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authordim <dim@FreeBSD.org>2013-04-08 18:45:10 +0000
committerdim <dim@FreeBSD.org>2013-04-08 18:45:10 +0000
commitc72c57c9e9b69944e3e009cd5e209634839581d3 (patch)
tree4fc2f184c499d106f29a386c452b49e5197bf63d /lib/StaticAnalyzer/Checkers/MallocChecker.cpp
parent5b20025c30d23d521e12c1f33ec8fa6b821952cd (diff)
downloadFreeBSD-src-c72c57c9e9b69944e3e009cd5e209634839581d3.zip
FreeBSD-src-c72c57c9e9b69944e3e009cd5e209634839581d3.tar.gz
Vendor import of clang trunk r178860:
http://llvm.org/svn/llvm-project/cfe/trunk@178860
Diffstat (limited to 'lib/StaticAnalyzer/Checkers/MallocChecker.cpp')
-rw-r--r--lib/StaticAnalyzer/Checkers/MallocChecker.cpp1096
1 files changed, 769 insertions, 327 deletions
diff --git a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index caf70ca..4b0e766 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -14,18 +14,19 @@
#include "ClangSACheckers.h"
#include "InterCheckerAPI.h"
+#include "clang/AST/Attr.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
-#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
-#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/ImmutableMap.h"
-#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include <climits>
@@ -34,6 +35,14 @@ using namespace ento;
namespace {
+// Used to check correspondence between allocators and deallocators.
+enum AllocationFamily {
+ AF_None,
+ AF_Malloc,
+ AF_CXXNew,
+ AF_CXXNewArray
+};
+
class RefState {
enum Kind { // Reference to allocated memory.
Allocated,
@@ -41,33 +50,55 @@ class RefState {
Released,
// The responsibility for freeing resources has transfered from
// this reference. A relinquished symbol should not be freed.
- Relinquished } K;
+ Relinquished };
+
const Stmt *S;
+ unsigned K : 2; // Kind enum, but stored as a bitfield.
+ unsigned Family : 30; // Rest of 32-bit word, currently just an allocation
+ // family.
+ RefState(Kind k, const Stmt *s, unsigned family)
+ : S(s), K(k), Family(family) {}
public:
- RefState(Kind k, const Stmt *s) : K(k), S(s) {}
-
bool isAllocated() const { return K == Allocated; }
bool isReleased() const { return K == Released; }
bool isRelinquished() const { return K == Relinquished; }
-
+ AllocationFamily getAllocationFamily() const {
+ return (AllocationFamily)Family;
+ }
const Stmt *getStmt() const { return S; }
bool operator==(const RefState &X) const {
- return K == X.K && S == X.S;
+ return K == X.K && S == X.S && Family == X.Family;
}
- static RefState getAllocated(const Stmt *s) {
- return RefState(Allocated, s);
+ static RefState getAllocated(unsigned family, const Stmt *s) {
+ return RefState(Allocated, s, family);
+ }
+ static RefState getReleased(unsigned family, const Stmt *s) {
+ return RefState(Released, s, family);
}
- static RefState getReleased(const Stmt *s) { return RefState(Released, s); }
- static RefState getRelinquished(const Stmt *s) {
- return RefState(Relinquished, s);
+ static RefState getRelinquished(unsigned family, const Stmt *s) {
+ return RefState(Relinquished, s, family);
}
void Profile(llvm::FoldingSetNodeID &ID) const {
ID.AddInteger(K);
ID.AddPointer(S);
+ ID.AddInteger(Family);
+ }
+
+ void dump(raw_ostream &OS) const {
+ static const char *Table[] = {
+ "Allocated",
+ "Released",
+ "Relinquished"
+ };
+ OS << Table[(unsigned) K];
+ }
+
+ LLVM_ATTRIBUTE_USED void dump() const {
+ dump(llvm::errs());
}
};
@@ -99,24 +130,27 @@ struct ReallocPair {
}
};
-typedef std::pair<const Stmt*, const MemRegion*> LeakInfo;
+typedef std::pair<const ExplodedNode*, const MemRegion*> LeakInfo;
class MallocChecker : public Checker<check::DeadSymbols,
- check::EndPath,
+ check::PointerEscape,
+ check::ConstPointerEscape,
check::PreStmt<ReturnStmt>,
check::PreStmt<CallExpr>,
check::PostStmt<CallExpr>,
+ check::PostStmt<CXXNewExpr>,
+ check::PreStmt<CXXDeleteExpr>,
check::PostStmt<BlockExpr>,
check::PostObjCMessage,
check::Location,
- check::Bind,
- eval::Assume,
- check::RegionChanges>
+ eval::Assume>
{
mutable OwningPtr<BugType> BT_DoubleFree;
mutable OwningPtr<BugType> BT_Leak;
mutable OwningPtr<BugType> BT_UseFree;
mutable OwningPtr<BugType> BT_BadFree;
+ mutable OwningPtr<BugType> BT_MismatchedDealloc;
+ mutable OwningPtr<BugType> BT_OffsetFree;
mutable IdentifierInfo *II_malloc, *II_free, *II_realloc, *II_calloc,
*II_valloc, *II_reallocf, *II_strndup, *II_strdup;
@@ -129,32 +163,33 @@ public:
struct ChecksFilter {
DefaultBool CMallocPessimistic;
DefaultBool CMallocOptimistic;
+ DefaultBool CNewDeleteChecker;
+ DefaultBool CMismatchedDeallocatorChecker;
};
ChecksFilter Filter;
void checkPreStmt(const CallExpr *S, CheckerContext &C) const;
void checkPostStmt(const CallExpr *CE, CheckerContext &C) const;
+ void checkPostStmt(const CXXNewExpr *NE, CheckerContext &C) const;
+ void checkPreStmt(const CXXDeleteExpr *DE, CheckerContext &C) const;
void checkPostObjCMessage(const ObjCMethodCall &Call, CheckerContext &C) const;
void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
- void checkEndPath(CheckerContext &C) const;
void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const;
ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond,
bool Assumption) const;
void checkLocation(SVal l, bool isLoad, const Stmt *S,
CheckerContext &C) const;
- void checkBind(SVal location, SVal val, const Stmt*S,
- CheckerContext &C) const;
- ProgramStateRef
- checkRegionChanges(ProgramStateRef state,
- const StoreManager::InvalidatedSymbols *invalidated,
- ArrayRef<const MemRegion *> ExplicitRegions,
- ArrayRef<const MemRegion *> Regions,
- const CallEvent *Call) const;
- bool wantsRegionChangeUpdate(ProgramStateRef state) const {
- return true;
- }
+
+ ProgramStateRef checkPointerEscape(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call,
+ PointerEscapeKind Kind) const;
+ ProgramStateRef checkConstPointerEscape(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call,
+ PointerEscapeKind Kind) const;
void printState(raw_ostream &Out, ProgramStateRef State,
const char *NL, const char *Sep) const;
@@ -162,31 +197,52 @@ public:
private:
void initIdentifierInfo(ASTContext &C) const;
+ /// \brief Determine family of a deallocation expression.
+ AllocationFamily getAllocationFamily(CheckerContext &C, const Stmt *S) const;
+
+ /// \brief Print names of allocators and deallocators.
+ ///
+ /// \returns true on success.
+ bool printAllocDeallocName(raw_ostream &os, CheckerContext &C,
+ const Expr *E) const;
+
+ /// \brief Print expected name of an allocator based on the deallocator's
+ /// family derived from the DeallocExpr.
+ void printExpectedAllocName(raw_ostream &os, CheckerContext &C,
+ const Expr *DeallocExpr) const;
+ /// \brief Print expected name of a deallocator based on the allocator's
+ /// family.
