path: root/Cython/Compiler/Options.py

#
#  Cython - Compilation-wide options and pragma declarations
#

from __future__ import absolute_import

import os

from Cython import Utils


class ShouldBeFromDirective(object):

    known_directives = []

    def __init__(self, options_name, directive_name=None, disallow=False):
        self.options_name = options_name
        self.directive_name = directive_name or options_name
        self.disallow = disallow
        self.known_directives.append(self)

    def __nonzero__(self):
        self._bad_access()

    def __int__(self):
        self._bad_access()

    def _bad_access(self):
        raise RuntimeError(repr(self))

    def __repr__(self):
        return "Illegal access of '%s' from Options module rather than directive '%s'" % (
            self.options_name, self.directive_name)


"""
The members of this module are documented using autodata in
Cython/docs/src/reference/compilation.rst.
See https://www.sphinx-doc.org/en/master/usage/extensions/autodoc.html#directive-autoattribute
for how autodata works.
Descriptions of those members should start with a #:
Donc forget to keep the docs in sync by removing and adding
the members in both this file and the .rst file.
"""

#: Whether or not to include docstring in the Python extension. If False, the binary size
#: will be smaller, but the ``__doc__`` attribute of any class or function will be an
#: empty string.
docstrings = True

#: Embed the source code position in the docstrings of functions and classes.
embed_pos_in_docstring = False

# undocumented
pre_import = None

#: Decref global variables in each module on exit for garbage collection.
#: 0: None, 1+: interned objects, 2+: cdef globals, 3+: types objects
#: Mostly for reducing noise in Valgrind as it typically executes at process exit
#: (when all memory will be reclaimed anyways).
#: Note that directly or indirectly executed cleanup code that makes use of global
#: variables or types may no longer be safe when enabling the respective level since
#: there is no guaranteed order in which the (reference counted) objects will
#: be cleaned up.  The order can change due to live references and reference cycles.
generate_cleanup_code = False

#: Should tp_clear() set object fields to None instead of clearing them to NULL?
clear_to_none = True

#: Generate an annotated HTML version of the input source files for debugging and optimisation purposes.
#: This has the same effect as the ``annotate`` argument in :func:`cythonize`.
annotate = False

# When annotating source files in HTML, include coverage information from
# this file.
annotate_coverage_xml = None

#: This will abort the compilation on the first error occurred rather than trying
#: to keep going and printing further error messages.
fast_fail = False

#: Turn all warnings into errors.
warning_errors = False

#: Make unknown names an error.  Python raises a NameError when
#: encountering unknown names at runtime, whereas this option makes
#: them a compile time error.  If you want full Python compatibility,
#: you should disable this option and also 'cache_builtins'.
error_on_unknown_names = True

#: Make uninitialized local variable reference a compile time error.
#: Python raises UnboundLocalError at runtime, whereas this option makes
#: them a compile time error. Note that this option affects only variables
#: of "python object" type.
error_on_uninitialized = True

#: This will convert statements of the form ``for i in range(...)``
#: to ``for i from ...`` when ``i`` is a C integer type, and the direction
#: (i.e. sign of step) can be determined.
#: WARNING: This may change the semantics if the range causes assignment to
#: i to overflow. Specifically, if this option is set, an error will be
#: raised before the loop is entered, whereas without this option the loop
#: will execute until an overflowing value is encountered.
convert_range = True

#: Perform lookups on builtin names only once, at module initialisation
#: time.  This will prevent the module from getting imported if a
#: builtin name that it uses cannot be found during initialisation.
#: Default is True.
#: Note that some legacy builtins are automatically remapped
#: from their Python 2 names to their Python 3 names by Cython
#: when building in Python 3.x,
#: so that they do not get in the way even if this option is enabled.
cache_builtins = True

#: Generate branch prediction hints to speed up error handling etc.
gcc_branch_hints = True

#: Enable this to allow one to write ``your_module.foo = ...`` to overwrite the
#: definition if the cpdef function foo, at the cost of an extra dictionary
#: lookup on every call.
#: If this is false it generates only the Python wrapper and no override check.
lookup_module_cpdef = False

#: Whether or not to embed the Python interpreter, for use in making a
#: standalone executable or calling from external libraries.
#: This will provide a C function which initialises the interpreter and
#: executes the body of this module.
#: See `this demo <https://github.com/cython/cython/tree/master/Demos/embed>`_
#: for a concrete example.
#: If true, the initialisation function is the C main() function, but
#: this option can also be set to a non-empty string to provide a function name explicitly.
#: Default is False.
embed = None

