} 111 112/// The call exit is simulated with a sequence of nodes, which occur between 113/// CallExitBegin and CallExitEnd. The following operations occur between the 114/// two program points: 115/// 1. CallExitBegin (triggers the start of call exit sequence) 116/// 2. Bind the return value 117/// 3. Run Remove dead bindings to clean up the dead symbols from the callee. 118/// 4. CallExitEnd (switch to the caller context) 119/// 5. PostStmt<CallExpr> 120void ExprEngine::processCallExit(ExplodedNode *CEBNode) { 121 // Step 1 CEBNode was generated before the call. 122 123 const StackFrameContext *calleeCtx = 124 CEBNode->getLocationContext()->getCurrentStackFrame(); 125 126 // The parent context might not be a stack frame, so make sure we 127 // look up the first enclosing stack frame. 128 const StackFrameContext *callerCtx = 129 calleeCtx->getParent()->getCurrentStackFrame(); 130 131 const Stmt *CE = calleeCtx->getCallSite(); 132 ProgramStateRef state = CEBNode->getState(); 133 // Find the last statement in the function and the corresponding basic block. 134 const Stmt *LastSt = 0; 135 const CFGBlock *Blk = 0; 136 llvm::tie(LastSt, Blk) = getLastStmt(CEBNode); 137 138 // Step 2: generate node with bound return value: CEBNode -> BindedRetNode. 139 140 // If the callee returns an expression, bind its value to CallExpr. 141 if (CE) { 142 if (const ReturnStmt *RS = dyn_cast_or_null<ReturnStmt>(LastSt)) { 143 const LocationContext *LCtx = CEBNode->getLocationContext(); 144 SVal V = state->getSVal(RS, LCtx); 145 state = state->BindExpr(CE, callerCtx, V); 146 } 147 148 // Bind the constructed object value to CXXConstructExpr. 149 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(CE)) { 150 loc::MemRegionVal This = 151 svalBuilder.getCXXThis(CCE->getConstructor()->getParent(), calleeCtx); 152 SVal ThisV = state->getSVal(This); 153 154 // Always bind the region to the CXXConstructExpr. 155 state = state->BindExpr(CCE, callerCtx, ThisV); 156 } 157 } 158 159 // Generate a CallEvent /before/ cleaning the state, so that we can get the 160 // correct value for 'this' (if necessary). 161 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 162 CallEventRef<> Call = CEMgr.getCaller(calleeCtx, state); 163 164 // Step 3: BindedRetNode -> CleanedNodes 165 // If we can find a statement and a block in the inlined function, run remove 166 // dead bindings before returning from the call. This is important to ensure 167 // that we report the issues such as leaks in the stack contexts in which 168 // they occurred. 169 ExplodedNodeSet CleanedNodes; 170 if (LastSt && Blk) { 171 static SimpleProgramPointTag retValBind("ExprEngine : Bind Return Value"); 172 PostStmt Loc(LastSt, calleeCtx, &retValBind); 173 bool isNew; 174 ExplodedNode *BindedRetNode = G.getNode(Loc, state, false, &isNew); 175 BindedRetNode->addPredecessor(CEBNode, G); 176 if (!isNew) 177 return; 178 179 NodeBuilderContext Ctx(getCoreEngine(), Blk, BindedRetNode); 180 currBldrCtx = &Ctx; 181 // Here, we call the Symbol Reaper with 0 statement and caller location 182 // context, telling it to clean up everything in the callee's context 183 // (and it's children). We use LastStmt as a diagnostic statement, which 184 // which the PreStmtPurge Dead point will be associated. 