New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Clearer error message for dead assign #56439

Merged
merged 5 commits into from Dec 16, 2018

Conversation

Projects
None yet
6 participants
@JohnGinger
Contributor

JohnGinger commented Dec 2, 2018

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message #56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

@rust-highfive

This comment has been minimized.

Collaborator

rust-highfive commented Dec 2, 2018

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @petrochenkov (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see the contribution instructions for more information.

@rust-highfive

This comment has been minimized.

Collaborator

rust-highfive commented Dec 2, 2018

The job x86_64-gnu-llvm-5.0 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.
travis_time:end:09494bd3:start=1543765780359699405,finish=1543765781466632479,duration=1106933074
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#Pull-Requests-and-Security-Restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-5.0
---

[00:03:09] travis_fold:start:tidy
travis_time:start:tidy
tidy check
[00:03:10] tidy error: /checkout/src/librustc/middle/liveness.rs:1661: line longer than 100 chars
[00:03:10] tidy error: /checkout/src/librustc/middle/liveness.rs:1664: line longer than 100 chars
[00:03:11] some tidy checks failed
[00:03:11] 
[00:03:11] 
[00:03:11] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/tidy" "/checkout/src" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "--no-vendor" "--quiet"
[00:03:11] 
[00:03:11] 
[00:03:11] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/tools/tidy
[00:03:11] Build completed unsuccessfully in 0:00:58
[00:03:11] Build completed unsuccessfully in 0:00:58
[00:03:11] Makefile:79: recipe for target 'tidy' failed
[00:03:11] make: *** [tidy] Error 1
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:006cf5b0
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Sun Dec  2 15:53:01 UTC 2018
---
travis_time:end:02f303cf:start=1543765982192904323,finish=1543765982198075374,duration=5171051
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:00bcb8b7
$ 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:37d76a8b
travis_time:start:37d76a8b
$ 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:0031d646
$ 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)

@jonas-schievink

This comment has been minimized.

Contributor

jonas-schievink commented Dec 2, 2018

To further clarify what's being linted, the warning should also highlight the value it's talking about, not the variable the value is assigned to

@JohnGinger

This comment has been minimized.

Contributor

JohnGinger commented Dec 2, 2018

@jonas-schievink makes sense - I'm not sure I'd know how to do that though (without making a lot of changes to this file)

@rust-highfive

This comment has been minimized.