+ void printExpectedDeallocName(raw_ostream &os, AllocationFamily Family) const;
+
+ ///@{
/// Check if this is one of the functions which can allocate/reallocate memory
/// pointed to by one of its arguments.
bool isMemFunction(const FunctionDecl *FD, ASTContext &C) const;
bool isFreeFunction(const FunctionDecl *FD, ASTContext &C) const;
bool isAllocationFunction(const FunctionDecl *FD, ASTContext &C) const;
-
+ bool isStandardNewDelete(const FunctionDecl *FD, ASTContext &C) const;
+ ///@}
static ProgramStateRef MallocMemReturnsAttr(CheckerContext &C,
const CallExpr *CE,
const OwnershipAttr* Att);
static ProgramStateRef MallocMemAux(CheckerContext &C, const CallExpr *CE,
const Expr *SizeEx, SVal Init,
- ProgramStateRef state) {
+ ProgramStateRef State,
+ AllocationFamily Family = AF_Malloc) {
return MallocMemAux(C, CE,
- state->getSVal(SizeEx, C.getLocationContext()),
- Init, state);
+ State->getSVal(SizeEx, C.getLocationContext()),
+ Init, State, Family);
}
static ProgramStateRef MallocMemAux(CheckerContext &C, const CallExpr *CE,
SVal SizeEx, SVal Init,
- ProgramStateRef state);
+ ProgramStateRef State,
+ AllocationFamily Family = AF_Malloc);
/// Update the RefState to reflect the new memory allocation.
- static ProgramStateRef MallocUpdateRefState(CheckerContext &C,
- const CallExpr *CE,
- ProgramStateRef state);
+ static ProgramStateRef
+ MallocUpdateRefState(CheckerContext &C, const Expr *E, ProgramStateRef State,
+ AllocationFamily Family = AF_Malloc);
ProgramStateRef FreeMemAttr(CheckerContext &C, const CallExpr *CE,
const OwnershipAttr* Att) const;
@@ -209,17 +265,43 @@ private:
///\brief Check if the memory associated with this symbol was released.
bool isReleased(SymbolRef Sym, CheckerContext &C) const;
- bool checkUseAfterFree(SymbolRef Sym, CheckerContext &C,
- const Stmt *S = 0) const;
-
- /// Check if the function is not known to us. So, for example, we could
- /// conservatively assume it can free/reallocate it's pointer arguments.
- bool doesNotFreeMemory(const CallEvent *Call,
- ProgramStateRef State) const;
+ bool checkUseAfterFree(SymbolRef Sym, CheckerContext &C, const Stmt *S) const;
+
+ /// Check if the function is known not to free memory, or if it is
+ /// "interesting" and should be modeled explicitly.
+ ///
+ /// We assume that pointers do not escape through calls to system functions
+ /// not handled by this checker.
+ bool doesNotFreeMemOrInteresting(const CallEvent *Call,
+ ProgramStateRef State) const;
+
+ // Implementation of the checkPointerEscape callabcks.
+ ProgramStateRef checkPointerEscapeAux(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call,
+ PointerEscapeKind Kind,
+ bool(*CheckRefState)(const RefState*)) const;
+
+ // Used to suppress warnings if they are not related to the tracked family
+ // (derived from AllocDeallocStmt).
+ bool isTrackedFamily(AllocationFamily Family) const;
+ bool isTrackedFamily(CheckerContext &C, const Stmt *AllocDeallocStmt) const;
+ bool isTrackedFamily(CheckerContext &C, SymbolRef Sym) const;
static bool SummarizeValue(raw_ostream &os, SVal V);
static bool SummarizeRegion(raw_ostream &os, const MemRegion *MR);
- void ReportBadFree(CheckerContext &C, SVal ArgVal, SourceRange range) const;
+ void ReportBadFree(CheckerContext &C, SVal ArgVal, SourceRange Range,
+ const Expr *DeallocExpr) const;
+ void ReportMismatchedDealloc(CheckerContext &C, SourceRange Range,
+ const Expr *DeallocExpr,
+ const RefState *RS) const;
+ void ReportOffsetFree(CheckerContext &C, SVal ArgVal, SourceRange Range,
+ const Expr *DeallocExpr,
+ const Expr *AllocExpr = 0) const;
+ void ReportUseAfterFree(CheckerContext &C, SourceRange Range,
+ SymbolRef Sym) const;
+ void ReportDoubleFree(CheckerContext &C, SourceRange Range, bool Released,
+ SymbolRef Sym, SymbolRef PrevSym) const;
/// Find the location of the allocation for Sym on the path leading to the
/// exploded node N.
@@ -264,14 +346,14 @@ private:
inline bool isAllocated(const RefState *S, const RefState *SPrev,
const Stmt *Stmt) {
// Did not track -> allocated. Other state (released) -> allocated.
- return (Stmt && isa<CallExpr>(Stmt) &&
+ return (Stmt && (isa<CallExpr>(Stmt) || isa<CXXNewExpr>(Stmt)) &&
(S && S->isAllocated()) && (!SPrev || !SPrev->isAllocated()));
}
inline bool isReleased(const RefState *S, const RefState *SPrev,
const Stmt *Stmt) {
// Did not track -> released. Other state (allocated) -> released.
- return (Stmt && isa<CallExpr>(Stmt) &&
+ return (Stmt && (isa<CallExpr>(Stmt) || isa<CXXDeleteExpr>(Stmt)) &&
(S && S->isReleased()) && (!SPrev || !SPrev->isReleased()));
}
@@ -381,6 +463,9 @@ bool MallocChecker::isMemFunction(const FunctionDecl *FD, ASTContext &C) const {
if (isAllocationFunction(FD, C))
return true;
+ if (isStandardNewDelete(FD, C))
+ return true;
+
return false;
}
@@ -432,6 +517,39 @@ bool MallocChecker::isFreeFunction(const FunctionDecl *FD, ASTContext &C) const
return false;
}
+// Tells if the callee is one of the following:
+// 1) A global non-placement new/delete operator function.
+// 2) A global placement operator function with the single placement argument
+// of type std::nothrow_t.
+bool MallocChecker::isStandardNewDelete(const FunctionDecl *FD,
+ ASTContext &C) const {
+ if (!FD)
+ return false;
+
+ OverloadedOperatorKind Kind = FD->getOverloadedOperator();
+ if (Kind != OO_New && Kind != OO_Array_New &&
+ Kind != OO_Delete && Kind != OO_Array_Delete)
+ return false;
+
+ // Skip all operator new/delete methods.
+ if (isa<CXXMethodDecl>(FD))
+ return false;
+
+ // Return true if tested operator is a standard placement nothrow operator.
+ if (FD->getNumParams() == 2) {
+ QualType T = FD->getParamDecl(1)->getType();
+ if (const IdentifierInfo *II = T.getBaseTypeIdentifier())
+ return II->getName().equals("nothrow_t");
+ }
+
+ // Skip placement operators.
+ if (FD->getNumParams() != 1 || FD->isVariadic())
+ return false;
+
+ // One of the standard new/new[]/delete/delete[] non-placement operators.
+ return true;
+}
+
void MallocChecker::checkPostStmt(const CallExpr *CE, CheckerContext &C) const {
if (C.wasInlined)
return;
@@ -464,9 +582,26 @@ void MallocChecker::checkPostStmt(const CallExpr *CE, CheckerContext &C) const {
} else if (FunI == II_strndup) {
State = MallocUpdateRefState(C, CE, State);
}
+ else if (isStandardNewDelete(FD, C.getASTContext())) {
+ // Process direct calls to operator new/new[]/delete/delete[] functions
+ // as distinct from new/new[]/delete/delete[] expressions that are
+ // processed by the checkPostStmt callbacks for CXXNewExpr and
+ // CXXDeleteExpr.
+ OverloadedOperatorKind K = FD->getOverloadedOperator();
+ if (K == OO_New)
+ State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State,
+ AF_CXXNew);
+ else if (K == OO_Array_New)
+ State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State,
+ AF_CXXNewArray);
+ else if (K == OO_Delete || K == OO_Array_Delete)
+ State = FreeMemAux(C, CE, State, 0, false, ReleasedAllocatedMemory);
+ else
+ llvm_unreachable("not a new/delete operator");
+ }
}
- if (Filter.CMallocOptimistic) {
+ if (Filter.CMallocOptimistic || Filter.CMismatchedDeallocatorChecker) {
// Check all the attributes, if there are any.
