[PATCH] D157252: [clang][ExprConst] Handle 0 type size in builtin_memcpy etc.

[Timm Bäder via Phabricator via cfe-commits]

tbaeder added inline comments.


================
Comment at: clang/test/Sema/builtin-memcpy.c:4-8
+int b() {
+  struct {      } a[10];
+  __builtin_memcpy(&a[2], a, 2); // expected-warning {{buffer has size 0, but size argument is 2}}
+  return 0;
+}
----------------
aaron.ballman wrote:
> The only other test I'd like to see is one like:
> ```
> constexpr int b() {
>   struct {      } a[10];
>   __builtin_memcpy(&a[2], a, 2); // UB here should be caught, right?
>   return 0;
> }
> 
> static_assert(b() == 0, "");
> ```
> (if that's follow-up work, that's fine too, just leave a test with a FIXME comment.)
Nope, clang accepts that and GCC rejects the function when calling.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157252/new/

https://reviews.llvm.org/D157252