70 lines
2.3 KiB
C++
70 lines
2.3 KiB
C++
|
//=== PointerArithChecker.cpp - Pointer arithmetic checker -----*- C++ -*--===//
|
||
|
|
//
|
||
|
|
// The LLVM Compiler Infrastructure
|
||
|
|
//
|
||
|
|
// This file is distributed under the University of Illinois Open Source
|
||
|
|
// License. See LICENSE.TXT for details.
|
||
|
|
//
|
||
|
|
//===----------------------------------------------------------------------===//
|
||
|
|
//
|
||
|
|
// This files defines PointerArithChecker, a builtin checker that checks for
|
||
|
|
// pointer arithmetic on locations other than array elements.
|
||
|
|
//
|
||
|
|
//===----------------------------------------------------------------------===//
|
||
|
|
|
||
|
|
#include "ClangSACheckers.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"
|
||
|
|
|
||
|
|
using namespace clang;
|
||
|
|
using namespace ento;
|
||
|
|
|
||
|
|
namespace {
|
||
|
|
class PointerArithChecker
|
||
|
|
: public Checker< check::PreStmt<BinaryOperator> > {
|
||
|
|
mutable OwningPtr<BuiltinBug> BT;
|
||
|
|
|
||
|
|
public:
|
||
|
|
void checkPreStmt(const BinaryOperator *B, CheckerContext &C) const;
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
void PointerArithChecker::checkPreStmt(const BinaryOperator *B,
|
||
|
|
CheckerContext &C) const {
|
||
|
|
if (B->getOpcode() != BO_Sub && B->getOpcode() != BO_Add)
|
||
|
|
return;
|
||
|
|
|
||
|
|
ProgramStateRef state = C.getState();
|
||
|
|
const LocationContext *LCtx = C.getLocationContext();
|
||
|
|
SVal LV = state->getSVal(B->getLHS(), LCtx);
|
||
|
|
SVal RV = state->getSVal(B->getRHS(), LCtx);
|
||
|
|
|
||
|
|
const MemRegion *LR = LV.getAsRegion();
|
||
|
|
|
||
|
|
if (!LR || !RV.isConstant())
|
||
|
|
return;
|
||
|
|
|
||
|
|
// If pointer arithmetic is done on variables of non-array type, this often
|
||
|
|
// means behavior rely on memory organization, which is dangerous.
|
||
|
|
if (isa<VarRegion>(LR) || isa<CodeTextRegion>(LR) ||
|
||
|
|
isa<CompoundLiteralRegion>(LR)) {
|
||
|
|
|
||
|
|
if (ExplodedNode *N = C.addTransition()) {
|
||
|
|
if (!BT)
|
||
|
|
BT.reset(new BuiltinBug("Dangerous pointer arithmetic",
|
||
|
|
"Pointer arithmetic done on non-array variables "
|
||
|
|
"means reliance on memory layout, which is "
|
||
|
|
"dangerous."));
|
||
|
|
BugReport *R = new BugReport(*BT, BT->getDescription(), N);
|
||
|
|
R->addRange(B->getSourceRange());
|
||
|
|
C.EmitReport(R);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void ento::registerPointerArithChecker(CheckerManager &mgr) {
|
||
|
|
mgr.registerChecker<PointerArithChecker>();
|
||
|
|
}
|