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->getBaseRegion(),
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 bool CallEvent::isCalled(const CallDescription &CD) const {
214 assert(getKind() != CE_ObjCMessage && "Obj-C methods are not supported");
216 CD.II = &getState()->getStateManager().getContext().Idents.get(CD.FuncName);
217 if (getCalleeIdentifier() != CD.II)
219 return (CD.RequiredArgs == CallDescription::NoArgRequirement ||
220 CD.RequiredArgs == getNumArgs());
223 SVal CallEvent::getArgSVal(unsigned Index) const {
224 const Expr *ArgE = getArgExpr(Index);
227 return getSVal(ArgE);
230 SourceRange CallEvent::getArgSourceRange(unsigned Index) const {
231 const Expr *ArgE = getArgExpr(Index);
233 return SourceRange();
234 return ArgE->getSourceRange();
237 SVal CallEvent::getReturnValue() const {
238 const Expr *E = getOriginExpr();
240 return UndefinedVal();
244 LLVM_DUMP_METHOD void CallEvent::dump() const { dump(llvm::errs()); }
246 void CallEvent::dump(raw_ostream &Out) const {
247 ASTContext &Ctx = getState()->getStateManager().getContext();
248 if (const Expr *E = getOriginExpr()) {
249 E->printPretty(Out, nullptr, Ctx.getPrintingPolicy());
254 if (const Decl *D = getDecl()) {
256 D->print(Out, Ctx.getPrintingPolicy());
260 // FIXME: a string representation of the kind would be nice.
261 Out << "Unknown call (type " << getKind() << ")";
265 bool CallEvent::isCallStmt(const Stmt *S) {
266 return isa<CallExpr>(S) || isa<ObjCMessageExpr>(S)
267 || isa<CXXConstructExpr>(S)
268 || isa<CXXNewExpr>(S);
271 QualType CallEvent::getDeclaredResultType(const Decl *D) {
273 if (const FunctionDecl* FD = dyn_cast<FunctionDecl>(D))
274 return FD->getReturnType();
275 if (const ObjCMethodDecl* MD = dyn_cast<ObjCMethodDecl>(D))
276 return MD->getReturnType();
277 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
278 // Blocks are difficult because the return type may not be stored in the
279 // BlockDecl itself. The AST should probably be enhanced, but for now we
280 // just do what we can.
281 // If the block is declared without an explicit argument list, the
282 // signature-as-written just includes the return type, not the entire
284 // FIXME: All blocks should have signatures-as-written, even if the return
285 // type is inferred. (That's signified with a dependent result type.)
286 if (const TypeSourceInfo *TSI = BD->getSignatureAsWritten()) {
287 QualType Ty = TSI->getType();
288 if (const FunctionType *FT = Ty->getAs<FunctionType>())
289 Ty = FT->getReturnType();
290 if (!Ty->isDependentType())
297 llvm_unreachable("unknown callable kind");
300 bool CallEvent::isVariadic(const Decl *D) {
303 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
304 return FD->isVariadic();
305 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
306 return MD->isVariadic();
307 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D))
308 return BD->isVariadic();
310 llvm_unreachable("unknown callable kind");
313 static void addParameterValuesToBindings(const StackFrameContext *CalleeCtx,
314 CallEvent::BindingsTy &Bindings,
316 const CallEvent &Call,
317 ArrayRef<ParmVarDecl*> parameters) {
318 MemRegionManager &MRMgr = SVB.getRegionManager();
320 // If the function has fewer parameters than the call has arguments, we simply
321 // do not bind any values to them.
322 unsigned NumArgs = Call.getNumArgs();
324 ArrayRef<ParmVarDecl*>::iterator I = parameters.begin(), E = parameters.end();
325 for (; I != E && Idx < NumArgs; ++I, ++Idx) {
326 const ParmVarDecl *ParamDecl = *I;
327 assert(ParamDecl && "Formal parameter has no decl?");
329 SVal ArgVal = Call.getArgSVal(Idx);
330 if (!ArgVal.isUnknown()) {
331 Loc ParamLoc = SVB.makeLoc(MRMgr.getVarRegion(ParamDecl, CalleeCtx));
332 Bindings.push_back(std::make_pair(ParamLoc, ArgVal));
336 // FIXME: Variadic arguments are not handled at all right now.
