[cfe-commits] r91216 - in /cfe/trunk: include/clang/Analysis/PathSensitive/Checker.h lib/Analysis/MallocChecker.cpp test/Analysis/malloc.c
Zhongxing Xu
xuzhongxing at gmail.com
Sat Dec 12 04:29:38 PST 2009
Author: zhongxingxu
Date: Sat Dec 12 06:29:38 2009
New Revision: 91216
URL: http://llvm.org/viewvc/llvm-project?rev=91216&view=rev
Log:
Add initial support for realloc() in MallocChecker.
Modified:
cfe/trunk/include/clang/Analysis/PathSensitive/Checker.h
cfe/trunk/lib/Analysis/MallocChecker.cpp
cfe/trunk/test/Analysis/malloc.c
Modified: cfe/trunk/include/clang/Analysis/PathSensitive/Checker.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/PathSensitive/Checker.h?rev=91216&r1=91215&r2=91216&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/PathSensitive/Checker.h (original)
+++ cfe/trunk/include/clang/Analysis/PathSensitive/Checker.h Sat Dec 12 06:29:38 2009
@@ -90,6 +90,10 @@
return Eng.getValueManager();
}
+ SValuator &getSValuator() {
+ return Eng.getSValuator();
+ }
+
ExplodedNode *GenerateNode(bool autoTransition = true) {
assert(statement && "Only transitions with statements currently supported");
ExplodedNode *N = GenerateNodeImpl(statement, getState(), false);
Modified: cfe/trunk/lib/Analysis/MallocChecker.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/MallocChecker.cpp?rev=91216&r1=91215&r2=91216&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/MallocChecker.cpp (original)
+++ cfe/trunk/lib/Analysis/MallocChecker.cpp Sat Dec 12 06:29:38 2009
@@ -52,11 +52,11 @@
class MallocChecker : public CheckerVisitor<MallocChecker> {
BuiltinBug *BT_DoubleFree;
BuiltinBug *BT_Leak;
- IdentifierInfo *II_malloc;
- IdentifierInfo *II_free;
+ IdentifierInfo *II_malloc, *II_free, *II_realloc;
public:
- MallocChecker() : BT_DoubleFree(0), BT_Leak(0), II_malloc(0), II_free(0) {}
+ MallocChecker()
+ : BT_DoubleFree(0), BT_Leak(0), II_malloc(0), II_free(0), II_realloc(0) {}
static void *getTag();
bool EvalCallExpr(CheckerContext &C, const CallExpr *CE);
void EvalDeadSymbols(CheckerContext &C,const Stmt *S,SymbolReaper &SymReaper);
@@ -64,7 +64,13 @@
void PreVisitReturnStmt(CheckerContext &C, const ReturnStmt *S);
private:
void MallocMem(CheckerContext &C, const CallExpr *CE);
+ const GRState *MallocMemAux(CheckerContext &C, const CallExpr *CE,
+ const GRState *state);
void FreeMem(CheckerContext &C, const CallExpr *CE);
+ const GRState *FreeMemAux(CheckerContext &C, const CallExpr *CE,
+ const GRState *state);
+
+ void ReallocMem(CheckerContext &C, const CallExpr *CE);
};
} // end anonymous namespace
@@ -99,6 +105,8 @@
II_malloc = &Ctx.Idents.get("malloc");
if (!II_free)
II_free = &Ctx.Idents.get("free");
+ if (!II_realloc)
+ II_realloc = &Ctx.Idents.get("realloc");
if (FD->getIdentifier() == II_malloc) {
MallocMem(C, CE);
@@ -110,26 +118,44 @@
return true;
}
+ if (FD->getIdentifier() == II_realloc) {
+ ReallocMem(C, CE);
+ return true;
+ }
+
return false;
}
void MallocChecker::MallocMem(CheckerContext &C, const CallExpr *CE) {
+ const GRState *state = MallocMemAux(C, CE, C.getState());
+ C.addTransition(state);
+}
+
+const GRState *MallocChecker::MallocMemAux(CheckerContext &C,
+ const CallExpr *CE,
+ const GRState *state) {
unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
ValueManager &ValMgr = C.getValueManager();
SVal RetVal = ValMgr.getConjuredSymbolVal(NULL, CE, CE->getType(), Count);
- const GRState *state = C.getState();
state = state->BindExpr(CE, RetVal);
SymbolRef Sym = RetVal.getAsLocSymbol();
assert(Sym);
// Set the symbol's state to Allocated.
