[RFC v4 1/2] Add [v]aprintf(3)

[Joseph Myers]

On Wed, 18 Mar 2026, Alejandro Colomar wrote:

> diff --git a/libio/bits/stdio2.h b/libio/bits/stdio2.h
> index 193494db..b9fed67e 100644
> --- a/libio/bits/stdio2.h
> +++ b/libio/bits/stdio2.h
> @@ -200,6 +200,18 @@ vdprintf (int __fd, const char *__restrict __fmt, __gnuc_va_list __ap)
>  
>  # ifdef __USE_GNU
>  #  ifdef __va_arg_pack
> +__fortify_function char *
> +__NTH (aprintf (const char *__restrict __fmt, ...))
> +{
> +  return __aprintf_chk (__USE_FORTIFY_LEVEL - 1, __fmt, __va_arg_pack ());
> +}
> +
> +__fortify_function char *
> +__NTH (__aprintf (const char *__restrict __fmt, ...))
> +{
> +  return __aprintf_chk (__USE_FORTIFY_LEVEL - 1, __fmt, __va_arg_pack ());
> +}

Why is an internal name __aprintf being defined or declared in installed 
headers at all?

> diff --git a/stdio-common/Versions b/stdio-common/Versions
> index 8e1cbf85..aee611b2 100644
> --- a/stdio-common/Versions
> +++ b/stdio-common/Versions
> @@ -70,6 +70,8 @@ libc {
>      __isoc23_vfscanf;
>      __isoc23_sscanf;
>      __isoc23_vsscanf;
> +  GLIBC_2.44 {
> +    aprintf;
>    }

I don't see how this (inserting unbalanced '{' rather than a proper 
GLIBC_2.44 section separate from other versions) could work; if it does, 
it must be because of insufficient syntax checking somewhere in version 
map processing.

-- 
Joseph S. Myers
josmyers@redhat.com