mercurial/ui.py

Make it possible to debug failed hook imports via use of --traceback

Prior to this change, if a Python hook module failed to load (e.g. due
to an import error or path problem), it was impossible to figure out
why the error occurred, because the ImportErrors that got raised were
caught but never displayed.

If run with --traceback or ui.traceback=True, hg now prints tracebacks
of both of the ImportError instances that get raised before it bails.

# ui.py - user interface bits for mercurial
#
# Copyright 2005-2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

from i18n import _
import errno, getpass, os, socket, sys, tempfile, traceback
import config, util, error

_booleans = {'1': True, 'yes': True, 'true': True, 'on': True,
             '0': False, 'no': False, 'false': False, 'off': False}

class ui(object):
    def __init__(self, src=None):
        self._buffers = []
        self.quiet = self.verbose = self.debugflag = self.tracebackflag = False
        self._reportuntrusted = True
        self._ocfg = config.config() # overlay
        self._tcfg = config.config() # trusted
        self._ucfg = config.config() # untrusted
        self._trustusers = set()
        self._trustgroups = set()

        if src:
            self._tcfg = src._tcfg.copy()
            self._ucfg = src._ucfg.copy()
            self._ocfg = src._ocfg.copy()
            self._trustusers = src._trustusers.copy()
            self._trustgroups = src._trustgroups.copy()
            self.fixconfig()
        else:
            # we always trust global config files
            for f in util.rcpath():
                self.readconfig(f, trust=True)

    def copy(self):
        return self.__class__(self)

    def _is_trusted(self, fp, f):
        st = util.fstat(fp)
        if util.isowner(st):
            return True

        tusers, tgroups = self._trustusers, self._trustgroups
        if '*' in tusers or '*' in tgroups:
            return True

        user = util.username(st.st_uid)
        group = util.groupname(st.st_gid)
        if user in tusers or group in tgroups or user == util.username():
            return True

        if self._reportuntrusted:
            self.warn(_('Not trusting file %s from untrusted '
                        'user %s, group %s\n') % (f, user, group))
        return False

    def readconfig(self, filename, root=None, trust=False,
                   sections=None, remap=None):
        try:
            fp = open(filename)
        except IOError:
            if not sections: # ignore unless we were looking for something
                return
            raise

        cfg = config.config()
        trusted = sections or trust or self._is_trusted(fp, filename)

        try:
            cfg.read(filename, fp, sections=sections, remap=remap)
        except error.ConfigError, inst:
            if trusted:
                raise
            self.warn(_("Ignored: %s\n") % str(inst))

        if trusted:
            self._tcfg.update(cfg)
            self._tcfg.update(self._ocfg)
        self._ucfg.update(cfg)
        self._ucfg.update(self._ocfg)

        if root is None:
            root = os.path.expanduser('~')
        self.fixconfig(root=root)

    def fixconfig(self, root=None):
        # translate paths relative to root (or home) into absolute paths
        root = root or os.getcwd()
        for c in self._tcfg, self._ucfg, self._ocfg:
            for n, p in c.items('paths'):
                if p and "://" not in p and not os.path.isabs(p):
                    c.set("paths", n, os.path.normpath(os.path.join(root, p)))

        # update ui options
        self.debugflag = self.configbool('ui', 'debug')
        self.verbose = self.debugflag or self.configbool('ui', 'verbose')
        self.quiet = not self.debugflag and self.configbool('ui', 'quiet')
        if self.verbose and self.quiet:
            self.quiet = self.verbose = False
        self._reportuntrusted = self.configbool("ui", "report_untrusted", True)
        self.tracebackflag = self.configbool('ui', 'traceback', False)

