#include "Python.h"

#include "pycore_tuple.h" // _PyTuple_FromArray()

#include "pycore_object.h" // _PyObject_GC_TRACK()

#include "structmember.h" // PyMemberDef

#include "pycore_structseq.h" // PyStructSequence_InitType()

#include "pycore_initconfig.h" // _PyStatus_OK()

static const char visible_length_key[] = "n_sequence_fields";

static const char real_length_key[] = "n_fields";

static const char unnamed_fields_key[] = "n_unnamed_fields";

static const char match_args_key[] = "__match_args__";

const char * const PyStructSequence_UnnamedField = "unnamed field";

static Py_ssize_t

get_type_attr_as_size(PyTypeObject *tp, PyObject *name)

{

PyObject *v = PyDict_GetItemWithError(tp->tp_dict, name);

if (v == NULL && !PyErr_Occurred()) {

PyErr_Format(PyExc_TypeError,

"Missed attribute '%U' of type %s",

name, tp->tp_name);

}

return PyLong_AsSsize_t(v);

}

#define VISIBLE_SIZE(op) Py_SIZE(op)

#define VISIBLE_SIZE_TP(tp) \

get_type_attr_as_size(tp, &_Py_ID(n_sequence_fields))

#define REAL_SIZE_TP(tp) \

get_type_attr_as_size(tp, &_Py_ID(n_fields))

#define REAL_SIZE(op) REAL_SIZE_TP(Py_TYPE(op))

#define UNNAMED_FIELDS_TP(tp) \

get_type_attr_as_size(tp, &_Py_ID(n_unnamed_fields))

#define UNNAMED_FIELDS(op) UNNAMED_FIELDS_TP(Py_TYPE(op))

PyObject *

PyStructSequence_New(PyTypeObject *type)

{

PyStructSequence *obj;

Py_ssize_t size = REAL_SIZE_TP(type), i;

if (size < 0) {

return NULL;

}

Py_ssize_t vsize = VISIBLE_SIZE_TP(type);

if (vsize < 0) {

return NULL;

}

obj = PyObject_GC_NewVar(PyStructSequence, type, size);

if (obj == NULL)

return NULL;

/* Hack the size of the variable object, so invisible fields don't appear

Py_SET_SIZE(obj, vsize);

for (i = 0; i < size; i++)

obj->ob_item[i] = NULL;

return (PyObject*)obj;

}

PyStructSequence_SetItem(PyObject* op, Py_ssize_t i, PyObject* v)

{

PyStructSequence_SET_ITEM(op, i, v);

}

PyStructSequence_GetItem(PyObject* op, Py_ssize_t i)

{

return PyStructSequence_GET_ITEM(op, i);

}

static int

structseq_traverse(PyStructSequence *obj, visitproc visit, void *arg)

{

if (Py_TYPE(obj)->tp_flags & Py_TPFLAGS_HEAPTYPE) {

Py_VISIT(Py_TYPE(obj));

}

Py_ssize_t i, size;

size = REAL_SIZE(obj);

for (i = 0; i < size; ++i) {

Py_VISIT(obj->ob_item[i]);

}

return 0;

}

static void

structseq_dealloc(PyStructSequence *obj)

{

Py_ssize_t i, size;

PyObject_GC_UnTrack(obj);

PyTypeObject *tp = Py_TYPE(obj);

size = REAL_SIZE(obj);

for (i = 0; i < size; ++i) {

Py_XDECREF(obj->ob_item[i]);

}

PyObject_GC_Del(obj);

if (_PyType_HasFeature(tp, Py_TPFLAGS_HEAPTYPE)) {

Py_DECREF(tp);

}

}

#include "clinic/structseq.c.h"

static PyObject *

structseq_new_impl(PyTypeObject *type, PyObject *arg, PyObject *dict)

{

PyObject *ob;

PyStructSequence *res = NULL;

Py_ssize_t len, min_len, max_len, i, n_unnamed_fields;

min_len = VISIBLE_SIZE_TP(type);

if (min_len < 0) {

return NULL;

}

max_len = REAL_SIZE_TP(type);

if (max_len < 0) {

return NULL;

}

n_unnamed_fields = UNNAMED_FIELDS_TP(type);

if (n_unnamed_fields < 0) {

return NULL;

}

arg = PySequence_Fast(arg, "constructor requires a sequence");

if (!arg) {

return NULL;

