Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / clang / 2dabd4372c50019fa00aae223ce634e0e754a3f2 / . / lib / Analysis / CFRefCount.cpp
blob: cb0cbd16812211496469dbdfa9d6cef8cac52a1e [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/GRState.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/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 <sstream>
#include <stdarg.h>
using namespace clang;
//===----------------------------------------------------------------------===//
// Utility functions.
//===----------------------------------------------------------------------===//
using llvm::CStrInCStrNoCase;
// 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."
//
static bool followsFundamentalRule(const char* s) {
while (*s == '_') ++s;
return CStrInCStrNoCase(s, "create") || CStrInCStrNoCase(s, "copy") ||
CStrInCStrNoCase(s, "new") == s || CStrInCStrNoCase(s, "alloc") == s;
}
static bool followsReturnRule(const char* s) {
while (*s == '_') ++s;
return followsFundamentalRule(s) || CStrInCStrNoCase(s, "init") == s;
}
//===----------------------------------------------------------------------===//
// 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 isCFRefType(QualType T) {
if (!T->isPointerType())
return false;
// Check the typedef for the name "CF" and the substring "Ref".
TypedefType* TD = dyn_cast<TypedefType>(T.getTypePtr());
if (!TD)
return false;
const char* TDName = TD->getDecl()->getIdentifier()->getName();
assert (TDName);
if (TDName[0] != 'C' || TDName[1] != 'F')
return false;
if (strstr(TDName, "Ref") == 0)
return false;
return true;
}
static bool isCGRefType(QualType T) {
if (!T->isPointerType())
return false;
// Check the typedef for the name "CG" and the substring "Ref".
TypedefType* TD = dyn_cast<TypedefType>(T.getTypePtr());
if (!TD)
return false;
const char* TDName = TD->getDecl()->getIdentifier()->getName();
assert (TDName);
if (TDName[0] != 'C' || TDName[1] != 'G')
return false;
if (strstr(TDName, "Ref") == 0)
return false;
return true;
}
static bool isNSType(QualType T) {
if (!T->isPointerType())
return false;
ObjCInterfaceType* OT = dyn_cast<ObjCInterfaceType>(T.getTypePtr());
if (!OT)
return false;
const char* ClsName = OT->getDecl()->getIdentifier()->getName();
assert (ClsName);
if (ClsName[0] != 'N' || ClsName[1] != 'S')
return false;
return true;
}
//===----------------------------------------------------------------------===//
// 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 { IncRef, DecRef, DoNothing, DoNothingByRef,
StopTracking, MayEscape, SelfOwn, Autorelease };
/// 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, ReceiverAlias };
private:
unsigned Data;
RetEffect(Kind k, unsigned D = 0) { Data = (D << 3) | (unsigned) k; }
public:
Kind getKind() const { return (Kind) (Data & 0x7); }
unsigned getIndex() const {
assert(getKind() == Alias);
return Data >> 3;
}
static RetEffect MakeAlias(unsigned Idx) {
return RetEffect(Alias, Idx);
}
static RetEffect MakeReceiverAlias() {
return RetEffect(ReceiverAlias);
}
static RetEffect MakeOwned(bool isAllocated = false) {
return RetEffect(isAllocated ? OwnedAllocatedSymbol : OwnedSymbol);
}
static RetEffect MakeNotOwned() {
return RetEffect(NotOwnedSymbol);
}
static RetEffect MakeNoRet() {
return RetEffect(NoRet);
}
operator Kind() const {
return getKind();
}
void Profile(llvm::FoldingSetNodeID& ID) const {
ID.AddInteger(Data);
}
};
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(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(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(FunctionDecl* FD, UnaryFuncKind func);
RetainSummary* getNSSummary(FunctionDecl* FD, const char* FName);
RetainSummary* getCFSummary(FunctionDecl* FD, const char* FName);
RetainSummary* getCGSummary(FunctionDecl* FD, const char* FName);
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(ObjCMessageExpr* ME);
void InitializeClassMethodSummaries();
void InitializeMethodSummaries();
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 addInstMethSummary(const char* Cls, RetainSummary* Summ, va_list argp) {
IdentifierInfo* ClsII = &Ctx.Idents.get(Cls);
llvm::SmallVector<IdentifierInfo*, 10> II;
while (const char* s = va_arg(argp, const char*))
II.push_back(&Ctx.Idents.get(s));
Selector S = Ctx.Selectors.getSelector(II.size(), &II[0]);
ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ;
}
void addInstMethSummary(const char* Cls, RetainSummary* Summ, ...) {
va_list argp;
va_start(argp, Summ);
addInstMethSummary(Cls, 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);
addInstMethSummary(Cls, 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* getMethodSummary(ObjCMessageExpr* ME, ObjCInterfaceDecl* ID);
RetainSummary* getClassMethodSummary(IdentifierInfo* ClsName, Selector S);
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;
}
//===----------------------------------------------------------------------===//
// Summary creation for functions (largely uses of Core Foundation).