        # update trust information
        self._trustusers.update(self.configlist('trusted', 'users'))
        self._trustgroups.update(self.configlist('trusted', 'groups'))

    def setconfig(self, section, name, value):
        for cfg in (self._ocfg, self._tcfg, self._ucfg):
            cfg.set(section, name, value)
        self.fixconfig()

    def _data(self, untrusted):
        return untrusted and self._ucfg or self._tcfg

    def configsource(self, section, name, untrusted=False):
        return self._data(untrusted).source(section, name) or 'none'

    def config(self, section, name, default=None, untrusted=False):
        value = self._data(untrusted).get(section, name, default)
        if self.debugflag and not untrusted and self._reportuntrusted:
            uvalue = self._ucfg.get(section, name)
            if uvalue is not None and uvalue != value:
                self.debug(_("ignoring untrusted configuration option "
                             "%s.%s = %s\n") % (section, name, uvalue))
        return value

    def configbool(self, section, name, default=False, untrusted=False):
        v = self.config(section, name, None, untrusted)
        if v is None:
            return default
        if v.lower() not in _booleans:
            raise error.ConfigError(_("%s.%s not a boolean ('%s')")
                                    % (section, name, v))
        return _booleans[v.lower()]

    def configlist(self, section, name, default=None, untrusted=False):
        """Return a list of comma/space separated strings"""
        result = self.config(section, name, untrusted=untrusted)
        if result is None:
            result = default or []
        if isinstance(result, basestring):
            result = result.replace(",", " ").split()
        return result

    def has_section(self, section, untrusted=False):
        '''tell whether section exists in config.'''
        return section in self._data(untrusted)

    def configitems(self, section, untrusted=False):
        items = self._data(untrusted).items(section)
        if self.debugflag and not untrusted and self._reportuntrusted:
            for k, v in self._ucfg.items(section):
                if self._tcfg.get(section, k) != v:
                    self.debug(_("ignoring untrusted configuration option "
                                "%s.%s = %s\n") % (section, k, v))
        return items

    def walkconfig(self, untrusted=False):
        cfg = self._data(untrusted)
        for section in cfg.sections():
            for name, value in self.configitems(section, untrusted):
                yield section, name, str(value).replace('\n', '\\n')

    def username(self):
        """Return default username to be used in commits.

        Searched in this order: $HGUSER, [ui] section of hgrcs, $EMAIL
        and stop searching if one of these is set.
        If not found and ui.askusername is True, ask the user, else use
        ($LOGNAME or $USER or $LNAME or $USERNAME) + "@full.hostname".
        """
        user = os.environ.get("HGUSER")
        if user is None:
            user = self.config("ui", "username")
        if user is None:
            user = os.environ.get("EMAIL")
        if user is None and self.configbool("ui", "askusername"):
            user = self.prompt(_("enter a commit username:"), default=None)
        if user is None and not self.interactive():
            try:
                user = '%s@%s' % (util.getuser(), socket.getfqdn())
                self.warn(_("No username found, using '%s' instead\n") % user)
            except KeyError:
                pass
        if not user:
            raise util.Abort(_('no username supplied (see "hg help config")'))
        if "\n" in user:
            raise util.Abort(_("username %s contains a newline\n") % repr(user))
        return user

    def shortuser(self, user):
        """Return a short representation of a user name or email address."""
        if not self.verbose: user = util.shortuser(user)
        return user

    def _path(self, loc):
        p = self.config('paths', loc)
        if p:
            if '%%' in p:
                self.warn("(deprecated '%%' in path %s=%s from %s)\n" %
                          (loc, p, self.configsource('paths', loc)))
                p = p.replace('%%', '%')
            p = util.expandpath(p)
        return p

    def expandpath(self, loc, default=None):
        """Return repository location relative to cwd or from [paths]"""
        if "://" in loc or os.path.isdir(os.path.join(loc, '.hg')):
            return loc

        path = self._path(loc)
        if not path and default is not None:
            path = self._path(default)
        return path or loc

    def pushbuffer(self):
        self._buffers.append([])

    def popbuffer(self):
        return "".join(self._buffers.pop())

    def write(self, *args):
        if self._buffers:
            self._buffers[-1].extend([str(a) for a in args])
        else:
            for a in args:
                sys.stdout.write(str(a))

    def write_err(self, *args):
        try:
            if not sys.stdout.closed: sys.stdout.flush()
            for a in args:
                sys.stderr.write(str(a))
            # stderr may be buffered under win32 when redirected to files,
            # including stdout.
            if not sys.stderr.closed: sys.stderr.flush()
        except IOError, inst:
            if inst.errno != errno.EPIPE:
                raise

