bpo-46881: Statically allocate and initialize the latin1 characters. (GH-31616)

This commit is contained in:
Kumar Aditya 2022-03-10 04:32:00 +05:30 committed by GitHub
parent e801e88744
commit 8714b6fa27
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 317 additions and 66 deletions

View File

@ -350,6 +350,14 @@ struct _Py_global_strings {
STRUCT_FOR_ID(write) STRUCT_FOR_ID(write)
STRUCT_FOR_ID(zipimporter) STRUCT_FOR_ID(zipimporter)
} identifiers; } identifiers;
struct {
PyASCIIObject _ascii;
uint8_t _data[2];
} ascii[128];
struct {
PyCompactUnicodeObject _latin1;
uint8_t _data[2];
} latin1[128];
}; };
/* End auto-generated code */ /* End auto-generated code */

View File

@ -93,26 +93,34 @@ extern "C" {
_PyBytes_SIMPLE_INIT(CH, 1) \ _PyBytes_SIMPLE_INIT(CH, 1) \
} }
#define _PyUnicode_ASCII_BASE_INIT(LITERAL, ASCII) \
{ \
.ob_base = _PyObject_IMMORTAL_INIT(&PyUnicode_Type), \
.length = sizeof(LITERAL) - 1, \
.hash = -1, \
.state = { \
.kind = 1, \
.compact = 1, \
.ascii = ASCII, \
.ready = 1, \
}, \
}
#define _PyASCIIObject_INIT(LITERAL) \ #define _PyASCIIObject_INIT(LITERAL) \
{ \ { \
._ascii = { \ ._ascii = _PyUnicode_ASCII_BASE_INIT(LITERAL, 1), \
.ob_base = _PyObject_IMMORTAL_INIT(&PyUnicode_Type), \ ._data = LITERAL \
.length = sizeof(LITERAL) - 1, \
.hash = -1, \
.state = { \
.kind = 1, \
.compact = 1, \
.ascii = 1, \
.ready = 1, \
}, \
}, \
._data = LITERAL, \
} }
#define INIT_STR(NAME, LITERAL) \ #define INIT_STR(NAME, LITERAL) \
._ ## NAME = _PyASCIIObject_INIT(LITERAL) ._ ## NAME = _PyASCIIObject_INIT(LITERAL)
#define INIT_ID(NAME) \ #define INIT_ID(NAME) \
._ ## NAME = _PyASCIIObject_INIT(#NAME) ._ ## NAME = _PyASCIIObject_INIT(#NAME)
#define _PyUnicode_LATIN1_INIT(LITERAL) \
{ \
._latin1 = { \
._base = _PyUnicode_ASCII_BASE_INIT(LITERAL, 0), \
}, \
._data = LITERAL, \
}
/* The following is auto-generated by Tools/scripts/generate_global_objects.py. */ /* The following is auto-generated by Tools/scripts/generate_global_objects.py. */
#define _Py_global_objects_INIT { \ #define _Py_global_objects_INIT { \
@ -965,6 +973,266 @@ extern "C" {
INIT_ID(write), \ INIT_ID(write), \
INIT_ID(zipimporter), \ INIT_ID(zipimporter), \
}, \ }, \
.ascii = { \
_PyASCIIObject_INIT("\x00"), \
_PyASCIIObject_INIT("\x01"), \
_PyASCIIObject_INIT("\x02"), \
_PyASCIIObject_INIT("\x03"), \
_PyASCIIObject_INIT("\x04"), \
_PyASCIIObject_INIT("\x05"), \
_PyASCIIObject_INIT("\x06"), \
_PyASCIIObject_INIT("\x07"), \
_PyASCIIObject_INIT("\x08"), \
_PyASCIIObject_INIT("\x09"), \
_PyASCIIObject_INIT("\x0a"), \
_PyASCIIObject_INIT("\x0b"), \
_PyASCIIObject_INIT("\x0c"), \
_PyASCIIObject_INIT("\x0d"), \
