From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Fri, 9 Nov 2018 14:21:16 +0000 (+0100)
Subject: codegen: Transfer ownership of compact class to DestroysInstance method
X-Git-Tag: 0.43.1~114
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bf8c09bf3a5e637880941ee6f59a73e934cf609e;p=thirdparty%2Fvala.git

codegen: Transfer ownership of compact class to DestroysInstance method

Otherwise it is impossible to call an instance method of a compact class
which is a destructor.

See https://gitlab.gnome.org/GNOME/vala/issues/645
---

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 394d710e1..3f277f737 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -3963,6 +3963,17 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 		ccode.add_expression (ccall);
 	}
 
+	bool is_compact_class_destructor_call (Expression expr) {
+		unowned Class? cl = expr.value_type.data_type as Class;
+		if (cl != null && cl.is_compact && expr.parent_node is MemberAccess) {
+			unowned MethodType? mt = ((MemberAccess) expr.parent_node).value_type as MethodType;
+			if (mt != null && mt.method_symbol != null && mt.method_symbol.get_attribute ("DestroysInstance") != null) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	public override void visit_expression (Expression expr) {
 		if (get_cvalue (expr) != null && !expr.lvalue) {
 			if (expr.formal_value_type is GenericType && !(expr.value_type is GenericType)) {
@@ -3980,7 +3991,15 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			if (expr.value_type != null) {
 				// FIXME: temporary workaround until the refactoring is complete, not all target_value have a value_type
 				expr.target_value.value_type = expr.value_type;
-				expr.target_value = transform_value (expr.target_value, expr.target_type, expr);
+
+				if (is_compact_class_destructor_call (expr)) {
+					// transfer ownership here and consume given instance
+					var temp_value = store_temp_value (expr.target_value, expr);
+					ccode.add_assignment (get_cvalue (expr), new CCodeConstant ("NULL"));
+					expr.target_value = temp_value;
+				} else {
+					expr.target_value = transform_value (expr.target_value, expr.target_type, expr);
+				}
 			}
 
 			if (expr.target_value == null) {
diff --git a/tests/Makefile.am b/tests/Makefile.am
index b84d952a6..2ceb6cb1f 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -245,6 +245,7 @@ TESTS = \
 	delegates/bug792077.vala \
 	objects/chainup.vala \
 	objects/classes.vala \
+	objects/compact-class-destructor.vala \
 	objects/constructor-variadic.test \
 	objects/constructors.vala \
 	objects/destructors.vala \
diff --git a/tests/objects/compact-class-destructor.vala b/tests/objects/compact-class-destructor.vala
new file mode 100644
index 000000000..2d6d8a442
--- /dev/null
+++ b/tests/objects/compact-class-destructor.vala
@@ -0,0 +1,17 @@
+[Compact]
+class Foo {
+	[DestroysInstance]
+	public int destroy () {
+		//FIXME No free possible due to broken sizeof(Foo)
+		// https://gitlab.gnome.org/GNOME/vala/issues/442
+		Slice.free (sizeof (int), this);
+		return 42;
+	}
+}
+
+void main () {
+	var foo = new Foo ();
+	var res = foo.destroy ();
+	assert (foo == null);
+	assert (res == 42);
+}