/* Tokenizer implementation */

#define PY_SSIZE_T_CLEAN

#include "Python.h"

#include "pycore_call.h" // _PyObject_CallNoArgs()

#include <ctype.h>

#include <assert.h>

#include "tokenizer.h"

#include "errcode.h"

#include "unicodeobject.h"

#include "bytesobject.h"

#include "fileobject.h"

#include "abstract.h"

/* Alternate tab spacing */

#define ALTTABSIZE 1

#define is_potential_identifier_start(c) (\

(c >= 'a' && c <= 'z')\

|| (c >= 'A' && c <= 'Z')\

|| c == '_'\

|| (c >= 128))

#define is_potential_identifier_char(c) (\

(c >= 'a' && c <= 'z')\

|| (c >= 'A' && c <= 'Z')\

|| (c >= '0' && c <= '9')\

|| c == '_'\

|| (c >= 128))

/* Don't ever change this -- it would break the portability of Python code */

#define TABSIZE 8

/* Forward */

static struct tok_state *tok_new(void);

static int tok_nextc(struct tok_state *tok);

static void tok_backup(struct tok_state *tok, int c);

static int syntaxerror(struct tok_state *tok, const char *format, ...);

/* Spaces in this constant are treated as "zero or more spaces or tabs" when

tokenizing. */

static const char* type_comment_prefix = "# type: ";

/* Create and initialize a new tok_state structure */

static struct tok_state *

tok_new(void)

{

struct tok_state *tok = (struct tok_state *)PyMem_Malloc(

sizeof(struct tok_state));

if (tok == NULL)

return NULL;

tok->buf = tok->cur = tok->inp = NULL;

tok->fp_interactive = 0;

tok->interactive_src_start = NULL;

tok->interactive_src_end = NULL;

tok->start = NULL;

tok->end = NULL;

tok->done = E_OK;

tok->fp = NULL;

tok->input = NULL;

tok->tabsize = TABSIZE;

tok->indent = 0;

tok->indstack[0] = 0;

tok->atbol = 1;

tok->pendin = 0;

tok->prompt = tok->nextprompt = NULL;

tok->lineno = 0;

tok->level = 0;

tok->altindstack[0] = 0;

tok->decoding_state = STATE_INIT;

tok->decoding_erred = 0;

tok->enc = NULL;

tok->encoding = NULL;

tok->cont_line = 0;

tok->filename = NULL;

tok->decoding_readline = NULL;

tok->decoding_buffer = NULL;

tok->type_comments = 0;

tok->async_hacks = 0;

tok->async_def = 0;

tok->async_def_indent = 0;

tok->async_def_nl = 0;

tok->interactive_underflow = IUNDERFLOW_NORMAL;

tok->str = NULL;

#ifdef Py_DEBUG

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

#endif

return tok;

}

static char *

new_string(const char *s, Py_ssize_t len, struct tok_state *tok)

{

char* result = (char *)PyMem_Malloc(len + 1);

if (!result) {

tok->done = E_NOMEM;

return NULL;

}

memcpy(result, s, len);

result[len] = '\0';

return result;

}

static char *

error_ret(struct tok_state *tok) /* XXX */

{

tok->decoding_erred = 1;

if (tok->fp != NULL && tok->buf != NULL) /* see _PyTokenizer_Free */

PyMem_Free(tok->buf);

tok->buf = tok->cur = tok->inp = NULL;

tok->start = NULL;

tok->end = NULL;

tok->done = E_DECODE;

return NULL; /* as if it were EOF */

}

static const char *

get_normal_name(const char *s) /* for utf-8 and latin-1 */

{

char buf[13];

int i;

for (i = 0; i < 12; i++) {

int c = s[i];

if (c == '\0')

break;

else if (c == '_')

buf[i] = '-';

else

buf[i] = tolower(c);

