ExprEngineCallAndReturn.cpp revision 9eb214a691663a04ee61197e7d605128c85e09f7
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 in this 70 // stack frame. 71 while (Node) { 72 const ProgramPoint &PP = Node->getLocation(); 73 74 if (PP.getLocationContext()->getCurrentStackFrame() == SF) { 75 if (const StmtPoint *SP = dyn_cast<StmtPoint>(&PP)) { 76 S = SP->getStmt(); 77 break; 78 } else if (const CallExitEnd *CEE = dyn_cast<CallExitEnd>(&PP)) { 79 S = CEE->getCalleeContext()->getCallSite(); 80 if (S) 81 break; 82 83 // If there is no statement, this is an implicitly-generated call. 84 // We'll walk backwards over it and then continue the loop to find 85 // an actual statement. 86 const CallEnter *CE; 87 do { 88 Node = Node->getFirstPred(); 89 CE = Node->getLocationAs<CallEnter>(); 90 } while (!CE || CE->getCalleeContext() != CEE->getCalleeContext()); 91 92 // Continue searching the graph. 93 } 94 } else if (const CallEnter *CE = dyn_cast<CallEnter>(&PP)) { 95 // If we reached the CallEnter for this function, it has no statements. 96 if (CE->getCalleeContext() == SF) 97 break; 98 } 99 100 Node = *Node->pred_begin(); 101 } 102 103 const CFGBlock *Blk = 0; 104 if (S) { 105 // Now, get the enclosing basic block. 106 while (Node && Node->pred_size() >=1 ) { 107 const ProgramPoint &PP = Node->getLocation(); 108 if (isa<BlockEdge>(PP) && 109 (PP.getLocationContext()->getCurrentStackFrame() == SF)) { 110 BlockEdge &EPP = cast<BlockEdge>(PP); 111 Blk = EPP.getDst(); 112 break; 113 } 114 Node = *Node->pred_begin(); 115 } 116 } 117 118 return std::pair<const Stmt*, const CFGBlock*>(S, Blk); 119} 120 121/// The call exit is simulated with a sequence of nodes, which occur between 122/// CallExitBegin and CallExitEnd. The following operations occur between the 123/// two program points: 124/// 1. CallExitBegin (triggers the start of call exit sequence) 125/// 2. Bind the return value 126/// 3. Run Remove dead bindings to clean up the dead symbols from the callee. 127/// 4. CallExitEnd (switch to the caller context) 128/// 5. PostStmt<CallExpr> 129void ExprEngine::processCallExit(ExplodedNode *CEBNode) { 130 // Step 1 CEBNode was generated before the call. 131 132 const StackFrameContext *calleeCtx = 133 CEBNode->getLocationContext()->getCurrentStackFrame(); 134 135 // The parent context might not be a stack frame, so make sure we 136 // look up the first enclosing stack frame. 137 const StackFrameContext *callerCtx = 138 calleeCtx->getParent()->getCurrentStackFrame(); 139 140 const Stmt *CE = calleeCtx->getCallSite(); 141 ProgramStateRef state = CEBNode->getState(); 142 // Find the last statement in the function and the corresponding basic block. 143 const Stmt *LastSt = 0; 144 const CFGBlock *Blk = 0; 145 llvm::tie(LastSt, Blk) = getLastStmt(CEBNode); 146 147 // Step 2: generate node with bound return value: CEBNode -> BindedRetNode. 148 149 // If the callee returns an expression, bind its value to CallExpr. 150 if (CE) { 151 if (const ReturnStmt *RS = dyn_cast_or_null<ReturnStmt>(LastSt)) { 152 const LocationContext *LCtx = CEBNode->getLocationContext(); 153 SVal V = state->getSVal(RS, LCtx); 154 state = state->BindExpr(CE, callerCtx, V); 155 } 156 157 // Bind the constructed object value to CXXConstructExpr. 158 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(CE)) { 159 loc::MemRegionVal This = 160 svalBuilder.getCXXThis(CCE->getConstructor()->getParent(), calleeCtx); 161 SVal ThisV = state->getSVal(This); 162 163 // Always bind the region to the CXXConstructExpr. 164 state = state->BindExpr(CCE, callerCtx, ThisV); 165 } 166 } 167 168 // Generate a CallEvent /before/ cleaning the state, so that we can get the 169 // correct value for 'this' (if necessary). 