339 ArrayRef<ParmVarDecl*> AnyFunctionCall::parameters() const {
340 const FunctionDecl *D = getDecl();
343 return D->parameters();
346 void AnyFunctionCall::getInitialStackFrameContents(
347 const StackFrameContext *CalleeCtx,
348 BindingsTy &Bindings) const {
349 const FunctionDecl *D = cast<FunctionDecl>(CalleeCtx->getDecl());
350 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
351 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
355 bool AnyFunctionCall::argumentsMayEscape() const {
356 if (CallEvent::argumentsMayEscape() || hasVoidPointerToNonConstArg())
359 const FunctionDecl *D = getDecl();
363 const IdentifierInfo *II = D->getIdentifier();
367 // This set of "escaping" APIs is
369 // - 'int pthread_setspecific(ptheread_key k, const void *)' stores a
370 // value into thread local storage. The value can later be retrieved with
371 // 'void *ptheread_getspecific(pthread_key)'. So even thought the
372 // parameter is 'const void *', the region escapes through the call.
373 if (II->isStr("pthread_setspecific"))
376 // - xpc_connection_set_context stores a value which can be retrieved later
377 // with xpc_connection_get_context.
378 if (II->isStr("xpc_connection_set_context"))
381 // - funopen - sets a buffer for future IO calls.
382 if (II->isStr("funopen"))
385 StringRef FName = II->getName();
387 // - CoreFoundation functions that end with "NoCopy" can free a passed-in
388 // buffer even if it is const.
389 if (FName.endswith("NoCopy"))
392 // - NSXXInsertXX, for example NSMapInsertIfAbsent, since they can
393 // be deallocated by NSMapRemove.
394 if (FName.startswith("NS") && (FName.find("Insert") != StringRef::npos))
397 // - Many CF containers allow objects to escape through custom
398 // allocators/deallocators upon container construction. (PR12101)
399 if (FName.startswith("CF") || FName.startswith("CG")) {
400 return StrInStrNoCase(FName, "InsertValue") != StringRef::npos ||
401 StrInStrNoCase(FName, "AddValue") != StringRef::npos ||
402 StrInStrNoCase(FName, "SetValue") != StringRef::npos ||
403 StrInStrNoCase(FName, "WithData") != StringRef::npos ||
404 StrInStrNoCase(FName, "AppendValue") != StringRef::npos ||
405 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos;
412 const FunctionDecl *SimpleFunctionCall::getDecl() const {
413 const FunctionDecl *D = getOriginExpr()->getDirectCallee();
417 return getSVal(getOriginExpr()->getCallee()).getAsFunctionDecl();
421 const FunctionDecl *CXXInstanceCall::getDecl() const {
422 const CallExpr *CE = cast_or_null<CallExpr>(getOriginExpr());
424 return AnyFunctionCall::getDecl();
426 const FunctionDecl *D = CE->getDirectCallee();
430 return getSVal(CE->getCallee()).getAsFunctionDecl();
433 void CXXInstanceCall::getExtraInvalidatedValues(
434 ValueList &Values, RegionAndSymbolInvalidationTraits *ETraits) const {
435 SVal ThisVal = getCXXThisVal();
436 Values.push_back(ThisVal);
438 // Don't invalidate if the method is const and there are no mutable fields.
439 if (const CXXMethodDecl *D = cast_or_null<CXXMethodDecl>(getDecl())) {
442 // Get the record decl for the class of 'This'. D->getParent() may return a
443 // base class decl, rather than the class of the instance which needs to be
444 // checked for mutable fields.
445 const Expr *Ex = getCXXThisExpr()->ignoreParenBaseCasts();
446 const CXXRecordDecl *ParentRecord = Ex->getType()->getAsCXXRecordDecl();
447 if (!ParentRecord || ParentRecord->hasMutableFields())
450 const MemRegion *ThisRegion = ThisVal.getAsRegion();
454 ETraits->setTrait(ThisRegion->getBaseRegion(),
455 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
459 SVal CXXInstanceCall::getCXXThisVal() const {
460 const Expr *Base = getCXXThisExpr();
461 // FIXME: This doesn't handle an overloaded ->* operator.
