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# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
# For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt
"""Control of and utilities for debugging."""
from __future__ import annotations
import contextlib
import functools
import inspect
import io
import itertools
import os
import pprint
import re
import reprlib
import sys
import types
import _thread
from typing import (
cast,
Any, Callable, IO, Iterable, Iterator, Mapping, Optional, List, Tuple,
)
from coverage.misc import human_sorted_items, isolate_module
from coverage.types import TWritable
os = isolate_module(os)
# When debugging, it can be helpful to force some options, especially when
# debugging the configuration mechanisms you usually use to control debugging!
# This is a list of forced debugging options.
FORCED_DEBUG: List[str] = []
FORCED_DEBUG_FILE = None
class DebugControl:
"""Control and output for debugging."""
show_repr_attr = False # For AutoReprMixin
def __init__(
self,
options: Iterable[str],
output: Optional[IO[str]],
file_name: Optional[str] = None,
) -> None:
"""Configure the options and output file for debugging."""
self.options = list(options) + FORCED_DEBUG
self.suppress_callers = False
filters = []
if self.should("pid"):
filters.append(add_pid_and_tid)
self.output = DebugOutputFile.get_one(
output,
file_name=file_name,
show_process=self.should("process"),
filters=filters,
)
self.raw_output = self.output.outfile
def __repr__(self) -> str:
return f"<DebugControl options={self.options!r} raw_output={self.raw_output!r}>"
def should(self, option: str) -> bool:
"""Decide whether to output debug information in category `option`."""
if option == "callers" and self.suppress_callers:
return False
return (option in self.options)
@contextlib.contextmanager
def without_callers(self) -> Iterator[None]:
"""A context manager to prevent call stacks from being logged."""
old = self.suppress_callers
self.suppress_callers = True
try:
yield
finally:
self.suppress_callers = old
def write(self, msg: str) -> None:
"""Write a line of debug output.
`msg` is the line to write. A newline will be appended.
"""
self.output.write(msg+"\n")
if self.should("self"):
caller_self = inspect.stack()[1][0].f_locals.get("self")
if caller_self is not None:
self.output.write(f"self: {caller_self!r}\n")
if self.should("callers"):
dump_stack_frames(out=self.output, skip=1)
self.output.flush()
class DebugControlString(DebugControl):
"""A `DebugControl` that writes to a StringIO, for testing."""
def __init__(self, options: Iterable[str]) -> None:
super().__init__(options, io.StringIO())
def get_output(self) -> str:
"""Get the output text from the `DebugControl`."""
return cast(str, self.raw_output.getvalue()) # type: ignore
class NoDebugging(DebugControl):
"""A replacement for DebugControl that will never try to do anything."""
def __init__(self) -> None:
# pylint: disable=super-init-not-called
...
def should(self, option: str) -> bool:
"""Should we write debug messages? Never."""
return False
def write(self, msg: str) -> None:
"""This will never be called."""
raise AssertionError("NoDebugging.write should never be called.")
def info_header(label: str) -> str:
"""Make a nice header string."""
return "--{:-<60s}".format(" "+label+" ")
def info_formatter(info: Iterable[Tuple[str, Any]]) -> Iterator[str]:
"""Produce a sequence of formatted lines from info.
`info` is a sequence of pairs (label, data). The produced lines are
nicely formatted, ready to print.
"""
info = list(info)
if not info:
return
label_len = 30
assert all(len(l) < label_len for l, _ in info)
for label, data in info:
if data == []:
data = "-none-"
if isinstance(data, tuple) and len(repr(tuple(data))) < 30:
# Convert to tuple to scrub namedtuples.
yield "%*s: %r" % (label_len, label, tuple(data))
elif isinstance(data, (list, set, tuple)):
prefix = "%*s:" % (label_len, label)
for e in data:
yield "%*s %s" % (label_len+1, prefix, e)
prefix = ""
else:
yield "%*s: %s" % (label_len, label, data)
def write_formatted_info(
write: Callable[[str], None],
header: str,
info: Iterable[Tuple[str, Any]],
) -> None:
"""Write a sequence of (label,data) pairs nicely.
