gnulib-tool: indicating the presence of gnulib modules

[Bruno Haible]

Hi,

Several modules already define a C macro that indicates the presence of the
particular module:

close-stream.m4:  AC_DEFINE([GNULIB_CLOSE_STREAM], [1],
fcntl-safer.m4:  AC_DEFINE([GNULIB_FCNTL_SAFER], [1],
fts.m4:  AC_DEFINE([_LGPL_PACKAGE], 1,
gc-arcfour.m4:  AC_DEFINE(GC_USE_ARCFOUR, 1,
gc-arctwo.m4:  AC_DEFINE(GC_USE_ARCTWO, 1,
gc-des.m4:  AC_DEFINE(GC_USE_DES, 1, [Define if you want to support DES through 
GC.])
gc-hmac-md5.m4:  AC_DEFINE(GC_USE_HMAC_MD5, 1,
gc-hmac-sha1.m4:  AC_DEFINE(GC_USE_HMAC_SHA1, 1,
gc-md2.m4:  AC_DEFINE(GC_USE_MD2, 1, [Define if you want to support MD2 through 
GC.])
gc-md4.m4:  AC_DEFINE(GC_USE_MD4, 1, [Define if you want to support MD4 through 
GC.])
gc-md5.m4:  AC_DEFINE(GC_USE_MD5, 1, [Define if you want to support MD5 through 
GC.])
gc-random.m4:  AC_DEFINE(GC_USE_RANDOM, 1, [Define if you want to support RNG 
through GC.])
gc-rijndael.m4:  AC_DEFINE(GC_USE_RIJNDAEL, 1,
gc-sha1.m4:  AC_DEFINE(GC_USE_SHA1, 1,
stdio-safer.m4:  AC_DEFINE([GNULIB_FOPEN_SAFER], [1],
fwriteerror:AC_DEFINE([GNULIB_FWRITEERROR], 1,

Some more new modules need the same pattern as well. So I'm adding this
automatic definition of macros to gnulib-tool; the macros will be defined
through config.h.

In the presence of multiple gnulib-tool invocations from the same directory
with the same configure.ac file, such macros may indicate the wrong thing
(because if you build libgnuA.a and libgnuB.a, the module may be compiled
into libgnuA but not into libgnuB). But I think that judicious use of
library dependencies can avoid most of the problems; and as a last resort,
the remaining problems can be solved by splitting the configure.ac file.


2007-01-01  Bruno Haible  <address@hidden>

        * gnulib-tool (func_emit_copyright_notice): Bump year.
        (func_get_autoconf_snippet): Emit a GNULIB_<modulename> macro.

*** gnulib-20061223/gnulib-tool.bak     2006-12-23 21:15:28.000000000 +0100
--- gnulib-20061223/gnulib-tool 2007-01-01 14:23:14.000000000 +0100
***************
*** 1,6 ****
  #! /bin/sh
  #
! # Copyright (C) 2002-2006 Free Software Foundation, Inc.
  #
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
--- 1,6 ----
  #! /bin/sh
  #
! # Copyright (C) 2002-2007 Free Software Foundation, Inc.
  #
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
***************
*** 192,198 ****
  # outputs to stdout a header for a generated file.
  func_emit_copyright_notice ()
  {
!   echo "# Copyright (C) 2004-2006 Free Software Foundation, Inc."
    echo "#"
    echo "# This file is free software, distributed under the terms of the GNU"
    echo "# General Public License.  As a special exception to the GNU General"
--- 192,198 ----
  # outputs to stdout a header for a generated file.
  func_emit_copyright_notice ()
  {
!   echo "# Copyright (C) 2004-2007 Free Software Foundation, Inc."
    echo "#"
    echo "# This file is free software, distributed under the terms of the GNU"
    echo "# General Public License.  As a special exception to the GNU General"
***************
*** 939,944 ****
--- 939,947 ----
  {
    func_lookup_file "modules/$1"
    $SED -n -e "/^configure\.ac$sed_extract_prog" < "$lookedup_file"
+   # Define a C macro indicating the presence of the given module.
+   echo "  AC_DEFINE([GNULIB_"`echo "$1" | LC_ALL=C tr 'a-z' 'A-Z' | sed -e 
's,[-./],_,g'`"], [1],"
+   echo "    [Define to 1 when using the gnulib module $1.])"
  }
  
  # func_get_automake_snippet module