//===----------------------------------------------------------------------===//
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.
const char* FName = FD->getIdentifier()->getName();
RetainSummary *S = 0;
FunctionType* FT = dyn_cast<FunctionType>(FD->getType());
do {
if (FT) {
QualType T = FT->getResultType();
if (isCFRefType(T)) {
S = getCFSummary(FD, FName);
break;
}
if (isCGRefType(T)) {
S = getCGSummary(FD, FName );
break;
}
// 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;
}
}
// Ignore the prefix '_'
while (*FName == '_') ++FName;
if (FName[0] == 'C') {
if (FName[1] == 'F')
S = getCFSummary(FD, FName);
else if (FName[1] == 'G')
S = getCGSummary(FD, FName);
}
else if (FName[0] == 'N' && FName[1] == 'S')
S = getNSSummary(FD, FName);
}
while (0);
FuncSummaries[FD] = S;
return S;
}
RetainSummary* RetainSummaryManager::getNSSummary(FunctionDecl* FD,
const char* FName) {
FName += 2;
if (strcmp(FName, "MakeCollectable") == 0)
return getUnarySummary(FD, cfmakecollectable);
return 0;
}
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::getCFSummary(FunctionDecl* FD,
const char* FName) {
if (FName[0] == 'C' && FName[1] == 'F')
FName += 2;
if (isRetain(FD, FName))
return getUnarySummary(FD, cfretain);
if (isRelease(FD, FName))
return getUnarySummary(FD, cfrelease);
if (strcmp(FName, "MakeCollectable") == 0)
return getUnarySummary(FD, cfmakecollectable);
return getCFCreateGetRuleSummary(FD, FName);
}
RetainSummary* RetainSummaryManager::getCGSummary(FunctionDecl* FD,
const char* FName) {
if (FName[0] == 'C' && FName[1] == 'G')
FName += 2;
if (isRelease(FD, FName))
return getUnarySummary(FD, cfrelease);
if (isRetain(FD, FName))
return getUnarySummary(FD, cfretain);
return getCFCreateGetRuleSummary(FD, FName);
}
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(FunctionDecl* FD, UnaryFuncKind func) {
FunctionTypeProto* FT =
dyn_cast<FunctionTypeProto>(FD->getType().getTypePtr());
if (FT) {
if (FT->getNumArgs() != 1)
return 0;
TypedefType* ArgT = dyn_cast<TypedefType>(FT->getArgType(0).getTypePtr());
if (!ArgT)
return 0;
if (!ArgT->isPointerType())
return NULL;
}
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: {
if (GCEnabled)
ScratchArgs.push_back(std::make_pair(0, DecRef));
return getPersistentSummary(RetEffect::MakeAlias(0),
DoNothing, DoNothing);
}
default:
assert (false && "Not a supported unary function.");
return 0;
}
}
RetainSummary* RetainSummaryManager::getCFSummaryCreateRule(FunctionDecl* FD) {
FunctionType* FT =
dyn_cast<FunctionType>(FD->getType().getTypePtr());
if (FT) {
QualType ResTy = FT->getResultType();
if (!isCFRefType(ResTy) && !isCGRefType(ResTy))
return getPersistentSummary(RetEffect::MakeNoRet());
}
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(true));
}
RetainSummary* RetainSummaryManager::getCFSummaryGetRule(FunctionDecl* FD) {
FunctionType* FT =
dyn_cast<FunctionType>(FD->getType().getTypePtr());
if (FT) {
QualType RetTy = FT->getResultType();
// FIXME: For now we assume that all pointer types returned are referenced
// counted. Since this is the "Get" rule, we assume non-ownership, which
// works fine for things that are not reference counted. We do this because
// some generic data structures return "void*". We need something better
// in the future.
if (!isCFRefType(RetTy) && !RetTy->isPointerType())
return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
}
// FIXME: Add special-cases for functions that retain/release. For now
// just handle the default case.
assert (ScratchArgs.empty());
return getPersistentSummary(RetEffect::MakeNotOwned(), DoNothing, DoNothing);
}
//===----------------------------------------------------------------------===//
// Summary creation for Selectors.
//===----------------------------------------------------------------------===//
RetainSummary*
RetainSummaryManager::getInitMethodSummary(ObjCMessageExpr* ME) {
assert(ScratchArgs.empty());
RetainSummary* Summ =
getPersistentSummary(RetEffect::MakeReceiverAlias());
ObjCMethodSummaries[ME] = Summ;
return Summ;
}
RetainSummary*
RetainSummaryManager::getMethodSummary(ObjCMessageExpr* ME,
ObjCInterfaceDecl* ID) {
Selector S = ME->getSelector();
// Look up a summary in our summary cache.
ObjCMethodSummariesTy::iterator I = ObjCMethodSummaries.find(ID, S);
if (I != ObjCMethodSummaries.end())
return I->second;
if (!ME->getType()->isPointerType())
return 0;
// "initXXX": pass-through for receiver.
const char* s = S.getIdentifierInfoForSlot(0)->getName();
assert (ScratchArgs.empty());
if (strncmp(s, "init", 4) == 0 || strncmp(s, "_init", 5) == 0)
return getInitMethodSummary(ME);
// "copyXXX", "createXXX", "newXXX": allocators.
if (!isNSType(ME->getReceiver()->getType()))
return 0;
if (followsFundamentalRule(s)) {
RetEffect E = isGCEnabled() ? RetEffect::MakeNoRet()
: RetEffect::MakeOwned(true);
RetainSummary* Summ = getPersistentSummary(E);
ObjCMethodSummaries[ME] = Summ;
return Summ;
}
return 0;
}
RetainSummary*
RetainSummaryManager::getClassMethodSummary(IdentifierInfo* ClsName,
Selector S) {
// FIXME: Eventually we should properly do class method summaries, but
// it requires us being able to walk the type hierarchy. Unfortunately,
// we cannot do this with just an IdentifierInfo* for the class name.
