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

The original intent of this commit was to catch potential null dereferences
early, but it breaks the common "home-grown offsetof" idiom (PR13927):

 (((struct Foo *)0)->member - ((struct foo *)0))

As it turns out, this appears to be legal in C, per a footnote in
C11 6.5.3.2: "Thus, &*E is equivalent to E (even if E is a null pointer)".
In C++ this issue is still open:
  http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#232

We'll just have to make sure we have good path notes in the future.

This reverts r164441 / 9be016dcd1ca3986873a7b66bd4bc027309ceb59.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164958 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 7 deletions

diff --git a/test/Analysis/fields.c b/test/Analysis/fields.c
index a10d5a8060..da0847a560 100644
--- a/test/Analysis/fields.c
+++ b/test/Analysis/fields.c
@@ -26,10 +26,3 @@ void test() {
   Point p;
   (void)(p = getit()).x;
 }
-
-
-void testNullAddress() {
-  Point *p = 0;
-  int *px = &p->x; // expected-warning{{Access to field 'x' results in a dereference of a null pointer (loaded from variable 'p')}}
-  *px = 1; // No warning because analysis stops at the previous line.
-}