bpo-30860: Consolidate stateful runtime globals. (#3397)

* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals

Other globals are excluded (see globals.txt and check-c-globals.py).

3 files changed, 981 insertions, 0 deletions

diff --git a/Tools/c-globals/README b/Tools/c-globals/README
new file mode 100644
index 0000000..d0e6e8e
--- /dev/null
+++ b/Tools/c-globals/README
@@ -0,0 +1,41 @@
+#######################################
+# C Globals and CPython Runtime State.
+
+CPython's C code makes extensive use of global variables.  Each global
+falls into one of several categories:
+
+* (effectively) constants (incl. static types)
+* globals used exclusively in main or in the REPL
+* freelists, caches, and counters
+* process-global state
+* module state
+* Python runtime state
+
+The ignored-globals.txt file is organized similarly.  Of the different
+categories, the last two are problematic and generally should not exist
+in the codebase.
+
+Globals that hold module state (i.e. in Modules/*.c) cause problems
+when multiple interpreters are in use.  For more info, see PEP 3121,
+which addresses the situation for extension modules in general.
+
+Globals in the last category should be avoided as well.  The problem
+isn't with the Python runtime having state.  Rather, the problem is with
+that state being spread thoughout the codebase in dozens of individual
+globals.  Unlike the other globals, the runtime state represents a set
+of values that are constantly shifting in a complex way.  When they are
+spread out it's harder to get a clear picture of what the runtime
+involves.  Furthermore, when they are spread out it complicates efforts
+that change the runtime.
+
+Consequently, the globals for Python's runtime state have been
+consolidated under a single top-level _PyRuntime global. No new globals
+should be added for runtime state.  Instead, they should be added to
+_PyRuntimeState or one of its sub-structs.  The check-c-globals script
+should be run to ensure that no new globals have been added:
+
+  python3 Tools/c-globals/check-c-globals.py
+
+If it reports any globals then they should be resolved.  If the globals
+are runtime state then they should be folded into _PyRuntimeState.
+Otherwise they should be added to ignored-globals.txt.
diff --git a/Tools/c-globals/check-c-globals.py b/Tools/c-globals/check-c-globals.py
new file mode 100644
index 0000000..1de69a8
--- /dev/null
+++ b/Tools/c-globals/check-c-globals.py
@@ -0,0 +1,446 @@
+
+from collections import namedtuple
+import glob
+import os.path
+import re
+import shutil
+import sys
+import subprocess
+
+
+VERBOSITY = 2
+
+C_GLOBALS_DIR = os.path.abspath(os.path.dirname(__file__))
+TOOLS_DIR = os.path.dirname(C_GLOBALS_DIR)
+ROOT_DIR = os.path.dirname(TOOLS_DIR)
+GLOBALS_FILE = os.path.join(C_GLOBALS_DIR, 'ignored-globals.txt')
+
+SOURCE_DIRS = ['Include', 'Objects', 'Modules', 'Parser', 'Python']
+
+CAPI_REGEX = re.compile(r'^ *PyAPI_DATA\([^)]*\) \W*(_?Py\w+(?:, \w+)*\w).*;.*$')
+
+
+IGNORED_VARS = {
+        '_DYNAMIC',
+        '_GLOBAL_OFFSET_TABLE_',
+        '__JCR_LIST__',
+        '__JCR_END__',
+        '__TMC_END__',
+        '__bss_start',
+        '__data_start',
+        '__dso_handle',
+        '_edata',
+        '_end',
+        }
+
+
+def find_capi_vars(root):
+    capi_vars = {}
+    for dirname in SOURCE_DIRS:
+        for filename in glob.glob(os.path.join(ROOT_DIR, dirname, '**/*.[hc]'),
+                                  recursive=True):
+            with open(filename) as file:
+                for name in _find_capi_vars(file):
+                    if name in capi_vars:
+                        assert not filename.endswith('.c')
+                        assert capi_vars[name].endswith('.c')
+                    capi_vars[name] = filename
+    return capi_vars
+
+
+def _find_capi_vars(lines):
+    for line in lines:
+        if not line.startswith('PyAPI_DATA'):
+            continue
+        assert '{' not in line
+        match = CAPI_REGEX.match(line)
+        assert match
+        names, = match.groups()
+        for name in names.split(', '):
+            yield name
+
+
+def _read_global_names(filename):
+    # These variables are shared between all interpreters in the process.
