add --pure flag to setup.py

This flag will make the build_py step install the pure Python modules
in mercurial/pure/ into mercurial/ and furthermore prevent building
the C extensions.

setup.py

@@ -1,218 +1,247
 #!/usr/bin/env python
 #
 # This is the mercurial setup script.
 #
 # 'python setup.py install', or
 # 'python setup.py --help' for more options
 
 import sys
 if not hasattr(sys, 'version_info') or sys.version_info < (2, 3, 0, 'final'):
     raise SystemExit("Mercurial requires python 2.3 or later.")
 
 # Solaris Python packaging brain damage
 try:
     import hashlib
     sha = hashlib.sha1()
 except:
     try:
         import sha
     except:
         raise SystemExit(
             "Couldn't import standard hashlib (incomplete Python install).")
 
 try:
     import zlib
 except:
     raise SystemExit(
         "Couldn't import standard zlib (incomplete Python install).")
 
 import os, time
 import shutil
 import tempfile
 from distutils.core import setup, Extension
+from distutils.dist import Distribution
 from distutils.command.install_data import install_data
 from distutils.command.build import build
+from distutils.command.build_py import build_py
 from distutils.spawn import spawn, find_executable
 from distutils.ccompiler import new_compiler
 
 extra = {}
 scripts = ['hg']
 if os.name == 'nt':
     scripts.append('contrib/win32/hg.bat')
 
 # simplified version of distutils.ccompiler.CCompiler.has_function
 # that actually removes its temporary files.
 def has_function(cc, funcname):
     tmpdir = tempfile.mkdtemp(prefix='hg-install-')
     devnull = oldstderr = None
     try:
         try:
             fname = os.path.join(tmpdir, 'funcname.c')
             f = open(fname, 'w')
             f.write('int main(void) {\n')
             f.write('    %s();\n' % funcname)
             f.write('}\n')
             f.close()
             # Redirect stderr to /dev/null to hide any error messages
             # from the compiler.
             # This will have to be changed if we ever have to check
             # for a function on Windows.
             devnull = open('/dev/null', 'w')
             oldstderr = os.dup(sys.stderr.fileno())
             os.dup2(devnull.fileno(), sys.stderr.fileno())
             objects = cc.compile([fname])
             cc.link_executable(objects, os.path.join(tmpdir, "a.out"))
         except:
             return False
         return True
     finally:
         if oldstderr is not None:
             os.dup2(oldstderr, sys.stderr.fileno())
         if devnull is not None:
             devnull.close()
         shutil.rmtree(tmpdir)
 
 # py2exe needs to be installed to work
 try:
     import py2exe
 
     # Help py2exe to find win32com.shell
     try:
         import modulefinder
         import win32com
         for p in win32com.__path__[1:]: # Take the path to win32comext
             modulefinder.AddPackagePath("win32com", p)
         pn = "win32com.shell"
         __import__(pn)
         m = sys.modules[pn]
         for p in m.__path__[1:]:
             modulefinder.AddPackagePath(pn, p)
     except ImportError:
         pass
 
     extra['console'] = ['hg']
 
 except ImportError:
     pass
 
 try:
     # execute hg out of this directory with a custom environment which
     # includes the pure Python modules in mercurial/pure
     pypath = os.environ.get('PYTHONPATH', '')
     purepath = os.path.join('mercurial', 'pure')
     os.environ['PYTHONPATH'] = os.pathsep.join(['mercurial', purepath, pypath])
     cmd = '%s id -it' % os.path.join('.', 'hg')
     l = os.popen(cmd).read().split()
     os.environ['PYTHONPATH'] = pypath
     while len(l) > 1 and l[-1][0].isalpha(): # remove non-numbered tags
         l.pop()
     version = l and l[-1] or 'unknown' # latest tag or revision number
     if version.endswith('+'):
         version += time.strftime('%Y%m%d')
 
 except OSError:
     version = "unknown"
 
 f = file("mercurial/__version__.py", "w")
 f.write('# this file is autogenerated by setup.py\n')
 f.write('version = "%s"\n' % version)
 f.close()
 
 class install_package_data(install_data):
     def finalize_options(self):
         self.set_undefined_options('install',
                                    ('install_lib', 'install_dir'))
         install_data.finalize_options(self)
 
 class build_mo(build):
 
