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cpython/Parser/lexer/lexer.c

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#include "Python.h"
#include "pycore_token.h"
#include "pycore_unicodeobject.h"
#include "errcode.h"
#include "state.h"
#include "../tokenizer/helpers.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))
#ifdef Py_DEBUG
static inline tokenizer_mode* TOK_GET_MODE(struct tok_state* tok) {
assert(tok->tok_mode_stack_index >= 0);
assert(tok->tok_mode_stack_index < MAXFSTRINGLEVEL);
return &(tok->tok_mode_stack[tok->tok_mode_stack_index]);
}
static inline tokenizer_mode* TOK_NEXT_MODE(struct tok_state* tok) {
assert(tok->tok_mode_stack_index >= 0);
assert(tok->tok_mode_stack_index + 1 < MAXFSTRINGLEVEL);
return &(tok->tok_mode_stack[++tok->tok_mode_stack_index]);
}
#else
#define TOK_GET_MODE(tok) (&(tok->tok_mode_stack[tok->tok_mode_stack_index]))
#define TOK_NEXT_MODE(tok) (&(tok->tok_mode_stack[++tok->tok_mode_stack_index]))
#endif
#define MAKE_TOKEN(token_type) _PyLexer_token_setup(tok, token, token_type, p_start, p_end)
#define MAKE_TYPE_COMMENT_TOKEN(token_type, col_offset, end_col_offset) (\
_PyLexer_type_comment_token_setup(tok, token, token_type, col_offset, end_col_offset, p_start, p_end))
/* Spaces in this constant are treated as "zero or more spaces or tabs" when
tokenizing. */
static const char* type_comment_prefix = "# type: ";
static inline int
contains_null_bytes(const char* str, size_t size)
{
return memchr(str, 0, size) != NULL;
}
/* Get next char, updating state; error code goes into tok->done */
static int
tok_nextc(struct tok_state *tok)
{
int rc;
for (;;) {
if (tok->cur != tok->inp) {
if ((unsigned int) tok->col_offset >= (unsigned int) INT_MAX) {
tok->done = E_COLUMNOVERFLOW;
return EOF;
}
tok->col_offset++;
return Py_CHARMASK(*tok->cur++); /* Fast path */
}
if (tok->done != E_OK) {
return EOF;
}
rc = tok->underflow(tok);
#if defined(Py_DEBUG)
if (tok->debug) {
fprintf(stderr, "line[%d] = ", tok->lineno);
_PyTokenizer_print_escape(stderr, tok->cur, tok->inp - tok->cur);
fprintf(stderr, " tok->done = %d\n", tok->done);
}
#endif
if (!rc) {
tok->cur = tok->inp;
return EOF;
}
tok->line_start = tok->cur;
if (contains_null_bytes(tok->line_start, tok->inp - tok->line_start)) {
_PyTokenizer_syntaxerror(tok, "source code cannot contain null bytes");
tok->cur = tok->inp;
return EOF;
}
}
Py_UNREACHABLE();
}
/* Back-up one character */
static void
tok_backup(struct tok_state *tok, int c)
{
if (c != EOF) {
if (--tok->cur < tok->buf) {
Py_FatalError("tokenizer beginning of buffer");
}
if ((int)(unsigned char)*tok->cur != Py_CHARMASK(c)) {
Py_FatalError("tok_backup: wrong character");
}
tok->col_offset--;
}
}
static int
set_fstring_expr(struct tok_state* tok, struct token *token, char c) {
assert(token != NULL);
assert(c == '}' || c == ':' || c == '!');
tokenizer_mode *tok_mode = TOK_GET_MODE(tok);
if (!tok_mode->f_string_debug || token->metadata) {
return 0;
}
PyObject *res = NULL;
// Check if there is a # character in the expression
int hash_detected = 0;
for (Py_ssize_t i = 0; i < tok_mode->last_expr_size - tok_mode->last_expr_end; i++) {
if (tok_mode->last_expr_buffer[i] == '#') {
hash_detected = 1;
break;
}
}
if (hash_detected) {
