1 //===- Calls.cpp - Wrapper for all function and method calls ------*- 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 /// \file This file defines CallEvent and its subclasses, which represent path-
11 /// sensitive instances of different kinds of function and method calls
12 /// (C, C++, and Objective-C).
14 //===----------------------------------------------------------------------===//
16 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
17 #include "clang/AST/ParentMap.h"
18 #include "clang/Analysis/ProgramPoint.h"
19 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
20 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicTypeMap.h"
21 #include "llvm/ADT/SmallSet.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/Support/raw_ostream.h"
25 using namespace clang;
28 QualType CallEvent::getResultType() const {
29 const Expr *E = getOriginExpr();
30 assert(E && "Calls without origin expressions do not have results");
31 QualType ResultTy = E->getType();
33 ASTContext &Ctx = getState()->getStateManager().getContext();
35 // A function that returns a reference to 'int' will have a result type
36 // of simply 'int'. Check the origin expr's value kind to recover the
38 switch (E->getValueKind()) {
40 ResultTy = Ctx.getLValueReferenceType(ResultTy);
43 ResultTy = Ctx.getRValueReferenceType(ResultTy);
46 // No adjustment is necessary.
53 static bool isCallback(QualType T) {
54 // If a parameter is a block or a callback, assume it can modify pointer.
55 if (T->isBlockPointerType() ||
56 T->isFunctionPointerType() ||
60 // Check if a callback is passed inside a struct (for both, struct passed by
61 // reference and by value). Dig just one level into the struct for now.
63 if (T->isAnyPointerType() || T->isReferenceType())
64 T = T->getPointeeType();
66 if (const RecordType *RT = T->getAsStructureType()) {
67 const RecordDecl *RD = RT->getDecl();
68 for (const auto *I : RD->fields()) {
69 QualType FieldT = I->getType();
70 if (FieldT->isBlockPointerType() || FieldT->isFunctionPointerType())
77 static bool isVoidPointerToNonConst(QualType T) {
78 if (const PointerType *PT = T->getAs<PointerType>()) {
79 QualType PointeeTy = PT->getPointeeType();
80 if (PointeeTy.isConstQualified())
82 return PointeeTy->isVoidType();
87 bool CallEvent::hasNonNullArgumentsWithType(bool (*Condition)(QualType)) const {
88 unsigned NumOfArgs = getNumArgs();
90 // If calling using a function pointer, assume the function does not
91 // satisfy the callback.
92 // TODO: We could check the types of the arguments here.
97 for (CallEvent::param_type_iterator I = param_type_begin(),
99 I != E && Idx < NumOfArgs; ++I, ++Idx) {
100 if (NumOfArgs <= Idx)
103 // If the parameter is 0, it's harmless.
104 if (getArgSVal(Idx).isZeroConstant())
113 bool CallEvent::hasNonZeroCallbackArg() const {
114 return hasNonNullArgumentsWithType(isCallback);
117 bool CallEvent::hasVoidPointerToNonConstArg() const {
118 return hasNonNullArgumentsWithType(isVoidPointerToNonConst);
121 bool CallEvent::isGlobalCFunction(StringRef FunctionName) const {
122 const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(getDecl());
126 return CheckerContext::isCLibraryFunction(FD, FunctionName);
129 /// \brief Returns true if a type is a pointer-to-const or reference-to-const
130 /// with no further indirection.
131 static bool isPointerToConst(QualType Ty) {
132 QualType PointeeTy = Ty->getPointeeType();
133 if (PointeeTy == QualType())
135 if (!PointeeTy.isConstQualified())
137 if (PointeeTy->isAnyPointerType())
142 // Try to retrieve the function declaration and find the function parameter
143 // types which are pointers/references to a non-pointer const.
144 // We will not invalidate the corresponding argument regions.
145 static void findPtrToConstParams(llvm::SmallSet<unsigned, 4> &PreserveArgs,
146 const CallEvent &Call) {
148 for (CallEvent::param_type_iterator I = Call.param_type_begin(),
149 E = Call.param_type_end();
150 I != E; ++I, ++Idx) {
151 if (isPointerToConst(*I))
152 PreserveArgs.insert(Idx);
156 ProgramStateRef CallEvent::invalidateRegions(unsigned BlockCount,
157 ProgramStateRef Orig) const {
158 ProgramStateRef Result = (Orig ? Orig : getState());
160 // Don't invalidate anything if the callee is marked pure/const.
