Does gengtyped gt-*.h depends upon the configuration of the compiler?

[Basile Starynkevitch <basile at starynkevitch dot net>]

Hello All,

Sylvestre Ledru is very nicely trying to package MELT as a packaged 
debian plugin for GCC 4.5 - MELT can be compiled either as an entire GCC 
branch, or as a GCC 4.5 -i.e. trunk- plugin.

However, we seems to have found some difficult issue. As Diego added 
into the documentation:
http://gcc.gnu.org/onlinedocs/gccint/Plugins.html#Plugins

"Plugins needing to use gengtype require a GCC build directory for the 
 same version of GCC that they will be linked against."

The MELT plugin uses PLUGIN_REGISTER_GGC_ROOTS et PLUGIN_GGC_MARKING

So it needs to run gengtype to generate the GGC roots table specific to 
MELT. MELT also have its own GTY-ed struct in melt-runtime.h & some 
GTY-ed roots in melt-runtime.c

MELT only need gengtype to generate its gt-melt-runtime.h but I have no 
idea if that file depends upon the configuration (and notably the target 
for which GCC is built). The GTY-ed data of MELT does not depend (IMHO) 
upon the configuration directly (in the sense that there is no #ifdef 
around GTY-ed struct), but of course it points to data like Gimple or 
Tree which I imagine depend upon the configuration of GCC (notably 
--enable-check but perhaps also the target ...)

In other words, would a gt-melt-runtime.h generated on 
Debian/Linux/AMD64 would be ok for a Debian/Linux/x86 or 
Debian/Linux/ARM? I blindly guess that probably not, but I am not sure.

Apparently, the constraint that gengtype requires availability of both 
the source & the build trees of the GCC for which the plugin is built is 
quite unnatural (but of course I understand why it is needed) and could 
be perhaps incompatible with the way many Linux distributions (including 
Debian) are naturally packaging GCC.

Comments are welcome.

Regards.

--
Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359
8, rue de la Faiencerie, 92340 Bourg La Reine, France
*** opinions {are only mines, sont seulement les miennes} ***