1 //=-- ExprEngineCallAndReturn.cpp - Support for call/return -----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines ExprEngine's support for calls and returns.
12 //===----------------------------------------------------------------------===//
14 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
15 #include "PrettyStackTraceLocationContext.h"
16 #include "clang/AST/CXXInheritance.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/ParentMap.h"
19 #include "clang/Analysis/Analyses/LiveVariables.h"
20 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
21 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
22 #include "llvm/ADT/SmallSet.h"
23 #include "llvm/ADT/Statistic.h"
24 #include "llvm/Support/SaveAndRestore.h"
26 using namespace clang;
29 #define DEBUG_TYPE "ExprEngine"
31 STATISTIC(NumOfDynamicDispatchPathSplits,
32 "The # of times we split the path due to imprecise dynamic dispatch info");
34 STATISTIC(NumInlinedCalls,
35 "The # of times we inlined a call");
37 STATISTIC(NumReachedInlineCountMax,
38 "The # of times we reached inline count maximum");
40 void ExprEngine::processCallEnter(CallEnter CE, ExplodedNode *Pred) {
41 // Get the entry block in the CFG of the callee.
42 const StackFrameContext *calleeCtx = CE.getCalleeContext();
43 PrettyStackTraceLocationContext CrashInfo(calleeCtx);
45 const CFG *CalleeCFG = calleeCtx->getCFG();
46 const CFGBlock *Entry = &(CalleeCFG->getEntry());
49 assert(Entry->empty());
50 assert(Entry->succ_size() == 1);
52 // Get the solitary successor.
53 const CFGBlock *Succ = *(Entry->succ_begin());
55 // Construct an edge representing the starting location in the callee.
56 BlockEdge Loc(Entry, Succ, calleeCtx);
58 ProgramStateRef state = Pred->getState();
60 // Construct a new node and add it to the worklist.
62 ExplodedNode *Node = G.getNode(Loc, state, false, &isNew);
63 Node->addPredecessor(Pred, G);
65 Engine.getWorkList()->enqueue(Node);
68 // Find the last statement on the path to the exploded node and the
69 // corresponding Block.
70 static std::pair<const Stmt*,
71 const CFGBlock*> getLastStmt(const ExplodedNode *Node) {
72 const Stmt *S = nullptr;
73 const CFGBlock *Blk = nullptr;
74 const StackFrameContext *SF =
75 Node->getLocation().getLocationContext()->getCurrentStackFrame();
77 // Back up through the ExplodedGraph until we reach a statement node in this
80 const ProgramPoint &PP = Node->getLocation();
82 if (PP.getLocationContext()->getCurrentStackFrame() == SF) {
83 if (Optional<StmtPoint> SP = PP.getAs<StmtPoint>()) {
86 } else if (Optional<CallExitEnd> CEE = PP.getAs<CallExitEnd>()) {
87 S = CEE->getCalleeContext()->getCallSite();
91 // If there is no statement, this is an implicitly-generated call.
92 // We'll walk backwards over it and then continue the loop to find
93 // an actual statement.
94 Optional<CallEnter> CE;
96 Node = Node->getFirstPred();
97 CE = Node->getLocationAs<CallEnter>();
98 } while (!CE || CE->getCalleeContext() != CEE->getCalleeContext());
100 // Continue searching the graph.
101 } else if (Optional<BlockEdge> BE = PP.getAs<BlockEdge>()) {
104 } else if (Optional<CallEnter> CE = PP.getAs<CallEnter>()) {
105 // If we reached the CallEnter for this function, it has no statements.
106 if (CE->getCalleeContext() == SF)
110 if (Node->pred_empty())
111 return std::make_pair(nullptr, nullptr);
113 Node = *Node->pred_begin();
116 return std::make_pair(S, Blk);
119 /// Adjusts a return value when the called function's return type does not
120 /// match the caller's expression type. This can happen when a dynamic call
121 /// is devirtualized, and the overridding method has a covariant (more specific)
122 /// return type than the parent's method. For C++ objects, this means we need
123 /// to add base casts.
124 static SVal adjustReturnValue(SVal V, QualType ExpectedTy, QualType ActualTy,
125 StoreManager &StoreMgr) {
126 // For now, the only adjustments we handle apply only to locations.
130 // If the types already match, don't do any unnecessary work.
131 ExpectedTy = ExpectedTy.getCanonicalType();
132 ActualTy = ActualTy.getCanonicalType();
133 if (ExpectedTy == ActualTy)
136 // No adjustment is needed between Objective-C pointer types.
137 if (ExpectedTy->isObjCObjectPointerType() &&
138 ActualTy->isObjCObjectPointerType())
141 // C++ object pointers may need "derived-to-base" casts.
142 const CXXRecordDecl *ExpectedClass = ExpectedTy->getPointeeCXXRecordDecl();
143 const CXXRecordDecl *ActualClass = ActualTy->getPointeeCXXRecordDecl();
144 if (ExpectedClass && ActualClass) {
145 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
146 /*DetectVirtual=*/false);
147 if (ActualClass->isDerivedFrom(ExpectedClass, Paths) &&
148 !Paths.isAmbiguous(ActualTy->getCanonicalTypeUnqualified())) {
149 return StoreMgr.evalDerivedToBase(V, Paths.front());
153 // Unfortunately, Objective-C does not enforce that overridden methods have
154 // covariant return types, so we can't assert that that never happens.
155 // Be safe and return UnknownVal().
159 void ExprEngine::removeDeadOnEndOfFunction(NodeBuilderContext& BC,
161 ExplodedNodeSet &Dst) {
162 // Find the last statement in the function and the corresponding basic block.
163 const Stmt *LastSt = nullptr;
164 const CFGBlock *Blk = nullptr;
165 std::tie(LastSt, Blk) = getLastStmt(Pred);
166 if (!Blk || !LastSt) {
171 // Here, we destroy the current location context. We use the current
172 // function's entire body as a diagnostic statement, with which the program
173 // point will be associated. However, we only want to use LastStmt as a
174 // reference for what to clean up if it's a ReturnStmt; otherwise, everything
176 SaveAndRestore<const NodeBuilderContext *> NodeContextRAII(currBldrCtx, &BC);
177 const LocationContext *LCtx = Pred->getLocationContext();
178 removeDead(Pred, Dst, dyn_cast<ReturnStmt>(LastSt), LCtx,
179 LCtx->getAnalysisDeclContext()->getBody(),
180 ProgramPoint::PostStmtPurgeDeadSymbolsKind);
183 static bool wasDifferentDeclUsedForInlining(CallEventRef<> Call,
184 const StackFrameContext *calleeCtx) {
185 const Decl *RuntimeCallee = calleeCtx->getDecl();
186 const Decl *StaticDecl = Call->getDecl();
187 assert(RuntimeCallee);
190 return RuntimeCallee->getCanonicalDecl() != StaticDecl->getCanonicalDecl();
193 /// Returns true if the CXXConstructExpr \p E was intended to construct a
194 /// prvalue for the region in \p V.
196 /// Note that we can't just test for rvalue vs. glvalue because
197 /// CXXConstructExprs embedded in DeclStmts and initializers are considered
198 /// rvalues by the AST, and the analyzer would like to treat them as lvalues.
199 static bool isTemporaryPRValue(const CXXConstructExpr *E, SVal V) {
203 const MemRegion *MR = V.getAsRegion();
207 return isa<CXXTempObjectRegion>(MR);
210 /// The call exit is simulated with a sequence of nodes, which occur between
211 /// CallExitBegin and CallExitEnd. The following operations occur between the
212 /// two program points:
213 /// 1. CallExitBegin (triggers the start of call exit sequence)
214 /// 2. Bind the return value
215 /// 3. Run Remove dead bindings to clean up the dead symbols from the callee.
216 /// 4. CallExitEnd (switch to the caller context)
217 /// 5. PostStmt<CallExpr>
218 void ExprEngine::processCallExit(ExplodedNode *CEBNode) {
219 // Step 1 CEBNode was generated before the call.
220 PrettyStackTraceLocationContext CrashInfo(CEBNode->getLocationContext());
221 const StackFrameContext *calleeCtx =
222 CEBNode->getLocationContext()->getCurrentStackFrame();
224 // The parent context might not be a stack frame, so make sure we
225 // look up the first enclosing stack frame.
226 const StackFrameContext *callerCtx =
227 calleeCtx->getParent()->getCurrentStackFrame();
229 const Stmt *CE = calleeCtx->getCallSite();
230 ProgramStateRef state = CEBNode->getState();
231 // Find the last statement in the function and the corresponding basic block.
232 const Stmt *LastSt = nullptr;
233 const CFGBlock *Blk = nullptr;
234 std::tie(LastSt, Blk) = getLastStmt(CEBNode);
236 // Generate a CallEvent /before/ cleaning the state, so that we can get the
237 // correct value for 'this' (if necessary).
238 CallEventManager &CEMgr = getStateManager().getCallEventManager();
239 CallEventRef<> Call = CEMgr.getCaller(calleeCtx, state);
241 // Step 2: generate node with bound return value: CEBNode -> BindedRetNode.
