* automake.in (handle_languages): Define %DEPBASE% conditionally

on subdir-objects.  Define SUBDIROBJ.  Do not clean *_.c files
here ...
(lang_c_finish): ... do it here.
(handle_single_transform_list): Do not output specific rules for
subdir-objects files which are not renamed.  This should reduce
the size of Makefiles with lots of subdirectory sources.
* lib/depcomp: Simplify computation of dependency output, and use
DEPDIR.
* lib/am/depend2.am (%EXT%.o, %EXT%.obj, %EXT%.lo): Adjust call
to depcomp.  Compute depbase on-the-fly in generic fastdep rules
for subdir-objects.
* tests/ansi9.test: Do not grep for an explicit rule that
we no longer expect.  Really run $MAKE to make sure the chain
of rules works.
* tests/yacc5.test: Do not grep for an explicit rule that
we no longer expect.  Adjust to use set -e.

7 files changed, 134 insertions, 53 deletions

diff --git a/ChangeLog b/ChangeLog
index af475bb0f..b483cbd74 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,23 @@
+2003-12-31  Alexandre Duret-Lutz  <adl@gnu.org>
+
+	* automake.in (handle_languages): Define %DEPBASE% conditionally
+	on subdir-objects.  Define SUBDIROBJ.  Do not clean *_.c files
+	here ...
+	(lang_c_finish): ... do it here.
+	(handle_single_transform_list): Do not output specific rules for
+	subdir-objects files which are not renamed.  This should reduce
+	the size of Makefiles with lots of subdirectory sources.
+	* lib/depcomp: Simplify computation of dependency output, and use
+	DEPDIR.
+	* lib/am/depend2.am (%EXT%.o, %EXT%.obj, %EXT%.lo): Adjust call
+	to depcomp.  Compute depbase on-the-fly in generic fastdep rules
+	for subdir-objects.
+	* tests/ansi9.test: Do not grep for an explicit rule that
+	we no longer expect.  Really run $MAKE to make sure the chain
+	of rules works.
+	* tests/yacc5.test: Do not grep for an explicit rule that
+	we no longer expect.  Adjust to use set -e.
+
 2003-12-27  Alexandre Duret-Lutz  <adl@gnu.org>
 
 	* automake.in (@common_files): Move configure, configure.ac, and
diff --git a/NEWS b/NEWS
index eac173b4b..f70c7d60a 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,9 @@
 New in 1.8a:
 
-* Nothing yet.
+* Inference rules are used to compile sources in subdirectories when the
+  `subdir-objects' option is used and no per-target flags are used.  This
+  should reduce the size of some projects a lot, because Automake used to
+  output an explicit rule for each such object in the past.
 
 New in 1.8:
 
diff --git a/automake.in b/automake.in
index c6cf31ea9..a373e6212 100755
--- a/automake.in
+++ b/automake.in
@@ -1087,6 +1087,27 @@ sub handle_languages
 	    # This is not used by depend2.am.
 	    my $der_ext = (&{$lang->output_extensions} ($ext))[0];
 
+	    # When we output an inference rule like `.c.o:' we
+	    # have two cases to consider: either subdir-objects
+	    # is used, or it is not.
+	    #
+	    # In the latter case the rule is used to build objects
+	    # in the current directory, and dependencies always
+	    # go into `./$(DEPDIR)/'.  We can hard-code this value.
+	    #
+	    # In the former case the rule can be used to build
+	    # objects in sub-directories too.  Dependencies should
+	    # go into the appropriate sub-directories, e.g.,
+	    # `sub/$(DEPDIR)/'.  The value of this directory
+	    # need the be computed on-the-fly.
+	    #
+	    # DEPBASE holds the name of this directory, plus the
+	    # basename part of the object file (extensions Po, TPo,
+	    # Plo, TPlo will be added later as appropriate).  It is
+	    # either hardcoded, or a shell variable (`$depbase') that
+	    # will be computed by the rule.
+	    my $depbase =
+	      option ('subdir-objects') ? '$$depbase' : '$(DEPDIR)/$*';
 	    $output_rules .=
 	      file_contents ($rule_file,
 			     new Automake::Location,
@@ -1095,11 +1116,7 @@ sub handle_languages
 