170 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 171 CallEventRef<> Call = CEMgr.getCaller(calleeCtx, state); 172 173 // Step 3: BindedRetNode -> CleanedNodes 174 // If we can find a statement and a block in the inlined function, run remove 175 // dead bindings before returning from the call. This is important to ensure 176 // that we report the issues such as leaks in the stack contexts in which 177 // they occurred. 178 ExplodedNodeSet CleanedNodes; 179 if (LastSt && Blk && AMgr.options.AnalysisPurgeOpt != PurgeNone) { 180 static SimpleProgramPointTag retValBind("ExprEngine : Bind Return Value"); 181 PostStmt Loc(LastSt, calleeCtx, &retValBind); 182 bool isNew; 183 ExplodedNode *BindedRetNode = G.getNode(Loc, state, false, &isNew); 184 BindedRetNode->addPredecessor(CEBNode, G); 185 if (!isNew) 186 return; 187 188 NodeBuilderContext Ctx(getCoreEngine(), Blk, BindedRetNode); 189 currBldrCtx = &Ctx; 190 // Here, we call the Symbol Reaper with 0 statement and caller location 191 // context, telling it to clean up everything in the callee's context 192 // (and it's children). We use LastStmt as a diagnostic statement, which 193 // which the PreStmtPurge Dead point will be associated. 194 removeDead(BindedRetNode, CleanedNodes, 0, callerCtx, LastSt, 195 ProgramPoint::PostStmtPurgeDeadSymbolsKind); 196 currBldrCtx = 0; 197 } else { 198 CleanedNodes.Add(CEBNode); 199 } 200 201 for (ExplodedNodeSet::iterator I = CleanedNodes.begin(), 202 E = CleanedNodes.end(); I != E; ++I) { 203 204 // Step 4: Generate the CallExit and leave the callee's context. 205 // CleanedNodes -> CEENode 206 CallExitEnd Loc(calleeCtx, callerCtx); 207 bool isNew; 208 ProgramStateRef CEEState = (*I == CEBNode) ? state : (*I)->getState(); 209 ExplodedNode *CEENode = G.getNode(Loc, CEEState, false, &isNew); 210 CEENode->addPredecessor(*I, G); 211 if (!isNew) 212 return; 213 214 // Step 5: Perform the post-condition check of the CallExpr and enqueue the 215 // result onto the work list. 216 // CEENode -> Dst -> WorkList 217 NodeBuilderContext Ctx(Engine, calleeCtx->getCallSiteBlock(), CEENode); 218 SaveAndRestore<const NodeBuilderContext*> NBCSave(currBldrCtx, 219 &Ctx); 220 SaveAndRestore<unsigned> CBISave(currStmtIdx, calleeCtx->getIndex()); 221 222 CallEventRef<> UpdatedCall = Call.cloneWithState(CEEState); 223 224 ExplodedNodeSet DstPostCall; 225 getCheckerManager().runCheckersForPostCall(DstPostCall, CEENode, 226 *UpdatedCall, *this, 227 /*WasInlined=*/true); 228 229 ExplodedNodeSet Dst; 230 if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(Call)) { 231 getCheckerManager().runCheckersForPostObjCMessage(Dst, DstPostCall, *Msg, 232 *this, 233 /*WasInlined=*/true); 234 } else if (CE) { 235 getCheckerManager().runCheckersForPostStmt(Dst, DstPostCall, CE, 236 *this, /*WasInlined=*/true); 237 } else { 238 Dst.insert(DstPostCall); 239 } 240 241 // Enqueue the next element in the block. 242 for (ExplodedNodeSet::iterator PSI = Dst.begin(), PSE = Dst.end(); 243 PSI != PSE; ++PSI) { 244 Engine.getWorkList()->enqueue(*PSI, calleeCtx->getCallSiteBlock(), 245 calleeCtx->getIndex()+1); 246 } 247 } 248} 249 250static unsigned getNumberStackFrames(const LocationContext *LCtx) { 251 unsigned count = 0; 252 while (LCtx) { 253 if (isa<StackFrameContext>(LCtx)) 254 ++count; 255 LCtx = LCtx->getParent(); 256 } 257 return count; 258} 259 260// Determine if we should inline the call. 261bool ExprEngine::shouldInlineDecl(const Decl *D, ExplodedNode *Pred) { 262 AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(D); 263 const CFG *CalleeCFG = CalleeADC->getCFG(); 264 265 // It is possible that the CFG cannot be constructed. 