[vala] Support reference transfer for delegates

[Jürg Billeter <juergbi src gnome org>]

commit cc8693d42c4870100522b34fa22c0bf35ec3b12e
Author: Luca Bruno <lucabru src gnome org>
Date:   Sun Jan 9 18:20:13 2011 +0100

    Support reference transfer for delegates
    
    Fixes bug 632411.

 codegen/valaccodebasemodule.vala          |   20 +++++++++++++++++---
 vala/valareferencetransferexpression.vala |    8 --------
 2 files changed, 17 insertions(+), 11 deletions(-)
---
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index ba0cac1..2808d09 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -274,6 +274,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 	public TypeSymbol gbytearray_type;
 	public TypeSymbol gptrarray_type;
 	public TypeSymbol gthreadpool_type;
+	public DataType gdestroynotify_type;
 	public DataType gquark_type;
 	public Struct gvalue_type;
 	public Class gvariant_type;
@@ -412,6 +413,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			gbytearray_type = (TypeSymbol) glib_ns.scope.lookup ("ByteArray");
 			gptrarray_type = (TypeSymbol) glib_ns.scope.lookup ("PtrArray");
 			gthreadpool_type = (TypeSymbol) glib_ns.scope.lookup ("ThreadPool");
+			gdestroynotify_type = new DelegateType ((Delegate) glib_ns.scope.lookup ("DestroyNotify"));
 
 			gquark_type = new IntegerType ((Struct) glib_ns.scope.lookup ("Quark"));
 			gvalue_type = (Struct) glib_ns.scope.lookup ("Value");
@@ -4731,7 +4733,9 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 		var cvar = get_variable_cexpression (temp_decl.name);
 
 		ccode.add_expression (new CCodeAssignment (cvar, get_cvalue (expr.inner)));
-		ccode.add_expression (new CCodeAssignment (get_cvalue (expr.inner), new CCodeConstant ("NULL")));
+		if (!(expr.value_type is DelegateType)) {
+			ccode.add_expression (new CCodeAssignment (get_cvalue (expr.inner), new CCodeConstant ("NULL")));
+		}
 
 		set_cvalue (expr, cvar);
 
@@ -4744,10 +4748,20 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 
 		var delegate_type = expr.value_type as DelegateType;
 		if (delegate_type != null && delegate_type.delegate_symbol.has_target) {
+			var temp_target_decl = get_temp_variable (new PointerType (new VoidType ()), true, expr, false);
+			emit_temp_var (temp_target_decl);
+			var target_cvar = get_variable_cexpression (temp_target_decl.name);
 			CCodeExpression target_destroy_notify;
-			set_delegate_target (expr, get_delegate_target_cexpression (expr.inner, out target_destroy_notify));
+			var target = get_delegate_target_cexpression (expr.inner, out target_destroy_notify);
+			ccode.add_expression (new CCodeAssignment (target_cvar, target));
+			set_delegate_target (expr, target_cvar);
 			if (target_destroy_notify != null) {
-				set_delegate_target_destroy_notify (expr, target_destroy_notify);
+				var temp_target_destroy_notify_decl = get_temp_variable (gdestroynotify_type, true, expr, false);
+				emit_temp_var (temp_target_destroy_notify_decl);
+				var target_destroy_notify_cvar = get_variable_cexpression (temp_target_destroy_notify_decl.name);
+				ccode.add_expression (new CCodeAssignment (target_destroy_notify_cvar, target_destroy_notify));
+				ccode.add_expression (new CCodeAssignment (target_destroy_notify, new CCodeConstant ("NULL")));
+				set_delegate_target_destroy_notify (expr, target_destroy_notify_cvar);
 			}
 		}
 	}
diff --git a/vala/valareferencetransferexpression.vala b/vala/valareferencetransferexpression.vala
index 5e34282..2d82ac0 100644
--- a/vala/valareferencetransferexpression.vala
+++ b/vala/valareferencetransferexpression.vala
@@ -101,14 +101,6 @@ public class Vala.ReferenceTransferExpression : Expression {
 			return false;
 		}
 
-		if (inner.value_type is DelegateType) {
-			// would require fixing code generator to ensure _target_destroy_notify
-			// is set to NULL as well after reference transfer, leads to double free otherwise
-			error = true;
-			Report.error (source_reference, "Reference transfer not supported for delegates");
-			return false;
-		}
-
 		value_type = inner.value_type.copy ();
 		value_type.value_owned = true;