_PyASCIIObject_INIT("\x0e"), \
_PyASCIIObject_INIT("\x0f"), \
_PyASCIIObject_INIT("\x10"), \
_PyASCIIObject_INIT("\x11"), \
_PyASCIIObject_INIT("\x12"), \
_PyASCIIObject_INIT("\x13"), \
_PyASCIIObject_INIT("\x14"), \
_PyASCIIObject_INIT("\x15"), \
_PyASCIIObject_INIT("\x16"), \
_PyASCIIObject_INIT("\x17"), \
_PyASCIIObject_INIT("\x18"), \
_PyASCIIObject_INIT("\x19"), \
_PyASCIIObject_INIT("\x1a"), \
_PyASCIIObject_INIT("\x1b"), \
_PyASCIIObject_INIT("\x1c"), \
_PyASCIIObject_INIT("\x1d"), \
_PyASCIIObject_INIT("\x1e"), \
_PyASCIIObject_INIT("\x1f"), \
_PyASCIIObject_INIT("\x20"), \
_PyASCIIObject_INIT("\x21"), \
_PyASCIIObject_INIT("\x22"), \
_PyASCIIObject_INIT("\x23"), \
_PyASCIIObject_INIT("\x24"), \
_PyASCIIObject_INIT("\x25"), \
_PyASCIIObject_INIT("\x26"), \
_PyASCIIObject_INIT("\x27"), \
_PyASCIIObject_INIT("\x28"), \
_PyASCIIObject_INIT("\x29"), \
_PyASCIIObject_INIT("\x2a"), \
_PyASCIIObject_INIT("\x2b"), \
_PyASCIIObject_INIT("\x2c"), \
_PyASCIIObject_INIT("\x2d"), \
_PyASCIIObject_INIT("\x2e"), \
_PyASCIIObject_INIT("\x2f"), \
_PyASCIIObject_INIT("\x30"), \
_PyASCIIObject_INIT("\x31"), \
_PyASCIIObject_INIT("\x32"), \
_PyASCIIObject_INIT("\x33"), \
_PyASCIIObject_INIT("\x34"), \
_PyASCIIObject_INIT("\x35"), \
_PyASCIIObject_INIT("\x36"), \
_PyASCIIObject_INIT("\x37"), \
_PyASCIIObject_INIT("\x38"), \
_PyASCIIObject_INIT("\x39"), \
_PyASCIIObject_INIT("\x3a"), \
_PyASCIIObject_INIT("\x3b"), \
_PyASCIIObject_INIT("\x3c"), \
_PyASCIIObject_INIT("\x3d"), \
_PyASCIIObject_INIT("\x3e"), \
_PyASCIIObject_INIT("\x3f"), \
_PyASCIIObject_INIT("\x40"), \
_PyASCIIObject_INIT("\x41"), \
_PyASCIIObject_INIT("\x42"), \
_PyASCIIObject_INIT("\x43"), \
_PyASCIIObject_INIT("\x44"), \
_PyASCIIObject_INIT("\x45"), \
_PyASCIIObject_INIT("\x46"), \
_PyASCIIObject_INIT("\x47"), \
_PyASCIIObject_INIT("\x48"), \
_PyASCIIObject_INIT("\x49"), \
_PyASCIIObject_INIT("\x4a"), \
_PyASCIIObject_INIT("\x4b"), \
_PyASCIIObject_INIT("\x4c"), \
_PyASCIIObject_INIT("\x4d"), \
_PyASCIIObject_INIT("\x4e"), \
_PyASCIIObject_INIT("\x4f"), \
_PyASCIIObject_INIT("\x50"), \
_PyASCIIObject_INIT("\x51"), \
_PyASCIIObject_INIT("\x52"), \
_PyASCIIObject_INIT("\x53"), \
_PyASCIIObject_INIT("\x54"), \
_PyASCIIObject_INIT("\x55"), \
_PyASCIIObject_INIT("\x56"), \
_PyASCIIObject_INIT("\x57"), \
_PyASCIIObject_INIT("\x58"), \
_PyASCIIObject_INIT("\x59"), \
_PyASCIIObject_INIT("\x5a"), \
_PyASCIIObject_INIT("\x5b"), \
_PyASCIIObject_INIT("\x5c"), \
_PyASCIIObject_INIT("\x5d"), \
_PyASCIIObject_INIT("\x5e"), \
_PyASCIIObject_INIT("\x5f"), \
_PyASCIIObject_INIT("\x60"), \
_PyASCIIObject_INIT("\x61"), \
_PyASCIIObject_INIT("\x62"), \
_PyASCIIObject_INIT("\x63"), \