+    with open(filename) as file:
+        return {line.partition('#')[0].strip()
+                for line in file
+                if line.strip() and not line.startswith('#')}
+
+
+def _is_global_var(name, globalnames):
+    if _is_autogen_var(name):
+        return True
+    if _is_type_var(name):
+        return True
+    if _is_module(name):
+        return True
+    if _is_exception(name):
+        return True
+    if _is_compiler(name):
+        return True
+    return name in globalnames
+
+
+def _is_autogen_var(name):
+    return (
+        name.startswith('PyId_') or
+        '.' in name or
+        # Objects/typeobject.c
+        name.startswith('op_id.') or
+        name.startswith('rop_id.') or
+        # Python/graminit.c
+        name.startswith('arcs_') or
+        name.startswith('states_')
+        )
+
+
+def _is_type_var(name):
+    if name.endswith(('Type', '_Type', '_type')):  # XXX Always a static type?
+        return True
+    if name.endswith('_desc'):  # for structseq types
+        return True
+    return (
+        name.startswith('doc_') or
+        name.endswith(('_doc', '__doc__', '_docstring')) or
+        name.endswith('_methods') or
+        name.endswith('_fields') or
+        name.endswith(('_memberlist', '_members')) or
+        name.endswith('_slots') or
+        name.endswith(('_getset', '_getsets', '_getsetlist')) or
+        name.endswith('_as_mapping') or
+        name.endswith('_as_number') or
+        name.endswith('_as_sequence') or
+        name.endswith('_as_buffer') or
+        name.endswith('_as_async')
+        )
+
+
+def _is_module(name):
+    if name.endswith(('_functions', 'Methods', '_Methods')):
+        return True
+    if name == 'module_def':
+        return True
+    if name == 'initialized':
+        return True
+    return name.endswith(('module', '_Module'))
+
+
+def _is_exception(name):
+    # Other vars are enumerated in globals-core.txt.
+    if not name.startswith(('PyExc_', '_PyExc_')):
+        return False
+    return name.endswith(('Error', 'Warning'))
+
+
+def _is_compiler(name):
+    return (
+        # Python/Pythyon-ast.c
+        name.endswith('_type') or
+        name.endswith('_singleton') or
+        name.endswith('_attributes')
+        )
+
+
+class Var(namedtuple('Var', 'name kind scope capi filename')):
+
+    @classmethod
+    def parse_nm(cls, line, expected, ignored, capi_vars, globalnames):
+        _, _, line = line.partition(' ')  # strip off the address
+        line = line.strip()
+        kind, _, line = line.partition(' ')
+        if kind in ignored or ():
+            return None
+        elif kind not in expected or ():
+            raise RuntimeError('unsupported NM type {!r}'.format(kind))
+
+        name, _, filename = line.partition('\t')
+        name = name.strip()
+        if _is_autogen_var(name):
+            return None
+        if _is_global_var(name, globalnames):
+            scope = 'global'
+        else:
+            scope = None
+        capi = (name in capi_vars or ())
+        if filename:
+            filename = os.path.relpath(filename.partition(':')[0])
+        return cls(name, kind, scope, capi, filename or '~???~')
+
+    @property
+    def external(self):
+        return self.kind.isupper()
+
+
+def find_vars(root, globals_filename=GLOBALS_FILE):
+    python = os.path.join(root, 'python')
+    if not os.path.exists(python):
+        raise RuntimeError('python binary missing (need to build it first?)')
