fix fp when [undocumented_unsafe_blocks] not able to detect comment on globally defined const/static variables

[J-ZhengLi]

fixes: #11246

changelog: fix detection on global variables for [undocumented_unsafe_blocks]

[rustbot]

r? @Centri3

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[J-ZhengLi]

I'm only 70% sure of this... so, can someone please confirm this for me? 😆

(also please forgive my terrible English...)

[Centri3]

I think this is because a const's initializer is a body, and when getting a body's value's parent it'll get wherever the body's used; see the HIR for const A: u32 = { 0 }: https://rust.godbolt.org/z/3cY4vaq6T

So this is getting the Expr every other time, yet here, it's getting the Const/Static, then nothing, afaik? So maybe we just need to handle ItemKind::Const and ItemKind::Static parents as well.

I think we already do that so maybe the issue is somewhere within that block.

[J-ZhengLi]

wait a minute, I think I unintentionally increase the search span for other scenarios (actually not, but the search span for module level const/static was too big because I forgor to add a break), let me see if I can find a better solution

[Centri3]

Interestingly, unnecessary_safety_comment doesn't have the same issue despite mostly sharing the same code. I'll see if we can replicate what it does since it looks like there is an issue in block_has_safety_comment or block_parents_have_safety_comment that stmt_has_safety_comment doesn't have.

[J-ZhengLi]

Interestingly, unnecessary_safety_comment doesn't have the same issue despite mostly sharing the same code. I'll see if we can replicate what it does since it looks like there is an issue in block_has_safety_comment or block_parents_have_safety_comment that stmt_has_safety_comment doesn't have.

it is the get_body_search_span function that's causing troubles, I think...

the rest of change I've made was mainly refractoring. _{tbh I had trouble understanding most of its code lol}

[Centri3]

This version looks fine to me. I don't particularly like maybe_global_var but ah well; I have nothing to suggest over it.

@bors r+

[bors]

📌 Commit 6eec4a3 has been approved by Centri3

It is now in the queue for this repository.

[bors]

⌛ Testing commit 6eec4a3 with merge bcf856b...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: Centri3
Pushing bcf856b to master...