# In previous iterations of Cython, globals() gave the first non-Cython module
# globals in the call stack.  Sage relies on this behavior for variable injection.
old_style_globals = ShouldBeFromDirective('old_style_globals')

#: Allows cimporting from a pyx file without a pxd file.
cimport_from_pyx = False

#: Maximum number of dimensions for buffers -- set lower than number of
#: dimensions in numpy, as
#: slices are passed by value and involve a lot of copying.
buffer_max_dims = 8

#: Number of function closure instances to keep in a freelist (0: no freelists)
closure_freelist_size = 8


def get_directive_defaults():
    # To add an item to this list, all accesses should be changed to use the new
    # directive, and the global option itself should be set to an instance of
    # ShouldBeFromDirective.
    for old_option in ShouldBeFromDirective.known_directives:
        value = globals().get(old_option.options_name)
        assert old_option.directive_name in _directive_defaults
        if not isinstance(value, ShouldBeFromDirective):
            if old_option.disallow:
                raise RuntimeError(
                    "Option '%s' must be set from directive '%s'" % (
                    old_option.option_name, old_option.directive_name))
            else:
                # Warn?
                _directive_defaults[old_option.directive_name] = value
    return _directive_defaults

def copy_inherited_directives(outer_directives, **new_directives):
    # A few directives are not copied downwards and this function removes them.
    # For example, test_assert_path_exists and test_fail_if_path_exists should not be inherited
    #  otherwise they can produce very misleading test failures
    new_directives_out = dict(outer_directives)
    for name in ('test_assert_path_exists', 'test_fail_if_path_exists', 'test_assert_c_code_has', 'test_fail_if_c_code_has'):
        new_directives_out.pop(name, None)
    new_directives_out.update(new_directives)
    return new_directives_out

# Declare compiler directives
_directive_defaults = {
    'binding': True,  # was False before 3.0
    'boundscheck' : True,
    'nonecheck' : False,
    'initializedcheck' : True,
    'embedsignature' : False,
    'auto_cpdef': False,
    'auto_pickle': None,
    'cdivision': False,  # was True before 0.12
    'cdivision_warnings': False,
    'c_api_binop_methods': False,  # was True before 3.0
    'overflowcheck': False,
    'overflowcheck.fold': True,
    'always_allow_keywords': True,
    'allow_none_for_extension_args': True,
    'wraparound' : True,
    'ccomplex' : False,  # use C99/C++ for complex types and arith
    'callspec' : "",
    'nogil' : False,
    'profile': False,
    'linetrace': False,
    'emit_code_comments': True,  # copy original source code into C code comments
    'annotation_typing': True,  # read type declarations from Python function annotations
    'infer_types': None,
    'infer_types.verbose': False,
    'autotestdict': True,
    'autotestdict.cdef': False,
    'autotestdict.all': False,
    'language_level': None,
    'fast_getattr': False,  # Undocumented until we come up with a better way to handle this everywhere.
    'py2_import': False,  # For backward compatibility of Cython's source code in Py3 source mode
    'preliminary_late_includes_cy28': False,  # Temporary directive in 0.28, to be removed in a later version (see GH#2079).
    'iterable_coroutine': False,  # Make async coroutines backwards compatible with the old asyncio yield-from syntax.
    'c_string_type': 'bytes',
    'c_string_encoding': '',
    'type_version_tag': True,  # enables Py_TPFLAGS_HAVE_VERSION_TAG on extension types
    'unraisable_tracebacks': True,
    'old_style_globals': False,
    'np_pythran': False,
    'fast_gil': False,
    'cpp_locals': False,  # uses std::optional for C++ locals, so that they work more like Python locals
    'legacy_implicit_noexcept': False,

    # set __file__ and/or __path__ to known source/target path at import time (instead of not having them available)
    'set_initial_path' : None,  # SOURCEFILE or "/full/path/to/module"

    'warn': None,
    'warn.undeclared': False,
    'warn.unreachable': True,
    'warn.maybe_uninitialized': False,
    'warn.unused': False,
    'warn.unused_arg': False,
    'warn.unused_result': False,
    'warn.multiple_declarators': True,

# optimizations
    'optimize.inline_defnode_calls': True,
    'optimize.unpack_method_calls': True,  # increases code size when True
    'optimize.unpack_method_calls_in_pyinit': False,  # uselessly increases code size when True
    'optimize.use_switch': True,

