| //==-- RetainCountChecker.cpp - Checks for leaks and other issues -*- C++ -*--// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the methods for RetainCountChecker, which implements |
| // a reference count checker for Core Foundation and Cocoa on (Mac OS X). |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "AllocationDiagnostics.h" |
| #include "ClangSACheckers.h" |
| #include "SelectorExtras.h" |
| #include "clang/AST/Attr.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/DeclObjC.h" |
| #include "clang/AST/ParentMap.h" |
| #include "clang/Analysis/DomainSpecific/CocoaConventions.h" |
| #include "clang/Basic/LangOptions.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/StaticAnalyzer/Checkers/ObjCRetainCount.h" |
| #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" |
| #include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h" |
| #include "clang/StaticAnalyzer/Core/Checker.h" |
| #include "clang/StaticAnalyzer/Core/CheckerManager.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/FoldingSet.h" |
| #include "llvm/ADT/ImmutableList.h" |
| #include "llvm/ADT/ImmutableMap.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include <cstdarg> |
| #include <utility> |
| |
| using namespace clang; |
| using namespace ento; |
| using namespace objc_retain; |
| using llvm::StrInStrNoCase; |
| |
| //===----------------------------------------------------------------------===// |
| // Adapters for FoldingSet. |
| //===----------------------------------------------------------------------===// |
| |
| namespace llvm { |
| template <> struct FoldingSetTrait<ArgEffect> { |
| static inline void Profile(const ArgEffect X, FoldingSetNodeID &ID) { |
| ID.AddInteger((unsigned) X); |
| } |
| }; |
| template <> struct FoldingSetTrait<RetEffect> { |
| static inline void Profile(const RetEffect &X, FoldingSetNodeID &ID) { |
| ID.AddInteger((unsigned) X.getKind()); |
| ID.AddInteger((unsigned) X.getObjKind()); |
| } |
| }; |
| } // end llvm namespace |
| |
| //===----------------------------------------------------------------------===// |
| // Reference-counting logic (typestate + counts). |
| //===----------------------------------------------------------------------===// |
| |
| /// ArgEffects summarizes the effects of a function/method call on all of |
| /// its arguments. |
| typedef llvm::ImmutableMap<unsigned,ArgEffect> ArgEffects; |
| |
| namespace { |
| class RefVal { |
| public: |
| enum Kind { |
| Owned = 0, // Owning reference. |
| NotOwned, // Reference is not owned by still valid (not freed). |
| Released, // Object has been released. |
| ReturnedOwned, // Returned object passes ownership to caller. |
| ReturnedNotOwned, // Return object does not pass ownership to caller. |
| ERROR_START, |
| ErrorDeallocNotOwned, // -dealloc called on non-owned object. |
| ErrorDeallocGC, // Calling -dealloc with GC enabled. |
| ErrorUseAfterRelease, // Object used after released. |
| ErrorReleaseNotOwned, // Release of an object that was not owned. |
| ERROR_LEAK_START, |
| ErrorLeak, // A memory leak due to excessive reference counts. |
| ErrorLeakReturned, // A memory leak due to the returning method not having |
| // the correct naming conventions. |
| ErrorGCLeakReturned, |
| ErrorOverAutorelease, |
| ErrorReturnedNotOwned |
| }; |
| |
| /// Tracks how an object referenced by an ivar has been used. |
| /// |
| /// This accounts for us not knowing if an arbitrary ivar is supposed to be |
| /// stored at +0 or +1. |
| enum class IvarAccessHistory { |
| None, |
| AccessedDirectly, |
| ReleasedAfterDirectAccess |
| }; |
| |
| private: |
| /// The number of outstanding retains. |
| unsigned Cnt; |
| /// The number of outstanding autoreleases. |
| unsigned ACnt; |
| /// The (static) type of the object at the time we started tracking it. |
| QualType T; |
| |
| /// The current state of the object. |
| /// |
| /// See the RefVal::Kind enum for possible values. |
| unsigned RawKind : 5; |
| |
| /// The kind of object being tracked (CF or ObjC), if known. |
| /// |
| /// See the RetEffect::ObjKind enum for possible values. |
| unsigned RawObjectKind : 2; |
| |
| /// True if the current state and/or retain count may turn out to not be the |
| /// best possible approximation of the reference counting state. |
| /// |
| /// If true, the checker may decide to throw away ("override") this state |
| /// in favor of something else when it sees the object being used in new ways. |
| /// |
| /// This setting should not be propagated to state derived from this state. |
| /// Once we start deriving new states, it would be inconsistent to override |
| /// them. |
| unsigned RawIvarAccessHistory : 2; |
| |
| RefVal(Kind k, RetEffect::ObjKind o, unsigned cnt, unsigned acnt, QualType t, |
| IvarAccessHistory IvarAccess) |
| : Cnt(cnt), ACnt(acnt), T(t), RawKind(static_cast<unsigned>(k)), |
| RawObjectKind(static_cast<unsigned>(o)), |
| RawIvarAccessHistory(static_cast<unsigned>(IvarAccess)) { |
| assert(getKind() == k && "not enough bits for the kind"); |
| assert(getObjKind() == o && "not enough bits for the object kind"); |
| assert(getIvarAccessHistory() == IvarAccess && "not enough bits"); |
| } |
| |
| public: |
| Kind getKind() const { return static_cast<Kind>(RawKind); } |
| |
| RetEffect::ObjKind getObjKind() const { |
| return static_cast<RetEffect::ObjKind>(RawObjectKind); |
| } |
| |
| unsigned getCount() const { return Cnt; } |
| unsigned getAutoreleaseCount() const { return ACnt; } |
| unsigned getCombinedCounts() const { return Cnt + ACnt; } |
| void clearCounts() { |
| Cnt = 0; |
| ACnt = 0; |
| } |
| void setCount(unsigned i) { |
| Cnt = i; |
| } |
| void setAutoreleaseCount(unsigned i) { |
| ACnt = i; |
| } |
| |
| QualType getType() const { return T; } |
| |
| /// Returns what the analyzer knows about direct accesses to a particular |
| /// instance variable. |
| /// |
| /// If the object with this refcount wasn't originally from an Objective-C |
| /// ivar region, this should always return IvarAccessHistory::None. |
| IvarAccessHistory getIvarAccessHistory() const { |
| return static_cast<IvarAccessHistory>(RawIvarAccessHistory); |
| } |
| |
| bool isOwned() const { |
| return getKind() == Owned; |
| } |
| |
| bool isNotOwned() const { |
| return getKind() == NotOwned; |
| } |
| |
| bool isReturnedOwned() const { |
| return getKind() == ReturnedOwned; |
| } |
| |
| bool isReturnedNotOwned() const { |
| return getKind() == ReturnedNotOwned; |
| } |
| |
| /// Create a state for an object whose lifetime is the responsibility of the |
| /// current function, at least partially. |
| /// |
| /// Most commonly, this is an owned object with a retain count of +1. |
| static RefVal makeOwned(RetEffect::ObjKind o, QualType t, |
| unsigned Count = 1) { |
| return RefVal(Owned, o, Count, 0, t, IvarAccessHistory::None); |
| } |
| |
| /// Create a state for an object whose lifetime is not the responsibility of |
| /// the current function. |
| /// |
| /// Most commonly, this is an unowned object with a retain count of +0. |
| static RefVal makeNotOwned(RetEffect::ObjKind o, QualType t, |
| unsigned Count = 0) { |
| return RefVal(NotOwned, o, Count, 0, t, IvarAccessHistory::None); |
| } |
| |
| RefVal operator-(size_t i) const { |
| return RefVal(getKind(), getObjKind(), getCount() - i, |
| getAutoreleaseCount(), getType(), getIvarAccessHistory()); |
| } |
| |
| RefVal operator+(size_t i) const { |
| return RefVal(getKind(), getObjKind(), getCount() + i, |
| getAutoreleaseCount(), getType(), getIvarAccessHistory()); |
| } |
| |
| RefVal operator^(Kind k) const { |
| return RefVal(k, getObjKind(), getCount(), getAutoreleaseCount(), |
| getType(), getIvarAccessHistory()); |
| } |
| |
| RefVal autorelease() const { |
| return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount()+1, |
| getType(), getIvarAccessHistory()); |
| } |
| |
| RefVal withIvarAccess() const { |
| assert(getIvarAccessHistory() == IvarAccessHistory::None); |
| return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount(), |
| getType(), IvarAccessHistory::AccessedDirectly); |
| } |
| |
| RefVal releaseViaIvar() const { |
| assert(getIvarAccessHistory() == IvarAccessHistory::AccessedDirectly); |
| return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount(), |
| getType(), IvarAccessHistory::ReleasedAfterDirectAccess); |
| } |
| |
| // Comparison, profiling, and pretty-printing. |
| |
| bool hasSameState(const RefVal &X) const { |
| return getKind() == X.getKind() && Cnt == X.Cnt && ACnt == X.ACnt && |
| getIvarAccessHistory() == X.getIvarAccessHistory(); |
| } |
| |
| bool operator==(const RefVal& X) const { |
| return T == X.T && hasSameState(X) && getObjKind() == X.getObjKind(); |
| } |
| |
| void Profile(llvm::FoldingSetNodeID& ID) const { |
| ID.Add(T); |
| ID.AddInteger(RawKind); |
| ID.AddInteger(Cnt); |
| ID.AddInteger(ACnt); |
| ID.AddInteger(RawObjectKind); |
| ID.AddInteger(RawIvarAccessHistory); |
| } |
| |
| void print(raw_ostream &Out) const; |
| }; |
| |
| void RefVal::print(raw_ostream &Out) const { |
| if (!T.isNull()) |
| Out << "Tracked " << T.getAsString() << '/'; |
| |
| switch (getKind()) { |
| default: llvm_unreachable("Invalid RefVal kind"); |
| case Owned: { |
| Out << "Owned"; |
| unsigned cnt = getCount(); |
| if (cnt) Out << " (+ " << cnt << ")"; |
| break; |
| } |
| |
| case NotOwned: { |
| Out << "NotOwned"; |
| unsigned cnt = getCount(); |
| if (cnt) Out << " (+ " << cnt << ")"; |
| break; |
| } |
| |
| case ReturnedOwned: { |
| Out << "ReturnedOwned"; |
| unsigned cnt = getCount(); |
| if (cnt) Out << " (+ " << cnt << ")"; |
| break; |
| } |
| |
| case ReturnedNotOwned: { |
| Out << "ReturnedNotOwned"; |
| unsigned cnt = getCount(); |
| if (cnt) Out << " (+ " << cnt << ")"; |
| break; |
| } |
| |
| case Released: |
| Out << "Released"; |
| break; |
| |
| case ErrorDeallocGC: |
| Out << "-dealloc (GC)"; |
| break; |
| |
| case ErrorDeallocNotOwned: |
| Out << "-dealloc (not-owned)"; |
| break; |
| |
| case ErrorLeak: |
| Out << "Leaked"; |
| break; |
| |
| case ErrorLeakReturned: |
| Out << "Leaked (Bad naming)"; |
| break; |
| |
| case ErrorGCLeakReturned: |
| Out << "Leaked (GC-ed at return)"; |
| break; |
| |
| case ErrorUseAfterRelease: |
| Out << "Use-After-Release [ERROR]"; |
| break; |
| |
| case ErrorReleaseNotOwned: |
| Out << "Release of Not-Owned [ERROR]"; |
| break; |
| |
| case RefVal::ErrorOverAutorelease: |
| Out << "Over-autoreleased"; |
| break; |
| |
| case RefVal::ErrorReturnedNotOwned: |
| Out << "Non-owned object returned instead of owned"; |
| break; |
| } |
| |
| switch (getIvarAccessHistory()) { |
| case IvarAccessHistory::None: |
| break; |
| case IvarAccessHistory::AccessedDirectly: |
| Out << " [direct ivar access]"; |
| break; |
| case IvarAccessHistory::ReleasedAfterDirectAccess: |
| Out << " [released after direct ivar access]"; |
| } |
| |
| if (ACnt) { |
| Out << " [autorelease -" << ACnt << ']'; |
| } |
| } |
| } //end anonymous namespace |
| |
| //===----------------------------------------------------------------------===// |
| // RefBindings - State used to track object reference counts. |
| //===----------------------------------------------------------------------===// |
| |
| REGISTER_MAP_WITH_PROGRAMSTATE(RefBindings, SymbolRef, RefVal) |
| |
| static inline const RefVal *getRefBinding(ProgramStateRef State, |
| SymbolRef Sym) { |
| return State->get<RefBindings>(Sym); |
| } |
| |
| static inline ProgramStateRef setRefBinding(ProgramStateRef State, |
| SymbolRef Sym, RefVal Val) { |
| return State->set<RefBindings>(Sym, Val); |
| } |
| |
| static ProgramStateRef removeRefBinding(ProgramStateRef State, SymbolRef Sym) { |
| return State->remove<RefBindings>(Sym); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Function/Method behavior summaries. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class RetainSummary { |
| /// Args - a map of (index, ArgEffect) pairs, where index |
| /// specifies the argument (starting from 0). This can be sparsely |
| /// populated; arguments with no entry in Args use 'DefaultArgEffect'. |
| ArgEffects Args; |
| |
| /// DefaultArgEffect - The default ArgEffect to apply to arguments that |
| /// do not have an entry in Args. |
| ArgEffect DefaultArgEffect; |
| |
| /// Receiver - If this summary applies to an Objective-C message expression, |
| /// this is the effect applied to the state of the receiver. |
| ArgEffect Receiver; |
| |
| /// Ret - The effect on the return value. Used to indicate if the |
| /// function/method call returns a new tracked symbol. |
| RetEffect Ret; |
| |
| public: |
| RetainSummary(ArgEffects A, RetEffect R, ArgEffect defaultEff, |
| ArgEffect ReceiverEff) |
| : Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R) {} |
| |
| /// getArg - Return the argument effect on the argument specified by |
| /// idx (starting from 0). |
| ArgEffect getArg(unsigned idx) const { |
| if (const ArgEffect *AE = Args.lookup(idx)) |
| return *AE; |
| |
| return DefaultArgEffect; |
| } |
| |
| void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) { |
| Args = af.add(Args, idx, e); |
| } |
| |
| /// setDefaultArgEffect - Set the default argument effect. |
| void setDefaultArgEffect(ArgEffect E) { |
| DefaultArgEffect = E; |
| } |
| |
| /// getRetEffect - Returns the effect on the return value of the call. |
| RetEffect getRetEffect() const { return Ret; } |
| |
| /// setRetEffect - Set the effect of the return value of the call. |
| void setRetEffect(RetEffect E) { Ret = E; } |
| |
| |
| /// Sets the effect on the receiver of the message. |
| void setReceiverEffect(ArgEffect e) { Receiver = e; } |
| |
| /// getReceiverEffect - Returns the effect on the receiver of the call. |
| /// This is only meaningful if the summary applies to an ObjCMessageExpr*. |
| ArgEffect getReceiverEffect() const { return Receiver; } |
| |
| /// Test if two retain summaries are identical. Note that merely equivalent |
| /// summaries are not necessarily identical (for example, if an explicit |
| /// argument effect matches the default effect). |
| bool operator==(const RetainSummary &Other) const { |
| return Args == Other.Args && DefaultArgEffect == Other.DefaultArgEffect && |
| Receiver == Other.Receiver && Ret == Other.Ret; |
| } |
| |
| /// Profile this summary for inclusion in a FoldingSet. |
| void Profile(llvm::FoldingSetNodeID& ID) const { |
| ID.Add(Args); |
| ID.Add(DefaultArgEffect); |
| ID.Add(Receiver); |
| ID.Add(Ret); |
| } |
| |
| /// A retain summary is simple if it has no ArgEffects other than the default. |
| bool isSimple() const { |
| return Args.isEmpty(); |
| } |
| |
| private: |
| ArgEffects getArgEffects() const { return Args; } |
| ArgEffect getDefaultArgEffect() const { return DefaultArgEffect; } |
| |
| friend class RetainSummaryManager; |
| friend class RetainCountChecker; |
| }; |
| } // end anonymous namespace |
| |
| //===----------------------------------------------------------------------===// |
| // Data structures for constructing summaries. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class ObjCSummaryKey { |
| IdentifierInfo* II; |
| Selector S; |
| public: |
| ObjCSummaryKey(IdentifierInfo* ii, Selector s) |
| : II(ii), S(s) {} |
| |
| ObjCSummaryKey(const ObjCInterfaceDecl *d, Selector s) |
| : II(d ? d->getIdentifier() : nullptr), S(s) {} |
| |
| ObjCSummaryKey(Selector s) |
| : II(nullptr), S(s) {} |
| |
| IdentifierInfo *getIdentifier() const { return II; } |
| Selector getSelector() const { return S; } |
| }; |
| } // end anonymous namespace |
| |
| namespace llvm { |
| template <> struct DenseMapInfo<ObjCSummaryKey> { |
| static inline ObjCSummaryKey getEmptyKey() { |
| return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getEmptyKey(), |
| DenseMapInfo<Selector>::getEmptyKey()); |
| } |
| |
| static inline ObjCSummaryKey getTombstoneKey() { |
| return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getTombstoneKey(), |
| DenseMapInfo<Selector>::getTombstoneKey()); |
| } |
| |
| static unsigned getHashValue(const ObjCSummaryKey &V) { |
| typedef std::pair<IdentifierInfo*, Selector> PairTy; |
| return DenseMapInfo<PairTy>::getHashValue(PairTy(V.getIdentifier(), |
| V.getSelector())); |
| } |
| |
| static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) { |
| return LHS.getIdentifier() == RHS.getIdentifier() && |
| LHS.getSelector() == RHS.getSelector(); |
| } |
| |
| }; |
| } // end llvm namespace |
| |
| namespace { |
| class ObjCSummaryCache { |
| typedef llvm::DenseMap<ObjCSummaryKey, const RetainSummary *> MapTy; |
| MapTy M; |
| public: |
| ObjCSummaryCache() {} |
| |
| const RetainSummary * find(const ObjCInterfaceDecl *D, Selector S) { |
| // Do a lookup with the (D,S) pair. If we find a match return |
| // the iterator. |
| ObjCSummaryKey K(D, S); |
| MapTy::iterator I = M.find(K); |
| |
| if (I != M.end()) |
| return I->second; |
| if (!D) |
| return nullptr; |
| |
| // Walk the super chain. If we find a hit with a parent, we'll end |
| // up returning that summary. We actually allow that key (null,S), as |
| // we cache summaries for the null ObjCInterfaceDecl* to allow us to |
| // generate initial summaries without having to worry about NSObject |
| // being declared. |
| // FIXME: We may change this at some point. |
| for (ObjCInterfaceDecl *C=D->getSuperClass() ;; C=C->getSuperClass()) { |
| if ((I = M.find(ObjCSummaryKey(C, S))) != M.end()) |
| break; |
| |
| if (!C) |
| return nullptr; |
| } |
| |
| // Cache the summary with original key to make the next lookup faster |
| // and return the iterator. |
| const RetainSummary *Summ = I->second; |
| M[K] = Summ; |
| return Summ; |
| } |
| |
| const RetainSummary *find(IdentifierInfo* II, Selector S) { |
| // FIXME: Class method lookup. Right now we don't have a good way |
