search

rust-lang / rust

Empowering everyone to build reliable and efficient software.
https://www.rust-lang.org
Other
98.77k stars 12.76k forks source link

Fix span of unsafe attribute diagnostic #133270

Open ehuss opened 1 day ago

ehuss commented 1 day ago

This fixes the span of the unsafe_attr_outside_unsafe diagnostic when the attribute uses cfg_attr and comes from a macro. Previously the span it was pointing to was in the wrong place (offset by 2 bytes in the start, and 1 byte in the end), causing a corrupt suggestion.

The problem is that the lint was trying to do manual byte manipulation of the Attribute span to get within the #[ and ] tokens. However, when the attribute comes from cfg_attr, that span starts from the attribute path (like no_mangle), not the #[ of the cfg_attr.

The solution here is to store the span of the AttrItem while parsing, so that we know for sure that it covers the correct range (the path and all args). We could not use AttrItem::span() (which is removed in this PR), because that function did not correctly account for the path and arguments coming from separate expansion contexts. For example, in the macro expansion of #[$p = $a], the span would be $p = because you are not allowed to generate a span across expansion contexts.

Fixes #132908

rustbot commented 1 day ago

r? @petrochenkov

rustbot has assigned @petrochenkov. They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

petrochenkov commented 3 hours ago

@bors try @rust-timer queue

rust-timer commented 3 hours ago

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

bors commented 3 hours ago

:hourglass: Trying commit 92fe7447af3f1483195a562d4149e2f6931792d6 with merge 46c9e3a092ea03e1b0a4f75f57a4c0997f490346...

bors commented 1 hour ago

:sunny: Try build successful - checks-actions Build commit: 46c9e3a092ea03e1b0a4f75f57a4c0997f490346 (46c9e3a092ea03e1b0a4f75f57a4c0997f490346)

rust-timer commented 1 hour ago

Queued 46c9e3a092ea03e1b0a4f75f57a4c0997f490346 with parent a7d9ebdf088f166e91759ec5b3b0625e3c1d0c82, future comparison URL. There is currently 1 preceding artifact in the queue. It will probably take at least ~2.2 hours until the benchmark run finishes.