relocatability tweaks

[Paolo Bonzini]

This patch does the following:

1) Split part of gl_RELOCATABLE_NOP into a separate 
gl_RELOCATABLE_ENABLE macro.  The reason will be apparent from the other 
changes.

2) Add a gl_RELOCATABLE_DEFAULT macro that changes the default for 
--enable-relocatable.

3) Make gl_RELOCATABLE_NOP default to "yes".  This just means "print yes 
on the configure script line", since the resulting package *will* be 
relocatable.

Ok to install?

Paolo

2008-03-15  Paolo Bonzini  <address@hidden>

        * m4/relocatable-lib.m4 (gl_RELOCATABLE_LIBRARY_BODY):
        Require gl_RELOCATABLE_ENABLE.
        (gl_RELOCATABLE_ENABLE): Split out of gl_RELOCATABLE_NOP.
        (gl_RELOCATABLE_DEFAULT): New.
        (gl_RELOCATABLE_NOP): Build from gl_RELOCATABLE_ENABLE
        and gl_RELOCATABLE_DEFAULT.

diff --git a/m4/relocatable-lib.m4 b/m4/relocatable-lib.m4
index 4c90677..3a2e56f 100644
--- a/m4/relocatable-lib.m4
+++ b/m4/relocatable-lib.m4
@@ -16,7 +16,7 @@ AC_DEFUN([gl_RELOCATABLE_LIBRARY],
 ])
 AC_DEFUN([gl_RELOCATABLE_LIBRARY_BODY],
 [
-  AC_REQUIRE([gl_RELOCATABLE_NOP])
+  AC_REQUIRE([gl_RELOCATABLE_ENABLE])
   dnl Easier to put this here once, instead of into the DEFS of each Makefile.
   if test "X$prefix" = "XNONE"; then
     reloc_final_prefix="$ac_default_prefix"
@@ -41,6 +41,14 @@ AC_DEFUN([gl_RELOCATABLE_LIBRARY_SEPARATE],
 dnl Support for relocatable packages for which it is a nop.
 AC_DEFUN([gl_RELOCATABLE_NOP],
 [
+  AC_REQUIRE([gl_RELOCATABLE_DEFAULT])
+  AC_REQUIRE([gl_RELOCATABLE_ENABLE])
+])
+
+AC_DEFUN([gl_RELOCATABLE_DEFAULT], [])
+
+AC_DEFUN([gl_RELOCATABLE_ENABLE],
+[
   AC_MSG_CHECKING([whether to activate relocatable installation])
   AC_ARG_ENABLE(relocatable,
     [  --enable-relocatable    install a package that can be moved in the 
filesystem],
@@ -49,7 +57,7 @@ AC_DEFUN([gl_RELOCATABLE_NOP],
      else
        RELOCATABLE=no
      fi
-    ], RELOCATABLE=no)
+    ], [RELOCATABLE=m4_provide_if([gl_RELOCATABLE_DEFAULT], [yes], [no])
   AC_SUBST(RELOCATABLE)
   AC_MSG_RESULT([$RELOCATABLE])
 ])