| // of going between IdentifierInfo* and the class hierarchy. |
| MapTy::iterator I = M.find(ObjCSummaryKey(II, S)); |
| |
| if (I == M.end()) |
| I = M.find(ObjCSummaryKey(S)); |
| |
| return I == M.end() ? nullptr : I->second; |
| } |
| |
| const RetainSummary *& operator[](ObjCSummaryKey K) { |
| return M[K]; |
| } |
| |
| const RetainSummary *& operator[](Selector S) { |
| return M[ ObjCSummaryKey(S) ]; |
| } |
| }; |
| } // end anonymous namespace |
| |
| //===----------------------------------------------------------------------===// |
| // Data structures for managing collections of summaries. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class RetainSummaryManager { |
| |
| //==-----------------------------------------------------------------==// |
| // Typedefs. |
| //==-----------------------------------------------------------------==// |
| |
| typedef llvm::DenseMap<const FunctionDecl*, const RetainSummary *> |
| FuncSummariesTy; |
| |
| typedef ObjCSummaryCache ObjCMethodSummariesTy; |
| |
| typedef llvm::FoldingSetNodeWrapper<RetainSummary> CachedSummaryNode; |
| |
| //==-----------------------------------------------------------------==// |
| // Data. |
| //==-----------------------------------------------------------------==// |
| |
| /// Ctx - The ASTContext object for the analyzed ASTs. |
| ASTContext &Ctx; |
| |
| /// GCEnabled - Records whether or not the analyzed code runs in GC mode. |
| const bool GCEnabled; |
| |
| /// Records whether or not the analyzed code runs in ARC mode. |
| const bool ARCEnabled; |
| |
| /// FuncSummaries - A map from FunctionDecls to summaries. |
| FuncSummariesTy FuncSummaries; |
| |
| /// ObjCClassMethodSummaries - A map from selectors (for instance methods) |
| /// to summaries. |
| ObjCMethodSummariesTy ObjCClassMethodSummaries; |
| |
| /// ObjCMethodSummaries - A map from selectors to summaries. |
| ObjCMethodSummariesTy ObjCMethodSummaries; |
| |
| /// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects, |
| /// and all other data used by the checker. |
| llvm::BumpPtrAllocator BPAlloc; |
| |
| /// AF - A factory for ArgEffects objects. |
| ArgEffects::Factory AF; |
| |
| /// ScratchArgs - A holding buffer for construct ArgEffects. |
| ArgEffects ScratchArgs; |
| |
| /// ObjCAllocRetE - Default return effect for methods returning Objective-C |
| /// objects. |
| RetEffect ObjCAllocRetE; |
| |
| /// ObjCInitRetE - Default return effect for init methods returning |
| /// Objective-C objects. |
| RetEffect ObjCInitRetE; |
| |
| /// SimpleSummaries - Used for uniquing summaries that don't have special |
| /// effects. |
| llvm::FoldingSet<CachedSummaryNode> SimpleSummaries; |
| |
| //==-----------------------------------------------------------------==// |
| // Methods. |
| //==-----------------------------------------------------------------==// |
| |
| /// getArgEffects - Returns a persistent ArgEffects object based on the |
| /// data in ScratchArgs. |
| ArgEffects getArgEffects(); |
| |
| enum UnaryFuncKind { cfretain, cfrelease, cfautorelease, cfmakecollectable }; |
| |
| const RetainSummary *getUnarySummary(const FunctionType* FT, |
| UnaryFuncKind func); |
| |
| const RetainSummary *getCFSummaryCreateRule(const FunctionDecl *FD); |
| const RetainSummary *getCFSummaryGetRule(const FunctionDecl *FD); |
| const RetainSummary *getCFCreateGetRuleSummary(const FunctionDecl *FD); |
| |
| const RetainSummary *getPersistentSummary(const RetainSummary &OldSumm); |
| |
| const RetainSummary *getPersistentSummary(RetEffect RetEff, |
| ArgEffect ReceiverEff = DoNothing, |
| ArgEffect DefaultEff = MayEscape) { |
| RetainSummary Summ(getArgEffects(), RetEff, DefaultEff, ReceiverEff); |
| return getPersistentSummary(Summ); |
| } |
| |
| const RetainSummary *getDoNothingSummary() { |
| return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } |
| |
| const RetainSummary *getDefaultSummary() { |
| return getPersistentSummary(RetEffect::MakeNoRet(), |
| DoNothing, MayEscape); |
| } |
| |
| const RetainSummary *getPersistentStopSummary() { |
| return getPersistentSummary(RetEffect::MakeNoRet(), |
| StopTracking, StopTracking); |
| } |
| |
| void InitializeClassMethodSummaries(); |
| void InitializeMethodSummaries(); |
| private: |
| void addNSObjectClsMethSummary(Selector S, const RetainSummary *Summ) { |
| ObjCClassMethodSummaries[S] = Summ; |
| } |
| |
| void addNSObjectMethSummary(Selector S, const RetainSummary *Summ) { |
| ObjCMethodSummaries[S] = Summ; |
| } |
| |
| void addClassMethSummary(const char* Cls, const char* name, |
| const RetainSummary *Summ, bool isNullary = true) { |
| IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); |
| Selector S = isNullary ? GetNullarySelector(name, Ctx) |
| : GetUnarySelector(name, Ctx); |
| ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; |
| } |
| |
| void addInstMethSummary(const char* Cls, const char* nullaryName, |
| const RetainSummary *Summ) { |
| IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); |
| Selector S = GetNullarySelector(nullaryName, Ctx); |
| ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; |
| } |
| |
| template <typename... Keywords> |
| void addMethodSummary(IdentifierInfo *ClsII, ObjCMethodSummariesTy &Summaries, |
| const RetainSummary *Summ, Keywords *... Kws) { |
| Selector S = getKeywordSelector(Ctx, Kws...); |
| Summaries[ObjCSummaryKey(ClsII, S)] = Summ; |
| } |
| |
| template <typename... Keywords> |
| void addInstMethSummary(const char *Cls, const RetainSummary *Summ, |
| Keywords *... Kws) { |
| addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, Kws...); |
| } |
| |
| template <typename... Keywords> |
| void addClsMethSummary(const char *Cls, const RetainSummary *Summ, |
| Keywords *... Kws) { |
| addMethodSummary(&Ctx.Idents.get(Cls), ObjCClassMethodSummaries, Summ, |
| Kws...); |
| } |
| |
| template <typename... Keywords> |
| void addClsMethSummary(IdentifierInfo *II, const RetainSummary *Summ, |
| Keywords *... Kws) { |
| addMethodSummary(II, ObjCClassMethodSummaries, Summ, Kws...); |
| } |
| |
| public: |
| |
| RetainSummaryManager(ASTContext &ctx, bool gcenabled, bool usesARC) |
| : Ctx(ctx), |
| GCEnabled(gcenabled), |
| ARCEnabled(usesARC), |
| AF(BPAlloc), ScratchArgs(AF.getEmptyMap()), |
| ObjCAllocRetE(gcenabled |
| ? RetEffect::MakeGCNotOwned() |
| : (usesARC ? RetEffect::MakeNotOwned(RetEffect::ObjC) |
| : RetEffect::MakeOwned(RetEffect::ObjC))), |
| ObjCInitRetE(gcenabled |
| ? RetEffect::MakeGCNotOwned() |
| : (usesARC ? RetEffect::MakeNotOwned(RetEffect::ObjC) |
| : RetEffect::MakeOwnedWhenTrackedReceiver())) { |
| InitializeClassMethodSummaries(); |
| InitializeMethodSummaries(); |
| } |
| |
| const RetainSummary *getSummary(const CallEvent &Call, |
| ProgramStateRef State = nullptr); |
| |
| const RetainSummary *getFunctionSummary(const FunctionDecl *FD); |
| |
| const RetainSummary *getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, |
| const ObjCMethodDecl *MD, |
| QualType RetTy, |
| ObjCMethodSummariesTy &CachedSummaries); |
| |
| const RetainSummary *getInstanceMethodSummary(const ObjCMethodCall &M, |
| ProgramStateRef State); |
| |
| const RetainSummary *getClassMethodSummary(const ObjCMethodCall &M) { |
| assert(!M.isInstanceMessage()); |
| const ObjCInterfaceDecl *Class = M.getReceiverInterface(); |
| |
| return getMethodSummary(M.getSelector(), Class, M.getDecl(), |
| M.getResultType(), ObjCClassMethodSummaries); |
| } |
| |
| /// getMethodSummary - This version of getMethodSummary is used to query |
| /// the summary for the current method being analyzed. |
| const RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) { |
| const ObjCInterfaceDecl *ID = MD->getClassInterface(); |
| Selector S = MD->getSelector(); |
| QualType ResultTy = MD->getReturnType(); |
| |
| ObjCMethodSummariesTy *CachedSummaries; |
| if (MD->isInstanceMethod()) |
| CachedSummaries = &ObjCMethodSummaries; |
| else |
| CachedSummaries = &ObjCClassMethodSummaries; |
| |
| return getMethodSummary(S, ID, MD, ResultTy, *CachedSummaries); |
| } |
| |
| const RetainSummary *getStandardMethodSummary(const ObjCMethodDecl *MD, |
| Selector S, QualType RetTy); |
| |
| /// Determine if there is a special return effect for this function or method. |
| Optional<RetEffect> getRetEffectFromAnnotations(QualType RetTy, |
| const Decl *D); |
| |
| void updateSummaryFromAnnotations(const RetainSummary *&Summ, |
| const ObjCMethodDecl *MD); |
| |
| void updateSummaryFromAnnotations(const RetainSummary *&Summ, |
| const FunctionDecl *FD); |
| |
| void updateSummaryForCall(const RetainSummary *&Summ, |
| const CallEvent &Call); |
| |
| bool isGCEnabled() const { return GCEnabled; } |
| |
| bool isARCEnabled() const { return ARCEnabled; } |
| |
| bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; } |
| |
| RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; } |
| |
| friend class RetainSummaryTemplate; |
| }; |
| |
| // Used to avoid allocating long-term (BPAlloc'd) memory for default retain |
| // summaries. If a function or method looks like it has a default summary, but |
| // it has annotations, the annotations are added to the stack-based template |
| // and then copied into managed memory. |
| class RetainSummaryTemplate { |
| RetainSummaryManager &Manager; |
| const RetainSummary *&RealSummary; |
| RetainSummary ScratchSummary; |
| bool Accessed; |
| public: |
| RetainSummaryTemplate(const RetainSummary *&real, RetainSummaryManager &mgr) |
| : Manager(mgr), RealSummary(real), ScratchSummary(*real), Accessed(false) {} |
| |
| ~RetainSummaryTemplate() { |
| if (Accessed) |
| RealSummary = Manager.getPersistentSummary(ScratchSummary); |
| } |
| |
| RetainSummary &operator*() { |
| Accessed = true; |
| return ScratchSummary; |
| } |
| |
| RetainSummary *operator->() { |
| Accessed = true; |
| return &ScratchSummary; |
| } |
| }; |
| |
| } // end anonymous namespace |
| |
| //===----------------------------------------------------------------------===// |
| // Implementation of checker data structures. |
| //===----------------------------------------------------------------------===// |
| |
| ArgEffects RetainSummaryManager::getArgEffects() { |
| ArgEffects AE = ScratchArgs; |
| ScratchArgs = AF.getEmptyMap(); |
| return AE; |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getPersistentSummary(const RetainSummary &OldSumm) { |
| // Unique "simple" summaries -- those without ArgEffects. |
| if (OldSumm.isSimple()) { |
| llvm::FoldingSetNodeID ID; |
| OldSumm.Profile(ID); |
| |
| void *Pos; |
| CachedSummaryNode *N = SimpleSummaries.FindNodeOrInsertPos(ID, Pos); |
| |
| if (!N) { |
| N = (CachedSummaryNode *) BPAlloc.Allocate<CachedSummaryNode>(); |
| new (N) CachedSummaryNode(OldSumm); |
| SimpleSummaries.InsertNode(N, Pos); |
| } |
| |
| return &N->getValue(); |
| } |
| |
| RetainSummary *Summ = (RetainSummary *) BPAlloc.Allocate<RetainSummary>(); |
| new (Summ) RetainSummary(OldSumm); |
| return Summ; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Summary creation for functions (largely uses of Core Foundation). |
| //===----------------------------------------------------------------------===// |
| |
| static bool isRetain(const FunctionDecl *FD, StringRef FName) { |
| return FName.startswith_lower("retain") || FName.endswith_lower("retain"); |
| } |
| |
| static bool isRelease(const FunctionDecl *FD, StringRef FName) { |
| return FName.startswith_lower("release") || FName.endswith_lower("release"); |
| } |
| |
| static bool isAutorelease(const FunctionDecl *FD, StringRef FName) { |
| return FName.startswith_lower("autorelease") || |
| FName.endswith_lower("autorelease"); |
| } |
| |
| static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName) { |
| // FIXME: Remove FunctionDecl parameter. |
| // FIXME: Is it really okay if MakeCollectable isn't a suffix? |
| return FName.find_lower("MakeCollectable") != StringRef::npos; |
| } |
| |
| static ArgEffect getStopTrackingHardEquivalent(ArgEffect E) { |
| switch (E) { |
| case DoNothing: |
| case Autorelease: |
| case DecRefBridgedTransferred: |
| case IncRef: |
| case IncRefMsg: |
| case MakeCollectable: |
| case UnretainedOutParameter: |
| case RetainedOutParameter: |
| case MayEscape: |
| case StopTracking: |
| case StopTrackingHard: |
| return StopTrackingHard; |
| case DecRef: |
| case DecRefAndStopTrackingHard: |
| return DecRefAndStopTrackingHard; |
| case DecRefMsg: |
| case DecRefMsgAndStopTrackingHard: |
| return DecRefMsgAndStopTrackingHard; |
| case Dealloc: |
| return Dealloc; |
| } |
| |
| llvm_unreachable("Unknown ArgEffect kind"); |
| } |
| |
| void RetainSummaryManager::updateSummaryForCall(const RetainSummary *&S, |
| const CallEvent &Call) { |
| if (Call.hasNonZeroCallbackArg()) { |
| ArgEffect RecEffect = |
| getStopTrackingHardEquivalent(S->getReceiverEffect()); |
| ArgEffect DefEffect = |
| getStopTrackingHardEquivalent(S->getDefaultArgEffect()); |
| |
| ArgEffects CustomArgEffects = S->getArgEffects(); |
| for (ArgEffects::iterator I = CustomArgEffects.begin(), |
| E = CustomArgEffects.end(); |
| I != E; ++I) { |
| ArgEffect Translated = getStopTrackingHardEquivalent(I->second); |
| if (Translated != DefEffect) |
| ScratchArgs = AF.add(ScratchArgs, I->first, Translated); |
| } |
| |
| RetEffect RE = RetEffect::MakeNoRetHard(); |
| |
| // Special cases where the callback argument CANNOT free the return value. |
| // This can generally only happen if we know that the callback will only be |
| // called when the return value is already being deallocated. |
| if (const SimpleFunctionCall *FC = dyn_cast<SimpleFunctionCall>(&Call)) { |
| if (IdentifierInfo *Name = FC->getDecl()->getIdentifier()) { |
| // When the CGBitmapContext is deallocated, the callback here will free |
| // the associated data buffer. |
| // The callback in dispatch_data_create frees the buffer, but not |
| // the data object. |
| if (Name->isStr("CGBitmapContextCreateWithData") || |
| Name->isStr("dispatch_data_create")) |
| RE = S->getRetEffect(); |
| } |
| } |
| |
| S = getPersistentSummary(RE, RecEffect, DefEffect); |
| } |
| |
| // Special case '[super init];' and '[self init];' |
| // |
| // Even though calling '[super init]' without assigning the result to self |
| // and checking if the parent returns 'nil' is a bad pattern, it is common. |
| // Additionally, our Self Init checker already warns about it. To avoid |
| // overwhelming the user with messages from both checkers, we model the case |
| // of '[super init]' in cases when it is not consumed by another expression |
| // as if the call preserves the value of 'self'; essentially, assuming it can |
| // never fail and return 'nil'. |
| // Note, we don't want to just stop tracking the value since we want the |
| // RetainCount checker to report leaks and use-after-free if SelfInit checker |
| // is turned off. |
| if (const ObjCMethodCall *MC = dyn_cast<ObjCMethodCall>(&Call)) { |
| if (MC->getMethodFamily() == OMF_init && MC->isReceiverSelfOrSuper()) { |
| |
| // Check if the message is not consumed, we know it will not be used in |
| // an assignment, ex: "self = [super init]". |
| const Expr *ME = MC->getOriginExpr(); |
| const LocationContext *LCtx = MC->getLocationContext(); |
| ParentMap &PM = LCtx->getAnalysisDeclContext()->getParentMap(); |
| if (!PM.isConsumedExpr(ME)) { |
| RetainSummaryTemplate ModifiableSummaryTemplate(S, *this); |
| ModifiableSummaryTemplate->setReceiverEffect(DoNothing); |
| ModifiableSummaryTemplate->setRetEffect(RetEffect::MakeNoRet()); |
| } |
| } |
| } |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getSummary(const CallEvent &Call, |
| ProgramStateRef State) { |
| const RetainSummary *Summ; |
| switch (Call.getKind()) { |
| case CE_Function: |
| Summ = getFunctionSummary(cast<SimpleFunctionCall>(Call).getDecl()); |
| break; |
| case CE_CXXMember: |
| case CE_CXXMemberOperator: |
| case CE_Block: |
| case CE_CXXConstructor: |
| case CE_CXXDestructor: |
| case CE_CXXAllocator: |
| // FIXME: These calls are currently unsupported. |
| return getPersistentStopSummary(); |
| case CE_ObjCMessage: { |
| const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call); |
| if (Msg.isInstanceMessage()) |
| Summ = getInstanceMethodSummary(Msg, State); |
| else |
| Summ = getClassMethodSummary(Msg); |
| break; |
| } |
| } |
| |
| updateSummaryForCall(Summ, Call); |
| |
| assert(Summ && "Unknown call type?"); |
| return Summ; |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) { |
| // If we don't know what function we're calling, use our default summary. |
| if (!FD) |
| return getDefaultSummary(); |
| |
| // Look up a summary in our cache of FunctionDecls -> Summaries. |
| FuncSummariesTy::iterator I = FuncSummaries.find(FD); |
| if (I != FuncSummaries.end()) |
| return I->second; |
| |
| // No summary? Generate one. |
| const RetainSummary *S = nullptr; |
| bool AllowAnnotations = true; |
| |
| do { |
| // We generate "stop" summaries for implicitly defined functions. |
| if (FD->isImplicit()) { |
| S = getPersistentStopSummary(); |
| break; |
| } |
| |
| // [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the |
| // function's type. |
| const FunctionType* FT = FD->getType()->getAs<FunctionType>(); |
| const IdentifierInfo *II = FD->getIdentifier(); |
| if (!II) |
| break; |
| |
| StringRef FName = II->getName(); |
| |
| // Strip away preceding '_'. Doing this here will effect all the checks |
| // down below. |
| FName = FName.substr(FName.find_first_not_of('_')); |
| |
| // Inspect the result type. |
| QualType RetTy = FT->getReturnType(); |
| std::string RetTyName = RetTy.getAsString(); |
| |
| // FIXME: This should all be refactored into a chain of "summary lookup" |
| // filters. |
| assert(ScratchArgs.isEmpty()); |
| |