Collaborator

rust-highfive commented Dec 2, 2018

The job x86_64-gnu-llvm-5.0 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.
travis_time:end:2066a831:start=1543768649367594094,finish=1543768650374595136,duration=1007001042
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#Pull-Requests-and-Security-Restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-5.0
---
[00:45:52] .................................................................................................... 2600/5107
[00:45:56] .................................................................................................... 2700/5107
[00:45:59] .................................................................................................... 2800/5107
[00:46:02] .................................................................................................... 2900/5107
[00:46:05] ................................F................................................................... 3000/5107
[00:46:09] ...................................F......F..................................i...................... 3100/5107
[00:46:15] ........................................ii..i..ii................................................... 3300/5107
[00:46:18] .................................................................................................... 3400/5107
[00:46:21] .................................................................................................... 3500/5107
[00:46:24] .....................ii............................................................................. 3600/5107
---
[00:47:10] 
[00:47:10] ---- [ui] ui/lint/issue-47390-unused-variable-in-struct-pattern.rs stdout ----
[00:47:10] diff of stderr:
[00:47:10] 
[00:47:10] 44    = note: consider using `_hours_are_suns` instead
[00:47:10] 45 
[00:47:10] 46 warning: value assigned to `hours_are_suns` is never read
[00:47:10]on_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `i_think_continually`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:36:9\n   |\nLL |     let i_think_continually = 2;\n   |         ^^^^^^^^^^^^^^^^^^^ help: consider using `_i_think_continually` instead\n   |\nnote: lint level defined here\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:15:9\n   |\nLL | #![warn(unused)] // UI tests pass `-A unused` (#43896)\n   |         ^^^^^^\n   = note: #[warn(unused_variables)] implied by #[warn(unused)]\n\n"}
[00:47:10] {"message":"unused variable: `mut_unused_var`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1061,"byte_end":1075,"line_start":43,"line_end":43,"column_start":13,"column_end":27,"is_primary":true,"text":[{"text":"    let mut mut_unused_var = 1;","highlight_start":13,"highlight_end":27}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"consider using `_mut_unused_var` instead","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1061,"byte_end":1075,"line_start":43,"line_end":43,"column_start":13,"column_end":27,"is_primary":true,"text":[{"text":"    let mut mut_unused_var = 1;","highlight_start":13,"highlight_end":27}],"label":null,"suggested_replacement":"_mut_unused_var","suggestion_aansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1847,"byte_end":1851,"line_start":78,"line_end":78,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"        (Large::Suit { case },) => {}","highlight_start":24,"highlight_end":28}],"label":null,"suggested_replacement":"case: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `case`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:78:24\n   |\nLL |         (Large::Suit { case },) => {}\n   |                        ^^^^ help: try ignoring the field: `case: _`\n\n"}
[00:47:10] {"message":"unused variable: `case`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1936,"byte_end":1940,"line_start":83,"line_end":83,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"        [Large::Suit { case }] => {}","highlight_start":24,"highlight_end":28}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1936,"byte_end":1940,"line_start":83,"line_end":83,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"     nused-variable-in-struct-pattern.rs:88:29\n   |\nLL |         Tuple(Large::Suit { case }, ()) => {}\n   |                             ^^^^ help: try ignoring the field: `case: _`\n\n"}
[00:47:10] {"message":"variable does not need to be mutable","code":{"code":"unused_mut","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1057,"byte_end":1075,"line_start":43,"line_end":43,"column_start":9,"column_end":27,"is_primary":true,"text":[{"text":"    let mut mut_unused_var = 1;","highlight_start":9,"highlight_end":27}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"lint level defined here","code":null,"level":"note","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":542,"byte_end":548,"line_start":15,"line_end":15,"column_start":9,"column_end":15,"is_primary":true,"text":[{"text":"#![warn(unused)] // UI tests pass `-A unused` (#43896)","highlight_start":9,"highlight_end":15}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":null},{"message":"#[warn(unused_mut)] implied by #[warn(unused)]","code":null,"level":"note","spans":[],"children":[],"rendered":null},{"message":"remove this `mut`","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1057,"byte_end":1061,"line_start":43,"line_end":43,"column_start":9,"column_end":13,"is_primary":true,"text":[{"te7:10] +                      (maybe it is overwritten before being read)
[00:47:10] 21    |
[00:47:10] 21    |
[00:47:10] 22 LL | fn f4(mut x: i32) { //~ ERROR: value passed to `x` is never read
[00:47:10] 23    |           ^
[00:47:10] 24 
[00:47:10] 25 error: value assigned to `x` is never read
[00:47:10] 25 error: value assigned to `x` is never read
[00:47:10] +                      (maybe it is overwritten before being read)
[00:47:10] 27    |
[00:47:10] 27    |
[00:47:10] 28 LL |     x = 4; //~ ERROR: value assigned to `x` is never read
[00:47:10] 
[00:47:10] The actual stderr differed from the expected stderr.
[00:47:10] Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/liveness/liveness-dead/liveness-dead.stderr
[00:47:10] Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/liveness/liveness-dead/liveness-dead.stderr
[00:47:10] To update references, rerun the tests and pass the `--bless` flag
[00:47:10] To only update this specific test, also pass `--test-args liveness/liveness-dead.rs`
[00:47:10] error: 1 errors occurred comparing output.
[00:47:10] status: exit code: 1
[00:47:10] status: exit code: 1
[00:47:10] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/liveness/liveness-dead.rs" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/liveness/liveness-dead/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/liveness/liveness-dead/auxiliary" "-A" "unused"
[00:47:10] stdout:
[00:47:10] ----------rwritten before being read)\n  --> /checkout/src/test/ui/liveness/liveness-dead.rs:30:11\n   |\nLL | fn f4(mut x: i32) { //~ ERROR: value passed to `x` is never read\n   |           ^\n\n"}
[00:47:10] {"message":"value assigned to `x` is never read\n                     (maybe it is overwritten before being read)","code":{"code":"unused_assignments","explanation":null},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/liveness/liveness-dead.rs","byte_start":925,"byte_end":926,"line_start":37,"line_end":37,"column_start":5,"column_end":6,"is_primary":true,"text":[{"text":"    x = 4; //~ ERROR: value assigned to `x` is never read","highlight_start":5,"highlight_end":6}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: value assigned to `x` is never read\n                     (maybe it is overwritten before being read)\n  --> /checkout/src/test/ui/liveness/liveness-dead.rs:37:5\n   |\nLL |     x = 4; //~ ERROR: value assigned to `x` is never read\n   |     ^\n\n"}
[00:47:10] {"message":"aborting due to 4 previous errors","code":null,"level":"error","spans":[],"children":[],"rendered":"error: aborting due to 4 previous errors\n\n"}
[00:47:10] ------------------------------------------
[00:47:10] 
[00:47:10] thread '[ui] ui/liveness/liveness-dead.rs' panicked at 'explicit panic', src/tools/compiletest/src/runtest.rs:3282:9
[00:47:10] 
---
[00:47:10] 
[00:47:10] ------------------------------------------
[00:47:10] stderr:
[00:47:10] ------------------------------------------
[00:47:10] {"message":"unreachable statement","code":{"code":"unreachable_code","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/liveness/liveness-unused.rs","byte_start":1974,"byte_end":1990,"line_start":102,"line_end":102,"column_start":9,"column_end":25,"is_primary":true,"text":[{"text":"        drop(*x as i32); //~ WARNING unreachable statement","highlight_start":9,"highlight_end":25}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"lint level defined here","code":null,"level":"note","spans":[{"file_name":"/checkout/src/test/ui/liveness/liveness-unused.rs","byte_start":475,"byte_end":481,"line_start":11,"line_end":11,"column_start":9,"column_end":15,"is_primary":true,"text":[{"text":"#![warn(unused)]","highlight_start":9,"highlight_end":15}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":null},{"message":"#[warn(unreachable_code)] implied by #[warn(unused)]","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"warning: unreachable statement\n  --> /checkout/src/test/ui/liveness/liveness-unused.rs:102:9\n   |\nLL |         drop(*x as i32); //~ WARNING unreachable statement\n   |         ^^^^^^^^^^^^^^^^\n   |\nnote: lint level defined here\n  --> /checkout/src/test/ui/liveness/liveness-unused.rs:11:9\n   |\nLLe) {\n   |       ^ help: consider using `_x` instead\n   |\nnote: lint level defined here\n  --> /checkout/src/test/ui/liveness/liveness-unused.rs:12:9\n   |\nLL | #![deny(unused_variables)]\n   |         ^^^^^^^^^^^^^^^^\n\n"}
[00:47:10] {"message":"unused variable: `x`","code":{"code":"unused_variables","explanation":null},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/liveness/liveness-unused.rs","byte_start":697,"byte_end":698,"line_start":22,"line_end":22,"column_start":8,"column_end":9,"is_primary":true,"text":[{"text":"fn f1b(x: &mut isize) {","highlight_start":8,"highlight_end":9}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"consider using `_x` instead","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/liveness/liveness-unused.rs","byte_start":697,"byte_end":698,"line_start":22,"line_end":22,"column_start":8,"column_end":9,"is_primary":true,"text":[{"text":"fn f1b(x: &mut isize) {","highlight_start":8,"highlight_end":9}],"label":null,"suggested_replacement":"_x","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"error: unused variable: `x`\n  --> /checkout/src/test/ui/liveness/liveness-unused.rs:22:8\n   |\nLL | fn f1b(x: &mut isize) {\n   |        ^ help: consider using `_x` instead\n\n"}
[00:47:10] {"message":"unused variable: `x`","code":{"code":"unused_variables","explanation":null},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/liveness/liveness-unused.rs","byte_start":820,"byte_end":821,"line_start":30,"line_end":30,"column_start":light_start":9,"highlight_end":10}],"label":null,"suggested_replacement":"_x","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"error: unused variable: `x`\n  --> /checkout/src/test/ui/liveness/liveness-unused.rs:35:9\n   |\nLL |     let x = 3;\n   |         ^ help: consider using `_x` instead\n\n"}
[00:47:10] {"message":"variable `x` is assigned to, but never used","code":{"code":"unused_variables","explanation":null},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/liveness/liveness-unused.rs","byte_start":955,"byte_end":956,"line_start":40,"line_end":40,"column_start":13,"column_end":14,"is_primary":true,"text":[{"text":"    let mut x = 3;","highlight_start":13,"highlight_end":14}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"consider using `_x` instead","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"error: variable `x` is assigned to, but never used\n  --> /checkout/src/test/ui/liveness/liveness-unused.rs:40:13\n   |\nLL |     let mut x = 3;\n   |             ^\n   |\n   = note: consider using `_x` instead\n\n"}
[00:47:10] {"message":"value assigned to `x` is never read\n                     (maybe it is overwritten before being read)","code":{"code":"unused_assignments","explanation":null},"level":"error","spans":[{"file_name":"/checkout/src/test/ui/liveness/liveness-unused.rs","byte_start":1025,"byte_end":1026,"line_start":42,"line_end":42,"column_start":5,"column_end":6,"is_primary":true,"text":[{"text":"    x += 4;","highlight_start":5,"hig

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)

@petrochenkov

This comment has been minimized.

