1 files changed, 55 insertions, 0 deletions
diff --git a/clang/lib/StaticAnalyzer/Checkers/UndefinedArraySubscriptChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UndefinedArraySubscriptChecker.cpp
new file mode 100644
index 0000000..0297c4e
--- /dev/null
+++ b/clang/lib/StaticAnalyzer/Checkers/UndefinedArraySubscriptChecker.cpp
@@ -0,0 +1,55 @@
+//===--- UndefinedArraySubscriptChecker.h ----------------------*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines UndefinedArraySubscriptChecker, a builtin check in ExprEngine
+// that performs checks for undefined array subscripts.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class UndefinedArraySubscriptChecker
+  : public Checker< check::PreStmt<ArraySubscriptExpr> > {
+  mutable OwningPtr<BugType> BT;
+
+public:
+  void checkPreStmt(const ArraySubscriptExpr *A, CheckerContext &C) const;
+};
+} // end anonymous namespace
+
+void 
+UndefinedArraySubscriptChecker::checkPreStmt(const ArraySubscriptExpr *A,
+                                             CheckerContext &C) const {
+  if (C.getState()->getSVal(A->getIdx(), C.getLocationContext()).isUndef()) {
+    if (ExplodedNode *N = C.generateSink()) {
+      if (!BT)
+        BT.reset(new BuiltinBug("Array subscript is undefined"));
+
+      // Generate a report for this bug.
+      BugReport *R = new BugReport(*BT, BT->getName(), N);
+      R->addRange(A->getIdx()->getSourceRange());
+      R->addVisitor(bugreporter::getTrackNullOrUndefValueVisitor(N,
+                                                                 A->getIdx(),
+                                                                 R));
+      C.EmitReport(R);
+    }
+  }
+}
+
+void ento::registerUndefinedArraySubscriptChecker(CheckerManager &mgr) {
+  mgr.registerChecker<UndefinedArraySubscriptChecker>();
+}