blob: d0618d0dddfe0b8e369ee99cca3507b9d85c7fe7 [file] [log] [blame]
//==-- 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/AST/ParentMap.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/Calls.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/ImmutableList.h"
#include "llvm/ADT/ImmutableMap.h"
#include "llvm/ADT/SmallString.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 {
CheckerContext *C;
const ProgramPointTag *tag;
public:
GenericNodeBuilderRefCount(CheckerContext &c,
const ProgramPointTag *t = 0)
: C(&c), tag(t){}
ExplodedNode *MakeNode(ProgramStateRef state, ExplodedNode *Pred,
bool MarkAsSink = false) {
return C->addTransition(state, Pred, tag, MarkAsSink);
}
};
} // 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,
DecRefAndStopTracking, DecRefMsgAndStopTracking,
IncRefMsg, IncRef, MakeCollectable, MayEscape,
NewAutoreleasePool, 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);
}
void Profile(llvm::FoldingSetNodeID& ID) const {
ID.AddInteger((unsigned) K);
ID.AddInteger((unsigned) O);
}
};
//===----------------------------------------------------------------------===//
// 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 - a map of (index, ArgEffect) pairs, where index
/// specifies the argument (starting from 0). This can be sparsely
/// populated; arguments with no entry in Args use 'DefaultArgEffect'.
ArgEffects Args;
/// DefaultArgEffect - The default ArgEffect to apply to arguments that
/// do not have an entry in Args.
ArgEffect DefaultArgEffect;
/// Receiver - If this summary applies to an Objective-C message expression,
/// this is the effect applied to the state of the receiver.
ArgEffect Receiver;
/// Ret - The effect on the return value. Used to indicate if the
/// function/method call returns a new tracked symbol.
RetEffect Ret;
public:
RetainSummary(ArgEffects A, RetEffect R, ArgEffect defaultEff,
ArgEffect ReceiverEff)
: Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R) {}
/// getArg - Return the argument effect on the argument specified by
/// idx (starting from 0).
ArgEffect getArg(unsigned idx) const {
if (const ArgEffect *AE = Args.lookup(idx))
return *AE;
return DefaultArgEffect;
}
void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) {
Args = af.add(Args, idx, e);
}
/// setDefaultArgEffect - Set the default argument effect.
void setDefaultArgEffect(ArgEffect E) {
DefaultArgEffect = E;
}
/// getRetEffect - Returns the effect on the return value of the call.
RetEffect getRetEffect() const { return Ret; }
/// setRetEffect - Set the effect of the return value of the call.
void setRetEffect(RetEffect E) { Ret = E; }
/// Sets the effect on the receiver of the message.
void setReceiverEffect(ArgEffect e) { Receiver = e; }
/// getReceiverEffect - Returns the effect on the receiver of the call.
/// This is only meaningful if the summary applies to an ObjCMessageExpr*.
ArgEffect getReceiverEffect() const { return Receiver; }
/// Test if two retain summaries are identical. Note that merely equivalent
/// summaries are not necessarily identical (for example, if an explicit
/// argument effect matches the default effect).
bool operator==(const RetainSummary &Other) const {
return Args == Other.Args && DefaultArgEffect == Other.DefaultArgEffect &&
Receiver == Other.Receiver && Ret == Other.Ret;
}
/// Profile this summary for inclusion in a FoldingSet.
void Profile(llvm::FoldingSetNodeID& ID) const {
ID.Add(Args);
ID.Add(DefaultArgEffect);
ID.Add(Receiver);
ID.Add(Ret);
}
/// A retain summary is simple if it has no ArgEffects other than the default.
bool isSimple() const {
return Args.isEmpty();
}
private:
ArgEffects getArgEffects() const { return Args; }
ArgEffect getDefaultArgEffect() const { return DefaultArgEffect; }
friend class RetainSummaryManager;
};
} // 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(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) {
typedef std::pair<IdentifierInfo*, Selector> PairTy;
return DenseMapInfo<PairTy>::getHashValue(PairTy(V.getIdentifier(),
V.getSelector()));
}
static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) {
return LHS.getIdentifier() == RHS.getIdentifier() &&
LHS.getSelector() == RHS.getSelector();
}
};
template <>
struct isPodLike<ObjCSummaryKey> { static const bool value = true; };
} // end llvm namespace
namespace {
class ObjCSummaryCache {
typedef llvm::DenseMap<ObjCSummaryKey, const RetainSummary *> MapTy;
MapTy M;
public:
ObjCSummaryCache() {}
const RetainSummary * find(const ObjCInterfaceDecl *D, Selector S) {
// Do a lookup with the (D,S) pair. If we find a match return
// the iterator.
ObjCSummaryKey K(D, S);
MapTy::iterator I = M.find(K);
if (I != M.end())
return I->second;
if (!D)
return NULL;
// 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.
const RetainSummary *Summ = I->second;
M[K] = Summ;
return Summ;
}
const 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;
}
const RetainSummary *& operator[](ObjCSummaryKey K) {
return M[K];
}
const RetainSummary *& operator[](Selector S) {
return M[ ObjCSummaryKey(S) ];
}
};
} // end anonymous namespace
//===----------------------------------------------------------------------===//
// Data structures for managing collections of summaries.