Contributor

petrochenkov commented Dec 2, 2018

Perhaps the "overwritten" message can be reported only if the value is actually overwritten, not simply unread? If there's no necessary infra, then the wording change seems okay.
r? @nikomatsakis

@rust-highfive

This comment has been minimized.

Collaborator

rust-highfive commented Dec 3, 2018

The job x86_64-gnu-llvm-5.0 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.
travis_time:end:09cf9760:start=1543833019891751622,finish=1543833080791020695,duration=60899269073
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#Pull-Requests-and-Security-Restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-5.0
---
[00:47:17] .................................................................................................... 2600/5107
[00:47:22] .................................................................................................... 2700/5107
[00:47:25] .................................................................................................... 2800/5107
[00:47:28] .................................................................................................... 2900/5107
[00:47:31] ................................F................................................................... 3000/5107
[00:47:38] .................................................................................................... 3200/5107
[00:47:41] ........................................ii..i..ii................................................... 3300/5107
[00:47:45] .................................................................................................... 3400/5107
[00:47:48] .................................................................................................... 3500/5107
---
[00:48:38] 
[00:48:38] ---- [ui] ui/lint/issue-47390-unused-variable-in-struct-pattern.rs stdout ----
[00:48:38] diff of stderr:
[00:48:38] 
[00:48:38] 44    = note: consider using `_hours_are_suns` instead
[00:48:38] 45 
[00:48:38] 46 warning: value assigned to `hours_are_suns` is never read
[00:48:38] +                      (maybe it is overwritten before being read)
[00:48:38] 48    |
[00:48:38] 48    |
[00:48:38] 49 LL |         hours_are_suns = false;
[00:48:38] 
[00:48:38] The actual stderr differed from the expected stderr.
[00:48:38] Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/lint/issue-47390-unused-variable-in-struct-pattern/issue-47390-unused-variable-in-struct-pattern.stderr
[00:48:38] Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/lint/issue-47390-unused-variable-in-struct-pattern/issue-47390-unused-variable-in-struct-pattern.stderr
[00:48:38] To update references, rerun the tests and pass the `--bless` flag
[00:48:38] To only update this specific test, also pass `--test-args lint/issue-47390-unused-variable-in-struct-pattern.rs`
[00:48:38] error: 1 errors occurred comparing output.
[00:48:38] status: exit code: 0
[00:48:38] status: exit code: 0
[00:48:38] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/lint/issue-47390-unused-variable-in-struct-pattern/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/lint/issue-47390-unused-variable-in-struct-pattern/auxiliary" "-A" "unused"
[00:48:38] ------------------------------------------
[00:48:38] 
[00:48:38] ------------------------------------------
[00:48:38] stderr:
[00:48:38] stderr:
[00:48:38] ------------------------------------------
[00:48:38] {"message":"unused variable: `i_think_continually`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":868,"byte_end":887,"line_start":36,"line_end":36,"column_start":9,"column_end":28,"is_primary":true,"text":[{"text":"    let i_think_continually = 2;","highlight_start":9,"highlight_end":28}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"lint level defined here","code":null,"level":"note","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":542,"byte_end":548,"line_start":15,"line_end":15,"column_start":9,"column_end":15,"is_primary":true,"text":[{"text":"#![warn(unused)] // UI tests pass `-A unused` (#43896)","highlight_start":9,"highlight_end":15}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":null},{"message":"#[warn(unused_variables)] implied by #[warn(unused)]","code":null,"level":"note","spans":[],"children":[],"rendered":null},{"message":"consider using `_i_think_continually` instead","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":868,"byte_end":887,"line_start":36,"line_end":36,"column_start":9,"column_end":28,"is_primary":true,"text":[{"text":"    let i_think_continually = 2;","highlight_start":9,"highlight_end":28}],"label":null,"suggested_replacement":"_i_think_continually","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `i_think_continually`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:36:9\n   |\nLL |     let i_think_continually = 2;\n   |         ^^^^^^^^^^^^^^^^^^^ help: consider using `_i_think_continually` instead\n   |\nnote: lint level defined here\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:15:9\n   |\nLL | #![warn(unused)] // UI tests pass `-A unused` (#43896)\n   |         ^^^^^^\n   = note: #[warn(unused_variables)] implied by #[warn(unused)]\n\n"}
[00:48:38] {"message":"unused variable: `mut_unused_var`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1061,"byte_end":1075,"line_start":43,"line_end":43,"column_start":13,"column_end":27,"is_primary":true,"text":[{"text":"    let mut mut_unused_var = 1;","highlight_start":13,"highlight_end":27}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"consider using `_mut_unused_var` instead","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1061,"byte_end":1075,"line_start":43,"line_end":43,"column_start":13,"column_end":27,"is_primary":true,"text":[{"text":"    let mut mut_unused_var = 1;","highlight_start":13,"highlight_end":27}],"label":null,"suggested_replacement":"_mut_unused_var","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `mut_unused_var`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:43:13\n   |\nLL |     let mut mut_unused_var = 1;\n   |             ^^^^^^^^^^^^^^ help: consider using `_mut_unused_var` instead\n\n"}
[00:48:38] {"message":"unused variable: `var`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1095,"byte_end":1098,"line_start":45,"line_end":45,"column_start":14,"column_end":17,"is_primary":true,"text":[{"text":"    let (mut var, unused_var) = (1, 2);","highlight_start":14,"highlight_end":17}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"consider using `_var` instead","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1095,"byte_end":1098,"line_start":45,"line_end":45,"column_start":14,"column_end":17,"is_primary":true,"text":[{"text":"    let (mut var, unused_var) = (1, 2);","highlight_start":14,"highlight_end":17}],"label":null,"suggested_replacement":"_var","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `var`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:45:14\n   |\nLL |     let (mut var, unused_var) = (1, 2);\n   |              ^^^ help: consider using `_var` instead\n\n"}
[00:48:38] {"message":"unused variable: `unused_var`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1100,"byte_end":1110,"line_start":45,"line_end":45,"column_start":19,"column_end":29,"is_primary":true,"text":[{"text":"    let (mut var, unused_var) = (1, 2);","highlight_start":19,"highlight_end":29}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"consider using `_unused_var` instead","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1100,"byte_end":1110,"line_start":45,"line_end":45,"column_start":19,"column_end":29,"is_primary":true,"text":[{"text":"    let (mut var, unused_var) = (1, 2);","highlight_start":19,"highlight_end":29}],"label":null,"suggested_replacement":"_unused_var","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `unused_var`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:45:19\n   |\nLL |     let (mut var, unused_var) = (1, 2);\n   |                   ^^^^^^^^^^ help: consider using `_unused_var` instead\n\n"}
[00:48:38] {"message":"unused variable: `corridors_of_light`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1148,"byte_end":1166,"line_start":47,"line_end":47,"column_start":26,"column_end":44,"is_primary":true,"text":[{"text":"    if let SoulHistory { corridors_of_light,","highlight_start":26,"highlight_end":44}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1148,"byte_end":1166,"line_start":47,"line_end":47,"column_start":26,"column_end":44,"is_primary":true,"text":[{"text":"    if let SoulHistory { corridors_of_light,","highlight_start":26,"highlight_end":44}],"label":null,"suggested_replacement":"corridors_of_light: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `corridors_of_light`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:47:26\n   |\nLL |     if let SoulHistory { corridors_of_light,\n   |                          ^^^^^^^^^^^^^^^^^^ help: try ignoring the field: `corridors_of_light: _`\n\n"}
[00:48:38] {"message":"variable `hours_are_suns` is assigned to, but never used","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1197,"byte_end":1211,"line_start":48,"line_end":48,"column_start":30,"column_end":44,"is_primary":true,"text":[{"text":"                         mut hours_are_suns,","highlight_start":30,"highlight_end":44}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"consider using `_hours_are_suns` instead","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"warning: variable `hours_are_suns` is assigned to, but never used\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:48:30\n   |\nLL |                          mut hours_are_suns,\n   |                              ^^^^^^^^^^^^^^\n   |\n   = note: consider using `_hours_are_suns` instead\n\n"}
[00:48:38] {"message":"value assigned to `hours_are_suns` is never read\n                     (maybe it is overwritten before being read)","code":{"code":"unused_assignments","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1307,"byte_end":1321,"line_start":50,"line_end":50,"column_start":9,"column_end":23,"is_primary":true,"text":[{"text":"        hours_are_suns = false;","highlight_start":9,"highlight_end":23}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"lint level defined here","code":null,"level":"note","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":542,"byte_end":548,"line_start":15,"line_end":15,"column_start":9,"column_end":15,"is_primary":true,"text":[{"text":"#![warn(unused)] // UI tests pass `-A unused` (#43896)","highlight_start":9,"highlight_end":15}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":null},{"message":"#[warn(unused_assignments)] implied by #[warn(unused)]","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"warning: value assigned to `hours_are_suns` is never read\n                     (maybe it is overwritten before being read)\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:50:9\n   |\nLL |         hours_are_suns = false;\n   |         ^^^^^^^^^^^^^^\n   |\nnote: lint level defined here\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:15:9\n   |\nLL | #![warn(unused)] // UI tests pass `-A unused` (#43896)\n   |         ^^^^^^\n   = note: #[warn(unused_assignments)] implied by #[warn(unused)]\n\n"}