}

if (dict && !PyDict_Check(dict)) {

PyErr_Format(PyExc_TypeError,

"%.500s() takes a dict as second arg, if any",

type->tp_name);

Py_DECREF(arg);

return NULL;

}

len = PySequence_Fast_GET_SIZE(arg);

if (min_len != max_len) {

if (len < min_len) {

PyErr_Format(PyExc_TypeError,

"%.500s() takes an at least %zd-sequence (%zd-sequence given)",

type->tp_name, min_len, len);

Py_DECREF(arg);

return NULL;

}

if (len > max_len) {

PyErr_Format(PyExc_TypeError,

"%.500s() takes an at most %zd-sequence (%zd-sequence given)",

type->tp_name, max_len, len);

Py_DECREF(arg);

return NULL;

}

}

else {

if (len != min_len) {

PyErr_Format(PyExc_TypeError,

"%.500s() takes a %zd-sequence (%zd-sequence given)",

type->tp_name, min_len, len);

Py_DECREF(arg);

return NULL;

}

}

res = (PyStructSequence*) PyStructSequence_New(type);

if (res == NULL) {

Py_DECREF(arg);

return NULL;

}

for (i = 0; i < len; ++i) {

PyObject *v = PySequence_Fast_GET_ITEM(arg, i);

Py_INCREF(v);

res->ob_item[i] = v;

}

Py_DECREF(arg);

for (; i < max_len; ++i) {

if (dict == NULL) {

ob = Py_None;

}

else {

ob = _PyDict_GetItemStringWithError(dict,

type->tp_members[i-n_unnamed_fields].name);

if (ob == NULL) {

if (PyErr_Occurred()) {

Py_DECREF(res);

return NULL;

}

ob = Py_None;

}

}

Py_INCREF(ob);

res->ob_item[i] = ob;

}

_PyObject_GC_TRACK(res);

return (PyObject*) res;

}

static PyObject *

structseq_repr(PyStructSequence *obj)

{

PyTypeObject *typ = Py_TYPE(obj);

_PyUnicodeWriter writer;

/* Write "typename(" */

PyObject *type_name = PyUnicode_DecodeUTF8(typ->tp_name,

strlen(typ->tp_name),

NULL);

if (type_name == NULL) {

return NULL;

}

_PyUnicodeWriter_Init(&writer);

writer.overallocate = 1;

/* count 5 characters per item: "x=1, " */

writer.min_length = (PyUnicode_GET_LENGTH(type_name) + 1

+ VISIBLE_SIZE(obj) * 5 + 1);

if (_PyUnicodeWriter_WriteStr(&writer, type_name) < 0) {

Py_DECREF(type_name);

goto error;

}

Py_DECREF(type_name);

if (_PyUnicodeWriter_WriteChar(&writer, '(') < 0) {

goto error;

}

for (Py_ssize_t i=0; i < VISIBLE_SIZE(obj); i++) {

if (i > 0) {

/* Write ", " */

if (_PyUnicodeWriter_WriteASCIIString(&writer, ", ", 2) < 0) {

goto error;

}

}

/* Write "name=repr" */

const char *name_utf8 = typ->tp_members[i].name;

if (name_utf8 == NULL) {

PyErr_Format(PyExc_SystemError, "In structseq_repr(), member %zd name is NULL"

" for type %.500s", i, typ->tp_name);

goto error;

}

PyObject *name = PyUnicode_DecodeUTF8(name_utf8, strlen(name_utf8), NULL);

if (name == NULL) {

goto error;

}

if (_PyUnicodeWriter_WriteStr(&writer, name) < 0) {

Py_DECREF(name);

goto error;

}

Py_DECREF(name);

if (_PyUnicodeWriter_WriteChar(&writer, '=') < 0) {

goto error;

}

PyObject *value = PyStructSequence_GET_ITEM(obj, i);

assert(value != NULL);

PyObject *repr = PyObject_Repr(value);

if (repr == NULL) {

goto error;

}

if (_PyUnicodeWriter_WriteStr(&writer, repr) < 0) {

Py_DECREF(repr);

goto error;

}

Py_DECREF(repr);

}

if (_PyUnicodeWriter_WriteChar(&writer, ')') < 0) {

goto error;

}

return _PyUnicodeWriter_Finish(&writer);

error:

_PyUnicodeWriter_Dealloc(&writer);

return NULL;

}

static PyObject *

structseq_reduce(PyStructSequence* self, PyObject *Py_UNUSED(ignored))

{

PyObject* tup = NULL;

PyObject* dict = NULL;