//===----------------------------------------------------------------------===//
namespace {
class RetainSummaryManager {
//==-----------------------------------------------------------------==//
// Typedefs.
//==-----------------------------------------------------------------==//
typedef llvm::DenseMap<const FunctionDecl*, const RetainSummary *>
FuncSummariesTy;
typedef ObjCSummaryCache ObjCMethodSummariesTy;
typedef llvm::FoldingSetNodeWrapper<RetainSummary> CachedSummaryNode;
//==-----------------------------------------------------------------==//
// Data.
//==-----------------------------------------------------------------==//
/// Ctx - The ASTContext object for the analyzed ASTs.
ASTContext &Ctx;
/// GCEnabled - Records whether or not the analyzed code runs in GC mode.
const bool GCEnabled;
/// Records whether or not the analyzed code runs in ARC mode.
const bool ARCEnabled;
/// FuncSummaries - A map from FunctionDecls to summaries.
FuncSummariesTy FuncSummaries;
/// ObjCClassMethodSummaries - A map from selectors (for instance methods)
/// to summaries.
ObjCMethodSummariesTy ObjCClassMethodSummaries;
/// ObjCMethodSummaries - A map from selectors to summaries.
ObjCMethodSummariesTy ObjCMethodSummaries;
/// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects,
/// and all other data used by the checker.
llvm::BumpPtrAllocator BPAlloc;
/// AF - A factory for ArgEffects objects.
ArgEffects::Factory AF;
/// ScratchArgs - A holding buffer for construct ArgEffects.
ArgEffects ScratchArgs;
/// ObjCAllocRetE - Default return effect for methods returning Objective-C
/// objects.
RetEffect ObjCAllocRetE;
/// ObjCInitRetE - Default return effect for init methods returning
/// Objective-C objects.
RetEffect ObjCInitRetE;
/// SimpleSummaries - Used for uniquing summaries that don't have special
/// effects.
llvm::FoldingSet<CachedSummaryNode> SimpleSummaries;
//==-----------------------------------------------------------------==//
// Methods.
//==-----------------------------------------------------------------==//
/// getArgEffects - Returns a persistent ArgEffects object based on the
/// data in ScratchArgs.
ArgEffects getArgEffects();
enum UnaryFuncKind { cfretain, cfrelease, cfmakecollectable };
const RetainSummary *getUnarySummary(const FunctionType* FT,
UnaryFuncKind func);
const RetainSummary *getCFSummaryCreateRule(const FunctionDecl *FD);
const RetainSummary *getCFSummaryGetRule(const FunctionDecl *FD);
const RetainSummary *getCFCreateGetRuleSummary(const FunctionDecl *FD);
const RetainSummary *getPersistentSummary(const RetainSummary &OldSumm);
const RetainSummary *getPersistentSummary(RetEffect RetEff,
ArgEffect ReceiverEff = DoNothing,
ArgEffect DefaultEff = MayEscape) {
RetainSummary Summ(getArgEffects(), RetEff, DefaultEff, ReceiverEff);
return getPersistentSummary(Summ);
}
const RetainSummary *getDoNothingSummary() {
return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
}
const RetainSummary *getDefaultSummary() {
return getPersistentSummary(RetEffect::MakeNoRet(),
DoNothing, MayEscape);
}
const RetainSummary *getPersistentStopSummary() {
return getPersistentSummary(RetEffect::MakeNoRet(),
StopTracking, StopTracking);
}
void InitializeClassMethodSummaries();
void InitializeMethodSummaries();
private:
void addNSObjectClsMethSummary(Selector S, const RetainSummary *Summ) {
ObjCClassMethodSummaries[S] = Summ;
}
void addNSObjectMethSummary(Selector S, const RetainSummary *Summ) {
ObjCMethodSummaries[S] = Summ;
}
void addClassMethSummary(const char* Cls, const char* name,
const RetainSummary *Summ, bool isNullary = true) {
IdentifierInfo* ClsII = &Ctx.Idents.get(Cls);
Selector S = isNullary ? GetNullarySelector(name, Ctx)
: GetUnarySelector(name, Ctx);
ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ;
}
void addInstMethSummary(const char* Cls, const char* nullaryName,
const RetainSummary *Summ) {
IdentifierInfo* ClsII = &Ctx.Idents.get(Cls);
Selector S = GetNullarySelector(nullaryName, Ctx);
ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ;
}
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,
const RetainSummary * Summ, va_list argp) {
Selector S = generateSelector(argp);
Summaries[ObjCSummaryKey(ClsII, S)] = Summ;
}
void addInstMethSummary(const char* Cls, const 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, const RetainSummary * Summ, ...) {
va_list argp;
va_start(argp, Summ);
addMethodSummary(&Ctx.Idents.get(Cls),ObjCClassMethodSummaries, Summ, argp);
va_end(argp);
}
void addClsMethSummary(IdentifierInfo *II, const 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())) {
InitializeClassMethodSummaries();
InitializeMethodSummaries();
}
const RetainSummary *getSummary(const CallEvent &Call,
ProgramStateRef State = 0);
const RetainSummary *getFunctionSummary(const FunctionDecl *FD);
const RetainSummary *getMethodSummary(Selector S, const ObjCInterfaceDecl *ID,
const ObjCMethodDecl *MD,
QualType RetTy,
ObjCMethodSummariesTy &CachedSummaries);
const RetainSummary *getInstanceMethodSummary(const ObjCMethodCall &M,
ProgramStateRef State);
const RetainSummary *getClassMethodSummary(const ObjCMethodCall &M) {
assert(!M.isInstanceMessage());
const ObjCInterfaceDecl *Class = M.getReceiverInterface();
return getMethodSummary(M.getSelector(), Class, M.getDecl(),
M.getResultType(), ObjCClassMethodSummaries);
}
/// getMethodSummary - This version of getMethodSummary is used to query
/// the summary for the current method being analyzed.
const RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) {
const ObjCInterfaceDecl *ID = MD->getClassInterface();
Selector S = MD->getSelector();
QualType ResultTy = MD->getResultType();
ObjCMethodSummariesTy *CachedSummaries;
if (MD->isInstanceMethod())
CachedSummaries = &ObjCMethodSummaries;
else
CachedSummaries = &ObjCClassMethodSummaries;
return getMethodSummary(S, ID, MD, ResultTy, *CachedSummaries);
}
const RetainSummary *getStandardMethodSummary(const ObjCMethodDecl *MD,
Selector S, QualType RetTy);
void updateSummaryFromAnnotations(const RetainSummary *&Summ,
const ObjCMethodDecl *MD);
void updateSummaryFromAnnotations(const RetainSummary *&Summ,
const FunctionDecl *FD);
void updateSummaryForCall(const RetainSummary *&Summ,
const CallEvent &Call);
bool isGCEnabled() const { return GCEnabled; }
bool isARCEnabled() const { return ARCEnabled; }
bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; }
RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; }
friend class RetainSummaryTemplate;
};
// Used to avoid allocating long-term (BPAlloc'd) memory for default retain
// summaries. If a function or method looks like it has a default summary, but
// it has annotations, the annotations are added to the stack-based template
// and then copied into managed memory.
class RetainSummaryTemplate {
RetainSummaryManager &Manager;
const RetainSummary *&RealSummary;
RetainSummary ScratchSummary;
bool Accessed;
public:
RetainSummaryTemplate(const RetainSummary *&real, RetainSummaryManager &mgr)
: Manager(mgr), RealSummary(real), ScratchSummary(*real), Accessed(false) {}
~RetainSummaryTemplate() {
if (Accessed)
RealSummary = Manager.getPersistentSummary(ScratchSummary);
}
RetainSummary &operator*() {
Accessed = true;
return ScratchSummary;
}
RetainSummary *operator->() {
Accessed = true;
return &ScratchSummary;
}
};
} // end anonymous namespace
//===----------------------------------------------------------------------===//
// Implementation of checker data structures.
//===----------------------------------------------------------------------===//
ArgEffects RetainSummaryManager::getArgEffects() {
ArgEffects AE = ScratchArgs;
ScratchArgs = AF.getEmptyMap();
return AE;
}
const RetainSummary *
RetainSummaryManager::getPersistentSummary(const RetainSummary &OldSumm) {
// Unique "simple" summaries -- those without ArgEffects.
if (OldSumm.isSimple()) {
llvm::FoldingSetNodeID ID;
OldSumm.Profile(ID);
void *Pos;
CachedSummaryNode *N = SimpleSummaries.FindNodeOrInsertPos(ID, Pos);
if (!N) {
N = (CachedSummaryNode *) BPAlloc.Allocate<CachedSummaryNode>();
new (N) CachedSummaryNode(OldSumm);
SimpleSummaries.InsertNode(N, Pos);
}
return &N->getValue();
}
RetainSummary *Summ = (RetainSummary *) BPAlloc.Allocate<RetainSummary>();
new (Summ) RetainSummary(OldSumm);
return Summ;
}
//===----------------------------------------------------------------------===//
// Summary creation for functions (largely uses of Core Foundation).
