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gerrit-public.fairphone.software / platform / external / clang / 70a6576c9c8d21ff2361574f4937a2e73bd57779 / . / lib / Analysis / CFRefCount.cpp
blob: a12542eaaa4d97eb94f9a327d874a633cd9ae0fc [file] [log] [blame]
// CFRefCount.cpp - Transfer functions for tracking simple values -*- 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 CFRefCount, which implements
// a reference count checker for Core Foundation (Mac OS X).
//
//===----------------------------------------------------------------------===//
#include "GRSimpleVals.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Analysis/PathSensitive/GRExprEngineBuilders.h"
#include "clang/Analysis/PathSensitive/GRStateTrait.h"
#include "clang/Analysis/PathDiagnostic.h"
#include "clang/Analysis/LocalCheckers.h"
#include "clang/Analysis/PathDiagnostic.h"
#include "clang/Analysis/PathSensitive/BugReporter.h"
#include "clang/Analysis/PathSensitive/SymbolManager.h"
#include "clang/AST/DeclObjC.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/ImmutableMap.h"
#include "llvm/ADT/ImmutableList.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/Compiler.h"
#include "llvm/ADT/STLExtras.h"
#include <ostream>
#include <stdarg.h>
using namespace clang;
//===----------------------------------------------------------------------===//
// Utility functions.
//===----------------------------------------------------------------------===//
// The "fundamental rule" for naming conventions of methods:
// (url broken into two lines)
// http://developer.apple.com/documentation/Cocoa/Conceptual/
// MemoryMgmt/Tasks/MemoryManagementRules.html
//
// "You take ownership of an object if you create it using a method whose name
// begins with “alloc” or “new” or contains “copy” (for example, alloc,
// newObject, or mutableCopy), or if you send it a retain message. You are
// responsible for relinquishing ownership of objects you own using release
// or autorelease. Any other time you receive an object, you must
// not release it."
//
using llvm::CStrInCStrNoCase;
using llvm::StringsEqualNoCase;
enum NamingConvention { NoConvention, CreateRule, InitRule };
static inline bool isWordEnd(char ch, char prev, char next) {
return ch == '\0'
|| (islower(prev) && isupper(ch)) // xxxC
|| (isupper(prev) && isupper(ch) && islower(next)) // XXCreate
|| !isalpha(ch);
}
static inline const char* parseWord(const char* s) {
char ch = *s, prev = '\0';
assert(ch != '\0');
char next = *(s+1);
while (!isWordEnd(ch, prev, next)) {
prev = ch;
ch = next;
next = *((++s)+1);
}
return s;
}
static NamingConvention deriveNamingConvention(const char* s) {
// A method/function name may contain a prefix. We don't know it is there,
// however, until we encounter the first '_'.
bool InPossiblePrefix = true;
bool AtBeginning = true;
NamingConvention C = NoConvention;
while (*s != '\0') {
// Skip '_'.
if (*s == '_') {
if (InPossiblePrefix) {
InPossiblePrefix = false;
AtBeginning = true;
// Discard whatever 'convention' we
// had already derived since it occurs
// in the prefix.
C = NoConvention;
}
++s;
continue;
}
// Skip numbers, ':', etc.
if (!isalpha(*s)) {
++s;
continue;
}
const char *wordEnd = parseWord(s);
assert(wordEnd > s);
unsigned len = wordEnd - s;
switch (len) {
default:
break;
case 3:
// Methods starting with 'new' follow the create rule.
if (AtBeginning && StringsEqualNoCase("new", s, len))
C = CreateRule;
break;
case 4:
// Methods starting with 'alloc' or contain 'copy' follow the
// create rule
if (C == NoConvention && StringsEqualNoCase("copy", s, len))
C = CreateRule;
else // Methods starting with 'init' follow the init rule.
if (AtBeginning && StringsEqualNoCase("init", s, len))
C = InitRule;
break;
case 5:
if (AtBeginning && StringsEqualNoCase("alloc", s, len))
C = CreateRule;
break;
}
// If we aren't in the prefix and have a derived convention then just
// return it now.
if (!InPossiblePrefix && C != NoConvention)
return C;
AtBeginning = false;
s = wordEnd;
}
// We will get here if there wasn't more than one word
// after the prefix.
return C;
}
static bool followsFundamentalRule(const char* s) {
return deriveNamingConvention(s) == CreateRule;
}
static const ObjCMethodDecl*
ResolveToInterfaceMethodDecl(const ObjCMethodDecl *MD, ASTContext &Context) {
ObjCInterfaceDecl *ID =
const_cast<ObjCInterfaceDecl*>(MD->getClassInterface());
return MD->isInstanceMethod()
? ID->lookupInstanceMethod(Context, MD->getSelector())
: ID->lookupClassMethod(Context, MD->getSelector());
}
//===----------------------------------------------------------------------===//
// Selector creation functions.
//===----------------------------------------------------------------------===//
static inline Selector GetNullarySelector(const char* name, ASTContext& Ctx) {
IdentifierInfo* II = &Ctx.Idents.get(name);
return Ctx.Selectors.getSelector(0, &II);
}
static inline Selector GetUnarySelector(const char* name, ASTContext& Ctx) {
IdentifierInfo* II = &Ctx.Idents.get(name);
return Ctx.Selectors.getSelector(1, &II);
}
//===----------------------------------------------------------------------===//
// Type querying functions.
//===----------------------------------------------------------------------===//
static bool hasPrefix(const char* s, const char* prefix) {
if (!prefix)
return true;
char c = *s;
char cP = *prefix;
while (c != '\0' && cP != '\0') {
if (c != cP) break;
c = *(++s);
cP = *(++prefix);
}
return cP == '\0';
}
static bool hasSuffix(const char* s, const char* suffix) {
const char* loc = strstr(s, suffix);
return loc && strcmp(suffix, loc) == 0;
}
static bool isRefType(QualType RetTy, const char* prefix,
ASTContext* Ctx = 0, const char* name = 0) {
if (TypedefType* TD = dyn_cast<TypedefType>(RetTy.getTypePtr())) {
const char* TDName = TD->getDecl()->getIdentifier()->getName();
return hasPrefix(TDName, prefix) && hasSuffix(TDName, "Ref");
}
if (!Ctx || !name)
return false;
// Is the type void*?
const PointerType* PT = RetTy->getAsPointerType();
if (!(PT->getPointeeType().getUnqualifiedType() == Ctx->VoidTy))
return false;
// Does the name start with the prefix?
return hasPrefix(name, prefix);
}
//===----------------------------------------------------------------------===//
// Primitives used for constructing summaries for function/method calls.
//===----------------------------------------------------------------------===//
namespace {
/// ArgEffect is used to summarize a function/method call's effect on a
/// particular argument.
enum ArgEffect { Autorelease, Dealloc, DecRef, DecRefMsg, DoNothing,
DoNothingByRef, IncRefMsg, IncRef, MakeCollectable, MayEscape,
NewAutoreleasePool, SelfOwn, StopTracking };
/// ArgEffects summarizes the effects of a function/method call on all of
/// its arguments.
typedef std::vector<std::pair<unsigned,ArgEffect> > ArgEffects;
}
namespace llvm {
template <> struct FoldingSetTrait<ArgEffects> {
static void Profile(const ArgEffects& X, FoldingSetNodeID& ID) {
for (ArgEffects::const_iterator I = X.begin(), E = X.end(); I!= E; ++I) {
ID.AddInteger(I->first);
ID.AddInteger((unsigned) I->second);
}
}
};
} // end llvm namespace
namespace {
/// RetEffect is used to summarize a function/method call's behavior with
/// respect to its return value.
class VISIBILITY_HIDDEN RetEffect {
public:
enum Kind { NoRet, Alias, OwnedSymbol, OwnedAllocatedSymbol,
NotOwnedSymbol, GCNotOwnedSymbol, ReceiverAlias };
enum ObjKind { CF, ObjC, AnyObj };
private:
Kind K;
ObjKind O;
unsigned index;
RetEffect(Kind k, unsigned idx = 0) : K(k), O(AnyObj), index(idx) {}
RetEffect(Kind k, ObjKind o) : K(k), O(o), index(0) {}
public:
Kind getKind() const { return K; }
ObjKind getObjKind() const { return O; }
unsigned getIndex() const {
assert(getKind() == Alias);
return index;
}
bool isOwned() const {
return K == OwnedSymbol || K == OwnedAllocatedSymbol;
}
static RetEffect MakeAlias(unsigned Idx) {
return RetEffect(Alias, Idx);
}
static RetEffect MakeReceiverAlias() {
return RetEffect(ReceiverAlias);
}
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 MakeNoRet() {
return RetEffect(NoRet);
}
void Profile(llvm::FoldingSetNodeID& ID) const {
ID.AddInteger((unsigned)K);
ID.AddInteger((unsigned)O);
ID.AddInteger(index);
}
};
class VISIBILITY_HIDDEN RetainSummary : public llvm::FoldingSetNode {
/// 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, returns an
/// alias of one of the arguments in the call, and so on.
RetEffect Ret;
/// EndPath - Indicates that execution of this method/function should
/// terminate the simulation of a path.
bool EndPath;
public:
RetainSummary(ArgEffects* A, RetEffect R, ArgEffect defaultEff,
ArgEffect ReceiverEff, bool endpath = false)
: Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R),
EndPath(endpath) {}
/// getArg - Return the argument effect on the argument specified by
/// idx (starting from 0).
ArgEffect getArg(unsigned idx) const {
if (!Args)
return DefaultArgEffect;
// If Args is present, it is likely to contain only 1 element.
// Just do a linear search. Do it from the back because functions with
// large numbers of arguments will be tail heavy with respect to which
// argument they actually modify with respect to the reference count.
for (ArgEffects::reverse_iterator I=Args->rbegin(), E=Args->rend();
I!=E; ++I) {
if (idx > I->first)
return DefaultArgEffect;
if (idx == I->first)
return I->second;
}
return DefaultArgEffect;
}
/// getRetEffect - Returns the effect on the return value of the call.
