268 lines
8.3 KiB
Python
268 lines
8.3 KiB
Python
import sys
|
|
from types import CodeType
|
|
|
|
from . import TemplateSyntaxError
|
|
from ._compat import PYPY
|
|
from .utils import internal_code
|
|
from .utils import missing
|
|
|
|
|
|
def rewrite_traceback_stack(source=None):
|
|
"""Rewrite the current exception to replace any tracebacks from
|
|
within compiled template code with tracebacks that look like they
|
|
came from the template source.
|
|
|
|
This must be called within an ``except`` block.
|
|
|
|
:param exc_info: A :meth:`sys.exc_info` tuple. If not provided,
|
|
the current ``exc_info`` is used.
|
|
:param source: For ``TemplateSyntaxError``, the original source if
|
|
known.
|
|
:return: A :meth:`sys.exc_info` tuple that can be re-raised.
|
|
"""
|
|
exc_type, exc_value, tb = sys.exc_info()
|
|
|
|
if isinstance(exc_value, TemplateSyntaxError) and not exc_value.translated:
|
|
exc_value.translated = True
|
|
exc_value.source = source
|
|
|
|
try:
|
|
# Remove the old traceback on Python 3, otherwise the frames
|
|
# from the compiler still show up.
|
|
exc_value.with_traceback(None)
|
|
except AttributeError:
|
|
pass
|
|
|
|
# Outside of runtime, so the frame isn't executing template
|
|
# code, but it still needs to point at the template.
|
|
tb = fake_traceback(
|
|
exc_value, None, exc_value.filename or "<unknown>", exc_value.lineno
|
|
)
|
|
else:
|
|
# Skip the frame for the render function.
|
|
tb = tb.tb_next
|
|
|
|
stack = []
|
|
|
|
# Build the stack of traceback object, replacing any in template
|
|
# code with the source file and line information.
|
|
while tb is not None:
|
|
# Skip frames decorated with @internalcode. These are internal
|
|
# calls that aren't useful in template debugging output.
|
|
if tb.tb_frame.f_code in internal_code:
|
|
tb = tb.tb_next
|
|
continue
|
|
|
|
template = tb.tb_frame.f_globals.get("__jinja_template__")
|
|
|
|
if template is not None:
|
|
lineno = template.get_corresponding_lineno(tb.tb_lineno)
|
|
fake_tb = fake_traceback(exc_value, tb, template.filename, lineno)
|
|
stack.append(fake_tb)
|
|
else:
|
|
stack.append(tb)
|
|
|
|
tb = tb.tb_next
|
|
|
|
tb_next = None
|
|
|
|
# Assign tb_next in reverse to avoid circular references.
|
|
for tb in reversed(stack):
|
|
tb_next = tb_set_next(tb, tb_next)
|
|
|
|
return exc_type, exc_value, tb_next
|
|
|
|
|
|
def fake_traceback(exc_value, tb, filename, lineno):
|
|
"""Produce a new traceback object that looks like it came from the
|
|
template source instead of the compiled code. The filename, line
|
|
number, and location name will point to the template, and the local
|
|
variables will be the current template context.
|
|
|
|
:param exc_value: The original exception to be re-raised to create
|
|
the new traceback.
|
|
:param tb: The original traceback to get the local variables and
|
|
code info from.
|
|
:param filename: The template filename.
|
|
:param lineno: The line number in the template source.
|
|
"""
|
|
if tb is not None:
|
|
# Replace the real locals with the context that would be
|
|
# available at that point in the template.
|
|
locals = get_template_locals(tb.tb_frame.f_locals)
|
|
locals.pop("__jinja_exception__", None)
|
|
else:
|
|
locals = {}
|
|
|
|
globals = {
|
|
"__name__": filename,
|
|
"__file__": filename,
|
|
"__jinja_exception__": exc_value,
|
|
}
|
|
# Raise an exception at the correct line number.
|
|
code = compile("\n" * (lineno - 1) + "raise __jinja_exception__", filename, "exec")
|
|
|
|
# Build a new code object that points to the template file and
|
|
# replaces the location with a block name.
|
|
try:
|
|
location = "template"
|
|
|
|
if tb is not None:
|
|
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:]
