# -*- coding: utf-8 -*-
"""
werkzeug.debug.tbtools
~~~~~~~~~~~~~~~~~~~~~~
This module provides various traceback related utility functions.
:copyright: (c) 2014 by the Werkzeug Team, see AUTHORS for more details.
:license: BSD.
"""
import re
import os
import sys
import json
import inspect
import traceback
import codecs
from tokenize import TokenError
from werkzeug.utils import cached_property, escape
from werkzeug.debug.console import Console
from werkzeug._compat import range_type, PY2, text_type, string_types, \
to_native, to_unicode
from werkzeug.filesystem import get_filesystem_encoding
_coding_re = re.compile(br'coding[:=]\s*([-\w.]+)')
_line_re = re.compile(br'^(.*?)$(?m)')
_funcdef_re = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')
UTF8_COOKIE = b'\xef\xbb\xbf'
system_exceptions = (SystemExit, KeyboardInterrupt)
try:
system_exceptions += (GeneratorExit,)
except NameError:
pass
HEADER = u'''\
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>%(title)s // Werkzeug Debugger</title>
<link rel="stylesheet" href="?__debugger__=yes&cmd=resource&f=style.css"
type="text/css">
<!-- We need to make sure this has a favicon so that the debugger does
not by accident trigger a request to /favicon.ico which might
change the application state. -->
<link rel="shortcut icon"
href="?__debugger__=yes&cmd=resource&f=console.png">
<script src="?__debugger__=yes&cmd=resource&f=jquery.js"></script>
<script src="?__debugger__=yes&cmd=resource&f=debugger.js"></script>
<script type="text/javascript">
var TRACEBACK = %(traceback_id)d,
CONSOLE_MODE = %(console)s,
EVALEX = %(evalex)s,
EVALEX_TRUSTED = %(evalex_trusted)s,
SECRET = "%(secret)s";
</script>
</head>
<body>
<div class="debugger">
'''
FOOTER = u'''\
<div class="footer">
Brought to you by <strong class="arthur">DON'T PANIC</strong>, your
friendly Werkzeug powered traceback interpreter.
</div>
</div>
<div class="pin-prompt">
<div class="inner">
<h3>Console Locked</h3>
<p>
The console is locked and needs to be unlocked by entering the PIN.
You can find the PIN printed out on the standard output of your
shell that runs the server.
<form>
<p>PIN:
<input type=text name=pin size=14>
<input type=submit name=btn value="Confirm Pin">
</form>
</div>
</div>
</body>
</html>
'''
PAGE_HTML = HEADER + u'''\
<h1>%(exception_type)s</h1>
<div class="detail">
<p class="errormsg">%(exception)s</p>
</div>
<h2 class="traceback">Traceback <em>(most recent call last)</em></h2>
%(summary)s
<div class="plain">
<form action="/?__debugger__=yes&cmd=paste" method="post">
<p>
<input type="hidden" name="language" value="pytb">
This is the Copy/Paste friendly version of the traceback. <span
class="pastemessage">You can also paste this traceback into
a <a href="https://gist.github.com/">gist</a>:
<input type="submit" value="create paste"></span>
</p>
<textarea cols="50" rows="10" name="code" readonly>%(plaintext)s</textarea>
</form>
</div>
<div class="explanation">
The debugger caught an exception in your WSGI application. You can now
look at the traceback which led to the error. <span class="nojavascript">
If you enable JavaScript you can also use additional features such as code
execution (if the evalex feature is enabled), automatic pasting of the
exceptions and much more.</span>
</div>
''' + FOOTER + '''
<!--
%(plaintext_cs)s
-->
'''
CONSOLE_HTML = HEADER + u'''\
<h1>Interactive Console</h1>
<div class="explanation">
In this console you can execute Python expressions in the context of the
application. The initial namespace was created by the debugger automatically.
</div>
<div class="console"><div class="inner">The Console requires JavaScript.</div></div>
''' + FOOTER
SUMMARY_HTML = u'''\
<div class="%(classes)s">
%(title)s
<ul>%(frames)s</ul>
%(description)s
</div>
'''
FRAME_HTML = u'''\
<div class="frame" id="frame-%(id)d">
<h4>File <cite class="filename">"%(filename)s"</cite>,
line <em class="line">%(lineno)s</em>,
in <code class="function">%(function_name)s</code></h4>
<div class="source">%(lines)s</div>
</div>
'''
SOURCE_LINE_HTML = u'''\
<tr class="%(classes)s">
<td class=lineno>%(lineno)s</td>
<td>%(code)s</td>
</tr>
'''
def render_console_html(secret, evalex_trusted=True):
return CONSOLE_HTML % {
'evalex': 'true',
'evalex_trusted': evalex_trusted and 'true' or 'false',
'console': 'true',
'title': 'Console',
'secret': secret,
'traceback_id': -1
}
def get_current_traceback(ignore_system_exceptions=False,
show_hidden_frames=False, skip=0):
"""Get the current exception info as `Traceback` object. Per default
calling this method will reraise system exceptions such as generator exit,
system exit or others. This behavior can be disabled by passing `False`
to the function as first parameter.