RetEffect getRetEffect() const {
return Ret;
}
/// isEndPath - Returns true if executing the given method/function should
/// terminate the path.
bool isEndPath() const { return EndPath; }
/// 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;
}
typedef ArgEffects::const_iterator ExprIterator;
ExprIterator begin_args() const { return Args->begin(); }
ExprIterator end_args() const { return Args->end(); }
static void Profile(llvm::FoldingSetNodeID& ID, ArgEffects* A,
RetEffect RetEff, ArgEffect DefaultEff,
ArgEffect ReceiverEff, bool EndPath) {
ID.AddPointer(A);
ID.Add(RetEff);
ID.AddInteger((unsigned) DefaultEff);
ID.AddInteger((unsigned) ReceiverEff);
ID.AddInteger((unsigned) EndPath);
}
void Profile(llvm::FoldingSetNodeID& ID) const {
Profile(ID, Args, Ret, DefaultArgEffect, Receiver, EndPath);
}
};
} // end anonymous namespace
//===----------------------------------------------------------------------===//
// Data structures for constructing summaries.
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN 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) {
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());
}
static bool isPod() {
return DenseMapInfo<ObjCInterfaceDecl*>::isPod() &&
DenseMapInfo<Selector>::isPod();
}
};
} // end llvm namespace
namespace {
class VISIBILITY_HIDDEN ObjCSummaryCache {
typedef llvm::DenseMap<ObjCSummaryKey, RetainSummary*> MapTy;
MapTy M;
public:
ObjCSummaryCache() {}
typedef MapTy::iterator iterator;
iterator 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);
}
iterator 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;
// 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 I;
}
// Cache the summary with original key to make the next lookup faster
// and return the iterator.
M[K] = I->second;
return I;
}
iterator find(Expr* Receiver, Selector S) {
return find(getReceiverDecl(Receiver), S);
}
iterator 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.
iterator I = M.find(ObjCSummaryKey(II, S));
return I == M.end() ? M.find(ObjCSummaryKey(S)) : I;
}
ObjCInterfaceDecl* getReceiverDecl(Expr* E) {
const PointerType* PT = E->getType()->getAsPointerType();
if (!PT) return 0;
ObjCInterfaceType* OI = dyn_cast<ObjCInterfaceType>(PT->getPointeeType());
if (!OI) return 0;
return OI ? OI->getDecl() : 0;
}
iterator end() { return M.end(); }
RetainSummary*& operator[](ObjCMessageExpr* ME) {
Selector S = ME->getSelector();
if (Expr* Receiver = ME->getReceiver()) {
ObjCInterfaceDecl* OD = getReceiverDecl(Receiver);
return OD ? M[ObjCSummaryKey(OD->getIdentifier(), S)] : M[S];
}
return M[ObjCSummaryKey(ME->getClassName(), S)];
}
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 VISIBILITY_HIDDEN RetainSummaryManager {
//==-----------------------------------------------------------------==//
// Typedefs.
//==-----------------------------------------------------------------==//
typedef llvm::FoldingSet<llvm::FoldingSetNodeWrapper<ArgEffects> >
ArgEffectsSetTy;
typedef llvm::FoldingSet<RetainSummary>
SummarySetTy;
typedef llvm::DenseMap<FunctionDecl*, RetainSummary*>
FuncSummariesTy;
typedef ObjCSummaryCache ObjCMethodSummariesTy;
//==-----------------------------------------------------------------==//
// Data.
//==-----------------------------------------------------------------==//
/// Ctx - The ASTContext object for the analyzed ASTs.
ASTContext& Ctx;
/// CFDictionaryCreateII - An IdentifierInfo* representing the indentifier
/// "CFDictionaryCreate".
IdentifierInfo* CFDictionaryCreateII;
/// GCEnabled - Records whether or not the analyzed code runs in GC mode.
const bool GCEnabled;
/// SummarySet - A FoldingSet of uniqued summaries.
SummarySetTy SummarySet;
/// 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;
/// ArgEffectsSet - A FoldingSet of uniqued ArgEffects.
ArgEffectsSetTy ArgEffectsSet;
/// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects,
/// and all other data used by the checker.
llvm::BumpPtrAllocator BPAlloc;
/// ScratchArgs - A holding buffer for construct ArgEffects.
ArgEffects ScratchArgs;
RetainSummary* StopSummary;
//==-----------------------------------------------------------------==//
// Methods.
//==-----------------------------------------------------------------==//
/// getArgEffects - Returns a persistent ArgEffects object based on the
/// data in ScratchArgs.
ArgEffects* getArgEffects();
enum UnaryFuncKind { cfretain, cfrelease, cfmakecollectable };
public:
RetainSummary* getUnarySummary(const FunctionType* FT, UnaryFuncKind func);
RetainSummary* getCFSummaryCreateRule(FunctionDecl* FD);
RetainSummary* getCFSummaryGetRule(FunctionDecl* FD);
RetainSummary* getCFCreateGetRuleSummary(FunctionDecl* FD, const char* FName);
RetainSummary* getPersistentSummary(ArgEffects* AE, RetEffect RetEff,
ArgEffect ReceiverEff = DoNothing,
ArgEffect DefaultEff = MayEscape,
bool isEndPath = false);
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();
bool isTrackedObjectType(QualType T);
private:
void addClsMethSummary(IdentifierInfo* ClsII, Selector S,
RetainSummary* Summ) {
ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ;
}
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) {
llvm::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);
}
void addPanicSummary(const char* Cls, ...) {
RetainSummary* Summ = getPersistentSummary(0, RetEffect::MakeNoRet(),
DoNothing, DoNothing, true);
va_list argp;
va_start (argp, Cls);
addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, argp);
va_end(argp);
}
public:
RetainSummaryManager(ASTContext& ctx, bool gcenabled)
: Ctx(ctx),
CFDictionaryCreateII(&ctx.Idents.get("CFDictionaryCreate")),
GCEnabled(gcenabled), StopSummary(0) {
InitializeClassMethodSummaries();
InitializeMethodSummaries();
}
~RetainSummaryManager();
RetainSummary* getSummary(FunctionDecl* FD);
RetainSummary* getInstanceMethodSummary(ObjCMessageExpr* ME,
const ObjCInterfaceDecl* ID) {
return getInstanceMethodSummary(ME->getSelector(), ME->getClassName(),
ID, ME->getMethodDecl(), ME->getType());
}
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(ObjCMessageExpr *ME) {
return getClassMethodSummary(ME->getSelector(), ME->getClassName(),
ME->getClassInfo().first,
ME->getMethodDecl(), ME->getType());
}
/// 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();
// Resolve the method decl last.
MD = ResolveToInterfaceMethodDecl(MD, Ctx);
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);
RetainSummary* getMethodSummaryFromAnnotations(const ObjCMethodDecl *MD);
bool isGCEnabled() const { return GCEnabled; }
};
} // end anonymous namespace
//===----------------------------------------------------------------------===//
// Implementation of checker data structures.
//===----------------------------------------------------------------------===//
RetainSummaryManager::~RetainSummaryManager() {
// FIXME: The ArgEffects could eventually be allocated from BPAlloc,
// mitigating the need to do explicit cleanup of the
// Argument-Effect summaries.
for (ArgEffectsSetTy::iterator I = ArgEffectsSet.begin(),
E = ArgEffectsSet.end(); I!=E; ++I)
I->getValue().~ArgEffects();
}
ArgEffects* RetainSummaryManager::getArgEffects() {
if (ScratchArgs.empty())
return NULL;
// Compute a profile for a non-empty ScratchArgs.
llvm::FoldingSetNodeID profile;
profile.Add(ScratchArgs);
void* InsertPos;
// Look up the uniqued copy, or create a new one.
llvm::FoldingSetNodeWrapper<ArgEffects>* E =
ArgEffectsSet.FindNodeOrInsertPos(profile, InsertPos);
if (E) {
ScratchArgs.clear();
return &E->getValue();
}
E = (llvm::FoldingSetNodeWrapper<ArgEffects>*)
BPAlloc.Allocate<llvm::FoldingSetNodeWrapper<ArgEffects> >();
new (E) llvm::FoldingSetNodeWrapper<ArgEffects>(ScratchArgs);
ArgEffectsSet.InsertNode(E, InsertPos);
ScratchArgs.clear();
return &E->getValue();
}
RetainSummary*
RetainSummaryManager::getPersistentSummary(ArgEffects* AE, RetEffect RetEff,
ArgEffect ReceiverEff,
ArgEffect DefaultEff,
bool isEndPath) {
// Generate a profile for the summary.
llvm::FoldingSetNodeID profile;
RetainSummary::Profile(profile, AE, RetEff, DefaultEff, ReceiverEff,
isEndPath);
// Look up the uniqued summary, or create one if it doesn't exist.
void* InsertPos;
RetainSummary* Summ = SummarySet.FindNodeOrInsertPos(profile, InsertPos);
if (Summ)
return Summ;
// Create the summary and return it.
Summ = (RetainSummary*) BPAlloc.Allocate<RetainSummary>();
new (Summ) RetainSummary(AE, RetEff, DefaultEff, ReceiverEff, isEndPath);
SummarySet.InsertNode(Summ, InsertPos);
return Summ;
}
//===----------------------------------------------------------------------===//
// Predicates.
//===----------------------------------------------------------------------===//
bool RetainSummaryManager::isTrackedObjectType(QualType Ty) {
if (!Ctx.isObjCObjectPointerType(Ty))
return false;
// We assume that id<..>, id, and "Class" all represent tracked objects.
const PointerType *PT = Ty->getAsPointerType();
if (PT == 0)
return true;
const ObjCInterfaceType *OT = PT->getPointeeType()->getAsObjCInterfaceType();
// We assume that id<..>, id, and "Class" all represent tracked objects.
if (!OT)
return true;
// Does the interface subclass NSObject?
// FIXME: We can memoize here if this gets too expensive.
