Re: [PATCH 2/2] don't compile gcvt if posix < 200112

On Tue, 2019-07-23 at 08:14 +0900, [email protected] wrote:
> From: uchan-nos <[email protected]>
> 
> ---
>  newlib/libc/stdlib/efgcvt.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/newlib/libc/stdlib/efgcvt.c b/newlib/libc/stdlib/efgcvt.c
> index 9314bf361..c1684f35a 100644
> --- a/newlib/libc/stdlib/efgcvt.c
> +++ b/newlib/libc/stdlib/efgcvt.c
> @@ -102,6 +102,8 @@ Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
>  #include <stdlib.h>
>  #include "local.h"
>  
> +#if __XSI_VISIBLE >= 4 && __POSIX_VISIBLE < 200112
> +
>  char *
>  fcvt (double d,
>  	int ndigit,
> @@ -163,3 +165,5 @@ gcvt (double d,
>    }
>    return (_gcvt (_REENT, d, ndigit, buf, 'g', 0) ? tbuf : 0);
>  }
> +
> +#endif // __XSI_VISIBLE >= 4 && __POSIX_VISIBLE < 200112

This patch is incorrect.  The C library must provide all possible
interfaces; guards are only intended for headers, to control what is
declared (and therefore available to userspace code) based on the
chosen standard(s).

-- 
Yaakov Selkowitz
Senior Software Engineer - Platform Enablement
Red Hat, Inc.