async/await: improve not-send errors by davidtwco · Pull Request #64895 · rust-lang/rust

davidtwco · 2019-09-29T13:40:40Z

note: future does not implement `std::marker::Send` because this value is used across an await
  --> $DIR/issue-64130-non-send-future-diags.rs:15:5
   |
LL |     let g = x.lock().unwrap();
   |         - has type `std::sync::MutexGuard<'_, u32>`
LL |     baz().await;
   |     ^^^^^^^^^^^ await occurs here, with `g` maybe used later
LL | }
   | - `g` is later dropped here

r? @nikomatsakis

Centril

Just some nits.

src/librustc/traits/error_reporting.rs

davidtwco · 2019-09-29T19:20:15Z

I'm not sure where the duplicate diagnostic item error is coming from, a quick glance only found the rustc_diagnostic_item attribute that I added.

Centril · 2019-09-29T19:21:35Z

cc @oli-obk ^---

src/libstd/future.rs

src/librustc/traits/error_reporting.rs

oli-obk · 2019-09-30T19:32:15Z

@bors r+

bors · 2019-09-30T19:32:17Z

📌 Commit 28be5ae8c558613e59a56eb83f069da47eda56ed has been approved by oli-obk

nikomatsakis

This is awesome. Beautiful work. My one concern is that I think we can do better still with the error, but I'm sort of inclined to land this PR and continue that work afterwards.

src/test/ui/async-await/issue-64130-non-send-future-diags.stderr

src/librustc/traits/error_reporting.rs

src/librustc_typeck/check/generator_interior.rs

src/librustc/ty/context.rs

This commit improves obligation errors for async/await: ``` note: future does not implement `std::marker::Send` because this value is used across an await --> $DIR/issue-64130-non-send-future-diags.rs:15:5 | LL | let g = x.lock().unwrap(); | - has type `std::sync::MutexGuard<'_, u32>` LL | baz().await; | ^^^^^^^^^^^ await occurs here, with `g` maybe used later LL | } | - `g` is later dropped here ``` Signed-off-by: David Wood <david@davidtw.co>

nikomatsakis · 2019-09-30T23:22:56Z

@bors r+

bors · 2019-09-30T23:22:58Z

📌 Commit 04fa9b1 has been approved by nikomatsakis

@nikomatsakis

…efinition, r=nikomatsakis async/await: improve not-send errors cc rust-lang#64130. ``` note: future does not implement `std::marker::Send` because this value is used across an await --> $DIR/issue-64130-non-send-future-diags.rs:15:5 | LL | let g = x.lock().unwrap(); | - has type `std::sync::MutexGuard<'_, u32>` LL | baz().await; | ^^^^^^^^^^^ await occurs here, with `g` maybe used later LL | } | - `g` is later dropped here ``` r? @nikomatsakis

@ghost

Rollup of 10 pull requests Successful merges: - #63674 (syntax: Support modern attribute syntax in the `meta` matcher) - #63931 (Stabilize macros in some more positions) - #64887 (syntax: recover trailing `|` in or-patterns) - #64895 (async/await: improve not-send errors) - #64896 (Remove legacy grammar) - #64907 (A small amount of tidying-up factored out from PR #64648) - #64928 (Add tests for some issues) - #64930 (Silence unreachable code lint from await desugaring) - #64935 (Improve code clarity) - #64937 (Deduplicate closure type errors) Failed merges: r? @ghost

bors · 2019-10-01T11:53:15Z

☔ The latest upstream changes (presumably #64946) made this pull request unmergeable. Please resolve the merge conflicts.

ghost · 2019-10-02T08:26:01Z

~~It appears that~~ this causes ICE #64964 (comment)

~~I'm currently retesting that by applying this PR on top of the rust compilation that succeeded without it.~~confirmed

nikomatsakis · 2019-10-03T08:36:21Z

I'd like to nominate this PR (and the follow-up #64989) for inclusion in beta. It's not the sort of thing I would normally include, but this error is (a) one of the most common problems I hear people complaining about with async-await and (b) particularly opaque without this fix. Moreover, it is early in the cycle, so it will presumably get a reasonable amount of testing before landing. The change is relatively low risk, in that it is confined to error reporting.

pnkfelix · 2019-10-03T18:37:53Z

discussed at rustc meeting. accepted for beta backport in tandem with PR #64989 (since that fixes an ICE this injected).

[beta] backport rollup This includes a bunch of PRs: * Fix redundant semicolon lint interaction with proc macro attributes #64387 * Upgrade async/await to "used" keywords. #64875 * syntax: fix dropping of attribute on first param of non-method assocated fn #64894 * async/await: improve not-send errors #64895 * Silence unreachable code lint from await desugaring #64930 * Always mark rust and rust-call abi's as unwind #65020 * Account for macro invocation in `let mut $pat` diagnostic. #65123 * Ensure that associated `async fn`s have unique fresh param names #65142 * Add troubleshooting section to PGO chapter in rustc book. #65402 * Upgrade GCC to 8.3.0, glibc to 1.17.0 and crosstool-ng to 1.24.0 for dist-armv7-linux #65302 * Optimize `try_expand_impl_trait_type` #65293 * use precalculated dominators in explain_borrow #65172 * Fix ICE #64964 #64989

