1 //===- CallEvent.cpp - Wrapper for all function and method calls ----------===//
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/ASTContext.h"
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/DeclBase.h"
20 #include "clang/AST/DeclCXX.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/AST/Expr.h"
23 #include "clang/AST/ExprCXX.h"
24 #include "clang/AST/ExprObjC.h"
25 #include "clang/AST/ParentMap.h"
26 #include "clang/AST/Stmt.h"
27 #include "clang/AST/Type.h"
28 #include "clang/Analysis/AnalysisDeclContext.h"
29 #include "clang/Analysis/CFG.h"
30 #include "clang/Analysis/ProgramPoint.h"
31 #include "clang/CrossTU/CrossTranslationUnit.h"
32 #include "clang/Basic/IdentifierTable.h"
33 #include "clang/Basic/LLVM.h"
34 #include "clang/Basic/SourceLocation.h"
35 #include "clang/Basic/SourceManager.h"
36 #include "clang/Basic/Specifiers.h"
37 #include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
38 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
39 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicTypeInfo.h"
40 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicTypeMap.h"
41 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
42 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
43 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
44 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
45 #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
46 #include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
47 #include "llvm/ADT/ArrayRef.h"
48 #include "llvm/ADT/DenseMap.h"
49 #include "llvm/ADT/None.h"
50 #include "llvm/ADT/Optional.h"
51 #include "llvm/ADT/PointerIntPair.h"
52 #include "llvm/ADT/SmallSet.h"
53 #include "llvm/ADT/SmallVector.h"
54 #include "llvm/ADT/StringExtras.h"
55 #include "llvm/ADT/StringRef.h"
56 #include "llvm/Support/Casting.h"
57 #include "llvm/Support/Compiler.h"
58 #include "llvm/Support/Debug.h"
59 #include "llvm/Support/ErrorHandling.h"
60 #include "llvm/Support/raw_ostream.h"
64 #define DEBUG_TYPE "static-analyzer-call-event"
66 using namespace clang;
69 QualType CallEvent::getResultType() const {
70 ASTContext &Ctx = getState()->getStateManager().getContext();
71 const Expr *E = getOriginExpr();
76 QualType ResultTy = E->getType();
78 // A function that returns a reference to 'int' will have a result type
79 // of simply 'int'. Check the origin expr's value kind to recover the
81 switch (E->getValueKind()) {
83 ResultTy = Ctx.getLValueReferenceType(ResultTy);
86 ResultTy = Ctx.getRValueReferenceType(ResultTy);
89 // No adjustment is necessary.
96 static bool isCallback(QualType T) {
97 // If a parameter is a block or a callback, assume it can modify pointer.
98 if (T->isBlockPointerType() ||
99 T->isFunctionPointerType() ||
103 // Check if a callback is passed inside a struct (for both, struct passed by
104 // reference and by value). Dig just one level into the struct for now.
106 if (T->isAnyPointerType() || T->isReferenceType())
107 T = T->getPointeeType();
109 if (const RecordType *RT = T->getAsStructureType()) {
110 const RecordDecl *RD = RT->getDecl();
111 for (const auto *I : RD->fields()) {
112 QualType FieldT = I->getType();
113 if (FieldT->isBlockPointerType() || FieldT->isFunctionPointerType())
120 static bool isVoidPointerToNonConst(QualType T) {
121 if (const auto *PT = T->getAs<PointerType>()) {
122 QualType PointeeTy = PT->getPointeeType();
123 if (PointeeTy.isConstQualified())
125 return PointeeTy->isVoidType();
130 bool CallEvent::hasNonNullArgumentsWithType(bool (*Condition)(QualType)) const {
131 unsigned NumOfArgs = getNumArgs();
133 // If calling using a function pointer, assume the function does not
134 // satisfy the callback.
135 // TODO: We could check the types of the arguments here.
140 for (CallEvent::param_type_iterator I = param_type_begin(),
141 E = param_type_end();
142 I != E && Idx < NumOfArgs; ++I, ++Idx) {
143 // If the parameter is 0, it's harmless.
144 if (getArgSVal(Idx).isZeroConstant())
153 bool CallEvent::hasNonZeroCallbackArg() const {
154 return hasNonNullArgumentsWithType(isCallback);
157 bool CallEvent::hasVoidPointerToNonConstArg() const {
158 return hasNonNullArgumentsWithType(isVoidPointerToNonConst);
161 bool CallEvent::isGlobalCFunction(StringRef FunctionName) const {
162 const auto *FD = dyn_cast_or_null<FunctionDecl>(getDecl());
166 return CheckerContext::isCLibraryFunction(FD, FunctionName);
169 /// Returns true if a type is a pointer-to-const or reference-to-const
170 /// with no further indirection.
171 static bool isPointerToConst(QualType Ty) {
172 QualType PointeeTy = Ty->getPointeeType();
173 if (PointeeTy == QualType())
175 if (!PointeeTy.isConstQualified())
177 if (PointeeTy->isAnyPointerType())
182 // Try to retrieve the function declaration and find the function parameter
183 // types which are pointers/references to a non-pointer const.
184 // We will not invalidate the corresponding argument regions.
185 static void findPtrToConstParams(llvm::SmallSet<unsigned, 4> &PreserveArgs,
186 const CallEvent &Call) {
188 for (CallEvent::param_type_iterator I = Call.param_type_begin(),
189 E = Call.param_type_end();
190 I != E; ++I, ++Idx) {
191 if (isPointerToConst(*I))
192 PreserveArgs.insert(Idx);
196 ProgramStateRef CallEvent::invalidateRegions(unsigned BlockCount,
197 ProgramStateRef Orig) const {
198 ProgramStateRef Result = (Orig ? Orig : getState());
200 // Don't invalidate anything if the callee is marked pure/const.
