#include <Python.h>

#include "pycore_ast.h" // _PyAST_Validate(),

#include <errcode.h>

#include "tokenizer.h"

#include "pegen.h"

// Internal parser functions

asdl_stmt_seq*

_PyPegen_interactive_exit(Parser *p)

{

if (p->errcode) {

*(p->errcode) = E_EOF;

}

return NULL;

}

Py_ssize_t

_PyPegen_byte_offset_to_character_offset(PyObject *line, Py_ssize_t col_offset)

{

const char *str = PyUnicode_AsUTF8(line);

if (!str) {

return -1;

}

Py_ssize_t len = strlen(str);

if (col_offset > len + 1) {

col_offset = len + 1;

}

assert(col_offset >= 0);

PyObject *text = PyUnicode_DecodeUTF8(str, col_offset, "replace");

if (!text) {

return -1;

}

Py_ssize_t size = PyUnicode_GET_LENGTH(text);

Py_DECREF(text);

return size;

}

// Here, mark is the start of the node, while p->mark is the end.

// If node==NULL, they should be the same.

int

_PyPegen_insert_memo(Parser *p, int mark, int type, void *node)

{

// Insert in front

Memo *m = _PyArena_Malloc(p->arena, sizeof(Memo));

if (m == NULL) {

return -1;

}

m->type = type;

m->node = node;

m->mark = p->mark;

m->next = p->tokens[mark]->memo;

p->tokens[mark]->memo = m;

return 0;

}

// Like _PyPegen_insert_memo(), but updates an existing node if found.

int

_PyPegen_update_memo(Parser *p, int mark, int type, void *node)

{

for (Memo *m = p->tokens[mark]->memo; m != NULL; m = m->next) {

if (m->type == type) {

// Update existing node.

m->node = node;

m->mark = p->mark;

return 0;

}

}

// Insert new node.

return _PyPegen_insert_memo(p, mark, type, node);

}

static int

init_normalization(Parser *p)

{

if (p->normalize) {

return 1;

}

p->normalize = _PyImport_GetModuleAttrString("unicodedata", "normalize");

if (!p->normalize)

{

return 0;

}

return 1;

}

static int

growable_comment_array_init(growable_comment_array *arr, size_t initial_size) {

assert(initial_size > 0);

arr->items = PyMem_Malloc(initial_size * sizeof(*arr->items));

arr->size = initial_size;

arr->num_items = 0;

return arr->items != NULL;

}

static int

growable_comment_array_add(growable_comment_array *arr, int lineno, char *comment) {

if (arr->num_items >= arr->size) {

size_t new_size = arr->size * 2;

void *new_items_array = PyMem_Realloc(arr->items, new_size * sizeof(*arr->items));

if (!new_items_array) {

return 0;

}

arr->items = new_items_array;

arr->size = new_size;

}

arr->items[arr->num_items].lineno = lineno;

arr->items[arr->num_items].comment = comment; // Take ownership

arr->num_items++;

return 1;

}

static void

growable_comment_array_deallocate(growable_comment_array *arr) {

for (unsigned i = 0; i < arr->num_items; i++) {

PyMem_Free(arr->items[i].comment);

}

PyMem_Free(arr->items);

}

static int

_get_keyword_or_name_type(Parser *p, const char *name, int name_len)

{

assert(name_len > 0);

if (name_len >= p->n_keyword_lists ||

p->keywords[name_len] == NULL ||

p->keywords[name_len]->type == -1) {

return NAME;

}

for (KeywordToken *k = p->keywords[name_len]; k != NULL && k->type != -1; k++) {

if (strncmp(k->str, name, name_len) == 0) {

return k->type;

}

}

return NAME;

}

static int

initialize_token(Parser *p, Token *token, const char *start, const char *end, int token_type) {

assert(token != NULL);

token->type = (token_type == NAME) ? _get_keyword_or_name_type(p, start, (int)(end - start)) : token_type;

token->bytes = PyBytes_FromStringAndSize(start, end - start);

if (token->bytes == NULL) {

return -1;

}

if (_PyArena_AddPyObject(p->arena, token->bytes) < 0) {

Py_DECREF(token->bytes);

return -1;

