Makefile

cborutil: implement sans I/O decoder

The vendored CBOR package decodes by calling read(n) on an object.
There are a number of disadvantages to this:

* Uses blocking I/O. If sufficient data is not available, the decoder
  will hang until it is.
* No support for partial reads. If the read(n) returns less data than
  requested, the decoder raises an error.
* Requires the use of a file like object. If the original data is in
  say a buffer, we need to "cast" it to e.g. a BytesIO to appease the
  decoder.

In addition, the vendored CBOR decoder doesn't provide flexibility
that we desire. Specifically:

* It buffers indefinite length bytestrings instead of streaming them.
* It doesn't allow limiting the set of types that can be decoded. This
  property is useful when implementing a "hardened" decoder that is
  less susceptible to abusive input.
* It doesn't provide sufficient "hook points" and introspection to
  institute checks around behavior. These are useful for implementing
  a "hardened" decoder.

This all adds up to a reasonable set of justifications for writing our
own decoder.

So, this commit implements our own CBOR decoder.

At the heart of the decoder is a function that decodes a single "item"
from a buffer. This item can be a complete simple value or a special
value, such as "start of array." Using this function, we can build a
decoder that effectively iterates over the stream of decoded items and
builds up higher-level values, such as arrays, maps, sets, and indefinite
length bytestrings. And we can do this without performing I/O in the
decoder itself.

The core of the sans I/O decoder will probably not be used directly.
Instead, it is expected that we'll build utility functions for invoking
the decoder given specific input types. This will allow extreme
flexibility in how data is delivered to the decoder.

I'm pretty happy with the state of the decoder modulo the TODO items
to track wanted features to help with a "hardened" decoder. The one
thing I could be convinced to change is the handling of semantic tags.
Since we only support a single semantic tag (sets), I thought it would
be easier to handle them inline in decodeitem(). This is simpler now.
But if we add support for other semantic tags, it will likely be easier
to move semantic tag handling outside of decodeitem(). But, properly
supporting semantic tags opens up a whole can of worms, as many
semantic tags imply new types. I'm optimistic we won't need these in
Mercurial. But who knows.

I'm also pretty happy with the test coverage. Writing comprehensive
tests for partial decoding did flush out a handful of bugs. One
general improvement to testing would be fuzz testing for partial
decoding. I may implement that later. I also anticipate switching the
wire protocol code to this new decoder will flush out any lingering
bugs.

Differential Revision: https://phab.mercurial-scm.org/D4414

# 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 ?= $(HGROOT)/build/pythons
PURE=
PYFILESCMD=find mercurial hgext doc -name '*.py'
PYFILES:=$(shell $(PYFILESCMD))
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 **.cc or **.h) and not "listfile:contrib/clang-format-ignorelist"'`

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/templatefuncs.py \
	  mercurial/templatekw.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.
	$(PYFILESCMD) | 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

packaging_targets := \
  centos5 \
  centos6 \
  centos7 \
  deb \
  docker-centos5 \
  docker-centos6 \
  docker-centos7 \
  docker-debian-jessie \
  docker-debian-stretch \
  docker-fedora20 \
  docker-fedora21 \
  docker-fedora28 \
  docker-ubuntu-trusty \
  docker-ubuntu-trusty-ppa \
  docker-ubuntu-xenial \
  docker-ubuntu-xenial-ppa \
  docker-ubuntu-artful \
  docker-ubuntu-artful-ppa \
  docker-ubuntu-bionic \
  docker-ubuntu-bionic-ppa \
  fedora20 \
  fedora21 \
  fedora28 \
  linux-wheels \
  linux-wheels-x86_64 \
  linux-wheels-i686 \
  ppa

# Forward packaging targets for convenience.
$(packaging_targets):
	$(MAKE) -C contrib/packaging $@

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/packaging/macosx/distribution.xml \
	  --package-path build/ \
	  --version "$${HGVER}" \
	  --resources contrib/packaging/macosx/ \
	  "$${OUTPUTDIR:-dist/}"/Mercurial-"$${HGVER}"-macosx"$${OSXVER}".pkg

.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 \
	$(packaging_targets) \
	osx