meson: use correct generated files for wayland protocols

Previously, the set of files generated by protocols/meson.build was
ignored and the existing files from src/protocols/*.h were used.

- Move prebuilt protocols private code to a separate translation unit,
  not included by meson.build
- Control the set of protocol headers to use with include paths

Makefile

@@ -38,6 +38,7 @@ ifeq (0,${WAYLAND})
 SRC := $(sort $(shell ${FIND} src/ -not \( -path src/wayland -prune \) -name '*.c'))
 else
 # with Wayland support
+CFLAGS += -Isrc/wayland/protocols
 SRC := $(sort $(shell ${FIND} src/ -name '*.c'))
 endif
 OBJ := ${SRC:.c=.o}

src/wayland/foreign_toplevel.c

@@ -2,8 +2,7 @@
 #include <stdio.h>
 #include <stdbool.h>
 #include <stdlib.h>
-#include "protocols/wlr-foreign-toplevel-management-unstable-v1-client-header.h"
-/* #include "protocols/wlr-foreign-toplevel-management-unstable-v1.h" */
+#include "wlr-foreign-toplevel-management-unstable-v1-client-header.h"
 
 #include "foreign_toplevel.h"
 #include "../dunst.h"

src/wayland/protocols.c

@@ -0,0 +1,4 @@
+#include "protocols/xdg-shell.h"
+#include "protocols/wlr-layer-shell-unstable-v1.h"
+#include "protocols/wlr-foreign-toplevel-management-unstable-v1.h"
+#include "protocols/idle.h"

src/wayland/protocols/meson.build

@@ -6,7 +6,7 @@ wayland_scanner_prog = find_program(wayland_scanner_path, native: true)
 
 wayland_scanner_code = generator(
 	wayland_scanner_prog,
-	output: '@BASENAME@.h',
+	output: '@BASENAME@.c',
 	arguments: ['private-code', '@INPUT@', '@OUTPUT@'],
 )
 

src/wayland/wl.c

@@ -18,14 +18,10 @@
 #include <string.h>
 #include <glib.h>
 
-#include "protocols/xdg-shell-client-header.h"
-#include "protocols/xdg-shell.h"
-#include "protocols/wlr-layer-shell-unstable-v1-client-header.h"
-#include "protocols/wlr-layer-shell-unstable-v1.h"
-#include "protocols/wlr-foreign-toplevel-management-unstable-v1-client-header.h"
-#include "protocols/wlr-foreign-toplevel-management-unstable-v1.h"
-#include "protocols/idle-client-header.h"
-#include "protocols/idle.h"
+#include "xdg-shell-client-header.h"
+#include "wlr-layer-shell-unstable-v1-client-header.h"
+#include "wlr-foreign-toplevel-management-unstable-v1-client-header.h"
+#include "idle-client-header.h"
 #include "pool-buffer.h"