From fa69d6030a3e53967d72cf9b7ba428f3b35d0af5 Mon Sep 17 00:00:00 2001
From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Mon, 20 Jul 2020 20:11:13 +0200
Subject: [PATCH] vala: Allow prototype access to signal with emitter

Fixes https://gitlab.gnome.org/GNOME/vala/issues/1040
---
 tests/Makefile.am                             |  3 ++
 .../signals-prototype-access-invalid-2.test   | 12 +++++
 .../signals-prototype-access-invalid.test     | 16 +++++++
 tests/objects/signals-prototype-access.vala   | 47 +++++++++++++++++++
 vala/valamemberaccess.vala                    | 22 +++++++++
 vala/valasignal.vala                          |  6 ++-
 6 files changed, 104 insertions(+), 2 deletions(-)
 create mode 100644 tests/objects/signals-prototype-access-invalid-2.test
 create mode 100644 tests/objects/signals-prototype-access-invalid.test
 create mode 100644 tests/objects/signals-prototype-access.vala

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 7183499d7..49f2b3a99 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -416,6 +416,9 @@ TESTS = \
 	objects/signals-fundamental-return.vala \
 	objects/signals-gobject-return.vala \
 	objects/signals-lambda-delegate.vala \
+	objects/signals-prototype-access.vala \
+	objects/signals-prototype-access-invalid.test \
+	objects/signals-prototype-access-invalid-2.test \
 	objects/signals-struct-return.vala \
 	objects/singleton.vala \
 	objects/test-025.vala \
diff --git a/tests/objects/signals-prototype-access-invalid-2.test b/tests/objects/signals-prototype-access-invalid-2.test
new file mode 100644
index 000000000..ad1c800fb
--- /dev/null
+++ b/tests/objects/signals-prototype-access-invalid-2.test
@@ -0,0 +1,12 @@
+Invalid Code
+
+delegate void FooFunc ();
+
+class Foo {
+	public signal int bar ();
+}
+
+void main () {
+	var foo = new Foo ();
+	FooFunc func = Foo.bar;
+}
diff --git a/tests/objects/signals-prototype-access-invalid.test b/tests/objects/signals-prototype-access-invalid.test
new file mode 100644
index 000000000..83a1b79d7
--- /dev/null
+++ b/tests/objects/signals-prototype-access-invalid.test
@@ -0,0 +1,16 @@
+Invalid Code
+
+[CCode (has_target = false)]
+delegate void FooFunc (Foo foo);
+
+class Foo {
+	public signal int bar ();
+
+	public void manam (FooFunc func) {
+	}
+}
+
+void main () {
+	var foo = new Foo ();
+	foo.manam (Foo.bar);
+}
diff --git a/tests/objects/signals-prototype-access.vala b/tests/objects/signals-prototype-access.vala
new file mode 100644
index 000000000..39d70aeeb
--- /dev/null
+++ b/tests/objects/signals-prototype-access.vala
@@ -0,0 +1,47 @@
+[CCode (has_target = false)]
+delegate int FooFunc (Foo foo);
+
+delegate int BarFunc ();
+
+class Foo {
+	[HasEmitter]
+	public virtual signal int bar () {
+		return 23;
+	}
+
+	public void manam (FooFunc func) {
+		assert (func (this) == 23);
+	}
+
+	public void minim (BarFunc func) {
+		assert (func () == 23);
+	}
+}
+
+void main () {
+	var foo = new Foo ();
+	{
+		foo.manam (Foo.bar);
+		foo.manam ((FooFunc) Foo.bar);
+	}
+	{
+		FooFunc func = Foo.bar;
+		assert (func (foo) == 23);
+	}
+	{
+		FooFunc func = (FooFunc) Foo.bar;
+		assert (func (foo) == 23);
+	}
+	{
+		foo.minim (foo.bar);
+		foo.minim ((BarFunc) foo.bar);
+	}
+	{
+		BarFunc func = foo.bar;
+		assert (func () == 23);
+	}
+	{
+		BarFunc func = (BarFunc) foo.bar;
+		assert (func () == 23);
+	}
+}
diff --git a/vala/valamemberaccess.vala b/vala/valamemberaccess.vala
index 89e0a795f..2bb8d462d 100644
--- a/vala/valamemberaccess.vala
+++ b/vala/valamemberaccess.vala
@@ -512,6 +512,28 @@ public class Vala.MemberAccess : Expression {
 			return false;
 		}
 
+		if (symbol_reference is Signal) {
+			unowned Signal sig = (Signal) symbol_reference;
+			unowned CodeNode? ma = this;
+			while (ma.parent_node is MemberAccess) {
+				ma = ma.parent_node;
+			}
+			unowned CodeNode? parent = ma.parent_node;
+			if (parent != null && !(parent is ElementAccess) && !(((MemberAccess) ma).inner is BaseAccess)
+			    && (!(parent is MethodCall) || ((MethodCall) parent).get_argument_list ().contains (this))) {
+				if (sig.get_attribute ("HasEmitter") != null) {
+					if (!sig.check (context)) {
+						return false;
+					}
+					symbol_reference = sig.emitter;
+				} else {
+					error = true;
+					Report.error (source_reference, "Signal `%s' requires emitter in this context".printf (symbol_reference.get_full_name ()));
+					return false;
+				}
+			}
+		}
+
 		var member = symbol_reference;
 		var access = SymbolAccessibility.PUBLIC;
 		bool instance = false;
diff --git a/vala/valasignal.vala b/vala/valasignal.vala
index 2881c3b2f..a79fae7f5 100644
--- a/vala/valasignal.vala
+++ b/vala/valasignal.vala
@@ -250,7 +250,7 @@ public class Vala.Signal : Symbol, Callable {
 			default_handler.check (context);
 		}
 
-		if (!external_package && get_attribute ("HasEmitter") != null) {
+		if (get_attribute ("HasEmitter") != null) {
 			emitter = new Method (name, return_type, source_reference);
 
 			emitter.owner = owner;
@@ -274,7 +274,9 @@ public class Vala.Signal : Symbol, Callable {
 			var cl = parent_symbol as ObjectTypeSymbol;
 
 			cl.add_hidden_method (emitter);
-			emitter.check (context);
+			if (!external_package) {
+				emitter.check (context);
+			}
 		}
 
 
-- 
2.47.2