remove strftime dependencies on multibyte modules?

[Paul Eggert]

Now that Emacs is using gnulib I'd like to improve it to use more
gnulib modules.  I started with strftime, but ran into a problem
with unwanted dependencies, and propose the following patch.

Bruno, could you please look into this when you have the time?
One detail requires OSF expertise, which I lack.


>From bd376d673a82007fef0b88cd24ffe16334f106d5 Mon Sep 17 00:00:00 2001
From: Paul Eggert <address@hidden>
Date: Mon, 17 Jan 2011 23:14:33 -0800
Subject: [PATCH] strftime: remove dependencies on multibyte modules

strftime depended on mbrlen, mbsinit, and wchar, but these modules
are needed only if ! MULTIBYTE_IS_FORMAT_SAFE, and that is true
only if __osf__ is defined, and I suspect OSF doesn't need these
other modules.  If my guess is wrong, we'll need to come up with a
variant of strftime that doesn't need the multibyte modules.

I discovered this problem when attempting modify Emacs to use the
strftime module.  With the previous gnulib, this caused Emacs to
need 31 new files, ranging from lib/config.charset to
m4/wint_t.m4.  This was overkill and I expect would be offputting
to the Emacs maintainers.  After this change, only 6 new files are
needed, namely strftime.[ch], srtftime.m4, stdbool.in.h,
stdbool.m4, and tm_gmtoff.m4.

* m4/strftime.m4 (gl_FUNC_STRFTIME): Do not require AC_TYPE_MBSTATE_T,
and do not check for wchar.h.
* modules/strftime (Files): Remove m4/mbstate_t.m4.
(Depends-on): Remove mbrlen, mbsinit, wchar.
---
 ChangeLog        |   23 +++++++++++++++++++++++
 m4/strftime.m4   |    2 --
 modules/strftime |    4 ----
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6a61910..9b278e6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,26 @@
+2011-01-17  Paul Eggert  <address@hidden>
+
+       strftime: remove dependencies on multibyte modules
+
+       strftime depended on mbrlen, mbsinit, and wchar, but these modules
+       are needed only if ! MULTIBYTE_IS_FORMAT_SAFE, and that is true
+       only if __osf__ is defined, and I suspect OSF doesn't need these
+       other modules.  If my guess is wrong, we'll need to come up with a
+       variant of strftime that doesn't need the multibyte modules.
+
+       I discovered this problem when attempting modify Emacs to use the
+       strftime module.  With the previous gnulib, this caused Emacs to
+       need 31 new files, ranging from lib/config.charset to
+       m4/wint_t.m4.  This was overkill and I expect would be offputting
+       to the Emacs maintainers.  After this change, only 6 new files are
+       needed, namely strftime.[ch], srtftime.m4, stdbool.in.h,
+       stdbool.m4, and tm_gmtoff.m4.
+
+       * m4/strftime.m4 (gl_FUNC_STRFTIME): Do not require AC_TYPE_MBSTATE_T,
+       and do not check for wchar.h.
+       * modules/strftime (Files): Remove m4/mbstate_t.m4.
+       (Depends-on): Remove mbrlen, mbsinit, wchar.
+
 2011-01-17  Eric Blake  <address@hidden>
 
        sigaction: relax license from LGPLv3+ to LGPLv2+
diff --git a/m4/strftime.m4 b/m4/strftime.m4
index d2a6f7e..d9de341 100644
--- a/m4/strftime.m4
+++ b/m4/strftime.m4
@@ -21,11 +21,9 @@ AC_DEFUN([gl_FUNC_STRFTIME],
  # This defines (or not) HAVE_TZNAME and HAVE_TM_ZONE.
  AC_REQUIRE([AC_STRUCT_TIMEZONE])
 
- AC_REQUIRE([AC_TYPE_MBSTATE_T])
  AC_REQUIRE([gl_TM_GMTOFF])
 
  AC_CHECK_FUNCS_ONCE([tzset])
- AC_CHECK_HEADERS_ONCE([wchar.h])
 
  AC_DEFINE([my_strftime], [nstrftime],
    [Define to the name of the strftime replacement function.])
diff --git a/modules/strftime b/modules/strftime
index dc53916..0af5e13 100644
--- a/modules/strftime
+++ b/modules/strftime
@@ -4,17 +4,13 @@ nstrftime() function: convert date and time to string, with 
GNU extensions.
 Files:
 lib/strftime.h
 lib/strftime.c
-m4/mbstate_t.m4
 m4/tm_gmtoff.m4
 m4/strftime.m4
 
 Depends-on:
 extensions
-mbrlen
-mbsinit
 stdbool
 time_r
-wchar
 
 configure.ac:
 gl_FUNC_GNU_STRFTIME
-- 
1.7.3