view Makefile @ 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

# If you want to change PREFIX, do not just edit it below. The changed
# value wont get passed on to recursive make calls. You should instead
# override the variable on the command like:
#
# % make PREFIX=/opt/ install

export PREFIX=/usr/local
PYTHON=python
$(eval HGROOT := $(shell pwd))
HGPYTHONS ?= $(HGROOT)/build/pythons
PURE=
PYFILES:=$(shell find mercurial hgext doc -name '*.py')
DOCFILES=mercurial/help/*.txt
export LANGUAGE=C
export LC_ALL=C
TESTFLAGS ?= $(shell echo $$HGTESTFLAGS)
OSXVERSIONFLAGS ?= $(shell echo $$OSXVERSIONFLAGS)

# Set this to e.g. "mingw32" to use a non-default compiler.
COMPILER=

COMPILERFLAG_tmp_ =
COMPILERFLAG_tmp_${COMPILER} ?= -c $(COMPILER)
COMPILERFLAG=${COMPILERFLAG_tmp_${COMPILER}}

help:
	@echo 'Commonly used make targets:'
	@echo '  all          - build program and documentation'
	@echo '  install      - install program and man pages to $$PREFIX ($(PREFIX))'
	@echo '  install-home - install with setup.py install --home=$$HOME ($(HOME))'
	@echo '  local        - build for inplace usage'
	@echo '  tests        - run all tests in the automatic test suite'
	@echo '  test-foo     - run only specified tests (e.g. test-merge1.t)'
	@echo '  dist         - run all tests and create a source tarball in dist/'
	@echo '  clean        - remove files created by other targets'
	@echo '                 (except installed files or dist source tarball)'
	@echo '  update-pot   - update i18n/hg.pot'
	@echo
	@echo 'Example for a system-wide installation under /usr/local:'
	@echo '  make all && su -c "make install" && hg version'
	@echo
	@echo 'Example for a local installation (usable in this directory):'
	@echo '  make local && ./hg version'

all: build doc

local:
	$(PYTHON) setup.py $(PURE) \
	  build_py -c -d . \
	  build_ext $(COMPILERFLAG) -i \
	  build_hgexe $(COMPILERFLAG) -i \
	  build_mo
	env HGRCPATH= $(PYTHON) hg version

build:
	$(PYTHON) setup.py $(PURE) build $(COMPILERFLAG)

wheel:
	FORCE_SETUPTOOLS=1 $(PYTHON) setup.py $(PURE) bdist_wheel $(COMPILERFLAG)

doc:
	$(MAKE) -C doc

cleanbutpackages:
	-$(PYTHON) setup.py clean --all # ignore errors from this command
	find contrib doc hgext hgext3rd i18n mercurial tests hgdemandimport \
		\( -name '*.py[cdo]' -o -name '*.so' \) -exec rm -f '{}' ';'
	rm -f MANIFEST MANIFEST.in hgext/__index__.py tests/*.err
	rm -f mercurial/__modulepolicy__.py
	if test -d .hg; then rm -f mercurial/__version__.py; fi
	rm -rf build mercurial/locale
	$(MAKE) -C doc clean
	$(MAKE) -C contrib/chg distclean

clean: cleanbutpackages
	rm -rf packages

install: install-bin install-doc

install-bin: build
	$(PYTHON) setup.py $(PURE) install --root="$(DESTDIR)/" --prefix="$(PREFIX)" --force

install-doc: doc
	cd doc && $(MAKE) $(MFLAGS) install

install-home: install-home-bin install-home-doc

install-home-bin: build
	$(PYTHON) setup.py $(PURE) install --home="$(HOME)" --prefix="" --force

install-home-doc: doc
	cd doc && $(MAKE) $(MFLAGS) PREFIX="$(HOME)" install

MANIFEST-doc:
	$(MAKE) -C doc MANIFEST

MANIFEST.in: MANIFEST-doc
	hg manifest | sed -e 's/^/include /' > MANIFEST.in
	echo include mercurial/__version__.py >> MANIFEST.in
	sed -e 's/^/include /' < doc/MANIFEST >> MANIFEST.in

dist:	tests dist-notests

dist-notests:	doc MANIFEST.in
	TAR_OPTIONS="--owner=root --group=root --mode=u+w,go-w,a+rX-s" $(PYTHON) setup.py -q sdist

check: tests

tests:
	cd tests && $(PYTHON) run-tests.py $(TESTFLAGS)

