view doc/check-seclevel.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
#
# checkseclevel - checking section title levels in each online help documents

import sys, os
import optparse

# import from the live mercurial repo
sys.path.insert(0, "..")
# fall back to pure modules if required C extensions are not available
sys.path.append(os.path.join('..', 'mercurial', 'pure'))
from mercurial import demandimport; demandimport.enable()
from mercurial.commands import table
from mercurial.help import helptable
from mercurial import extensions
from mercurial import minirst

_verbose = False

def verbose(msg):
    if _verbose:
        print msg

def error(msg):
    sys.stderr.write('%s\n' % msg)

level2mark = ['"', '=', '-', '.', '#']
reservedmarks = ['"']

mark2level = {}
for m, l in zip(level2mark, xrange(len(level2mark))):
    if m not in reservedmarks:
        mark2level[m] = l

initlevel_topic = 0
initlevel_cmd = 1
initlevel_ext = 1
initlevel_ext_cmd = 3

def showavailables(initlevel):
    error('    available marks and order of them in this help: %s' %
          (', '.join(['%r' % (m * 4) for m in level2mark[initlevel + 1:]])))

def checkseclevel(doc, name, initlevel):
    verbose('checking "%s"' % name)
    blocks, pruned = minirst.parse(doc, 0, ['verbose'])
    errorcnt = 0
    curlevel = initlevel
    for block in blocks:
        if block['type'] != 'section':
            continue
        mark = block['underline']
        title = block['lines'][0]
        if (mark not in mark2level) or (mark2level[mark] <= initlevel):
            error('invalid section mark %r for "%s" of %s' %
                  (mark * 4, title, name))
            showavailables(initlevel)
            errorcnt += 1
            continue
        nextlevel = mark2level[mark]
        if curlevel < nextlevel and curlevel + 1 != nextlevel:
            error('gap of section level at "%s" of %s' %
                  (title, name))
            showavailables(initlevel)
            errorcnt += 1
            continue
        verbose('appropriate section level for "%s %s"' %
                (mark * (nextlevel * 2), title))
        curlevel = nextlevel

    return errorcnt

def checkcmdtable(cmdtable, namefmt, initlevel):
    errorcnt = 0
    for k, entry in cmdtable.items():
        name = k.split("|")[0].lstrip("^")
        if not entry[0].__doc__:
            verbose('skip checking %s: no help document' %
                    (namefmt % name))
            continue
        errorcnt += checkseclevel(entry[0].__doc__,
                                  namefmt % name,
                                  initlevel)
    return errorcnt

def checkhghelps():
    errorcnt = 0
    for names, sec, doc in helptable:
        if callable(doc):
            doc = doc()
        errorcnt += checkseclevel(doc,
                                  '%s help topic' % names[0],
                                  initlevel_topic)

    errorcnt += checkcmdtable(table, '%s command', initlevel_cmd)

    for name in sorted(extensions.enabled().keys() +
                       extensions.disabled().keys()):
        mod = extensions.load(None, name, None)
        if not mod.__doc__:
            verbose('skip checking %s extension: no help document' % name)
            continue
        errorcnt += checkseclevel(mod.__doc__,
                                  '%s extension' % name,
                                  initlevel_ext)

        cmdtable = getattr(mod, 'cmdtable', None)
        if cmdtable:
            errorcnt += checkcmdtable(cmdtable,
                                      '%s command of ' + name + ' extension',
                                      initlevel_ext_cmd)
    return errorcnt

def checkfile(filename, initlevel):
    if filename == '-':
        filename = 'stdin'
        doc = sys.stdin.read()
    else:
        fp = open(filename)
        try:
            doc = fp.read()
        finally:
            fp.close()

    verbose('checking input from %s with initlevel %d' %
            (filename, initlevel))
    return checkseclevel(doc, 'input from %s' % filename, initlevel)

if __name__ == "__main__":
    optparser = optparse.OptionParser("""%prog [options]

This checks all help documents of Mercurial (topics, commands,
extensions and commands of them), if no file is specified by --file
option.
""")
    optparser.add_option("-v", "--verbose",
                         help="enable additional output",
                         action="store_true")
    optparser.add_option("-f", "--file",
                         help="filename to read in (or '-' for stdin)",
                         action="store", default="")

    optparser.add_option("-t", "--topic",
                         help="parse file as help topic",
                         action="store_const", dest="initlevel", const=0)
    optparser.add_option("-c", "--command",
                         help="parse file as help of core command",
                         action="store_const", dest="initlevel", const=1)
    optparser.add_option("-e", "--extension",
                         help="parse file as help of extension",
                         action="store_const", dest="initlevel", const=1)
    optparser.add_option("-C", "--extension-command",
                         help="parse file as help of extension command",
                         action="store_const", dest="initlevel", const=3)

    optparser.add_option("-l", "--initlevel",
                         help="set initial section level manually",
                         action="store", type="int", default=0)

    (options, args) = optparser.parse_args()

    _verbose = options.verbose

    if options.file:
        if checkfile(options.file, options.initlevel):
            sys.exit(1)
    else:
        if checkhghelps():
            sys.exit(1)