}

buf[i] = '\0';

if (strcmp(buf, "utf-8") == 0 ||

strncmp(buf, "utf-8-", 6) == 0)

return "utf-8";

else if (strcmp(buf, "latin-1") == 0 ||

strcmp(buf, "iso-8859-1") == 0 ||

strcmp(buf, "iso-latin-1") == 0 ||

strncmp(buf, "latin-1-", 8) == 0 ||

strncmp(buf, "iso-8859-1-", 11) == 0 ||

strncmp(buf, "iso-latin-1-", 12) == 0)

return "iso-8859-1";

else

return s;

}

/* Return the coding spec in S, or NULL if none is found. */

static int

get_coding_spec(const char *s, char **spec, Py_ssize_t size, struct tok_state *tok)

{

Py_ssize_t i;

*spec = NULL;

/* Coding spec must be in a comment, and that comment must be

* the only statement on the source code line. */

for (i = 0; i < size - 6; i++) {

if (s[i] == '#')

break;

if (s[i] != ' ' && s[i] != '\t' && s[i] != '\014')

return 1;

}

for (; i < size - 6; i++) { /* XXX inefficient search */

const char* t = s + i;

if (memcmp(t, "coding", 6) == 0) {

const char* begin = NULL;

t += 6;

if (t[0] != ':' && t[0] != '=')

continue;

do {

t++;

} while (t[0] == ' ' || t[0] == '\t');

begin = t;

while (Py_ISALNUM(t[0]) ||

t[0] == '-' || t[0] == '_' || t[0] == '.')

t++;

if (begin < t) {

char* r = new_string(begin, t - begin, tok);

const char* q;

if (!r)

return 0;

q = get_normal_name(r);

if (r != q) {

PyMem_Free(r);

r = new_string(q, strlen(q), tok);

if (!r)

return 0;

}

*spec = r;

break;

}

}

}

return 1;

}

/* Check whether the line contains a coding spec. If it does,

invoke the set_readline function for the new encoding.

This function receives the tok_state and the new encoding.

Return 1 on success, 0 on failure. */

static int

check_coding_spec(const char* line, Py_ssize_t size, struct tok_state *tok,

int set_readline(struct tok_state *, const char *))

{

char *cs;

if (tok->cont_line) {

/* It's a continuation line, so it can't be a coding spec. */

tok->decoding_state = STATE_NORMAL;

return 1;

}

if (!get_coding_spec(line, &cs, size, tok)) {

return 0;

}

if (!cs) {

Py_ssize_t i;

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

if (line[i] == '#' || line[i] == '\n' || line[i] == '\r')

break;

if (line[i] != ' ' && line[i] != '\t' && line[i] != '\014') {

/* Stop checking coding spec after a line containing

* anything except a comment. */

tok->decoding_state = STATE_NORMAL;

break;

}

}

return 1;

}

tok->decoding_state = STATE_NORMAL;

if (tok->encoding == NULL) {

assert(tok->decoding_readline == NULL);

if (strcmp(cs, "utf-8") != 0 && !set_readline(tok, cs)) {

error_ret(tok);

PyErr_Format(PyExc_SyntaxError, "encoding problem: %s", cs);

PyMem_Free(cs);

return 0;

}

tok->encoding = cs;

} else { /* then, compare cs with BOM */

if (strcmp(tok->encoding, cs) != 0) {

error_ret(tok);

PyErr_Format(PyExc_SyntaxError,

"encoding problem: %s with BOM", cs);

PyMem_Free(cs);

return 0;

}

PyMem_Free(cs);

}

return 1;

}

/* See whether the file starts with a BOM. If it does,

invoke the set_readline function with the new encoding.

Return 1 on success, 0 on failure. */

static int

check_bom(int get_char(struct tok_state *),

void unget_char(int, struct tok_state *),

int set_readline(struct tok_state *, const char *),

struct tok_state *tok)

{

int ch1, ch2, ch3;

ch1 = get_char(tok);

tok->decoding_state = STATE_SEEK_CODING;

if (ch1 == EOF) {

return 1;

} else if (ch1 == 0xEF) {

ch2 = get_char(tok);

if (ch2 != 0xBB) {

unget_char(ch2, tok);

unget_char(ch1, tok);

return 1;