| if (FName == "pthread_create" || FName == "pthread_setspecific") { |
| // Part of: <rdar://problem/7299394> and <rdar://problem/11282706>. |
| // This will be addressed better with IPA. |
| S = getPersistentStopSummary(); |
| } else if (FName == "NSMakeCollectable") { |
| // Handle: id NSMakeCollectable(CFTypeRef) |
| S = (RetTy->isObjCIdType()) |
| ? getUnarySummary(FT, cfmakecollectable) |
| : getPersistentStopSummary(); |
| // The headers on OS X 10.8 use cf_consumed/ns_returns_retained, |
| // but we can fully model NSMakeCollectable ourselves. |
| AllowAnnotations = false; |
| } else if (FName == "CFPlugInInstanceCreate") { |
| S = getPersistentSummary(RetEffect::MakeNoRet()); |
| } else if (FName == "IORegistryEntrySearchCFProperty" |
| || (RetTyName == "CFMutableDictionaryRef" && ( |
| FName == "IOBSDNameMatching" || |
| FName == "IOServiceMatching" || |
| FName == "IOServiceNameMatching" || |
| FName == "IORegistryEntryIDMatching" || |
| FName == "IOOpenFirmwarePathMatching" |
| ))) { |
| // Part of <rdar://problem/6961230>. (IOKit) |
| // This should be addressed using a API table. |
| S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF), |
| DoNothing, DoNothing); |
| } else if (FName == "IOServiceGetMatchingService" || |
| FName == "IOServiceGetMatchingServices") { |
| // FIXES: <rdar://problem/6326900> |
| // This should be addressed using a API table. This strcmp is also |
| // a little gross, but there is no need to super optimize here. |
| ScratchArgs = AF.add(ScratchArgs, 1, DecRef); |
| S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } else if (FName == "IOServiceAddNotification" || |
| FName == "IOServiceAddMatchingNotification") { |
| // Part of <rdar://problem/6961230>. (IOKit) |
| // This should be addressed using a API table. |
| ScratchArgs = AF.add(ScratchArgs, 2, DecRef); |
| S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } else if (FName == "CVPixelBufferCreateWithBytes") { |
| // FIXES: <rdar://problem/7283567> |
| // Eventually this can be improved by recognizing that the pixel |
| // buffer passed to CVPixelBufferCreateWithBytes is released via |
| // a callback and doing full IPA to make sure this is done correctly. |
| // FIXME: This function has an out parameter that returns an |
| // allocated object. |
| ScratchArgs = AF.add(ScratchArgs, 7, StopTracking); |
| S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } else if (FName == "CGBitmapContextCreateWithData") { |
| // FIXES: <rdar://problem/7358899> |
| // Eventually this can be improved by recognizing that 'releaseInfo' |
| // passed to CGBitmapContextCreateWithData is released via |
| // a callback and doing full IPA to make sure this is done correctly. |
| ScratchArgs = AF.add(ScratchArgs, 8, StopTracking); |
| S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF), |
| DoNothing, DoNothing); |
| } else if (FName == "CVPixelBufferCreateWithPlanarBytes") { |
| // FIXES: <rdar://problem/7283567> |
| // Eventually this can be improved by recognizing that the pixel |
| // buffer passed to CVPixelBufferCreateWithPlanarBytes is released |
| // via a callback and doing full IPA to make sure this is done |
| // correctly. |
| ScratchArgs = AF.add(ScratchArgs, 12, StopTracking); |
| S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } else if (FName == "VTCompressionSessionEncodeFrame") { |
| // The context argument passed to VTCompressionSessionEncodeFrame() |
| // is passed to the callback specified when creating the session |
| // (e.g. with VTCompressionSessionCreate()) which can release it. |
| // To account for this possibility, conservatively stop tracking |
| // the context. |
| ScratchArgs = AF.add(ScratchArgs, 5, StopTracking); |
| S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } else if (FName == "dispatch_set_context" || |
| FName == "xpc_connection_set_context") { |
| // <rdar://problem/11059275> - The analyzer currently doesn't have |
| // a good way to reason about the finalizer function for libdispatch. |
| // If we pass a context object that is memory managed, stop tracking it. |
| // <rdar://problem/13783514> - Same problem, but for XPC. |
| // FIXME: this hack should possibly go away once we can handle |
| // libdispatch and XPC finalizers. |
| ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); |
| S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } else if (FName.startswith("NSLog")) { |
| S = getDoNothingSummary(); |
| } else if (FName.startswith("NS") && |
| (FName.find("Insert") != StringRef::npos)) { |
| // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can |
| // be deallocated by NSMapRemove. (radar://11152419) |
| ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); |
| ScratchArgs = AF.add(ScratchArgs, 2, StopTracking); |
| S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } |
| |
| // Did we get a summary? |
| if (S) |
| break; |
| |
| if (RetTy->isPointerType()) { |
| // For CoreFoundation ('CF') types. |
| if (cocoa::isRefType(RetTy, "CF", FName)) { |
| if (isRetain(FD, FName)) { |
| S = getUnarySummary(FT, cfretain); |
| // CFRetain isn't supposed to be annotated. However, this may as well |
| // be a user-made "safe" CFRetain function that is incorrectly |
| // annotated as cf_returns_retained due to lack of better options. |
| // We want to ignore such annotation. |
| AllowAnnotations = false; |
| } else if (isAutorelease(FD, FName)) { |
| S = getUnarySummary(FT, cfautorelease); |
| // The headers use cf_consumed, but we can fully model CFAutorelease |
| // ourselves. |
| AllowAnnotations = false; |
| } else if (isMakeCollectable(FD, FName)) { |
| S = getUnarySummary(FT, cfmakecollectable); |
| AllowAnnotations = false; |
| } else { |
| S = getCFCreateGetRuleSummary(FD); |
| } |
| |
| break; |
| } |
| |
| // For CoreGraphics ('CG') and CoreVideo ('CV') types. |
| if (cocoa::isRefType(RetTy, "CG", FName) || |
| cocoa::isRefType(RetTy, "CV", FName)) { |
| if (isRetain(FD, FName)) |
| S = getUnarySummary(FT, cfretain); |
| else |
| S = getCFCreateGetRuleSummary(FD); |
| |
| break; |
| } |
| |
| // For all other CF-style types, use the Create/Get |
| // rule for summaries but don't support Retain functions |
| // with framework-specific prefixes. |
| if (coreFoundation::isCFObjectRef(RetTy)) { |
| S = getCFCreateGetRuleSummary(FD); |
| break; |
| } |
| |
| if (FD->hasAttr<CFAuditedTransferAttr>()) { |
| S = getCFCreateGetRuleSummary(FD); |
| break; |
| } |
| |
| break; |
| } |
| |
| // Check for release functions, the only kind of functions that we care |
| // about that don't return a pointer type. |
| if (FName.size() >= 2 && |
| FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) { |
| // Test for 'CGCF'. |
| FName = FName.substr(FName.startswith("CGCF") ? 4 : 2); |
| |
| if (isRelease(FD, FName)) |
| S = getUnarySummary(FT, cfrelease); |
| else { |
| assert (ScratchArgs.isEmpty()); |
| // Remaining CoreFoundation and CoreGraphics functions. |
| // We use to assume that they all strictly followed the ownership idiom |
| // and that ownership cannot be transferred. While this is technically |
| // correct, many methods allow a tracked object to escape. For example: |
| // |
| // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...); |
| // CFDictionaryAddValue(y, key, x); |
| // CFRelease(x); |
| // ... it is okay to use 'x' since 'y' has a reference to it |
| // |
| // We handle this and similar cases with the follow heuristic. If the |
| // function name contains "InsertValue", "SetValue", "AddValue", |
| // "AppendValue", or "SetAttribute", then we assume that arguments may |
| // "escape." This means that something else holds on to the object, |
| // allowing it be used even after its local retain count drops to 0. |
| ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos|| |
| StrInStrNoCase(FName, "AddValue") != StringRef::npos || |
| StrInStrNoCase(FName, "SetValue") != StringRef::npos || |
| StrInStrNoCase(FName, "AppendValue") != StringRef::npos|| |
| StrInStrNoCase(FName, "SetAttribute") != StringRef::npos) |
| ? MayEscape : DoNothing; |
| |
| S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E); |
| } |
| } |
| } |
| while (0); |
| |
| // If we got all the way here without any luck, use a default summary. |
| if (!S) |
| S = getDefaultSummary(); |
| |
| // Annotations override defaults. |
| if (AllowAnnotations) |
| updateSummaryFromAnnotations(S, FD); |
| |
| FuncSummaries[FD] = S; |
| return S; |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) { |
| if (coreFoundation::followsCreateRule(FD)) |
| return getCFSummaryCreateRule(FD); |
| |
| return getCFSummaryGetRule(FD); |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getUnarySummary(const FunctionType* FT, |
| UnaryFuncKind func) { |
| |
| // Sanity check that this is *really* a unary function. This can |
| // happen if people do weird things. |
| const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT); |
| if (!FTP || FTP->getNumParams() != 1) |
| return getPersistentStopSummary(); |
| |
| assert (ScratchArgs.isEmpty()); |
| |
| ArgEffect Effect; |
| switch (func) { |
| case cfretain: Effect = IncRef; break; |
| case cfrelease: Effect = DecRef; break; |
| case cfautorelease: Effect = Autorelease; break; |
| case cfmakecollectable: Effect = MakeCollectable; break; |
| } |
| |
| ScratchArgs = AF.add(ScratchArgs, 0, Effect); |
| return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) { |
| assert (ScratchArgs.isEmpty()); |
| |
| return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF)); |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) { |
| assert (ScratchArgs.isEmpty()); |
| return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF), |
| DoNothing, DoNothing); |
| } |
| |
| /// Returns true if the declaration 'D' is annotated with 'rcAnnotation'. |
| static bool hasRCAnnotation(const Decl *D, StringRef rcAnnotation) { |
| for (const auto *Ann : D->specific_attrs<AnnotateAttr>()) { |
| if (Ann->getAnnotation() == rcAnnotation) |
| return true; |
| } |
| return false; |
| } |
| |
| /// Returns true if the function declaration 'FD' contains |
| /// 'rc_ownership_trusted_implementation' annotate attribute. |
| static bool isTrustedReferenceCountImplementation(const FunctionDecl *FD) { |
| return hasRCAnnotation(FD, "rc_ownership_trusted_implementation"); |
| } |
| |
| static bool isGeneralizedObjectRef(QualType Ty) { |
| if (Ty.getAsString().substr(0, 4) == "isl_") |
| return true; |
| else |
| return false; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Summary creation for Selectors. |
| //===----------------------------------------------------------------------===// |
| |
| Optional<RetEffect> |
| RetainSummaryManager::getRetEffectFromAnnotations(QualType RetTy, |
| const Decl *D) { |
| if (cocoa::isCocoaObjectRef(RetTy)) { |
| if (D->hasAttr<NSReturnsRetainedAttr>()) |
| return ObjCAllocRetE; |
| |
| if (D->hasAttr<NSReturnsNotRetainedAttr>() || |
| D->hasAttr<NSReturnsAutoreleasedAttr>()) |
| return RetEffect::MakeNotOwned(RetEffect::ObjC); |
| |
| } else if (!RetTy->isPointerType()) { |
| return None; |
| } |
| |
| if (D->hasAttr<CFReturnsRetainedAttr>()) |
| return RetEffect::MakeOwned(RetEffect::CF); |
| else if (hasRCAnnotation(D, "rc_ownership_returns_retained")) |
| return RetEffect::MakeOwned(RetEffect::Generalized); |
| |
| if (D->hasAttr<CFReturnsNotRetainedAttr>()) |
| return RetEffect::MakeNotOwned(RetEffect::CF); |
| |
| return None; |
| } |
| |
| void |
| RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, |
| const FunctionDecl *FD) { |
| if (!FD) |
| return; |
| |
| assert(Summ && "Must have a summary to add annotations to."); |
| RetainSummaryTemplate Template(Summ, *this); |
| |
| // Effects on the parameters. |
| unsigned parm_idx = 0; |
| for (FunctionDecl::param_const_iterator pi = FD->param_begin(), |
| pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) { |
| const ParmVarDecl *pd = *pi; |
| if (pd->hasAttr<NSConsumedAttr>()) |
| Template->addArg(AF, parm_idx, DecRefMsg); |
| else if (pd->hasAttr<CFConsumedAttr>() || |
| hasRCAnnotation(pd, "rc_ownership_consumed")) |
| Template->addArg(AF, parm_idx, DecRef); |
| else if (pd->hasAttr<CFReturnsRetainedAttr>() || |
| hasRCAnnotation(pd, "rc_ownership_returns_retained")) { |
| QualType PointeeTy = pd->getType()->getPointeeType(); |
| if (!PointeeTy.isNull()) |
| if (coreFoundation::isCFObjectRef(PointeeTy)) |
| Template->addArg(AF, parm_idx, RetainedOutParameter); |
| } else if (pd->hasAttr<CFReturnsNotRetainedAttr>()) { |
| QualType PointeeTy = pd->getType()->getPointeeType(); |
| if (!PointeeTy.isNull()) |
| if (coreFoundation::isCFObjectRef(PointeeTy)) |
| Template->addArg(AF, parm_idx, UnretainedOutParameter); |
| } |
| } |
| |
| QualType RetTy = FD->getReturnType(); |
| if (Optional<RetEffect> RetE = getRetEffectFromAnnotations(RetTy, FD)) |
| Template->setRetEffect(*RetE); |
| } |
| |
| void |
| RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, |
| const ObjCMethodDecl *MD) { |
| if (!MD) |
| return; |
| |
| assert(Summ && "Must have a valid summary to add annotations to"); |
| RetainSummaryTemplate Template(Summ, *this); |
| |
| // Effects on the receiver. |
| if (MD->hasAttr<NSConsumesSelfAttr>()) |
| Template->setReceiverEffect(DecRefMsg); |
| |
| // Effects on the parameters. |
| unsigned parm_idx = 0; |
| for (ObjCMethodDecl::param_const_iterator |
| pi=MD->param_begin(), pe=MD->param_end(); |
| pi != pe; ++pi, ++parm_idx) { |
| const ParmVarDecl *pd = *pi; |
| if (pd->hasAttr<NSConsumedAttr>()) |
| Template->addArg(AF, parm_idx, DecRefMsg); |
| else if (pd->hasAttr<CFConsumedAttr>()) { |
| Template->addArg(AF, parm_idx, DecRef); |
| } else if (pd->hasAttr<CFReturnsRetainedAttr>()) { |
| QualType PointeeTy = pd->getType()->getPointeeType(); |
| if (!PointeeTy.isNull()) |
| if (coreFoundation::isCFObjectRef(PointeeTy)) |
| Template->addArg(AF, parm_idx, RetainedOutParameter); |
| } else if (pd->hasAttr<CFReturnsNotRetainedAttr>()) { |
| QualType PointeeTy = pd->getType()->getPointeeType(); |
| if (!PointeeTy.isNull()) |
| if (coreFoundation::isCFObjectRef(PointeeTy)) |
| Template->addArg(AF, parm_idx, UnretainedOutParameter); |
| } |
| } |
| |
| QualType RetTy = MD->getReturnType(); |
| if (Optional<RetEffect> RetE = getRetEffectFromAnnotations(RetTy, MD)) |
| Template->setRetEffect(*RetE); |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD, |
| Selector S, QualType RetTy) { |
| // Any special effects? |
| ArgEffect ReceiverEff = DoNothing; |
| RetEffect ResultEff = RetEffect::MakeNoRet(); |
| |
| // Check the method family, and apply any default annotations. |
| switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) { |
| case OMF_None: |
| case OMF_initialize: |
| case OMF_performSelector: |
| // Assume all Objective-C methods follow Cocoa Memory Management rules. |
| // FIXME: Does the non-threaded performSelector family really belong here? |
| // The selector could be, say, @selector(copy). |
| if (cocoa::isCocoaObjectRef(RetTy)) |
| ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC); |
| else if (coreFoundation::isCFObjectRef(RetTy)) { |
| // ObjCMethodDecl currently doesn't consider CF objects as valid return |
| // values for alloc, new, copy, or mutableCopy, so we have to |
| // double-check with the selector. This is ugly, but there aren't that |
| // many Objective-C methods that return CF objects, right? |
| if (MD) { |
| switch (S.getMethodFamily()) { |
| case OMF_alloc: |
| case OMF_new: |
| case OMF_copy: |
| case OMF_mutableCopy: |
| ResultEff = RetEffect::MakeOwned(RetEffect::CF); |
| break; |
| default: |
| ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); |
| break; |
| } |
| } else { |
| ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); |
| } |
| } |
| break; |
| case OMF_init: |
| ResultEff = ObjCInitRetE; |
| ReceiverEff = DecRefMsg; |
| break; |
| case OMF_alloc: |
| case OMF_new: |
| case OMF_copy: |
| case OMF_mutableCopy: |
| if (cocoa::isCocoaObjectRef(RetTy)) |
| ResultEff = ObjCAllocRetE; |
| else if (coreFoundation::isCFObjectRef(RetTy)) |
| ResultEff = RetEffect::MakeOwned(RetEffect::CF); |
| break; |
| case OMF_autorelease: |
| ReceiverEff = Autorelease; |
| break; |
| case OMF_retain: |
| ReceiverEff = IncRefMsg; |
| break; |
| case OMF_release: |
| ReceiverEff = DecRefMsg; |
| break; |
| case OMF_dealloc: |
| ReceiverEff = Dealloc; |
| break; |
| case OMF_self: |
| // -self is handled specially by the ExprEngine to propagate the receiver. |
| break; |
| case OMF_retainCount: |
| case OMF_finalize: |
| // These methods don't return objects. |
| break; |
| } |
| |
| // If one of the arguments in the selector has the keyword 'delegate' we |
| // should stop tracking the reference count for the receiver. This is |
| // because the reference count is quite possibly handled by a delegate |
| // method. |
| if (S.isKeywordSelector()) { |
| for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) { |
| StringRef Slot = S.getNameForSlot(i); |
| if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) { |
| if (ResultEff == ObjCInitRetE) |
| ResultEff = RetEffect::MakeNoRetHard(); |
| else |
| ReceiverEff = StopTrackingHard; |
| } |
| } |
| } |
| |
| if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing && |
| ResultEff.getKind() == RetEffect::NoRet) |
| return getDefaultSummary(); |
| |
| return getPersistentSummary(ResultEff, ReceiverEff, MayEscape); |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg, |
| ProgramStateRef State) { |
| const ObjCInterfaceDecl *ReceiverClass = nullptr; |
| |
| // We do better tracking of the type of the object than the core ExprEngine. |
| // See if we have its type in our private state. |
| // FIXME: Eventually replace the use of state->get<RefBindings> with |