//===----------------------------------------------------------------------===//
static bool isRetain(const FunctionDecl *FD, StringRef FName) {
return FName.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;
}
static ArgEffect getStopTrackingEquivalent(ArgEffect E) {
switch (E) {
case DoNothing:
case Autorelease:
case DecRefBridgedTransfered:
case IncRef:
case IncRefMsg:
case MakeCollectable:
case MayEscape:
case NewAutoreleasePool:
case StopTracking:
return StopTracking;
case DecRef:
case DecRefAndStopTracking:
return DecRefAndStopTracking;
case DecRefMsg:
case DecRefMsgAndStopTracking:
return DecRefMsgAndStopTracking;
case Dealloc:
return Dealloc;
}
llvm_unreachable("Unknown ArgEffect kind");
}
void RetainSummaryManager::updateSummaryForCall(const RetainSummary *&S,
const CallEvent &Call) {
if (Call.hasNonZeroCallbackArg()) {
ArgEffect RecEffect = getStopTrackingEquivalent(S->getReceiverEffect());
ArgEffect DefEffect = getStopTrackingEquivalent(S->getDefaultArgEffect());
ArgEffects CustomArgEffects = S->getArgEffects();
for (ArgEffects::iterator I = CustomArgEffects.begin(),
E = CustomArgEffects.end();
I != E; ++I) {
ArgEffect Translated = getStopTrackingEquivalent(I->second);
if (Translated != DefEffect)
ScratchArgs = AF.add(ScratchArgs, I->first, Translated);
}
RetEffect RE = RetEffect::MakeNoRet();
// Special cases where the callback argument CANNOT free the return value.
// This can generally only happen if we know that the callback will only be
// called when the return value is already being deallocated.
if (const FunctionCall *FC = dyn_cast<FunctionCall>(&Call)) {
IdentifierInfo *Name = FC->getDecl()->getIdentifier();
// This callback frees the associated buffer.
if (Name->isStr("CGBitmapContextCreateWithData"))
RE = S->getRetEffect();
}
S = getPersistentSummary(RE, RecEffect, DefEffect);
}
}
const RetainSummary *
RetainSummaryManager::getSummary(const CallEvent &Call,
ProgramStateRef State) {
const RetainSummary *Summ;
switch (Call.getKind()) {
case CE_Function:
Summ = getFunctionSummary(cast<FunctionCall>(Call).getDecl());
break;
case CE_CXXMember:
case CE_CXXMemberOperator:
case CE_Block:
case CE_CXXConstructor:
case CE_CXXAllocator:
// FIXME: These calls are currently unsupported.
return getPersistentStopSummary();
case CE_ObjCMessage:
case CE_ObjCPropertyAccess: {
const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call);
if (Msg.isInstanceMessage())
Summ = getInstanceMethodSummary(Msg, State);
else
Summ = getClassMethodSummary(Msg);
break;
}
}
updateSummaryForCall(Summ, Call);
assert(Summ && "Unknown call type?");
return Summ;
}
const RetainSummary *
RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) {
// If we don't know what function we're calling, use our default summary.
if (!FD)
return getDefaultSummary();
// Look up a summary in our cache of FunctionDecls -> Summaries.
FuncSummariesTy::iterator I = FuncSummaries.find(FD);
if (I != FuncSummaries.end())
return I->second;
// No summary? Generate one.
const RetainSummary *S = 0;
do {
// We generate "stop" summaries for implicitly defined functions.
if (FD->isImplicit()) {
S = getPersistentStopSummary();
break;
}
// [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the
// function's type.
const FunctionType* FT = FD->getType()->getAs<FunctionType>();
const IdentifierInfo *II = FD->getIdentifier();
if (!II)
break;
StringRef FName = II->getName();
// Strip away preceding '_'. Doing this here will effect all the checks
// down below.
FName = FName.substr(FName.find_first_not_of('_'));
// Inspect the result type.
QualType RetTy = FT->getResultType();
// FIXME: This should all be refactored into a chain of "summary lookup"
// filters.
assert(ScratchArgs.isEmpty());
if (FName == "pthread_create" || FName == "pthread_setspecific") {
// Part of: <rdar://problem/7299394> and <rdar://problem/11282706>.
// This will be addressed better with IPA.
S = getPersistentStopSummary();
} else if (FName == "NSMakeCollectable") {
// Handle: id NSMakeCollectable(CFTypeRef)
S = (RetTy->isObjCIdType())
? getUnarySummary(FT, cfmakecollectable)
: getPersistentStopSummary();
} else if (FName == "IOBSDNameMatching" ||
FName == "IOServiceMatching" ||
FName == "IOServiceNameMatching" ||
FName == "IORegistryEntrySearchCFProperty" ||
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);
} else if (FName == "dispatch_set_context") {
// <rdar://problem/11059275> - The analyzer currently doesn't have
// a good way to reason about the finalizer function for libdispatch.
// If we pass a context object that is memory managed, stop tracking it.
// FIXME: this hack should possibly go away once we can handle
// libdispatch finalizers.
