forked from OSchip/llvm-project
79 lines
2.5 KiB
C++
79 lines
2.5 KiB
C++
//=== CastToStructChecker.cpp - Fixed address usage checker ----*- 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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// This files defines CastToStructChecker, a builtin checker that checks for
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// cast from non-struct pointer to struct pointer.
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// This check corresponds to CWE-588.
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//
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//===----------------------------------------------------------------------===//
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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 CastToStructChecker
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: public CheckerVisitor<CastToStructChecker> {
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BuiltinBug *BT;
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public:
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CastToStructChecker() : 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 *CastToStructChecker::getTag() {
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static int x;
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return &x;
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}
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void CastToStructChecker::PreVisitCastExpr(CheckerContext &C,
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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 OrigTy = Ctx.getCanonicalType(E->getType());
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QualType ToTy = Ctx.getCanonicalType(CE->getType());
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PointerType *OrigPTy = dyn_cast<PointerType>(OrigTy.getTypePtr());
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PointerType *ToPTy = dyn_cast<PointerType>(ToTy.getTypePtr());
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if (!ToPTy || !OrigPTy)
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return;
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QualType OrigPointeeTy = OrigPTy->getPointeeType();
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QualType ToPointeeTy = ToPTy->getPointeeType();
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if (!ToPointeeTy->isStructureOrClassType())
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return;
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// We allow cast from void*.
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if (OrigPointeeTy->isVoidType())
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return;
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// Now the cast-to-type is struct pointer, the original type is not void*.
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if (!OrigPointeeTy->isRecordType()) {
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if (ExplodedNode *N = C.GenerateNode()) {
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if (!BT)
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BT = new BuiltinBug("Cast from non-struct type to struct type",
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"Casting a non-structure type to a structure type "
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"and accessing a field can lead to memory access "
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"errors or data corruption.");
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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::RegisterCastToStructChecker(GRExprEngine &Eng) {
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Eng.registerCheck(new CastToStructChecker());
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}
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