IdentifierInfo* NSObjectII = &Ctx.Idents.get("NSObject");
ObjCInterfaceDecl* ID = OT->getDecl();
for ( ; ID ; ID = ID->getSuperClass())
if (ID->getIdentifier() == NSObjectII)
return true;
return false;
}
//===----------------------------------------------------------------------===//
// Summary creation for functions (largely uses of Core Foundation).
//===----------------------------------------------------------------------===//
static bool isRetain(FunctionDecl* FD, const char* FName) {
const char* loc = strstr(FName, "Retain");
return loc && loc[sizeof("Retain")-1] == '\0';
}
static bool isRelease(FunctionDecl* FD, const char* FName) {
const char* loc = strstr(FName, "Release");
return loc && loc[sizeof("Release")-1] == '\0';
}
RetainSummary* RetainSummaryManager::getSummary(FunctionDecl* FD) {
SourceLocation Loc = FD->getLocation();
if (!Loc.isFileID())
return NULL;
// 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;
}
// [PR 3337] Use 'getAsFunctionType' to strip away any typedefs on the
// function's type.
const FunctionType* FT = FD->getType()->getAsFunctionType();
const char* FName = FD->getIdentifier()->getName();
// Strip away preceding '_'. Doing this here will effect all the checks
// down below.
while (*FName == '_') ++FName;
// Inspect the result type.
QualType RetTy = FT->getResultType();
// FIXME: This should all be refactored into a chain of "summary lookup"
// filters.
if (strcmp(FName, "IOServiceGetMatchingServices") == 0) {
// 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.
assert (ScratchArgs.empty());
ScratchArgs.push_back(std::make_pair(1, DecRef));
S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
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
// Handle: id NSMakeCollectable(CFTypeRef)
if (strcmp(FName, "NSMakeCollectable") == 0) {
S = (RetTy == Ctx.getObjCIdType())
? getUnarySummary(FT, cfmakecollectable)
: getPersistentStopSummary();
break;
}
if (RetTy->isPointerType()) {
// For CoreFoundation ('CF') types.
if (isRefType(RetTy, "CF", &Ctx, FName)) {
if (isRetain(FD, FName))
S = getUnarySummary(FT, cfretain);
else if (strstr(FName, "MakeCollectable"))
S = getUnarySummary(FT, cfmakecollectable);
else
S = getCFCreateGetRuleSummary(FD, FName);
break;
}
// For CoreGraphics ('CG') types.
if (isRefType(RetTy, "CG", &Ctx, FName)) {
if (isRetain(FD, FName))
S = getUnarySummary(FT, cfretain);
else
S = getCFCreateGetRuleSummary(FD, FName);
break;
}
// For the Disk Arbitration API (DiskArbitration/DADisk.h)
if (isRefType(RetTy, "DADisk") ||
isRefType(RetTy, "DADissenter") ||
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'.
if (FName[1] == 'G' && FName[2] == 'C' && FName[3] == 'F')
FName += 4;
else
FName += 2;
if (isRelease(FD, FName))
S = getUnarySummary(FT, cfrelease);
else {
assert (ScratchArgs.empty());
// 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" or "AddValue" then
// we assume that arguments may "escape."
//
ArgEffect E = (CStrInCStrNoCase(FName, "InsertValue") ||
CStrInCStrNoCase(FName, "AddValue") ||
CStrInCStrNoCase(FName, "SetValue") ||
CStrInCStrNoCase(FName, "AppendValue"))
? MayEscape : DoNothing;
S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E);
}
}
}
while (0);
FuncSummaries[FD] = S;
return S;
}
RetainSummary*
RetainSummaryManager::getCFCreateGetRuleSummary(FunctionDecl* FD,
const char* FName) {
if (strstr(FName, "Create") || strstr(FName, "Copy"))
return getCFSummaryCreateRule(FD);
if (strstr(FName, "Get"))
return getCFSummaryGetRule(FD);
return 0;
}
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.empty());
switch (func) {
case cfretain: {
ScratchArgs.push_back(std::make_pair(0, IncRef));
return getPersistentSummary(RetEffect::MakeAlias(0),
DoNothing, DoNothing);
}
case cfrelease: {
ScratchArgs.push_back(std::make_pair(0, DecRef));
return getPersistentSummary(RetEffect::MakeNoRet(),
DoNothing, DoNothing);
}
case cfmakecollectable: {
ScratchArgs.push_back(std::make_pair(0, MakeCollectable));
return getPersistentSummary(RetEffect::MakeAlias(0),DoNothing, DoNothing);
}
default:
assert (false && "Not a supported unary function.");
return 0;
}
}
RetainSummary* RetainSummaryManager::getCFSummaryCreateRule(FunctionDecl* FD) {
assert (ScratchArgs.empty());
if (FD->getIdentifier() == CFDictionaryCreateII) {
ScratchArgs.push_back(std::make_pair(1, DoNothingByRef));
ScratchArgs.push_back(std::make_pair(2, DoNothingByRef));
}
return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true));
}
RetainSummary* RetainSummaryManager::getCFSummaryGetRule(FunctionDecl* FD) {
assert (ScratchArgs.empty());
return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF),
DoNothing, DoNothing);
}
//===----------------------------------------------------------------------===//
// Summary creation for Selectors.
//===----------------------------------------------------------------------===//
RetainSummary*
RetainSummaryManager::getInitMethodSummary(QualType RetTy) {
assert(ScratchArgs.empty());
// 'init' methods only return an alias if the return type is a location type.
return getPersistentSummary(Loc::IsLocType(RetTy)
? RetEffect::MakeReceiverAlias()
: RetEffect::MakeNoRet());
}
RetainSummary*
RetainSummaryManager::getMethodSummaryFromAnnotations(const ObjCMethodDecl *MD){
if (!MD)
return 0;
assert(ScratchArgs.empty());
// Determine if there is a special return effect for this method.
bool hasRetEffect = false;
RetEffect RE = RetEffect::MakeNoRet();
if (isTrackedObjectType(MD->getResultType())) {
if (MD->getAttr<ObjCOwnershipReturnsAttr>()) {
RE = isGCEnabled() ? RetEffect::MakeGCNotOwned()
: RetEffect::MakeOwned(RetEffect::ObjC, true);
hasRetEffect = true;
}
else {
// Default to 'not owned'.
RE = RetEffect::MakeNotOwned(RetEffect::ObjC);
}
}
// Determine if there are any arguments with a specific ArgEffect.
bool hasArgEffect = false;
unsigned i = 0;
for (ObjCMethodDecl::param_iterator I = MD->param_begin(),
E = MD->param_end(); I != E; ++I, ++i) {
if ((*I)->getAttr<ObjCOwnershipRetainAttr>()) {
ScratchArgs.push_back(std::make_pair(i, IncRefMsg));
hasArgEffect = true;
}
else if ((*I)->getAttr<ObjCOwnershipCFRetainAttr>()) {
ScratchArgs.push_back(std::make_pair(i, IncRef));
hasArgEffect = true;
}
else if ((*I)->getAttr<ObjCOwnershipReleaseAttr>()) {
ScratchArgs.push_back(std::make_pair(i, DecRefMsg));
hasArgEffect = true;
}
else if ((*I)->getAttr<ObjCOwnershipCFReleaseAttr>()) {
ScratchArgs.push_back(std::make_pair(i, DecRef));
hasArgEffect = true;
}
else if ((*I)->getAttr<ObjCOwnershipMakeCollectableAttr>()) {
ScratchArgs.push_back(std::make_pair(i, MakeCollectable));
hasArgEffect = true;
}
}
if (!hasRetEffect && !hasArgEffect)
return 0;
return getPersistentSummary(RE);
}
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.getUnqualifiedType() == Ctx.VoidPtrTy)
ScratchArgs.push_back(std::make_pair(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 (CStrInCStrNoCase(&str[0], "delegate:")) ReceiverEff = StopTracking;
}
// Look for methods that return an owned object.
if (!isTrackedObjectType(RetTy)) {
if (ScratchArgs.empty() && ReceiverEff == DoNothing)
return 0;
return getPersistentSummary(RetEffect::MakeNoRet(), ReceiverEff,
MayEscape);
}
// EXPERIMENTAL: Assume the Cocoa conventions for all objects returned
// by instance methods.
RetEffect E =
followsFundamentalRule(S.getIdentifierInfoForSlot(0)->getName())
? (isGCEnabled() ? RetEffect::MakeGCNotOwned()
: RetEffect::MakeOwned(RetEffect::ObjC, true))
: RetEffect::MakeNotOwned(RetEffect::ObjC);
return getPersistentSummary(E, ReceiverEff, MayEscape);
}
RetainSummary*
RetainSummaryManager::getInstanceMethodSummary(Selector S,
IdentifierInfo *ClsName,
const ObjCInterfaceDecl* ID,
const ObjCMethodDecl *MD,
QualType RetTy) {
// Look up a summary in our summary cache.
ObjCMethodSummariesTy::iterator I = ObjCMethodSummaries.find(ID, ClsName, S);
if (I != ObjCMethodSummaries.end())
return I->second;
assert(ScratchArgs.empty());
// Annotations take precedence over all other ways to derive
// summaries.
RetainSummary *Summ = getMethodSummaryFromAnnotations(MD);
if (!Summ) {
// "initXXX": pass-through for receiver.
if (deriveNamingConvention(S.getIdentifierInfoForSlot(0)->getName())
== InitRule)
Summ = getInitMethodSummary(RetTy);
else
Summ = getCommonMethodSummary(MD, S, RetTy);
}
ObjCMethodSummaries[ObjCSummaryKey(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.");
ObjCMethodSummariesTy::iterator I =
ObjCClassMethodSummaries.find(ID, ClsName, S);
if (I != ObjCClassMethodSummaries.end())
return I->second;
// Annotations take precedence over all other ways to derive
// summaries.
