view tests/test-rebase-named-branches.t @ 35569:964212780daf

rust: implementation of `hg` This commit provides a mostly-working implementation of the `hg` script in Rust along with scaffolding to support Rust in the repository. If you are familiar with Rust, the contents of the added rust/ directory should be pretty straightforward. We create an "hgcli" package that implements a binary application to run Mercurial. The output of this package is an "hg" binary. Our Rust `hg` (henceforth "rhg") essentially is a port of the existing `hg` Python script. The main difference is the creation of the embedded CPython interpreter is handled by the binary itself instead of relying on the shebang. In that sense, rhg is more similar to the "exe wrapper" we currently use on Windows. However, unlike the exe wrapper, rhg does not call the `hg` Python script. Instead, it uses the CPython APIs to import mercurial modules and call appropriate functions. The amount of code here is surprisingly small. It is my intent to replace the existing C-based exe wrapper with rhg. Preferably in the next Mercurial release. This should be achievable - at least for some Mercurial distributions. The future/timeline for rhg on other platforms is less clear. We already ship a hg.exe on Windows. So if we get the quirks with Rust worked out, shipping a Rust-based hg.exe should hopefully not be too contentious. Now onto the implementation. We're using python27-sys and the cpython crates for talking to the CPython API. We currently don't use too much functionality of the cpython crate and could have probably cut it out. However, it does provide a reasonable abstraction over unsafe {} CPython function calls. While we still have our fair share of those, at least we're not dealing with too much refcounting, error checking, etc. So I think the use of the cpython crate is justified. Plus, there is not-yet-implemented functionality that could benefit from cpython. I see our use of this crate only increasing. The cpython and python27-sys crates are not without their issues. The cpython crate didn't seem to account for the embedding use case in its design. Instead, it seems to assume that you are building a Python extension. It is making some questionable decisions around certain CPython APIs. For example, it insists that PyEval_ThreadsInitialized() is called and that the Python code likely isn't the main thread in the underlying application. It is also missing some functionality that is important for embedded use cases (such as exporting the path to the Python interpreter from its build script). After spending several hours trying to wrangle python27-sys and cpython, I gave up and forked the project on GitHub. Our Cargo.toml tracks this fork. I'm optimistic that the upstream project will accept our contributions and we can eventually unfork. There is a non-trivial amount of code in our custom Cargo build script. Our build.rs (which is called as part of building the hgcli crate): * Validates that the Python interpreter that was detected by the python27-sys crate provides a shared library (we only support shared library linking at this time - although this restriction could be loosened). * Validates that the Python is built with UCS-4 support. This ensures maximum Unicode compatibility. * Exports variables to the crate build allowing the built crate to e.g. find the path to the Python interpreter. The produced rhg should be considered alpha quality. There are several known deficiencies. Many of these are documented with inline TODOs. Probably the biggest limitation of rhg is that it assumes it is running from the ./rust/target/<target> directory of a source distribution. So, rhg is currently not very practical for real-world use. But, if you can `cargo build` it, running the binary *should* yield a working Mercurial CLI. In order to support using rhg with the test harness, we needed to hack up run-tests.py so the path to Mercurial's Python files is set properly. The change is extremely hacky and is only intended to be a stop-gap until the test harness gains first-class support for installing rhg. This will likely occur after we support running rhg outside the source directory. Despite its officially alpha quality, rhg copes extremely well with the test harness (at least on Linux). Using `run-tests.py --with-hg ../rust/target/debug/hg`, I only encounter the following failures: * test-run-tests.t -- Warnings emitted about using an unexpected Mercurial library. This is due to the hacky nature of setting the Python directory when run-tests.py detected rhg. * test-devel-warnings.t -- Expected stack trace missing frame for `hg` (This is expected since we no longer have an `hg` script!) * test-convert.t -- Test running `$PYTHON "$BINDIR"/hg`, which obviously assumes `hg` is a Python script. * test-merge-tools.t -- Same assumption about `hg` being executable with Python. * test-http-bad-server.t -- Seeing exit code 255 instead of 1 around line 358. * test-blackbox.t -- Exit code 255 instead of 1. * test-basic.t -- Exit code 255 instead of 1. It certainly looks like we have a bug around exit code handling. I don't think it is severe enough to hold up review and landing of this initial implementation. Perfect is the enemy of good. Differential Revision: https://phab.mercurial-scm.org/D1581
author Gregory Szorc <gregory.szorc@gmail.com>
date Wed, 10 Jan 2018 08:53:22 -0800
parents 4441705b7111
children 89630d0b3e23
line wrap: on
line source