243 // If the callee returns an expression, bind its value to CallExpr.
245 if (const ReturnStmt *RS = dyn_cast_or_null<ReturnStmt>(LastSt)) {
246 const LocationContext *LCtx = CEBNode->getLocationContext();
247 SVal V = state->getSVal(RS, LCtx);
249 // Ensure that the return type matches the type of the returned Expr.
250 if (wasDifferentDeclUsedForInlining(Call, calleeCtx)) {
251 QualType ReturnedTy =
252 CallEvent::getDeclaredResultType(calleeCtx->getDecl());
253 if (!ReturnedTy.isNull()) {
254 if (const Expr *Ex = dyn_cast<Expr>(CE)) {
255 V = adjustReturnValue(V, Ex->getType(), ReturnedTy,
261 state = state->BindExpr(CE, callerCtx, V);
264 // Bind the constructed object value to CXXConstructExpr.
265 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(CE)) {
266 loc::MemRegionVal This =
267 svalBuilder.getCXXThis(CCE->getConstructor()->getParent(), calleeCtx);
268 SVal ThisV = state->getSVal(This);
270 // If the constructed object is a temporary prvalue, get its bindings.
271 if (isTemporaryPRValue(CCE, ThisV))
272 ThisV = state->getSVal(ThisV.castAs<Loc>());
274 state = state->BindExpr(CCE, callerCtx, ThisV);
278 // Step 3: BindedRetNode -> CleanedNodes
279 // If we can find a statement and a block in the inlined function, run remove
280 // dead bindings before returning from the call. This is important to ensure
281 // that we report the issues such as leaks in the stack contexts in which
283 ExplodedNodeSet CleanedNodes;
284 if (LastSt && Blk && AMgr.options.AnalysisPurgeOpt != PurgeNone) {
285 static SimpleProgramPointTag retValBind("ExprEngine", "Bind Return Value");
286 PostStmt Loc(LastSt, calleeCtx, &retValBind);
288 ExplodedNode *BindedRetNode = G.getNode(Loc, state, false, &isNew);
289 BindedRetNode->addPredecessor(CEBNode, G);
293 NodeBuilderContext Ctx(getCoreEngine(), Blk, BindedRetNode);
295 // Here, we call the Symbol Reaper with 0 statement and callee location
296 // context, telling it to clean up everything in the callee's context
297 // (and its children). We use the callee's function body as a diagnostic
298 // statement, with which the program point will be associated.
299 removeDead(BindedRetNode, CleanedNodes, nullptr, calleeCtx,
300 calleeCtx->getAnalysisDeclContext()->getBody(),
301 ProgramPoint::PostStmtPurgeDeadSymbolsKind);
302 currBldrCtx = nullptr;
304 CleanedNodes.Add(CEBNode);
307 for (ExplodedNodeSet::iterator I = CleanedNodes.begin(),
308 E = CleanedNodes.end(); I != E; ++I) {
310 // Step 4: Generate the CallExit and leave the callee's context.
311 // CleanedNodes -> CEENode
312 CallExitEnd Loc(calleeCtx, callerCtx);
314 ProgramStateRef CEEState = (*I == CEBNode) ? state : (*I)->getState();
315 ExplodedNode *CEENode = G.getNode(Loc, CEEState, false, &isNew);
316 CEENode->addPredecessor(*I, G);
320 // Step 5: Perform the post-condition check of the CallExpr and enqueue the
321 // result onto the work list.
322 // CEENode -> Dst -> WorkList
323 NodeBuilderContext Ctx(Engine, calleeCtx->getCallSiteBlock(), CEENode);
324 SaveAndRestore<const NodeBuilderContext*> NBCSave(currBldrCtx,
326 SaveAndRestore<unsigned> CBISave(currStmtIdx, calleeCtx->getIndex());
328 CallEventRef<> UpdatedCall = Call.cloneWithState(CEEState);
330 ExplodedNodeSet DstPostCall;
331 getCheckerManager().runCheckersForPostCall(DstPostCall, CEENode,
333 /*WasInlined=*/true);
336 if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(Call)) {
337 getCheckerManager().runCheckersForPostObjCMessage(Dst, DstPostCall, *Msg,
339 /*WasInlined=*/true);
341 getCheckerManager().runCheckersForPostStmt(Dst, DstPostCall, CE,
342 *this, /*WasInlined=*/true);
344 Dst.insert(DstPostCall);
347 // Enqueue the next element in the block.