266 // Be safe, and check if the CalleeCFG is valid. 267 if (!CalleeCFG) 268 return false; 269 270 if (getNumberStackFrames(Pred->getLocationContext()) 271 == AMgr.options.InlineMaxStackDepth) 272 return false; 273 274 if (Engine.FunctionSummaries->hasReachedMaxBlockCount(D)) 275 return false; 276 277 if (CalleeCFG->getNumBlockIDs() > AMgr.options.InlineMaxFunctionSize) 278 return false; 279 280 // Do not inline variadic calls (for now). 281 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) { 282 if (BD->isVariadic()) 283 return false; 284 } 285 else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 286 if (FD->isVariadic()) 287 return false; 288 } 289 290 // It is possible that the live variables analysis cannot be 291 // run. If so, bail out. 292 if (!CalleeADC->getAnalysis<RelaxedLiveVariables>()) 293 return false; 294 295 return true; 296} 297 298/// The GDM component containing the dynamic dispatch bifurcation info. When 299/// the exact type of the receiver is not known, we want to explore both paths - 300/// one on which we do inline it and the other one on which we don't. This is 301/// done to ensure we do not drop coverage. 302/// This is the map from the receiver region to a bool, specifying either we 303/// consider this region's information precise or not along the given path. 304namespace clang { 305namespace ento { 306enum DynamicDispatchMode { DynamicDispatchModeInlined = 1, 307 DynamicDispatchModeConservative }; 308 309struct DynamicDispatchBifurcationMap {}; 310typedef llvm::ImmutableMap<const MemRegion*, 311 unsigned int> DynamicDispatchBifur; 312template<> struct ProgramStateTrait<DynamicDispatchBifurcationMap> 313 : public ProgramStatePartialTrait<DynamicDispatchBifur> { 314 static void *GDMIndex() { static int index; return &index; } 315}; 316 317}} 318 319bool ExprEngine::inlineCall(const CallEvent &Call, const Decl *D, 320 NodeBuilder &Bldr, ExplodedNode *Pred, 321 ProgramStateRef State) { 322 assert(D); 323 324 const LocationContext *CurLC = Pred->getLocationContext(); 325 const StackFrameContext *CallerSFC = CurLC->getCurrentStackFrame(); 326 const LocationContext *ParentOfCallee = 0; 327 328 const AnalyzerOptions &Opts = getAnalysisManager().options; 329 330 // FIXME: Refactor this check into a hypothetical CallEvent::canInline. 331 switch (Call.getKind()) { 332 case CE_Function: 333 break; 334 case CE_CXXMember: 335 case CE_CXXMemberOperator: 336 if (!Opts.mayInlineCXXMemberFunction(CIMK_MemberFunctions)) 337 return false; 338 break; 339 case CE_CXXConstructor: { 340 if (!Opts.mayInlineCXXMemberFunction(CIMK_Constructors)) 341 return false; 342 343 const CXXConstructorCall &Ctor = cast<CXXConstructorCall>(Call); 344 345 // FIXME: We don't handle constructors or destructors for arrays properly. 346 const MemRegion *Target = Ctor.getCXXThisVal().getAsRegion(); 347 if (Target && isa<ElementRegion>(Target)) 348 return false; 349 350 // FIXME: This is a hack. We don't use the correct region for a new 351 // expression, so if we inline the constructor its result will just be 352 // thrown away. This short-term hack is tracked in <rdar://problem/12180598> 353 // and the longer-term possible fix is discussed in PR12014. 354 const CXXConstructExpr *CtorExpr = Ctor.getOriginExpr(); 355 if (const Stmt *Parent = CurLC->getParentMap().getParent(CtorExpr)) 356 if (isa<CXXNewExpr>(Parent)) 357 return false; 358 359 // Inlining constructors requires including initializers in the CFG. 360 const AnalysisDeclContext *ADC = CallerSFC->getAnalysisDeclContext(); 361 assert(ADC->getCFGBuildOptions().AddInitializers && "No CFG initializers"); 362 (void)ADC; 363 364 // If the destructor is trivial, it's always safe to inline the constructor. 