+    capi_vars = find_capi_vars(root)
+    globalnames = _read_global_names(globals_filename)
+
+    nm = shutil.which('nm')
+    if nm is None:
+        # XXX Use dumpbin.exe /SYMBOLS on Windows.
+        raise NotImplementedError
+    else:
+        yield from (var
+                    for var in _find_var_symbols(python, nm, capi_vars,
+                                                 globalnames)
+                    if var.name not in IGNORED_VARS)
+
+
+NM_FUNCS = set('Tt')
+NM_PUBLIC_VARS = set('BD')
+NM_PRIVATE_VARS = set('bd')
+NM_VARS = NM_PUBLIC_VARS | NM_PRIVATE_VARS
+NM_DATA = set('Rr')
+NM_OTHER = set('ACGgiINpSsuUVvWw-?')
+NM_IGNORED = NM_FUNCS | NM_DATA | NM_OTHER
+
+
+def _find_var_symbols(python, nm, capi_vars, globalnames):
+    args = [nm,
+            '--line-numbers',
+            python]
+    out = subprocess.check_output(args)
+    for line in out.decode('utf-8').splitlines():
+        var = Var.parse_nm(line, NM_VARS, NM_IGNORED, capi_vars, globalnames)
+        if var is None:
+            continue
+        yield var
+
+
+#######################################
+
+class Filter(namedtuple('Filter', 'name op value action')):
+
+    @classmethod
+    def parse(cls, raw):
+        action = '+'
+        if raw.startswith(('+', '-')):
+            action = raw[0]
+            raw = raw[1:]
+        # XXX Support < and >?
+        name, op, value = raw.partition('=')
+        return cls(name, op, value, action)
+
+    def check(self, var):
+        value = getattr(var, self.name, None)
+        if not self.op:
+            matched = bool(value)
+        elif self.op == '=':
+            matched = (value == self.value)
+        else:
+            raise NotImplementedError
+
+        if self.action == '+':
+            return matched
+        elif self.action == '-':
+            return not matched
+        else:
+            raise NotImplementedError
+
+
+def filter_var(var, filters):
+    for filter in filters:
+        if not filter.check(var):
+            return False
+    return True
+
+
+def make_sort_key(spec):
+    columns = [(col.strip('_'), '_' if col.startswith('_') else '')
+               for col in spec]
+    def sort_key(var):
+        return tuple(getattr(var, col).lstrip(prefix)
+                     for col, prefix in columns)
+    return sort_key
+
+
+def make_groups(allvars, spec):
+    group = spec
+    groups = {}
+    for var in allvars:
+        value = getattr(var, group)
+        key = '{}: {}'.format(group, value)
+        try:
+            groupvars = groups[key]
+        except KeyError:
+            groupvars = groups[key] = []
+        groupvars.append(var)
+    return groups
+
+
+def format_groups(groups, columns, fmts, widths):
+    for group in sorted(groups):
+        groupvars = groups[group]
+        yield '', 0
+        yield '  # {}'.format(group), 0
+        yield from format_vars(groupvars, columns, fmts, widths)
+
+
+def format_vars(allvars, columns, fmts, widths):
+    fmt = ' '.join(fmts[col] for col in columns)
+    fmt = ' ' + fmt.replace(' ', '   ') + ' '  # for div margin
+    header = fmt.replace(':', ':^').format(*(col.upper() for col in columns))
+    yield header, 0
+    div = ' '.join('-'*(widths[col]+2) for col in columns)
+    yield div, 0
+    for var in allvars:
+        values = (getattr(var, col) for col in columns)
+        row = fmt.format(*('X' if val is True else val or ''
+                           for val in values))
+        yield row, 1
+    yield div, 0
+
+
+#######################################
