Suggest dereferencing non-lval mutable reference on assignment by compiler-errors · Pull Request #94639 · rust-lang/rust

compiler-errors · 2022-03-05T07:18:13Z

Adds deref suggestions for LHS of assignment (or assign-binop) when it implements DerefMut
Fixes missing deref suggestions for LHS when it isn't a place expr

Fixes #46276
Fixes #93980

rust-highfive · 2022-03-05T07:18:16Z

r? @matthewjasper

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

compiler-errors · 2022-04-05T00:15:23Z

r? rust-lang/compiler

wesleywiser · 2022-04-07T13:57:31Z

compiler/rustc_typeck/src/check/coercion.rs

I'm a bit concerned this statement is easy to miss. Is it possible we can move this method to somewhere in the diagnostics code? Or perhaps naming this method so that it includes some mention of this being for diagnostics only.

wesleywiser · 2022-04-07T14:05:10Z

src/test/ui/typeck/issue-93486.stderr

Do we know why we lost this message? (It seems like it is correct unlike the one in the previous commit so I'm surprised it's missing.)

i think it's bc i added must_apply_modulo_regions when checking if the type implements the trait, instead of may_apply, and the fact that we have an infer var on the lhs. i'll see if it causes too many false errors here.

compiler-errors · 2022-04-14T18:54:23Z

@rustbot author

compiler-errors · 2022-04-21T04:14:56Z

@rustbot ready

compiler-errors · 2022-04-21T06:25:34Z

src/test/ui/issues/issue-5239-1.stderr

This is kinda a regression, but not actually... &isize doesn't have a +=. Perhaps we could suggest changing the ref to ref mut, but that seems out of scope for this PR.

wesleywiser

r=me with or without nit. Nice work! 💯

wesleywiser · 2022-04-26T20:49:45Z

compiler/rustc_typeck/src/check/expr.rs

nit: "piece of" just reads a bit awkwardly to me. Maybe "consider dereferencing here to assign to the mutably borrowed memory"?

compiler-errors · 2022-05-18T04:21:52Z

@bors r=wesleywiser

bors · 2022-05-18T04:21:54Z

📌 Commit d50d3fc has been approved by wesleywiser

Rollup of 6 pull requests Successful merges: - rust-lang#94639 (Suggest dereferencing non-lval mutable reference on assignment) - rust-lang#95979 (update coherence docs, fix generator + opaque type ICE) - rust-lang#96378 (Mention traits and types involved in unstable trait upcasting) - rust-lang#96917 (Make HashMap fall back to RtlGenRandom if BCryptGenRandom fails) - rust-lang#97101 (Add tracking issue for ExitCode::exit_process) - rust-lang#97123 (Clean fix for rust-lang#96223) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup

estebank · 2022-05-18T16:10:46Z

compiler/rustc_typeck/src/check/demand.rs

+                                // Suppressing this diagnostic, we'll properly print it in `check_expr_assign`
+                                return None;


@compiler-errors For future reference, adding a delay_span_bug here might be a good idea to protect from miscompilations in the face of refactors.

shoot, yeah. i can add one in a follow-up.

Actually, this just suppresses a suggestion, not the error itself. And the other case I actually did suppress a real error, I downgraded it to a delayed bug. See: https://github.com/rust-lang/rust/pull/94639/files#diff-c46757032f463a1170b40e5c41d569ce058668cfe259774fb8a7936e3fdd82f4R57

@compiler-errors perfect!

rust-highfive assigned matthewjasper Mar 5, 2022

rustbot added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Mar 5, 2022

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Mar 5, 2022

rust-highfive assigned wesleywiser and unassigned matthewjasper Apr 5, 2022

wesleywiser reviewed Apr 7, 2022

View reviewed changes

rustbot 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-review Status: Awaiting review from the assignee but also interested parties. labels Apr 14, 2022

compiler-errors force-pushed the rval-mutref branch from 58316f3 to 0af2014 Compare April 21, 2022 04:14

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Apr 21, 2022

This comment has been minimized.

Sign in to view

compiler-errors force-pushed the rval-mutref branch from 0af2014 to b03a154 Compare April 21, 2022 06:24

compiler-errors commented Apr 21, 2022

View reviewed changes

wesleywiser approved these changes Apr 26, 2022

View reviewed changes

wesleywiser 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-review Status: Awaiting review from the assignee but also interested parties. labels May 18, 2022

compiler-errors added 3 commits May 17, 2022 20:21

Suggest deref non-lvalue mutable reference

a5c4f4c

better error for bad LHS in binop-assign

b26580f

better lvalue errors for things implementing DerefMut

d50d3fc

compiler-errors force-pushed the rval-mutref branch from b03a154 to d50d3fc Compare May 18, 2022 04:21

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-author Status: This is awaiting some action (such as code changes or more information) from the author. labels May 18, 2022

Dylan-DPC mentioned this pull request May 18, 2022

Rollup of 6 pull requests #97135

Merged

bors merged commit 64c58a1 into rust-lang:master May 18, 2022

rustbot added this to the 1.63.0 milestone May 18, 2022

estebank reviewed May 18, 2022

View reviewed changes

steffahn mentioned this pull request Sep 3, 2022

panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1425:13 #101376

Closed

compiler-errors deleted the rval-mutref branch August 11, 2023 20:19

		// Suppressing this diagnostic, we'll properly print it in `check_expr_assign`
		return None;

Uh oh!

Conversation

compiler-errors commented Mar 5, 2022 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

rust-highfive commented Mar 5, 2022

Uh oh!

compiler-errors commented Apr 5, 2022

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

compiler-errors commented Apr 14, 2022

Uh oh!

compiler-errors commented Apr 21, 2022

Uh oh!

This comment has been minimized.

Choose a reason for hiding this comment

Uh oh!

wesleywiser left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

compiler-errors commented May 18, 2022

Uh oh!

bors commented May 18, 2022

Uh oh!

estebank May 18, 2022 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

8 participants

compiler-errors commented Mar 5, 2022 •

edited

Loading

estebank May 18, 2022 •

edited

Loading