365 if (Ctor.getDecl()->getParent()->hasTrivialDestructor()) 366 break; 367 368 // For other types, only inline constructors if destructor inlining is 369 // also enabled. 370 if (!Opts.mayInlineCXXMemberFunction(CIMK_Destructors)) 371 return false; 372 373 // FIXME: This is a hack. We don't handle temporary destructors 374 // right now, so we shouldn't inline their constructors. 375 if (CtorExpr->getConstructionKind() == CXXConstructExpr::CK_Complete) 376 if (!Target || !isa<DeclRegion>(Target)) 377 return false; 378 379 break; 380 } 381 case CE_CXXDestructor: { 382 if (!Opts.mayInlineCXXMemberFunction(CIMK_Destructors)) 383 return false; 384 385 // Inlining destructors requires building the CFG correctly. 386 const AnalysisDeclContext *ADC = CallerSFC->getAnalysisDeclContext(); 387 assert(ADC->getCFGBuildOptions().AddImplicitDtors && "No CFG destructors"); 388 (void)ADC; 389 390 const CXXDestructorCall &Dtor = cast<CXXDestructorCall>(Call); 391 392 // FIXME: We don't handle constructors or destructors for arrays properly. 393 const MemRegion *Target = Dtor.getCXXThisVal().getAsRegion(); 394 if (Target && isa<ElementRegion>(Target)) 395 return false; 396 397 break; 398 } 399 case CE_CXXAllocator: 400 // Do not inline allocators until we model deallocators. 401 // This is unfortunate, but basically necessary for smart pointers and such. 402 return false; 403 case CE_Block: { 404 const BlockDataRegion *BR = cast<BlockCall>(Call).getBlockRegion(); 405 assert(BR && "If we have the block definition we should have its region"); 406 AnalysisDeclContext *BlockCtx = AMgr.getAnalysisDeclContext(D); 407 ParentOfCallee = BlockCtx->getBlockInvocationContext(CallerSFC, 408 cast<BlockDecl>(D), 409 BR); 410 break; 411 } 412 case CE_ObjCMessage: 413 if (!(getAnalysisManager().options.IPAMode == DynamicDispatch || 414 getAnalysisManager().options.IPAMode == DynamicDispatchBifurcate)) 415 return false; 416 break; 417 } 418 419 if (!shouldInlineDecl(D, Pred)) 420 return false; 421 422 if (!ParentOfCallee) 423 ParentOfCallee = CallerSFC; 424 425 // This may be NULL, but that's fine. 426 const Expr *CallE = Call.getOriginExpr(); 427 428 // Construct a new stack frame for the callee. 429 AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(D); 430 const StackFrameContext *CalleeSFC = 431 CalleeADC->getStackFrame(ParentOfCallee, CallE, 432 currBldrCtx->getBlock(), 433 currStmtIdx); 434 435 CallEnter Loc(CallE, CalleeSFC, CurLC); 436 437 // Construct a new state which contains the mapping from actual to 438 // formal arguments. 439 State = State->enterStackFrame(Call, CalleeSFC); 440 441 bool isNew; 442 if (ExplodedNode *N = G.getNode(Loc, State, false, &isNew)) { 443 N->addPredecessor(Pred, G); 444 if (isNew) 445 Engine.getWorkList()->enqueue(N); 446 } 447 448 // If we decided to inline the call, the successor has been manually 449 // added onto the work list so remove it from the node builder. 450 Bldr.takeNodes(Pred); 451 452 NumInlinedCalls++; 453 454 // Mark the decl as visited. 455 if (VisitedCallees) 456 VisitedCallees->insert(D); 457 458 return true; 459} 460 461static ProgramStateRef getInlineFailedState(ProgramStateRef State, 462 const Stmt *CallE) { 463 void *ReplayState = State->get<ReplayWithoutInlining>(); 464 if (!ReplayState) 465 return 0; 466 467 assert(ReplayState == (const void*)CallE && "Backtracked to the wrong call."); 468 (void)CallE; 469 470 return State->remove<ReplayWithoutInlining>(); 471} 472 473void ExprEngine::VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 474 ExplodedNodeSet &dst) { 475 // Perform the previsit of the CallExpr. 