| // a generic API for reasoning about the Objective-C types of symbolic |
| // objects. |
| SVal ReceiverV = Msg.getReceiverSVal(); |
| if (SymbolRef Sym = ReceiverV.getAsLocSymbol()) |
| if (const RefVal *T = getRefBinding(State, Sym)) |
| if (const ObjCObjectPointerType *PT = |
| T->getType()->getAs<ObjCObjectPointerType>()) |
| ReceiverClass = PT->getInterfaceDecl(); |
| |
| // If we don't know what kind of object this is, fall back to its static type. |
| if (!ReceiverClass) |
| ReceiverClass = Msg.getReceiverInterface(); |
| |
| // FIXME: The receiver could be a reference to a class, meaning that |
| // we should use the class method. |
| // id x = [NSObject class]; |
| // [x performSelector:... withObject:... afterDelay:...]; |
| Selector S = Msg.getSelector(); |
| const ObjCMethodDecl *Method = Msg.getDecl(); |
| if (!Method && ReceiverClass) |
| Method = ReceiverClass->getInstanceMethod(S); |
| |
| return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(), |
| ObjCMethodSummaries); |
| } |
| |
| const RetainSummary * |
| RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, |
| const ObjCMethodDecl *MD, QualType RetTy, |
| ObjCMethodSummariesTy &CachedSummaries) { |
| |
| // Look up a summary in our summary cache. |
| const RetainSummary *Summ = CachedSummaries.find(ID, S); |
| |
| if (!Summ) { |
| Summ = getStandardMethodSummary(MD, S, RetTy); |
| |
| // Annotations override defaults. |
| updateSummaryFromAnnotations(Summ, MD); |
| |
| // Memoize the summary. |
| CachedSummaries[ObjCSummaryKey(ID, S)] = Summ; |
| } |
| |
| return Summ; |
| } |
| |
| void RetainSummaryManager::InitializeClassMethodSummaries() { |
| assert(ScratchArgs.isEmpty()); |
| // Create the [NSAssertionHandler currentHander] summary. |
| addClassMethSummary("NSAssertionHandler", "currentHandler", |
| getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC))); |
| |
| // Create the [NSAutoreleasePool addObject:] summary. |
| ScratchArgs = AF.add(ScratchArgs, 0, Autorelease); |
| addClassMethSummary("NSAutoreleasePool", "addObject", |
| getPersistentSummary(RetEffect::MakeNoRet(), |
| DoNothing, Autorelease)); |
| } |
| |
| void RetainSummaryManager::InitializeMethodSummaries() { |
| |
| assert (ScratchArgs.isEmpty()); |
| |
| // Create the "init" selector. It just acts as a pass-through for the |
| // receiver. |
| const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg); |
| addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm); |
| |
| // awakeAfterUsingCoder: behaves basically like an 'init' method. It |
| // claims the receiver and returns a retained object. |
| addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx), |
| InitSumm); |
| |
| // The next methods are allocators. |
| const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE); |
| const RetainSummary *CFAllocSumm = |
| getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF)); |
| |
| // Create the "retain" selector. |
| RetEffect NoRet = RetEffect::MakeNoRet(); |
| const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg); |
| addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ); |
| |
| // Create the "release" selector. |
| Summ = getPersistentSummary(NoRet, DecRefMsg); |
| addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ); |
| |
| // Create the -dealloc summary. |
| Summ = getPersistentSummary(NoRet, Dealloc); |
| addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ); |
| |
| // Create the "autorelease" selector. |
| Summ = getPersistentSummary(NoRet, Autorelease); |
| addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ); |
| |
| // For NSWindow, allocated objects are (initially) self-owned. |
| // FIXME: For now we opt for false negatives with NSWindow, as these objects |
| // self-own themselves. However, they only do this once they are displayed. |
| // Thus, we need to track an NSWindow's display status. |
| // This is tracked in <rdar://problem/6062711>. |
| // See also http://llvm.org/bugs/show_bug.cgi?id=3714. |
| const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(), |
| StopTracking, |
| StopTracking); |
| |
| addClassMethSummary("NSWindow", "alloc", NoTrackYet); |
| |
| // For NSPanel (which subclasses NSWindow), allocated objects are not |
| // self-owned. |
| // FIXME: For now we don't track NSPanels. object for the same reason |
| // as for NSWindow objects. |
| addClassMethSummary("NSPanel", "alloc", NoTrackYet); |
| |
| // For NSNull, objects returned by +null are singletons that ignore |
| // retain/release semantics. Just don't track them. |
| // <rdar://problem/12858915> |
| addClassMethSummary("NSNull", "null", NoTrackYet); |
| |
| // Don't track allocated autorelease pools, as it is okay to prematurely |
| // exit a method. |
| addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet); |
| addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false); |
| addClassMethSummary("NSAutoreleasePool", "new", NoTrackYet); |
| |
| // Create summaries QCRenderer/QCView -createSnapShotImageOfType: |
| addInstMethSummary("QCRenderer", AllocSumm, "createSnapshotImageOfType"); |
| addInstMethSummary("QCView", AllocSumm, "createSnapshotImageOfType"); |
| |
| // Create summaries for CIContext, 'createCGImage' and |
| // 'createCGLayerWithSize'. These objects are CF objects, and are not |
| // automatically garbage collected. |
| addInstMethSummary("CIContext", CFAllocSumm, "createCGImage", "fromRect"); |
| addInstMethSummary("CIContext", CFAllocSumm, "createCGImage", "fromRect", |
| "format", "colorSpace"); |
| addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", "info"); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Error reporting. |
| //===----------------------------------------------------------------------===// |
| namespace { |
| typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *> |
| SummaryLogTy; |
| |
| //===-------------===// |
| // Bug Descriptions. // |
| //===-------------===// |
| |
| class CFRefBug : public BugType { |
| protected: |
| CFRefBug(const CheckerBase *checker, StringRef name) |
| : BugType(checker, name, categories::MemoryCoreFoundationObjectiveC) {} |
| |
| public: |
| |
| // FIXME: Eventually remove. |
| virtual const char *getDescription() const = 0; |
| |
| virtual bool isLeak() const { return false; } |
| }; |
| |
| class UseAfterRelease : public CFRefBug { |
| public: |
| UseAfterRelease(const CheckerBase *checker) |
| : CFRefBug(checker, "Use-after-release") {} |
| |
| const char *getDescription() const override { |
| return "Reference-counted object is used after it is released"; |
| } |
| }; |
| |
| class BadRelease : public CFRefBug { |
| public: |
| BadRelease(const CheckerBase *checker) : CFRefBug(checker, "Bad release") {} |
| |
| const char *getDescription() const override { |
| return "Incorrect decrement of the reference count of an object that is " |
| "not owned at this point by the caller"; |
| } |
| }; |
| |
| class DeallocGC : public CFRefBug { |
| public: |
| DeallocGC(const CheckerBase *checker) |
| : CFRefBug(checker, "-dealloc called while using garbage collection") {} |
| |
| const char *getDescription() const override { |
| return "-dealloc called while using garbage collection"; |
| } |
| }; |
| |
| class DeallocNotOwned : public CFRefBug { |
| public: |
| DeallocNotOwned(const CheckerBase *checker) |
| : CFRefBug(checker, "-dealloc sent to non-exclusively owned object") {} |
| |
| const char *getDescription() const override { |
| return "-dealloc sent to object that may be referenced elsewhere"; |
| } |
| }; |
| |
| class OverAutorelease : public CFRefBug { |
| public: |
| OverAutorelease(const CheckerBase *checker) |
| : CFRefBug(checker, "Object autoreleased too many times") {} |
| |
| const char *getDescription() const override { |
| return "Object autoreleased too many times"; |
| } |
| }; |
| |
| class ReturnedNotOwnedForOwned : public CFRefBug { |
| public: |
| ReturnedNotOwnedForOwned(const CheckerBase *checker) |
| : CFRefBug(checker, "Method should return an owned object") {} |
| |
| const char *getDescription() const override { |
| return "Object with a +0 retain count returned to caller where a +1 " |
| "(owning) retain count is expected"; |
| } |
| }; |
| |
| class Leak : public CFRefBug { |
| public: |
| Leak(const CheckerBase *checker, StringRef name) : CFRefBug(checker, name) { |
| // Leaks should not be reported if they are post-dominated by a sink. |
| setSuppressOnSink(true); |
| } |
| |
| const char *getDescription() const override { return ""; } |
| |
| bool isLeak() const override { return true; } |
| }; |
| |
| //===---------===// |
| // Bug Reports. // |
| //===---------===// |
| class CFRefReportVisitor : public BugReporterVisitor { |
| protected: |
| SymbolRef Sym; |
| const SummaryLogTy &SummaryLog; |
| bool GCEnabled; |
| |
| public: |
| CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log) |
| : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {} |
| |
| void Profile(llvm::FoldingSetNodeID &ID) const override { |
| static int x = 0; |
| ID.AddPointer(&x); |
| ID.AddPointer(Sym); |
| } |
| |
| std::shared_ptr<PathDiagnosticPiece> VisitNode(const ExplodedNode *N, |
| const ExplodedNode *PrevN, |
| BugReporterContext &BRC, |
| BugReport &BR) override; |
| |
| std::shared_ptr<PathDiagnosticPiece> getEndPath(BugReporterContext &BRC, |
| const ExplodedNode *N, |
| BugReport &BR) override; |
| }; |
| |
| class CFRefLeakReportVisitor : public CFRefReportVisitor { |
| public: |
| CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled, |
| const SummaryLogTy &log) |
| : CFRefReportVisitor(sym, GCEnabled, log) {} |
| |
| std::shared_ptr<PathDiagnosticPiece> getEndPath(BugReporterContext &BRC, |
| const ExplodedNode *N, |
| BugReport &BR) override; |
| }; |
| |
| class CFRefReport : public BugReport { |
| void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled); |
| |
| public: |
| CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, |
| const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, |
| bool registerVisitor = true) |
| : BugReport(D, D.getDescription(), n) { |
| if (registerVisitor) |
| addVisitor(llvm::make_unique<CFRefReportVisitor>(sym, GCEnabled, Log)); |
| addGCModeDescription(LOpts, GCEnabled); |
| } |
| |
| CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, |
| const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, |
| StringRef endText) |
| : BugReport(D, D.getDescription(), endText, n) { |
| addVisitor(llvm::make_unique<CFRefReportVisitor>(sym, GCEnabled, Log)); |
| addGCModeDescription(LOpts, GCEnabled); |
| } |
| |
| llvm::iterator_range<ranges_iterator> getRanges() override { |
| const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType()); |
| if (!BugTy.isLeak()) |
| return BugReport::getRanges(); |
| return llvm::make_range(ranges_iterator(), ranges_iterator()); |
| } |
| }; |
| |
| class CFRefLeakReport : public CFRefReport { |
| const MemRegion* AllocBinding; |
| const Stmt *AllocStmt; |
| |
| // Finds the function declaration where a leak warning for the parameter 'sym' should be raised. |
| void deriveParamLocation(CheckerContext &Ctx, SymbolRef sym); |
| // Finds the location where a leak warning for 'sym' should be raised. |
| void deriveAllocLocation(CheckerContext &Ctx, SymbolRef sym); |
| // Produces description of a leak warning which is printed on the console. |
| void createDescription(CheckerContext &Ctx, bool GCEnabled, bool IncludeAllocationLine); |
| |
| public: |
| CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, |
| const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, |
| CheckerContext &Ctx, |
| bool IncludeAllocationLine); |
| |
| PathDiagnosticLocation getLocation(const SourceManager &SM) const override { |
| assert(Location.isValid()); |
| return Location; |
| } |
| }; |
| } // end anonymous namespace |
| |
| void CFRefReport::addGCModeDescription(const LangOptions &LOpts, |
| bool GCEnabled) { |
| const char *GCModeDescription = nullptr; |
| |
| switch (LOpts.getGC()) { |
| case LangOptions::GCOnly: |
| assert(GCEnabled); |
| GCModeDescription = "Code is compiled to only use garbage collection"; |
| break; |
| |
| case LangOptions::NonGC: |
| assert(!GCEnabled); |
| GCModeDescription = "Code is compiled to use reference counts"; |
| break; |
| |
| case LangOptions::HybridGC: |
| if (GCEnabled) { |
| GCModeDescription = "Code is compiled to use either garbage collection " |
| "(GC) or reference counts (non-GC). The bug occurs " |
| "with GC enabled"; |
| break; |
| } else { |
| GCModeDescription = "Code is compiled to use either garbage collection " |
| "(GC) or reference counts (non-GC). The bug occurs " |
| "in non-GC mode"; |
| break; |
| } |
| } |
| |
| assert(GCModeDescription && "invalid/unknown GC mode"); |
| addExtraText(GCModeDescription); |
| } |
| |
| static bool isNumericLiteralExpression(const Expr *E) { |
| // FIXME: This set of cases was copied from SemaExprObjC. |
| return isa<IntegerLiteral>(E) || |
| isa<CharacterLiteral>(E) || |
| isa<FloatingLiteral>(E) || |
| isa<ObjCBoolLiteralExpr>(E) || |
| isa<CXXBoolLiteralExpr>(E); |
| } |
| |
| static Optional<std::string> describeRegion(const MemRegion *MR) { |
| if (const auto *VR = dyn_cast_or_null<VarRegion>(MR)) |
| return std::string(VR->getDecl()->getName()); |
| // Once we support more storage locations for bindings, |
| // this would need to be improved. |
| return None; |
| } |
| |
| /// Returns true if this stack frame is for an Objective-C method that is a |
| /// property getter or setter whose body has been synthesized by the analyzer. |
| static bool isSynthesizedAccessor(const StackFrameContext *SFC) { |
| auto Method = dyn_cast_or_null<ObjCMethodDecl>(SFC->getDecl()); |
| if (!Method || !Method->isPropertyAccessor()) |
| return false; |
| |
| return SFC->getAnalysisDeclContext()->isBodyAutosynthesized(); |
| } |
| |
| std::shared_ptr<PathDiagnosticPiece> |
| CFRefReportVisitor::VisitNode(const ExplodedNode *N, const ExplodedNode *PrevN, |
| BugReporterContext &BRC, BugReport &BR) { |
| // FIXME: We will eventually need to handle non-statement-based events |
| // (__attribute__((cleanup))). |
| if (!N->getLocation().getAs<StmtPoint>()) |
| return nullptr; |
| |
| // Check if the type state has changed. |
| ProgramStateRef PrevSt = PrevN->getState(); |
| ProgramStateRef CurrSt = N->getState(); |
| const LocationContext *LCtx = N->getLocationContext(); |
| |
| const RefVal* CurrT = getRefBinding(CurrSt, Sym); |
| if (!CurrT) return nullptr; |
| |
| const RefVal &CurrV = *CurrT; |
| const RefVal *PrevT = getRefBinding(PrevSt, Sym); |
| |
| // Create a string buffer to constain all the useful things we want |
| // to tell the user. |
| std::string sbuf; |
| llvm::raw_string_ostream os(sbuf); |
| |
| // This is the allocation site since the previous node had no bindings |
| // for this symbol. |
| if (!PrevT) { |
| const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); |
| |
| if (isa<ObjCIvarRefExpr>(S) && |
| isSynthesizedAccessor(LCtx->getStackFrame())) { |
| S = LCtx->getStackFrame()->getCallSite(); |
| } |
| |
| if (isa<ObjCArrayLiteral>(S)) { |
| os << "NSArray literal is an object with a +0 retain count"; |
| } |
| else if (isa<ObjCDictionaryLiteral>(S)) { |
| os << "NSDictionary literal is an object with a +0 retain count"; |
| } |
| else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) { |
| if (isNumericLiteralExpression(BL->getSubExpr())) |
| os << "NSNumber literal is an object with a +0 retain count"; |
| else { |
| const ObjCInterfaceDecl *BoxClass = nullptr; |
| if (const ObjCMethodDecl *Method = BL->getBoxingMethod()) |
| BoxClass = Method->getClassInterface(); |
| |
| // We should always be able to find the boxing class interface, |
| // but consider this future-proofing. |
| if (BoxClass) |
| os << *BoxClass << " b"; |
| else |
| os << "B"; |
| |
| os << "oxed expression produces an object with a +0 retain count"; |
| } |
| } |
| else if (isa<ObjCIvarRefExpr>(S)) { |
| os << "Object loaded from instance variable"; |
| } |
| else { |
| if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { |
| // Get the name of the callee (if it is available). |
| SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx); |
| if (const FunctionDecl *FD = X.getAsFunctionDecl()) |
| os << "Call to function '" << *FD << '\''; |
| else |
| os << "function call"; |
| } |
| else { |
| assert(isa<ObjCMessageExpr>(S)); |
| CallEventManager &Mgr = CurrSt->getStateManager().getCallEventManager(); |
| CallEventRef<ObjCMethodCall> Call |
| = Mgr.getObjCMethodCall(cast<ObjCMessageExpr>(S), CurrSt, LCtx); |
| |
| switch (Call->getMessageKind()) { |
| case OCM_Message: |
| os << "Method"; |
| break; |
| case OCM_PropertyAccess: |
| os << "Property"; |
| break; |
| case OCM_Subscript: |
| os << "Subscript"; |
| break; |
| } |
| } |
| |
| if (CurrV.getObjKind() == RetEffect::CF) { |
| os << " returns a Core Foundation object of type " |
| << Sym->getType().getAsString() << " with a "; |
| } else if (CurrV.getObjKind() == RetEffect::Generalized) { |
| os << " returns an object of type " << Sym->getType().getAsString() |
| << " with a "; |
| } else { |
| assert (CurrV.getObjKind() == RetEffect::ObjC); |
| QualType T = Sym->getType(); |
| if (!isa<ObjCObjectPointerType>(T)) { |
| os << " returns an Objective-C object with a "; |
| } else { |
| const ObjCObjectPointerType *PT = cast<ObjCObjectPointerType>(T); |
| os << " returns an instance of " |
| << PT->getPointeeType().getAsString() << " with a "; |
| } |
| } |
| |
| if (CurrV.isOwned()) { |
| os << "+1 retain count"; |
| |
| if (GCEnabled) { |
| assert(CurrV.getObjKind() == RetEffect::CF); |
| os << ". " |
| "Core Foundation objects are not automatically garbage collected."; |
| } |
| } |
| else { |
| assert (CurrV.isNotOwned()); |
| os << "+0 retain count"; |
| } |
