ugly stuff with the Python traceback system in order to achieve tracebacks
with correct line numbers, locals and contents.
- :copyright: Copyright 2008 by Armin Ronacher.
- :license: BSD.
+ :copyright: (c) 2010 by the Jinja Team.
+ :license: BSD, see LICENSE for more details.
"""
import sys
-from jinja2.utils import CodeType
+import traceback
+from types import TracebackType
+from jinja2.utils import CodeType, missing, internal_code
+from jinja2.exceptions import TemplateSyntaxError
+
+# on pypy we can take advantage of transparent proxies
+try:
+ from __pypy__ import tproxy
+except ImportError:
+ tproxy = None
+
+
+# how does the raise helper look like?
+try:
+ exec "raise TypeError, 'foo'"
+except SyntaxError:
+ raise_helper = 'raise __jinja_exception__[1]'
+except TypeError:
+ raise_helper = 'raise __jinja_exception__[0], __jinja_exception__[1]'
+
+
+class TracebackFrameProxy(object):
+ """Proxies a traceback frame."""
+
+ def __init__(self, tb):
+ self.tb = tb
+ self._tb_next = None
+
+ @property
+ def tb_next(self):
+ return self._tb_next
+
+ def set_next(self, next):
+ if tb_set_next is not None:
+ try:
+ tb_set_next(self.tb, next and next.tb or None)
+ except Exception:
+ # this function can fail due to all the hackery it does
+ # on various python implementations. We just catch errors
+ # down and ignore them if necessary.
+ pass
+ self._tb_next = next
+
+ @property
+ def is_jinja_frame(self):
+ return '__jinja_template__' in self.tb.tb_frame.f_globals
+
+ def __getattr__(self, name):
+ return getattr(self.tb, name)
+
+
+def make_frame_proxy(frame):
+ proxy = TracebackFrameProxy(frame)
+ if tproxy is None:
+ return proxy
+ def operation_handler(operation, *args, **kwargs):
+ if operation in ('__getattribute__', '__getattr__'):
+ return getattr(proxy, args[0])
+ elif operation == '__setattr__':
+ proxy.__setattr__(*args, **kwargs)
+ else:
+ return getattr(proxy, operation)(*args, **kwargs)
+ return tproxy(TracebackType, operation_handler)
+
+
+class ProcessedTraceback(object):
+ """Holds a Jinja preprocessed traceback for priting or reraising."""
+
+ def __init__(self, exc_type, exc_value, frames):
+ assert frames, 'no frames for this traceback?'
+ self.exc_type = exc_type
+ self.exc_value = exc_value
+ self.frames = frames
+
+ # newly concatenate the frames (which are proxies)
+ prev_tb = None
+ for tb in self.frames:
+ if prev_tb is not None:
+ prev_tb.set_next(tb)
+ prev_tb = tb
+ prev_tb.set_next(None)
+
+ def render_as_text(self, limit=None):
+ """Return a string with the traceback."""
+ lines = traceback.format_exception(self.exc_type, self.exc_value,
+ self.frames[0], limit=limit)
+ return ''.join(lines).rstrip()
+
+ def render_as_html(self, full=False):
+ """Return a unicode string with the traceback as rendered HTML."""
+ from jinja2.debugrenderer import render_traceback
+ return u'%s\n\n<!--\n%s\n-->' % (
+ render_traceback(self, full=full),
+ self.render_as_text().decode('utf-8', 'replace')
+ )
+
+ @property
+ def is_template_syntax_error(self):
+ """`True` if this is a template syntax error."""
+ return isinstance(self.exc_value, TemplateSyntaxError)
+
+ @property
+ def exc_info(self):
+ """Exception info tuple with a proxy around the frame objects."""
+ return self.exc_type, self.exc_value, self.frames[0]
+
+ @property
+ def standard_exc_info(self):
+ """Standard python exc_info for re-raising"""
+ tb = self.frames[0]
+ # the frame will be an actual traceback (or transparent proxy) if
+ # we are on pypy or a python implementation with support for tproxy
+ if type(tb) is not TracebackType:
+ tb = tb.tb
+ return self.exc_type, self.exc_value, tb
-def translate_exception(exc_info):
+def make_traceback(exc_info, source_hint=None):
+ """Creates a processed traceback object from the exc_info."""
+ exc_type, exc_value, tb = exc_info
+ if isinstance(exc_value, TemplateSyntaxError):
+ exc_info = translate_syntax_error(exc_value, source_hint)
+ initial_skip = 0
+ else:
+ initial_skip = 1
+ return translate_exception(exc_info, initial_skip)
+
+
+def translate_syntax_error(error, source=None):
+ """Rewrites a syntax error to please traceback systems."""
+ error.source = source
+ error.translated = True
+ exc_info = (error.__class__, error, None)
+ filename = error.filename
+ if filename is None:
+ filename = '<unknown>'
+ return fake_exc_info(exc_info, filename, error.lineno)
+
+
+def translate_exception(exc_info, initial_skip=0):
"""If passed an exc_info it will automatically rewrite the exceptions
all the way down to the correct line numbers and frames.
"""
- result_tb = prev_tb = None
- initial_tb = tb = exc_info[2].tb_next
+ tb = exc_info[2]
+ frames = []
+
+ # skip some internal frames if wanted
+ for x in xrange(initial_skip):
+ if tb is not None:
+ tb = tb.tb_next
+ initial_tb = tb
while tb is not None:
+ # skip frames decorated with @internalcode. These are internal
+ # calls we can't avoid and that are useless in template debugging
+ # output.
