[analyzer] Move RetainReleaseChecker to the Checkers library and rename it to RetainCountChecker...and clean up the file while I'm at it.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139002 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp b/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
new file mode 100644
index 0000000..fce2cc3
--- /dev/null
+++ b/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
@@ -0,0 +1,3600 @@
+//==-- 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 "ClangSACheckers.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Analysis/DomainSpecific/CocoaConventions.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngineBuilders.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/StringExtras.h"
+#include <cstdarg>
+
+using namespace clang;
+using namespace ento;
+using llvm::StrInStrNoCase;
+
+namespace {
+/// Wrapper around different kinds of node builder, so that helper functions
+/// can have a common interface.
+class GenericNodeBuilderRefCount {
+ StmtNodeBuilder *SNB;
+ const Stmt *S;
+ const ProgramPointTag *tag;
+ EndOfFunctionNodeBuilder *ENB;
+public:
+ GenericNodeBuilderRefCount(StmtNodeBuilder &snb, const Stmt *s,
+ const ProgramPointTag *t)
+ : SNB(&snb), S(s), tag(t), ENB(0) {}
+
+ GenericNodeBuilderRefCount(EndOfFunctionNodeBuilder &enb)
+ : SNB(0), S(0), tag(0), ENB(&enb) {}
+
+ ExplodedNode *MakeNode(const ProgramState *state, ExplodedNode *Pred) {
+ if (SNB)
+ return SNB->generateNode(PostStmt(S, Pred->getLocationContext(), tag),
+ state, Pred);
+
+ assert(ENB);
+ return ENB->generateNode(state, Pred);
+ }
+};
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// Primitives used for constructing summaries for function/method calls.
+//===----------------------------------------------------------------------===//
+
+/// ArgEffect is used to summarize a function/method call's effect on a
+/// particular argument.
+enum ArgEffect { DoNothing, Autorelease, Dealloc, DecRef, DecRefMsg,
+ DecRefBridgedTransfered,
+ IncRefMsg, IncRef, MakeCollectable, MayEscape,
+ NewAutoreleasePool, SelfOwn, StopTracking };
+
+namespace llvm {
+template <> struct FoldingSetTrait<ArgEffect> {
+static inline void Profile(const ArgEffect X, FoldingSetNodeID& ID) {
+ ID.AddInteger((unsigned) X);
+}
+};
+} // end llvm namespace
+
+/// ArgEffects summarizes the effects of a function/method call on all of
+/// its arguments.
+typedef llvm::ImmutableMap<unsigned,ArgEffect> ArgEffects;
+
+namespace {
+
+/// RetEffect is used to summarize a function/method call's behavior with
+/// respect to its return value.
+class RetEffect {
+public:
+ enum Kind { NoRet, OwnedSymbol, OwnedAllocatedSymbol,
+ NotOwnedSymbol, GCNotOwnedSymbol, ARCNotOwnedSymbol,
+ OwnedWhenTrackedReceiver };
+
+ enum ObjKind { CF, ObjC, AnyObj };
+
+private:
+ Kind K;
+ ObjKind O;
+
+ RetEffect(Kind k, ObjKind o = AnyObj) : K(k), O(o) {}
+
+public:
+ Kind getKind() const { return K; }
+
+ ObjKind getObjKind() const { return O; }
+
+ bool isOwned() const {
+ return K == OwnedSymbol || K == OwnedAllocatedSymbol ||
+ K == OwnedWhenTrackedReceiver;
+ }
+
+ bool operator==(const RetEffect &Other) const {
+ return K == Other.K && O == Other.O;
+ }
+
+ static RetEffect MakeOwnedWhenTrackedReceiver() {
+ return RetEffect(OwnedWhenTrackedReceiver, ObjC);
+ }
+
+ static RetEffect MakeOwned(ObjKind o, bool isAllocated = false) {
+ return RetEffect(isAllocated ? OwnedAllocatedSymbol : OwnedSymbol, o);
+ }
+ static RetEffect MakeNotOwned(ObjKind o) {
+ return RetEffect(NotOwnedSymbol, o);
+ }
+ static RetEffect MakeGCNotOwned() {
+ return RetEffect(GCNotOwnedSymbol, ObjC);
+ }
+ static RetEffect MakeARCNotOwned() {
+ return RetEffect(ARCNotOwnedSymbol, ObjC);
+ }
+ static RetEffect MakeNoRet() {
+ return RetEffect(NoRet);
+ }
+};
+
+//===----------------------------------------------------------------------===//
+// Reference-counting logic (typestate + counts).
+//===----------------------------------------------------------------------===//
+
+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
+ };
+
+private:
+ Kind kind;
+ RetEffect::ObjKind okind;
+ unsigned Cnt;
+ unsigned ACnt;
+ QualType T;
+
+ RefVal(Kind k, RetEffect::ObjKind o, unsigned cnt, unsigned acnt, QualType t)
+ : kind(k), okind(o), Cnt(cnt), ACnt(acnt), T(t) {}
+
+public:
+ Kind getKind() const { return kind; }
+
+ RetEffect::ObjKind getObjKind() const { return okind; }
+
+ 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; }
+
+ bool isOwned() const {
+ return getKind() == Owned;
+ }
+
+ bool isNotOwned() const {
+ return getKind() == NotOwned;
+ }
+
+ bool isReturnedOwned() const {
+ return getKind() == ReturnedOwned;
+ }
+
+ bool isReturnedNotOwned() const {
+ return getKind() == ReturnedNotOwned;
+ }
+
+ static RefVal makeOwned(RetEffect::ObjKind o, QualType t,
+ unsigned Count = 1) {
+ return RefVal(Owned, o, Count, 0, t);
+ }
+
+ static RefVal makeNotOwned(RetEffect::ObjKind o, QualType t,
+ unsigned Count = 0) {
+ return RefVal(NotOwned, o, Count, 0, t);
+ }
+
+ // Comparison, profiling, and pretty-printing.
+
+ bool operator==(const RefVal& X) const {
+ return kind == X.kind && Cnt == X.Cnt && T == X.T && ACnt == X.ACnt;
+ }
+
+ RefVal operator-(size_t i) const {
+ return RefVal(getKind(), getObjKind(), getCount() - i,
+ getAutoreleaseCount(), getType());
+ }
+
+ RefVal operator+(size_t i) const {
+ return RefVal(getKind(), getObjKind(), getCount() + i,
+ getAutoreleaseCount(), getType());
+ }
+
+ RefVal operator^(Kind k) const {
+ return RefVal(k, getObjKind(), getCount(), getAutoreleaseCount(),
+ getType());
+ }
+
+ RefVal autorelease() const {
+ return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount()+1,
+ getType());
+ }
+
+ void Profile(llvm::FoldingSetNodeID& ID) const {
+ ID.AddInteger((unsigned) kind);
+ ID.AddInteger(Cnt);
+ ID.AddInteger(ACnt);
+ ID.Add(T);
+ }
+
+ 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;
+ }
+
+ if (ACnt) {
+ Out << " [ARC +" << ACnt << ']';
+ }
+}
+} //end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// RefBindings - State used to track object reference counts.
+//===----------------------------------------------------------------------===//
+
+typedef llvm::ImmutableMap<SymbolRef, RefVal> RefBindings;
+
+namespace clang {
+namespace ento {
+template<>
+struct ProgramStateTrait<RefBindings>
+ : public ProgramStatePartialTrait<RefBindings> {
+ static void *GDMIndex() {
+ static int RefBIndex = 0;
+ return &RefBIndex;
+ }
+};
+}
+}
+
+//===----------------------------------------------------------------------===//
+// Function/Method behavior summaries.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class RetainSummary {
+ /// Args - an ordered vector 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;
+ }
+};
+} // 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() : 0), S(s) {}
+
+ ObjCSummaryKey(const ObjCInterfaceDecl *d, IdentifierInfo *ii, Selector s)
+ : II(d ? d->getIdentifier() : ii), S(s) {}
+
+ ObjCSummaryKey(Selector s)
+ : II(0), S(s) {}
+
+ IdentifierInfo* getIdentifier() const { return II; }
+ Selector getSelector() const { return S; }
+};
+}
+
+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) {
+ return (DenseMapInfo<IdentifierInfo*>::getHashValue(V.getIdentifier())
+ & 0x88888888)
+ | (DenseMapInfo<Selector>::getHashValue(V.getSelector())
+ & 0x55555555);
+ }
+
+ static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) {
+ return DenseMapInfo<IdentifierInfo*>::isEqual(LHS.getIdentifier(),
+ RHS.getIdentifier()) &&
+ DenseMapInfo<Selector>::isEqual(LHS.getSelector(),
+ RHS.getSelector());
+ }
+
+};
+template <>
+struct isPodLike<ObjCSummaryKey> { static const bool value = true; };
+} // end llvm namespace
+
+namespace {
+class ObjCSummaryCache {
+ typedef llvm::DenseMap<ObjCSummaryKey, RetainSummary*> MapTy;
+ MapTy M;
+public:
+ ObjCSummaryCache() {}
+
+ RetainSummary* find(const ObjCInterfaceDecl *D, IdentifierInfo *ClsName,
+ Selector S) {
+ // Lookup the method using the decl for the class @interface. If we
+ // have no decl, lookup using the class name.
+ return D ? find(D, S) : find(ClsName, S);
+ }
+
+ 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() || !D)
+ return I->second;
+
+ // 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 NULL;
+ }
+
+ // Cache the summary with original key to make the next lookup faster
+ // and return the iterator.
+ RetainSummary *Summ = I->second;
+ M[K] = Summ;
+ return Summ;
+ }
+
+ RetainSummary* find(IdentifierInfo* II, Selector S) {
+ // FIXME: Class method lookup. Right now we dont' 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() ? NULL : I->second;
+ }
+
+ RetainSummary*& operator[](ObjCSummaryKey K) {
+ return M[K];
+ }
+
+ 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*, RetainSummary*>
+ FuncSummariesTy;
+
+ typedef ObjCSummaryCache ObjCMethodSummariesTy;
+
+ //==-----------------------------------------------------------------==//
+ // 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;
+
+ RetainSummary DefaultSummary;
+ RetainSummary* StopSummary;
+
+ //==-----------------------------------------------------------------==//
+ // Methods.
+ //==-----------------------------------------------------------------==//
+
+ /// getArgEffects - Returns a persistent ArgEffects object based on the
+ /// data in ScratchArgs.
