UndefinedArraySubscriptChecker.cpp revision 6f42b62b6194f53bcbc349f5d17388e1936535d7 
1//===--- UndefinedArraySubscriptChecker.h ----------------------*- C++ -*--===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This defines UndefinedArraySubscriptChecker, a builtin check in ExprEngine
11// that performs checks for undefined array subscripts.
12//
13//===----------------------------------------------------------------------===//
14
15#include "ClangSACheckers.h"
16#include "clang/StaticAnalyzer/Core/Checker.h"
17#include "clang/StaticAnalyzer/Core/CheckerManager.h"
18#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
19#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
20
21using namespace clang;
22using namespace ento;
23
24namespace {
25class UndefinedArraySubscriptChecker
26  : public Checker< check::PreStmt<ArraySubscriptExpr> > {
27  mutable OwningPtr<BugType> BT;
28
29public:
30  void checkPreStmt(const ArraySubscriptExpr *A, CheckerContext &C) const;
31};
32} // end anonymous namespace
33
34void
35UndefinedArraySubscriptChecker::checkPreStmt(const ArraySubscriptExpr *A,
36                                             CheckerContext &C) const {
37  if (C.getState()->getSVal(A->getIdx(), C.getLocationContext()).isUndef()) {
38    if (ExplodedNode *N = C.generateSink()) {
39      if (!BT)
40        BT.reset(new BuiltinBug("Array subscript is undefined"));
41
42      // Generate a report for this bug.
43      BugReport *R = new BugReport(*BT, BT->getName(), N);
44      R->addRange(A->getIdx()->getSourceRange());
45      R->addVisitor(bugreporter::getTrackNullOrUndefValueVisitor(N,
46                                                                 A->getIdx()));
47      C.EmitReport(R);
48    }
49  }
50}
51
52void ento::registerUndefinedArraySubscriptChecker(CheckerManager &mgr) {
53  mgr.registerChecker<UndefinedArraySubscriptChecker>();
54}
55