476 ExplodedNodeSet dstPreVisit; 477 getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, CE, *this); 478 479 // Get the call in its initial state. We use this as a template to perform 480 // all the checks. 481 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 482 CallEventRef<> CallTemplate 483 = CEMgr.getSimpleCall(CE, Pred->getState(), Pred->getLocationContext()); 484 485 // Evaluate the function call. We try each of the checkers 486 // to see if the can evaluate the function call. 487 ExplodedNodeSet dstCallEvaluated; 488 for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end(); 489 I != E; ++I) { 490 evalCall(dstCallEvaluated, *I, *CallTemplate); 491 } 492 493 // Finally, perform the post-condition check of the CallExpr and store 494 // the created nodes in 'Dst'. 495 // Note that if the call was inlined, dstCallEvaluated will be empty. 496 // The post-CallExpr check will occur in processCallExit. 497 getCheckerManager().runCheckersForPostStmt(dst, dstCallEvaluated, CE, 498 *this); 499} 500 501void ExprEngine::evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred, 502 const CallEvent &Call) { 503 // WARNING: At this time, the state attached to 'Call' may be older than the 504 // state in 'Pred'. This is a minor optimization since CheckerManager will 505 // use an updated CallEvent instance when calling checkers, but if 'Call' is 506 // ever used directly in this function all callers should be updated to pass 507 // the most recent state. (It is probably not worth doing the work here since 508 // for some callers this will not be necessary.) 509 510 // Run any pre-call checks using the generic call interface. 511 ExplodedNodeSet dstPreVisit; 512 getCheckerManager().runCheckersForPreCall(dstPreVisit, Pred, Call, *this); 513 514 // Actually evaluate the function call. We try each of the checkers 515 // to see if the can evaluate the function call, and get a callback at 516 // defaultEvalCall if all of them fail. 517 ExplodedNodeSet dstCallEvaluated; 518 getCheckerManager().runCheckersForEvalCall(dstCallEvaluated, dstPreVisit, 519 Call, *this); 520 521 // Finally, run any post-call checks. 522 getCheckerManager().runCheckersForPostCall(Dst, dstCallEvaluated, 523 Call, *this); 524} 525 526ProgramStateRef ExprEngine::bindReturnValue(const CallEvent &Call, 527 const LocationContext *LCtx, 528 ProgramStateRef State) { 529 const Expr *E = Call.getOriginExpr(); 530 if (!E) 531 return State; 532 533 // Some method families have known return values. 534 if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(&Call)) { 535 switch (Msg->getMethodFamily()) { 536 default: 537 break; 538 case OMF_autorelease: 539 case OMF_retain: 540 case OMF_self: { 541 // These methods return their receivers. 542 return State->BindExpr(E, LCtx, Msg->getReceiverSVal()); 543 } 544 } 545 } else if (const CXXConstructorCall *C = dyn_cast<CXXConstructorCall>(&Call)){ 546 return State->BindExpr(E, LCtx, C->getCXXThisVal()); 547 } 548 549 // Conjure a symbol if the return value is unknown. 550 QualType ResultTy = Call.getResultType(); 551 SValBuilder &SVB = getSValBuilder(); 552 unsigned Count = currBldrCtx->blockCount(); 553 SVal R = SVB.conjureSymbolVal(0, E, LCtx, ResultTy, Count); 554 return State->BindExpr(E, LCtx, R); 555} 556 557// Conservatively evaluate call by invalidating regions and binding 558// a conjured return value. 