| } |
| |
| PathDiagnosticLocation Pos(S, BRC.getSourceManager(), |
| N->getLocationContext()); |
| return std::make_shared<PathDiagnosticEventPiece>(Pos, os.str()); |
| } |
| |
| // Gather up the effects that were performed on the object at this |
| // program point |
| SmallVector<ArgEffect, 2> AEffects; |
| |
| const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N); |
| if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) { |
| // We only have summaries attached to nodes after evaluating CallExpr and |
| // ObjCMessageExprs. |
| const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); |
| |
| if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { |
| // Iterate through the parameter expressions and see if the symbol |
| // was ever passed as an argument. |
| unsigned i = 0; |
| |
| for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end(); |
| AI!=AE; ++AI, ++i) { |
| |
| // Retrieve the value of the argument. Is it the symbol |
| // we are interested in? |
| if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym) |
| continue; |
| |
| // We have an argument. Get the effect! |
| AEffects.push_back(Summ->getArg(i)); |
| } |
| } |
| else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) { |
| if (const Expr *receiver = ME->getInstanceReceiver()) |
| if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx) |
| .getAsLocSymbol() == Sym) { |
| // The symbol we are tracking is the receiver. |
| AEffects.push_back(Summ->getReceiverEffect()); |
| } |
| } |
| } |
| |
| do { |
| // Get the previous type state. |
| RefVal PrevV = *PrevT; |
| |
| // Specially handle -dealloc. |
| if (!GCEnabled && std::find(AEffects.begin(), AEffects.end(), Dealloc) != |
| AEffects.end()) { |
| // Determine if the object's reference count was pushed to zero. |
| assert(!PrevV.hasSameState(CurrV) && "The state should have changed."); |
| // We may not have transitioned to 'release' if we hit an error. |
| // This case is handled elsewhere. |
| if (CurrV.getKind() == RefVal::Released) { |
| assert(CurrV.getCombinedCounts() == 0); |
| os << "Object released by directly sending the '-dealloc' message"; |
| break; |
| } |
| } |
| |
| // Specially handle CFMakeCollectable and friends. |
| if (std::find(AEffects.begin(), AEffects.end(), MakeCollectable) != |
| AEffects.end()) { |
| // Get the name of the function. |
| const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); |
| SVal X = |
| CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx); |
| const FunctionDecl *FD = X.getAsFunctionDecl(); |
| |
| if (GCEnabled) { |
| // Determine if the object's reference count was pushed to zero. |
| assert(!PrevV.hasSameState(CurrV) && "The state should have changed."); |
| |
| os << "In GC mode a call to '" << *FD |
| << "' decrements an object's retain count and registers the " |
| "object with the garbage collector. "; |
| |
| if (CurrV.getKind() == RefVal::Released) { |
| assert(CurrV.getCount() == 0); |
| os << "Since it now has a 0 retain count the object can be " |
| "automatically collected by the garbage collector."; |
| } |
| else |
| os << "An object must have a 0 retain count to be garbage collected. " |
| "After this call its retain count is +" << CurrV.getCount() |
| << '.'; |
| } |
| else |
| os << "When GC is not enabled a call to '" << *FD |
| << "' has no effect on its argument."; |
| |
| // Nothing more to say. |
| break; |
| } |
| |
| // Determine if the typestate has changed. |
| if (!PrevV.hasSameState(CurrV)) |
| switch (CurrV.getKind()) { |
| case RefVal::Owned: |
| case RefVal::NotOwned: |
| if (PrevV.getCount() == CurrV.getCount()) { |
| // Did an autorelease message get sent? |
| if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount()) |
| return nullptr; |
| |
| assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount()); |
| os << "Object autoreleased"; |
| break; |
| } |
| |
| if (PrevV.getCount() > CurrV.getCount()) |
| os << "Reference count decremented."; |
| else |
| os << "Reference count incremented."; |
| |
| if (unsigned Count = CurrV.getCount()) |
| os << " The object now has a +" << Count << " retain count."; |
| |
| if (PrevV.getKind() == RefVal::Released) { |
| assert(GCEnabled && CurrV.getCount() > 0); |
| os << " The object is not eligible for garbage collection until " |
| "the retain count reaches 0 again."; |
| } |
| |
| break; |
| |
| case RefVal::Released: |
| if (CurrV.getIvarAccessHistory() == |
| RefVal::IvarAccessHistory::ReleasedAfterDirectAccess && |
| CurrV.getIvarAccessHistory() != PrevV.getIvarAccessHistory()) { |
| os << "Strong instance variable relinquished. "; |
| } |
| os << "Object released."; |
| break; |
| |
| case RefVal::ReturnedOwned: |
| // Autoreleases can be applied after marking a node ReturnedOwned. |
| if (CurrV.getAutoreleaseCount()) |
| return nullptr; |
| |
| os << "Object returned to caller as an owning reference (single " |
| "retain count transferred to caller)"; |
| break; |
| |
| case RefVal::ReturnedNotOwned: |
| os << "Object returned to caller with a +0 retain count"; |
| break; |
| |
| default: |
| return nullptr; |
| } |
| |
| // Emit any remaining diagnostics for the argument effects (if any). |
| for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(), |
| E=AEffects.end(); I != E; ++I) { |
| |
| // A bunch of things have alternate behavior under GC. |
| if (GCEnabled) |
| switch (*I) { |
| default: break; |
| case Autorelease: |
| os << "In GC mode an 'autorelease' has no effect."; |
| continue; |
| case IncRefMsg: |
| os << "In GC mode the 'retain' message has no effect."; |
| continue; |
| case DecRefMsg: |
| os << "In GC mode the 'release' message has no effect."; |
| continue; |
| } |
| } |
| } while (0); |
| |
| if (os.str().empty()) |
| return nullptr; // We have nothing to say! |
| |
| const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); |
| PathDiagnosticLocation Pos(S, BRC.getSourceManager(), |
| N->getLocationContext()); |
| auto P = std::make_shared<PathDiagnosticEventPiece>(Pos, os.str()); |
| |
| // Add the range by scanning the children of the statement for any bindings |
| // to Sym. |
| for (const Stmt *Child : S->children()) |
| if (const Expr *Exp = dyn_cast_or_null<Expr>(Child)) |
| if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) { |
| P->addRange(Exp->getSourceRange()); |
| break; |
| } |
| |
| return std::move(P); |
| } |
| |
| namespace { |
| // Find the first node in the current function context that referred to the |
| // tracked symbol and the memory location that value was stored to. Note, the |
| // value is only reported if the allocation occurred in the same function as |
| // the leak. The function can also return a location context, which should be |
| // treated as interesting. |
| struct AllocationInfo { |
| const ExplodedNode* N; |
| const MemRegion *R; |
| const LocationContext *InterestingMethodContext; |
| AllocationInfo(const ExplodedNode *InN, |
| const MemRegion *InR, |
| const LocationContext *InInterestingMethodContext) : |
| N(InN), R(InR), InterestingMethodContext(InInterestingMethodContext) {} |
| }; |
| } // end anonymous namespace |
| |
| static AllocationInfo |
| GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N, |
| SymbolRef Sym) { |
| const ExplodedNode *AllocationNode = N; |
| const ExplodedNode *AllocationNodeInCurrentOrParentContext = N; |
| const MemRegion *FirstBinding = nullptr; |
| const LocationContext *LeakContext = N->getLocationContext(); |
| |
| // The location context of the init method called on the leaked object, if |
| // available. |
| const LocationContext *InitMethodContext = nullptr; |
| |
| while (N) { |
| ProgramStateRef St = N->getState(); |
| const LocationContext *NContext = N->getLocationContext(); |
| |
| if (!getRefBinding(St, Sym)) |
| break; |
| |
| StoreManager::FindUniqueBinding FB(Sym); |
| StateMgr.iterBindings(St, FB); |
| |
| if (FB) { |
| const MemRegion *R = FB.getRegion(); |
| const VarRegion *VR = R->getBaseRegion()->getAs<VarRegion>(); |
| // Do not show local variables belonging to a function other than |
| // where the error is reported. |
| if (!VR || VR->getStackFrame() == LeakContext->getStackFrame()) |
| FirstBinding = R; |
| } |
| |
| // AllocationNode is the last node in which the symbol was tracked. |
| AllocationNode = N; |
| |
| // AllocationNodeInCurrentContext, is the last node in the current or |
| // parent context in which the symbol was tracked. |
| // |
| // Note that the allocation site might be in the parent conext. For example, |
| // the case where an allocation happens in a block that captures a reference |
| // to it and that reference is overwritten/dropped by another call to |
| // the block. |
| if (NContext == LeakContext || NContext->isParentOf(LeakContext)) |
| AllocationNodeInCurrentOrParentContext = N; |
| |
| // Find the last init that was called on the given symbol and store the |
| // init method's location context. |
| if (!InitMethodContext) |
| if (Optional<CallEnter> CEP = N->getLocation().getAs<CallEnter>()) { |
| const Stmt *CE = CEP->getCallExpr(); |
| if (const ObjCMessageExpr *ME = dyn_cast_or_null<ObjCMessageExpr>(CE)) { |
| const Stmt *RecExpr = ME->getInstanceReceiver(); |
| if (RecExpr) { |
| SVal RecV = St->getSVal(RecExpr, NContext); |
| if (ME->getMethodFamily() == OMF_init && RecV.getAsSymbol() == Sym) |
| InitMethodContext = CEP->getCalleeContext(); |
| } |
| } |
| } |
| |
| N = N->pred_empty() ? nullptr : *(N->pred_begin()); |
| } |
| |
| // If we are reporting a leak of the object that was allocated with alloc, |
| // mark its init method as interesting. |
| const LocationContext *InterestingMethodContext = nullptr; |
| if (InitMethodContext) { |
| const ProgramPoint AllocPP = AllocationNode->getLocation(); |
| if (Optional<StmtPoint> SP = AllocPP.getAs<StmtPoint>()) |
| if (const ObjCMessageExpr *ME = SP->getStmtAs<ObjCMessageExpr>()) |
| if (ME->getMethodFamily() == OMF_alloc) |
| InterestingMethodContext = InitMethodContext; |
| } |
| |
| // If allocation happened in a function different from the leak node context, |
| // do not report the binding. |
| assert(N && "Could not find allocation node"); |
| if (N->getLocationContext() != LeakContext) { |
| FirstBinding = nullptr; |
| } |
| |
| return AllocationInfo(AllocationNodeInCurrentOrParentContext, |
| FirstBinding, |
| InterestingMethodContext); |
| } |
| |
| std::shared_ptr<PathDiagnosticPiece> |
| CFRefReportVisitor::getEndPath(BugReporterContext &BRC, |
| const ExplodedNode *EndN, BugReport &BR) { |
| BR.markInteresting(Sym); |
| return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR); |
| } |
| |
| std::shared_ptr<PathDiagnosticPiece> |
| CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC, |
| const ExplodedNode *EndN, BugReport &BR) { |
| |
| // Tell the BugReporterContext to report cases when the tracked symbol is |
| // assigned to different variables, etc. |
| BR.markInteresting(Sym); |
| |
| // We are reporting a leak. Walk up the graph to get to the first node where |
| // the symbol appeared, and also get the first VarDecl that tracked object |
| // is stored to. |
| AllocationInfo AllocI = |
| GetAllocationSite(BRC.getStateManager(), EndN, Sym); |
| |
| const MemRegion* FirstBinding = AllocI.R; |
| BR.markInteresting(AllocI.InterestingMethodContext); |
| |
| SourceManager& SM = BRC.getSourceManager(); |
| |
| // Compute an actual location for the leak. Sometimes a leak doesn't |
| // occur at an actual statement (e.g., transition between blocks; end |
| // of function) so we need to walk the graph and compute a real location. |
| const ExplodedNode *LeakN = EndN; |
| PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM); |
| |
| std::string sbuf; |
| llvm::raw_string_ostream os(sbuf); |
| |
| os << "Object leaked: "; |
| |
| Optional<std::string> RegionDescription = describeRegion(FirstBinding); |
| if (RegionDescription) { |
| os << "object allocated and stored into '" << *RegionDescription << '\''; |
| } |
| else |
| os << "allocated object"; |
| |
| // Get the retain count. |
| const RefVal* RV = getRefBinding(EndN->getState(), Sym); |
| assert(RV); |
| |
| if (RV->getKind() == RefVal::ErrorLeakReturned) { |
| // FIXME: Per comments in rdar://6320065, "create" only applies to CF |
| // objects. Only "copy", "alloc", "retain" and "new" transfer ownership |
| // to the caller for NS objects. |
| const Decl *D = &EndN->getCodeDecl(); |
| |
| os << (isa<ObjCMethodDecl>(D) ? " is returned from a method " |
| : " is returned from a function "); |
| |
| if (D->hasAttr<CFReturnsNotRetainedAttr>()) |
| os << "that is annotated as CF_RETURNS_NOT_RETAINED"; |
| else if (D->hasAttr<NSReturnsNotRetainedAttr>()) |
| os << "that is annotated as NS_RETURNS_NOT_RETAINED"; |
| else { |
| if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { |
| if (BRC.getASTContext().getLangOpts().ObjCAutoRefCount) { |
| os << "managed by Automatic Reference Counting"; |
| } else { |
| os << "whose name ('" << MD->getSelector().getAsString() |
| << "') does not start with " |
| "'copy', 'mutableCopy', 'alloc' or 'new'." |
| " This violates the naming convention rules" |
| " given in the Memory Management Guide for Cocoa"; |
| } |
| } |
| else { |
| const FunctionDecl *FD = cast<FunctionDecl>(D); |
| os << "whose name ('" << *FD |
| << "') does not contain 'Copy' or 'Create'. This violates the naming" |
| " convention rules given in the Memory Management Guide for Core" |
| " Foundation"; |
| } |
| } |
| } |
| else if (RV->getKind() == RefVal::ErrorGCLeakReturned) { |
| const ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl()); |
| os << " and returned from method '" << MD.getSelector().getAsString() |
| << "' is potentially leaked when using garbage collection. Callers " |
| "of this method do not expect a returned object with a +1 retain " |
| "count since they expect the object to be managed by the garbage " |
| "collector"; |
| } |
| else |
| os << " is not referenced later in this execution path and has a retain " |
| "count of +" << RV->getCount(); |
| |
| return std::make_shared<PathDiagnosticEventPiece>(L, os.str()); |
| } |
| |
| void CFRefLeakReport::deriveParamLocation(CheckerContext &Ctx, SymbolRef sym) { |
| const SourceManager& SMgr = Ctx.getSourceManager(); |
| |
| if (!sym->getOriginRegion()) |
| return; |
| |
| auto *Region = dyn_cast<DeclRegion>(sym->getOriginRegion()); |
| if (Region) { |
| const Decl *PDecl = Region->getDecl(); |
| if (PDecl && isa<ParmVarDecl>(PDecl)) { |
| PathDiagnosticLocation ParamLocation = PathDiagnosticLocation::create(PDecl, SMgr); |
| Location = ParamLocation; |
| UniqueingLocation = ParamLocation; |
| UniqueingDecl = Ctx.getLocationContext()->getDecl(); |
| } |
| } |
| } |
| |
| void CFRefLeakReport::deriveAllocLocation(CheckerContext &Ctx,SymbolRef sym) { |
| // Most bug reports are cached at the location where they occurred. |
| // With leaks, we want to unique them by the location where they were |
| // allocated, and only report a single path. To do this, we need to find |
| // the allocation site of a piece of tracked memory, which we do via a |
| // call to GetAllocationSite. This will walk the ExplodedGraph backwards. |
| // Note that this is *not* the trimmed graph; we are guaranteed, however, |
| // that all ancestor nodes that represent the allocation site have the |
| // same SourceLocation. |
| const ExplodedNode *AllocNode = nullptr; |
| |
| const SourceManager& SMgr = Ctx.getSourceManager(); |
| |
| AllocationInfo AllocI = |
| GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym); |
| |
| AllocNode = AllocI.N; |
| AllocBinding = AllocI.R; |
| markInteresting(AllocI.InterestingMethodContext); |
| |
| // Get the SourceLocation for the allocation site. |
| // FIXME: This will crash the analyzer if an allocation comes from an |
| // implicit call (ex: a destructor call). |
| // (Currently there are no such allocations in Cocoa, though.) |
| AllocStmt = PathDiagnosticLocation::getStmt(AllocNode); |
| |
| if (!AllocStmt) { |
| AllocBinding = nullptr; |
| return; |
| } |
| |
| PathDiagnosticLocation AllocLocation = |
| PathDiagnosticLocation::createBegin(AllocStmt, SMgr, |
| AllocNode->getLocationContext()); |
| Location = AllocLocation; |
| |
| // Set uniqieing info, which will be used for unique the bug reports. The |
| // leaks should be uniqued on the allocation site. |
| UniqueingLocation = AllocLocation; |
| UniqueingDecl = AllocNode->getLocationContext()->getDecl(); |
| } |
| |
| void CFRefLeakReport::createDescription(CheckerContext &Ctx, bool GCEnabled, |
| bool IncludeAllocationLine) { |
| assert(Location.isValid() && UniqueingDecl && UniqueingLocation.isValid()); |
| Description.clear(); |
| llvm::raw_string_ostream os(Description); |
| os << "Potential leak "; |
| if (GCEnabled) |
| os << "(when using garbage collection) "; |
| os << "of an object"; |
| |
| Optional<std::string> RegionDescription = describeRegion(AllocBinding); |
| if (RegionDescription) { |
| os << " stored into '" << *RegionDescription << '\''; |
| if (IncludeAllocationLine) { |
| FullSourceLoc SL(AllocStmt->getLocStart(), Ctx.getSourceManager()); |
| os << " (allocated on line " << SL.getSpellingLineNumber() << ")"; |
| } |
| } |
| } |
| |
| CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, |
| bool GCEnabled, const SummaryLogTy &Log, |
| ExplodedNode *n, SymbolRef sym, |
| CheckerContext &Ctx, |
| bool IncludeAllocationLine) |
| : CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) { |
| |
| deriveAllocLocation(Ctx, sym); |
| if (!AllocBinding) |
| deriveParamLocation(Ctx, sym); |
| |
| createDescription(Ctx, GCEnabled, IncludeAllocationLine); |
| |
| addVisitor(llvm::make_unique<CFRefLeakReportVisitor>(sym, GCEnabled, Log)); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Main checker logic. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class RetainCountChecker |
