from AM_CONFIG_HEADER to AC_CONFIG_HEADERS

Here is something that seems to work.  (I hope Akim will not
have an heart attack we he come back from holiday and see this.)

What should happen to AM_CONFIG_HEADER now that
AC_CONFIG_HEADERS can be used?  This patch documents it as
obsolete, that's what I think makes more sense.

Another approach would be to still recommend AM_CONFIG_HEADER
over AC_CONFIG_HEADERS, even if both work identically (I fear
this would be confusing).

2002-04-14  Alexandre Duret-Lutz  <duret_g@xxxxxxxx>

        * m4/header.m4 (_AM_CONFIG_HEADER_INSINUATE): New function,
        override AC_CONFIG_HEADERS with AM_CONFIG_HEADER.
        (_AM_CONFIG_HEADER): Use _AM_AC_CONFIG_HEADERS.
        * m4/init.m4: Call _AM_CONFIG_HEADER_INSINUATE.
        * tests/stamph2.test: Use AC_CONFIG_HEADERS for some of the config
        files.
        * tests/confh5.test: New file.
        * tests/Makefile.am (TESTS): Add confh5.test.
        * automake.texi (Optional, Public macros): Update descriptions
        of AC_CONFIG_HEADERS and AM_CONFIG_HEADER.

Index: NEWS
===================================================================
RCS file: /cvs/automake/automake/NEWS,v
retrieving revision 1.176
diff -u -r1.176 NEWS
--- NEWS        13 Apr 2002 21:26:34 -0000      1.176
+++ NEWS        14 Apr 2002 15:04:34 -0000
@@ -1,4 +1,6 @@
 New in 1.6a:
+* It is no longuer a requirement to use AM_CONFIG_HEADER instead of
+  AC_CONFIG_HEADERS.  AM_CONFIG_HEADER is obsolete.
 * Use Autoconf's --trace interface to inspect configure.ac and get
   a more accurate view of it.
 * automake --output-dir is deprecated
Index: automake.texi
===================================================================
RCS file: /cvs/automake/automake/automake.texi,v
retrieving revision 1.272
diff -u -r1.272 automake.texi
--- automake.texi       13 Apr 2002 21:26:34 -0000      1.272
+++ automake.texi       14 Apr 2002 15:04:56 -0000
@@ -1115,12 +1115,11 @@
 and their effects are:
 
 @table @code
-@item AC_CONFIG_HEADER
-Automake requires the use of @code{AM_CONFIG_HEADER} (@pxref{Macros}),
-which is similar to @code{AC_CONFIG_HEADER} (@pxref{Configuration
-Headers, , Configuration Header Files, autoconf, The Autoconf Manual}),
-but does some useful Automake-specific work.
-@cvindex AC_CONFIG_HEADER
+@item AC_CONFIG_HEADERS
+Automake will generate rules to rebuild these headers.  Older versions
+of Automake required the use of @code{AM_CONFIG_HEADER}
+(@pxref{Macros}); this no longuer the case today.
+@cvindex AC_CONFIG_HEADERS
 
 @item AC_CONFIG_AUX_DIR
 Automake will look for various helper scripts, such as
@@ -1385,7 +1384,8 @@
 @table @code
 @item AM_CONFIG_HEADER
 Automake will generate rules to automatically regenerate the config
-header.
+header.  This obsolete macro is a synonym of @code{AC_CONFIG_HEADERS}
+today (@pxref{Optional}).
 @cvindex AM_CONFIG_HEADER
 
 @item AM_ENABLE_MULTILIB
@@ -2326,7 +2326,7 @@
 Automake already provides some @samp{-I} options automatically.  In
 particular it generates @samp{-I$(srcdir)}, @samp{-I.}, and a @samp{-I}
 pointing to the directory holding @file{config.h} (if you've used
-@code{AC_CONFIG_HEADER} or @code{AM_CONFIG_HEADER}).  You can disable
+@code{AC_CONFIG_HEADERS} or @code{AM_CONFIG_HEADER}).  You can disable
 the default @samp{-I} options using the @samp{nostdinc} option.
 
