scripts/libc: do not build add-ons by default

Currently, no --enable-add-ons option is passed to libc configure when
"$(do_libc_add_ons_list ,)" is empty, which makes configure automatically search
for present add-ons. In that case, all present add-ons are built, although
no add-on was selected by the user in the config. Moreover, this can make the
configure fail if some non-standard add-ons like eglibc-localedef are present.

This behavior also leads to an inconsistency from a user point of view between
the following cases:
- LIBC_ADDONS_LIST="", LIBC_GLIBC_USE_PORTS=n and THREADS="none" in the config,
which makes "$(do_libc_add_ons_list ,)" return "", so all present add-ons
are built.
- LIBC_ADDONS_LIST="", LIBC_GLIBC_USE_PORTS=n and THREADS!="none" in the
config, which makes "$(do_libc_add_ons_list ,)" return the add-on supporting
the chosen threading implementation, e.g. "nptl", so only this add-on is
built.

This patch disables the building of all add-ons in that case.

It is still possible to build all present add-ons by adding --enable-add-ons to
LIBC_GLIBC_EXTRA_CONFIG_ARRAY.

Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>

http://in3www.epfl.ch/~schaffne/glibc-configure-apple-as.patch

http://sources.redhat.com/ml/crossgcc/2004-02/msg00151.html

The following makes it possible to configure glibc-2.3.2 on Mac OS X,

where the assembler but doesn't understand the --version flag.

Fixes the symptom

checking whether ld is GNU ld... no

checking for /usr/libexec/gcc/darwin/ppc/as... /usr/libexec/gcc/darwin/ppc/as

checking version of /usr/libexec/gcc/darwin/ppc/as...

<PAUSES HERE AND JUST SITS THERE DOING NOTHING>

NOTE:  This patch should apparently be pushed upstream so we don't need to

keep adding it here.

--- glibc-2.3.2/configure~	Wed Feb 26 09:20:48 2003

+++ glibc-2.3.2/configure	Fri Feb 27 13:12:53 2004

@@ -4524,7 +4524,7 @@

   # Found it, now check the version.

   { echo "$as_me:$LINENO: checking version of $AS" >&5

 echo $ECHO_N "checking version of $AS... $ECHO_C" >&6; }

-  ac_prog_version=`$AS --version 2>&1 | sed -n 's/^.*GNU assembler.* \([0-9]*\.[0-9.]*\).*$/\1/p'`

+  ac_prog_version=`$AS -v </dev/null 2>&1 | sed -n 's/^.*GNU assembler.* \([0-9]*\.[0-9.]*\).*$/\1/p'`

   case $ac_prog_version in

     '') ac_prog_version="v. ?.??, bad"; ac_verc_fail=yes;;

     2.1[3-9]*)