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Merged
merged 1 commit into from
Sep 26, 2022
Merged

Suggest Default::default() when binding isn't initialized #102184

merged 1 commit into from
Sep 26, 2022

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chenyukang
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Fixes #102087

@rustbot rustbot added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Sep 23, 2022
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r? @nagisa

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

@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Sep 23, 2022
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My first try on the type-checking part, there are several parts I'm not sure.

@chenyukang chenyukang force-pushed the fix-102087-add-binding-sugg branch from 8356aa8 to 2bfab8e Compare September 24, 2022 12:01
nagisa
nagisa reviewed Sep 24, 2022
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compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs Outdated

let mut visitor = LetVisitor { decl_span, ty_span: None };
visitor.visit_body(&body);
if let Some(ty_span) = visitor.ty_span {
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@nagisa nagisa Sep 24, 2022 •
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Hm, seems quite unfortunate that we only handle the bindings that have a specified type. As such code like this isn’t really covered:

fn apple(_: u32) { }

fn banana() {
    let chaenomeles;
    apple(chaenomeles);
}

Not saying though that this needs to be implemented here and now, but perhaps a FIXME comment or an issue for this would be warranted.

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Fixed the code to support this scenario now, the type infer know it's a u32, so here we give this suggestion:

error[E0381]: used binding `chaenomeles` isn't initialized
 --> bug.rs:5:11
  |
4 |     let chaenomeles;
  |         ----------- binding declared here but left uninitialized
5 |     apple(chaenomeles);
  |           ^^^^^^^^^^^ `chaenomeles` used here but it isn't initialized
  |
help: consider assigning a value
  |
4 |     let chaenomeles = 0;
  |                     +++

@chenyukang chenyukang force-pushed the fix-102087-add-binding-sugg branch 2 times, most recently from 85582e6 to 21b9222 Compare September 24, 2022 15:06
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nagisa commented Sep 24, 2022

This is quite awesome!

@bors r+

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bors commented Sep 24, 2022

📌 Commit 21b9222 has been approved by nagisa

It is now in the queue for this repository.

@bors 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 24, 2022
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Sep 24, 2022
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Rollup merge of rust-lang#102184 - chenyukang:fix-102087-add-binding-…
66fe5d3 
…sugg, r=nagisa

Suggest Default::default() when binding isn't initialized

Fixes rust-lang#102087
@matthiaskrgr matthiaskrgr mentioned this pull request Sep 24, 2022
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@bors r- failed in a rollup (test needs update)
https://github.com/rust-lang-ci/rust/actions/runs/3120399661/jobs/5060949966#step:25:24352
#102247

@bors 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 Sep 25, 2022
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chenyukang commented Sep 25, 2022 •
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@bors r- failed in a rollup (test needs update) https://github.com/rust-lang-ci/rust/actions/runs/3120399661/jobs/5060949966#step:25:24352 #102247

updated it!
How can we avoid this happend for those testcase which depended on some specific arch?
I just manually removed the only-aarch64 and generated the stderr.

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nagisa commented Sep 25, 2022

How can we avoid this happend for those testcase which depended on some specific arch? I just manually removed the only-aarch64 and generated the stderr.

Unfortunately that’s the downside of only running the tests on the specified architecture. The more appropriate thing to do is to write the test in a way that is able to cross-compile if necessary to test target-specific details, but this isn’t always feasible (e.g. when test depends on libstd.)

The most straightfoward thing to do today is to just let bors deal with it, to be honest.

@bors r+ rollup=never

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bors commented Sep 25, 2022

📌 Commit 8b2a008fd2edfd01c8f9ede3d5131dbea5d0d725 has been approved by nagisa

It is now in the queue for this repository.

@bors 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 Sep 25, 2022
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nagisa commented Sep 25, 2022

@bors r-

Could you squash the commits a little please? Commits like “cleanup” or “update test” don’t really carry themselves.

@bors 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 Sep 25, 2022
@chenyukang chenyukang force-pushed the fix-102087-add-binding-sugg branch from 8b2a008 to 672e3f4 Compare September 25, 2022 23:57
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@bors r-

Could you squash the commits a little please? Commits like “cleanup” or “update test” don’t really carry themselves.

squashed!

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nagisa commented Sep 26, 2022

@bors r+

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bors commented Sep 26, 2022

📌 Commit 672e3f4 has been approved by nagisa

It is now in the queue for this repository.

@bors 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 Sep 26, 2022
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bors commented Sep 26, 2022

⌛ Testing commit 672e3f4 with merge 84946fe...

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bors commented Sep 26, 2022

☀️ Test successful - checks-actions
Approved by: nagisa
Pushing 84946fe to master...

@bors bors added the merged-by-bors This PR was explicitly merged by bors. label Sep 26, 2022
@bors bors merged commit 84946fe into rust-lang:master Sep 26, 2022
@rustbot rustbot added this to the 1.66.0 milestone Sep 26, 2022
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Finished benchmarking commit (84946fe): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

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)		 -4.0% [-4.0%, -4.0%] 1
All ❌✅ (primary) - - 0

Cycles

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

Footnotes

  1. the arithmetic mean of the percent change ↩

  2. number of relevant changes ↩

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Papercut: Suggest Default::default() when binding isn't initialized
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