Mercurial > hg
view tests/test-split.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 | 9b3f95d9783d |
children | 1a09dad8b85a |
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#testcases obsstore-on obsstore-off $ cat > $TESTTMP/editor.py <<EOF > #!$PYTHON > import os, sys > path = os.path.join(os.environ['TESTTMP'], 'messages') > messages = open(path).read().split('--\n') > prompt = open(sys.argv[1]).read() > sys.stdout.write(''.join('EDITOR: %s' % l for l in prompt.splitlines(True))) > sys.stdout.flush() > with open(sys.argv[1], 'w') as f: > f.write(messages[0]) > with open(path, 'w') as f: > f.write('--\n'.join(messages[1:])) > EOF $ cat >> $HGRCPATH <<EOF > [extensions] > drawdag=$TESTDIR/drawdag.py > split= > [ui] > interactive=1 > color=no > paginate=never > [diff] > git=1 > unified=0 > [alias] > glog=log -G -T '{rev}:{node|short} {desc} {bookmarks}\n' > EOF #if obsstore-on $ cat >> $HGRCPATH <<EOF > [experimental] > evolution=all > EOF #endif $ hg init a $ cd a Nothing to split $ hg split nothing to split [1] $ hg commit -m empty --config ui.allowemptycommit=1 $ hg split abort: cannot split an empty revision [255] $ rm -rf .hg $ hg init Cannot split working directory $ hg split -r 'wdir()' abort: cannot split working directory [255] Generate some content. The sed filter drop CR on Windows, which is dropped in the a > b line. $ $TESTDIR/seq.py 1 5 | sed 's/\r$//' >> a $ hg ci -m a1 -A a -q $ hg bookmark -i r1 $ sed 's/1/11/;s/3/33/;s/5/55/' a > b $ mv b a $ hg ci -m a2 -q $ hg bookmark -i r2 Cannot split a public changeset $ hg phase --public -r 'all()' $ hg split . abort: cannot split public changeset (see 'hg help phases' for details) [255] $ hg phase --draft -f -r 'all()' Cannot split while working directory is dirty $ touch dirty $ hg add dirty $ hg split . abort: uncommitted changes [255] $ hg forget dirty $ rm dirty Split a head $ cp -R . ../b $ cp -R . ../c $ hg bookmark r3 $ hg split 'all()' abort: cannot split multiple revisions [255] $ runsplit() { > cat > $TESTTMP/messages <<EOF > split 1 > -- > split 2 > -- > split 3 > EOF > cat <<EOF | hg split "$@" > y > y > y > y > y > y > EOF > } $ HGEDITOR=false runsplit diff --git a/a b/a 1 hunks, 1 lines changed examine changes to 'a'? [Ynesfdaq?] y @@ -5,1 +5,1 @@ 4 -5 +55 record this change to 'a'? [Ynesfdaq?] y transaction abort! rollback completed abort: edit failed: false exited with status 1 [255] $ hg status $ HGEDITOR="\"$PYTHON\" $TESTTMP/editor.py" $ runsplit diff --git a/a b/a 1 hunks, 1 lines changed examine changes to 'a'? [Ynesfdaq?] y @@ -5,1 +5,1 @@ 4 -5 +55 record this change to 'a'? [Ynesfdaq?] y EDITOR: HG: Splitting 1df0d5c5a3ab. Write commit message for the first split changeset. EDITOR: a2 EDITOR: EDITOR: EDITOR: HG: Enter commit message. Lines beginning with 'HG:' are removed. EDITOR: HG: Leave message empty to abort commit. EDITOR: HG: -- EDITOR: HG: user: test EDITOR: HG: branch 'default' EDITOR: HG: changed a created new head diff --git a/a b/a 1 hunks, 1 lines