201 if (const Decl *callee = getDecl())
202 if (callee->hasAttr<PureAttr>() || callee->hasAttr<ConstAttr>())
205 SmallVector<SVal, 8> ValuesToInvalidate;
206 RegionAndSymbolInvalidationTraits ETraits;
208 getExtraInvalidatedValues(ValuesToInvalidate, &ETraits);
210 // Indexes of arguments whose values will be preserved by the call.
211 llvm::SmallSet<unsigned, 4> PreserveArgs;
212 if (!argumentsMayEscape())
213 findPtrToConstParams(PreserveArgs, *this);
215 for (unsigned Idx = 0, Count = getNumArgs(); Idx != Count; ++Idx) {
216 // Mark this region for invalidation. We batch invalidate regions
217 // below for efficiency.
218 if (PreserveArgs.count(Idx))
219 if (const MemRegion *MR = getArgSVal(Idx).getAsRegion())
220 ETraits.setTrait(MR->getBaseRegion(),
221 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
222 // TODO: Factor this out + handle the lower level const pointers.
224 ValuesToInvalidate.push_back(getArgSVal(Idx));
227 // Invalidate designated regions using the batch invalidation API.
228 // NOTE: Even if RegionsToInvalidate is empty, we may still invalidate
230 return Result->invalidateRegions(ValuesToInvalidate, getOriginExpr(),
231 BlockCount, getLocationContext(),
232 /*CausedByPointerEscape*/ true,
233 /*Symbols=*/nullptr, this, &ETraits);
236 ProgramPoint CallEvent::getProgramPoint(bool IsPreVisit,
237 const ProgramPointTag *Tag) const {
238 if (const Expr *E = getOriginExpr()) {
240 return PreStmt(E, getLocationContext(), Tag);
241 return PostStmt(E, getLocationContext(), Tag);
244 const Decl *D = getDecl();
245 assert(D && "Cannot get a program point without a statement or decl");
247 SourceLocation Loc = getSourceRange().getBegin();
249 return PreImplicitCall(D, Loc, getLocationContext(), Tag);
250 return PostImplicitCall(D, Loc, getLocationContext(), Tag);
253 bool CallEvent::isCalled(const CallDescription &CD) const {
254 // FIXME: Add ObjC Message support.
255 if (getKind() == CE_ObjCMessage)
257 if (!CD.IsLookupDone) {
258 CD.IsLookupDone = true;
259 CD.II = &getState()->getStateManager().getContext().Idents.get(CD.FuncName);
261 const IdentifierInfo *II = getCalleeIdentifier();
262 if (!II || II != CD.II)
264 return (CD.RequiredArgs == CallDescription::NoArgRequirement ||
265 CD.RequiredArgs == getNumArgs());
268 SVal CallEvent::getArgSVal(unsigned Index) const {
269 const Expr *ArgE = getArgExpr(Index);
272 return getSVal(ArgE);
275 SourceRange CallEvent::getArgSourceRange(unsigned Index) const {
276 const Expr *ArgE = getArgExpr(Index);
279 return ArgE->getSourceRange();
282 SVal CallEvent::getReturnValue() const {
283 const Expr *E = getOriginExpr();
285 return UndefinedVal();
289 LLVM_DUMP_METHOD void CallEvent::dump() const { dump(llvm::errs()); }
291 void CallEvent::dump(raw_ostream &Out) const {
292 ASTContext &Ctx = getState()->getStateManager().getContext();
293 if (const Expr *E = getOriginExpr()) {
294 E->printPretty(Out, nullptr, Ctx.getPrintingPolicy());
299 if (const Decl *D = getDecl()) {
301 D->print(Out, Ctx.getPrintingPolicy());
305 // FIXME: a string representation of the kind would be nice.
306 Out << "Unknown call (type " << getKind() << ")";
309 bool CallEvent::isCallStmt(const Stmt *S) {
310 return isa<CallExpr>(S) || isa<ObjCMessageExpr>(S)
311 || isa<CXXConstructExpr>(S)
312 || isa<CXXNewExpr>(S);
315 QualType CallEvent::getDeclaredResultType(const Decl *D) {
317 if (const auto *FD = dyn_cast<FunctionDecl>(D))
318 return FD->getReturnType();
319 if (const auto *MD = dyn_cast<ObjCMethodDecl>(D))
320 return MD->getReturnType();
321 if (const auto *BD = dyn_cast<BlockDecl>(D)) {
322 // Blocks are difficult because the return type may not be stored in the
323 // BlockDecl itself. The AST should probably be enhanced, but for now we
324 // just do what we can.
325 // If the block is declared without an explicit argument list, the
326 // signature-as-written just includes the return type, not the entire
328 // FIXME: All blocks should have signatures-as-written, even if the return
329 // type is inferred. (That's signified with a dependent result type.)
330 if (const TypeSourceInfo *TSI = BD->getSignatureAsWritten()) {
331 QualType Ty = TSI->getType();
332 if (const FunctionType *FT = Ty->getAs<FunctionType>())
333 Ty = FT->getReturnType();
334 if (!Ty->isDependentType())
341 llvm_unreachable("unknown callable kind");
344 bool CallEvent::isVariadic(const Decl *D) {
347 if (const auto *FD = dyn_cast<FunctionDecl>(D))
348 return FD->isVariadic();
349 if (const auto *MD = dyn_cast<ObjCMethodDecl>(D))
350 return MD->isVariadic();
351 if (const auto *BD = dyn_cast<BlockDecl>(D))
352 return BD->isVariadic();
354 llvm_unreachable("unknown callable kind");
357 static void addParameterValuesToBindings(const StackFrameContext *CalleeCtx,
358 CallEvent::BindingsTy &Bindings,
360 const CallEvent &Call,
361 ArrayRef<ParmVarDecl*> parameters) {
362 MemRegionManager &MRMgr = SVB.getRegionManager();
364 // If the function has fewer parameters than the call has arguments, we simply
365 // do not bind any values to them.
