gccrs: Prevent initialization related warnings/errors for Optional

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80635#c53

gcc/rust/ChangeLog:

	* util/rust-optional.h
	(class Optional): Add volatile field to union.

Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>

diff --git a/gcc/rust/util/rust-optional.h b/gcc/rust/util/rust-optional.h
index 30880cd41db0dd8722ad0b71c64d81f8f8d40e24..e545c1596cee2b22bb71ec021485bcf64b70b51e 100644 (file)
--- a/gcc/rust/util/rust-optional.h
+++ b/gcc/rust/util/rust-optional.h
@@ -86,6 +86,10 @@ private:
   union
   {
     T value;
+    // prevents initialization warnings
+    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80635#c53
+    // FIXME: remove
+    volatile char unused;
   };
 
   Optional (tag_some, const T &value) : field_is_some (true), value (value) {}