ScratchArgs = AF.add(ScratchArgs, 1, StopTracking);
S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
} else if (FName.startswith("NSLog")) {
S = getDoNothingSummary();
} else if (FName.startswith("NS") &&
(FName.find("Insert") != StringRef::npos)) {
// Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can
// be deallocated by NSMapRemove. (radar://11152419)
ScratchArgs = AF.add(ScratchArgs, 1, StopTracking);
ScratchArgs = AF.add(ScratchArgs, 2, StopTracking);
S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
}
// Did we get a summary?
if (S)
break;
// 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);
break;
}
// For CoreGraphics ('CG') types.
if (cocoa::isRefType(RetTy, "CG", FName)) {
if (isRetain(FD, FName))
S = getUnarySummary(FT, cfretain);
else
S = getCFCreateGetRuleSummary(FD);
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);
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);
// If we got all the way here without any luck, use a default summary.
if (!S)
S = getDefaultSummary();
// Annotations override defaults.
updateSummaryFromAnnotations(S, FD);
FuncSummaries[FD] = S;
return S;
}
const RetainSummary *
RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) {
if (coreFoundation::followsCreateRule(FD))
return getCFSummaryCreateRule(FD);
return getCFSummaryGetRule(FD);
}
const RetainSummary *
RetainSummaryManager::getUnarySummary(const FunctionType* FT,
UnaryFuncKind func) {
// Sanity check that this is *really* a unary function. This can
// happen if people do weird things.
const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT);
if (!FTP || FTP->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;
}
ScratchArgs = AF.add(ScratchArgs, 0, Effect);
return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
}
const RetainSummary *
RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) {
assert (ScratchArgs.isEmpty());
return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true));
}
const RetainSummary *
RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) {
assert (ScratchArgs.isEmpty());
return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF),
DoNothing, DoNothing);
}
//===----------------------------------------------------------------------===//
// Summary creation for Selectors.
//===----------------------------------------------------------------------===//
void
RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ,
const FunctionDecl *FD) {
if (!FD)
return;
assert(Summ && "Must have a summary to add annotations to.");
RetainSummaryTemplate Template(Summ, *this);
// Effects on the parameters.
unsigned parm_idx = 0;
for (FunctionDecl::param_const_iterator pi = FD->param_begin(),
pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) {
const ParmVarDecl *pd = *pi;
if (pd->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(const RetainSummary *&Summ,
const ObjCMethodDecl *MD) {
if (!MD)
return;
assert(Summ && "Must have a valid summary to add annotations to");
RetainSummaryTemplate Template(Summ, *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_const_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));
}
}
const RetainSummary *
RetainSummaryManager::getStandardMethodSummary(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_const_iterator I = MD->param_begin(),
E = MD->param_end(); I != E; ++I, ++i)
if (const ParmVarDecl *PD = *I) {
QualType Ty = Ctx.getCanonicalType(PD->getType());
if (Ty.getLocalUnqualifiedType() == Ctx.VoidPtrTy)
ScratchArgs = AF.add(ScratchArgs, i, StopTracking);
}
}
// Any special effects?
ArgEffect ReceiverEff = DoNothing;
RetEffect ResultEff = RetEffect::MakeNoRet();
// Check the method family, and apply any default annotations.
switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) {
case OMF_None:
case OMF_performSelector:
// Assume all Objective-C methods follow Cocoa Memory Management rules.
// FIXME: Does the non-threaded performSelector family really belong here?
// The selector could be, say, @selector(copy).
if (cocoa::isCocoaObjectRef(RetTy))
ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC);
else if (coreFoundation::isCFObjectRef(RetTy)) {
// ObjCMethodDecl currently doesn't consider CF objects as valid return
// values for alloc, new, copy, or mutableCopy, so we have to
// double-check with the selector. This is ugly, but there aren't that
// many Objective-C methods that return CF objects, right?
if (MD) {
switch (S.getMethodFamily()) {
case OMF_alloc:
case OMF_new:
case OMF_copy:
case OMF_mutableCopy:
ResultEff = RetEffect::MakeOwned(RetEffect::CF, true);
break;
default:
ResultEff = RetEffect::MakeNotOwned(RetEffect::CF);
break;
}
} else {
ResultEff = RetEffect::MakeNotOwned(RetEffect::CF);
}
}
break;
case OMF_init:
ResultEff = ObjCInitRetE;
ReceiverEff = DecRefMsg;
break;
case OMF_alloc:
case OMF_new:
case OMF_copy:
case OMF_mutableCopy:
if (cocoa::isCocoaObjectRef(RetTy))
ResultEff = ObjCAllocRetE;
else if (coreFoundation::isCFObjectRef(RetTy))
ResultEff = RetEffect::MakeOwned(RetEffect::CF, true);
break;
case OMF_autorelease:
ReceiverEff = Autorelease;
break;
case OMF_retain:
ReceiverEff = IncRefMsg;
break;
case OMF_release:
ReceiverEff = DecRefMsg;
break;
case OMF_dealloc:
ReceiverEff = Dealloc;
break;
case OMF_self:
// -self is handled specially by the ExprEngine to propagate the receiver.
break;
case OMF_retainCount:
case OMF_finalize:
// These methods don't return objects.
break;
}
// If one of the arguments in the selector has the keyword 'delegate' we
// should stop tracking the reference count for the receiver. This is
// because the reference count is quite possibly handled by a delegate
// method.
if (S.isKeywordSelector()) {
for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) {
StringRef Slot = S.getNameForSlot(i);
if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) {
if (ResultEff == ObjCInitRetE)
ResultEff = RetEffect::MakeNoRet();
else
ReceiverEff = StopTracking;
}
}
}
if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing &&
ResultEff.getKind() == RetEffect::NoRet)
return getDefaultSummary();
return getPersistentSummary(ResultEff, ReceiverEff, MayEscape);
}
const RetainSummary *
RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg,
ProgramStateRef State) {
const ObjCInterfaceDecl *ReceiverClass = 0;
// We do better tracking of the type of the object than the core ExprEngine.