- C.addTransition(state->set<RegionState>(Sym, RefState::getAllocated(CE)));
+ return state->set<RegionState>(Sym, RefState::getAllocated(CE));
}
void MallocChecker::FreeMem(CheckerContext &C, const CallExpr *CE) {
- const GRState *state = C.getState();
+ const GRState *state = FreeMemAux(C, CE, C.getState());
+
+ if (state)
+ C.addTransition(state);
+}
+
+const GRState *MallocChecker::FreeMemAux(CheckerContext &C, const CallExpr *CE,
+ const GRState *state) {
SVal ArgVal = state->getSVal(CE->getArg(0));
SymbolRef Sym = ArgVal.getAsLocSymbol();
assert(Sym);
@@ -149,13 +175,59 @@
BT_DoubleFree->getDescription(), N);
C.EmitReport(R);
}
- return;
+ return NULL;
}
// Normal free.
- const GRState *FreedState
- = state->set<RegionState>(Sym, RefState::getReleased(CE));
- C.addTransition(FreedState);
+ return state->set<RegionState>(Sym, RefState::getReleased(CE));
+}
+
+void MallocChecker::ReallocMem(CheckerContext &C, const CallExpr *CE) {
+ const GRState *state = C.getState();
+ const Expr *Arg0 = CE->getArg(0);
+ DefinedOrUnknownSVal Arg0Val=cast<DefinedOrUnknownSVal>(state->getSVal(Arg0));
+
+ ValueManager &ValMgr = C.getValueManager();
+ SValuator &SVator = C.getSValuator();
+
+ DefinedOrUnknownSVal PtrEQ = SVator.EvalEQ(state, Arg0Val, ValMgr.makeNull());
+
+ // If the ptr is NULL, the call is equivalent to malloc(size).
+ if (const GRState *stateEqual = state->Assume(PtrEQ, true)) {
+ // Hack: set the NULL symbolic region to released to suppress false warning.
+ // In the future we should add more states for allocated regions, e.g.,
+ // CheckedNull, CheckedNonNull.
+
+ SymbolRef Sym = Arg0Val.getAsLocSymbol();
+ if (Sym)
+ stateEqual = stateEqual->set<RegionState>(Sym, RefState::getReleased(CE));
+
+ const GRState *stateMalloc = MallocMemAux(C, CE, stateEqual);
+ C.addTransition(stateMalloc);
+ }
+
+ if (const GRState *stateNotEqual = state->Assume(PtrEQ, false)) {
+ const Expr *Arg1 = CE->getArg(1);
+ DefinedOrUnknownSVal Arg1Val =
+ cast<DefinedOrUnknownSVal>(stateNotEqual->getSVal(Arg1));
+ DefinedOrUnknownSVal SizeZero = SVator.EvalEQ(stateNotEqual, Arg1Val,
+ ValMgr.makeIntValWithPtrWidth(0, false));
+
+ if (const GRState *stateSizeZero = stateNotEqual->Assume(SizeZero, true)) {
+ const GRState *stateFree = FreeMemAux(C, CE, stateSizeZero);
+ if (stateFree)
+ C.addTransition(stateFree->BindExpr(CE, UndefinedVal(), true));
+ }
+
+ if (const GRState *stateSizeNotZero=stateNotEqual->Assume(SizeZero,false)) {
+ const GRState *stateFree = FreeMemAux(C, CE, stateSizeNotZero);
+ if (stateFree) {
+ // FIXME: We should copy the content of the original buffer.
+ const GRState *stateRealloc = MallocMemAux(C, CE, stateFree);
+ C.addTransition(stateRealloc);
+ }
+ }
+ }
}
void MallocChecker::EvalDeadSymbols(CheckerContext &C, const Stmt *S,
Modified: cfe/trunk/test/Analysis/malloc.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/malloc.c?rev=91216&r1=91215&r2=91216&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/malloc.c (original)
+++ cfe/trunk/test/Analysis/malloc.c Sat Dec 12 06:29:38 2009
@@ -2,6 +2,8 @@
typedef __typeof(sizeof(int)) size_t;
void *malloc(size_t);
void free(void *);
+void *realloc(void *ptr, size_t size);
+void *calloc(size_t nmemb, size_t size);
void f1() {
int *p = malloc(10);
@@ -35,3 +37,9 @@
p_f4 = malloc(10);
return p_f4; // no-warning
}
+
+int *f5() {
+ int *q = malloc(10);
+ q = realloc(q, 20);
+ return q; // no-warning
+}
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