Various steps in moving away from the big reflection enum to reflection functions by oli-obk · Pull Request #159727 · rust-lang/rust

oli-obk · 2026-07-22T16:00:28Z

tracking issue: #146922

Some more of these and we can turn the big TyKind enum into one without any data, but I think these are enough steps for one PR, don't wanna turn it into a mega PR

rustbot · 2026-07-22T16:00:31Z

Some changes occurred to the CTFE machinery

cc @RalfJung, @lcnr

Some changes occurred to the intrinsics. Make sure the CTFE / Miri interpreter
gets adapted for the changes, if necessary.

cc @rust-lang/miri, @RalfJung, @lcnr

rustbot · 2026-07-22T16:00:34Z

r? @JohnTitor

rustbot has assigned @JohnTitor.
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

Why was this reviewer chosen?

The reviewer was selected based on:

Owners of files modified in this PR: compiler
compiler expanded to 74 candidates
Random selection from 20 candidates

@fmease

… r=fmease Enforce that we don't generate code for comptime fns ... by ICEing if you try to compute a symbol for them. There are various other ways we can assert it, but they were all a bit icky or already unreachable. r? @fmease (since you asked about it in rust-lang#159727 (comment))

@fmease

Rollup merge of #159777 - oli-obk:really-comptime-this-time, r=fmease Enforce that we don't generate code for comptime fns ... by ICEing if you try to compute a symbol for them. There are various other ways we can assert it, but they were all a bit icky or already unreachable. r? @fmease (since you asked about it in #159727 (comment))

@fmease

Enforce that we don't generate code for comptime fns ... by ICEing if you try to compute a symbol for them. There are various other ways we can assert it, but they were all a bit icky or already unreachable. r? @fmease (since you asked about it in rust-lang/rust#159727 (comment))

oli-obk · 2026-08-03T12:13:43Z

@JohnTitor this is ready for review

JohnTitor

Sorry for the delay!
r=me once my questions and @fmease's comment are resolved.

View changes since this review

rustbot · 2026-08-04T09:19:12Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

oli-obk · 2026-08-04T09:26:22Z

@bors r=JohnTitor

rust-bors · 2026-08-04T09:26:25Z

📌 Commit cecd4a4 has been approved by JohnTitor

It is now in the queue for this repository.

🌲 The tree is currently closed for pull requests below priority 10. This pull request will be tested once the tree is reopened.

Reason for tree closure: manually handling queue due to backlog

Various steps in moving away from the big reflection enum to reflection functions tracking issue: rust-lang#146922 Some more of these and we can turn the big TyKind enum into one without any data, but I think these are enough steps for one PR, don't wanna turn it into a mega PR

…uwer Rollup of 22 pull requests Successful merges: - #160426 (`rust-analyzer` subtree update) - #160372 (Derive the allocator used by tools from rustc's allocator) - #146882 (fully deprecate the legacy integral modules) - #158727 (std: use `readdir` on nearly all UNIX platforms) - #159727 (Various steps in moving away from the big reflection enum to reflection functions) - #160443 (normalize in relations, not generalize, when relating infer with alias) - #160457 (implement -Zllvm-target-feature) - #160480 (Single-pass ASCII lower/upper case conversion) - #160502 (Reduce number of miri tests executed on PR CI) - #157430 (std::random: use little-endian for reproducibility) - #158110 (fix macro attribute feature-gate span) - #159975 (Use real ThinVec in StmtDebugInfos) - #160001 (Suggest mutable method when iterating over binding) - #160024 (Fix mono reachability with no-op landing pads) - #160154 (Add regression test for HRTB associated type projection closure) - #160176 (No more `tests/ui/issues`!) - #160326 (Remove hidden_glob_reexports) - #160407 (Add regression tests for a number of ICEs and diagnostics issues labelled `E-needs-test`) - #160430 (bootstrap: Don't produce mutated/filtered PathSets during command-line matching) - #160472 (Minor fixes to `core::io` & `alloc::io` Documentation) - #160486 (Remove unused `FreeRegionsVisitor`) - #160496 (clarify non-determinism docs for algebraic operations) Failed merges: - #160501 (Add bootstrap CLI snapshot test for testing miri)