_PyASCIIObject_INIT("\x64"), \
_PyASCIIObject_INIT("\x65"), \
_PyASCIIObject_INIT("\x66"), \
_PyASCIIObject_INIT("\x67"), \
_PyASCIIObject_INIT("\x68"), \
_PyASCIIObject_INIT("\x69"), \
_PyASCIIObject_INIT("\x6a"), \
_PyASCIIObject_INIT("\x6b"), \
_PyASCIIObject_INIT("\x6c"), \
_PyASCIIObject_INIT("\x6d"), \
_PyASCIIObject_INIT("\x6e"), \
_PyASCIIObject_INIT("\x6f"), \
_PyASCIIObject_INIT("\x70"), \
_PyASCIIObject_INIT("\x71"), \
_PyASCIIObject_INIT("\x72"), \
_PyASCIIObject_INIT("\x73"), \
_PyASCIIObject_INIT("\x74"), \
_PyASCIIObject_INIT("\x75"), \
_PyASCIIObject_INIT("\x76"), \
_PyASCIIObject_INIT("\x77"), \
_PyASCIIObject_INIT("\x78"), \
_PyASCIIObject_INIT("\x79"), \
_PyASCIIObject_INIT("\x7a"), \
_PyASCIIObject_INIT("\x7b"), \
_PyASCIIObject_INIT("\x7c"), \
_PyASCIIObject_INIT("\x7d"), \
_PyASCIIObject_INIT("\x7e"), \
_PyASCIIObject_INIT("\x7f"), \
}, \
.latin1 = { \
_PyUnicode_LATIN1_INIT("\x80"), \
_PyUnicode_LATIN1_INIT("\x81"), \
_PyUnicode_LATIN1_INIT("\x82"), \
_PyUnicode_LATIN1_INIT("\x83"), \
_PyUnicode_LATIN1_INIT("\x84"), \
_PyUnicode_LATIN1_INIT("\x85"), \
_PyUnicode_LATIN1_INIT("\x86"), \
_PyUnicode_LATIN1_INIT("\x87"), \
_PyUnicode_LATIN1_INIT("\x88"), \
_PyUnicode_LATIN1_INIT("\x89"), \
_PyUnicode_LATIN1_INIT("\x8a"), \
_PyUnicode_LATIN1_INIT("\x8b"), \
_PyUnicode_LATIN1_INIT("\x8c"), \
_PyUnicode_LATIN1_INIT("\x8d"), \
_PyUnicode_LATIN1_INIT("\x8e"), \
_PyUnicode_LATIN1_INIT("\x8f"), \
_PyUnicode_LATIN1_INIT("\x90"), \
_PyUnicode_LATIN1_INIT("\x91"), \
_PyUnicode_LATIN1_INIT("\x92"), \
_PyUnicode_LATIN1_INIT("\x93"), \
_PyUnicode_LATIN1_INIT("\x94"), \
_PyUnicode_LATIN1_INIT("\x95"), \
_PyUnicode_LATIN1_INIT("\x96"), \
_PyUnicode_LATIN1_INIT("\x97"), \
_PyUnicode_LATIN1_INIT("\x98"), \
_PyUnicode_LATIN1_INIT("\x99"), \
_PyUnicode_LATIN1_INIT("\x9a"), \
_PyUnicode_LATIN1_INIT("\x9b"), \
_PyUnicode_LATIN1_INIT("\x9c"), \
_PyUnicode_LATIN1_INIT("\x9d"), \
_PyUnicode_LATIN1_INIT("\x9e"), \
_PyUnicode_LATIN1_INIT("\x9f"), \
_PyUnicode_LATIN1_INIT("\xa0"), \
_PyUnicode_LATIN1_INIT("\xa1"), \
_PyUnicode_LATIN1_INIT("\xa2"), \
_PyUnicode_LATIN1_INIT("\xa3"), \
_PyUnicode_LATIN1_INIT("\xa4"), \
_PyUnicode_LATIN1_INIT("\xa5"), \
_PyUnicode_LATIN1_INIT("\xa6"), \
_PyUnicode_LATIN1_INIT("\xa7"), \
_PyUnicode_LATIN1_INIT("\xa8"), \
_PyUnicode_LATIN1_INIT("\xa9"), \
_PyUnicode_LATIN1_INIT("\xaa"), \
_PyUnicode_LATIN1_INIT("\xab"), \
_PyUnicode_LATIN1_INIT("\xac"), \
_PyUnicode_LATIN1_INIT("\xad"), \
_PyUnicode_LATIN1_INIT("\xae"), \
_PyUnicode_LATIN1_INIT("\xaf"), \
_PyUnicode_LATIN1_INIT("\xb0"), \
_PyUnicode_LATIN1_INIT("\xb1"), \
_PyUnicode_LATIN1_INIT("\xb2"), \
_PyUnicode_LATIN1_INIT("\xb3"), \
