build: Avoid lots of duplications in Makefile.

We define a number of make variables, each of which becomes a cpp
define as well as an m4 macro via suitable -D var=val options for
cpp and m4. With the current approach we repeat the name of each
variables twice. Example:

	URL := http://people.tuebingen.mpg.de/maan/$(PACKAGE)/
	M4 += -D "URL=$(URL)"
	XCPPFLAGS += -DURL='"$(URL)"'

This is tedious and error-prone. Be a bit smarter by introducing
the DEFINES make variable which gets expanded twice to create the
command line options for m4 and cpp.

diff --git a/Makefile b/Makefile
index 52998ba48eae3f21d75b86fc67f838e9db62ba46..c0e2f51db98b2741bd5cfef4ecf3a8e30511c64b 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -10,6 +10,26 @@ else
        SAY = @echo '$(strip $(1))'
 endif
 
+PACKAGE := micoforia
+DEFINES = \
+       $(call DEFINE,PACKAGE,$(PACKAGE)) \
+       $(call DEFINE,AUTHOR,Andre Noll) \
+       $(call DEFINE,COPYRIGHT_YEAR,2019) \
+       $(call DEFINE,SLOGAN,Minimal Containers for Instant Access) \
+       $(call DEFINE,EMAIL,maan@tuebingen.mpg.de) \
+       $(call DEFINE,URL,http://people.tuebingen.mpg.de/maan/$(PACKAGE)/) \
+       $(call DEFINE,CLONE_URL,git://git.tuebingen.mpg.de/$(PACKAGE)) \
+       $(call DEFINE,GITWEB_URL,http://git.tuebingen.mpg.de/$(PACKAGE).git) \
+       $(call DEFINE,HOME_URL,http://people.tuebingen.mpg.de/maan/) \
+       $(call DEFINE,LICENSE,GNU GPL version 3) \
+       $(call DEFINE,LICENSE_URL,https://www.gnu.org/licenses/gpl-3.0-standalone.html)
+DEFINE = -D$(1)='"$(2)"'
+# LOGLEVELS is special because it is defined unquoted
+LOGLEVELS := LL_DEBUG,LL_INFO,LL_NOTICE,LL_WARNING,LL_ERROR,LL_CRIT,LL_EMERG
+CPP_DEFINES := $(DEFINES) -DLOGLEVELS='$(LOGLEVELS)'
+DEFINE = -D "$(1)=$(2)"
+M4_DEFINES := $(DEFINES)
+
 .ONESHELL:
 .SHELLFLAGS := -ec
 PREFIX ?= /usr/local
@@ -21,19 +41,6 @@ B := build
 all := micoforia micoforia.8
 all: $(all)
 
-PACKAGE := micoforia
-SLOGAN := Minimal Containers for Instant Access
-AUTHOR := Andre Noll
-EMAIL := maan@tuebingen.mpg.de
-COPYRIGHT_YEAR := 2019
-URL := http://people.tuebingen.mpg.de/maan/$(PACKAGE)/
-CLONE_URL := git://git.tuebingen.mpg.de/$(PACKAGE)
-GITWEB_URL := http://git.tuebingen.mpg.de/$(PACKAGE).git
-HOME_URL := http://people.tuebingen.mpg.de/maan/
-LICENSE := GNU GPL version 3
-LICENSE_URL := https://www.gnu.org/licenses/gpl-3.0-standalone.html
-LOGLEVELS := LL_DEBUG,LL_INFO,LL_NOTICE,LL_WARNING,LL_ERROR,LL_CRIT,LL_EMERG
-
 units := micoforia util version micoforia.lsg
 deps := $(addprefix $(B)/, $(addsuffix .d, $(units)))
 objs := $(addprefix $(B)/, $(addsuffix .o, $(units)))
@@ -43,34 +50,9 @@ ifeq ($(findstring clean, $(MAKECMDGOALS)),)
 -include $(B)/config.mak
 endif
 
-M4 += \
-       -D "AUTHOR=$(AUTHOR)" \
-       -D "COPYRIGHT_YEAR=$(COPYRIGHT_YEAR)" \
-       -D "PACKAGE=$(PACKAGE)" \
-       -D "SLOGAN=$(SLOGAN)" \
-       -D "EMAIL=$(EMAIL)" \
-       -D "URL=$(URL)" \
-       -D "CLONE_URL=$(CLONE_URL)" \
-       -D "GITWEB_URL=$(GITWEB_URL)" \
-       -D "HOME_URL=$(HOME_URL)" \
-       -D "LICENSE=$(LICENSE)" \
-       -D "LICENSE_URL=$(LICENSE_URL)" \
-       defs.m4
-
-XCPPFLAGS :=
-XCPPFLAGS += -I$(B)
-XCPPFLAGS += -Wunused-macros
-XCPPFLAGS += -DCOPYRIGHT_YEAR='"$(COPYRIGHT_YEAR)"'
-XCPPFLAGS += -DPACKAGE='"$(PACKAGE)"'
-XCPPFLAGS += -DAUTHOR='"$(AUTHOR)"'
-XCPPFLAGS += -DEMAIL='"$(EMAIL)"'
-XCPPFLAGS += -DURL='"$(URL)"'
-XCPPFLAGS += -DCLONE_URL='"$(CLONE_URL)"'
-XCPPFLAGS += -DGITWEB_URL='"$(GITWEB_URL)"'
-XCPPFLAGS += -DHOME_URL='"$(HOME_URL)"'
-XCPPFLAGS += -DLOGLEVELS='$(LOGLEVELS)'
-XCPPFLAGS += -DLICENSE='"$(LICENSE)"'
-XCPPFLAGS += -DLICENSE_URL='"$(LICENSE_URL)"'
+M4 += $(M4_DEFINES) defs.m4
+
+XCPPFLAGS := $(CPP_DEFINES) -I$(B) -Wunused-macros
 
 XCFLAGS :=
 XCFLAGS += -fno-strict-aliasing