// See if we have its type in our private state.
// FIXME: Eventually replace the use of state->get<RefBindings> with
// a generic API for reasoning about the Objective-C types of symbolic
// objects.
SVal ReceiverV = Msg.getReceiverSVal();
if (SymbolRef Sym = ReceiverV.getAsLocSymbol())
if (const RefVal *T = State->get<RefBindings>(Sym))
if (const ObjCObjectPointerType *PT =
T->getType()->getAs<ObjCObjectPointerType>())
ReceiverClass = PT->getInterfaceDecl();
// If we don't know what kind of object this is, fall back to its static type.
if (!ReceiverClass)
ReceiverClass = Msg.getReceiverInterface();
// FIXME: The receiver could be a reference to a class, meaning that
// we should use the class method.
// id x = [NSObject class];
// [x performSelector:... withObject:... afterDelay:...];
Selector S = Msg.getSelector();
const ObjCMethodDecl *Method = Msg.getDecl();
if (!Method && ReceiverClass)
Method = ReceiverClass->getInstanceMethod(S);
return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(),
ObjCMethodSummaries);
}
const RetainSummary *
RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID,
const ObjCMethodDecl *MD, QualType RetTy,
ObjCMethodSummariesTy &CachedSummaries) {
// Look up a summary in our summary cache.
const RetainSummary *Summ = CachedSummaries.find(ID, S);
if (!Summ) {
Summ = getStandardMethodSummary(MD, S, RetTy);
// Annotations override defaults.
updateSummaryFromAnnotations(Summ, MD);
// Memoize the summary.
CachedSummaries[ObjCSummaryKey(ID, S)] = Summ;
}
return Summ;
}
void RetainSummaryManager::InitializeClassMethodSummaries() {
assert(ScratchArgs.isEmpty());
// Create the [NSAssertionHandler currentHander] summary.
addClassMethSummary("NSAssertionHandler", "currentHandler",
getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC)));
// Create the [NSAutoreleasePool addObject:] summary.
ScratchArgs = AF.add(ScratchArgs, 0, Autorelease);
addClassMethSummary("NSAutoreleasePool", "addObject",
getPersistentSummary(RetEffect::MakeNoRet(),
DoNothing, Autorelease));
}
void RetainSummaryManager::InitializeMethodSummaries() {
assert (ScratchArgs.isEmpty());
// Create the "init" selector. It just acts as a pass-through for the
// receiver.
const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg);
addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm);
// awakeAfterUsingCoder: behaves basically like an 'init' method. It
// claims the receiver and returns a retained object.
addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx),
InitSumm);
// The next methods are allocators.
const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE);
const RetainSummary *CFAllocSumm =
getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true));
// Create the "retain" selector.
RetEffect NoRet = RetEffect::MakeNoRet();
const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg);
addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ);
// Create the "release" selector.
Summ = getPersistentSummary(NoRet, DecRefMsg);
addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ);
// Create the "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.
const 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);
addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false);
// 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(ProgramStateRef state) {
ARStack stack = state->get<AutoreleaseStack>();
return stack.isEmpty() ? SymbolRef() : stack.getHead();
}
static ProgramStateRef
SendAutorelease(ProgramStateRef 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, categories::MemoryCoreFoundationObjectiveC) {}
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 {
public:
Leak(StringRef name)
: CFRefBug(name) {
// Leaks should not be reported if they are post-dominated by a sink.
setSuppressOnSink(true);
}
const char *getDescription() const { return ""; }
bool isLeak() const { return true; }
};
//===---------===//
// Bug Reports. //
//===---------===//
class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> {
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);
virtual BugReporterVisitor *clone() const {
// The curiously-recurring template pattern only works for one level of
// subclassing. Rather than make a new template base for
// CFRefReportVisitor, we simply override clone() to do the right thing.