465 SVal ThisVal = getSVal(Base);
466 assert(ThisVal.isUnknownOrUndef() || ThisVal.getAs<Loc>());
471 RuntimeDefinition CXXInstanceCall::getRuntimeDefinition() const {
472 // Do we have a decl at all?
473 const Decl *D = getDecl();
475 return RuntimeDefinition();
477 // If the method is non-virtual, we know we can inline it.
478 const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
479 if (!MD->isVirtual())
480 return AnyFunctionCall::getRuntimeDefinition();
482 // Do we know the implicit 'this' object being called?
483 const MemRegion *R = getCXXThisVal().getAsRegion();
485 return RuntimeDefinition();
487 // Do we know anything about the type of 'this'?
488 DynamicTypeInfo DynType = getDynamicTypeInfo(getState(), R);
489 if (!DynType.isValid())
490 return RuntimeDefinition();
492 // Is the type a C++ class? (This is mostly a defensive check.)
493 QualType RegionType = DynType.getType()->getPointeeType();
494 assert(!RegionType.isNull() && "DynamicTypeInfo should always be a pointer.");
496 const CXXRecordDecl *RD = RegionType->getAsCXXRecordDecl();
497 if (!RD || !RD->hasDefinition())
498 return RuntimeDefinition();
500 // Find the decl for this method in that class.
501 const CXXMethodDecl *Result = MD->getCorrespondingMethodInClass(RD, true);
503 // We might not even get the original statically-resolved method due to
504 // some particularly nasty casting (e.g. casts to sister classes).
505 // However, we should at least be able to search up and down our own class
506 // hierarchy, and some real bugs have been caught by checking this.
507 assert(!RD->isDerivedFrom(MD->getParent()) && "Couldn't find known method");
509 // FIXME: This is checking that our DynamicTypeInfo is at least as good as
510 // the static type. However, because we currently don't update
511 // DynamicTypeInfo when an object is cast, we can't actually be sure the
512 // DynamicTypeInfo is up to date. This assert should be re-enabled once
513 // this is fixed. <rdar://problem/12287087>
514 //assert(!MD->getParent()->isDerivedFrom(RD) && "Bad DynamicTypeInfo");
516 return RuntimeDefinition();
519 // Does the decl that we found have an implementation?
520 const FunctionDecl *Definition;
521 if (!Result->hasBody(Definition))
522 return RuntimeDefinition();
524 // We found a definition. If we're not sure that this devirtualization is
525 // actually what will happen at runtime, make sure to provide the region so
526 // that ExprEngine can decide what to do with it.
527 if (DynType.canBeASubClass())
528 return RuntimeDefinition(Definition, R->StripCasts());
529 return RuntimeDefinition(Definition, /*DispatchRegion=*/nullptr);
532 void CXXInstanceCall::getInitialStackFrameContents(
533 const StackFrameContext *CalleeCtx,
534 BindingsTy &Bindings) const {
535 AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings);
537 // Handle the binding of 'this' in the new stack frame.
538 SVal ThisVal = getCXXThisVal();
539 if (!ThisVal.isUnknown()) {
540 ProgramStateManager &StateMgr = getState()->getStateManager();
541 SValBuilder &SVB = StateMgr.getSValBuilder();
543 const CXXMethodDecl *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl());
544 Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx);
546 // If we devirtualized to a different member function, we need to make sure
547 // we have the proper layering of CXXBaseObjectRegions.
548 if (MD->getCanonicalDecl() != getDecl()->getCanonicalDecl()) {
549 ASTContext &Ctx = SVB.getContext();
550 const CXXRecordDecl *Class = MD->getParent();
551 QualType Ty = Ctx.getPointerType(Ctx.getRecordType(Class));
553 // FIXME: CallEvent maybe shouldn't be directly accessing StoreManager.
