Re: need to define _ISOC99_SOURCE

[Ulrich Drepper <drepper at redhat dot com>]

"Joseph S. Myers" <jsm28@cam.ac.uk> writes:

> In this particular case, since <wchar.h> and <wctype.h> were first added
> in AMD1, functions defined there should not be conditioned in them, just
> as all headers define ISO C:1990 things unconditionally, headers such as
> <unistd.h> define POSIX.1 things unconditionally, etc..

No.  Wrong.  Headers of these names were stupidly used before
standardizations.  Also, if you are using functionality from a certain
standard you must define the appropriate feature selection macro.
Otherwise the system is allowed to do anything.

> (The defintion of __USE_ANSI seems unnecessary: it is nowhere
> used.

Might be.

> # define _ISOC99_SOURCE 1
> 
> to the default defines in the case that no feature test macros or strict
> standards conformance has been specified:
> 
> #if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
>      !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
>      !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
>      !defined _BSD_SOURCE && !defined _SVID_SOURCE)
> # define _BSD_SOURCE    1
> # define _SVID_SOURCE   1
> #endif

No.  The compiler flag must match.  Go to the gcc people and make them
use ICO C99 as the standard.

-- 
---------------.                          ,-.   1325 Chesapeake Terrace
Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
Red Hat          `--' drepper at redhat.com   `------------------------