RetainSummary *Summ = getMethodSummaryFromAnnotations(MD);
if (!Summ)
Summ = getCommonMethodSummary(MD, S, RetTy);
ObjCClassMethodSummaries[ObjCSummaryKey(ClsName, S)] = Summ;
return Summ;
}
void RetainSummaryManager::InitializeClassMethodSummaries() {
assert (ScratchArgs.empty());
RetEffect E = isGCEnabled() ? RetEffect::MakeGCNotOwned()
: RetEffect::MakeOwned(RetEffect::ObjC, true);
RetainSummary* Summ = getPersistentSummary(E);
// Create the summaries for "alloc", "new", and "allocWithZone:" for
// NSObject and its derivatives.
addNSObjectClsMethSummary(GetNullarySelector("alloc", Ctx), Summ);
addNSObjectClsMethSummary(GetNullarySelector("new", Ctx), Summ);
addNSObjectClsMethSummary(GetUnarySelector("allocWithZone", Ctx), Summ);
// Create the [NSAssertionHandler currentHander] summary.
addClsMethSummary(&Ctx.Idents.get("NSAssertionHandler"),
GetNullarySelector("currentHandler", Ctx),
getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC)));
// Create the [NSAutoreleasePool addObject:] summary.
ScratchArgs.push_back(std::make_pair(0, Autorelease));
addClsMethSummary(&Ctx.Idents.get("NSAutoreleasePool"),
GetUnarySelector("addObject", Ctx),
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.
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.empty());
// Create the "init" selector. It just acts as a pass-through for the
// receiver.
RetainSummary* InitSumm =
getPersistentSummary(RetEffect::MakeReceiverAlias());
addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm);
// The next methods are allocators.
RetEffect E = isGCEnabled() ? RetEffect::MakeGCNotOwned()
: RetEffect::MakeOwned(RetEffect::ObjC, true);
RetainSummary* Summ = getPersistentSummary(E);
// Create the "copy" selector.
addNSObjectMethSummary(GetNullarySelector("copy", Ctx), Summ);
// Create the "mutableCopy" selector.
addNSObjectMethSummary(GetNullarySelector("mutableCopy", Ctx), Summ);
// Create the "retain" selector.
E = RetEffect::MakeReceiverAlias();
Summ = getPersistentSummary(E, IncRefMsg);
addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ);
// Create the "release" selector.
Summ = getPersistentSummary(E, DecRefMsg);
addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ);
// Create the "drain" selector.
Summ = getPersistentSummary(E, isGCEnabled() ? DoNothing : DecRef);
addNSObjectMethSummary(GetNullarySelector("drain", Ctx), Summ);
// Create the -dealloc summary.
Summ = getPersistentSummary(RetEffect::MakeNoRet(), Dealloc);
addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ);
// Create the "autorelease" selector.
Summ = getPersistentSummary(E, Autorelease);
addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ);
// Specially handle NSAutoreleasePool.
addInstMethSummary("NSAutoreleasePool", "init",
getPersistentSummary(RetEffect::MakeReceiverAlias(),
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());
addClassMethSummary("NSWindow", "alloc", NoTrackYet);
#if 0
RetainSummary *NSWindowSumm =
getPersistentSummary(RetEffect::MakeReceiverAlias(), StopTracking);
addInstMethSummary("NSWindow", NSWindowSumm, "initWithContentRect",
"styleMask", "backing", "defer", NULL);
addInstMethSummary("NSWindow", NSWindowSumm, "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);
addInstMethSummary("NSPanel", InitSumm, "initWithContentRect",
"styleMask", "backing", "defer", NULL);
addInstMethSummary("NSPanel", InitSumm, "initWithContentRect",
"styleMask", "backing", "defer", "screen", NULL);
// Create NSAssertionHandler summaries.
addPanicSummary("NSAssertionHandler", "handleFailureInFunction", "file",
"lineNumber", "description", NULL);
addPanicSummary("NSAssertionHandler", "handleFailureInMethod", "object",
"file", "lineNumber", "description", NULL);
}
//===----------------------------------------------------------------------===//
// Reference-counting logic (typestate + counts).
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN 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.
};
private:
Kind kind;
RetEffect::ObjKind okind;
unsigned Cnt;
QualType T;
RefVal(Kind k, RetEffect::ObjKind o, unsigned cnt, QualType t)
: kind(k), okind(o), Cnt(cnt), T(t) {}
RefVal(Kind k, unsigned cnt = 0)
: kind(k), okind(RetEffect::AnyObj), Cnt(cnt) {}
public:
Kind getKind() const { return kind; }
RetEffect::ObjKind getObjKind() const { return okind; }
unsigned getCount() const { return Cnt; }
void clearCounts() { Cnt = 0; }
QualType getType() const { return T; }
// Useful predicates.
static bool isError(Kind k) { return k >= ERROR_START; }
static bool isLeak(Kind k) { return k >= ERROR_LEAK_START; }
bool isOwned() const {
return getKind() == Owned;
}
bool isNotOwned() const {
return getKind() == NotOwned;
}
bool isReturnedOwned() const {
return getKind() == ReturnedOwned;
}
bool isReturnedNotOwned() const {
return getKind() == ReturnedNotOwned;
}
bool isNonLeakError() const {
Kind k = getKind();
return isError(k) && !isLeak(k);
}
static RefVal makeOwned(RetEffect::ObjKind o, QualType t,
unsigned Count = 1) {
return RefVal(Owned, o, Count, t);
}
static RefVal makeNotOwned(RetEffect::ObjKind o, QualType t,
unsigned Count = 0) {
return RefVal(NotOwned, o, Count, t);
}
static RefVal makeReturnedOwned(unsigned Count) {
return RefVal(ReturnedOwned, Count);
}
static RefVal makeReturnedNotOwned() {
return RefVal(ReturnedNotOwned);
}
// Comparison, profiling, and pretty-printing.
bool operator==(const RefVal& X) const {
return kind == X.kind && Cnt == X.Cnt && T == X.T;
}
RefVal operator-(size_t i) const {
return RefVal(getKind(), getObjKind(), getCount() - i, getType());
}
RefVal operator+(size_t i) const {
return RefVal(getKind(), getObjKind(), getCount() + i, getType());
}
RefVal operator^(Kind k) const {
return RefVal(k, getObjKind(), getCount(), getType());
}
void Profile(llvm::FoldingSetNodeID& ID) const {
ID.AddInteger((unsigned) kind);
ID.AddInteger(Cnt);
ID.Add(T);
}
void print(std::ostream& Out) const;
};
void RefVal::print(std::ostream& Out) const {
if (!T.isNull())
Out << "Tracked Type:" << T.getAsString() << '\n';
switch (getKind()) {
default: assert(false);
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 ErrorUseAfterRelease:
Out << "Use-After-Release [ERROR]";
break;
case ErrorReleaseNotOwned:
Out << "Release of Not-Owned [ERROR]";
break;
}
}
} // end anonymous namespace
//===----------------------------------------------------------------------===//
// RefBindings - State used to track object reference counts.
//===----------------------------------------------------------------------===//
typedef llvm::ImmutableMap<SymbolRef, RefVal> RefBindings;
static int RefBIndex = 0;
static std::pair<const void*, const void*> LeakProgramPointTag(&RefBIndex, 0);
namespace clang {
template<>
struct GRStateTrait<RefBindings> : public GRStatePartialTrait<RefBindings> {
static inline void* GDMIndex() { return &RefBIndex; }
};
}
//===----------------------------------------------------------------------===//
// 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 VISIBILITY_HIDDEN AutoreleasePoolContents {}; }
namespace { class VISIBILITY_HIDDEN AutoreleaseStack {}; }
namespace clang {
template<> struct GRStateTrait<AutoreleaseStack>
: public GRStatePartialTrait<ARStack> {
static inline void* GDMIndex() { return &AutoRBIndex; }
};
template<> struct GRStateTrait<AutoreleasePoolContents>
: public GRStatePartialTrait<ARPoolContents> {
static inline void* GDMIndex() { return &AutoRCIndex; }
};
} // end clang namespace
static SymbolRef GetCurrentAutoreleasePool(const GRState* state) {
ARStack stack = state->get<AutoreleaseStack>();
return stack.isEmpty() ? SymbolRef() : stack.getHead();
}
static GRStateRef SendAutorelease(GRStateRef 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);
}
//===----------------------------------------------------------------------===//
// Transfer functions.
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN CFRefCount : public GRSimpleVals {
public:
class BindingsPrinter : public GRState::Printer {
public:
virtual void Print(std::ostream& Out, const GRState* state,
const char* nl, const char* sep);
};
private:
typedef llvm::DenseMap<const GRExprEngine::NodeTy*, const RetainSummary*>
SummaryLogTy;
RetainSummaryManager Summaries;
SummaryLogTy SummaryLog;
const LangOptions& LOpts;
ARCounts::Factory ARCountFactory;
BugType *useAfterRelease, *releaseNotOwned;
BugType *deallocGC, *deallocNotOwned;
BugType *leakWithinFunction, *leakAtReturn;
BugReporter *BR;
GRStateRef Update(GRStateRef state, SymbolRef sym, RefVal V, ArgEffect E,
RefVal::Kind& hasErr);
void ProcessNonLeakError(ExplodedNodeSet<GRState>& Dst,
GRStmtNodeBuilder<GRState>& Builder,
Expr* NodeExpr, Expr* ErrorExpr,
ExplodedNode<GRState>* Pred,
const GRState* St,
RefVal::Kind hasErr, SymbolRef Sym);
std::pair<GRStateRef, bool>
HandleSymbolDeath(GRStateManager& VMgr, const GRState* St,
const Decl* CD, SymbolRef sid, RefVal V, bool& hasLeak);
public:
CFRefCount(ASTContext& Ctx, bool gcenabled, const LangOptions& lopts)
: Summaries(Ctx, gcenabled),
LOpts(lopts), useAfterRelease(0), releaseNotOwned(0),
deallocGC(0), deallocNotOwned(0),
leakWithinFunction(0), leakAtReturn(0), BR(0) {}
virtual ~CFRefCount() {}
void RegisterChecks(BugReporter &BR);
virtual void RegisterPrinters(std::vector<GRState::Printer*>& Printers) {
Printers.push_back(new BindingsPrinter());
}
bool isGCEnabled() const { return Summaries.isGCEnabled(); }
const LangOptions& getLangOptions() const { return LOpts; }
const RetainSummary *getSummaryOfNode(const ExplodedNode<GRState> *N) const {
SummaryLogTy::const_iterator I = SummaryLog.find(N);
return I == SummaryLog.end() ? 0 : I->second;
}
// Calls.