185 removeDead(BindedRetNode, CleanedNodes, 0, callerCtx, LastSt, 186 ProgramPoint::PostStmtPurgeDeadSymbolsKind); 187 currBldrCtx = 0; 188 } else { 189 CleanedNodes.Add(CEBNode); 190 } 191 192 for (ExplodedNodeSet::iterator I = CleanedNodes.begin(), 193 E = CleanedNodes.end(); I != E; ++I) { 194 195 // Step 4: Generate the CallExit and leave the callee's context. 196 // CleanedNodes -> CEENode 197 CallExitEnd Loc(calleeCtx, callerCtx); 198 bool isNew; 199 ProgramStateRef CEEState = (*I == CEBNode) ? state : (*I)->getState(); 200 ExplodedNode *CEENode = G.getNode(Loc, CEEState, false, &isNew); 201 CEENode->addPredecessor(*I, G); 202 if (!isNew) 203 return; 204 205 // Step 5: Perform the post-condition check of the CallExpr and enqueue the 206 // result onto the work list. 207 // CEENode -> Dst -> WorkList 208 NodeBuilderContext Ctx(Engine, calleeCtx->getCallSiteBlock(), CEENode); 209 SaveAndRestore<const NodeBuilderContext*> NBCSave(currBldrCtx, 210 &Ctx); 211 SaveAndRestore<unsigned> CBISave(currStmtIdx, calleeCtx->getIndex()); 212 213 CallEventRef<> UpdatedCall = Call.cloneWithState(CEEState); 214 215 ExplodedNodeSet DstPostCall; 216 getCheckerManager().runCheckersForPostCall(DstPostCall, CEENode, 217 *UpdatedCall, *this, 218 /*WasInlined=*/true); 219 220 ExplodedNodeSet Dst; 221 if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(Call)) { 222 getCheckerManager().runCheckersForPostObjCMessage(Dst, DstPostCall, *Msg, 223 *this, 224 /*WasInlined=*/true); 225 } else if (CE) { 226 getCheckerManager().runCheckersForPostStmt(Dst, DstPostCall, CE, 227 *this, /*WasInlined=*/true); 228 } else { 229 Dst.insert(DstPostCall); 230 } 231 232 // Enqueue the next element in the block. 233 for (ExplodedNodeSet::iterator PSI = Dst.begin(), PSE = Dst.end(); 234 PSI != PSE; ++PSI) { 235 Engine.getWorkList()->enqueue(*PSI, calleeCtx->getCallSiteBlock(), 236 calleeCtx->getIndex()+1); 237 } 238 } 239} 240 241static unsigned getNumberStackFrames(const LocationContext *LCtx) { 242 unsigned count = 0; 243 while (LCtx) { 244 if (isa<StackFrameContext>(LCtx)) 245 ++count; 246 LCtx = LCtx->getParent(); 247 } 248 return count; 249} 250 251// Determine if we should inline the call. 252bool ExprEngine::shouldInlineDecl(const Decl *D, ExplodedNode *Pred) { 253 AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(D); 254 const CFG *CalleeCFG = CalleeADC->getCFG(); 255 256 // It is possible that the CFG cannot be constructed. 257 // Be safe, and check if the CalleeCFG is valid. 258 if (!CalleeCFG) 259 return false; 260 261 if (getNumberStackFrames(Pred->getLocationContext()) 262 == AMgr.InlineMaxStackDepth) 263 return false; 264 265 if (Engine.FunctionSummaries->hasReachedMaxBlockCount(D)) 266 return false; 267 268 if (CalleeCFG->getNumBlockIDs() > AMgr.InlineMaxFunctionSize) 269 return false; 270 271 // Do not inline variadic calls (for now). 272 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) { 273 if (BD->isVariadic()) 274 return false; 275 } 276 else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 277 if (FD->isVariadic()) 278 return false; 279 } 280 281 // It is possible that the live variables analysis cannot be 282 // run. If so, bail out. 283 if (!CalleeADC->getAnalysis<RelaxedLiveVariables>()) 284 return false; 285 286 return true; 287} 288 289/// The GDM component containing the dynamic dispatch bifurcation info. When 290/// the exact type of the receiver is not known, we want to explore both paths - 291/// one on which we do inline it and the other one on which we don't. This is 292/// done to ensure we do not drop coverage. 