make Condvar, Mutex, RwLock const constructors work with the `unsupported` impl #98457

japaric · 2022-06-24T14:24:14Z

applying this patch locally to the rust-src component fixes #98378

however, the solution seems wrong to me because PR #97791 didn't add any rustc_const_stable attribute to underlying implementations like std::sys::unix::futex, so I must be missing something about how const-stability is checked ... maybe the restricted_std feature (gate?) has an effect?

fixes #98378
fixes #98293 (probably)

rust-highfive · 2022-06-24T14:24:17Z

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If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

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rust-highfive · 2022-06-24T14:24:18Z

r? @joshtriplett

(rust-highfive has picked a reviewer for you, use r? to override)

Ayush1325 · 2022-06-27T09:57:14Z

I had to add #[rustc_const_stable(feature = "const_locks", since = "1.63.0")] to the MovableMutex and MovableRwLock as well, but that fixes #98293 for UEFI as well.

…impl

japaric · 2022-06-27T10:38:13Z

I had to add #[rustc_const_stable(feature = "const_locks", since = "1.63.0")] to the MovableMutex and MovableRwLock as well, but that fixes #98293 for UEFI as well.

my bad. I meant to apply rustc_const_stable to the movable mutex/rwlock rather than the static ones. fixed that and checked that both thumbv7m and uefi work

kjetilkjeka · 2022-07-12T11:29:05Z

This is also a problem on nvptx64-nvidia-cuda. I have confirmed that your patch fixes it there as well.

tmandry · 2022-07-21T13:38:27Z

r? @m-ou-se

kjetilkjeka · 2022-08-16T11:40:18Z

Now with llvm-15 being merged the bug this PR fixes is a blocker for using bugfixes from LLVM for the nvptx64-nvidia-cuda target as this target does not come with prebuilt corelib.

kjetilkjeka · 2022-09-23T09:19:52Z

I realize this bug is one that must necessarily be prioritized lower than a lot of the other great work @m-ou-se is doing. I also realize that it is not at all my place to request attention to things just because I personally care about them. But I do think it is unfortunate that -Zbuild-std has been in many cases unusable for many months. So I will still do this small nudge in case this PR has simply been forgotten about.

Maybe there are other qualified persons that will have the bandwidth to look at this in the near future? What do you think @tmandry

m-ou-se · 2022-09-23T09:32:07Z

Apologies for the delay, and thanks for the reminder. (My past few weeks (months?) have been very chaotic. I'll have more time for reviewing again soon.)

however, the solution seems wrong to me because PR #97791 didn't add any rustc_const_stable attribute to underlying implementations like std::sys::unix::futex, so I must be missing something about how const-stability is checked ... maybe the restricted_std feature (gate?) has an effect?

Yeah that seems odd. Not sure why this is the case, but figuring that out doesn't have to block this change.

@bors r+

bors · 2022-09-23T09:32:08Z

📌 Commit 513eda0 has been approved by m-ou-se

It is now in the queue for this repository.

bors · 2022-09-25T04:12:33Z

⌛ Testing commit 513eda0 with merge e20fabb...

bors · 2022-09-25T06:53:05Z

☀️ Test successful - checks-actions
Approved by: m-ou-se
Pushing e20fabb to master...

rust-timer · 2022-09-25T07:56:35Z

Finished benchmarking commit (e20fabb): comparison URL.

Overall result: ✅ improvements - 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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.3%	[-2.0%, -0.5%]	2
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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.2%	[-3.9%, -2.6%]	2
All ❌✅ (primary)	-	-	0

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)	4.8%	[4.2%, 5.4%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-4.9%	[-4.9%, -4.9%]	1
All ❌✅ (primary)	-	-	0

the arithmetic mean of the percent change ↩ ↩² ↩³
number of relevant changes ↩ ↩² ↩³

