contrib/Makefile.python

dirstate-tree: Change status() results to not borrow DirstateMap

The `status` function takes a `&'tree mut DirstateMap<'on_disk>` parameter.
`'on_disk` borrows a read-only byte buffer with the contents of the
`.hg/dirstate` file. `DirstateMap` internally uses represents file paths as
`std::borrow::Cow<'on_disk, HgPath>`, which borrows the byte buffer when
possible and allocates an owned string if not, such as for files added to the
dirstate after it was loaded from disk.

Previously the return type of of `status` has a `'tree` lifetime, meaning it
could borrow all paths from the `DirstateMap`. With this changeset, that
lifetime is changed to `'on_disk` meaning that only paths from the byte buffer
can be borrowed, and paths allocated by `DirstateMap` must be copied.

Usually most paths are in the byte buffer, and most paths are not part of the
return value of `status`, so the number of extra copies should be small.

This change will enable `status` to mutate the `DirstateMap` after it has
finished constructing its return value. Previously such mutation would be
prevented by possible on-going borrows.

Differential Revision: https://phab.mercurial-scm.org/D10824

PYTHONVER=2.7.16
PYTHONNAME=python-
PREFIX=$(HOME)/bin/prefix-$(PYTHONNAME)$(PYTHONVER)
SYMLINKDIR=$(HOME)/bin

help:
	@echo
	@echo 'Make a custom installation of a Python version'
	@echo
	@echo 'Common make parameters:'
	@echo '  PYTHONVER=...    [$(PYTHONVER)]'
	@echo '  PREFIX=...       [$(PREFIX)]'
	@echo '  SYMLINKDIR=...   [$(SYMLINKDIR) creating $(PYTHONNAME)$(PYTHONVER)]'
	@echo
	@echo 'Common make targets:'
	@echo '  python    - install Python $$PYTHONVER in $$PREFIX'
	@echo '  symlink   - create a $$SYMLINKDIR/$(PYTHONNAME)$$PYTHONVER symlink'
	@echo
	@echo 'Example: create a temporary Python installation:'
	@echo '  $$ make -f Makefile.python python PYTHONVER=${PYTHONVER} PREFIX=/tmp/p27'
	@echo '  $$ /tmp/p27/bin/python -V'
	@echo '  Python 2.7'
	@echo
	@echo 'Some external libraries are required for building Python: zlib bzip2 openssl.'
	@echo 'Make sure their development packages are installed systemwide.'
# fedora: yum install zlib-devel bzip2-devel openssl-devel
# debian: apt-get install zlib1g-dev libbz2-dev libssl-dev
	@echo
	@echo 'To build a nice collection of interesting Python versions:'
	@echo '  $$ for v in 2.{6{,.1,.2,.9},7{,.8,.10}}; do'
	@echo '    make -f Makefile.python symlink PYTHONVER=$$v || break; done'
	@echo 'To run a Mercurial test on all these Python versions:'
	@echo '  $$ for py in `cd ~/bin && ls $(PYTHONNAME)2.*`; do'
	@echo '    echo $$py; $$py run-tests.py test-http.t; echo; done'
	@echo

export LANGUAGE=C
export LC_ALL=C

python: $(PREFIX)/bin/python docutils
	printf 'import sys, zlib, bz2, docutils, ssl' | $(PREFIX)/bin/python

PYTHON_SRCDIR=Python-$(PYTHONVER)
PYTHON_SRCFILE=$(PYTHON_SRCDIR).tgz

$(PREFIX)/bin/python:
	[ -f $(PYTHON_SRCFILE) ] || wget http://www.python.org/ftp/python/$(PYTHONVER)/$(PYTHON_SRCFILE) || curl -OL http://www.python.org/ftp/python/$(PYTHONVER)/$(PYTHON_SRCFILE) || [ -f $(PYTHON_SRCFILE) ]
	rm -rf $(PYTHON_SRCDIR)
	tar xf $(PYTHON_SRCFILE)
	# Debian/Ubuntu disables SSLv2,3 the hard way, disable it on old Pythons too
	-sed -i 's,self.*SSLv[23]_method(),0;//\0,g' $(PYTHON_SRCDIR)/Modules/_ssl.c
	# Find multiarch system libraries on Ubuntu and disable fortify error when setting argv
	LDFLAGS="-L/usr/lib/`dpkg-architecture -qDEB_HOST_MULTIARCH`"; \
	BASECFLAGS=-U_FORTIFY_SOURCE; \
	export LDFLAGS BASECFLAGS; \
	cd $(PYTHON_SRCDIR) && ./configure --prefix=$(PREFIX) && make all SVNVERSION=pwd && make install
	printf 'import sys, zlib, bz2, ssl' | $(PREFIX)/bin/python
	rm -rf $(PYTHON_SRCDIR)

DOCUTILSVER=0.12
DOCUTILS_SRCDIR=docutils-$(DOCUTILSVER)
DOCUTILS_SRCFILE=$(DOCUTILS_SRCDIR).tar.gz

docutils: $(PREFIX)/bin/python
	@$(PREFIX)/bin/python -c 'import docutils' || ( set -ex; \
	[ -f $(DOCUTILS_SRCFILE) ] || wget http://downloads.sourceforge.net/project/docutils/docutils/$(DOCUTILSVER)/$(DOCUTILS_SRCFILE) || [ -f $(DOCUTILS_SRCFILE) ]; \
	rm -rf $(DOCUTILS_SRCDIR); \
	tar xf $(DOCUTILS_SRCFILE); \
	cd $(DOCUTILS_SRCDIR) && $(PREFIX)/bin/python setup.py install --prefix=$(PREFIX); \
	$(PREFIX)/bin/python -c 'import docutils'; \
	rm -rf $(DOCUTILS_SRCDIR); )

symlink: python $(SYMLINKDIR)
	ln -sf $(PREFIX)/bin/python $(SYMLINKDIR)/$(PYTHONNAME)$(PYTHONVER)

.PHONY: help python docutils symlink