+ ArgEffects getArgEffects();
+
+ enum UnaryFuncKind { cfretain, cfrelease, cfmakecollectable };
+
+public:
+ RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; }
+
+ RetainSummary* getUnarySummary(const FunctionType* FT, UnaryFuncKind func);
+
+ RetainSummary* getCFSummaryCreateRule(const FunctionDecl *FD);
+ RetainSummary* getCFSummaryGetRule(const FunctionDecl *FD);
+ RetainSummary* getCFCreateGetRuleSummary(const FunctionDecl *FD,
+ StringRef FName);
+
+ RetainSummary* getPersistentSummary(ArgEffects AE, RetEffect RetEff,
+ ArgEffect ReceiverEff = DoNothing,
+ ArgEffect DefaultEff = MayEscape);
+
+ RetainSummary* getPersistentSummary(RetEffect RE,
+ ArgEffect ReceiverEff = DoNothing,
+ ArgEffect DefaultEff = MayEscape) {
+ return getPersistentSummary(getArgEffects(), RE, ReceiverEff, DefaultEff);
+ }
+
+ RetainSummary *getPersistentStopSummary() {
+ if (StopSummary)
+ return StopSummary;
+
+ StopSummary = getPersistentSummary(RetEffect::MakeNoRet(),
+ StopTracking, StopTracking);
+
+ return StopSummary;
+ }
+
+ RetainSummary *getInitMethodSummary(QualType RetTy);
+
+ void InitializeClassMethodSummaries();
+ void InitializeMethodSummaries();
+private:
+ void addNSObjectClsMethSummary(Selector S, RetainSummary *Summ) {
+ ObjCClassMethodSummaries[S] = Summ;
+ }
+
+ void addNSObjectMethSummary(Selector S, RetainSummary *Summ) {
+ ObjCMethodSummaries[S] = Summ;
+ }
+
+ void addClassMethSummary(const char* Cls, const char* nullaryName,
+ RetainSummary *Summ) {
+ IdentifierInfo* ClsII = &Ctx.Idents.get(Cls);
+ Selector S = GetNullarySelector(nullaryName, Ctx);
+ ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ;
+ }
+
+ void addInstMethSummary(const char* Cls, const char* nullaryName,
+ RetainSummary *Summ) {
+ IdentifierInfo* ClsII = &Ctx.Idents.get(Cls);
+ Selector S = GetNullarySelector(nullaryName, Ctx);
+ ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ;
+ }
+
+ Selector generateSelector(va_list argp) {
+ SmallVector<IdentifierInfo*, 10> II;
+
+ while (const char* s = va_arg(argp, const char*))
+ II.push_back(&Ctx.Idents.get(s));
+
+ return Ctx.Selectors.getSelector(II.size(), &II[0]);
+ }
+
+ void addMethodSummary(IdentifierInfo *ClsII, ObjCMethodSummariesTy& Summaries,
+ RetainSummary* Summ, va_list argp) {
+ Selector S = generateSelector(argp);
+ Summaries[ObjCSummaryKey(ClsII, S)] = Summ;
+ }
+
+ void addInstMethSummary(const char* Cls, RetainSummary* Summ, ...) {
+ va_list argp;
+ va_start(argp, Summ);
+ addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, argp);
+ va_end(argp);
+ }
+
+ void addClsMethSummary(const char* Cls, RetainSummary* Summ, ...) {
+ va_list argp;
+ va_start(argp, Summ);
+ addMethodSummary(&Ctx.Idents.get(Cls),ObjCClassMethodSummaries, Summ, argp);
+ va_end(argp);
+ }
+
+ void addClsMethSummary(IdentifierInfo *II, RetainSummary* Summ, ...) {
+ va_list argp;
+ va_start(argp, Summ);
+ addMethodSummary(II, ObjCClassMethodSummaries, Summ, argp);
+ va_end(argp);
+ }
+
+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::MakeARCNotOwned()
+ : RetEffect::MakeOwned(RetEffect::ObjC, true))),
+ ObjCInitRetE(gcenabled
+ ? RetEffect::MakeGCNotOwned()
+ : (usesARC ? RetEffect::MakeARCNotOwned()
+ : RetEffect::MakeOwnedWhenTrackedReceiver())),
+ DefaultSummary(AF.getEmptyMap() /* per-argument effects (none) */,
+ RetEffect::MakeNoRet() /* return effect */,
+ MayEscape, /* default argument effect */
+ DoNothing /* receiver effect */),
+ StopSummary(0) {
+
+ InitializeClassMethodSummaries();
+ InitializeMethodSummaries();
+ }
+
+ RetainSummary* getSummary(const FunctionDecl *FD);
+
+ RetainSummary *getInstanceMethodSummary(const ObjCMessage &msg,
+ const ProgramState *state,
+ const LocationContext *LC);
+
+ RetainSummary* getInstanceMethodSummary(const ObjCMessage &msg,
+ const ObjCInterfaceDecl *ID) {
+ return getInstanceMethodSummary(msg.getSelector(), 0,
+ ID, msg.getMethodDecl(), msg.getType(Ctx));
+ }
+
+ RetainSummary* getInstanceMethodSummary(Selector S, IdentifierInfo *ClsName,
+ const ObjCInterfaceDecl *ID,
+ const ObjCMethodDecl *MD,
+ QualType RetTy);
+
+ RetainSummary *getClassMethodSummary(Selector S, IdentifierInfo *ClsName,
+ const ObjCInterfaceDecl *ID,
+ const ObjCMethodDecl *MD,
+ QualType RetTy);
+
+ RetainSummary *getClassMethodSummary(const ObjCMessage &msg) {
+ const ObjCInterfaceDecl *Class = 0;
+ if (!msg.isInstanceMessage())
+ Class = msg.getReceiverInterface();
+
+ return getClassMethodSummary(msg.getSelector(),
+ Class? Class->getIdentifier() : 0,
+ Class,
+ msg.getMethodDecl(), msg.getType(Ctx));
+ }
+
+ /// getMethodSummary - This version of getMethodSummary is used to query
+ /// the summary for the current method being analyzed.
+ RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) {
+ // FIXME: Eventually this should be unneeded.
+ const ObjCInterfaceDecl *ID = MD->getClassInterface();
+ Selector S = MD->getSelector();
+ IdentifierInfo *ClsName = ID->getIdentifier();
+ QualType ResultTy = MD->getResultType();
+
+ if (MD->isInstanceMethod())
+ return getInstanceMethodSummary(S, ClsName, ID, MD, ResultTy);
+ else
+ return getClassMethodSummary(S, ClsName, ID, MD, ResultTy);
+ }
+
+ RetainSummary* getCommonMethodSummary(const ObjCMethodDecl *MD,
+ Selector S, QualType RetTy);
+
+ void updateSummaryFromAnnotations(RetainSummary *&Summ,
+ const ObjCMethodDecl *MD);
+
+ void updateSummaryFromAnnotations(RetainSummary *&Summ,
+ const FunctionDecl *FD);
+
+ bool isGCEnabled() const { return GCEnabled; }
+
+ bool isARCEnabled() const { return ARCEnabled; }
+
+ bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; }
+
+ RetainSummary *copySummary(RetainSummary *OldSumm) {
+ RetainSummary *Summ = (RetainSummary*) BPAlloc.Allocate<RetainSummary>();
+ new (Summ) RetainSummary(*OldSumm);
+ return Summ;
+ }
+};
+
+// 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;
+ RetainSummary *&RealSummary;
+ RetainSummary ScratchSummary;
+ bool Accessed;
+public:
+ RetainSummaryTemplate(RetainSummary *&real, const RetainSummary &base,
+ RetainSummaryManager &manager)
+ : Manager(manager), RealSummary(real), ScratchSummary(base), Accessed(false)
+ {}
+
+ ~RetainSummaryTemplate() {
+ if (!RealSummary && Accessed)
+ RealSummary = Manager.copySummary(&ScratchSummary);
+ }
+
+ RetainSummary &operator*() {
+ Accessed = true;
+ return RealSummary ? *RealSummary : ScratchSummary;
+ }
+
+ RetainSummary *operator->() {
+ Accessed = true;
+ return RealSummary ? RealSummary : &ScratchSummary;
+ }
+};
+
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// Implementation of checker data structures.
+//===----------------------------------------------------------------------===//
+
+ArgEffects RetainSummaryManager::getArgEffects() {
+ ArgEffects AE = ScratchArgs;
+ ScratchArgs = AF.getEmptyMap();
+ return AE;
+}
+
+RetainSummary*
+RetainSummaryManager::getPersistentSummary(ArgEffects AE, RetEffect RetEff,
+ ArgEffect ReceiverEff,
+ ArgEffect DefaultEff) {
+ // Create the summary and return it.
+ RetainSummary *Summ = (RetainSummary*) BPAlloc.Allocate<RetainSummary>();
+ new (Summ) RetainSummary(AE, RetEff, DefaultEff, ReceiverEff);
+ return Summ;
+}
+
+//===----------------------------------------------------------------------===//
+// Summary creation for functions (largely uses of Core Foundation).
+//===----------------------------------------------------------------------===//
+
+static bool isRetain(const FunctionDecl *FD, StringRef FName) {
+ return FName.endswith("Retain");
+}
+
+static bool isRelease(const FunctionDecl *FD, StringRef FName) {
+ return FName.endswith("Release");
+}
+
+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("MakeCollectable") != StringRef::npos;
+}
+
+RetainSummary* RetainSummaryManager::getSummary(const FunctionDecl *FD) {
+ // 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.
+ RetainSummary *S = 0;
+
+ do {
+ // We generate "stop" summaries for implicitly defined functions.
+ if (FD->isImplicit()) {
+ S = getPersistentStopSummary();
+ break;
+ }
+ // For C++ methods, generate an implicit "stop" summary as well. We
+ // can relax this once we have a clear policy for C++ methods and
+ // ownership attributes.
+ if (isa<CXXMethodDecl>(FD)) {
+ 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->getResultType();
+
+ // FIXME: This should all be refactored into a chain of "summary lookup"
+ // filters.
+ assert(ScratchArgs.isEmpty());
+
+ if (FName == "pthread_create") {
+ // Part of: <rdar://problem/7299394>. This will be addressed
+ // better with IPA.
+ S = getPersistentStopSummary();
+ } else if (FName == "NSMakeCollectable") {
+ // Handle: id NSMakeCollectable(CFTypeRef)
+ S = (RetTy->isObjCIdType())
+ ? getUnarySummary(FT, cfmakecollectable)
+ : getPersistentStopSummary();
+ } else if (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, true),
+ 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, true),
+ 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);
+ }
+
+ // Did we get a summary?
+ if (S)
+ break;
+
+ // Enable this code once the semantics of NSDeallocateObject are resolved
+ // for GC. <rdar://problem/6619988>
+#if 0
+ // Handle: NSDeallocateObject(id anObject);
+ // This method does allow 'nil' (although we don't check it now).
