Re: configure is not checking everything

[Thomas Dickey]

On Thu, 6 Sep 2007, Eric Blake wrote:

> I'd also like to point out that:
>
> > > case "$host" in
> > >   *-linux*)
> > >     AC_DEFINE(PLATFORM_LINUX, 1, [Define if you are compiling for Linux])
> > >     ;;
>
> Many variants of these defines are already available in system headers or
> predefined by the compiler, so you need not litter them into your config.h

Sadly, the predefined symbols are not standardized, and it's possible
(you will certainly encounter this with enough experience) to find
cases where some less-than-ingenious packager helps things in the
wrong direction by predefining some of them.

> file.  Furthermore, platform-specific checks are not the autoconf way...

The "autoconf way" is to devise a compile-time or run-time check to look 
for a feature.  There are, and probably always will be subtle defects
which cannot be tested automatically.

short: use the autoconf tests where they can be, but it's not the last 
word.

--
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net