366 unsigned NumArgs = Call.getNumArgs();
368 ArrayRef<ParmVarDecl*>::iterator I = parameters.begin(), E = parameters.end();
369 for (; I != E && Idx < NumArgs; ++I, ++Idx) {
370 const ParmVarDecl *ParamDecl = *I;
371 assert(ParamDecl && "Formal parameter has no decl?");
373 SVal ArgVal = Call.getArgSVal(Idx);
374 if (!ArgVal.isUnknown()) {
375 Loc ParamLoc = SVB.makeLoc(MRMgr.getVarRegion(ParamDecl, CalleeCtx));
376 Bindings.push_back(std::make_pair(ParamLoc, ArgVal));
380 // FIXME: Variadic arguments are not handled at all right now.
383 ArrayRef<ParmVarDecl*> AnyFunctionCall::parameters() const {
384 const FunctionDecl *D = getDecl();
387 return D->parameters();
390 RuntimeDefinition AnyFunctionCall::getRuntimeDefinition() const {
391 const FunctionDecl *FD = getDecl();
395 // Note that the AnalysisDeclContext will have the FunctionDecl with
396 // the definition (if one exists).
397 AnalysisDeclContext *AD =
398 getLocationContext()->getAnalysisDeclContext()->
399 getManager()->getContext(FD);
400 bool IsAutosynthesized;
401 Stmt* Body = AD->getBody(IsAutosynthesized);
403 if (IsAutosynthesized)
404 llvm::dbgs() << "Using autosynthesized body for " << FD->getName()
408 const Decl* Decl = AD->getDecl();
409 return RuntimeDefinition(Decl);
412 SubEngine *Engine = getState()->getStateManager().getOwningEngine();
413 AnalyzerOptions &Opts = Engine->getAnalysisManager().options;
415 // Try to get CTU definition only if CTUDir is provided.
416 if (!Opts.naiveCTUEnabled())
419 cross_tu::CrossTranslationUnitContext &CTUCtx =
420 *Engine->getCrossTranslationUnitContext();
421 llvm::Expected<const FunctionDecl *> CTUDeclOrError =
422 CTUCtx.getCrossTUDefinition(FD, Opts.getCTUDir(), Opts.getCTUIndexName());
424 if (!CTUDeclOrError) {
425 handleAllErrors(CTUDeclOrError.takeError(),
426 [&](const cross_tu::IndexError &IE) {
427 CTUCtx.emitCrossTUDiagnostics(IE);
432 return RuntimeDefinition(*CTUDeclOrError);
435 void AnyFunctionCall::getInitialStackFrameContents(
436 const StackFrameContext *CalleeCtx,
437 BindingsTy &Bindings) const {
438 const auto *D = cast<FunctionDecl>(CalleeCtx->getDecl());
439 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
440 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
444 bool AnyFunctionCall::argumentsMayEscape() const {
445 if (CallEvent::argumentsMayEscape() || hasVoidPointerToNonConstArg())
448 const FunctionDecl *D = getDecl();
452 const IdentifierInfo *II = D->getIdentifier();
456 // This set of "escaping" APIs is
458 // - 'int pthread_setspecific(ptheread_key k, const void *)' stores a
459 // value into thread local storage. The value can later be retrieved with
460 // 'void *ptheread_getspecific(pthread_key)'. So even thought the
461 // parameter is 'const void *', the region escapes through the call.
462 if (II->isStr("pthread_setspecific"))
465 // - xpc_connection_set_context stores a value which can be retrieved later
466 // with xpc_connection_get_context.
467 if (II->isStr("xpc_connection_set_context"))
470 // - funopen - sets a buffer for future IO calls.
471 if (II->isStr("funopen"))
474 // - __cxa_demangle - can reallocate memory and can return the pointer to
476 if (II->isStr("__cxa_demangle"))
479 StringRef FName = II->getName();
481 // - CoreFoundation functions that end with "NoCopy" can free a passed-in
482 // buffer even if it is const.
483 if (FName.endswith("NoCopy"))
486 // - NSXXInsertXX, for example NSMapInsertIfAbsent, since they can
487 // be deallocated by NSMapRemove.
488 if (FName.startswith("NS") && (FName.find("Insert") != StringRef::npos))
491 // - Many CF containers allow objects to escape through custom
492 // allocators/deallocators upon container construction. (PR12101)
493 if (FName.startswith("CF") || FName.startswith("CG")) {
494 return StrInStrNoCase(FName, "InsertValue") != StringRef::npos ||
495 StrInStrNoCase(FName, "AddValue") != StringRef::npos ||
496 StrInStrNoCase(FName, "SetValue") != StringRef::npos ||
497 StrInStrNoCase(FName, "WithData") != StringRef::npos ||
498 StrInStrNoCase(FName, "AppendValue") != StringRef::npos ||
499 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos;
505 const FunctionDecl *SimpleFunctionCall::getDecl() const {
506 const FunctionDecl *D = getOriginExpr()->getDirectCallee();
510 return getSVal(getOriginExpr()->getCallee()).getAsFunctionDecl();
513 const FunctionDecl *CXXInstanceCall::getDecl() const {
514 const auto *CE = cast_or_null<CallExpr>(getOriginExpr());
516 return AnyFunctionCall::getDecl();
518 const FunctionDecl *D = CE->getDirectCallee();
522 return getSVal(CE->getCallee()).getAsFunctionDecl();
525 void CXXInstanceCall::getExtraInvalidatedValues(
526 ValueList &Values, RegionAndSymbolInvalidationTraits *ETraits) const {
527 SVal ThisVal = getCXXThisVal();
528 Values.push_back(ThisVal);
530 // Don't invalidate if the method is const and there are no mutable fields.
