rust/compiler/rustc_mir_build/src/thir/cx/expr.rs, branch autohttps://github.com/rust-lang/rust
http://git.dreamy.place/mirrors/rust/atom?h=auto2025-09-09T12:49:16+00:00erase_regions to erase_and_anonymize_regions2025-09-09T12:49:16+00:00Boxyrust@boxyuwu.dev2025-08-21T15:50:54+00:00urn:sha1:e379c7758667f900aaf5551c4553c7d4c121e3e1loop match: error on `#[const_continue]` outside `#[loop_match]`2025-07-31T22:28:52+00:00Folkert de Vriesfolkert@folkertdev.nl2025-07-25T13:18:51+00:00urn:sha1:040f71e8123b5994177f787e64aecd9b06cdfa7eremove rustc_attr_data_structures2025-07-31T12:19:27+00:00Jana Dönszelmannjana@donsz.nl2025-07-31T09:00:40+00:00urn:sha1:e1d3ad89c7a2ad4f5d944a7fee1298ffe8c99645fix: Reject upvar scrutinees for `loop_match`2025-07-28T13:24:58+00:00Shoyu Vanillamodulo641@gmail.com2025-07-25T14:07:13+00:00urn:sha1:d87b4f2c77add3404f7469ea72f1d7c51e2a29dcuse let chains in hir, lint, mir2025-07-28T01:10:14+00:00KivooeoKivooeo123@gmail.com2025-07-26T01:21:54+00:00urn:sha1:bae38bad7803be7fdf1878188da9650f82548016loop match: run exhaustiveness check2025-07-01T13:53:50+00:00Folkert de Vriesfolkert@folkertdev.nl2025-07-01T13:29:09+00:00urn:sha1:aa7cc5d2f453853a4025cf029f3e42625c7e1e18Rollup merge of #138780 - trifectatechfoundation:loop_match_attr, r=oli-obk,traviscross2025-06-25T02:45:30+00:00Jubileeworkingjubilee@gmail.com2025-06-25T02:45:30+00:00urn:sha1:f542909d1ceae371fe0e236e00276109522fa86d
Add `#[loop_match]` for improved DFA codegen
tracking issue: https://github.com/rust-lang/rust/issues/132306
project goal: https://github.com/rust-lang/rust-project-goals/issues/258
This PR adds the `#[loop_match]` attribute, which aims to improve code generation for state machines. For some (very exciting) benchmarks, see https://github.com/rust-lang/rust-project-goals/issues/258#issuecomment-2732965199
Currently, a very restricted syntax pattern is accepted. We'd like to get feedback and merge this now before we go too far in a direction that others have concerns with.
## current state
We accept code that looks like this
```rust
#[loop_match]
loop {
state = 'blk: {
match state {
State::A => {
#[const_continue]
break 'blk State::B
}
State::B => { /* ... */ }
/* ... */
}
}
}
```
- a loop should have the same semantics with and without `#[loop_match]`: normal `continue` and `break` continue to work
- `#[const_continue]` is only allowed in loops annotated with `#[loop_match]`
- the loop body needs to have this particular shape (a single assignment to the match scrutinee, with the body a labelled block containing just a match)
## future work
- perform const evaluation on the `break` value
- support more state/scrutinee types
## maybe future work
- allow `continue 'label value` syntax, which `#[const_continue]` could then use.
- allow the match to be on an arbitrary expression (e.g. `State::Initial`)
- attempt to also optimize `break`/`continue` expressions that are not marked with `#[const_continue]`
r? ``@traviscross``
Add `#[loop_match]` for improved DFA codegen2025-06-23T18:43:04+00:00bjorn317426603+bjorn3@users.noreply.github.com2025-02-18T13:16:57+00:00urn:sha1:ba5556d239c11232dc8d95123ea70a2783019476
Co-authored-by: Folkert de Vries <folkert@folkertdev.nl>
Move the place in `&pin mut $place` when `!Unpin` to ensure soundness2025-06-15T02:31:11+00:00Frank Kingfrankking1729@gmail.com2025-04-04T04:15:23+00:00urn:sha1:afdb54a673243c83660417b540af888f7690f0fbImplement pinned borrows, part of `pin_ergonomics`2025-06-15T02:21:29+00:00Frank Kingfrankking1729@gmail.com2025-01-19T14:01:11+00:00urn:sha1:e627f88f88de85cc52ff1c99a076909084806c98