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"
  > EOF

  $ hg init a
  $ cd a
  $ hg unbundle "$TESTDIR/bundles/rebase.hg"
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  new changesets cd010b8cd998:02de42196ebe
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up tip
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd ..

  $ hg clone -q -u . a a1

  $ cd a1

  $ hg update 3
  3 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg branch dev-one
  marked working directory as branch dev-one
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -m 'dev-one named branch'

  $ hg update 7
  2 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ hg branch dev-two
  marked working directory as branch dev-two

  $ echo x > x

  $ hg add x

  $ hg ci -m 'dev-two named branch'

  $ hg tglog
  @  9: cb039b7cae8e 'dev-two named branch' dev-two
  |
  | o  8: 643fc9128048 'dev-one named branch' dev-one
  | |
  o |  7: 02de42196ebe 'H'
  | |
  +---o  6: eea13746799a 'G'
  | | |
  o | |  5: 24b6387c8c8c 'F'
  | | |
  +---o  4: 9520eea781bc 'E'
  | |
  | o  3: 32af7686d403 'D'
  | |
  | o  2: 5fddd98957c8 'C'
  | |
  | o  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  

Branch name containing a dash (issue3181)

  $ hg rebase -b dev-two -d dev-one --keepbranches
  rebasing 5:24b6387c8c8c "F"
  rebasing 6:eea13746799a "G"
  rebasing 7:02de42196ebe "H"
  rebasing 9:cb039b7cae8e "dev-two named branch" (tip)
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/24b6387c8c8c-24cb8001-rebase.hg

  $ hg tglog
  @  9: 9e70cd31750f 'dev-two named branch' dev-two
  |
  o  8: 31d0e4ba75e6 'H'
  |
  | o  7: 4b988a958030 'G'
  |/|
  o |  6: 24de4aff8e28 'F'
  | |
  o |  5: 643fc9128048 'dev-one named branch' dev-one
  | |
  | o  4: 9520eea781bc 'E'
  | |
  o |  3: 32af7686d403 'D'
  | |
  o |  2: 5fddd98957c8 'C'
  | |
  o |  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg rebase -s dev-one -d 0 --keepbranches
  rebasing 5:643fc9128048 "dev-one named branch"
  rebasing 6:24de4aff8e28 "F"
  rebasing 7:4b988a958030 "G"
  rebasing 8:31d0e4ba75e6 "H"
  rebasing 9:9e70cd31750f "dev-two named branch" (tip)
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/643fc9128048-c4ee9ef5-rebase.hg

  $ hg tglog
  @  9: 59c2e59309fe 'dev-two named branch' dev-two
  |
  o  8: 904590360559 'H'
  |
  | o  7: 1a1e6f72ec38 'G'
  |/|
  o |  6: 42aa3cf0fa7a 'F'
  | |
  o |  5: bc8139ee757c 'dev-one named branch' dev-one
  | |
  | o  4: 9520eea781bc 'E'
  |/
  | o  3: 32af7686d403 'D'
  | |
  | o  2: 5fddd98957c8 'C'
  | |
  | o  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg update 3
  3 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ hg branch -f dev-one
  marked working directory as branch dev-one
  $ hg ci -m 'dev-one named branch'
  created new head

