From 9665ad72c03410a47f9c527ba95fa6e38cfc9b56 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@tuebingen.mpg.de>
Date: Wed, 8 May 2024 23:52:35 +0200
Subject: [PATCH] build: Generate intermediate files in build/.

This way the intermediate files don't clobber the top level of the
working directory. Also the clean phony target becomes simpler.
---
 .gitignore |  8 +-------
 Makefile   | 46 +++++++++++++++++++++++++++-------------------
 2 files changed, 28 insertions(+), 26 deletions(-)

diff --git a/.gitignore b/.gitignore
index aedd74e..c8ab019 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,11 +1,5 @@
 Makefile.local
-version.c
-*.o
-*.d
 *.swp
-dss.lsg.*
+build/*
 dss
-dss.suite
 dss.1.gz
-dss.1.html
-index.html
diff --git a/Makefile b/Makefile
index e6fd7e0..3be6b21 100644
--- a/Makefile
+++ b/Makefile
@@ -41,12 +41,12 @@ INSTALL ?= install
 INSTALL_PROGRAM ?= $(INSTALL)
 INSTALL_DATA ?= $(INSTALL) -m 644
 MKDIR_P := mkdir -p
-VERSION := $(shell ./version-gen.sh $(PACKAGE) version.c)
+B := build
+VERSION := $(shell $(MKDIR_P) $(B) && ./version-gen.sh $(PACKAGE) $(B)/version.c)
 RM := rm -f
 LSG := lopsubgen
 GROFF := groff -m man -Thtml -P -l -P -r
 GZIP := gzip -cfn9
-units := $(PACKAGE) $(PACKAGE).lsg str file exec sig daemon df tv snap ipc version
 M4 := m4 \
 	-D "AUTHOR=$(AUTHOR)" \
 	-D "PACKAGE=$(PACKAGE)" \
@@ -62,16 +62,19 @@ M4 := m4 \
 	-D "DESCRIPTION1=$(DESCRIPTION1)" \
 	-D "DESCRIPTION2=$(DESCRIPTION2)" \
 	-D "DESCRIPTION3=$(DESCRIPTION3)"
-objs := $(addsuffix .o, $(units))
-deps := $(addsuffix .d, $(units))
+c_source := $(PACKAGE) str file exec sig daemon df tv snap ipc
+c_generated := $(B)/$(PACKAGE).lsg $(B)/version
+objs := $(addsuffix .o, $(c_generated) $(addprefix $(B)/, $(c_source)))
+deps := $(objs:.o=.d)
 all := $(PACKAGE) $(PACKAGE).1.gz
 
 all: $(all)
 man: $(PACKAGE).1.gz
-$(objs): $(PACKAGE).lsg.h Makefile
+$(objs): $(B)/$(PACKAGE).lsg.h Makefile
 -include $(deps)
 
 DSS_CPPFLAGS += -Wunused-macros
+DSS_CPPFLAGS += -I$(B)
 
 DSS_CFLAGS := -Wno-sign-compare -g -Wunused -Wundef
 DSS_CFLAGS += -Wredundant-decls
@@ -86,6 +89,9 @@ DSS_CFLAGS += -Wunused-parameter
 DSS_CFLAGS += -Wbad-function-cast
 DSS_CFLAGS += -Wshadow
 
+CC_CMD = $(CC) -c -o $@ $(DSS_CPPFLAGS) $(CPPFLAGS) $(DSS_CFLAGS) $(CFLAGS) \
+		-MMD -MF $(B)/$(*F).d -MT $@ $<
+
 .ONESHELL:
 .SHELLFLAGS := -ec
 ifeq ("$(origin V)", "command line")
@@ -93,40 +99,42 @@ ifeq ("$(origin V)", "command line")
 else
 	SAY = @printf '%s\n' '$(strip $(1))'
 endif
-version.c:
+$(B)/version.c:
 	$(call SAY, VG $@)
 	./version-gen.sh $(PACKAGE) version.c > /dev/null
 $(PACKAGE): $(objs)
 	$(call SAY, LD $@)
 	$(CC) -o $@ $(objs) $(LDFLAGS) -llopsub
-%.o: %.c
+$(B)/%.o: $(B)/%.c
+	$(call SAY, CC $<)
+	$(CC_CMD)
+$(B)/%.o: %.c
 	$(call SAY, CC $<)
-	$(CC) -c -o $@ $(DSS_CPPFLAGS) $(CPPFLAGS) $(DSS_CFLAGS) $(CFLAGS) \
-		-MMD -MF $(*F).d -MT $@ $<
+	$(CC_CMD)
+
 .PHONY: all clean install README
-.PRECIOUS: %.lsg.c %.lsg.h %.suite %.1
-$(PACKAGE).suite: $(PACKAGE).suite.m4 Makefile
+.PRECIOUS: $(B)/%.lsg.c $(B)/%.lsg.h $(B)/%.suite $(B)/%.1
+$(B)/$(PACKAGE).suite: $(PACKAGE).suite.m4 Makefile
 	$(call SAY, M4 $<)
 	$(M4) $< > $@
-%.lsg.h: %.suite
+$(B)/%.lsg.h: $(B)/%.suite
 	$(call SAY, LSGH $<)
 	$(LSG) --gen-h=$@ < $<
-%.lsg.c: %.suite
+$(B)/%.lsg.c: $(B)/%.suite
 	$(call SAY, LSGC $<)
 	$(LSG) --gen-c=$@ < $<
-%.1: %.suite
+$(B)/%.1: $(B)/%.suite
 	$(call SAY, LSGM $<)
 	$(LSG) --gen-man=$@ --version-string=$(VERSION) < $<
-%.1.gz: %.1
+%.1.gz: $(B)/%.1
 	$(call SAY, GZIP $<)
 	$(GZIP) < $< > $@
-%.1.html: %.1
+$(B)/%.1.html: $(B)/%.1
 	$(call SAY, GROFF $<)
 	$(GROFF) $< > $@
 clean:
 	$(call SAY, CLEAN)
-	$(RM) *.[od] $(all) *.html $(PACKAGE).1 $(PACKAGE).suite \
-		$(PACKAGE).lsg.[ch] version.c
+	$(RM) -r $(B) $(all)
 
 ifneq ($(findstring strip, $(MAKECMDGOALS)),)
        strip_option := -s
@@ -159,7 +167,7 @@ endef
 README:
 	@printf '%s\n' "$(README)"
 
-index.html: index.html.m4 Makefile
+$(B)/index.html: index.html.m4 Makefile
 	$(call SAY, M4 $@)
 	$(M4) $< > $@
 
-- 
2.39.2