[PATCH] Undef __INT64_C/__UINT64_C for glibc build and test

[Collin Funk]

"H.J. Lu" <hjl.tools@gmail.com> writes:

> Since clang 20 defines __INT64_C and __UINT64_C as built-in macros, undef
> them for glibc build and test.  This fixes BZ #33311.
>
> Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
> ---
>  include/stdint.h | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/include/stdint.h b/include/stdint.h
> index 7f428741d7..8db6187c49 100644
> --- a/include/stdint.h
> +++ b/include/stdint.h
> @@ -1 +1,6 @@
> +#ifndef _STDINT_H
> +/* NB: Clang 20 defines them as built-in macros.  */
> +#undef __INT64_C
> +#undef __UINT64_C
>  #include <stdlib/stdint.h>
> +#endif

Should we just do all the others while we are at it? They are also
defined [1]. Confirmed on my system:

$ echo | clang -dM -E - | grep -F '_C('
#define __INT16_C(c) c
#define __INT32_C(c) c
#define __INT64_C(c) c##L
#define __INT8_C(c) c
#define __INTMAX_C(c) c##L
#define __UINT16_C(c) c
#define __UINT32_C(c) c##U
#define __UINT64_C(c) c##UL
#define __UINT8_C(c) c
#define __UINTMAX_C(c) c##UL

Collin

[1] https://github.com/llvm/llvm-project/commit/33ad474c45e6d7a0de7bc75e15e27cf6cb9ff895