161 if (const Decl *callee = getDecl())
162 if (callee->hasAttr<PureAttr>() || callee->hasAttr<ConstAttr>())
165 SmallVector<SVal, 8> ValuesToInvalidate;
166 RegionAndSymbolInvalidationTraits ETraits;
168 getExtraInvalidatedValues(ValuesToInvalidate, &ETraits);
170 // Indexes of arguments whose values will be preserved by the call.
171 llvm::SmallSet<unsigned, 4> PreserveArgs;
172 if (!argumentsMayEscape())
173 findPtrToConstParams(PreserveArgs, *this);
175 for (unsigned Idx = 0, Count = getNumArgs(); Idx != Count; ++Idx) {
176 // Mark this region for invalidation. We batch invalidate regions
177 // below for efficiency.
178 if (PreserveArgs.count(Idx))
179 if (const MemRegion *MR = getArgSVal(Idx).getAsRegion())
180 ETraits.setTrait(MR->StripCasts(),
181 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
182 // TODO: Factor this out + handle the lower level const pointers.
184 ValuesToInvalidate.push_back(getArgSVal(Idx));
187 // Invalidate designated regions using the batch invalidation API.
188 // NOTE: Even if RegionsToInvalidate is empty, we may still invalidate
190 return Result->invalidateRegions(ValuesToInvalidate, getOriginExpr(),
191 BlockCount, getLocationContext(),
192 /*CausedByPointerEscape*/ true,
193 /*Symbols=*/nullptr, this, &ETraits);
196 ProgramPoint CallEvent::getProgramPoint(bool IsPreVisit,
197 const ProgramPointTag *Tag) const {
198 if (const Expr *E = getOriginExpr()) {
200 return PreStmt(E, getLocationContext(), Tag);
201 return PostStmt(E, getLocationContext(), Tag);
204 const Decl *D = getDecl();
205 assert(D && "Cannot get a program point without a statement or decl");
207 SourceLocation Loc = getSourceRange().getBegin();
209 return PreImplicitCall(D, Loc, getLocationContext(), Tag);
210 return PostImplicitCall(D, Loc, getLocationContext(), Tag);
213 SVal CallEvent::getArgSVal(unsigned Index) const {
214 const Expr *ArgE = getArgExpr(Index);
217 return getSVal(ArgE);
220 SourceRange CallEvent::getArgSourceRange(unsigned Index) const {
221 const Expr *ArgE = getArgExpr(Index);
223 return SourceRange();
224 return ArgE->getSourceRange();
227 SVal CallEvent::getReturnValue() const {
228 const Expr *E = getOriginExpr();
230 return UndefinedVal();
234 LLVM_DUMP_METHOD void CallEvent::dump() const { dump(llvm::errs()); }
236 void CallEvent::dump(raw_ostream &Out) const {
237 ASTContext &Ctx = getState()->getStateManager().getContext();
238 if (const Expr *E = getOriginExpr()) {
239 E->printPretty(Out, nullptr, Ctx.getPrintingPolicy());
244 if (const Decl *D = getDecl()) {
246 D->print(Out, Ctx.getPrintingPolicy());
250 // FIXME: a string representation of the kind would be nice.
251 Out << "Unknown call (type " << getKind() << ")";
255 bool CallEvent::isCallStmt(const Stmt *S) {
256 return isa<CallExpr>(S) || isa<ObjCMessageExpr>(S)
257 || isa<CXXConstructExpr>(S)
258 || isa<CXXNewExpr>(S);
261 QualType CallEvent::getDeclaredResultType(const Decl *D) {
263 if (const FunctionDecl* FD = dyn_cast<FunctionDecl>(D))
264 return FD->getReturnType();
265 if (const ObjCMethodDecl* MD = dyn_cast<ObjCMethodDecl>(D))
266 return MD->getReturnType();
267 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
268 // Blocks are difficult because the return type may not be stored in the
269 // BlockDecl itself. The AST should probably be enhanced, but for now we
270 // just do what we can.
271 // If the block is declared without an explicit argument list, the
272 // signature-as-written just includes the return type, not the entire
274 // FIXME: All blocks should have signatures-as-written, even if the return
275 // type is inferred. (That's signified with a dependent result type.)