}

ch3 = get_char(tok);

if (ch3 != 0xBF) {

unget_char(ch3, tok);

unget_char(ch2, tok);

unget_char(ch1, tok);

return 1;

}

} else {

unget_char(ch1, tok);

return 1;

}

if (tok->encoding != NULL)

PyMem_Free(tok->encoding);

tok->encoding = new_string("utf-8", 5, tok);

if (!tok->encoding)

return 0;

/* No need to set_readline: input is already utf-8 */

return 1;

}

static int

tok_concatenate_interactive_new_line(struct tok_state *tok, const char *line) {

assert(tok->fp_interactive);

if (!line) {

return 0;

}

Py_ssize_t current_size = tok->interactive_src_end - tok->interactive_src_start;

Py_ssize_t line_size = strlen(line);

char last_char = line[line_size > 0 ? line_size - 1 : line_size];

if (last_char != '\n') {

line_size += 1;

}

char* new_str = tok->interactive_src_start;

new_str = PyMem_Realloc(new_str, current_size + line_size + 1);

if (!new_str) {

if (tok->interactive_src_start) {

PyMem_Free(tok->interactive_src_start);

}

tok->interactive_src_start = NULL;

tok->interactive_src_end = NULL;

tok->done = E_NOMEM;

return -1;

}

strcpy(new_str + current_size, line);

if (last_char != '\n') {

/* Last line does not end in \n, fake one */

new_str[current_size + line_size - 1] = '\n';

new_str[current_size + line_size] = '\0';

}

tok->interactive_src_start = new_str;

tok->interactive_src_end = new_str + current_size + line_size;

return 0;

}

/* Read a line of text from TOK into S, using the stream in TOK.

Return NULL on failure, else S.

On entry, tok->decoding_buffer will be one of:

1) NULL: need to call tok->decoding_readline to get a new line

2) PyUnicodeObject *: decoding_feof has called tok->decoding_readline and

stored the result in tok->decoding_buffer

3) PyByteArrayObject *: previous call to tok_readline_recode did not have enough room

(in the s buffer) to copy entire contents of the line read

by tok->decoding_readline. tok->decoding_buffer has the overflow.

In this case, tok_readline_recode is called in a loop (with an expanded buffer)

until the buffer ends with a '\n' (or until the end of the file is

reached): see tok_nextc and its calls to tok_reserve_buf.

*/

static int

tok_reserve_buf(struct tok_state *tok, Py_ssize_t size)

{

Py_ssize_t cur = tok->cur - tok->buf;

Py_ssize_t oldsize = tok->inp - tok->buf;

Py_ssize_t newsize = oldsize + Py_MAX(size, oldsize >> 1);

if (newsize > tok->end - tok->buf) {

char *newbuf = tok->buf;

Py_ssize_t start = tok->start == NULL ? -1 : tok->start - tok->buf;

Py_ssize_t line_start = tok->start == NULL ? -1 : tok->line_start - tok->buf;

Py_ssize_t multi_line_start = tok->multi_line_start - tok->buf;

newbuf = (char *)PyMem_Realloc(newbuf, newsize);

if (newbuf == NULL) {

tok->done = E_NOMEM;

return 0;

}

tok->buf = newbuf;

tok->cur = tok->buf + cur;

tok->inp = tok->buf + oldsize;

tok->end = tok->buf + newsize;

tok->start = start < 0 ? NULL : tok->buf + start;

tok->line_start = line_start < 0 ? NULL : tok->buf + line_start;

tok->multi_line_start = multi_line_start < 0 ? NULL : tok->buf + multi_line_start;

}

return 1;

}

static int

tok_readline_recode(struct tok_state *tok) {

PyObject *line;

const char *buf;

Py_ssize_t buflen;

line = tok->decoding_buffer;

if (line == NULL) {

line = PyObject_CallNoArgs(tok->decoding_readline);

if (line == NULL) {

error_ret(tok);

goto error;

}

}

else {

tok->decoding_buffer = NULL;

}

buf = PyUnicode_AsUTF8AndSize(line, &buflen);

if (buf == NULL) {

error_ret(tok);

goto error;

}

if (!tok_reserve_buf(tok, buflen + 1)) {

goto error;

}

memcpy(tok->inp, buf, buflen);

tok->inp += buflen;

*tok->inp = '\0';

if (tok->fp_interactive &&

tok_concatenate_interactive_new_line(tok, buf) == -1) {

goto error;

}

Py_DECREF(line);

return 1;

error:

Py_XDECREF(line);

return 0;

}

/* Set the readline function for TOK to a StreamReader's

readline function. The StreamReader is named ENC.

