forked from OSchip/llvm-project
93 lines
2.9 KiB
C++
93 lines
2.9 KiB
C++
//== ArrayBoundChecker.cpp ------------------------------*- C++ -*--==//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines ArrayBoundChecker, which is a path-sensitive check
|
|
// which looks for an out-of-bound array element access.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "ExprEngineInternalChecks.h"
|
|
#include "clang/StaticAnalyzer/BugReporter/BugType.h"
|
|
#include "clang/StaticAnalyzer/PathSensitive/CheckerVisitor.h"
|
|
#include "clang/StaticAnalyzer/PathSensitive/ExprEngine.h"
|
|
|
|
using namespace clang;
|
|
using namespace ento;
|
|
|
|
namespace {
|
|
class ArrayBoundChecker :
|
|
public CheckerVisitor<ArrayBoundChecker> {
|
|
BuiltinBug *BT;
|
|
public:
|
|
ArrayBoundChecker() : BT(0) {}
|
|
static void *getTag() { static int x = 0; return &x; }
|
|
void visitLocation(CheckerContext &C, const Stmt *S, SVal l, bool isLoad);
|
|
};
|
|
}
|
|
|
|
void ento::RegisterArrayBoundChecker(ExprEngine &Eng) {
|
|
Eng.registerCheck(new ArrayBoundChecker());
|
|
}
|
|
|
|
void ArrayBoundChecker::visitLocation(CheckerContext &C, const Stmt *S, SVal l,
|
|
bool isLoad) {
|
|
// Check for out of bound array element access.
|
|
const MemRegion *R = l.getAsRegion();
|
|
if (!R)
|
|
return;
|
|
|
|
const ElementRegion *ER = dyn_cast<ElementRegion>(R);
|
|
if (!ER)
|
|
return;
|
|
|
|
// Get the index of the accessed element.
|
|
DefinedOrUnknownSVal Idx = cast<DefinedOrUnknownSVal>(ER->getIndex());
|
|
|
|
// Zero index is always in bound, this also passes ElementRegions created for
|
|
// pointer casts.
|
|
if (Idx.isZeroConstant())
|
|
return;
|
|
|
|
const GRState *state = C.getState();
|
|
|
|
// Get the size of the array.
|
|
DefinedOrUnknownSVal NumElements
|
|
= C.getStoreManager().getSizeInElements(state, ER->getSuperRegion(),
|
|
ER->getValueType());
|
|
|
|
const GRState *StInBound = state->assumeInBound(Idx, NumElements, true);
|
|
const GRState *StOutBound = state->assumeInBound(Idx, NumElements, false);
|
|
if (StOutBound && !StInBound) {
|
|
ExplodedNode *N = C.generateSink(StOutBound);
|
|
if (!N)
|
|
return;
|
|
|
|
if (!BT)
|
|
BT = new BuiltinBug("Out-of-bound array access",
|
|
"Access out-of-bound array element (buffer overflow)");
|
|
|
|
// FIXME: It would be nice to eventually make this diagnostic more clear,
|
|
// e.g., by referencing the original declaration or by saying *why* this
|
|
// reference is outside the range.
|
|
|
|
// Generate a report for this bug.
|
|
RangedBugReport *report =
|
|
new RangedBugReport(*BT, BT->getDescription(), N);
|
|
|
|
report->addRange(S->getSourceRange());
|
|
C.EmitReport(report);
|
|
return;
|
|
}
|
|
|
|
// Array bound check succeeded. From this point forward the array bound
|
|
// should always succeed.
|
|
assert(StInBound);
|
|
C.addTransition(StInBound);
|
|
}
|