import codecs
import inspect
import os
import re
import sys
import sysconfig
import traceback
import typing as t
from html import escape
from tokenize import TokenError
from types import CodeType
from types import TracebackType
from .._internal import _to_str
from ..filesystem import get_filesystem_encoding
from ..utils import cached_property
from .console import Console
_coding_re = re.compile(br"coding[:=]\s*([-\w.]+)")
_line_re = re.compile(br"^(.*?)$", re.MULTILINE)
_funcdef_re = re.compile(r"^(\s*def\s)|(.*(?
%(title)s // Werkzeug Debugger
"""
FOOTER = """\
Console Locked
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.
"""
PAGE_HTML = (
HEADER
+ """\
%(exception_type)s
%(exception)s
Traceback (most recent call last)
%(summary)s
This is the Copy/Paste friendly version of the traceback.
The debugger caught an exception in your WSGI application. You can now
look at the traceback which led to the error.
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.
In this console you can execute Python expressions in the context of the
application. The initial namespace was created by the debugger automatically.
The Console requires JavaScript.
"""
+ FOOTER
)
SUMMARY_HTML = """\
%(title)s
%(frames)s
%(description)s
"""
FRAME_HTML = """\
File "%(filename)s",
line %(lineno)s,
in %(function_name)s
%(lines)s
"""
SOURCE_LINE_HTML = """\
%(lineno)s
%(code)s
"""
def render_console_html(secret: str, evalex_trusted: bool = True) -> str:
return CONSOLE_HTML % {
"evalex": "true",
"evalex_trusted": "true" if evalex_trusted else "false",
"console": "true",
"title": "Console",
"secret": secret,
"traceback_id": -1,
}
def get_current_traceback(
ignore_system_exceptions: bool = False,
show_hidden_frames: bool = False,
skip: int = 0,
) -> "Traceback":
"""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.
"""
info = t.cast(
t.Tuple[t.Type[BaseException], BaseException, TracebackType], sys.exc_info()
)
exc_type, exc_value, tb = info
if ignore_system_exceptions and exc_type in {
SystemExit,
KeyboardInterrupt,
GeneratorExit,
}:
raise
for _ in range(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:
"""Helper for the source renderer."""
__slots__ = ("lineno", "code", "in_frame", "current")
def __init__(self, lineno: int, code: str) -> None:
self.lineno = lineno
self.code = code
self.in_frame = False
self.current = False
@property
def classes(self) -> t.List[str]:
rv = ["line"]
if self.in_frame:
rv.append("in-frame")
if self.current:
rv.append("current")
return rv
def render(self) -> str:
return SOURCE_LINE_HTML % {
"classes": " ".join(self.classes),
"lineno": self.lineno,
"code": escape(self.code),
}
class Traceback:
"""Wraps a traceback."""
def __init__(
self,
exc_type: t.Type[BaseException],
exc_value: BaseException,
tb: TracebackType,
) -> None:
self.exc_type = exc_type
self.exc_value = exc_value
self.tb = tb
exception_type = exc_type.__name__
if exc_type.__module__ not in {"builtins", "__builtin__", "exceptions"}:
exception_type = f"{exc_type.__module__}.{exception_type}"
self.exception_type = exception_type
self.groups = []
memo = set()
while True:
self.groups.append(Group(exc_type, exc_value, tb))
memo.add(id(exc_value))
exc_value = exc_value.__cause__ or exc_value.__context__ # type: ignore
if exc_value is None or id(exc_value) in memo:
break
exc_type = type(exc_value)
tb = exc_value.__traceback__ # type: ignore
self.groups.reverse()
self.frames = [frame for group in self.groups for frame in group.frames]
def filter_hidden_frames(self) -> None:
"""Remove the frames according to the paste spec."""
for group in self.groups:
group.filter_hidden_frames()
self.frames[:] = [frame for group in self.groups for frame in group.frames]
@property
def is_syntax_error(self) -> bool:
"""Is it a syntax error?"""
return isinstance(self.exc_value, SyntaxError)
@property
def exception(self) -> str:
"""String representation of the final exception."""
return self.groups[-1].exception
def log(self, logfile: t.Optional[t.IO[str]] = None) -> None:
"""Log the ASCII traceback into a file object."""
if logfile is None:
logfile = sys.stderr
tb = f"{self.plaintext.rstrip()}\n"
logfile.write(tb)
def render_summary(self, include_title: bool = True) -> str:
"""Render the traceback for the interactive console."""
title = ""
classes = ["traceback"]
if not self.frames:
classes.append("noframe-traceback")
frames = []
else:
library_frames = sum(frame.is_library for frame in self.frames)
mark_lib = 0 < library_frames < len(self.frames)
frames = [group.render(mark_lib=mark_lib) for group in self.groups]
if include_title:
if self.is_syntax_error:
title = "Syntax Error"
else:
title = "Traceback (most recent call last):"
if self.is_syntax_error:
description = f"
",
"frames": "\n".join(frames),
"description": description,
}
def render_full(
self,
evalex: bool = False,
secret: t.Optional[str] = None,
evalex_trusted: bool = True,
) -> str:
"""Render the Full HTML page with the traceback info."""
exc = escape(self.exception)
return PAGE_HTML % {
"evalex": "true" if evalex else "false",
"evalex_trusted": "true" if evalex_trusted else "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,
}
@cached_property
def plaintext(self) -> str:
return "\n".join([group.render_text() for group in self.groups])
@property
def id(self) -> int:
return id(self)
class Group:
"""A group of frames for an exception in a traceback. If the
exception has a ``__cause__`` or ``__context__``, there are multiple
exception groups.