 @item INCLUDES
Index: m4/header.m4
===================================================================
RCS file: /cvs/automake/automake/m4/header.m4,v
retrieving revision 1.14
diff -u -r1.14 header.m4
--- m4/header.m4        26 Oct 2001 09:59:59 -0000      1.14
+++ m4/header.m4        14 Apr 2002 15:05:04 -0000
@@ -62,7 +62,7 @@
 AC_DEFUN([_AM_CONFIG_HEADER],
 [# Add the stamp file to the list of files AC keeps track of,
 # along with our hook.
-AC_CONFIG_HEADERS([$1],
+_AM_AC_CONFIG_HEADERS([$1],
                   [# update the timestamp
 echo 'timestamp for $1' >"_AM_STAMP([$1])"
 $2],
@@ -75,3 +75,20 @@
 AC_DEFUN([AM_CONFIG_HEADER],
 [AC_FOREACH([_AM_File], [$1], [_AM_CONFIG_HEADER(_AM_File, [$2], [$3])])
 ])# AM_CONFIG_HEADER
+
+
+# _AM_CONFIG_HEADER_INSINUATE
+# ---------------------------
+# Replace AC_CONFIG_HEADERS with our AM_CONFIG_HEADER.
+# We don't care about AC_CONFIG_HEADER (without S): it's an obsolete
+# Autoconf macro which will simply call AC_CONFIG_HEADERS (with S).
+AC_DEFUN([_AM_CONFIG_HEADER_INSINUATE], [
+dnl Since the substitution is only effective after AM_INIT_AUTOMAKE,
+dnl make sure AC_CONFIG_HEADERS is not called before.
+AC_BEFORE([AM_INIT_AUTOMAKE], [AC_CONFIG_HEADERS])dnl
+dnl Save the previous AC_CONFIG_HEADERS definition
+m4_rename([AC_CONFIG_HEADERS], [_AM_AC_CONFIG_HEADERS])dnl
+dnl Setup ours.
+dnl (Don't use m4_copy because we are tracing AM_CONFIG_HEADER.)
+AC_DEFUN([AC_CONFIG_HEADERS], [AM_CONFIG_HEADER($][@)])dnl
+])
Index: m4/init.m4
===================================================================
RCS file: /cvs/automake/automake/m4/init.m4,v
retrieving revision 1.44
diff -u -r1.44 init.m4
--- m4/init.m4  17 Mar 2002 23:18:00 -0000      1.44
+++ m4/init.m4  14 Apr 2002 15:05:04 -0000
@@ -87,13 +87,14 @@
 AC_REQUIRE([AC_PROG_MAKE_SET])dnl
 
 _AM_IF_OPTION([no-dependencies],,
-[AC_PROVIDE_IFELSE([AC_PROG_][CC],
+[AC_PROVIDE_IFELSE([AC_PROG_CC],
                   [_AM_DEPENDENCIES(CC)],
-                  [define([AC_PROG_][CC],
-                          defn([AC_PROG_][CC])[_AM_DEPENDENCIES(CC)])])dnl
-AC_PROVIDE_IFELSE([AC_PROG_][CXX],
+                  [define([AC_PROG_CC],
+                          defn([AC_PROG_CC])[_AM_DEPENDENCIES(CC)])])dnl
+AC_PROVIDE_IFELSE([AC_PROG_CXX],
                   [_AM_DEPENDENCIES(CXX)],
-                  [define([AC_PROG_][CXX],
-                          defn([AC_PROG_][CXX])[_AM_DEPENDENCIES(CXX)])])dnl
+                  [define([AC_PROG_CXX],
+                          defn([AC_PROG_CXX])[_AM_DEPENDENCIES(CXX)])])dnl
 ])
+_AM_CONFIG_HEADER_INSINUATE
 ])
Index: tests/Makefile.am
===================================================================
RCS file: /cvs/automake/automake/tests/Makefile.am,v
retrieving revision 1.388
diff -u -r1.388 Makefile.am
--- tests/Makefile.am   13 Apr 2002 21:48:35 -0000      1.388
+++ tests/Makefile.am   14 Apr 2002 15:05:04 -0000
@@ -92,6 +92,7 @@
 confdist.test \
 confh.test \
 confh4.test \
+confh5.test \
 config.test \
 confincl.test \
 confsub.test \
Index: tests/confh5.test
===================================================================
RCS file: tests/confh5.test
diff -N tests/confh5.test
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ tests/confh5.test   14 Apr 2002 15:05:11 -0000
@@ -0,0 +1,19 @@
+#! /bin/sh
+
+# Make sure Autoconf complains if AC_CONFIG_HEADERS appears
+# before AM_INIT_AUTOMAKE.
+
+. $srcdir/defs || exit 1
+
+cat > configure.in << 'END'
+AC_INIT
+AC_CONFIG_HEADERS(config.h)
+AM_INIT_AUTOMAKE(nonesuch, nonesuch)
+AC_OUTPUT
+END
+
+: > config.h.in
+
+$ACLOCAL || exit 1
+$AUTOCONF 2>&1 | grep AC_CONFIG_HEADERS || exit 1
+:
Index: tests/stamph2.test
===================================================================
RCS file: /cvs/automake/automake/tests/stamph2.test,v
retrieving revision 1.5
diff -u -r1.5 stamph2.test
--- tests/stamph2.test  26 Dec 2001 08:22:06 -0000      1.5
+++ tests/stamph2.test  14 Apr 2002 15:05:11 -0000
@@ -3,18 +3,16 @@
 # Make sure stamp-h* files are created where we expect
 . $srcdir/defs || exit 1
 
-cat > configure.in << END
-AC_INIT(Makefile.am)
-AM_INIT_AUTOMAKE($me, 1.0)
+cat >> configure.in << END
 AM_CONFIG_HEADER(1.h
                  2.h:config.hin
-                 3.h:sdir1/config1.hin
-
-                 sdir1/4.h
-                 sdir1/5.h:config.hin
-                 sdir1/6.h:sdir1/config1.hin
-                 sdir1/7.h:sdir2/config2.hin)
-AC_OUTPUT(Makefile)
+                 3.h:sdir1/config1.hin)
+# AM_CONFIG_HEADER and AC_CONFIG_HEADERS should be synonyms.
+AC_CONFIG_HEADERS(sdir1/4.h
+                  sdir1/5.h:config.hin
+                  sdir1/6.h:sdir1/config1.hin
+                  sdir1/7.h:sdir2/config2.hin)
+AC_OUTPUT
 END
 
 : > Makefile.am
-- 
Alexandre Duret-Lutz