// There can be multiple of these attributes.
if (FD->hasAttrs())
@@ -488,37 +623,91 @@ void MallocChecker::checkPostStmt(const CallExpr *CE, CheckerContext &C) const {
C.addTransition(State);
}
-static bool isFreeWhenDoneSetToZero(const ObjCMethodCall &Call) {
+void MallocChecker::checkPostStmt(const CXXNewExpr *NE,
+ CheckerContext &C) const {
+
+ if (NE->getNumPlacementArgs())
+ for (CXXNewExpr::const_arg_iterator I = NE->placement_arg_begin(),
+ E = NE->placement_arg_end(); I != E; ++I)
+ if (SymbolRef Sym = C.getSVal(*I).getAsSymbol())
+ checkUseAfterFree(Sym, C, *I);
+
+ if (!isStandardNewDelete(NE->getOperatorNew(), C.getASTContext()))
+ return;
+
+ ProgramStateRef State = C.getState();
+ // The return value from operator new is bound to a specified initialization
+ // value (if any) and we don't want to loose this value. So we call
+ // MallocUpdateRefState() instead of MallocMemAux() which breakes the
+ // existing binding.
+ State = MallocUpdateRefState(C, NE, State, NE->isArray() ? AF_CXXNewArray
+ : AF_CXXNew);
+ C.addTransition(State);
+}
+
+void MallocChecker::checkPreStmt(const CXXDeleteExpr *DE,
+ CheckerContext &C) const {
+
+ if (!Filter.CNewDeleteChecker)
+ if (SymbolRef Sym = C.getSVal(DE->getArgument()).getAsSymbol())
+ checkUseAfterFree(Sym, C, DE->getArgument());
+
+ if (!isStandardNewDelete(DE->getOperatorDelete(), C.getASTContext()))
+ return;
+
+ ProgramStateRef State = C.getState();
+ bool ReleasedAllocated;
+ State = FreeMemAux(C, DE->getArgument(), DE, State,
+ /*Hold*/false, ReleasedAllocated);
+
+ C.addTransition(State);
+}
+
+static bool isKnownDeallocObjCMethodName(const ObjCMethodCall &Call) {
+ // If the first selector piece is one of the names below, assume that the
+ // object takes ownership of the memory, promising to eventually deallocate it
+ // with free().
+ // Ex: [NSData dataWithBytesNoCopy:bytes length:10];
+ // (...unless a 'freeWhenDone' parameter is false, but that's checked later.)
+ StringRef FirstSlot = Call.getSelector().getNameForSlot(0);
+ if (FirstSlot == "dataWithBytesNoCopy" ||
+ FirstSlot == "initWithBytesNoCopy" ||
+ FirstSlot == "initWithCharactersNoCopy")
+ return true;
+
+ return false;
+}
+
+static Optional<bool> getFreeWhenDoneArg(const ObjCMethodCall &Call) {
Selector S = Call.getSelector();
+
+ // FIXME: We should not rely on fully-constrained symbols being folded.
for (unsigned i = 1; i < S.getNumArgs(); ++i)
if (S.getNameForSlot(i).equals("freeWhenDone"))
- if (Call.getArgSVal(i).isConstant(0))
- return true;
+ return !Call.getArgSVal(i).isZeroConstant();
- return false;
+ return None;
}
void MallocChecker::checkPostObjCMessage(const ObjCMethodCall &Call,
CheckerContext &C) const {
- // If the first selector is dataWithBytesNoCopy, assume that the memory will
- // be released with 'free' by the new object.
- // Ex: [NSData dataWithBytesNoCopy:bytes length:10];
- // Unless 'freeWhenDone' param set to 0.
- // TODO: Check that the memory was allocated with malloc.
- bool ReleasedAllocatedMemory = false;
- Selector S = Call.getSelector();
- if ((S.getNameForSlot(0) == "dataWithBytesNoCopy" ||
- S.getNameForSlot(0) == "initWithBytesNoCopy" ||
- S.getNameForSlot(0) == "initWithCharactersNoCopy") &&
- !isFreeWhenDoneSetToZero(Call)){
- unsigned int argIdx = 0;
- ProgramStateRef State = FreeMemAux(C, Call.getArgExpr(argIdx),
- Call.getOriginExpr(), C.getState(), true,
- ReleasedAllocatedMemory,
- /* RetNullOnFailure*/ true);
-
- C.addTransition(State);
- }
+ if (C.wasInlined)
+ return;
+
+ if (!isKnownDeallocObjCMethodName(Call))
+ return;
+
+ if (Optional<bool> FreeWhenDone = getFreeWhenDoneArg(Call))
+ if (!*FreeWhenDone)
+ return;
+
+ bool ReleasedAllocatedMemory;
+ ProgramStateRef State = FreeMemAux(C, Call.getArgExpr(0),
+ Call.getOriginExpr(), C.getState(),
+ /*Hold=*/true, ReleasedAllocatedMemory,
+ /*RetNullOnFailure=*/true);
+
+ C.addTransition(State);
}
ProgramStateRef MallocChecker::MallocMemReturnsAttr(CheckerContext &C,
@@ -537,7 +726,8 @@ ProgramStateRef MallocChecker::MallocMemReturnsAttr(CheckerContext &C,
ProgramStateRef MallocChecker::MallocMemAux(CheckerContext &C,
const CallExpr *CE,
SVal Size, SVal Init,
- ProgramStateRef state) {
+ ProgramStateRef State,
+ AllocationFamily Family) {
// Bind the return value to the symbolic value from the heap region.
// TODO: We could rewrite post visit to eval call; 'malloc' does not have
@@ -545,52 +735,52 @@ ProgramStateRef MallocChecker::MallocMemAux(CheckerContext &C,
unsigned Count = C.blockCount();
SValBuilder &svalBuilder = C.getSValBuilder();
const LocationContext *LCtx = C.getPredecessor()->getLocationContext();
- DefinedSVal RetVal =
- cast<DefinedSVal>(svalBuilder.getConjuredHeapSymbolVal(CE, LCtx, Count));
- state = state->BindExpr(CE, C.getLocationContext(), RetVal);
+ DefinedSVal RetVal = svalBuilder.getConjuredHeapSymbolVal(CE, LCtx, Count)
+ .castAs<DefinedSVal>();
+ State = State->BindExpr(CE, C.getLocationContext(), RetVal);
// We expect the malloc functions to return a pointer.
- if (!isa<Loc>(RetVal))
+ if (!RetVal.getAs<Loc>())
return 0;
// Fill the region with the initialization value.
- state = state->bindDefault(RetVal, Init);
+ State = State->bindDefault(RetVal, Init);
// Set the region's extent equal to the Size parameter.
const SymbolicRegion *R =
dyn_cast_or_null<SymbolicRegion>(RetVal.getAsRegion());
if (!R)
return 0;
- if (isa<DefinedOrUnknownSVal>(Size)) {
+ if (Optional<DefinedOrUnknownSVal> DefinedSize =
+ Size.getAs<DefinedOrUnknownSVal>()) {
SValBuilder &svalBuilder = C.getSValBuilder();
DefinedOrUnknownSVal Extent = R->getExtent(svalBuilder);
- DefinedOrUnknownSVal DefinedSize = cast<DefinedOrUnknownSVal>(Size);
DefinedOrUnknownSVal extentMatchesSize =
- svalBuilder.evalEQ(state, Extent, DefinedSize);
+ svalBuilder.evalEQ(State, Extent, *DefinedSize);
- state = state->assume(extentMatchesSize, true);
- assert(state);
+ State = State->assume(extentMatchesSize, true);
+ assert(State);
}
- return MallocUpdateRefState(C, CE, state);
+ return MallocUpdateRefState(C, CE, State, Family);
}
ProgramStateRef MallocChecker::MallocUpdateRefState(CheckerContext &C,
- const CallExpr *CE,
- ProgramStateRef state) {
+ const Expr *E,
+ ProgramStateRef State,
+ AllocationFamily Family) {
// Get the return value.
- SVal retVal = state->getSVal(CE, C.getLocationContext());
+ SVal retVal = State->getSVal(E, C.getLocationContext());
// We expect the malloc functions to return a pointer.
- if (!isa<Loc>(retVal))
+ if (!retVal.getAs<Loc>())
return 0;
SymbolRef Sym = retVal.getAsLocSymbol();
assert(Sym);
// Set the symbol's state to Allocated.
