contrib/Makefile.python

statprof: separate functions and "line", assume 4 digit line numbers

Previously, the profile output looked like this (I've removed many lines that
are mostly inconsequential):

```
| 100.0%  0.02s  hg:             <module>          line 43:  dispatch.run()
| 100.0%  0.02s  dispatch.py:    run               line 115:  status = dispatch(req)
| 100.0%  0.02s  dispatch.py:    _runcatchfunc     line 432:  return _dispatch(req)
 \ 50.0%  0.01s  dispatch.py:    _dispatch         line 1228:  return runcommand(
   | 50.0%  0.01s  dispatch.py:    runcommand      line 883:  ret = _runcommand(ui, optio...
   | 50.0%  0.01s  dispatch.py:    _runcommand     line 1240:  return cmdfunc()
   | 50.0%  0.01s  localrepo.py:   __getitem__     line 1670:  quick_access = self._quick_...
   | 50.0%  0.01s  localrepo.py:   _quick_access_changeidline 1650:  return self._quick_access_c...
   | 50.0%  0.01s  localrepo.py:   __get__         line 179:  return getattr(unfi, self.n...
   | 50.0%  0.01s  util.py:        __get__         line 1747:  result = self.func(obj)
   | 50.0%  0.01s  localrepo.py:   _quick_access_changeid_wcline  1611:  cl = self.unfiltered().chan...
   | 50.0%  0.01s  localrepo.py:   __get__         line 110:  return super(_basefilecache...
   | 50.0%  0.01s  util.py:        __getattribute__line 245:  self.__spec__.loader.exec_m...
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: exec_moduleline            783:
   | 50.0%  0.01s  <frozen importlib._bootstrap>: _call_with_frames_removedline                 219:
   | 50.0%  0.01s  changelog.py:   <module>        line 376:  class changelog(revlog.revl...
   | 50.0%  0.01s  util.py:        __getattribute__line 245:  self.__spec__.loader.exec_m...
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: exec_moduleline            779:
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: get_codeline         868:
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: path_statsline           1012:
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: _path_statline           87:
```

This has a few problems, though I'm only addressing some of them.

1.  If the stuff before "line ###" is long, there's no separation between the
    function name and the "line" string.
2.  If the stuff before "line ###" is really long, there's excessive separation
    between the "line" string and the line number.
3.  We frequently have 4-digit line numbers, the code on the right wasn't
    dynamically indented and ended up quite messy looking.

To solve these problems, I've added a ", " prefix before "line" iff it would
otherwise not have any separation such as spaces. I've added a 'max' so that we
never use a negative width (which is the cause of problem #2 above), and I've
added a default assumption of 4 digit line numbers (but again using a 'max' so
this shouldn't cause problems if we go beyond that.

With these changes, it now looks like this:

```
| 100.0%  0.02s  hg:             <module>          line 43:   dispatch.run()
| 100.0%  0.02s  dispatch.py:    run               line 115:  status = dispatch(req)
| 100.0%  0.02s  dispatch.py:    _runcatchfunc     line 432:  return _dispatch(req)
 \ 50.0%  0.01s  dispatch.py:    _dispatch         line 1228: return runcommand(
   | 50.0%  0.01s  dispatch.py:    runcommand      line 883:  ret = _runcommand(ui, optio...
   | 50.0%  0.01s  dispatch.py:    _runcommand     line 1240: return cmdfunc()
   | 50.0%  0.01s  localrepo.py:   __getitem__     line 1670: quick_access = self._quick_...
   | 50.0%  0.01s  localrepo.py:   _quick_access_changeid, line 1650: return self._quick_access_c...
   | 50.0%  0.01s  localrepo.py:   __get__         line 179:  return getattr(unfi, self.n...
   | 50.0%  0.01s  util.py:        __get__         line 1747: result = self.func(obj)
   | 50.0%  0.01s  localrepo.py:   _quick_access_changeid_wc, line 1611: cl = self.unfiltered().chan...
   | 50.0%  0.01s  localrepo.py:   __get__         line 110:  return super(_basefilecache...
   | 50.0%  0.01s  util.py:        __getattribute__, line 245:  self.__spec__.loader.exec_m...
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: exec_module, line 783:
   | 50.0%  0.01s  <frozen importlib._bootstrap>: _call_with_frames_removed, line 219:
   | 50.0%  0.01s  changelog.py:   <module>        line 376:  class changelog(revlog.revl...
   | 50.0%  0.01s  util.py:        __getattribute__, line 245:  self.__spec__.loader.exec_m...
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: exec_module, line 779:
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: get_code, line 868:
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: path_stats, line 1012:
   | 50.0%  0.01s  <frozen importlib._bootstrap_external>: _path_stat, line 87:
```

Differential Revision: https://phab.mercurial-scm.org/D9511

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