276 if (const TypeSourceInfo *TSI = BD->getSignatureAsWritten()) {
277 QualType Ty = TSI->getType();
278 if (const FunctionType *FT = Ty->getAs<FunctionType>())
279 Ty = FT->getReturnType();
280 if (!Ty->isDependentType())
287 llvm_unreachable("unknown callable kind");
290 bool CallEvent::isVariadic(const Decl *D) {
293 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
294 return FD->isVariadic();
295 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
296 return MD->isVariadic();
297 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D))
298 return BD->isVariadic();
300 llvm_unreachable("unknown callable kind");
303 static void addParameterValuesToBindings(const StackFrameContext *CalleeCtx,
304 CallEvent::BindingsTy &Bindings,
306 const CallEvent &Call,
307 ArrayRef<ParmVarDecl*> parameters) {
308 MemRegionManager &MRMgr = SVB.getRegionManager();
310 // If the function has fewer parameters than the call has arguments, we simply
311 // do not bind any values to them.
312 unsigned NumArgs = Call.getNumArgs();
314 ArrayRef<ParmVarDecl*>::iterator I = parameters.begin(), E = parameters.end();
315 for (; I != E && Idx < NumArgs; ++I, ++Idx) {
316 const ParmVarDecl *ParamDecl = *I;
317 assert(ParamDecl && "Formal parameter has no decl?");
319 SVal ArgVal = Call.getArgSVal(Idx);
320 if (!ArgVal.isUnknown()) {
321 Loc ParamLoc = SVB.makeLoc(MRMgr.getVarRegion(ParamDecl, CalleeCtx));
322 Bindings.push_back(std::make_pair(ParamLoc, ArgVal));
326 // FIXME: Variadic arguments are not handled at all right now.
329 ArrayRef<ParmVarDecl*> AnyFunctionCall::parameters() const {
330 const FunctionDecl *D = getDecl();
333 return D->parameters();
336 void AnyFunctionCall::getInitialStackFrameContents(
337 const StackFrameContext *CalleeCtx,
338 BindingsTy &Bindings) const {
339 const FunctionDecl *D = cast<FunctionDecl>(CalleeCtx->getDecl());
340 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
341 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
345 bool AnyFunctionCall::argumentsMayEscape() const {
346 if (CallEvent::argumentsMayEscape() || hasVoidPointerToNonConstArg())
349 const FunctionDecl *D = getDecl();
353 const IdentifierInfo *II = D->getIdentifier();
357 // This set of "escaping" APIs is
359 // - 'int pthread_setspecific(ptheread_key k, const void *)' stores a
360 // value into thread local storage. The value can later be retrieved with
361 // 'void *ptheread_getspecific(pthread_key)'. So even thought the
362 // parameter is 'const void *', the region escapes through the call.
363 if (II->isStr("pthread_setspecific"))
366 // - xpc_connection_set_context stores a value which can be retrieved later
367 // with xpc_connection_get_context.
368 if (II->isStr("xpc_connection_set_context"))
371 // - funopen - sets a buffer for future IO calls.
372 if (II->isStr("funopen"))
375 StringRef FName = II->getName();
377 // - CoreFoundation functions that end with "NoCopy" can free a passed-in
378 // buffer even if it is const.
379 if (FName.endswith("NoCopy"))
382 // - NSXXInsertXX, for example NSMapInsertIfAbsent, since they can
383 // be deallocated by NSMapRemove.
384 if (FName.startswith("NS") && (FName.find("Insert") != StringRef::npos))
387 // - Many CF containers allow objects to escape through custom
388 // allocators/deallocators upon container construction. (PR12101)
389 if (FName.startswith("CF") || FName.startswith("CG")) {
390 return StrInStrNoCase(FName, "InsertValue") != StringRef::npos ||
391 StrInStrNoCase(FName, "AddValue") != StringRef::npos ||
392 StrInStrNoCase(FName, "SetValue") != StringRef::npos ||
393 StrInStrNoCase(FName, "WithData") != StringRef::npos ||
394 StrInStrNoCase(FName, "AppendValue") != StringRef::npos ||
395 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos;
402 const FunctionDecl *SimpleFunctionCall::getDecl() const {
403 const FunctionDecl *D = getOriginExpr()->getDirectCallee();
407 return getSVal(getOriginExpr()->getCallee()).getAsFunctionDecl();
411 const FunctionDecl *CXXInstanceCall::getDecl() const {
412 const CallExpr *CE = cast_or_null<CallExpr>(getOriginExpr());
414 return AnyFunctionCall::getDecl();
416 const FunctionDecl *D = CE->getDirectCallee();
420 return getSVal(CE->getCallee()).getAsFunctionDecl();
423 void CXXInstanceCall::getExtraInvalidatedValues(
424 ValueList &Values, RegionAndSymbolInvalidationTraits *ETraits) const {
425 SVal ThisVal = getCXXThisVal();
426 Values.push_back(ThisVal);
428 // Don't invalidate if the method is const and there are no mutable fields.