+
+COLUMNS = 'name,external,capi,scope,filename'
+COLUMN_NAMES = COLUMNS.split(',')
+
+COLUMN_WIDTHS = {col: len(col)
+                 for col in COLUMN_NAMES}
+COLUMN_WIDTHS.update({
+        'name': 50,
+        'scope': 7,
+        'filename': 40,
+        })
+COLUMN_FORMATS = {col: '{:%s}' % width
+                  for col, width in COLUMN_WIDTHS.items()}
+for col in COLUMN_FORMATS:
+    if COLUMN_WIDTHS[col] == len(col):
+        COLUMN_FORMATS[col] = COLUMN_FORMATS[col].replace(':', ':^')
+
+
+def _parse_filters_arg(raw, error):
+    filters = []
+    for value in raw.split(','):
+        value=value.strip()
+        if not value:
+            continue
+        try:
+            filter = Filter.parse(value)
+            if filter.name not in COLUMN_NAMES:
+                raise Exception('unsupported column {!r}'.format(filter.name))
+        except Exception as e:
+            error('bad filter {!r}: {}'.format(raw, e))
+        filters.append(filter)
+    return filters
+
+
+def _parse_columns_arg(raw, error):
+    columns = raw.split(',')
+    for column in columns:
+        if column not in COLUMN_NAMES:
+            error('unsupported column {!r}'.format(column))
+    return columns
+
+
+def _parse_sort_arg(raw, error):
+    sort = raw.split(',')
+    for column in sort:
+        if column.lstrip('_') not in COLUMN_NAMES:
+            error('unsupported column {!r}'.format(column))
+    return sort
+
+
+def _parse_group_arg(raw, error):
+    if not raw:
+        return raw
+    group = raw
+    if group not in COLUMN_NAMES:
+        error('unsupported column {!r}'.format(group))
+    if group != 'filename':
+        error('unsupported group {!r}'.format(group))
+    return group
+
+
+def parse_args(argv=None):
+    if argv is None:
+        argv = sys.argv[1:]
+
+    import argparse
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument('-v', '--verbose', action='count', default=0)
+    parser.add_argument('-q', '--quiet', action='count', default=0)
+
+    parser.add_argument('--filters', default='-scope',
+                        help='[[-]<COLUMN>[=<GLOB>]] ...')
+
+    parser.add_argument('--columns', default=COLUMNS,
+                        help='a comma-separated list of columns to show')
+    parser.add_argument('--sort', default='filename,_name',
+                        help='a comma-separated list of columns to sort')
+    parser.add_argument('--group',
+                        help='group by the given column name (- to not group)')
+
+    parser.add_argument('--rc-on-match', dest='rc', type=int)
+
+    parser.add_argument('filename', nargs='?', default=GLOBALS_FILE)
+
+    args = parser.parse_args(argv)
+
+    verbose = vars(args).pop('verbose', 0)
+    quiet = vars(args).pop('quiet', 0)
+    args.verbosity = max(0, VERBOSITY + verbose - quiet)
+
+    if args.sort.startswith('filename') and not args.group:
+        args.group = 'filename'
+
+    if args.rc is None:
+        if '-scope=core' in args.filters or 'core' not in args.filters:
+            args.rc = 0
+        else:
+            args.rc = 1
+
+    args.filters = _parse_filters_arg(args.filters, parser.error)
+    args.columns = _parse_columns_arg(args.columns, parser.error)
+    args.sort = _parse_sort_arg(args.sort, parser.error)
+    args.group = _parse_group_arg(args.group, parser.error)
+
+    return args
+
+
+def main(root=ROOT_DIR, filename=GLOBALS_FILE,
+         filters=None, columns=COLUMN_NAMES, sort=None, group=None,
+         verbosity=VERBOSITY, rc=1):
+
+    log = lambda msg: ...