# remove unreachable code
    'remove_unreachable': True,

# control flow debug directives
    'control_flow.dot_output': "",  # Graphviz output filename
    'control_flow.dot_annotate_defs': False,  # Annotate definitions

# test support
    'test_assert_path_exists' : [],
    'test_fail_if_path_exists' : [],
    'test_assert_c_code_has' : [],
    'test_fail_if_c_code_has' : [],

# experimental, subject to change
    'formal_grammar': False,
}

# Extra warning directives
extra_warnings = {
    'warn.maybe_uninitialized': True,
    'warn.unreachable': True,
    'warn.unused': True,
}

def one_of(*args):
    def validate(name, value):
        if value not in args:
            raise ValueError("%s directive must be one of %s, got '%s'" % (
                name, args, value))
        else:
            return value
    return validate


def normalise_encoding_name(option_name, encoding):
    """
    >>> normalise_encoding_name('c_string_encoding', 'ascii')
    'ascii'
    >>> normalise_encoding_name('c_string_encoding', 'AsCIi')
    'ascii'
    >>> normalise_encoding_name('c_string_encoding', 'us-ascii')
    'ascii'
    >>> normalise_encoding_name('c_string_encoding', 'utF8')
    'utf8'
    >>> normalise_encoding_name('c_string_encoding', 'utF-8')
    'utf8'
    >>> normalise_encoding_name('c_string_encoding', 'deFAuLT')
    'default'
    >>> normalise_encoding_name('c_string_encoding', 'default')
    'default'
    >>> normalise_encoding_name('c_string_encoding', 'SeriousLyNoSuch--Encoding')
    'SeriousLyNoSuch--Encoding'
    """
    if not encoding:
        return ''
    if encoding.lower() in ('default', 'ascii', 'utf8'):
        return encoding.lower()
    import codecs
    try:
        decoder = codecs.getdecoder(encoding)
    except LookupError:
        return encoding  # may exists at runtime ...
    for name in ('ascii', 'utf8'):
        if codecs.getdecoder(name) == decoder:
            return name
    return encoding

# use as a sential value to defer analysis of the arguments
# instead of analysing them in InterpretCompilerDirectives. The dataclass directives are quite
# complicated and it's easier to deal with them at the point the dataclass is created
class DEFER_ANALYSIS_OF_ARGUMENTS:
    pass
DEFER_ANALYSIS_OF_ARGUMENTS = DEFER_ANALYSIS_OF_ARGUMENTS()

# Override types possibilities above, if needed
directive_types = {
    'language_level': str,  # values can be None/2/3/'3str', where None == 2+warning
    'auto_pickle': bool,
    'locals': dict,
    'final' : bool,  # final cdef classes and methods
    'nogil' : bool,
    'internal' : bool,  # cdef class visibility in the module dict
    'infer_types' : bool,  # values can be True/None/False
    'binding' : bool,
    'cfunc' : None,  # decorators do not take directive value
    'ccall' : None,
    'inline' : None,
    'staticmethod' : None,
    'cclass' : None,
    'no_gc_clear' : bool,
    'no_gc' : bool,
    'returns' : type,
    'exceptval': type,  # actually (type, check=True/False), but has its own parser
    'set_initial_path': str,
    'freelist': int,
    'c_string_type': one_of('bytes', 'bytearray', 'str', 'unicode'),
    'c_string_encoding': normalise_encoding_name,
    'trashcan': bool,
    'total_ordering': bool,
    'dataclasses.dataclass': DEFER_ANALYSIS_OF_ARGUMENTS,
    'dataclasses.field': DEFER_ANALYSIS_OF_ARGUMENTS,
}

for key, val in _directive_defaults.items():
    if key not in directive_types:
        directive_types[key] = type(val)