"""
exc_type, exc_value, tb = sys.exc_info()
if ignore_system_exceptions and exc_type in system_exceptions:
raise
for x in range_type(skip):
if tb.tb_next is None:
break
tb = tb.tb_next
tb = Traceback(exc_type, exc_value, tb)
if not show_hidden_frames:
tb.filter_hidden_frames()
return tb
class Line(object):
"""Helper for the source renderer."""
__slots__ = ('lineno', 'code', 'in_frame', 'current')
def __init__(self, lineno, code):
self.lineno = lineno
self.code = code
self.in_frame = False
self.current = False
def classes(self):
rv = ['line']
if self.in_frame:
rv.append('in-frame')
if self.current:
rv.append('current')
return rv
classes = property(classes)
def render(self):
return SOURCE_LINE_HTML % {
'classes': u' '.join(self.classes),
'lineno': self.lineno,
'code': escape(self.code)
}
class Traceback(object):
"""Wraps a traceback."""
def __init__(self, exc_type, exc_value, tb):
self.exc_type = exc_type
self.exc_value = exc_value
if not isinstance(exc_type, str):
exception_type = exc_type.__name__
if exc_type.__module__ not in ('__builtin__', 'exceptions'):
exception_type = exc_type.__module__ + '.' + exception_type
else:
exception_type = exc_type
self.exception_type = exception_type
# we only add frames to the list that are not hidden. This follows
# the the magic variables as defined by paste.exceptions.collector
self.frames = []
while tb:
self.frames.append(Frame(exc_type, exc_value, tb))
tb = tb.tb_next
def filter_hidden_frames(self):
"""Remove the frames according to the paste spec."""
if not self.frames:
return
new_frames = []
hidden = False
for frame in self.frames:
hide = frame.hide
if hide in ('before', 'before_and_this'):
new_frames = []
hidden = False
if hide == 'before_and_this':
continue
elif hide in ('reset', 'reset_and_this'):
hidden = False
if hide == 'reset_and_this':
continue
elif hide in ('after', 'after_and_this'):
hidden = True
if hide == 'after_and_this':
continue
elif hide or hidden:
continue
new_frames.append(frame)
# if we only have one frame and that frame is from the codeop
# module, remove it.
if len(new_frames) == 1 and self.frames[0].module == 'codeop':
del self.frames[:]
# if the last frame is missing something went terrible wrong :(
elif self.frames[-1] in new_frames:
self.frames[:] = new_frames
def is_syntax_error(self):
"""Is it a syntax error?"""
return isinstance(self.exc_value, SyntaxError)
is_syntax_error = property(is_syntax_error)
def exception(self):
"""String representation of the exception."""
buf = traceback.format_exception_only(self.exc_type, self.exc_value)
rv = ''.join(buf).strip()
return rv.decode('utf-8', 'replace') if PY2 else rv
exception = property(exception)
def log(self, logfile=None):
"""Log the ASCII traceback into a file object."""
if logfile is None:
logfile = sys.stderr
tb = self.plaintext.rstrip() + u'\n'
if PY2:
tb = tb.encode('utf-8', 'replace')
logfile.write(tb)
def paste(self):
"""Create a paste and return the paste id."""
data = json.dumps({
'description': 'Werkzeug Internal Server Error',
'public': False,
'files': {
'traceback.txt': {
'content': self.plaintext
}
}
}).encode('utf-8')
try:
from urllib2 import urlopen
except ImportError:
from urllib.request import urlopen
rv = urlopen('https://api.github.com/gists', data=data)
resp = json.loads(rv.read().decode('utf-8'))
rv.close()
return {
'url': resp['html_url'],
'id': resp['id']
}
def render_summary(self, include_title=True):
"""Render the traceback for the interactive console."""
title = ''
frames = []
classes = ['traceback']
if not self.frames:
classes.append('noframe-traceback')
if include_title:
if self.is_syntax_error:
title = u'Syntax Error'
else:
title = u'Traceback <em>(most recent call last)</em>:'
for frame in self.frames:
frames.append(u'<li%s>%s' % (
frame.info and u' title="%s"' % escape(frame.info) or u'',
frame.render()
))
if self.is_syntax_error:
description_wrapper = u'<pre class=syntaxerror>%s</pre>'
else:
description_wrapper = u'<blockquote>%s</blockquote>'
return SUMMARY_HTML % {
'classes': u' '.join(classes),
'title': title and u'<h3>%s</h3>' % title or u'',
'frames': u'\n'.join(frames),
'description': description_wrapper % escape(self.exception)
}
def render_full(self, evalex=False, secret=None,
evalex_trusted=True):
"""Render the Full HTML page with the traceback info."""
