Re: [bug-diffutils] [PATCH] build: enable 'subdir-objects' automake option

[Stefano Lattarini]

Hi Paul.

On 05/02/2013 09:38 PM, Paul Eggert wrote:
> On 05/01/13 05:49, Stefano Lattarini wrote:
>> -AM_INIT_AUTOMAKE([1.11 dist-xz no-dist-gzip color-tests parallel-tests])
>> +AM_INIT_AUTOMAKE([1.11 dist-xz no-dist-gzip subdir-objects
>> +                       color-tests parallel-tests])
> 
> Thanks.  The Automake 1.13.1 manual says that if you use
> subdir-objects, you must also invoke AM_PROG_CC_C_O.
> But the diffutils configure.ac doesn't do that.
> Should it?  Or is this part of the Automake manual
> not quite right?
> 
> http://www.gnu.org/software/automake/manual/automake.html#List-of-Automake-options
>
No, you and the manual are perfectly right.  I stupidly tried my
patch only with the development version of Automake, that has
been improved not to require an explicit call to AM_PROG_CC_C_O
even when the 'subdir-objects' option is in use.

Here is an improved patch, tested with both Automake 1.13.1 and
bleeding-edge Automake.

Thanks,
  Stefano

---- 8< ---- 8< ---- 8< ---- 8< ---- 8< ---- 8< ---- 8< ---- 8< ----

>From ab9218d98b7b8141f72b5afbc61e21ba61bd4e8e Mon Sep 17 00:00:00 2001
Message-Id: <address@hidden>
From: Stefano Lattarini <address@hidden>
Date: Wed, 1 May 2013 14:28:29 +0200
Subject: [PATCH] build: enable 'subdir-objects' automake option

The future major Automake version (2.0, ETA at least one year from now)
might enable that option unconditionally, so better get prepared in due
time.

* configure.ac (AM_INIT_AUTOMAKE): Adjust.
(AM_PROG_CC_C_O): New, required by Automake up to 1.13.x when the
'subdir-objects' is in use.

Copyright-paperwork-exempt: yes
Signed-off-by: Stefano Lattarini <address@hidden>
---
 configure.ac | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index aea40fc..90bebc9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -26,13 +26,15 @@ AC_CONFIG_SRCDIR([src/diff.c])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([m4])

-AM_INIT_AUTOMAKE([1.11 dist-xz no-dist-gzip color-tests parallel-tests])
+AM_INIT_AUTOMAKE([1.11 dist-xz no-dist-gzip subdir-objects
+                       color-tests parallel-tests])
 AM_SILENT_RULES([yes]) # make --enable-silent-rules the default.

 AC_CONFIG_HEADER([lib/config.h:lib/config.hin])

 AC_PROG_AWK
 AC_PROG_CC
+AM_PROG_CC_C_O
 AM_MISSING_PROG([HELP2MAN], [help2man])
 AC_PROG_RANLIB
 gl_EARLY
-- 
1.8.3.rc0.19.g7e6a0cc