555 ThisVal = StateMgr.getStoreManager().evalDynamicCast(ThisVal, Ty, Failed);
556 assert(!Failed && "Calling an incorrectly devirtualized method");
559 if (!ThisVal.isUnknown())
560 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
566 const Expr *CXXMemberCall::getCXXThisExpr() const {
567 return getOriginExpr()->getImplicitObjectArgument();
570 RuntimeDefinition CXXMemberCall::getRuntimeDefinition() const {
571 // C++11 [expr.call]p1: ...If the selected function is non-virtual, or if the
572 // id-expression in the class member access expression is a qualified-id,
573 // that function is called. Otherwise, its final overrider in the dynamic type
574 // of the object expression is called.
575 if (const MemberExpr *ME = dyn_cast<MemberExpr>(getOriginExpr()->getCallee()))
576 if (ME->hasQualifier())
577 return AnyFunctionCall::getRuntimeDefinition();
579 return CXXInstanceCall::getRuntimeDefinition();
583 const Expr *CXXMemberOperatorCall::getCXXThisExpr() const {
584 return getOriginExpr()->getArg(0);
588 const BlockDataRegion *BlockCall::getBlockRegion() const {
589 const Expr *Callee = getOriginExpr()->getCallee();
590 const MemRegion *DataReg = getSVal(Callee).getAsRegion();
592 return dyn_cast_or_null<BlockDataRegion>(DataReg);
595 ArrayRef<ParmVarDecl*> BlockCall::parameters() const {
596 const BlockDecl *D = getDecl();
599 return D->parameters();
602 void BlockCall::getExtraInvalidatedValues(ValueList &Values,
603 RegionAndSymbolInvalidationTraits *ETraits) const {
604 // FIXME: This also needs to invalidate captured globals.
605 if (const MemRegion *R = getBlockRegion())
606 Values.push_back(loc::MemRegionVal(R));
609 void BlockCall::getInitialStackFrameContents(const StackFrameContext *CalleeCtx,
610 BindingsTy &Bindings) const {
611 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
612 ArrayRef<ParmVarDecl*> Params;
613 if (isConversionFromLambda()) {
614 auto *LambdaOperatorDecl = cast<CXXMethodDecl>(CalleeCtx->getDecl());
615 Params = LambdaOperatorDecl->parameters();
617 // For blocks converted from a C++ lambda, the callee declaration is the
618 // operator() method on the lambda so we bind "this" to
619 // the lambda captured by the block.
620 const VarRegion *CapturedLambdaRegion = getRegionStoringCapturedLambda();
621 SVal ThisVal = loc::MemRegionVal(CapturedLambdaRegion);
622 Loc ThisLoc = SVB.getCXXThis(LambdaOperatorDecl, CalleeCtx);
623 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
625 Params = cast<BlockDecl>(CalleeCtx->getDecl())->parameters();
628 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
633 SVal CXXConstructorCall::getCXXThisVal() const {
635 return loc::MemRegionVal(static_cast<const MemRegion *>(Data));
639 void CXXConstructorCall::getExtraInvalidatedValues(ValueList &Values,
640 RegionAndSymbolInvalidationTraits *ETraits) const {
642 Values.push_back(loc::MemRegionVal(static_cast<const MemRegion *>(Data)));
645 void CXXConstructorCall::getInitialStackFrameContents(
646 const StackFrameContext *CalleeCtx,
647 BindingsTy &Bindings) const {
648 AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings);
650 SVal ThisVal = getCXXThisVal();
651 if (!ThisVal.isUnknown()) {
652 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
653 const CXXMethodDecl *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl());
654 Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx);
655 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
659 SVal CXXDestructorCall::getCXXThisVal() const {
661 return loc::MemRegionVal(DtorDataTy::getFromOpaqueValue(Data).getPointer());
665 RuntimeDefinition CXXDestructorCall::getRuntimeDefinition() const {
666 // Base destructors are always called non-virtually.
667 // Skip CXXInstanceCall's devirtualization logic in this case.
