Import m4/ld-output-def.m4

m4/ld-output-def.m4

@@ -0,0 +1,29 @@
+# ld-output-def.m4 serial 2
+dnl Copyright (C) 2008-2013 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 From Simon Josefsson
+
+# gl_LD_OUTPUT_DEF()
+# -------------
+# Check if linker supports -Wl,--output-def and define automake
+# conditional HAVE_LD_OUTPUT_DEF if it is.
+AC_DEFUN([gl_LD_OUTPUT_DEF],
+[
+  AC_CACHE_CHECK([if gcc/ld supports -Wl,--output-def],
+    [gl_cv_ld_output_def],
+    [if test "$enable_shared" = no; then
+       gl_cv_ld_output_def="not needed, shared libraries are disabled"
+     else
+       gl_ldflags_save=$LDFLAGS
+       LDFLAGS="-Wl,--output-def,conftest.def"
+       AC_LINK_IFELSE([AC_LANG_PROGRAM([])],
+                   [gl_cv_ld_output_def=yes],
+                   [gl_cv_ld_output_def=no])
+       rm -f conftest.def
+       LDFLAGS="$gl_ldflags_save"
+     fi])
+  AM_CONDITIONAL([HAVE_LD_OUTPUT_DEF], test "x$gl_cv_ld_output_def" = "xyes")
+])