build: use dicts instead of get_variable

Closes: https://github.com/swaywm/wlroots/issues/1963

backend/wayland/meson.build

@@ -16,5 +16,5 @@ client_protos = [
 ]
 
 foreach proto : client_protos
-	wlr_files += get_variable(proto.underscorify() + '_client_h')
+	wlr_files += protocols_client_header[proto]
 endforeach

examples/meson.build

@@ -167,7 +167,7 @@ clients = {
 foreach name, info : compositors
 	extra_src = []
 	foreach p : info.get('proto', [])
-		extra_src += get_variable(p.underscorify() + '_server_h')
+		extra_src += protocols_server_header[p]
 	endforeach
 
 	executable(
@@ -182,8 +182,8 @@ endforeach
 foreach name, info : clients
 	extra_src = []
 	foreach p : info.get('proto')
-		extra_src += get_variable(p.underscorify() + '_c')
-		extra_src += get_variable(p.underscorify() + '_client_h')
+		extra_src += protocols_code[p]
+		extra_src += protocols_client_header[p]
 	endforeach
 
 	executable(

protocol/meson.build

@@ -46,6 +46,9 @@ protocols = {
 	'wlr-virtual-pointer-unstable-v1': 'wlr-virtual-pointer-unstable-v1.xml',
 }
 
+protocols_code = {}
+protocols_server_header = {}
+protocols_client_header = {}
 foreach name, path : protocols
 	code = custom_target(
 		name.underscorify() + '_c',
@@ -71,7 +74,7 @@ foreach name, path : protocols
 		build_by_default: false,
 	)
 
-	set_variable(name.underscorify() + '_c', code)
-	set_variable(name.underscorify() + '_server_h', server_header)
-	set_variable(name.underscorify() + '_client_h', client_header)
+	protocols_code += { name: code }
+	protocols_server_header += { name: server_header }
+	protocols_client_header += { name: client_header }
 endforeach