+# Check for plugin support
+AC_ARG_ENABLE(plugin,
+[ --enable-plugin enable plugin support],
+enable_plugin=$enableval,
+enable_plugin=yes; default_plugin=yes)
+
+pluginlibs=
+if test x"$enable_plugin" = x"yes"; then
+ # Check that the host supports -rdynamic and -ldl
+ have_rdynamic=no
+ have_dl=no
+ saved_LDFLAGS="$LDFLAGS"
+ saved_LIBS="$LIBS"
+ LIBS=
+
+ # Check -rdynamic
+ LDFLAGS="$LDFLAGS -rdynamic"
+ AC_MSG_CHECKING([for -rdynamic])
+ AC_TRY_LINK([],[return 0;],
+ [AC_MSG_RESULT([yes]); have_rdynamic=yes],
+ [AC_MSG_RESULT([no])])
+ if test x"$have_rdynamic" = x"yes" ; then
+ pluginlibs="-rdynamic"
+ fi
+
+ # Check -ldl
+ LDFLAGS="$LDFLAGS -ldl"
+ AC_MSG_CHECKING([for -ldl])
+ AC_TRY_LINK(
+ [#include <dlfcn.h>],
+ [volatile int f = 0; if (f) dlopen ("dummy", 0);],
+ [AC_MSG_RESULT([yes]); have_dl=yes],
+ [AC_MSG_RESULT([no])])
+ if test x"$have_dl" = x"yes"; then
+ pluginlibs="$pluginlibs -ldl"
+ fi
+
+ # Check that we can build shared objects with -fPIC -shared
+ LDFLAGS="$LDFLAGS -fPIC -shared"
+ AC_MSG_CHECKING([for -fPIC -shared])
+ AC_TRY_LINK(
+ [extern int X;],[return X == 0;],
+ [AC_MSG_RESULT([yes]); have_pic_shared=yes],
+ [AC_MSG_RESULT([no]); have_pic_shared=no])
+ if test x"$have_pic_shared" != x"yes"; then
+ pluginlibs=
+ enable_plugin=no
+ fi
+
+ # If plugin support had been requested but not available, fail.
+ if test x"$enable_plugin" = x"no" ; then
+ if test x"$default_plugin" != x"yes"; then
+ AC_MSG_ERROR([
+Building GCC with plugin support requires a host that supports
+-fPIC, -shared, -ldl and -rdynamic.])
+ fi
+ fi
+
+ LDFLAGS="$saved_LDFLAGS"
+ LIBS="$saved_LIBS"
+fi
+
+AC_SUBST(pluginlibs)
+AC_SUBST(enable_plugin)
+if test x"$enable_plugin" = x"yes"; then
+ AC_DEFINE(ENABLE_PLUGIN, 1, [Define to enable plugin support.])
+fi
+