forked from OSchip/llvm-project
92 lines
2.8 KiB
C++
92 lines
2.8 KiB
C++
//== ArrayBoundChecker.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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// This file defines ArrayBoundChecker, which is a path-sensitive check
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// which looks for an out-of-bound array element access.
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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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#include "clang/Checker/PathSensitive/GRExprEngine.h"
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using namespace clang;
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namespace {
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class ArrayBoundChecker :
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public CheckerVisitor<ArrayBoundChecker> {
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BuiltinBug *BT;
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public:
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ArrayBoundChecker() : BT(0) {}
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static void *getTag();
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void VisitLocation(CheckerContext &C, const Stmt *S, SVal l);
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};
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}
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void clang::RegisterArrayBoundChecker(GRExprEngine &Eng) {
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Eng.registerCheck(new ArrayBoundChecker());
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}
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void *ArrayBoundChecker::getTag() {
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static int x = 0; return &x;
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}
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void ArrayBoundChecker::VisitLocation(CheckerContext &C, const Stmt *S, SVal l){
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// Check for out of bound array element access.
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const MemRegion *R = l.getAsRegion();
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if (!R)
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return;
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R = R->StripCasts();
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const ElementRegion *ER = dyn_cast<ElementRegion>(R);
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if (!ER)
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return;
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// Get the index of the accessed element.
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DefinedOrUnknownSVal &Idx = cast<DefinedOrUnknownSVal>(ER->getIndex());
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const GRState *state = C.getState();
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// Get the size of the array.
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DefinedOrUnknownSVal NumElements
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= C.getStoreManager().getSizeInElements(state, ER->getSuperRegion(),
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ER->getValueType(C.getASTContext()));
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const GRState *StInBound = state->AssumeInBound(Idx, NumElements, true);
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const GRState *StOutBound = state->AssumeInBound(Idx, NumElements, false);
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if (StOutBound && !StInBound) {
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ExplodedNode *N = C.GenerateSink(StOutBound);
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if (!N)
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return;
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if (!BT)
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BT = new BuiltinBug("Out-of-bound array access",
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"Access out-of-bound array element (buffer overflow)");
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// FIXME: It would be nice to eventually make this diagnostic more clear,
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// e.g., by referencing the original declaration or by saying *why* this
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// reference is outside the range.
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// Generate a report for this bug.
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RangedBugReport *report =
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new RangedBugReport(*BT, BT->getDescription(), N);
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report->addRange(S->getSourceRange());
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C.EmitReport(report);
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return;
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}
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// Array bound check succeeded. From this point forward the array bound
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// should always succeed.
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assert(StInBound);
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C.addTransition(StInBound);
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}
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