I am trying to fix a multilib build problem and am hoping a build expert can help me figure out a fix/workaround to my problem.
I am building a multilib mips compiler using '--with-synci' on the configure line. This means that gcc will pass the '-msynci' option to cc1 by default. The problem occurs when one of my multilib targets (like -mips32) does not support synci. This means that any compilation done with -mips32 will generate a warning during compilation. Unfortunately, this means that I have configure problems with libstdc++-v3 because the configure test for _GLIBCXX_PTRDIFF_T_IS_INT uses -Werror and the -msynci warning that I get causes the test to do the wrong thing. I looked at using MULTILIB_EXTRA_OPTS to add -mno-synci to the compile but I don't want to use this flag on all multilib compiles, only ones with -mips32. After the documentation for MULTILIB_EXTRA_OPTS in fragments.texi is a section on SPECS but I don't really understand how to use this and I couldn't find an example of another target using SPECS to change the multilib build of libraries. Can any one point me to an example of someone using this? Ideally I would like a MULTILIB_EXTRA_OPTS type variable that could add extra flags to some multilib versions but not others. That doesn't seem to exist though. Anyone have any ideas on how to deal with this problem? Steve Ellcey sell...@mips.com
