RegionStore/BasicStore: do not return UndefinedVal for accesses to concrete addresses; instead return UnknownVal. This

leads it up to checkers (e.g., DereferenceChecker) to guard against illegal accesses (e.g., null dereferences).

Fixes PR 5272 and <rdar://problem/6839683>.

llvm-svn: 118852

1 files changed, 3 insertions, 4 deletions

diff --git a/clang/lib/Checker/BasicStore.cpp b/clang/lib/Checker/BasicStore.cpp
index f82e1b20be9..5221ae3495f 100644
--- a/clang/lib/Checker/BasicStore.cpp
+++ b/clang/lib/Checker/BasicStore.cpp
@@ -194,10 +194,9 @@ SVal BasicStoreManager::Retrieve(Store store, Loc loc, QualType T) {
     }
 
     case loc::ConcreteIntKind:
-      // Some clients may call GetSVal with such an option simply because
-      // they are doing a quick scan through their Locs (potentially to
-      // invalidate their bindings).  Just return Undefined.
-      return UndefinedVal();
+      // Support direct accesses to memory.  It's up to individual checkers
+      // to flag an error.
+      return UnknownVal();
 
     default:
       assert (false && "Invalid Loc.");