// Look up a summary in our cache of Selectors -> Summaries.
ObjCMethodSummariesTy::iterator I = ObjCClassMethodSummaries.find(ClsName, S);
if (I != ObjCClassMethodSummaries.end())
return I->second;
return 0;
}
void RetainSummaryManager::InitializeClassMethodSummaries() {
assert (ScratchArgs.empty());
RetEffect E = isGCEnabled() ? RetEffect::MakeNoRet()
: RetEffect::MakeOwned(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()));
// Create the [NSAutoreleasePool addObject:] summary.
if (!isGCEnabled()) {
ScratchArgs.push_back(std::make_pair(0, Autorelease));
addClsMethSummary(&Ctx.Idents.get("NSAutoreleasePool"),
GetUnarySelector("addObject", Ctx),
getPersistentSummary(RetEffect::MakeNoRet(),
DoNothing, DoNothing));
}
}
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::MakeNoRet()
: RetEffect::MakeOwned(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, isGCEnabled() ? DoNothing : IncRef);
addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ);
// Create the "release" selector.
Summ = getPersistentSummary(E, isGCEnabled() ? DoNothing : DecRef);
addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ);
// Create the "drain" selector.
Summ = getPersistentSummary(E, isGCEnabled() ? DoNothing : DecRef);
addNSObjectMethSummary(GetNullarySelector("drain", Ctx), Summ);
// Create the "autorelease" selector.
Summ = getPersistentSummary(E, isGCEnabled() ? DoNothing : Autorelease);
addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ);
// For NSWindow, allocated objects are (initially) self-owned.
RetainSummary *NSWindowSumm =
getPersistentSummary(RetEffect::MakeReceiverAlias(), SelfOwn);
addInstMethSummary("NSWindow", NSWindowSumm, "initWithContentRect",
"styleMask", "backing", "defer", NULL);
addInstMethSummary("NSWindow", NSWindowSumm, "initWithContentRect",
"styleMask", "backing", "defer", "screen", NULL);
// For NSPanel (which subclasses NSWindow), allocated objects are not
// self-owned.
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.
ErrorUseAfterRelease, // Object used after released.
ErrorReleaseNotOwned, // Release of an object that was not owned.
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;
unsigned Cnt;
QualType T;
RefVal(Kind k, unsigned cnt, QualType t) : kind(k), Cnt(cnt), T(t) {}
RefVal(Kind k, unsigned cnt = 0) : kind(k), Cnt(cnt) {}
public:
Kind getKind() const { return kind; }
unsigned getCount() const { return Cnt; }
QualType getType() const { return T; }
// Useful predicates.
static bool isError(Kind k) { return k >= ErrorUseAfterRelease; }
static bool isLeak(Kind k) { return k >= ErrorLeak; }
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);
}
// State creation: normal state.
static RefVal makeOwned(QualType t, unsigned Count = 1) {
return RefVal(Owned, Count, t);
}
static RefVal makeNotOwned(QualType t, unsigned Count = 0) {
return RefVal(NotOwned, 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(), getCount() - i, getType());
}
RefVal operator+(size_t i) const {
return RefVal(getKind(), getCount() + i, getType());
}
RefVal operator^(Kind k) const {
return RefVal(k, 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 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;
namespace clang {
template<>
struct GRStateTrait<RefBindings> : public GRStatePartialTrait<RefBindings> {
static inline void* GDMIndex() { return &RefBIndex; }
};
}
//===----------------------------------------------------------------------===//
// ARBindings - State used to track objects in autorelease pools.
//===----------------------------------------------------------------------===//
typedef llvm::ImmutableSet<SymbolRef> ARPoolContents;
typedef llvm::ImmutableList< std::pair<SymbolRef, ARPoolContents*> > ARBindings;
static int AutoRBIndex = 0;
namespace clang {
template<>
struct GRStateTrait<ARBindings> : public GRStatePartialTrait<ARBindings> {
static inline void* GDMIndex() { return &AutoRBIndex; }
};
}
//===----------------------------------------------------------------------===//
// Transfer functions.
//===----------------------------------------------------------------------===//
namespace {
class VISIBILITY_HIDDEN CFRefCount : public GRSimpleVals {
public:
// Type definitions.
