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