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//===--- UndefinedArgChecker.h - Undefined arguments checker ----*- C++ -*--==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This defines BadCallChecker, a builtin check in GRExprEngine that performs
// checks for undefined arguments.
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/PathSensitive/CheckerVisitor.h"
#include "clang/Analysis/PathSensitive/BugReporter.h"
#include "GRExprEngineInternalChecks.h"
using namespace clang;
namespace {
class VISIBILITY_HIDDEN UndefinedArgChecker
: public CheckerVisitor<UndefinedArgChecker> {
BugType *BT_call_null;
BugType *BT_call_undef;
BugType *BT_call_arg;
BugType *BT_msg_undef;
BugType *BT_msg_arg;
public:
UndefinedArgChecker() :
BT_call_null(0), BT_call_undef(0), BT_call_arg(0),
BT_msg_undef(0), BT_msg_arg(0) {}
static void *getTag() {
static int x = 0;
return &x;
}
void PreVisitCallExpr(CheckerContext &C, const CallExpr *CE);
void PreVisitObjCMessageExpr(CheckerContext &C, const ObjCMessageExpr *ME);
private:
void EmitBadCall(BugType *BT, CheckerContext &C, const CallExpr *CE);
};
} // end anonymous namespace
void clang::RegisterUndefinedArgChecker(GRExprEngine &Eng) {
Eng.registerCheck(new UndefinedArgChecker());
}
void UndefinedArgChecker::EmitBadCall(BugType *BT, CheckerContext &C,
const CallExpr *CE) {
ExplodedNode *N = C.GenerateNode(CE, true);
if (!N)
return;
EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getName(), N);
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue,
bugreporter::GetCalleeExpr(N));
C.EmitReport(R);
}
void UndefinedArgChecker::PreVisitCallExpr(CheckerContext &C,
const CallExpr *CE){
const Expr *Callee = CE->getCallee()->IgnoreParens();
SVal L = C.getState()->getSVal(Callee);
if (L.isUndef()) {
if (!BT_call_undef)
BT_call_undef =
new BuiltinBug("Called function pointer is an undefined pointer value");
EmitBadCall(BT_call_undef, C, CE);
return;
}
if (isa<loc::ConcreteInt>(L)) {
if (!BT_call_null)
BT_call_null =
new BuiltinBug("Called function pointer is null (null dereference)");
EmitBadCall(BT_call_null, C, CE);
}
for (CallExpr::const_arg_iterator I = CE->arg_begin(), E = CE->arg_end();
I != E; ++I) {
if (C.getState()->getSVal(*I).isUndef()) {
if (ExplodedNode *N = C.GenerateNode(CE, true)) {
if (!BT_call_arg)
BT_call_arg = new BuiltinBug("Pass-by-value argument in function call"
" is undefined");
// Generate a report for this bug.
EnhancedBugReport *R = new EnhancedBugReport(*BT_call_arg,
BT_call_arg->getName(), N);
R->addRange((*I)->getSourceRange());
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, *I);
C.EmitReport(R);
return;
}
}
}
}
void UndefinedArgChecker::PreVisitObjCMessageExpr(CheckerContext &C,
const ObjCMessageExpr *ME) {
const GRState *state = C.getState();
if (const Expr *receiver = ME->getReceiver())
if (state->getSVal(receiver).isUndef()) {
if (ExplodedNode *N = C.GenerateNode(ME, true)) {
if (!BT_msg_undef)
BT_msg_undef =
new BuiltinBug("Receiver in message expression is a garbage value");
EnhancedBugReport *R =
new EnhancedBugReport(*BT_msg_undef, BT_msg_undef->getName(), N);
R->addRange(receiver->getSourceRange());
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue,
receiver);
C.EmitReport(R);
}
return;
}
// Check for any arguments that are uninitialized/undefined.
for (ObjCMessageExpr::const_arg_iterator I = ME->arg_begin(), E = ME->arg_end();
I != E; ++I) {
if (state->getSVal(*I).isUndef()) {
if (ExplodedNode *N = C.GenerateNode(ME, true)) {
if (!BT_msg_arg)
BT_msg_arg =
new BuiltinBug("Pass-by-value argument in message expression"
" is undefined");
// Generate a report for this bug.
EnhancedBugReport *R = new EnhancedBugReport(*BT_msg_arg,
BT_msg_arg->getName(), N);
R->addRange((*I)->getSourceRange());
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, *I);
C.EmitReport(R);
return;
}
}
}
}
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