[Vala] [RFC, PATCH] add async keyword to vapigen

[Philipp Zabel <philipp zabel gmail com>]

Hi, the following patch adds support for an "async" attribute to
vapigen. This can be used in metadata to fix up the binding of
asynchronous methods that don't end in _async like this:

diff --git a/vapi/packages/gio-2.0/gio-2.0.metadata b/vapi/packages/gio-2.0/gio-2.0.metadata
index 1ca9522..e458e86 100644
--- a/vapi/packages/gio-2.0/gio-2.0.metadata
+++ b/vapi/packages/gio-2.0/gio-2.0.metadata
@@ -48,6 +48,7 @@ GFileMonitor::changed.other_file nullable="1"
 g_file_monitor_directory hidden="1"
 g_file_monitor_dir hidden="1"
 g_file_monitor_file hidden="1"
+g_file_mount_enclosing_volume async="1"
 g_file_move.progress_callback_data hidden="1"
 g_file_new_for_commandline_arg transfer_ownership="1"
 g_file_new_for_path transfer_ownership="1"

Or would it be better to make the parser recognize asynchronous
functions that don't end in _async?

regards
Philipp

diff --git a/vapigen/valagidlparser.vala b/vapigen/valagidlparser.vala
index 6cb068f..efa49dd 100644
--- a/vapigen/valagidlparser.vala
+++ b/vapigen/valagidlparser.vala
@@ -1148,7 +1148,13 @@ public class Vala.GIdlParser : CodeVisitor {
        void handle_async_methods (ObjectTypeSymbol type_symbol) {
                foreach (Method m in type_symbol.get_methods ()) {
                        if (m.coroutine) {
-                               var finish_method = type_symbol.scope.lookup (m.name.substring (0, 
m.name.length - "_async".length) + "_finish") as Method;
+                               string finish_method_base;
+                               if (m.name.has_suffix ("_async")) {
+                                       finish_method_base = m.name.substring (0, m.name.length - 
"_async".length);
+                               } else {
+                                       finish_method_base = m.name;
+                               }
+                               var finish_method = type_symbol.scope.lookup (finish_method_base + "_finish") 
as Method;
                                if (finish_method != null) {
                                        m.return_type = finish_method.return_type.copy ();
                                        foreach (var param in finish_method.get_parameters ()) {
@@ -1520,6 +1526,11 @@ public class Vala.GIdlParser : CodeVisitor {
                                        }
                                } else if (nv[0] == "vfunc_name") {
                                        m.vfunc_name = eval (nv[1]);
+                               } else if (nv[0] == "async") {
+                                       if (eval (nv[1]) == "1") {
+                                               // force async function, even if it doesn't end in _async
+                                               m.coroutine = true;
+                                       }
                                }
                        }
                }
@@ -1558,7 +1569,7 @@ public class Vala.GIdlParser : CodeVisitor {
                                }
                        }
 
-                       if (param type  interface == "GAsyncReadyCallback" && symbol.has_suffix ("_async")) {
+                       if (param type  interface == "GAsyncReadyCallback" && (symbol.has_suffix ("_async") 
|| m.coroutine)) {
                                // async method
                                m.coroutine = true;
                                continue;