changed examine changes to 'a'? [Ynesfdaq?] y @@ -3,1 +3,1 @@ 2 -3 +33 record this change to 'a'? [Ynesfdaq?] y EDITOR: HG: Splitting 1df0d5c5a3ab. So far it has been split into: EDITOR: HG: - e704349bd21b: split 1 EDITOR: HG: Write commit message for the next split changeset. EDITOR: a2 EDITOR: EDITOR: EDITOR: HG: Enter commit message. Lines beginning with 'HG:' are removed. EDITOR: HG: Leave message empty to abort commit. EDITOR: HG: -- EDITOR: HG: user: test EDITOR: HG: branch 'default' EDITOR: HG: changed a diff --git a/a b/a 1 hunks, 1 lines changed examine changes to 'a'? [Ynesfdaq?] y @@ -1,1 +1,1 @@ -1 +11 record this change to 'a'? [Ynesfdaq?] y EDITOR: HG: Splitting 1df0d5c5a3ab. So far it has been split into: EDITOR: HG: - e704349bd21b: split 1 EDITOR: HG: - a09ad58faae3: split 2 EDITOR: HG: Write commit message for the next split changeset. EDITOR: a2 EDITOR: EDITOR: EDITOR: HG: Enter commit message. Lines beginning with 'HG:' are removed. EDITOR: HG: Leave message empty to abort commit. EDITOR: HG: -- EDITOR: HG: user: test EDITOR: HG: branch 'default' EDITOR: HG: changed a saved backup bundle to $TESTTMP/a/.hg/strip-backup/1df0d5c5a3ab-8341b760-split.hg (obsstore-off !) #if obsstore-off $ hg bookmark r1 0:a61bcde8c529 r2 3:00eebaf8d2e2 * r3 3:00eebaf8d2e2 $ hg glog -p @ 3:00eebaf8d2e2 split 3 r2 r3 | diff --git a/a b/a | --- a/a | +++ b/a | @@ -1,1 +1,1 @@ | -1 | +11 | o 2:a09ad58faae3 split 2 | diff --git a/a b/a | --- a/a | +++ b/a | @@ -3,1 +3,1 @@ | -3 | +33 | o 1:e704349bd21b split 1 | diff --git a/a b/a | --- a/a | +++ b/a | @@ -5,1 +5,1 @@ | -5 | +55 | o 0:a61bcde8c529 a1 r1 diff --git a/a b/a new file mode 100644 --- /dev/null +++ b/a @@ -0,0 +1,5 @@ +1 +2 +3 +4 +5 #else $ hg bookmark r1 0:a61bcde8c529 r2 4:00eebaf8d2e2 * r3 4:00eebaf8d2e2 $ hg glog @ 4:00eebaf8d2e2 split 3 r2 r3 | o 3:a09ad58faae3 split 2 | o 2:e704349bd21b split 1 | o 0:a61bcde8c529 a1 r1 #endif Split a head while working parent is not that head $ cd $TESTTMP/b $ hg up 0 -q $ hg bookmark r3 $ runsplit tip >/dev/null #if obsstore-off $ hg bookmark r1 0:a61bcde8c529 r2 3:00eebaf8d2e2 * r3 0:a61bcde8c529 $ hg glog o 3:00eebaf8d2e2 split 3 r2 | o 2:a09ad58faae3 split 2 | o 1:e704349bd21b split 1 | @ 0:a61bcde8c529 a1 r1 r3 #else $ hg bookmark r1 0:a61bcde8c529 r2 4:00eebaf8d2e2 * r3 0:a61bcde8c529 $ hg glog o 4:00eebaf8d2e2 split 3 r2 | o 3:a09ad58faae3 split 2 | o 2:e704349bd21b split 1 | @ 0:a61bcde8c529 a1 r1 r3 #endif Split a non-head $ cd $TESTTMP/c $ echo d > d $ hg ci -m d1 -A d $ hg bookmark -i d1 $ echo 2 >> d $ hg ci -m d2 $ echo 3 >> d $ hg ci -m d3 $ hg bookmark -i d3 $ hg up '.