PyObject* result;

Py_ssize_t n_fields, n_visible_fields, n_unnamed_fields, i;

n_fields = REAL_SIZE(self);

if (n_fields < 0) {

return NULL;

}

n_visible_fields = VISIBLE_SIZE(self);

n_unnamed_fields = UNNAMED_FIELDS(self);

if (n_unnamed_fields < 0) {

return NULL;

}

tup = _PyTuple_FromArray(self->ob_item, n_visible_fields);

if (!tup)

goto error;

dict = PyDict_New();

if (!dict)

goto error;

for (i = n_visible_fields; i < n_fields; i++) {

const char *n = Py_TYPE(self)->tp_members[i-n_unnamed_fields].name;

if (PyDict_SetItemString(dict, n, self->ob_item[i]) < 0)

goto error;

}

result = Py_BuildValue("(O(OO))", Py_TYPE(self), tup, dict);

Py_DECREF(tup);

Py_DECREF(dict);

return result;

error:

Py_XDECREF(tup);

Py_XDECREF(dict);

return NULL;

}

static PyMethodDef structseq_methods[] = {

{"__reduce__", (PyCFunction)structseq_reduce, METH_NOARGS, NULL},

{NULL, NULL}

};

static Py_ssize_t

count_members(PyStructSequence_Desc *desc, Py_ssize_t *n_unnamed_members) {

Py_ssize_t i;

*n_unnamed_members = 0;

for (i = 0; desc->fields[i].name != NULL; ++i) {

if (desc->fields[i].name == PyStructSequence_UnnamedField) {

(*n_unnamed_members)++;

}

}

return i;

}

static int

initialize_structseq_dict(PyStructSequence_Desc *desc, PyObject* dict,

Py_ssize_t n_members, Py_ssize_t n_unnamed_members) {

PyObject *v;

#define SET_DICT_FROM_SIZE(key, value) \

do { \

v = PyLong_FromSsize_t(value); \

if (v == NULL) { \

return -1; \

} \

if (PyDict_SetItemString(dict, key, v) < 0) { \

Py_DECREF(v); \

return -1; \

} \

Py_DECREF(v); \

} while (0)

SET_DICT_FROM_SIZE(visible_length_key, desc->n_in_sequence);

SET_DICT_FROM_SIZE(real_length_key, n_members);

SET_DICT_FROM_SIZE(unnamed_fields_key, n_unnamed_members);

// Prepare and set __match_args__

Py_ssize_t i, k;

PyObject* keys = PyTuple_New(desc->n_in_sequence);

if (keys == NULL) {

return -1;

}

for (i = k = 0; i < desc->n_in_sequence; ++i) {

if (desc->fields[i].name == PyStructSequence_UnnamedField) {

continue;

}

PyObject* new_member = PyUnicode_FromString(desc->fields[i].name);

if (new_member == NULL) {

goto error;

}

PyTuple_SET_ITEM(keys, k, new_member);

k++;

}

if (_PyTuple_Resize(&keys, k) == -1) {

goto error;

}

if (PyDict_SetItemString(dict, match_args_key, keys) < 0) {

goto error;

}

Py_DECREF(keys);

return 0;

error:

Py_DECREF(keys);

return -1;

}

static void

initialize_members(PyStructSequence_Desc *desc, PyMemberDef* members,

Py_ssize_t n_members) {

Py_ssize_t i, k;

for (i = k = 0; i < n_members; ++i) {

if (desc->fields[i].name == PyStructSequence_UnnamedField) {

continue;

}

/* The names and docstrings in these MemberDefs are statically */

/* allocated so it is expected that they'll outlive the MemberDef */

members[k].name = desc->fields[i].name;

members[k].type = T_OBJECT;

members[k].offset = offsetof(PyStructSequence, ob_item)

+ i * sizeof(PyObject*);

members[k].flags = READONLY;

members[k].doc = desc->fields[i].doc;

k++;

}

members[k].name = NULL;

}

_PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc,

unsigned long tp_flags)

{

PyMemberDef *members;

Py_ssize_t n_members, n_unnamed_members;

#ifdef Py_TRACE_REFS

/* if the type object was chained, unchain it first

if (type->ob_base.ob_base._ob_next) {

_Py_ForgetReference((PyObject *)type);

}

/* PyTypeObject has already been initialized */

if (Py_REFCNT(type) != 0) {

PyErr_BadInternalCall();

return -1;

