codegen: Add "error_pos" CCode attribute and use it as needed

This makes it possible to use non-standard error parameter positions
within the vala source.

Fixes https://gitlab.gnome.org/GNOME/vala/issues/728

1 files changed, 47 insertions, 0 deletions

diff --git a/tests/delegates/error-pos.vala b/tests/delegates/error-pos.vala
new file mode 100644
index 000000000..2e9301a68
--- /dev/null
+++ b/tests/delegates/error-pos.vala
@@ -0,0 +1,47 @@
+errordomain FooError {
+	BAR;
+}
+
+[CCode (error_pos = 1.8, instance_pos = 1.9)]
+delegate string FooFunc (int i) throws FooError;
+
+class Bar {
+	[CCode (error_pos = 0.8)]
+	public string foo (int i) throws FooError {
+		assert (this is Bar);
+		return "%i".printf (i);
+	}
+
+	[CCode (error_pos = 0.8)]
+	public string faz (int i) throws FooError {
+		assert (this is Bar);
+		throw new FooError.BAR ("%i".printf (i));
+	}
+}
+
+void foo (FooFunc f) {
+	try {
+		assert (f (23) == "23");
+	} catch {
+		assert_not_reached ();
+	}
+}
+
+void main () {
+	try {
+		var bar = new Bar ();
+		assert (bar.foo (42) == "42");
+		foo (bar.foo);
+	} catch {
+		assert_not_reached ();
+	}
+
+	try {
+		var bar = new Bar ();
+		bar.faz (42);
+	} catch (FooError.BAR e) {
+		assert (e.message == "42");
+	} catch {
+		assert_not_reached ();
+	}
+}