[patch] Fix --enable-plugins --without-python

[Jan Kratochvil <jan.kratochvil@redhat.com>]

Hi,

currently --enable-plugins --without-python will:
Reading symbols from .../gdb...I'm sorry, Dave, I can't do that.  Symbol format `elf64-x86-64' unknown.

due to missing elfread.c due to:

 configure:14941: checking for ELF support in BFD
 configure:14960: gcc -o conftest -g -I./../include -I../bfd -I./../bfd     -L../bfd -L../libiberty conftest.c -lbfd -liberty  -lncurses -lz -lm    >&5
-configure:14960: $? = 0
-configure:14968: result: yes
+/usr/bin/ld: ../bfd/libbfd.a(plugin.o): undefined reference to symbol 'dlsym@@GLIBC_2.2.5'
+/usr/bin/ld: note: 'dlsym@@GLIBC_2.2.5' is defined in DSO /lib64/libdl.so.2 so try adding it to the linker command line
+[...]
+configure:14968: result: no

Tested on x86_64-fedora13-linux-gnu.

As bfd/ uses just:

bfd/configure.in
# AC_PLUGINS setting $plugins is called by ACX_LARGEFILE.
ACX_LARGEFILE
AM_CONDITIONAL(PLUGINS, test "$plugins" = "yes")

bfd/Makefile.am
if PLUGINS
LIBDL = -ldl
endif

and I believe bfd/ is assumed to have the same configure options as gdb/ (is
it?) proposing this patch.


Thanks,
Jan


gdb/
2010-10-17  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix configure --enable-plugins --without-python.
	* configure.ac (for ELF support in BFD) <"$plugins" = "yes">: New.
	* configure: Regenerate.

--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1838,6 +1838,9 @@ OLD_LIBS=$LIBS
 CFLAGS="$CFLAGS -I${srcdir}/../include -I../bfd -I${srcdir}/../bfd"
 LDFLAGS="$LDFLAGS -L../bfd -L../libiberty"
 intl=`echo $LIBINTL | sed 's,${top_builddir}/,,g'`
+if test "$plugins" = "yes"; then
+  LIBS="-ldl $LIBS"
+fi
 LIBS="-lbfd -liberty $intl $LIBS"
 AC_CACHE_CHECK([for ELF support in BFD], gdb_cv_var_elf,
 [AC_TRY_LINK(
@@ -1851,6 +1854,9 @@ if test $gdb_cv_var_elf = yes; then
   CONFIG_OBS="$CONFIG_OBS elfread.o"
   AC_DEFINE(HAVE_ELF, 1,
 	    [Define if ELF support should be included.])
+  if test "$plugins" = "yes"; then
+    OLD_LIBS="-ldl $OLD_LIBS"
+  fi
 fi
 CFLAGS=$OLD_CFLAGS
 LDFLAGS=$OLD_LDFLAGS