429 if (const CXXMethodDecl *D = cast_or_null<CXXMethodDecl>(getDecl())) {
432 // Get the record decl for the class of 'This'. D->getParent() may return a
433 // base class decl, rather than the class of the instance which needs to be
434 // checked for mutable fields.
435 const Expr *Ex = getCXXThisExpr()->ignoreParenBaseCasts();
436 const CXXRecordDecl *ParentRecord = Ex->getType()->getAsCXXRecordDecl();
437 if (!ParentRecord || ParentRecord->hasMutableFields())
440 const MemRegion *ThisRegion = ThisVal.getAsRegion();
444 ETraits->setTrait(ThisRegion->getBaseRegion(),
445 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
449 SVal CXXInstanceCall::getCXXThisVal() const {
450 const Expr *Base = getCXXThisExpr();
451 // FIXME: This doesn't handle an overloaded ->* operator.
455 SVal ThisVal = getSVal(Base);
456 assert(ThisVal.isUnknownOrUndef() || ThisVal.getAs<Loc>());
461 RuntimeDefinition CXXInstanceCall::getRuntimeDefinition() const {
462 // Do we have a decl at all?
463 const Decl *D = getDecl();
465 return RuntimeDefinition();
467 // If the method is non-virtual, we know we can inline it.
468 const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
469 if (!MD->isVirtual())
470 return AnyFunctionCall::getRuntimeDefinition();
472 // Do we know the implicit 'this' object being called?
473 const MemRegion *R = getCXXThisVal().getAsRegion();
475 return RuntimeDefinition();
477 // Do we know anything about the type of 'this'?
478 DynamicTypeInfo DynType = getDynamicTypeInfo(getState(), R);
479 if (!DynType.isValid())
480 return RuntimeDefinition();
482 // Is the type a C++ class? (This is mostly a defensive check.)
483 QualType RegionType = DynType.getType()->getPointeeType();
484 assert(!RegionType.isNull() && "DynamicTypeInfo should always be a pointer.");
486 const CXXRecordDecl *RD = RegionType->getAsCXXRecordDecl();
487 if (!RD || !RD->hasDefinition())
488 return RuntimeDefinition();
490 // Find the decl for this method in that class.
491 const CXXMethodDecl *Result = MD->getCorrespondingMethodInClass(RD, true);
493 // We might not even get the original statically-resolved method due to
494 // some particularly nasty casting (e.g. casts to sister classes).
495 // However, we should at least be able to search up and down our own class
496 // hierarchy, and some real bugs have been caught by checking this.
497 assert(!RD->isDerivedFrom(MD->getParent()) && "Couldn't find known method");
499 // FIXME: This is checking that our DynamicTypeInfo is at least as good as
500 // the static type. However, because we currently don't update
501 // DynamicTypeInfo when an object is cast, we can't actually be sure the
502 // DynamicTypeInfo is up to date. This assert should be re-enabled once
503 // this is fixed. <rdar://problem/12287087>
504 //assert(!MD->getParent()->isDerivedFrom(RD) && "Bad DynamicTypeInfo");
506 return RuntimeDefinition();
509 // Does the decl that we found have an implementation?
510 const FunctionDecl *Definition;
511 if (!Result->hasBody(Definition))
512 return RuntimeDefinition();
514 // We found a definition. If we're not sure that this devirtualization is
515 // actually what will happen at runtime, make sure to provide the region so
516 // that ExprEngine can decide what to do with it.
517 if (DynType.canBeASubClass())
518 return RuntimeDefinition(Definition, R->StripCasts());
519 return RuntimeDefinition(Definition, /*DispatchRegion=*/nullptr);
522 void CXXInstanceCall::getInitialStackFrameContents(
523 const StackFrameContext *CalleeCtx,
524 BindingsTy &Bindings) const {
525 AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings);
527 // Handle the binding of 'this' in the new stack frame.
528 SVal ThisVal = getCXXThisVal();
529 if (!ThisVal.isUnknown()) {
530 ProgramStateManager &StateMgr = getState()->getStateManager();
531 SValBuilder &SVB = StateMgr.getSValBuilder();
533 const CXXMethodDecl *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl());
534 Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx);
536 // If we devirtualized to a different member function, we need to make sure
537 // we have the proper layering of CXXBaseObjectRegions.
