Fix for issue #58050

[asettouf]

Hi,

a quick PR to mention in the compiler error message that ? is a macro operator, as according to issue #58050

It passed python x.py test src/tools/tidy locally, as well as the recommendation to run /x.py test src/test/ui --stage 1 --bless.

Let me know if anything else is needed.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @michaelwoerister (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 Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed.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.

[asettouf]

@varkor Good suggestions, my bad!

[varkor]

@asettouf: I should have clarified — the other two messages needed the same changes (I've made specific suggestions now). After that, it looks good to me!

[rust-highfive]

The job x86_64-gnu-llvm-6.0 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:2d9c83f6:start=1549189075181025206,finish=1549189155925707163,duration=80744681957
$ 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-6.0
---
[00:56:23] .................................................................................................... 2900/5362
[00:56:26] .................................................................................................... 3000/5362
[00:56:29] .................................................................................................... 3100/5362
[00:56:33] .................................................................................................... 3200/5362
[00:56:36] .........F.........i................................................................................ 3300/5362
[00:56:42] .................................................................................................... 3500/5362
[00:56:46] .................................................................................................... 3600/5362
[00:56:48] ..................................................................................ii................ 3700/5362
[00:56:51] .................................................................................................... 3800/5362
---
[00:57:46] 
[00:57:46] ---- [ui] ui/macros/macro-at-most-once-rep-2015-ques-rep.rs stdout ----
[00:57:46] diff of stderr:
[00:57:46] 
[00:57:46] 12 LL |     ($(a),?) => {} //~ERROR expected `*` or `+`
[00:57:46] 14    |
[00:57:46] -    = note: `?` is not a macro repetition operator in the 2015 edition, but is accepted in the 2018 edition
[00:57:46] -    = note: `?` is not a macro repetition operator in the 2015 edition, but is accepted in the 2018 edition
[00:57:46] +    = note: `?` is not a macro repetition operator in the 2015 edition,but is accepted in the 2018 edition
[00:57:46] 17 error: aborting due to 2 previous errors
[00:57:46] 18 
[00:57:46] 
[00:57:46] 
[00:57:46] 
[00:57:46] The actual stderr differed from the expected stderr.
[00:57:46] Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/macros/macro-at-most-once-rep-2015-ques-rep/macro-at-most-once-rep-2015-ques-rep.stderr
[00:57:46] To update references, rerun the tests and pass the `--bless` flag
[00:57:46] To only update this specific test, also pass `--test-args macros/macro-at-most-once-rep-2015-ques-rep.rs`
[00:57:46] error: 1 errors occurred comparing output.
[00:57:46] status: exit code: 1
[00:57:46] status: exit code: 1
[00:57:46] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/macros/macro-at-most-once-rep-2015-ques-rep.rs" "-Zthreads=1" "--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/macros/macro-at-most-once-rep-2015-ques-rep/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--edition=2015" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/macros/macro-at-most-once-rep-2015-ques-rep/auxiliary" "-A" "unused"
[00:57:46] ------------------------------------------
[00:57:46] 
[00:57:46] ------------------------------------------
[00:57:46] stderr:
[00:57:46] stderr:
[00:57:46] ------------------------------------------
[00:57:46] {"message":"expected `*` or `+`","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-2015-ques-rep.rs","byte_start":138,"byte_end":139,"line_start":6,"line_end":6,"column_start":10,"column_end":11,"is_primary":true,"text":[{"text":"    ($(a)?) => {} //~ERROR expected `*` or `+`","highlight_start":10,"highlight_end":11}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"`?` is not a macro repetition operator in the 2015 edition, but is accepted in the 2018 edition","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"error: expected `*` or `+`\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-2015-ques-rep.rs:6:10\n   |\nLL |     ($(a)?) => {} //~ERROR expected `*` or `+`\n   |          ^\n   |\n   = note: `?` is not a macro repetition operator in the 2015 edition, but is accepted in the 2018 edition\n\n"}
[00:57:46] {"message":"expected `*` or `+`","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-2015-ques-rep.rs","byte_start":208,"byte_end":209,"line_start":10,"line_end":10,"column_start":11,"column_end":12,"is_primary":true,"text":[{"text":"    ($(a),?) => {} //~ERROR expected `*` or `+`","highlight_start":11,"highlight_end":12}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"`?` is not a macro repetition operator in the 2015 edition,but is accepted in the 2018 edition","code":null,"level":"note","spans":[],"children":[],"rendered":null}],"rendered":"error: expected `*` or `+`\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-2015-ques-rep.rs:10:11\n   |\nLL |     ($(a),?) => {} //~ERROR expected `*` or `+`\n   |           ^\n   |\n   = note: `?` is not a macro repetition operator in the 2015 edition,but is accepted in the 2018 edition\n\n"}
[00:57:46] 
[00:57:46] ------------------------------------------
[00:57:46] 
[00:57:46] thread '[ui] ui/macros/macro-at-most-once-rep-2015-ques-rep.rs' panicked at 'explicit panic', src/tools/compiletest/src/runtest.rs:3295:9
---
[00:57:46] 
[00:57:46] thread 'main' panicked at 'Some tests failed', src/tools/compiletest/src/main.rs:502:22
[00:57:46] 
[00:57:46] 
[00:57:46] 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-6.0/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" "6.0.0\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
[00:57:46] 
[00:57:46] 
[00:57:46] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[00:57:46] Build completed unsuccessfully in 0:03:53
[00:57:46] Build completed unsuccessfully in 0:03:53
[00:57:46] make: *** [check] Error 1
[00:57:46] Makefile:48: recipe for target 'check' failed
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:0b6ade4a
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Sun Feb  3 11:17:10 UTC 2019
---
travis_time:end:07927e33:start=1549192631263599608,finish=1549192631267688379,duration=4088771
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:0f2ececc
$ 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:0146f1f8
travis_time:start:0146f1f8
$ 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:2c55ed2a
$ 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)

[michaelwoerister]

@varkor, do you want to take over the review? You seem to already have taken a close look at this.

[varkor]

@asettouf: this looks good now! If you could squash your changes into a single commit, then I'll approve. (Note also that we avoid merge commits in Rust, so if you get any conflicts you should rebase on top of master instead.)

r? @varkor

[varkor]

@asettouf: are you able to squash the commits? Everything looks great other than that.

[asettouf]

@varkor Sorry for the delay, it's been squashed. Besides, I made a slight mistake not creating a branch on my repo and then proceeded with merging rust:master into mine, which I just reverted. (that's why in the long message of the commit you can see a revert happening)

[varkor]

@asettouf: thanks! That's perfect.

@bors r+

[bors]

📌 Commit c1f3d15 has been approved by varkor