[PATCH] D149000: Update with warning message for comparison to NULL pointer

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added inline comments.


================
Comment at: clang/test/Sema/conditional-expr.c:89
   char x;
-  return ((((&x) != ((void *) 0)) ? (*(&x) = ((char) 1)) : (void) ((void *) 0)), (unsigned long) ((void *) 0)); // expected-warning {{C99 forbids conditional expressions with only one void side}}
 }
----------------
The C99 warning should not be dropped -- that was a valid pedantic diagnostic: https://godbolt.org/z/Tz3zGY8d4


================
Comment at: clang/test/SemaCXX/constant-expression-cxx2a.cpp:252
   // ... but in the complete object, the same is not true, so the runtime fails.
-  static_assert(dynamic_cast<const A*>(static_cast<const C2*>(&g)) == nullptr);
+  static_assert(dynamic_cast<const A*>(static_cast<const C2*>(&g)) == nullptr); // expected-warning {{comparison of address of 'g' equal to a null pointer is always false}}
 
----------------
shafik wrote:
> I don't believe we should be emitting a diagnostic for this case. The `static_assert` passes. CC @aaron.ballman 
Agreed, this new diagnostic should not be triggered


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D149000/new/

https://reviews.llvm.org/D149000