Py_ssize_t input_length = tok_mode->last_expr_size - tok_mode->last_expr_end;
char *result = (char *)PyMem_Malloc((input_length + 1) * sizeof(char));
if (!result) {
return -1;
}
Py_ssize_t i = 0;
Py_ssize_t j = 0;
for (i = 0, j = 0; i < input_length; i++) {
if (tok_mode->last_expr_buffer[i] == '#') {
// Skip characters until newline or end of string
while (tok_mode->last_expr_buffer[i] != '\0' && i < input_length) {
if (tok_mode->last_expr_buffer[i] == '\n') {
result[j++] = tok_mode->last_expr_buffer[i];
break;
}
i++;
}
} else {
result[j++] = tok_mode->last_expr_buffer[i];
}
}
result[j] = '\0'; // Null-terminate the result string
res = PyUnicode_DecodeUTF8(result, j, NULL);
PyMem_Free(result);
} else {
res = PyUnicode_DecodeUTF8(
tok_mode->last_expr_buffer,
tok_mode->last_expr_size - tok_mode->last_expr_end,
NULL
);
}
if (!res) {
return -1;
}
token->metadata = res;
return 0;
}
int
_PyLexer_update_fstring_expr(struct tok_state *tok, char cur)
{
assert(tok->cur != NULL);
Py_ssize_t size = strlen(tok->cur);
tokenizer_mode *tok_mode = TOK_GET_MODE(tok);
switch (cur) {
case 0:
if (!tok_mode->last_expr_buffer || tok_mode->last_expr_end >= 0) {
return 1;
}
char *new_buffer = PyMem_Realloc(
tok_mode->last_expr_buffer,
tok_mode->last_expr_size + size
);
if (new_buffer == NULL) {
PyMem_Free(tok_mode->last_expr_buffer);
goto error;
}
tok_mode->last_expr_buffer = new_buffer;
strncpy(tok_mode->last_expr_buffer + tok_mode->last_expr_size, tok->cur, size);
tok_mode->last_expr_size += size;
break;
case '{':
if (tok_mode->last_expr_buffer != NULL) {
PyMem_Free(tok_mode->last_expr_buffer);
}
tok_mode->last_expr_buffer = PyMem_Malloc(size);
if (tok_mode->last_expr_buffer == NULL) {
goto error;
}
tok_mode->last_expr_size = size;
tok_mode->last_expr_end = -1;
strncpy(tok_mode->last_expr_buffer, tok->cur, size);
break;
case '}':
case '!':
tok_mode->last_expr_end = strlen(tok->start);
break;
case ':':
if (tok_mode->last_expr_end == -1) {
tok_mode->last_expr_end = strlen(tok->start);
}
break;
default:
Py_UNREACHABLE();
}
return 1;
error:
tok->done = E_NOMEM;
return 0;
}
static int
lookahead(struct tok_state *tok, const char *test)
{
const char *s = test;
int res = 0;
while (1) {
int c = tok_nextc(tok);
if (*s == 0) {
res = !is_potential_identifier_char(c);
}
else if (c == *s) {
s++;
continue;
}
tok_backup(tok, c);
while (s != test) {
tok_backup(tok, *--s);
}
return res;
}
}
static int
verify_end_of_number(struct tok_state *tok, int c, const char *kind) {
if (tok->tok_extra_tokens) {
// When we are parsing extra tokens, we don't want to emit warnings
// about invalid literals, because we want to be a bit more liberal.
return 1;
}
/* Emit a deprecation warning only if the numeric literal is immediately
* followed by one of keywords which can occur after a numeric literal
* in valid code: "and", "else", "for", "if", "in", "is" and "or".
* It allows to gradually deprecate existing valid code without adding
* warning before error in most cases of invalid numeric literal (which
* would be confusing and break existing tests).
* Raise a syntax error with slightly better message than plain
* "invalid syntax" if the numeric literal is immediately followed by
* other keyword or identifier.