[00:48:38] {"message":"unused variable: `fire`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1427,"byte_end":1431,"line_start":54,"line_end":54,"column_start":32,"column_end":36,"is_primary":true,"text":[{"text":"    let LovelyAmbition { lips, fire } = the_spirit;","highlight_start":32,"highlight_end":36}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1427,"byte_end":1431,"line_start":54,"line_end":54,"column_start":32,"column_end":36,"is_primary":true,"text":[{"text":"    let LovelyAmbition { lips, fire } = the_spirit;","highlight_start":32,"highlight_end":36}],"label":null,"suggested_replacement":"fire: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `fire`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:54:32\n   |\nLL |     let LovelyAmbition { lips, fire } = the_spirit;\n   |                                ^^^^ help: try ignoring the field: `fire: _`\n\n"}
[00:48:38] {"message":"unused variable: `case`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1586,"byte_end":1590,"line_start":63,"line_end":63,"column_start":23,"column_end":27,"is_primary":true,"text":[{"text":"        Large::Suit { case } => {}","highlight_start":23,"highlight_end":27}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1586,"byte_end":1590,"line_start":63,"line_end":63,"column_start":23,"column_end":27,"is_primary":true,"text":[{"text":"        Large::Suit { case } => {}","highlight_start":23,"highlight_end":27}],"label":null,"suggested_replacement":"case: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `case`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:63:23\n   |\nLL |         Large::Suit { case } => {}\n   |                       ^^^^ help: try ignoring the field: `case: _`\n\n"}
[00:48:38] {"message":"unused variable: `case`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1672,"byte_end":1676,"line_start":68,"line_end":68,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"        &Large::Suit { case } => {}","highlight_start":24,"highlight_end":28}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1672,"byte_end":1676,"line_start":68,"line_end":68,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"        &Large::Suit { case } => {}","highlight_start":24,"highlight_end":28}],"label":null,"suggested_replacement":"case: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `case`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:68:24\n   |\nLL |         &Large::Suit { case } => {}\n   |                        ^^^^ help: try ignoring the field: `case: _`\n\n"}
[00:48:38] {"message":"unused variable: `case`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1759,"byte_end":1763,"line_start":73,"line_end":73,"column_start":27,"column_end":31,"is_primary":true,"text":[{"text":"        box Large::Suit { case } => {}","highlight_start":27,"highlight_end":31}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1759,"byte_end":1763,"line_start":73,"line_end":73,"column_start":27,"column_end":31,"is_primary":true,"text":[{"text":"        box Large::Suit { case } => {}","highlight_start":27,"highlight_end":31}],"label":null,"suggested_replacement":"case: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `case`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:73:27\n   |\nLL |         box Large::Suit { case } => {}\n   |                           ^^^^ help: try ignoring the field: `case: _`\n\n"}
[00:48:38] {"message":"unused variable: `case`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1847,"byte_end":1851,"line_start":78,"line_end":78,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"        (Large::Suit { case },) => {}","highlight_start":24,"highlight_end":28}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1847,"byte_end":1851,"line_start":78,"line_end":78,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"        (Large::Suit { case },) => {}","highlight_start":24,"highlight_end":28}],"label":null,"suggested_replacement":"case: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `case`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:78:24\n   |\nLL |         (Large::Suit { case },) => {}\n   |                        ^^^^ help: try ignoring the field: `case: _`\n\n"}
[00:48:38] {"message":"unused variable: `case`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1936,"byte_end":1940,"line_start":83,"line_end":83,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"        [Large::Suit { case }] => {}","highlight_start":24,"highlight_end":28}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1936,"byte_end":1940,"line_start":83,"line_end":83,"column_start":24,"column_end":28,"is_primary":true,"text":[{"text":"        [Large::Suit { case }] => {}","highlight_start":24,"highlight_end":28}],"label":null,"suggested_replacement":"case: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `case`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:83:24\n   |\nLL |         [Large::Suit { case }] => {}\n   |                        ^^^^ help: try ignoring the field: `case: _`\n\n"}
[00:48:38] {"message":"unused variable: `case`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":2045,"byte_end":2049,"line_start":88,"line_end":88,"column_start":29,"column_end":33,"is_primary":true,"text":[{"text":"        Tuple(Large::Suit { case }, ()) => {}","highlight_start":29,"highlight_end":33}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"try ignoring the field","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":2045,"byte_end":2049,"line_start":88,"line_end":88,"column_start":29,"column_end":33,"is_primary":true,"text":[{"text":"        Tuple(Large::Suit { case }, ()) => {}","highlight_start":29,"highlight_end":33}],"label":null,"suggested_replacement":"case: _","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `case`\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:88:29\n   |\nLL |         Tuple(Large::Suit { case }, ()) => {}\n   |                             ^^^^ help: try ignoring the field: `case: _`\n\n"}
[00:48:38] {"message":"variable does not need to be mutable","code":{"code":"unused_mut","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1057,"byte_end":1075,"line_start":43,"line_end":43,"column_start":9,"column_end":27,"is_primary":true,"text":[{"text":"    let mut mut_unused_var = 1;","highlight_start":9,"highlight_end":27}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"lint level defined here","code":null,"level":"note","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":542,"byte_end":548,"line_start":15,"line_end":15,"column_start":9,"column_end":15,"is_primary":true,"text":[{"text":"#![warn(unused)] // UI tests pass `-A unused` (#43896)","highlight_start":9,"highlight_end":15}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":null},{"message":"#[warn(unused_mut)] implied by #[warn(unused)]","code":null,"level":"note","spans":[],"children":[],"rendered":null},{"message":"remove this `mut`","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1057,"byte_end":1061,"line_start":43,"line_end":43,"column_start":9,"column_end":13,"is_primary":true,"text":[{"text":"    let mut mut_unused_var = 1;","highlight_start":9,"highlight_end":13}],"label":null,"suggested_replacement":"","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: variable does not need to be mutable\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:43:9\n   |\nLL |     let mut mut_unused_var = 1;\n   |         ----^^^^^^^^^^^^^^\n   |         |\n   |         help: remove this `mut`\n   |\nnote: lint level defined here\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:15:9\n   |\nLL | #![warn(unused)] // UI tests pass `-A unused` (#43896)\n   |         ^^^^^^\n   = note: #[warn(unused_mut)] implied by #[warn(unused)]\n\n"}
[00:48:38] {"message":"variable does not need to be mutable","code":{"code":"unused_mut","explanation":null},"level":"warning","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1091,"byte_end":1098,"line_start":45,"line_end":45,"column_start":10,"column_end":17,"is_primary":true,"text":[{"text":"    let (mut var, unused_var) = (1, 2);","highlight_start":10,"highlight_end":17}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"remove this `mut`","code":null,"level":"help","spans":[{"file_name":"/checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs","byte_start":1091,"byte_end":1095,"line_start":45,"line_end":45,"column_start":10,"column_end":14,"is_primary":true,"text":[{"text":"    let (mut var, unused_var) = (1, 2);","highlight_start":10,"highlight_end":14}],"label":null,"suggested_replacement":"","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: variable does not need to be mutable\n  --> /checkout/src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.rs:45:10\n   |\nLL |     let (mut var, unused_var) = (1, 2);\n   |          ----^^^\n   |          |\n   |          help: remove this `mut`\n\n"}
[00:48:38] ------------------------------------------
[00:48:38] 
[00:48:38] thread '[ui] ui/lint/issue-47390-unused-variable-in-struct-pattern.rs' panicked at 'explicit panic', src/tools/compiletest/src/runtest.rs:3282:9
[00:48:38] note: Run with `RUST_BACKTRACE=1` for a backtrace.
---
[00:48:38] test result: FAILED. 5082 passed; 1 failed; 24 ignored; 0 measured; 0 filtered out
[00:48:38] 
[00:48:38] 
[00:48:38] 
[00:48:38] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/ui" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "ui" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-5.0/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--target-rustcflags" "-Crpath -O -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python2.7" "--lldb-python" "/usr/bin/python2.7" "--gdb" "/usr/bin/gdb" "--quiet" "--llvm-version" "5.0.0\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
[00:48:38] 
[00:48:38] 
[00:48:38] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[00:48:38] Build completed unsuccessfully in 0:03:52
[00:48:38] Build completed unsuccessfully in 0:03:52
[00:48:38] Makefile:58: recipe for target 'check' failed
[00:48:38] make: *** [check] Error 1
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:133f2bb6
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Mon Dec  3 11:20:09 UTC 2018