293/// This is the map from the receiver region to a bool, specifying either we 294/// consider this region's information precise or not along the given path. 295namespace clang { 296namespace ento { 297enum DynamicDispatchMode { DynamicDispatchModeInlined = 1, 298 DynamicDispatchModeConservative }; 299 300struct DynamicDispatchBifurcationMap {}; 301typedef llvm::ImmutableMap<const MemRegion*, 302 unsigned int> DynamicDispatchBifur; 303template<> struct ProgramStateTrait<DynamicDispatchBifurcationMap> 304 : public ProgramStatePartialTrait<DynamicDispatchBifur> { 305 static void *GDMIndex() { static int index; return &index; } 306}; 307 308}} 309 310static bool shouldInlineCXX(AnalysisManager &AMgr) { 311 switch (AMgr.IPAMode) { 312 case None: 313 case BasicInlining: 314 return false; 315 case Inlining: 316 case DynamicDispatch: 317 case DynamicDispatchBifurcate: 318 return true; 319 case NumIPAModes: 320 llvm_unreachable("not actually a valid option"); 321 } 322 llvm_unreachable("bogus IPAMode"); 323} 324 325bool ExprEngine::inlineCall(const CallEvent &Call, const Decl *D, 326 NodeBuilder &Bldr, ExplodedNode *Pred, 327 ProgramStateRef State) { 328 assert(D); 329 330 const LocationContext *CurLC = Pred->getLocationContext(); 331 const StackFrameContext *CallerSFC = CurLC->getCurrentStackFrame(); 332 const LocationContext *ParentOfCallee = 0; 333 334 // FIXME: Refactor this check into a hypothetical CallEvent::canInline. 335 switch (Call.getKind()) { 336 case CE_Function: 337 break; 338 case CE_CXXMember: 339 case CE_CXXMemberOperator: 340 if (!shouldInlineCXX(getAnalysisManager())) 341 return false; 342 break; 343 case CE_CXXConstructor: { 344 if (!shouldInlineCXX(getAnalysisManager())) 345 return false; 346 347 const CXXConstructorCall &Ctor = cast<CXXConstructorCall>(Call); 348 349 // FIXME: We don't handle constructors or destructors for arrays properly. 350 const MemRegion *Target = Ctor.getCXXThisVal().getAsRegion(); 351 if (Target && isa<ElementRegion>(Target)) 352 return false; 353 354 // FIXME: This is a hack. We don't use the correct region for a new 355 // expression, so if we inline the constructor its result will just be 356 // thrown away. This short-term hack is tracked in <rdar://problem/12180598> 357 // and the longer-term possible fix is discussed in PR12014. 358 const CXXConstructExpr *CtorExpr = Ctor.getOriginExpr(); 359 if (const Stmt *Parent = CurLC->getParentMap().getParent(CtorExpr)) 360 if (isa<CXXNewExpr>(Parent)) 361 return false; 362 363 // If the destructor is trivial, it's always safe to inline the constructor. 364 if (Ctor.getDecl()->getParent()->hasTrivialDestructor()) 365 break; 366 367 // For other types, only inline constructors if we built the CFGs for the 368 // destructor properly. 369 const AnalysisDeclContext *ADC = CallerSFC->getAnalysisDeclContext(); 370 assert(ADC->getCFGBuildOptions().AddInitializers && "No CFG initializers"); 371 if (!ADC->getCFGBuildOptions().AddImplicitDtors) 372 return false; 373 374 // FIXME: This is a hack. We don't handle temporary destructors 375 // right now, so we shouldn't inline their constructors. 376 if (CtorExpr->getConstructionKind() == CXXConstructExpr::CK_Complete) 377 if (!Target || !isa<DeclRegion>(Target)) 378 return false; 379 380 break; 381 } 382 case CE_CXXDestructor: { 383 if (!shouldInlineCXX(getAnalysisManager())) 384 return false; 385 386 // Only inline constructors and destructors if we built the CFGs for them 387 // properly. 