Manishearth · 2022-10-04T21:44:17Z

(Wanted to nominate it for backporting before I realized it would have no effect, see thread for more details)

mark sys_common::once::generic::Once::new const-stable Attempt to address rust-lang#103191 by marking the impl const-stable. Picked the declaration from the callsite: https://github.com/rust-lang/rust/blob/21b246587c2687935bd6004ffa5dcc4f4dd6600d/library/std/src/sync/once.rs#L67 This is similar to rust-lang#98457. With this in, `python3 x.py build library/std --target x86_64-unknown-none` succeeds.

mark sys_common::once::generic::Once::new const-stable Attempt to address rust-lang/rust#103191 by marking the impl const-stable. Picked the declaration from the callsite: https://github.com/rust-lang/rust/blob/21b246587c2687935bd6004ffa5dcc4f4dd6600d/library/std/src/sync/once.rs#L67 This is similar to rust-lang/rust#98457. With this in, `python3 x.py build library/std --target x86_64-unknown-none` succeeds.

rust-highfive assigned joshtriplett Jun 24, 2022

rustbot added the T-libs Relevant to the library team, which will review and decide on the PR/issue. label Jun 24, 2022

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jun 24, 2022

japaric mentioned this pull request Jun 24, 2022

libstd: -Z build-std is now broken for Cortex-M targets #98378

Closed

make Condvar, Mutex, RwLock const constructors work with unsupported …

513eda0

…impl

japaric force-pushed the gh98378 branch from 4dab4de to 513eda0 Compare June 27, 2022 10:37

rust-highfive assigned m-ou-se and unassigned joshtriplett Jul 21, 2022

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 Sep 23, 2022

bors added the merged-by-bors This PR was explicitly merged by bors. label Sep 25, 2022

bors merged commit e20fabb into rust-lang:master Sep 25, 2022

rustbot added this to the 1.66.0 milestone Sep 25, 2022

This was referenced Oct 18, 2022

libstd: -Z build-std is newly broken for, e.g., x86_64-unknown-none; error: sys_common::once::generic::Once::new is not yet stable as a const fn #103191

Closed

mark sys_common::once::generic::Once::new const-stable #103193

Merged

compiler-errors mentioned this pull request Jun 21, 2023

Rust allows impl Fn(T<'a>) -> T<'b> to be : 'static, which is unsound #112905

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make Condvar, Mutex, RwLock const constructors work with the `unsupported` impl #98457

make Condvar, Mutex, RwLock const constructors work with the `unsupported` impl #98457

japaric commented Jun 24, 2022

rust-highfive commented Jun 24, 2022

rust-highfive commented Jun 24, 2022

Ayush1325 commented Jun 27, 2022

japaric commented Jun 27, 2022

kjetilkjeka commented Jul 12, 2022

tmandry commented Jul 21, 2022

kjetilkjeka commented Aug 16, 2022

kjetilkjeka commented Sep 23, 2022

m-ou-se commented Sep 23, 2022

bors commented Sep 23, 2022

bors commented Sep 25, 2022

bors commented Sep 25, 2022

rust-timer commented Sep 25, 2022

Manishearth commented Oct 4, 2022

make Condvar, Mutex, RwLock const constructors work with the unsupported impl #98457

make Condvar, Mutex, RwLock const constructors work with the unsupported impl #98457

Conversation

japaric commented Jun 24, 2022

rust-highfive commented Jun 24, 2022

rust-highfive commented Jun 24, 2022

Ayush1325 commented Jun 27, 2022

japaric commented Jun 27, 2022

kjetilkjeka commented Jul 12, 2022

tmandry commented Jul 21, 2022

kjetilkjeka commented Aug 16, 2022

kjetilkjeka commented Sep 23, 2022

m-ou-se commented Sep 23, 2022

bors commented Sep 23, 2022

bors commented Sep 25, 2022

bors commented Sep 25, 2022

rust-timer commented Sep 25, 2022

Overall result: ✅ improvements - no action needed

Instruction count

Max RSS (memory usage)

Cycles

Footnotes

Manishearth commented Oct 4, 2022

make Condvar, Mutex, RwLock const constructors work with the `unsupported` impl #98457

make Condvar, Mutex, RwLock const constructors work with the `unsupported` impl #98457