538 if (MD->getCanonicalDecl() != getDecl()->getCanonicalDecl()) {
539 ASTContext &Ctx = SVB.getContext();
540 const CXXRecordDecl *Class = MD->getParent();
541 QualType Ty = Ctx.getPointerType(Ctx.getRecordType(Class));
543 // FIXME: CallEvent maybe shouldn't be directly accessing StoreManager.
545 ThisVal = StateMgr.getStoreManager().evalDynamicCast(ThisVal, Ty, Failed);
546 assert(!Failed && "Calling an incorrectly devirtualized method");
549 if (!ThisVal.isUnknown())
550 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
556 const Expr *CXXMemberCall::getCXXThisExpr() const {
557 return getOriginExpr()->getImplicitObjectArgument();
560 RuntimeDefinition CXXMemberCall::getRuntimeDefinition() const {
561 // C++11 [expr.call]p1: ...If the selected function is non-virtual, or if the
562 // id-expression in the class member access expression is a qualified-id,
563 // that function is called. Otherwise, its final overrider in the dynamic type
564 // of the object expression is called.
565 if (const MemberExpr *ME = dyn_cast<MemberExpr>(getOriginExpr()->getCallee()))
566 if (ME->hasQualifier())
567 return AnyFunctionCall::getRuntimeDefinition();
569 return CXXInstanceCall::getRuntimeDefinition();
573 const Expr *CXXMemberOperatorCall::getCXXThisExpr() const {
574 return getOriginExpr()->getArg(0);
578 const BlockDataRegion *BlockCall::getBlockRegion() const {
579 const Expr *Callee = getOriginExpr()->getCallee();
580 const MemRegion *DataReg = getSVal(Callee).getAsRegion();
582 return dyn_cast_or_null<BlockDataRegion>(DataReg);
585 ArrayRef<ParmVarDecl*> BlockCall::parameters() const {
586 const BlockDecl *D = getDecl();
589 return D->parameters();
592 void BlockCall::getExtraInvalidatedValues(ValueList &Values,
593 RegionAndSymbolInvalidationTraits *ETraits) const {
594 // FIXME: This also needs to invalidate captured globals.
595 if (const MemRegion *R = getBlockRegion())
596 Values.push_back(loc::MemRegionVal(R));
599 void BlockCall::getInitialStackFrameContents(const StackFrameContext *CalleeCtx,
600 BindingsTy &Bindings) const {
601 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
602 ArrayRef<ParmVarDecl*> Params;
603 if (isConversionFromLambda()) {
604 auto *LambdaOperatorDecl = cast<CXXMethodDecl>(CalleeCtx->getDecl());
605 Params = LambdaOperatorDecl->parameters();
607 // For blocks converted from a C++ lambda, the callee declaration is the
608 // operator() method on the lambda so we bind "this" to
609 // the lambda captured by the block.
610 const VarRegion *CapturedLambdaRegion = getRegionStoringCapturedLambda();
611 SVal ThisVal = loc::MemRegionVal(CapturedLambdaRegion);
612 Loc ThisLoc = SVB.getCXXThis(LambdaOperatorDecl, CalleeCtx);
613 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
615 Params = cast<BlockDecl>(CalleeCtx->getDecl())->parameters();
618 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
623 SVal CXXConstructorCall::getCXXThisVal() const {
625 return loc::MemRegionVal(static_cast<const MemRegion *>(Data));
629 void CXXConstructorCall::getExtraInvalidatedValues(ValueList &Values,
630 RegionAndSymbolInvalidationTraits *ETraits) const {
632 Values.push_back(loc::MemRegionVal(static_cast<const MemRegion *>(Data)));
635 void CXXConstructorCall::getInitialStackFrameContents(
636 const StackFrameContext *CalleeCtx,
637 BindingsTy &Bindings) const {
638 AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings);
640 SVal ThisVal = getCXXThisVal();
641 if (!ThisVal.isUnknown()) {
642 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
643 const CXXMethodDecl *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl());
644 Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx);
645 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
649 SVal CXXDestructorCall::getCXXThisVal() const {
651 return loc::MemRegionVal(DtorDataTy::getFromOpaqueValue(Data).getPointer());
655 RuntimeDefinition CXXDestructorCall::getRuntimeDefinition() const {
656 // Base destructors are always called non-virtually.
657 // Skip CXXInstanceCall's devirtualization logic in this case.