void EvalSummary(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
Expr* Ex,
Expr* Receiver,
RetainSummary* Summ,
ExprIterator arg_beg, ExprIterator arg_end,
ExplodedNode<GRState>* Pred);
virtual void EvalCall(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
CallExpr* CE, SVal L,
ExplodedNode<GRState>* Pred);
virtual void EvalObjCMessageExpr(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Engine,
GRStmtNodeBuilder<GRState>& Builder,
ObjCMessageExpr* ME,
ExplodedNode<GRState>* Pred);
bool EvalObjCMessageExprAux(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Engine,
GRStmtNodeBuilder<GRState>& Builder,
ObjCMessageExpr* ME,
ExplodedNode<GRState>* Pred);
// Stores.
virtual void EvalBind(GRStmtNodeBuilderRef& B, SVal location, SVal val);
// End-of-path.
virtual void EvalEndPath(GRExprEngine& Engine,
GREndPathNodeBuilder<GRState>& Builder);
virtual void EvalDeadSymbols(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Engine,
GRStmtNodeBuilder<GRState>& Builder,
ExplodedNode<GRState>* Pred,
Stmt* S, const GRState* state,
SymbolReaper& SymReaper);
// Return statements.
virtual void EvalReturn(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Engine,
GRStmtNodeBuilder<GRState>& Builder,
ReturnStmt* S,
ExplodedNode<GRState>* Pred);
// Assumptions.
virtual const GRState* EvalAssume(GRStateManager& VMgr,
const GRState* St, SVal Cond,
bool Assumption, bool& isFeasible);
};
} // end anonymous namespace
static void PrintPool(std::ostream &Out, SymbolRef Sym, const GRState *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 J=cnts->begin(), EJ=cnts->end(); J != EJ; ++J)
Out << '(' << J.getKey() << ',' << J.getData() << ')';
Out << '}';
}
void CFRefCount::BindingsPrinter::Print(std::ostream& Out, const GRState* state,
const char* nl, const char* sep) {
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.
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;
}
//===----------------------------------------------------------------------===//
// Error reporting.
//===----------------------------------------------------------------------===//
namespace {
//===-------------===//
// Bug Descriptions. //
//===-------------===//
class VISIBILITY_HIDDEN CFRefBug : public BugType {
protected:
CFRefCount& TF;
CFRefBug(CFRefCount* tf, const char* name)
: BugType(name, "Memory (Core Foundation/Objective-C)"), TF(*tf) {}
public:
CFRefCount& getTF() { return TF; }
const CFRefCount& getTF() const { return TF; }
// FIXME: Eventually remove.
virtual const char* getDescription() const = 0;
virtual bool isLeak() const { return false; }
};
class VISIBILITY_HIDDEN UseAfterRelease : public CFRefBug {
public:
UseAfterRelease(CFRefCount* tf)
: CFRefBug(tf, "Use-after-release") {}
const char* getDescription() const {
return "Reference-counted object is used after it is released";
}
};
class VISIBILITY_HIDDEN BadRelease : public CFRefBug {
public:
BadRelease(CFRefCount* tf) : CFRefBug(tf, "Bad release") {}
const char* getDescription() const {
return "Incorrect decrement of the reference count of an "
"object is not owned at this point by the caller";
}
};
class VISIBILITY_HIDDEN DeallocGC : public CFRefBug {
public:
DeallocGC(CFRefCount *tf) : CFRefBug(tf,
"-dealloc called while using GC") {}
const char *getDescription() const {
return "-dealloc called while using GC";
}
};
class VISIBILITY_HIDDEN DeallocNotOwned : public CFRefBug {
public:
DeallocNotOwned(CFRefCount *tf) : CFRefBug(tf,
"-dealloc sent to non-exclusively owned object") {}
const char *getDescription() const {
return "-dealloc sent to object that may be referenced elsewhere";
}
};
class VISIBILITY_HIDDEN Leak : public CFRefBug {
const bool isReturn;
protected:
Leak(CFRefCount* tf, const char* name, bool isRet)
: CFRefBug(tf, name), isReturn(isRet) {}
public:
const char* getDescription() const { return ""; }
bool isLeak() const { return true; }
};
class VISIBILITY_HIDDEN LeakAtReturn : public Leak {
public:
LeakAtReturn(CFRefCount* tf, const char* name)
: Leak(tf, name, true) {}
};
class VISIBILITY_HIDDEN LeakWithinFunction : public Leak {
public:
LeakWithinFunction(CFRefCount* tf, const char* name)
: Leak(tf, name, false) {}
};
//===---------===//
// Bug Reports. //
//===---------===//
class VISIBILITY_HIDDEN CFRefReport : public RangedBugReport {
protected:
SymbolRef Sym;
const CFRefCount &TF;
public:
CFRefReport(CFRefBug& D, const CFRefCount &tf,
ExplodedNode<GRState> *n, SymbolRef sym)
: RangedBugReport(D, D.getDescription(), n), Sym(sym), TF(tf) {}
virtual ~CFRefReport() {}
CFRefBug& getBugType() {
return (CFRefBug&) RangedBugReport::getBugType();
}
const CFRefBug& getBugType() const {
return (const CFRefBug&) RangedBugReport::getBugType();
}
virtual void getRanges(BugReporter& BR, const SourceRange*& beg,
const SourceRange*& end) {
if (!getBugType().isLeak())
RangedBugReport::getRanges(BR, beg, end);
else
beg = end = 0;
}
SymbolRef getSymbol() const { return Sym; }
PathDiagnosticPiece* getEndPath(BugReporter& BR,
const ExplodedNode<GRState>* N);
std::pair<const char**,const char**> getExtraDescriptiveText();
PathDiagnosticPiece* VisitNode(const ExplodedNode<GRState>* N,
const ExplodedNode<GRState>* PrevN,
const ExplodedGraph<GRState>& G,
BugReporter& BR,
NodeResolver& NR);
};
class VISIBILITY_HIDDEN CFRefLeakReport : public CFRefReport {
SourceLocation AllocSite;
const MemRegion* AllocBinding;
public:
CFRefLeakReport(CFRefBug& D, const CFRefCount &tf,
ExplodedNode<GRState> *n, SymbolRef sym,
GRExprEngine& Eng);
PathDiagnosticPiece* getEndPath(BugReporter& BR,
const ExplodedNode<GRState>* N);
SourceLocation getLocation() const { return AllocSite; }
};
} // end anonymous namespace
void CFRefCount::RegisterChecks(BugReporter& BR) {
useAfterRelease = new UseAfterRelease(this);
BR.Register(useAfterRelease);
releaseNotOwned = new BadRelease(this);
BR.Register(releaseNotOwned);
deallocGC = new DeallocGC(this);
BR.Register(deallocGC);
deallocNotOwned = new DeallocNotOwned(this);
BR.Register(deallocNotOwned);
// First register "return" leaks.
const char* name = 0;
if (isGCEnabled())
name = "Leak of returned object when using garbage collection";
else if (getLangOptions().getGCMode() == LangOptions::HybridGC)
name = "Leak of returned object when not using garbage collection (GC) in "
"dual GC/non-GC code";
else {
assert(getLangOptions().getGCMode() == LangOptions::NonGC);
name = "Leak of returned object";
}
leakAtReturn = new LeakAtReturn(this, name);
BR.Register(leakAtReturn);
// Second, register leaks within a function/method.
if (isGCEnabled())
name = "Leak of object when using garbage collection";
else if (getLangOptions().getGCMode() == LangOptions::HybridGC)
name = "Leak of object when not using garbage collection (GC) in "
"dual GC/non-GC code";
else {
assert(getLangOptions().getGCMode() == LangOptions::NonGC);
name = "Leak";
}
leakWithinFunction = new LeakWithinFunction(this, name);
BR.Register(leakWithinFunction);
// Save the reference to the BugReporter.
this->BR = &BR;
}
static const char* Msgs[] = {
// GC only
"Code is compiled to only use garbage collection",
// No GC.
"Code is compiled to use reference counts",
// Hybrid, with GC.
"Code is compiled to use either garbage collection (GC) or reference counts"
" (non-GC). The bug occurs with GC enabled",
// Hybrid, without GC
"Code is compiled to use either garbage collection (GC) or reference counts"
" (non-GC). The bug occurs in non-GC mode"
};
std::pair<const char**,const char**> CFRefReport::getExtraDescriptiveText() {
CFRefCount& TF = static_cast<CFRefBug&>(getBugType()).getTF();
switch (TF.getLangOptions().getGCMode()) {
default:
assert(false);
case LangOptions::GCOnly:
assert (TF.isGCEnabled());
return std::make_pair(&Msgs[0], &Msgs[0]+1);
case LangOptions::NonGC:
assert (!TF.isGCEnabled());
return std::make_pair(&Msgs[1], &Msgs[1]+1);
case LangOptions::HybridGC:
if (TF.isGCEnabled())
return std::make_pair(&Msgs[2], &Msgs[2]+1);
else
return std::make_pair(&Msgs[3], &Msgs[3]+1);
}
}
static inline bool contains(const llvm::SmallVectorImpl<ArgEffect>& V,
ArgEffect X) {
for (llvm::SmallVectorImpl<ArgEffect>::const_iterator I=V.begin(), E=V.end();
I!=E; ++I)
if (*I == X) return true;
return false;
}
PathDiagnosticPiece* CFRefReport::VisitNode(const ExplodedNode<GRState>* N,
const ExplodedNode<GRState>* PrevN,
const ExplodedGraph<GRState>& G,
BugReporter& BR,
NodeResolver& NR) {
// Check if the type state has changed.
