forked from OSchip/llvm-project
73 lines
2.3 KiB
C++
73 lines
2.3 KiB
C++
//=== PointerArithChecker.cpp - Pointer arithmetic 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 PointerArithChecker, a builtin checker that checks for
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// pointer arithmetic on locations other than array elements.
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//
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//===----------------------------------------------------------------------===//
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#include "GRExprEngineInternalChecks.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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using namespace clang;
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namespace {
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class PointerArithChecker
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: public CheckerVisitor<PointerArithChecker> {
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BuiltinBug *BT;
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public:
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PointerArithChecker() : BT(0) {}
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static void *getTag();
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void PreVisitBinaryOperator(CheckerContext &C, const BinaryOperator *B);
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};
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}
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void *PointerArithChecker::getTag() {
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static int x;
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return &x;
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}
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void PointerArithChecker::PreVisitBinaryOperator(CheckerContext &C,
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const BinaryOperator *B) {
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if (B->getOpcode() != BinaryOperator::Sub &&
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B->getOpcode() != BinaryOperator::Add)
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return;
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const GRState *state = C.getState();
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SVal LV = state->getSVal(B->getLHS());
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SVal RV = state->getSVal(B->getRHS());
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const MemRegion *LR = LV.getAsRegion();
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if (!LR || !RV.isConstant())
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return;
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// If pointer arithmetic is done on variables of non-array type, this often
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// means behavior rely on memory organization, which is dangerous.
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if (isa<VarRegion>(LR) || isa<CodeTextRegion>(LR) ||
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isa<CompoundLiteralRegion>(LR)) {
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if (ExplodedNode *N = C.GenerateNode()) {
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if (!BT)
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BT = new BuiltinBug("Dangerous pointer arithmetic",
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"Pointer arithmetic done on non-array variables "
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"means reliance on memory layout, which is "
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"dangerous.");
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RangedBugReport *R = new RangedBugReport(*BT, BT->getDescription(), N);
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R->addRange(B->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::RegisterPointerArithChecker(GRExprEngine &Eng) {
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Eng.registerCheck(new PointerArithChecker());
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}
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