[Automake-ng] [PATCH 2/4] [ng] deptrack: refactoring for "fastdep" mode

[Stefano Lattarini]

* lib/am/depcomp2.am: Use more GNU make capabilities in the rules
implementing fast dependency tracking.  This change nicely reduce
the size and complexity of the existing code.
* automake.in (handle_languages): Simplify accordingly.
---
 automake.in       |   30 ------------------------------
 lib/am/depend2.am |   46 ++++++++++++++++++++++++----------------------
 2 files changed, 24 insertions(+), 52 deletions(-)

diff --git a/automake.in b/automake.in
index 521d6cf..637efca 100644
--- a/automake.in
+++ b/automake.in
@@ -1385,27 +1385,6 @@ 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
-           # needs to 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,
@@ -1414,7 +1393,6 @@ sub handle_languages
 
                             'DERIVED-EXT' => $der_ext,
 
-                            DEPBASE   => $depbase,
                             BASE      => '$*',
                             SOURCE    => '$<',
                             SOURCEFLAG => $sourceflags{$ext} || '',
@@ -1472,20 +1450,12 @@ sub handle_languages
            # We _need_ `-o' for per object rules.
            my $output_flag = $lang->output_flag || '-o';
 
-           my $depbase = dirname ($obj);
-           $depbase = ''
-               if $depbase eq '.';
-           $depbase .= '/'
-               unless $depbase eq '';
-           $depbase .= '$(DEPDIR)/' . basename ($obj);
-
            $output_rules .=
              file_contents ($rule_file,
                             new Automake::Location,
                             %transform,
                             GENERIC   => 0,
 
-                            DEPBASE   => $depbase,
                             BASE      => $obj,
                             SOURCE    => $source,
                             SOURCEFLAG => $sourceflags{$srcext} || '',
diff --git a/lib/am/depend2.am b/lib/am/depend2.am
index 9a193a4..b948a2a 100644
--- a/lib/am/depend2.am
+++ b/lib/am/depend2.am
@@ -1,6 +1,7 @@
 ## automake - create Makefile.in from Makefile.am
 ## Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
-## 2003, 2004, 2006, 2008, 2009, 2010  Free Software Foundation, Inc.
+## 2003, 2004, 2006, 2008, 2009, 2010, 2012 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
@@ -57,19 +58,23 @@
 ## line and is therefore easier to spot.  (We need an extra line when
 ## depbase is used.)
 