348 for (ExplodedNodeSet::iterator PSI = Dst.begin(), PSE = Dst.end();
350 Engine.getWorkList()->enqueue(*PSI, calleeCtx->getCallSiteBlock(),
351 calleeCtx->getIndex()+1);
356 void ExprEngine::examineStackFrames(const Decl *D, const LocationContext *LCtx,
357 bool &IsRecursive, unsigned &StackDepth) {
362 if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LCtx)) {
363 const Decl *DI = SFC->getDecl();
365 // Mark recursive (and mutually recursive) functions and always count
366 // them when measuring the stack depth.
370 LCtx = LCtx->getParent();
374 // Do not count the small functions when determining the stack depth.
375 AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(DI);
376 const CFG *CalleeCFG = CalleeADC->getCFG();
377 if (CalleeCFG->getNumBlockIDs() > AMgr.options.getAlwaysInlineSize())
380 LCtx = LCtx->getParent();
385 static bool IsInStdNamespace(const FunctionDecl *FD) {
386 const DeclContext *DC = FD->getEnclosingNamespaceContext();
387 const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC);
391 while (const DeclContext *Parent = ND->getParent()) {
392 if (!isa<NamespaceDecl>(Parent))
394 ND = cast<NamespaceDecl>(Parent);
397 return ND->isStdNamespace();
400 // The GDM component containing the dynamic dispatch bifurcation info. When
401 // the exact type of the receiver is not known, we want to explore both paths -
402 // one on which we do inline it and the other one on which we don't. This is
403 // done to ensure we do not drop coverage.
404 // This is the map from the receiver region to a bool, specifying either we
405 // consider this region's information precise or not along the given path.
407 enum DynamicDispatchMode {
408 DynamicDispatchModeInlined = 1,
409 DynamicDispatchModeConservative
412 REGISTER_TRAIT_WITH_PROGRAMSTATE(DynamicDispatchBifurcationMap,
413 CLANG_ENTO_PROGRAMSTATE_MAP(const MemRegion *,
416 bool ExprEngine::inlineCall(const CallEvent &Call, const Decl *D,
417 NodeBuilder &Bldr, ExplodedNode *Pred,
418 ProgramStateRef State) {
421 const LocationContext *CurLC = Pred->getLocationContext();
422 const StackFrameContext *CallerSFC = CurLC->getCurrentStackFrame();
423 const LocationContext *ParentOfCallee = CallerSFC;
424 if (Call.getKind() == CE_Block) {
425 const BlockDataRegion *BR = cast<BlockCall>(Call).getBlockRegion();
426 assert(BR && "If we have the block definition we should have its region");
427 AnalysisDeclContext *BlockCtx = AMgr.getAnalysisDeclContext(D);
428 ParentOfCallee = BlockCtx->getBlockInvocationContext(CallerSFC,
433 // This may be NULL, but that's fine.
434 const Expr *CallE = Call.getOriginExpr();
436 // Construct a new stack frame for the callee.
437 AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(D);
438 const StackFrameContext *CalleeSFC =
439 CalleeADC->getStackFrame(ParentOfCallee, CallE,
440 currBldrCtx->getBlock(),
444 CallEnter Loc(CallE, CalleeSFC, CurLC);
446 // Construct a new state which contains the mapping from actual to
448 State = State->enterStackFrame(Call, CalleeSFC);
451 if (ExplodedNode *N = G.getNode(Loc, State, false, &isNew)) {
452 N->addPredecessor(Pred, G);
454 Engine.getWorkList()->enqueue(N);
457 // If we decided to inline the call, the successor has been manually
458 // added onto the work list so remove it from the node builder.
459 Bldr.takeNodes(Pred);
463 // Mark the decl as visited.
465 VisitedCallees->insert(D);
470 static ProgramStateRef getInlineFailedState(ProgramStateRef State,
472 const void *ReplayState = State->get<ReplayWithoutInlining>();
476 assert(ReplayState == CallE && "Backtracked to the wrong call.");
479 return State->remove<ReplayWithoutInlining>();
482 void ExprEngine::VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred,
483 ExplodedNodeSet &dst) {
484 // Perform the previsit of the CallExpr.
485 ExplodedNodeSet dstPreVisit;
486 getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, CE, *this);
488 // Get the call in its initial state. We use this as a template to perform
490 CallEventManager &CEMgr = getStateManager().getCallEventManager();
491 CallEventRef<> CallTemplate
492 = CEMgr.getSimpleCall(CE, Pred->getState(), Pred->getLocationContext());
494 // Evaluate the function call. We try each of the checkers
495 // to see if the can evaluate the function call.
496 ExplodedNodeSet dstCallEvaluated;
497 for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end();
499 evalCall(dstCallEvaluated, *I, *CallTemplate);
502 // Finally, perform the post-condition check of the CallExpr and store
503 // the created nodes in 'Dst'.