typedef llvm::DenseMap<GRExprEngine::NodeTy*,std::pair<Expr*, SymbolRef> >
ReleasesNotOwnedTy;
typedef ReleasesNotOwnedTy UseAfterReleasesTy;
typedef llvm::DenseMap<GRExprEngine::NodeTy*,
std::vector<std::pair<SymbolRef,bool> >*>
LeaksTy;
class BindingsPrinter : public GRState::Printer {
public:
virtual void Print(std::ostream& Out, const GRState* state,
const char* nl, const char* sep);
};
private:
RetainSummaryManager Summaries;
const LangOptions& LOpts;
UseAfterReleasesTy UseAfterReleases;
ReleasesNotOwnedTy ReleasesNotOwned;
LeaksTy Leaks;
RefBindings Update(RefBindings B, SymbolRef sym, RefVal V, ArgEffect E,
RefVal::Kind& hasErr, RefBindings::Factory& RefBFactory);
RefVal::Kind& Update(GRStateRef& state, SymbolRef sym, RefVal V,
ArgEffect E, RefVal::Kind& hasErr) {
state = state.set<RefBindings>(Update(state.get<RefBindings>(), sym, V,
E, hasErr,
state.get_context<RefBindings>()));
return 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) {}
virtual ~CFRefCount() {
for (LeaksTy::iterator I = Leaks.begin(), E = Leaks.end(); I!=E; ++I)
delete I->second;
}
virtual void RegisterChecks(GRExprEngine& Eng);
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; }
// 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 EvalStore(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Engine,
GRStmtNodeBuilder<GRState>& Builder,
Expr* E, ExplodedNode<GRState>* Pred,
const GRState* St, SVal TargetLV, 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* St,
const GRStateManager::DeadSymbolsTy& Dead);
// 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);
// Error iterators.
typedef UseAfterReleasesTy::iterator use_after_iterator;
typedef ReleasesNotOwnedTy::iterator bad_release_iterator;
typedef LeaksTy::iterator leaks_iterator;
use_after_iterator use_after_begin() { return UseAfterReleases.begin(); }
use_after_iterator use_after_end() { return UseAfterReleases.end(); }
bad_release_iterator bad_release_begin() { return ReleasesNotOwned.begin(); }
bad_release_iterator bad_release_end() { return ReleasesNotOwned.end(); }
leaks_iterator leaks_begin() { return Leaks.begin(); }
leaks_iterator leaks_end() { return Leaks.end(); }
};
} // end anonymous namespace
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;
}
}
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;
}
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;
switch (hasErr) {
default: assert(false);
case RefVal::ErrorUseAfterRelease:
UseAfterReleases[N] = std::make_pair(ErrorExpr, Sym);
break;
case RefVal::ErrorReleaseNotOwned:
ReleasesNotOwned[N] = std::make_pair(ErrorExpr, Sym);
break;
}
}
/// 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.isObjCIdType(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.GetSVal(*I);
if (isa<loc::SymbolVal>(V)) {
SymbolRef Sym = cast<loc::SymbolVal>(V).getSymbol();
if (RefBindings::data_type* T = state.get<RefBindings>(Sym))
if (Update(state, Sym, *T, GetArgE(Summ, idx), hasErr)) {
ErrorExpr = *I;
ErrorSym = Sym;
break;
}
}
else if (isa<Loc>(V)) {
#if 0
// Nuke all arguments passed by reference.
StateMgr.Unbind(StVals, cast<Loc>(V));
#else
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.
// Is the invalidated variable something that we were tracking?
SVal X = state.GetSVal(*MR);
if (isa<loc::SymbolVal>(X)) {
SymbolRef Sym = cast<loc::SymbolVal>(X).getSymbol();
state = state.remove<RefBindings>(Sym);
}
const TypedRegion* R = dyn_cast<TypedRegion>(MR->getRegion());
if (R) {
// Set the value of the variable to be a conjured symbol.
unsigned Count = Builder.getCurrentBlockCount();
QualType T = R->getType(Ctx);
// FIXME: handle structs.
if (Loc::IsLocType(T) || (T->isIntegerType() && T->isScalarType())) {
SymbolRef NewSym =
Eng.getSymbolManager().getConjuredSymbol(*I, T, Count);
state = state.BindLoc(*MR,
Loc::IsLocType(T)
? cast<SVal>(loc::SymbolVal(NewSym))
: cast<SVal>(nonloc::SymbolVal(NewSym)));
}
else {
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));
}
#endif
}
else if (isa<nonloc::LocAsInteger>(V))
state = state.Unbind(cast<nonloc::LocAsInteger>(V).getLoc());
}
// Evaluate the effect on the message receiver.
if (!ErrorExpr && Receiver) {
SVal V = state.GetSVal(Receiver);
if (isa<loc::SymbolVal>(V)) {
SymbolRef Sym = cast<loc::SymbolVal>(V).getSymbol();
if (const RefVal* T = state.get<RefBindings>(Sym))
if (Update(state, Sym, *T, GetReceiverE(Summ), 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();
SymbolRef Sym = Eng.getSymbolManager().getConjuredSymbol(Ex, Count);
SVal X = Loc::IsLocType(Ex->getType())
? cast<SVal>(loc::SymbolVal(Sym))
: cast<SVal>(nonloc::SymbolVal(Sym));
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.GetSVal(*(arg_beg+idx));
state = state.BindExpr(Ex, V, false);
break;
}
case RetEffect::ReceiverAlias: {
assert (Receiver);
SVal V = state.GetSVal(Receiver);
state = state.BindExpr(Ex, V, false);
break;
}
case RetEffect::OwnedAllocatedSymbol:
case RetEffect::OwnedSymbol: {
unsigned Count = Builder.getCurrentBlockCount();
SymbolRef Sym = Eng.getSymbolManager().getConjuredSymbol(Ex, Count);
QualType RetT = GetReturnType(Ex, Eng.getContext());
state = state.set<RefBindings>(Sym, RefVal::makeOwned(RetT));
state = state.BindExpr(Ex, loc::SymbolVal(Sym), false);
#if 0
RefBindings B = GetRefBindings(StImpl);
SetRefBindings(StImpl, RefBFactory.Add(B, Sym, RefVal::makeOwned(RetT)));
#endif
// FIXME: Add a flag to the checker where allocations are allowed to fail.