+if %?FIRST%
+?SUBDIROBJ?am__depdir = $(dir $@)/$(DEPDIR)
+?!SUBDIROBJ?am__depdir = $(DEPDIR)
+## FIXME: more precise in the removal of the suffix?
+am__depbase = $(am__depdir)/$(basename $(notdir $@))
+endif %?FIRST%
+
 if %?NONLIBTOOL%
 ?GENERIC?%EXT%.o:
 ?!GENERIC?%OBJ%: %SOURCE%
 if %FASTDEP%
 ## In fast-dep mode, we can always use -o.
+       %VERBOSE%%COMPILE% -MT $@ -MD -MP -MF $(am__depbase).Tpo %-c% -o $@ \
+?GENERIC?      %SOURCEFLAG%%SOURCE%
 ## For non-suffix rules, we must emulate a VPATH search on %SOURCE%.
-?!GENERIC?     %VERBOSE%%COMPILE% -MT %OBJ% -MD -MP -MF %DEPBASE%.Tpo %-c% -o 
%OBJ% %SOURCEFLAG%`test -f '%SOURCE%' || echo '$(srcdir)/'`%SOURCE%
-?!GENERIC?     %SILENT%$(am__mv) %DEPBASE%.Tpo %DEPBASE%.Po
-?GENERIC??!SUBDIROBJ?  %VERBOSE%%COMPILE% -MT %OBJ% -MD -MP -MF %DEPBASE%.Tpo 
%-c% -o %OBJ% %SOURCEFLAG%%SOURCE%
-?GENERIC??!SUBDIROBJ?  %SILENT%$(am__mv) %DEPBASE%.Tpo %DEPBASE%.Po
-?GENERIC??SUBDIROBJ?   %VERBOSE%depbase=`echo %OBJ% | sed 
's|[^/]*$$|$(DEPDIR)/&|;s|\.o$$||'`;\
-?GENERIC??SUBDIROBJ?   %COMPILE% -MT %OBJ% -MD -MP -MF %DEPBASE%.Tpo %-c% -o 
%OBJ% %SOURCEFLAG%%SOURCE% &&\
-?GENERIC??SUBDIROBJ?   $(am__mv) %DEPBASE%.Tpo %DEPBASE%.Po
+?!GENERIC?     %SOURCEFLAG%`test -f '%SOURCE%' || echo '$(srcdir)/'`%SOURCE%
+       %SILENT%$(am__mv) $(am__depbase).Tpo $(am__depbase).Po
 else !%FASTDEP%
 if %AMDEP%
        %VERBOSE%source='%SOURCE%' object='%OBJ%' libtool=no @AMDEPBACKSLASH@
@@ -89,14 +94,14 @@ endif !%FASTDEP%
 ?!GENERIC?%OBJOBJ%: %SOURCE%
 if %FASTDEP%
 ## In fast-dep mode, we can always use -o.
+       %VERBOSE%%COMPILE% -MT $@ -MD -MP -MF $(am__depbase).Tpo %-c% -o $@ \
+?GENERIC?      %SOURCEFLAG%`$(CYGPATH_W) '%SOURCE%'`
 ## For non-suffix rules, we must emulate a VPATH search on %SOURCE%.
-?!GENERIC?     %VERBOSE%%COMPILE% -MT %OBJOBJ% -MD -MP -MF %DEPBASE%.Tpo %-c% 
-o %OBJOBJ% %SOURCEFLAG%`if test -f '%SOURCE%'; then $(CYGPATH_W) '%SOURCE%'; 
else $(CYGPATH_W) '$(srcdir)/%SOURCE%'; fi`
-?!GENERIC?     %SILENT%$(am__mv) %DEPBASE%.Tpo %DEPBASE%.Po
-?GENERIC??!SUBDIROBJ?  %VERBOSE%%COMPILE% -MT %OBJOBJ% -MD -MP -MF 
%DEPBASE%.Tpo %-c% -o %OBJOBJ% %SOURCEFLAG%`$(CYGPATH_W) '%SOURCE%'`
-?GENERIC??!SUBDIROBJ?  %SILENT%$(am__mv) %DEPBASE%.Tpo %DEPBASE%.Po
-?GENERIC??SUBDIROBJ?   %VERBOSE%depbase=`echo %OBJ% | sed 
's|[^/]*$$|$(DEPDIR)/&|;s|\.obj$$||'`;\
-?GENERIC??SUBDIROBJ?   %COMPILE% -MT %OBJOBJ% -MD -MP -MF %DEPBASE%.Tpo %-c% 
-o %OBJOBJ% %SOURCEFLAG%`$(CYGPATH_W) '%SOURCE%'` &&\
-?GENERIC??SUBDIROBJ?   $(am__mv) %DEPBASE%.Tpo %DEPBASE%.Po
+?!GENERIC?     %SOURCEFLAG%`if test -f '%SOURCE%';  \
+?!GENERIC?       then $(CYGPATH_W) '%SOURCE%'; \
+?!GENERIC?       else $(CYGPATH_W) '$(srcdir)/%SOURCE%'; \
+?!GENERIC?     fi`
+       %SILENT%$(am__mv) $(am__depbase).Tpo $(am__depbase).Po
 else !%FASTDEP%
 if %AMDEP%
        %VERBOSE%source='%SOURCE%' object='%OBJOBJ%' libtool=no @AMDEPBACKSLASH@
@@ -118,14 +123,11 @@ if %?LIBTOOL%
 ?!GENERIC?%LTOBJ%: %SOURCE%
 if %FASTDEP%
 ## In fast-dep mode, we can always use -o.
+       %VERBOSE%%LTCOMPILE% -MT $@ -MD -MP -MF $(am__depbase).Tpo %-c% -o $@ \
+?GENERIC?      %SOURCEFLAG%%SOURCE%
 ## For non-suffix rules, we must emulate a VPATH search on %SOURCE%.
-?!GENERIC?     %VERBOSE%%LTCOMPILE% -MT %LTOBJ% -MD -MP -MF %DEPBASE%.Tpo %-c% 
-o %LTOBJ% %SOURCEFLAG%`test -f '%SOURCE%' || echo '$(srcdir)/'`%SOURCE%
-?!GENERIC?     %SILENT%$(am__mv) %DEPBASE%.Tpo %DEPBASE%.Plo
-?GENERIC??!SUBDIROBJ?  %VERBOSE%%LTCOMPILE% -MT %LTOBJ% -MD -MP -MF 
%DEPBASE%.Tpo %-c% -o %LTOBJ% %SOURCEFLAG%%SOURCE%
-?GENERIC??!SUBDIROBJ?  %SILENT%$(am__mv) %DEPBASE%.Tpo %DEPBASE%.Plo
-?GENERIC??SUBDIROBJ?   %VERBOSE%depbase=`echo %OBJ% | sed 
's|[^/]*$$|$(DEPDIR)/&|;s|\.lo$$||'`;\
-?GENERIC??SUBDIROBJ?   %LTCOMPILE% -MT %LTOBJ% -MD -MP -MF %DEPBASE%.Tpo %-c% 
-o %LTOBJ% %SOURCEFLAG%%SOURCE% &&\
-?GENERIC??SUBDIROBJ?   $(am__mv) %DEPBASE%.Tpo %DEPBASE%.Plo
+?!GENERIC?     %SOURCEFLAG%`test -f '%SOURCE%' || echo '$(srcdir)/'`%SOURCE%
+       %SILENT%$(am__mv) $(am__depbase).Tpo $(am__depbase).Plo
 else !%FASTDEP%
 if %AMDEP%
        %VERBOSE%source='%SOURCE%' object='%LTOBJ%' libtool=yes @AMDEPBACKSLASH@
-- 
1.7.7.3