504 // Note that if the call was inlined, dstCallEvaluated will be empty.
505 // The post-CallExpr check will occur in processCallExit.
506 getCheckerManager().runCheckersForPostStmt(dst, dstCallEvaluated, CE,
510 void ExprEngine::evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred,
511 const CallEvent &Call) {
512 // WARNING: At this time, the state attached to 'Call' may be older than the
513 // state in 'Pred'. This is a minor optimization since CheckerManager will
514 // use an updated CallEvent instance when calling checkers, but if 'Call' is
515 // ever used directly in this function all callers should be updated to pass
516 // the most recent state. (It is probably not worth doing the work here since
517 // for some callers this will not be necessary.)
519 // Run any pre-call checks using the generic call interface.
520 ExplodedNodeSet dstPreVisit;
521 getCheckerManager().runCheckersForPreCall(dstPreVisit, Pred, Call, *this);
523 // Actually evaluate the function call. We try each of the checkers
524 // to see if the can evaluate the function call, and get a callback at
525 // defaultEvalCall if all of them fail.
526 ExplodedNodeSet dstCallEvaluated;
527 getCheckerManager().runCheckersForEvalCall(dstCallEvaluated, dstPreVisit,
530 // Finally, run any post-call checks.
531 getCheckerManager().runCheckersForPostCall(Dst, dstCallEvaluated,
535 ProgramStateRef ExprEngine::bindReturnValue(const CallEvent &Call,
536 const LocationContext *LCtx,
537 ProgramStateRef State) {
538 const Expr *E = Call.getOriginExpr();
542 // Some method families have known return values.
543 if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(&Call)) {
544 switch (Msg->getMethodFamily()) {
547 case OMF_autorelease:
550 // These methods return their receivers.
551 return State->BindExpr(E, LCtx, Msg->getReceiverSVal());
554 } else if (const CXXConstructorCall *C = dyn_cast<CXXConstructorCall>(&Call)){
555 SVal ThisV = C->getCXXThisVal();
557 // If the constructed object is a temporary prvalue, get its bindings.
558 if (isTemporaryPRValue(cast<CXXConstructExpr>(E), ThisV))
559 ThisV = State->getSVal(ThisV.castAs<Loc>());
561 return State->BindExpr(E, LCtx, ThisV);
564 // Conjure a symbol if the return value is unknown.
565 QualType ResultTy = Call.getResultType();
566 SValBuilder &SVB = getSValBuilder();
567 unsigned Count = currBldrCtx->blockCount();
568 SVal R = SVB.conjureSymbolVal(nullptr, E, LCtx, ResultTy, Count);
569 return State->BindExpr(E, LCtx, R);
572 // Conservatively evaluate call by invalidating regions and binding
573 // a conjured return value.
574 void ExprEngine::conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr,
576 ProgramStateRef State) {
577 State = Call.invalidateRegions(currBldrCtx->blockCount(), State);
578 State = bindReturnValue(Call, Pred->getLocationContext(), State);
580 // And make the result node.
581 Bldr.generateNode(Call.getProgramPoint(), State, Pred);
584 enum CallInlinePolicy {
590 static CallInlinePolicy mayInlineCallKind(const CallEvent &Call,
591 const ExplodedNode *Pred,
592 AnalyzerOptions &Opts) {
593 const LocationContext *CurLC = Pred->getLocationContext();
594 const StackFrameContext *CallerSFC = CurLC->getCurrentStackFrame();
595 switch (Call.getKind()) {
600 case CE_CXXMemberOperator:
601 if (!Opts.mayInlineCXXMemberFunction(CIMK_MemberFunctions))
602 return CIP_DisallowedAlways;
604 case CE_CXXConstructor: {
605 if (!Opts.mayInlineCXXMemberFunction(CIMK_Constructors))
606 return CIP_DisallowedAlways;
608 const CXXConstructorCall &Ctor = cast<CXXConstructorCall>(Call);
610 // FIXME: We don't handle constructors or destructors for arrays properly.
611 // Even once we do, we still need to be careful about implicitly-generated
612 // initializers for array fields in default move/copy constructors.
613 const MemRegion *Target = Ctor.getCXXThisVal().getAsRegion();
614 if (Target && isa<ElementRegion>(Target))
615 return CIP_DisallowedOnce;
617 // FIXME: This is a hack. We don't use the correct region for a new
618 // expression, so if we inline the constructor its result will just be
619 // thrown away. This short-term hack is tracked in <rdar://problem/12180598>
620 // and the longer-term possible fix is discussed in PR12014.