531 if (const auto *D = cast_or_null<CXXMethodDecl>(getDecl())) {
534 // Get the record decl for the class of 'This'. D->getParent() may return a
535 // base class decl, rather than the class of the instance which needs to be
536 // checked for mutable fields.
537 // TODO: We might as well look at the dynamic type of the object.
538 const Expr *Ex = getCXXThisExpr()->ignoreParenBaseCasts();
539 QualType T = Ex->getType();
540 if (T->isPointerType()) // Arrow or implicit-this syntax?
541 T = T->getPointeeType();
542 const CXXRecordDecl *ParentRecord = T->getAsCXXRecordDecl();
543 assert(ParentRecord);
544 if (ParentRecord->hasMutableFields())
547 const MemRegion *ThisRegion = ThisVal.getAsRegion();
551 ETraits->setTrait(ThisRegion->getBaseRegion(),
552 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
556 SVal CXXInstanceCall::getCXXThisVal() const {
557 const Expr *Base = getCXXThisExpr();
558 // FIXME: This doesn't handle an overloaded ->* operator.
562 SVal ThisVal = getSVal(Base);
563 assert(ThisVal.isUnknownOrUndef() || ThisVal.getAs<Loc>());
567 RuntimeDefinition CXXInstanceCall::getRuntimeDefinition() const {
568 // Do we have a decl at all?
569 const Decl *D = getDecl();
573 // If the method is non-virtual, we know we can inline it.
574 const auto *MD = cast<CXXMethodDecl>(D);
575 if (!MD->isVirtual())
576 return AnyFunctionCall::getRuntimeDefinition();
578 // Do we know the implicit 'this' object being called?
579 const MemRegion *R = getCXXThisVal().getAsRegion();
583 // Do we know anything about the type of 'this'?
584 DynamicTypeInfo DynType = getDynamicTypeInfo(getState(), R);
585 if (!DynType.isValid())
588 // Is the type a C++ class? (This is mostly a defensive check.)
589 QualType RegionType = DynType.getType()->getPointeeType();
590 assert(!RegionType.isNull() && "DynamicTypeInfo should always be a pointer.");
592 const CXXRecordDecl *RD = RegionType->getAsCXXRecordDecl();
593 if (!RD || !RD->hasDefinition())
596 // Find the decl for this method in that class.
597 const CXXMethodDecl *Result = MD->getCorrespondingMethodInClass(RD, true);
599 // We might not even get the original statically-resolved method due to
600 // some particularly nasty casting (e.g. casts to sister classes).
601 // However, we should at least be able to search up and down our own class
602 // hierarchy, and some real bugs have been caught by checking this.
603 assert(!RD->isDerivedFrom(MD->getParent()) && "Couldn't find known method");
605 // FIXME: This is checking that our DynamicTypeInfo is at least as good as
606 // the static type. However, because we currently don't update
607 // DynamicTypeInfo when an object is cast, we can't actually be sure the
608 // DynamicTypeInfo is up to date. This assert should be re-enabled once
609 // this is fixed. <rdar://problem/12287087>
610 //assert(!MD->getParent()->isDerivedFrom(RD) && "Bad DynamicTypeInfo");
615 // Does the decl that we found have an implementation?
616 const FunctionDecl *Definition;
617 if (!Result->hasBody(Definition))
620 // We found a definition. If we're not sure that this devirtualization is
621 // actually what will happen at runtime, make sure to provide the region so
622 // that ExprEngine can decide what to do with it.
623 if (DynType.canBeASubClass())
624 return RuntimeDefinition(Definition, R->StripCasts());
625 return RuntimeDefinition(Definition, /*DispatchRegion=*/nullptr);
628 void CXXInstanceCall::getInitialStackFrameContents(
629 const StackFrameContext *CalleeCtx,
630 BindingsTy &Bindings) const {
631 AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings);
633 // Handle the binding of 'this' in the new stack frame.
634 SVal ThisVal = getCXXThisVal();
635 if (!ThisVal.isUnknown()) {
636 ProgramStateManager &StateMgr = getState()->getStateManager();
637 SValBuilder &SVB = StateMgr.getSValBuilder();
639 const auto *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl());
640 Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx);
642 // If we devirtualized to a different member function, we need to make sure
643 // we have the proper layering of CXXBaseObjectRegions.
644 if (MD->getCanonicalDecl() != getDecl()->getCanonicalDecl()) {
645 ASTContext &Ctx = SVB.getContext();
646 const CXXRecordDecl *Class = MD->getParent();
647 QualType Ty = Ctx.getPointerType(Ctx.getRecordType(Class));
649 // FIXME: CallEvent maybe shouldn't be directly accessing StoreManager.
651 ThisVal = StateMgr.getStoreManager().attemptDownCast(ThisVal, Ty, Failed);
653 // We might have suffered some sort of placement new earlier, so
654 // we're constructing in a completely unexpected storage.
655 // Fall back to a generic pointer cast for this-value.
656 const CXXMethodDecl *StaticMD = cast<CXXMethodDecl>(getDecl());
657 const CXXRecordDecl *StaticClass = StaticMD->getParent();
658 QualType StaticTy = Ctx.getPointerType(Ctx.getRecordType(StaticClass));
659 ThisVal = SVB.evalCast(ThisVal, Ty, StaticTy);
663 if (!ThisVal.isUnknown())
664 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
668 const Expr *CXXMemberCall::getCXXThisExpr() const {
669 return getOriginExpr()->getImplicitObjectArgument();
672 RuntimeDefinition CXXMemberCall::getRuntimeDefinition() const {
673 // C++11 [expr.call]p1: ...If the selected function is non-virtual, or if the
674 // id-expression in the class member access expression is a qualified-id,
675 // that function is called. Otherwise, its final overrider in the dynamic type
676 // of the object expression is called.