668 if (isBaseDestructor())
669 return AnyFunctionCall::getRuntimeDefinition();
671 return CXXInstanceCall::getRuntimeDefinition();
674 ArrayRef<ParmVarDecl*> ObjCMethodCall::parameters() const {
675 const ObjCMethodDecl *D = getDecl();
678 return D->parameters();
681 void ObjCMethodCall::getExtraInvalidatedValues(
682 ValueList &Values, RegionAndSymbolInvalidationTraits *ETraits) const {
684 // If the method call is a setter for property known to be backed by
685 // an instance variable, don't invalidate the entire receiver, just
686 // the storage for that instance variable.
687 if (const ObjCPropertyDecl *PropDecl = getAccessedProperty()) {
688 if (const ObjCIvarDecl *PropIvar = PropDecl->getPropertyIvarDecl()) {
689 SVal IvarLVal = getState()->getLValue(PropIvar, getReceiverSVal());
690 const MemRegion *IvarRegion = IvarLVal.getAsRegion();
693 RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
694 ETraits->setTrait(IvarRegion,
695 RegionAndSymbolInvalidationTraits::TK_SuppressEscape);
696 Values.push_back(IvarLVal);
701 Values.push_back(getReceiverSVal());
704 SVal ObjCMethodCall::getSelfSVal() const {
705 const LocationContext *LCtx = getLocationContext();
706 const ImplicitParamDecl *SelfDecl = LCtx->getSelfDecl();
709 return getState()->getSVal(getState()->getRegion(SelfDecl, LCtx));
712 SVal ObjCMethodCall::getReceiverSVal() const {
713 // FIXME: Is this the best way to handle class receivers?
714 if (!isInstanceMessage())
717 if (const Expr *RecE = getOriginExpr()->getInstanceReceiver())
718 return getSVal(RecE);
720 // An instance message with no expression means we are sending to super.
721 // In this case the object reference is the same as 'self'.
722 assert(getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance);
723 SVal SelfVal = getSelfSVal();
724 assert(SelfVal.isValid() && "Calling super but not in ObjC method");
728 bool ObjCMethodCall::isReceiverSelfOrSuper() const {
729 if (getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance ||
730 getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperClass)
733 if (!isInstanceMessage())
736 SVal RecVal = getSVal(getOriginExpr()->getInstanceReceiver());
738 return (RecVal == getSelfSVal());
741 SourceRange ObjCMethodCall::getSourceRange() const {
742 switch (getMessageKind()) {
744 return getOriginExpr()->getSourceRange();
745 case OCM_PropertyAccess:
747 return getContainingPseudoObjectExpr()->getSourceRange();
749 llvm_unreachable("unknown message kind");
752 typedef llvm::PointerIntPair<const PseudoObjectExpr *, 2> ObjCMessageDataTy;
754 const PseudoObjectExpr *ObjCMethodCall::getContainingPseudoObjectExpr() const {
755 assert(Data && "Lazy lookup not yet performed.");
756 assert(getMessageKind() != OCM_Message && "Explicit message send.");
757 return ObjCMessageDataTy::getFromOpaqueValue(Data).getPointer();
761 getSyntacticFromForPseudoObjectExpr(const PseudoObjectExpr *POE) {
762 const Expr *Syntactic = POE->getSyntacticForm();
764 // This handles the funny case of assigning to the result of a getter.
765 // This can happen if the getter returns a non-const reference.
766 if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(Syntactic))
767 Syntactic = BO->getLHS();
772 ObjCMessageKind ObjCMethodCall::getMessageKind() const {
775 // Find the parent, ignoring implicit casts.
776 ParentMap &PM = getLocationContext()->getParentMap();
777 const Stmt *S = PM.getParentIgnoreParenCasts(getOriginExpr());
779 // Check if parent is a PseudoObjectExpr.
780 if (const PseudoObjectExpr *POE = dyn_cast_or_null<PseudoObjectExpr>(S)) {
781 const Expr *Syntactic = getSyntacticFromForPseudoObjectExpr(POE);
784 switch (Syntactic->getStmtClass()) {
785 case Stmt::ObjCPropertyRefExprClass:
786 K = OCM_PropertyAccess;
788 case Stmt::ObjCSubscriptRefExprClass:
792 // FIXME: Can this ever happen?
