Add eval hack in `super_relate_consts` back #103279

compiler-errors · 2022-10-20T02:04:13Z

Partially reverts 01adb7e.

This extra eval call still needs to happen, for example, in normalize_param_env_or_error when a param-env predicate has an unnormalized constant, since the param-env candidates never get normalized during candidate assembly (everywhere else we can assume that they are normalized fully).

r? @lcnr, though I feel like I've assigned quite a few PRs to you in the last few days, so feel free to reassign to someone else familiar with this code if you're busy!

cc #103243 (fixes the issue, but don't want to auto-close that until a backport is performed).

Mark-Simulacrum · 2022-10-20T02:24:30Z

Beta nominating (fixes regression).

rustbot · 2022-10-20T03:03:34Z

Some changes occurred to the CTFE / Miri engine

cc @rust-lang/miri

compiler-errors · 2022-10-20T03:04:57Z

The second commit in this stack suppresses a few triggered debug assertions (

rust/compiler/rustc_trait_selection/src/traits/codegen.rs

Line 28 in 283abbf

    
           debug_assert_eq!(trait_ref, tcx.normalize_erasing_regions(param_env, trait_ref));

) discovered after fixing this issue.

These don't necessarily need to be backported since the triggered assertion is a debug_assert_eq!.

lcnr

nits, then r=me

lcnr · 2022-10-20T07:26:34Z

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -587,7 +587,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
            }
            mir::ConstantKind::Val(val, ty) => self.const_val_to_op(*val, *ty, layout),
            mir::ConstantKind::Unevaluated(uv, _) => {
-                let instance = self.resolve(uv.def, uv.substs)?;
+                let substs = self.tcx.normalize_erasing_regions(self.param_env, uv.substs);


that shouldn't be necessary because the const should already be normalized here. You could add a debug assert that this normalize call would be a noop though.

This is necessary, because we still triggered a debug assertion without it. Not needed for the backport, per se.

oh, ok 🤔 then we should normalize further above, can keep this with a FIXME for now ^^

~~What do you mean further above? The unevaluated constants are the only ones that need normalization, right?~~ edit: nvm i see

Also, to be more clear: this normalization is needed because of the const prop lint in mir_drops_elaborated_and_const_checked, which happens before optimized MIR. Only after optimizing the MIR can we guarantee that the RevealAll pass has happened and that the body's constants are normalized, so any call to resolve before that needs to be manually normalized.

yeah, the const prop lint should still normalize itself if it uses Reveal::All

to not block anything here: can you add a FIXME and then we merge this as is for now?

There's a FIXME now

lcnr · 2022-10-20T07:28:45Z

compiler/rustc_mir_build/src/thir/pattern/mod.rs

-        let substs = self.typeck_results.node_substs(id);
+        let substs = self
+            .tcx
+            .normalize_erasing_regions(param_env_reveal_all, self.typeck_results.node_substs(id));


that normalize call seems correct and useful. Considering that we want to backport this, is this call necessary to fix these regressions? I guess I am fine with keeping this even if not 🤷

lcnr · 2022-10-20T07:30:27Z

compiler/rustc_middle/src/ty/relate.rs

+    // HACK(consts): We still need to eagerly evaluate consts when
+    // relating them because during `normalize_param_env_or_error`,
+    // we may relate an evaluated constant in a obligation against
+    // an unnormalized (i.e. unevaluated) const in the param-env.


Suggested change

// HACK(consts): We still need to eagerly evaluate consts when

// relating them because during `normalize_param_env_or_error`,

// we may relate an evaluated constant in a obligation against

// an unnormalized (i.e. unevaluated) const in the param-env.

// HACK(const_generics): We still need to eagerly evaluate consts when

// relating them because during `normalize_param_env_or_error`,

// we may relate an evaluated constant in a obligation against

// an unnormalized (i.e. unevaluated) const in the param-env.

// FIXME(generic_const_exprs): Once we always lazily unify unevaluated constants

// these `eval` calls can be removed.

that's also probably broken with feature(generic_const_exprs) because with that constants can refer to higher ranked lifetimes and some type relations don't actually convert bound variables to placeholders/infer when unifying, so this would cause an ICE.

Can you change this to only run if gce is not enabled.

lcnr · 2022-10-20T08:28:25Z

@bors try @rust-timer queue

rust-timer · 2022-10-20T08:28:27Z

Awaiting bors try build completion.

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

bors · 2022-10-20T08:28:35Z

⌛ Trying commit 66a57355761afc93595f4bbc6ed50330f408a2cd with merge 165ab7a9eeecf3abb7cf89dd992dd4a1d333ce12...

bors · 2022-10-20T10:53:02Z

☀️ Try build successful - checks-actions
Build commit: 165ab7a9eeecf3abb7cf89dd992dd4a1d333ce12 (165ab7a9eeecf3abb7cf89dd992dd4a1d333ce12)

rust-timer · 2022-10-20T10:53:04Z

Queued 165ab7a9eeecf3abb7cf89dd992dd4a1d333ce12 with parent ebdde35, future comparison URL.

apiraino · 2022-10-20T14:19:56Z

Beta backport accepted as per compiler team on Zulip

@rustbot label +beta-accepted

rust-timer · 2022-10-20T14:25:12Z

Finished benchmarking commit (165ab7a9eeecf3abb7cf89dd992dd4a1d333ce12): comparison URL.