directive_scopes = {  # defaults to available everywhere
    # 'module', 'function', 'class', 'with statement'
    'auto_pickle': ('module', 'cclass'),
    'final' : ('cclass', 'function'),
    'nogil' : ('function', 'with statement'),
    'inline' : ('function',),
    'cfunc' : ('function', 'with statement'),
    'ccall' : ('function', 'with statement'),
    'returns' : ('function',),
    'exceptval' : ('function',),
    'locals' : ('function',),
    'staticmethod' : ('function',),  # FIXME: analysis currently lacks more specific function scope
    'no_gc_clear' : ('cclass',),
    'no_gc' : ('cclass',),
    'internal' : ('cclass',),
    'cclass' : ('class', 'cclass', 'with statement'),
    'autotestdict' : ('module',),
    'autotestdict.all' : ('module',),
    'autotestdict.cdef' : ('module',),
    'set_initial_path' : ('module',),
    'test_assert_path_exists' : ('function', 'class', 'cclass'),
    'test_fail_if_path_exists' : ('function', 'class', 'cclass'),
    'test_assert_c_code_has' : ('module',),
    'test_fail_if_c_code_has' : ('module',),
    'freelist': ('cclass',),
    'emit_code_comments': ('module',),
    # Avoid scope-specific to/from_py_functions for c_string.
    'c_string_type': ('module',),
    'c_string_encoding': ('module',),
    'type_version_tag': ('module', 'cclass'),
    'language_level': ('module',),
    # globals() could conceivably be controlled at a finer granularity,
    # but that would complicate the implementation
    'old_style_globals': ('module',),
    'np_pythran': ('module',),
    'fast_gil': ('module',),
    'iterable_coroutine': ('module', 'function'),
    'trashcan' : ('cclass',),
    'total_ordering': ('cclass', ),
    'dataclasses.dataclass' : ('class', 'cclass',),
    'cpp_locals': ('module', 'function', 'cclass'),  # I don't think they make sense in a with_statement
    'legacy_implicit_noexcept': ('module', ),
}


# a list of directives that (when used as a decorator) are only applied to
# the object they decorate and not to its children.
immediate_decorator_directives = {
    'cfunc', 'ccall', 'cclass', 'dataclasses.dataclass',
    # function signature directives
    'inline', 'exceptval', 'returns',
    # class directives
    'freelist', 'no_gc', 'no_gc_clear', 'type_version_tag', 'final',
    'auto_pickle', 'internal',
    # testing directives
    'test_fail_if_path_exists', 'test_assert_path_exists',
}


def parse_directive_value(name, value, relaxed_bool=False):
    """
    Parses value as an option value for the given name and returns
    the interpreted value. None is returned if the option does not exist.

    >>> print(parse_directive_value('nonexisting', 'asdf asdfd'))
    None
    >>> parse_directive_value('boundscheck', 'True')
    True
    >>> parse_directive_value('boundscheck', 'true')
    Traceback (most recent call last):
       ...
    ValueError: boundscheck directive must be set to True or False, got 'true'

    >>> parse_directive_value('c_string_encoding', 'us-ascii')
    'ascii'
    >>> parse_directive_value('c_string_type', 'str')
    'str'
    >>> parse_directive_value('c_string_type', 'bytes')
    'bytes'
    >>> parse_directive_value('c_string_type', 'bytearray')
    'bytearray'
    >>> parse_directive_value('c_string_type', 'unicode')
    'unicode'
    >>> parse_directive_value('c_string_type', 'unnicode')
    Traceback (most recent call last):
    ValueError: c_string_type directive must be one of ('bytes', 'bytearray', 'str', 'unicode'), got 'unnicode'
    """
    type = directive_types.get(name)
    if not type:
        return None
    orig_value = value
    if type is bool:
        value = str(value)
        if value == 'True':
            return True
        if value == 'False':
            return False
        if relaxed_bool:
            value = value.lower()
            if value in ("true", "yes"):
                return True
            elif value in ("false", "no"):
                return False
        raise ValueError("%s directive must be set to True or False, got '%s'" % (
            name, orig_value))
    elif type is int:
        try:
            return int(value)
        except ValueError:
            raise ValueError("%s directive must be set to an integer, got '%s'" % (
                name, orig_value))
    elif type is str:
        return str(value)
    elif callable(type):
        return type(name, value)
    else:
        assert False


def parse_directive_list(s, relaxed_bool=False, ignore_unknown=False,
                         current_settings=None):
    """
    Parses a comma-separated list of pragma options. Whitespace
    is not considered.

