view i18n/check-translation.py @ 25561:50a6c3c55db1 stable

parsers: do not cache RevlogError type (issue4451)

Index lookups raise RevlogError when the lookup fails. The previous
implementation was caching a reference to the RevlogError type in a
static variable. This assumed that the "mercurial.error" module was
only loaded once and there was only a single copy of it floating
around in memory. Unfortunately, in some situations - including
certain mod_wsgi configurations - this was not the case: the
"mercurial.error" module could be reloaded. It was possible for a
"RevlogError" reference from the first interpreter to be used by
a second interpreter. While the underlying thing was a
"mercurial.error.RevlogError," the object IDs were different, so
the Python code in revlog.py was failing to catch the exception! This
error has existed since the C index lookup code was implemented in
changeset e8d37b78acfb, which was first released in Mercurial 2.2 in
2012.
http://emptysqua.re/blog/python-c-extensions-and-mod-wsgi/#static-variables-are-shared
contains more details.

This patch removes the caching of the RevlogError type from the
function.

Since pretty much the entire function was refactored and the return
value of the function wasn't used, I changed the function signature
to not return anything.

For reasons unknown to me, we were calling PyErr_SetObject()
with the type of RevlogError and an instance of RevlogError. This
was equivalent to the Python code "raise RevlogError(RevlogError)".
This seemed wonky and completely unnecessary. The Python code only
cares about the type of the exception, not its contents. So I got
rid of this complexity.

This is my first Python C extension patch. Please give extra scrutiny
to it during review.

#!/usr/bin/env python
#
# check-translation.py - check Mercurial specific translation problems

import polib
import re

checkers = []

def levelchecker(level, msgidpat):
    def decorator(func):
        if msgidpat:
            match = re.compile(msgidpat).search
        else:
            match = lambda msgid: True
        checkers.append((func, level))
        func.match = match
        return func
    return decorator

def match(checker, pe):
    """Examine whether POEntry "pe" is target of specified checker or not
    """
    if not checker.match(pe.msgid):
        return
    # examine suppression by translator comment
    nochecker = 'no-%s-check' % checker.__name__
    for tc in pe.tcomment.split():
        if nochecker == tc:
            return
    return True

####################

def fatalchecker(msgidpat=None):
    return levelchecker('fatal', msgidpat)

@fatalchecker(r'\$\$')
def promptchoice(pe):
    """Check translation of the string given to "ui.promptchoice()"

    >>> pe = polib.POEntry(
    ...     msgid ='prompt$$missing &sep$$missing &amp$$followed by &none',
    ...     msgstr='prompt  missing &sep$$missing  amp$$followed by none&')
    >>> match(promptchoice, pe)
    True
    >>> for e in promptchoice(pe): print e
    number of choices differs between msgid and msgstr
    msgstr has invalid choice missing '&'
    msgstr has invalid '&' followed by none
    """
    idchoices = [c.rstrip(' ') for c in pe.msgid.split('$$')[1:]]
    strchoices = [c.rstrip(' ') for c in pe.msgstr.split('$$')[1:]]

    if len(idchoices) != len(strchoices):
        yield "number of choices differs between msgid and msgstr"

    indices = [(c, c.find('&')) for c in strchoices]
    if [c for c, i in indices if i == -1]:
        yield "msgstr has invalid choice missing '&'"
    if [c for c, i in indices if len(c) == i + 1]:
        yield "msgstr has invalid '&' followed by none"

####################

def warningchecker(msgidpat=None):
    return levelchecker('warning', msgidpat)

@warningchecker()
def taildoublecolons(pe):
    """Check equality of tail '::'-ness between msgid and msgstr

    >>> pe = polib.POEntry(
    ...     msgid ='ends with ::',
    ...     msgstr='ends with ::')
    >>> for e in taildoublecolons(pe): print e
    >>> pe = polib.POEntry(
    ...     msgid ='ends with ::',
    ...     msgstr='ends without double-colons')
    >>> for e in taildoublecolons(pe): print e
    tail '::'-ness differs between msgid and msgstr
    >>> pe = polib.POEntry(
    ...     msgid ='ends without double-colons',
    ...     msgstr='ends with ::')
    >>> for e in taildoublecolons(pe): print e
    tail '::'-ness differs between msgid and msgstr
    """
    if pe.msgid.endswith('::') != pe.msgstr.endswith('::'):
        yield "tail '::'-ness differs between msgid and msgstr"

@warningchecker()
def indentation(pe):
    """Check equality of initial indentation between msgid and msgstr

    This may report unexpected warning, because this doesn't aware
    the syntax of rst document and the context of msgstr.

    >>> pe = polib.POEntry(
    ...     msgid ='    indented text',
    ...     msgstr='  narrowed indentation')
    >>> for e in indentation(pe): print e
    initial indentation width differs betweeen msgid and msgstr
    """
    idindent = len(pe.msgid) - len(pe.msgid.lstrip())
    strindent = len(pe.msgstr) - len(pe.msgstr.lstrip())
    if idindent != strindent:
        yield "initial indentation width differs betweeen msgid and msgstr"

####################

def check(pofile, fatal=True, warning=False):
    targetlevel = { 'fatal': fatal, 'warning': warning }
    targetcheckers = [(checker, level)
                      for checker, level in checkers
                      if targetlevel[level]]
    if not targetcheckers:
        return []

    detected = []
    for pe in pofile.translated_entries():
        errors = []
        for checker, level in targetcheckers:
            if match(checker, pe):
                errors.extend((level, checker.__name__, error)
                              for error in checker(pe))
        if errors:
            detected.append((pe, errors))
    return detected

########################################

if __name__ == "__main__":
    import sys
    import optparse

    optparser = optparse.OptionParser("""%prog [options] pofile ...

This checks Mercurial specific translation problems in specified
'*.po' files.

Each detected problems are shown in the format below::

    filename:linenum:type(checker): problem detail .....

"type" is "fatal" or "warning". "checker" is the name of the function
detecting corresponded error.

Checking by checker "foo" on the specific msgstr can be suppressed by
the "translator comment" like below. Multiple "no-xxxx-check" should
be separated by whitespaces::

    # no-foo-check
    msgid = "....."
    msgstr = "....."
""")
    optparser.add_option("", "--warning",
                         help="show also warning level problems",
                         action="store_true")
    optparser.add_option("", "--doctest",
                         help="run doctest of this tool, instead of check",
                         action="store_true")
    (options, args) = optparser.parse_args()

    if options.doctest:
        import os
        if 'TERM' in os.environ:
            del os.environ['TERM']
        import doctest
        failures, tests = doctest.testmod()
        sys.exit(failures and 1 or 0)

    # replace polib._POFileParser to show linenum of problematic msgstr
    class ExtPOFileParser(polib._POFileParser):
        def process(self, symbol, linenum):
            super(ExtPOFileParser, self).process(symbol, linenum)
            if symbol == 'MS': # msgstr
                self.current_entry.linenum = linenum
    polib._POFileParser = ExtPOFileParser

    detected = []
    warning = options.warning
    for f in args:
        detected.extend((f, pe, errors)
                        for pe, errors in check(polib.pofile(f),
                                                warning=warning))
    if detected:
        for f, pe, errors in detected:
            for level, checker, error in errors:
                sys.stderr.write('%s:%d:%s(%s): %s\n'
                                 % (f, pe.linenum, level, checker, error))
        sys.exit(1)