This function is called from check_bom and check_coding_spec.

ENC is usually identical to the future value of tok->encoding,

except for the (currently unsupported) case of UTF-16.

Return 1 on success, 0 on failure. */

static int

fp_setreadl(struct tok_state *tok, const char* enc)

{

PyObject *readline, *open, *stream;

int fd;

long pos;

fd = fileno(tok->fp);

/* Due to buffering the file offset for fd can be different from the file

* position of tok->fp. If tok->fp was opened in text mode on Windows,

* its file position counts CRLF as one char and can't be directly mapped

* to the file offset for fd. Instead we step back one byte and read to

* the end of line.*/

pos = ftell(tok->fp);

if (pos == -1 ||

lseek(fd, (off_t)(pos > 0 ? pos - 1 : pos), SEEK_SET) == (off_t)-1) {

PyErr_SetFromErrnoWithFilename(PyExc_OSError, NULL);

return 0;

}

open = _PyImport_GetModuleAttrString("io", "open");

if (open == NULL) {

return 0;

}

stream = PyObject_CallFunction(open, "isisOOO",

fd, "r", -1, enc, Py_None, Py_None, Py_False);

Py_DECREF(open);

if (stream == NULL) {

return 0;

}

readline = PyObject_GetAttr(stream, &_Py_ID(readline));

Py_DECREF(stream);

if (readline == NULL) {

return 0;

}

Py_XSETREF(tok->decoding_readline, readline);

if (pos > 0) {

PyObject *bufobj = _PyObject_CallNoArgs(readline);

if (bufobj == NULL) {

return 0;

}

Py_DECREF(bufobj);

}

return 1;

}

/* Fetch the next byte from TOK. */

static int fp_getc(struct tok_state *tok) {

return getc(tok->fp);

}

/* Unfetch the last byte back into TOK. */

static void fp_ungetc(int c, struct tok_state *tok) {

ungetc(c, tok->fp);

}

/* Check whether the characters at s start a valid

UTF-8 sequence. Return the number of characters forming

the sequence if yes, 0 if not. */

static int valid_utf8(const unsigned char* s)

{

int expected = 0;

int length;

if (*s < 0x80)

/* single-byte code */

return 1;

if (*s < 0xc0)

/* following byte */

return 0;

if (*s < 0xE0)

expected = 1;

else if (*s < 0xF0)

expected = 2;

else if (*s < 0xF8)

expected = 3;

else

return 0;

length = expected + 1;

for (; expected; expected--)

if (s[expected] < 0x80 || s[expected] >= 0xC0)

return 0;

return length;

}

static int

ensure_utf8(char *line, struct tok_state *tok)

{

int badchar = 0;

unsigned char *c;

int length;

for (c = (unsigned char *)line; *c; c += length) {

if (!(length = valid_utf8(c))) {

badchar = *c;

break;

}

}

if (badchar) {

/* Need to add 1 to the line number, since this line

has not been counted, yet. */

PyErr_Format(PyExc_SyntaxError,

"Non-UTF-8 code starting with '\\x%.2x' "

"in file %U on line %i, "

"but no encoding declared; "

"see https://peps.python.org/pep-0263/ for details",

badchar, tok->filename, tok->lineno + 1);

return 0;

}

return 1;

}

/* Fetch a byte from TOK, using the string buffer. */

static int

buf_getc(struct tok_state *tok) {

return Py_CHARMASK(*tok->str++);

}

/* Unfetch a byte from TOK, using the string buffer. */

static void

buf_ungetc(int c, struct tok_state *tok) {

tok->str--;

assert(Py_CHARMASK(*tok->str) == c); /* tok->cur may point to read-only segment */

