tests/check-perf-code.py

setup: avoid attempting to invoke the system-wide hg.exe on Windows

On Windows, the executable in the current directory gets priority over anything
in $PATH (both for cmd.exe and MSYS).  That means, the former code was launching
the local hg.exe instead of the system-wide one, if it was previously built.  If
that failed, it then fell back to the local hg code, but run through python.exe.

I'm not sure what it is about ef7119cd4965, but that started throwing up a
messagebox that python37.dll couldn't be loaded.  (And indeed, python37 is not
in $PATH by default.)  Invoking the local hg via the current python avoids that.

#!/usr/bin/env python
#
# check-perf-code - (historical) portability checker for contrib/perf.py

from __future__ import absolute_import

import os
import sys

# write static check patterns here
perfpypats = [
  [
    (r'(branchmap|repoview)\.subsettable',
     "use getbranchmapsubsettable() for early Mercurial"),
    (r'\.(vfs|svfs|opener|sopener)',
     "use getvfs()/getsvfs() for early Mercurial"),
    (r'ui\.configint',
     "use getint() instead of ui.configint() for early Mercurial"),
  ],
  # warnings
  [
  ]
]

def modulewhitelist(names):
    replacement = [('.py', ''), ('.c', ''), # trim suffix
                   ('mercurial%s' % (os.sep), ''), # trim "mercurial/" path
                  ]
    ignored = {'__init__'}
    modules = {}

    # convert from file name to module name, and count # of appearances
    for name in names:
        name = name.strip()
        for old, new in replacement:
            name = name.replace(old, new)
        if name not in ignored:
            modules[name] = modules.get(name, 0) + 1

    # list up module names, which appear multiple times
    whitelist = []
    for name, count in modules.items():
        if count > 1:
            whitelist.append(name)

    return whitelist

if __name__ == "__main__":
    # in this case, it is assumed that result of "hg files" at
    # multiple revisions is given via stdin
    whitelist = modulewhitelist(sys.stdin)
    assert whitelist, "module whitelist is empty"

    # build up module whitelist check from file names given at runtime
    perfpypats[0].append(
        # this matching pattern assumes importing modules from
        # "mercurial" package in the current style below, for simplicity
        #
        #    from mercurial import (
        #        foo,
        #        bar,
        #        baz
        #    )
        ((r'from mercurial import [(][a-z0-9, \n#]*\n(?! *%s,|^[ #]*\n|[)])'
          % ',| *'.join(whitelist)),
         "import newer module separately in try clause for early Mercurial"
         ))

    # import contrib/check-code.py as checkcode
    assert 'RUNTESTDIR' in os.environ, "use check-perf-code.py in *.t script"
    contribpath = os.path.join(os.environ['RUNTESTDIR'], '..', 'contrib')
    sys.path.insert(0, contribpath)
    checkcode = __import__('check-code')

    # register perf.py specific entry with "checks" in check-code.py
    checkcode.checks.append(('perf.py', r'contrib/perf.py$', '',
                             checkcode.pyfilters, perfpypats))

    sys.exit(checkcode.main())