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Add check for illegal whence argument of fseek. 

llvm-svn: 106742
This commit is contained in:
Zhongxing Xu 2010-06-24 13:36:41 +00:00
parent a7e5dd6c3a
commit facf8a8e74
2 changed files with 35 additions and 3 deletions
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31
clang/lib/Checker/StreamChecker.cpp
View File

@ -27,14 +27,14 @@ class StreamChecker : public CheckerVisitor<StreamChecker> {
IdentifierInfo *II_fopen, *II_fread, *II_fwrite,
*II_fseek, *II_ftell, *II_rewind, *II_fgetpos, *II_fsetpos,
*II_clearerr, *II_feof, *II_ferror, *II_fileno;
BuiltinBug *BT_nullfp;
BuiltinBug *BT_nullfp, *BT_illegalwhence;
public:
StreamChecker()
: II_fopen(0), II_fread(0), II_fwrite(0),
II_fseek(0), II_ftell(0), II_rewind(0), II_fgetpos(0), II_fsetpos(0),
II_clearerr(0), II_feof(0), II_ferror(0), II_fileno(0),
BT_nullfp(0) {}
BT_nullfp(0), BT_illegalwhence(0) {}
static void *getTag() {
static int x;
@ -186,8 +186,33 @@ void StreamChecker::Fwrite(CheckerContext &C, const CallExpr *CE) {
void StreamChecker::Fseek(CheckerContext &C, const CallExpr *CE) {
const GRState *state = C.getState();
if (!CheckNullStream(state->getSVal(CE->getArg(0)), state, C))
if (!(state = CheckNullStream(state->getSVal(CE->getArg(0)), state, C)))
return;
// Check the legality of the 'whence' argument of 'fseek'.
SVal Whence = state->getSVal(CE->getArg(2));
bool WhenceIsLegal = true;
const nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&Whence);
if (!CI)
WhenceIsLegal = false;
int64_t x = CI->getValue().getSExtValue();
if (!(x == 0 || x == 1 || x == 2))
WhenceIsLegal = false;
if (!WhenceIsLegal) {
if (ExplodedNode *N = C.GenerateSink(state)) {
if (!BT_illegalwhence)
BT_illegalwhence = new BuiltinBug("Illegal whence argument",
"The whence argument to fseek() should be "
"SEEK_SET, SEEK_END, or SEEK_CUR.");
BugReport *R = new BugReport(*BT_illegalwhence,
BT_illegalwhence->getDescription(), N);
C.EmitReport(R);
}
return;
}
C.addTransition(state);
}
void StreamChecker::Ftell(CheckerContext &C, const CallExpr *CE) {

7
clang/test/Analysis/stream.c
View File

@ -32,3 +32,10 @@ void f4(void) {
rewind(p); // expected-warning {{Stream pointer might be NULL.}}
}
void f5(void) {
FILE *p = fopen("foo", "r");
if (!p)
return;
fseek(p, 1, SEEK_SET); // no-warning
fseek(p, 1, 3); // expected-warning {{The whence argument to fseek() should be SEEK_SET, SEEK_END, or SEEK_CUR.}}
}