621 const CXXConstructExpr *CtorExpr = Ctor.getOriginExpr();
622 if (const Stmt *Parent = CurLC->getParentMap().getParent(CtorExpr))
623 if (isa<CXXNewExpr>(Parent))
624 return CIP_DisallowedOnce;
626 // Inlining constructors requires including initializers in the CFG.
627 const AnalysisDeclContext *ADC = CallerSFC->getAnalysisDeclContext();
628 assert(ADC->getCFGBuildOptions().AddInitializers && "No CFG initializers");
631 // If the destructor is trivial, it's always safe to inline the constructor.
632 if (Ctor.getDecl()->getParent()->hasTrivialDestructor())
635 // For other types, only inline constructors if destructor inlining is
637 if (!Opts.mayInlineCXXMemberFunction(CIMK_Destructors))
638 return CIP_DisallowedAlways;
640 // FIXME: This is a hack. We don't handle temporary destructors
641 // right now, so we shouldn't inline their constructors.
642 if (CtorExpr->getConstructionKind() == CXXConstructExpr::CK_Complete)
643 if (!Target || !isa<DeclRegion>(Target))
644 return CIP_DisallowedOnce;
648 case CE_CXXDestructor: {
649 if (!Opts.mayInlineCXXMemberFunction(CIMK_Destructors))
650 return CIP_DisallowedAlways;
652 // Inlining destructors requires building the CFG correctly.
653 const AnalysisDeclContext *ADC = CallerSFC->getAnalysisDeclContext();
654 assert(ADC->getCFGBuildOptions().AddImplicitDtors && "No CFG destructors");
657 const CXXDestructorCall &Dtor = cast<CXXDestructorCall>(Call);
659 // FIXME: We don't handle constructors or destructors for arrays properly.
660 const MemRegion *Target = Dtor.getCXXThisVal().getAsRegion();
661 if (Target && isa<ElementRegion>(Target))
662 return CIP_DisallowedOnce;
666 case CE_CXXAllocator:
667 if (Opts.mayInlineCXXAllocator())
669 // Do not inline allocators until we model deallocators.
670 // This is unfortunate, but basically necessary for smart pointers and such.
671 return CIP_DisallowedAlways;
673 if (!Opts.mayInlineObjCMethod())
674 return CIP_DisallowedAlways;
675 if (!(Opts.getIPAMode() == IPAK_DynamicDispatch ||
676 Opts.getIPAMode() == IPAK_DynamicDispatchBifurcate))
677 return CIP_DisallowedAlways;
684 /// Returns true if the given C++ class contains a member with the given name.
685 static bool hasMember(const ASTContext &Ctx, const CXXRecordDecl *RD,
687 const IdentifierInfo &II = Ctx.Idents.get(Name);
688 DeclarationName DeclName = Ctx.DeclarationNames.getIdentifier(&II);
689 if (!RD->lookup(DeclName).empty())
692 CXXBasePaths Paths(false, false, false);
693 if (RD->lookupInBases(&CXXRecordDecl::FindOrdinaryMember,
694 DeclName.getAsOpaquePtr(),
701 /// Returns true if the given C++ class is a container or iterator.
703 /// Our heuristic for this is whether it contains a method named 'begin()' or a
704 /// nested type named 'iterator' or 'iterator_category'.
705 static bool isContainerClass(const ASTContext &Ctx, const CXXRecordDecl *RD) {
706 return hasMember(Ctx, RD, "begin") ||
707 hasMember(Ctx, RD, "iterator") ||
708 hasMember(Ctx, RD, "iterator_category");
711 /// Returns true if the given function refers to a method of a C++ container
714 /// We generally do a poor job modeling most containers right now, and might
715 /// prefer not to inline their methods.
716 static bool isContainerMethod(const ASTContext &Ctx,
717 const FunctionDecl *FD) {
718 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD))
719 return isContainerClass(Ctx, MD->getParent());
723 /// Returns true if the given function is the destructor of a class named
725 static bool isCXXSharedPtrDtor(const FunctionDecl *FD) {
726 const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(FD);
730 const CXXRecordDecl *RD = Dtor->getParent();
731 if (const IdentifierInfo *II = RD->getDeclName().getAsIdentifierInfo())
732 if (II->isStr("shared_ptr"))
738 /// Returns true if the function in \p CalleeADC may be inlined in general.
740 /// This checks static properties of the function, such as its signature and
741 /// CFG, to determine whether the analyzer should ever consider inlining it,
743 static bool mayInlineDecl(AnalysisDeclContext *CalleeADC,
744 AnalyzerOptions &Opts) {
745 // FIXME: Do not inline variadic calls.