559void ExprEngine::conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr, 560 ExplodedNode *Pred, ProgramStateRef State) { 561 State = Call.invalidateRegions(currBldrCtx->blockCount(), State); 562 State = bindReturnValue(Call, Pred->getLocationContext(), State); 563 564 // And make the result node. 565 Bldr.generateNode(Call.getProgramPoint(), State, Pred); 566} 567 568void ExprEngine::defaultEvalCall(NodeBuilder &Bldr, ExplodedNode *Pred, 569 const CallEvent &CallTemplate) { 570 // Make sure we have the most recent state attached to the call. 571 ProgramStateRef State = Pred->getState(); 572 CallEventRef<> Call = CallTemplate.cloneWithState(State); 573 574 if (!getAnalysisManager().shouldInlineCall()) { 575 conservativeEvalCall(*Call, Bldr, Pred, State); 576 return; 577 } 578 // Try to inline the call. 579 // The origin expression here is just used as a kind of checksum; 580 // this should still be safe even for CallEvents that don't come from exprs. 581 const Expr *E = Call->getOriginExpr(); 582 ProgramStateRef InlinedFailedState = getInlineFailedState(State, E); 583 584 if (InlinedFailedState) { 585 // If we already tried once and failed, make sure we don't retry later. 586 State = InlinedFailedState; 587 } else { 588 RuntimeDefinition RD = Call->getRuntimeDefinition(); 589 const Decl *D = RD.getDecl(); 590 if (D) { 591 if (RD.mayHaveOtherDefinitions()) { 592 // Explore with and without inlining the call. 593 if (getAnalysisManager().options.IPAMode == DynamicDispatchBifurcate) { 594 BifurcateCall(RD.getDispatchRegion(), *Call, D, Bldr, Pred); 595 return; 596 } 597 598 // Don't inline if we're not in any dynamic dispatch mode. 599 if (getAnalysisManager().options.IPAMode != DynamicDispatch) { 600 conservativeEvalCall(*Call, Bldr, Pred, State); 601 return; 602 } 603 } 604 605 // We are not bifurcating and we do have a Decl, so just inline. 606 if (inlineCall(*Call, D, Bldr, Pred, State)) 607 return; 608 } 609 } 610 611 // If we can't inline it, handle the return value and invalidate the regions. 612 conservativeEvalCall(*Call, Bldr, Pred, State); 613} 614 615void ExprEngine::BifurcateCall(const MemRegion *BifurReg, 616 const CallEvent &Call, const Decl *D, 617 NodeBuilder &Bldr, ExplodedNode *Pred) { 618 assert(BifurReg); 619 BifurReg = BifurReg->StripCasts(); 620 621 // Check if we've performed the split already - note, we only want 622 // to split the path once per memory region. 623 ProgramStateRef State = Pred->getState(); 624 const unsigned int *BState = 625 State->get<DynamicDispatchBifurcationMap>(BifurReg); 626 if (BState) { 627 // If we are on "inline path", keep inlining if possible. 628 if (*BState == DynamicDispatchModeInlined) 629 if (inlineCall(Call, D, Bldr, Pred, State)) 630 return; 631 // If inline failed, or we are on the path where we assume we 632 // don't have enough info about the receiver to inline, conjure the 633 // return value and invalidate the regions. 634 conservativeEvalCall(Call, Bldr, Pred, State); 635 return; 636 } 637 638 // If we got here, this is the first time we process a message to this 639 // region, so split the path. 640 ProgramStateRef IState = 641 State->set<DynamicDispatchBifurcationMap>(BifurReg, 642 DynamicDispatchModeInlined); 643 inlineCall(Call, D, Bldr, Pred, IState); 644 645 ProgramStateRef NoIState = 646 State->set<DynamicDispatchBifurcationMap>(BifurReg, 647 DynamicDispatchModeConservative); 648 conservativeEvalCall(Call, Bldr, Pred, NoIState); 649 650 NumOfDynamicDispatchPathSplits++; 651 return; 652} 653 654 655void ExprEngine::VisitReturnStmt(const ReturnStmt *RS, ExplodedNode *Pred, 656 ExplodedNodeSet &Dst) { 657 658 ExplodedNodeSet dstPreVisit; 659 getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, RS, *this); 660 661 StmtNodeBuilder B(dstPreVisit, Dst, *currBldrCtx); 662 663 if (RS->getRetValue()) { 664 for (ExplodedNodeSet::iterator it = dstPreVisit.begin(), 665 ei = dstPreVisit.end(); it != ei; ++it) { 666 B.generateNode(RS, *it, (*it)->getState()); 667 } 668 } 669} 670