diff options
Diffstat (limited to 'Lib/warnings.py')
| -rw-r--r-- | Lib/warnings.py | 127 |
1 files changed, 104 insertions, 23 deletions
diff --git a/Lib/warnings.py b/Lib/warnings.py index c6631fcbf4..5badb0be37 100644 --- a/Lib/warnings.py +++ b/Lib/warnings.py @@ -2,39 +2,120 @@ import sys + __all__ = ["warn", "warn_explicit", "showwarning", "formatwarning", "filterwarnings", "simplefilter", "resetwarnings", "catch_warnings"] - def showwarning(message, category, filename, lineno, file=None, line=None): """Hook to write a warning to a file; replace if you like.""" + msg = WarningMessage(message, category, filename, lineno, file, line) + _showwarnmsg_impl(msg) + +def formatwarning(message, category, filename, lineno, line=None): + """Function to format a warning the standard way.""" + msg = WarningMessage(message, category, filename, lineno, None, line) + return _formatwarnmsg_impl(msg) + +def _showwarnmsg_impl(msg): + file = msg.file if file is None: file = sys.stderr if file is None: - # sys.stderr is None when run with pythonw.exe - warnings get lost + # sys.stderr is None when run with pythonw.exe: + # warnings get lost return + text = _formatwarnmsg(msg) try: - file.write(formatwarning(message, category, filename, lineno, line)) + file.write(text) except OSError: - pass # the file (probably stderr) is invalid - this warning gets lost. + # the file (probably stderr) is invalid - this warning gets lost. + pass -def formatwarning(message, category, filename, lineno, line=None): - """Function to format a warning the standard way.""" - s = "%s:%s: %s: %s\n" % (filename, lineno, category.__name__, message) - if line is None: +def _formatwarnmsg_impl(msg): + s = ("%s:%s: %s: %s\n" + % (msg.filename, msg.lineno, msg.category.__name__, + msg.message)) + + if msg.line is None: try: import linecache - line = linecache.getline(filename, lineno) + line = linecache.getline(msg.filename, msg.lineno) except Exception: # When a warning is logged during Python shutdown, linecache # and the import machinery don't work anymore line = None + linecache = None + else: + line = msg.line if line: line = line.strip() s += " %s\n" % line + + if msg.source is not None: + try: + import tracemalloc + tb = tracemalloc.get_object_traceback(msg.source) + except Exception: + # When a warning is logged during Python shutdown, tracemalloc + # and the import machinery don't work anymore + tb = None + + if tb is not None: + s += 'Object allocated at (most recent call first):\n' + for frame in tb: + s += (' File "%s", lineno %s\n' + % (frame.filename, frame.lineno)) + + try: + if linecache is not None: + line = linecache.getline(frame.filename, frame.lineno) + else: + line = None + except Exception: + line = None + if line: + line = line.strip() + s += ' %s\n' % line return s +# Keep a reference to check if the function was replaced +_showwarning_orig = showwarning + +def _showwarnmsg(msg): + """Hook to write a warning to a file; replace if you like.""" + try: + sw = showwarning + except NameError: + pass + else: + if sw is not _showwarning_orig: + # warnings.showwarning() was replaced + if not callable(sw): + raise TypeError("warnings.showwarning() must be set to a " + "function or method") + + sw(msg.message, msg.category, msg.filename, msg.lineno, + msg.file, msg.line) + return + _showwarnmsg_impl(msg) + +# Keep a reference to check if the function was replaced +_formatwarning_orig = formatwarning + +def _formatwarnmsg(msg): + """Function to format a warning the standard way.""" + try: + fw = formatwarning + except NameError: + pass + else: + if fw is not _formatwarning_orig: + # warnings.formatwarning() was replaced + return fw(msg.message, msg.category, + msg.filename, msg.lineno, line=msg.line) + return _formatwarnmsg_impl(msg) + def filterwarnings(action, message="", category=Warning, module="", lineno=0, append=False): """Insert an entry into the list of warnings filters (at the front). @@ -185,7 +266,7 @@ def _next_external_frame(frame): # Code typically replaced by _warnings -def warn(message, category=None, stacklevel=1): +def warn(message, category=None, stacklevel=1, source=None): """Issue a warning, or maybe ignore it or raise an exception.""" # Check if message is already a Warning object if isinstance(message, Warning): @@ -235,10 +316,11 @@ def warn(message, category=None, stacklevel=1): filename = module registry = globals.setdefault("__warningregistry__", {}) warn_explicit(message, category, filename, lineno, module, registry, - globals) + globals, source) def warn_explicit(message, category, filename, lineno, - module=None, registry=None, module_globals=None): + module=None, registry=None, module_globals=None, + source=None): lineno = int(lineno) if module is None: module = filename or "<unknown>" @@ -303,22 +385,18 @@ def warn_explicit(message, category, filename, lineno, raise RuntimeError( "Unrecognized action (%r) in warnings.filters:\n %s" % (action, item)) - if not callable(showwarning): - raise TypeError("warnings.showwarning() must be set to a " - "function or method") # Print message and context - showwarning(message, category, filename, lineno) + msg = WarningMessage(message, category, filename, lineno, source) + _showwarnmsg(msg) class WarningMessage(object): - """Holds the result of a single showwarning() call.""" - _WARNING_DETAILS = ("message", "category", "filename", "lineno", "file", - "line") + "line", "source") def __init__(self, message, category, filename, lineno, file=None, - line=None): + line=None, source=None): local_values = locals() for attr in self._WARNING_DETAILS: setattr(self, attr, local_values[attr]) @@ -376,11 +454,13 @@ class catch_warnings(object): self._module.filters = self._filters[:] self._module._filters_mutated() self._showwarning = self._module.showwarning + self._showwarnmsg_impl = self._module._showwarnmsg_impl if self._record: log = [] - def showwarning(*args, **kwargs): - log.append(WarningMessage(*args, **kwargs)) - self._module.showwarning = showwarning + self._module._showwarnmsg_impl = log.append + # Reset showwarning() to the default implementation to make sure + # that _showwarnmsg() calls _showwarnmsg_impl() + self._module.showwarning = self._module._showwarning_orig return log else: return None @@ -391,6 +471,7 @@ class catch_warnings(object): self._module.filters = self._filters self._module._filters_mutated() self._module.showwarning = self._showwarning + self._module._showwarnmsg_impl = self._showwarnmsg_impl # filters contains a sequence of filter 5-tuples |