if (RE.getKind() == RetEffect::OwnedAllocatedSymbol)
state = state.AddNE(Sym, Eng.getBasicVals().getZeroWithPtrWidth());
break;
}
case RetEffect::NotOwnedSymbol: {
unsigned Count = Builder.getCurrentBlockCount();
SymbolRef Sym = Eng.getSymbolManager().getConjuredSymbol(Ex, Count);
QualType RetT = GetReturnType(Ex, Eng.getContext());
state = state.set<RefBindings>(Sym, RefVal::makeNotOwned(RetT));
state = state.BindExpr(Ex, loc::SymbolVal(Sym), false);
break;
}
}
// Is this a sink?
if (IsEndPath(Summ))
Builder.MakeSinkNode(Dst, Ex, Pred, state);
else
Builder.MakeNode(Dst, Ex, Pred, state);
}
void CFRefCount::EvalCall(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
CallExpr* CE, SVal L,
ExplodedNode<GRState>* Pred) {
RetainSummary* Summ = !isa<loc::FuncVal>(L) ? 0
: Summaries.getSummary(cast<loc::FuncVal>(L).getDecl());
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.
const GRState* St = Builder.GetState(Pred);
SVal V = Eng.getStateManager().GetSVal(St, Receiver );
if (isa<loc::SymbolVal>(V)) {
SymbolRef Sym = cast<loc::SymbolVal>(V).getSymbol();
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();
}
}
}
Summ = Summaries.getMethodSummary(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().GetSVal(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->getClassName(),
ME->getSelector());
EvalSummary(Dst, Eng, Builder, ME, ME->getReceiver(), Summ,
ME->arg_begin(), ME->arg_end(), Pred);
}
// Stores.
void CFRefCount::EvalStore(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
Expr* E, ExplodedNode<GRState>* Pred,
const GRState* St, SVal TargetLV, SVal Val) {
// Check if we have a binding for "Val" and if we are storing it to something
// we don't understand or otherwise the value "escapes" the function.
if (!isa<loc::SymbolVal>(Val))
return;
// 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.
SymbolRef Sym = cast<loc::SymbolVal>(Val).getSymbol();
GRStateRef state(St, Eng.getStateManager());
if (!isa<loc::MemRegionVal>(TargetLV))
escapes = true;
else {
const MemRegion* R = cast<loc::MemRegionVal>(TargetLV).getRegion();
escapes = !Eng.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).
GRStateRef stateNew = state.BindLoc(cast<Loc>(TargetLV), Val);
escapes = (stateNew == state);
}
}
if (!escapes)
return;
// Do we have a reference count binding?
// FIXME: Is this step even needed? We do blow away the binding anyway.
if (!state.get<RefBindings>(Sym))
return;
// Nuke the binding.
state = state.remove<RefBindings>(Sym);
// Hand of the remaining logic to the parent implementation.
GRSimpleVals::EvalStore(Dst, Eng, Builder, E, Pred, state, TargetLV, Val);
}
// End-of-path.
std::pair<GRStateRef,bool>
CFRefCount::HandleSymbolDeath(GRStateManager& VMgr,
const GRState* St, const Decl* CD,
SymbolRef sid,
RefVal V, bool& hasLeak) {
GRStateRef state(St, VMgr);
assert ((!V.isReturnedOwned() || CD) &&
"CodeDecl must be available for reporting ReturnOwned errors.");
if (V.isReturnedOwned() && V.getCount() == 0)
if (const ObjCMethodDecl* MD = dyn_cast<ObjCMethodDecl>(CD)) {
std::string s = MD->getSelector().getAsString();
if (!followsReturnRule(s.c_str())) {
hasLeak = true;
state = state.set<RefBindings>(sid, V ^ RefVal::ErrorLeakReturned);
return std::make_pair(state, true);
}
}
// All other cases.
hasLeak = V.isOwned() ||
((V.isNotOwned() || V.isReturnedOwned()) && V.getCount() > 0);
if (!hasLeak)
return std::make_pair(state.remove<RefBindings>(sid), false);
return std::make_pair(state.set<RefBindings>(sid, V ^ RefVal::ErrorLeak),
false);
}
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;
std::vector<std::pair<SymbolRef,bool> >*& LeaksAtNode = Leaks[N];
assert (!LeaksAtNode);
LeaksAtNode = new std::vector<std::pair<SymbolRef,bool> >();
for (llvm::SmallVector<std::pair<SymbolRef,bool>, 10>::iterator
I = Leaked.begin(), E = Leaked.end(); I != E; ++I)
(*LeaksAtNode).push_back(*I);
}
// Dead symbols.
void CFRefCount::EvalDeadSymbols(ExplodedNodeSet<GRState>& Dst,
GRExprEngine& Eng,
GRStmtNodeBuilder<GRState>& Builder,
ExplodedNode<GRState>* Pred,
Stmt* S,
const GRState* St,
const GRStateManager::DeadSymbolsTy& Dead) {
// FIXME: a lot of copy-and-paste from EvalEndPath. Refactor.
