[vala/wip/issue/658: 39/48] Handle ref/out error msgs for anonymous delegates

[Rico Tzschichholz <ricotz src gnome org>]

commit 48e899710ef4290677e7370eccefbdc545b87359
Author: Nick Schrader <nick schrader mailbox org>
Date:   Sun Oct 25 18:47:52 2020 -0300

    Handle ref/out error msgs for anonymous delegates

 tests/Makefile.am                            |  3 +++
 tests/delegates/anonymous-inner-ref-out.vala | 24 ++++++++++++++++++++++++
 tests/delegates/anonymous-out.test           | 15 +++++++++++++++
 tests/delegates/anonymous-ref.test           | 15 +++++++++++++++
 vala/valaparser.vala                         | 11 +++++++++++
 5 files changed, 68 insertions(+)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index df58af998..ba5f24a1d 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -341,8 +341,11 @@ TESTS = \
        delegates/anonymous.vala \
        delegates/anonymous-array.vala \
        delegates/anonymous-generics.test \
+       delegates/anonymous-inner-ref-out.vala \
        delegates/anonymous-optional-param.test \
+       delegates/anonymous-out.test \
        delegates/anonymous-params.test \
+       delegates/anonymous-ref.test \
        delegates/anonymous-throws.test \
        delegates/anonymous-type-param.vala \
        delegates/anonymous-variadic.test \
diff --git a/tests/delegates/anonymous-inner-ref-out.vala b/tests/delegates/anonymous-inner-ref-out.vala
new file mode 100644
index 000000000..a4a268a63
--- /dev/null
+++ b/tests/delegates/anonymous-inner-ref-out.vala
@@ -0,0 +1,24 @@
+void main() {
+    f(t);
+    g(d);
+}
+
+void f(delegate(ref int) => void x) {
+    int i = 42;
+    x(ref i);
+    assert (i == 7);
+}
+
+void g(delegate(out int) => void y) {
+    int i;
+    y(out i);
+    assert (i == 42);
+}
+
+void t(ref int a) {
+    a = 7;
+}
+
+void d(out int a) {
+    a = 42;
+}
diff --git a/tests/delegates/anonymous-out.test b/tests/delegates/anonymous-out.test
new file mode 100644
index 000000000..30105b705
--- /dev/null
+++ b/tests/delegates/anonymous-out.test
@@ -0,0 +1,15 @@
+Invalid Code
+
+/*
+ * 13.8-13.32: error: Anonymous delegates cannot be `out` parameters
+ * void f(ref delegate(int) => void x) {
+ *        ^^^^^^^^^^^^^^^^^^^^^^^^^
+ */
+
+void main() {
+    assert (true);
+}
+
+void f(out delegate(int) => void x) {
+    x(42);
+}
diff --git a/tests/delegates/anonymous-ref.test b/tests/delegates/anonymous-ref.test
new file mode 100644
index 000000000..6bcc73b88
--- /dev/null
+++ b/tests/delegates/anonymous-ref.test
@@ -0,0 +1,15 @@
+Invalid Code
+
+/*
+ * 13.8-13.32: error: Anonymous delegates cannot be `ref` parameters
+ * void f(ref delegate(int) => void x) {
+ *        ^^^^^^^^^^^^^^^^^^^^^^^^^
+ */
+
+void main() {
+    assert (true);
+}
+
+void f(ref delegate(int) => void x) {
+    x(42);
+}
diff --git a/vala/valaparser.vala b/vala/valaparser.vala
index 7a5ad9bb5..785cb206c 100644
--- a/vala/valaparser.vala
+++ b/vala/valaparser.vala
@@ -3550,16 +3550,27 @@ public class Vala.Parser : CodeVisitor {
                }
 
                DataType type;
+               string pretty_direction = null;
                if (direction == ParameterDirection.IN) {
                        // in parameters are unowned by default
                        type = parse_type (false, false, false, parent, method);
                } else if (direction == ParameterDirection.REF) {
                        // ref parameters own the value by default
                        type = parse_type (true, true, false, parent, method);
+                       pretty_direction = "ref";
                } else {
                        // out parameters own the value by default
                        type = parse_type (true, false, false, parent, method);
+                       pretty_direction = "out";
                }
+
+               var possibly_delegate = type as DelegateType;
+               if (possibly_delegate != null 
+                               && possibly_delegate.delegate_symbol.anonymous 
+                               && pretty_direction != null) {
+                       Report.error (get_src (begin), "Anonymous delegates cannot be `" + pretty_direction + 
"` parameters");
+               }
+
                string id = parse_identifier ();
 
                type = parse_inline_array_type (type);