Commit fe6ddb83 authored by Aymeric Augustin's avatar Aymeric Augustin
Browse files

Fixed #24704 -- Made the autoreloader survive SyntaxErrors. 

With this change, it's expected to survive anything except errors
that make it impossible to import the settings. It's too complex
to fallback to a sensible behavior with a broken settings module.

Harcoding things about runserver in ManagementUtility.execute is
atrocious but it's the only way out of the chicken'n'egg problem:
the current implementation of the autoreloader primarily watches
imported Python modules -- and then a few other things that were
bolted on top of this design -- but we want it to kick in even if
the project contains import-time errors and django.setup() fails.

At some point we should throw away this code and replace it by an
off-the-shelf autoreloader that watches the working directory and
re-runs `django-admin runserver` whenever something changes.
parent c2fcba2a

django/core/management/__init__.py

+15 −2
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ from django.core.management.base import ( 
    BaseCommand, CommandError, CommandParser, handle_default_options,

)

from django.core.management.color import color_style

from django.utils import lru_cache, six

from django.utils import autoreload, lru_cache, six

from django.utils._os import npath, upath
@@ -308,6 +308,19 @@ class ManagementUtility(object): 
                settings.configure()



        if settings.configured:

            # Start the auto-reloading dev server even if the code is broken.

            # The hardcoded condition is a code smell but we can't rely on a

            # flag on the command class because we haven't located it yet.

            if subcommand == 'runserver' and '--noreload' not in self.argv:

                try:

                    autoreload.check_errors(django.setup)()

                except Exception:

                    # The exception will be raised later in the child process

                    # started by the autoreloader.

                    pass



            # In all other cases, django.setup() is required to succeed.

            else:

                django.setup()



        self.autocomplete()

django/core/management/commands/runserver.py

+4 −0
Original line number Diff line number Diff line
@@ -104,6 +104,10 @@ class Command(BaseCommand): 
            self.inner_run(None, **options)



    def inner_run(self, *args, **options):

        # If an exception was silenced in ManagementUtility.execute in order

        # to be raised in the child process, raise it now.

        autoreload.raise_last_exception()



        threading = options.get('use_threading')

        shutdown_message = options.get('shutdown_message', '')

        quit_command = 'CTRL-BREAK' if sys.platform == 'win32' else 'CONTROL-C'

django/utils/autoreload.py

+12 −1
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ import traceback 
from django.apps import apps

from django.conf import settings

from django.core.signals import request_finished

from django.utils import six

from django.utils._os import npath

from django.utils.six.moves import _thread as thread
@@ -72,6 +73,7 @@ I18N_MODIFIED = 2 
_mtimes = {}

_win = (sys.platform == "win32")



_exception = None

_error_files = []

_cached_modules = set()

_cached_filenames = []
@@ -219,11 +221,14 @@ def code_changed(): 


def check_errors(fn):

    def wrapper(*args, **kwargs):

        global _exception

        try:

            fn(*args, **kwargs)

        except (ImportError, IndentationError, NameError, SyntaxError,

                TypeError, AttributeError):

            et, ev, tb = sys.exc_info()

            _exception = sys.exc_info()



            et, ev, tb = _exception



            if getattr(ev, 'filename', None) is None:

                # get the filename from the last item in the stack
@@ -239,6 +244,12 @@ def check_errors(fn): 
    return wrapper





def raise_last_exception():

    global _exception

    if _exception is not None:

        six.reraise(*_exception)





def ensure_echo_on():

    if termios:

        fd = sys.stdin

docs/releases/1.8.5.txt

+2 −0
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ Django 1.8.5 fixes several bugs in 1.8.4. 
Bugfixes

========



* Made the development server's autoreload more robust (:ticket:`24704`).



* Fixed ``AssertionError`` in some delete queries with a model containing a

  field that is both a foreign and primary key (:ticket:`24951`).