658 if (isBaseDestructor())
659 return AnyFunctionCall::getRuntimeDefinition();
661 return CXXInstanceCall::getRuntimeDefinition();
664 ArrayRef<ParmVarDecl*> ObjCMethodCall::parameters() const {
665 const ObjCMethodDecl *D = getDecl();
668 return D->parameters();
672 ObjCMethodCall::getExtraInvalidatedValues(ValueList &Values,
673 RegionAndSymbolInvalidationTraits *ETraits) const {
674 Values.push_back(getReceiverSVal());
677 SVal ObjCMethodCall::getSelfSVal() const {
678 const LocationContext *LCtx = getLocationContext();
679 const ImplicitParamDecl *SelfDecl = LCtx->getSelfDecl();
682 return getState()->getSVal(getState()->getRegion(SelfDecl, LCtx));
685 SVal ObjCMethodCall::getReceiverSVal() const {
686 // FIXME: Is this the best way to handle class receivers?
687 if (!isInstanceMessage())
690 if (const Expr *RecE = getOriginExpr()->getInstanceReceiver())
691 return getSVal(RecE);
693 // An instance message with no expression means we are sending to super.
694 // In this case the object reference is the same as 'self'.
695 assert(getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance);
696 SVal SelfVal = getSelfSVal();
697 assert(SelfVal.isValid() && "Calling super but not in ObjC method");
701 bool ObjCMethodCall::isReceiverSelfOrSuper() const {
702 if (getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance ||
703 getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperClass)
706 if (!isInstanceMessage())
709 SVal RecVal = getSVal(getOriginExpr()->getInstanceReceiver());
711 return (RecVal == getSelfSVal());
714 SourceRange ObjCMethodCall::getSourceRange() const {
715 switch (getMessageKind()) {
717 return getOriginExpr()->getSourceRange();
718 case OCM_PropertyAccess:
720 return getContainingPseudoObjectExpr()->getSourceRange();
722 llvm_unreachable("unknown message kind");
725 typedef llvm::PointerIntPair<const PseudoObjectExpr *, 2> ObjCMessageDataTy;
727 const PseudoObjectExpr *ObjCMethodCall::getContainingPseudoObjectExpr() const {
728 assert(Data && "Lazy lookup not yet performed.");
729 assert(getMessageKind() != OCM_Message && "Explicit message send.");
730 return ObjCMessageDataTy::getFromOpaqueValue(Data).getPointer();
733 ObjCMessageKind ObjCMethodCall::getMessageKind() const {
736 // Find the parent, ignoring implicit casts.
737 ParentMap &PM = getLocationContext()->getParentMap();
738 const Stmt *S = PM.getParentIgnoreParenCasts(getOriginExpr());
740 // Check if parent is a PseudoObjectExpr.
741 if (const PseudoObjectExpr *POE = dyn_cast_or_null<PseudoObjectExpr>(S)) {
742 const Expr *Syntactic = POE->getSyntacticForm();
744 // This handles the funny case of assigning to the result of a getter.
745 // This can happen if the getter returns a non-const reference.
746 if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(Syntactic))
747 Syntactic = BO->getLHS();
750 switch (Syntactic->getStmtClass()) {
751 case Stmt::ObjCPropertyRefExprClass:
752 K = OCM_PropertyAccess;
754 case Stmt::ObjCSubscriptRefExprClass:
758 // FIXME: Can this ever happen?
763 if (K != OCM_Message) {
764 const_cast<ObjCMethodCall *>(this)->Data
765 = ObjCMessageDataTy(POE, K).getOpaqueValue();
766 assert(getMessageKind() == K);
771 const_cast<ObjCMethodCall *>(this)->Data
772 = ObjCMessageDataTy(nullptr, 1).getOpaqueValue();
773 assert(getMessageKind() == OCM_Message);
777 ObjCMessageDataTy Info = ObjCMessageDataTy::getFromOpaqueValue(Data);
778 if (!Info.getPointer())
780 return static_cast<ObjCMessageKind>(Info.getInt());
784 bool ObjCMethodCall::canBeOverridenInSubclass(ObjCInterfaceDecl *IDecl,
785 Selector Sel) const {
787 const SourceManager &SM =
788 getState()->getStateManager().getContext().getSourceManager();
790 // If the class interface is declared inside the main file, assume it is not
792 // TODO: It could actually be subclassed if the subclass is private as well.
793 // This is probably very rare.
794 SourceLocation InterfLoc = IDecl->getEndOfDefinitionLoc();
795 if (InterfLoc.isValid() && SM.isInMainFile(InterfLoc))
798 // Assume that property accessors are not overridden.
799 if (getMessageKind() == OCM_PropertyAccess)
802 // We assume that if the method is public (declared outside of main file) or
803 // has a parent which publicly declares the method, the method could be
804 // overridden in a subclass.