+ if (strcmp(FName, "NSDeallocateObject") == 0) {
+ return RetTy == Ctx.VoidTy
+ ? getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, Dealloc)
+ : getPersistentStopSummary();
+ }
+#endif
+
+ if (RetTy->isPointerType()) {
+ // For CoreFoundation ('CF') types.
+ if (cocoa::isRefType(RetTy, "CF", FName)) {
+ if (isRetain(FD, FName))
+ S = getUnarySummary(FT, cfretain);
+ else if (isMakeCollectable(FD, FName))
+ S = getUnarySummary(FT, cfmakecollectable);
+ else
+ S = getCFCreateGetRuleSummary(FD, FName);
+
+ break;
+ }
+
+ // For CoreGraphics ('CG') types.
+ if (cocoa::isRefType(RetTy, "CG", FName)) {
+ if (isRetain(FD, FName))
+ S = getUnarySummary(FT, cfretain);
+ else
+ S = getCFCreateGetRuleSummary(FD, FName);
+
+ break;
+ }
+
+ // For the Disk Arbitration API (DiskArbitration/DADisk.h)
+ if (cocoa::isRefType(RetTy, "DADisk") ||
+ cocoa::isRefType(RetTy, "DADissenter") ||
+ cocoa::isRefType(RetTy, "DASessionRef")) {
+ S = getCFCreateGetRuleSummary(FD, FName);
+ break;
+ }
+
+ break;
+ }
+
+ // Check for release functions, the only kind of functions that we care
+ // about that don't return a pointer type.
+ if (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);
+
+ // Annotations override defaults.
+ updateSummaryFromAnnotations(S, FD);
+
+ FuncSummaries[FD] = S;
+ return S;
+}
+
+RetainSummary*
+RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD,
+ StringRef FName) {
+ if (coreFoundation::followsCreateRule(FName))
+ return getCFSummaryCreateRule(FD);
+
+ return getCFSummaryGetRule(FD);
+}
+
+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->getNumArgs() != 1)
+ return getPersistentStopSummary();
+
+ assert (ScratchArgs.isEmpty());
+
+ ArgEffect Effect;
+ switch (func) {
+ case cfretain: Effect = IncRef; break;
+ case cfrelease: Effect = DecRef; break;
+ case cfmakecollectable: Effect = MakeCollectable; break;
+ default: llvm_unreachable("Not a supported unary function.");
+ }
+
+ ScratchArgs = AF.add(ScratchArgs, 0, Effect);
+ return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
+}
+
+RetainSummary*
+RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) {
+ assert (ScratchArgs.isEmpty());
+
+ return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true));
+}
+
+RetainSummary*
+RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) {
+ assert (ScratchArgs.isEmpty());
+ return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF),
+ DoNothing, DoNothing);
+}
+
+//===----------------------------------------------------------------------===//
+// Summary creation for Selectors.
+//===----------------------------------------------------------------------===//
+
+RetainSummary*
+RetainSummaryManager::getInitMethodSummary(QualType RetTy) {
+ assert(ScratchArgs.isEmpty());
+ // 'init' methods conceptually return a newly allocated object and claim
+ // the receiver.
+ if (cocoa::isCocoaObjectRef(RetTy) ||
+ coreFoundation::isCFObjectRef(RetTy))
+ return getPersistentSummary(ObjCInitRetE, DecRefMsg);
+
+ return 0;
+}
+
+void
+RetainSummaryManager::updateSummaryFromAnnotations(RetainSummary *&Summ,
+ const FunctionDecl *FD) {
+ if (!FD)
+ return;
+
+ RetainSummaryTemplate Template(Summ, DefaultSummary, *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->getAttr<NSConsumedAttr>()) {
+ if (!GCEnabled) {
+ Template->addArg(AF, parm_idx, DecRef);
+ }
+ } else if (pd->getAttr<CFConsumedAttr>()) {
+ Template->addArg(AF, parm_idx, DecRef);
+ }
+ }
+
+ QualType RetTy = FD->getResultType();
+
+ // Determine if there is a special return effect for this method.
+ if (cocoa::isCocoaObjectRef(RetTy)) {
+ if (FD->getAttr<NSReturnsRetainedAttr>()) {
+ Template->setRetEffect(ObjCAllocRetE);
+ }
+ else if (FD->getAttr<CFReturnsRetainedAttr>()) {
+ Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true));
+ }
+ else if (FD->getAttr<NSReturnsNotRetainedAttr>()) {
+ Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC));
+ }
+ else if (FD->getAttr<CFReturnsNotRetainedAttr>()) {
+ Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF));
+ }
+ } else if (RetTy->getAs<PointerType>()) {
+ if (FD->getAttr<CFReturnsRetainedAttr>()) {
+ Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true));
+ }
+ else if (FD->getAttr<CFReturnsNotRetainedAttr>()) {
+ Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF));
+ }
+ }
+}
+
+void
+RetainSummaryManager::updateSummaryFromAnnotations(RetainSummary *&Summ,
+ const ObjCMethodDecl *MD) {
+ if (!MD)
+ return;
+
+ RetainSummaryTemplate Template(Summ, DefaultSummary, *this);
+
+ bool isTrackedLoc = false;
+
+ // Effects on the receiver.
+ if (MD->getAttr<NSConsumesSelfAttr>()) {
+ if (!GCEnabled)
+ Template->setReceiverEffect(DecRefMsg);
+ }
+
+ // Effects on the parameters.
+ unsigned parm_idx = 0;
+ for (ObjCMethodDecl::param_iterator pi=MD->param_begin(), pe=MD->param_end();
+ pi != pe; ++pi, ++parm_idx) {
+ const ParmVarDecl *pd = *pi;
+ if (pd->getAttr<NSConsumedAttr>()) {
+ if (!GCEnabled)
+ Template->addArg(AF, parm_idx, DecRef);
+ }
+ else if(pd->getAttr<CFConsumedAttr>()) {
+ Template->addArg(AF, parm_idx, DecRef);
+ }
+ }
+
+ // Determine if there is a special return effect for this method.
+ if (cocoa::isCocoaObjectRef(MD->getResultType())) {
+ if (MD->getAttr<NSReturnsRetainedAttr>()) {
+ Template->setRetEffect(ObjCAllocRetE);
+ return;
+ }
+ if (MD->getAttr<NSReturnsNotRetainedAttr>()) {
+ Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC));
+ return;
+ }
+
+ isTrackedLoc = true;
+ } else {
+ isTrackedLoc = MD->getResultType()->getAs<PointerType>() != NULL;
+ }
+
+ if (isTrackedLoc) {
+ if (MD->getAttr<CFReturnsRetainedAttr>())
+ Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true));
+ else if (MD->getAttr<CFReturnsNotRetainedAttr>())
+ Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF));
+ }
+}
+
+RetainSummary*
+RetainSummaryManager::getCommonMethodSummary(const ObjCMethodDecl *MD,
+ Selector S, QualType RetTy) {
+
+ if (MD) {
+ // Scan the method decl for 'void*' arguments. These should be treated
+ // as 'StopTracking' because they are often used with delegates.
+ // Delegates are a frequent form of false positives with the retain
+ // count checker.
+ unsigned i = 0;
+ for (ObjCMethodDecl::param_iterator I = MD->param_begin(),
+ E = MD->param_end(); I != E; ++I, ++i)
+ if (ParmVarDecl *PD = *I) {
+ QualType Ty = Ctx.getCanonicalType(PD->getType());
+ if (Ty.getLocalUnqualifiedType() == Ctx.VoidPtrTy)
+ ScratchArgs = AF.add(ScratchArgs, i, StopTracking);
+ }
+ }
+
+ // Any special effect for the receiver?
+ ArgEffect ReceiverEff = DoNothing;
+
+ // 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()) {
+ const std::string &str = S.getAsString();
+ assert(!str.empty());
+ if (StrInStrNoCase(str, "delegate:") != StringRef::npos)
+ ReceiverEff = StopTracking;
+ }
+
+ // Look for methods that return an owned object.
+ if (cocoa::isCocoaObjectRef(RetTy)) {
+ // EXPERIMENTAL: assume the Cocoa conventions for all objects returned
+ // by instance methods.
+ RetEffect E = cocoa::followsFundamentalRule(S, MD)
+ ? ObjCAllocRetE : RetEffect::MakeNotOwned(RetEffect::ObjC);
+
+ return getPersistentSummary(E, ReceiverEff, MayEscape);
+ }
+
+ // Look for methods that return an owned core foundation object.
+ if (coreFoundation::isCFObjectRef(RetTy)) {
+ RetEffect E = cocoa::followsFundamentalRule(S, MD)
+ ? RetEffect::MakeOwned(RetEffect::CF, true)
+ : RetEffect::MakeNotOwned(RetEffect::CF);
+
+ return getPersistentSummary(E, ReceiverEff, MayEscape);
+ }
+
+ if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing)
+ return 0;
+
+ return getPersistentSummary(RetEffect::MakeNoRet(), ReceiverEff, MayEscape);
+}
+
+RetainSummary*
+RetainSummaryManager::getInstanceMethodSummary(const ObjCMessage &msg,
+ const ProgramState *state,
+ const LocationContext *LC) {
+
+ // We need the type-information of the tracked receiver object
+ // Retrieve it from the state.
+ const Expr *Receiver = msg.getInstanceReceiver();
+ const ObjCInterfaceDecl *ID = 0;
+
+ // FIXME: Is this really working as expected? There are cases where
+ // we just use the 'ID' from the message expression.
+ SVal receiverV;
+
+ if (Receiver) {
+ receiverV = state->getSValAsScalarOrLoc(Receiver);
+
+ // FIXME: Eventually replace the use of state->get<RefBindings> with
+ // a generic API for reasoning about the Objective-C types of symbolic
+ // objects.
+ if (SymbolRef Sym = receiverV.getAsLocSymbol())
+ if (const RefVal *T = state->get<RefBindings>(Sym))
+ if (const ObjCObjectPointerType* PT =
+ T->getType()->getAs<ObjCObjectPointerType>())
+ ID = PT->getInterfaceDecl();
+
+ // FIXME: this is a hack. This may or may not be the actual method
+ // that is called.
+ if (!ID) {
+ if (const ObjCObjectPointerType *PT =
+ Receiver->getType()->getAs<ObjCObjectPointerType>())
+ ID = PT->getInterfaceDecl();
+ }
+ } else {
+ // FIXME: Hack for 'super'.
+ ID = msg.getReceiverInterface();
+ }
+
+ // FIXME: The receiver could be a reference to a class, meaning that
+ // we should use the class method.
+ return getInstanceMethodSummary(msg, ID);
+}
+
+RetainSummary*
+RetainSummaryManager::getInstanceMethodSummary(Selector S,
+ IdentifierInfo *ClsName,
+ const ObjCInterfaceDecl *ID,
+ const ObjCMethodDecl *MD,
+ QualType RetTy) {
+
+ // Look up a summary in our summary cache.
