From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Thu, 5 Apr 2018 06:22:25 +0000 (+0200)
Subject: vala: Check for matching ownership of type-arguments
X-Git-Tag: 0.43.1~127
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fmerge-requests%2F27%2Fhead;p=thirdparty%2Fvala.git

vala: Check for matching ownership of type-arguments

Non-boxed simple types can't be unowned and are therefore ignored.

Fixes https://gitlab.gnome.org/GNOME/vala/issues/696
---

diff --git a/tests/Makefile.am b/tests/Makefile.am
index fd0d24675..800284942 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -619,6 +619,7 @@ TESTS = \
 	semantic/struct-field-initializer.test \
 	semantic/struct-invalid-base.test \
 	semantic/struct-recursive.test \
+	semantic/type-argument-ownership-mismatch.test \
 	semantic/yield-call-requires-async-context.test \
 	semantic/yield-call-requires-async-method.test \
 	semantic/yield-creation-requires-async-context.test \
diff --git a/tests/semantic/type-argument-ownership-mismatch.test b/tests/semantic/type-argument-ownership-mismatch.test
new file mode 100644
index 000000000..a4dd9cb7e
--- /dev/null
+++ b/tests/semantic/type-argument-ownership-mismatch.test
@@ -0,0 +1,11 @@
+Invalid Code
+
+class Foo<T> {
+}
+
+Foo<string> foo () {
+	return new Foo<unowned string> ();
+}
+
+void main () {
+}
diff --git a/vala/valadatatype.vala b/vala/valadatatype.vala
index 8c52a4bfa..1e2f2c4cf 100644
--- a/vala/valadatatype.vala
+++ b/vala/valadatatype.vala
@@ -305,11 +305,25 @@ public abstract class Vala.DataType : CodeNode {
 			return true;
 		}
 
+		// check for matching ownership of type-arguments
+		var type_args = get_type_arguments ();
+		var target_type_args = target_type.get_type_arguments ();
+		if (type_args.size == target_type_args.size) {
+			for (int i = 0; i < type_args.size; i++) {
+				var type_arg = type_args[i];
+				var target_type_arg = target_type_args[i];
+				// Ignore non-boxed simple-type structs
+				if (!type_arg.is_non_null_simple_type ()
+				    && type_arg.is_weak () != target_type_arg.is_weak ()) {
+					return false;
+				}
+			}
+		}
+
 		if (data_type != null && target_type.data_type != null && data_type.is_subtype_of (target_type.data_type)) {
 			var base_type = SemanticAnalyzer.get_instance_base_type_for_member(this, target_type.data_type, this);
 			// check compatibility of generic type arguments
 			var base_type_args = base_type.get_type_arguments();
-			var target_type_args = target_type.get_type_arguments();
 			if (base_type_args.size == target_type_args.size) {
 				for (int i = 0; i < base_type_args.size; i++) {
 					// mutable generic types require type argument equality,
@@ -418,6 +432,14 @@ public abstract class Vala.DataType : CodeNode {
 		return is_real_struct_type () && !nullable;
 	}
 
+	bool is_non_null_simple_type () {
+		unowned Struct s = data_type as Struct;
+		if (s != null && s.is_simple_type ()) {
+			return !nullable;
+		}
+		return false;
+	}
+
 	/**
 	 * Returns whether the value needs to be disposed, i.e. whether
 	 * allocated memory or other resources need to be released when