}

type->tp_name = desc->name;

type->tp_basicsize = sizeof(PyStructSequence) - sizeof(PyObject *);

type->tp_itemsize = sizeof(PyObject *);

type->tp_dealloc = (destructor)structseq_dealloc;

type->tp_repr = (reprfunc)structseq_repr;

type->tp_doc = desc->doc;

type->tp_base = &PyTuple_Type;

type->tp_methods = structseq_methods;

type->tp_new = structseq_new;

type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | tp_flags;

type->tp_traverse = (traverseproc) structseq_traverse;

n_members = count_members(desc, &n_unnamed_members);

members = PyMem_NEW(PyMemberDef, n_members - n_unnamed_members + 1);

if (members == NULL) {

PyErr_NoMemory();

return -1;

}

initialize_members(desc, members, n_members);

type->tp_members = members;

if (PyType_Ready(type) < 0) {

PyMem_Free(members);

return -1;

}

Py_INCREF(type);

if (initialize_structseq_dict(

desc, type->tp_dict, n_members, n_unnamed_members) < 0) {

PyMem_Free(members);

Py_DECREF(type);

return -1;

}

return 0;

}

PyStructSequence_InitType2(PyTypeObject *type, PyStructSequence_Desc *desc)

{

return _PyStructSequence_InitType(type, desc, 0);

}

PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc)

{

(void)PyStructSequence_InitType2(type, desc);

}

_PyStructSequence_FiniType(PyTypeObject *type)

{

// Ensure that the type is initialized

assert(type->tp_name != NULL);

assert(type->tp_base == &PyTuple_Type);

// Cannot delete a type if it still has subclasses

if (type->tp_subclasses != NULL) {

return;

}

// Undo PyStructSequence_NewType()

type->tp_name = NULL;

PyMem_Free(type->tp_members);

_PyStaticType_Dealloc(type);

assert(Py_REFCNT(type) == 1);

// Undo Py_INCREF(type) of _PyStructSequence_InitType().

// Don't use Py_DECREF(): static type must not be deallocated

Py_SET_REFCNT(type, 0);

#ifdef Py_REF_DEBUG

_Py_RefTotal--;

// Make sure that _PyStructSequence_InitType() will initialize

// the type again

assert(Py_REFCNT(type) == 0);

assert(type->tp_name == NULL);

}

PyTypeObject *

_PyStructSequence_NewType(PyStructSequence_Desc *desc, unsigned long tp_flags)

{

PyMemberDef *members;

PyTypeObject *type;

PyType_Slot slots[8];

PyType_Spec spec;

Py_ssize_t n_members, n_unnamed_members;

/* Initialize MemberDefs */

n_members = count_members(desc, &n_unnamed_members);

members = PyMem_NEW(PyMemberDef, n_members - n_unnamed_members + 1);

if (members == NULL) {

PyErr_NoMemory();

return NULL;

}

initialize_members(desc, members, n_members);

/* Initialize Slots */

slots[0] = (PyType_Slot){Py_tp_dealloc, (destructor)structseq_dealloc};

slots[1] = (PyType_Slot){Py_tp_repr, (reprfunc)structseq_repr};

slots[2] = (PyType_Slot){Py_tp_doc, (void *)desc->doc};

slots[3] = (PyType_Slot){Py_tp_methods, structseq_methods};

slots[4] = (PyType_Slot){Py_tp_new, structseq_new};

slots[5] = (PyType_Slot){Py_tp_members, members};

slots[6] = (PyType_Slot){Py_tp_traverse, (traverseproc)structseq_traverse};

slots[7] = (PyType_Slot){0, 0};

/* Initialize Spec */

/* The name in this PyType_Spec is statically allocated so it is */

/* expected that it'll outlive the PyType_Spec */

spec.name = desc->name;

spec.basicsize = sizeof(PyStructSequence) - sizeof(PyObject *);

spec.itemsize = sizeof(PyObject *);

spec.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | tp_flags;

spec.slots = slots;

type = (PyTypeObject *)PyType_FromSpecWithBases(&spec, (PyObject *)&PyTuple_Type);

PyMem_Free(members);

if (type == NULL) {

return NULL;

}

if (initialize_structseq_dict(

desc, type->tp_dict, n_members, n_unnamed_members) < 0) {

Py_DECREF(type);

return NULL;

}

return type;

}

PyTypeObject *

PyStructSequence_NewType(PyStructSequence_Desc *desc)

{

return _PyStructSequence_NewType(desc, 0);

}