+ RetainSummary *Summ = ObjCMethodSummaries.find(ID, ClsName, S);
+
+ if (!Summ) {
+ assert(ScratchArgs.isEmpty());
+
+ // "initXXX": pass-through for receiver.
+ if (cocoa::deriveNamingConvention(S, MD) == cocoa::InitRule)
+ Summ = getInitMethodSummary(RetTy);
+ else
+ Summ = getCommonMethodSummary(MD, S, RetTy);
+
+ // Annotations override defaults.
+ updateSummaryFromAnnotations(Summ, MD);
+
+ // Memoize the summary.
+ ObjCMethodSummaries[ObjCSummaryKey(ID, ClsName, S)] = Summ;
+ }
+
+ return Summ;
+}
+
+RetainSummary*
+RetainSummaryManager::getClassMethodSummary(Selector S, IdentifierInfo *ClsName,
+ const ObjCInterfaceDecl *ID,
+ const ObjCMethodDecl *MD,
+ QualType RetTy) {
+
+ assert(ClsName && "Class name must be specified.");
+ RetainSummary *Summ = ObjCClassMethodSummaries.find(ID, ClsName, S);
+
+ if (!Summ) {
+ Summ = getCommonMethodSummary(MD, S, RetTy);
+
+ // Annotations override defaults.
+ updateSummaryFromAnnotations(Summ, MD);
+
+ // Memoize the summary.
+ ObjCClassMethodSummaries[ObjCSummaryKey(ID, ClsName, 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));
+
+ // Create the summaries for [NSObject performSelector...]. We treat
+ // these as 'stop tracking' for the arguments because they are often
+ // used for delegates that can release the object. When we have better
+ // inter-procedural analysis we can potentially do something better. This
+ // workaround is to remove false positives.
+ RetainSummary *Summ =
+ getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, StopTracking);
+ IdentifierInfo *NSObjectII = &Ctx.Idents.get("NSObject");
+ addClsMethSummary(NSObjectII, Summ, "performSelector", "withObject",
+ "afterDelay", NULL);
+ addClsMethSummary(NSObjectII, Summ, "performSelector", "withObject",
+ "afterDelay", "inModes", NULL);
+ addClsMethSummary(NSObjectII, Summ, "performSelectorOnMainThread",
+ "withObject", "waitUntilDone", NULL);
+ addClsMethSummary(NSObjectII, Summ, "performSelectorOnMainThread",
+ "withObject", "waitUntilDone", "modes", NULL);
+ addClsMethSummary(NSObjectII, Summ, "performSelector", "onThread",
+ "withObject", "waitUntilDone", NULL);
+ addClsMethSummary(NSObjectII, Summ, "performSelector", "onThread",
+ "withObject", "waitUntilDone", "modes", NULL);
+ addClsMethSummary(NSObjectII, Summ, "performSelectorInBackground",
+ "withObject", NULL);
+}
+
+void RetainSummaryManager::InitializeMethodSummaries() {
+
+ assert (ScratchArgs.isEmpty());
+
+ // Create the "init" selector. It just acts as a pass-through for the
+ // receiver.
+ 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.
+ RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE);
+ RetainSummary *CFAllocSumm =
+ getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true));
+
+ // Create the "retain" selector.
+ RetEffect NoRet = RetEffect::MakeNoRet();
+ 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 "drain" selector.
+ Summ = getPersistentSummary(NoRet, isGCEnabled() ? DoNothing : DecRef);
+ addNSObjectMethSummary(GetNullarySelector("drain", 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);
+
+ // Specially handle NSAutoreleasePool.
+ addInstMethSummary("NSAutoreleasePool", "init",
+ getPersistentSummary(NoRet, NewAutoreleasePool));
+
+ // 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.
+ RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(),
+ StopTracking,
+ StopTracking);
+
+ addClassMethSummary("NSWindow", "alloc", NoTrackYet);
+
+#if 0
+ addInstMethSummary("NSWindow", NoTrackYet, "initWithContentRect",
+ "styleMask", "backing", "defer", NULL);
+
+ addInstMethSummary("NSWindow", NoTrackYet, "initWithContentRect",
+ "styleMask", "backing", "defer", "screen", NULL);
+#endif
+
+ // 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);
+
+#if 0
+ addInstMethSummary("NSPanel", NoTrackYet, "initWithContentRect",
+ "styleMask", "backing", "defer", NULL);
+
+ addInstMethSummary("NSPanel", NoTrackYet, "initWithContentRect",
+ "styleMask", "backing", "defer", "screen", NULL);
+#endif
+
+ // Don't track allocated autorelease pools yet, as it is okay to prematurely
+ // exit a method.
+ addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet);
+
+ // Create summaries QCRenderer/QCView -createSnapShotImageOfType:
+ addInstMethSummary("QCRenderer", AllocSumm,
+ "createSnapshotImageOfType", NULL);
+ addInstMethSummary("QCView", AllocSumm,
+ "createSnapshotImageOfType", NULL);
+
+ // Create summaries for CIContext, 'createCGImage' and
+ // 'createCGLayerWithSize'. These objects are CF objects, and are not
+ // automatically garbage collected.
+ addInstMethSummary("CIContext", CFAllocSumm,
+ "createCGImage", "fromRect", NULL);
+ addInstMethSummary("CIContext", CFAllocSumm,
+ "createCGImage", "fromRect", "format", "colorSpace", NULL);
+ addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize",
+ "info", NULL);
+}
+
+//===----------------------------------------------------------------------===//
+// AutoreleaseBindings - State used to track objects in autorelease pools.
+//===----------------------------------------------------------------------===//
+
+typedef llvm::ImmutableMap<SymbolRef, unsigned> ARCounts;
+typedef llvm::ImmutableMap<SymbolRef, ARCounts> ARPoolContents;
+typedef llvm::ImmutableList<SymbolRef> ARStack;
+
+static int AutoRCIndex = 0;
+static int AutoRBIndex = 0;
+
+namespace { class AutoreleasePoolContents {}; }
+namespace { class AutoreleaseStack {}; }
+
+namespace clang {
+namespace ento {
+template<> struct ProgramStateTrait<AutoreleaseStack>
+ : public ProgramStatePartialTrait<ARStack> {
+ static inline void *GDMIndex() { return &AutoRBIndex; }
+};
+
+template<> struct ProgramStateTrait<AutoreleasePoolContents>
+ : public ProgramStatePartialTrait<ARPoolContents> {
+ static inline void *GDMIndex() { return &AutoRCIndex; }
+};
+} // end GR namespace
+} // end clang namespace
+
+static SymbolRef GetCurrentAutoreleasePool(const ProgramState *state) {
+ ARStack stack = state->get<AutoreleaseStack>();
+ return stack.isEmpty() ? SymbolRef() : stack.getHead();
+}
+
+static const ProgramState *
+SendAutorelease(const ProgramState *state,
+ ARCounts::Factory &F,
+ SymbolRef sym) {
+ SymbolRef pool = GetCurrentAutoreleasePool(state);
+ const ARCounts *cnts = state->get<AutoreleasePoolContents>(pool);
+ ARCounts newCnts(0);
+
+ if (cnts) {
+ const unsigned *cnt = (*cnts).lookup(sym);
+ newCnts = F.add(*cnts, sym, cnt ? *cnt + 1 : 1);
+ }
+ else
+ newCnts = F.add(F.getEmptyMap(), sym, 1);
+
+ return state->set<AutoreleasePoolContents>(pool, newCnts);
+}
+
+//===----------------------------------------------------------------------===//
+// Error reporting.
+//===----------------------------------------------------------------------===//
+namespace {
+ typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *>
+ SummaryLogTy;
+
+ //===-------------===//
+ // Bug Descriptions. //
+ //===-------------===//
+
+ class CFRefBug : public BugType {
+ protected:
+ CFRefBug(StringRef name)
+ : BugType(name, "Memory (Core Foundation/Objective-C)") {}
+ public:
+
+ // FIXME: Eventually remove.
+ virtual const char *getDescription() const = 0;
+
+ virtual bool isLeak() const { return false; }
+ };
+
+ class UseAfterRelease : public CFRefBug {
+ public:
+ UseAfterRelease() : CFRefBug("Use-after-release") {}
+
+ const char *getDescription() const {
+ return "Reference-counted object is used after it is released";
+ }
+ };
+
+ class BadRelease : public CFRefBug {
+ public:
+ BadRelease() : CFRefBug("Bad release") {}
+
+ const char *getDescription() const {
+ 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()
+ : CFRefBug("-dealloc called while using garbage collection") {}
+
+ const char *getDescription() const {
+ return "-dealloc called while using garbage collection";
+ }
+ };
+
+ class DeallocNotOwned : public CFRefBug {
+ public:
+ DeallocNotOwned()
+ : CFRefBug("-dealloc sent to non-exclusively owned object") {}
+
+ const char *getDescription() const {
+ return "-dealloc sent to object that may be referenced elsewhere";
+ }
+ };
+
+ class OverAutorelease : public CFRefBug {
+ public:
+ OverAutorelease()
+ : CFRefBug("Object sent -autorelease too many times") {}
+
+ const char *getDescription() const {
+ return "Object sent -autorelease too many times";
+ }
+ };
+
+ class ReturnedNotOwnedForOwned : public CFRefBug {
+ public:
+ ReturnedNotOwnedForOwned()
+ : CFRefBug("Method should return an owned object") {}
+
+ const char *getDescription() const {
+ return "Object with a +0 retain count returned to caller where a +1 "
+ "(owning) retain count is expected";
+ }
+ };
+
+ class Leak : public CFRefBug {
+ const bool isReturn;
+ protected:
+ Leak(StringRef name, bool isRet)
+ : CFRefBug(name), isReturn(isRet) {
+ // Leaks should not be reported if they are post-dominated by a sink.
