From: Yotam Nachum <me@yotam.net>
Date: Sat, 6 Nov 2021 17:05:13 +0000 (+0200)
Subject: vala: Don't allow casting real structs to classes or simple-types
X-Git-Tag: 0.55.1~77
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af730d4eef2879b487fff6f949a01b69b3b78f5f;p=thirdparty%2Fvala.git

vala: Don't allow casting real structs to classes or simple-types

This led to C compiler errors or obvious runtimes failures.

Fixes https://gitlab.gnome.org/GNOME/vala/issues/1249
---

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 9a6c4b3f2..ad65913ce 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -345,6 +345,8 @@ TESTS = \
 	enums/bug763831.vala \
 	enums/bug780050.vala \
 	structs/cast-struct-boxed.vala \
+	structs/cast-struct-to-class.test \
+	structs/cast-struct-to-simple-struct.test \
 	structs/struct_only.vala \
 	structs/struct-base-types.vala \
 	structs/struct-boxed-cast.vala \
diff --git a/tests/structs/cast-struct-to-class.test b/tests/structs/cast-struct-to-class.test
new file mode 100644
index 000000000..c87931ea0
--- /dev/null
+++ b/tests/structs/cast-struct-to-class.test
@@ -0,0 +1,10 @@
+Invalid Code
+
+struct Foo {
+	public int i;
+}
+
+void main () {
+	Foo foo = { 42 };
+	Object bar = (Object) foo;
+}
diff --git a/tests/structs/cast-struct-to-simple-struct.test b/tests/structs/cast-struct-to-simple-struct.test
new file mode 100644
index 000000000..3cb6681fc
--- /dev/null
+++ b/tests/structs/cast-struct-to-simple-struct.test
@@ -0,0 +1,10 @@
+Invalid Code
+
+struct Foo {
+	public int i;
+}
+
+void main () {
+	Foo foo = { 42 };
+	int bar = (int) foo;
+}
diff --git a/vala/valacastexpression.vala b/vala/valacastexpression.vala
index 732b99a71..5d0783e41 100644
--- a/vala/valacastexpression.vala
+++ b/vala/valacastexpression.vala
@@ -170,6 +170,15 @@ public class Vala.CastExpression : Expression {
 			return false;
 		}
 
+		// Allow casting to array or pointer type
+		if (!(type_reference is ArrayType || type_reference is PointerType)) {
+			if (!type_reference.is_real_struct_type () && inner.value_type.is_real_struct_type ()
+			    && (context.profile != Profile.GOBJECT || !(is_gvariant (context, inner.value_type) || is_gvalue (context, inner.value_type)))) {
+				error = true;
+				Report.error (source_reference, "Casting of struct `%s' to `%s' is not allowed", inner.value_type.to_qualified_string (), type_reference.to_qualified_string ());
+			}
+		}
+
 		if (type_reference is DelegateType && inner.value_type is MethodType) {
 			if (target_type != null) {
 				inner.value_type.value_owned = target_type.value_owned;