1 # gcc-plugin.m4 -*- Autoconf -*- 2 # Check whether GCC is able to be built with plugin support. 3 4 dnl Copyright (C) 2014 Free Software Foundation, Inc. 5 dnl This file is free software, distributed under the terms of the GNU 6 dnl General Public License. As a special exception to the GNU General 7 dnl Public License, this file may be distributed as part of a program 8 dnl that contains a configuration script generated by Autoconf, under 9 dnl the same distribution terms as the rest of that program. 10 11 # Check for plugin support. 12 # Respects --enable-plugin. 13 # Sets the shell variables enable_plugin and pluginlibs. 14 AC_DEFUN([GCC_ENABLE_PLUGINS], 15 [# Check for plugin support 16 AC_ARG_ENABLE(plugin, 17 [AS_HELP_STRING([--enable-plugin], [enable plugin support])], 18 enable_plugin=$enableval, 19 enable_plugin=yes; default_plugin=yes) 20 21 pluginlibs= 22 23 case "${host}" in 24 *-*-darwin*) 25 if test x$build = x$host; then 26 export_sym_check="nm${exeext} -g" 27 elif test x$host = x$target; then 28 export_sym_check="$gcc_cv_nm -g" 29 else 30 export_sym_check= 31 fi 32 ;; 33 *) 34 if test x$build = x$host; then 35 export_sym_check="objdump${exeext} -T" 36 elif test x$host = x$target; then 37 export_sym_check="$gcc_cv_objdump -T" 38 else 39 export_sym_check= 40 fi 41 ;; 42 esac 43 44 if test x"$enable_plugin" = x"yes"; then 45 46 AC_MSG_CHECKING([for exported symbols]) 47 if test "x$export_sym_check" != x; then 48 echo "int main() {return 0;} int foobar() {return 0;}" > conftest.c 49 ${CC} ${CFLAGS} ${LDFLAGS} conftest.c -o conftest$ac_exeext > /dev/null 2>&1 50 if $export_sym_check conftest$ac_exeext | grep -q foobar > /dev/null; then 51 : # No need to use a flag 52 AC_MSG_RESULT([yes]) 53 else 54 AC_MSG_RESULT([yes]) 55 AC_MSG_CHECKING([for -rdynamic]) 56 ${CC} ${CFLAGS} ${LDFLAGS} -rdynamic conftest.c -o conftest$ac_exeext > /dev/null 2>&1 57 if $export_sym_check conftest$ac_exeext | grep -q foobar > /dev/null; then 58 plugin_rdynamic=yes 59 pluginlibs="-rdynamic" 60 else 61 plugin_rdynamic=no 62 enable_plugin=no 63 fi 64 AC_MSG_RESULT([$plugin_rdynamic]) 65 fi 66 else 67 AC_MSG_RESULT([unable to check]) 68 fi 69 70 # Check -ldl 71 saved_LIBS="$LIBS" 72 AC_SEARCH_LIBS([dlopen], [dl]) 73 if test x"$ac_cv_search_dlopen" = x"-ldl"; then 74 pluginlibs="$pluginlibs -ldl" 75 fi 76 LIBS="$saved_LIBS" 77 78 # Check that we can build shared objects with -fPIC -shared 79 saved_LDFLAGS="$LDFLAGS" 80 saved_CFLAGS="$CFLAGS" 81 case "${host}" in 82 *-*-darwin*) 83 CFLAGS=`echo $CFLAGS | sed s/-mdynamic-no-pic//g` 84 CFLAGS="$CFLAGS -fPIC" 85 LDFLAGS="$LDFLAGS -shared -undefined dynamic_lookup" 86 ;; 87 *) 88 CFLAGS="$CFLAGS -fPIC" 89 LDFLAGS="$LDFLAGS -fPIC -shared" 90 ;; 91 esac 92 AC_MSG_CHECKING([for -fPIC -shared]) 93 AC_TRY_LINK( 94 [extern int X;],[return X == 0;], 95 [AC_MSG_RESULT([yes]); have_pic_shared=yes], 96 [AC_MSG_RESULT([no]); have_pic_shared=no]) 97 if test x"$have_pic_shared" != x"yes" -o x"$ac_cv_search_dlopen" = x"no"; then 98 pluginlibs= 99 enable_plugin=no 100 fi 101 LDFLAGS="$saved_LDFLAGS" 102 CFLAGS="$saved_CFLAGS" 103 104 # If plugin support had been requested but not available, fail. 105 if test x"$enable_plugin" = x"no" ; then 106 if test x"$default_plugin" != x"yes"; then 107 AC_MSG_ERROR([ 108 Building GCC with plugin support requires a host that supports 109 -fPIC, -shared, -ldl and -rdynamic.]) 110 fi 111 fi 112 fi 113 ]) 114