|
|
|
|
# Collect arguments for the new code object. CodeType only
|
|
# accepts positional arguments, and arguments were inserted in
|
|
# new Python versions.
|
|
code_args = []
|
|
|
|
for attr in (
|
|
"argcount",
|
|
"posonlyargcount", # Python 3.8
|
|
"kwonlyargcount", # Python 3
|
|
"nlocals",
|
|
"stacksize",
|
|
"flags",
|
|
"code", # codestring
|
|
"consts", # constants
|
|
"names",
|
|
"varnames",
|
|
("filename", filename),
|
|
("name", location),
|
|
"firstlineno",
|
|
"lnotab",
|
|
"freevars",
|
|
"cellvars",
|
|
):
|
|
if isinstance(attr, tuple):
|
|
# Replace with given value.
|
|
code_args.append(attr[1])
|
|
continue
|
|
|
|
try:
|
|
# Copy original value if it exists.
|
|
code_args.append(getattr(code, "co_" + attr))
|
|
except AttributeError:
|
|
# Some arguments were added later.
|
|
continue
|
|
|
|
code = CodeType(*code_args)
|
|
except Exception:
|
|
# Some environments such as Google App Engine don't support
|
|
# modifying code objects.
|
|
pass
|
|
|
|
# Execute the new code, which is guaranteed to raise, and return
|
|
# the new traceback without this frame.
|
|
try:
|
|
exec(code, globals, locals)
|
|
except BaseException:
|
|
return sys.exc_info()[2].tb_next
|
|
|
|
|
|
def get_template_locals(real_locals):
|
|
"""Based on the runtime locals, get the context that would be
|
|
available at that point in the template.
|
|
"""
|
|
# Start with the current template context.
|
|
ctx = real_locals.get("context")
|
|
|
|
if ctx:
|
|
data = ctx.get_all().copy()
|
|
else:
|
|
data = {}
|
|
|
|
# Might be in a derived context that only sets local variables
|
|
# rather than pushing a context. Local variables follow the scheme
|
|
# l_depth_name. Find the highest-depth local that has a value for
|
|
# each name.
|
|
local_overrides = {}
|
|
|
|
for name, value in real_locals.items():
|
|
if not name.startswith("l_") or value is missing:
|
|
# Not a template variable, or no longer relevant.
|
|
continue
|
|
|
|
try:
|
|
_, 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)
|
|
|
|
# Modify the context with any derived context.
|
|
for name, (_, value) in local_overrides.items():
|
|
if value is missing:
|
|
data.pop(name, None)
|
|
else:
|
|
data[name] = value
|
|
|
|
return data
|
|
|
|
|
|
if sys.version_info >= (3, 7):
|
|
# tb_next is directly assignable as of Python 3.7
|
|
def tb_set_next(tb, tb_next):
|
|
tb.tb_next = tb_next
|
|
return tb
|
|
|
|
|
|
elif PYPY:
|
|
# PyPy might have special support, and won't work with ctypes.
|
|
try:
|
|
import tputil
|
|
except ImportError:
|
|
# Without tproxy support, use the original traceback.
|
|
def tb_set_next(tb, tb_next):
|
|
return tb
|
|
|
|
else:
|
|
# With tproxy support, create a proxy around the traceback that
|
|
# returns the new tb_next.
|
|
def tb_set_next(tb, tb_next):
|
|
def controller(op):
|
|
if op.opname == "__getattribute__" and op.args[0] == "tb_next":
|
|
return tb_next
|
|
|
|
return op.delegate()
|
|
|
|
return tputil.make_proxy(controller, obj=tb)
|
|
|
|
|
|
else:
|
|
# Use ctypes to assign tb_next at the C level since it's read-only
|
|
# from Python.
|
|
import ctypes
|
|
|
|
class _CTraceback(ctypes.Structure):
|
|
_fields_ = [
|
|
# Extra PyObject slots when compiled with Py_TRACE_REFS.
|
|
("PyObject_HEAD", ctypes.c_byte * object().__sizeof__()),
|
|
# Only care about tb_next as an object, not a traceback.
|
|
("tb_next", ctypes.py_object),
|
|
]
|
|
|
|
def tb_set_next(tb, tb_next):
|
|
c_tb = _CTraceback.from_address(id(tb))
|
|
|
|
# Clear out the old tb_next.
|
|
if tb.tb_next is not None:
|
|
c_tb_next = ctypes.py_object(tb.tb_next)
|
|
c_tb.tb_next = ctypes.py_object()
|
|
ctypes.pythonapi.Py_DecRef(c_tb_next)
|
|
|
|
# Assign the new tb_next.
|
|
if tb_next is not None:
|
|
c_tb_next = ctypes.py_object(tb_next)
|
|
ctypes.pythonapi.Py_IncRef(c_tb_next)
|
|
c_tb.tb_next = c_tb_next
|
|
|
|
return tb
|