Source code for cocotb.result

# Copyright (c) 2013 Potential Ventures Ltd
# Copyright (c) 2013 SolarFlare Communications Inc
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#
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#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright
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#       SolarFlare Communications Inc nor the
#       names of its contributors may be used to endorse or promote products
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# TODO: Could use cStringIO?
import traceback
import sys
import warnings
from io import StringIO

"""Exceptions and functions for simulation result handling."""


def raise_error(obj, msg):
    """Create a :exc:`TestError` exception and raise it after printing a traceback.

    .. deprecated:: 1.3
        Raise a standard Python exception instead of calling this function.
        A stacktrace will be printed by cocotb automatically if the exception is unhandled.

    Args:
        obj: Object with a log method.
        msg (str): The log message.
    """
    warnings.warn(
        "``raise_error`` is deprecated - raise a standard Exception instead",
        DeprecationWarning, stacklevel=2)
    _raise_error(obj, msg)


def _raise_error(obj, msg):
    exc_info = sys.exc_info()
    buff = StringIO()
    traceback.print_exception(*exc_info, file=buff)
    obj.log.error("%s\n%s" % (msg, buff.getvalue()))
    exception = TestError(msg)
    exception.stderr.write(buff.getvalue())
    raise exception


def create_error(obj, msg):
    """Like :func:`raise_error`, but return the exception rather than raise it,
    simply to avoid too many levels of nested `try/except` blocks.

    .. deprecated:: 1.3
        Raise a standard Python exception instead of calling this function.

    Args:
        obj: Object with a log method.
        msg (str): The log message.
    """
    warnings.warn(
        "``create_error`` is deprecated - raise a standard Exception instead",
        DeprecationWarning, stacklevel=2)
    try:
        # use the private version to avoid multiple warnings
        _raise_error(obj, msg)
    except TestError as error:
        return error
    return TestError("Creating error traceback failed")


class ReturnValue(Exception):
    """
    Helper exception needed for Python versions prior to 3.3.

    .. deprecated:: 1.4
        Use a :keyword:`return` statement instead; this works in all supported versions of Python.
    """

    def __init__(self, retval):
        warnings.warn(
            "``ReturnValue`` is deprecated, use a normal return statement instead.",
            DeprecationWarning,
            stacklevel=2)
        self.retval = retval


class TestComplete(Exception):
    """Exception showing that the test was completed. Sub-exceptions detail the exit status."""

    def __init__(self, *args, **kwargs):
        super(TestComplete, self).__init__(*args, **kwargs)
        self.stdout = StringIO()
        self.stderr = StringIO()


class ExternalException(Exception):
    """Exception thrown by :class:`cocotb.external` functions."""

    def __init__(self, exception):
        self.exception = exception


class TestError(TestComplete):
    """
    Exception showing that the test was completed with severity Error.

    .. deprecated:: 1.5
        Raise a standard Python exception instead.
        A stacktrace will be printed by cocotb automatically if the exception is unhandled.
    """

    def __init__(self, *args, **kwargs):
        warnings.warn(
            "TestError is deprecated - raise a standard Exception instead",
            DeprecationWarning, stacklevel=2)
        super().__init__(*args, **kwargs)


class TestFailure(TestComplete, AssertionError):
    """Exception showing that the test was completed with severity Failure."""
    pass


class TestSuccess(TestComplete):
    """Exception showing that the test was completed successfully."""
    pass


class SimFailure(TestComplete):
    """Exception showing that the simulator exited unsuccessfully."""
    pass


class SimTimeoutError(TimeoutError):
    """Exception for when a timeout, in terms of simulation time, occurs."""
    pass