http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55243
--- Comment #16 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2012-12-10 18:47:13 UTC --- > > So t-multilib is autogenerated in the source tree during the build??? > > Jepp. Top $(srcdir)/gcc/config/avr/t-multilib reads: > > > # Auto-generated Makefile Snip > # Generated by : ./gcc/config/avr/genmultilib.awk > # Generated from : ./gcc/config/avr/avr-mcus.def > # Used by : tmake_file from Makefile and genmultilib But this is a no-no, the compiler should be buildable with read-only sources once it is packaged in the release tarballs. > Rationale is that avr-gcc supports an, IMHO, insane number of -mmcu=<device>. > In order to keep various parts of the compiler in sync, some bits are > auto-generated, amongst them documentation, t-multilib and .opt parts. > > Procedure is a move-if-change scheme, i.e. the auto-generated files are in the > repository and the procedure to build them is similar to building configure > from configure.ac and then putting both configure.ac /and/ configure into the > repo. Building configure from configure.c isn't done at build time. Either you generate t-multilib like configure and you can put it in $(srcdir) or you generate it at build time and you must put it in $(builddir).