}

token->level = p->tok->level;

const char *line_start = token_type == STRING ? p->tok->multi_line_start : p->tok->line_start;

int lineno = token_type == STRING ? p->tok->first_lineno : p->tok->lineno;

int end_lineno = p->tok->lineno;

int col_offset = (start != NULL && start >= line_start) ? (int)(start - line_start) : -1;

int end_col_offset = (end != NULL && end >= p->tok->line_start) ? (int)(end - p->tok->line_start) : -1;

token->lineno = lineno;

token->col_offset = p->tok->lineno == p->starting_lineno ? p->starting_col_offset + col_offset : col_offset;

token->end_lineno = end_lineno;

token->end_col_offset = p->tok->lineno == p->starting_lineno ? p->starting_col_offset + end_col_offset : end_col_offset;

p->fill += 1;

if (token_type == ERRORTOKEN && p->tok->done == E_DECODE) {

return _Pypegen_raise_decode_error(p);

}

return (token_type == ERRORTOKEN ? _Pypegen_tokenizer_error(p) : 0);

}

static int

_resize_tokens_array(Parser *p) {

int newsize = p->size * 2;

Token **new_tokens = PyMem_Realloc(p->tokens, newsize * sizeof(Token *));

if (new_tokens == NULL) {

PyErr_NoMemory();

return -1;

}

p->tokens = new_tokens;

for (int i = p->size; i < newsize; i++) {

p->tokens[i] = PyMem_Calloc(1, sizeof(Token));

if (p->tokens[i] == NULL) {

p->size = i; // Needed, in order to cleanup correctly after parser fails

PyErr_NoMemory();

return -1;

}

}

p->size = newsize;

return 0;

}

int

_PyPegen_fill_token(Parser *p)

{

const char *start;

const char *end;

int type = _PyTokenizer_Get(p->tok, &start, &end);

// Record and skip '# type: ignore' comments

while (type == TYPE_IGNORE) {

Py_ssize_t len = end - start;

char *tag = PyMem_Malloc(len + 1);

if (tag == NULL) {

PyErr_NoMemory();

return -1;

}

strncpy(tag, start, len);

tag[len] = '\0';

// Ownership of tag passes to the growable array

if (!growable_comment_array_add(&p->type_ignore_comments, p->tok->lineno, tag)) {

PyErr_NoMemory();

return -1;

}

type = _PyTokenizer_Get(p->tok, &start, &end);

}

// If we have reached the end and we are in single input mode we need to insert a newline and reset the parsing

if (p->start_rule == Py_single_input && type == ENDMARKER && p->parsing_started) {

type = NEWLINE; /* Add an extra newline */

p->parsing_started = 0;

if (p->tok->indent && !(p->flags & PyPARSE_DONT_IMPLY_DEDENT)) {

p->tok->pendin = -p->tok->indent;

p->tok->indent = 0;

}

}

else {

p->parsing_started = 1;

}

// Check if we are at the limit of the token array capacity and resize if needed

if ((p->fill == p->size) && (_resize_tokens_array(p) != 0)) {

return -1;

}

Token *t = p->tokens[p->fill];

return initialize_token(p, t, start, end, type);

}

#if defined(Py_DEBUG)

// Instrumentation to count the effectiveness of memoization.

// The array counts the number of tokens skipped by memoization,

// indexed by type.

#define NSTATISTICS 2000

static long memo_statistics[NSTATISTICS];

void

_PyPegen_clear_memo_statistics()

{

for (int i = 0; i < NSTATISTICS; i++) {

memo_statistics[i] = 0;

}

}

PyObject *

_PyPegen_get_memo_statistics()

{

PyObject *ret = PyList_New(NSTATISTICS);

if (ret == NULL) {

return NULL;

}

for (int i = 0; i < NSTATISTICS; i++) {

PyObject *value = PyLong_FromLong(memo_statistics[i]);

if (value == NULL) {

Py_DECREF(ret);

return NULL;

}

// PyList_SetItem borrows a reference to value.

if (PyList_SetItem(ret, i, value) < 0) {

Py_DECREF(ret);

return NULL;

}

}

return ret;

}

#endif

int // bool

_PyPegen_is_memoized(Parser *p, int type, void *pres)

{

if (p->mark == p->fill) {

if (_PyPegen_fill_token(p) < 0) {

p->error_indicator = 1;

return -1;

}

}

Token *t = p->tokens[p->mark];

for (Memo *m = t->memo; m != NULL; m = m->next) {

if (m->type == type) {

#if defined(PY_DEBUG)

if (0 <= type && type < NSTATISTICS) {

long count = m->mark - p->mark;