- return state->set<RegionState>(Sym, RefState::getAllocated(CE));
-
+ return State->set<RegionState>(Sym, RefState::getAllocated(Family, E));
}
ProgramStateRef MallocChecker::FreeMemAttr(CheckerContext &C,
@@ -629,8 +819,8 @@ ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C,
/// Checks if the previous call to free on the given symbol failed - if free
/// failed, returns true. Also, returns the corresponding return value symbol.
-bool didPreviousFreeFail(ProgramStateRef State,
- SymbolRef Sym, SymbolRef &RetStatusSymbol) {
+static bool didPreviousFreeFail(ProgramStateRef State,
+ SymbolRef Sym, SymbolRef &RetStatusSymbol) {
const SymbolRef *Ret = State->get<FreeReturnValue>(Sym);
if (Ret) {
assert(*Ret && "We should not store the null return symbol");
@@ -642,6 +832,107 @@ bool didPreviousFreeFail(ProgramStateRef State,
return false;
}
+AllocationFamily MallocChecker::getAllocationFamily(CheckerContext &C,
+ const Stmt *S) const {
+ if (!S)
+ return AF_None;
+
+ if (const CallExpr *CE = dyn_cast<CallExpr>(S)) {
+ const FunctionDecl *FD = C.getCalleeDecl(CE);
+
+ if (!FD)
+ FD = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
+
+ ASTContext &Ctx = C.getASTContext();
+
+ if (isAllocationFunction(FD, Ctx) || isFreeFunction(FD, Ctx))
+ return AF_Malloc;
+
+ if (isStandardNewDelete(FD, Ctx)) {
+ OverloadedOperatorKind Kind = FD->getOverloadedOperator();
+ if (Kind == OO_New || Kind == OO_Delete)
+ return AF_CXXNew;
+ else if (Kind == OO_Array_New || Kind == OO_Array_Delete)
+ return AF_CXXNewArray;
+ }
+
+ return AF_None;
+ }
+
+ if (const CXXNewExpr *NE = dyn_cast<CXXNewExpr>(S))
+ return NE->isArray() ? AF_CXXNewArray : AF_CXXNew;
+
+ if (const CXXDeleteExpr *DE = dyn_cast<CXXDeleteExpr>(S))
+ return DE->isArrayForm() ? AF_CXXNewArray : AF_CXXNew;
+
+ if (isa<ObjCMessageExpr>(S))
+ return AF_Malloc;
+
+ return AF_None;
+}
+
+bool MallocChecker::printAllocDeallocName(raw_ostream &os, CheckerContext &C,
+ const Expr *E) const {
+ if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
+ // FIXME: This doesn't handle indirect calls.
+ const FunctionDecl *FD = CE->getDirectCallee();
+ if (!FD)
+ return false;
+
+ os << *FD;
+ if (!FD->isOverloadedOperator())
+ os << "()";
+ return true;
+ }
+
+ if (const ObjCMessageExpr *Msg = dyn_cast<ObjCMessageExpr>(E)) {
+ if (Msg->isInstanceMessage())
+ os << "-";
+ else
+ os << "+";
+ os << Msg->getSelector().getAsString();
+ return true;
+ }
+
+ if (const CXXNewExpr *NE = dyn_cast<CXXNewExpr>(E)) {
+ os << "'"
+ << getOperatorSpelling(NE->getOperatorNew()->getOverloadedOperator())
+ << "'";
+ return true;
+ }
+
+ if (const CXXDeleteExpr *DE = dyn_cast<CXXDeleteExpr>(E)) {
+ os << "'"
+ << getOperatorSpelling(DE->getOperatorDelete()->getOverloadedOperator())
+ << "'";
+ return true;
+ }
+
+ return false;
+}
+
+void MallocChecker::printExpectedAllocName(raw_ostream &os, CheckerContext &C,
+ const Expr *E) const {
+ AllocationFamily Family = getAllocationFamily(C, E);
+
+ switch(Family) {
+ case AF_Malloc: os << "malloc()"; return;
+ case AF_CXXNew: os << "'new'"; return;
+ case AF_CXXNewArray: os << "'new[]'"; return;
+ case AF_None: llvm_unreachable("not a deallocation expression");
+ }
+}
+
+void MallocChecker::printExpectedDeallocName(raw_ostream &os,
+ AllocationFamily Family) const {
+ switch(Family) {
+ case AF_Malloc: os << "free()"; return;
+ case AF_CXXNew: os << "'delete'"; return;
+ case AF_CXXNewArray: os << "'delete[]'"; return;
+ case AF_None: llvm_unreachable("suspicious AF_None argument");
+ }
+}
+
ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C,
const Expr *ArgExpr,
const Expr *ParentExpr,
@@ -651,12 +942,12 @@ ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C,
bool ReturnsNullOnFailure) const {
SVal ArgVal = State->getSVal(ArgExpr, C.getLocationContext());
- if (!isa<DefinedOrUnknownSVal>(ArgVal))
+ if (!ArgVal.getAs<DefinedOrUnknownSVal>())
return 0;
- DefinedOrUnknownSVal location = cast<DefinedOrUnknownSVal>(ArgVal);
+ DefinedOrUnknownSVal location = ArgVal.castAs<DefinedOrUnknownSVal>();
// Check for null dereferences.
- if (!isa<Loc>(location))
+ if (!location.getAs<Loc>())
return 0;
// The explicit NULL case, no operation is performed.
@@ -675,7 +966,7 @@ ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C,
// Nonlocs can't be freed, of course.
// Non-region locations (labels and fixed addresses) also shouldn't be freed.
if (!R) {
- ReportBadFree(C, ArgVal, ArgExpr->getSourceRange());
+ ReportBadFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr);
return 0;
}
@@ -683,13 +974,14 @@ ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C,
// Blocks might show up as heap data, but should not be free()d
if (isa<BlockDataRegion>(R)) {
- ReportBadFree(C, ArgVal, ArgExpr->getSourceRange());
+ ReportBadFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr);
return 0;
}
const MemSpaceRegion *MS = R->getMemorySpace();
- // Parameters, locals, statics, and globals shouldn't be freed.
+ // Parameters, locals, statics, globals, and memory returned by alloca()
+ // shouldn't be freed.
if (!(isa<UnknownSpaceRegion>(MS) || isa<HeapSpaceRegion>(MS))) {
// FIXME: at the time this code was written, malloc() regions were
// represented by conjured symbols, which are all in UnknownSpaceRegion.
@@ -699,46 +991,59 @@ ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C,
// function, so UnknownSpaceRegion is always a possibility.
// False negatives are better than false positives.
- ReportBadFree(C, ArgVal, ArgExpr->getSourceRange());
+ ReportBadFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr);
return 0;
}
-
- const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R);
+
+ const SymbolicRegion *SrBase = dyn_cast<SymbolicRegion>(R->getBaseRegion());
// Various cases could lead to non-symbol values here.
// For now, ignore them.
- if (!SR)
+ if (!SrBase)
return 0;
- SymbolRef Sym = SR->getSymbol();
- const RefState *RS = State->get<RegionState>(Sym);
+ SymbolRef SymBase = SrBase->getSymbol();
+ const RefState *RsBase = State->get<RegionState>(SymBase);
SymbolRef PreviousRetStatusSymbol = 0;
- // Check double free.
- if (RS &&
- (RS->isReleased() || RS->isRelinquished()) &&
- !didPreviousFreeFail(State, Sym, PreviousRetStatusSymbol)) {
-
- if (ExplodedNode *N = C.generateSink()) {
- if (!BT_DoubleFree)
- BT_DoubleFree.reset(
- new BugType("Double free", "Memory Error"));
- BugReport *R = new BugReport(*BT_DoubleFree,
- (RS->isReleased() ? "Attempt to free released memory" :
- "Attempt to free non-owned memory"), N);
- R->addRange(ArgExpr->getSourceRange());
- R->markInteresting(Sym);
- if (PreviousRetStatusSymbol)
- R->markInteresting(PreviousRetStatusSymbol);
- R->addVisitor(new MallocBugVisitor(Sym));
- C.emitReport(R);
+ if (RsBase) {
+
+ bool DeallocMatchesAlloc =
+ RsBase->getAllocationFamily() == AF_None ||
+ RsBase->getAllocationFamily() == getAllocationFamily(C, ParentExpr);
+
+ // Check if an expected deallocation function matches the real one.
