David Wood 7744a86963 lint/ctypes: stricter () return type checks ...

`()` is normally FFI-unsafe, but is FFI-safe when used as a return type.
It is also desirable that a transparent newtype for `()` is FFI-safe when
used as a return type.

In order to support this, when an type was deemed FFI-unsafe, because of
a `()` type, and was used in return type - then the type was considered
FFI-safe. However, this was the wrong approach - it didn't check that the
`()` was part of a transparent newtype! The consequence of this is that
the presence of a `()` type in a more complex return type would make it
the entire type be considered safe (as long as the `()` type was the
first that the lint found) - which is obviously incorrect.

Instead, this logic is removed, and a unit return type or a transparent
wrapper around a unit is checked for directly for functions and fn-ptrs.

Signed-off-by: David Wood <david@davidtw.co>
(cherry picked from commit f53cef31f5ea41c9a5ab8e5335637a6873b9f0b5)

2023-08-11 18:41:21 -07:00

..

src

lint/ctypes: stricter () return type checks

2023-08-11 18:41:21 -07:00

Cargo.toml

Add rustc_fluent_macro to decouple fluent from rustc_macros

2023-04-18 18:56:22 +00:00

messages.ftl

Rename cast_ref_to_mut lint to invalid_reference_casting

2023-08-11 18:37:37 -07:00