"ctypes" lint name is confusing

[brson]

I just wrote #[allow(ctypes)] which means "allow non-c types".

[brson]

ffi_rust_types is more accurate.

[nathantypanski]

Aren't they literally "types from C", or "C-compatible data types"?

I think it's an analogy to the ctypes Python module.

[brson]

@nathantypanski yes, but the problem is not with the meaning of "ctypes" but with the pairing of "allow" and "ctypes".

When you read the words "allow ctypes" you intuitively think, "by typing these words I am allowed to use C types", but that is not what #[allow(ctypes)] means: it means "allow me to not use C types".

[Rdbaker]

So would one just need to change every occurrence of CTYPES in src/librustc/lint/builtin.rs to FFI_RUST_TYPES?

[Rdbaker]

@brson I realize this probably isn't high on the priority list, but I would really appreciate if you took a look at my PR

[Manishearth]

This is now called improper_ctypes.