Move folding & visiting traits into type library #107924

eggyal · 2023-02-11T10:56:01Z

This is a rework of #107712, following feedback on that PR.

In particular, this version uses trait aliases to reduce the API churn for trait consumers. Doing so requires a workaround for #107747 until its fix in #107803 is merged into the stage0 compiler; this workaround, which uses conditional compilation based on the bootstrap configuration predicate, sits in dedicated commit b409329 for ease of reversion.

The possibility of the rustc_middle crate retaining its own distinct versions of each folding/visiting trait, blanket-implemented on all types that implement the respective trait in the type library, was also explored: however since this would necessitate making each rustc_middle trait a subtrait of the respective type library trait (so that such blanket implementations can delegate their generic methods), no benefit would be gained.

r? types

rustbot · 2023-02-11T10:56:11Z

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred to the core trait solver

cc @rust-lang/initiative-trait-system-refactor

Some changes occured in abstract_const.rs

cc @BoxyUwU

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

Some changes occurred in const_evaluatable.rs

cc @BoxyUwU

Some changes occurred to the CTFE / Miri engine

cc @rust-lang/miri

eggyal · 2023-02-11T11:04:17Z

I should add that, in contrast to the previous PR, this version splits methods from the TypeVisitable trait into an extension trait that is retained solely in rustc_middle.

jackh726 · 2023-02-11T18:43:03Z

r? @jackh726

bors · 2023-02-13T04:55:21Z

☔ The latest upstream changes (presumably #107869) made this pull request unmergeable. Please resolve the merge conflicts.

Only required until fix rust-lang#107803 is merged into stage0 compiler, expected when beta 1.69.0 is released on 2023-03-09, then this commit can be reverted.

compiler/rustc_middle/src/ty/layout.rs

oli-obk · 2023-02-13T12:34:54Z

@bors r+ p=5 (extremely bitrotty)

bors · 2023-02-13T12:34:56Z

📌 Commit 63ad5d0 has been approved by oli-obk

It is now in the queue for this repository.

bors · 2023-02-13T16:50:37Z

⌛ Testing commit 63ad5d0 with merge a3c9eed...

bors · 2023-02-13T20:22:44Z

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing a3c9eed to master...

rust-timer · 2023-02-13T21:41:30Z

Finished benchmarking commit (a3c9eed): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.5%	[0.3%, 0.6%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.0%	[1.0%, 1.0%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.1%	[-3.1%, -3.1%]	1
All ❌✅ (primary)	1.0%	[1.0%, 1.0%]	1

Cycles

This benchmark run did not return any relevant results for this metric.

…s, r=oli-obk Remove type-traversal trait aliases rust-lang#107924 moved the type traversal (folding and visiting) traits into the type library, but created trait aliases in `rustc_middle` to minimise both the API churn for trait consumers and the arising boilerplate. As mentioned in that PR, an alternative approach of defining subtraits with blanket implementations of the respective supertraits was also considered at that time but was ruled out as not adding much value. Unfortunately, it has since emerged that rust-analyzer has difficulty with these trait aliases at present, resulting in a degraded contributor experience (see the recent [r-a has become useless](https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/r-a.20has.20become.20useless) topic on the #t-compiler/help Zulip stream). This PR removes the trait aliases, and accordingly the underlying type library traits are now used directly; they are parameterised by `TyCtxt<'tcx>` rather than just the `'tcx` lifetime, and imports have been updated to reflect the fact that the trait aliases' explicitly named traits are no longer automatically brought into scope. These changes also roll-back the (no-longer required) workarounds to rust-lang#107747 that were made in b409329. Since this PR is just a find+replace together with the changes necessary for compilation & tidy to pass, it's currently just one mega-commit. Let me know if you'd like it broken up. r? `@oli-obk`

…e_lib_with_trait_alias, r=oli-obk Move folding & visiting traits into type library This is a rework of rust-lang#107712, following feedback on that PR. In particular, this version uses trait aliases to reduce the API churn for trait consumers. Doing so requires a workaround for rust-lang#107747 until its fix in rust-lang#107803 is merged into the stage0 compiler; this workaround, which uses conditional compilation based on the `bootstrap` configuration predicate, sits in dedicated commit b409329 for ease of reversion. The possibility of the `rustc_middle` crate retaining its own distinct versions of each folding/visiting trait, blanket-implemented on all types that implement the respective trait in the type library, was also explored: however since this would necessitate making each `rustc_middle` trait a subtrait of the respective type library trait (so that such blanket implementations can delegate their generic methods), no benefit would be gained. r? types