746 if (CallEvent::isVariadic(CalleeADC->getDecl()))
749 // Check certain C++-related inlining policies.
750 ASTContext &Ctx = CalleeADC->getASTContext();
751 if (Ctx.getLangOpts().CPlusPlus) {
752 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CalleeADC->getDecl())) {
753 // Conditionally control the inlining of template functions.
754 if (!Opts.mayInlineTemplateFunctions())
755 if (FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate)
758 // Conditionally control the inlining of C++ standard library functions.
759 if (!Opts.mayInlineCXXStandardLibrary())
760 if (Ctx.getSourceManager().isInSystemHeader(FD->getLocation()))
761 if (IsInStdNamespace(FD))
764 // Conditionally control the inlining of methods on objects that look
765 // like C++ containers.
766 if (!Opts.mayInlineCXXContainerMethods())
767 if (!Ctx.getSourceManager().isInMainFile(FD->getLocation()))
768 if (isContainerMethod(Ctx, FD))
771 // Conditionally control the inlining of the destructor of C++ shared_ptr.
772 // We don't currently do a good job modeling shared_ptr because we can't
773 // see the reference count, so treating as opaque is probably the best
775 if (!Opts.mayInlineCXXSharedPtrDtor())
776 if (isCXXSharedPtrDtor(FD))
782 // It is possible that the CFG cannot be constructed.
783 // Be safe, and check if the CalleeCFG is valid.
784 const CFG *CalleeCFG = CalleeADC->getCFG();
788 // Do not inline large functions.
789 if (CalleeCFG->getNumBlockIDs() > Opts.getMaxInlinableSize())
792 // It is possible that the live variables analysis cannot be
793 // run. If so, bail out.
794 if (!CalleeADC->getAnalysis<RelaxedLiveVariables>())
800 bool ExprEngine::shouldInlineCall(const CallEvent &Call, const Decl *D,
801 const ExplodedNode *Pred) {
805 AnalysisManager &AMgr = getAnalysisManager();
806 AnalyzerOptions &Opts = AMgr.options;
807 AnalysisDeclContextManager &ADCMgr = AMgr.getAnalysisDeclContextManager();
808 AnalysisDeclContext *CalleeADC = ADCMgr.getContext(D);
810 // Temporary object destructor processing is currently broken, so we never
812 // FIXME: Remove this once temp destructors are working.
813 if (isa<CXXDestructorCall>(Call)) {
814 if ((*currBldrCtx->getBlock())[currStmtIdx].getAs<CFGTemporaryDtor>())
818 // The auto-synthesized bodies are essential to inline as they are
819 // usually small and commonly used. Note: we should do this check early on to
820 // ensure we always inline these calls.
821 if (CalleeADC->isBodyAutosynthesized())
824 if (!AMgr.shouldInlineCall())
827 // Check if this function has been marked as non-inlinable.
828 Optional<bool> MayInline = Engine.FunctionSummaries->mayInline(D);
829 if (MayInline.hasValue()) {
830 if (!MayInline.getValue())
834 // We haven't actually checked the static properties of this function yet.
835 // Do that now, and record our decision in the function summaries.
836 if (mayInlineDecl(CalleeADC, Opts)) {
837 Engine.FunctionSummaries->markMayInline(D);
839 Engine.FunctionSummaries->markShouldNotInline(D);
844 // Check if we should inline a call based on its kind.
845 // FIXME: this checks both static and dynamic properties of the call, which
846 // means we're redoing a bit of work that could be cached in the function
848 CallInlinePolicy CIP = mayInlineCallKind(Call, Pred, Opts);
849 if (CIP != CIP_Allowed) {
850 if (CIP == CIP_DisallowedAlways) {
851 assert(!MayInline.hasValue() || MayInline.getValue());
852 Engine.FunctionSummaries->markShouldNotInline(D);
857 const CFG *CalleeCFG = CalleeADC->getCFG();
859 // Do not inline if recursive or we've reached max stack frame count.
860 bool IsRecursive = false;
861 unsigned StackDepth = 0;
862 examineStackFrames(D, Pred->getLocationContext(), IsRecursive, StackDepth);
863 if ((StackDepth >= Opts.InlineMaxStackDepth) &&
864 ((CalleeCFG->getNumBlockIDs() > Opts.getAlwaysInlineSize())
868 // Do not inline large functions too many times.