677 if (const auto *ME = dyn_cast<MemberExpr>(getOriginExpr()->getCallee()))
678 if (ME->hasQualifier())
679 return AnyFunctionCall::getRuntimeDefinition();
681 return CXXInstanceCall::getRuntimeDefinition();
684 const Expr *CXXMemberOperatorCall::getCXXThisExpr() const {
685 return getOriginExpr()->getArg(0);
688 const BlockDataRegion *BlockCall::getBlockRegion() const {
689 const Expr *Callee = getOriginExpr()->getCallee();
690 const MemRegion *DataReg = getSVal(Callee).getAsRegion();
692 return dyn_cast_or_null<BlockDataRegion>(DataReg);
695 ArrayRef<ParmVarDecl*> BlockCall::parameters() const {
696 const BlockDecl *D = getDecl();
699 return D->parameters();
702 void BlockCall::getExtraInvalidatedValues(ValueList &Values,
703 RegionAndSymbolInvalidationTraits *ETraits) const {
704 // FIXME: This also needs to invalidate captured globals.
705 if (const MemRegion *R = getBlockRegion())
706 Values.push_back(loc::MemRegionVal(R));
709 void BlockCall::getInitialStackFrameContents(const StackFrameContext *CalleeCtx,
710 BindingsTy &Bindings) const {
711 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
712 ArrayRef<ParmVarDecl*> Params;
713 if (isConversionFromLambda()) {
714 auto *LambdaOperatorDecl = cast<CXXMethodDecl>(CalleeCtx->getDecl());
715 Params = LambdaOperatorDecl->parameters();
717 // For blocks converted from a C++ lambda, the callee declaration is the
718 // operator() method on the lambda so we bind "this" to
719 // the lambda captured by the block.
720 const VarRegion *CapturedLambdaRegion = getRegionStoringCapturedLambda();
721 SVal ThisVal = loc::MemRegionVal(CapturedLambdaRegion);
722 Loc ThisLoc = SVB.getCXXThis(LambdaOperatorDecl, CalleeCtx);
723 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
725 Params = cast<BlockDecl>(CalleeCtx->getDecl())->parameters();
728 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
732 SVal CXXConstructorCall::getCXXThisVal() const {
734 return loc::MemRegionVal(static_cast<const MemRegion *>(Data));
738 void CXXConstructorCall::getExtraInvalidatedValues(ValueList &Values,
739 RegionAndSymbolInvalidationTraits *ETraits) const {
741 loc::MemRegionVal MV(static_cast<const MemRegion *>(Data));
742 if (SymbolRef Sym = MV.getAsSymbol(true))
743 ETraits->setTrait(Sym,
744 RegionAndSymbolInvalidationTraits::TK_SuppressEscape);
745 Values.push_back(MV);
749 void CXXConstructorCall::getInitialStackFrameContents(
750 const StackFrameContext *CalleeCtx,
751 BindingsTy &Bindings) const {
752 AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings);
754 SVal ThisVal = getCXXThisVal();
755 if (!ThisVal.isUnknown()) {
756 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
757 const auto *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl());
758 Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx);
759 Bindings.push_back(std::make_pair(ThisLoc, ThisVal));
763 SVal CXXDestructorCall::getCXXThisVal() const {
765 return loc::MemRegionVal(DtorDataTy::getFromOpaqueValue(Data).getPointer());
769 RuntimeDefinition CXXDestructorCall::getRuntimeDefinition() const {
770 // Base destructors are always called non-virtually.
771 // Skip CXXInstanceCall's devirtualization logic in this case.
772 if (isBaseDestructor())
773 return AnyFunctionCall::getRuntimeDefinition();
775 return CXXInstanceCall::getRuntimeDefinition();
778 ArrayRef<ParmVarDecl*> ObjCMethodCall::parameters() const {
779 const ObjCMethodDecl *D = getDecl();
782 return D->parameters();
785 void ObjCMethodCall::getExtraInvalidatedValues(
786 ValueList &Values, RegionAndSymbolInvalidationTraits *ETraits) const {
788 // If the method call is a setter for property known to be backed by
789 // an instance variable, don't invalidate the entire receiver, just
790 // the storage for that instance variable.
791 if (const ObjCPropertyDecl *PropDecl = getAccessedProperty()) {
792 if (const ObjCIvarDecl *PropIvar = PropDecl->getPropertyIvarDecl()) {
793 SVal IvarLVal = getState()->getLValue(PropIvar, getReceiverSVal());
794 if (const MemRegion *IvarRegion = IvarLVal.getAsRegion()) {
797 RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
800 RegionAndSymbolInvalidationTraits::TK_SuppressEscape);
801 Values.push_back(IvarLVal);
807 Values.push_back(getReceiverSVal());
810 SVal ObjCMethodCall::getSelfSVal() const {
811 const LocationContext *LCtx = getLocationContext();
812 const ImplicitParamDecl *SelfDecl = LCtx->getSelfDecl();
815 return getState()->getSVal(getState()->getRegion(SelfDecl, LCtx));
818 SVal ObjCMethodCall::getReceiverSVal() const {
819 // FIXME: Is this the best way to handle class receivers?
820 if (!isInstanceMessage())
823 if (const Expr *RecE = getOriginExpr()->getInstanceReceiver())
824 return getSVal(RecE);
826 // An instance message with no expression means we are sending to super.
827 // In this case the object reference is the same as 'self'.