}

/* Set the readline function for TOK to ENC. For the string-based

tokenizer, this means to just record the encoding. */

static int

buf_setreadl(struct tok_state *tok, const char* enc) {

tok->enc = enc;

return 1;

}

/* Return a UTF-8 encoding Python string object from the

C byte string STR, which is encoded with ENC. */

static PyObject *

translate_into_utf8(const char* str, const char* enc) {

PyObject *utf8;

PyObject* buf = PyUnicode_Decode(str, strlen(str), enc, NULL);

if (buf == NULL)

return NULL;

utf8 = PyUnicode_AsUTF8String(buf);

Py_DECREF(buf);

return utf8;

}

static char *

translate_newlines(const char *s, int exec_input, struct tok_state *tok) {

int skip_next_lf = 0;

size_t needed_length = strlen(s) + 2, final_length;

char *buf, *current;

char c = '\0';

buf = PyMem_Malloc(needed_length);

if (buf == NULL) {

tok->done = E_NOMEM;

return NULL;

}

for (current = buf; *s; s++, current++) {

c = *s;

if (skip_next_lf) {

skip_next_lf = 0;

if (c == '\n') {

c = *++s;

if (!c)

break;

}

}

if (c == '\r') {

skip_next_lf = 1;

c = '\n';

}

*current = c;

}

/* If this is exec input, add a newline to the end of the string if

there isn't one already. */

if (exec_input && c != '\n') {

*current = '\n';

current++;

}

*current = '\0';

final_length = current - buf + 1;

if (final_length < needed_length && final_length) {

/* should never fail */

char* result = PyMem_Realloc(buf, final_length);

if (result == NULL) {

PyMem_Free(buf);

}

buf = result;

}

return buf;

}

/* Decode a byte string STR for use as the buffer of TOK.

Look for encoding declarations inside STR, and record them

inside TOK. */

static char *

decode_str(const char *input, int single, struct tok_state *tok)

{

PyObject* utf8 = NULL;

char *str;

const char *s;

const char *newl[2] = {NULL, NULL};

int lineno = 0;

tok->input = str = translate_newlines(input, single, tok);

if (str == NULL)

return NULL;

tok->enc = NULL;

tok->str = str;

if (!check_bom(buf_getc, buf_ungetc, buf_setreadl, tok))

return error_ret(tok);

str = tok->str; /* string after BOM if any */

assert(str);

if (tok->enc != NULL) {

utf8 = translate_into_utf8(str, tok->enc);

if (utf8 == NULL)

return error_ret(tok);

str = PyBytes_AsString(utf8);

}

for (s = str;; s++) {

if (*s == '\0') break;

else if (*s == '\n') {

assert(lineno < 2);

newl[lineno] = s;

lineno++;

if (lineno == 2) break;

}

}

tok->enc = NULL;

/* need to check line 1 and 2 separately since check_coding_spec

assumes a single line as input */

if (newl[0]) {

if (!check_coding_spec(str, newl[0] - str, tok, buf_setreadl)) {

return NULL;

}

if (tok->enc == NULL && tok->decoding_state != STATE_NORMAL && newl[1]) {

if (!check_coding_spec(newl[0]+1, newl[1] - newl[0],

tok, buf_setreadl))

return NULL;

}

}

if (tok->enc != NULL) {

assert(utf8 == NULL);

utf8 = translate_into_utf8(str, tok->enc);

if (utf8 == NULL)

return error_ret(tok);

str = PyBytes_AS_STRING(utf8);

}

assert(tok->decoding_buffer == NULL);

tok->decoding_buffer = utf8; /* CAUTION */

return str;

}

/* Set up tokenizer for string */

struct tok_state *

_PyTokenizer_FromString(const char *str, int exec_input)

{

struct tok_state *tok = tok_new();

char *decoded;

if (tok == NULL)

return NULL;

decoded = decode_str(str, exec_input, tok);

if (decoded == NULL) {

_PyTokenizer_Free(tok);

return NULL;