+ setSuppressOnSink(true);
+ }
+ public:
+
+ const char *getDescription() const { return ""; }
+
+ bool isLeak() const { return true; }
+ };
+
+ class LeakAtReturn : public Leak {
+ public:
+ LeakAtReturn(StringRef name)
+ : Leak(name, true) {}
+ };
+
+ class LeakWithinFunction : public Leak {
+ public:
+ LeakWithinFunction(StringRef name)
+ : Leak(name, false) {}
+ };
+
+ //===---------===//
+ // 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) {}
+
+ virtual void Profile(llvm::FoldingSetNodeID &ID) const {
+ static int x = 0;
+ ID.AddPointer(&x);
+ ID.AddPointer(Sym);
+ }
+
+ virtual PathDiagnosticPiece *VisitNode(const ExplodedNode *N,
+ const ExplodedNode *PrevN,
+ BugReporterContext &BRC,
+ BugReport &BR);
+
+ virtual PathDiagnosticPiece *getEndPath(BugReporterContext &BRC,
+ const ExplodedNode *N,
+ BugReport &BR);
+ };
+
+ class CFRefLeakReportVisitor : public CFRefReportVisitor {
+ public:
+ CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled,
+ const SummaryLogTy &log)
+ : CFRefReportVisitor(sym, GCEnabled, log) {}
+
+ PathDiagnosticPiece *getEndPath(BugReporterContext &BRC,
+ const ExplodedNode *N,
+ BugReport &BR);
+ };
+
+ 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(new 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(new CFRefReportVisitor(sym, GCEnabled, Log));
+ addGCModeDescription(LOpts, GCEnabled);
+ }
+
+ virtual std::pair<ranges_iterator, ranges_iterator> getRanges() {
+ const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType());
+ if (!BugTy.isLeak())
+ return BugReport::getRanges();
+ else
+ return std::make_pair(ranges_iterator(), ranges_iterator());
+ }
+ };
+
+ class CFRefLeakReport : public CFRefReport {
+ SourceLocation AllocSite;
+ const MemRegion* AllocBinding;
+
+ public:
+ CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled,
+ const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym,
+ ExprEngine &Eng);
+
+ SourceLocation getLocation() const { return AllocSite; }
+ };
+} // end anonymous namespace
+
+void CFRefReport::addGCModeDescription(const LangOptions &LOpts,
+ bool GCEnabled) {
+ const char *GCModeDescription = 0;
+
+ switch (LOpts.getGCMode()) {
+ 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);
+}
+
+// FIXME: This should be a method on SmallVector.
+static inline bool contains(const SmallVectorImpl<ArgEffect>& V,
+ ArgEffect X) {
+ for (SmallVectorImpl<ArgEffect>::const_iterator I=V.begin(), E=V.end();
+ I!=E; ++I)
+ if (*I == X) return true;
+
+ return false;
+}
+
+PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N,
+ const ExplodedNode *PrevN,
+ BugReporterContext &BRC,
+ BugReport &BR) {
+
+ if (!isa<StmtPoint>(N->getLocation()))
+ return NULL;
+
+ // Check if the type state has changed.
+ const ProgramState *PrevSt = PrevN->getState();
+ const ProgramState *CurrSt = N->getState();
+
+ const RefVal* CurrT = CurrSt->get<RefBindings>(Sym);
+ if (!CurrT) return NULL;
+
+ const RefVal &CurrV = *CurrT;
+ const RefVal *PrevT = PrevSt->get<RefBindings>(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 = cast<StmtPoint>(N->getLocation()).getStmt();
+
+ if (const CallExpr *CE = dyn_cast<CallExpr>(S)) {
+ // Get the name of the callee (if it is available).
+ SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee());
+ if (const FunctionDecl *FD = X.getAsFunctionDecl())
+ os << "Call to function '" << FD << '\'';
+ else
+ os << "function call";
+ }
+ else if (isa<ObjCMessageExpr>(S)) {
+ os << "Method";
+ } else {
+ os << "Property";
+ }
+
+ if (CurrV.getObjKind() == RetEffect::CF) {
+ os << " returns a Core Foundation object with a ";
+ }
+ else {
+ assert (CurrV.getObjKind() == RetEffect::ObjC);
+ os << " returns an Objective-C object 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());
+ return new 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 = cast<StmtPoint>(N->getLocation()).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).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).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 && contains(AEffects, Dealloc)) {
+ // Determine if the object's reference count was pushed to zero.
+ assert(!(PrevV == CurrV) && "The typestate *must* 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 (contains(AEffects, MakeCollectable)) {
+ // Get the name of the function.
+ const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt();
+ SVal X = CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee());
+ const FunctionDecl *FD = X.getAsFunctionDecl();
+
+ if (GCEnabled) {
+ // Determine if the object's reference count was pushed to zero.
+ assert(!(PrevV == CurrV) && "The typestate *must* 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 == 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 0;
+
+ assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount());
+ os << "Object sent -autorelease message";
+ 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:
+ os << "Object released.";
+ break;
+
+ case RefVal::ReturnedOwned:
+ 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 NULL;
+ }
+
+ // 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 0; // We have nothing to say!
+
+ const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt();
+ PathDiagnosticLocation Pos(S, BRC.getSourceManager());
+ PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str());
+
+ // Add the range by scanning the children of the statement for any bindings
+ // to Sym.
+ for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end();
+ I!=E; ++I)
+ if (const Expr *Exp = dyn_cast_or_null<Expr>(*I))
+ if (CurrSt->getSValAsScalarOrLoc(Exp).getAsLocSymbol() == Sym) {
+ P->addRange(Exp->getSourceRange());
+ break;
+ }
+
+ return P;
+}
+
+namespace {
+ class FindUniqueBinding :
+ public StoreManager::BindingsHandler {
+ SymbolRef Sym;
+ const MemRegion* Binding;
+ bool First;
+
+ public:
+ FindUniqueBinding(SymbolRef sym) : Sym(sym), Binding(0), First(true) {}
+
+ bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R,
+ SVal val) {
+
+ SymbolRef SymV = val.getAsSymbol();
+ if (!SymV || SymV != Sym)
+ return true;
+
+ if (Binding) {
+ First = false;
+ return false;
+ }
+ else
+ Binding = R;
+
+ return true;
+ }
+
+ operator bool() { return First && Binding; }
+ const MemRegion* getRegion() { return Binding; }
+ };
+}
+
+static std::pair<const ExplodedNode*,const MemRegion*>
+GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N,
+ SymbolRef Sym) {
+
+ // Find both first node that referred to the tracked symbol and the
+ // memory location that value was store to.
+ const ExplodedNode *Last = N;
+ const MemRegion* FirstBinding = 0;
+
+ while (N) {
+ const ProgramState *St = N->getState();
+ RefBindings B = St->get<RefBindings>();
+
+ if (!B.lookup(Sym))
+ break;
+
+ FindUniqueBinding FB(Sym);
+ StateMgr.iterBindings(St, FB);
+ if (FB) FirstBinding = FB.getRegion();
+
+ Last = N;
+ N = N->pred_empty() ? NULL : *(N->pred_begin());
+ }
+
+ return std::make_pair(Last, FirstBinding);
+}
+
+PathDiagnosticPiece*
+CFRefReportVisitor::getEndPath(BugReporterContext &BRC,
+ const ExplodedNode *EndN,
+ BugReport &BR) {
+ // Tell the BugReporterContext to report cases when the tracked symbol is
+ // assigned to different variables, etc.
+ BRC.addNotableSymbol(Sym);
+ return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR);
+}
+
+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.
+ BRC.addNotableSymbol(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.
+ const ExplodedNode *AllocNode = 0;
+ const MemRegion* FirstBinding = 0;
+
+ llvm::tie(AllocNode, FirstBinding) =
+ GetAllocationSite(BRC.getStateManager(), EndN, Sym);
+
+ SourceManager& SMgr = 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;
+
+ while (LeakN) {
+ ProgramPoint P = LeakN->getLocation();
+
+ if (const StmtPoint *PS = dyn_cast<StmtPoint>(&P)) {
+ L = PathDiagnosticLocation(PS->getStmt()->getLocStart(), SMgr);
+ break;
+ }
+ else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
+ if (const Stmt *Term = BE->getSrc()->getTerminator()) {
+ L = PathDiagnosticLocation(Term->getLocStart(), SMgr);
+ break;
+ }
+ }
+
+ LeakN = LeakN->succ_empty() ? 0 : *(LeakN->succ_begin());
+ }
+
+ if (!L.isValid()) {
+ const Decl &D = EndN->getCodeDecl();
+ L = PathDiagnosticLocation(D.getBodyRBrace(), SMgr);
+ }
+
+ std::string sbuf;
+ llvm::raw_string_ostream os(sbuf);
+
+ os << "Object leaked: ";
+
+ if (FirstBinding) {
+ os << "object allocated and stored into '"
+ << FirstBinding->getString() << '\'';
+ }
+ else
+ os << "allocated object";
+
+ // Get the retain count.
+ const RefVal* RV = EndN->getState()->get<RefBindings>(Sym);
+
+ 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();
+ if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
+ os << " is returned from a method 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 << " is return from a function whose name ('"
+ << FD->getNameAsString()
+ << "') does not contain 'Copy' or 'Create'. This violates the naming"
+ " convention rules given the Memory Management Guide for Core"
+ " Foundation";
+ }
+ }
+ else if (RV->getKind() == RefVal::ErrorGCLeakReturned) {
+ 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 new PathDiagnosticEventPiece(L, os.str());
+}
+
+CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts,
+ bool GCEnabled, const SummaryLogTy &Log,
+ ExplodedNode *n, SymbolRef sym,
+ ExprEngine &Eng)
+: CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) {
+
+ // 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 = 0;
+
+ llvm::tie(AllocNode, AllocBinding) = // Set AllocBinding.
+ GetAllocationSite(Eng.getStateManager(), getErrorNode(), sym);
+
+ // Get the SourceLocation for the allocation site.
+ ProgramPoint P = AllocNode->getLocation();
+ AllocSite = cast<PostStmt>(P).getStmt()->getLocStart();
+
+ // Fill in the description of the bug.
+ Description.clear();
+ llvm::raw_string_ostream os(Description);
+ SourceManager& SMgr = Eng.getContext().getSourceManager();
+ unsigned AllocLine = SMgr.getExpansionLineNumber(AllocSite);
+ os << "Potential leak ";
+ if (GCEnabled)
+ os << "(when using garbage collection) ";
+ os << "of an object allocated on line " << AllocLine;
+
+ // FIXME: AllocBinding doesn't get populated for RegionStore yet.
+ if (AllocBinding)
+ os << " and stored into '" << AllocBinding->getString() << '\'';
+
+ addVisitor(new CFRefLeakReportVisitor(sym, GCEnabled, Log));
+}
+
+//===----------------------------------------------------------------------===//
+// Main checker logic.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class RetainCountChecker
+ : public Checker< check::Bind,
+ check::DeadSymbols,
+ check::EndAnalysis,
+ check::EndPath,
+ check::PostStmt<BlockExpr>,
+ check::PostStmt<CastExpr>,
+ check::PostStmt<CallExpr>,
+ check::PostStmt<CXXConstructExpr>,
+ check::PostObjCMessage,
+ check::PreStmt<ReturnStmt>,
+ check::RegionChanges,
+ eval::Assume,
+ eval::Call > {
+ mutable llvm::OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned;
+ mutable llvm::OwningPtr<CFRefBug> deallocGC, deallocNotOwned;
+ mutable llvm::OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned;
+ mutable llvm::OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn;
+ mutable llvm::OwningPtr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC;
+
+ typedef llvm::DenseMap<SymbolRef, const SimpleProgramPointTag *> SymbolTagMap;
+
+ // This map is only used to ensure proper deletion of any allocated tags.