828 assert(getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance);
829 SVal SelfVal = getSelfSVal();
830 assert(SelfVal.isValid() && "Calling super but not in ObjC method");
834 bool ObjCMethodCall::isReceiverSelfOrSuper() const {
835 if (getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance ||
836 getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperClass)
839 if (!isInstanceMessage())
842 SVal RecVal = getSVal(getOriginExpr()->getInstanceReceiver());
844 return (RecVal == getSelfSVal());
847 SourceRange ObjCMethodCall::getSourceRange() const {
848 switch (getMessageKind()) {
850 return getOriginExpr()->getSourceRange();
851 case OCM_PropertyAccess:
853 return getContainingPseudoObjectExpr()->getSourceRange();
855 llvm_unreachable("unknown message kind");
858 using ObjCMessageDataTy = llvm::PointerIntPair<const PseudoObjectExpr *, 2>;
860 const PseudoObjectExpr *ObjCMethodCall::getContainingPseudoObjectExpr() const {
861 assert(Data && "Lazy lookup not yet performed.");
862 assert(getMessageKind() != OCM_Message && "Explicit message send.");
863 return ObjCMessageDataTy::getFromOpaqueValue(Data).getPointer();
867 getSyntacticFromForPseudoObjectExpr(const PseudoObjectExpr *POE) {
868 const Expr *Syntactic = POE->getSyntacticForm();
870 // This handles the funny case of assigning to the result of a getter.
871 // This can happen if the getter returns a non-const reference.
872 if (const auto *BO = dyn_cast<BinaryOperator>(Syntactic))
873 Syntactic = BO->getLHS();
878 ObjCMessageKind ObjCMethodCall::getMessageKind() const {
880 // Find the parent, ignoring implicit casts.
881 ParentMap &PM = getLocationContext()->getParentMap();
882 const Stmt *S = PM.getParentIgnoreParenCasts(getOriginExpr());
884 // Check if parent is a PseudoObjectExpr.
885 if (const auto *POE = dyn_cast_or_null<PseudoObjectExpr>(S)) {
886 const Expr *Syntactic = getSyntacticFromForPseudoObjectExpr(POE);
889 switch (Syntactic->getStmtClass()) {
890 case Stmt::ObjCPropertyRefExprClass:
891 K = OCM_PropertyAccess;
893 case Stmt::ObjCSubscriptRefExprClass:
897 // FIXME: Can this ever happen?
902 if (K != OCM_Message) {
903 const_cast<ObjCMethodCall *>(this)->Data
904 = ObjCMessageDataTy(POE, K).getOpaqueValue();
905 assert(getMessageKind() == K);
910 const_cast<ObjCMethodCall *>(this)->Data
911 = ObjCMessageDataTy(nullptr, 1).getOpaqueValue();
912 assert(getMessageKind() == OCM_Message);
916 ObjCMessageDataTy Info = ObjCMessageDataTy::getFromOpaqueValue(Data);
917 if (!Info.getPointer())
919 return static_cast<ObjCMessageKind>(Info.getInt());
922 const ObjCPropertyDecl *ObjCMethodCall::getAccessedProperty() const {
923 // Look for properties accessed with property syntax (foo.bar = ...)
924 if ( getMessageKind() == OCM_PropertyAccess) {
925 const PseudoObjectExpr *POE = getContainingPseudoObjectExpr();
926 assert(POE && "Property access without PseudoObjectExpr?");
928 const Expr *Syntactic = getSyntacticFromForPseudoObjectExpr(POE);
929 auto *RefExpr = cast<ObjCPropertyRefExpr>(Syntactic);
931 if (RefExpr->isExplicitProperty())
932 return RefExpr->getExplicitProperty();
935 // Look for properties accessed with method syntax ([foo setBar:...]).
936 const ObjCMethodDecl *MD = getDecl();
937 if (!MD || !MD->isPropertyAccessor())
940 // Note: This is potentially quite slow.
941 return MD->findPropertyDecl();
944 bool ObjCMethodCall::canBeOverridenInSubclass(ObjCInterfaceDecl *IDecl,
945 Selector Sel) const {
947 AnalysisManager &AMgr =
948 getState()->getStateManager().getOwningEngine()->getAnalysisManager();
949 // If the class interface is declared inside the main file, assume it is not
951 // TODO: It could actually be subclassed if the subclass is private as well.
952 // This is probably very rare.
953 SourceLocation InterfLoc = IDecl->getEndOfDefinitionLoc();
954 if (InterfLoc.isValid() && AMgr.isInCodeFile(InterfLoc))
957 // Assume that property accessors are not overridden.
958 if (getMessageKind() == OCM_PropertyAccess)
961 // We assume that if the method is public (declared outside of main file) or
962 // has a parent which publicly declares the method, the method could be
963 // overridden in a subclass.
965 // Find the first declaration in the class hierarchy that declares
967 ObjCMethodDecl *D = nullptr;
969 D = IDecl->lookupMethod(Sel, true);
971 // Cannot find a public definition.
975 // If outside the main file,
976 if (D->getLocation().isValid() && !AMgr.isInCodeFile(D->getLocation()))
979 if (D->isOverriding()) {
980 // Search in the superclass on the next iteration.
981 IDecl = D->getClassInterface();
985 IDecl = IDecl->getSuperClass();
995 llvm_unreachable("The while loop should always terminate.");
998 static const ObjCMethodDecl *findDefiningRedecl(const ObjCMethodDecl *MD) {
1002 // Find the redeclaration that defines the method.
1003 if (!MD->hasBody()) {
1004 for (auto I : MD->redecls())
1006 MD = cast<ObjCMethodDecl>(I);
1011 static bool isCallToSelfClass(const ObjCMessageExpr *ME) {
1012 const Expr* InstRec = ME->getInstanceReceiver();
1015 const auto *InstRecIg = dyn_cast<DeclRefExpr>(InstRec->IgnoreParenImpCasts());
1017 // Check that receiver is called 'self'.
1018 if (!InstRecIg || !InstRecIg->getFoundDecl() ||
1019 !InstRecIg->getFoundDecl()->getName().equals("self"))
1022 // Check that the method name is 'class'.
