How to prevent multilib builds if OS support missing?

["Ulrich Weigand" <Ulrich dot Weigand at de dot ibm dot com>]

Hello,

is there some mechanism to prevent a gcc build from failing because
some multilibbed library cannot be built due to missing OS support
(missing libraries, binutils support etc.)?

I had thought that code in config-ml.in could be used for that purpose,
e.g. there is sparc code with the comment:
  # We will not be able to create libraries with -m64 if
  # we cannot even link a trivial program.  If usually
  # indicates the 64bit libraries are missing.
which subsequently disables the -m64 multilib builds.

However, when I've added similar code to disable -m31 builds on
s390x-ibm-linux systems where 31bit libraries are missing, gcc
still did not build, because it still tried unsuccessfully to
build a multilibbed libgcc_s.so.

Apparently, config-ml.in is not even used inside the gcc/ directory
at all, only for the target libraries (libstdc++ etc.).

Is there some corresponding facility to disable multilibbed variants
of libgcc if OS support is missing?


Mit freundlichen Gruessen / Best Regards

Ulrich Weigand

--
  Dr. Ulrich Weigand
  Linux for S/390 Design & Development
  IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen
  Phone: +49-7031/16-3727   ---   Email: Ulrich.Weigand@de.ibm.com