+ if (!DeallocMatchesAlloc && RsBase->isAllocated()) {
+ ReportMismatchedDealloc(C, ArgExpr->getSourceRange(), ParentExpr, RsBase);
+ return 0;
+ }
+
+ // Check double free.
+ if (DeallocMatchesAlloc &&
+ (RsBase->isReleased() || RsBase->isRelinquished()) &&
+ !didPreviousFreeFail(State, SymBase, PreviousRetStatusSymbol)) {
+ ReportDoubleFree(C, ParentExpr->getSourceRange(), RsBase->isReleased(),
+ SymBase, PreviousRetStatusSymbol);
+ return 0;
+ }
+
+ // Check if the memory location being freed is the actual location
+ // allocated, or an offset.
+ RegionOffset Offset = R->getAsOffset();
+ if (RsBase->isAllocated() &&
+ Offset.isValid() &&
+ !Offset.hasSymbolicOffset() &&
+ Offset.getOffset() != 0) {
+ const Expr *AllocExpr = cast<Expr>(RsBase->getStmt());
+ ReportOffsetFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr,
+ AllocExpr);
+ return 0;
}
- return 0;
}
- ReleasedAllocated = (RS != 0);
+ ReleasedAllocated = (RsBase != 0);
// Clean out the info on previous call to free return info.
- State = State->remove<FreeReturnValue>(Sym);
+ State = State->remove<FreeReturnValue>(SymBase);
// Keep track of the return value. If it is NULL, we will know that free
// failed.
@@ -746,23 +1051,60 @@ ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C,
SVal RetVal = C.getSVal(ParentExpr);
SymbolRef RetStatusSymbol = RetVal.getAsSymbol();
if (RetStatusSymbol) {
- C.getSymbolManager().addSymbolDependency(Sym, RetStatusSymbol);
- State = State->set<FreeReturnValue>(Sym, RetStatusSymbol);
+ C.getSymbolManager().addSymbolDependency(SymBase, RetStatusSymbol);
+ State = State->set<FreeReturnValue>(SymBase, RetStatusSymbol);
}
}
+ AllocationFamily Family = RsBase ? RsBase->getAllocationFamily() : AF_None;
// Normal free.
if (Hold)
- return State->set<RegionState>(Sym, RefState::getRelinquished(ParentExpr));
- return State->set<RegionState>(Sym, RefState::getReleased(ParentExpr));
+ return State->set<RegionState>(SymBase,
+ RefState::getRelinquished(Family,
+ ParentExpr));
+
+ return State->set<RegionState>(SymBase,
+ RefState::getReleased(Family, ParentExpr));
+}
+
+bool MallocChecker::isTrackedFamily(AllocationFamily Family) const {
+ switch (Family) {
+ case AF_Malloc: {
+ if (!Filter.CMallocOptimistic && !Filter.CMallocPessimistic)
+ return false;
+ return true;
+ }
+ case AF_CXXNew:
+ case AF_CXXNewArray: {
+ if (!Filter.CNewDeleteChecker)
+ return false;
+ return true;
+ }
+ case AF_None: {
+ return true;
+ }
+ }
+ llvm_unreachable("unhandled family");
+}
+
+bool MallocChecker::isTrackedFamily(CheckerContext &C,
+ const Stmt *AllocDeallocStmt) const {
+ return isTrackedFamily(getAllocationFamily(C, AllocDeallocStmt));
+}
+
+bool MallocChecker::isTrackedFamily(CheckerContext &C, SymbolRef Sym) const {
+ const RefState *RS = C.getState()->get<RegionState>(Sym);
+
+ return RS ? isTrackedFamily(RS->getAllocationFamily())
+ : isTrackedFamily(AF_None);
}
bool MallocChecker::SummarizeValue(raw_ostream &os, SVal V) {
- if (nonloc::ConcreteInt *IntVal = dyn_cast<nonloc::ConcreteInt>(&V))
+ if (Optional<nonloc::ConcreteInt> IntVal = V.getAs<nonloc::ConcreteInt>())
os << "an integer (" << IntVal->getValue() << ")";
- else if (loc::ConcreteInt *ConstAddr = dyn_cast<loc::ConcreteInt>(&V))
+ else if (Optional<loc::ConcreteInt> ConstAddr = V.getAs<loc::ConcreteInt>())
os << "a constant address (" << ConstAddr->getValue() << ")";
- else if (loc::GotoLabel *Label = dyn_cast<loc::GotoLabel>(&V))
+ else if (Optional<loc::GotoLabel> Label = V.getAs<loc::GotoLabel>())
os << "the address of the label '" << Label->getLabel()->getName() << "'";
else
return false;
@@ -844,41 +1186,192 @@ bool MallocChecker::SummarizeRegion(raw_ostream &os,
}
}
-void MallocChecker::ReportBadFree(CheckerContext &C, SVal ArgVal,
- SourceRange range) const {
+void MallocChecker::ReportBadFree(CheckerContext &C, SVal ArgVal,
+ SourceRange Range,
+ const Expr *DeallocExpr) const {
+
+ if (!Filter.CMallocOptimistic && !Filter.CMallocPessimistic &&
+ !Filter.CNewDeleteChecker)
+ return;
+
+ if (!isTrackedFamily(C, DeallocExpr))
+ return;
+
if (ExplodedNode *N = C.generateSink()) {
if (!BT_BadFree)
BT_BadFree.reset(new BugType("Bad free", "Memory Error"));
SmallString<100> buf;
llvm::raw_svector_ostream os(buf);
-
+
const MemRegion *MR = ArgVal.getAsRegion();
- if (MR) {
- while (const ElementRegion *ER = dyn_cast<ElementRegion>(MR))
- MR = ER->getSuperRegion();
-
- // Special case for alloca()
- if (isa<AllocaRegion>(MR))
- os << "Argument to free() was allocated by alloca(), not malloc()";
- else {
- os << "Argument to free() is ";
- if (SummarizeRegion(os, MR))
- os << ", which is not memory allocated by malloc()";
- else
- os << "not memory allocated by malloc()";
- }
- } else {
- os << "Argument to free() is ";
- if (SummarizeValue(os, ArgVal))
- os << ", which is not memory allocated by malloc()";
+ while (const ElementRegion *ER = dyn_cast_or_null<ElementRegion>(MR))
+ MR = ER->getSuperRegion();
+
+ if (MR && isa<AllocaRegion>(MR))
+ os << "Memory allocated by alloca() should not be deallocated";
+ else {
+ os << "Argument to ";
+ if (!printAllocDeallocName(os, C, DeallocExpr))
+ os << "deallocator";
+
+ os << " is ";
+ bool Summarized = MR ? SummarizeRegion(os, MR)
+ : SummarizeValue(os, ArgVal);
+ if (Summarized)
+ os << ", which is not memory allocated by ";
else
- os << "not memory allocated by malloc()";
+ os << "not memory allocated by ";
+
+ printExpectedAllocName(os, C, DeallocExpr);
}
-
+
BugReport *R = new BugReport(*BT_BadFree, os.str(), N);
R->markInteresting(MR);
- R->addRange(range);
+ R->addRange(Range);
+ C.emitReport(R);
+ }
+}
+
+void MallocChecker::ReportMismatchedDealloc(CheckerContext &C,
+ SourceRange Range,
+ const Expr *DeallocExpr,
+ const RefState *RS) const {
+
+ if (!Filter.CMismatchedDeallocatorChecker)
