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//=== CastSizeChecker.cpp ---------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// CastSizeChecker checks when casting a malloc'ed symbolic region to type T,
// whether the size of the symbolic region is a multiple of the size of T.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/CharUnits.h"
#include "clang/Checker/BugReporter/BugType.h"
#include "clang/Checker/PathSensitive/CheckerVisitor.h"
#include "GRExprEngineInternalChecks.h"
using namespace clang;
namespace {
class CastSizeChecker : public CheckerVisitor<CastSizeChecker> {
BuiltinBug *BT;
public:
CastSizeChecker() : BT(0) {}
static void *getTag();
void PreVisitCastExpr(CheckerContext &C, const CastExpr *B);
};
}
void *CastSizeChecker::getTag() {
static int x;
return &x;
}
void CastSizeChecker::PreVisitCastExpr(CheckerContext &C, const CastExpr *CE) {
const Expr *E = CE->getSubExpr();
ASTContext &Ctx = C.getASTContext();
QualType ToTy = Ctx.getCanonicalType(CE->getType());
PointerType *ToPTy = dyn_cast<PointerType>(ToTy.getTypePtr());
if (!ToPTy)
return;
QualType ToPointeeTy = ToPTy->getPointeeType();
const MemRegion *R = C.getState()->getSVal(E).getAsRegion();
if (R == 0)
return;
const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R);
if (SR == 0)
return;
llvm::Optional<SVal> V =
C.getEngine().getStoreManager().getExtent(C.getState(), SR);
if (!V)
return;
const nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(V);
if (!CI)
return;
CharUnits RegionSize = CharUnits::fromQuantity(CI->getValue().getSExtValue());
CharUnits TypeSize = C.getASTContext().getTypeSizeInChars(ToPointeeTy);
if (RegionSize % TypeSize != 0) {
if (ExplodedNode *N = C.GenerateSink()) {
if (!BT)
BT = new BuiltinBug("Cast region with wrong size.",
"Cast a region whose size is not a multiple of the"
" destination type size.");
RangedBugReport *R = new RangedBugReport(*BT, BT->getDescription(), N);
R->addRange(CE->getSourceRange());
C.EmitReport(R);
}
}
}
void clang::RegisterCastSizeChecker(GRExprEngine &Eng) {
Eng.registerCheck(new CastSizeChecker());
}
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