Mercurial > hg
view tests/test-bisect3.t @ 49000:dd6b67d5c256 stable
rust: fix unsound `OwningDirstateMap`
As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.
The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.
I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.
In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.
Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.
Differential Revision: https://phab.mercurial-scm.org/D12429
author | Raphaël Gomès <rgomes@octobus.net> |
---|---|
date | Tue, 05 Apr 2022 10:55:28 +0200 |
parents | f51ff655d338 |
children |
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# Here we create a simple DAG which has just enough of the required # topology to test all the bisection status labels: # # 13--14 # / # 0--1--2--3---------9--10--11--12 # \ / # 4--5--6--7--8 $ hg init $ echo '0' >a $ hg add a $ hg ci -u test -d '0 0' -m '0' $ echo '1' >a $ hg ci -u test -d '1 0' -m '1' branch 2-3 $ echo '2' >b $ hg add b $ hg ci -u test -d '2 0' -m '2' $ echo '3' >b $ hg ci -u test -d '3 0' -m '3' branch 4-8 $ hg up -r 1 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo '4' >c $ hg add c $ hg ci -u test -d '4 0' -m '4' created new head $ echo '5' >c $ hg ci -u test -d '5 0' -m '5' $ echo '6' >c $ hg ci -u test -d '6 0' -m '6' $ echo '7' >c $ hg ci -u test -d '7 0' -m '7' $ echo '8' >c $ hg ci -u test -d '8 0' -m '8' merge $ hg merge -r 3 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -u test -d '9 0' -m '9=8+3' $ echo '10' >a $ hg ci -u test -d '10 0' -m '10' $ echo '11' >a $ hg ci -u test -d '11 0' -m '11' $ echo '12' >a $ hg ci -u test -d '12 0' -m '12' unrelated branch $ hg up -r 3 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo '13' >d $ hg add d $ hg ci -u test -d '13 0' -m '13' created new head $ echo '14' >d $ hg ci -u test -d '14 0' -m '14' mark changesets $ hg bisect --reset $ hg bisect --good 4 $ hg bisect --good 6 $ hg bisect --bad 12 Testing changeset 9:2197c557e14c "9=8+3" (6 changesets remaining, ~2 tests) 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg bisect --bad 10 Testing changeset 8:e74a86251f58 "8" (4 changesets remaining, ~2 tests) 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg bisect --skip 7 Testing changeset 8:e74a86251f58 "8" (4 changesets remaining, ~2 tests) 0 files updated, 0 files merged, 0 files removed, 0 files unresolved test template $ hg log --template '{rev}:{node|short} {bisect}\n' 14:cbf2f3105bbf 13:e07efca37c43 12:98c6b56349c0 bad 11:03f491376e63 bad (implicit) 10:c012b15e2409 bad 9:2197c557e14c untested 8:e74a86251f58 untested 7:a5f87041c899 skipped 6:7d997bedcd8d good 5:2dd1875f1028 good (implicit) 4:2a1daef14cd4 good 3:8417d459b90c ignored 2:e1355ee1f23e ignored 1:ce7c85e06a9f good (implicit) 0:b4e73ffab476 good (implicit) $ hg log --template '{bisect|shortbisect} {rev}:{node|short}\n' 14:cbf2f3105bbf 13:e07efca37c43 B 12:98c6b56349c0 B 11:03f491376e63 B 10:c012b15e2409 U 9:2197c557e14c U 8:e74a86251f58 S 7:a5f87041c899 G 6:7d997bedcd8d G 5:2dd1875f1028 G 4:2a1daef14cd4 I 3:8417d459b90c I 2:e1355ee1f23e G 1:ce7c85e06a9f G 0:b4e73ffab476 test style $ hg log --style bisect changeset: 14:cbf2f3105bbf bisect: tag: tip user: test date: Thu Jan 01 00:00:14 1970 +0000 summary: 14 changeset: 13:e07efca37c43 bisect: parent: 3:8417d459b90c user: test date: Thu Jan 01 00:00:13 1970 +0000 summary: 13 changeset: 12:98c6b56349c0 bisect: bad user: test date: Thu Jan 01 00:00:12 1970 +0000 summary: 12 changeset: 11:03f491376e63 bisect: bad (implicit) user: test date: Thu Jan 01 00:00:11 1970 +0000 summary: 11 changeset: 10:c012b15e2409 bisect: bad user: test date: Thu Jan 01 00:00:10 1970 +0000 summary: 10 changeset: 9:2197c557e14c bisect: untested parent: 8:e74a86251f58 parent: 3:8417d459b90c user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: 9=8+3 changeset: 8:e74a86251f58 bisect: untested user: test date: Thu Jan 01 00:00:08 1970 +0000 summary: 8 changeset: 7:a5f87041c899 bisect: skipped user: test date: Thu Jan 01 00:00:07 1970 +0000 summary: 7 changeset: 6:7d997bedcd8d bisect: good user: test date: Thu Jan 01 00:00:06 1970 +0000 summary: 6 changeset: 5:2dd1875f1028 bisect: good (implicit) user: test date: Thu Jan 01 00:00:05 1970 +0000 summary: 5 changeset: 4:2a1daef14cd4 bisect: good parent: 1:ce7c85e06a9f user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: 4 changeset: 3:8417d459b90c bisect: ignored user: test date: Thu Jan 01 00:00:03 1970 +0000 summary: 3 changeset: 2:e1355ee1f23e bisect: ignored user: test date: Thu Jan 01 00:00:02 1970 +0000 summary: 2 changeset: 1:ce7c85e06a9f bisect: good (implicit) user: test date: Thu Jan 01 00:00:01 1970 +0000 summary: 1 changeset: 0:b4e73ffab476 bisect: good (implicit) user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 0 $ hg log --quiet --style bisect 14:cbf2f3105bbf 13:e07efca37c43 B 12:98c6b56349c0 B 11:03f491376e63 B 10:c012b15e2409 U 9:2197c557e14c U 8:e74a86251f58 S 7:a5f87041c899 G 6:7d997bedcd8d G 5:2dd1875f1028 G 4:2a1daef14cd4 I 3:8417d459b90c I 2:e1355ee1f23e G 1:ce7c85e06a9f G 0:b4e73ffab476 $ hg --config extensions.color= --color=debug log --quiet --style bisect [log.bisect| ] 14:cbf2f3105bbf [log.bisect| ] 13:e07efca37c43 [log.bisect bisect.bad|B] 12:98c6b56349c0 [log.bisect bisect.bad|B] 11:03f491376e63 [log.bisect bisect.bad|B] 10:c012b15e2409 [log.bisect bisect.untested|U] 9:2197c557e14c [log.bisect bisect.untested|U] 8:e74a86251f58 [log.bisect bisect.skipped|S] 7:a5f87041c899 [log.bisect bisect.good|G] 6:7d997bedcd8d [log.bisect bisect.good|G] 5:2dd1875f1028 [log.bisect bisect.good|G] 4:2a1daef14cd4 [log.bisect bisect.ignored|I] 3:8417d459b90c [log.bisect bisect.ignored|I] 2:e1355ee1f23e [log.bisect bisect.good|G] 1:ce7c85e06a9f [log.bisect bisect.good|G] 0:b4e73ffab476