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)

} else {
self.ir.tcx.lint_hir(lint::builtin::UNUSED_ASSIGNMENTS, hir_id, sp,
&format!("value assigned to `{}` is never read", name));
&format!("value assigned to `{}` is never read
(maybe it is overwritten before being read)", name));

This comment has been minimized.

@nikomatsakis

nikomatsakis Dec 4, 2018

Contributor

Hmm, it's a nice idea to make a suggestion like this. It'd be nicer if we could find the overwriting assignment. But i'm reluctant to suggest trying to implement that, since this liveness code is ripe to be rewritten completely.

Still, I think that including the suggestion in a parenthetical makes it less likely to be noticed, and more likely to wrap around on the terminal.

A middle option would be to create a "help". You could change this code from self.ir.tcx.lint_hir(..) to:

let msg = self.ir.tcx.self.struct_span_lint_hir(...)
  .help("maybe it is overwritten before being read?")
  .emit();

and I think things would look better.

This comment has been minimized.

@JohnGinger

JohnGinger Dec 7, 2018

Contributor

Sounds good to me.

I could try rewriting the liveness code, but I don't think I know enough about how it works...

This comment has been minimized.

@nikomatsakis

nikomatsakis Dec 11, 2018

Contributor

I'd love to talk you through it =) but it'd obviously be a rather bigger endeavor :)

This comment has been minimized.

@JohnGinger

JohnGinger Dec 12, 2018

Contributor

I'm happy to try :)

@nikomatsakis

This comment has been minimized.

Contributor

nikomatsakis commented Dec 11, 2018

@bors r+ rollup

@bors

This comment has been minimized.