[beta] backport rollup This includes a bunch of PRs: * Fix redundant semicolon lint interaction with proc macro attributes #64387 * Upgrade async/await to "used" keywords. #64875 * syntax: fix dropping of attribute on first param of non-method assocated fn #64894 * async/await: improve not-send errors #64895 * Silence unreachable code lint from await desugaring #64930 * Always mark rust and rust-call abi's as unwind #65020 * Account for macro invocation in `let mut $pat` diagnostic. #65123 * Ensure that associated `async fn`s have unique fresh param names #65142 * Add troubleshooting section to PGO chapter in rustc book. #65402 * Upgrade GCC to 8.3.0, glibc to 1.17.0 and crosstool-ng to 1.24.0 for dist-armv7-linux #65302 * Optimize `try_expand_impl_trait_type` #65293 * use precalculated dominators in explain_borrow #65172 * Fix ICE #64964 #64989 * [beta] Revert "Auto merge of #62948 - matklad:failable-file-loading, r=petro… #65273 * save-analysis: Don't ICE when resolving qualified type paths in struct members #65353 * save-analysis: Nest tables when processing impl block definitions #65511 * Avoid ICE when checking `Destination` of `break` inside a closure #65518 * Avoid ICE when adjusting bad self ty #65755 * workaround msys2 bug #65762

@nikomatsakis

…provements, r=nikomatsakis async/await: improve not-send errors, part 2 Part of #64130. Fixes #65667. This PR improves the errors introduced in #64895 so that they have specialized messages for `Send` and `Sync`. r? @nikomatsakis

rust-highfive assigned nikomatsakis Sep 29, 2019

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Sep 29, 2019

This comment has been minimized.

Sign in to view

davidtwco force-pushed the issue-64130-async-error-definition branch from 42ce06e to f7cb10d Compare September 29, 2019 17:36

Centril reviewed Sep 29, 2019

View reviewed changes

This comment has been minimized.

Sign in to view

davidtwco force-pushed the issue-64130-async-error-definition branch from f7cb10d to bdaec6a Compare September 29, 2019 19:18

This comment has been minimized.

Sign in to view

oli-obk reviewed Sep 30, 2019

View reviewed changes

src/libstd/future.rs Outdated Show resolved Hide resolved

davidtwco force-pushed the issue-64130-async-error-definition branch from bdaec6a to e0f08b5 Compare September 30, 2019 09:13

oli-obk reviewed Sep 30, 2019

View reviewed changes

src/librustc/traits/error_reporting.rs Outdated Show resolved Hide resolved

src/librustc/traits/error_reporting.rs Outdated Show resolved Hide resolved

src/librustc/traits/error_reporting.rs Outdated Show resolved Hide resolved

davidtwco force-pushed the issue-64130-async-error-definition branch from e0f08b5 to 28be5ae Compare September 30, 2019 18:29

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 30, 2019

nikomatsakis requested changes Sep 30, 2019

View reviewed changes

davidtwco force-pushed the issue-64130-async-error-definition branch from 28be5ae to 9076646 Compare September 30, 2019 22:15

nikomatsakis requested changes Sep 30, 2019

View reviewed changes

src/librustc/ty/context.rs Outdated Show resolved Hide resolved

src/librustc/ty/context.rs Outdated Show resolved Hide resolved

davidtwco force-pushed the issue-64130-async-error-definition branch from 9076646 to 04fa9b1 Compare September 30, 2019 22:41

nikomatsakis approved these changes Sep 30, 2019

View reviewed changes

Centril mentioned this pull request Oct 1, 2019

Rollup of 10 pull requests #64946

Merged

bors merged commit 04fa9b1 into rust-lang:master Oct 1, 2019

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 1, 2019

davidtwco deleted the issue-64130-async-error-definition branch October 1, 2019 15:32

sinkuu mentioned this pull request Oct 2, 2019

ICE while compiling hyper (StableHasher: unexpected region '_#0r) #64964

Closed

nikomatsakis added the beta-nominated Nominated for backporting to the compiler in the beta channel. label Oct 3, 2019

nikomatsakis mentioned this pull request Oct 3, 2019

Fix ICE #64964 #64989

Merged

Centril added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Oct 3, 2019

pnkfelix added the beta-accepted Accepted for backporting to the compiler in the beta channel. label Oct 3, 2019

davidtwco mentioned this pull request Oct 12, 2019

async/await: improve not-send errors, part 2 #65345

Merged

Mark-Simulacrum removed the beta-nominated Nominated for backporting to the compiler in the beta channel. label Oct 22, 2019

Mark-Simulacrum mentioned this pull request Oct 22, 2019

[beta] backport rollup #65708

Merged

tmandry mentioned this pull request Dec 17, 2019

non-send futures error at point of use, but could cite point of definition in some cases #64130

Closed

eddyb mentioned this pull request Apr 6, 2020

note_obligation_cause reporting for non-async/await not optimal #70818

Closed

Uh oh!

Conversation

davidtwco commented Sep 29, 2019 • edited by nikomatsakis Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

This comment has been minimized.

Centril left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

This comment has been minimized.

davidtwco commented Sep 29, 2019

Uh oh!

Centril commented Sep 29, 2019

Uh oh!

This comment has been minimized.

Uh oh!

Uh oh!

Uh oh!

Uh oh!

oli-obk commented Sep 30, 2019

Uh oh!

bors commented Sep 30, 2019

Uh oh!

nikomatsakis left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

nikomatsakis commented Sep 30, 2019

Uh oh!

bors commented Sep 30, 2019

Uh oh!

bors commented Oct 1, 2019

Uh oh!

ghost commented Oct 2, 2019 • edited by ghost Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

nikomatsakis commented Oct 3, 2019

Uh oh!

pnkfelix commented Oct 3, 2019

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

8 participants

davidtwco commented Sep 29, 2019 •

edited by nikomatsakis

Loading

ghost commented Oct 2, 2019 •

edited by ghost

Loading