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Date: Fri, 21 Dec 2012 12:23:00 -0000
From: Richard Biener <rguenther@suse.de>
To: Eric Botcazou <ebotcazou@adacore.com>
Cc: gcc-patches@gcc.gnu.org, laurent@guerby.net
Subject: Re: [PATCH] Include gmp.h from system.h to fix PR54659
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On Fri, 21 Dec 2012, Eric Botcazou wrote:

> > This runs into issues with Ada which basically does (ugh)
> > 
> > #ifdef __cplusplus
> > extern "C" {
> > #endif
> > 
> > #include "system.h"
> > 
> > #endif __cplusplus
> > }
> > #endif
> > 
> > which of course wrecks any system header doing __cplusplus
> > conditional stuff (such as gmp.h including iosfwd).  The patch
> > un-kludges this by wrapping system.h inside extern "C++" when
> > compiling with the C++ frontend.
> > 
> > But - really - Ada people - can you fix that on your side please?
> > (CCed people doing r176210)
> 
> Like so?  I cannot believe that all this fuss was about moving 3 lines within 
> less than a dozen of files...

The patch looks fine to me (though it's not 100% obvious to me as not only
system headers are now no longer in extern "C" - which is why I simply
tried the un-wrapping).  So, if you think that's ok please commit it.

It certainly helps not to rely on compilers handling nested extern "foo"
correctly ...

Thanks,
Richard.