// A memoized negative result counts for one.

if (count <= 0) {

count = 1;

}

memo_statistics[type] += count;

}

#endif

p->mark = m->mark;

*(void **)(pres) = m->node;

return 1;

}

}

return 0;

}

int

_PyPegen_lookahead_with_name(int positive, expr_ty (func)(Parser *), Parser *p)

{

int mark = p->mark;

void *res = func(p);

p->mark = mark;

return (res != NULL) == positive;

}

int

_PyPegen_lookahead_with_string(int positive, expr_ty (func)(Parser *, const char*), Parser *p, const char* arg)

{

int mark = p->mark;

void *res = func(p, arg);

p->mark = mark;

return (res != NULL) == positive;

}

int

_PyPegen_lookahead_with_int(int positive, Token *(func)(Parser *, int), Parser *p, int arg)

{

int mark = p->mark;

void *res = func(p, arg);

p->mark = mark;

return (res != NULL) == positive;

}

int

_PyPegen_lookahead(int positive, void *(func)(Parser *), Parser *p)

{

int mark = p->mark;

void *res = (void*)func(p);

p->mark = mark;

return (res != NULL) == positive;

}

Token *

_PyPegen_expect_token(Parser *p, int type)

{

if (p->mark == p->fill) {

if (_PyPegen_fill_token(p) < 0) {

p->error_indicator = 1;

return NULL;

}

}

Token *t = p->tokens[p->mark];

if (t->type != type) {

return NULL;

}

p->mark += 1;

return t;

}

void*

_PyPegen_expect_forced_result(Parser *p, void* result, const char* expected) {

if (p->error_indicator == 1) {

return NULL;

}

if (result == NULL) {

RAISE_SYNTAX_ERROR("expected (%s)", expected);

return NULL;

}

return result;

}

Token *

_PyPegen_expect_forced_token(Parser *p, int type, const char* expected) {

if (p->error_indicator == 1) {

return NULL;

}

if (p->mark == p->fill) {

if (_PyPegen_fill_token(p) < 0) {

p->error_indicator = 1;

return NULL;

}

}

Token *t = p->tokens[p->mark];

if (t->type != type) {

RAISE_SYNTAX_ERROR_KNOWN_LOCATION(t, "expected '%s'", expected);

return NULL;

}

p->mark += 1;

return t;

}

expr_ty

_PyPegen_expect_soft_keyword(Parser *p, const char *keyword)

{

if (p->mark == p->fill) {

if (_PyPegen_fill_token(p) < 0) {

p->error_indicator = 1;

return NULL;

}

}

Token *t = p->tokens[p->mark];

if (t->type != NAME) {

return NULL;

}

const char *s = PyBytes_AsString(t->bytes);

if (!s) {

p->error_indicator = 1;

return NULL;

}

if (strcmp(s, keyword) != 0) {

return NULL;

}

return _PyPegen_name_token(p);

}

Token *

_PyPegen_get_last_nonnwhitespace_token(Parser *p)

{

assert(p->mark >= 0);

Token *token = NULL;

for (int m = p->mark - 1; m >= 0; m--) {

token = p->tokens[m];

if (token->type != ENDMARKER && (token->type < NEWLINE || token->type > DEDENT)) {

break;

}

}

return token;

}

PyObject *

_PyPegen_new_identifier(Parser *p, const char *n)

{

PyObject *id = PyUnicode_DecodeUTF8(n, strlen(n), NULL);

if (!id) {

goto error;

}

/* PyUnicode_DecodeUTF8 should always return a ready string. */

assert(PyUnicode_IS_READY(id));

/* Check whether there are non-ASCII characters in the

identifier; if so, normalize to NFKC. */

if (!PyUnicode_IS_ASCII(id))

{

PyObject *id2;

if (!init_normalization(p))

{

Py_DECREF(id);

goto error;

}

PyObject *form = PyUnicode_InternFromString("NFKC");

if (form == NULL)

{

Py_DECREF(id);

goto error;

}

PyObject *args[2] = {form, id};

id2 = _PyObject_FastCall(p->normalize, args, 2);

Py_DECREF(id);

Py_DECREF(form);

if (!id2) {

goto error;

}

if (!PyUnicode_Check(id2))

{

PyErr_Format(PyExc_TypeError,

"unicodedata.normalize() must return a string, not "

