view tests/test-rename.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

  $ hg init
  $ mkdir d1 d1/d11 d2
  $ echo d1/a > d1/a
  $ echo d1/ba > d1/ba
  $ echo d1/a1 > d1/d11/a1
  $ echo d1/b > d1/b
  $ echo d2/b > d2/b
  $ hg add d1/a d1/b d1/ba d1/d11/a1 d2/b
  $ hg commit -m "1"

rename a single file

  $ hg rename d1/d11/a1 d2/c
  $ hg --config ui.portablefilenames=abort rename d1/a d1/con.xml
  abort: filename contains 'con', which is reserved on Windows: d1/con.xml
  [255]
  $ hg sum
  parent: 0:9b4b6e7b2c26 tip
   1
  branch: default
  commit: 1 renamed
  update: (current)
  phases: 1 draft
  $ hg status -C
  A d2/c
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d2/c

rename a single file using absolute paths

  $ hg rename `pwd`/d1/d11/a1 `pwd`/d2/c
  $ hg status -C
  A d2/c
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d2/c

rename --after a single file

  $ mv d1/d11/a1 d2/c
  $ hg rename --after d1/d11/a1 d2/c
  $ hg status -C
  A d2/c
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d2/c

rename --after a single file when src and tgt already tracked

  $ mv d1/d11/a1 d2/c
  $ hg addrem -s 0
  removing d1/d11/a1
  adding d2/c
  $ hg rename --after d1/d11/a1 d2/c
  $ hg status -C
  A d2/c
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d2/c

rename --after a single file to a nonexistent target filename

  $ hg rename --after d1/a dummy
  d1/a: not recording move - dummy does not exist

move a single file to an existing directory

  $ hg rename d1/d11/a1 d2
  $ hg status -C
  A d2/a1
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d2/a1

move --after a single file to an existing directory

  $ mv d1/d11/a1 d2
  $ hg rename --after d1/d11/a1 d2
  $ hg status -C
  A d2/a1
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d2/a1

rename a file using a relative path

  $ (cd d1/d11; hg rename ../../d2/b e)
  $ hg status -C
  A d1/d11/e
    d2/b
  R d2/b
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d1/d11/e

rename --after a file using a relative path

  $ (cd d1/d11; mv ../../d2/b e; hg rename --after ../../d2/b e)
  $ hg status -C
  A d1/d11/e
    d2/b
  R d2/b
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d1/d11/e

rename directory d1 as d3

  $ hg rename d1/ d3
  moving d1/a to d3/a
  moving d1/b to d3/b
  moving d1/ba to d3/ba
  moving d1/d11/a1 to d3/d11/a1
  $ hg status -C
  A d3/a
    d1/a
  A d3/b
    d1/b
  A d3/ba
    d1/ba
  A d3/d11/a1
    d1/d11/a1
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  $ hg update -C
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

rename --after directory d1 as d3

  $ mv d1 d3
  $ hg rename --after d1 d3
  moving d1/a to d3/a
  moving d1/b to d3/b
  moving d1/ba to d3/ba
  moving d1/d11/a1 to d3/d11/a1
  $ hg status -C
  A d3/a
    d1/a
  A d3/b
    d1/b
  A d3/ba
    d1/ba
  A d3/d11/a1
    d1/d11/a1
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  $ hg update -C
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

move a directory using a relative path

  $ (cd d2; mkdir d3; hg rename ../d1/d11 d3)
  moving ../d1/d11/a1 to d3/d11/a1
  $ hg status -C
  A d2/d3/d11/a1
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d2/d3

move --after a directory using a relative path

  $ (cd d2; mkdir d3; mv ../d1/d11 d3; hg rename --after ../d1/d11 d3)
  moving ../d1/d11/a1 to d3/d11/a1
  $ hg status -C
  A d2/d3/d11/a1
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d2/d3

move directory d1/d11 to an existing directory d2 (removes empty d1)

  $ hg rename d1/d11/ d2
  moving d1/d11/a1 to d2/d11/a1
  $ hg status -C
  A d2/d11/a1
    d1/d11/a1
  R d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d2/d11

move directories d1 and d2 to a new directory d3

  $ mkdir d3
  $ hg rename d1 d2 d3
  moving d1/a to d3/d1/a
  moving d1/b to d3/d1/b
  moving d1/ba to d3/d1/ba
  moving d1/d11/a1 to d3/d1/d11/a1
  moving d2/b to d3/d2/b
  $ hg status -C
  A d3/d1/a
    d1/a
  A d3/d1/b
    d1/b
  A d3/d1/ba
    d1/ba
  A d3/d1/d11/a1
    d1/d11/a1
  A d3/d2/b
    d2/b
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  R d2/b
  $ hg update -C
  5 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

move --after directories d1 and d2 to a new directory d3

  $ mkdir d3
  $ mv d1 d2 d3
  $ hg rename --after d1 d2 d3
  moving d1/a to d3/d1/a
  moving d1/b to d3/d1/b
  moving d1/ba to d3/d1/ba
  moving d1/d11/a1 to d3/d1/d11/a1
  moving d2/b to d3/d2/b
  $ hg status -C
  A d3/d1/a
    d1/a
  A d3/d1/b
    d1/b
  A d3/d1/ba
    d1/ba
  A d3/d1/d11/a1
    d1/d11/a1
  A d3/d2/b
    d2/b
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  R d2/b
  $ hg update -C
  5 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

move everything under directory d1 to existing directory d2, do not
overwrite existing files (d2/b)

