[vala/0.36] codegen: Always assign original variable when consuming instance to destroy

[Rico Tzschichholz <ricotz src gnome org>]

commit e82e0191e4f5727fac883cbe7021dba1661e21cc
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Mon Apr 8 10:00:19 2019 +0200

    codegen: Always assign original variable when consuming instance to destroy
    
    Fixes https://gitlab.gnome.org/GNOME/vala/issues/781

 codegen/valaccodebasemodule.vala            | 15 +++---
 tests/objects/compact-class-destructor.vala | 83 ++++++++++++++++++++++++++++-
 vala/valamemberaccess.vala                  |  7 +++
 3 files changed, 95 insertions(+), 10 deletions(-)
---
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 2474dc9db..2184cc083 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -3966,15 +3966,7 @@ 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;
-
-                               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);
-                               }
+                               expr.target_value = transform_value (expr.target_value, expr.target_type, 
expr);
                        }
 
                        if (expr.target_value == null) {
@@ -3992,6 +3984,11 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
                        if (!(expr.value_type is ValueType && !expr.value_type.nullable)) {
                                ((GLibValue) expr.target_value).non_null = expr.is_non_null ();
                        }
+               } else if (expr.value_type != null && 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;
                }
        }
 
diff --git a/tests/objects/compact-class-destructor.vala b/tests/objects/compact-class-destructor.vala
index 2d6d8a442..7aa4604b0 100644
--- a/tests/objects/compact-class-destructor.vala
+++ b/tests/objects/compact-class-destructor.vala
@@ -9,9 +9,90 @@ class Foo {
        }
 }
 
-void main () {
+void bar () throws Error {
+}
+
+Foo get_foo () {
+       return new Foo ();
+}
+
+class Bar {
+       Foo faz;
+
+       public void instance_simple () {
+               var foo = new Foo ();
+               var res = foo.destroy ();
+
+               assert (foo == null);
+               assert (res == 42);
+       }
+
+       public void instance_field () {
+               bar ();
+
+               faz = new Foo ();
+               var res = faz.destroy ();
+
+               assert (faz == null);
+               assert (res == 42);
+       }
+}
+
+Foo faz;
+
+void field () {
+       bar ();
+
+       faz = new Foo ();
+       var res = faz.destroy ();
+
+       assert (faz == null);
+       assert (res == 42);
+}
+
+void local () {
+       bar ();
+
        var foo = new Foo ();
        var res = foo.destroy ();
+
        assert (foo == null);
        assert (res == 42);
 }
+
+void parameter (owned Foo foo) {
+       bar ();
+
+       var res = foo.destroy ();
+
+       assert (foo == null);
+       assert (res == 42);
+}
+
+void simple () {
+       var foo = new Foo ();
+       var res = foo.destroy ();
+
+       assert (foo == null);
+       assert (res == 42);
+}
+
+void returned () {
+       bar ();
+
+       var res = get_foo ().destroy ();
+
+       assert (res == 42);
+}
+
+void main () {
+       simple ();
+       field ();
+       local ();
+       parameter (new Foo ());
+       returned ();
+
+       var bar = new Bar ();
+       bar.instance_simple ();
+       bar.instance_field ();
+}
diff --git a/vala/valamemberaccess.vala b/vala/valamemberaccess.vala
index a57e68cad..55fdaad1c 100644
--- a/vala/valamemberaccess.vala
+++ b/vala/valamemberaccess.vala
@@ -891,6 +891,13 @@ public class Vala.MemberAccess : Expression {
                                ma.check_lvalue_access ();
                        }
                }
+
+               if (symbol_reference is Method && ((Method) symbol_reference).get_attribute 
("DestroysInstance") != null) {
+                       if (ma != null) {
+                               ma.lvalue = true;
+                               ma.check_lvalue_access ();
+                       }
+               }
        }
 
        public override void emit (CodeGenerator codegen) {