797 if (K != OCM_Message) {
798 const_cast<ObjCMethodCall *>(this)->Data
799 = ObjCMessageDataTy(POE, K).getOpaqueValue();
800 assert(getMessageKind() == K);
805 const_cast<ObjCMethodCall *>(this)->Data
806 = ObjCMessageDataTy(nullptr, 1).getOpaqueValue();
807 assert(getMessageKind() == OCM_Message);
811 ObjCMessageDataTy Info = ObjCMessageDataTy::getFromOpaqueValue(Data);
812 if (!Info.getPointer())
814 return static_cast<ObjCMessageKind>(Info.getInt());
817 const ObjCPropertyDecl *ObjCMethodCall::getAccessedProperty() const {
818 // Look for properties accessed with property syntax (foo.bar = ...)
819 if ( getMessageKind() == OCM_PropertyAccess) {
820 const PseudoObjectExpr *POE = getContainingPseudoObjectExpr();
821 assert(POE && "Property access without PseudoObjectExpr?");
823 const Expr *Syntactic = getSyntacticFromForPseudoObjectExpr(POE);
824 auto *RefExpr = cast<ObjCPropertyRefExpr>(Syntactic);
826 if (RefExpr->isExplicitProperty())
827 return RefExpr->getExplicitProperty();
830 // Look for properties accessed with method syntax ([foo setBar:...]).
831 const ObjCMethodDecl *MD = getDecl();
832 if (!MD || !MD->isPropertyAccessor())
835 // Note: This is potentially quite slow.
836 return MD->findPropertyDecl();
839 bool ObjCMethodCall::canBeOverridenInSubclass(ObjCInterfaceDecl *IDecl,
840 Selector Sel) const {
842 const SourceManager &SM =
843 getState()->getStateManager().getContext().getSourceManager();
845 // If the class interface is declared inside the main file, assume it is not
847 // TODO: It could actually be subclassed if the subclass is private as well.
848 // This is probably very rare.
849 SourceLocation InterfLoc = IDecl->getEndOfDefinitionLoc();
850 if (InterfLoc.isValid() && SM.isInMainFile(InterfLoc))
853 // Assume that property accessors are not overridden.
854 if (getMessageKind() == OCM_PropertyAccess)
857 // We assume that if the method is public (declared outside of main file) or
858 // has a parent which publicly declares the method, the method could be
859 // overridden in a subclass.
861 // Find the first declaration in the class hierarchy that declares
863 ObjCMethodDecl *D = nullptr;
865 D = IDecl->lookupMethod(Sel, true);
867 // Cannot find a public definition.
871 // If outside the main file,
872 if (D->getLocation().isValid() && !SM.isInMainFile(D->getLocation()))
875 if (D->isOverriding()) {
876 // Search in the superclass on the next iteration.
877 IDecl = D->getClassInterface();
881 IDecl = IDecl->getSuperClass();
891 llvm_unreachable("The while loop should always terminate.");
894 RuntimeDefinition ObjCMethodCall::getRuntimeDefinition() const {
895 const ObjCMessageExpr *E = getOriginExpr();
897 Selector Sel = E->getSelector();
899 if (E->isInstanceMessage()) {
901 // Find the receiver type.
902 const ObjCObjectPointerType *ReceiverT = nullptr;
903 bool CanBeSubClassed = false;
904 QualType SupersType = E->getSuperType();
905 const MemRegion *Receiver = nullptr;
907 if (!SupersType.isNull()) {
908 // Super always means the type of immediate predecessor to the method
909 // where the call occurs.
910 ReceiverT = cast<ObjCObjectPointerType>(SupersType);
912 Receiver = getReceiverSVal().getAsRegion();
914 return RuntimeDefinition();
916 DynamicTypeInfo DTI = getDynamicTypeInfo(getState(), Receiver);
917 QualType DynType = DTI.getType();
918 CanBeSubClassed = DTI.canBeASubClass();
919 ReceiverT = dyn_cast<ObjCObjectPointerType>(DynType);
921 if (ReceiverT && CanBeSubClassed)
922 if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl())
923 if (!canBeOverridenInSubclass(IDecl, Sel))
924 CanBeSubClassed = false;
927 // Lookup the method implementation.