 			     'DERIVED-EXT' => $der_ext,
 
-			     # In this situation we know that the
-			     # object is in this directory, so
-			     # $(DEPDIR) is the correct location for
-			     # dependencies.
-			     DEPBASE   => '$(DEPDIR)/$*',
+			     DEPBASE   => $depbase,
 			     BASE      => '$*',
 			     SOURCE    => '$<',
 			     OBJ       => '$@',
@@ -1108,7 +1125,8 @@ sub handle_languages
 
 			     COMPILE   => '$(' . $lang->compiler . ')',
 			     LTCOMPILE => '$(LT' . $lang->compiler . ')',
-			     -o        => $output_flag);
+			     -o        => $output_flag,
+			     SUBDIROBJ => !! option 'subdir-objects');
 	}
 
 	# Now include code for each specially handled object with this
@@ -1209,11 +1227,6 @@ sub handle_languages
 		  if $source !~ /\$U/;
 
 		(my $source_ = $source) =~ s/\$U/_/g;
-		# Explicitly clean the _.c files if they are in
-		# a subdirectory. (In the current directory they get
-		# erased by a `rm -f *_.c' rule.)
-		$clean_files{$source_} = MOSTLY_CLEAN
-		  if $objdir ne '.';
 		# Output an additional rule if _.c and .c are not in
 		# the same directory.  (_.c is always in $objdir.)
 		if ($objdir ne $srcdir)
@@ -1531,13 +1544,37 @@ sub handle_single_transform_list ($$$$@)
                 $object = $directory . '/' . $object;
             }
 
-            # If doing dependency tracking, then we can't print
-            # the rule.  If we have a subdir object, we need to
-            # generate an explicit rule.  Actually, in any case
-            # where the object is not in `.' we need a special
-            # rule.  The per-object rules in this case are
-            # generated later, by handle_languages.
-            if ($renamed || $directory ne '')
+	    # If the object file has been renamed (because per-target
+	    # flags are used) we cannot compile the file with an
+	    # inference rule: we need an explicit rule.
+	    #
+	    # If the source is in a subdirectory and the object is in
+	    # the current directory, we also need an explicit rule.
+	    #
+	    # If both source and object files are in a subdirectory
+	    # (this happens when the subdir-objects option is used),
+	    # then the inference will work.
+	    #
+	    # The latter case deserves a historical note.  When the
+	    # subdir-objects option was added on 1999-04-11 it was
+	    # thought that inferences rules would work for
+	    # subdirectory objects too.  Later, on 1999-11-22,
+	    # automake was changed to output explicit rules even for
+	    # subdir-objects.  Nobody remembers why, but this occured
+	    # soon after the merge of the user-dep-gen-branch so it
+	    # might be related.  In late 2003 people complained about
+	    # the size of the generated Makefile.ins (libgcj, with
+	    # 2200+ subdir objects was reported to have a 9MB
+	    # Makefile), so we now rely on inference rules again.
+	    # Maybe we'll run across the same issue as in the past,
+	    # but at least this time we can document it.  However since
+	    # dependency tracking has evolved it is possible that
+	    # our old problem no longer exists.
+	    # Using inference rules for subdir-objects has been tested
+	    # with GNU make, Solaris make, Ultrix make, BSD make,
+	    # HP-UX make, and OSF1 make successfully.
+            if ($renamed ||
+		($directory ne '' && ! option 'subdir-objects'))
             {
                 my $obj_sans_ext = substr ($object, 0,
 					   - length ($this_obj_ext));
@@ -4935,6 +4972,12 @@ sub lang_c_finish
  	    push (@objects, $base . '_.$(OBJEXT)');
  	    push (@objects, $base . '_.lo')
 	      if var ('LIBTOOL');
+
+	    # Explicitly clean the _.c files if they are in a
+	    # subdirectory. (In the current directory they get erased
+	    # by a `rm -f *_.c' rule.)
+	    $clean_files{$base . '_.c'} = MOSTLY_CLEAN
+	      if dirname ($base) ne '.';
  	}
 
