Speed up tidy

[Mark-Simulacrum]

master:
Time (mean ± σ): 3.478 s ± 0.033 s [User: 3.298 s, System: 0.178 s]
Range (min … max): 3.425 s … 3.525 s 10 runs

This PR:
Time (mean ± σ): 1.098 s ± 0.006 s [User: 783.7 ms, System: 310.2 ms]
Range (min … max): 1.092 s … 1.113 s 10 runs

Alleviates #59884. For the most part each commit stands on its own. Timings are on warm filesystem cache.

r? @eddyb

[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:00978e6b:start=1561152293273614327,finish=1561152294076285515,duration=802671188
$ 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
$ export GCP_CACHE_BUCKET=rust-lang-ci-cache
$ export AWS_ACCESS_KEY_ID=AKIA46X5W6CZEJZ6XT55
---
travis_time:start:test_assembly
Check compiletest suite=assembly mode=assembly (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[01:03:56] 
[01:03:56] running 9 tests
[01:03:56] iiiiiiiii
[01:03:56] 
[01:03:56]  finished in 0.150
[01:03:56] travis_fold:end:test_assembly

---
travis_time:start:test_debuginfo
Check compiletest suite=debuginfo mode=debuginfo-gdb+lldb (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[01:04:12] 
[01:04:12] running 122 tests
[01:04:36] .iiiii...i.....i..i...i..i.i.i..i.ii..i.i.....i..i....i..........iiii..........i...ii...i.......ii.i 100/122
[01:04:41] .i.i......iii.i.....ii
[01:04:41] 
[01:04:41]  finished in 28.924
[01:04:41] travis_fold:end:test_debuginfo

---
travis_time:start:stage0-unstable-book-gen
Building stage0 tool unstable-book-gen (x86_64-unknown-linux-gnu)
[01:29:22]    Compiling num-traits v0.2.6
[01:29:24]    Compiling unstable-book-gen v0.1.0 (/checkout/src/tools/unstable-book-gen)
[01:29:24] error[E0432]: unresolved import `tidy::features::collect_lib_features`
[01:29:24]  --> src/tools/unstable-book-gen/src/main.rs:8:41
[01:29:24]   |
[01:29:24] 8 | use tidy::features::{Feature, Features, collect_lib_features, collect_lang_features};
[01:29:24]   |                                         |
[01:29:24]   |                                         no `collect_lib_features` in `features`
[01:29:24]   |                                         help: a similar name exists in the module: `collect_lang_features`
[01:29:24] 
---
travis_time:end:042fd443:start=1561157671392699414,finish=1561157671397850919,duration=5151505
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:03ccfe64
$ 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:0784c58c
travis_time:start:0784c58c
$ 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:02da1b9e
$ 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)

[eddyb]

@bors r+

[bors]

📌 Commit 2a0d1cc4182d6cb3433175f3b8ace42e3d99dec3 has been approved by eddyb

[bors]

🔒 Merge conflict

This pull request and the master branch diverged in a way that cannot be automatically merged. Please rebase on top of the latest master branch, and let the reviewer approve again.

How do I rebase?

Assuming self is your fork and upstream is this repository, you can resolve the conflict following these steps:

1. git checkout tidy-fast (switch to your branch)
2. git fetch upstream master (retrieve the latest master)
3. git rebase upstream/master -p (rebase on top of it)
4. Follow the on-screen instruction to resolve conflicts (check git status if you got lost).
5. git push self tidy-fast --force-with-lease (update this PR)

You may also read Git Rebasing to Resolve Conflicts by Drew Blessing for a short tutorial.

Please avoid the "Resolve conflicts" button on GitHub. It uses git merge instead of git rebase which makes the PR commit history more difficult to read.

Sometimes step 4 will complete without asking for resolution. This is usually due to difference between how Cargo.lock conflict is handled during merge and rebase. This is normal, and you should still perform step 5 to update this PR.

Error message

warning: Cannot merge binary files: Cargo.lock (HEAD vs. heads/homu-tmp)
Auto-merging Cargo.lock
CONFLICT (content): Merge conflict in Cargo.lock
Automatic merge failed; fix conflicts and then commit the result.

[Mark-Simulacrum]

@bors r=eddyb

[bors]

📌 Commit 777951c has been approved by eddyb

[bors]

⌛ Testing commit 777951c with merge de7c4e4...

[bors]

☀️ Test successful - checks-travis, status-appveyor
Approved by: eddyb
Pushing de7c4e4 to master...