| # If possible, ignore libraries that are not depended on. |
| |
| dnl Copyright (C) 2006 Free Software Foundation, Inc. |
| dnl This file is free software; the Free Software Foundation |
| dnl gives unlimited permission to copy and/or distribute it, |
| dnl with or without modifications, as long as this notice is preserved. |
| |
| dnl Written by Paul Eggert. |
| |
| AC_DEFUN([gl_IGNORE_UNUSED_LIBRARIES], |
| [ |
| AC_CACHE_CHECK([for flag to ignore unused libraries], |
| [gl_cv_ignore_unused_libraries], |
| [gl_cv_ignore_unused_libraries=none |
| gl_saved_ldflags=$LDFLAGS |
| gl_saved_libs=$LIBS |
| # Link with -lm to detect binutils 2.16 bug with --as-needed; see |
| # <http://lists.gnu.org/archive/html/bug-gnulib/2006-06/msg00131.html>. |
| LIBS="$LIBS -lm" |
| # Use long option sequences like '-z ignore' to test for the feature, |
| # to forestall problems with linkers that have -z, -i, -g, -n, etc. flags. |
| # GCC + binutils likes '-Wl,--as-needed'. |
| # GCC + Solaris ld likes '-Wl,-z,ignore'. |
| # Sun C likes '-z ignore'. |
| # Don't try bare '--as-needed'; nothing likes it and the HP-UX 11.11 |
| # native cc issues annoying warnings and then ignores it, |
| # which would cause us to incorrectly conclude that it worked. |
| for gl_flags in \ |
| '-Wl,--as-needed' \ |
| '-Wl,-z,ignore' \ |
| '-z ignore' |
| do |
| LDFLAGS="$gl_flags $LDFLAGS" |
| AC_LINK_IFELSE([AC_LANG_PROGRAM()], |
| [gl_cv_ignore_unused_libraries=$gl_flags]) |
| LDFLAGS=$gl_saved_ldflags |
| test "$gl_cv_ignore_unused_libraries" != none && break |
| done |
| LIBS=$gl_saved_libs]) |
| |
| test "$gl_cv_ignore_unused_libraries" != none && |
| LDFLAGS="$LDFLAGS $gl_cv_ignore_unused_libraries" |
| ]) |