"""
def __init__(
self,
exc_type: t.Type[BaseException],
exc_value: BaseException,
tb: TracebackType,
) -> None:
self.exc_type = exc_type
self.exc_value = exc_value
self.info = None
if exc_value.__cause__ is not None:
self.info = (
"The above exception was the direct cause of the following exception"
)
elif exc_value.__context__ is not None:
self.info = (
"During handling of the above exception, another exception occurred"
)
self.frames = []
while tb is not None:
self.frames.append(Frame(exc_type, exc_value, tb))
tb = tb.tb_next # type: ignore
def filter_hidden_frames(self) -> None:
# An exception may not have a traceback to filter frames, such
# as one re-raised from ProcessPoolExecutor.
if not self.frames:
return
new_frames: t.List[Frame] = []
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
@property
def exception(self) -> str:
"""String representation of the exception."""
buf = traceback.format_exception_only(self.exc_type, self.exc_value)
rv = "".join(buf).strip()
return _to_str(rv, "utf-8", "replace")
def render(self, mark_lib: bool = True) -> str:
out = []
if self.info is not None:
out.append(f'
{self.info}:
')
for frame in self.frames:
title = f' title="{escape(frame.info)}"' if frame.info else ""
out.append(f"{frame.render(mark_lib=mark_lib)}")
return "\n".join(out)
def render_text(self) -> str:
out = []
if self.info is not None:
out.append(f"\n{self.info}:\n")
out.append("Traceback (most recent call last):")
for frame in self.frames:
out.append(frame.render_text())
out.append(self.exception)
return "\n".join(out)
class Frame:
"""A single frame in a traceback."""
def __init__(
self,
exc_type: t.Type[BaseException],
exc_value: BaseException,
tb: TracebackType,
) -> None:
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_str(fn, get_filesystem_encoding())
self.module = self.globals.get("__name__", self.locals.get("__name__"))
self.loader = self.globals.get("__loader__", self.locals.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:
info = _to_str(info, "utf-8", "replace")
self.info = info
def render(self, mark_lib: bool = True) -> str:
"""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(),
"library": "library" if mark_lib and self.is_library else "",
}
@cached_property
def is_library(self) -> bool:
return any(
self.filename.startswith(os.path.realpath(path))
for path in sysconfig.get_paths().values()
)
def render_text(self) -> str:
return (
f' File "{self.filename}", line {self.lineno}, in {self.function_name}\n'
f" {self.current_line.strip()}"
)
def render_line_context(self) -> str:
before, current, after = self.get_context_lines()
rv = []
def render_line(line: str, cls: str) -> None:
line = line.expandtabs().rstrip()
stripped_line = line.strip()
prefix = len(line) - len(stripped_line)
rv.append(
f'
{" " * prefix}'
f"{escape(stripped_line) if stripped_line else ' '}
"
)
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) -> t.List[Line]:
"""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([f"{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: t.Union[str, CodeType], mode: str = "single") -> t.Any:
"""Evaluate code in the context of the frame."""
if isinstance(code, str):
code = compile(code, "", mode)
return eval(code, self.globals, self.locals)
@cached_property
def sourcelines(self) -> t.List[str]:
"""The sourcecode of the file as list of 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:
with open(self.filename, mode="rb") as f:
source = f.read()
except OSError:
return []
# already str? return right away
if isinstance(source, str):
return source.splitlines()
charset = "utf-8"
if source.startswith(codecs.BOM_UTF8):
source = source[3:]
else:
for idx, match in enumerate(_line_re.finditer(source)):
coding_match = _coding_re.search(match.group())
if coding_match is not None:
charset = coding_match.group(1).decode("utf-8")
break
if idx > 1:
break
# on broken cookies we fall back to utf-8 too
charset = _to_str(charset)
try:
codecs.lookup(charset)
except LookupError:
charset = "utf-8"
return source.decode(charset, "replace").splitlines()
def get_context_lines(
self, context: int = 5
) -> t.Tuple[t.List[str], str, t.List[str]]:
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) -> str:
try:
return self.sourcelines[self.lineno - 1]
except IndexError:
return ""
@cached_property
def console(self) -> Console:
return Console(self.globals, self.locals)
@property
def id(self) -> int:
return id(self)