806 // Find the first declaration in the class hierarchy that declares
808 ObjCMethodDecl *D = nullptr;
810 D = IDecl->lookupMethod(Sel, true);
812 // Cannot find a public definition.
816 // If outside the main file,
817 if (D->getLocation().isValid() && !SM.isInMainFile(D->getLocation()))
820 if (D->isOverriding()) {
821 // Search in the superclass on the next iteration.
822 IDecl = D->getClassInterface();
826 IDecl = IDecl->getSuperClass();
836 llvm_unreachable("The while loop should always terminate.");
839 RuntimeDefinition ObjCMethodCall::getRuntimeDefinition() const {
840 const ObjCMessageExpr *E = getOriginExpr();
842 Selector Sel = E->getSelector();
844 if (E->isInstanceMessage()) {
846 // Find the receiver type.
847 const ObjCObjectPointerType *ReceiverT = nullptr;
848 bool CanBeSubClassed = false;
849 QualType SupersType = E->getSuperType();
850 const MemRegion *Receiver = nullptr;
852 if (!SupersType.isNull()) {
853 // Super always means the type of immediate predecessor to the method
854 // where the call occurs.
855 ReceiverT = cast<ObjCObjectPointerType>(SupersType);
857 Receiver = getReceiverSVal().getAsRegion();
859 return RuntimeDefinition();
861 DynamicTypeInfo DTI = getDynamicTypeInfo(getState(), Receiver);
862 QualType DynType = DTI.getType();
863 CanBeSubClassed = DTI.canBeASubClass();
864 ReceiverT = dyn_cast<ObjCObjectPointerType>(DynType);
866 if (ReceiverT && CanBeSubClassed)
867 if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl())
868 if (!canBeOverridenInSubclass(IDecl, Sel))
869 CanBeSubClassed = false;
872 // Lookup the method implementation.
874 if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) {
875 // Repeatedly calling lookupPrivateMethod() is expensive, especially
876 // when in many cases it returns null. We cache the results so
877 // that repeated queries on the same ObjCIntefaceDecl and Selector
878 // don't incur the same cost. On some test cases, we can see the
879 // same query being issued thousands of times.
881 // NOTE: This cache is essentially a "global" variable, but it
882 // only gets lazily created when we get here. The value of the
883 // cache probably comes from it being global across ExprEngines,
884 // where the same queries may get issued. If we are worried about
885 // concurrency, or possibly loading/unloading ASTs, etc., we may
886 // need to revisit this someday. In terms of memory, this table
887 // stays around until clang quits, which also may be bad if we
888 // need to release memory.
889 typedef std::pair<const ObjCInterfaceDecl*, Selector>
891 typedef llvm::DenseMap<PrivateMethodKey,
892 Optional<const ObjCMethodDecl *> >
895 static PrivateMethodCache PMC;
896 Optional<const ObjCMethodDecl *> &Val = PMC[std::make_pair(IDecl, Sel)];
898 // Query lookupPrivateMethod() if the cache does not hit.
899 if (!Val.hasValue()) {
900 Val = IDecl->lookupPrivateMethod(Sel);
902 // If the method is a property accessor, we should try to "inline" it
903 // even if we don't actually have an implementation.
905 if (const ObjCMethodDecl *CompileTimeMD = E->getMethodDecl())
906 if (CompileTimeMD->isPropertyAccessor())
907 Val = IDecl->lookupInstanceMethod(Sel);
910 const ObjCMethodDecl *MD = Val.getValue();
912 return RuntimeDefinition(MD, Receiver);
914 return RuntimeDefinition(MD, nullptr);
918 // This is a class method.
919 // If we have type info for the receiver class, we are calling via
921 if (ObjCInterfaceDecl *IDecl = E->getReceiverInterface()) {
922 // Find/Return the method implementation.