  	# Make all _.o (and _.lo) files depend on ansi2knr.
diff --git a/lib/am/depend2.am b/lib/am/depend2.am
index 0a6ec6f76..24ec0c749 100644
--- a/lib/am/depend2.am
+++ b/lib/am/depend2.am
@@ -56,7 +56,8 @@
 ## compile rules so that they are output on a single line (instead of 5)
 ## would be a good compromise.  Actually we use two line rather than one,
 ## because this way %SOURCE% is always located at the end of the first
-## line and is therefore easier to spot.
+## line and is therefore easier to spot.  (We need an extra line when
+## depbase is used.)
 
 ?GENERIC?%EXT%.o:
 ?!GENERIC?%OBJ%: %SOURCE%
@@ -64,13 +65,13 @@ if %FASTDEP%
 ## In fast-dep mode, we can always use -o.
 ## For non-suffix rules, we must emulate a VPATH search on %SOURCE%.
 ?!GENERIC?	if %COMPILE% -MT %OBJ% -MD -MP -MF "%DEPBASE%.Tpo" %-c% -o %OBJ% `test -f '%SOURCE%' || echo '$(srcdir)/'`%SOURCE%; \
+?SUBDIROBJ??GENERIC?	depbase=`echo %OBJ% | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.o$$||'`; \
 ?GENERIC?	if %COMPILE% -MT %OBJ% -MD -MP -MF "%DEPBASE%.Tpo" %-c% -o %OBJ% %SOURCE%; \
 	then mv -f "%DEPBASE%.Tpo" "%DEPBASE%.Po"; else rm -f "%DEPBASE%.Tpo"; exit 1; fi
 else !%FASTDEP%
 if %AMDEP%
 	source='%SOURCE%' object='%OBJ%' libtool=no @AMDEPBACKSLASH@
-	depfile='%DEPBASE%.Po' tmpdepfile='%DEPBASE%.TPo' @AMDEPBACKSLASH@
-	$(%FPFX%DEPMODE) $(depcomp) @AMDEPBACKSLASH@
+	DEPDIR=$(DEPDIR) $(%FPFX%DEPMODE) $(depcomp) @AMDEPBACKSLASH@
 endif %AMDEP%
 if %?GENERIC%
 ?-o?	%COMPILE% %-c% %-o% %OBJ% %SOURCE%
@@ -88,13 +89,13 @@ if %FASTDEP%
 ## In fast-dep mode, we can always use -o.
 ## For non-suffix rules, we must emulate a VPATH search on %SOURCE%.
 ?!GENERIC?	if %COMPILE% -MT %OBJOBJ% -MD -MP -MF "%DEPBASE%.Tpo" %-c% -o %OBJOBJ% `if test -f '%SOURCE%'; then $(CYGPATH_W) '%SOURCE%'; else $(CYGPATH_W) '$(srcdir)/%SOURCE%'; fi`; \
+?SUBDIROBJ??GENERIC?	depbase=`echo %OBJ% | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.obj$$||'`; \