}

tok->buf = tok->cur = tok->inp = decoded;

tok->end = decoded;

return tok;

}

/* Set up tokenizer for UTF-8 string */

struct tok_state *

_PyTokenizer_FromUTF8(const char *str, int exec_input)

{

struct tok_state *tok = tok_new();

char *translated;

if (tok == NULL)

return NULL;

tok->input = translated = translate_newlines(str, exec_input, tok);

if (translated == NULL) {

_PyTokenizer_Free(tok);

return NULL;

}

tok->decoding_state = STATE_NORMAL;

tok->enc = NULL;

tok->str = translated;

tok->encoding = new_string("utf-8", 5, tok);

if (!tok->encoding) {

_PyTokenizer_Free(tok);

return NULL;

}

tok->buf = tok->cur = tok->inp = translated;

tok->end = translated;

return tok;

}

/* Set up tokenizer for file */

struct tok_state *

_PyTokenizer_FromFile(FILE *fp, const char* enc,

const char *ps1, const char *ps2)

{

struct tok_state *tok = tok_new();

if (tok == NULL)

return NULL;

if ((tok->buf = (char *)PyMem_Malloc(BUFSIZ)) == NULL) {

_PyTokenizer_Free(tok);

return NULL;

}

tok->cur = tok->inp = tok->buf;

tok->end = tok->buf + BUFSIZ;

tok->fp = fp;

tok->prompt = ps1;

tok->nextprompt = ps2;

if (enc != NULL) {

/* Must copy encoding declaration since it

gets copied into the parse tree. */

tok->encoding = new_string(enc, strlen(enc), tok);

if (!tok->encoding) {

_PyTokenizer_Free(tok);

return NULL;

}

tok->decoding_state = STATE_NORMAL;

}

return tok;

}

/* Free a tok_state structure */

void

_PyTokenizer_Free(struct tok_state *tok)

{

if (tok->encoding != NULL) {

PyMem_Free(tok->encoding);

}

Py_XDECREF(tok->decoding_readline);

Py_XDECREF(tok->decoding_buffer);

Py_XDECREF(tok->filename);

if (tok->fp != NULL && tok->buf != NULL) {

PyMem_Free(tok->buf);

}

if (tok->input) {

PyMem_Free(tok->input);

}

if (tok->interactive_src_start != NULL) {

PyMem_Free(tok->interactive_src_start);

}

PyMem_Free(tok);

}

static int

tok_readline_raw(struct tok_state *tok)

{

do {

if (!tok_reserve_buf(tok, BUFSIZ)) {

return 0;

}

char *line = Py_UniversalNewlineFgets(tok->inp,

(int)(tok->end - tok->inp),

tok->fp, NULL);

if (line == NULL) {

return 1;

}

if (tok->fp_interactive &&

tok_concatenate_interactive_new_line(tok, line) == -1) {

return 0;

}

tok->inp = strchr(tok->inp, '\0');

if (tok->inp == tok->buf) {

return 0;

}

} while (tok->inp[-1] != '\n');

return 1;

}

static int

tok_underflow_string(struct tok_state *tok) {

char *end = strchr(tok->inp, '\n');

if (end != NULL) {

end++;

}

else {

end = strchr(tok->inp, '\0');

if (end == tok->inp) {

tok->done = E_EOF;

return 0;

}

}

if (tok->start == NULL) {

tok->buf = tok->cur;

}

tok->line_start = tok->cur;

tok->lineno++;

tok->inp = end;

return 1;

}

static int

tok_underflow_interactive(struct tok_state *tok) {

if (tok->interactive_underflow == IUNDERFLOW_STOP) {

tok->done = E_INTERACT_STOP;

return 1;

}

char *newtok = PyOS_Readline(tok->fp ? tok->fp : stdin, stdout, tok->prompt);

if (newtok != NULL) {

char *translated = translate_newlines(newtok, 0, tok);

PyMem_Free(newtok);

if (translated == NULL) {

return 0;

}

newtok = translated;

}

if (tok->encoding && newtok && *newtok) {

/* Recode to UTF-8 */

Py_ssize_t buflen;

const char* buf;