869 if ((Engine.FunctionSummaries->getNumTimesInlined(D) >
870 Opts.getMaxTimesInlineLarge()) &&
871 CalleeCFG->getNumBlockIDs() > 13) {
872 NumReachedInlineCountMax++;
876 if (HowToInline == Inline_Minimal &&
877 (CalleeCFG->getNumBlockIDs() > Opts.getAlwaysInlineSize()
881 Engine.FunctionSummaries->bumpNumTimesInlined(D);
886 static bool isTrivialObjectAssignment(const CallEvent &Call) {
887 const CXXInstanceCall *ICall = dyn_cast<CXXInstanceCall>(&Call);
891 const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(ICall->getDecl());
894 if (!(MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()))
897 return MD->isTrivial();
900 void ExprEngine::defaultEvalCall(NodeBuilder &Bldr, ExplodedNode *Pred,
901 const CallEvent &CallTemplate) {
902 // Make sure we have the most recent state attached to the call.
903 ProgramStateRef State = Pred->getState();
904 CallEventRef<> Call = CallTemplate.cloneWithState(State);
906 // Special-case trivial assignment operators.
907 if (isTrivialObjectAssignment(*Call)) {
908 performTrivialCopy(Bldr, Pred, *Call);
912 // Try to inline the call.
913 // The origin expression here is just used as a kind of checksum;
914 // this should still be safe even for CallEvents that don't come from exprs.
915 const Expr *E = Call->getOriginExpr();
917 ProgramStateRef InlinedFailedState = getInlineFailedState(State, E);
918 if (InlinedFailedState) {
919 // If we already tried once and failed, make sure we don't retry later.
920 State = InlinedFailedState;
922 RuntimeDefinition RD = Call->getRuntimeDefinition();
923 const Decl *D = RD.getDecl();
924 if (shouldInlineCall(*Call, D, Pred)) {
925 if (RD.mayHaveOtherDefinitions()) {
926 AnalyzerOptions &Options = getAnalysisManager().options;
928 // Explore with and without inlining the call.
929 if (Options.getIPAMode() == IPAK_DynamicDispatchBifurcate) {
930 BifurcateCall(RD.getDispatchRegion(), *Call, D, Bldr, Pred);
934 // Don't inline if we're not in any dynamic dispatch mode.
935 if (Options.getIPAMode() != IPAK_DynamicDispatch) {
936 conservativeEvalCall(*Call, Bldr, Pred, State);
941 // We are not bifurcating and we do have a Decl, so just inline.
942 if (inlineCall(*Call, D, Bldr, Pred, State))
947 // If we can't inline it, handle the return value and invalidate the regions.
948 conservativeEvalCall(*Call, Bldr, Pred, State);
951 void ExprEngine::BifurcateCall(const MemRegion *BifurReg,
952 const CallEvent &Call, const Decl *D,
953 NodeBuilder &Bldr, ExplodedNode *Pred) {
955 BifurReg = BifurReg->StripCasts();
957 // Check if we've performed the split already - note, we only want
958 // to split the path once per memory region.
959 ProgramStateRef State = Pred->getState();
960 const unsigned *BState =
961 State->get<DynamicDispatchBifurcationMap>(BifurReg);
963 // If we are on "inline path", keep inlining if possible.
964 if (*BState == DynamicDispatchModeInlined)
965 if (inlineCall(Call, D, Bldr, Pred, State))
967 // If inline failed, or we are on the path where we assume we
968 // don't have enough info about the receiver to inline, conjure the
969 // return value and invalidate the regions.
970 conservativeEvalCall(Call, Bldr, Pred, State);
974 // If we got here, this is the first time we process a message to this
975 // region, so split the path.
976 ProgramStateRef IState =
977 State->set<DynamicDispatchBifurcationMap>(BifurReg,
978 DynamicDispatchModeInlined);
979 inlineCall(Call, D, Bldr, Pred, IState);
981 ProgramStateRef NoIState =
982 State->set<DynamicDispatchBifurcationMap>(BifurReg,
983 DynamicDispatchModeConservative);
984 conservativeEvalCall(Call, Bldr, Pred, NoIState);
986 NumOfDynamicDispatchPathSplits++;
991 void ExprEngine::VisitReturnStmt(const ReturnStmt *RS, ExplodedNode *Pred,
992 ExplodedNodeSet &Dst) {
994 ExplodedNodeSet dstPreVisit;
995 getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, RS, *this);
997 StmtNodeBuilder B(dstPreVisit, Dst, *currBldrCtx);
999 if (RS->getRetValue()) {
1000 for (ExplodedNodeSet::iterator it = dstPreVisit.begin(),
1001 ei = dstPreVisit.end(); it != ei; ++it) {
1002 B.generateNode(RS, *it, (*it)->getState());