http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55243
--- Comment #14 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2012-12-10 18:25:19 UTC --- (In reply to comment #12) > 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 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. However, the auto-build runs automatically and thus needs some tools, namely $(SHELL), $(AWK), $(CC_FOR_BUILD), $(RUN_GEN) and $(STAMP).