+ mutable SymbolTagMap DeadSymbolTags;
+
+ mutable llvm::OwningPtr<RetainSummaryManager> Summaries;
+ mutable llvm::OwningPtr<RetainSummaryManager> SummariesGC;
+
+ mutable ARCounts::Factory ARCountFactory;
+
+ mutable SummaryLogTy SummaryLog;
+ mutable bool ShouldResetSummaryLog;
+
+public:
+ RetainCountChecker() : ShouldResetSummaryLog(false) {}
+
+ virtual ~RetainCountChecker() {
+ 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 LeakWithinFunction("Leak of object when "
+ "using garbage "
+ "collection"));
+ return leakWithinFunctionGC.get();
+ } else {
+ if (!leakWithinFunction) {
+ if (LOpts.getGCMode() == LangOptions::HybridGC) {
+ leakWithinFunction.reset(new LeakWithinFunction("Leak of object when "
+ "not using garbage "
+ "collection (GC) in "
+ "dual GC/non-GC "
+ "code"));
+ } else {
+ leakWithinFunction.reset(new LeakWithinFunction("Leak"));
+ }
+ }
+ return leakWithinFunction.get();
+ }
+ }
+
+ CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const {
+ if (GCEnabled) {
+ if (!leakAtReturnGC)
+ leakAtReturnGC.reset(new LeakAtReturn("Leak of returned object when "
+ "using garbage collection"));
+ return leakAtReturnGC.get();
+ } else {
+ if (!leakAtReturn) {
+ if (LOpts.getGCMode() == LangOptions::HybridGC) {
+ leakAtReturn.reset(new LeakAtReturn("Leak of returned object when "
+ "not using garbage collection "
+ "(GC) in dual GC/non-GC code"));
+ } else {
+ leakAtReturn.reset(new LeakAtReturn("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.getLangOptions().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, const ProgramState *State,
+ const char *NL, const char *Sep) const;
+
+ void checkBind(SVal loc, SVal val, CheckerContext &C) const;
+ void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
+ void checkPostStmt(const CastExpr *CE, CheckerContext &C) const;
+
+ void checkPostStmt(const CallExpr *CE, CheckerContext &C) const;
+ void checkPostStmt(const CXXConstructExpr *CE, CheckerContext &C) const;
+ void checkPostObjCMessage(const ObjCMessage &Msg, CheckerContext &C) const;
+ void checkSummary(const RetainSummary &Summ, const CallOrObjCMessage &Call,
+ CheckerContext &C) const;
+
+ bool evalCall(const CallExpr *CE, CheckerContext &C) const;
+
+ const ProgramState *evalAssume(const ProgramState *state, SVal Cond,
+ bool Assumption) const;
+
+ const ProgramState *
+ checkRegionChanges(const ProgramState *state,
+ const StoreManager::InvalidatedSymbols *invalidated,
+ ArrayRef<const MemRegion *> ExplicitRegions,
+ ArrayRef<const MemRegion *> Regions) const;
+
+ bool wantsRegionChangeUpdate(const ProgramState *state) const {
+ return true;
+ }
+
+ void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const;
+ void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C,
+ ExplodedNode *Pred, RetEffect RE, RefVal X,
+ SymbolRef Sym, const ProgramState *state) const;
+
+ void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
+ void checkEndPath(EndOfFunctionNodeBuilder &Builder, ExprEngine &Eng) const;
+
+ const ProgramState *updateSymbol(const ProgramState *state, SymbolRef sym,
+ RefVal V, ArgEffect E, RefVal::Kind &hasErr,
+ CheckerContext &C) const;
+
+ void processNonLeakError(const ProgramState *St, SourceRange ErrorRange,
+ RefVal::Kind ErrorKind, SymbolRef Sym,
+ CheckerContext &C) const;
+
+ const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const;
+
+ const ProgramState *handleSymbolDeath(const ProgramState *state,
+ SymbolRef sid, RefVal V,
+ SmallVectorImpl<SymbolRef> &Leaked) const;
+
+ std::pair<ExplodedNode *, const ProgramState *>
+ handleAutoreleaseCounts(const ProgramState *state,
+ GenericNodeBuilderRefCount Bd, ExplodedNode *Pred,
+ ExprEngine &Eng, SymbolRef Sym, RefVal V) const;
+
+ ExplodedNode *processLeaks(const ProgramState *state,
+ SmallVectorImpl<SymbolRef> &Leaked,
+ GenericNodeBuilderRefCount &Builder,
+ ExprEngine &Eng,
+ ExplodedNode *Pred = 0) const;
+};
+} // end anonymous namespace
+
+namespace {
+class StopTrackingCallback : public SymbolVisitor {
+ const ProgramState *state;
+public:
+ StopTrackingCallback(const ProgramState *st) : state(st) {}
+ const ProgramState *getState() const { return state; }
+
+ bool VisitSymbol(SymbolRef sym) {
+ 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;
+
+ const ProgramState *state = C.getState();
+ const BlockDataRegion *R =
+ cast<BlockDataRegion>(state->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.getPredecessor()->getLocationContext();
+ MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager();
+
+ for ( ; I != E; ++I) {
+ const VarRegion *VR = *I;
+ 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 = DecRefBridgedTransfered;
+ break;
+ }
+
+ const ProgramState *state = C.getState();
+ SymbolRef Sym = state->getSVal(CE).getAsLocSymbol();
+ if (!Sym)
+ return;
+ const RefVal* T = state->get<RefBindings>(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?
+ // Should we assert that there is no error?
+ return;
+ }
+
+ C.generateNode(state);
+}
+
+void RetainCountChecker::checkPostStmt(const CallExpr *CE,
+ CheckerContext &C) const {
+ // Get the callee.
+ const ProgramState *state = C.getState();
+ const Expr *Callee = CE->getCallee();
+ SVal L = state->getSVal(Callee);
+
+ RetainSummaryManager &Summaries = getSummaryManager(C);
+ RetainSummary *Summ = 0;
+
+ // FIXME: Better support for blocks. For now we stop tracking anything
+ // that is passed to blocks.
+ // FIXME: Need to handle variables that are "captured" by the block.
+ if (dyn_cast_or_null<BlockDataRegion>(L.getAsRegion())) {
+ Summ = Summaries.getPersistentStopSummary();
+ } else if (const FunctionDecl *FD = L.getAsFunctionDecl()) {
+ Summ = Summaries.getSummary(FD);
+ } else if (const CXXMemberCallExpr *me = dyn_cast<CXXMemberCallExpr>(CE)) {
+ if (const CXXMethodDecl *MD = me->getMethodDecl())
+ Summ = Summaries.getSummary(MD);
+ }
+
+ // If we didn't get a summary, this function doesn't affect retain counts.
+ if (!Summ)
+ return;
+
+ checkSummary(*Summ, CallOrObjCMessage(CE, state), C);
+}
+
+void RetainCountChecker::checkPostStmt(const CXXConstructExpr *CE,
+ CheckerContext &C) const {
+ const CXXConstructorDecl *Ctor = CE->getConstructor();
+ if (!Ctor)
+ return;
+
+ RetainSummaryManager &Summaries = getSummaryManager(C);
+ RetainSummary *Summ = Summaries.getSummary(Ctor);
+
+ // If we didn't get a summary, this constructor doesn't affect retain counts.
+ if (!Summ)
+ return;
+
+ const ProgramState *state = C.getState();
+ checkSummary(*Summ, CallOrObjCMessage(CE, state), C);
+}
+
+void RetainCountChecker::checkPostObjCMessage(const ObjCMessage &Msg,
+ CheckerContext &C) const {
+ const ProgramState *state = C.getState();
+ ExplodedNode *Pred = C.getPredecessor();
+
+ RetainSummaryManager &Summaries = getSummaryManager(C);
+
+ RetainSummary *Summ;
+ if (Msg.isInstanceMessage()) {
+ const LocationContext *LC = Pred->getLocationContext();
+ Summ = Summaries.getInstanceMethodSummary(Msg, state, LC);
+ } else {
+ Summ = Summaries.getClassMethodSummary(Msg);
+ }
+
+ // If we didn't get a summary, this message doesn't affect retain counts.
+ if (!Summ)
+ return;
+
+ checkSummary(*Summ, CallOrObjCMessage(Msg, state), 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 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;
+}
+
+void RetainCountChecker::checkSummary(const RetainSummary &Summ,
+ const CallOrObjCMessage &CallOrMsg,
+ CheckerContext &C) const {
+ const ProgramState *state = C.getState();
+
+ // Evaluate the effect of the arguments.
+ RefVal::Kind hasErr = (RefVal::Kind) 0;
+ SourceRange ErrorRange;
+ SymbolRef ErrorSym = 0;
+
+ for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) {
+ SVal V = CallOrMsg.getArgSVal(idx);
+
+ if (SymbolRef Sym = V.getAsLocSymbol()) {
+ if (RefBindings::data_type *T = state->get<RefBindings>(Sym)) {
+ state = updateSymbol(state, Sym, *T, Summ.getArg(idx), hasErr, C);
+ if (hasErr) {
+ ErrorRange = CallOrMsg.getArgSourceRange(idx);
+ ErrorSym = Sym;
+ break;
+ }
+ }
+ }
+ }
+
+ // Evaluate the effect on the message receiver.
+ bool ReceiverIsTracked = false;
+ if (!hasErr && CallOrMsg.isObjCMessage()) {
+ const LocationContext *LC = C.getPredecessor()->getLocationContext();
+ SVal Receiver = CallOrMsg.getInstanceMessageReceiver(LC);
+ if (SymbolRef Sym = Receiver.getAsLocSymbol()) {
+ if (const RefVal *T = state->get<RefBindings>(Sym)) {
+ ReceiverIsTracked = true;
+ state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(),
+ hasErr, C);
+ if (hasErr) {
+ ErrorRange = CallOrMsg.getReceiverSourceRange();
+ 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."); break;
+
+ case RetEffect::NoRet:
+ // No work necessary.
+ break;
+
+ case RetEffect::OwnedAllocatedSymbol:
+ case RetEffect::OwnedSymbol: {
+ SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr()).getAsSymbol();
+ if (!Sym)
+ break;
+
+ // Use the result type from callOrMsg as it automatically adjusts
+ // for methods/functions that return references.