// This could be trouble someday if BugReporterVisitorImpl is ever
// used for something else besides a convenient implementation of clone().
return new CFRefLeakReportVisitor(*this);
}
};
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 {
const MemRegion* AllocBinding;
public:
CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled,
const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym,
CheckerContext &Ctx);
PathDiagnosticLocation getLocation(const SourceManager &SM) const {
assert(Location.isValid());
return Location;
}
};
} // end anonymous namespace
void CFRefReport::addGCModeDescription(const LangOptions &LOpts,
bool GCEnabled) {
const char *GCModeDescription = 0;
switch (LOpts.getGC()) {
case LangOptions::GCOnly:
assert(GCEnabled);
GCModeDescription = "Code is compiled to only use garbage collection";
break;
case LangOptions::NonGC:
assert(!GCEnabled);
GCModeDescription = "Code is compiled to use reference counts";
break;
case LangOptions::HybridGC:
if (GCEnabled) {
GCModeDescription = "Code is compiled to use either garbage collection "
"(GC) or reference counts (non-GC). The bug occurs "
"with GC enabled";
break;
} else {
GCModeDescription = "Code is compiled to use either garbage collection "
"(GC) or reference counts (non-GC). The bug occurs "
"in non-GC mode";
break;
}
}
assert(GCModeDescription && "invalid/unknown GC mode");
addExtraText(GCModeDescription);
}
// 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;
}
static bool isNumericLiteralExpression(const Expr *E) {
// FIXME: This set of cases was copied from SemaExprObjC.
return isa<IntegerLiteral>(E) ||
isa<CharacterLiteral>(E) ||
isa<FloatingLiteral>(E) ||
isa<ObjCBoolLiteralExpr>(E) ||
isa<CXXBoolLiteralExpr>(E);
}
static bool isPropertyAccess(const Stmt *S, ParentMap &PM) {
unsigned maxDepth = 4;
while (S && maxDepth) {
if (const PseudoObjectExpr *PO = dyn_cast<PseudoObjectExpr>(S)) {
if (!isa<ObjCMessageExpr>(PO->getSyntacticForm()))
return true;
return false;
}
S = PM.getParent(S);
--maxDepth;
}
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.
ProgramStateRef PrevSt = PrevN->getState();
ProgramStateRef CurrSt = N->getState();
const LocationContext *LCtx = N->getLocationContext();
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 (isa<ObjCArrayLiteral>(S)) {
os << "NSArray literal is an object with a +0 retain count";
}
else if (isa<ObjCDictionaryLiteral>(S)) {
os << "NSDictionary literal is an object with a +0 retain count";
}
else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) {
if (isNumericLiteralExpression(BL->getSubExpr()))
os << "NSNumber literal is an object with a +0 retain count";
else {
const ObjCInterfaceDecl *BoxClass = 0;
if (const ObjCMethodDecl *Method = BL->getBoxingMethod())
BoxClass = Method->getClassInterface();
// We should always be able to find the boxing class interface,
// but consider this future-proofing.
if (BoxClass)
os << *BoxClass << " b";
else
os << "B";
os << "oxed expression produces an object with a +0 retain count";
}
}
else {
if (const CallExpr *CE = dyn_cast<CallExpr>(S)) {
// Get the name of the callee (if it is available).
SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx);
if (const FunctionDecl *FD = X.getAsFunctionDecl())
os << "Call to function '" << *FD << '\'';
else
os << "function call";
}
else {
assert(isa<ObjCMessageExpr>(S));
// The message expression may have between written directly or as
// a property access. Lazily determine which case we are looking at.
os << (isPropertyAccess(S, N->getParentMap()) ? "Property" : "Method");
}
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(),
N->getLocationContext());
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, LCtx).getAsLocSymbol() != Sym)
continue;
// We have an argument. Get the effect!
AEffects.push_back(Summ->getArg(i));
}
}
else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) {
if (const Expr *receiver = ME->getInstanceReceiver())
if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx)
.getAsLocSymbol() == Sym) {
// The symbol we are tracking is the receiver.
AEffects.push_back(Summ->getReceiverEffect());
}
}
}
do {
// Get the previous type state.
RefVal PrevV = *PrevT;
// Specially handle -dealloc.
if (!GCEnabled && 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(), LCtx);
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:
// Autoreleases can be applied after marking a node ReturnedOwned.
if (CurrV.getAutoreleaseCount())
return NULL;
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(),
N->getLocationContext());
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, LCtx).getAsLocSymbol() == Sym) {
P->addRange(Exp->getSourceRange());
break;
}
return P;
}
// Find the first node in the current function context that referred to the
// tracked symbol and the memory location that value was stored to. Note, the
// value is only reported if the allocation occurred in the same function as
// the leak.
static std::pair<const ExplodedNode*,const MemRegion*>
GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N,
SymbolRef Sym) {
const ExplodedNode *Last = N;
const MemRegion* FirstBinding = 0;
const LocationContext *LeakContext = N->getLocationContext();
while (N) {
ProgramStateRef St = N->getState();
RefBindings B = St->get<RefBindings>();
if (!B.lookup(Sym))
break;
StoreManager::FindUniqueBinding FB(Sym);
StateMgr.iterBindings(St, FB);
if (FB) FirstBinding = FB.getRegion();
// Allocation node, is the last node in the current context in which the
// symbol was tracked.
if (N->getLocationContext() == LeakContext)
Last = N;
N = N->pred_empty() ? NULL : *(N->pred_begin());
}
// If allocation happened in a function different from the leak node context,
// do not report the binding.
if (N->getLocationContext() != LeakContext) {
FirstBinding = 0;
}
return std::make_pair(Last, FirstBinding);
}
PathDiagnosticPiece*
CFRefReportVisitor::getEndPath(BugReporterContext &BRC,
const ExplodedNode *EndN,
BugReport &BR) {
BR.markInteresting(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.