Rollup merge of #159727 - oli-obk:reflection_stuff, r=JohnTitor Various steps in moving away from the big reflection enum to reflection functions tracking issue: #146922 Some more of these and we can turn the big TyKind enum into one without any data, but I think these are enough steps for one PR, don't wanna turn it into a mega PR

…uwer Rollup of 22 pull requests Successful merges: - rust-lang/rust#160426 (`rust-analyzer` subtree update) - rust-lang/rust#160372 (Derive the allocator used by tools from rustc's allocator) - rust-lang/rust#146882 (fully deprecate the legacy integral modules) - rust-lang/rust#158727 (std: use `readdir` on nearly all UNIX platforms) - rust-lang/rust#159727 (Various steps in moving away from the big reflection enum to reflection functions) - rust-lang/rust#160443 (normalize in relations, not generalize, when relating infer with alias) - rust-lang/rust#160457 (implement -Zllvm-target-feature) - rust-lang/rust#160480 (Single-pass ASCII lower/upper case conversion) - rust-lang/rust#160502 (Reduce number of miri tests executed on PR CI) - rust-lang/rust#157430 (std::random: use little-endian for reproducibility) - rust-lang/rust#158110 (fix macro attribute feature-gate span) - rust-lang/rust#159975 (Use real ThinVec in StmtDebugInfos) - rust-lang/rust#160001 (Suggest mutable method when iterating over binding) - rust-lang/rust#160024 (Fix mono reachability with no-op landing pads) - rust-lang/rust#160154 (Add regression test for HRTB associated type projection closure) - rust-lang/rust#160176 (No more `tests/ui/issues`!) - rust-lang/rust#160326 (Remove hidden_glob_reexports) - rust-lang/rust#160407 (Add regression tests for a number of ICEs and diagnostics issues labelled `E-needs-test`) - rust-lang/rust#160430 (bootstrap: Don't produce mutated/filtered PathSets during command-line matching) - rust-lang/rust#160472 (Minor fixes to `core::io` & `alloc::io` Documentation) - rust-lang/rust#160486 (Remove unused `FreeRegionsVisitor`) - rust-lang/rust#160496 (clarify non-determinism docs for algebraic operations) Failed merges: - rust-lang/rust#160501 (Add bootstrap CLI snapshot test for testing miri)

JonathanBrouwer · 2026-08-06T20:18:15Z

@rust-timer build 114cbc0

rust-timer · 2026-08-06T22:52:45Z

Finished benchmarking commit (114cbc0): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.2%, 0.3%]	5
Regressions ❌ (secondary)	1.5%	[0.1%, 2.6%]	16
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.1%	[-0.1%, -0.1%]	3
All ❌✅ (primary)	0.2%	[0.2%, 0.3%]	5

Max RSS (memory usage)

Results (primary -0.4%, secondary 16.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.6%	[0.6%, 0.6%]	1
Regressions ❌ (secondary)	20.7%	[0.6%, 29.9%]	16
Improvements ✅ (primary)	-0.9%	[-1.2%, -0.6%]	2
Improvements ✅ (secondary)	-2.7%	[-6.2%, -0.4%]	4
All ❌✅ (primary)	-0.4%	[-1.2%, 0.6%]	3

Cycles

Results (primary 1.0%, secondary 8.6%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	1.4%	[0.6%, 3.3%]	4
Regressions ❌ (secondary)	10.6%	[0.4%, 30.7%]	28
Improvements ✅ (primary)	-0.5%	[-0.5%, -0.5%]	1
Improvements ✅ (secondary)	-5.8%	[-14.0%, -0.9%]	4
All ❌✅ (primary)	1.0%	[-0.5%, 3.3%]	5