RefBindings B = St->get<RefBindings>();
llvm::SmallVector<std::pair<SymbolRef,bool>, 10> Leaked;
for (GRStateManager::DeadSymbolsTy::const_iterator
I=Dead.begin(), E=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())
return;
ExplodedNode<GRState>* N = Builder.MakeNode(Dst, S, Pred, St);
if (!N)
return;
std::vector<std::pair<SymbolRef,bool> >*& LeaksAtNode = Leaks[N];
assert (!LeaksAtNode);
LeaksAtNode = new std::vector<std::pair<SymbolRef,bool> >();
for (llvm::SmallVector<std::pair<SymbolRef,bool>, 10>::iterator
I = Leaked.begin(), E = Leaked.end(); I != E; ++I)
(*LeaksAtNode).push_back(*I);
}
// 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());
SVal V = state.GetSVal(RetE);
if (!isa<loc::SymbolVal>(V))
return;
// Get the reference count binding (if any).
SymbolRef Sym = cast<loc::SymbolVal>(V).getSymbol();
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);
Builder.MakeNode(Dst, S, Pred, state);
}
// 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;
}
RefBindings CFRefCount::Update(RefBindings B, SymbolRef sym,
RefVal V, ArgEffect E,
RefVal::Kind& hasErr,
RefBindings::Factory& RefBFactory) {
// FIXME: This dispatch can potentially be sped up by unifiying it into
// a single switch statement. Opt for simplicity for now.
switch (E) {
default:
assert (false && "Unhandled CFRef transition.");
case MayEscape:
if (V.getKind() == RefVal::Owned) {
V = V ^ RefVal::NotOwned;
break;
}
// Fall-through.
case DoNothingByRef:
case DoNothing:
if (!isGCEnabled() && V.getKind() == RefVal::Released) {
V = V ^ RefVal::ErrorUseAfterRelease;
hasErr = V.getKind();
break;
}
return B;
case Autorelease:
case StopTracking:
return RefBFactory.Remove(B, sym);
case IncRef:
switch (V.getKind()) {
default:
assert(false);
case RefVal::Owned:
case RefVal::NotOwned:
V = V + 1;
break;
case RefVal::Released:
if (isGCEnabled())
V = V ^ RefVal::Owned;
else {
V = V ^ RefVal::ErrorUseAfterRelease;
hasErr = V.getKind();
}
break;
}
break;
case SelfOwn:
V = V ^ RefVal::NotOwned;
// Fall-through.
case DecRef:
switch (V.getKind()) {
default:
assert (false);
case RefVal::Owned:
V = V.getCount() > 1 ? V - 1 : V ^ RefVal::Released;
break;
case RefVal::NotOwned:
if (V.getCount() > 0)
V = V - 1;
else {
V = V ^ RefVal::ErrorReleaseNotOwned;
hasErr = V.getKind();
}
break;
case RefVal::Released:
V = V ^ RefVal::ErrorUseAfterRelease;
hasErr = V.getKind();
break;
}
break;
}
return RefBFactory.Add(B, sym, V);
}
//===----------------------------------------------------------------------===//
// Error reporting.
//===----------------------------------------------------------------------===//
namespace {
//===-------------===//
// Bug Descriptions. //
//===-------------===//
class VISIBILITY_HIDDEN CFRefBug : public BugTypeCacheLocation {
protected:
CFRefCount& TF;
public:
CFRefBug(CFRefCount& tf) : TF(tf) {}
CFRefCount& getTF() { return TF; }
const CFRefCount& getTF() const { return TF; }
virtual bool isLeak() const { return false; }
const char* getCategory() const {
return "Memory (Core Foundation/Objective-C)";
}
};
class VISIBILITY_HIDDEN UseAfterRelease : public CFRefBug {
public:
UseAfterRelease(CFRefCount& tf) : CFRefBug(tf) {}
virtual const char* getName() const {
return "use-after-release";
}
virtual const char* getDescription() const {
return "Reference-counted object is used after it is released.";
}
virtual void EmitWarnings(BugReporter& BR);
};
class VISIBILITY_HIDDEN BadRelease : public CFRefBug {
public:
BadRelease(CFRefCount& tf) : CFRefBug(tf) {}
virtual const char* getName() const {
return "bad release";
}
virtual const char* getDescription() const {
return "Incorrect decrement of the reference count of a "
"CoreFoundation object: "
"The object is not owned at this point by the caller.";
}
virtual void EmitWarnings(BugReporter& BR);
};
class VISIBILITY_HIDDEN Leak : public CFRefBug {
bool isReturn;
public:
Leak(CFRefCount& tf) : CFRefBug(tf) {}
void setIsReturn(bool x) { isReturn = x; }
virtual const char* getName() const {
if (!isReturn) {
if (getTF().isGCEnabled())
return "leak (GC)";
if (getTF().getLangOptions().getGCMode() == LangOptions::HybridGC)
return "leak (hybrid MM, non-GC)";
assert (getTF().getLangOptions().getGCMode() == LangOptions::NonGC);
return "leak";
}
else {
if (getTF().isGCEnabled())
return "[naming convention] leak of returned object (GC)";
if (getTF().getLangOptions().getGCMode() == LangOptions::HybridGC)
return "[naming convention] leak of returned object (hybrid MM, "
"non-GC)";
assert (getTF().getLangOptions().getGCMode() == LangOptions::NonGC);
return "[naming convention] leak of returned object";
}
}
virtual const char* getDescription() const {
return "Object leaked";
}
virtual void EmitWarnings(BugReporter& BR);
virtual void GetErrorNodes(std::vector<ExplodedNode<GRState>*>& Nodes);
virtual bool isLeak() const { return true; }
virtual bool isCached(BugReport& R);
};
//===---------===//
// Bug Reports. //
//===---------===//
class VISIBILITY_HIDDEN CFRefReport : public RangedBugReport {
SymbolRef Sym;
public:
CFRefReport(CFRefBug& D, ExplodedNode<GRState> *n, SymbolRef sym)
: RangedBugReport(D, n), Sym(sym) {}
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; }
virtual PathDiagnosticPiece* getEndPath(BugReporter& BR,
ExplodedNode<GRState>* N);
virtual std::pair<const char**,const char**> getExtraDescriptiveText();
virtual PathDiagnosticPiece* VisitNode(ExplodedNode<GRState>* N,
ExplodedNode<GRState>* PrevN,
ExplodedGraph<GRState>& G,
BugReporter& BR);
};
} // end anonymous namespace
void CFRefCount::RegisterChecks(GRExprEngine& Eng) {
Eng.Register(new UseAfterRelease(*this));
Eng.Register(new BadRelease(*this));
Eng.Register(new Leak(*this));
}
static const char* Msgs[] = {
"Code is compiled in garbage collection only mode" // GC only
" (the bug occurs with garbage collection enabled).",
"Code is compiled without garbage collection.", // No GC.