  $ hg tglog
  @  10: 643fc9128048 'dev-one named branch' dev-one
  |
  | o  9: 59c2e59309fe 'dev-two named branch' dev-two
  | |
  | o  8: 904590360559 'H'
  | |
  | | o  7: 1a1e6f72ec38 'G'
  | |/|
  | o |  6: 42aa3cf0fa7a 'F'
  | | |
  | o |  5: bc8139ee757c 'dev-one named branch' dev-one
  | | |
  | | o  4: 9520eea781bc 'E'
  | |/
  o |  3: 32af7686d403 'D'
  | |
  o |  2: 5fddd98957c8 'C'
  | |
  o |  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg rebase -b 'max(branch("dev-two"))' -d dev-one --keepbranches
  rebasing 5:bc8139ee757c "dev-one named branch"
  note: rebase of 5:bc8139ee757c created no changes to commit
  rebasing 6:42aa3cf0fa7a "F"
  rebasing 7:1a1e6f72ec38 "G"
  rebasing 8:904590360559 "H"
  rebasing 9:59c2e59309fe "dev-two named branch"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/bc8139ee757c-f11c1080-rebase.hg

  $ hg tglog
  o  9: 71325f8bc082 'dev-two named branch' dev-two
  |
  o  8: 12b2bc666e20 'H'
  |
  | o  7: 549f007a9f5f 'G'
  |/|
  o |  6: 679f28760620 'F'
  | |
  @ |  5: 643fc9128048 'dev-one named branch' dev-one
  | |
  | o  4: 9520eea781bc 'E'
  | |
  o |  3: 32af7686d403 'D'
  | |
  o |  2: 5fddd98957c8 'C'
  | |
  o |  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg rebase -s 'max(branch("dev-one"))' -d 0 --keepbranches
  rebasing 5:643fc9128048 "dev-one named branch"
  rebasing 6:679f28760620 "F"
  rebasing 7:549f007a9f5f "G"
  rebasing 8:12b2bc666e20 "H"
  rebasing 9:71325f8bc082 "dev-two named branch" (tip)
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/643fc9128048-6cdd1a52-rebase.hg

  $ hg tglog
  o  9: 3944801ae4ea 'dev-two named branch' dev-two
  |
  o  8: 8e279d293175 'H'
  |
  | o  7: aeefee77ab01 'G'
  |/|
  o |  6: e908b85f3729 'F'
  | |
  @ |  5: bc8139ee757c 'dev-one named branch' dev-one
  | |
  | o  4: 9520eea781bc 'E'
  |/
  | o  3: 32af7686d403 'D'
  | |
  | o  2: 5fddd98957c8 'C'
  | |
  | o  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg up -r 0 > /dev/null

Rebasing descendant onto ancestor across different named branches

  $ hg rebase -s 1 -d 9 --keepbranches
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/42ccdea3bb16-3cb021d3-rebase.hg

  $ hg tglog
  o  9: e9f862ce8bad 'D'
  |
  o  8: a0d543090fa4 'C'
  |
  o  7: 3bdb949809d9 'B'
  |
  o  6: 3944801ae4ea 'dev-two named branch' dev-two
  |
  o  5: 8e279d293175 'H'
  |
  | o  4: aeefee77ab01 'G'
  |/|
  o |  3: e908b85f3729 'F'
  | |
  o |  2: bc8139ee757c 'dev-one named branch' dev-one
  | |
  | o  1: 9520eea781bc 'E'
  |/
  @  0: cd010b8cd998 'A'
  
  $ hg rebase -s 5 -d 6
  abort: source and destination form a cycle
  [255]

  $ hg rebase -s 6 -d 5
  rebasing 6:3944801ae4ea "dev-two named branch"
  rebasing 7:3bdb949809d9 "B"
  rebasing 8:a0d543090fa4 "C"
  rebasing 9:e9f862ce8bad "D" (tip)
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/3944801ae4ea-fb46ed74-rebase.hg

  $ hg tglog
  o  9: e522577ccdbd 'D'
  |
  o  8: 810110211f50 'C'
  |
  o  7: 160b0930ccc6 'B'
  |
  o  6: c57724c84928 'dev-two named branch'
  |
  o  5: 8e279d293175 'H'
  |
  | o  4: aeefee77ab01 'G'
  |/|
  o |  3: e908b85f3729 'F'
  | |
  o |  2: bc8139ee757c 'dev-one named branch' dev-one
  | |
  | o  1: 9520eea781bc 'E'
  |/
  @  0: cd010b8cd998 'A'
  

Reopen branch by rebase

  $ hg up -qr3
  $ hg branch -q b
  $ hg ci -m 'create b'
  $ hg ci -m 'close b' --close
  $ hg rebase -b 8 -d b
  reopening closed branch head 2b586e70108d
  rebasing 5:8e279d293175 "H"
  rebasing 6:c57724c84928 "dev-two named branch"
  rebasing 7:160b0930ccc6 "B"
  rebasing 8:810110211f50 "C"
  rebasing 9:e522577ccdbd "D"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/8e279d293175-b023e27c-rebase.hg

  $ cd ..

