source: trunk/src/gcc/config-ml.in@ 272

# Configure fragment invoked in the post-target section for subdirs
# wanting multilib support.
#
# It is advisable to support a few --enable/--disable options to let the
# user select which libraries s/he really wants.
#
# Subdirectories wishing to use multilib should put the following lines
# in the "post-target" section of configure.in.
#
# if [ "${srcdir}" = "." ] ; then
#   if [ "${with_target_subdir}" != "." ] ; then
#     . ${with_multisrctop}../../config-ml.in
#   else
#     . ${with_multisrctop}../config-ml.in
#   fi
# else
#   . ${srcdir}/../config-ml.in
# fi
#
#
# Things are complicated because 6 separate cases must be handled:
# 2 (native, cross) x 3 (absolute-path, relative-not-dot, dot) = 6.
#
# srcdir=. is special.  It must handle make programs that don't handle VPATH.
# To implement this, a symlink tree is built for each library and for each
# multilib subdir.
#
# The build tree is layed out as
#
# ./
#   newlib
#   m68020/
#          newlib
#          m68881/
#                 newlib
#
# The nice feature about this arrangement is that inter-library references
# in the build tree work without having to care where you are.  Note that
# inter-library references also work in the source tree because symlink trees
# are built when srcdir=.
#
# Unfortunately, trying to access the libraries in the build tree requires
# the user to manually choose which library to use as GCC won't be able to
# find the right one.  This is viewed as the lesser of two evils.
#
# Configure variables:
# ${with_target_subdir} = "." for native, or ${target_alias} for cross.
# Set by top level Makefile.
# ${with_multisrctop} = how many levels of multilibs there are in the source
# tree.  It exists to handle the case of configuring in the source tree:
# ${srcdir} is not constant.
# ${with_multisubdir} = name of multilib subdirectory (eg: m68020/m68881).
#
# Makefile variables:
# MULTISRCTOP = number of multilib levels in source tree (+1 if cross)
# (FIXME: note that this is different than ${with_multisrctop}.  Check out.).
# MULTIBUILDTOP = number of multilib levels in build tree
# MULTIDIRS = list of multilib subdirs (eg: m68000 m68020 ...)
# (only defined in each library's main Makefile).
# MULTISUBDIR = installed subdirectory name with leading '/' (eg: /m68000)
# (only defined in each multilib subdir).

# FIXME: Multilib is currently disabled by default for everything other than
# newlib.  It is up to each target to turn on multilib support for the other
# libraries as desired.

# We have to handle being invoked by both Cygnus configure and Autoconf.
#
# Cygnus configure incoming variables:
# srcdir, subdir, host, arguments
#
# Autoconf incoming variables:
# srcdir, host, ac_configure_args
#
# We *could* figure srcdir and host out, but we'd have to do work that
# our caller has already done to figure them out and requiring these two
# seems reasonable.
# Note that `host' in this case is GCC's `target'.  Target libraries are
# configured for a particular host.

if [ -n "${ac_configure_args}" ]; then
  Makefile=${ac_file-Makefile}
  ml_config_shell=${CONFIG_SHELL-/bin/sh}
  ml_arguments="${ac_configure_args}"
  ml_realsrcdir=${srcdir}
else
  Makefile=${Makefile-Makefile}
  ml_config_shell=${config_shell-/bin/sh}
  ml_arguments="${arguments}"
  if [ -n "${subdir}" -a "${subdir}" != "." ] ; then
    ml_realsrcdir=${srcdir}/${subdir}
  else
    ml_realsrcdir=${srcdir}
  fi
fi

# Scan all the arguments and set all the ones we need.

ml_verbose=--verbose
for option in ${ml_arguments}
do
  case $option in
  --*) ;;
  -*) option=-$option ;;
  esac

  case $option in
  --*=*)
        optarg=`echo $option | sed -e 's/^[^=]*=//'`
        ;;
  esac

  case $option in
  --disable-*)
        enableopt=`echo ${option} | sed 's:^--disable-:enable_:;s:-:_:g'`
        eval $enableopt=no
        ;;
  --enable-*)
        case "$option" in
        *=*)    ;;
        *)      optarg=yes ;;
        esac
        enableopt=`echo ${option} | sed 's:^--::;s:=.*$::;s:-:_:g'`
        eval $enableopt="$optarg"
        ;;
  --norecursion | --no*)
        ml_norecursion=yes
        ;;
  --silent | --sil* | --quiet | --q*)
        ml_verbose=--silent
        ;;
  --verbose | --v | --verb*)
        ml_verbose=--verbose
        ;;
  --with-*)
        case "$option" in
        *=*)    ;;
        *)      optarg=yes ;;
        esac
        withopt=`echo ${option} | sed 's:^--::;s:=.*$::;s:-:_:g'`
        eval $withopt="$optarg"
        ;;
  --without-*)
        withopt=`echo ${option} | sed 's:^--::;s:out::;s:-:_:g'`
        eval $withopt=no
        ;;
  esac
done

# Only do this if --enable-multilib.
if [ "${enable_multilib}" = yes ]; then

# Compute whether this is the library's top level directory
# (ie: not a multilib subdirectory, and not a subdirectory like newlib/src).
# ${with_multisubdir} tells us we're in the right branch, but we could be
# in a subdir of that.
# ??? The previous version could void this test by separating the process into
# two files: one that only the library's toplevel configure.in ran (to
# configure the multilib subdirs), and another that all configure.in's ran to
# update the Makefile.  It seemed reasonable to collapse all multilib support
# into one file, but it does leave us with having to perform this test.