_PyUnicode_LATIN1_INIT("\xb4"), \
_PyUnicode_LATIN1_INIT("\xb5"), \
_PyUnicode_LATIN1_INIT("\xb6"), \
_PyUnicode_LATIN1_INIT("\xb7"), \
_PyUnicode_LATIN1_INIT("\xb8"), \
_PyUnicode_LATIN1_INIT("\xb9"), \
_PyUnicode_LATIN1_INIT("\xba"), \
_PyUnicode_LATIN1_INIT("\xbb"), \
_PyUnicode_LATIN1_INIT("\xbc"), \
_PyUnicode_LATIN1_INIT("\xbd"), \
_PyUnicode_LATIN1_INIT("\xbe"), \
_PyUnicode_LATIN1_INIT("\xbf"), \
_PyUnicode_LATIN1_INIT("\xc0"), \
_PyUnicode_LATIN1_INIT("\xc1"), \
_PyUnicode_LATIN1_INIT("\xc2"), \
_PyUnicode_LATIN1_INIT("\xc3"), \
_PyUnicode_LATIN1_INIT("\xc4"), \
_PyUnicode_LATIN1_INIT("\xc5"), \
_PyUnicode_LATIN1_INIT("\xc6"), \
_PyUnicode_LATIN1_INIT("\xc7"), \
_PyUnicode_LATIN1_INIT("\xc8"), \
_PyUnicode_LATIN1_INIT("\xc9"), \
_PyUnicode_LATIN1_INIT("\xca"), \
_PyUnicode_LATIN1_INIT("\xcb"), \
_PyUnicode_LATIN1_INIT("\xcc"), \
_PyUnicode_LATIN1_INIT("\xcd"), \
_PyUnicode_LATIN1_INIT("\xce"), \
_PyUnicode_LATIN1_INIT("\xcf"), \
_PyUnicode_LATIN1_INIT("\xd0"), \
_PyUnicode_LATIN1_INIT("\xd1"), \
_PyUnicode_LATIN1_INIT("\xd2"), \
_PyUnicode_LATIN1_INIT("\xd3"), \
_PyUnicode_LATIN1_INIT("\xd4"), \
_PyUnicode_LATIN1_INIT("\xd5"), \
_PyUnicode_LATIN1_INIT("\xd6"), \
_PyUnicode_LATIN1_INIT("\xd7"), \
_PyUnicode_LATIN1_INIT("\xd8"), \
_PyUnicode_LATIN1_INIT("\xd9"), \
_PyUnicode_LATIN1_INIT("\xda"), \
_PyUnicode_LATIN1_INIT("\xdb"), \
_PyUnicode_LATIN1_INIT("\xdc"), \
_PyUnicode_LATIN1_INIT("\xdd"), \
_PyUnicode_LATIN1_INIT("\xde"), \
_PyUnicode_LATIN1_INIT("\xdf"), \
_PyUnicode_LATIN1_INIT("\xe0"), \
_PyUnicode_LATIN1_INIT("\xe1"), \
_PyUnicode_LATIN1_INIT("\xe2"), \
_PyUnicode_LATIN1_INIT("\xe3"), \
_PyUnicode_LATIN1_INIT("\xe4"), \
_PyUnicode_LATIN1_INIT("\xe5"), \
_PyUnicode_LATIN1_INIT("\xe6"), \
_PyUnicode_LATIN1_INIT("\xe7"), \
_PyUnicode_LATIN1_INIT("\xe8"), \
_PyUnicode_LATIN1_INIT("\xe9"), \
_PyUnicode_LATIN1_INIT("\xea"), \
_PyUnicode_LATIN1_INIT("\xeb"), \
_PyUnicode_LATIN1_INIT("\xec"), \
_PyUnicode_LATIN1_INIT("\xed"), \
_PyUnicode_LATIN1_INIT("\xee"), \
_PyUnicode_LATIN1_INIT("\xef"), \
_PyUnicode_LATIN1_INIT("\xf0"), \
_PyUnicode_LATIN1_INIT("\xf1"), \
_PyUnicode_LATIN1_INIT("\xf2"), \
_PyUnicode_LATIN1_INIT("\xf3"), \
_PyUnicode_LATIN1_INIT("\xf4"), \
_PyUnicode_LATIN1_INIT("\xf5"), \
_PyUnicode_LATIN1_INIT("\xf6"), \
_PyUnicode_LATIN1_INIT("\xf7"), \
_PyUnicode_LATIN1_INIT("\xf8"), \
_PyUnicode_LATIN1_INIT("\xf9"), \
_PyUnicode_LATIN1_INIT("\xfa"), \
_PyUnicode_LATIN1_INIT("\xfb"), \
_PyUnicode_LATIN1_INIT("\xfc"), \
_PyUnicode_LATIN1_INIT("\xfd"), \
_PyUnicode_LATIN1_INIT("\xfe"), \
_PyUnicode_LATIN1_INIT("\xff"), \
}, \
}, \ }, \
\ \
.tuple_empty = { \ .tuple_empty = { \

