Re: PATCH to pre-select languages to be build (was: Re: No Fortran - IS ANYBODY WORKING ON IT?)

[Jeffrey A Law <law at cygnus dot com>]

  In message <13840.57066.10628.804866@slsvhmt>you write:
  > On Wed, 16 September 1998, 08:39:53, manfred@s-direktnet.de wrote:
  > 
  >  > On Tue, 15 September 1998, 02:10:15, law@cygnus.com wrote:
  >  > 
  >  >  > 
  >  >  > This kind of scheme works better if we ever have an option to
  >  >  > enable/disable a language at configure time.  ie --disable-chill
  >  >  > or something like that to disable the chill compiler, even if
  >  >  > it is in your source tree  and you don't remember LANGUAGES="..." :-)
  >  > 
  >  > Is anybody working on this already? I'd like to implement this as I've
  >  > stumbled across this especially on my damn slow  68k machine (which is
  >  > - even worse  - using multilibs  :-(  ); but unfortunately  I'm rather
  >  > busy doing other things at the moment, I  guess I'll be having a patch
  >  > available in 1 to 2 weeks. OK?
  >  > 
  >  > manfred
  > 
  > The  approach you were talking about  assumes,  everybody who wants to
  > restrict the languages to a particular subset
  > 
  >   - knows which languages do exist and which do I want.
  > 
  > My patch below goes the other way round. It's  based on the assumption
  > that most people
  > 
  >   - know which languages they actually want to build.
  > 
  > If the "--disable-chill"  would have been  available before the recent
  > languages had been introduced, all users, that only  wanted "c c++" to
  > be  built, would  still  get the  new  compilers,  simply because they
  > didn't know such a beast exists.
I think there's a much simpler way to do this.  Something like this in gcc/configure.in
# Figure out what language subdirectories are present.
subdirs=
for lang in ${srcdir}/*/config-lang.in ..
do
        case $lang in
        ..) ;;
        # The odd quoting in the next line works around
        # an apparent bug in bash 1.12 on linux.
        ${srcdir}/[[*]]/config-lang.in) ;;
        # CYGNUS LOCAL nofortran/law
        ${srcdir}/f/config-lang.in)
          if [[ x$enable_fortran = xyes ]]; then
                subdirs="$subdirs `echo $lang | sed -e 's,^.*/\([[^/]]*\)/config-lang.in$,\1,'`"
          fi
          ;;
        ${srcdir}/objc/config-lang.in)
          if [[ x$enable_objc = xyes ]]; then
                subdirs="$subdirs `echo $lang | sed -e 's,^.*/\([[^/]]*\)/config-lang.in$,\1,'`"
          fi
          ;;
        # END CYGNUS LOCAL
        *) subdirs="$subdirs `echo $lang | sed -e 's,^.*/\([[^/]]*\)/config-lang.in$,\1,'`" ;;
        esac
done

This is what we're using inside Cygnus to disable fortran & objc.  It's easily
extended to handle additional languages and to support a full enable/disable
syntax.

We then have the associated runtime libraries automatically disable themselves
if the proper compiler isn't found in <objdir>/gcc.  This should be fairly
simple too, though we haven't actually tried it.

jeff