single life #55432

zackmdavis · 2018-10-28T07:33:29Z

structured ~~autofixable~~ (well, pending disambiguate between multiple suggestions and a single multi-span suggestion; or, JSON error format is not round-trippable #53934 and rustfix should handle multi-span suggestions rustfix#141) suggestions for the single-use-lifetimes lint in the case of function and method reference args
don't consider the anonymous lifetime '_ as "single-use" (it's intended for exactly this sort of thing)

It would be nice to demonstrate the shining correctness here with more run-rustfix tests than this, but unfortunately, that doesn't work with multipart suggestions yet (rust-lang#53934). While we're here, reword the zero-use lifetime suggestion to "elide the unused lifetime" instead of "remove it". (It's classier.)

killercup

Nice!

single life
opened PR half past midnight on a saturday

checks out

zackmdavis · 2018-10-28T18:44:33Z

😅 💔

nikomatsakis

LGTM! I had one suggestion but it's pre-existing, really

nikomatsakis · 2018-10-29T13:26:40Z

src/test/ui/single-use-lifetime/zero-uses-in-fn.stderr


 error: lifetime parameter `'b` never used
  --> $DIR/zero-uses-in-fn.rs:18:17
   |
 LL | fn november<'a, 'b>(s: &'a str) -> (&'a str) {
   |               --^^
   |               |
-   |               help: remove it
+   |               help: elide the unused lifetime


This...looks funny, no? It seems like we'd be better off making this suggestion "out of line"?

nikomatsakis · 2018-10-29T13:28:01Z

@bors r+

bors · 2018-10-29T13:28:02Z

📌 Commit faea5bb has been approved by nikomatsakis

bors · 2018-11-04T04:23:33Z

⌛ Testing commit faea5bb with merge 9a89b6433c0e1a90228a3256fea0007c726a5b07...

bors · 2018-11-04T06:56:05Z

💔 Test failed - status-travis

rust-highfive · 2018-11-04T06:56:07Z

The job x86_64-gnu-distcheck of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[02:29:01] warning: spurious network error (2 tries remaining): curl error: Could not resolve host: github.com
[02:29:01] ; class=Net (12)
[02:29:21] warning: spurious network error (1 tries remaining): curl error: Could not resolve host: github.com
[02:29:21] ; class=Net (12)
[02:29:41] error: failed to load source for a dependency on `rand`
[02:29:41] Caused by:
[02:29:41]   Unable to update registry `https://github.com/rust-lang/crates.io-index`
[02:29:41] 
[02:29:41] Caused by:
[02:29:41] Caused by:
[02:29:41]   failed to fetch `https://github.com/rust-lang/crates.io-index`
[02:29:41] 
[02:29:41] Caused by:
[02:29:41]   curl error: Could not resolve host: github.com
[02:29:41] ; class=Net (12)
[02:29:41] 
[02:29:41] 
[02:29:41] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "generate-lockfile" "--manifest-path" "/checkout/obj/build/tmp/distcheck-src/rust-src/lib/rustlib/src/rust/src/libstd/Cargo.toml"
[02:29:41] 
[02:29:41] 
[02:29:41] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test distcheck
[02:29:41] Build completed unsuccessfully in 2:26:38
---
travis_time:end:05e1b992:start=1541314526985736513,finish=1541314526993865921,duration=8129408
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:26c9542a
$ ln -s . checkout && for CORE in obj/cores/core.*; do EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|'); if [ -f "$EXE" ]; then printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE"; gdb --batch -q -c "$CORE" "$EXE" -iex 'set auto-load off' -iex 'dir src/' -iex 'set sysroot .' -ex bt -ex q; echo travis_fold":"end:crashlog; fi; done || true
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:00d50ecb
travis_time:start:00d50ecb
$ cat ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
cat: ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers: No such file or directory
travis_fold:end:after_failure.5
travis_fold:start:after_failure.6
travis_time:start:0ccc1db6
$ dmesg | grep -i kill

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

zackmdavis · 2018-11-04T07:05:04Z

[02:29:41] Caused by:
[02:29:41]   failed to fetch `https://github.com/rust-lang/crates.io-index`
[02:29:41] 
[02:29:41] Caused by:
[02:29:41]   curl error: Could not resolve host: github.com
[02:29:41] ; class=Net (12)

@bors retry

bors · 2018-11-04T09:45:55Z

⌛ Testing commit faea5bb with merge 86b88e6...

@nikomatsakis

single life * structured ~~autofixable~~ (well, pending #53934 and rust-lang/rustfix#141) suggestions for the single-use-lifetimes lint in the case of function and method reference args * don't consider the anonymous lifetime `'_` as "single-use" (it's intended for exactly this sort of thing) ![single_life](https://user-images.githubusercontent.com/1076988/47613227-3b2b6400-da48-11e8-8efd-cb975ddf537d.png) r? @nikomatsakis

bors · 2018-11-04T12:20:48Z

☀️ Test successful - status-appveyor, status-travis
Approved by: nikomatsakis
Pushing 86b88e6 to master...

zackmdavis added 2 commits October 28, 2018 00:14

single-use-lifetime lint: don't false-positive on the anonymous lifetime

faea5bb

rust-highfive assigned nikomatsakis Oct 28, 2018

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Oct 28, 2018

killercup reviewed Oct 28, 2018

View reviewed changes

nikomatsakis approved these changes Oct 29, 2018

View reviewed changes

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 Oct 29, 2018

bors added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Nov 4, 2018

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 Nov 4, 2018

bors merged commit faea5bb into rust-lang:master Nov 4, 2018

zackmdavis deleted the single_life branch November 5, 2018 07:25

zackmdavis mentioned this pull request Jul 6, 2019

single_use_lifetimes should have suggestions #46944

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

single life #55432

single life #55432

zackmdavis commented Oct 28, 2018 •

edited

Loading

killercup left a comment •

edited

Loading

zackmdavis commented Oct 28, 2018

nikomatsakis left a comment

nikomatsakis Oct 29, 2018

nikomatsakis commented Oct 29, 2018

bors commented Oct 29, 2018

bors commented Nov 4, 2018

bors commented Nov 4, 2018

rust-highfive commented Nov 4, 2018

zackmdavis commented Nov 4, 2018

bors commented Nov 4, 2018

bors commented Nov 4, 2018

single life #55432

single life #55432

Conversation

zackmdavis commented Oct 28, 2018 • edited Loading

killercup left a comment • edited Loading

Choose a reason for hiding this comment

zackmdavis commented Oct 28, 2018

nikomatsakis left a comment

Choose a reason for hiding this comment

nikomatsakis Oct 29, 2018

Choose a reason for hiding this comment

nikomatsakis commented Oct 29, 2018

bors commented Oct 29, 2018

bors commented Nov 4, 2018

bors commented Nov 4, 2018

rust-highfive commented Nov 4, 2018

zackmdavis commented Nov 4, 2018

bors commented Nov 4, 2018

bors commented Nov 4, 2018

zackmdavis commented Oct 28, 2018 •

edited

Loading

killercup left a comment •

edited

Loading