From f413cb32470d9c2598416772bc0166c6f974ec9f Mon Sep 17 00:00:00 2001
From: Simon Werbeck <simon.werbeck@gmail.com>
Date: Mon, 30 Sep 2019 16:37:33 +0200
Subject: [PATCH] codegen: Fix custom reference-counting for compact classes

This fix defers emitting G_DEFINE_AUTOPTR_CLEANUP_FUNC when a compact
class defines custom unref function and set by ccode "unref_function".
---
 codegen/valagtypemodule.vala                | 40 +++++++++++++++------
 tests/Makefile.am                           |  1 +
 tests/objects/compact-class-custom-ref.vala | 29 +++++++++++++++
 3 files changed, 60 insertions(+), 10 deletions(-)
 create mode 100644 tests/objects/compact-class-custom-ref.vala

diff --git a/codegen/valagtypemodule.vala b/codegen/valagtypemodule.vala
index 4eb7878a1..bae49b2c5 100644
--- a/codegen/valagtypemodule.vala
+++ b/codegen/valagtypemodule.vala
@@ -195,17 +195,21 @@ public class Vala.GTypeModule : GErrorModule {
 		while (base_class.base_class != null) {
 			base_class = base_class.base_class;
 		}
-		string autoptr_cleanup_func;
-		if (is_reference_counting (base_class)) {
-			autoptr_cleanup_func = get_ccode_unref_function (base_class);
-		} else {
-			autoptr_cleanup_func = get_ccode_free_function (base_class);
-		}
-		if (autoptr_cleanup_func == null || autoptr_cleanup_func == "") {
-			Report.error (cl.source_reference, "internal error: autoptr_cleanup_func not available");
+		// Custom unref-methods need to be emitted before G_DEFINE_AUTOPTR_CLEANUP_FUNC,
+		// so we guard against that special case and handle it in generate_method_declaration.
+		if (!(base_class.is_compact && is_reference_counting (base_class))) {
+			string autoptr_cleanup_func;
+			if (is_reference_counting (base_class)) {
+				autoptr_cleanup_func = get_ccode_unref_function (base_class);
+			} else {
+				autoptr_cleanup_func = get_ccode_free_function (base_class);
+			}
+			if (autoptr_cleanup_func == null || autoptr_cleanup_func == "") {
+				Report.error (cl.source_reference, "internal error: autoptr_cleanup_func not available");
+			}
+			decl_space.add_type_member_declaration (new CCodeIdentifier ("G_DEFINE_AUTOPTR_CLEANUP_FUNC (%s, %s)".printf (get_ccode_name (cl), autoptr_cleanup_func)));
+			decl_space.add_type_member_declaration (new CCodeNewline ());
 		}
-		decl_space.add_type_member_declaration (new CCodeIdentifier ("G_DEFINE_AUTOPTR_CLEANUP_FUNC (%s, %s)".printf (get_ccode_name (cl), autoptr_cleanup_func)));
-		decl_space.add_type_member_declaration (new CCodeNewline ());
 	}
 
 	public override void generate_class_struct_declaration (Class cl, CCodeFile decl_space) {
@@ -441,6 +445,22 @@ public class Vala.GTypeModule : GErrorModule {
 		}
 	}
 
+	public override bool generate_method_declaration (Method m, CCodeFile decl_space) {
+		if (base.generate_method_declaration (m, decl_space)) {
+			// Custom unref-methods need to be emitted before G_DEFINE_AUTOPTR_CLEANUP_FUNC,
+			// in addition to the non-ref-countable case in generate_class_declaration.
+			unowned Class? cl = m.parent_symbol as Class;
+			if (cl != null && cl.is_compact && get_ccode_unref_function (cl) == get_ccode_name (m)) {
+				decl_space.add_type_member_declaration (new CCodeIdentifier ("G_DEFINE_AUTOPTR_CLEANUP_FUNC (%s, %s)".printf (get_ccode_name (cl), get_ccode_name (m))));
+				decl_space.add_type_member_declaration (new CCodeNewline ());
+			}
+
+			return true;
+		}
+
+		return false;
+	}
+
 	public virtual void generate_virtual_method_declaration (Method m, CCodeFile decl_space, CCodeStruct type_struct) {
 		if (!m.is_abstract && !m.is_virtual) {
 			return;
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 011fefa1a..ba8f2b0c6 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -305,6 +305,7 @@ TESTS = \
 	objects/compact-class.vala \
 	objects/compact-class-destructor.vala \
 	objects/compact-class-refcount.vala \
+	objects/compact-class-custom-ref.vala \
 	objects/constructor-abstract-public.test \
 	objects/constructor-variadic.test \
 	objects/constructors.vala \
diff --git a/tests/objects/compact-class-custom-ref.vala b/tests/objects/compact-class-custom-ref.vala
new file mode 100644
index 000000000..7830665e1
--- /dev/null
+++ b/tests/objects/compact-class-custom-ref.vala
@@ -0,0 +1,29 @@
+[Compact]
+[CCode (ref_function = "foo_ref", unref_function = "foo_unref")]
+public class Foo {
+	[CCode (type = "volatile int")]
+	public int ref_count = 1;
+
+	public unowned Foo ref () {
+		AtomicInt.inc (ref ref_count);
+		return this;
+	}
+
+	public void unref () {
+		if (AtomicInt.dec_and_test (ref ref_count)) {
+			free ();
+		}
+	}
+
+	[DestroysInstance]
+	extern void free ();
+}
+
+void main () {
+	var foo = new Foo ();
+	assert(foo.ref_count == 1);
+	foo.ref ();
+	assert(foo.ref_count == 2);
+	foo.unref ();
+	assert(foo.ref_count == 1);
+}
-- 
2.47.2