929 if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) {
930 // Repeatedly calling lookupPrivateMethod() is expensive, especially
931 // when in many cases it returns null. We cache the results so
932 // that repeated queries on the same ObjCIntefaceDecl and Selector
933 // don't incur the same cost. On some test cases, we can see the
934 // same query being issued thousands of times.
936 // NOTE: This cache is essentially a "global" variable, but it
937 // only gets lazily created when we get here. The value of the
938 // cache probably comes from it being global across ExprEngines,
939 // where the same queries may get issued. If we are worried about
940 // concurrency, or possibly loading/unloading ASTs, etc., we may
941 // need to revisit this someday. In terms of memory, this table
942 // stays around until clang quits, which also may be bad if we
943 // need to release memory.
944 typedef std::pair<const ObjCInterfaceDecl*, Selector>
946 typedef llvm::DenseMap<PrivateMethodKey,
947 Optional<const ObjCMethodDecl *> >
950 static PrivateMethodCache PMC;
951 Optional<const ObjCMethodDecl *> &Val = PMC[std::make_pair(IDecl, Sel)];
953 // Query lookupPrivateMethod() if the cache does not hit.
954 if (!Val.hasValue()) {
955 Val = IDecl->lookupPrivateMethod(Sel);
957 // If the method is a property accessor, we should try to "inline" it
958 // even if we don't actually have an implementation.
960 if (const ObjCMethodDecl *CompileTimeMD = E->getMethodDecl())
961 if (CompileTimeMD->isPropertyAccessor()) {
962 if (!CompileTimeMD->getSelfDecl() &&
963 isa<ObjCCategoryDecl>(CompileTimeMD->getDeclContext())) {
964 // If the method is an accessor in a category, and it doesn't
965 // have a self declaration, first
966 // try to find the method in a class extension. This
967 // works around a bug in Sema where multiple accessors
968 // are synthesized for properties in class
969 // extensions that are redeclared in a category and the
970 // the implicit parameters are not filled in for
971 // the method on the category.
972 // This ensures we find the accessor in the extension, which
973 // has the implicit parameters filled in.
974 auto *ID = CompileTimeMD->getClassInterface();
975 for (auto *CatDecl : ID->visible_extensions()) {
976 Val = CatDecl->getMethod(Sel,
977 CompileTimeMD->isInstanceMethod());
983 Val = IDecl->lookupInstanceMethod(Sel);
987 const ObjCMethodDecl *MD = Val.getValue();
989 return RuntimeDefinition(MD, Receiver);
991 return RuntimeDefinition(MD, nullptr);
995 // This is a class method.
996 // If we have type info for the receiver class, we are calling via
998 if (ObjCInterfaceDecl *IDecl = E->getReceiverInterface()) {
999 // Find/Return the method implementation.
1000 return RuntimeDefinition(IDecl->lookupPrivateClassMethod(Sel));
1004 return RuntimeDefinition();
1007 bool ObjCMethodCall::argumentsMayEscape() const {
1008 if (isInSystemHeader() && !isInstanceMessage()) {
1009 Selector Sel = getSelector();
1010 if (Sel.getNumArgs() == 1 &&
1011 Sel.getIdentifierInfoForSlot(0)->isStr("valueWithPointer"))
1015 return CallEvent::argumentsMayEscape();
1018 void ObjCMethodCall::getInitialStackFrameContents(
1019 const StackFrameContext *CalleeCtx,
1020 BindingsTy &Bindings) const {
1021 const ObjCMethodDecl *D = cast<ObjCMethodDecl>(CalleeCtx->getDecl());
1022 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
1023 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
1026 SVal SelfVal = getReceiverSVal();
1027 if (!SelfVal.isUnknown()) {
1028 const VarDecl *SelfD = CalleeCtx->getAnalysisDeclContext()->getSelfDecl();
1029 MemRegionManager &MRMgr = SVB.getRegionManager();
1030 Loc SelfLoc = SVB.makeLoc(MRMgr.getVarRegion(SelfD, CalleeCtx));
1031 Bindings.push_back(std::make_pair(SelfLoc, SelfVal));
1036 CallEventManager::getSimpleCall(const CallExpr *CE, ProgramStateRef State,
1037 const LocationContext *LCtx) {
1038 if (const CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(CE))
1039 return create<CXXMemberCall>(MCE, State, LCtx);
1041 if (const CXXOperatorCallExpr *OpCE = dyn_cast<CXXOperatorCallExpr>(CE)) {
1042 const FunctionDecl *DirectCallee = OpCE->getDirectCallee();
1043 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DirectCallee))
1044 if (MD->isInstance())
1045 return create<CXXMemberOperatorCall>(OpCE, State, LCtx);
1047 } else if (CE->getCallee()->getType()->isBlockPointerType()) {
1048 return create<BlockCall>(CE, State, LCtx);
1051 // Otherwise, it's a normal function call, static member function call, or
1052 // something we can't reason about.
