[analyzer] Check that a member expr is valid even when the result is an lvalue.

We want to catch cases like this early, so that we can produce better
diagnostics and path notes:

  Point *p = 0;
  int *px = &p->x; // should warn here
  *px = 1;

llvm-svn: 164441

1 files changed, 5 insertions, 4 deletions

diff --git a/clang/test/Analysis/nullptr.cpp b/clang/test/Analysis/nullptr.cpp
index 050c3f8dc56..80ef5fbf6d0 100644
--- a/clang/test/Analysis/nullptr.cpp
+++ b/clang/test/Analysis/nullptr.cpp
@@ -23,10 +23,11 @@ void foo3(void) {
   };
   char *np = nullptr;
   // casting a nullptr to anything should be caught eventually
-  int *ip = &(((struct foo *)np)->f);
-  *ip = 0;  // expected-warning{{Dereference of null pointer}}
-  // should be error here too, but analysis gets stopped
-//  *np = 0;
+  int *ip = &(((struct foo *)np)->f);  // expected-warning{{Access to field 'f' results in a dereference of a null pointer (loaded from variable 'np')}}
+
+  // Analysis stops at the first problem case, so we won't actually warn here.
+  *ip = 0;
+  *np = 0;
 }
 
 // nullptr is implemented as a zero integer value, so should be able to compare