[analyzer] Tighten up safety in the use of lazy bindings.

- When deciding if we can reuse a lazy binding, make sure to check if there
  are additional bindings in the sub-region.
- When reading from a lazy binding, don't accidentally strip off casts or
  base object regions. This slows down lazy binding reading a bit but is
  necessary for type sanity when treating one class as another.

A bit of minor refactoring allowed these two checks to be unified in a nice
early-return-using helper function.

<rdar://problem/13239840>

llvm-svn: 175703

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/test/Analysis/array-struct-region.c b/clang/test/Analysis/array-struct-region.c
index dfb4cf13a9b..6817124afe5 100644
--- a/clang/test/Analysis/array-struct-region.c
+++ b/clang/test/Analysis/array-struct-region.c
@@ -285,6 +285,13 @@ void testArrayStructCopy() {
   clang_analyzer_eval(s3.data[0] == 'a'); // expected-warning{{TRUE}}
   clang_analyzer_eval(s3.data[1] == 'b'); // expected-warning{{TRUE}}
   clang_analyzer_eval(s3.data[2] == 'c'); // expected-warning{{TRUE}}
+
+  s3.data[0] = 'z';
+  ShortString s4 = s3;
+
+  clang_analyzer_eval(s4.data[0] == 'z'); // expected-warning{{TRUE}}
+  clang_analyzer_eval(s4.data[1] == 'b'); // expected-warning{{TRUE}}
+  clang_analyzer_eval(s4.data[2] == 'c'); // expected-warning{{TRUE}}
 }
 
 void testArrayStructCopyNested() {