`write` is a function write(str) that accepts each line of output.
`header` is a string to start the section. `info` is a sequence of
(label, data) pairs, where label is a str, and data can be a single
value, or a list/set/tuple.
"""
write(info_header(header))
for line in info_formatter(info):
write(f" {line}")
def short_stack(limit: Optional[int] = None, skip: int = 0) -> str:
"""Return a string summarizing the call stack.
The string is multi-line, with one line per stack frame. Each line shows
the function name, the file name, and the line number:
...
start_import_stop : /Users/ned/coverage/trunk/tests/coveragetest.py @95
import_local_file : /Users/ned/coverage/trunk/tests/coveragetest.py @81
import_local_file : /Users/ned/coverage/trunk/coverage/backward.py @159
...
`limit` is the number of frames to include, defaulting to all of them.
`skip` is the number of frames to skip, so that debugging functions can
call this and not be included in the result.
"""
stack = inspect.stack()[limit:skip:-1]
return "\n".join("%30s : %s:%d" % (t[3], t[1], t[2]) for t in stack)
def dump_stack_frames(
limit: Optional[int] = None,
out: Optional[TWritable] = None,
skip: int = 0
) -> None:
"""Print a summary of the stack to stdout, or someplace else."""
fout = out or sys.stdout
fout.write(short_stack(limit=limit, skip=skip+1))
fout.write("\n")
def clipped_repr(text: str, numchars: int = 50) -> str:
"""`repr(text)`, but limited to `numchars`."""
r = reprlib.Repr()
r.maxstring = numchars
return r.repr(text)
def short_id(id64: int) -> int:
"""Given a 64-bit id, make a shorter 16-bit one."""
id16 = 0
for offset in range(0, 64, 16):
id16 ^= id64 >> offset
return id16 & 0xFFFF
def add_pid_and_tid(text: str) -> str:
"""A filter to add pid and tid to debug messages."""
# Thread ids are useful, but too long. Make a shorter one.
tid = f"{short_id(_thread.get_ident()):04x}"
text = f"{os.getpid():5d}.{tid}: {text}"
return text
class AutoReprMixin:
"""A mixin implementing an automatic __repr__ for debugging."""
auto_repr_ignore = ["auto_repr_ignore", "$coverage.object_id"]
def __repr__(self) -> str:
show_attrs = (
(k, v) for k, v in self.__dict__.items()
if getattr(v, "show_repr_attr", True)
and not callable(v)
and k not in self.auto_repr_ignore
)
return "<{klass} @0x{id:x} {attrs}>".format(
klass=self.__class__.__name__,
id=id(self),
attrs=" ".join(f"{k}={v!r}" for k, v in show_attrs),
)
def simplify(v: Any) -> Any: # pragma: debugging
"""Turn things which are nearly dict/list/etc into dict/list/etc."""
if isinstance(v, dict):
return {k:simplify(vv) for k, vv in v.items()}
elif isinstance(v, (list, tuple)):
return type(v)(simplify(vv) for vv in v)
elif hasattr(v, "__dict__"):
return simplify({"."+k: v for k, v in v.__dict__.items()})
else:
return v
def pp(v: Any) -> None: # pragma: debugging
"""Debug helper to pretty-print data, including SimpleNamespace objects."""
# Might not be needed in 3.9+
pprint.pprint(simplify(v))
def filter_text(text: str, filters: Iterable[Callable[[str], str]]) -> str:
"""Run `text` through a series of filters.
`filters` is a list of functions. Each takes a string and returns a
string. Each is run in turn.
Returns: the final string that results after all of the filters have
run.
