Use pkg-config for tinywl deps

tinywl/Makefile

@@ -1,23 +1,26 @@
-WAYLAND_PROTOCOLS=/usr/share/wayland-protocols
+WAYLAND_PROTOCOLS=$(shell pkg-config --variable=pkgdatadir wayland-protocols)
+WAYLAND_SCANNER=$(shell pkg-config --variable=wayland_scanner wayland-scanner)
+LIBS=\
+	 $(shell pkg-config --cflags --libs wlroots) \
+	 $(shell pkg-config --cflags --libs wayland-server) \
+	 $(shell pkg-config --cflags --libs xkbcommon)
 
 # 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_SCANNER) server-header \
 		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
 
 xdg-shell-protocol.c: xdg-shell-protocol.h
-	wayland-scanner private-code \
+	$(WAYLAND_SCANNER) private-code \
 		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
 
 tinywl: tinywl.c xdg-shell-protocol.h xdg-shell-protocol.c
 	$(CC) $(CFLAGS) \
 		-g -Werror -I. \
 		-DWLR_USE_UNSTABLE \
-		$(shell pkg-config --cflags --libs wlroots) \
-		$(shell pkg-config --cflags --libs wayland-server) \
-		$(shell pkg-config --cflags --libs xkbcommon) \
+		$(LIBS) \
 		-o $@ $<
 
 clean: