Re: [Vincent Lefevre] Bug#325866: autoconf: AC_COMPILE_IFELSE generates a test that doesn't work on IRIX64

[Ralf Wildenhues]

* Noah Misch wrote on Wed, Sep 07, 2005 at 11:41:42PM CEST:
> On Fri, Sep 02, 2005 at 08:17:51AM +0200, Vincent Lefevre wrote:
> > 
> > Would grepping "^  #error directive:" break anything elsewhere?
> 
> That is probably safe, but it adds a fork to every AC_COMPILE_IFELSE.  Cygwin
> would suffer especially.
> 
> If we did use that approach, it would remain unwise to use #error in tests,
> because you would introduce a silent dependency on the next release of 
> Autoconf.
> Older versions would produce a `configure' that works almost everywhere, but 
> not
> with this compiler on IRIX.
> 
> I recommend removing usage of #error from tests if portability to compilers 
> with
> this flaw is important.

Fixed in CVS Autoconf by documenting that #error should be avoided.

Cheers,
Ralf