    >>> parse_directive_list('      ')
    {}
    >>> (parse_directive_list('boundscheck=True') ==
    ... {'boundscheck': True})
    True
    >>> parse_directive_list('  asdf')
    Traceback (most recent call last):
       ...
    ValueError: Expected "=" in option "asdf"
    >>> parse_directive_list('boundscheck=hey')
    Traceback (most recent call last):
       ...
    ValueError: boundscheck directive must be set to True or False, got 'hey'
    >>> parse_directive_list('unknown=True')
    Traceback (most recent call last):
       ...
    ValueError: Unknown option: "unknown"
    >>> warnings = parse_directive_list('warn.all=True')
    >>> len(warnings) > 1
    True
    >>> sum(warnings.values()) == len(warnings)  # all true.
    True
    """
    if current_settings is None:
        result = {}
    else:
        result = current_settings
    for item in s.split(','):
        item = item.strip()
        if not item:
            continue
        if '=' not in item:
            raise ValueError('Expected "=" in option "%s"' % item)
        name, value = [s.strip() for s in item.strip().split('=', 1)]
        if name not in _directive_defaults:
            found = False
            if name.endswith('.all'):
                prefix = name[:-3]
                for directive in _directive_defaults:
                    if directive.startswith(prefix):
                        found = True
                        parsed_value = parse_directive_value(directive, value, relaxed_bool=relaxed_bool)
                        result[directive] = parsed_value
            if not found and not ignore_unknown:
                raise ValueError('Unknown option: "%s"' % name)
        elif directive_types.get(name) is list:
            if name in result:
                result[name].append(value)
            else:
                result[name] = [value]
        else:
            parsed_value = parse_directive_value(name, value, relaxed_bool=relaxed_bool)
            result[name] = parsed_value
    return result


def parse_variable_value(value):
    """
    Parses value as an option value for the given name and returns
    the interpreted value.

    >>> parse_variable_value('True')
    True
    >>> parse_variable_value('true')
    'true'
    >>> parse_variable_value('us-ascii')
    'us-ascii'
    >>> parse_variable_value('str')
    'str'
    >>> parse_variable_value('123')
    123
    >>> parse_variable_value('1.23')
    1.23

    """
    if value == "True":
        return True
    elif value == "False":
        return False
    elif value == "None":
        return None
    elif value.isdigit():
        return int(value)
    else:
        try:
            value = float(value)
        except Exception:
            # Not a float
            pass
        return value


def parse_compile_time_env(s, current_settings=None):
    """
    Parses a comma-separated list of pragma options. Whitespace
    is not considered.

    >>> parse_compile_time_env('      ')
    {}
    >>> (parse_compile_time_env('HAVE_OPENMP=True') ==
    ... {'HAVE_OPENMP': True})
    True
    >>> parse_compile_time_env('  asdf')
    Traceback (most recent call last):
       ...
    ValueError: Expected "=" in option "asdf"
    >>> parse_compile_time_env('NUM_THREADS=4') == {'NUM_THREADS': 4}
    True
    >>> parse_compile_time_env('unknown=anything') == {'unknown': 'anything'}
    True
    """
    if current_settings is None:
        result = {}
    else:
        result = current_settings
    for item in s.split(','):
        item = item.strip()
        if not item:
            continue
        if '=' not in item:
            raise ValueError('Expected "=" in option "%s"' % item)
        name, value = [s.strip() for s in item.split('=', 1)]
        result[name] = parse_variable_value(value)
    return result


# ------------------------------------------------------------------------
# CompilationOptions are constructed from user input and are the `option`
#  object passed throughout the compilation pipeline.

class CompilationOptions(object):
    r"""
    See default_options at the end of this module for a list of all possible
    options and CmdLine.usage and CmdLine.parse_command_line() for their
    meaning.
    """
    def __init__(self, defaults=None, **kw):
        self.include_path = []
        if defaults:
            if isinstance(defaults, CompilationOptions):
                defaults = defaults.__dict__
        else:
            defaults = default_options

        options = dict(defaults)
        options.update(kw)

        # let's assume 'default_options' contains a value for most known compiler options
        # and validate against them
        unknown_options = set(options) - set(default_options)
        # ignore valid options that are not in the defaults
        unknown_options.difference_update(['include_path'])
        if unknown_options:
            message = "got unknown compilation option%s, please remove: %s" % (
                's' if len(unknown_options) > 1 else '',
                ', '.join(unknown_options))
            raise ValueError(message)

        directive_defaults = get_directive_defaults()
        directives = dict(options['compiler_directives'])  # copy mutable field
        # check for invalid directives
        unknown_directives = set(directives) - set(directive_defaults)
        if unknown_directives:
            message = "got unknown compiler directive%s: %s" % (
                's' if len(unknown_directives) > 1 else '',
                ', '.join(unknown_directives))
            raise ValueError(message)
        options['compiler_directives'] = directives
        if directives.get('np_pythran', False) and not options['cplus']:
            import warnings
            warnings.warn("C++ mode forced when in Pythran mode!")
            options['cplus'] = True
        if 'language_level' in directives and 'language_level' not in kw:
            options['language_level'] = directives['language_level']
        elif not options.get('language_level'):
            options['language_level'] = directive_defaults.get('language_level')
        if 'formal_grammar' in directives and 'formal_grammar' not in kw:
            options['formal_grammar'] = directives['formal_grammar']
        if options['cache'] is True:
            options['cache'] = os.path.join(Utils.get_cython_cache_dir(), 'compiler')