  $ hg rename d1/* d2
  d2/b: not overwriting - file already committed
  (hg rename --force to replace the file by recording a rename)
  moving d1/d11/a1 to d2/d11/a1
  $ hg status -C
  A d2/a
    d1/a
  A d2/ba
    d1/ba
  A d2/d11/a1
    d1/d11/a1
  R d1/a
  R d1/ba
  R d1/d11/a1
  $ diff -u d1/b d2/b
  --- d1/b	* (glob)
  +++ d2/b	* (glob)
  @@ * (glob)
  -d1/b
  +d2/b
  [1]
  $ hg update -C
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d2/a d2/ba d2/d11/a1

attempt to move one file into a non-existent directory

  $ hg rename d1/a dx/
  abort: destination dx/ is not a directory
  [255]
  $ hg status -C
  $ hg update -C
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

attempt to move potentially more than one file into a non-existent directory

  $ hg rename 'glob:d1/**' dx
  abort: with multiple sources, destination must be an existing directory
  [255]

move every file under d1 to d2/d21

  $ mkdir d2/d21
  $ hg rename 'glob:d1/**' d2/d21
  moving d1/a to d2/d21/a
  moving d1/b to d2/d21/b
  moving d1/ba to d2/d21/ba
  moving d1/d11/a1 to d2/d21/a1
  $ hg status -C
  A d2/d21/a
    d1/a
  A d2/d21/a1
    d1/d11/a1
  A d2/d21/b
    d1/b
  A d2/d21/ba
    d1/ba
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  $ hg update -C
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d2/d21

move --after some files under d1 to d2/d21

  $ mkdir d2/d21
  $ mv d1/a d1/d11/a1 d2/d21
  $ hg rename --after 'glob:d1/**' d2/d21
  moving d1/a to d2/d21/a
  d1/b: not recording move - d2/d21/b does not exist
  d1/ba: not recording move - d2/d21/ba does not exist
  moving d1/d11/a1 to d2/d21/a1
  $ hg status -C
  A d2/d21/a
    d1/a
  A d2/d21/a1
    d1/d11/a1
  R d1/a
  R d1/d11/a1
  $ hg update -C
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d2/d21

move every file under d1 starting with an 'a' to d2/d21 (regexp)

  $ mkdir d2/d21
  $ hg rename 're:d1/([^a][^/]*/)*a.*' d2/d21
  moving d1/a to d2/d21/a
  moving d1/d11/a1 to d2/d21/a1
  $ hg status -C
  A d2/d21/a
    d1/a
  A d2/d21/a1
    d1/d11/a1
  R d1/a
  R d1/d11/a1
  $ hg update -C
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d2/d21

attempt to overwrite an existing file

  $ echo "ca" > d1/ca
  $ hg rename d1/ba d1/ca
  d1/ca: not overwriting - file exists
  (hg rename --after to record the rename)
  $ hg status -C
  ? d1/ca
  $ hg update -C
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

forced overwrite of an existing file

  $ echo "ca" > d1/ca
  $ hg rename --force d1/ba d1/ca
  $ hg status -C
  A d1/ca
    d1/ba
  R d1/ba
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d1/ca

attempt to overwrite an existing broken symlink

#if symlink
  $ ln -s ba d1/ca
  $ hg rename --traceback d1/ba d1/ca
  d1/ca: not overwriting - file exists
  (hg rename --after to record the rename)
  $ hg status -C
  ? d1/ca
  $ hg update -C
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d1/ca

replace a symlink with a file

  $ ln -s ba d1/ca
  $ hg rename --force d1/ba d1/ca
  $ hg status -C
  A d1/ca
    d1/ba
  R d1/ba
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d1/ca
#endif

do not copy more than one source file to the same destination file

  $ mkdir d3
  $ hg rename d1/* d2/* d3
  moving d1/d11/a1 to d3/d11/a1
  d3/b: not overwriting - d2/b collides with d1/b
  $ hg status -C
  A d3/a
    d1/a
  A d3/b
    d1/b
  A d3/ba
    d1/ba
  A d3/d11/a1
    d1/d11/a1
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  $ hg update -C
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

move a whole subtree with "hg rename ."

  $ mkdir d3
  $ (cd d1; hg rename . ../d3)
  moving a to ../d3/d1/a
  moving b to ../d3/d1/b
  moving ba to ../d3/d1/ba
  moving d11/a1 to ../d3/d1/d11/a1
  $ hg status -C
  A d3/d1/a
    d1/a
  A d3/d1/b
    d1/b
  A d3/d1/ba
    d1/ba
  A d3/d1/d11/a1
    d1/d11/a1
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  $ hg update -C
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

move a whole subtree with "hg rename --after ."

