Fix the miri tool

[oli-obk]

r? @eddyb

cc @bjorn3

fixes#49777

[rust-highfive]

Warning

• These commits modify submodules.

[eddyb]

Can this early-return index, without going through read_discriminant_value?

[eddyb]

I'm not sure the comment is correct. Also, read_discriminant_as_variant_index seems slightly better as a name?

[eddyb]

Please call the layout/codegen/memory counterpart "tag" not "discriminant".

[eddyb]

Are there no helpers in miri to do "integer casts" (zext/sext/trunc) without repeating these bitops all over the place?

[oli-obk]

nope ^^ I'll take my own advice and open an easy issue

[eddyb]

This should also use "discriminant" vs "tag" terminology. Also, I wish the discr field in Variants::Tagged was called tag.

[rust-highfive]

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.

Resolving deltas: 100% (614347/614347), completed with 4877 local objects.
---
[00:00:11] error: Server does not allow request for unadvertised object 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e
[00:00:11] Fetched in submodule path 'src/tools/miri', but it did not contain 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e. Direct fetching of that commit failed.
---
[00:00:13] error: Server does not allow request for unadvertised object 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e
[00:00:13] Fetched in submodule path 'src/tools/miri', but it did not contain 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e. Direct fetching of that commit failed.
---
[00:00:15] error: Server does not allow request for unadvertised object 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e
[00:00:15] Fetched in submodule path 'src/tools/miri', but it did not contain 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e. Direct fetching of that commit failed.
---
[00:00:17] error: Server does not allow request for unadvertised object 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e
[00:00:17] Fetched in submodule path 'src/tools/miri', but it did not contain 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e. Direct fetching of that commit failed.
---
[00:00:18] error: Server does not allow request for unadvertised object 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e
[00:00:18] Fetched in submodule path 'src/tools/miri', but it did not contain 3f1b2bdd6895f9aedb22601bd28bc690d5a55a1e. Direct fetching of that commit failed.
[00:00:18] The command has failed after 5 attempts.
---
$ ls -lat $HOME/Library/Logs/DiagnosticReports/
ls: cannot access /home/travis/Library/Logs/DiagnosticReports/: No such file or directory
travis_time:end:35898fee:start=1523630087062695198,finish=1523630087069131913,duration=6436715
travis_fold:end:after_failure.2
travis_fold:start:after_failure.3
travis_time:start:3b914e40
$ find $HOME/Library/Logs/DiagnosticReports -type f -name '*.crash' -not -name '*.stage2-*.crash' -not -name 'com.apple.CoreSimulator.CoreSimulatorService-*.crash' -exec printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" {} \; -exec head -750 {} \; -exec echo travis_fold":"end:crashlog \; || true
find: `/home/travis/Library/Logs/DiagnosticReports': No such file or directory
travis_time:end:3b914e40:start=1523630087075375511,finish=1523630087081524122,duration=6148611
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:0ad3767c
$ dmesg | grep -i kill
[ 11.828926] init: failsafe main process (1096) kille

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)

[oli-obk]

I created a long lived branch in the miri repo which we're going to merge, not rebase or force-push in any other way.

[bors]

☔ The latest upstream changes (presumably #49949) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #50056) made this pull request unmergeable. Please resolve the merge conflicts.

[eddyb]

@bors r+

[bors]

📌 Commit 3084c06 has been approved by eddyb

[bors]

⌛ Testing commit 3084c06 with merge f5203d1...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: eddyb
Pushing f5203d1 to master...

[kennytm-githubbot]

📣 Toolstate changed by #49933!

Tested on commit f5203d1.
Direct link to PR: #49933

🎉 miri on windows: build-fail → test-fail.
🎉 miri on linux: build-fail → test-fail.