388 const AnalysisDeclContext *ADC = CallerSFC->getAnalysisDeclContext(); 389 if (!ADC->getCFGBuildOptions().AddImplicitDtors) 390 return false; 391 392 const CXXDestructorCall &Dtor = cast<CXXDestructorCall>(Call); 393 394 // FIXME: We don't handle constructors or destructors for arrays properly. 395 const MemRegion *Target = Dtor.getCXXThisVal().getAsRegion(); 396 if (Target && isa<ElementRegion>(Target)) 397 return false; 398 399 break; 400 } 401 case CE_CXXAllocator: 402 if (!shouldInlineCXX(getAnalysisManager())) 403 return false; 404 405 // Do not inline allocators until we model deallocators. 406 // This is unfortunate, but basically necessary for smart pointers and such. 407 return false; 408 case CE_Block: { 409 const BlockDataRegion *BR = cast<BlockCall>(Call).getBlockRegion(); 410 assert(BR && "If we have the block definition we should have its region"); 411 AnalysisDeclContext *BlockCtx = AMgr.getAnalysisDeclContext(D); 412 ParentOfCallee = BlockCtx->getBlockInvocationContext(CallerSFC, 413 cast<BlockDecl>(D), 414 BR); 415 break; 416 } 417 case CE_ObjCMessage: 418 if (!(getAnalysisManager().IPAMode == DynamicDispatch || 419 getAnalysisManager().IPAMode == DynamicDispatchBifurcate)) 420 return false; 421 break; 422 } 423 424 if (!shouldInlineDecl(D, Pred)) 425 return false; 426 427 if (!ParentOfCallee) 428 ParentOfCallee = CallerSFC; 429 430 // This may be NULL, but that's fine. 431 const Expr *CallE = Call.getOriginExpr(); 432 433 // Construct a new stack frame for the callee. 434 AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(D); 435 const StackFrameContext *CalleeSFC = 436 CalleeADC->getStackFrame(ParentOfCallee, CallE, 437 currBldrCtx->getBlock(), 438 currStmtIdx); 439 440 CallEnter Loc(CallE, CalleeSFC, CurLC); 441 442 // Construct a new state which contains the mapping from actual to 443 // formal arguments. 444 State = State->enterStackFrame(Call, CalleeSFC); 445 446 bool isNew; 447 if (ExplodedNode *N = G.getNode(Loc, State, false, &isNew)) { 448 N->addPredecessor(Pred, G); 449 if (isNew) 450 Engine.getWorkList()->enqueue(N); 451 } 452 453 // If we decided to inline the call, the successor has been manually 454 // added onto the work list so remove it from the node builder. 455 Bldr.takeNodes(Pred); 456 457 NumInlinedCalls++; 458 459 return true; 460} 461 462static ProgramStateRef getInlineFailedState(ProgramStateRef State, 463 const Stmt *CallE) { 464 void *ReplayState = State->get<ReplayWithoutInlining>(); 465 if (!ReplayState) 466 return 0; 467 468 assert(ReplayState == (const void*)CallE && "Backtracked to the wrong call."); 469 (void)CallE; 470 471 return State->remove<ReplayWithoutInlining>(); 472} 473 474void ExprEngine::VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 475 ExplodedNodeSet &dst) { 476 // Perform the previsit of the CallExpr. 477 ExplodedNodeSet dstPreVisit; 478 getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, CE, *this); 479 480 // Get the call in its initial state. We use this as a template to perform 481 // all the checks. 482 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 483 CallEventRef<> CallTemplate 484 = CEMgr.getSimpleCall(CE, Pred->getState(), Pred->getLocationContext()); 485 486 // Evaluate the function call. We try each of the checkers 487 // to see if the can evaluate the function call. 488 ExplodedNodeSet dstCallEvaluated; 489 for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end(); 490 I != E; ++I) { 491 evalCall(dstCallEvaluated, *I, *CallTemplate); 492 } 493 494 // Finally, perform the post-condition check of the CallExpr and store 495 // the created nodes in 'Dst'. 496 // Note that if the call was inlined, dstCallEvaluated will be empty. 497 // The post-CallExpr check will occur in processCallExit. 498 getCheckerManager().runCheckersForPostStmt(dst, dstCallEvaluated, CE, 499 *this); 500} 501 502void ExprEngine::evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred, 503 const CallEvent &Call) { 504 // WARNING: At this time, the state attached to 'Call' may be older than the 505 // state in 'Pred'. This is a minor optimization since CheckerManager will 506 // use an updated CallEvent instance when calling checkers, but if 'Call' is 507 // ever used directly in this function all callers should be updated to pass 508 // the most recent state. (It is probably not worth doing the work here since 509 // for some callers this will not be necessary.) 510 511 // Run any pre-call checks using the generic call interface. 512 ExplodedNodeSet dstPreVisit; 513 getCheckerManager().runCheckersForPreCall(dstPreVisit, Pred, Call, *this); 514 515 // Actually evaluate the function call. We try each of the checkers 516 // to see if the can evaluate the function call, and get a callback at 517 // defaultEvalCall if all of them fail. 518 ExplodedNodeSet dstCallEvaluated; 519 getCheckerManager().runCheckersForEvalCall(dstCallEvaluated, dstPreVisit, 520 Call, *this); 521 522 // Finally, run any post-call checks. 523 getCheckerManager().runCheckersForPostCall(Dst, dstCallEvaluated, 524 Call, *this); 525} 526 527ProgramStateRef ExprEngine::bindReturnValue(const CallEvent &Call, 528 const LocationContext *LCtx, 529 ProgramStateRef State) { 530 const Expr *E = Call.getOriginExpr(); 531 if (!E) 532 return State; 533 534 // Some method families have known return values. 535 if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(&Call)) { 536 switch (Msg->getMethodFamily()) { 537 default: 538 break; 539 case OMF_autorelease: 540 case OMF_retain: 541 case OMF_self: { 542 // These methods return their receivers. 543 return State->BindExpr(E, LCtx, Msg->getReceiverSVal()); 544 } 545 } 546 } else if (const CXXConstructorCall *C = dyn_cast<CXXConstructorCall>(&Call)){ 547 return State->BindExpr(E, LCtx, C->getCXXThisVal()); 548 } 549 550 // Conjure a symbol if the return value is unknown. 551 QualType ResultTy = Call.getResultType(); 552 SValBuilder &SVB = getSValBuilder(); 553 unsigned Count = currBldrCtx->blockCount(); 554 SVal R = SVB.conjureSymbolVal(0, E, LCtx, ResultTy, Count); 555 return State->BindExpr(E, LCtx, R); 556} 557 558// Conservatively evaluate call by invalidating regions and binding 559// a conjured return value. 560void ExprEngine::conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr, 561 ExplodedNode *Pred, ProgramStateRef State) { 562 State = Call.invalidateRegions(currBldrCtx->blockCount(), State); 563 State = bindReturnValue(Call, Pred->getLocationContext(), State); 564 565 // And make the result node. 566 Bldr.generateNode(Call.getProgramPoint(), State, Pred); 567} 568 569void ExprEngine::defaultEvalCall(NodeBuilder &Bldr, ExplodedNode *Pred, 570 const CallEvent &CallTemplate) { 571 // Make sure we have the most recent state attached to the call. 572 ProgramStateRef State = Pred->getState(); 573 CallEventRef<> Call = CallTemplate.cloneWithState(State); 574 575 if (!getAnalysisManager().shouldInlineCall()) { 576 conservativeEvalCall(*Call, Bldr, Pred, State); 577 return; 578 } 579 // Try to inline the call. 580 // The origin expression here is just used as a kind of checksum; 581 // this should still be safe even for CallEvents that don't come from exprs. 