  $ mkdir d3
  $ mv d1/* d3
  $ (cd d1; hg rename --after . ../d3)
  moving a to ../d3/a
  moving b to ../d3/b
  moving ba to ../d3/ba
  moving d11/a1 to ../d3/d11/a1
  $ hg status -C
  A d3/a
    d1/a
  A d3/b
    d1/b
  A d3/ba
    d1/ba
  A d3/d11/a1
    d1/d11/a1
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  $ hg update -C
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

move the parent tree with "hg rename .."

  $ (cd d1/d11; hg rename .. ../../d3)
  moving ../a to ../../d3/a
  moving ../b to ../../d3/b
  moving ../ba to ../../d3/ba
  moving a1 to ../../d3/d11/a1
  $ hg status -C
  A d3/a
    d1/a
  A d3/b
    d1/b
  A d3/ba
    d1/ba
  A d3/d11/a1
    d1/d11/a1
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  $ hg update -C
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

skip removed files

  $ hg remove d1/b
  $ hg rename d1 d3
  moving d1/a to d3/a
  moving d1/ba to d3/ba
  moving d1/d11/a1 to d3/d11/a1
  $ hg status -C
  A d3/a
    d1/a
  A d3/ba
    d1/ba
  A d3/d11/a1
    d1/d11/a1
  R d1/a
  R d1/b
  R d1/ba
  R d1/d11/a1
  $ hg update -C
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf d3

transitive rename

  $ hg rename d1/b d1/bb
  $ hg rename d1/bb d1/bc
  $ hg status -C
  A d1/bc
    d1/b
  R d1/b
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d1/bc

transitive rename --after

  $ hg rename d1/b d1/bb
  $ mv d1/bb d1/bc
  $ hg rename --after d1/bb d1/bc
  $ hg status -C
  A d1/bc
    d1/b
  R d1/b
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d1/bc

  $ echo "# idempotent renames (d1/b -> d1/bb followed by d1/bb -> d1/b)"
  # idempotent renames (d1/b -> d1/bb followed by d1/bb -> d1/b)
  $ hg rename d1/b d1/bb
  $ echo "some stuff added to d1/bb" >> d1/bb
  $ hg rename d1/bb d1/b
  $ hg status -C
  M d1/b
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

overwriting with renames (issue1959)

  $ hg rename d1/a d1/c
  $ hg rename d1/b d1/a
  $ hg status -C
  M d1/a
    d1/b
  A d1/c
    d1/a
  R d1/b
  $ hg diff --git
  diff --git a/d1/a b/d1/a
  --- a/d1/a
  +++ b/d1/a
  @@ -1,1 +1,1 @@
  -d1/a
  +d1/b
  diff --git a/d1/b b/d1/b
  deleted file mode 100644
  --- a/d1/b
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -d1/b
  diff --git a/d1/a b/d1/c
  copy from d1/a
  copy to d1/c
  $ hg update -C
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm d1/c # The file was marked as added, so 'hg update' action  was 'forget'

check illegal path components

  $ hg rename d1/d11/a1 .hg/foo
  abort: path contains illegal component: .hg/foo
  [255]
  $ hg status -C
  $ hg rename d1/d11/a1 ../foo
  abort: ../foo not under root '$TESTTMP'
  [255]
  $ hg status -C

  $ mv d1/d11/a1 .hg/foo
  $ hg rename --after d1/d11/a1 .hg/foo
  abort: path contains illegal component: .hg/foo
  [255]
  $ hg status -C
  ! d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm .hg/foo

  $ hg rename d1/d11/a1 .hg
  abort: path contains illegal component: .hg/a1
  [255]
  $ hg --config extensions.largefiles= rename d1/d11/a1 .hg
  The fsmonitor extension is incompatible with the largefiles extension and has been disabled. (fsmonitor !)
  abort: path contains illegal component: .hg/a1
  [255]
  $ hg status -C
  $ hg rename d1/d11/a1 ..
  abort: ../a1 not under root '$TESTTMP'
  [255]
  $ hg --config extensions.largefiles= rename d1/d11/a1 ..
  The fsmonitor extension is incompatible with the largefiles extension and has been disabled. (fsmonitor !)
  abort: ../a1 not under root '$TESTTMP'
  [255]
  $ hg status -C

  $ mv d1/d11/a1 .hg
  $ hg rename --after d1/d11/a1 .hg
  abort: path contains illegal component: .hg/a1
  [255]
  $ hg status -C
  ! d1/d11/a1
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm .hg/a1

  $ (cd d1/d11; hg rename ../../d2/b ../../.hg/foo)
  abort: path contains illegal component: .hg/foo
  [255]
  $ hg status -C
  $ (cd d1/d11; hg rename ../../d2/b ../../../foo)
  abort: ../../../foo not under root '$TESTTMP'
  [255]
  $ hg status -C