Fix for 'Cygwin List O' Issues' #4: complain-then-attempt-anyway

[Charles Wilson]

Originally, allow_undefined_flag was set to 'unsupported' for 
cygwin/mingw.  In the early days of 'auto-import' support in binutils, 
this caused libtool to refuse to build shared libs at all.  So, we set 
allow_undefined=   . (empty)  This was accepted into libtool CVS earlier 
this year (20020531) -- but had been in the cygwin branch for a long time.

Well, over that period both libtool and binutils' support of auto-import 
had improved, and this 'unsetting' of allow_undefined_flag is no longer 
necessary -- and even causes problems now!

So, we revert that portion of the 20020531 patch

2002-11-01  Charles Wilson  <address@hidden>

        * libtool.m4 (AC_LIBTOOL_LANG_CXX_CONFIG): restore setting
        allow_undefined_flag=unsupported for cygwin and mingw.
        (AC_LIBTOOL_PROG_LD_SHLIBS): ditto, for both "normal" gcc/ld
        and for the (unmaintained?) MSVC case.

--Chuck

Index: libtool.m4
===================================================================
RCS file: /cvsroot/libtool/libtool/libtool.m4,v
retrieving revision 1.273
diff -u -r1.273 libtool.m4
--- libtool.m4  31 Oct 2002 00:52:39 -0000      1.273
+++ libtool.m4  1 Nov 2002 01:34:18 -0000
@@ -2645,6 +2650,7 @@
     # _LT_AC_TAGVAR(hardcode_libdir_flag_spec, $1) is actually meaningless,
     # as there is no search path for DLLs.
     _LT_AC_TAGVAR(hardcode_libdir_flag_spec, $1)='-L$libdir'
+    _LT_AC_TAGVAR(allow_undefined_flag, $1)=unsupported
     _LT_AC_TAGVAR(always_export_symbols, $1)=no
 
     if $LD --help 2>&1 | egrep 'auto-import' > /dev/null; then
@@ -2657,6 +2663,7 @@
 
   mingw* | pw32* )
     _LT_AC_TAGVAR(hardcode_libdir_flag_spec, $1)='-L$libdir'
+    _LT_AC_TAGVAR(allow_undefined_flag, $1)=unsupported
     _LT_AC_TAGVAR(always_export_symbols, $1)=no
 
     if $LD --help 2>&1 | egrep 'auto-import' > /dev/null; then
@@ -4649,6 +4656,7 @@
       # _LT_AC_TAGVAR(hardcode_libdir_flag_spec, $1) is actually meaningless,
       # as there is no search path for DLLs.
       _LT_AC_TAGVAR(hardcode_libdir_flag_spec, $1)='-L$libdir'
+      _LT_AC_TAGVAR(allow_undefined_flag, $1)=unsupported
       _LT_AC_TAGVAR(always_export_symbols, $1)=no
 
       if $LD --help 2>&1 | egrep 'auto-import' > /dev/null; then
@@ -4877,6 +4877,7 @@
       # hardcode_libdir_flag_spec is actually meaningless, as there is
       # no search path for DLLs.
       _LT_AC_TAGVAR(hardcode_libdir_flag_spec, $1)=' '
+      _LT_AC_TAGVAR(allow_undefined_flag, $1)=unsupported
       # Tell ltmain to make .lib files, not .a files.
       libext=lib
       # FIXME: Setting linknames here is a bad hack.