1053 return create<SimpleFunctionCall>(CE, State, LCtx);
1058 CallEventManager::getCaller(const StackFrameContext *CalleeCtx,
1059 ProgramStateRef State) {
1060 const LocationContext *ParentCtx = CalleeCtx->getParent();
1061 const LocationContext *CallerCtx = ParentCtx->getCurrentStackFrame();
1062 assert(CallerCtx && "This should not be used for top-level stack frames");
1064 const Stmt *CallSite = CalleeCtx->getCallSite();
1067 if (const CallExpr *CE = dyn_cast<CallExpr>(CallSite))
1068 return getSimpleCall(CE, State, CallerCtx);
1070 switch (CallSite->getStmtClass()) {
1071 case Stmt::CXXConstructExprClass:
1072 case Stmt::CXXTemporaryObjectExprClass: {
1073 SValBuilder &SVB = State->getStateManager().getSValBuilder();
1074 const CXXMethodDecl *Ctor = cast<CXXMethodDecl>(CalleeCtx->getDecl());
1075 Loc ThisPtr = SVB.getCXXThis(Ctor, CalleeCtx);
1076 SVal ThisVal = State->getSVal(ThisPtr);
1078 return getCXXConstructorCall(cast<CXXConstructExpr>(CallSite),
1079 ThisVal.getAsRegion(), State, CallerCtx);
1081 case Stmt::CXXNewExprClass:
1082 return getCXXAllocatorCall(cast<CXXNewExpr>(CallSite), State, CallerCtx);
1083 case Stmt::ObjCMessageExprClass:
1084 return getObjCMethodCall(cast<ObjCMessageExpr>(CallSite),
1087 llvm_unreachable("This is not an inlineable statement.");
1091 // Fall back to the CFG. The only thing we haven't handled yet is
1092 // destructors, though this could change in the future.
1093 const CFGBlock *B = CalleeCtx->getCallSiteBlock();
1094 CFGElement E = (*B)[CalleeCtx->getIndex()];
1095 assert(E.getAs<CFGImplicitDtor>() &&
1096 "All other CFG elements should have exprs");
1097 assert(!E.getAs<CFGTemporaryDtor>() && "We don't handle temporaries yet");
1099 SValBuilder &SVB = State->getStateManager().getSValBuilder();
1100 const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CalleeCtx->getDecl());
1101 Loc ThisPtr = SVB.getCXXThis(Dtor, CalleeCtx);
1102 SVal ThisVal = State->getSVal(ThisPtr);
1104 const Stmt *Trigger;
1105 if (Optional<CFGAutomaticObjDtor> AutoDtor = E.getAs<CFGAutomaticObjDtor>())
1106 Trigger = AutoDtor->getTriggerStmt();
1107 else if (Optional<CFGDeleteDtor> DeleteDtor = E.getAs<CFGDeleteDtor>())
1108 Trigger = cast<Stmt>(DeleteDtor->getDeleteExpr());
1110 Trigger = Dtor->getBody();
1112 return getCXXDestructorCall(Dtor, Trigger, ThisVal.getAsRegion(),
1113 E.getAs<CFGBaseDtor>().hasValue(), State,