From: Ben Darnell <ben@bendarnell.com>
Date: Sun, 2 Sep 2012 16:55:31 +0000 (-0700)
Subject: Improve autoreload for import-time errors.
X-Git-Tag: v3.0.0~263^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fd9bcb2e11a5299a4e63e8a7017c435d098b1fec;p=thirdparty%2Ftornado.git

Improve autoreload for import-time errors.

We already had a special case for SyntaxErrors, but NameErrors and other
import-time errors could leave a file unwatched.
---

diff --git a/tornado/autoreload.py b/tornado/autoreload.py
index 55a10d10c..940c2be7a 100644
--- a/tornado/autoreload.py
+++ b/tornado/autoreload.py
@@ -71,6 +71,7 @@ import logging
 import os
 import pkgutil
 import sys
+import traceback
 import types
 import subprocess
 
@@ -275,7 +276,16 @@ def main():
         logging.info("Script exited with status %s", e.code)
     except Exception, e:
         logging.warning("Script exited with uncaught exception", exc_info=True)
+        # If an exception occurred at import time, the file with the error
+        # never made it into sys.modules and so we won't know to watch it.
+        # Just to make sure we've covered everything, walk the stack trace
+        # from the exception and watch every file.
+        for (filename, lineno, name, line) in traceback.extract_tb(sys.exc_info()[2]):
+            watch(filename)
         if isinstance(e, SyntaxError):
+            # SyntaxErrors are special:  their innermost stack frame is fake
+            # so extract_tb won't see it and we have to get the filename
+            # from the exception object.
             watch(e.filename)
     else:
         logging.info("Script exited normally")