| : public Checker< check::Bind, |
| check::DeadSymbols, |
| check::EndAnalysis, |
| check::BeginFunction, |
| check::EndFunction, |
| check::PostStmt<BlockExpr>, |
| check::PostStmt<CastExpr>, |
| check::PostStmt<ObjCArrayLiteral>, |
| check::PostStmt<ObjCDictionaryLiteral>, |
| check::PostStmt<ObjCBoxedExpr>, |
| check::PostStmt<ObjCIvarRefExpr>, |
| check::PostCall, |
| check::PreStmt<ReturnStmt>, |
| check::RegionChanges, |
| eval::Assume, |
| eval::Call > { |
| mutable std::unique_ptr<CFRefBug> useAfterRelease, releaseNotOwned; |
| mutable std::unique_ptr<CFRefBug> deallocGC, deallocNotOwned; |
| mutable std::unique_ptr<CFRefBug> overAutorelease, returnNotOwnedForOwned; |
| mutable std::unique_ptr<CFRefBug> leakWithinFunction, leakAtReturn; |
| mutable std::unique_ptr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC; |
| |
| typedef llvm::DenseMap<SymbolRef, const CheckerProgramPointTag *> SymbolTagMap; |
| |
| // This map is only used to ensure proper deletion of any allocated tags. |
| mutable SymbolTagMap DeadSymbolTags; |
| |
| mutable std::unique_ptr<RetainSummaryManager> Summaries; |
| mutable std::unique_ptr<RetainSummaryManager> SummariesGC; |
| mutable SummaryLogTy SummaryLog; |
| mutable bool ShouldResetSummaryLog; |
| |
| /// Optional setting to indicate if leak reports should include |
| /// the allocation line. |
| mutable bool IncludeAllocationLine; |
| |
| public: |
| RetainCountChecker(AnalyzerOptions &AO) |
| : ShouldResetSummaryLog(false), |
| IncludeAllocationLine(shouldIncludeAllocationSiteInLeakDiagnostics(AO)) {} |
| |
| ~RetainCountChecker() override { DeleteContainerSeconds(DeadSymbolTags); } |
| |
| void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR, |
| ExprEngine &Eng) const { |
| // FIXME: This is a hack to make sure the summary log gets cleared between |
| // analyses of different code bodies. |
| // |
| // Why is this necessary? Because a checker's lifetime is tied to a |
| // translation unit, but an ExplodedGraph's lifetime is just a code body. |
| // Once in a blue moon, a new ExplodedNode will have the same address as an |
| // old one with an associated summary, and the bug report visitor gets very |
| // confused. (To make things worse, the summary lifetime is currently also |
| // tied to a code body, so we get a crash instead of incorrect results.) |
| // |
| // Why is this a bad solution? Because if the lifetime of the ExplodedGraph |
| // changes, things will start going wrong again. Really the lifetime of this |
| // log needs to be tied to either the specific nodes in it or the entire |
| // ExplodedGraph, not to a specific part of the code being analyzed. |
| // |
| // (Also, having stateful local data means that the same checker can't be |
| // used from multiple threads, but a lot of checkers have incorrect |
| // assumptions about that anyway. So that wasn't a priority at the time of |
| // this fix.) |
| // |
| // This happens at the end of analysis, but bug reports are emitted /after/ |
| // this point. So we can't just clear the summary log now. Instead, we mark |
| // that the next time we access the summary log, it should be cleared. |
| |
| // If we never reset the summary log during /this/ code body analysis, |
| // there were no new summaries. There might still have been summaries from |
| // the /last/ analysis, so clear them out to make sure the bug report |
| // visitors don't get confused. |
| if (ShouldResetSummaryLog) |
| SummaryLog.clear(); |
| |
| ShouldResetSummaryLog = !SummaryLog.empty(); |
| } |
| |
| CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts, |
| bool GCEnabled) const { |
| if (GCEnabled) { |
| if (!leakWithinFunctionGC) |
| leakWithinFunctionGC.reset(new Leak(this, "Leak of object when using " |
| "garbage collection")); |
| return leakWithinFunctionGC.get(); |
| } else { |
| if (!leakWithinFunction) { |
| if (LOpts.getGC() == LangOptions::HybridGC) { |
| leakWithinFunction.reset(new Leak(this, |
| "Leak of object when not using " |
| "garbage collection (GC) in " |
| "dual GC/non-GC code")); |
| } else { |
| leakWithinFunction.reset(new Leak(this, "Leak")); |
| } |
| } |
| return leakWithinFunction.get(); |
| } |
| } |
| |
| CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const { |
| if (GCEnabled) { |
| if (!leakAtReturnGC) |
| leakAtReturnGC.reset(new Leak(this, |
| "Leak of returned object when using " |
| "garbage collection")); |
| return leakAtReturnGC.get(); |
| } else { |
| if (!leakAtReturn) { |
| if (LOpts.getGC() == LangOptions::HybridGC) { |
| leakAtReturn.reset(new Leak(this, |
| "Leak of returned object when not using " |
| "garbage collection (GC) in dual " |
| "GC/non-GC code")); |
| } else { |
| leakAtReturn.reset(new Leak(this, "Leak of returned object")); |
| } |
| } |
| return leakAtReturn.get(); |
| } |
| } |
| |
| RetainSummaryManager &getSummaryManager(ASTContext &Ctx, |
| bool GCEnabled) const { |
| // FIXME: We don't support ARC being turned on and off during one analysis. |
| // (nor, for that matter, do we support changing ASTContexts) |
| bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount; |
| if (GCEnabled) { |
| if (!SummariesGC) |
| SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled)); |
| else |
| assert(SummariesGC->isARCEnabled() == ARCEnabled); |
| return *SummariesGC; |
| } else { |
| if (!Summaries) |
| Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled)); |
| else |
| assert(Summaries->isARCEnabled() == ARCEnabled); |
| return *Summaries; |
| } |
| } |
| |
| RetainSummaryManager &getSummaryManager(CheckerContext &C) const { |
| return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled()); |
| } |
| |
| void printState(raw_ostream &Out, ProgramStateRef State, |
| const char *NL, const char *Sep) const override; |
| |
| void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; |
| void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const; |
| void checkPostStmt(const CastExpr *CE, CheckerContext &C) const; |
| |
| void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const; |
| void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const; |
| void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const; |
| |
| void checkPostStmt(const ObjCIvarRefExpr *IRE, CheckerContext &C) const; |
| |
| void checkPostCall(const CallEvent &Call, CheckerContext &C) const; |
| |
| void checkSummary(const RetainSummary &Summ, const CallEvent &Call, |
| CheckerContext &C) const; |
| |
| void processSummaryOfInlined(const RetainSummary &Summ, |
| const CallEvent &Call, |
| CheckerContext &C) const; |
| |
| bool evalCall(const CallExpr *CE, CheckerContext &C) const; |
| |
| ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, |
| bool Assumption) const; |
| |
| ProgramStateRef |
| checkRegionChanges(ProgramStateRef state, |
| const InvalidatedSymbols *invalidated, |
| ArrayRef<const MemRegion *> ExplicitRegions, |
| ArrayRef<const MemRegion *> Regions, |
| const LocationContext* LCtx, |
| const CallEvent *Call) const; |
| |
| void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const; |
| void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, |
| ExplodedNode *Pred, RetEffect RE, RefVal X, |
| SymbolRef Sym, ProgramStateRef state) const; |
| |
| void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; |
| void checkBeginFunction(CheckerContext &C) const; |
| void checkEndFunction(const ReturnStmt *RS, CheckerContext &C) const; |
| |
| ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, |
| RefVal V, ArgEffect E, RefVal::Kind &hasErr, |
| CheckerContext &C) const; |
| |
| void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, |
| RefVal::Kind ErrorKind, SymbolRef Sym, |
| CheckerContext &C) const; |
| |
| void processObjCLiterals(CheckerContext &C, const Expr *Ex) const; |
| |
| const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const; |
| |
| ProgramStateRef handleSymbolDeath(ProgramStateRef state, |
| SymbolRef sid, RefVal V, |
| SmallVectorImpl<SymbolRef> &Leaked) const; |
| |
| ProgramStateRef |
| handleAutoreleaseCounts(ProgramStateRef state, ExplodedNode *Pred, |
| const ProgramPointTag *Tag, CheckerContext &Ctx, |
| SymbolRef Sym, RefVal V) const; |
| |
| ExplodedNode *processLeaks(ProgramStateRef state, |
| SmallVectorImpl<SymbolRef> &Leaked, |
| CheckerContext &Ctx, |
| ExplodedNode *Pred = nullptr) const; |
| }; |
| } // end anonymous namespace |
| |
| namespace { |
| class StopTrackingCallback final : public SymbolVisitor { |
| ProgramStateRef state; |
| public: |
| StopTrackingCallback(ProgramStateRef st) : state(std::move(st)) {} |
| ProgramStateRef getState() const { return state; } |
| |
| bool VisitSymbol(SymbolRef sym) override { |
| state = state->remove<RefBindings>(sym); |
| return true; |
| } |
| }; |
| } // end anonymous namespace |
| |
| //===----------------------------------------------------------------------===// |
| // Handle statements that may have an effect on refcounts. |
| //===----------------------------------------------------------------------===// |
| |
| void RetainCountChecker::checkPostStmt(const BlockExpr *BE, |
| CheckerContext &C) const { |
| |
| // Scan the BlockDecRefExprs for any object the retain count checker |
| // may be tracking. |
| if (!BE->getBlockDecl()->hasCaptures()) |
| return; |
| |
| ProgramStateRef state = C.getState(); |
| auto *R = cast<BlockDataRegion>(C.getSVal(BE).getAsRegion()); |
| |
| BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(), |
| E = R->referenced_vars_end(); |
| |
| if (I == E) |
| return; |
| |
| // FIXME: For now we invalidate the tracking of all symbols passed to blocks |
| // via captured variables, even though captured variables result in a copy |
| // and in implicit increment/decrement of a retain count. |
| SmallVector<const MemRegion*, 10> Regions; |
| const LocationContext *LC = C.getLocationContext(); |
| MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager(); |
| |
| for ( ; I != E; ++I) { |
| const VarRegion *VR = I.getCapturedRegion(); |
| if (VR->getSuperRegion() == R) { |
| VR = MemMgr.getVarRegion(VR->getDecl(), LC); |
| } |
| Regions.push_back(VR); |
| } |
| |
| state = |
| state->scanReachableSymbols<StopTrackingCallback>(Regions.data(), |
| Regions.data() + Regions.size()).getState(); |
| C.addTransition(state); |
| } |
| |
| void RetainCountChecker::checkPostStmt(const CastExpr *CE, |
| CheckerContext &C) const { |
| const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE); |
| if (!BE) |
| return; |
| |
| ArgEffect AE = IncRef; |
| |
| switch (BE->getBridgeKind()) { |
| case clang::OBC_Bridge: |
| // Do nothing. |
| return; |
| case clang::OBC_BridgeRetained: |
| AE = IncRef; |
| break; |
| case clang::OBC_BridgeTransfer: |
| AE = DecRefBridgedTransferred; |
| break; |
| } |
| |
| ProgramStateRef state = C.getState(); |
| SymbolRef Sym = C.getSVal(CE).getAsLocSymbol(); |
| if (!Sym) |
| return; |
| const RefVal* T = getRefBinding(state, Sym); |
| if (!T) |
| return; |
| |
| RefVal::Kind hasErr = (RefVal::Kind) 0; |
| state = updateSymbol(state, Sym, *T, AE, hasErr, C); |
| |
| if (hasErr) { |
| // FIXME: If we get an error during a bridge cast, should we report it? |
| return; |
| } |
| |
| C.addTransition(state); |
| } |
| |
| void RetainCountChecker::processObjCLiterals(CheckerContext &C, |
| const Expr *Ex) const { |
| ProgramStateRef state = C.getState(); |
| const ExplodedNode *pred = C.getPredecessor(); |
| for (const Stmt *Child : Ex->children()) { |
| SVal V = pred->getSVal(Child); |
| if (SymbolRef sym = V.getAsSymbol()) |
| if (const RefVal* T = getRefBinding(state, sym)) { |
| RefVal::Kind hasErr = (RefVal::Kind) 0; |
| state = updateSymbol(state, sym, *T, MayEscape, hasErr, C); |
| if (hasErr) { |
| processNonLeakError(state, Child->getSourceRange(), hasErr, sym, C); |
| return; |
| } |
| } |
| } |
| |
| // Return the object as autoreleased. |
| // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC); |
| if (SymbolRef sym = |
| state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) { |
| QualType ResultTy = Ex->getType(); |
| state = setRefBinding(state, sym, |
| RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); |
| } |
| |
| C.addTransition(state); |
| } |
| |
| void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL, |
| CheckerContext &C) const { |
| // Apply the 'MayEscape' to all values. |
| processObjCLiterals(C, AL); |
| } |
| |
| void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, |
| CheckerContext &C) const { |
| // Apply the 'MayEscape' to all keys and values. |
| processObjCLiterals(C, DL); |
| } |
| |
| void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex, |
| CheckerContext &C) const { |
| const ExplodedNode *Pred = C.getPredecessor(); |
| ProgramStateRef State = Pred->getState(); |
| |
| if (SymbolRef Sym = Pred->getSVal(Ex).getAsSymbol()) { |
| QualType ResultTy = Ex->getType(); |
| State = setRefBinding(State, Sym, |
| RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); |
| } |
| |
| C.addTransition(State); |
| } |
| |
| void RetainCountChecker::checkPostStmt(const ObjCIvarRefExpr *IRE, |
| CheckerContext &C) const { |
| Optional<Loc> IVarLoc = C.getSVal(IRE).getAs<Loc>(); |
| if (!IVarLoc) |
| return; |
| |
| ProgramStateRef State = C.getState(); |
| SymbolRef Sym = State->getSVal(*IVarLoc).getAsSymbol(); |
| if (!Sym || !dyn_cast_or_null<ObjCIvarRegion>(Sym->getOriginRegion())) |
| return; |
| |
| // Accessing an ivar directly is unusual. If we've done that, be more |
| // forgiving about what the surrounding code is allowed to do. |
| |
| QualType Ty = Sym->getType(); |
| RetEffect::ObjKind Kind; |
| if (Ty->isObjCRetainableType()) |
| Kind = RetEffect::ObjC; |
| else if (coreFoundation::isCFObjectRef(Ty)) |
| Kind = RetEffect::CF; |
| else |
| return; |
| |
| // If the value is already known to be nil, don't bother tracking it. |
| ConstraintManager &CMgr = State->getConstraintManager(); |
| if (CMgr.isNull(State, Sym).isConstrainedTrue()) |
| return; |
| |
| if (const RefVal *RV = getRefBinding(State, Sym)) { |
| // If we've seen this symbol before, or we're only seeing it now because |
| // of something the analyzer has synthesized, don't do anything. |
| if (RV->getIvarAccessHistory() != RefVal::IvarAccessHistory::None || |
| isSynthesizedAccessor(C.getStackFrame())) { |
| return; |
| } |
| |
| // Note that this value has been loaded from an ivar. |
| C.addTransition(setRefBinding(State, Sym, RV->withIvarAccess())); |
| return; |
| } |
| |
| RefVal PlusZero = RefVal::makeNotOwned(Kind, Ty); |
| |
| // In a synthesized accessor, the effective retain count is +0. |
| if (isSynthesizedAccessor(C.getStackFrame())) { |
| C.addTransition(setRefBinding(State, Sym, PlusZero)); |
| return; |
| } |
| |
| State = setRefBinding(State, Sym, PlusZero.withIvarAccess()); |
| C.addTransition(State); |
| } |
| |
| void RetainCountChecker::checkPostCall(const CallEvent &Call, |
| CheckerContext &C) const { |
| RetainSummaryManager &Summaries = getSummaryManager(C); |
| const RetainSummary *Summ = Summaries.getSummary(Call, C.getState()); |
| |
| if (C.wasInlined) { |
| processSummaryOfInlined(*Summ, Call, C); |
| return; |
| } |
| checkSummary(*Summ, Call, C); |
| } |
| |
| /// GetReturnType - Used to get the return type of a message expression or |
| /// function call with the intention of affixing that type to a tracked symbol. |
| /// While the return type can be queried directly from RetEx, when |
| /// invoking class methods we augment to the return type to be that of |
| /// a pointer to the class (as opposed it just being id). |
| // FIXME: We may be able to do this with related result types instead. |
| // This function is probably overestimating. |
| static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) { |
| QualType RetTy = RetE->getType(); |
| // If RetE is not a message expression just return its type. |
| // If RetE is a message expression, return its types if it is something |
| /// more specific than id. |
| if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE)) |
| if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>()) |
| if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() || |
| PT->isObjCClassType()) { |
| // At this point we know the return type of the message expression is |
| // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this |
| // is a call to a class method whose type we can resolve. In such |
| // cases, promote the return type to XXX* (where XXX is the class). |
| const ObjCInterfaceDecl *D = ME->getReceiverInterface(); |
| return !D ? RetTy : |
| Ctx.getObjCObjectPointerType(Ctx.getObjCInterfaceType(D)); |
| } |
| |
| return RetTy; |
| } |
| |
| // We don't always get the exact modeling of the function with regards to the |
| // retain count checker even when the function is inlined. For example, we need |
| // to stop tracking the symbols which were marked with StopTrackingHard. |
| void RetainCountChecker::processSummaryOfInlined(const RetainSummary &Summ, |
| const CallEvent &CallOrMsg, |
| CheckerContext &C) const { |
| ProgramStateRef state = C.getState(); |
| |
| // Evaluate the effect of the arguments. |
| for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { |
| if (Summ.getArg(idx) == StopTrackingHard) { |
| SVal V = CallOrMsg.getArgSVal(idx); |
| if (SymbolRef Sym = V.getAsLocSymbol()) { |
| state = removeRefBinding(state, Sym); |
| } |
| } |
| } |
| |
| // Evaluate the effect on the message receiver. |
| const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); |
| if (MsgInvocation) { |
| if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { |
| if (Summ.getReceiverEffect() == StopTrackingHard) { |
| state = removeRefBinding(state, Sym); |