"Code is compiled for use with and without garbage collection (GC)."
" The bug occurs with GC enabled.", // Hybrid, with GC.
"Code is compiled for use with and without garbage collection (GC)."
" The bug occurs in non-GC mode." // Hyrbird, without GC/
};
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);
}
}
PathDiagnosticPiece* CFRefReport::VisitNode(ExplodedNode<GRState>* N,
ExplodedNode<GRState>* PrevN,
ExplodedGraph<GRState>& G,
BugReporter& BR) {
// Check if the type state has changed.
const GRState* PrevSt = PrevN->getState();
const GRState* CurrSt = N->getState();
RefBindings PrevB = PrevSt->get<RefBindings>();
RefBindings CurrB = CurrSt->get<RefBindings>();
const RefVal* PrevT = PrevB.lookup(Sym);
const RefVal* CurrT = CurrB.lookup(Sym);
if (!CurrT)
return NULL;
const char* Msg = NULL;
const RefVal& CurrV = *CurrB.lookup(Sym);
if (!PrevT) {
Stmt* S = cast<PostStmt>(N->getLocation()).getStmt();
if (CurrV.isOwned()) {
if (isa<CallExpr>(S))
Msg = "Function call returns an object with a +1 retain count"
" (owning reference).";
else {
assert (isa<ObjCMessageExpr>(S));
Msg = "Method returns an object with a +1 retain count"
" (owning reference).";
}
}
else {
assert (CurrV.isNotOwned());
if (isa<CallExpr>(S))
Msg = "Function call returns an object with a +0 retain count"
" (non-owning reference).";
else {
assert (isa<ObjCMessageExpr>(S));
Msg = "Method returns an object with a +0 retain count"
" (non-owning reference).";
}
}
FullSourceLoc Pos(S->getLocStart(), BR.getContext().getSourceManager());
PathDiagnosticPiece* P = new PathDiagnosticPiece(Pos, Msg);
if (Expr* Exp = dyn_cast<Expr>(S))
P->addRange(Exp->getSourceRange());
return P;
}
// Determine if the typestate has changed.
RefVal PrevV = *PrevB.lookup(Sym);
if (PrevV == CurrV)
return NULL;
// The typestate has changed.
std::ostringstream os;
std::string s;
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 << " Object has +" << Count;
if (Count > 1)
os << " retain counts.";
else
os << " retain count.";
}
s = os.str();
Msg = s.c_str();
break;
case RefVal::Released:
Msg = "Object released.";
break;
case RefVal::ReturnedOwned:
Msg = "Object returned to caller as an owning reference (single retain "
"count transferred to caller).";
break;
case RefVal::ReturnedNotOwned:
Msg = "Object returned to caller with a +0 (non-owning) retain count.";
break;
default:
return NULL;
}
Stmt* S = cast<PostStmt>(N->getLocation()).getStmt();
FullSourceLoc Pos(S->getLocStart(), BR.getContext().getSourceManager());
PathDiagnosticPiece* P = new PathDiagnosticPiece(Pos, Msg);
// Add the range by scanning the children of the statement for any bindings
// to Sym.
