Attribute panic when applying clippy attributes to new

[thedrow]

🐛 Bug Reports

When reporting a bug, please provide the following information. If this is not a bug report you can just discard this template.

🌍 Environment

• Your operating system and version: Ubuntu 18.04
• Your python version: 3.7
• How did you install python (e.g. apt or pyenv)? Did you use a virtualenv?: pyenv, yes
• Your rust version (rustc --version): rustc 1.37.0-nightly (17e62f77f 2019-07-01)
• Are you using the latest pyo3 version? Have you tried using latest master (replace version = "0.x.y" with git = "https://github.com/PyO3/pyo3")? I'm using 0.7.0. Haven't tried with master

💥 Reproducing

   #[pymethods]
    impl UUID {
        #[new]
        #[allow(clippy::too_many_arguments)]
        #[allow(clippy::new_ret_no_self)]
        fn new(
            obj: &PyRawObject,
            hex: Option<&str>,
            bytes: Option<Py<PyBytes>>,
            bytes_le: Option<Py<PyBytes>>,
            fields: Option<Py<PyTuple>>,
            int: Option<u128>,
            version: Option<u8>,
            py: Python,
        ) -> PyResult<()> {}

This results in the following error:

error: custom attribute panicked
  --> src/lib.rs:23:5
   |
23 |     #[pymethods]
   |     ^^^^^^^^^^^^
   |
   = help: message: called `Option::unwrap()` on a `None` value

I'd like to disable some clippy warnings which are not relevant in PyO3 or for my code.
This is currently not possible.

[vitaly-burovoy]

It seems the correct variant is to move "allow" lines right before the "impl" (wrapped by the "pymethods") block:

#[allow(clippy::new_ret_no_self)]
#[allow(clippy::too_many_arguments)]
#[pymethods]
impl UUID {
    #[new]
    fn new(
        obj: &PyRawObject,
        hex: Option<&str>,
        bytes: Option<Py<PyBytes>>,
        bytes_le: Option<Py<PyBytes>>,
        fields: Option<Py<PyTuple>>,
        int: Option<u128>,
        version: Option<u8>,
        py: Python,
    ) -> PyResult<()> {}

[thedrow]

Which is fine I guess but it applies to the entire implementation instead of one function.

[althonos]

What happens with

#[pymethods]
impl UUID {
        #[allow(clippy::too_many_arguments)]
        #[allow(clippy::new_ret_no_self)]
        #[new]
        fn new(
           ...
        ) -> PyResult<()> {}
}

?

[thedrow]

Same panic.

[vitaly-burovoy]

Which is fine I guess but it applies to the entire implementation instead of one function.

No, it applies just to a block. You can limit this attribute to a single function just moving it to a different "impl" block:

#[allow(clippy::new_ret_no_self)]
#[allow(clippy::too_many_arguments)]
#[pymethods]
impl UUID {
    #[new]
    fn new(
        obj: &PyRawObject,
        hex: Option<&str>,
        bytes: Option<Py<PyBytes>>,
        bytes_le: Option<Py<PyBytes>>,
        fields: Option<Py<PyTuple>>,
        int: Option<u128>,
        version: Option<u8>,
        py: Python,
    ) -> PyResult<()> {...}
}

#[pymethods]
impl UUID {
// Here is no "clippy::too_many_arguments" allowed
    fn other_method(...) {...}
...
}

[thedrow]

I guess that's a workaround but we should fix this bug anyway.

[Alexander-N]

Can't reproduce. @thedrow Could you try with the current master?

[thedrow]

This bug is fixed with 0.8.0.
I didn't even need to try master.