test-%:
	cd tests && $(PYTHON) run-tests.py $(TESTFLAGS) $@

testpy-%:
	@echo Looking for Python $* in $(HGPYTHONS)
	[ -e $(HGPYTHONS)/$*/bin/python ] || ( \
	cd $$(mktemp --directory --tmpdir) && \
        $(MAKE) -f $(HGROOT)/contrib/Makefile.python PYTHONVER=$* PREFIX=$(HGPYTHONS)/$* python )
	cd tests && $(HGPYTHONS)/$*/bin/python run-tests.py $(TESTFLAGS)

check-code:
	hg manifest | xargs python contrib/check-code.py

format-c:
	clang-format --style file -i \
	  `hg files 'set:(**.c or **.h) and not "listfile:contrib/clang-format-blacklist"'`

update-pot: i18n/hg.pot

i18n/hg.pot: $(PYFILES) $(DOCFILES) i18n/posplit i18n/hggettext
	$(PYTHON) i18n/hggettext mercurial/commands.py \
	  hgext/*.py hgext/*/__init__.py \
	  mercurial/fileset.py mercurial/revset.py \
	  mercurial/templatefilters.py mercurial/templatekw.py \
	  mercurial/templater.py \
	  mercurial/filemerge.py \
	  mercurial/hgweb/webcommands.py \
	  mercurial/util.py \
	  $(DOCFILES) > i18n/hg.pot.tmp
        # All strings marked for translation in Mercurial contain
        # ASCII characters only. But some files contain string
        # literals like this '\037\213'. xgettext thinks it has to
        # parse them even though they are not marked for translation.
        # Extracting with an explicit encoding of ISO-8859-1 will make
        # xgettext "parse" and ignore them.
	echo $(PYFILES) | xargs \
	  xgettext --package-name "Mercurial" \
	  --msgid-bugs-address "<[e-mail]>" \
	  --copyright-holder "Matt Mackall <[e-mail]> and others" \
	  --from-code ISO-8859-1 --join --sort-by-file --add-comments=i18n: \
	  -d hg -p i18n -o hg.pot.tmp
	$(PYTHON) i18n/posplit i18n/hg.pot.tmp
        # The target file is not created before the last step. So it never is in
        # an intermediate state.
	mv -f i18n/hg.pot.tmp i18n/hg.pot

%.po: i18n/hg.pot
        # work on a temporary copy for never having a half completed target
	cp $@ $@.tmp
	msgmerge --no-location --update $@.tmp $^
	mv -f $@.tmp $@

# Packaging targets

osx:
	rm -rf build/mercurial
	/usr/bin/python2.7 setup.py install --optimize=1 \
	  --root=build/mercurial/ --prefix=/usr/local/ \
	  --install-lib=/Library/Python/2.7/site-packages/
	make -C doc all install DESTDIR="$(PWD)/build/mercurial/"
        # Place a bogon .DS_Store file in the target dir so we can be
        # sure it doesn't get included in the final package.
	touch build/mercurial/.DS_Store
        # install zsh completions - this location appears to be
        # searched by default as of macOS Sierra.
	install -d build/mercurial/usr/local/share/zsh/site-functions/
	install -m 0644 contrib/zsh_completion build/mercurial/usr/local/share/zsh/site-functions/_hg
        # install bash completions - there doesn't appear to be a
        # place that's searched by default for bash, so we'll follow
        # the lead of Apple's git install and just put it in a
        # location of our own.
	install -d build/mercurial/usr/local/hg/contrib/
	install -m 0644 contrib/bash_completion build/mercurial/usr/local/hg/contrib/hg-completion.bash
	make -C contrib/chg \
	  HGPATH=/usr/local/bin/hg \
	  PYTHON=/usr/bin/python2.7 \
	  HGEXTDIR=/Library/Python/2.7/site-packages/hgext \
	  DESTDIR=../../build/mercurial \
	  PREFIX=/usr/local \
	  clean install
	mkdir -p $${OUTPUTDIR:-dist}
	HGVER=$$(python contrib/genosxversion.py $(OSXVERSIONFLAGS) build/mercurial/Library/Python/2.7/site-packages/mercurial/__version__.py) && \
	OSXVER=$$(sw_vers -productVersion | cut -d. -f1,2) && \
	pkgbuild --filter \\.DS_Store --root build/mercurial/ \
	  --identifier org.mercurial-scm.mercurial \
	  --version "$${HGVER}" \
	  build/mercurial.pkg && \
	productbuild --distribution contrib/macosx/distribution.xml \
	  --package-path build/ \
	  --version "$${HGVER}" \
	  --resources contrib/macosx/ \
	  "$${OUTPUTDIR:-dist/}"/Mercurial-"$${HGVER}"-macosx"$${OSXVER}".pkg

