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Simplify some code for lowering THIR patterns by Zalathar · Pull Request #136435 · rust-lang/rust

@rustbot rustbot added S-waiting-on-review

Status: Awaiting review from the assignee but also interested parties.

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Feb 2, 2025

bors added a commit to rust-lang-ci/rust that referenced this pull request

Feb 2, 2025 
Simplify some code for lowering THIR patterns

I've been playing around with some radically different ways of storing THIR patterns, and while those experiments haven't yet produced a clear win, I have noticed various smaller things in the existing code that can be made a bit nicer.

Some of the more significant changes:
- With a little bit of extra effort (and thoughtful use of Arc), we can completely remove an entire layer of `'pat` lifetimes from the intermediate data structures used for match lowering.
- In several places, lists of THIR patterns were being double-boxed for no apparent reason.

@Zalathar 

By storing `PatRange` in an Arc, and copying a few fields out of `Pat`, we can
greatly simplify the lifetimes involved in match lowering.
These particular patterns make it harder to experiment with alternate
representations for THIR patterns and subpatterns.

@Zalathar 

This does mean that we have to resolve the list of arm IDs twice, but it's
unclear whether that even matters, whereas the cleaner signature is a nice
improvement.

@bors bors added S-waiting-on-bors

Status: Waiting on bors to run and complete tests. Bors will change the label on completion.

and removed S-waiting-on-review

Status: Awaiting review from the assignee but also interested parties.

labels

Feb 4, 2025

bors added a commit to rust-lang-ci/rust that referenced this pull request

Feb 6, 2025 
…iaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#136073 (Always compute coroutine layout for eagerly emitting recursive layout errors)
 - rust-lang#136235 (Pretty print pattern type values with transmute if they don't satisfy their pattern)
 - rust-lang#136311 (Ensure that we never try to monomorphize the upcasting or vtable calls of impossible dyn types)
 - rust-lang#136315 (Use short ty string for binop and unop errors)
 - rust-lang#136393 (Fix accidentally not emitting overflowing literals lints anymore in patterns)
 - rust-lang#136435 (Simplify some code for lowering THIR patterns)
 - rust-lang#136630 (Change two std process tests to not output to std{out,err}, and fix test suite stat reset in bootstrap CI test rendering)

r? `@ghost`
`@rustbot` modify labels: rollup

bors added a commit to rust-lang-ci/rust that referenced this pull request

Feb 6, 2025 
Rollup of 7 pull requests

Successful merges:

 - rust-lang#136073 (Always compute coroutine layout for eagerly emitting recursive layout errors)
 - rust-lang#136235 (Pretty print pattern type values with transmute if they don't satisfy their pattern)
 - rust-lang#136311 (Ensure that we never try to monomorphize the upcasting or vtable calls of impossible dyn types)
 - rust-lang#136315 (Use short ty string for binop and unop errors)
 - rust-lang#136393 (Fix accidentally not emitting overflowing literals lints anymore in patterns)
 - rust-lang#136435 (Simplify some code for lowering THIR patterns)
 - rust-lang#136630 (Change two std process tests to not output to std{out,err}, and fix test suite stat reset in bootstrap CI test rendering)

r? `@ghost`
`@rustbot` modify labels: rollup

try-job: aarch64-gnu-debug

bors added a commit to rust-lang-ci/rust that referenced this pull request

Feb 6, 2025 
…iaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#136073 (Always compute coroutine layout for eagerly emitting recursive layout errors)
 - rust-lang#136235 (Pretty print pattern type values with transmute if they don't satisfy their pattern)
 - rust-lang#136311 (Ensure that we never try to monomorphize the upcasting or vtable calls of impossible dyn types)
 - rust-lang#136315 (Use short ty string for binop and unop errors)
 - rust-lang#136393 (Fix accidentally not emitting overflowing literals lints anymore in patterns)
 - rust-lang#136435 (Simplify some code for lowering THIR patterns)
 - rust-lang#136630 (Change two std process tests to not output to std{out,err}, and fix test suite stat reset in bootstrap CI test rendering)

r? `@ghost`
`@rustbot` modify labels: rollup

try-job: aarch64-gnu-debug

rust-timer added a commit to rust-lang-ci/rust that referenced this pull request

Feb 6, 2025 
Rollup merge of rust-lang#136435 - Zalathar:thir-pat-stuff, r=Nadrieril

Simplify some code for lowering THIR patterns

I've been playing around with some radically different ways of storing THIR patterns, and while those experiments haven't yet produced a clear win, I have noticed various smaller things in the existing code that can be made a bit nicer.

Some of the more significant changes:
- With a little bit of extra effort (and thoughtful use of Arc), we can completely remove an entire layer of `'pat` lifetimes from the intermediate data structures used for match lowering.
- In several places, lists of THIR patterns were being double-boxed for no apparent reason.

flip1995 pushed a commit to flip1995/rust that referenced this pull request

Feb 20, 2025 
…iaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#136073 (Always compute coroutine layout for eagerly emitting recursive layout errors)
 - rust-lang#136235 (Pretty print pattern type values with transmute if they don't satisfy their pattern)
 - rust-lang#136311 (Ensure that we never try to monomorphize the upcasting or vtable calls of impossible dyn types)
 - rust-lang#136315 (Use short ty string for binop and unop errors)
 - rust-lang#136393 (Fix accidentally not emitting overflowing literals lints anymore in patterns)
 - rust-lang#136435 (Simplify some code for lowering THIR patterns)
 - rust-lang#136630 (Change two std process tests to not output to std{out,err}, and fix test suite stat reset in bootstrap CI test rendering)

r? `@ghost`
`@rustbot` modify labels: rollup

try-job: aarch64-gnu-debug