[Analyzer] Iterator Checkers - Make range errors and invalidated access fatal

Range errors (dereferencing or incrementing the past-the-end iterator or
decrementing the iterator of the first element of the range) and access of
invalidated iterators lead to undefined behavior. There is no point to
continue the analysis after such an error on the same execution path, but
terminate it by a sink node (fatal error). This also improves the
performance and helps avoiding double reports (e.g. in case of nested
iterators).

Differential Revision: https://reviews.llvm.org/D62893

llvm-svn: 370314

1 files changed, 6 insertions, 8 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp
index 5fe7ba55786..ee2ed43ec57 100644
--- a/clang/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp
@@ -356,14 +356,12 @@ bool isZero(ProgramStateRef State, const NonLoc &Val);
 
 IteratorChecker::IteratorChecker() {
   OutOfRangeBugType.reset(
-      new BugType(this, "Iterator out of range", "Misuse of STL APIs",
-                  /*SuppressOnSink=*/true));
+      new BugType(this, "Iterator out of range", "Misuse of STL APIs"));
   MismatchedBugType.reset(
       new BugType(this, "Iterator(s) mismatched", "Misuse of STL APIs",
                   /*SuppressOnSink=*/true));
   InvalidatedBugType.reset(
-      new BugType(this, "Iterator invalidated", "Misuse of STL APIs",
-                  /*SuppressOnSink=*/true));
+      new BugType(this, "Iterator invalidated", "Misuse of STL APIs"));
 }
 
 void IteratorChecker::checkPreCall(const CallEvent &Call,
@@ -928,7 +926,7 @@ void IteratorChecker::verifyDereference(CheckerContext &C,
   auto State = C.getState();
   const auto *Pos = getIteratorPosition(State, Val);
   if (Pos && isPastTheEnd(State, *Pos)) {
-    auto *N = C.generateNonFatalErrorNode(State);
+    auto *N = C.generateErrorNode(State);
     if (!N)
       return;
     reportOutOfRangeBug("Past-the-end iterator dereferenced.", Val, C, N);
@@ -940,7 +938,7 @@ void IteratorChecker::verifyAccess(CheckerContext &C, const SVal &Val) const {
   auto State = C.getState();
   const auto *Pos = getIteratorPosition(State, Val);
   if (Pos && !Pos->isValid()) {
-    auto *N = C.generateNonFatalErrorNode(State);
+    auto *N = C.generateErrorNode(State);
     if (!N) {
       return;
     }
@@ -1048,14 +1046,14 @@ void IteratorChecker::verifyRandomIncrOrDecr(CheckerContext &C,
   // The result may be the past-end iterator of the container, but any other
   // out of range position is undefined behaviour
   if (isAheadOfRange(State, advancePosition(C, Op, *Pos, Value))) {
-    auto *N = C.generateNonFatalErrorNode(State);
+    auto *N = C.generateErrorNode(State);
     if (!N)
       return;
     reportOutOfRangeBug("Iterator decremented ahead of its valid range.", LHS,
                         C, N);
   }
   if (isBehindPastTheEnd(State, advancePosition(C, Op, *Pos, Value))) {
-    auto *N = C.generateNonFatalErrorNode(State);
+    auto *N = C.generateErrorNode(State);
     if (!N)
       return;
     reportOutOfRangeBug("Iterator incremented behind the past-the-end "