1023 if (ME->getSelector().getNumArgs() != 0 ||
1024 !ME->getSelector().getNameForSlot(0).equals("class"))
1030 RuntimeDefinition ObjCMethodCall::getRuntimeDefinition() const {
1031 const ObjCMessageExpr *E = getOriginExpr();
1033 Selector Sel = E->getSelector();
1035 if (E->isInstanceMessage()) {
1036 // Find the receiver type.
1037 const ObjCObjectPointerType *ReceiverT = nullptr;
1038 bool CanBeSubClassed = false;
1039 QualType SupersType = E->getSuperType();
1040 const MemRegion *Receiver = nullptr;
1042 if (!SupersType.isNull()) {
1043 // The receiver is guaranteed to be 'super' in this case.
1044 // Super always means the type of immediate predecessor to the method
1045 // where the call occurs.
1046 ReceiverT = cast<ObjCObjectPointerType>(SupersType);
1048 Receiver = getReceiverSVal().getAsRegion();
1052 DynamicTypeInfo DTI = getDynamicTypeInfo(getState(), Receiver);
1053 if (!DTI.isValid()) {
1054 assert(isa<AllocaRegion>(Receiver) &&
1055 "Unhandled untyped region class!");
1059 QualType DynType = DTI.getType();
1060 CanBeSubClassed = DTI.canBeASubClass();
1061 ReceiverT = dyn_cast<ObjCObjectPointerType>(DynType.getCanonicalType());
1063 if (ReceiverT && CanBeSubClassed)
1064 if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl())
1065 if (!canBeOverridenInSubclass(IDecl, Sel))
1066 CanBeSubClassed = false;
1069 // Handle special cases of '[self classMethod]' and
1070 // '[[self class] classMethod]', which are treated by the compiler as
1071 // instance (not class) messages. We will statically dispatch to those.
1072 if (auto *PT = dyn_cast_or_null<ObjCObjectPointerType>(ReceiverT)) {
1073 // For [self classMethod], return the compiler visible declaration.
1074 if (PT->getObjectType()->isObjCClass() &&
1075 Receiver == getSelfSVal().getAsRegion())
1076 return RuntimeDefinition(findDefiningRedecl(E->getMethodDecl()));
1078 // Similarly, handle [[self class] classMethod].
1079 // TODO: We are currently doing a syntactic match for this pattern with is
1080 // limiting as the test cases in Analysis/inlining/InlineObjCClassMethod.m
1081 // shows. A better way would be to associate the meta type with the symbol
1082 // using the dynamic type info tracking and use it here. We can add a new
1083 // SVal for ObjC 'Class' values that know what interface declaration they
1084 // come from. Then 'self' in a class method would be filled in with
1085 // something meaningful in ObjCMethodCall::getReceiverSVal() and we could
1086 // do proper dynamic dispatch for class methods just like we do for
1087 // instance methods now.
1088 if (E->getInstanceReceiver())
1089 if (const auto *M = dyn_cast<ObjCMessageExpr>(E->getInstanceReceiver()))
1090 if (isCallToSelfClass(M))
1091 return RuntimeDefinition(findDefiningRedecl(E->getMethodDecl()));
1094 // Lookup the instance method implementation.
1096 if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) {
1097 // Repeatedly calling lookupPrivateMethod() is expensive, especially
1098 // when in many cases it returns null. We cache the results so
1099 // that repeated queries on the same ObjCIntefaceDecl and Selector
1100 // don't incur the same cost. On some test cases, we can see the
1101 // same query being issued thousands of times.
1103 // NOTE: This cache is essentially a "global" variable, but it
1104 // only gets lazily created when we get here. The value of the
1105 // cache probably comes from it being global across ExprEngines,
1106 // where the same queries may get issued. If we are worried about
1107 // concurrency, or possibly loading/unloading ASTs, etc., we may
1108 // need to revisit this someday. In terms of memory, this table
1109 // stays around until clang quits, which also may be bad if we
1110 // need to release memory.
1111 using PrivateMethodKey = std::pair<const ObjCInterfaceDecl *, Selector>;
1112 using PrivateMethodCache =
1113 llvm::DenseMap<PrivateMethodKey, Optional<const ObjCMethodDecl *>>;
1115 static PrivateMethodCache PMC;
1116 Optional<const ObjCMethodDecl *> &Val = PMC[std::make_pair(IDecl, Sel)];
1118 // Query lookupPrivateMethod() if the cache does not hit.
1119 if (!Val.hasValue()) {
1120 Val = IDecl->lookupPrivateMethod(Sel);
1122 // If the method is a property accessor, we should try to "inline" it
1123 // even if we don't actually have an implementation.
1125 if (const ObjCMethodDecl *CompileTimeMD = E->getMethodDecl())
1126 if (CompileTimeMD->isPropertyAccessor()) {
1127 if (!CompileTimeMD->getSelfDecl() &&
1128 isa<ObjCCategoryDecl>(CompileTimeMD->getDeclContext())) {
1129 // If the method is an accessor in a category, and it doesn't
1130 // have a self declaration, first
1131 // try to find the method in a class extension. This
1132 // works around a bug in Sema where multiple accessors
1133 // are synthesized for properties in class
1134 // extensions that are redeclared in a category and the
1135 // the implicit parameters are not filled in for
1136 // the method on the category.
1137 // This ensures we find the accessor in the extension, which
1138 // has the implicit parameters filled in.
1139 auto *ID = CompileTimeMD->getClassInterface();
1140 for (auto *CatDecl : ID->visible_extensions()) {
1141 Val = CatDecl->getMethod(Sel,
1142 CompileTimeMD->isInstanceMethod());
1148 Val = IDecl->lookupInstanceMethod(Sel);
1152 const ObjCMethodDecl *MD = Val.getValue();
1153 if (CanBeSubClassed)
1154 return RuntimeDefinition(MD, Receiver);
1156 return RuntimeDefinition(MD, nullptr);
1159 // This is a class method.