BR.markInteresting(Sym);
// We are reporting a leak. Walk up the graph to get to the first node where
// the symbol appeared, and also get the first VarDecl that tracked object
// is stored to.
const ExplodedNode *AllocNode = 0;
const MemRegion* FirstBinding = 0;
llvm::tie(AllocNode, FirstBinding) =
GetAllocationSite(BRC.getStateManager(), EndN, Sym);
SourceManager& SM = BRC.getSourceManager();
// Compute an actual location for the leak. Sometimes a leak doesn't
// occur at an actual statement (e.g., transition between blocks; end
// of function) so we need to walk the graph and compute a real location.
const ExplodedNode *LeakN = EndN;
PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM);
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "Object leaked: ";
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 returned from a function whose name ('"
<< *FD
<< "') does not contain 'Copy' or 'Create'. This violates the naming"
" convention rules given in the Memory Management Guide for Core"
" Foundation";
}
}
else if (RV->getKind() == RefVal::ErrorGCLeakReturned) {
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,
CheckerContext &Ctx)
: 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;
const SourceManager& SMgr = Ctx.getSourceManager();
llvm::tie(AllocNode, AllocBinding) = // Set AllocBinding.
GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym);
// Get the SourceLocation for the allocation site.
ProgramPoint P = AllocNode->getLocation();
const Stmt *AllocStmt = cast<PostStmt>(P).getStmt();
Location = PathDiagnosticLocation::createBegin(AllocStmt, SMgr,
n->getLocationContext());
// Fill in the description of the bug.
Description.clear();
llvm::raw_string_ostream os(Description);
os << "Potential leak ";
if (GCEnabled)
os << "(when using garbage collection) ";
os << "of an object";
// FIXME: AllocBinding doesn't get populated for RegionStore yet.
if (AllocBinding)
os << " 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<ObjCArrayLiteral>,
check::PostStmt<ObjCDictionaryLiteral>,
check::PostStmt<ObjCBoxedExpr>,
check::PostCall,
check::PreStmt<ReturnStmt>,
check::RegionChanges,
eval::Assume,
eval::Call > {
mutable OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned;
mutable OwningPtr<CFRefBug> deallocGC, deallocNotOwned;
mutable OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned;
mutable OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn;
mutable 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 OwningPtr<RetainSummaryManager> Summaries;
mutable 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 Leak("Leak of object when using "
"garbage collection"));
return leakWithinFunctionGC.get();
} else {
if (!leakWithinFunction) {
if (LOpts.getGC() == LangOptions::HybridGC) {
leakWithinFunction.reset(new Leak("Leak of object when not using "
"garbage collection (GC) in "
"dual GC/non-GC code"));
} else {
leakWithinFunction.reset(new Leak("Leak"));
}
}
return leakWithinFunction.get();
}
}
CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const {
if (GCEnabled) {
if (!leakAtReturnGC)
leakAtReturnGC.reset(new Leak("Leak of returned object when using "
"garbage collection"));
return leakAtReturnGC.get();
} else {
if (!leakAtReturn) {
if (LOpts.getGC() == LangOptions::HybridGC) {
leakAtReturn.reset(new Leak("Leak of returned object when not using "
"garbage collection (GC) in dual "
"GC/non-GC code"));
} else {
leakAtReturn.reset(new Leak("Leak of returned object"));
}
}
return leakAtReturn.get();
}
}
RetainSummaryManager &getSummaryManager(ASTContext &Ctx,
bool GCEnabled) const {
// FIXME: We don't support ARC being turned on and off during one analysis.
// (nor, for that matter, do we support changing ASTContexts)
bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount;
if (GCEnabled) {
if (!SummariesGC)
SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled));
else
assert(SummariesGC->isARCEnabled() == ARCEnabled);
return *SummariesGC;
} else {
if (!Summaries)
Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled));
else
assert(Summaries->isARCEnabled() == ARCEnabled);
return *Summaries;
}
}
RetainSummaryManager &getSummaryManager(CheckerContext &C) const {
return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled());
}
void printState(raw_ostream &Out, ProgramStateRef State,
const char *NL, const char *Sep) const;
void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const;
void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
void checkPostStmt(const CastExpr *CE, CheckerContext &C) const;
void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const;
void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const;
void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const;
void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
void checkSummary(const RetainSummary &Summ, const CallEvent &Call,
CheckerContext &C) const;
bool evalCall(const CallExpr *CE, CheckerContext &C) const;
ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond,
bool Assumption) const;
ProgramStateRef
checkRegionChanges(ProgramStateRef state,
const StoreManager::InvalidatedSymbols *invalidated,
ArrayRef<const MemRegion *> ExplicitRegions,
ArrayRef<const MemRegion *> Regions,
const CallEvent *Call) const;
bool wantsRegionChangeUpdate(ProgramStateRef 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,