Rebase to other head on branch

Set up a case:

  $ hg init case1
  $ cd case1
  $ touch f
  $ hg ci -qAm0
  $ hg branch -q b
  $ echo >> f
  $ hg ci -qAm 'b1'
  $ hg up -qr -2
  $ hg branch -qf b
  $ hg ci -qm 'b2'
  $ hg up -qr -3
  $ hg branch -q c
  $ hg ci -m 'c1'

  $ hg tglog
  @  3: c062e3ecd6c6 'c1' c
  |
  | o  2: 792845bb77ee 'b2' b
  |/
  | o  1: 40039acb7ca5 'b1' b
  |/
  o  0: d681519c3ea7 '0'
  
  $ hg clone -q . ../case2

rebase 'b2' to another lower branch head

  $ hg up -qr 2
  $ hg rebase
  rebasing 2:792845bb77ee "b2"
  note: rebase of 2:792845bb77ee created no changes to commit
  saved backup bundle to $TESTTMP/case1/.hg/strip-backup/792845bb77ee-627120ee-rebase.hg
  $ hg tglog
  o  2: c062e3ecd6c6 'c1' c
  |
  | @  1: 40039acb7ca5 'b1' b
  |/
  o  0: d681519c3ea7 '0'
  

rebase 'b1' on top of the tip of the branch ('b2') - ignoring the tip branch ('c1')

  $ cd ../case2
  $ hg up -qr 1
  $ hg rebase
  rebasing 1:40039acb7ca5 "b1"
  saved backup bundle to $TESTTMP/case2/.hg/strip-backup/40039acb7ca5-342b72d1-rebase.hg
  $ hg tglog
  @  3: 76abc1c6f8c7 'b1' b
  |
  | o  2: c062e3ecd6c6 'c1' c
  | |
  o |  1: 792845bb77ee 'b2' b
  |/
  o  0: d681519c3ea7 '0'
  

rebase 'c1' to the branch head 'c2' that is closed

  $ hg branch -qf c
  $ hg ci -qm 'c2 closed' --close
  $ hg up -qr 2
  $ hg tglog
  _  4: 8427af5d86f2 'c2 closed' c
  |
  o  3: 76abc1c6f8c7 'b1' b
  |
  | @  2: c062e3ecd6c6 'c1' c
  | |
  o |  1: 792845bb77ee 'b2' b
  |/
  o  0: d681519c3ea7 '0'
  
  $ hg rebase
  abort: branch 'c' has one head - please rebase to an explicit rev
  (run 'hg heads' to see all heads)
  [255]
  $ hg tglog
  _  4: 8427af5d86f2 'c2 closed' c
  |
  o  3: 76abc1c6f8c7 'b1' b
  |
  | @  2: c062e3ecd6c6 'c1' c
  | |
  o |  1: 792845bb77ee 'b2' b
  |/
  o  0: d681519c3ea7 '0'
  

  $ hg up -cr 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch x
  marked working directory as branch x
  $ hg rebase -r 3:: -d .
  rebasing 3:76abc1c6f8c7 "b1"
  rebasing 4:8427af5d86f2 "c2 closed" (tip)
  note: rebase of 4:8427af5d86f2 created no changes to commit
  saved backup bundle to $TESTTMP/case2/.hg/strip-backup/76abc1c6f8c7-cd698d13-rebase.hg
  $ hg tglog
  o  3: 117b0ed08075 'b1' x
  |
  | o  2: c062e3ecd6c6 'c1' c
  | |
  @ |  1: 792845bb77ee 'b2' b
  |/
  o  0: d681519c3ea7 '0'
  

  $ cd ..