    def flush(self):
        try: sys.stdout.flush()
        except: pass
        try: sys.stderr.flush()
        except: pass

    def interactive(self):
        i = self.configbool("ui", "interactive", None)
        if i is None:
            return sys.stdin.isatty()
        return i

    def _readline(self, prompt=''):
        if sys.stdin.isatty():
            try:
                # magically add command line editing support, where
                # available
                import readline
                # force demandimport to really load the module
                readline.read_history_file
                # windows sometimes raises something other than ImportError
            except Exception:
                pass
        line = raw_input(prompt)
        # When stdin is in binary mode on Windows, it can cause
        # raw_input() to emit an extra trailing carriage return
        if os.linesep == '\r\n' and line and line[-1] == '\r':
            line = line[:-1]
        return line

    def prompt(self, msg, default="y"):
        """Prompt user with msg, read response.
        If ui is not interactive, the default is returned.
        """
        if not self.interactive():
            self.write(msg, ' ', default, "\n")
            return default
        try:
            r = self._readline(msg + ' ')
            if not r:
                return default
            return r
        except EOFError:
            raise util.Abort(_('response expected'))

    def promptchoice(self, msg, choices, default=0):
        """Prompt user with msg, read response, and ensure it matches
        one of the provided choices. The index of the choice is returned.
        choices is a sequence of acceptable responses with the format:
        ('&None', 'E&xec', 'Sym&link') Responses are case insensitive.
        If ui is not interactive, the default is returned.
        """
        resps = [s[s.index('&')+1].lower() for s in choices]
        while True:
            r = self.prompt(msg, resps[default])
            if r.lower() in resps:
                return resps.index(r.lower())
            self.write(_("unrecognized response\n"))


    def getpass(self, prompt=None, default=None):
        if not self.interactive(): return default
        try:
            return getpass.getpass(prompt or _('password: '))
        except EOFError:
            raise util.Abort(_('response expected'))
    def status(self, *msg):
        if not self.quiet: self.write(*msg)
    def warn(self, *msg):
        self.write_err(*msg)
    def note(self, *msg):
        if self.verbose: self.write(*msg)
    def debug(self, *msg):
        if self.debugflag: self.write(*msg)
    def edit(self, text, user):
        (fd, name) = tempfile.mkstemp(prefix="hg-editor-", suffix=".txt",
                                      text=True)
        try:
            f = os.fdopen(fd, "w")
            f.write(text)
            f.close()

            editor = self.geteditor()

            util.system("%s \"%s\"" % (editor, name),
                        environ={'HGUSER': user},
                        onerr=util.Abort, errprefix=_("edit failed"))

            f = open(name)
            t = f.read()
            f.close()
        finally:
            os.unlink(name)

        return t

    def traceback(self, exc=None):
        '''print exception traceback if traceback printing enabled.
        only to call in exception handler. returns true if traceback
        printed.'''
        if self.tracebackflag:
            if exc:
                traceback.print_exception(exc[0], exc[1], exc[2])
            else:
                traceback.print_exc()
        return self.tracebackflag

    def geteditor(self):
        '''return editor to use'''
        return (os.environ.get("HGEDITOR") or
                self.config("ui", "editor") or
                os.environ.get("VISUAL") or
                os.environ.get("EDITOR", "vi"))

    def progress(self, topic, pos, item="", unit="", total=None):
        '''show a progress message

        With stock hg, this is simply a debug message that is hidden
        by default, but with extensions or GUI tools it may be
        visible. 'topic' is the current operation, 'item' is a
        non-numeric marker of the current position (ie the currently
        in-process file), 'pos' is the current numeric position (ie
        revision, bytes, etc.), unit is a corresponding unit label,
        and total is the highest expected pos.

        Multiple nested topics may be active at a time. All topics
        should be marked closed by setting pos to None at termination.
        '''

        if pos == None or not self.debugflag:
            return

        if unit:
            unit = ' ' + unit
        if item:
            item = ' ' + item

        if total:
            pct = 100.0 * pos / total
            self.debug('%s:%s %s/%s%s (%4.2g%%)\n'
                     % (topic, item, pos, total, unit, pct))
        else:
            self.debug('%s:%s %s%s\n' % (topic, item, pos, unit))