+ return;
+
+ if (ExplodedNode *N = C.generateSink()) {
+ if (!BT_MismatchedDealloc)
+ BT_MismatchedDealloc.reset(new BugType("Bad deallocator",
+ "Memory Error"));
+
+ SmallString<100> buf;
+ llvm::raw_svector_ostream os(buf);
+
+ const Expr *AllocExpr = cast<Expr>(RS->getStmt());
+ SmallString<20> AllocBuf;
+ llvm::raw_svector_ostream AllocOs(AllocBuf);
+ SmallString<20> DeallocBuf;
+ llvm::raw_svector_ostream DeallocOs(DeallocBuf);
+
+ os << "Memory";
+ if (printAllocDeallocName(AllocOs, C, AllocExpr))
+ os << " allocated by " << AllocOs.str();
+
+ os << " should be deallocated by ";
+ printExpectedDeallocName(os, RS->getAllocationFamily());
+
+ if (printAllocDeallocName(DeallocOs, C, DeallocExpr))
+ os << ", not " << DeallocOs.str();
+
+ BugReport *R = new BugReport(*BT_MismatchedDealloc, os.str(), N);
+ R->addRange(Range);
+ C.emitReport(R);
+ }
+}
+
+void MallocChecker::ReportOffsetFree(CheckerContext &C, SVal ArgVal,
+ SourceRange Range, const Expr *DeallocExpr,
+ const Expr *AllocExpr) const {
+
+ if (!Filter.CMallocOptimistic && !Filter.CMallocPessimistic &&
+ !Filter.CNewDeleteChecker)
+ return;
+
+ if (!isTrackedFamily(C, AllocExpr))
+ return;
+
+ ExplodedNode *N = C.generateSink();
+ if (N == NULL)
+ return;
+
+ if (!BT_OffsetFree)
+ BT_OffsetFree.reset(new BugType("Offset free", "Memory Error"));
+
+ SmallString<100> buf;
+ llvm::raw_svector_ostream os(buf);
+ SmallString<20> AllocNameBuf;
+ llvm::raw_svector_ostream AllocNameOs(AllocNameBuf);
+
+ const MemRegion *MR = ArgVal.getAsRegion();
+ assert(MR && "Only MemRegion based symbols can have offset free errors");
+
+ RegionOffset Offset = MR->getAsOffset();
+ assert((Offset.isValid() &&
+ !Offset.hasSymbolicOffset() &&
+ Offset.getOffset() != 0) &&
+ "Only symbols with a valid offset can have offset free errors");
+
+ int offsetBytes = Offset.getOffset() / C.getASTContext().getCharWidth();
+
+ os << "Argument to ";
+ if (!printAllocDeallocName(os, C, DeallocExpr))
+ os << "deallocator";
+ os << " is offset by "
+ << offsetBytes
+ << " "
+ << ((abs(offsetBytes) > 1) ? "bytes" : "byte")
+ << " from the start of ";
+ if (AllocExpr && printAllocDeallocName(AllocNameOs, C, AllocExpr))
+ os << "memory allocated by " << AllocNameOs.str();
+ else
+ os << "allocated memory";
+
+ BugReport *R = new BugReport(*BT_OffsetFree, os.str(), N);
+ R->markInteresting(MR->getBaseRegion());
+ R->addRange(Range);
+ C.emitReport(R);
+}
+
+void MallocChecker::ReportUseAfterFree(CheckerContext &C, SourceRange Range,
+ SymbolRef Sym) const {
+
+ if (!Filter.CMallocOptimistic && !Filter.CMallocPessimistic &&
+ !Filter.CNewDeleteChecker)
+ return;
+
+ if (!isTrackedFamily(C, Sym))
+ return;
+
+ if (ExplodedNode *N = C.generateSink()) {
+ if (!BT_UseFree)
+ BT_UseFree.reset(new BugType("Use-after-free", "Memory Error"));
+
+ BugReport *R = new BugReport(*BT_UseFree,
+ "Use of memory after it is freed", N);
+
+ R->markInteresting(Sym);
+ R->addRange(Range);
+ R->addVisitor(new MallocBugVisitor(Sym));
+ C.emitReport(R);
+ }
+}
+
+void MallocChecker::ReportDoubleFree(CheckerContext &C, SourceRange Range,
+ bool Released, SymbolRef Sym,
+ SymbolRef PrevSym) const {
+
+ if (!Filter.CMallocOptimistic && !Filter.CMallocPessimistic &&
+ !Filter.CNewDeleteChecker)
+ return;
+
+ if (!isTrackedFamily(C, Sym))
+ return;
+
+ if (ExplodedNode *N = C.generateSink()) {
+ if (!BT_DoubleFree)
+ BT_DoubleFree.reset(new BugType("Double free", "Memory Error"));
+
+ BugReport *R = new BugReport(*BT_DoubleFree,
+ (Released ? "Attempt to free released memory"
+ : "Attempt to free non-owned memory"),
+ N);
+ R->addRange(Range);
+ R->markInteresting(Sym);
+ if (PrevSym)
+ R->markInteresting(PrevSym);
+ R->addVisitor(new MallocBugVisitor(Sym));
C.emitReport(R);
}
}
@@ -893,9 +1386,9 @@ ProgramStateRef MallocChecker::ReallocMem(CheckerContext &C,
const Expr *arg0Expr = CE->getArg(0);
const LocationContext *LCtx = C.getLocationContext();
SVal Arg0Val = state->getSVal(arg0Expr, LCtx);
- if (!isa<DefinedOrUnknownSVal>(Arg0Val))
+ if (!Arg0Val.getAs<DefinedOrUnknownSVal>())
return 0;
- DefinedOrUnknownSVal arg0Val = cast<DefinedOrUnknownSVal>(Arg0Val);
+ DefinedOrUnknownSVal arg0Val = Arg0Val.castAs<DefinedOrUnknownSVal>();
SValBuilder &svalBuilder = C.getSValBuilder();
@@ -909,9 +1402,9 @@ ProgramStateRef MallocChecker::ReallocMem(CheckerContext &C,
// Get the value of the size argument.
SVal Arg1ValG = state->getSVal(Arg1, LCtx);
- if (!isa<DefinedOrUnknownSVal>(Arg1ValG))
+ if (!Arg1ValG.getAs<DefinedOrUnknownSVal>())
return 0;
- DefinedOrUnknownSVal Arg1Val = cast<DefinedOrUnknownSVal>(Arg1ValG);
+ DefinedOrUnknownSVal Arg1Val = Arg1ValG.castAs<DefinedOrUnknownSVal>();
// Compare the size argument to 0.
DefinedOrUnknownSVal SizeZero =
@@ -1032,18 +1525,19 @@ MallocChecker::getAllocationSite(const ExplodedNode *N, SymbolRef Sym,
N = N->pred_empty() ? NULL : *(N->pred_begin());
}
- ProgramPoint P = AllocNode->getLocation();
- const Stmt *AllocationStmt = 0;
- if (CallExitEnd *Exit = dyn_cast<CallExitEnd>(&P))
- AllocationStmt = Exit->getCalleeContext()->getCallSite();
- else if (StmtPoint *SP = dyn_cast<StmtPoint>(&P))
- AllocationStmt = SP->getStmt();
-
- return LeakInfo(AllocationStmt, ReferenceRegion);
+ return LeakInfo(AllocNode, ReferenceRegion);
}
void MallocChecker::reportLeak(SymbolRef Sym, ExplodedNode *N,
CheckerContext &C) const {
+
+ if (!Filter.CMallocOptimistic && !Filter.CMallocPessimistic &&
+ !Filter.CNewDeleteChecker)
+ return;
+
+ if (!isTrackedFamily(C, Sym))
+ return;
+
assert(N);
if (!BT_Leak) {
BT_Leak.reset(new BugType("Memory leak", "Memory Error"));
@@ -1059,12 +1553,20 @@ void MallocChecker::reportLeak(SymbolRef Sym, ExplodedNode *N,
// With leaks, we want to unique them by the location where they were
// allocated, and only report a single path.