+ if tb.tb_frame.f_code in internal_code:
+ tb = tb.tb_next
+ continue
+
+ # save a reference to the next frame if we override the current
+ # one with a faked one.
+ next = tb.tb_next
+
+ # fake template exceptions
template = tb.tb_frame.f_globals.get('__jinja_template__')
if template is not None:
lineno = template.get_corresponding_lineno(tb.tb_lineno)
tb = fake_exc_info(exc_info[:2] + (tb,), template.filename,
- lineno, prev_tb)[2]
- if result_tb is None:
- result_tb = tb
- prev_tb = tb
- tb = tb.tb_next
+ lineno)[2]
+
+ frames.append(make_frame_proxy(tb))
+ tb = next
+
+ # if we don't have any exceptions in the frames left, we have to
+ # reraise it unchanged.
+ # XXX: can we backup here? when could this happen?
+ if not frames:
+ raise exc_info[0], exc_info[1], exc_info[2]
- return exc_info[:2] + (result_tb or initial_tb,)
+ return ProcessedTraceback(exc_info[0], exc_info[1], frames)
-def fake_exc_info(exc_info, filename, lineno, tb_back=None):
+def fake_exc_info(exc_info, filename, lineno):
"""Helper for `translate_exception`."""
exc_type, exc_value, tb = exc_info
# figure the real context out
- real_locals = tb.tb_frame.f_locals.copy()
- ctx = real_locals.get('context')
- if ctx:
- locals = ctx.get_all()
+ if tb is not None:
+ real_locals = tb.tb_frame.f_locals.copy()
+ ctx = real_locals.get('context')
+ if ctx:
+ locals = ctx.get_all()
+ else:
+ locals = {}
+ for name, value in real_locals.iteritems():
+ if name.startswith('l_') and value is not missing:
+ locals[name[2:]] = value
+
+ # if there is a local called __jinja_exception__, we get
+ # rid of it to not break the debug functionality.
+ locals.pop('__jinja_exception__', None)
else:
locals = {}
- for name, value in real_locals.iteritems():
- if name.startswith('l_'):
- locals[name[2:]] = value
-
- # if there is a local called __jinja_exception__, we get
- # rid of it to not break the debug functionality.
- locals.pop('__jinja_exception__', None)
# assamble fake globals we need
globals = {
'__name__': filename,
'__file__': filename,
- '__jinja_exception__': exc_info[:2]
+ '__jinja_exception__': exc_info[:2],
+
+ # we don't want to keep the reference to the template around
+ # to not cause circular dependencies, but we mark it as Jinja
+ # frame for the ProcessedTraceback
+ '__jinja_template__': None
}
# and fake the exception
- code = compile('\n' * (lineno - 1) + 'raise __jinja_exception__[0], ' +
- '__jinja_exception__[1]', filename, 'exec')
+ code = compile('\n' * (lineno - 1) + raise_helper, filename, 'exec')
# if it's possible, change the name of the code. This won't work
# on some python environments such as google appengine
try:
- function = tb.tb_frame.f_code.co_name
- if function == 'root':
- location = 'top-level template code'
- elif function.startswith('block_'):
- location = 'block "%s"' % function[6:]
- else:
+ if tb is None:
location = 'template'
+ else:
+ function = tb.tb_frame.f_code.co_name
+ if function == 'root':
+ location = 'top-level template code'
+ elif function.startswith('block_'):
+ location = 'block "%s"' % function[6:]
+ else:
+ location = 'template'
code = CodeType(0, code.co_nlocals, code.co_stacksize,
code.co_flags, code.co_code, code.co_consts,
code.co_names, code.co_varnames, filename,
exc_info = sys.exc_info()
new_tb = exc_info[2].tb_next
- # now we can patch the exc info accordingly
- if tb_set_next is not None:
- if tb_back is not None:
- tb_set_next(tb_back, new_tb)
- if tb is not None:
- tb_set_next(new_tb, tb.tb_next)
-
# return without this frame
return exc_info[:2] + (new_tb,)
def _init_ugly_crap():
"""This function implements a few ugly things so that we can patch the
traceback objects. The function returned allows resetting `tb_next` on
- any python traceback object.
+ any python traceback object. Do not attempt to use this on non cpython
+ interpreters
"""
import ctypes
from types import TracebackType
]
# python with trace
- if object.__basicsize__ != ctypes.sizeof(_PyObject):
+ if hasattr(sys, 'getobjects'):
class _PyObject(ctypes.Structure):
pass
_PyObject._fields_ = [
return tb_set_next
-# try to get a tb_set_next implementation
-try:
- from jinja2._speedups import tb_set_next
-except ImportError:
+# try to get a tb_set_next implementation if we don't have transparent
+# proxies.
+tb_set_next = None
+if tproxy is None:
try:
- tb_set_next = _init_ugly_crap()
- except:
- tb_set_next = None
-del _init_ugly_crap
+ from jinja2._debugsupport import tb_set_next
+ except ImportError:
+ try:
+ tb_set_next = _init_ugly_crap()
+ except:
+ pass
+ del _init_ugly_crap
projects / libfirm / blobdiff