[Geany-devel] G_VA_COPY problem

[Lex Trotman]

On 12 March 2011 11:48, Colomban Wendling <lists.ban at herbesfolles.org> wrote:
> Le 12/03/2011 01:28, Lex Trotman a écrit :
>> On 12 March 2011 06:30, Colomban Wendling <lists.ban at herbesfolles.org> wrote:
>>> Le 11/03/2011 19:57, Nick Treleaven a écrit :
>>>> Hi,
>>>> tagmanager/mio/mio-memory.c uses G_VA_COPY() but on my system this is
>>>> defined as va_copy() (by glibconfig.h, I think).
>>>>
>>>> When I compile with my usual flags including warnings and -ansi,
>>>> va_copy is not defined. Any ideas how to solve this?
>>>>
>>>> It seems to be a GLib issue that may be solved in newer versions - I
>>>> still have glib2-2.14.4-1.fc8. Is anyone else using -ansi?
>>> Hum, that's problematic, right... This problem still happens with GLib 2.28.
>>> However, it may be quite hard to fix in the GLib side: they find the
>>> proper implementation at configure time, and if none found fallback to
>>> manual copy (implementation depends on the target then).
>>> The problem is that GLib has been built without -ansi on your system and
>>> found a working va_copy, but -ansi disabled it a compile-time...
>>
>> Ouch nasty, raises the point that maybe we shouldn't be building the
>> application with different compile flags to the major binary
>> libraries, there ciould be other potential problems.
> I guess this kind of problem only apply when using a compiler flag that
> changes the subset of functionality supported by the compiler (e.g. -std=*).

Yep, or maybe like one of our other discussions, anything that
specifies an ABI, or maybe a machine specification.  If the library
was made with 686 and Geany with 486 or the other way around I'm not
sure what potential problems could occur.

For example my GTK is built with -pthread and -D_REENTRANT, so there
is the potential for the -D_REENTRANT to change GTK headers if its not
correctly applied to Geany and all plugin builds. No specification of
which machine though.  Hopefully such things are handled by autofools
and waf.

>
> Even things like -Werror=implicit-function-declaration (again :D)
> wouldn't be a problem IMO: either the library headers pass fine with it
> or the library has serious problems that better get fixed.

Agree.  But of course if you need the library what do you do??

Cheers
Lex

>
> Cheers,
> Colomban
>