deb:
	contrib/builddeb

ppa:
	contrib/builddeb --source-only

contrib/docker/debian-%: contrib/docker/debian.template
	sed "s/__CODENAME__/$*/" $< > $@

docker-debian-jessie: contrib/docker/debian-jessie
	mkdir -p packages/debian-jessie
	contrib/dockerdeb debian jessie

docker-debian-stretch: contrib/docker/debian-stretch
	mkdir -p packages/debian-stretch
	contrib/dockerdeb debian stretch

contrib/docker/ubuntu-%: contrib/docker/ubuntu.template
	sed "s/__CODENAME__/$*/" $< > $@

docker-ubuntu-trusty: contrib/docker/ubuntu-trusty
	contrib/dockerdeb ubuntu trusty

docker-ubuntu-trusty-ppa: contrib/docker/ubuntu-trusty
	contrib/dockerdeb ubuntu trusty --source-only

docker-ubuntu-xenial: contrib/docker/ubuntu-xenial
	contrib/dockerdeb ubuntu xenial

docker-ubuntu-xenial-ppa: contrib/docker/ubuntu-xenial
	contrib/dockerdeb ubuntu xenial --source-only

docker-ubuntu-yakkety: contrib/docker/ubuntu-yakkety
	contrib/dockerdeb ubuntu yakkety

docker-ubuntu-yakkety-ppa: contrib/docker/ubuntu-yakkety
	contrib/dockerdeb ubuntu yakkety --source-only

docker-ubuntu-zesty: contrib/docker/ubuntu-zesty
	contrib/dockerdeb ubuntu zesty

docker-ubuntu-zesty-ppa: contrib/docker/ubuntu-zesty
	contrib/dockerdeb ubuntu zesty --source-only

fedora20:
	mkdir -p packages/fedora20
	contrib/buildrpm
	cp rpmbuild/RPMS/*/* packages/fedora20
	cp rpmbuild/SRPMS/* packages/fedora20
	rm -rf rpmbuild

docker-fedora20:
	mkdir -p packages/fedora20
	contrib/dockerrpm fedora20

fedora21:
	mkdir -p packages/fedora21
	contrib/buildrpm
	cp rpmbuild/RPMS/*/* packages/fedora21
	cp rpmbuild/SRPMS/* packages/fedora21
	rm -rf rpmbuild

docker-fedora21:
	mkdir -p packages/fedora21
	contrib/dockerrpm fedora21

centos5:
	mkdir -p packages/centos5
	contrib/buildrpm --withpython
	cp rpmbuild/RPMS/*/* packages/centos5
	cp rpmbuild/SRPMS/* packages/centos5

docker-centos5:
	mkdir -p packages/centos5
	contrib/dockerrpm centos5 --withpython

centos6:
	mkdir -p packages/centos6
	contrib/buildrpm --withpython
	cp rpmbuild/RPMS/*/* packages/centos6
	cp rpmbuild/SRPMS/* packages/centos6

docker-centos6:
	mkdir -p packages/centos6
	contrib/dockerrpm centos6 --withpython

centos7:
	mkdir -p packages/centos7
	contrib/buildrpm
	cp rpmbuild/RPMS/*/* packages/centos7
	cp rpmbuild/SRPMS/* packages/centos7

docker-centos7:
	mkdir -p packages/centos7
	contrib/dockerrpm centos7

linux-wheels: linux-wheels-x86_64 linux-wheels-i686

linux-wheels-x86_64:
	docker run -e "HGTEST_JOBS=$(shell nproc)" --rm -ti -v `pwd`:/src quay.io/pypa/manylinux1_x86_64 /src/contrib/build-linux-wheels.sh

linux-wheels-i686:
	docker run -e "HGTEST_JOBS=$(shell nproc)" --rm -ti -v `pwd`:/src quay.io/pypa/manylinux1_i686 linux32 /src/contrib/build-linux-wheels.sh

.PHONY: help all local build doc cleanbutpackages clean install install-bin \
	install-doc install-home install-home-bin install-home-doc \
	dist dist-notests check tests check-code format-c update-pot \
	osx deb ppa docker-debian-jessie docker-debian-stretch \
	docker-ubuntu-trusty docker-ubuntu-trusty-ppa \
	docker-ubuntu-xenial docker-ubuntu-xenial-ppa \
	docker-ubuntu-yakkety docker-ubuntu-yakkety-ppa \
	docker-ubuntu-zesty docker-ubuntu-zesty-ppa \
	fedora20 docker-fedora20 fedora21 docker-fedora21 \
	centos5 docker-centos5 centos6 docker-centos6 centos7 docker-centos7 \
	linux-wheels