1# ld-version-script.m4 serial 4
2dnl Copyright (C) 2008-2015 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7dnl From Simon Josefsson
8
9# FIXME: The test below returns a false positive for mingw
10# cross-compiles, 'local:' statements does not reduce number of
11# exported symbols in a DLL.  Use --disable-ld-version-script to work
12# around the problem.
13
14# gl_LD_VERSION_SCRIPT
15# --------------------
16# Check if LD supports linker scripts, and define automake conditional
17# HAVE_LD_VERSION_SCRIPT if so.
18AC_DEFUN([gl_LD_VERSION_SCRIPT],
19[
20  AC_ARG_ENABLE([ld-version-script],
21    [AS_HELP_STRING([--enable-ld-version-script],
22       [enable linker version script (default is enabled when possible)])],
23    [have_ld_version_script=$enableval],
24    [AC_CACHE_CHECK([if LD -Wl,--version-script works],
25       [gl_cv_sys_ld_version_script],
26       [gl_cv_sys_ld_version_script=no
27        save_LDFLAGS=$LDFLAGS
28        LDFLAGS="$LDFLAGS -Wl,--version-script=conftest.map"
29        echo foo >conftest.map
30        AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
31          [],
32          [cat > conftest.map <<EOF
33VERS_1 {
34        global: sym;
35};
36
37VERS_2 {
38        global: sym;
39} VERS_1;
40EOF
41           AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
42             [gl_cv_sys_ld_version_script=yes])])
43        rm -f conftest.map
44        LDFLAGS=$save_LDFLAGS])
45     have_ld_version_script=$gl_cv_sys_ld_version_script])
46  AM_CONDITIONAL([HAVE_LD_VERSION_SCRIPT],
47    [test "$have_ld_version_script" = yes])
48])
49