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Diffstat (limited to 'lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp')
| -rw-r--r-- | lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp | 4156 |
1 files changed, 0 insertions, 4156 deletions
diff --git a/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp b/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp deleted file mode 100644 index 9c85c09837239..0000000000000 --- a/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp +++ /dev/null @@ -1,4156 +0,0 @@ -//==-- 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 |