+    if verbosity >= 2:
+        log = lambda msg: print(msg)
+
+    allvars = (var
+               for var in find_vars(root, filename)
+               if filter_var(var, filters))
+    if sort:
+        allvars = sorted(allvars, key=make_sort_key(sort))
+
+    if group:
+        try:
+            columns.remove(group)
+        except ValueError:
+            pass
+        grouped = make_groups(allvars, group)
+        lines = format_groups(grouped, columns, COLUMN_FORMATS, COLUMN_WIDTHS)
+    else:
+        lines = format_vars(allvars, columns, COLUMN_FORMATS, COLUMN_WIDTHS)
+
+    total = 0
+    for line, count in lines:
+        total += count
+        log(line)
+    log('\ntotal: {}'.format(total))
+
+    if total and rc:
+        print('ERROR: found unsafe globals', file=sys.stderr)
+        return rc
+    return 0
+
+
+if __name__ == '__main__':
+    args = parse_args()
+    sys.exit(
+            main(**vars(args)))
diff --git a/Tools/c-globals/ignored-globals.txt b/Tools/c-globals/ignored-globals.txt
new file mode 100644
index 0000000..4fafba6
--- /dev/null
+++ b/Tools/c-globals/ignored-globals.txt
@@ -0,0 +1,494 @@
+# All variables declared here are shared between all interpreters
+# in a single process.  That means that they must not be changed
+# unless that change should apply to all interpreters.
+#
+# See check-c-globals.py.
+#
+# Many generic names are handled via the script:
+#
+# * most exceptions and all warnings handled via _is_exception()
+# * for builtin modules, generic names are handled via _is_module()
+# * generic names for static types handled via _is_type_var()
+# * AST vars handled via _is_compiler()
+
+
+#######################################
+# main
+
+# Modules/getpath.c
+exec_prefix
+module_search_path
+prefix
+progpath
+
+# Modules/main.c
+orig_argc
+orig_argv
+
+# Python/getopt.c
+opt_ptr
+_PyOS_optarg
+_PyOS_opterr
+_PyOS_optind
+
+
+#######################################
+# REPL
+
+# Parser/myreadline.c
+PyOS_InputHook
+PyOS_ReadlineFunctionPointer
+_PyOS_ReadlineLock
+_PyOS_ReadlineTState
+
+
+#######################################
+# state
+
+# Python/dtoa.c
+p5s
+pmem_next  # very slight race
+private_mem  # very slight race
+
+# Python/import.c
+# For the moment the import lock stays global.  Ultimately there should
+# be a global lock for extension modules and a per-interpreter lock.
+import_lock
+import_lock_level
+import_lock_thread
+
+# Python/pylifecycle.c
+_PyRuntime
+
+
+#---------------------------------
+# module globals (PyObject)
+
+# Modules/_functoolsmodule.c
+kwd_mark
+
+# Modules/_localemodule.c
+Error
+
+# Modules/_threadmodule.c
+ThreadError
+
+# Modules/_tracemalloc.c
+unknown_filename
+
+# Modules/gcmodule.c
+gc_str
+
+# Modules/posixmodule.c
+billion
+posix_putenv_garbage
+
+# Modules/signalmodule.c
+DefaultHandler
+IgnoreHandler
+IntHandler
+ItimerError
+
+# Modules/zipimport.c
+ZipImportError
+zip_directory_cache
+
+
+#---------------------------------
+# module globals (other)
+
+# Modules/_tracemalloc.c
+allocators
+tables_lock
+tracemalloc_config
+tracemalloc_empty_traceback
+tracemalloc_filenames
+tracemalloc_peak_traced_memory
+tracemalloc_reentrant_key