"""
clean_text = text.rstrip()
ending = text[len(clean_text):]
text = clean_text
for fn in filters:
lines = []
for line in text.splitlines():
lines.extend(fn(line).splitlines())
text = "\n".join(lines)
return text + ending
class CwdTracker:
"""A class to add cwd info to debug messages."""
def __init__(self) -> None:
self.cwd: Optional[str] = None
def filter(self, text: str) -> str:
"""Add a cwd message for each new cwd."""
cwd = os.getcwd()
if cwd != self.cwd:
text = f"cwd is now {cwd!r}\n" + text
self.cwd = cwd
return text
class DebugOutputFile:
"""A file-like object that includes pid and cwd information."""
def __init__(
self,
outfile: Optional[IO[str]],
show_process: bool,
filters: Iterable[Callable[[str], str]],
):
self.outfile = outfile
self.show_process = show_process
self.filters = list(filters)
if self.show_process:
self.filters.insert(0, CwdTracker().filter)
self.write(f"New process: executable: {sys.executable!r}\n")
self.write("New process: cmd: {!r}\n".format(getattr(sys, "argv", None)))
if hasattr(os, "getppid"):
self.write(f"New process: pid: {os.getpid()!r}, parent pid: {os.getppid()!r}\n")
@classmethod
def get_one(
cls,
fileobj: Optional[IO[str]] = None,
file_name: Optional[str] = None,
show_process: bool = True,
filters: Iterable[Callable[[str], str]] = (),
interim: bool = False,
) -> DebugOutputFile:
"""Get a DebugOutputFile.
If `fileobj` is provided, then a new DebugOutputFile is made with it.
If `fileobj` isn't provided, then a file is chosen (`file_name` if
provided, or COVERAGE_DEBUG_FILE, or stderr), and a process-wide
singleton DebugOutputFile is made.
`show_process` controls whether the debug file adds process-level
information, and filters is a list of other message filters to apply.
`filters` are the text filters to apply to the stream to annotate with
pids, etc.
If `interim` is true, then a future `get_one` can replace this one.
"""
if fileobj is not None:
# Make DebugOutputFile around the fileobj passed.
return cls(fileobj, show_process, filters)
the_one, is_interim = cls._get_singleton_data()
if the_one is None or is_interim:
if file_name is not None:
fileobj = open(file_name, "a", encoding="utf-8")
else:
file_name = os.environ.get("COVERAGE_DEBUG_FILE", FORCED_DEBUG_FILE)
if file_name in ("stdout", "stderr"):
fileobj = getattr(sys, file_name)
elif file_name:
fileobj = open(file_name, "a", encoding="utf-8")
else:
fileobj = sys.stderr
the_one = cls(fileobj, show_process, filters)
cls._set_singleton_data(the_one, interim)
return the_one
# Because of the way igor.py deletes and re-imports modules,
# this class can be defined more than once. But we really want
# a process-wide singleton. So stash it in sys.modules instead of
# on a class attribute. Yes, this is aggressively gross.
SYS_MOD_NAME = "$coverage.debug.DebugOutputFile.the_one"
SINGLETON_ATTR = "the_one_and_is_interim"
@classmethod
def _set_singleton_data(cls, the_one: DebugOutputFile, interim: bool) -> None:
"""Set the one DebugOutputFile to rule them all."""
singleton_module = types.ModuleType(cls.SYS_MOD_NAME)
setattr(singleton_module, cls.SINGLETON_ATTR, (the_one, interim))
sys.modules[cls.SYS_MOD_NAME] = singleton_module
@classmethod
def _get_singleton_data(cls) -> Tuple[Optional[DebugOutputFile], bool]:
"""Get the one DebugOutputFile."""
singleton_module = sys.modules.get(cls.SYS_MOD_NAME)
return getattr(singleton_module, cls.SINGLETON_ATTR, (None, True))
@classmethod
def _del_singleton_data(cls) -> None:
"""Delete the one DebugOutputFile, just for tests to use."""
if cls.SYS_MOD_NAME in sys.modules:
del sys.modules[cls.SYS_MOD_NAME]
def write(self, text: str) -> None:
"""Just like file.write, but filter through all our filters."""
assert self.outfile is not None
self.outfile.write(filter_text(text, self.filters))
self.outfile.flush()
def flush(self) -> None:
"""Flush our file."""