| } |
| } |
| } |
| |
| // Consult the summary for the return value. |
| RetEffect RE = Summ.getRetEffect(); |
| if (RE.getKind() == RetEffect::NoRetHard) { |
| SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); |
| if (Sym) |
| state = removeRefBinding(state, Sym); |
| } |
| |
| C.addTransition(state); |
| } |
| |
| static ProgramStateRef updateOutParameter(ProgramStateRef State, |
| SVal ArgVal, |
| ArgEffect Effect) { |
| auto *ArgRegion = dyn_cast_or_null<TypedValueRegion>(ArgVal.getAsRegion()); |
| if (!ArgRegion) |
| return State; |
| |
| QualType PointeeTy = ArgRegion->getValueType(); |
| if (!coreFoundation::isCFObjectRef(PointeeTy)) |
| return State; |
| |
| SVal PointeeVal = State->getSVal(ArgRegion); |
| SymbolRef Pointee = PointeeVal.getAsLocSymbol(); |
| if (!Pointee) |
| return State; |
| |
| switch (Effect) { |
| case UnretainedOutParameter: |
| State = setRefBinding(State, Pointee, |
| RefVal::makeNotOwned(RetEffect::CF, PointeeTy)); |
| break; |
| case RetainedOutParameter: |
| // Do nothing. Retained out parameters will either point to a +1 reference |
| // or NULL, but the way you check for failure differs depending on the API. |
| // Consequently, we don't have a good way to track them yet. |
| break; |
| |
| default: |
| llvm_unreachable("only for out parameters"); |
| } |
| |
| return State; |
| } |
| |
| void RetainCountChecker::checkSummary(const RetainSummary &Summ, |
| const CallEvent &CallOrMsg, |
| CheckerContext &C) const { |
| ProgramStateRef state = C.getState(); |
| |
| // Evaluate the effect of the arguments. |
| RefVal::Kind hasErr = (RefVal::Kind) 0; |
| SourceRange ErrorRange; |
| SymbolRef ErrorSym = nullptr; |
| |
| for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { |
| SVal V = CallOrMsg.getArgSVal(idx); |
| |
| ArgEffect Effect = Summ.getArg(idx); |
| if (Effect == RetainedOutParameter || Effect == UnretainedOutParameter) { |
| state = updateOutParameter(state, V, Effect); |
| } else if (SymbolRef Sym = V.getAsLocSymbol()) { |
| if (const RefVal *T = getRefBinding(state, Sym)) { |
| state = updateSymbol(state, Sym, *T, Effect, hasErr, C); |
| if (hasErr) { |
| ErrorRange = CallOrMsg.getArgSourceRange(idx); |
| ErrorSym = Sym; |
| break; |
| } |
| } |
| } |
| } |
| |
| // Evaluate the effect on the message receiver. |
| bool ReceiverIsTracked = false; |
| if (!hasErr) { |
| const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); |
| if (MsgInvocation) { |
| if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { |
| if (const RefVal *T = getRefBinding(state, Sym)) { |
| ReceiverIsTracked = true; |
| state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(), |
| hasErr, C); |
| if (hasErr) { |
| ErrorRange = MsgInvocation->getOriginExpr()->getReceiverRange(); |
| ErrorSym = Sym; |
| } |
| } |
| } |
| } |
| } |
| |
| // Process any errors. |
| if (hasErr) { |
| processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C); |
| return; |
| } |
| |
| // Consult the summary for the return value. |
| RetEffect RE = Summ.getRetEffect(); |
| |
| if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) { |
| if (ReceiverIsTracked) |
| RE = getSummaryManager(C).getObjAllocRetEffect(); |
| else |
| RE = RetEffect::MakeNoRet(); |
| } |
| |
| switch (RE.getKind()) { |
| default: |
| llvm_unreachable("Unhandled RetEffect."); |
| |
| case RetEffect::NoRet: |
| case RetEffect::NoRetHard: |
| // No work necessary. |
| break; |
| |
| case RetEffect::OwnedSymbol: { |
| SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); |
| if (!Sym) |
| break; |
| |
| // Use the result type from the CallEvent as it automatically adjusts |
| // for methods/functions that return references. |
| QualType ResultTy = CallOrMsg.getResultType(); |
| state = setRefBinding(state, Sym, RefVal::makeOwned(RE.getObjKind(), |
| ResultTy)); |
| |
| // FIXME: Add a flag to the checker where allocations are assumed to |
| // *not* fail. |
| break; |
| } |
| |
| case RetEffect::GCNotOwnedSymbol: |
| case RetEffect::NotOwnedSymbol: { |
| const Expr *Ex = CallOrMsg.getOriginExpr(); |
| SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); |
| if (!Sym) |
| break; |
| assert(Ex); |
| // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *. |
| QualType ResultTy = GetReturnType(Ex, C.getASTContext()); |
| state = setRefBinding(state, Sym, RefVal::makeNotOwned(RE.getObjKind(), |
| ResultTy)); |
| break; |
| } |
| } |
| |
| // This check is actually necessary; otherwise the statement builder thinks |
| // we've hit a previously-found path. |
| // Normally addTransition takes care of this, but we want the node pointer. |
| ExplodedNode *NewNode; |
| if (state == C.getState()) { |
| NewNode = C.getPredecessor(); |
| } else { |
| NewNode = C.addTransition(state); |
| } |
| |
| // Annotate the node with summary we used. |
| if (NewNode) { |
| // FIXME: This is ugly. See checkEndAnalysis for why it's necessary. |
| if (ShouldResetSummaryLog) { |
| SummaryLog.clear(); |
| ShouldResetSummaryLog = false; |
| } |
| SummaryLog[NewNode] = &Summ; |
| } |
| } |
| |
| ProgramStateRef |
| RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym, |
| RefVal V, ArgEffect E, RefVal::Kind &hasErr, |
| CheckerContext &C) const { |
| // In GC mode [... release] and [... retain] do nothing. |
| // In ARC mode they shouldn't exist at all, but we just ignore them. |
| bool IgnoreRetainMsg = C.isObjCGCEnabled(); |
| if (!IgnoreRetainMsg) |
| IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount; |
| |
| switch (E) { |
| default: |
| break; |
| case IncRefMsg: |
| E = IgnoreRetainMsg ? DoNothing : IncRef; |
| break; |
| case DecRefMsg: |
| E = IgnoreRetainMsg ? DoNothing : DecRef; |
| break; |
| case DecRefMsgAndStopTrackingHard: |
| E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTrackingHard; |
| break; |
| case MakeCollectable: |
| E = C.isObjCGCEnabled() ? DecRef : DoNothing; |
| break; |
| } |
| |
| // Handle all use-after-releases. |
| if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) { |
| V = V ^ RefVal::ErrorUseAfterRelease; |
| hasErr = V.getKind(); |
| return setRefBinding(state, sym, V); |
| } |
| |
| switch (E) { |
| case DecRefMsg: |
| case IncRefMsg: |
| case MakeCollectable: |
| case DecRefMsgAndStopTrackingHard: |
| llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted"); |
| |
| case UnretainedOutParameter: |
| case RetainedOutParameter: |
| llvm_unreachable("Applies to pointer-to-pointer parameters, which should " |
| "not have ref state."); |
| |
| case Dealloc: |
| // Any use of -dealloc in GC is *bad*. |
| if (C.isObjCGCEnabled()) { |
| V = V ^ RefVal::ErrorDeallocGC; |
| hasErr = V.getKind(); |
| break; |
| } |
| |
| switch (V.getKind()) { |
| default: |
| llvm_unreachable("Invalid RefVal state for an explicit dealloc."); |
| case RefVal::Owned: |
| // The object immediately transitions to the released state. |
| V = V ^ RefVal::Released; |
| V.clearCounts(); |
| return setRefBinding(state, sym, V); |
| case RefVal::NotOwned: |
| V = V ^ RefVal::ErrorDeallocNotOwned; |
| hasErr = V.getKind(); |
| break; |
| } |
| break; |
| |
| case MayEscape: |
| if (V.getKind() == RefVal::Owned) { |
| V = V ^ RefVal::NotOwned; |
| break; |
| } |
| |
| // Fall-through. |
| |
| case DoNothing: |
| return state; |
| |
| case Autorelease: |
| if (C.isObjCGCEnabled()) |
| return state; |
| // Update the autorelease counts. |
| V = V.autorelease(); |
| break; |
| |
| case StopTracking: |
| case StopTrackingHard: |
| return removeRefBinding(state, sym); |
| |
| case IncRef: |
| switch (V.getKind()) { |
| default: |
| llvm_unreachable("Invalid RefVal state for a retain."); |
| case RefVal::Owned: |
| case RefVal::NotOwned: |
| V = V + 1; |
| break; |
| case RefVal::Released: |
| // Non-GC cases are handled above. |
| assert(C.isObjCGCEnabled()); |
| V = (V ^ RefVal::Owned) + 1; |
| break; |
| } |
| break; |
| |
| case DecRef: |
| case DecRefBridgedTransferred: |
| case DecRefAndStopTrackingHard: |
| switch (V.getKind()) { |
| default: |
| // case 'RefVal::Released' handled above. |
| llvm_unreachable("Invalid RefVal state for a release."); |
| |
| case RefVal::Owned: |
| assert(V.getCount() > 0); |
| if (V.getCount() == 1) { |
| if (E == DecRefBridgedTransferred || |
| V.getIvarAccessHistory() == |
| RefVal::IvarAccessHistory::AccessedDirectly) |
| V = V ^ RefVal::NotOwned; |
| else |
| V = V ^ RefVal::Released; |
| } else if (E == DecRefAndStopTrackingHard) { |
| return removeRefBinding(state, sym); |
| } |
| |
| V = V - 1; |
| break; |
| |
| case RefVal::NotOwned: |
| if (V.getCount() > 0) { |
| if (E == DecRefAndStopTrackingHard) |
| return removeRefBinding(state, sym); |
| V = V - 1; |
| } else if (V.getIvarAccessHistory() == |
| RefVal::IvarAccessHistory::AccessedDirectly) { |
| // Assume that the instance variable was holding on the object at |
| // +1, and we just didn't know. |
| if (E == DecRefAndStopTrackingHard) |
| return removeRefBinding(state, sym); |
| V = V.releaseViaIvar() ^ RefVal::Released; |
| } else { |
| V = V ^ RefVal::ErrorReleaseNotOwned; |
| hasErr = V.getKind(); |
| } |
| break; |
| |
| case RefVal::Released: |
| // Non-GC cases are handled above. |
| assert(C.isObjCGCEnabled()); |
| V = V ^ RefVal::ErrorUseAfterRelease; |
| hasErr = V.getKind(); |
| break; |
| } |
| break; |
| } |
| return setRefBinding(state, sym, V); |
| } |
| |
| void RetainCountChecker::processNonLeakError(ProgramStateRef St, |
| SourceRange ErrorRange, |
| RefVal::Kind ErrorKind, |
| SymbolRef Sym, |
| CheckerContext &C) const { |
| // HACK: Ignore retain-count issues on values accessed through ivars, |
| // because of cases like this: |
| // [_contentView retain]; |
| // [_contentView removeFromSuperview]; |
| // [self addSubview:_contentView]; // invalidates 'self' |
| // [_contentView release]; |
| if (const RefVal *RV = getRefBinding(St, Sym)) |
| if (RV->getIvarAccessHistory() != RefVal::IvarAccessHistory::None) |
| return; |
| |
| ExplodedNode *N = C.generateErrorNode(St); |
| if (!N) |
| return; |
| |
| CFRefBug *BT; |
| switch (ErrorKind) { |
| default: |
| llvm_unreachable("Unhandled error."); |
| case RefVal::ErrorUseAfterRelease: |
| if (!useAfterRelease) |
| useAfterRelease.reset(new UseAfterRelease(this)); |
| BT = useAfterRelease.get(); |
| break; |
| case RefVal::ErrorReleaseNotOwned: |
| if (!releaseNotOwned) |
| releaseNotOwned.reset(new BadRelease(this)); |
| BT = releaseNotOwned.get(); |
| break; |
| case RefVal::ErrorDeallocGC: |
| if (!deallocGC) |
| deallocGC.reset(new DeallocGC(this)); |
| BT = deallocGC.get(); |
| break; |
| case RefVal::ErrorDeallocNotOwned: |
| if (!deallocNotOwned) |
| deallocNotOwned.reset(new DeallocNotOwned(this)); |
| BT = deallocNotOwned.get(); |
| break; |
| } |
| |
| assert(BT); |
| auto report = std::unique_ptr<BugReport>( |
| new CFRefReport(*BT, C.getASTContext().getLangOpts(), C.isObjCGCEnabled(), |
| SummaryLog, N, Sym)); |
| report->addRange(ErrorRange); |
| C.emitReport(std::move(report)); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Handle the return values of retain-count-related functions. |
| //===----------------------------------------------------------------------===// |
| |
| bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const { |
| // Get the callee. We're only interested in simple C functions. |
| ProgramStateRef state = C.getState(); |
| const FunctionDecl *FD = C.getCalleeDecl(CE); |
| if (!FD) |
| return false; |
| |
| IdentifierInfo *II = FD->getIdentifier(); |
| if (!II) |
| return false; |
| |
| // For now, we're only handling the functions that return aliases of their |
| // arguments: CFRetain and CFMakeCollectable (and their families). |
| // Eventually we should add other functions we can model entirely, |
| // such as CFRelease, which don't invalidate their arguments or globals. |
| if (CE->getNumArgs() != 1) |
| return false; |
| |
| // Get the name of the function. |
| StringRef FName = II->getName(); |
| FName = FName.substr(FName.find_first_not_of('_')); |
| |
| // See if it's one of the specific functions we know how to eval. |
| bool canEval = false; |
| // See if the function has 'rc_ownership_trusted_implementation' |
| // annotate attribute. If it does, we will not inline it. |
| bool hasTrustedImplementationAnnotation = false; |
| |
| QualType ResultTy = CE->getCallReturnType(C.getASTContext()); |
| if (ResultTy->isObjCIdType()) { |
| // Handle: id NSMakeCollectable(CFTypeRef) |
| canEval = II->isStr("NSMakeCollectable"); |
| } else if (ResultTy->isPointerType()) { |
| // Handle: (CF|CG|CV)Retain |
| // CFAutorelease |
| // CFMakeCollectable |
| // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist). |
| if (cocoa::isRefType(ResultTy, "CF", FName) || |
| cocoa::isRefType(ResultTy, "CG", FName) || |
| cocoa::isRefType(ResultTy, "CV", FName)) { |
| canEval = isRetain(FD, FName) || isAutorelease(FD, FName) || |
| isMakeCollectable(FD, FName); |
| } else { |
| if (FD->getDefinition()) { |
| canEval = isTrustedReferenceCountImplementation(FD->getDefinition()); |
| hasTrustedImplementationAnnotation = canEval; |
| } |
| } |
| } |
| |
| if (!canEval) |
| return false; |
| |
| // Bind the return value. |
| const LocationContext *LCtx = C.getLocationContext(); |
| SVal RetVal = state->getSVal(CE->getArg(0), LCtx); |
| if (RetVal.isUnknown() || |
| (hasTrustedImplementationAnnotation && !ResultTy.isNull())) { |
| // If the receiver is unknown or the function has |
| // 'rc_ownership_trusted_implementation' annotate attribute, conjure a |
| // return value. |
| SValBuilder &SVB = C.getSValBuilder(); |
| RetVal = SVB.conjureSymbolVal(nullptr, CE, LCtx, ResultTy, C.blockCount()); |
| } |
| state = state->BindExpr(CE, LCtx, RetVal, false); |
| |
| // FIXME: This should not be necessary, but otherwise the argument seems to be |
| // considered alive during the next statement. |
| if (const MemRegion *ArgRegion = RetVal.getAsRegion()) { |
| // Save the refcount status of the argument. |
| SymbolRef Sym = RetVal.getAsLocSymbol(); |
| const RefVal *Binding = nullptr; |
| if (Sym) |
| Binding = getRefBinding(state, Sym); |
| |
| // Invalidate the argument region. |
| state = state->invalidateRegions( |
| ArgRegion, CE, C.blockCount(), LCtx, |
| /*CausesPointerEscape*/ hasTrustedImplementationAnnotation); |
| |
| // Restore the refcount status of the argument. |
| if (Binding) |
| state = setRefBinding(state, Sym, *Binding); |
| } |
| |
| C.addTransition(state); |
| return true; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Handle return statements. |
| //===----------------------------------------------------------------------===// |
| |
| void RetainCountChecker::checkPreStmt(const ReturnStmt *S, |
| CheckerContext &C) const { |
| |
| // Only adjust the reference count if this is the top-level call frame, |
| // and not the result of inlining. In the future, we should do |
| // better checking even for inlined calls, and see if they match |
| // with their expected semantics (e.g., the method should return a retained |
| // object, etc.). |
| if (!C.inTopFrame()) |
| return; |
| |
| const Expr *RetE = S->getRetValue(); |
| if (!RetE) |
| return; |
| |
| ProgramStateRef state = C.getState(); |
| SymbolRef Sym = |
| state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol(); |
| if (!Sym) |
| return; |
| |
| // Get the reference count binding (if any). |
| const RefVal *T = getRefBinding(state, Sym); |
| if (!T) |
| return; |
| |
| // Change the reference count. |
| RefVal X = *T; |
| |
| switch (X.getKind()) { |
| case RefVal::Owned: { |
| unsigned cnt = X.getCount(); |
| assert(cnt > 0); |
| X.setCount(cnt - 1); |
| X = X ^ RefVal::ReturnedOwned; |
| break; |
| } |
| |
| case RefVal::NotOwned: { |
| unsigned cnt = X.getCount(); |
| if (cnt) { |
| X.setCount(cnt - 1); |
| X = X ^ RefVal::ReturnedOwned; |
| } |
| else { |
| X = X ^ RefVal::ReturnedNotOwned; |
| } |
| break; |
| } |
| |
| default: |
| return; |
| } |
| |
| // Update the binding. |
| state = setRefBinding(state, Sym, X); |
| ExplodedNode *Pred = C.addTransition(state); |
| |
| // At this point we have updated the state properly. |
| // Everything after this is merely checking to see if the return value has |
| // been over- or under-retained. |
| |
| // Did we cache out? |
| if (!Pred) |
| return; |
| |
| // Update the autorelease counts. |
| static CheckerProgramPointTag AutoreleaseTag(this, "Autorelease"); |
| state = handleAutoreleaseCounts(state, Pred, &AutoreleaseTag, C, Sym, X); |
| |
| // Did we cache out? |
| if (!state) |
| return; |
| |
| // Get the updated binding. |
| T = getRefBinding(state, Sym); |
| assert(T); |
| X = *T; |
| |
| // Consult the summary of the enclosing method. |
| RetainSummaryManager &Summaries = getSummaryManager(C); |
| const Decl *CD = &Pred->getCodeDecl(); |
| RetEffect RE = RetEffect::MakeNoRet(); |
| |
| // FIXME: What is the convention for blocks? Is there one? |
| if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) { |
| const RetainSummary *Summ = Summaries.getMethodSummary(MD); |
| RE = Summ->getRetEffect(); |
| } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) { |
| if (!isa<CXXMethodDecl>(FD)) { |
| const RetainSummary *Summ = Summaries.getFunctionSummary(FD); |
| RE = Summ->getRetEffect(); |
| } |
| } |
| |
| checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state); |
| } |
| |
| void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S, |
| CheckerContext &C, |
| ExplodedNode *Pred, |
| RetEffect RE, RefVal X, |
| SymbolRef Sym, |
| ProgramStateRef state) const { |
| // HACK: Ignore retain-count issues on values accessed through ivars, |
| // because of cases like this: |
| // [_contentView retain]; |
| // [_contentView removeFromSuperview]; |
| // [self addSubview:_contentView]; // invalidates 'self' |
