diff options
Diffstat (limited to 'jinja2/debug.py')
| -rw-r--r-- | jinja2/debug.py | 467 |
1 files changed, 142 insertions, 325 deletions
diff --git a/jinja2/debug.py b/jinja2/debug.py index d3c1a3a..e0f0fc5 100644 --- a/jinja2/debug.py +++ b/jinja2/debug.py @@ -1,378 +1,195 @@ -# -*- coding: utf-8 -*- -""" - jinja2.debug - ~~~~~~~~~~~~ - - Implements the debug interface for Jinja. This module does some pretty - ugly stuff with the Python traceback system in order to achieve tracebacks - with correct line numbers, locals and contents. - - :copyright: (c) 2017 by the Jinja Team. - :license: BSD, see LICENSE for more details. -""" import sys -import traceback -from types import TracebackType, CodeType -from jinja2.utils import missing, internal_code -from jinja2.exceptions import TemplateSyntaxError -from jinja2._compat import iteritems, reraise, PY2 +from types import CodeType -# on pypy we can take advantage of transparent proxies -try: - from __pypy__ import tproxy -except ImportError: - tproxy = None +from jinja2 import TemplateSyntaxError +from jinja2._compat import PYPY +from jinja2.utils import internal_code +from jinja2.utils import missing -# 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]' +def rewrite_traceback_stack(source=None): + exc_type, exc_value, tb = sys.exc_info() + stack = [] - -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 printing 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 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 + exc_value.source = source + exc_value.translated = True + tb = retarget_traceback( + exc_value, tb, exc_value.filename or "<unknown>", exc_value.lineno + ) 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. - """ - tb = exc_info[2] - frames = [] - - # skip some internal frames if wanted - for x in range(initial_skip): - if tb is not None: - tb = tb.tb_next - initial_tb = tb + tb = tb.tb_next 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 + template = tb.tb_frame.f_globals.get("__jinja_template__") - # 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)[2] + fake_tb = retarget_traceback(exc_value, tb, template.filename, lineno) + stack.append(fake_tb) + else: + stack.append(tb) + + tb = tb.tb_next + + tb_next = None + + for tb in reversed(stack): + tb_next = tb_set_next(tb, tb_next) + + return exc_type, exc_value, tb_next + + +def retarget_traceback(exc_value, tb, filename, lineno): + if tb is not None: + locals = get_jinja_locals(tb.tb_frame.f_locals) + locals.pop("__jinja_exception__", None) + else: + locals = {} + + globals = { + "__name__": filename, + "__file__": filename, + "__jinja_exception__": exc_value, + } + code = compile('\n' * (lineno - 1) + "raise __jinja_exception__", filename, "exec") - frames.append(make_frame_proxy(tb)) - tb = next + try: + location = "template" - # 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: - reraise(exc_info[0], exc_info[1], exc_info[2]) + if tb is not None: + function = tb.tb_frame.f_code.co_name - return ProcessedTraceback(exc_info[0], exc_info[1], frames) + if function == "root": + location = "top-level template code" + elif function.startswith("block_"): + location = 'block "%s"' % function[6:] + + code_args = [] + + for attr in ( + "argcount", + "posonlyargcount", + "kwonlyargcount", + "nlocals", + "stacksize", + "flags", + "code", # codestring + "consts", # constants + "names", + "varnames", + ("filename", filename), + ("name", location), + "firstlineno", + "lnotab", + "freevars", + "cellvars", + ): + if isinstance(attr, tuple): + code_args.append(attr[1]) + continue + + try: + code_args.append(getattr(code, "co_" + attr)) + except AttributeError: + continue + + code = CodeType(*code_args) + except Exception: + pass + + try: + exec(code, globals, locals) + except: + return sys.exc_info()[2].tb_next def get_jinja_locals(real_locals): - ctx = real_locals.get('context') + ctx = real_locals.get("context") + if ctx: - locals = ctx.get_all().copy() + data = ctx.get_all().copy() else: - locals = {} + data = {} local_overrides = {} - for name, value in iteritems(real_locals): - if not name.startswith('l_') or value is missing: + for name, value in real_locals.items(): + if not name.startswith("l_") or value is missing: continue + try: - _, depth, name = name.split('_', 2) + _, depth, name = name.split("_", 2) depth = int(depth) except ValueError: continue + cur_depth = local_overrides.get(name, (-1,))[0] + if cur_depth < depth: local_overrides[name] = (depth, value) - for name, (_, value) in iteritems(local_overrides): + for name, (_, value) in local_overrides.items(): if value is missing: - locals.pop(name, None) + data.pop(name, None) else: - locals[name] = value + data[name] = value - return locals + return data -def fake_exc_info(exc_info, filename, lineno): - """Helper for `translate_exception`.""" - exc_type, exc_value, tb = exc_info - - # figure the real context out - if tb is not None: - locals = get_jinja_locals(tb.tb_frame.f_locals) - - # 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 = {} - - # assamble fake globals we need - globals = { - '__name__': filename, - '__file__': filename, - '__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_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 +if sys.version_info >= (3, 7): + def tb_set_next(tb, tb_next): + tb.tb_next = tb_next + return tb +elif PYPY: try: - 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' - - if PY2: - 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, - location, code.co_firstlineno, - code.co_lnotab, (), ()) - else: - code = CodeType(0, code.co_kwonlyargcount, - code.co_nlocals, code.co_stacksize, - code.co_flags, code.co_code, code.co_consts, - code.co_names, code.co_varnames, filename, - location, code.co_firstlineno, - code.co_lnotab, (), ()) - except Exception as e: - pass - - # execute the code and catch the new traceback - try: - exec(code, globals, locals) - except: - exc_info = sys.exc_info() - new_tb = exc_info[2].tb_next - - # return without this frame - return exc_info[:2] + (new_tb,) + import tputil + except ImportError: + def tb_set_next(tb, tb_next): + return tb + else: + def tb_set_next(tb, tb_next): + def controller(op): + if op.args[0] == "tb_next": + return tb_next + return op.delegate() -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. Do not attempt to use this on non cpython - interpreters - """ + return tputil.make_proxy(controller, obj=tb) +else: import ctypes - from types import TracebackType - - if PY2: - # figure out size of _Py_ssize_t for Python 2: - if hasattr(ctypes.pythonapi, 'Py_InitModule4_64'): - _Py_ssize_t = ctypes.c_int64 - else: - _Py_ssize_t = ctypes.c_int - else: - # platform ssize_t on Python 3 - _Py_ssize_t = ctypes.c_ssize_t - # regular python - class _PyObject(ctypes.Structure): + class _CTraceback(ctypes.Structure): pass - _PyObject._fields_ = [ - ('ob_refcnt', _Py_ssize_t), - ('ob_type', ctypes.POINTER(_PyObject)) - ] - # python with trace - if hasattr(sys, 'getobjects'): - class _PyObject(ctypes.Structure): - pass - _PyObject._fields_ = [ - ('_ob_next', ctypes.POINTER(_PyObject)), - ('_ob_prev', ctypes.POINTER(_PyObject)), - ('ob_refcnt', _Py_ssize_t), - ('ob_type', ctypes.POINTER(_PyObject)) - ] - - class _Traceback(_PyObject): - pass - _Traceback._fields_ = [ - ('tb_next', ctypes.POINTER(_Traceback)), - ('tb_frame', ctypes.POINTER(_PyObject)), - ('tb_lasti', ctypes.c_int), - ('tb_lineno', ctypes.c_int) + _c_traceback_p = ctypes.POINTER(_CTraceback) + _CTraceback._fields_ = [ + # Extra PyObject slots when compiled with Py_TRACE_REFS. + ("PyObject_HEAD", ctypes.c_byte * (32 if hasattr(sys, "getobjects") else 16)), + ("tb_next", _c_traceback_p), + ("tb_frame", ctypes.c_void_p), + ("tb_lasti", ctypes.c_int), + ("tb_lineno", ctypes.c_int), ] - def tb_set_next(tb, next): - """Set the tb_next attribute of a traceback object.""" - if not (isinstance(tb, TracebackType) and - (next is None or isinstance(next, TracebackType))): - raise TypeError('tb_set_next arguments must be traceback objects') - obj = _Traceback.from_address(id(tb)) - if tb.tb_next is not None: - old = _Traceback.from_address(id(tb.tb_next)) - old.ob_refcnt -= 1 - if next is None: - obj.tb_next = ctypes.POINTER(_Traceback)() - else: - next = _Traceback.from_address(id(next)) - next.ob_refcnt += 1 - obj.tb_next = ctypes.pointer(next) + def tb_set_next(tb, tb_next): + c_tb = _CTraceback.from_address(id(tb)) - return tb_set_next + # Clear out the old tb_next. + if tb.tb_next is not None: + c_old_tb = _CTraceback.from_address(id(tb.tb_next)) + c_tb.tb_next = _c_traceback_p() + ctypes.pythonapi.Py_DecRef(c_old_tb) + # Assign the new tb_next. + if tb_next is not None: + c_tb_next = _CTraceback.from_address(id(tb_next)) + ctypes.pythonapi.Py_IncRef(c_tb_next) + c_tb.tb_next = _c_traceback_p(c_tb_next) -# try to get a tb_set_next implementation if we don't have transparent -# proxies. -tb_set_next = None -if tproxy is None: - # traceback.tb_next can be modified since CPython 3.7 - if sys.version_info >= (3, 7): - def tb_set_next(tb, next): - tb.tb_next = next - else: - # On Python 3.6 and older, use ctypes - try: - tb_set_next = _init_ugly_crap() - except Exception: - pass -del _init_ugly_crap + return tb |