From: Antonio Terceiro <terceiro@...>
Date: 2011-06-25T03:50:21+09:00
Subject: Re: Explicitly setting compiler to C++ in extconf.rb...

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Michael Edgar escreveu isso a=ED:
> On Jun 23, 2011, at 7:30 PM, Antonio Terceiro wrote:
>=20
> > require 'rbconfig'
> > RbConfig::CONFIG['CPP'] =3D RbConfig::CONFIG['CPP'].gsub('gcc', 'g++')
> > require 'mkmf'
> > have_header('string') or raise('You need <string>')
> > create_makefile('test')
>=20
> Don't do this. The following is sufficient:
>=20
> require 'mkmf'
> have_library('stdc++')
> create_makefile('laser/BasicBlock')
>=20
> That's a working extconf.rb for a gem I'm actively working on. Adding std=
c++
> makes mkmf use g++ on my system.

Actualy mkmf uses g++ for C++ code (.cc,.cpp), and not because you
checked for 'stdc++'

The original problem is not checking for a C++ standard header, is
checking for a header that is actually a C++ header that happens to
#include a C++ standard header. Doing that with `gcc -E` instead of `g++
-E` will just not work.

Of course, mkmf could provide a way to say "please check for everything
using C++ instead of C".

--=20
Antonio Terceiro <terceiro@softwarelivre.org>
http://softwarelivre.org/terceiro



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