+ QualType ResultTy = CallOrMsg.getResultType(C.getASTContext());
+ state = state->set<RefBindings>(Sym, RefVal::makeOwned(RE.getObjKind(),
+ ResultTy));
+
+ // FIXME: Add a flag to the checker where allocations are assumed to
+ // *not* fail. (The code below is out-of-date, though.)
+#if 0
+ if (RE.getKind() == RetEffect::OwnedAllocatedSymbol) {
+ bool isFeasible;
+ state = state.assume(loc::SymbolVal(Sym), true, isFeasible);
+ assert(isFeasible && "Cannot assume fresh symbol is non-null.");
+ }
+#endif
+
+ break;
+ }
+
+ case RetEffect::GCNotOwnedSymbol:
+ case RetEffect::ARCNotOwnedSymbol:
+ case RetEffect::NotOwnedSymbol: {
+ const Expr *Ex = CallOrMsg.getOriginExpr();
+ SymbolRef Sym = state->getSVal(Ex).getAsSymbol();
+ if (!Sym)
+ break;
+
+ // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *.
+ QualType ResultTy = GetReturnType(Ex, C.getASTContext());
+ state = state->set<RefBindings>(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.generateNode(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;
+ }
+}
+
+
+const ProgramState *
+RetainCountChecker::updateSymbol(const ProgramState *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().getLangOptions().ObjCAutoRefCount;
+
+ switch (E) {
+ default: break;
+ case IncRefMsg: E = IgnoreRetainMsg ? DoNothing : IncRef; break;
+ case DecRefMsg: E = IgnoreRetainMsg ? DoNothing : DecRef; break;
+ case MakeCollectable: E = C.isObjCGCEnabled() ? DecRef : DoNothing; break;
+ case NewAutoreleasePool: E = C.isObjCGCEnabled() ? DoNothing :
+ NewAutoreleasePool; break;
+ }
+
+ // Handle all use-after-releases.
+ if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) {
+ V = V ^ RefVal::ErrorUseAfterRelease;
+ hasErr = V.getKind();
+ return state->set<RefBindings>(sym, V);
+ }
+
+ switch (E) {
+ case DecRefMsg:
+ case IncRefMsg:
+ case MakeCollectable:
+ llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted");
+ return 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.");
+ break;
+ case RefVal::Owned:
+ // The object immediately transitions to the released state.
+ V = V ^ RefVal::Released;
+ V.clearCounts();
+ return state->set<RefBindings>(sym, V);
+ case RefVal::NotOwned:
+ V = V ^ RefVal::ErrorDeallocNotOwned;
+ hasErr = V.getKind();
+ break;
+ }
+ break;
+
+ case NewAutoreleasePool:
+ assert(!C.isObjCGCEnabled());
+ return state->add<AutoreleaseStack>(sym);
+
+ 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.
+ state = SendAutorelease(state, ARCountFactory, sym);
+ V = V.autorelease();
+ break;
+
+ case StopTracking:
+ return state->remove<RefBindings>(sym);
+
+ case IncRef:
+ switch (V.getKind()) {
+ default:
+ llvm_unreachable("Invalid RefVal state for a retain.");
+ break;
+ 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 SelfOwn:
+ V = V ^ RefVal::NotOwned;
+ // Fall-through.
+ case DecRef:
+ case DecRefBridgedTransfered:
+ switch (V.getKind()) {
+ default:
+ // case 'RefVal::Released' handled above.
+ llvm_unreachable("Invalid RefVal state for a release.");
+ break;
+
+ case RefVal::Owned:
+ assert(V.getCount() > 0);
+ if (V.getCount() == 1)
+ V = V ^ (E == DecRefBridgedTransfered ?
+ RefVal::NotOwned : RefVal::Released);
+ V = V - 1;
+ break;
+
+ case RefVal::NotOwned:
+ if (V.getCount() > 0)
+ V = V - 1;
+ 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 state->set<RefBindings>(sym, V);
+}
+
+void RetainCountChecker::processNonLeakError(const ProgramState *St,
+ SourceRange ErrorRange,
+ RefVal::Kind ErrorKind,
+ SymbolRef Sym,
+ CheckerContext &C) const {
+ ExplodedNode *N = C.generateSink(St);
+ if (!N)
+ return;
+
+ CFRefBug *BT;
+ switch (ErrorKind) {
+ default:
+ llvm_unreachable("Unhandled error.");
+ return;
+ case RefVal::ErrorUseAfterRelease:
+ if (!useAfterRelease)
+ useAfterRelease.reset(new UseAfterRelease());
+ BT = &*useAfterRelease;
+ break;
+ case RefVal::ErrorReleaseNotOwned:
+ if (!releaseNotOwned)
+ releaseNotOwned.reset(new BadRelease());
+ BT = &*releaseNotOwned;
+ break;
+ case RefVal::ErrorDeallocGC:
+ if (!deallocGC)
+ deallocGC.reset(new DeallocGC());
+ BT = &*deallocGC;
+ break;
+ case RefVal::ErrorDeallocNotOwned:
+ if (!deallocNotOwned)
+ deallocNotOwned.reset(new DeallocNotOwned());
+ BT = &*deallocNotOwned;
+ break;
+ }
+
+ assert(BT);
+ CFRefReport *report = new CFRefReport(*BT, C.getASTContext().getLangOptions(),
+ C.isObjCGCEnabled(), SummaryLog,
+ N, Sym);
+ report->addRange(ErrorRange);
+ C.EmitReport(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.
+ const ProgramState *state = C.getState();
+ const Expr *Callee = CE->getCallee();
+ SVal L = state->getSVal(Callee);
+
+ const FunctionDecl *FD = L.getAsFunctionDecl();
+ 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;
+
+ QualType ResultTy = FD->getResultType();
+ if (ResultTy->isObjCIdType()) {
+ // Handle: id NSMakeCollectable(CFTypeRef)
+ canEval = II->isStr("NSMakeCollectable");
+ } else if (ResultTy->isPointerType()) {
+ // Handle: (CF|CG)Retain
+ // 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)) {
+ canEval = isRetain(FD, FName) || isMakeCollectable(FD, FName);
+ }
+ }
+
+ if (!canEval)
+ return false;
+
+ // Bind the return value.
+ SVal RetVal = state->getSVal(CE->getArg(0));
+ if (RetVal.isUnknown()) {
+ // If the receiver is unknown, conjure a return value.
+ SValBuilder &SVB = C.getSValBuilder();
+ unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
+ SVal RetVal = SVB.getConjuredSymbolVal(0, CE, ResultTy, Count);
+ }
+ state = state->BindExpr(CE, 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();
+ RefBindings::data_type *Binding = 0;
+ if (Sym)
+ Binding = state->get<RefBindings>(Sym);
+
+ // Invalidate the argument region.
+ unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
+ state = state->invalidateRegions(ArgRegion, CE, Count);
+
+ // Restore the refcount status of the argument.
+ if (Binding)
+ state = state->set<RefBindings>(Sym, *Binding);
+ }
+
+ C.addTransition(state);
+ return true;
+}
+
+//===----------------------------------------------------------------------===//
+// Handle return statements.
+//===----------------------------------------------------------------------===//
+
+void RetainCountChecker::checkPreStmt(const ReturnStmt *S,
+ CheckerContext &C) const {
+ const Expr *RetE = S->getRetValue();
+ if (!RetE)
+ return;
+
+ const ProgramState *state = C.getState();
+ SymbolRef Sym = state->getSValAsScalarOrLoc(RetE).getAsLocSymbol();
+ if (!Sym)
+ return;
+
+ // Get the reference count binding (if any).
+ const RefVal *T = state->get<RefBindings>(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 = state->set<RefBindings>(Sym, X);
+ ExplodedNode *Pred = C.generateNode(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 SimpleProgramPointTag
+ AutoreleaseTag("RetainCountChecker : Autorelease");
+ GenericNodeBuilderRefCount Bd(C.getNodeBuilder(), S, &AutoreleaseTag);
+ llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred,
+ C.getEngine(), Sym, X);
+
+ // Did we cache out?
+ if (!Pred)
+ return;
+
+ // Get the updated binding.
+ T = state->get<RefBindings>(Sym);
+ assert(T);
+ X = *T;
+
+ // Consult the summary of the enclosing method.
+ RetainSummaryManager &Summaries = getSummaryManager(C);
+ const Decl *CD = &Pred->getCodeDecl();
+
+ if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) {
+ // Unlike regular functions, /all/ ObjC methods are assumed to always
+ // follow Cocoa retain-count conventions, not just those with special
+ // names or attributes.
+ const RetainSummary *Summ = Summaries.getMethodSummary(MD);
+ RetEffect RE = Summ ? Summ->getRetEffect() : RetEffect::MakeNoRet();
+ checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state);
+ }
+
+ if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) {
+ if (!isa<CXXMethodDecl>(FD))
+ if (const RetainSummary *Summ = Summaries.getSummary(FD))
+ checkReturnWithRetEffect(S, C, Pred, Summ->getRetEffect(), X,
+ Sym, state);
+ }
+}
+
+void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S,
+ CheckerContext &C,
+ ExplodedNode *Pred,
+ RetEffect RE, RefVal X,
+ SymbolRef Sym,
+ const ProgramState *state) const {
+ // 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 = state->set<RefBindings>(Sym, X);
+ StmtNodeBuilder &Builder = C.getNodeBuilder();
+
+ static SimpleProgramPointTag
+ ReturnOwnLeakTag("RetainCountChecker : ReturnsOwnLeak");
+ ExplodedNode *N = Builder.generateNode(S, state, Pred,
+ &ReturnOwnLeakTag);
+ if (N) {
+ const LangOptions &LOpts = C.getASTContext().getLangOptions();
+ bool GCEnabled = C.isObjCGCEnabled();
+ CFRefReport *report =
+ new CFRefLeakReport(*getLeakAtReturnBug(LOpts, GCEnabled),
+ LOpts, GCEnabled, SummaryLog,
+ N, Sym, C.getEngine());
+ C.EmitReport(report);
+ }
+ }
+ }
+ } else if (X.isReturnedNotOwned()) {
+ if (RE.isOwned()) {
+ // Trying to return a not owned object to a caller expecting an
+ // owned object.
+ state = state->set<RefBindings>(Sym, X ^ RefVal::ErrorReturnedNotOwned);
+ StmtNodeBuilder &Builder = C.getNodeBuilder();
+
+ static SimpleProgramPointTag
+ ReturnNotOwnedTag("RetainCountChecker : ReturnNotOwnedForOwned");
+ ExplodedNode *N = Builder.generateNode(S, state, Pred,
+ &ReturnNotOwnedTag);
+ if (N) {
+ if (!returnNotOwnedForOwned)
+ returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned());
+
+ CFRefReport *report =
+ new CFRefReport(*returnNotOwnedForOwned,
+ C.getASTContext().getLangOptions(),
+ C.isObjCGCEnabled(), SummaryLog, N, Sym);
+ C.EmitReport(report);
+ }
+ }
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Check various ways a symbol can be invalidated.