GRStateManager &StMgr = cast<GRBugReporter>(BR).getStateManager();
GRStateRef PrevSt(PrevN->getState(), StMgr);
GRStateRef CurrSt(N->getState(), StMgr);
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) {
Stmt* S = cast<PostStmt>(N->getLocation()).getStmt();
if (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->getNameAsString() <<'\'';
else
os << "function call";
}
else {
assert (isa<ObjCMessageExpr>(S));
os << "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 (owning reference).";
if (static_cast<CFRefBug&>(getBugType()).getTF().isGCEnabled()) {
assert(CurrV.getObjKind() == RetEffect::CF);
os << " "
"Core Foundation objects are not automatically garbage collected.";
}
}
else {
assert (CurrV.isNotOwned());
os << "+0 retain count (non-owning reference).";
}
PathDiagnosticLocation Pos(S, BR.getContext().getSourceManager());
return new PathDiagnosticEventPiece(Pos, os.str());
}
// Gather up the effects that were performed on the object at this
// program point
llvm::SmallVector<ArgEffect, 2> AEffects;
if (const RetainSummary *Summ = TF.getSummaryOfNode(NR.getOriginalNode(N))) {
// We only have summaries attached to nodes after evaluating CallExpr and
// ObjCMessageExprs.
Stmt* S = cast<PostStmt>(N->getLocation()).getStmt();
if (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::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 (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) {
if (Expr *receiver = ME->getReceiver())
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 (!TF.isGCEnabled() && 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.getCount() == 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.
Stmt* S = cast<PostStmt>(N->getLocation()).getStmt();
SVal X = CurrSt.GetSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee());
const FunctionDecl* FD = X.getAsFunctionDecl();
const std::string& FName = FD->getNameAsString();
if (TF.isGCEnabled()) {
// 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 '" << FName
<< "' 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 '" << FName
<< "' 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())
return 0;
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(TF.isGCEnabled() && 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 (non-owning) retain count.";
break;
default:
return NULL;
}
// Emit any remaining diagnostics for the argument effects (if any).
for (llvm::SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(),
E=AEffects.end(); I != E; ++I) {
// A bunch of things have alternate behavior under GC.
if (TF.isGCEnabled())
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!
Stmt* S = cast<PostStmt>(N->getLocation()).getStmt();
PathDiagnosticLocation Pos(S, BR.getContext().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::child_iterator I = S->child_begin(), E = S->child_end(); I!=E; ++I)
if (Expr* Exp = dyn_cast_or_null<Expr>(*I))
if (CurrSt.GetSValAsScalarOrLoc(Exp).getAsLocSymbol() == Sym) {
P->addRange(Exp->getSourceRange());
break;
}
return P;
}
namespace {
class VISIBILITY_HIDDEN 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<GRState>*,const MemRegion*>
GetAllocationSite(GRStateManager& StateMgr, const ExplodedNode<GRState>* N,
SymbolRef Sym) {
// Find both first node that referred to the tracked symbol and the
// memory location that value was store to.
const ExplodedNode<GRState>* Last = N;
const MemRegion* FirstBinding = 0;
while (N) {
const GRState* 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*
CFRefReport::getEndPath(BugReporter& br, const ExplodedNode<GRState>* EndN) {
// Tell the BugReporter to report cases when the tracked symbol is
// assigned to different variables, etc.
GRBugReporter& BR = cast<GRBugReporter>(br);
cast<GRBugReporter>(BR).addNotableSymbol(Sym);
return RangedBugReport::getEndPath(BR, EndN);
}
PathDiagnosticPiece*
CFRefLeakReport::getEndPath(BugReporter& br, const ExplodedNode<GRState>* EndN){
GRBugReporter& BR = cast<GRBugReporter>(br);
// Tell the BugReporter to report cases when the tracked symbol is
// assigned to different variables, etc.
cast<GRBugReporter>(BR).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<GRState>* AllocNode = 0;
const MemRegion* FirstBinding = 0;
llvm::tie(AllocNode, FirstBinding) =
GetAllocationSite(BR.getStateManager(), EndN, Sym);
// Get the allocate site.
assert(AllocNode);
Stmt* FirstStmt = cast<PostStmt>(AllocNode->getLocation()).getStmt();
SourceManager& SMgr = BR.getContext().getSourceManager();
unsigned AllocLine =SMgr.getInstantiationLineNumber(FirstStmt->getLocStart());
// 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<GRState>* LeakN = EndN;
PathDiagnosticLocation L;
while (LeakN) {
ProgramPoint P = LeakN->getLocation();
if (const PostStmt *PS = dyn_cast<PostStmt>(&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 = BR.getStateManager().getCodeDecl();
L = PathDiagnosticLocation(D.getBodyRBrace(BR.getContext()), SMgr);
}
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "Object allocated on line " << AllocLine;
if (FirstBinding)
os << " and stored into '" << FirstBinding->getString() << '\'';
// 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
// ojbects. Only "copy", "alloc", "retain" and "new" transfer ownership
// to the caller for NS objects.
ObjCMethodDecl& MD = cast<ObjCMethodDecl>(BR.getGraph().getCodeDecl());
os << " is returned from a method whose name ('"
<< MD.getSelector().getAsString()
<< "') does not contain 'copy' or otherwise starts with"
" 'new' or 'alloc'. This violates the naming convention rules given"
" in the Memory Management Guide for Cocoa (object leaked)";
}
else
os << " is no longer referenced after this point and has a retain count of"
" +" << RV->getCount() << " (object leaked)";
return new PathDiagnosticEventPiece(L, os.str());
}
CFRefLeakReport::CFRefLeakReport(CFRefBug& D, const CFRefCount &tf,
ExplodedNode<GRState> *n,
SymbolRef sym, GRExprEngine& Eng)
: CFRefReport(D, tf, n, sym)
{
// Most bug reports are cached at the location where they occured.
// 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<GRState>* AllocNode = 0;
llvm::tie(AllocNode, AllocBinding) = // Set AllocBinding.
GetAllocationSite(Eng.getStateManager(), getEndNode(), getSymbol());
// 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.getInstantiationLineNumber(AllocSite);
os << "Potential leak of object allocated on line " << AllocLine;
// FIXME: AllocBinding doesn't get populated for RegionStore yet.
if (AllocBinding)
os << " and stored into '" << AllocBinding->getString() << '\'';
}
//===----------------------------------------------------------------------===//
// Main checker logic.
//===----------------------------------------------------------------------===//
static inline ArgEffect GetArgE(RetainSummary* Summ, unsigned idx) {
return Summ ? Summ->getArg(idx) : MayEscape;
}
static inline RetEffect GetRetEffect(RetainSummary* Summ) {
return Summ ? Summ->getRetEffect() : RetEffect::MakeNoRet();
}
static inline ArgEffect GetReceiverE(RetainSummary* Summ) {
return Summ ? Summ->getReceiverEffect() : DoNothing;
}
static inline bool IsEndPath(RetainSummary* Summ) {
return Summ ? Summ->isEndPath() : false;
}
/// 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).
static QualType GetReturnType(Expr* RetE, ASTContext& Ctx) {
QualType RetTy = RetE->getType();
// FIXME: We aren't handling id<...>.
const PointerType* PT = RetTy->getAsPointerType();
if (!PT)
return RetTy;
// If RetEx is not a message expression just return its type.
// If RetEx is a message expression, return its types if it is something
/// more specific than id.
ObjCMessageExpr* ME = dyn_cast<ObjCMessageExpr>(RetE);
if (!ME || !Ctx.isObjCIdStructType(PT->getPointeeType()))
return RetTy;
ObjCInterfaceDecl* D = ME->getClassInfo().first;
// At this point we know the return type of the message expression is id.
// If we have an ObjCInterceDecl, we know this is a call to a class method
// whose type we can resolve. In such cases, promote the return type to
// Class*.
return !D ? RetTy : Ctx.getPointerType(Ctx.getObjCInterfaceType(D));
}
void CFRefCount::EvalSummary(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
Expr* Ex,
Expr* Receiver,
RetainSummary* Summ,
ExprIterator arg_beg, ExprIterator arg_end,
ExplodedNode<GRState>* Pred) {
// Get the state.
GRStateRef state(Builder.GetState(Pred), Eng.getStateManager());
ASTContext& Ctx = Eng.getStateManager().getContext();
// Evaluate the effect of the arguments.
RefVal::Kind hasErr = (RefVal::Kind) 0;
unsigned idx = 0;
Expr* ErrorExpr = NULL;
SymbolRef ErrorSym = 0;
for (ExprIterator I = arg_beg; I != arg_end; ++I, ++idx) {
SVal V = state.GetSValAsScalarOrLoc(*I);
SymbolRef Sym = V.getAsLocSymbol();
if (Sym)
if (RefBindings::data_type* T = state.get<RefBindings>(Sym)) {
state = Update(state, Sym, *T, GetArgE(Summ, idx), hasErr);
if (hasErr) {
ErrorExpr = *I;
ErrorSym = Sym;
break;
}
continue;
}
if (isa<Loc>(V)) {
if (loc::MemRegionVal* MR = dyn_cast<loc::MemRegionVal>(&V)) {
if (GetArgE(Summ, idx) == DoNothingByRef)
continue;
// Invalidate the value of the variable passed by reference.
// FIXME: Either this logic should also be replicated in GRSimpleVals
// or should be pulled into a separate "constraint engine."
// FIXME: We can have collisions on the conjured symbol if the
// expression *I also creates conjured symbols. We probably want
// to identify conjured symbols by an expression pair: the enclosing
// expression (the context) and the expression itself. This should
// disambiguate conjured symbols.
const TypedRegion* R = dyn_cast<TypedRegion>(MR->getRegion());
if (R) {
// Is the invalidated variable something that we were tracking?
