#[deprecated] decorator is missing on enum access functions #985
Description
If you declare a message with a deprecated enum field, like so:
message Shirt {
Color deprecated_color = 1 [deprecated = true];
}
enum Color {
BLUE = 0;
RED = 1;
GREEN = 2;
}You don't get a deprecation warning if you try to use the deprecated_color access functions:
// This produces a deprecation warning:
shirt.deprecated_color = Color::Blue as _;
// But this does not:
shirt.set_deprecated_color(Color::Blue);I've made a reproducer for this bug here: https://github.com/Orycterope/prost_deprecation_reproducer
It looks like this is because the generated structure correctly marks the field as deprecated but not the access functions generated by #[prost(enumeration = "Color", tag = "1")].
To see the actual function generated by the macro I had to use cargo expand:
cargo expand -p prost_reproducer_app --color always items | less -r
...
#[allow(dead_code)]
impl Shirt {
///Returns the enum value of `deprecated_color`, or the default if the field is set to an invalid enum value.
pub fn deprecated_color(&self) -> Color {
::core::convert::TryFrom::try_from(self.deprecated_color)
.unwrap_or(Color::default())
}
///Sets `deprecated_color` to the provided enum value.
pub fn set_deprecated_color(&mut self, value: Color) {
self.deprecated_color = value as i32;
}
}We can see that the functions have no #[deprecated] decorator attached to them. However, they do access deprecated_color internally, which should raise a warning. I don't know why rustc silences it (just because it's a macro ? Couldn't find anything about this behavior), but it does.