exc = escape(self.exception)
return PAGE_HTML % {
'evalex': evalex and 'true' or 'false',
'evalex_trusted': evalex_trusted and 'true' or 'false',
'console': 'false',
'title': exc,
'exception': exc,
'exception_type': escape(self.exception_type),
'summary': self.render_summary(include_title=False),
'plaintext': escape(self.plaintext),
'plaintext_cs': re.sub('-{2,}', '-', self.plaintext),
'traceback_id': self.id,
'secret': secret
}
def generate_plaintext_traceback(self):
"""Like the plaintext attribute but returns a generator"""
yield u'Traceback (most recent call last):'
for frame in self.frames:
yield u' File "%s", line %s, in %s' % (
frame.filename,
frame.lineno,
frame.function_name
)
yield u' ' + frame.current_line.strip()
yield self.exception
def plaintext(self):
return u'\n'.join(self.generate_plaintext_traceback())
plaintext = cached_property(plaintext)
id = property(lambda x: id(x))
class Frame(object):
"""A single frame in a traceback."""
def __init__(self, exc_type, exc_value, tb):
self.lineno = tb.tb_lineno
self.function_name = tb.tb_frame.f_code.co_name
self.locals = tb.tb_frame.f_locals
self.globals = tb.tb_frame.f_globals
fn = inspect.getsourcefile(tb) or inspect.getfile(tb)
if fn[-4:] in ('.pyo', '.pyc'):
fn = fn[:-1]
# if it's a file on the file system resolve the real filename.
if os.path.isfile(fn):
fn = os.path.realpath(fn)
self.filename = to_unicode(fn, get_filesystem_encoding())
self.module = self.globals.get('__name__')
self.loader = self.globals.get('__loader__')
self.code = tb.tb_frame.f_code
# support for paste's traceback extensions
self.hide = self.locals.get('__traceback_hide__', False)
info = self.locals.get('__traceback_info__')
if info is not None:
try:
info = text_type(info)
except UnicodeError:
info = str(info).decode('utf-8', 'replace')
self.info = info
def render(self):
"""Render a single frame in a traceback."""
return FRAME_HTML % {
'id': self.id,
'filename': escape(self.filename),
'lineno': self.lineno,
'function_name': escape(self.function_name),
'lines': self.render_line_context(),
}
def render_line_context(self):
before, current, after = self.get_context_lines()
rv = []
def render_line(line, cls):
line = line.expandtabs().rstrip()
stripped_line = line.strip()
prefix = len(line) - len(stripped_line)
rv.append(
'<pre class="line %s"><span class="ws">%s</span>%s</pre>' % (
cls, ' ' * prefix, escape(stripped_line) or ' '))
for line in before:
render_line(line, 'before')
render_line(current, 'current')
for line in after:
render_line(line, 'after')
return '\n'.join(rv)
def get_annotated_lines(self):
"""Helper function that returns lines with extra information."""
lines = [Line(idx + 1, x) for idx, x in enumerate(self.sourcelines)]
# find function definition and mark lines
if hasattr(self.code, 'co_firstlineno'):
lineno = self.code.co_firstlineno - 1
while lineno > 0:
if _funcdef_re.match(lines[lineno].code):
break
lineno -= 1
try:
offset = len(inspect.getblock([x.code + '\n' for x
in lines[lineno:]]))
except TokenError:
offset = 0
for line in lines[lineno:lineno + offset]:
line.in_frame = True
# mark current line
try:
lines[self.lineno - 1].current = True
except IndexError:
pass
return lines
def eval(self, code, mode='single'):
"""Evaluate code in the context of the frame."""
if isinstance(code, string_types):
if PY2 and isinstance(code, unicode): # noqa
code = UTF8_COOKIE + code.encode('utf-8')
code = compile(code, '<interactive>', mode)
return eval(code, self.globals, self.locals)
@cached_property
def sourcelines(self):
"""The sourcecode of the file as list of unicode strings."""
# get sourcecode from loader or file
source = None
if self.loader is not None:
try:
if hasattr(self.loader, 'get_source'):
source = self.loader.get_source(self.module)
elif hasattr(self.loader, 'get_source_by_code'):
source = self.loader.get_source_by_code(self.code)
except Exception:
# we munch the exception so that we don't cause troubles
# if the loader is broken.
pass
if source is None:
try:
f = open(to_native(self.filename, get_filesystem_encoding()),
mode='rb')
except IOError:
return []
try:
source = f.read()
finally:
f.close()
# already unicode? return right away
if isinstance(source, text_type):
return source.splitlines()
# yes. it should be ascii, but we don't want to reject too many
# characters in the debugger if something breaks
charset = 'utf-8'
if source.startswith(UTF8_COOKIE):
source = source[3:]
else:
for idx, match in enumerate(_line_re.finditer(source)):
match = _coding_re.search(match.group())
if match is not None:
charset = match.group(1)
break
if idx > 1:
break
# on broken cookies we fall back to utf-8 too
charset = to_native(charset)
try:
codecs.lookup(charset)
except LookupError:
charset = 'utf-8'
return source.decode(charset, 'replace').splitlines()
def get_context_lines(self, context=5):
before = self.sourcelines[self.lineno - context - 1:self.lineno - 1]
past = self.sourcelines[self.lineno:self.lineno + context]
return (
before,
self.current_line,
past,
)
@property
def current_line(self):
try:
return self.sourcelines[self.lineno - 1]
except IndexError:
return u''
@cached_property
def console(self):
return Console(self.globals, self.locals)
id = property(lambda x: id(x))