vala: Warn about unsupported cast to void and drop it

Fixes https://gitlab.gnome.org/GNOME/vala/issues/1070

diff --git a/tests/Makefile.am b/tests/Makefile.am
index ec9c97b13c69b2114782e31a80f6585a99da15b1..d84703e651e2384c6cf9132568dc3f69936cf4c2 100644 (file)
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -948,6 +948,7 @@ TESTS = \
        semantic/assignment-signal-incompatible-type.test \
        semantic/cast-gvalue-unsupported.test \
        semantic/cast-gvariant-unsupported.test \
+       semantic/cast-void-not-allowed.vala \
        semantic/chainup-gobject-incompatible-type-property.test \
        semantic/chainup-gobject-unknown-property.test \
        semantic/chainup-gobject-unsupported-type-property.test \
@@ -1043,7 +1044,6 @@ TESTS = \
        semantic/localvariable-var-static-access-instance-property.test \
        semantic/localvariable-var-without-initializer.test \
        semantic/localvariable-void.test \
-       semantic/localvariable-void-initializer.test \
        semantic/member-access-async-callback-invalid.test \
        semantic/member-access-capture-out.test \
        semantic/member-access-capture-valist-parameter.test \

diff --git a/tests/semantic/cast-void-not-allowed.vala b/tests/semantic/cast-void-not-allowed.vala
new file mode 100644 (file)
index 0000000..dee3801
--- /dev/null
+++ b/tests/semantic/cast-void-not-allowed.vala
@@ -0,0 +1,11 @@
+bool success = false;
+
+bool foo () {
+       success = true;
+       return true;
+}
+
+void main () {
+       (void) foo ();
+       assert (success);
+}

diff --git a/tests/semantic/localvariable-void-initializer.test b/tests/semantic/localvariable-void-initializer.test
deleted file mode 100644 (file)
index fbfbbff..0000000
--- a/tests/semantic/localvariable-void-initializer.test
+++ /dev/null
@@ -1,5 +0,0 @@
-Invalid Code
-
-void main () {
-       var foo = (void) "foo";
-}

diff --git a/vala/valacastexpression.vala b/vala/valacastexpression.vala
index 9aff511facdf317630004756c1aefd4aaee25983..1d1dbb0f2a3aa1841843b400f5d76504585f1b4f 100644 (file)
--- a/vala/valacastexpression.vala
+++ b/vala/valacastexpression.vala
@@ -164,6 +164,13 @@ public class Vala.CastExpression : Expression {
 
                // FIXME: check whether cast is allowed
 
+               if (type_reference is VoidType) {
+                       Report.warning (source_reference, "Casting to `void' is not supported");
+                       context.analyzer.replaced_nodes.add (this);
+                       parent_node.replace_expression (this, inner);
+                       return inner.check (context);
+               }
+
                if (type_reference is DelegateType && inner.value_type is MethodType) {
                        if (target_type != null) {
                                inner.value_type.value_owned = target_type.value_owned;