View File

@ -44,9 +44,6 @@ struct _Py_unicode_ids {
}; };
struct _Py_unicode_state { struct _Py_unicode_state {
/* Single character Unicode strings in the Latin-1 range are being
shared as well. */
PyObject *latin1[256];
struct _Py_unicode_fs_codec fs_codec; struct _Py_unicode_fs_codec fs_codec;
// Unicode identifiers (_Py_Identifier): see _PyUnicode_FromId() // Unicode identifiers (_Py_Identifier): see _PyUnicode_FromId()

View File

@ -0,0 +1 @@
Statically allocate and initialize the latin1 characters.

View File

@ -206,6 +206,11 @@ extern "C" {
*_to++ = (to_type) *_iter++; \ *_to++ = (to_type) *_iter++; \
} while (0) } while (0)
#define LATIN1(ch) \
(ch < 128 \
? (PyObject*)&_Py_SINGLETON(strings).ascii[ch] \
: (PyObject*)&_Py_SINGLETON(strings).latin1[ch - 128])
#ifdef MS_WINDOWS #ifdef MS_WINDOWS
/* On Windows, overallocate by 50% is the best factor */ /* On Windows, overallocate by 50% is the best factor */
# define OVERALLOCATE_FACTOR 2 # define OVERALLOCATE_FACTOR 2
@ -249,14 +254,6 @@ static int unicode_is_singleton(PyObject *unicode);
#endif #endif
static struct _Py_unicode_state*
get_unicode_state(void)
{
PyInterpreterState *interp = _PyInterpreterState_GET();
return &interp->unicode;
}
// Return a borrowed reference to the empty string singleton. // Return a borrowed reference to the empty string singleton.
static inline PyObject* unicode_get_empty(void) static inline PyObject* unicode_get_empty(void)
{ {
@ -680,24 +677,10 @@ unicode_result_ready(PyObject *unicode)
if (kind == PyUnicode_1BYTE_KIND) { if (kind == PyUnicode_1BYTE_KIND) {
const Py_UCS1 *data = PyUnicode_1BYTE_DATA(unicode); const Py_UCS1 *data = PyUnicode_1BYTE_DATA(unicode);
Py_UCS1 ch = data[0]; Py_UCS1 ch = data[0];
struct _Py_unicode_state *state = get_unicode_state(); if (unicode != LATIN1(ch)) {
PyObject *latin1_char = state->latin1[ch]; Py_DECREF(unicode);
if (latin1_char != NULL) {
if (unicode != latin1_char) {
Py_INCREF(latin1_char);
Py_DECREF(unicode);
}
return latin1_char;
} }
else { return get_latin1_char(ch);
assert(_PyUnicode_CheckConsistency(unicode, 1));
Py_INCREF(unicode);
state->latin1[ch] = unicode;
return unicode;
}
}
else {
assert(PyUnicode_READ_CHAR(unicode, 0) >= 256);
} }
} }
@ -1990,11 +1973,10 @@ unicode_is_singleton(PyObject *unicode)
return 1; return 1;
} }
struct _Py_unicode_state *state = get_unicode_state();
PyASCIIObject *ascii = (PyASCIIObject *)unicode; PyASCIIObject *ascii = (PyASCIIObject *)unicode;
if (ascii->state.kind != PyUnicode_WCHAR_KIND && ascii->length == 1) { if (ascii->state.kind != PyUnicode_WCHAR_KIND && ascii->length == 1) {
Py_UCS4 ch = PyUnicode_READ_CHAR(unicode, 0); Py_UCS4 ch = PyUnicode_READ_CHAR(unicode, 0);
if (ch < 256 && state->latin1[ch] == unicode) { if (ch < 256 && LATIN1(ch) == unicode) {