582 const Expr *E = Call->getOriginExpr(); 583 ProgramStateRef InlinedFailedState = getInlineFailedState(State, E); 584 585 if (InlinedFailedState) { 586 // If we already tried once and failed, make sure we don't retry later. 587 State = InlinedFailedState; 588 } else { 589 RuntimeDefinition RD = Call->getRuntimeDefinition(); 590 const Decl *D = RD.getDecl(); 591 if (D) { 592 if (RD.mayHaveOtherDefinitions()) { 593 // Explore with and without inlining the call. 594 if (getAnalysisManager().IPAMode == DynamicDispatchBifurcate) { 595 BifurcateCall(RD.getDispatchRegion(), *Call, D, Bldr, Pred); 596 return; 597 } 598 599 // Don't inline if we're not in any dynamic dispatch mode. 600 if (getAnalysisManager().IPAMode != DynamicDispatch) { 601 conservativeEvalCall(*Call, Bldr, Pred, State); 602 return; 603 } 604 } 605 606 // We are not bifurcating and we do have a Decl, so just inline. 607 if (inlineCall(*Call, D, Bldr, Pred, State)) 608 return; 609 } 610 } 611 612 // If we can't inline it, handle the return value and invalidate the regions. 613 conservativeEvalCall(*Call, Bldr, Pred, State); 614} 615 616void ExprEngine::BifurcateCall(const MemRegion *BifurReg, 617 const CallEvent &Call, const Decl *D, 618 NodeBuilder &Bldr, ExplodedNode *Pred) { 619 assert(BifurReg); 620 BifurReg = BifurReg->StripCasts(); 621 622 // Check if we've performed the split already - note, we only want 623 // to split the path once per memory region. 624 ProgramStateRef State = Pred->getState(); 625 const unsigned int *BState = 626 State->get<DynamicDispatchBifurcationMap>(BifurReg); 627 if (BState) { 628 // If we are on "inline path", keep inlining if possible. 629 if (*BState == DynamicDispatchModeInlined) 630 if (inlineCall(Call, D, Bldr, Pred, State)) 631 return; 632 // If inline failed, or we are on the path where we assume we 633 // don't have enough info about the receiver to inline, conjure the 634 // return value and invalidate the regions. 635 conservativeEvalCall(Call, Bldr, Pred, State); 636 return; 637 } 638 639 // If we got here, this is the first time we process a message to this 640 // region, so split the path. 641 ProgramStateRef IState = 642 State->set<DynamicDispatchBifurcationMap>(BifurReg, 643 DynamicDispatchModeInlined); 644 inlineCall(Call, D, Bldr, Pred, IState); 645 646 ProgramStateRef NoIState = 647 State->set<DynamicDispatchBifurcationMap>(BifurReg, 648 DynamicDispatchModeConservative); 649 conservativeEvalCall(Call, Bldr, Pred, NoIState); 650 651 NumOfDynamicDispatchPathSplits++; 652 return; 653} 654 655 656void ExprEngine::VisitReturnStmt(const ReturnStmt *RS, ExplodedNode *Pred, 657 ExplodedNodeSet &Dst) { 658 659 ExplodedNodeSet dstPreVisit; 660 getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, RS, *this); 661 662 StmtNodeBuilder B(dstPreVisit, Dst, *currBldrCtx); 663 664 if (RS->getRetValue()) { 665 for (ExplodedNodeSet::iterator it = dstPreVisit.begin(), 666 ei = dstPreVisit.end(); it != ei; ++it) { 667 B.generateNode(RS, *it, (*it)->getState()); 668 } 669 } 670} 671