convert makefile to be more portable

Makefile

@@ -1,19 +1,60 @@
+.POSIX:
+.SUFFIXES:
+
 include config.mk
 
-CFLAGS += -I. -DWLR_USE_UNSTABLE -std=c99 -pedantic -DVERSION=\"$(VERSION)\"
+# flags for compiling
+DWLCPPFLAGS = -I. -DWLR_USE_UNSTABLE -DVERSION=\"$(VERSION)\"
 
-WAYLAND_PROTOCOLS=$(shell pkg-config --variable=pkgdatadir wayland-protocols)
-WAYLAND_SCANNER=$(shell pkg-config --variable=wayland_scanner wayland-scanner)
+# Wayland utils
+WAYLAND_PROTOCOLS = `pkg-config --variable=pkgdatadir wayland-protocols`
+WAYLAND_SCANNER   = `pkg-config --variable=wayland_scanner wayland-scanner`
 
-PKGS = wlroots wayland-server xcb xkbcommon libinput
-CFLAGS += $(foreach p,$(PKGS),$(shell pkg-config --cflags $(p)))
-LDLIBS += $(foreach p,$(PKGS),$(shell pkg-config --libs $(p)))
+# CFLAGS / LDFLAGS
+PKGS      = wlroots wayland-server xcb xkbcommon libinput
+DWLCFLAGS = `pkg-config --cflags $(PKGS)` $(DWLCPPFLAGS) $(CFLAGS) $(XWAYLAND)
+LDLIBS    = `pkg-config --libs $(PKGS)`
 
+# build rules
+
+# wayland-scanner is a tool which generates C headers and rigging for Wayland
+# protocols, which are specified in XML. wlroots requires you to rig these up
+# to your build system yourself and provide them in the include path.
 all: dwl
+dwl: dwl.o xdg-shell-protocol.o wlr-layer-shell-unstable-v1-protocol.o idle-protocol.o util.o
+	$(CC) $(LDLIBS) -o $@ dwl.o xdg-shell-protocol.o wlr-layer-shell-unstable-v1-protocol.o idle-protocol.o util.o
+dwl.o: dwl.c config.mk config.h client.h xdg-shell-protocol.h wlr-layer-shell-unstable-v1-protocol.h idle-protocol.h
+xdg-shell-protocol.o: xdg-shell-protocol.h xdg-shell-protocol.c
+wlr-layer-shell-unstable-v1-protocol.o: wlr-layer-shell-unstable-v1-protocol.h wlr-layer-shell-unstable-v1-protocol.c
+idle-protocol.o: idle-protocol.h idle-protocol.c
+util.o: util.c util.h
 
+# wayland scanner rules to generate .h / .c files
+xdg-shell-protocol.h:
+	$(WAYLAND_SCANNER) server-header \
+		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
+xdg-shell-protocol.c:
+	$(WAYLAND_SCANNER) private-code \
+		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
+wlr-layer-shell-unstable-v1-protocol.h:
+	$(WAYLAND_SCANNER) server-header \
+		protocols/wlr-layer-shell-unstable-v1.xml $@
+wlr-layer-shell-unstable-v1-protocol.c:
+	$(WAYLAND_SCANNER) private-code \
+		protocols/wlr-layer-shell-unstable-v1.xml $@
+idle-protocol.h:
+	$(WAYLAND_SCANNER) server-header \
+		protocols/idle.xml $@
+idle-protocol.c:
+	$(WAYLAND_SCANNER) private-code \
+		protocols/idle.xml $@
+
+config.h:
+	cp config.def.h $@
 clean:
 	rm -f dwl *.o *-protocol.h *-protocol.c
 
+# distribution archive
 dist: clean
 	mkdir -p dwl-$(VERSION)
 	cp -R LICENSE* Makefile README.md generate-version.sh client.h\
@@ -23,51 +64,18 @@ dist: clean
 	tar -caf dwl-$(VERSION).tar.gz dwl-$(VERSION)
 	rm -rf dwl-$(VERSION)
 
-install: dwl
-	install -Dm755 dwl $(DESTDIR)$(PREFIX)/bin/dwl
-	install -Dm644 dwl.1 $(DESTDIR)$(MANDIR)/man1/dwl.1
+# install rules
 
+install: dwl
+	mkdir -p $(DESTDIR)$(PREFIX)/bin
+	cp dwl $(DESTDIR)$(PREFIX)/bin
+	chmod 755 $(DESTDIR)$(PREFIX)/bin/dwl
+	mkdir -p $(DESTDIR)$(MANDIR)/man1
+	cp dwl.1 $(DESTDIR)$(MANDIR)/man1
+	chmod 644 $(DESTDIR)$(MANDIR)/man1/dwl.1
 uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/dwl $(DESTDIR)$(MANDIR)/man1/dwl.1
 
-.PHONY: all clean dist install uninstall
-
-# wayland-scanner is a tool which generates C headers and rigging for Wayland
-# protocols, which are specified in XML. wlroots requires you to rig these up
-# to your build system yourself and provide them in the include path.
-xdg-shell-protocol.h:
-	$(WAYLAND_SCANNER) server-header \
-		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
-
-xdg-shell-protocol.c:
-	$(WAYLAND_SCANNER) private-code \
-		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
-
-xdg-shell-protocol.o: xdg-shell-protocol.h
-
-wlr-layer-shell-unstable-v1-protocol.h:
-	$(WAYLAND_SCANNER) server-header \
-		protocols/wlr-layer-shell-unstable-v1.xml $@
-
-wlr-layer-shell-unstable-v1-protocol.c:
-	$(WAYLAND_SCANNER) private-code \
-		protocols/wlr-layer-shell-unstable-v1.xml $@
-
-wlr-layer-shell-unstable-v1-protocol.o: wlr-layer-shell-unstable-v1-protocol.h
-
-idle-protocol.h:
-	$(WAYLAND_SCANNER) server-header \
-		protocols/idle.xml $@
-
-idle-protocol.c:
-	$(WAYLAND_SCANNER) private-code \
-		protocols/idle.xml $@
-
-idle-protocol.o: idle-protocol.h
-
-config.h: | config.def.h
-	cp config.def.h $@
-
-dwl.o: config.mk config.h client.h xdg-shell-protocol.h wlr-layer-shell-unstable-v1-protocol.h idle-protocol.h util.h
-
-dwl: xdg-shell-protocol.o wlr-layer-shell-unstable-v1-protocol.o idle-protocol.o util.o
+.SUFFIXES: .c .o
+.c.o:
+	$(CC) $(CPPFLAGS) $(DWLCFLAGS) -c $<

config.mk

@@ -1,12 +1,13 @@
 _VERSION = 0.3.1
-VERSION = $(shell ./generate-version.sh $(_VERSION))
+VERSION  = `./generate-version.sh $(_VERSION)`
 
 # paths
 PREFIX = /usr/local
 MANDIR = $(PREFIX)/share/man
 
-# Default compile flags (overridable by environment)
-CFLAGS ?= -g -Wall -Wextra -Werror -Wno-unused-parameter -Wno-sign-compare -Wno-unused-function -Wno-unused-variable -Wno-unused-result -Wdeclaration-after-statement
+# Compile flags that can be used
+#CFLAGS = -pedantic -Wall -Wextra -Werror -Wno-unused-parameter -Wno-sign-compare -Wno-unused-function -Wno-unused-variable -Wno-unused-result -Wdeclaration-after-statement
 
+XWAYLAND =
 # Uncomment to build XWayland support
-#CFLAGS += -DXWAYLAND
+#XWAYLAND = -DXWAYLAND