[swap] lints now check if there is no_std or no_core attribute

[dswij]

Closes #7858

changelog: [swap] lints now check if there is no_std or no_core attribute

[rust-highfive]

r? @camsteffen

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[camsteffen]

Could use one more util std_or_core() -> Option<&'static str>. Shouldn't use empty strings as "none"`.

[dswij]

Was going for a direct return there on the last else statement, but I did this as a workaround since if_not_else is warning this

    let sugg = if !is_no_std_crate(cx) {
        "std"
    } else if !is_no_core_crate(cx) {
        "core"
    } else {
        return;
    };

Now that #7895 is merged, I think we can go for the above, wdyt?

[camsteffen]

I think std_or_core would be good to have in clippy_utils. You could sneak in a let-else.

let Some(sugg) = std_or_core(cx) else { return };

[dswij]

let-else sounds amazing

[dswij]

Oh whoops, semicolon-if-nothing-returned FP on this?

let Some(sugg) = std_or_core(cx) else { return };

produces

   --> src/swap.rs:116:5
    |
116 |     let Some(sugg) = std_or_core(cx) else { return };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add a `;` here: `let Some(sugg) = std_or_core(cx) else { return };;`
    |
    = note: `-D clippy::semicolon-if-nothing-returned` implied by `-D clippy::pedantic`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#semicolon_if_nothing_returned

I will open an issue for this

[camsteffen]

LGTM but we need to do something about the false positive in the CI build. Would you be interested in fixing that in another PR?

[dswij]

FP in CI build should be fixed by #7955 🙂

[camsteffen]

Nice. Can you squash some commits?

[dswij]

Nice. Can you squash some commits?

Done

[camsteffen]

@bors r+ thanks!

[bors]

📌 Commit dcd1a16 has been approved by camsteffen

[bors]

⌛ Testing commit dcd1a16 with merge 8389df9...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: camsteffen
Pushing 8389df9 to master...