PathDiagnosticLocation LocUsedForUniqueing;
- const Stmt *AllocStmt = 0;
+ const ExplodedNode *AllocNode = 0;
const MemRegion *Region = 0;
- llvm::tie(AllocStmt, Region) = getAllocationSite(N, Sym, C);
- if (AllocStmt)
- LocUsedForUniqueing = PathDiagnosticLocation::createBegin(AllocStmt,
- C.getSourceManager(), N->getLocationContext());
+ llvm::tie(AllocNode, Region) = getAllocationSite(N, Sym, C);
+
+ ProgramPoint P = AllocNode->getLocation();
+ const Stmt *AllocationStmt = 0;
+ if (Optional<CallExitEnd> Exit = P.getAs<CallExitEnd>())
+ AllocationStmt = Exit->getCalleeContext()->getCallSite();
+ else if (Optional<StmtPoint> SP = P.getAs<StmtPoint>())
+ AllocationStmt = SP->getStmt();
+ if (AllocationStmt)
+ LocUsedForUniqueing = PathDiagnosticLocation::createBegin(AllocationStmt,
+ C.getSourceManager(),
+ AllocNode->getLocationContext());
SmallString<200> buf;
llvm::raw_svector_ostream os(buf);
@@ -1075,7 +1577,9 @@ void MallocChecker::reportLeak(SymbolRef Sym, ExplodedNode *N,
os << '\'';
}
- BugReport *R = new BugReport(*BT_Leak, os.str(), N, LocUsedForUniqueing);
+ BugReport *R = new BugReport(*BT_Leak, os.str(), N,
+ LocUsedForUniqueing,
+ AllocNode->getLocationContext()->getDecl());
R->markInteresting(Sym);
R->addVisitor(new MallocBugVisitor(Sym, true));
C.emitReport(R);
@@ -1091,7 +1595,7 @@ void MallocChecker::checkDeadSymbols(SymbolReaper &SymReaper,
RegionStateTy RS = state->get<RegionState>();
RegionStateTy::Factory &F = state->get_context<RegionState>();
- llvm::SmallVector<SymbolRef, 2> Errors;
+ SmallVector<SymbolRef, 2> Errors;
for (RegionStateTy::iterator I = RS.begin(), E = RS.end(); I != E; ++I) {
if (SymReaper.isDead(I->first)) {
if (I->second.isAllocated())
@@ -1125,7 +1629,7 @@ void MallocChecker::checkDeadSymbols(SymbolReaper &SymReaper,
if (!Errors.empty()) {
static SimpleProgramPointTag Tag("MallocChecker : DeadSymbolsLeak");
N = C.addTransition(C.getState(), C.getPredecessor(), &Tag);
- for (llvm::SmallVector<SymbolRef, 2>::iterator
+ for (SmallVector<SymbolRef, 2>::iterator
I = Errors.begin(), E = Errors.end(); I != E; ++I) {
reportLeak(*I, N, C);
}
@@ -1134,27 +1638,14 @@ void MallocChecker::checkDeadSymbols(SymbolReaper &SymReaper,
C.addTransition(state->set<RegionState>(RS), N);
}
-void MallocChecker::checkEndPath(CheckerContext &C) const {
- ProgramStateRef state = C.getState();
- RegionStateTy M = state->get<RegionState>();
-
- // If inside inlined call, skip it.
- if (C.getLocationContext()->getParent() != 0)
- return;
-
- for (RegionStateTy::iterator I = M.begin(), E = M.end(); I != E; ++I) {
- RefState RS = I->second;
- if (RS.isAllocated()) {
- ExplodedNode *N = C.addTransition(state);
- if (N)
- reportLeak(I->first, N, C);
- }
- }
-}
-
void MallocChecker::checkPreStmt(const CallExpr *CE, CheckerContext &C) const {
// We will check for double free in the post visit.
- if (isFreeFunction(C.getCalleeDecl(CE), C.getASTContext()))
+ if ((Filter.CMallocOptimistic || Filter.CMallocPessimistic) &&
+ isFreeFunction(C.getCalleeDecl(CE), C.getASTContext()))
+ return;
+
+ if (Filter.CNewDeleteChecker &&
+ isStandardNewDelete(C.getCalleeDecl(CE), C.getASTContext()))
return;
// Check use after free, when a freed pointer is passed to a call.
@@ -1163,7 +1654,7 @@ void MallocChecker::checkPreStmt(const CallExpr *CE, CheckerContext &C) const {
E = CE->arg_end(); I != E; ++I) {
const Expr *A = *I;
if (A->getType().getTypePtr()->isAnyPointerType()) {
- SymbolRef Sym = State->getSVal(A, C.getLocationContext()).getAsSymbol();
+ SymbolRef Sym = C.getSVal(A).getAsSymbol();
if (!Sym)
continue;
if (checkUseAfterFree(Sym, C, A))
@@ -1193,15 +1684,7 @@ void MallocChecker::checkPreStmt(const ReturnStmt *S, CheckerContext &C) const {
// Check if we are returning freed memory.
if (Sym)
- if (checkUseAfterFree(Sym, C, E))
- return;
-
- // If this function body is not inlined, stop tracking any returned symbols.
- if (C.getLocationContext()->getParent() == 0) {
- State =
- State->scanReachableSymbols<StopTrackingCallback>(RetVal).getState();
- C.addTransition(State);
- }
+ checkUseAfterFree(Sym, C, E);
}
// TODO: Blocks should be either inlined or should call invalidate regions
@@ -1231,7 +1714,7 @@ void MallocChecker::checkPostStmt(const BlockExpr *BE,
MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager();
for ( ; I != E; ++I) {
- const VarRegion *VR = *I;
+ const VarRegion *VR = I.getCapturedRegion();
if (VR->getSuperRegion() == R) {
VR = MemMgr.getVarRegion(VR->getDecl(), LC);
}
@@ -1252,21 +1735,12 @@ bool MallocChecker::isReleased(SymbolRef Sym, CheckerContext &C) const {
bool MallocChecker::checkUseAfterFree(SymbolRef Sym, CheckerContext &C,
const Stmt *S) const {
+
if (isReleased(Sym, C)) {
- if (ExplodedNode *N = C.generateSink()) {
- if (!BT_UseFree)
- BT_UseFree.reset(new BugType("Use-after-free", "Memory Error"));
-
- BugReport *R = new BugReport(*BT_UseFree,
- "Use of memory after it is freed",N);
- if (S)
- R->addRange(S->getSourceRange());
- R->markInteresting(Sym);
- R->addVisitor(new MallocBugVisitor(Sym));
- C.emitReport(R);
- return true;
- }
+ ReportUseAfterFree(C, S->getSourceRange(), Sym);
+ return true;
}
+
return false;
}
@@ -1278,51 +1752,6 @@ void MallocChecker::checkLocation(SVal l, bool isLoad, const Stmt *S,
checkUseAfterFree(Sym, C, S);
}
-//===----------------------------------------------------------------------===//
-// Check various ways a symbol can be invalidated.
-// TODO: This logic (the next 3 functions) is copied/similar to the
-// RetainRelease checker. We might want to factor this out.
-//===----------------------------------------------------------------------===//
-
-// Stop tracking symbols when a value escapes as a result of checkBind.
-// A value escapes in three possible cases:
-// (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.
-void MallocChecker::checkBind(SVal loc, SVal val, const Stmt *S,
- CheckerContext &C) const {
- // Are we storing to something that causes the value to "escape"?
- bool escapes = true;
- ProgramStateRef state = C.getState();
-
- if (loc::MemRegionVal *regionLoc = dyn_cast<loc::MemRegionVal>(&loc)) {
- escapes = !regionLoc->getRegion()->hasStackStorage();
-
- if (!escapes) {
- // To test (3), generate a new state with the binding added. If it is
- // the same state, then it escapes (since the store cannot represent
- // the binding).
- // Do this only if we know that the store is not supposed to generate the
- // same state.
- SVal StoredVal = state->getSVal(regionLoc->getRegion());
- if (StoredVal != val)
- escapes = (state == (state->bindLoc(*regionLoc, val)));
- }
- }
-
- // If our store can represent the binding and we aren't storing to something
- // that doesn't have local storage then just return and have the simulation
- // state continue as is.
- if (!escapes)
- return;
-
- // Otherwise, find all symbols referenced by 'val' that we are tracking
- // and stop tracking them.
- state = state->scanReachableSymbols<StopTrackingCallback>(val).getState();
- C.addTransition(state);
-}
-
// If a symbolic region is assumed to NULL (or another constant), stop tracking
// it - assuming that allocation failed on this path.
