Stop suggesting missing semicolon with multiline indexing - #161207

hu-jeff · 2026-08-17T02:53:38Z

Making a change so that when the open bracket is on the same line as the thing being indexed, we don't suggest a semicolon. This does change some existing behaviour though:

foo[
  1,
  2]

Before, this example would recommend foo;[ and it will now suggest foo![ which is probably what was intended.

r? @kpreid

Closes #161147

rustbot · 2026-08-17T02:53:41Z

The parser was modified, potentially altering the grammar of (stable) Rust
which would be a breaking change.

cc @fmease

rustbot · 2026-08-17T02:53:43Z

Failed to set assignee to kpreid: invalid assignee

Note: Only org members with at least the repository "read" role, users with write permissions, or people who have commented on the PR may be assigned.

rustbot · 2026-08-17T02:53:43Z

Thanks for the pull request, and welcome! The Rust Project is excited to review your changes, and you should hear from @kpreid (or someone else) some time within the next two weeks.

Please see the contribution instructions for more information. Namely, in order to ensure the minimum review times lag, PR authors and assigned reviewers should ensure that the review label (S-waiting-on-review and S-waiting-on-author) stays updated, invoking these commands when appropriate:

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kpreid

This change seems like an improvement to me. I think ideally we would go farther by not making the semicolon suggestion when the expression is parenthesized or otherwise cannot be replaced by two statements, but that’s more work.

r? compiler

View changes since this review

Co-authored-by: Kevin Reid <kpreid@switchb.org>

fmease

Thanks, that's definitely an improvement!

I'm not a fan of this (preexisting) diagnostic / error recovery since it's so assertive despite having so many false positives.

This change seems like an improvement to me. I think ideally we would go farther by not making the semicolon suggestion when the expression is parenthesized or otherwise cannot be replaced by two statements, but that’s more work.

Agreed. I've pushed some FIXME comments to the branch (plus a bit of cleanup) outlining some of its issues.

@bors rollup
@bors r+ force

View changes since this review

rust-bors · 2026-11-02T19:21:24Z

📌 Commit 1971ad0 has been approved by fmease

It is now in the queue for this repository.

@kpreid

…ion, r=fmease Stop suggesting missing semicolon with multiline indexing Making a change so that when the open bracket is on the same line as the thing being indexed, we don't suggest a semicolon. This does change some existing behaviour though: ``` foo[ 1, 2] ``` Before, this example would recommend `foo;[` and it will now suggest `foo![` which is probably what was intended. r? @kpreid Closes rust-lang#161147

…uwer Rollup of 21 pull requests Successful merges: - #165331 (miri subtree update) - #165356 (portable-simd subtree update) - #162916 (rustdoc: Improve `ItemKind`) - #161035 (Tweak error for stmt macro expansion in expression context) - #163762 (Tweak "value not found" error to show more context when items with the same name are found) - #164155 (Implement `Vec::retain_unstable` ACP) - #164786 (Add regression test for issue 156423) - #165103 (add TrySendError::into_inner) - #157584 (Misc. `fmt_type` cleanups) - #161207 (Stop suggesting missing semicolon with multiline indexing) - #162070 (Add regression test for associated const equality param out of range ICE) - #162537 (Remove outdated windows-gnu test ignores) - #162978 (add regression test for #142717) - #163333 (va_arg: force right-adjust on `aarch64_be`) - #163377 (Avoid ICE when checking casts from function items) - #163399 (Support `cfg_version` in `doc_cfg`) - #165015 (Autolabel library modules) - #165181 (Implement `Duration::display_seconds`) - #165185 (Add codegen test for enumerate index bounds check elimination) - #165193 (Do attribute target checking on parameters with the new system) - #165292 (DropGuard: remove leading newlines from examples)

@kpreid

Rollup merge of #161207 - hu-jeff:fix-comma-indexing-expression, r=fmease Stop suggesting missing semicolon with multiline indexing Making a change so that when the open bracket is on the same line as the thing being indexed, we don't suggest a semicolon. This does change some existing behaviour though: ``` foo[ 1, 2] ``` Before, this example would recommend `foo;[` and it will now suggest `foo![` which is probably what was intended. r? @kpreid Closes #161147

…uwer Rollup of 21 pull requests Successful merges: - rust-lang/rust#165331 (miri subtree update) - rust-lang/rust#165356 (portable-simd subtree update) - rust-lang/rust#162916 (rustdoc: Improve `ItemKind`) - rust-lang/rust#161035 (Tweak error for stmt macro expansion in expression context) - rust-lang/rust#163762 (Tweak "value not found" error to show more context when items with the same name are found) - rust-lang/rust#164155 (Implement `Vec::retain_unstable` ACP) - rust-lang/rust#164786 (Add regression test for issue 156423) - rust-lang/rust#165103 (add TrySendError::into_inner) - rust-lang/rust#157584 (Misc. `fmt_type` cleanups) - rust-lang/rust#161207 (Stop suggesting missing semicolon with multiline indexing) - rust-lang/rust#162070 (Add regression test for associated const equality param out of range ICE) - rust-lang/rust#162537 (Remove outdated windows-gnu test ignores) - rust-lang/rust#162978 (add regression test for rust-lang/rust#142717) - rust-lang/rust#163333 (va_arg: force right-adjust on `aarch64_be`) - rust-lang/rust#163377 (Avoid ICE when checking casts from function items) - rust-lang/rust#163399 (Support `cfg_version` in `doc_cfg`) - rust-lang/rust#165015 (Autolabel library modules) - rust-lang/rust#165181 (Implement `Duration::display_seconds`) - rust-lang/rust#165185 (Add codegen test for enumerate index bounds check elimination) - rust-lang/rust#165193 (Do attribute target checking on parameters with the new system) - rust-lang/rust#165292 (DropGuard: remove leading newlines from examples)

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 Aug 17, 2026

kpreid mentioned this pull request Aug 17, 2026

Welcome message inconsistent with invalid assignee rust-lang/triagebot#2481

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kpreid approved these changes Aug 17, 2026

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Comment thread compiler/rustc_parse/src/parser/expr.rs Resolved

rustbot assigned wesleywiser Aug 17, 2026

fmease assigned fmease and unassigned wesleywiser Nov 2, 2026

hu-jeff and others added 3 commits November 2, 2026 20:11

Refine multiline check in suggest_missing_semicolon_before_array

bd7601b

Co-authored-by: Kevin Reid <kpreid@switchb.org>

Add FIXMEs to recover_from_missing_semicolon_before_array

b19e1b7

Move recover_from_missing_semicolon_before_array

1971ad0

fmease force-pushed the fix-comma-indexing-expression branch from 56927f3 to 1971ad0 Compare November 2, 2026 19:16

fmease approved these changes Nov 2, 2026

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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 Nov 2, 2026

This was referenced Nov 2, 2026

Rollup of 13 pull requests #165372

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Rollup of 21 pull requests #165375

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rust-bors Bot merged commit 8fa788c into rust-lang:main Nov 3, 2026
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rustbot added this to the 1.101.0 milestone Nov 3, 2026

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Stop suggesting missing semicolon with multiline indexing - #161207

Stop suggesting missing semicolon with multiline indexing#161207
rust-bors[bot] merged 3 commits into
rust-lang:mainfrom
hu-jeff:fix-comma-indexing-expression

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