SymbolRef Sym = state.GetSValAsScalarOrLoc(R).getAsLocSymbol();
// Remove any existing reference-count binding.
if (Sym) state = state.remove<RefBindings>(Sym);
if (R->isBoundable(Ctx)) {
// Set the value of the variable to be a conjured symbol.
unsigned Count = Builder.getCurrentBlockCount();
QualType T = R->getRValueType(Ctx);
if (Loc::IsLocType(T) || (T->isIntegerType() && T->isScalarType())){
ValueManager &ValMgr = Eng.getValueManager();
SVal V = ValMgr.getConjuredSymbolVal(*I, T, Count);
state = state.BindLoc(Loc::MakeVal(R), V);
}
else if (const RecordType *RT = T->getAsStructureType()) {
// Handle structs in a not so awesome way. Here we just
// eagerly bind new symbols to the fields. In reality we
// should have the store manager handle this. The idea is just
// to prototype some basic functionality here. All of this logic
// should one day soon just go away.
const RecordDecl *RD = RT->getDecl()->getDefinition(Ctx);
// No record definition. There is nothing we can do.
if (!RD)
continue;
MemRegionManager &MRMgr = state.getManager().getRegionManager();
// Iterate through the fields and construct new symbols.
for (RecordDecl::field_iterator FI=RD->field_begin(Ctx),
FE=RD->field_end(Ctx); FI!=FE; ++FI) {
// For now just handle scalar fields.
FieldDecl *FD = *FI;
QualType FT = FD->getType();
if (Loc::IsLocType(FT) ||
(FT->isIntegerType() && FT->isScalarType())) {
const FieldRegion* FR = MRMgr.getFieldRegion(FD, R);
ValueManager &ValMgr = Eng.getValueManager();
SVal V = ValMgr.getConjuredSymbolVal(*I, FT, Count);
state = state.BindLoc(Loc::MakeVal(FR), V);
}
}
}
else {
// Just blast away other values.
state = state.BindLoc(*MR, UnknownVal());
}
}
}
else
state = state.BindLoc(*MR, UnknownVal());
}
else {
// Nuke all other arguments passed by reference.
state = state.Unbind(cast<Loc>(V));
}
}
else if (isa<nonloc::LocAsInteger>(V))
state = state.Unbind(cast<nonloc::LocAsInteger>(V).getLoc());
}
// Evaluate the effect on the message receiver.
if (!ErrorExpr && Receiver) {
SymbolRef Sym = state.GetSValAsScalarOrLoc(Receiver).getAsLocSymbol();
if (Sym) {
if (const RefVal* T = state.get<RefBindings>(Sym)) {
state = Update(state, Sym, *T, GetReceiverE(Summ), hasErr);
if (hasErr) {
ErrorExpr = Receiver;
ErrorSym = Sym;
}
}
}
}
// Process any errors.
if (hasErr) {
ProcessNonLeakError(Dst, Builder, Ex, ErrorExpr, Pred, state,
hasErr, ErrorSym);
return;
}
// Consult the summary for the return value.
RetEffect RE = GetRetEffect(Summ);
switch (RE.getKind()) {
default:
assert (false && "Unhandled RetEffect."); break;
case RetEffect::NoRet: {
// Make up a symbol for the return value (not reference counted).
// FIXME: This is basically copy-and-paste from GRSimpleVals. We
// should compose behavior, not copy it.
// FIXME: We eventually should handle structs and other compound types
// that are returned by value.
QualType T = Ex->getType();
if (Loc::IsLocType(T) || (T->isIntegerType() && T->isScalarType())) {
unsigned Count = Builder.getCurrentBlockCount();
ValueManager &ValMgr = Eng.getValueManager();
SVal X = ValMgr.getConjuredSymbolVal(Ex, T, Count);
state = state.BindExpr(Ex, X, false);
}
break;
}
case RetEffect::Alias: {
unsigned idx = RE.getIndex();
assert (arg_end >= arg_beg);
assert (idx < (unsigned) (arg_end - arg_beg));
SVal V = state.GetSValAsScalarOrLoc(*(arg_beg+idx));
state = state.BindExpr(Ex, V, false);
break;
}
case RetEffect::ReceiverAlias: {
assert (Receiver);
SVal V = state.GetSValAsScalarOrLoc(Receiver);
state = state.BindExpr(Ex, V, false);
break;
}
case RetEffect::OwnedAllocatedSymbol:
case RetEffect::OwnedSymbol: {
unsigned Count = Builder.getCurrentBlockCount();
ValueManager &ValMgr = Eng.getValueManager();
SymbolRef Sym = ValMgr.getConjuredSymbol(Ex, Count);
QualType RetT = GetReturnType(Ex, ValMgr.getContext());
state = state.set<RefBindings>(Sym, RefVal::makeOwned(RE.getObjKind(),
RetT));
state = state.BindExpr(Ex, ValMgr.makeRegionVal(Sym), false);
// FIXME: Add a flag to the checker where allocations are assumed to
// *not fail.
#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::NotOwnedSymbol: {
unsigned Count = Builder.getCurrentBlockCount();
ValueManager &ValMgr = Eng.getValueManager();
SymbolRef Sym = ValMgr.getConjuredSymbol(Ex, Count);
QualType RetT = GetReturnType(Ex, ValMgr.getContext());
state = state.set<RefBindings>(Sym, RefVal::makeNotOwned(RE.getObjKind(),
RetT));
state = state.BindExpr(Ex, ValMgr.makeRegionVal(Sym), false);
break;
}
}
// Generate a sink node if we are at the end of a path.
GRExprEngine::NodeTy *NewNode =
IsEndPath(Summ) ? Builder.MakeSinkNode(Dst, Ex, Pred, state)
: Builder.MakeNode(Dst, Ex, Pred, state);
// Annotate the edge with summary we used.
// FIXME: This assumes that we always use the same summary when generating
// this node.
if (NewNode) SummaryLog[NewNode] = Summ;
}
void CFRefCount::EvalCall(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
CallExpr* CE, SVal L,
ExplodedNode<GRState>* Pred) {
const FunctionDecl* FD = L.getAsFunctionDecl();
RetainSummary* Summ = !FD ? 0
: Summaries.getSummary(const_cast<FunctionDecl*>(FD));
EvalSummary(Dst, Eng, Builder, CE, 0, Summ,
CE->arg_begin(), CE->arg_end(), Pred);
}
void CFRefCount::EvalObjCMessageExpr(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
ObjCMessageExpr* ME,
ExplodedNode<GRState>* Pred) {
RetainSummary* Summ;
if (Expr* Receiver = ME->getReceiver()) {
// We need the type-information of the tracked receiver object
// Retrieve it from the state.
ObjCInterfaceDecl* ID = 0;
// FIXME: Wouldn't it be great if this code could be reduced? It's just
// a chain of lookups.
// FIXME: Is this really working as expected? There are cases where
// we just use the 'ID' from the message expression.
const GRState* St = Builder.GetState(Pred);
SVal V = Eng.getStateManager().GetSValAsScalarOrLoc(St, Receiver);
SymbolRef Sym = V.getAsLocSymbol();
if (Sym) {
if (const RefVal* T = St->get<RefBindings>(Sym)) {
QualType Ty = T->getType();
if (const PointerType* PT = Ty->getAsPointerType()) {
QualType PointeeTy = PT->getPointeeType();
if (ObjCInterfaceType* IT = dyn_cast<ObjCInterfaceType>(PointeeTy))
ID = IT->getDecl();
}
}
}
// FIXME: The receiver could be a reference to a class, meaning that
// we should use the class method.
Summ = Summaries.getInstanceMethodSummary(ME, ID);
// Special-case: are we sending a mesage to "self"?
// This is a hack. When we have full-IP this should be removed.
if (!Summ) {
ObjCMethodDecl* MD =
dyn_cast<ObjCMethodDecl>(&Eng.getGraph().getCodeDecl());
if (MD) {
if (Expr* Receiver = ME->getReceiver()) {
SVal X = Eng.getStateManager().GetSValAsScalarOrLoc(St, Receiver);
if (loc::MemRegionVal* L = dyn_cast<loc::MemRegionVal>(&X))
if (L->getRegion() == Eng.getStateManager().getSelfRegion(St)) {
// Create a summmary where all of the arguments "StopTracking".
Summ = Summaries.getPersistentSummary(RetEffect::MakeNoRet(),
DoNothing,
StopTracking);
}
}
}
}
}
else
Summ = Summaries.getClassMethodSummary(ME);
EvalSummary(Dst, Eng, Builder, ME, ME->getReceiver(), Summ,
ME->arg_begin(), ME->arg_end(), Pred);
}
namespace {
class VISIBILITY_HIDDEN StopTrackingCallback : public SymbolVisitor {
GRStateRef state;
public:
StopTrackingCallback(GRStateRef st) : state(st) {}
GRStateRef getState() { return state; }
bool VisitSymbol(SymbolRef sym) {
state = state.remove<RefBindings>(sym);
return true;
}
const GRState* getState() const { return state.getState(); }
};
} // end anonymous namespace
void CFRefCount::EvalBind(GRStmtNodeBuilderRef& B, SVal location, SVal val) {
// Are we storing to something that causes the value to "escape"?
bool escapes = false;
// 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.
GRStateRef state = B.getState();
if (!isa<loc::MemRegionVal>(location))
escapes = true;
else {
const MemRegion* R = cast<loc::MemRegionVal>(location).getRegion();
escapes = !B.getStateManager().hasStackStorage(R);
if (!escapes) {
// To test (3), generate a new state with the binding removed. If it is
// the same state, then it escapes (since the store cannot represent
// the binding).
escapes = (state == (state.BindLoc(cast<Loc>(location), UnknownVal())));
}
}
// 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.
B.MakeNode(state.scanReachableSymbols<StopTrackingCallback>(val).getState());
}
std::pair<GRStateRef,bool>
CFRefCount::HandleSymbolDeath(GRStateManager& VMgr,
const GRState* St, const Decl* CD,
SymbolRef sid,
RefVal V, bool& hasLeak) {
// Any remaining leaks?
hasLeak = V.isOwned() ||
((V.isNotOwned() || V.isReturnedOwned()) && V.getCount() > 0);
GRStateRef state(St, VMgr);
if (!hasLeak)
return std::make_pair(state.remove<RefBindings>(sid), false);
return std::make_pair(state.set<RefBindings>(sid, V ^ RefVal::ErrorLeak),
false);
}
// Dead symbols.