return 1; return 1;
} }
} }
@ -2137,25 +2119,7 @@ unicode_write_cstr(PyObject *unicode, Py_ssize_t index,
static PyObject* static PyObject*
get_latin1_char(Py_UCS1 ch) get_latin1_char(Py_UCS1 ch)
{ {
struct _Py_unicode_state *state = get_unicode_state(); return Py_NewRef(LATIN1(ch));
PyObject *unicode = state->latin1[ch];
if (unicode) {
Py_INCREF(unicode);
return unicode;
}
unicode = PyUnicode_New(1, ch);
if (!unicode) {
return NULL;
}
PyUnicode_1BYTE_DATA(unicode)[0] = ch;
assert(_PyUnicode_CheckConsistency(unicode, 1));
Py_INCREF(unicode);
state->latin1[ch] = unicode;
return unicode;
} }
static PyObject* static PyObject*
@ -15535,6 +15499,10 @@ _PyUnicode_InitGlobalObjects(PyInterpreterState *interp)
#ifdef Py_DEBUG #ifdef Py_DEBUG
assert(_PyUnicode_CheckConsistency(&_Py_STR(empty), 1)); assert(_PyUnicode_CheckConsistency(&_Py_STR(empty), 1));
for (int i = 0; i < 256; i++) {
assert(_PyUnicode_CheckConsistency(LATIN1(i), 1));
}
#endif #endif
return _PyStatus_OK(); return _PyStatus_OK();
@ -16113,10 +16081,6 @@ _PyUnicode_Fini(PyInterpreterState *interp)
_PyUnicode_FiniEncodings(&state->fs_codec); _PyUnicode_FiniEncodings(&state->fs_codec);
unicode_clear_identifiers(state); unicode_clear_identifiers(state);
for (Py_ssize_t i = 0; i < 256; i++) {
Py_CLEAR(state->latin1[i]);
}
} }

View File

@ -196,6 +196,13 @@ def generate_global_strings(identifiers, strings):
for name in sorted(identifiers): for name in sorted(identifiers):
assert name.isidentifier(), name assert name.isidentifier(), name
printer.write(f'STRUCT_FOR_ID({name})') printer.write(f'STRUCT_FOR_ID({name})')
with printer.block('struct', ' ascii[128];'):
printer.write("PyASCIIObject _ascii;")
printer.write("uint8_t _data[2];")
with printer.block('struct', ' latin1[128];'):
printer.write("PyCompactUnicodeObject _latin1;")
printer.write("uint8_t _data[2];")
printer.write(END) printer.write(END)
printer.write(after) printer.write(after)
@ -252,6 +259,12 @@ def generate_runtime_init(identifiers, strings):
for name in sorted(identifiers): for name in sorted(identifiers):
assert name.isidentifier(), name assert name.isidentifier(), name
printer.write(f'INIT_ID({name}),') printer.write(f'INIT_ID({name}),')
with printer.block('.ascii =', ','):
for i in range(128):
printer.write(f'_PyASCIIObject_INIT("\\x{i:02x}"),')
with printer.block('.latin1 =', ','):
for i in range(128, 256):
printer.write(f'_PyUnicode_LATIN1_INIT("\\x{i:02x}"),')
printer.write('') printer.write('')
with printer.block('.tuple_empty =', ','): with printer.block('.tuple_empty =', ','):
printer.write('.ob_base = _PyVarObject_IMMORTAL_INIT(&PyTuple_Type, 0)') printer.write('.ob_base = _PyVarObject_IMMORTAL_INIT(&PyTuple_Type, 0)')