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 489.825s -> 489.583s (-0.05%)
Artifact size: 391.14 MiB -> 392.10 MiB (0.24%)

oli-obk · 2026-08-07T06:50:55Z

Huh. None of this should be in any path reachable on stable

oli-obk · 2026-08-07T06:56:53Z

The huge serde regression is in live_symbols_and_ignored_derived_traits, which also shouldn't be affected by this PR

JonathanBrouwer · 2026-08-07T07:53:05Z

Something funky is going on, all PRs in the rollup have this same result

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 Jul 22, 2026

rustbot assigned JohnTitor Jul 22, 2026

rustbot added the T-libs Relevant to the library team, which will review and decide on the PR/issue. label Jul 22, 2026

This comment has been minimized.

Sign in to view

fmease reviewed Jul 23, 2026

View reviewed changes

Comment thread library/core/src/intrinsics/mod.rs Outdated

This was referenced Jul 23, 2026

Enforce that we don't generate code for comptime fns #159777

Merged

reflection and comptime rust-lang/goals#406

Open

oli-obk force-pushed the reflection_stuff branch from f2afff8 to 0214ef6 Compare July 28, 2026 06:50

This comment has been minimized.

Sign in to view

JohnTitor approved these changes Aug 3, 2026

View reviewed changes

Comment thread compiler/rustc_const_eval/src/const_eval/machine.rs Outdated

Comment thread library/coretests/tests/mem/type_info.rs Outdated

Add reflection method for field names

c7fc5f2

oli-obk force-pushed the reflection_stuff branch from 0214ef6 to a06add3 Compare August 4, 2026 09:19

oli-obk added 4 commits August 4, 2026 11:20

Add reflection method for field offsets

20d5e78

Add reflection method for fetching non-exhaustiveness

538f556

Generalize some arguments to allow more kinds of input

9381472

Add reflection method for getting a type's generic args

cecd4a4

oli-obk force-pushed the reflection_stuff branch from a06add3 to cecd4a4 Compare August 4, 2026 09:25

rust-bors Bot 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 Aug 4, 2026

This was referenced Aug 4, 2026

Rollup of 14 pull requests #160507

Closed

Rollup of 22 pull requests #160517

Merged

rust-bors Bot merged commit ad0ba38 into rust-lang:main Aug 5, 2026
13 checks passed

rustbot added this to the 1.99.0 milestone Aug 5, 2026

This comment has been minimized.

Sign in to view

rustbot added the perf-regression Performance regression. label Aug 6, 2026

oli-obk deleted the reflection_stuff branch August 7, 2026 06:50

Uh oh!

Uh oh!

Conversation

oli-obk commented Jul 22, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

rustbot commented Jul 22, 2026

Uh oh!

rustbot commented Jul 22, 2026

Uh oh!

This comment has been minimized.

Uh oh!

This comment has been minimized.

oli-obk commented Aug 3, 2026

Uh oh!

JohnTitor left a comment • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

rustbot commented Aug 4, 2026

Uh oh!

oli-obk commented Aug 4, 2026

Uh oh!

rust-bors Bot commented Aug 4, 2026

Uh oh!

Uh oh!

JonathanBrouwer commented Aug 6, 2026

Uh oh!

This comment has been minimized.

rust-timer commented Aug 6, 2026

Overall result: ❌✅ regressions and improvements - please read:

Instruction count

Max RSS (memory usage)

Cycles

Binary size

Uh oh!

oli-obk commented Aug 7, 2026

Uh oh!

oli-obk commented Aug 7, 2026

Uh oh!

JonathanBrouwer commented Aug 7, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

7 participants

oli-obk commented Jul 22, 2026 •

edited by rustbot

Loading

JohnTitor left a comment •

edited by rustbot

Loading