^' -q $ hg bookmark d2 $ cp -R . ../d $ runsplit -r 1 | grep rebasing rebasing 2:b5c5ea414030 "d1" (d1) rebasing 3:f4a0a8d004cc "d2" (d2) rebasing 4:777940761eba "d3" (d3) #if obsstore-off $ hg bookmark d1 4:c4b449ef030e * d2 5:c9dd00ab36a3 d3 6:19f476bc865c r1 0:a61bcde8c529 r2 3:00eebaf8d2e2 $ hg glog -p o 6:19f476bc865c d3 d3 | diff --git a/d b/d | --- a/d | +++ b/d | @@ -2,0 +3,1 @@ | +3 | @ 5:c9dd00ab36a3 d2 d2 | diff --git a/d b/d | --- a/d | +++ b/d | @@ -1,0 +2,1 @@ | +2 | o 4:c4b449ef030e d1 d1 | diff --git a/d b/d | new file mode 100644 | --- /dev/null | +++ b/d | @@ -0,0 +1,1 @@ | +d | o 3:00eebaf8d2e2 split 3 r2 | diff --git a/a b/a | --- a/a | +++ b/a | @@ -1,1 +1,1 @@ | -1 | +11 | o 2:a09ad58faae3 split 2 | diff --git a/a b/a | --- a/a | +++ b/a | @@ -3,1 +3,1 @@ | -3 | +33 | o 1:e704349bd21b split 1 | diff --git a/a b/a | --- a/a | +++ b/a | @@ -5,1 +5,1 @@ | -5 | +55 | o 0:a61bcde8c529 a1 r1 diff --git a/a b/a new file mode 100644 --- /dev/null +++ b/a @@ -0,0 +1,5 @@ +1 +2 +3 +4 +5 #else $ hg bookmark d1 8:c4b449ef030e * d2 9:c9dd00ab36a3 d3 10:19f476bc865c r1 0:a61bcde8c529 r2 7:00eebaf8d2e2 $ hg glog o 10:19f476bc865c d3 d3 | @ 9:c9dd00ab36a3 d2 d2 | o 8:c4b449ef030e d1 d1 | o 7:00eebaf8d2e2 split 3 r2 | o 6:a09ad58faae3 split 2 | o 5:e704349bd21b split 1 | o 0:a61bcde8c529 a1 r1 #endif Split a non-head without rebase $ cd $TESTTMP/d #if obsstore-off $ runsplit -r 1 --no-rebase abort: cannot split changeset with children without rebase [255] #else $ runsplit -r 1 --no-rebase >/dev/null $ hg bookmark d1 2:b5c5ea414030 * d2 3:f4a0a8d004cc d3 4:777940761eba r1 0:a61bcde8c529 r2 7:00eebaf8d2e2 $ hg glog o 7:00eebaf8d2e2 split 3 r2 | o 6:a09ad58faae3 split 2 | o 5:e704349bd21b split 1 | | * 4:777940761eba d3 d3 | | | @ 3:f4a0a8d004cc d2 d2 | | | * 2:b5c5ea414030 d1 d1 | | | x 1:1df0d5c5a3ab a2 |/ o 0:a61bcde8c529 a1 r1 #endif Split a non-head with obsoleted descendants #if obsstore-on $ hg init $TESTTMP/e $ cd $TESTTMP/e $ hg debugdrawdag <<'EOS' > H I J > | | | > F G1 G2 # amend: G1 -> G2 > | | / # prune: F > C D E > \|/ > B > | > A > EOS $ eval `hg tags -T '{tag}={node}\n'` $ rm .hg/localtags $ hg split $B --config experimental.evolution=createmarkers abort: split would leave orphaned changesets behind [255] $ cat > $TESTTMP/messages <<EOF > Split B > EOF $ cat <<EOF | hg split $B > y > y > EOF diff --git a/B b/B new file mode 100644 examine changes to 'B'? [Ynesfdaq?] y @@ -0,0 +1,1 @@ +B \ No newline at end of file record this change to 'B'? [Ynesfdaq?] y EDITOR: HG: Splitting 112478962961. Write commit message for the first split changeset. EDITOR: B EDITOR: EDITOR: EDITOR: HG: Enter commit message. Lines beginning with 'HG:' are removed. EDITOR: HG: Leave message empty to abort commit. EDITOR: HG: -- EDITOR: HG: user: test EDITOR: HG: branch 'default' EDITOR: HG: added B created new head rebasing 2:26805aba1e60 "C" rebasing 3:be0ef73c17ad "D" rebasing 4:49cb92066bfd "E" rebasing 7:97a6268cc7ef "G2" rebasing 10:e2f1e425c0db "J" $ hg glog -r 'sort(all(), topo)' o 16:556c085f8b52 J | o 15:8761f6c9123f G2 | o 14:a7aeffe59b65 E | | o 13:e1e914ede9ab D |/ | o 12:01947e9b98aa C |/ o 11:0947baa74d47 Split B | | * 9:88ede1d5ee13 I | | | x 6:af8cbf225b7b G1 | | | x 3:be0ef73c17ad D | | | | * 8:74863e5b5074 H | | | | | x 5:ee481a2a1e69 F | | | | | x 2:26805aba1e60 C | |/ | x 1:112478962961 B |/ o 0:426bada5c675 A #endif