        self.__dict__.update(options)

    def configure_language_defaults(self, source_extension):
        if source_extension == 'py':
            if self.compiler_directives.get('binding') is None:
                self.compiler_directives['binding'] = True

    def get_fingerprint(self):
        r"""
        Return a string that contains all the options that are relevant for cache invalidation.
        """
        # Collect only the data that can affect the generated file(s).
        data = {}

        for key, value in self.__dict__.items():
            if key in ['show_version', 'errors_to_stderr', 'verbose', 'quiet']:
                # verbosity flags have no influence on the compilation result
                continue
            elif key in ['output_file', 'output_dir']:
                # ignore the exact name of the output file
                continue
            elif key in ['depfile']:
                # external build system dependency tracking file does not influence outputs
                continue
            elif key in ['timestamps']:
                # the cache cares about the content of files, not about the timestamps of sources
                continue
            elif key in ['cache']:
                # hopefully caching has no influence on the compilation result
                continue
            elif key in ['compiler_directives']:
                # directives passed on to the C compiler do not influence the generated C code
                continue
            elif key in ['include_path']:
                # this path changes which headers are tracked as dependencies,
                # it has no influence on the generated C code
                continue
            elif key in ['working_path']:
                # this path changes where modules and pxd files are found;
                # their content is part of the fingerprint anyway, their
                # absolute path does not matter
                continue
            elif key in ['create_extension']:
                # create_extension() has already mangled the options, e.g.,
                # embedded_metadata, when the fingerprint is computed so we
                # ignore it here.
                continue
            elif key in ['build_dir']:
                # the (temporary) directory where we collect dependencies
                # has no influence on the C output
                continue
            elif key in ['use_listing_file', 'generate_pxi', 'annotate', 'annotate_coverage_xml']:
                # all output files are contained in the cache so the types of
                # files generated must be part of the fingerprint
                data[key] = value
            elif key in ['formal_grammar', 'evaluate_tree_assertions']:
                # these bits can change whether compilation to C passes/fails
                data[key] = value
            elif key in ['embedded_metadata', 'emit_linenums',
                         'c_line_in_traceback', 'gdb_debug',
                         'relative_path_in_code_position_comments']:
                # the generated code contains additional bits when these are set
                data[key] = value
            elif key in ['cplus', 'language_level', 'compile_time_env', 'np_pythran']:
                # assorted bits that, e.g., influence the parser
                data[key] = value
            elif key == ['capi_reexport_cincludes']:
                if self.capi_reexport_cincludes:
                    # our caching implementation does not yet include fingerprints of all the header files
                    raise NotImplementedError('capi_reexport_cincludes is not compatible with Cython caching')
            elif key == ['common_utility_include_dir']:
                if self.common_utility_include_dir:
                    raise NotImplementedError('common_utility_include_dir is not compatible with Cython caching yet')
            else:
                # any unexpected option should go into the fingerprint; it's better
                # to recompile than to return incorrect results from the cache.
                data[key] = value

        def to_fingerprint(item):
            r"""
            Recursively turn item into a string, turning dicts into lists with
            deterministic ordering.
            """
            if isinstance(item, dict):
                item = sorted([(repr(key), to_fingerprint(value)) for key, value in item.items()])
            return repr(item)

        return to_fingerprint(data)


# ------------------------------------------------------------------------
#
#  Set the default options depending on the platform
#
# ------------------------------------------------------------------------

default_options = dict(
    show_version=0,
    use_listing_file=0,
    errors_to_stderr=1,
    cplus=0,
    output_file=None,
    depfile=None,
    annotate=None,
    annotate_coverage_xml=None,
    generate_pxi=0,
    capi_reexport_cincludes=0,
    working_path="",
    timestamps=None,
    verbose=0,
    quiet=0,
    compiler_directives={},
    embedded_metadata={},
    evaluate_tree_assertions=False,
    emit_linenums=False,
    relative_path_in_code_position_comments=True,
    c_line_in_traceback=True,
    language_level=None,  # warn but default to 2
    formal_grammar=False,
    gdb_debug=False,
    compile_time_env=None,
    module_name=None,
    common_utility_include_dir=None,
    output_dir=None,
    build_dir=None,
    cache=None,
    create_extension=None,
    np_pythran=False,
    legacy_implicit_noexcept=None,
)