// Return statements.
void CFRefCount::EvalReturn(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
ReturnStmt* S,
ExplodedNode<GRState>* Pred) {
Expr* RetE = S->getRetValue();
if (!RetE)
return;
GRStateRef state(Builder.GetState(Pred), Eng.getStateManager());
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 = RefVal::makeReturnedOwned(cnt - 1);
break;
}
case RefVal::NotOwned: {
unsigned cnt = X.getCount();
X = cnt ? RefVal::makeReturnedOwned(cnt - 1)
: RefVal::makeReturnedNotOwned();
break;
}
default:
return;
}
// Update the binding.
state = state.set<RefBindings>(Sym, X);
Pred = Builder.MakeNode(Dst, S, Pred, state);
// Any leaks or other errors?
if (X.isReturnedOwned() && X.getCount() == 0) {
const Decl *CD = &Eng.getStateManager().getCodeDecl();
if (const ObjCMethodDecl* MD = dyn_cast<ObjCMethodDecl>(CD)) {
RetainSummary *Summ = Summaries.getMethodSummary(MD);
if (!GetRetEffect(Summ).isOwned()) {
static int ReturnOwnLeakTag = 0;
state = state.set<RefBindings>(Sym, X ^ RefVal::ErrorLeakReturned);
// Generate an error node.
ExplodedNode<GRState> *N =
Builder.generateNode(PostStmt(S, &ReturnOwnLeakTag), state, Pred);
CFRefLeakReport *report =
new CFRefLeakReport(*static_cast<CFRefBug*>(leakAtReturn), *this,
N, Sym, Eng);
BR->EmitReport(report);
}
}
}
}
// Assumptions.
const GRState* CFRefCount::EvalAssume(GRStateManager& VMgr,
const GRState* St,
SVal Cond, bool Assumption,
bool& isFeasible) {
// 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 = St->get<RefBindings>();
if (B.isEmpty())
return St;
bool changed = false;
GRStateRef state(St, VMgr);
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 (VMgr.getSymVal(St, I.getKey())) {
changed = true;
B = RefBFactory.Remove(B, I.getKey());
}
}
if (changed)
state = state.set<RefBindings>(B);
return state;
}
GRStateRef CFRefCount::Update(GRStateRef state, SymbolRef sym,
RefVal V, ArgEffect E,
RefVal::Kind& hasErr) {
// In GC mode [... release] and [... retain] do nothing.
switch (E) {
default: break;
case IncRefMsg: E = isGCEnabled() ? DoNothing : IncRef; break;
case DecRefMsg: E = isGCEnabled() ? DoNothing : DecRef; break;
case MakeCollectable: E = isGCEnabled() ? DecRef : DoNothing; break;
case NewAutoreleasePool: E = isGCEnabled() ? DoNothing :
NewAutoreleasePool; break;
}
// Handle all use-after-releases.
if (!isGCEnabled() && V.getKind() == RefVal::Released) {
V = V ^ RefVal::ErrorUseAfterRelease;
hasErr = V.getKind();
return state.set<RefBindings>(sym, V);
}
switch (E) {
default:
assert (false && "Unhandled CFRef transition.");
case Dealloc:
// Any use of -dealloc in GC is *bad*.
if (isGCEnabled()) {
V = V ^ RefVal::ErrorDeallocGC;
hasErr = V.getKind();
break;
}
switch (V.getKind()) {
default:
assert(false && "Invalid case.");
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(!isGCEnabled());
return state.add<AutoreleaseStack>(sym);
case MayEscape:
if (V.getKind() == RefVal::Owned) {
V = V ^ RefVal::NotOwned;
break;
}
// Fall-through.
case DoNothingByRef:
case DoNothing:
return state;
case Autorelease:
if (isGCEnabled())
return state;
// Update the autorelease counts.
state = SendAutorelease(state, ARCountFactory, sym);
// Fall-through.
case StopTracking:
return state.remove<RefBindings>(sym);
case IncRef:
switch (V.getKind()) {
default:
assert(false);
case RefVal::Owned:
case RefVal::NotOwned:
V = V + 1;
break;
case RefVal::Released:
// Non-GC cases are handled above.
assert(isGCEnabled());
V = (V ^ RefVal::Owned) + 1;
break;
}
break;
case SelfOwn:
V = V ^ RefVal::NotOwned;
// Fall-through.
case DecRef:
switch (V.getKind()) {
default:
// case 'RefVal::Released' handled above.
assert (false);
case RefVal::Owned:
assert(V.getCount() > 0);
if (V.getCount() == 1) V = V ^ 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(isGCEnabled());
V = V ^ RefVal::ErrorUseAfterRelease;
hasErr = V.getKind();
break;
}
break;
}
return state.set<RefBindings>(sym, V);
}
//===----------------------------------------------------------------------===//
// Handle dead symbols and end-of-path.
//===----------------------------------------------------------------------===//
void CFRefCount::EvalEndPath(GRExprEngine& Eng,
GREndPathNodeBuilder<GRState>& Builder) {
const GRState* St = Builder.getState();
RefBindings B = St->get<RefBindings>();
llvm::SmallVector<std::pair<SymbolRef, bool>, 10> Leaked;
const Decl* CodeDecl = &Eng.getGraph().getCodeDecl();
for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
bool hasLeak = false;
std::pair<GRStateRef, bool> X =
HandleSymbolDeath(Eng.getStateManager(), St, CodeDecl,
(*I).first, (*I).second, hasLeak);
St = X.first;
if (hasLeak) Leaked.push_back(std::make_pair((*I).first, X.second));
}
if (Leaked.empty())
return;
ExplodedNode<GRState>* N = Builder.MakeNode(St);
if (!N)
return;
for (llvm::SmallVector<std::pair<SymbolRef,bool>, 10>::iterator
I = Leaked.begin(), E = Leaked.end(); I != E; ++I) {
CFRefBug *BT = static_cast<CFRefBug*>(I->second ? leakAtReturn
: leakWithinFunction);
assert(BT && "BugType not initialized.");
CFRefLeakReport* report = new CFRefLeakReport(*BT, *this, N, I->first, Eng);
BR->EmitReport(report);
}
}
void CFRefCount::EvalDeadSymbols(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
ExplodedNode<GRState>* Pred,
Stmt* S,
const GRState* St,
SymbolReaper& SymReaper) {
// FIXME: a lot of copy-and-paste from EvalEndPath. Refactor.
RefBindings B = St->get<RefBindings>();
llvm::SmallVector<std::pair<SymbolRef,bool>, 10> Leaked;
for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(),
E = SymReaper.dead_end(); I != E; ++I) {
const RefVal* T = B.lookup(*I);
if (!T) continue;
bool hasLeak = false;
std::pair<GRStateRef, bool> X
= HandleSymbolDeath(Eng.getStateManager(), St, 0, *I, *T, hasLeak);
St = X.first;
if (hasLeak)
Leaked.push_back(std::make_pair(*I,X.second));
}
if (!Leaked.empty()) {
// Create a new intermediate node representing the leak point. We
// use a special program point that represents this checker-specific
// transition. We use the address of RefBIndex as a unique tag for this
// checker. We will create another node (if we don't cache out) that
// removes the retain-count bindings from the state.
// NOTE: We use 'generateNode' so that it does interplay with the
// auto-transition logic.
ExplodedNode<GRState>* N =
Builder.generateNode(PostStmtCustom(S, &LeakProgramPointTag), St, Pred);
if (!N)
return;
// Generate the bug reports.
for (llvm::SmallVectorImpl<std::pair<SymbolRef,bool> >::iterator
I = Leaked.begin(), E = Leaked.end(); I != E; ++I) {
CFRefBug *BT = static_cast<CFRefBug*>(I->second ? leakAtReturn
: leakWithinFunction);
assert(BT && "BugType not initialized.");
CFRefLeakReport* report = new CFRefLeakReport(*BT, *this, N,
I->first, Eng);
BR->EmitReport(report);
}
Pred = N;
}
// Now generate a new node that nukes the old bindings.
GRStateRef state(St, Eng.getStateManager());
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);
Builder.MakeNode(Dst, S, Pred, state);
}
void CFRefCount::ProcessNonLeakError(ExplodedNodeSet<GRState>& Dst,
GRStmtNodeBuilder<GRState>& Builder,
Expr* NodeExpr, Expr* ErrorExpr,
ExplodedNode<GRState>* Pred,
const GRState* St,
RefVal::Kind hasErr, SymbolRef Sym) {
Builder.BuildSinks = true;
GRExprEngine::NodeTy* N = Builder.MakeNode(Dst, NodeExpr, Pred, St);
if (!N) return;
CFRefBug *BT = 0;
switch (hasErr) {
default:
assert(false && "Unhandled error.");
return;
case RefVal::ErrorUseAfterRelease:
BT = static_cast<CFRefBug*>(useAfterRelease);
break;
case RefVal::ErrorReleaseNotOwned:
BT = static_cast<CFRefBug*>(releaseNotOwned);
break;
case RefVal::ErrorDeallocGC:
BT = static_cast<CFRefBug*>(deallocGC);
break;
case RefVal::ErrorDeallocNotOwned:
BT = static_cast<CFRefBug*>(deallocNotOwned);
break;
}
CFRefReport *report = new CFRefReport(*BT, *this, N, Sym);
report->addRange(ErrorExpr->getSourceRange());
BR->EmitReport(report);
}
//===----------------------------------------------------------------------===//
// Transfer function creation for external clients.
//===----------------------------------------------------------------------===//
GRTransferFuncs* clang::MakeCFRefCountTF(ASTContext& Ctx, bool GCEnabled,
const LangOptions& lopts) {
return new CFRefCount(Ctx, GCEnabled, lopts);
}