GRStateManager& VSM = cast<GRBugReporter>(BR).getStateManager();
for (Stmt::child_iterator I = S->child_begin(), E = S->child_end(); I!=E; ++I)
if (Expr* Exp = dyn_cast_or_null<Expr>(*I)) {
SVal X = VSM.GetSVal(CurrSt, Exp);
if (loc::SymbolVal* SV = dyn_cast<loc::SymbolVal>(&X))
if (SV->getSymbol() == Sym) {
P->addRange(Exp->getSourceRange()); break;
}
}
return P;
}
namespace {
class VISIBILITY_HIDDEN FindUniqueBinding :
public StoreManager::BindingsHandler {
SymbolRef Sym;
MemRegion* Binding;
bool First;
public:
FindUniqueBinding(SymbolRef sym) : Sym(sym), Binding(0), First(true) {}
bool HandleBinding(StoreManager& SMgr, Store store, MemRegion* R, SVal val) {
if (const loc::SymbolVal* SV = dyn_cast<loc::SymbolVal>(&val)) {
if (SV->getSymbol() != Sym)
return true;
}
else if (const nonloc::SymbolVal* SV=dyn_cast<nonloc::SymbolVal>(&val)) {
if (SV->getSymbol() != Sym)
return true;
}
else
return true;
if (Binding) {
First = false;
return false;
}
else
Binding = R;
return true;
}
operator bool() { return First && Binding; }
MemRegion* getRegion() { return Binding; }
};
}
static std::pair<ExplodedNode<GRState>*,MemRegion*>
GetAllocationSite(GRStateManager* StateMgr, ExplodedNode<GRState>* N,
SymbolRef Sym) {
// Find both first node that referred to the tracked symbol and the
// memory location that value was store to.
ExplodedNode<GRState>* Last = N;
MemRegion* FirstBinding = 0;
while (N) {
const GRState* St = N->getState();
RefBindings B = St->get<RefBindings>();
if (!B.lookup(Sym))
break;
if (StateMgr) {
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,
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);
if (!getBugType().isLeak())
return RangedBugReport::getEndPath(BR, EndN);
// We are 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.
ExplodedNode<GRState>* AllocNode = 0;
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.getLogicalLineNumber(FirstStmt->getLocStart());
// Get the leak site. We may have multiple ExplodedNodes (one with the
// leak) that occur on the same line number; if the node with the leak
// has any immediate predecessor nodes with the same line number, find
// any transitive-successors that have a different statement and use that
// line number instead. This avoids emiting a diagnostic like:
//
// // 'y' is leaked.
// int x = foo(y);
//
// instead we want:
//
// int x = foo(y);
// // 'y' is leaked.
Stmt* S = getStmt(BR); // This is the statement where the leak occured.
assert (S);
unsigned EndLine = SMgr.getLogicalLineNumber(S->getLocStart());
// Look in the *trimmed* graph at the immediate predecessor of EndN. Does
// it occur on the same line?
PathDiagnosticPiece::DisplayHint Hint = PathDiagnosticPiece::Above;
assert (!EndN->pred_empty()); // Not possible to have 0 predecessors.
ExplodedNode<GRState> *Pred = *(EndN->pred_begin());
ProgramPoint PredPos = Pred->getLocation();
if (PostStmt* PredPS = dyn_cast<PostStmt>(&PredPos)) {
Stmt* SPred = PredPS->getStmt();
// Predecessor at same line?
if (SMgr.getLogicalLineNumber(SPred->getLocStart()) != EndLine) {
Hint = PathDiagnosticPiece::Below;
S = SPred;
}
}
// Generate the diagnostic.
FullSourceLoc L( S->getLocStart(), SMgr);
std::ostringstream os;
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 'create' or '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 PathDiagnosticPiece(L, os.str(), Hint);
}
void UseAfterRelease::EmitWarnings(BugReporter& BR) {
for (CFRefCount::use_after_iterator I = TF.use_after_begin(),
E = TF.use_after_end(); I != E; ++I) {
CFRefReport report(*this, I->first, I->second.second);
report.addRange(I->second.first->getSourceRange());
BR.EmitWarning(report);
}
}
void BadRelease::EmitWarnings(BugReporter& BR) {
for (CFRefCount::bad_release_iterator I = TF.bad_release_begin(),
E = TF.bad_release_end(); I != E; ++I) {
CFRefReport report(*this, I->first, I->second.second);
report.addRange(I->second.first->getSourceRange());
BR.EmitWarning(report);
}
}
void Leak::EmitWarnings(BugReporter& BR) {
for (CFRefCount::leaks_iterator I = TF.leaks_begin(),
E = TF.leaks_end(); I != E; ++I) {
std::vector<std::pair<SymbolRef, bool> >& SymV = *(I->second);
unsigned n = SymV.size();
for (unsigned i = 0; i < n; ++i) {
setIsReturn(SymV[i].second);
CFRefReport report(*this, I->first, SymV[i].first);
BR.EmitWarning(report);
}
}
}
void Leak::GetErrorNodes(std::vector<ExplodedNode<GRState>*>& Nodes) {
for (CFRefCount::leaks_iterator I=TF.leaks_begin(), E=TF.leaks_end();
I!=E; ++I)
Nodes.push_back(I->first);
}
bool Leak::isCached(BugReport& R) {
// 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.
SymbolRef Sym = static_cast<CFRefReport&>(R).getSymbol();
ExplodedNode<GRState>* AllocNode =
GetAllocationSite(0, R.getEndNode(), Sym).first;
if (!AllocNode)
return false;
return BugTypeCacheLocation::isCached(AllocNode->getLocation());
}
//===----------------------------------------------------------------------===//
// Transfer function creation for external clients.
//===----------------------------------------------------------------------===//
GRTransferFuncs* clang::MakeCFRefCountTF(ASTContext& Ctx, bool GCEnabled,
const LangOptions& lopts) {
return new CFRefCount(Ctx, GCEnabled, lopts);
}