 ?GENERIC?	if %COMPILE% -MT %OBJOBJ% -MD -MP -MF "%DEPBASE%.Tpo" %-c% -o %OBJOBJ% `$(CYGPATH_W) '%SOURCE%'`; \
 	then mv -f "%DEPBASE%.Tpo" "%DEPBASE%.Po"; else rm -f "%DEPBASE%.Tpo"; exit 1; fi
 else !%FASTDEP%
 if %AMDEP%
 	source='%SOURCE%' object='%OBJOBJ%' libtool=no @AMDEPBACKSLASH@
-	depfile='%DEPBASE%.Po' tmpdepfile='%DEPBASE%.TPo' @AMDEPBACKSLASH@
-	$(%FPFX%DEPMODE) $(depcomp) @AMDEPBACKSLASH@
+	DEPDIR=$(DEPDIR) $(%FPFX%DEPMODE) $(depcomp) @AMDEPBACKSLASH@
 endif %AMDEP%
 if %?GENERIC%
 ?-o?	%COMPILE% %-c% %-o% %OBJOBJ% `$(CYGPATH_W) '%SOURCE%'`
@@ -112,15 +113,14 @@ if %?LIBTOOL%
 if %FASTDEP%
 ## In fast-dep mode, we can always use -o.
 ## For non-suffix rules, we must emulate a VPATH search on %SOURCE%.
-?GENERIC?	if %LTCOMPILE% -MT %LTOBJ% -MD -MP -MF "%DEPBASE%.Tpo" %-c% -o %LTOBJ% %SOURCE%; \
-## For non-suffix rules, we must emulate a VPATH search on %SOURCE%.
 ?!GENERIC?	if %LTCOMPILE% -MT %LTOBJ% -MD -MP -MF "%DEPBASE%.Tpo" %-c% -o %LTOBJ% `test -f '%SOURCE%' || echo '$(srcdir)/'`%SOURCE%; \
+?SUBDIROBJ??GENERIC?	depbase=`echo %OBJ% | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.lo$$||'`; \
+?GENERIC?	if %LTCOMPILE% -MT %LTOBJ% -MD -MP -MF "%DEPBASE%.Tpo" %-c% -o %LTOBJ% %SOURCE%; \
 	then mv -f "%DEPBASE%.Tpo" "%DEPBASE%.Plo"; else rm -f "%DEPBASE%.Tpo"; exit 1; fi
 else !%FASTDEP%
 if %AMDEP%
 	source='%SOURCE%' object='%LTOBJ%' libtool=yes @AMDEPBACKSLASH@
-	depfile='%DEPBASE%.Plo' tmpdepfile='%DEPBASE%.TPlo' @AMDEPBACKSLASH@
-	$(%FPFX%DEPMODE) $(depcomp) @AMDEPBACKSLASH@
+	DEPDIR=$(DEPDIR) $(%FPFX%DEPMODE) $(depcomp) @AMDEPBACKSLASH@
 endif %AMDEP%
 ## We can always use `-o' with Libtool.
 ?GENERIC?	%LTCOMPILE% %-c% -o %LTOBJ% %SOURCE%
diff --git a/lib/depcomp b/lib/depcomp
index 9e5522d04..9beba448a 100755
--- a/lib/depcomp
+++ b/lib/depcomp
@@ -1,7 +1,7 @@
 #! /bin/sh
 # depcomp - compile a program generating dependencies as side-effects
 