…s, r=oli-obk Remove type-traversal trait aliases rust-lang#107924 moved the type traversal (folding and visiting) traits into the type library, but created trait aliases in `rustc_middle` to minimise both the API churn for trait consumers and the arising boilerplate. As mentioned in that PR, an alternative approach of defining subtraits with blanket implementations of the respective supertraits was also considered at that time but was ruled out as not adding much value. Unfortunately, it has since emerged that rust-analyzer has difficulty with these trait aliases at present, resulting in a degraded contributor experience (see the recent [r-a has become useless](https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/r-a.20has.20become.20useless) topic on the #t-compiler/help Zulip stream). This PR removes the trait aliases, and accordingly the underlying type library traits are now used directly; they are parameterised by `TyCtxt<'tcx>` rather than just the `'tcx` lifetime, and imports have been updated to reflect the fact that the trait aliases' explicitly named traits are no longer automatically brought into scope. These changes also roll-back the (no-longer required) workarounds to rust-lang#107747 that were made in b409329. Since this PR is just a find+replace together with the changes necessary for compilation & tidy to pass, it's currently just one mega-commit. Let me know if you'd like it broken up. r? `@oli-obk`

rustbot assigned spastorino Feb 11, 2023

eggyal force-pushed the move_fold_visit_traits_to_type_lib_with_trait_alias branch from 456ad1f to 3915c4e Compare February 11, 2023 11:17

rustbot assigned jackh726 and unassigned spastorino Feb 11, 2023

eggyal added 12 commits February 13, 2023 10:24

Move folding & visiting traits to ir submodules

62846d7

Alias folding/visiting traits instead of re-export

ba55a45

Split TypeVisitableExt from TypeVisitable

36d09e3

Workaround issue rust-lang#107747

b409329

Only required until fix rust-lang#107803 is merged into stage0 compiler, expected when beta 1.69.0 is released on 2023-03-09, then this commit can be reverted.

Move TypeVisitableExt from ir module

e8d152d

Project Binder and Predicate from Interner trait

38c522c

Constrain Interners to be Sized

0b7dda9

Make visiting traits generic over the Interner

dea342d

Make folding traits generic over the Interner

9783fcc

Make atomic structural impls generic over Interner

9fa6bb2

Move folding and visiting traits into type library

459e142

Rename folder traits' tcx method to interner

63ad5d0

eggyal force-pushed the move_fold_visit_traits_to_type_lib_with_trait_alias branch from 3915c4e to 63ad5d0 Compare February 13, 2023 10:29

oli-obk reviewed Feb 13, 2023

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compiler/rustc_middle/src/ty/layout.rs Show resolved Hide resolved

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 13, 2023

bors added the merged-by-bors This PR was explicitly merged by bors. label Feb 13, 2023

bors merged commit a3c9eed into rust-lang:master Feb 13, 2023

rustbot added this to the 1.69.0 milestone Feb 13, 2023

eggyal deleted the move_fold_visit_traits_to_type_lib_with_trait_alias branch February 13, 2023 20:30

eggyal mentioned this pull request Feb 14, 2023

align rustc and chalk folder type rust-lang/types-team#31

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eggyal mentioned this pull request Feb 22, 2023

Remove type-traversal trait aliases #108340

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Move folding & visiting traits into type library #107924

Move folding & visiting traits into type library #107924

eggyal commented Feb 11, 2023 •

edited

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rustbot commented Feb 11, 2023

eggyal commented Feb 11, 2023

jackh726 commented Feb 11, 2023

bors commented Feb 13, 2023

oli-obk commented Feb 13, 2023

bors commented Feb 13, 2023

bors commented Feb 13, 2023

bors commented Feb 13, 2023

rust-timer commented Feb 13, 2023

Move folding & visiting traits into type library #107924

Move folding & visiting traits into type library #107924

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eggyal commented Feb 11, 2023 • edited Loading

rustbot commented Feb 11, 2023

eggyal commented Feb 11, 2023

jackh726 commented Feb 11, 2023

bors commented Feb 13, 2023

oli-obk commented Feb 13, 2023

bors commented Feb 13, 2023

bors commented Feb 13, 2023

bors commented Feb 13, 2023

rust-timer commented Feb 13, 2023

Overall result: ❌ regressions - no action needed

Instruction count

Max RSS (memory usage)

Cycles

eggyal commented Feb 11, 2023 •

edited

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