Re: lib/regex_internal.h uses #if _LIBC instead of #if defined (_LIBC)

[Eric Blake]

Vladimir 'φ-coder/phcoder' Serbinenko <phcoder <at> gmail.com> writes:

> +#if (defined MB_CUR_MAX && HAVE_LOCALE_H && HAVE_WCTYPE_H &&
HAVE_ISWCTYPE && HAVE_WCSCOLL) || defined (_LIBC) 

Redundant parenthesis.  If we were to apply this, it should be:

defined _LIBC

but I'm inclined to not apply it.

> It's inconsistent with the rest of this file.

That may be true, but it's not enough to worry about.

> Additionally it creates a
> warning if -Wundef is defined which is a problem if project uses both
> -Wundef and -Werror.

It is not possible to use gnulib with -Wundef and -Werror in tandem.  There are 
MANY more instances of assuming that an undefined variable is 0.

You may also be interested in looking at how coreutils does things.  It 
enables -Werror for both gnulib and its own code, but intentionally omits -
Wundef from both sets of CFLAGS, as well as omitting several other -W flags 
from the gnulib-specific CFLAGS even though they are enabled for coreutils' own 
files.

-- 
Eric Blake