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Re: [PATCH] obstack: remove __STDC__ conditionals

From: Bruno Haible
Subject: Re: [PATCH] obstack: remove __STDC__ conditionals
Date: Thu, 26 Jan 2012 02:24:01 +0100
User-agent: KMail/4.7.4 (Linux/3.1.0-1.2-desktop; KDE/4.7.4; x86_64; ; )

Paul Eggert wrote:
> By the way, can anybody explain the following comment
> in m4/include_next.m4?
>   dnl gcc does not warn about some things, and on some systems (Solaris and 
> Interix)
>   dnl __STDC__ evaluates to 0 instead of to 1. The latter is an undesired side
>   dnl effect; we are therefore careful to use 'defined __STDC__' or '1' 
> instead
>   dnl of plain '__STDC__'.
> ...
> -#if defined __GNUC__ && defined __STDC__ && __STDC__
> +#if defined __GNUC__
>  /* NextStep 2.0 cc is really gcc 1.93 but it defines __GNUC__ = 2 and
>     does not implement __extension__.  But that compiler doesn't define
>     __GNUC_MINOR__.  */

These two comments refer to systems that were in use ca. 1992-1995. At
that time you could use "gcc -traditional", which would not define __STDC__,
and on some systems (esp. early SVR4 systems) __STDC__ was defined to 0
by the 'cc' compiler and then also by gcc (since it had to be compatible
with the header files - fixincludes was not as good in these days at it is

Thanks for the cleanup of this extremely old cruft.


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