From e249d1054762f7a3db4f04655dd662a221787a97 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Wed, 19 Jun 2013 20:33:43 +0200
Subject: [PATCH] Generate ggo dependencies automatically.

Currently we maintain the dependency list of each ggo file manually in
m4/gengetopt/makefile. This is tedious and error-prone, and missing
dependencies result in build failures which are not repeatable and
hard to locate.

This changes the build system to keep track of these dependencies
automatically. We now create one .m4d file for each executable. This
file lists the dependencies of the corresponding ggo file, i.e. those
m4 files which are included in order to make the ggo.

All .m4d files are pulled in from the main Makefile via the -include
directive, in the same way we include the object dependency files
(.d) generated by gcc.
---
 Makefile.in           |  5 ++++-
 m4/gengetopt/makefile | 36 +++++-------------------------------
 2 files changed, 9 insertions(+), 32 deletions(-)

diff --git a/Makefile.in b/Makefile.in
index af9a20c9..487a9efe 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -34,6 +34,7 @@ object_dir := $(build_dir)/objects
 dep_dir := $(build_dir)/deps
 man_dir := $(build_dir)/man/man1
 cmdline_dir := $(build_dir)/cmdline
+m4depdir := $(build_dir)/m4deps
 
 DEBUG_CPPFLAGS += -g -Wunused -Wundef -W
 DEBUG_CPPFLAGS += -Wredundant-decls
@@ -103,7 +104,7 @@ dep: $(deps)
 man: $(man_pages)
 tarball: $(tarball)
 
-$(object_dir) $(man_dir) $(ggo_dir) $(cmdline_dir) $(dep_dir):
+$(object_dir) $(man_dir) $(ggo_dir) $(cmdline_dir) $(dep_dir) $(m4depdir):
 	$(Q) $(MKDIR_P) $@
 
 -include $(m4_ggo_dir)/makefile
@@ -230,6 +231,7 @@ all_objs := @recv_objs@ @filter_objs@ @client_objs@ @gui_objs@ \
 	@audiod_objs@ @audioc_objs@ @fade_objs@ @server_objs@ \
 	@write_objs@ @afh_objs@ @play_objs@
 deps := $(addprefix $(dep_dir)/, $(all_objs:.o=.d))
+m4_deps := $(addprefix $(m4depdir)/, $(addsuffix .m4d, @executables@))
 
 recv_objs := $(addprefix $(object_dir)/, @recv_objs@)
 filter_objs := $(addprefix $(object_dir)/, @filter_objs@)
@@ -245,6 +247,7 @@ play_objs := $(addprefix $(object_dir)/, @play_objs@)
 
 ifeq ($(findstring clean, $(MAKECMDGOALS)),)
 -include $(deps)
+-include $(m4_deps)
 endif
 
 para_recv: $(recv_objs)
diff --git a/m4/gengetopt/makefile b/m4/gengetopt/makefile
index 548a3d5d..035f44a5 100644
--- a/m4/gengetopt/makefile
+++ b/m4/gengetopt/makefile
@@ -16,37 +16,11 @@ ifeq ($(ggo_descriptions_declared),no)
 	echo 'extern const char *$(*F)_args_info_description;' >> $(cmdline_dir)/$(*F).cmdline.h
 endif
 
-$(ggo_dir)/server.ggo $(ggo_dir)/audiod.ggo: \
-	$(m4_ggo_dir)/loglevel.m4 $(m4_ggo_dir)/color.m4 \
-	$(m4_ggo_dir)/config_file.m4 $(m4_ggo_dir)/logfile.m4 \
-	$(m4_ggo_dir)/daemon.m4 $(m4_ggo_dir)/user.m4 \
-	$(m4_ggo_dir)/group.m4 $(m4_ggo_dir)/log_timing.m4 \
-	$(m4_ggo_dir)/config_file.m4
-
-$(ggo_dir)/afh.ggo: $(m4_ggo_dir)/loglevel.m4
-$(ggo_dir)/audioc.ggo: \
-	$(m4_ggo_dir)/loglevel.m4 \
-	$(m4_ggo_dir)/history_file.m4 \
-	$(m4_ggo_dir)/complete.m4
-$(ggo_dir)/filter.ggo: $(m4_ggo_dir)/loglevel.m4
-$(ggo_dir)/fsck.ggo: $(m4_ggo_dir)/loglevel.m4
-$(ggo_dir)/gui.ggo: $(m4_ggo_dir)/loglevel.m4 $(m4_ggo_dir)/config_file.m4
-$(ggo_dir)/recv.ggo: $(m4_ggo_dir)/loglevel.m4
-$(ggo_dir)/write.ggo: $(m4_ggo_dir)/loglevel.m4 \
-	$(m4_ggo_dir)/channels.m4 \
-	$(m4_ggo_dir)/sample_rate.m4 \
-	$(m4_ggo_dir)/sample_format.m4
-$(ggo_dir)/client.ggo: \
-	$(m4_ggo_dir)/loglevel.m4 \
-	$(m4_ggo_dir)/config_file.m4 \
-	$(m4_ggo_dir)/history_file.m4 \
-	$(m4_ggo_dir)/complete.m4
-$(ggo_dir)/fade.ggo: $(m4_ggo_dir)/loglevel.m4 $(m4_ggo_dir)/config_file.m4
-$(ggo_dir)/resample_filter.ggo: \
-	$(m4_ggo_dir)/channels.m4 \
-	$(m4_ggo_dir)/sample_rate.m4 \
-	$(m4_ggo_dir)/sample_format.m4
-$(ggo_dir)/play.ggo: $(m4_ggo_dir)/loglevel.m4 $(m4_ggo_dir)/config_file.m4
+$(m4depdir)/%.m4d: $(m4_ggo_dir)/%.m4 | $(m4depdir)
+	@[ -z "$(Q)" ] || echo 'M4D $<'
+	$(Q) m4 -I $(m4_ggo_dir) --debug=i $< 3>&1 1>/dev/null 2>&3 \
+		| awk '{if ($$0 ~ "^m4debug: input read from ") \
+		print "$(ggo_dir)/$(*F).ggo: " $$NF}' > $@
 
 $(ggo_dir)/%.ggo: $(m4_ggo_dir)/%.m4 $(m4_ggo_dir)/header.m4 | $(ggo_dir)
 	@[ -z "$(Q)" ] || echo 'M4 $<'
-- 
2.39.2