Fix as many clippy problems as possible

[mrobinson]

Steps:

1. Get Servo building and running locally following project documentation at http://github.com/servo/servo.
2. Run ./mach cargo-clippy
3. Fix an issue by understanding what the error means and correcting the issue. For instance

warning: redundant field names in struct initialization
   --> components/remutex/lib.rs:168:13
    |
168 |             data: data,
    |             ^^^^^^^^^^ help: replace it with: `data`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
    = note: `#[warn(clippy::redundant_field_names)]` on by default

In this case `data: data` can just be replaced with `data`.

4. Open an pull request with your fix, filling out the template, and giving it a full name like the following "clippy: Fix a redundant field warning in components/remutex/lib.rs.
5. Include a link to this issue in your pull request description body.

As this issue is large enough to be worked on in parallel, please don't ask to assign it to yourself. If you want to post fixes for a particular section of code, just check the PRs linked here to make sure that you are fixing different issues.

[Payne680]

@mrobinson Please I will love to work on this task but can you give some resources on how to successfully run the project locally ?

[Loirooriol]

BTW, some of the clippy warnings can be fixed automatically, e.g.

CARGO_BUILD_RUSTC=rustc cargo clippy --fix -p layout_2020 --broken-code

will apply some fixes automatically in the layout_2020 crate (and its tests). But some warnings need to be addressed manually.

Note that this can mess up the formatting, so remember to run ./mach fmt afterwards.

[mrobinson]

BTW, some of the clippy warnings can be fixed automatically, e.g.

CARGO_BUILD_RUSTC=rustc cargo clippy --fix -p layout_2020 --broken-code

will apply some fixes automatically in the layout_2020 crate (and its tests). But some warnings need to be addressed manually.

Note that this can mess up the formatting, so remember to run ./mach fmt afterwards.

I do not recommend using clippy --fix as a new contributor actually. Sometimes it can change the logical meaning of the code that it changes, so it is better to do the fix manually. It's also a good way to start understanding a bit of the Servo code.

[eerii]

I'm going to copy this here since now the big pr is split into multiple ones, and it can be helpful so people looking to fix new warnings can know where to continue:

The prs above are fixes for most warnings until net is compiled, excluding:

• result_unit_err: use a custom Error type instead of Result<_, ()>
• missing_safety_doc: unsafe function's docs miss # Safety section

They also hopefully remove all clippy errors until script is compiled, so more warnings can be caught.

The next steps to tackle would be:

• Fix the remaining net warnings
• Create proper Error types for the first warnings
• Write safety documentation (probably best to leave it for someone that is familiar with the unsafe code in the project)
• Tackle script, which has 27358 ~2500 warnings and 433 10 errors

Edit: Update work that was already completed

[jahielkomu]

Hello everyone.
Is it just me or is ./mach cargo-clippy actually producing an error?

[sagudev]

What error?

[jahielkomu]

What error?

Thanks for asking @sagudev.
I have pasted what I get in this pastebin, https://paste.mozilla.org/Ea3ohjZt

It might be an isolated incident on my end.
Kindly advise how to go about it.

[sagudev]

This is due to #32208, you might need to do mach clean and mach bootstrap again (also make sure to have stable internet connection).

[jahielkomu]

This is due to #32208, you might need to do mach clean and mach bootstrap again (also make sure to have stable internet connection).

Alright, thanks again.
Let me do that.