"%.200s",

_PyType_Name(Py_TYPE(id2)));

Py_DECREF(id2);

goto error;

}

id = id2;

}

PyUnicode_InternInPlace(&id);

if (_PyArena_AddPyObject(p->arena, id) < 0)

{

Py_DECREF(id);

goto error;

}

return id;

error:

p->error_indicator = 1;

return NULL;

}

static expr_ty

_PyPegen_name_from_token(Parser *p, Token* t)

{

if (t == NULL) {

return NULL;

}

const char *s = PyBytes_AsString(t->bytes);

if (!s) {

p->error_indicator = 1;

return NULL;

}

PyObject *id = _PyPegen_new_identifier(p, s);

if (id == NULL) {

p->error_indicator = 1;

return NULL;

}

return _PyAST_Name(id, Load, t->lineno, t->col_offset, t->end_lineno,

t->end_col_offset, p->arena);

}

expr_ty

_PyPegen_name_token(Parser *p)

{

Token *t = _PyPegen_expect_token(p, NAME);

return _PyPegen_name_from_token(p, t);

}

void *

_PyPegen_string_token(Parser *p)

{

return _PyPegen_expect_token(p, STRING);

}

expr_ty _PyPegen_soft_keyword_token(Parser *p) {

Token *t = _PyPegen_expect_token(p, NAME);

if (t == NULL) {

return NULL;

}

char *the_token;

Py_ssize_t size;

PyBytes_AsStringAndSize(t->bytes, &the_token, &size);

for (char **keyword = p->soft_keywords; *keyword != NULL; keyword++) {

if (strncmp(*keyword, the_token, size) == 0) {

return _PyPegen_name_from_token(p, t);

}

}

return NULL;

}

static PyObject *

parsenumber_raw(const char *s)

{

const char *end;

long x;

double dx;

Py_complex compl;

int imflag;

assert(s != NULL);

errno = 0;

end = s + strlen(s) - 1;

imflag = *end == 'j' || *end == 'J';

if (s[0] == '0') {

x = (long)PyOS_strtoul(s, (char **)&end, 0);

if (x < 0 && errno == 0) {

return PyLong_FromString(s, (char **)0, 0);

}

}

else {

x = PyOS_strtol(s, (char **)&end, 0);

}

if (*end == '\0') {

if (errno != 0) {

return PyLong_FromString(s, (char **)0, 0);

}

return PyLong_FromLong(x);

}

/* XXX Huge floats may silently fail */

if (imflag) {

compl.real = 0.;

compl.imag = PyOS_string_to_double(s, (char **)&end, NULL);

if (compl.imag == -1.0 && PyErr_Occurred()) {

return NULL;

}

return PyComplex_FromCComplex(compl);

}

dx = PyOS_string_to_double(s, NULL, NULL);

if (dx == -1.0 && PyErr_Occurred()) {

return NULL;

}

return PyFloat_FromDouble(dx);

}

static PyObject *

parsenumber(const char *s)

{

char *dup;

char *end;

PyObject *res = NULL;

assert(s != NULL);

if (strchr(s, '_') == NULL) {

return parsenumber_raw(s);

}

/* Create a duplicate without underscores. */

dup = PyMem_Malloc(strlen(s) + 1);

if (dup == NULL) {

return PyErr_NoMemory();

}

end = dup;

for (; *s; s++) {

if (*s != '_') {

*end++ = *s;

}

}

*end = '\0';

res = parsenumber_raw(dup);

PyMem_Free(dup);

return res;

}

expr_ty

_PyPegen_number_token(Parser *p)

{

Token *t = _PyPegen_expect_token(p, NUMBER);

if (t == NULL) {

return NULL;

}

const char *num_raw = PyBytes_AsString(t->bytes);

if (num_raw == NULL) {

p->error_indicator = 1;

return NULL;

}

if (p->feature_version < 6 && strchr(num_raw, '_') != NULL) {

p->error_indicator = 1;

return RAISE_SYNTAX_ERROR("Underscores in numeric literals are only supported "

"in Python 3.6 and greater");

}

PyObject *c = parsenumber(num_raw);

if (c == NULL) {

p->error_indicator = 1;

return NULL;

}

if (_PyArena_AddPyObject(p->arena, c) < 0) {

Py_DECREF(c);

p->error_indicator = 1;

return NULL;

}

return _PyAST_Constant(c, NULL, t->lineno, t->col_offset, t->end_lineno,

t->end_col_offset, p->arena);

}

/* Check that the source for a single input statement really is a single

statement by looking at what is left in the buffer after parsing.