assert self.outfile is not None
self.outfile.flush()
def log(msg: str, stack: bool = False) -> None: # pragma: debugging
"""Write a log message as forcefully as possible."""
out = DebugOutputFile.get_one(interim=True)
out.write(msg+"\n")
if stack:
dump_stack_frames(out=out, skip=1)
def decorate_methods(
decorator: Callable[..., Any],
butnot: Iterable[str] = (),
private: bool = False,
) -> Callable[..., Any]: # pragma: debugging
"""A class decorator to apply a decorator to methods."""
def _decorator(cls): # type: ignore
for name, meth in inspect.getmembers(cls, inspect.isroutine):
if name not in cls.__dict__:
continue
if name != "__init__":
if not private and name.startswith("_"):
continue
if name in butnot:
continue
setattr(cls, name, decorator(meth))
return cls
return _decorator
def break_in_pudb(func: Callable[..., Any]) -> Callable[..., Any]: # pragma: debugging
"""A function decorator to stop in the debugger for each call."""
@functools.wraps(func)
def _wrapper(*args: Any, **kwargs: Any) -> Any:
import pudb
sys.stdout = sys.__stdout__
pudb.set_trace()
return func(*args, **kwargs)
return _wrapper
OBJ_IDS = itertools.count()
CALLS = itertools.count()
OBJ_ID_ATTR = "$coverage.object_id"
def show_calls(
show_args: bool = True,
show_stack: bool = False,
show_return: bool = False,
) -> Callable[..., Any]: # pragma: debugging
"""A method decorator to debug-log each call to the function."""
def _decorator(func: Callable[..., Any]) -> Callable[..., Any]:
@functools.wraps(func)
def _wrapper(self: Any, *args: Any, **kwargs: Any) -> Any:
oid = getattr(self, OBJ_ID_ATTR, None)
if oid is None:
oid = f"{os.getpid():08d} {next(OBJ_IDS):04d}"
setattr(self, OBJ_ID_ATTR, oid)
extra = ""
if show_args:
eargs = ", ".join(map(repr, args))
ekwargs = ", ".join("{}={!r}".format(*item) for item in kwargs.items())
extra += "("
extra += eargs
if eargs and ekwargs:
extra += ", "
extra += ekwargs
extra += ")"
if show_stack:
extra += " @ "
extra += "; ".join(_clean_stack_line(l) for l in short_stack().splitlines())
callid = next(CALLS)
msg = f"{oid} {callid:04d} {func.__name__}{extra}\n"
DebugOutputFile.get_one(interim=True).write(msg)
ret = func(self, *args, **kwargs)
if show_return:
msg = f"{oid} {callid:04d} {func.__name__} return {ret!r}\n"
DebugOutputFile.get_one(interim=True).write(msg)
return ret
return _wrapper
return _decorator
def _clean_stack_line(s: str) -> str: # pragma: debugging
"""Simplify some paths in a stack trace, for compactness."""
s = s.strip()
s = s.replace(os.path.dirname(__file__) + "/", "")
s = s.replace(os.path.dirname(os.__file__) + "/", "")
s = s.replace(sys.prefix + "/", "")
return s
def relevant_environment_display(env: Mapping[str, str]) -> List[Tuple[str, str]]:
"""Filter environment variables for a debug display.
Select variables to display (with COV or PY in the name, or HOME, TEMP, or
TMP), and also cloak sensitive values with asterisks.
Arguments:
env: a dict of environment variable names and values.
Returns:
A list of pairs (name, value) to show.
"""
slugs = {"COV", "PY"}
include = {"HOME", "TEMP", "TMP"}
cloak = {"API", "TOKEN", "KEY", "SECRET", "PASS", "SIGNATURE"}
to_show = []
for name, val in env.items():
keep = False
if name in include:
keep = True
elif any(slug in name for slug in slugs):
keep = True
if keep:
if any(slug in name for slug in cloak):
val = re.sub(r"\w", "*", val)
to_show.append((name, val))
return human_sorted_items(to_show)
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