+tracemalloc_traceback
+tracemalloc_tracebacks
+tracemalloc_traced_memory
+tracemalloc_traces
+
+# Modules/faulthandler.c
+fatal_error
+faulthandler_handlers
+old_stack
+stack
+thread
+user_signals
+
+# Modules/posixmodule.c
+posix_constants_confstr
+posix_constants_pathconf
+posix_constants_sysconf
+_stat_float_times  # deprecated, __main__-only
+structseq_new
+ticks_per_second
+
+# Modules/signalmodule.c
+Handlers  # main thread only
+is_tripped  # main thread only
+main_pid
+main_thread
+old_siginthandler
+wakeup_fd  # main thread only
+
+# Modules/zipimport.c
+zip_searchorder
+
+# Python/bltinmodule.c
+Py_FileSystemDefaultEncodeErrors
+Py_FileSystemDefaultEncoding
+Py_HasFileSystemDefaultEncoding
+
+# Python/sysmodule.c
+_PySys_ImplCacheTag
+_PySys_ImplName
+
+
+#---------------------------------
+# freelists
+
+# Modules/_collectionsmodule.c
+freeblocks
+numfreeblocks
+
+# Objects/classobject.c
+free_list
+numfree
+
+# Objects/dictobject.c
+free_list
+keys_free_list
+numfree
+numfreekeys
+
+# Objects/exceptions.c
+memerrors_freelist
+memerrors_numfree
+
+# Objects/floatobject.c
+free_list
+numfree
+
+# Objects/frameobject.c
+free_list
+numfree
+
+# Objects/genobject.c
+ag_asend_freelist
+ag_asend_freelist_free
+ag_value_freelist
+ag_value_freelist_free
+
+# Objects/listobject.c
+free_list
+numfree
+
+# Objects/methodobject.c
+free_list
+numfree
+
+# Objects/sliceobject.c
+slice_cache  # slight race
+
+# Objects/tupleobject.c
+free_list
+numfree
+
+# Python/dtoa.c
+freelist  # very slight race
+
+
+#---------------------------------
+# caches (PyObject)
+
+# Objects/typeobject.c
+method_cache  # only for static types
+next_version_tag  # only for static types
+
+# Python/dynload_shlib.c
+handles  # slight race during import
+nhandles  # slight race during import
+
+# Python/import.c
+extensions  # slight race on init during import
+
+
+#---------------------------------
+# caches (other)
+
+# Python/bootstrap_hash.c
+urandom_cache
+
+# Python/modsupport.c
+_Py_PackageContext  # Slight race during import!  Move to PyThreadState?
+
+
+#---------------------------------
+# counters
+
+# Objects/bytesobject.c
+null_strings
+one_strings
+
+# Objects/dictobject.c
+pydict_global_version
+
+# Objects/moduleobject.c
+max_module_number  # slight race during import
+
+
+#######################################
+# constants
+
+#---------------------------------
+# singletons
+
+# Objects/boolobject.c
+_Py_FalseStruct
+_Py_TrueStruct
+
+# Objects/object.c
+_Py_NoneStruct
+_Py_NotImplementedStruct
+
+# Objects/sliceobject.c
+_Py_EllipsisObject
+
+
+#---------------------------------
+# constants (other)
+
+# Modules/config.c
+_PyImport_Inittab
+
+# Objects/bytearrayobject.c
+_PyByteArray_empty_string
+
+# Objects/dictobject.c
+empty_keys_struct
+empty_values
+
+# Objects/floatobject.c
+detected_double_format
+detected_float_format
+double_format
+float_format
+
+# Objects/longobject.c
+_PyLong_DigitValue
+
+# Objects/object.c
+_Py_SwappedOp
+
+# Objects/obmalloc.c
+_PyMem_Debug
+
+# Objects/setobject.c
+_dummy_struct
+
+# Objects/structseq.c
+PyStructSequence_UnnamedField
+
+# Objects/typeobject.c
+name_op
+slotdefs  # almost
+slotdefs_initialized  # almost