Trailing whitespace and comments are OK. */

static int // bool

bad_single_statement(Parser *p)

{

char *cur = p->tok->cur;

char c = *cur;

for (;;) {

while (c == ' ' || c == '\t' || c == '\n' || c == '\014') {

c = *++cur;

}

if (!c) {

return 0;

}

if (c != '#') {

return 1;

}

/* Suck up comment. */

while (c && c != '\n') {

c = *++cur;

}

}

}

static int

compute_parser_flags(PyCompilerFlags *flags)

{

int parser_flags = 0;

if (!flags) {

return 0;

}

if (flags->cf_flags & PyCF_DONT_IMPLY_DEDENT) {

parser_flags |= PyPARSE_DONT_IMPLY_DEDENT;

}

if (flags->cf_flags & PyCF_IGNORE_COOKIE) {

parser_flags |= PyPARSE_IGNORE_COOKIE;

}

if (flags->cf_flags & CO_FUTURE_BARRY_AS_BDFL) {

parser_flags |= PyPARSE_BARRY_AS_BDFL;

}

if (flags->cf_flags & PyCF_TYPE_COMMENTS) {

parser_flags |= PyPARSE_TYPE_COMMENTS;

}

if ((flags->cf_flags & PyCF_ONLY_AST) && flags->cf_feature_version < 7) {

parser_flags |= PyPARSE_ASYNC_HACKS;

}

if (flags->cf_flags & PyCF_ALLOW_INCOMPLETE_INPUT) {

parser_flags |= PyPARSE_ALLOW_INCOMPLETE_INPUT;

}

return parser_flags;

}

// Parser API

Parser *

_PyPegen_Parser_New(struct tok_state *tok, int start_rule, int flags,

int feature_version, int *errcode, PyArena *arena)

{

Parser *p = PyMem_Malloc(sizeof(Parser));

if (p == NULL) {

return (Parser *) PyErr_NoMemory();

}

assert(tok != NULL);

tok->type_comments = (flags & PyPARSE_TYPE_COMMENTS) > 0;

tok->async_hacks = (flags & PyPARSE_ASYNC_HACKS) > 0;

p->tok = tok;

p->keywords = NULL;

p->n_keyword_lists = -1;

p->soft_keywords = NULL;

p->tokens = PyMem_Malloc(sizeof(Token *));

if (!p->tokens) {

PyMem_Free(p);

return (Parser *) PyErr_NoMemory();

}

p->tokens[0] = PyMem_Calloc(1, sizeof(Token));

if (!p->tokens) {

PyMem_Free(p->tokens);

PyMem_Free(p);

return (Parser *) PyErr_NoMemory();

}

if (!growable_comment_array_init(&p->type_ignore_comments, 10)) {

PyMem_Free(p->tokens[0]);

PyMem_Free(p->tokens);

PyMem_Free(p);

return (Parser *) PyErr_NoMemory();

}

p->mark = 0;

p->fill = 0;

p->size = 1;

p->errcode = errcode;

p->arena = arena;

p->start_rule = start_rule;

p->parsing_started = 0;

p->normalize = NULL;

p->error_indicator = 0;

p->starting_lineno = 0;

p->starting_col_offset = 0;

p->flags = flags;

p->feature_version = feature_version;

p->known_err_token = NULL;

p->level = 0;

p->call_invalid_rules = 0;

#ifdef Py_DEBUG

p->debug = _Py_GetConfig()->parser_debug;

#endif

return p;

}

void

_PyPegen_Parser_Free(Parser *p)

{

Py_XDECREF(p->normalize);

for (int i = 0; i < p->size; i++) {

PyMem_Free(p->tokens[i]);

}

PyMem_Free(p->tokens);

growable_comment_array_deallocate(&p->type_ignore_comments);

PyMem_Free(p);

}

static void

reset_parser_state_for_error_pass(Parser *p)

{

for (int i = 0; i < p->fill; i++) {

p->tokens[i]->memo = NULL;

}

p->mark = 0;

p->call_invalid_rules = 1;

// Don't try to get extra tokens in interactive mode when trying to

// raise specialized errors in the second pass.

p->tok->interactive_underflow = IUNDERFLOW_STOP;