923 return RuntimeDefinition(IDecl->lookupPrivateClassMethod(Sel));
927 return RuntimeDefinition();
930 bool ObjCMethodCall::argumentsMayEscape() const {
931 if (isInSystemHeader() && !isInstanceMessage()) {
932 Selector Sel = getSelector();
933 if (Sel.getNumArgs() == 1 &&
934 Sel.getIdentifierInfoForSlot(0)->isStr("valueWithPointer"))
938 return CallEvent::argumentsMayEscape();
941 void ObjCMethodCall::getInitialStackFrameContents(
942 const StackFrameContext *CalleeCtx,
943 BindingsTy &Bindings) const {
944 const ObjCMethodDecl *D = cast<ObjCMethodDecl>(CalleeCtx->getDecl());
945 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
946 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
949 SVal SelfVal = getReceiverSVal();
950 if (!SelfVal.isUnknown()) {
951 const VarDecl *SelfD = CalleeCtx->getAnalysisDeclContext()->getSelfDecl();
952 MemRegionManager &MRMgr = SVB.getRegionManager();
953 Loc SelfLoc = SVB.makeLoc(MRMgr.getVarRegion(SelfD, CalleeCtx));
954 Bindings.push_back(std::make_pair(SelfLoc, SelfVal));
959 CallEventManager::getSimpleCall(const CallExpr *CE, ProgramStateRef State,
960 const LocationContext *LCtx) {
961 if (const CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(CE))
962 return create<CXXMemberCall>(MCE, State, LCtx);
964 if (const CXXOperatorCallExpr *OpCE = dyn_cast<CXXOperatorCallExpr>(CE)) {
965 const FunctionDecl *DirectCallee = OpCE->getDirectCallee();
966 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DirectCallee))
967 if (MD->isInstance())
968 return create<CXXMemberOperatorCall>(OpCE, State, LCtx);
970 } else if (CE->getCallee()->getType()->isBlockPointerType()) {
971 return create<BlockCall>(CE, State, LCtx);
974 // Otherwise, it's a normal function call, static member function call, or
975 // something we can't reason about.
976 return create<SimpleFunctionCall>(CE, State, LCtx);
981 CallEventManager::getCaller(const StackFrameContext *CalleeCtx,
982 ProgramStateRef State) {
983 const LocationContext *ParentCtx = CalleeCtx->getParent();
984 const LocationContext *CallerCtx = ParentCtx->getCurrentStackFrame();
985 assert(CallerCtx && "This should not be used for top-level stack frames");
987 const Stmt *CallSite = CalleeCtx->getCallSite();
990 if (const CallExpr *CE = dyn_cast<CallExpr>(CallSite))
991 return getSimpleCall(CE, State, CallerCtx);
993 switch (CallSite->getStmtClass()) {
994 case Stmt::CXXConstructExprClass:
995 case Stmt::CXXTemporaryObjectExprClass: {
996 SValBuilder &SVB = State->getStateManager().getSValBuilder();
997 const CXXMethodDecl *Ctor = cast<CXXMethodDecl>(CalleeCtx->getDecl());
998 Loc ThisPtr = SVB.getCXXThis(Ctor, CalleeCtx);
999 SVal ThisVal = State->getSVal(ThisPtr);
1001 return getCXXConstructorCall(cast<CXXConstructExpr>(CallSite),
1002 ThisVal.getAsRegion(), State, CallerCtx);
1004 case Stmt::CXXNewExprClass:
1005 return getCXXAllocatorCall(cast<CXXNewExpr>(CallSite), State, CallerCtx);
1006 case Stmt::ObjCMessageExprClass:
1007 return getObjCMethodCall(cast<ObjCMessageExpr>(CallSite),
1010 llvm_unreachable("This is not an inlineable statement.");
1014 // Fall back to the CFG. The only thing we haven't handled yet is
1015 // destructors, though this could change in the future.
1016 const CFGBlock *B = CalleeCtx->getCallSiteBlock();
1017 CFGElement E = (*B)[CalleeCtx->getIndex()];
1018 assert(E.getAs<CFGImplicitDtor>() &&
1019 "All other CFG elements should have exprs");
1020 assert(!E.getAs<CFGTemporaryDtor>() && "We don't handle temporaries yet");
1022 SValBuilder &SVB = State->getStateManager().getSValBuilder();
1023 const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CalleeCtx->getDecl());
1024 Loc ThisPtr = SVB.getCXXThis(Dtor, CalleeCtx);
1025 SVal ThisVal = State->getSVal(ThisPtr);
1027 const Stmt *Trigger;
1028 if (Optional<CFGAutomaticObjDtor> AutoDtor = E.getAs<CFGAutomaticObjDtor>())
1029 Trigger = AutoDtor->getTriggerStmt();
1030 else if (Optional<CFGDeleteDtor> DeleteDtor = E.getAs<CFGDeleteDtor>())
1031 Trigger = cast<Stmt>(DeleteDtor->getDeleteExpr());
1033 Trigger = Dtor->getBody();
1035 return getCXXDestructorCall(Dtor, Trigger, ThisVal.getAsRegion(),
1036 E.getAs<CFGBaseDtor>().hasValue(), State,