PyObject *u = translate_into_utf8(newtok, tok->encoding);

PyMem_Free(newtok);

if (u == NULL) {

tok->done = E_DECODE;

return 0;

}

buflen = PyBytes_GET_SIZE(u);

buf = PyBytes_AS_STRING(u);

newtok = PyMem_Malloc(buflen+1);

if (newtok == NULL) {

Py_DECREF(u);

tok->done = E_NOMEM;

return 0;

}

strcpy(newtok, buf);

Py_DECREF(u);

}

if (tok->fp_interactive &&

tok_concatenate_interactive_new_line(tok, newtok) == -1) {

PyMem_Free(newtok);

return 0;

}

if (tok->nextprompt != NULL) {

tok->prompt = tok->nextprompt;

}

if (newtok == NULL) {

tok->done = E_INTR;

}

else if (*newtok == '\0') {

PyMem_Free(newtok);

tok->done = E_EOF;

}

else if (tok->start != NULL) {

Py_ssize_t cur_multi_line_start = tok->multi_line_start - tok->buf;

size_t size = strlen(newtok);

tok->lineno++;

if (!tok_reserve_buf(tok, size + 1)) {

PyMem_Free(tok->buf);

tok->buf = NULL;

PyMem_Free(newtok);

return 0;

}

memcpy(tok->cur, newtok, size + 1);

PyMem_Free(newtok);

tok->inp += size;

tok->multi_line_start = tok->buf + cur_multi_line_start;

}

else {

tok->lineno++;

PyMem_Free(tok->buf);

tok->buf = newtok;

tok->cur = tok->buf;

tok->line_start = tok->buf;

tok->inp = strchr(tok->buf, '\0');

tok->end = tok->inp + 1;

}

if (tok->done != E_OK) {

if (tok->prompt != NULL) {

PySys_WriteStderr("\n");

}

return 0;

}

return 1;

}

static int

tok_underflow_file(struct tok_state *tok) {

if (tok->start == NULL) {

tok->cur = tok->inp = tok->buf;

}

if (tok->decoding_state == STATE_INIT) {

/* We have not yet determined the encoding.

If an encoding is found, use the file-pointer

reader functions from now on. */

if (!check_bom(fp_getc, fp_ungetc, fp_setreadl, tok)) {

error_ret(tok);

return 0;

}

assert(tok->decoding_state != STATE_INIT);

}

/* Read until '\n' or EOF */

if (tok->decoding_readline != NULL) {

/* We already have a codec associated with this input. */

if (!tok_readline_recode(tok)) {

return 0;

}

}

else {

/* We want a 'raw' read. */

if (!tok_readline_raw(tok)) {

return 0;

}

}

if (tok->inp == tok->cur) {

tok->done = E_EOF;

return 0;

}

if (tok->inp[-1] != '\n') {

/* Last line does not end in \n, fake one */

*tok->inp++ = '\n';

*tok->inp = '\0';

}

tok->lineno++;

if (tok->decoding_state != STATE_NORMAL) {

if (tok->lineno > 2) {

tok->decoding_state = STATE_NORMAL;

}

else if (!check_coding_spec(tok->cur, strlen(tok->cur),

tok, fp_setreadl))

{

return 0;

}

}

/* The default encoding is UTF-8, so make sure we don't have any

non-UTF-8 sequences in it. */

if (!tok->encoding && !ensure_utf8(tok->cur, tok)) {

error_ret(tok);

return 0;

}

assert(tok->done == E_OK);

return tok->done == E_OK;

}

#if defined(Py_DEBUG)

static void

print_escape(FILE *f, const char *s, Py_ssize_t size)

{

if (s == NULL) {

fputs("NULL", f);

return;

}

putc('"', f);

while (size-- > 0) {

unsigned char c = *s++;

switch (c) {

case '\n': fputs("\\n", f); break;

case '\r': fputs("\\r", f); break;

case '\t': fputs("\\t", f); break;

case '\f': fputs("\\f", f); break;

case '\'': fputs("\\'", f); break;

case '"': fputs("\\\"", f); break;