}

static inline int

_is_end_of_source(Parser *p) {

int err = p->tok->done;

return err == E_EOF || err == E_EOFS || err == E_EOLS;

}

void *

_PyPegen_run_parser(Parser *p)

{

void *res = _PyPegen_parse(p);

assert(p->level == 0);

if (res == NULL) {

if ((p->flags & PyPARSE_ALLOW_INCOMPLETE_INPUT) && _is_end_of_source(p)) {

PyErr_Clear();

return RAISE_SYNTAX_ERROR("incomplete input");

}

if (PyErr_Occurred() && !PyErr_ExceptionMatches(PyExc_SyntaxError)) {

return NULL;

}

// Make a second parser pass. In this pass we activate heavier and slower checks

// to produce better error messages and more complete diagnostics. Extra "invalid_*"

// rules will be active during parsing.

Token *last_token = p->tokens[p->fill - 1];

reset_parser_state_for_error_pass(p);

_PyPegen_parse(p);

// Set SyntaxErrors accordingly depending on the parser/tokenizer status at the failure

// point.

_Pypegen_set_syntax_error(p, last_token);

return NULL;

}

if (p->start_rule == Py_single_input && bad_single_statement(p)) {

p->tok->done = E_BADSINGLE; // This is not necessary for now, but might be in the future

return RAISE_SYNTAX_ERROR("multiple statements found while compiling a single statement");

}

// test_peg_generator defines _Py_TEST_PEGEN to not call PyAST_Validate()

#if defined(Py_DEBUG) && !defined(_Py_TEST_PEGEN)

if (p->start_rule == Py_single_input ||

p->start_rule == Py_file_input ||

p->start_rule == Py_eval_input)

{

if (!_PyAST_Validate(res)) {

return NULL;

}

}

#endif

return res;

}

mod_ty

_PyPegen_run_parser_from_file_pointer(FILE *fp, int start_rule, PyObject *filename_ob,

const char *enc, const char *ps1, const char *ps2,

PyCompilerFlags *flags, int *errcode, PyArena *arena)

{

struct tok_state *tok = _PyTokenizer_FromFile(fp, enc, ps1, ps2);

if (tok == NULL) {

if (PyErr_Occurred()) {

_PyPegen_raise_tokenizer_init_error(filename_ob);

return NULL;

}

return NULL;

}

if (!tok->fp || ps1 != NULL || ps2 != NULL ||

PyUnicode_CompareWithASCIIString(filename_ob, "<stdin>") == 0) {

tok->fp_interactive = 1;

}

// This transfers the ownership to the tokenizer

tok->filename = filename_ob;

Py_INCREF(filename_ob);

// From here on we need to clean up even if there's an error

mod_ty result = NULL;

int parser_flags = compute_parser_flags(flags);

Parser *p = _PyPegen_Parser_New(tok, start_rule, parser_flags, PY_MINOR_VERSION,

errcode, arena);

if (p == NULL) {

goto error;

}

result = _PyPegen_run_parser(p);

_PyPegen_Parser_Free(p);

error:

_PyTokenizer_Free(tok);

return result;

}

mod_ty

_PyPegen_run_parser_from_string(const char *str, int start_rule, PyObject *filename_ob,

PyCompilerFlags *flags, PyArena *arena)

{

int exec_input = start_rule == Py_file_input;

struct tok_state *tok;

if (flags != NULL && flags->cf_flags & PyCF_IGNORE_COOKIE) {

tok = _PyTokenizer_FromUTF8(str, exec_input);

} else {

tok = _PyTokenizer_FromString(str, exec_input);

}

if (tok == NULL) {

if (PyErr_Occurred()) {

_PyPegen_raise_tokenizer_init_error(filename_ob);

}

return NULL;

}

// This transfers the ownership to the tokenizer

tok->filename = filename_ob;

Py_INCREF(filename_ob);

// We need to clear up from here on

mod_ty result = NULL;

int parser_flags = compute_parser_flags(flags);

int feature_version = flags && (flags->cf_flags & PyCF_ONLY_AST) ?

flags->cf_feature_version : PY_MINOR_VERSION;

Parser *p = _PyPegen_Parser_New(tok, start_rule, parser_flags, feature_version,

NULL, arena);

if (p == NULL) {

goto error;

}

result = _PyPegen_run_parser(p);

_PyPegen_Parser_Free(p);

error:

_PyTokenizer_Free(tok);

return result;

}