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Don't lint against named labels in naked_asm! #140871

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Don't lint against named labels in naked_asm! #140871

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@Amanieu Amanieu commented May 9, 2025

Naked functions are allowed to define global labels, just like global_asm!.

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rustbot commented May 9, 2025

r? @davidtwco

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@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels May 9, 2025
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@Amanieu
Don't lint against named labels in naked_asm!
6541903 
Naked functions are allowed to define global labels, just like
`global_asm!`.
@Amanieu Amanieu force-pushed the naked-asm-label branch from 7c3764e to 6541903 Compare May 9, 2025 22:11
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The previous attempt to allow this functionality in #88169. The justification in this PR doesn't really address what has changed since then to now. Could you please flesh out an explanation that touches on some of what was discussed in that PR?

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@rustbot rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels May 10, 2025
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tests/ui/asm/named-asm-labels.rs
Comment on lines -174 to -175
// Trigger on naked fns too, even though they can't be inlined, reusing a
// label or LTO can cause labels to break
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Why is this not a valid concern?

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I don't think the original reasoning for closing #88169 was correct (even though it did come from me). Fundamentally there's no reason why you can't define global symbols in naked functions, the issue is only with local symbols (.Lfoo) which are local to the object file (rustc doesn't guarantee that each asm block is in a separate object file).

In any case #128004 changed naked functions to use global_asm! internally so there's no reason to treat it different (this lint is already disabled for global_asm!).

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