Overall result: ❌ regressions - no action needed

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

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

Instruction count

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

	mean¹	range	count²
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.8%	[0.7%, 1.0%]	6
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

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

Cycles

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.

	mean¹	range	count²
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.6%	[2.3%, 2.8%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

the arithmetic mean of the percent change ↩ ↩²
number of relevant changes ↩ ↩²

compiler-errors · 2022-10-21T07:46:26Z

@bors r=lcnr addressed the outstanding nits

bors · 2022-10-21T07:46:28Z

📌 Commit e590835ef69bf5696ca3cdb4708fad409c401c65 has been approved by lcnr

It is now in the queue for this repository.

bors · 2022-10-23T09:59:06Z

☔ The latest upstream changes (presumably #103426) made this pull request unmergeable. Please resolve the merge conflicts.

compiler-errors · 2022-10-23T19:01:38Z

@bors r=lcnr

bors · 2022-10-23T19:01:39Z

📌 Commit 6e6fe30 has been approved by lcnr

It is now in the queue for this repository.

bors · 2022-10-26T05:17:50Z

⌛ Testing commit 6e6fe30 with merge d49e7e7...

bors · 2022-10-26T07:58:22Z

☀️ Test successful - checks-actions
Approved by: lcnr
Pushing d49e7e7 to master...

rust-timer · 2022-10-26T09:19:03Z

Finished benchmarking commit (d49e7e7): 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.

	mean¹	range	count²
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	1.3%	[1.3%, 1.4%]	6
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.

	mean¹	range	count²
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	7.0%	[7.0%, 7.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Cycles

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

the arithmetic mean of the percent change ↩ ↩²
number of relevant changes ↩ ↩²

…mulacrum [beta] backport rollup * poll_fn and Unpin: fix pinning rust-lang#102737 * Support raw-dylib functions being used inside inlined functions rust-lang#102988 * Fix line numbers for MIR inlined code rust-lang#103071 * Add architectures to fn create_object_file rust-lang#103240 * Add eval hack in super_relate_consts back rust-lang#103279 * Mark std::os::wasi::io::AsFd etc. as stable. rust-lang#103308 * Truncate thread names on Linux and Apple targets rust-lang#103379 * Do not consider repeated lifetime params for elision. rust-lang#103450 * rustdoc: add missing URL redirect rust-lang#103588 * Remove commit_if_ok probe from NLL type relation rust-lang#103601 Also includes a copy of the release notes. r? `@ghost`

… r=lcnr Add eval hack in `super_relate_consts` back Partially reverts 01adb7e. This extra eval call *still* needs to happen, for example, in `normalize_param_env_or_error` when a param-env predicate has an unnormalized constant, since the param-env candidates never get normalized during candidate assembly (everywhere else we can assume that they are normalized fully). r? `@lcnr,` though I feel like I've assigned quite a few PRs to you in the last few days, so feel free to reassign to someone else familiar with this code if you're busy! cc rust-lang#103243 (fixes the issue, but don't want to auto-close that until a backport is performed).

rust-highfive assigned lcnr Oct 20, 2022

rustbot added A-testsuite Area: The testsuite used to check the correctness of rustc T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Oct 20, 2022

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Oct 20, 2022

compiler-errors changed the title ~~Add normalize hack back~~ Add normalize hack in super_relate_consts back Oct 20, 2022

compiler-errors changed the title ~~Add normalize hack in super_relate_consts back~~ Add eval hack in super_relate_consts back Oct 20, 2022

compiler-errors mentioned this pull request Oct 20, 2022

regression: trait bound not satisfied #103243

Closed

Mark-Simulacrum added the beta-nominated Nominated for backporting to the compiler in the beta channel. label Oct 20, 2022

compiler-errors mentioned this pull request Oct 20, 2022

regression: associated consts cannot be referenced in patterns #103242

Closed

lcnr reviewed Oct 20, 2022

View reviewed changes

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Oct 20, 2022

rustbot added the beta-accepted Accepted for backporting to the compiler in the beta channel. label Oct 20, 2022

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Oct 20, 2022

compiler-errors force-pushed the normalize-hack-back branch from 66a5735 to e590835 Compare October 20, 2022 17:53

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 Oct 21, 2022

bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Oct 23, 2022

compiler-errors added 2 commits October 23, 2022 17:23

Add normalize hack back

dd51b36

Comment why normalization is needed for debug assertions

6e6fe30

compiler-errors force-pushed the normalize-hack-back branch from e590835 to 6e6fe30 Compare October 23, 2022 17:24

bors added the merged-by-bors This PR was explicitly merged by bors. label Oct 26, 2022

bors merged commit d49e7e7 into rust-lang:master Oct 26, 2022

rustbot added this to the 1.66.0 milestone Oct 26, 2022

Mark-Simulacrum removed the beta-nominated Nominated for backporting to the compiler in the beta channel. label Oct 29, 2022

Mark-Simulacrum modified the milestones: 1.66.0, 1.65.0 Oct 29, 2022

This was referenced Oct 29, 2022

Add test validating successful fix #103733

Closed

[beta] backport rollup #103739

Merged

compiler-errors deleted the normalize-hack-back branch November 2, 2022 02:53

This was referenced Feb 20, 2023

rustdoc: ICE: synthetic auto trait impls: unexpected result when selecting […] involving const in super trait bounds & item bounds #107715

Closed

Dedup elaborated predicates with const generic parameter in AutoTrait #108397

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Add eval hack in `super_relate_consts` back #103279

Add eval hack in `super_relate_consts` back #103279

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Add eval hack in super_relate_consts back #103279

Add eval hack in super_relate_consts back #103279

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Overall result: ❌ regressions - no action needed

Footnotes

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Overall result: ❌ regressions - no action needed

Footnotes

Add eval hack in `super_relate_consts` back #103279

Add eval hack in `super_relate_consts` back #103279

compiler-errors commented Oct 20, 2022 •

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