Contributor

bors commented Dec 11, 2018

📌 Commit c0e3f4b has been approved by nikomatsakis

pietroalbini added a commit to pietroalbini/rust that referenced this pull request Dec 11, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

bors added a commit that referenced this pull request Dec 11, 2018

Auto merge of #56728 - pietroalbini:rollup, r=pietroalbini
Rollup of 13 pull requests

Successful merges:

 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56507 (polonius tweaks)
 - #56572 (Contexually dependent error message for E0424 when value is assigned to "self")
 - #56609 (Unconditionally emit the target-cpu LLVM attribute.)
 - #56637 (rustdoc: Fix local reexports of proc macros)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56682 (Update the stdsimd submodule)
 - #56691 (fix install broken link)
 - #56702 ([self-profiler] Add column for percent of total time)
 - #56708 (Remove some unnecessary feature gates)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)

Failed merges:

r? @ghost

bors added a commit that referenced this pull request Dec 11, 2018

Auto merge of #56728 - pietroalbini:rollup, r=pietroalbini
Rollup of 13 pull requests

Successful merges:

 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56507 (polonius tweaks)
 - #56572 (Contexually dependent error message for E0424 when value is assigned to "self")
 - #56609 (Unconditionally emit the target-cpu LLVM attribute.)
 - #56637 (rustdoc: Fix local reexports of proc macros)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56682 (Update the stdsimd submodule)
 - #56691 (fix install broken link)
 - #56702 ([self-profiler] Add column for percent of total time)
 - #56708 (Remove some unnecessary feature gates)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)

Failed merges:

r? @ghost

bors added a commit that referenced this pull request Dec 12, 2018

Auto merge of #56728 - pietroalbini:rollup, r=pietroalbini
Rollup of 13 pull requests

Successful merges:

 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56507 (polonius tweaks)
 - #56572 (Contexually dependent error message for E0424 when value is assigned to "self")
 - #56609 (Unconditionally emit the target-cpu LLVM attribute.)
 - #56637 (rustdoc: Fix local reexports of proc macros)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56682 (Update the stdsimd submodule)
 - #56691 (fix install broken link)
 - #56702 ([self-profiler] Add column for percent of total time)
 - #56708 (Remove some unnecessary feature gates)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)

Failed merges:

r? @ghost

kennytm added a commit to kennytm/rust that referenced this pull request Dec 12, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

pietroalbini added a commit to pietroalbini/rust that referenced this pull request Dec 12, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

bors added a commit that referenced this pull request Dec 12, 2018

Auto merge of #56757 - pietroalbini:rollup, r=pietroalbini
Rollup of 17 pull requests

Successful merges:

 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56507 (polonius tweaks)
 - #56572 (Contexually dependent error message for E0424 when value is assigned to "self")
 - #56672 (Document time of back operations of a Linked List)
 - #56677 (#[must_use] on traits in stdlib)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56682 (Update the stdsimd submodule)
 - #56691 (fix install broken link)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)
 - #56713 (Test capacity of ZST vector)
 - #56718 (Use libbacktrace pretty-printing)
 - #56725 (fix rust-lang/rust issue #50583)
 - #56731 (Add missing urls in ffi module docs)
 - #56738 (Fix private_no_mangle_fns message grammar)
 - #56746 (Add test of current behavior (infer free region within closure body))

Failed merges:

r? @ghost

pietroalbini added a commit to pietroalbini/rust that referenced this pull request Dec 13, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

kennytm added a commit to kennytm/rust that referenced this pull request Dec 13, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

bors added a commit that referenced this pull request Dec 13, 2018

Auto merge of #56775 - kennytm:rollup, r=kennytm
Rollup of 34 pull requests

Successful merges:

 - #56142 ([std] Osstr lossy example)
 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56351 (Stabilize `linker-flavor` flag.)
 - #56439 (Clearer error message for dead assign)
 - #56490 (Add checked_add method to Instant time type)
 - #56507 (polonius tweaks)
 - #56562 (Update libc version required by rustc)
 - #56600 (bootstrap: fix edition)
 - #56609 (Unconditionally emit the target-cpu LLVM attribute.)
 - #56637 (rustdoc: Fix local reexports of proc macros)
 - #56658 (Add non-panicking `maybe_new_parser_from_file` variant)
 - #56672 (Document time of back operations of a Linked List)
 - #56677 (#[must_use] on traits in stdlib)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56691 (fix install broken link)
 - #56695 (Fix irrefutable matches on integer ranges)
 - #56699 (Use a `newtype_index!` within `Symbol`.)
 - #56702 ([self-profiler] Add column for percent of total time)
 - #56708 (Remove some unnecessary feature gates)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)
 - #56713 (Test capacity of ZST vector)
 - #56718 (Use libbacktrace pretty-printing)
 - #56725 (fix rust-lang/rust issue #50583)
 - #56731 (Add missing urls in ffi module docs)
 - #56738 (Fix private_no_mangle_fns message grammar)
 - #56742 (infer: remove Box from a returned Iterator)
 - #56746 (Add test of current behavior (infer free region within closure body))
 - #56747 (target: remove Box returned by get_targets)
 - #56749 (x86: Add the `adx` target feature to whitelist)
 - #56755 (Account for `impl Trait` when suggesting lifetime)
 - #56756 (Disable btree pretty-printers on older gdbs)
 - #56758 (Add short emoji status to toolstate updates)
 - #56783 (Add `--pinentry-mode=loopback` to deployment script)

bors added a commit that referenced this pull request Dec 13, 2018

Auto merge of #56775 - kennytm:rollup, r=kennytm
Rollup of 32 pull requests

Successful merges:

 - #56142 ([std] Osstr lossy example)
 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56351 (Stabilize `linker-flavor` flag.)
 - #56439 (Clearer error message for dead assign)
 - #56507 (polonius tweaks)
 - #56562 (Update libc version required by rustc)
 - #56600 (bootstrap: fix edition)
 - #56609 (Unconditionally emit the target-cpu LLVM attribute.)
 - #56637 (rustdoc: Fix local reexports of proc macros)
 - #56658 (Add non-panicking `maybe_new_parser_from_file` variant)
 - #56672 (Document time of back operations of a Linked List)
 - #56677 (#[must_use] on traits in stdlib)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56691 (fix install broken link)
 - #56695 (Fix irrefutable matches on integer ranges)
 - #56699 (Use a `newtype_index!` within `Symbol`.)
 - #56702 ([self-profiler] Add column for percent of total time)
 - #56708 (Remove some unnecessary feature gates)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)
 - #56713 (Test capacity of ZST vector)
 - #56718 (Use libbacktrace pretty-printing)
 - #56725 (fix rust-lang/rust issue #50583)
 - #56731 (Add missing urls in ffi module docs)
 - #56738 (Fix private_no_mangle_fns message grammar)
 - #56742 (infer: remove Box from a returned Iterator)
 - #56746 (Add test of current behavior (infer free region within closure body))
 - #56747 (target: remove Box returned by get_targets)
 - #56749 (x86: Add the `adx` target feature to whitelist)
 - #56755 (Account for `impl Trait` when suggesting lifetime)
 - #56756 (Disable btree pretty-printers on older gdbs)
 - #56758 (Add short emoji status to toolstate updates)

kennytm added a commit to kennytm/rust that referenced this pull request Dec 14, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

bors added a commit that referenced this pull request Dec 14, 2018

Auto merge of #56803 - kennytm:rollup, r=kennytm
Rollup of 36 pull requests

Successful merges:

 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56490 (Add checked_add method to Instant time type)
 - #56507 (polonius tweaks)
 - #56562 (Update libc version required by rustc)
 - #56600 (bootstrap: fix edition)
 - #56609 (Unconditionally emit the target-cpu LLVM attribute.)
 - #56658 (Add non-panicking `maybe_new_parser_from_file` variant)
 - #56672 (Document time of back operations of a Linked List)
 - #56677 (#[must_use] on traits in stdlib)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56691 (fix install broken link)
 - #56695 (Fix irrefutable matches on integer ranges)
 - #56699 (Use a `newtype_index!` within `Symbol`.)
 - #56702 ([self-profiler] Add column for percent of total time)
 - #56708 (Remove some unnecessary feature gates)
 - #56709 (Remove unneeded extra chars to reduce search-index size)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)
 - #56713 (Test capacity of ZST vector)
 - #56718 (Use libbacktrace pretty-printing)
 - #56725 (fix rust-lang/rust issue #50583)
 - #56731 (Add missing urls in ffi module docs)
 - #56738 (Fix private_no_mangle_fns message grammar)
 - #56742 (infer: remove Box from a returned Iterator)
 - #56744 (specialize: remove Boxes used by Children::insert)
 - #56746 (Add test of current behavior (infer free region within closure body))
 - #56747 (target: remove Box returned by get_targets)
 - #56749 (x86: Add the `adx` target feature to whitelist)
 - #56751 (Allow ptr::hash to accept fat pointers)
 - #56755 (Account for `impl Trait` when suggesting lifetime)
 - #56756 (Disable btree pretty-printers on older gdbs)
 - #56758 (Add short emoji status to toolstate updates)
 - #56760 (Deduplicate unsatisfied trait bounds)
 - #56769 (Add x86_64-unknown-uefi target)
 - #56789 (rustc: Add an unstable `simd_select_bitmask` intrinsic)

bors added a commit that referenced this pull request Dec 14, 2018

Auto merge of #56803 - kennytm:rollup, r=kennytm
Rollup of 36 pull requests

Successful merges:

 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56490 (Add checked_add method to Instant time type)
 - #56507 (polonius tweaks)
 - #56562 (Update libc version required by rustc)
 - #56600 (bootstrap: fix edition)
 - #56609 (Unconditionally emit the target-cpu LLVM attribute.)
 - #56658 (Add non-panicking `maybe_new_parser_from_file` variant)
 - #56672 (Document time of back operations of a Linked List)
 - #56677 (#[must_use] on traits in stdlib)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56691 (fix install broken link)
 - #56695 (Fix irrefutable matches on integer ranges)
 - #56699 (Use a `newtype_index!` within `Symbol`.)
 - #56702 ([self-profiler] Add column for percent of total time)
 - #56708 (Remove some unnecessary feature gates)
 - #56709 (Remove unneeded extra chars to reduce search-index size)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)
 - #56713 (Test capacity of ZST vector)
 - #56718 (Use libbacktrace pretty-printing)
 - #56725 (fix rust-lang/rust issue #50583)
 - #56731 (Add missing urls in ffi module docs)
 - #56738 (Fix private_no_mangle_fns message grammar)
 - #56742 (infer: remove Box from a returned Iterator)
 - #56744 (specialize: remove Boxes used by Children::insert)
 - #56746 (Add test of current behavior (infer free region within closure body))
 - #56747 (target: remove Box returned by get_targets)
 - #56749 (x86: Add the `adx` target feature to whitelist)
 - #56751 (Allow ptr::hash to accept fat pointers)
 - #56755 (Account for `impl Trait` when suggesting lifetime)
 - #56756 (Disable btree pretty-printers on older gdbs)
 - #56758 (Add short emoji status to toolstate updates)
 - #56760 (Deduplicate unsatisfied trait bounds)
 - #56769 (Add x86_64-unknown-uefi target)
 - #56789 (rustc: Add an unstable `simd_select_bitmask` intrinsic)

kennytm added a commit to kennytm/rust that referenced this pull request Dec 14, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

bors added a commit that referenced this pull request Dec 14, 2018

Auto merge of #56817 - kennytm:rollup, r=kennytm
Rollup of 27 pull requests (second batch)

Successful merges:

 - #53506 (Documentation for impl From for AtomicBool and other Atomic types)
 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56507 (polonius tweaks)
 - #56572 (Contexually dependent error message for E0424 when value is assigned to "self")
 - #56600 (bootstrap: fix edition)
 - #56672 (Document time of back operations of a Linked List)
 - #56677 (#[must_use] on traits in stdlib)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56682 (Update the stdsimd submodule)
 - #56691 (fix install broken link)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)
 - #56713 (Test capacity of ZST vector)
 - #56718 (Use libbacktrace pretty-printing)
 - #56725 (fix rust-lang/rust issue #50583)
 - #56731 (Add missing urls in ffi module docs)
 - #56738 (Fix private_no_mangle_fns message grammar)
 - #56746 (Add test of current behavior (infer free region within closure body))
 - #56747 (target: remove Box returned by get_targets)
 - #56751 (Allow ptr::hash to accept fat pointers)
 - #56755 (Account for `impl Trait` when suggesting lifetime)
 - #56758 (Add short emoji status to toolstate updates)
 - #56760 (Deduplicate unsatisfied trait bounds)
 - #56769 (Add x86_64-unknown-uefi target)
 - #56772 (fix issue 54153 by not testing issue-18804 on Windows nor OS X.)
 - #56808 (Fixes broken links)

Failed merges:

r? @ghost

pietroalbini added a commit to pietroalbini/rust that referenced this pull request Dec 14, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

bors added a commit that referenced this pull request Dec 14, 2018

Auto merge of #56830 - pietroalbini:rollup, r=pietroalbini
Rollup of 25 pull requests

Successful merges:

 - #53506 (Documentation for impl From for AtomicBool and other Atomic types)
 - #56203 (Add lint for items deprecated in future)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56507 (polonius tweaks)
 - #56672 (Document time of back operations of a Linked List)
 - #56677 (#[must_use] on traits in stdlib)
 - #56679 (overhaul external doc attribute diagnostics)
 - #56682 (Update the stdsimd submodule)
 - #56691 (fix install broken link)
 - #56710 (Always set the RDRAND and RDSEED features on SGX)
 - #56713 (Test capacity of ZST vector)
 - #56718 (Use libbacktrace pretty-printing)
 - #56725 (fix rust-lang/rust issue #50583)
 - #56731 (Add missing urls in ffi module docs)
 - #56738 (Fix private_no_mangle_fns message grammar)
 - #56746 (Add test of current behavior (infer free region within closure body))
 - #56747 (target: remove Box returned by get_targets)
 - #56751 (Allow ptr::hash to accept fat pointers)
 - #56755 (Account for `impl Trait` when suggesting lifetime)
 - #56758 (Add short emoji status to toolstate updates)
 - #56760 (Deduplicate unsatisfied trait bounds)
 - #56769 (Add x86_64-unknown-uefi target)
 - #56808 (Fixes broken links)
 - #56809 (Fix docs path to PermissionsExt)

Failed merges:

r? @ghost

Centril added a commit to Centril/rust that referenced this pull request Dec 16, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

bors added a commit that referenced this pull request Dec 16, 2018

Auto merge of #56873 - Centril:rollup, r=Centril
Rollup of 22 pull requests

Successful merges:

 - #53506 (Documentation for impl From for AtomicBool and other Atomic types)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56640 (Add FreeBSD unsigned char platforms to std::os::raw)
 - #56647 (Rework treatment of `$crate` in procedural macros)
 - #56648 (Fix BTreeMap UB)
 - #56672 (Document time of back operations of a Linked List)
 - #56706 (Make `const unsafe fn` bodies `unsafe`)
 - #56737 (`TokenStream` improvements)
 - #56742 (infer: remove Box from a returned Iterator)
 - #56761 (Suggest using `.display()` when trying to print a `Path`)
 - #56781 (Update LLVM submodule)
 - #56789 (rustc: Add an unstable `simd_select_bitmask` intrinsic)
 - #56790 (Make RValue::Discriminant a normal Shallow read)
 - #56793 (rustdoc: look for comments when scraping attributes/crates from doctests)
 - #56826 (rustc: Add the `cmpxchg16b` target feature on x86/x86_64)
 - #56832 (std: Use `rustc_demangle` from crates.io)
 - #56844 (Improve CSS rule)
 - #56850 (Fixed issue with using `Self` ctor in typedefs)
 - #56855 (Remove u8 cttz hack)
 - #56857 (Fix a small mistake regarding NaNs in a deprecation message)
 - #56858 (Fix doc of `std::fs::canonicalize`)

Failed merges:

r? @ghost

Centril added a commit to Centril/rust that referenced this pull request Dec 16, 2018

Rollup merge of rust-lang#56439 - JohnGinger:master, r=nikomatsakis
Clearer error message for dead assign

I'm not that this is the right place for this (if it needs an RFC or not).

I had the problem where I misunderstood the compiler lint message rust-lang#56436 and other people seem to have had the same problem https://www.reddit.com/r/rust/comments/8cy9p4/value_assigned_to_is_never_read/.

I think this new wording might be slightly clearer (and help out beginners like me). I'm very new though, so there might be some nuance I'm missing that would make this more confusing or a bad idea for other reasons.

I thought I would create a PR to make it easy to change the code if the consensus was that it would make sense to make a change.

If this is the wrong place for this sort of thing I'll happily delete/move it.

bors added a commit that referenced this pull request Dec 16, 2018

Auto merge of #56875 - Centril:rollup, r=Centril
Rollup of 20 pull requests

Successful merges:

 - #53506 (Documentation for impl From for AtomicBool and other Atomic types)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56640 (Add FreeBSD unsigned char platforms to std::os::raw)
 - #56648 (Fix BTreeMap UB)
 - #56672 (Document time of back operations of a Linked List)
 - #56706 (Make `const unsafe fn` bodies `unsafe`)
 - #56742 (infer: remove Box from a returned Iterator)
 - #56761 (Suggest using `.display()` when trying to print a `Path`)
 - #56781 (Update LLVM submodule)
 - #56789 (rustc: Add an unstable `simd_select_bitmask` intrinsic)
 - #56790 (Make RValue::Discriminant a normal Shallow read)
 - #56793 (rustdoc: look for comments when scraping attributes/crates from doctests)
 - #56826 (rustc: Add the `cmpxchg16b` target feature on x86/x86_64)
 - #56832 (std: Use `rustc_demangle` from crates.io)
 - #56844 (Improve CSS rule)
 - #56850 (Fixed issue with using `Self` ctor in typedefs)
 - #56855 (Remove u8 cttz hack)
 - #56857 (Fix a small mistake regarding NaNs in a deprecation message)
 - #56858 (Fix doc of `std::fs::canonicalize`)

Failed merges:

 - #56741 (treat ref-to-raw cast like a reborrow: do a special kind of retag)

r? @ghost

bors added a commit that referenced this pull request Dec 16, 2018

Auto merge of #56875 - Centril:rollup, r=Centril
Rollup of 20 pull requests

Successful merges:

 - #53506 (Documentation for impl From for AtomicBool and other Atomic types)
 - #56343 (Remove not used mod)
 - #56439 (Clearer error message for dead assign)
 - #56640 (Add FreeBSD unsigned char platforms to std::os::raw)
 - #56648 (Fix BTreeMap UB)
 - #56672 (Document time of back operations of a Linked List)
 - #56706 (Make `const unsafe fn` bodies `unsafe`)
 - #56742 (infer: remove Box from a returned Iterator)
 - #56761 (Suggest using `.display()` when trying to print a `Path`)
 - #56781 (Update LLVM submodule)
 - #56789 (rustc: Add an unstable `simd_select_bitmask` intrinsic)
 - #56790 (Make RValue::Discriminant a normal Shallow read)
 - #56793 (rustdoc: look for comments when scraping attributes/crates from doctests)
 - #56826 (rustc: Add the `cmpxchg16b` target feature on x86/x86_64)
 - #56832 (std: Use `rustc_demangle` from crates.io)
 - #56844 (Improve CSS rule)
 - #56850 (Fixed issue with using `Self` ctor in typedefs)
 - #56855 (Remove u8 cttz hack)
 - #56857 (Fix a small mistake regarding NaNs in a deprecation message)
 - #56858 (Fix doc of `std::fs::canonicalize`)

Failed merges:

 - #56741 (treat ref-to-raw cast like a reborrow: do a special kind of retag)

r? @ghost

@bors bors merged commit c0e3f4b into rust-lang:master Dec 16, 2018

1 check passed

continuous-integration/travis-ci/pr The Travis CI build passed
Details
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment