codegen: Use G_TYPE_INSTANCE_GET_INTERFACE to get vtable for base-access

Usage of the pre-assigned *_parent_iface field is only possible in classes
which explicitly implement an interface.

8 files changed, 113 insertions, 14 deletions

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 7ae022aa3..c9362387e 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -2391,6 +2391,22 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 		return get_cexpression ("self");
 	}
 
+	public CCodeExpression get_this_interface_cexpression (Interface iface) {
+		if (current_class.implements (iface)) {
+			return new CCodeIdentifier ("%s_%s_parent_iface".printf (get_ccode_lower_case_name (current_class), get_ccode_lower_case_name (iface)));
+		}
+
+		if (!current_class.is_a (iface)) {
+			Report.warning (current_class.source_reference, "internal: `%s' is not a `%s'".printf (current_class.get_full_name (), iface.get_full_name ()));
+		}
+
+		var vcast = new CCodeFunctionCall (new CCodeIdentifier ("G_TYPE_INSTANCE_GET_INTERFACE"));
+		vcast.add_argument (get_this_cexpression ());
+		vcast.add_argument (new CCodeIdentifier (get_ccode_type_id (iface)));
+		vcast.add_argument (new CCodeIdentifier (get_ccode_type_name (iface)));
+		return vcast;
+	}
+
 	public CCodeExpression get_inner_error_cexpression () {
 		return get_cexpression ("_inner_error%d_".printf (current_inner_error_id));
 	}
@@ -6185,9 +6201,9 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 				ccode.add_expression (ccall);
 			} else if (prop.base_interface_property != null) {
 				var base_iface = (Interface) prop.base_interface_property.parent_symbol;
-				string parent_iface_var = "%s_%s_parent_iface".printf (get_ccode_lower_case_name (current_class), get_ccode_lower_case_name (base_iface));
+				var vcast = get_this_interface_cexpression (base_iface);
 
-				var ccall = new CCodeFunctionCall (new CCodeMemberAccess.pointer (new CCodeIdentifier (parent_iface_var), "set_%s".printf (prop.name)));
+				var ccall = new CCodeFunctionCall (new CCodeMemberAccess.pointer (vcast, "set_%s".printf (prop.name)));
 				ccall.add_argument ((CCodeExpression) get_ccodenode (instance));
 				var cexpr = get_cvalue_ (value);
 				if (prop.property_type.is_real_non_null_struct_type ()) {
diff --git a/codegen/valaccodememberaccessmodule.vala b/codegen/valaccodememberaccessmodule.vala
index 8fb01eaa6..2359f4ba8 100644
--- a/codegen/valaccodememberaccessmodule.vala
+++ b/codegen/valaccodememberaccessmodule.vala
@@ -58,9 +58,9 @@ public abstract class Vala.CCodeMemberAccessModule : CCodeControlFlowModule {
 					return;
 				} else if (m.base_interface_method != null) {
 					var base_iface = (Interface) m.base_interface_method.parent_symbol;
-					string parent_iface_var = "%s_%s_parent_iface".printf (get_ccode_lower_case_name (current_class), get_ccode_lower_case_name (base_iface));
+					var vcast = get_this_interface_cexpression (base_iface);
 
-					set_cvalue (expr, new CCodeMemberAccess.pointer (new CCodeIdentifier (parent_iface_var), get_ccode_vfunc_name (m)));
+					set_cvalue (expr, new CCodeMemberAccess.pointer (vcast, get_ccode_vfunc_name (m)));
 					return;
 				}
 			}
@@ -206,9 +206,9 @@ public abstract class Vala.CCodeMemberAccessModule : CCodeControlFlowModule {
 					}
 				} else if (base_prop.parent_symbol is Interface) {
 					var base_iface = (Interface) base_prop.parent_symbol;
-					string parent_iface_var = "%s_%s_parent_iface".printf (get_ccode_lower_case_name (current_class), get_ccode_lower_case_name (base_iface));
+					var vcast = get_this_interface_cexpression (base_iface);
 
-					var ccall = new CCodeFunctionCall (new CCodeMemberAccess.pointer (new CCodeIdentifier (parent_iface_var), "get_%s".printf (prop.name)));
+					var ccall = new CCodeFunctionCall (new CCodeMemberAccess.pointer (vcast, "get_%s".printf (prop.name)));
 					ccall.add_argument (get_cvalue (expr.inner));
 					if (prop.property_type.is_real_non_null_struct_type ()) {
 						var temp_value = (GLibValue) create_temp_value (prop.get_accessor.value_type, false, expr);
diff --git a/codegen/valaccodemethodcallmodule.vala b/codegen/valaccodemethodcallmodule.vala
index d388e15b8..3a698d612 100644
--- a/codegen/valaccodemethodcallmodule.vala
+++ b/codegen/valaccodemethodcallmodule.vala
@@ -104,10 +104,10 @@ public class Vala.CCodeMethodCallModule : CCodeAssignmentModule {
 					finish_call.call = new CCodeMemberAccess.pointer (vcast, get_ccode_finish_vfunc_name (m));
 				} else if (m.base_interface_method != null) {
 					var base_iface = (Interface) m.base_interface_method.parent_symbol;
-					string parent_iface_var = "%s_%s_parent_iface".printf (get_ccode_lower_case_name (current_class), get_ccode_lower_case_name (base_iface));
+					var vcast = get_this_interface_cexpression (base_iface);
 
-					async_call.call = new CCodeMemberAccess.pointer (new CCodeIdentifier (parent_iface_var), get_ccode_vfunc_name (m));
-					finish_call.call = new CCodeMemberAccess.pointer (new CCodeIdentifier (parent_iface_var), get_ccode_finish_vfunc_name (m));
+					async_call.call = new CCodeMemberAccess.pointer (vcast, get_ccode_vfunc_name (m));
+					finish_call.call = new CCodeMemberAccess.pointer (vcast, get_ccode_finish_vfunc_name (m));
 				}
 			}
 
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 357ba6924..b6ed4f931 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -314,8 +314,11 @@ TESTS = \
 	objects/gsource.vala \
 	objects/instance-comparison.vala \
 	objects/interface_only.vala \
+	objects/interface-async-base-access.vala \
+	objects/interface-base-access.vala \
 	objects/interfaces.vala \
 	objects/interface-generics.vala \
+	objects/interface-property-base-access.vala \
 	objects/interface-virtual-override.vala \
 	objects/methods.vala \
 	objects/paramspec.vala \
diff --git a/tests/objects/interface-async-base-access.vala b/tests/objects/interface-async-base-access.vala
new file mode 100644
index 000000000..2c8bccfd9
--- /dev/null
+++ b/tests/objects/interface-async-base-access.vala
@@ -0,0 +1,25 @@
+interface IFoo {
+	public abstract async void foo ();
+}
+
+class Bar : IFoo {
+	public async void foo () {
+		reached = true;
+	}
+}
+
+class Foo : Bar {
+	public async void bar () {
+		yield base.foo ();
+	}
+}
+
+bool reached = false;
+
+void main () {
+	var foo = new Foo ();
+	assert (foo is IFoo);
+
+	foo.bar.begin ();
+	assert (reached);
+}
diff --git a/tests/objects/interface-base-access.vala b/tests/objects/interface-base-access.vala
new file mode 100644
index 000000000..f0e853e25
--- /dev/null
+++ b/tests/objects/interface-base-access.vala
@@ -0,0 +1,25 @@
+interface IFoo {
+	public abstract void foo ();
+}
+
+class Bar : IFoo {
+	public void foo () {
+		reached = true;
+	}
+}
+
+class Foo : Bar {
+	public void bar () {
+		base.foo ();
+	}
+}
+
+bool reached = false;
+
+void main () {
+	var foo = new Foo ();
+	assert (foo is IFoo);
+
+	foo.bar ();
+	assert (reached);
+}
diff --git a/tests/objects/interface-property-base-access.vala b/tests/objects/interface-property-base-access.vala
new file mode 100644
index 000000000..036ce8b1e
--- /dev/null
+++ b/tests/objects/interface-property-base-access.vala
@@ -0,0 +1,20 @@
+interface IFoo {
+	public abstract string foo { get; set; }
+}
+
+class Bar : IFoo {
+	public string foo { get; set; }
+}
+
+class Foo : Bar {
+	public string bar (string s) {
+		base.foo = s;
+		return base.foo;
+	}
+}
+
+void main () {
+	var foo = new Foo ();
+	assert (foo is IFoo);
+	assert (foo.bar ("foo") == "foo");
+}
diff --git a/vala/valaclass.vala b/vala/valaclass.vala
index 51e8fbade..9823d76a3 100644
--- a/vala/valaclass.vala
+++ b/vala/valaclass.vala
@@ -497,14 +497,14 @@ public class Vala.Class : ObjectTypeSymbol {
 		}
 	}
 
-	private bool class_is_a (Class cl, TypeSymbol t) {
-		if (cl == t) {
+	public bool is_a (ObjectTypeSymbol t) {
+		if (this == t) {
 			return true;
 		}
 
-		foreach (DataType base_type in cl.get_base_types ()) {
+		foreach (DataType base_type in get_base_types ()) {
 			if (base_type.data_type is Class) {
-				if (class_is_a ((Class) base_type.data_type, t)) {
+				if (((Class) base_type.data_type).is_a (t)) {
 					return true;
 				}
 			} else if (base_type.data_type == t) {
@@ -515,6 +515,16 @@ public class Vala.Class : ObjectTypeSymbol {
 		return false;
 	}
 
+	public bool implements (Interface i) {
+		foreach (DataType base_type in get_base_types ()) {
+			if (base_type.data_type == i) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	public override bool check (CodeContext context) {
 		if (checked) {
 			return !error;
@@ -695,7 +705,7 @@ public class Vala.Class : ObjectTypeSymbol {
 		/* check whether all prerequisites are met */
 		List<string> missing_prereqs = new ArrayList<string> ();
 		foreach (TypeSymbol prereq in prerequisites) {
-			if (!class_is_a (this, prereq)) {
+			if (!is_a ((ObjectTypeSymbol) prereq)) {
 				missing_prereqs.insert (0, prereq.get_full_name ());
 			}
 		}