ProgramStateRef MallocChecker::evalAssume(ProgramStateRef state,
@@ -1352,7 +1781,7 @@ ProgramStateRef MallocChecker::evalAssume(ProgramStateRef state,
if (RS->isReleased()) {
if (I.getData().Kind == RPToBeFreedAfterFailure)
state = state->set<RegionState>(ReallocSym,
- RefState::getAllocated(RS->getStmt()));
+ RefState::getAllocated(RS->getAllocationFamily(), RS->getStmt()));
else if (I.getData().Kind == RPDoNotTrackAfterFailure)
state = state->remove<RegionState>(ReallocSym);
else
@@ -1365,12 +1794,8 @@ ProgramStateRef MallocChecker::evalAssume(ProgramStateRef state,
return state;
}
-// Check if the function is known to us. So, for example, we could
-// conservatively assume it can free/reallocate its pointer arguments.
-// (We assume that the pointers cannot escape through calls to system
-// functions not handled by this checker.)
-bool MallocChecker::doesNotFreeMemory(const CallEvent *Call,
- ProgramStateRef State) const {
+bool MallocChecker::doesNotFreeMemOrInteresting(const CallEvent *Call,
+ ProgramStateRef State) const {
assert(Call);
// For now, assume that any C++ call can free memory.
@@ -1387,24 +1812,23 @@ bool MallocChecker::doesNotFreeMemory(const CallEvent *Call,
if (!Call->isInSystemHeader() || Call->hasNonZeroCallbackArg())
return false;
- Selector S = Msg->getSelector();
-
- // Whitelist the ObjC methods which do free memory.
- // - Anything containing 'freeWhenDone' param set to 1.
- // Ex: dataWithBytesNoCopy:length:freeWhenDone.
- for (unsigned i = 1; i < S.getNumArgs(); ++i) {
- if (S.getNameForSlot(i).equals("freeWhenDone")) {
- if (Call->getArgSVal(i).isConstant(1))
- return false;
- else
- return true;
- }
- }
+ // If it's a method we know about, handle it explicitly post-call.
+ // This should happen before the "freeWhenDone" check below.
+ if (isKnownDeallocObjCMethodName(*Msg))
+ return true;
- // If the first selector ends with NoCopy, assume that the ownership is
- // transferred as well.
- // Ex: [NSData dataWithBytesNoCopy:bytes length:10];
- StringRef FirstSlot = S.getNameForSlot(0);
+ // If there's a "freeWhenDone" parameter, but the method isn't one we know
+ // about, we can't be sure that the object will use free() to deallocate the
+ // memory, so we can't model it explicitly. The best we can do is use it to
+ // decide whether the pointer escapes.
+ if (Optional<bool> FreeWhenDone = getFreeWhenDoneArg(*Msg))
+ return !*FreeWhenDone;
+
+ // If the first selector piece ends with "NoCopy", and there is no
+ // "freeWhenDone" parameter set to zero, we know ownership is being
+ // transferred. Again, though, we can't be sure that the object will use
+ // free() to deallocate the memory, so we can't model it explicitly.
+ StringRef FirstSlot = Msg->getSelector().getNameForSlot(0);
if (FirstSlot.endswith("NoCopy"))
return false;
@@ -1509,41 +1933,50 @@ bool MallocChecker::doesNotFreeMemory(const CallEvent *Call,
return true;
}
-// If the symbol we are tracking is invalidated, but not explicitly (ex: the &p
-// escapes, when we are tracking p), do not track the symbol as we cannot reason
-// about it anymore.
-ProgramStateRef
-MallocChecker::checkRegionChanges(ProgramStateRef State,
- const StoreManager::InvalidatedSymbols *invalidated,
- ArrayRef<const MemRegion *> ExplicitRegions,
- ArrayRef<const MemRegion *> Regions,
- const CallEvent *Call) const {
- if (!invalidated || invalidated->empty())
- return State;
- llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols;
+static bool retTrue(const RefState *RS) {
+ return true;
+}
- // If it's a call which might free or reallocate memory, we assume that all
- // regions (explicit and implicit) escaped.
+static bool checkIfNewOrNewArrayFamily(const RefState *RS) {
+ return (RS->getAllocationFamily() == AF_CXXNewArray ||
+ RS->getAllocationFamily() == AF_CXXNew);
+}
- // Otherwise, whitelist explicit pointers; we still can track them.
- if (!Call || doesNotFreeMemory(Call, State)) {
- for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(),
- E = ExplicitRegions.end(); I != E; ++I) {
- if (const SymbolicRegion *R = (*I)->StripCasts()->getAs<SymbolicRegion>())
- WhitelistedSymbols.insert(R->getSymbol());
- }
+ProgramStateRef MallocChecker::checkPointerEscape(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call,
+ PointerEscapeKind Kind) const {
+ return checkPointerEscapeAux(State, Escaped, Call, Kind, &retTrue);
+}
+
+ProgramStateRef MallocChecker::checkConstPointerEscape(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call,
+ PointerEscapeKind Kind) const {
+ return checkPointerEscapeAux(State, Escaped, Call, Kind,
+ &checkIfNewOrNewArrayFamily);
+}
+
+ProgramStateRef MallocChecker::checkPointerEscapeAux(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call,
+ PointerEscapeKind Kind,
+ bool(*CheckRefState)(const RefState*)) const {
+ // If we know that the call does not free memory, or we want to process the
+ // call later, keep tracking the top level arguments.
+ if ((Kind == PSK_DirectEscapeOnCall ||
+ Kind == PSK_IndirectEscapeOnCall) &&
+ doesNotFreeMemOrInteresting(Call, State)) {
+ return State;
}
- for (StoreManager::InvalidatedSymbols::const_iterator I=invalidated->begin(),
- E = invalidated->end(); I!=E; ++I) {
+ for (InvalidatedSymbols::const_iterator I = Escaped.begin(),
+ E = Escaped.end();
+ I != E; ++I) {
SymbolRef sym = *I;
- if (WhitelistedSymbols.count(sym))
- continue;
- // The symbol escaped. Note, we assume that if the symbol is released,
- // passing it out will result in a use after free. We also keep tracking
- // relinquished symbols.
+
if (const RefState *RS = State->get<RegionState>(sym)) {
- if (RS->isAllocated())
+ if (RS->isAllocated() && CheckRefState(RS))
State = State->remove<RegionState>(sym);
}
}
@@ -1584,16 +2017,16 @@ MallocChecker::MallocBugVisitor::VisitNode(const ExplodedNode *N,
// Retrieve the associated statement.
ProgramPoint ProgLoc = N->getLocation();
- if (StmtPoint *SP = dyn_cast<StmtPoint>(&ProgLoc))
+ if (Optional<StmtPoint> SP = ProgLoc.getAs<StmtPoint>()) {
S = SP->getStmt();
- else if (CallExitEnd *Exit = dyn_cast<CallExitEnd>(&ProgLoc))
+ } else if (Optional<CallExitEnd> Exit = ProgLoc.getAs<CallExitEnd>()) {
S = Exit->getCalleeContext()->getCallSite();
- // If an assumption was made on a branch, it should be caught
- // here by looking at the state transition.
- else if (BlockEdge *Edge = dyn_cast<BlockEdge>(&ProgLoc)) {
- const CFGBlock *srcBlk = Edge->getSrc();
- S = srcBlk->getTerminator();
+ } else if (Optional<BlockEdge> Edge = ProgLoc.getAs<BlockEdge>()) {
+ // If an assumption was made on a branch, it should be caught
+ // here by looking at the state transition.
+ S = Edge->getSrc()->getTerminator();
}
+
if (!S)
return 0;
@@ -1658,8 +2091,15 @@ void MallocChecker::printState(raw_ostream &Out, ProgramStateRef State,
RegionStateTy RS = State->get<RegionState>();
- if (!RS.isEmpty())
- Out << "Has Malloc data" << NL;
+ if (!RS.isEmpty()) {
+ Out << Sep << "MallocChecker:" << NL;
+ for (RegionStateTy::iterator I = RS.begin(), E = RS.end(); I != E; ++I) {
+ I.getKey()->dumpToStream(Out);
+ Out << " : ";
+ I.getData().dump(Out);
+ Out << NL;
+ }
+ }
}
#define REGISTER_CHECKER(name) \
@@ -1670,3 +2110,5 @@ void ento::register##name(CheckerManager &mgr) {\
REGISTER_CHECKER(MallocPessimistic)
REGISTER_CHECKER(MallocOptimistic)
+REGISTER_CHECKER(NewDeleteChecker)
+REGISTER_CHECKER(MismatchedDeallocatorChecker)
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