| // [_contentView release]; |
| if (X.getIvarAccessHistory() != RefVal::IvarAccessHistory::None) |
| return; |
| |
| // Any leaks or other errors? |
| if (X.isReturnedOwned() && X.getCount() == 0) { |
| if (RE.getKind() != RetEffect::NoRet) { |
| bool hasError = false; |
| if (C.isObjCGCEnabled() && RE.getObjKind() == RetEffect::ObjC) { |
| // Things are more complicated with garbage collection. If the |
| // returned object is suppose to be an Objective-C object, we have |
| // a leak (as the caller expects a GC'ed object) because no |
| // method should return ownership unless it returns a CF object. |
| hasError = true; |
| X = X ^ RefVal::ErrorGCLeakReturned; |
| } |
| else if (!RE.isOwned()) { |
| // Either we are using GC and the returned object is a CF type |
| // or we aren't using GC. In either case, we expect that the |
| // enclosing method is expected to return ownership. |
| hasError = true; |
| X = X ^ RefVal::ErrorLeakReturned; |
| } |
| |
| if (hasError) { |
| // Generate an error node. |
| state = setRefBinding(state, Sym, X); |
| |
| static CheckerProgramPointTag ReturnOwnLeakTag(this, "ReturnsOwnLeak"); |
| ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag); |
| if (N) { |
| const LangOptions &LOpts = C.getASTContext().getLangOpts(); |
| bool GCEnabled = C.isObjCGCEnabled(); |
| C.emitReport(std::unique_ptr<BugReport>(new CFRefLeakReport( |
| *getLeakAtReturnBug(LOpts, GCEnabled), LOpts, GCEnabled, |
| SummaryLog, N, Sym, C, IncludeAllocationLine))); |
| } |
| } |
| } |
| } else if (X.isReturnedNotOwned()) { |
| if (RE.isOwned()) { |
| if (X.getIvarAccessHistory() == |
| RefVal::IvarAccessHistory::AccessedDirectly) { |
| // Assume the method was trying to transfer a +1 reference from a |
| // strong ivar to the caller. |
| state = setRefBinding(state, Sym, |
| X.releaseViaIvar() ^ RefVal::ReturnedOwned); |
| } else { |
| // Trying to return a not owned object to a caller expecting an |
| // owned object. |
| state = setRefBinding(state, Sym, X ^ RefVal::ErrorReturnedNotOwned); |
| |
| static CheckerProgramPointTag |
| ReturnNotOwnedTag(this, "ReturnNotOwnedForOwned"); |
| |
| ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag); |
| if (N) { |
| if (!returnNotOwnedForOwned) |
| returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned(this)); |
| |
| C.emitReport(std::unique_ptr<BugReport>(new CFRefReport( |
| *returnNotOwnedForOwned, C.getASTContext().getLangOpts(), |
| C.isObjCGCEnabled(), SummaryLog, N, Sym))); |
| } |
| } |
| } |
| } |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Check various ways a symbol can be invalidated. |
| //===----------------------------------------------------------------------===// |
| |
| void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S, |
| CheckerContext &C) const { |
| // Are we storing to something that causes the value to "escape"? |
| bool escapes = true; |
| |
| // A value escapes in three possible cases (this may change): |
| // |
| // (1) we are binding to something that is not a memory region. |
| // (2) we are binding to a memregion that does not have stack storage |
| // (3) we are binding to a memregion with stack storage that the store |
| // does not understand. |
| ProgramStateRef state = C.getState(); |
| |
| if (Optional<loc::MemRegionVal> regionLoc = loc.getAs<loc::MemRegionVal>()) { |
| escapes = !regionLoc->getRegion()->hasStackStorage(); |
| |
| if (!escapes) { |
| // To test (3), generate a new state with the binding added. If it is |
| // the same state, then it escapes (since the store cannot represent |
| // the binding). |
| // Do this only if we know that the store is not supposed to generate the |
| // same state. |
| SVal StoredVal = state->getSVal(regionLoc->getRegion()); |
| if (StoredVal != val) |
| escapes = (state == (state->bindLoc(*regionLoc, val, C.getLocationContext()))); |
| } |
| if (!escapes) { |
| // Case 4: We do not currently model what happens when a symbol is |
| // assigned to a struct field, so be conservative here and let the symbol |
| // go. TODO: This could definitely be improved upon. |
| escapes = !isa<VarRegion>(regionLoc->getRegion()); |
| } |
| } |
| |
| // If we are storing the value into an auto function scope variable annotated |
| // with (__attribute__((cleanup))), stop tracking the value to avoid leak |
| // false positives. |
| if (const VarRegion *LVR = dyn_cast_or_null<VarRegion>(loc.getAsRegion())) { |
| const VarDecl *VD = LVR->getDecl(); |
| if (VD->hasAttr<CleanupAttr>()) { |
| escapes = true; |
| } |
| } |
| |
| // If our store can represent the binding and we aren't storing to something |
| // that doesn't have local storage then just return and have the simulation |
| // state continue as is. |
| if (!escapes) |
| return; |
| |
| // Otherwise, find all symbols referenced by 'val' that we are tracking |
| // and stop tracking them. |
| state = state->scanReachableSymbols<StopTrackingCallback>(val).getState(); |
| C.addTransition(state); |
| } |
| |
| ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state, |
| SVal Cond, |
| bool Assumption) const { |
| // FIXME: We may add to the interface of evalAssume the list of symbols |
| // whose assumptions have changed. For now we just iterate through the |
| // bindings and check if any of the tracked symbols are NULL. This isn't |
| // too bad since the number of symbols we will track in practice are |
| // probably small and evalAssume is only called at branches and a few |
| // other places. |
| RefBindingsTy B = state->get<RefBindings>(); |
| |
| if (B.isEmpty()) |
| return state; |
| |
| bool changed = false; |
| RefBindingsTy::Factory &RefBFactory = state->get_context<RefBindings>(); |
| |
| for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { |
| // Check if the symbol is null stop tracking the symbol. |
| ConstraintManager &CMgr = state->getConstraintManager(); |
| ConditionTruthVal AllocFailed = CMgr.isNull(state, I.getKey()); |
| if (AllocFailed.isConstrainedTrue()) { |
| changed = true; |
| B = RefBFactory.remove(B, I.getKey()); |
| } |
| } |
| |
| if (changed) |
| state = state->set<RefBindings>(B); |
| |
| return state; |
| } |
| |
| ProgramStateRef |
| RetainCountChecker::checkRegionChanges(ProgramStateRef state, |
| const InvalidatedSymbols *invalidated, |
| ArrayRef<const MemRegion *> ExplicitRegions, |
| ArrayRef<const MemRegion *> Regions, |
| const LocationContext *LCtx, |
| const CallEvent *Call) const { |
| if (!invalidated) |
| return state; |
| |
| llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols; |
| for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(), |
| E = ExplicitRegions.end(); I != E; ++I) { |
| if (const SymbolicRegion *SR = (*I)->StripCasts()->getAs<SymbolicRegion>()) |
| WhitelistedSymbols.insert(SR->getSymbol()); |
| } |
| |
| for (InvalidatedSymbols::const_iterator I=invalidated->begin(), |
| E = invalidated->end(); I!=E; ++I) { |
| SymbolRef sym = *I; |
| if (WhitelistedSymbols.count(sym)) |
| continue; |
| // Remove any existing reference-count binding. |
| state = removeRefBinding(state, sym); |
| } |
| return state; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Handle dead symbols and end-of-path. |
| //===----------------------------------------------------------------------===// |
| |
| ProgramStateRef |
| RetainCountChecker::handleAutoreleaseCounts(ProgramStateRef state, |
| ExplodedNode *Pred, |
| const ProgramPointTag *Tag, |
| CheckerContext &Ctx, |
| SymbolRef Sym, RefVal V) const { |
| unsigned ACnt = V.getAutoreleaseCount(); |
| |
| // No autorelease counts? Nothing to be done. |
| if (!ACnt) |
| return state; |
| |
| assert(!Ctx.isObjCGCEnabled() && "Autorelease counts in GC mode?"); |
| unsigned Cnt = V.getCount(); |
| |
| // FIXME: Handle sending 'autorelease' to already released object. |
| |
| if (V.getKind() == RefVal::ReturnedOwned) |
| ++Cnt; |
| |
| // If we would over-release here, but we know the value came from an ivar, |
| // assume it was a strong ivar that's just been relinquished. |
| if (ACnt > Cnt && |
| V.getIvarAccessHistory() == RefVal::IvarAccessHistory::AccessedDirectly) { |
| V = V.releaseViaIvar(); |
| --ACnt; |
| } |
| |
| if (ACnt <= Cnt) { |
| if (ACnt == Cnt) { |
| V.clearCounts(); |
| if (V.getKind() == RefVal::ReturnedOwned) |
| V = V ^ RefVal::ReturnedNotOwned; |
| else |
| V = V ^ RefVal::NotOwned; |
| } else { |
| V.setCount(V.getCount() - ACnt); |
| V.setAutoreleaseCount(0); |
| } |
| return setRefBinding(state, Sym, V); |
| } |
| |
| // HACK: Ignore retain-count issues on values accessed through ivars, |
| // because of cases like this: |
| // [_contentView retain]; |
| // [_contentView removeFromSuperview]; |
| // [self addSubview:_contentView]; // invalidates 'self' |
| // [_contentView release]; |
| if (V.getIvarAccessHistory() != RefVal::IvarAccessHistory::None) |
| return state; |
| |
| // Woah! More autorelease counts then retain counts left. |
| // Emit hard error. |
| V = V ^ RefVal::ErrorOverAutorelease; |
| state = setRefBinding(state, Sym, V); |
| |
| ExplodedNode *N = Ctx.generateSink(state, Pred, Tag); |
| if (N) { |
| SmallString<128> sbuf; |
| llvm::raw_svector_ostream os(sbuf); |
| os << "Object was autoreleased "; |
| if (V.getAutoreleaseCount() > 1) |
| os << V.getAutoreleaseCount() << " times but the object "; |
| else |
| os << "but "; |
| os << "has a +" << V.getCount() << " retain count"; |
| |
| if (!overAutorelease) |
| overAutorelease.reset(new OverAutorelease(this)); |
| |
| const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); |
| Ctx.emitReport(std::unique_ptr<BugReport>( |
| new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false, |
| SummaryLog, N, Sym, os.str()))); |
| } |
| |
| return nullptr; |
| } |
| |
| ProgramStateRef |
| RetainCountChecker::handleSymbolDeath(ProgramStateRef state, |
| SymbolRef sid, RefVal V, |
| SmallVectorImpl<SymbolRef> &Leaked) const { |
| bool hasLeak; |
| |
| // HACK: Ignore retain-count issues on values accessed through ivars, |
| // because of cases like this: |
| // [_contentView retain]; |
| // [_contentView removeFromSuperview]; |
| // [self addSubview:_contentView]; // invalidates 'self' |
| // [_contentView release]; |
| if (V.getIvarAccessHistory() != RefVal::IvarAccessHistory::None) |
| hasLeak = false; |
| else if (V.isOwned()) |
| hasLeak = true; |
| else if (V.isNotOwned() || V.isReturnedOwned()) |
| hasLeak = (V.getCount() > 0); |
| else |
| hasLeak = false; |
| |
| if (!hasLeak) |
| return removeRefBinding(state, sid); |
| |
| Leaked.push_back(sid); |
| return setRefBinding(state, sid, V ^ RefVal::ErrorLeak); |
| } |
| |
| ExplodedNode * |
| RetainCountChecker::processLeaks(ProgramStateRef state, |
| SmallVectorImpl<SymbolRef> &Leaked, |
| CheckerContext &Ctx, |
| ExplodedNode *Pred) const { |
| // Generate an intermediate node representing the leak point. |
| ExplodedNode *N = Ctx.addTransition(state, Pred); |
| |
| if (N) { |
| for (SmallVectorImpl<SymbolRef>::iterator |
| I = Leaked.begin(), E = Leaked.end(); I != E; ++I) { |
| |
| const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); |
| bool GCEnabled = Ctx.isObjCGCEnabled(); |
| CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled) |
| : getLeakAtReturnBug(LOpts, GCEnabled); |
| assert(BT && "BugType not initialized."); |
| |
| Ctx.emitReport(std::unique_ptr<BugReport>( |
| new CFRefLeakReport(*BT, LOpts, GCEnabled, SummaryLog, N, *I, Ctx, |
| IncludeAllocationLine))); |
| } |
| } |
| |
| return N; |
| } |
| |
| void RetainCountChecker::checkBeginFunction(CheckerContext &Ctx) const { |
| if (!Ctx.inTopFrame()) |
| return; |
| |
| const LocationContext *LCtx = Ctx.getLocationContext(); |
| const FunctionDecl *FD = dyn_cast<FunctionDecl>(LCtx->getDecl()); |
| |
| if (!FD || isTrustedReferenceCountImplementation(FD)) |
| return; |
| |
| ProgramStateRef state = Ctx.getState(); |
| |
| const RetainSummary *FunctionSummary = getSummaryManager(Ctx).getFunctionSummary(FD); |
| ArgEffects CalleeSideArgEffects = FunctionSummary->getArgEffects(); |
| |
| for (unsigned idx = 0, e = FD->getNumParams(); idx != e; ++idx) { |
| const ParmVarDecl *Param = FD->getParamDecl(idx); |
| SymbolRef Sym = state->getSVal(state->getRegion(Param, LCtx)).getAsSymbol(); |
| |
| QualType Ty = Param->getType(); |
| const ArgEffect *AE = CalleeSideArgEffects.lookup(idx); |
| if (AE && *AE == DecRef && isGeneralizedObjectRef(Ty)) |
| state = setRefBinding(state, Sym, RefVal::makeOwned(RetEffect::ObjKind::Generalized, Ty)); |
| else if (isGeneralizedObjectRef(Ty)) |
| state = setRefBinding(state, Sym, RefVal::makeNotOwned(RetEffect::ObjKind::Generalized, Ty)); |
| } |
| |
| Ctx.addTransition(state); |
| } |
| |
| void RetainCountChecker::checkEndFunction(const ReturnStmt *RS, |
| CheckerContext &Ctx) const { |
| ProgramStateRef state = Ctx.getState(); |
| RefBindingsTy B = state->get<RefBindings>(); |
| ExplodedNode *Pred = Ctx.getPredecessor(); |
| |
| // Don't process anything within synthesized bodies. |
| const LocationContext *LCtx = Pred->getLocationContext(); |
| if (LCtx->getAnalysisDeclContext()->isBodyAutosynthesized()) { |
| assert(!LCtx->inTopFrame()); |
| return; |
| } |
| |
| for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { |
| state = handleAutoreleaseCounts(state, Pred, /*Tag=*/nullptr, Ctx, |
| I->first, I->second); |
| if (!state) |
| return; |
| } |
| |
| // If the current LocationContext has a parent, don't check for leaks. |
| // We will do that later. |
| // FIXME: we should instead check for imbalances of the retain/releases, |
| // and suggest annotations. |
| if (LCtx->getParent()) |
| return; |
| |
| B = state->get<RefBindings>(); |
| SmallVector<SymbolRef, 10> Leaked; |
| |
| for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) |
| state = handleSymbolDeath(state, I->first, I->second, Leaked); |
| |
| processLeaks(state, Leaked, Ctx, Pred); |
| } |
| |
| const ProgramPointTag * |
| RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const { |
| const CheckerProgramPointTag *&tag = DeadSymbolTags[sym]; |
| if (!tag) { |
| SmallString<64> buf; |
| llvm::raw_svector_ostream out(buf); |
| out << "Dead Symbol : "; |
| sym->dumpToStream(out); |
| tag = new CheckerProgramPointTag(this, out.str()); |
| } |
| return tag; |
| } |
| |
| void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper, |
| CheckerContext &C) const { |
| ExplodedNode *Pred = C.getPredecessor(); |
| |
| ProgramStateRef state = C.getState(); |
| RefBindingsTy B = state->get<RefBindings>(); |
| SmallVector<SymbolRef, 10> Leaked; |
| |
| // Update counts from autorelease pools |
| for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), |
| E = SymReaper.dead_end(); I != E; ++I) { |
| SymbolRef Sym = *I; |
| if (const RefVal *T = B.lookup(Sym)){ |
| // Use the symbol as the tag. |
| // FIXME: This might not be as unique as we would like. |
| const ProgramPointTag *Tag = getDeadSymbolTag(Sym); |
| state = handleAutoreleaseCounts(state, Pred, Tag, C, Sym, *T); |
| if (!state) |
| return; |
| |
| // Fetch the new reference count from the state, and use it to handle |
| // this symbol. |
| state = handleSymbolDeath(state, *I, *getRefBinding(state, Sym), Leaked); |
| } |
| } |
| |
| if (Leaked.empty()) { |
| C.addTransition(state); |
| return; |
| } |
| |
| Pred = processLeaks(state, Leaked, C, Pred); |
| |
| // Did we cache out? |
| if (!Pred) |
| return; |
| |
| // Now generate a new node that nukes the old bindings. |
| // The only bindings left at this point are the leaked symbols. |
| RefBindingsTy::Factory &F = state->get_context<RefBindings>(); |
| B = state->get<RefBindings>(); |
| |
| for (SmallVectorImpl<SymbolRef>::iterator I = Leaked.begin(), |
| E = Leaked.end(); |
| I != E; ++I) |
| B = F.remove(B, *I); |
| |
| state = state->set<RefBindings>(B); |
| C.addTransition(state, Pred); |
| } |
| |
| void RetainCountChecker::printState(raw_ostream &Out, ProgramStateRef State, |
| const char *NL, const char *Sep) const { |
| |
| RefBindingsTy B = State->get<RefBindings>(); |
| |
| if (B.isEmpty()) |
| return; |
| |
| Out << Sep << NL; |
| |
| for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { |
| Out << I->first << " : "; |
| I->second.print(Out); |
| Out << NL; |
| } |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Checker registration. |
| //===----------------------------------------------------------------------===// |
| |
| void ento::registerRetainCountChecker(CheckerManager &Mgr) { |
| Mgr.registerChecker<RetainCountChecker>(Mgr.getAnalyzerOptions()); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Implementation of the CallEffects API. |
| //===----------------------------------------------------------------------===// |
| |
| namespace clang { |
| namespace ento { |
| namespace objc_retain { |
| |
| // This is a bit gross, but it allows us to populate CallEffects without |
| // creating a bunch of accessors. This kind is very localized, so the |
| // damage of this macro is limited. |
| #define createCallEffect(D, KIND)\ |
| ASTContext &Ctx = D->getASTContext();\ |
| LangOptions L = Ctx.getLangOpts();\ |
| RetainSummaryManager M(Ctx, L.GCOnly, L.ObjCAutoRefCount);\ |
| const RetainSummary *S = M.get ## KIND ## Summary(D);\ |
| CallEffects CE(S->getRetEffect());\ |
| CE.Receiver = S->getReceiverEffect();\ |
| unsigned N = D->param_size();\ |
| for (unsigned i = 0; i < N; ++i) {\ |
| CE.Args.push_back(S->getArg(i));\ |
| } |
| |
| CallEffects CallEffects::getEffect(const ObjCMethodDecl *MD) { |
| createCallEffect(MD, Method); |
| return CE; |
| } |
| |
| CallEffects CallEffects::getEffect(const FunctionDecl *FD) { |
| createCallEffect(FD, Function); |
| return CE; |
| } |
| |
| #undef createCallEffect |
| |
| } // end namespace objc_retain |
| } // end namespace ento |
| } // end namespace clang |