# logexceptions.py - Write files containing info about Mercurial exceptions

#

# Copyright 2017 Matt Mackall <mpm@selenic.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import inspect

import os

import sys

import traceback

import uuid

from mercurial import (

    dispatch,

    extensions,

)

def handleexception(orig, ui):

    res = orig(ui)

    if not ui.environ.get(b'HGEXCEPTIONSDIR'):

        return res

    dest = os.path.join(ui.environ[b'HGEXCEPTIONSDIR'],

                        str(uuid.uuid4()).encode('ascii'))

    exc_type, exc_value, exc_tb = sys.exc_info()

    stack = []

    tb = exc_tb

    while tb:

        stack.append(tb)

        tb = tb.tb_next

    stack.reverse()

    hgframe = 'unknown'

    hgline = 'unknown'

    # Find the first Mercurial frame in the stack.

    for tb in stack:

        mod = inspect.getmodule(tb)

        if not mod.__name__.startswith(('hg', 'mercurial')):

            continue

        frame = tb.tb_frame

        try:

            with open(inspect.getsourcefile(tb), 'r') as fh:

                hgline = fh.readlines()[frame.f_lineno - 1].strip()

        except (IndexError, OSError):

            pass

        hgframe = '%s:%d' % (frame.f_code.co_filename, frame.f_lineno)

        break

    primary = traceback.extract_tb(exc_tb)[-1]

    primaryframe = '%s:%d' % (primary.filename, primary.lineno)

    with open(dest, 'wb') as fh:

        parts = [

            str(exc_value),

            primaryframe,

            hgframe,

            hgline,

        ]

        fh.write(b'\0'.join(p.encode('utf-8', 'replace') for p in parts))

def extsetup(ui):

    extensions.wrapfunction(dispatch, 'handlecommandexception',

                            handleexception)