+subtype_getsets_dict_only
+subtype_getsets_full
+subtype_getsets_weakref_only
+tp_new_methoddef
+
+# Objects/unicodeobject.c
+bloom_linebreak
+static_strings  # slight race
+
+# Parser/tokenizer.c
+_PyParser_TokenNames
+
+# Python/Python-ast.c
+alias_fields
+
+# Python/codecs.c
+Py_hexdigits
+ucnhash_CAPI  # slight performance-only race
+
+# Python/dynload_shlib.c
+_PyImport_DynLoadFiletab
+
+# Python/fileutils.c
+_Py_open_cloexec_works
+force_ascii
+
+# Python/frozen.c
+M___hello__
+PyImport_FrozenModules
+
+# Python/graminit.c
+_PyParser_Grammar
+dfas
+labels
+
+# Python/import.c
+PyImport_Inittab
+
+# Python/pylifecycle.c
+_TARGET_LOCALES
+
+
+#---------------------------------
+# initialized (PyObject)
+
+# Objects/bytesobject.c
+characters
+nullstring
+
+# Objects/exceptions.c
+PyExc_RecursionErrorInst
+errnomap
+
+# Objects/longobject.c
+_PyLong_One
+_PyLong_Zero
+small_ints
+
+# Objects/setobject.c
+emptyfrozenset
+
+# Objects/unicodeobject.c
+interned  # slight race on init in PyUnicode_InternInPlace()
+unicode_empty
+unicode_latin1
+
+
+#---------------------------------
+# initialized (other)
+
+# Python/getargs.c
+static_arg_parsers
+
+# Python/pyhash.c
+PyHash_Func
+_Py_HashSecret
+_Py_HashSecret_Initialized
+
+# Python/pylifecycle.c
+_Py_StandardStreamEncoding
+_Py_StandardStreamErrors
+default_home
+env_home
+progname
+Py_BytesWarningFlag
+Py_DebugFlag
+Py_DontWriteBytecodeFlag
+Py_FrozenFlag
+Py_HashRandomizationFlag
+Py_IgnoreEnvironmentFlag
+Py_InspectFlag
+Py_InteractiveFlag
+Py_IsolatedFlag
+Py_NoSiteFlag
+Py_NoUserSiteDirectory
+Py_OptimizeFlag
+Py_QuietFlag
+Py_UnbufferedStdioFlag
+Py_UseClassExceptionsFlag
+Py_VerboseFlag
+
+
+#---------------------------------
+# types
+
+# Modules/_threadmodule.c
+Locktype
+RLocktype
+localdummytype
+localtype
+
+# Objects/exceptions.c
+PyExc_BaseException
+PyExc_Exception
+PyExc_GeneratorExit
+PyExc_KeyboardInterrupt
+PyExc_StopAsyncIteration
+PyExc_StopIteration
+PyExc_SystemExit
+_PyExc_BaseException
+_PyExc_Exception
+_PyExc_GeneratorExit
+_PyExc_KeyboardInterrupt
+_PyExc_StopAsyncIteration
+_PyExc_StopIteration
+_PyExc_SystemExit
+
+# Objects/structseq.c
+_struct_sequence_template
+
+
+#---------------------------------
+# interned strings/bytes
+
+# Modules/_io/_iomodule.c
+_PyIO_empty_bytes
+_PyIO_empty_str
+_PyIO_str_close
+_PyIO_str_closed
+_PyIO_str_decode
+_PyIO_str_encode
+_PyIO_str_fileno
+_PyIO_str_flush
+_PyIO_str_getstate
+_PyIO_str_isatty
+_PyIO_str_newlines
+_PyIO_str_nl
+_PyIO_str_read
+_PyIO_str_read1
+_PyIO_str_readable
+_PyIO_str_readall
+_PyIO_str_readinto
+_PyIO_str_readline
+_PyIO_str_reset
+_PyIO_str_seek
+_PyIO_str_seekable
+_PyIO_str_setstate
+_PyIO_str_tell
+_PyIO_str_truncate
+_PyIO_str_writable
+_PyIO_str_write
+
+# Modules/_threadmodule.c
+str_dict
+
+# Objects/boolobject.c
+false_str
+true_str
+
+# Objects/listobject.c
+indexerr
+
+# Python/symtable.c
+__class__
+dictcomp
+genexpr
+lambda
+listcomp
+setcomp
+top
+
+# Python/sysmodule.c
+whatstrings
+
+
+#######################################
+# hacks
+
+# Objects/object.c
+_Py_abstract_hack
+
+# Objects/setobject.c
+_PySet_Dummy
+
+# Python/pylifecycle.c
+_PyOS_mystrnicmp_hack