+//===----------------------------------------------------------------------===//
+
+void RetainCountChecker::checkBind(SVal loc, SVal val,
+ 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.
+ const ProgramState *state = C.getState();
+
+ if (loc::MemRegionVal *regionLoc = dyn_cast<loc::MemRegionVal>(&loc)) {
+ 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).
+ escapes = (state == (state->bindLoc(*regionLoc, val)));
+ }
+ }
+
+ // 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);
+}
+
+const ProgramState *RetainCountChecker::evalAssume(const ProgramState *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.
+ RefBindings B = state->get<RefBindings>();
+
+ if (B.isEmpty())
+ return state;
+
+ bool changed = false;
+ RefBindings::Factory &RefBFactory = state->get_context<RefBindings>();
+
+ for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
+ // Check if the symbol is null (or equal to any constant).
+ // If this is the case, stop tracking the symbol.
+ if (state->getSymVal(I.getKey())) {
+ changed = true;
+ B = RefBFactory.remove(B, I.getKey());
+ }
+ }
+
+ if (changed)
+ state = state->set<RefBindings>(B);
+
+ return state;
+}
+
+const ProgramState *
+RetainCountChecker::checkRegionChanges(const ProgramState *state,
+ const StoreManager::InvalidatedSymbols *invalidated,
+ ArrayRef<const MemRegion *> ExplicitRegions,
+ ArrayRef<const MemRegion *> Regions) 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 (StoreManager::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 = state->remove<RefBindings>(sym);
+ }
+ return state;
+}
+
+//===----------------------------------------------------------------------===//
+// Handle dead symbols and end-of-path.
+//===----------------------------------------------------------------------===//
+
+std::pair<ExplodedNode *, const ProgramState *>
+RetainCountChecker::handleAutoreleaseCounts(const ProgramState *state,
+ GenericNodeBuilderRefCount Bd,
+ ExplodedNode *Pred, ExprEngine &Eng,
+ SymbolRef Sym, RefVal V) const {
+ unsigned ACnt = V.getAutoreleaseCount();
+
+ // No autorelease counts? Nothing to be done.
+ if (!ACnt)
+ return std::make_pair(Pred, state);
+
+ assert(!Eng.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 (ACnt <= Cnt) {
+ if (ACnt == Cnt) {
+ V.clearCounts();
+ if (V.getKind() == RefVal::ReturnedOwned)
+ V = V ^ RefVal::ReturnedNotOwned;
+ else
+ V = V ^ RefVal::NotOwned;
+ } else {
+ V.setCount(Cnt - ACnt);
+ V.setAutoreleaseCount(0);
+ }
+ state = state->set<RefBindings>(Sym, V);
+ ExplodedNode *N = Bd.MakeNode(state, Pred);
+ if (N == 0)
+ state = 0;
+ return std::make_pair(N, state);
+ }
+
+ // Woah! More autorelease counts then retain counts left.
+ // Emit hard error.
+ V = V ^ RefVal::ErrorOverAutorelease;
+ state = state->set<RefBindings>(Sym, V);
+
+ if (ExplodedNode *N = Bd.MakeNode(state, Pred)) {
+ N->markAsSink();
+
+ llvm::SmallString<128> sbuf;
+ llvm::raw_svector_ostream os(sbuf);
+ os << "Object over-autoreleased: object was sent -autorelease ";
+ if (V.getAutoreleaseCount() > 1)
+ os << V.getAutoreleaseCount() << " times ";
+ os << "but the object has a +" << V.getCount() << " retain count";
+
+ if (!overAutorelease)
+ overAutorelease.reset(new OverAutorelease());
+
+ const LangOptions &LOpts = Eng.getContext().getLangOptions();
+ CFRefReport *report =
+ new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false,
+ SummaryLog, N, Sym, os.str());
+ Eng.getBugReporter().EmitReport(report);
+ }
+
+ return std::make_pair((ExplodedNode *)0, (const ProgramState *)0);
+}
+
+const ProgramState *
+RetainCountChecker::handleSymbolDeath(const ProgramState *state,
+ SymbolRef sid, RefVal V,
+ SmallVectorImpl<SymbolRef> &Leaked) const {
+ bool hasLeak = false;
+ if (V.isOwned())
+ hasLeak = true;
+ else if (V.isNotOwned() || V.isReturnedOwned())
+ hasLeak = (V.getCount() > 0);
+
+ if (!hasLeak)
+ return state->remove<RefBindings>(sid);
+
+ Leaked.push_back(sid);
+ return state->set<RefBindings>(sid, V ^ RefVal::ErrorLeak);
+}
+
+ExplodedNode *
+RetainCountChecker::processLeaks(const ProgramState *state,
+ SmallVectorImpl<SymbolRef> &Leaked,
+ GenericNodeBuilderRefCount &Builder,
+ ExprEngine &Eng, ExplodedNode *Pred) const {
+ if (Leaked.empty())
+ return Pred;
+
+ // Generate an intermediate node representing the leak point.
+ ExplodedNode *N = Builder.MakeNode(state, Pred);
+
+ if (N) {
+ for (SmallVectorImpl<SymbolRef>::iterator
+ I = Leaked.begin(), E = Leaked.end(); I != E; ++I) {
+
+ const LangOptions &LOpts = Eng.getContext().getLangOptions();
+ bool GCEnabled = Eng.isObjCGCEnabled();
+ CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled)
+ : getLeakAtReturnBug(LOpts, GCEnabled);
+ assert(BT && "BugType not initialized.");
+
+ CFRefLeakReport *report = new CFRefLeakReport(*BT, LOpts, GCEnabled,
+ SummaryLog, N, *I, Eng);
+ Eng.getBugReporter().EmitReport(report);
+ }
+ }
+
+ return N;
+}
+
+void RetainCountChecker::checkEndPath(EndOfFunctionNodeBuilder &Builder,
+ ExprEngine &Eng) const {
+ const ProgramState *state = Builder.getState();
+ GenericNodeBuilderRefCount Bd(Builder);
+ RefBindings B = state->get<RefBindings>();
+ ExplodedNode *Pred = 0;
+
+ for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
+ llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred, Eng,
+ I->first, I->second);
+ if (!state)
+ return;
+ }
+
+ B = state->get<RefBindings>();
+ SmallVector<SymbolRef, 10> Leaked;
+
+ for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I)
+ state = handleSymbolDeath(state, I->first, I->second, Leaked);
+
+ processLeaks(state, Leaked, Bd, Eng, Pred);
+}
+
+const ProgramPointTag *
+RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const {
+ const SimpleProgramPointTag *&tag = DeadSymbolTags[sym];
+ if (!tag) {
+ llvm::SmallString<64> buf;
+ llvm::raw_svector_ostream out(buf);
+ out << "RetainCountChecker : Dead Symbol : " << sym->getSymbolID();
+ tag = new SimpleProgramPointTag(out.str());
+ }
+ return tag;
+}
+
+void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper,
+ CheckerContext &C) const {
+ StmtNodeBuilder &Builder = C.getNodeBuilder();
+ ExprEngine &Eng = C.getEngine();
+ const Stmt *S = C.getStmt();
+ ExplodedNode *Pred = C.getPredecessor();
+
+ const ProgramState *state = C.getState();
+ RefBindings B = state->get<RefBindings>();
+
+ // 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.
+ GenericNodeBuilderRefCount Bd(Builder, S, getDeadSymbolTag(Sym));
+ llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred, Eng,
+ Sym, *T);
+ if (!state)
+ return;
+ }
+ }
+
+ B = state->get<RefBindings>();
+ SmallVector<SymbolRef, 10> Leaked;
+
+ for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(),
+ E = SymReaper.dead_end(); I != E; ++I) {
+ if (const RefVal *T = B.lookup(*I))
+ state = handleSymbolDeath(state, *I, *T, Leaked);
+ }
+
+ {
+ GenericNodeBuilderRefCount Bd(Builder, S, this);
+ Pred = processLeaks(state, Leaked, Bd, Eng, Pred);
+ }
+
+ // Did we cache out?
+ if (!Pred)
+ return;
+
+ // Now generate a new node that nukes the old bindings.
+ RefBindings::Factory &F = state->get_context<RefBindings>();
+
+ for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(),
+ E = SymReaper.dead_end(); I != E; ++I)
+ B = F.remove(B, *I);
+
+ state = state->set<RefBindings>(B);
+ C.generateNode(state, Pred);
+}
+
+//===----------------------------------------------------------------------===//
+// Debug printing of refcount bindings and autorelease pools.
+//===----------------------------------------------------------------------===//
+
+static void PrintPool(raw_ostream &Out, SymbolRef Sym,
+ const ProgramState *State) {
+ Out << ' ';
+ if (Sym)
+ Out << Sym->getSymbolID();
+ else
+ Out << "<pool>";
+ Out << ":{";
+
+ // Get the contents of the pool.
+ if (const ARCounts *Cnts = State->get<AutoreleasePoolContents>(Sym))
+ for (ARCounts::iterator I = Cnts->begin(), E = Cnts->end(); I != E; ++I)
+ Out << '(' << I.getKey() << ',' << I.getData() << ')';
+
+ Out << '}';
+}
+
+bool UsesAutorelease(const ProgramState *state) {
+ // A state uses autorelease if it allocated an autorelease pool or if it has
+ // objects in the caller's autorelease pool.
+ return !state->get<AutoreleaseStack>().isEmpty() ||
+ state->get<AutoreleasePoolContents>(SymbolRef());
+}
+
+void RetainCountChecker::printState(raw_ostream &Out, const ProgramState *State,
+ const char *NL, const char *Sep) const {
+
+ RefBindings B = State->get<RefBindings>();
+
+ if (!B.isEmpty())
+ Out << Sep << NL;
+
+ for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
+ Out << I->first << " : ";
+ I->second.print(Out);
+ Out << NL;
+ }
+
+ // Print the autorelease stack.
+ if (UsesAutorelease(State)) {
+ Out << Sep << NL << "AR pool stack:";
+ ARStack Stack = State->get<AutoreleaseStack>();
+
+ PrintPool(Out, SymbolRef(), State); // Print the caller's pool.
+ for (ARStack::iterator I = Stack.begin(), E = Stack.end(); I != E; ++I)
+ PrintPool(Out, *I, State);
+
+ Out << NL;
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Checker registration.
+//===----------------------------------------------------------------------===//
+
+void ento::registerRetainCountChecker(CheckerManager &Mgr) {
+ Mgr.registerChecker<RetainCountChecker>();
+}
+