annotate contrib/hgfixes/fix_bytesmod.py @ 25329:101e84121c13

dispatch: disable demandimport for the --debugger option

Something in Python 2.7.9 or so broke the --debugger option with
ui.debugger = ipdb. I get the traceback below. There is some apparent
confusion with demandimport. This should be disabled anyway for the
--debugger option. The debugger must be imported right away, before
any other dispatch. There's no benefit in delaying the debugger
import.

This patch uses the demandimport.deactivated() context manager.

  Traceback (most recent call last):
    File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 121, in _runcatch
      debugmod = __import__(debugger)
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 115, in _demandimport
      return _hgextimport(_import, name, globals, locals, fromlist, level)
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 47, in _hgextimport
      return importfunc(name, globals, *args)
    File "/usr/lib/python2.7/dist-packages/ipdb/__init__.py", line 16, in <module>
      from ipdb.__main__ import set_trace, post_mortem, pm, run, runcall, runeval, launch_ipdb_on_exception
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 134, in _demandimport
      mod = _hgextimport(_origimport, name, globals, locals)
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 47, in _hgextimport
      return importfunc(name, globals, *args)
    File "/usr/lib/python2.7/dist-packages/ipdb/__main__.py", line 29, in <module>
      if IPython.__version__ > '0.10.2':
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 106, in __getattribute__
      self._load()
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 78, in _load
      mod = _hgextimport(_import, head, globals, locals, None, level)
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 47, in _hgextimport
      return importfunc(name, globals, *args)
    File "/usr/lib/python2.7/dist-packages/IPython/__init__.py", line 45, in <module>
      from .config.loader import Config
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 132, in _demandimport
      return _origimport(name, globals, locals, fromlist, level)
    File "/usr/lib/python2.7/dist-packages/IPython/config/__init__.py", line 16, in <module>
      from .application import *
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 115, in _demandimport
      return _hgextimport(_import, name, globals, locals, fromlist, level)
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 47, in _hgextimport
      return importfunc(name, globals, *args)
    File "/usr/lib/python2.7/dist-packages/IPython/config/application.py", line 30, in <module>
      from IPython.external.decorator import decorator
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 134, in _demandimport
      mod = _hgextimport(_origimport, name, globals, locals)
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 47, in _hgextimport
      return importfunc(name, globals, *args)
    File "/usr/lib/python2.7/dist-packages/IPython/external/decorator/__init__.py", line 2, in <module>
      from decorator import *
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 115, in _demandimport
      return _hgextimport(_import, name, globals, locals, fromlist, level)
    File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 47, in _hgextimport
      return importfunc(name, globals, *args)
    File "/usr/lib/python2.7/dist-packages/decorator.py", line 240, in <module>
      'ContextManager', (_GeneratorContextManager,), dict(__call__=__call__))

"""Fixer that changes bytes % whatever to a function that actually formats
it."""

from lib2to3 import fixer_base
from lib2to3.fixer_util import is_tuple, Call, Comma, Name, touch_import

# XXX: Implementing a blacklist in 2to3 turned out to be more troublesome than
# blacklisting some modules inside the fixers. So, this is what I came with.

blacklist = ['mercurial/demandimport.py',
             'mercurial/py3kcompat.py',
             'mercurial/i18n.py',
            ]

def isnumberremainder(formatstr, data):
    try:
        if data.value.isdigit():
            return True
    except AttributeError:
        return False

class FixBytesmod(fixer_base.BaseFix):
    # XXX: There's one case (I suppose) I can't handle: when a remainder
    # operation like foo % bar is performed, I can't really know what the
    # contents of foo and bar are. I believe the best approach is to "correct"
    # the to-be-converted code and let bytesformatter handle that case in
    # runtime.
    PATTERN = '''
              term< formatstr=STRING '%' data=STRING > |
              term< formatstr=STRING '%' data=atom > |
              term< formatstr=NAME '%' data=any > |
              term< formatstr=any '%' data=any >
              '''

    def transform(self, node, results):
        for bfn in blacklist:
            if self.filename.endswith(bfn):
                return
        if not self.filename.endswith('mercurial/py3kcompat.py'):
            touch_import('mercurial', 'py3kcompat', node=node)

        formatstr = results['formatstr'].clone()
        data = results['data'].clone()
        formatstr.prefix = '' # remove spaces from start

        if isnumberremainder(formatstr, data):
            return

        # We have two possibilities:
        # 1- An identifier or name is passed, it is going to be a leaf, thus, we
        #    just need to copy its value as an argument to the formatter;
        # 2- A tuple is explicitly passed. In this case, we're gonna explode it
        # to pass to the formatter
        # TODO: Check for normal strings. They don't need to be translated

        if is_tuple(data):
            args = [formatstr, Comma().clone()] + \
                   [c.clone() for c in data.children[:]]
        else:
            args = [formatstr, Comma().clone(), data]

        call = Call(Name('bytesformatter', prefix=' '), args)
        return call