-scriptversion=2003-11-08.23
+scriptversion=2003-12-28.12
 
 # Copyright (C) 1999, 2000, 2003 Free Software Foundation, Inc.
 
@@ -43,6 +43,7 @@ Environment variables:
   depmode     Dependency tracking mode.
   source      Source file read by `PROGRAMS ARGS'.
   object      Object file output by `PROGRAMS ARGS'.
+  DEPDIR      directory where to store dependencies.
   depfile     Dependency file to output.
   tmpdepfile  Temporary file to use when outputing dependencies.
   libtool     Whether libtool is used (yes/no).
@@ -61,18 +62,10 @@ if test -z "$depmode" || test -z "$source" || test -z "$object"; then
   echo "depcomp: Variables source, object and depmode must be set" 1>&2
   exit 1
 fi
-# `libtool' can also be set to `yes' or `no'.
-
-if test -z "$depfile"; then
-   base=`echo "$object" | sed -e 's,^.*/,,' -e 's,\.\([^.]*\)$,.P\1,'`
-   dir=`echo "$object" | sed 's,/.*$,/,'`
-   if test "$dir" = "$object"; then
-      dir=
-   fi
-   # FIXME: should be _deps on DOS.
-   depfile="$dir.deps/$base"
-fi
 
+# Dependencies for sub/bar.o or sub/bar.obj go into sub/.deps/bar.Po.
+depfile=${depfile-`echo "$object" |
+  sed 's|[^\\/]*$|'${DEPDIR-.deps}'/&|;s|\.\([^.]*\)$|.P\1|;s|Pobj$|Po|'`}
 tmpdepfile=${tmpdepfile-`echo "$depfile" | sed 's/\.\([^.]*\)$/.T\1/'`}
 
 rm -f "$tmpdepfile"
diff --git a/tests/ansi9.test b/tests/ansi9.test
index 477044af8..5740487d1 100755
--- a/tests/ansi9.test
+++ b/tests/ansi9.test
@@ -1,5 +1,5 @@
 #! /bin/sh
-# Copyright (C) 2002  Free Software Foundation, Inc.
+# Copyright (C) 2002, 2003  Free Software Foundation, Inc.
 #
 # This file is part of GNU Automake.
 #
@@ -22,6 +22,7 @@
 # can still be deansified.
 # Report from Paul D. Smith.
 
+required=gcc
 . ./defs || exit 1
 
 set -e
@@ -30,6 +31,7 @@ cat >>configure.in <<EOF
 AC_PROG_CC
 AM_PROG_CC_C_O
 AM_C_PROTOTYPES
+AC_OUTPUT
 EOF
 
 cat > Makefile.am << 'END'
@@ -38,10 +40,29 @@ noinst_PROGRAMS = loadavg sub/sub
 loadavg_SOURCES = loadavg.c
 loadavg_CFLAGS = -DTEST
 sub_sub_SOURCES = sub/sub.c
+# Force ansi2knr's use, regardless of the compiler.
+U=_
+ANSI2KNR=./ansi2knr
 END
 
+cat > loadavg.c << 'END'
+int
+main ()
+{
+   return 0;
+}
+END
+
+mkdir sub
+cp loadavg.c sub/sub.c
+
 $ACLOCAL
-$AUTOMAKE --add-missing
+$AUTOCONF
+$AUTOMAKE --add-missing -Wno-override
 
 $FGREP 'loadavg-loadavg$U.o: loadavg$U.c' Makefile.in
-$FGREP 'sub/sub$U.o: sub/sub$U.c' Makefile.in
+# The following rule should not exists, because the
+# default .o.c: inference rule is enough.
+$FGREP 'sub/sub$U.o: sub/sub$U.c' Makefile.in && exit 1
+./configure
+$MAKE sub/sub_.c
diff --git a/tests/yacc5.test b/tests/yacc5.test
index 7ce843970..02f868ea7 100755
--- a/tests/yacc5.test
+++ b/tests/yacc5.test
@@ -1,5 +1,5 @@
 #! /bin/sh
-# Copyright (C) 2001, 2002  Free Software Foundation, Inc.
+# Copyright (C) 2001, 2002, 2003  Free Software Foundation, Inc.
 #
 # This file is part of GNU Automake.
 #
@@ -23,6 +23,8 @@
 
 . ./defs || exit 1
 
+set -e
+
 cat > configure.in << 'END'
 AC_INIT
 AM_INIT_AUTOMAKE(nonesuch, nonesuch)
@@ -41,10 +43,10 @@ mkdir sub
 
 : > sub/maude.y
 
-$ACLOCAL || exit 1
-$AUTOMAKE -a || exit 1
+$ACLOCAL
+$AUTOMAKE -a
 
-grep '^maude\.c:' Makefile.in || exit 1
+grep '^maude\.c:' Makefile.in
 
 
 ## Try again with subdir-objects.
@@ -55,10 +57,11 @@ bin_PROGRAMS = maude
 maude_SOURCES = sub/maude.y
 END
 
-$ACLOCAL || exit 1
-$AUTOMAKE -a || exit 1
+$ACLOCAL
+$AUTOMAKE -a
 
-grep '^sub/maude\.c:' Makefile.in || exit 1
+# No rule needed, the default .y.c: inference rule is enough.
+grep '^sub/maude\.c:' Makefile.in && exit 1
 
 
 ## Try again with per-exe flags.
@@ -80,6 +83,4 @@ grep 'AM_YFLAGS.*maude' Makefile.in && exit 1
 grep 'maudec' Makefile.in && exit 1
 
 # Make sure the .o file is required.
-grep '^am_maude_OBJECTS.*maude' Makefile.in || exit 1
-
-exit 0
+grep '^am_maude_OBJECTS.*maude' Makefile.in