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f57351570e
along the way. Important changes: 1) To generate a sink node, use GenerateSink(); GenerateNode() is for generating regular transitions. This makes the API clearer and also allows us to use the 'bool' option to GenerateNode() for a different purpose. 2) GenerateNode() now automatically adds the generated node to the destination ExplodedNodeSet (autotransition) unless the client specifies otherwise with a bool flag. Several checkers did not call 'addTransition()' after calling 'GenerateNode()', causing the simulation path to be prematurely culled when a non-fail stop bug was encountered. 3) Add variants of GenerateNode()/GenerateSink() that take neither a Stmt* or a GRState*; most callers of GenerateNode() just pass in the same Stmt* as provided when the CheckerContext object is created; we can just use that the majority of the time. This cleanup also allows us to potentially coelesce the APIs for evaluating branches and end-of-paths (which currently directly use builders). 4) addTransition() no longer needs to be called except for a few cases. We now have a variant of addTransition() that takes a GRState*; this allows one to propagate the updated state without caring about generating a new node explicitly. This nicely cleaned up a bunch of cases that called autoTransition() with a bunch of conditional logic surround the call (that common logic has now been swallowed up by addTransition() itself). llvm-svn: 89707
78 lines
2.4 KiB
C++
78 lines
2.4 KiB
C++
//=== PointerSubChecker.cpp - Pointer subtraction 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 PointerSubChecker, a builtin checker that checks for
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// pointer subtractions on two pointers pointing to different memory chunks.
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// This check corresponds to CWE-469.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Analysis/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 VISIBILITY_HIDDEN PointerSubChecker
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: public CheckerVisitor<PointerSubChecker> {
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BuiltinBug *BT;
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public:
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PointerSubChecker() : 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 *PointerSubChecker::getTag() {
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static int x;
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return &x;
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}
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void PointerSubChecker::PreVisitBinaryOperator(CheckerContext &C,
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const BinaryOperator *B) {
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// When doing pointer subtraction, if the two pointers do not point to the
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// same memory chunk, emit a warning.
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if (B->getOpcode() != BinaryOperator::Sub)
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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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const MemRegion *RR = RV.getAsRegion();
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if (!(LR && RR))
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return;
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const MemRegion *BaseLR = LR->getBaseRegion();
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const MemRegion *BaseRR = RR->getBaseRegion();
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if (BaseLR == BaseRR)
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return;
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// Allow arithmetic on different symbolic regions.
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if (isa<SymbolicRegion>(BaseLR) || isa<SymbolicRegion>(BaseRR))
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return;
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if (ExplodedNode *N = C.GenerateNode()) {
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if (!BT)
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BT = new BuiltinBug("Pointer subtraction",
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"Subtraction of two pointers that do not point to "
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"the same memory chunk may cause incorrect result.");
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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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void clang::RegisterPointerSubChecker(GRExprEngine &Eng) {
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Eng.registerCheck(new PointerSubChecker());
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}
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