1160 // If we have type info for the receiver class, we are calling via
1162 if (ObjCInterfaceDecl *IDecl = E->getReceiverInterface()) {
1163 // Find/Return the method implementation.
1164 return RuntimeDefinition(IDecl->lookupPrivateClassMethod(Sel));
1171 bool ObjCMethodCall::argumentsMayEscape() const {
1172 if (isInSystemHeader() && !isInstanceMessage()) {
1173 Selector Sel = getSelector();
1174 if (Sel.getNumArgs() == 1 &&
1175 Sel.getIdentifierInfoForSlot(0)->isStr("valueWithPointer"))
1179 return CallEvent::argumentsMayEscape();
1182 void ObjCMethodCall::getInitialStackFrameContents(
1183 const StackFrameContext *CalleeCtx,
1184 BindingsTy &Bindings) const {
1185 const auto *D = cast<ObjCMethodDecl>(CalleeCtx->getDecl());
1186 SValBuilder &SVB = getState()->getStateManager().getSValBuilder();
1187 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this,
1190 SVal SelfVal = getReceiverSVal();
1191 if (!SelfVal.isUnknown()) {
1192 const VarDecl *SelfD = CalleeCtx->getAnalysisDeclContext()->getSelfDecl();
1193 MemRegionManager &MRMgr = SVB.getRegionManager();
1194 Loc SelfLoc = SVB.makeLoc(MRMgr.getVarRegion(SelfD, CalleeCtx));
1195 Bindings.push_back(std::make_pair(SelfLoc, SelfVal));
1200 CallEventManager::getSimpleCall(const CallExpr *CE, ProgramStateRef State,
1201 const LocationContext *LCtx) {
1202 if (const auto *MCE = dyn_cast<CXXMemberCallExpr>(CE))
1203 return create<CXXMemberCall>(MCE, State, LCtx);
1205 if (const auto *OpCE = dyn_cast<CXXOperatorCallExpr>(CE)) {
1206 const FunctionDecl *DirectCallee = OpCE->getDirectCallee();
1207 if (const auto *MD = dyn_cast<CXXMethodDecl>(DirectCallee))
1208 if (MD->isInstance())
1209 return create<CXXMemberOperatorCall>(OpCE, State, LCtx);
1211 } else if (CE->getCallee()->getType()->isBlockPointerType()) {
1212 return create<BlockCall>(CE, State, LCtx);
1215 // Otherwise, it's a normal function call, static member function call, or
1216 // something we can't reason about.
1217 return create<SimpleFunctionCall>(CE, State, LCtx);
1221 CallEventManager::getCaller(const StackFrameContext *CalleeCtx,
1222 ProgramStateRef State) {
1223 const LocationContext *ParentCtx = CalleeCtx->getParent();
1224 const LocationContext *CallerCtx = ParentCtx->getStackFrame();
1225 assert(CallerCtx && "This should not be used for top-level stack frames");
1227 const Stmt *CallSite = CalleeCtx->getCallSite();
1230 if (const CallExpr *CE = dyn_cast<CallExpr>(CallSite))
1231 return getSimpleCall(CE, State, CallerCtx);
1233 switch (CallSite->getStmtClass()) {
1234 case Stmt::CXXConstructExprClass:
1235 case Stmt::CXXTemporaryObjectExprClass: {
1236 SValBuilder &SVB = State->getStateManager().getSValBuilder();
1237 const auto *Ctor = cast<CXXMethodDecl>(CalleeCtx->getDecl());
1238 Loc ThisPtr = SVB.getCXXThis(Ctor, CalleeCtx);
1239 SVal ThisVal = State->getSVal(ThisPtr);
1241 return getCXXConstructorCall(cast<CXXConstructExpr>(CallSite),
1242 ThisVal.getAsRegion(), State, CallerCtx);
1244 case Stmt::CXXNewExprClass:
1245 return getCXXAllocatorCall(cast<CXXNewExpr>(CallSite), State, CallerCtx);
1246 case Stmt::ObjCMessageExprClass:
1247 return getObjCMethodCall(cast<ObjCMessageExpr>(CallSite),
1250 llvm_unreachable("This is not an inlineable statement.");
1254 // Fall back to the CFG. The only thing we haven't handled yet is
1255 // destructors, though this could change in the future.
1256 const CFGBlock *B = CalleeCtx->getCallSiteBlock();
1257 CFGElement E = (*B)[CalleeCtx->getIndex()];
1258 assert((E.getAs<CFGImplicitDtor>() || E.getAs<CFGTemporaryDtor>()) &&
1259 "All other CFG elements should have exprs");
1261 SValBuilder &SVB = State->getStateManager().getSValBuilder();
1262 const auto *Dtor = cast<CXXDestructorDecl>(CalleeCtx->getDecl());
1263 Loc ThisPtr = SVB.getCXXThis(Dtor, CalleeCtx);
1264 SVal ThisVal = State->getSVal(ThisPtr);
1266 const Stmt *Trigger;
1267 if (Optional<CFGAutomaticObjDtor> AutoDtor = E.getAs<CFGAutomaticObjDtor>())
1268 Trigger = AutoDtor->getTriggerStmt();
1269 else if (Optional<CFGDeleteDtor> DeleteDtor = E.getAs<CFGDeleteDtor>())
1270 Trigger = DeleteDtor->getDeleteExpr();
1272 Trigger = Dtor->getBody();
1274 return getCXXDestructorCall(Dtor, Trigger, ThisVal.getAsRegion(),
1275 E.getAs<CFGBaseDtor>().hasValue(), State,