     description = "build translations (.mo files)"
 
     def run(self):
         if not find_executable('msgfmt'):
             self.warn("could not find msgfmt executable, no translations "
                      "will be built")
             return
 
         podir = 'i18n'
         if not os.path.isdir(podir):
             self.warn("could not find %s/ directory" % podir)
             return
 
         join = os.path.join
         for po in os.listdir(podir):
             if not po.endswith('.po'):
                 continue
             pofile = join(podir, po)
             modir = join('locale', po[:-3], 'LC_MESSAGES')
             mofile = join(modir, 'hg.mo')
             cmd = ['msgfmt', '-v', '-o', mofile, pofile]
             if sys.platform != 'sunos5':
                 # msgfmt on Solaris does not know about -c
                 cmd.append('-c')
             self.mkpath(modir)
             self.make_file([pofile], mofile, spawn, (cmd,))
             self.distribution.data_files.append((join('mercurial', modir),
                                                  [mofile]))
 
 build.sub_commands.append(('build_mo', None))
 
+Distribution.pure = 0
+Distribution.global_options.append(('pure', None, "use pure (slow) Python "
+                                    "code instead of C extensions"))
+
+class hg_build_py(build_py):
+
+    def finalize_options(self):
+        build_py.finalize_options(self)
+
+        if self.distribution.pure:
+            if self.py_modules is None:
+                self.py_modules = []
+            for ext in self.distribution.ext_modules:
+                if ext.name.startswith("mercurial."):
+                    self.py_modules.append("mercurial.pure.%s" % ext.name[10:])
+            self.distribution.ext_modules = []
+
+    def find_modules(self):
+        modules = build_py.find_modules(self)
+        for module in modules:
+            if module[0] == "mercurial.pure":
+                if module[1] != "__init__":
+                    yield ("mercurial", module[1], module[2])
+            else:
+                yield module
+
 cmdclass = {'install_data': install_package_data,
-            'build_mo': build_mo}
+            'build_mo': build_mo,
+            'build_py': hg_build_py}
 
 ext_modules=[
     Extension('mercurial.base85', ['mercurial/base85.c']),
     Extension('mercurial.bdiff', ['mercurial/bdiff.c']),
     Extension('mercurial.diffhelpers', ['mercurial/diffhelpers.c']),
     Extension('mercurial.mpatch', ['mercurial/mpatch.c']),
     Extension('mercurial.parsers', ['mercurial/parsers.c']),
     ]
 
 packages = ['mercurial', 'mercurial.hgweb', 'hgext', 'hgext.convert',
             'hgext.highlight', 'hgext.zeroconf', ]
 
 try:
     import msvcrt
     ext_modules.append(Extension('mercurial.osutil', ['mercurial/osutil.c']))
 except ImportError:
     pass
 
 try:
     import posix
     ext_modules.append(Extension('mercurial.osutil', ['mercurial/osutil.c']))
 
     if sys.platform == 'linux2' and os.uname()[2] > '2.6':
         # The inotify extension is only usable with Linux 2.6 kernels.
         # You also need a reasonably recent C library.
         cc = new_compiler()
         if has_function(cc, 'inotify_add_watch'):
             ext_modules.append(Extension('hgext.inotify.linux._inotify',
                                          ['hgext/inotify/linux/_inotify.c']))
             packages.extend(['hgext.inotify', 'hgext.inotify.linux'])
 except ImportError:
     pass
 
 datafiles = []
 for root in ('templates', 'i18n'):
     for dir, dirs, files in os.walk(root):
         datafiles.append((os.path.join('mercurial', dir),
                           [os.path.join(dir, file_) for file_ in files]))
 
 setup(name='mercurial',
       version=version,
       author='Matt Mackall',
       author_email='[e-mail]',
       url='http://selenic.com/mercurial',
       description='Scalable distributed SCM',
       license='GNU GPL',
       scripts=scripts,
       packages=packages,
       ext_modules=ext_modules,
       data_files=datafiles,
       cmdclass=cmdclass,
       options=dict(py2exe=dict(packages=['hgext', 'email']),
                    bdist_mpkg=dict(zipdist=True,
                                    license='COPYING',
                                    readme='contrib/macosx/Readme.html',
                                    welcome='contrib/macosx/Welcome.html')),
       **extra)