*/
int r = 0;
if (c == 'a') {
r = lookahead(tok, "nd");
}
else if (c == 'e') {
r = lookahead(tok, "lse");
}
else if (c == 'f') {
r = lookahead(tok, "or");
}
else if (c == 'i') {
int c2 = tok_nextc(tok);
if (c2 == 'f' || c2 == 'n' || c2 == 's') {
r = 1;
}
tok_backup(tok, c2);
}
else if (c == 'o') {
r = lookahead(tok, "r");
}
else if (c == 'n') {
r = lookahead(tok, "ot");
}
if (r) {
tok_backup(tok, c);
if (_PyTokenizer_parser_warn(tok, PyExc_SyntaxWarning,
"invalid %s literal", kind))
{
return 0;
}
tok_nextc(tok);
}
else /* In future releases, only error will remain. */
if (c < 128 && is_potential_identifier_char(c)) {
tok_backup(tok, c);
_PyTokenizer_syntaxerror(tok, "invalid %s literal", kind);
return 0;
}
return 1;
}
/* Verify that the identifier follows PEP 3131. */
static int
verify_identifier(struct tok_state *tok)
{
if (tok->tok_extra_tokens) {
return 1;
}
PyObject *s;
if (tok->decoding_erred)
return 0;
s = PyUnicode_DecodeUTF8(tok->start, tok->cur - tok->start, NULL);
if (s == NULL) {
if (PyErr_ExceptionMatches(PyExc_UnicodeDecodeError)) {
tok->done = E_DECODE;
}
else {
tok->done = E_ERROR;
}
return 0;
}
Py_ssize_t invalid = _PyUnicode_ScanIdentifier(s);
assert(invalid >= 0);
assert(PyUnicode_GET_LENGTH(s) > 0);
if (invalid < PyUnicode_GET_LENGTH(s)) {
Py_UCS4 ch = PyUnicode_READ_CHAR(s, invalid);
if (invalid + 1 < PyUnicode_GET_LENGTH(s)) {
/* Determine the offset in UTF-8 encoded input */
Py_SETREF(s, PyUnicode_Substring(s, 0, invalid + 1));
if (s != NULL) {
Py_SETREF(s, PyUnicode_AsUTF8String(s));
}
if (s == NULL) {
tok->done = E_ERROR;
return 0;
}
tok->cur = (char *)tok->start + PyBytes_GET_SIZE(s);
}
Py_DECREF(s);
if (Py_UNICODE_ISPRINTABLE(ch)) {
_PyTokenizer_syntaxerror(tok, "invalid character '%c' (U+%04X)", ch, ch);
}
else {
_PyTokenizer_syntaxerror(tok, "invalid non-printable character U+%04X", ch);
}
return 0;
}
Py_DECREF(s);
return 1;
}
static int
tok_decimal_tail(struct tok_state *tok)
{
int c;
while (1) {
do {
c = tok_nextc(tok);
} while (Py_ISDIGIT(c));
if (c != '_') {
break;
}
c = tok_nextc(tok);
if (!Py_ISDIGIT(c)) {
tok_backup(tok, c);
_PyTokenizer_syntaxerror(tok, "invalid decimal literal");
return 0;
}
}
return c;
}
static inline int
tok_continuation_line(struct tok_state *tok) {
int c = tok_nextc(tok);
if (c == '\r') {
c = tok_nextc(tok);
}
if (c != '\n') {
tok->done = E_LINECONT;
return -1;
}
c = tok_nextc(tok);
if (c == EOF) {
tok->done = E_EOF;
tok->cur = tok->inp;
return -1;
} else {
tok_backup(tok, c);
}
return c;
}
static int
tok_get_normal_mode(struct tok_state *tok, tokenizer_mode* current_tok, struct token *token)
{
int c;
int blankline, nonascii;
const char *p_start = NULL;
const char *p_end = NULL;
nextline:
tok->start = NULL;
tok->starting_col_offset = -1;
blankline = 0;
/* Get indentation level */
if (tok->atbol) {
int col = 0;
int altcol = 0;
tok->atbol = 0;
int cont_line_col = 0;
for (;;) {
c = tok_nextc(tok);
if (c == ' ') {
col++, altcol++;
}
else if (c == '\t') {
col = (col / tok->tabsize + 1) * tok->tabsize;
altcol = (altcol / ALTTABSIZE + 1) * ALTTABSIZE;
}
else if (c == '\014') {/* Control-L (formfeed) */
col = altcol = 0; /* For Emacs users */
}
else if (c == '\\') {
// Indentation cannot be split over multiple physical lines
// using backslashes. This means that if we found a backslash
// preceded by whitespace, **the first one we find** determines
// the level of indentation of whatever comes next.
cont_line_col = cont_line_col ? cont_line_col : col;
if ((c = tok_continuation_line(tok)) == -1) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
else {
break;
}
}
tok_backup(tok, c);
if (c == '#' || c == '\n' || c == '\r') {
/* Lines with only whitespace and/or comments
shouldn't affect the indentation and are
not passed to the parser as NEWLINE tokens,
except *totally* empty lines in interactive
mode, which signal the end of a command group. */
if (col == 0 && c == '\n' && tok->prompt != NULL) {
blankline = 0; /* Let it through */
}
else if (tok->prompt != NULL && tok->lineno == 1) {
/* In interactive mode, if the first line contains
only spaces and/or a comment, let it through. */
blankline = 0;
col = altcol = 0;
}
else {
blankline = 1; /* Ignore completely */
}
/* We can't jump back right here since we still
may need to skip to the end of a comment */
}
if (!blankline && tok->level == 0) {
col = cont_line_col ? cont_line_col : col;
altcol = cont_line_col ? cont_line_col : altcol;
if (col == tok->indstack[tok->indent]) {
/* No change */
if (altcol != tok->altindstack[tok->indent]) {
return MAKE_TOKEN(_PyTokenizer_indenterror(tok));
}
}
else if (col > tok->indstack[tok->indent]) {
/* Indent -- always one */
if (tok->indent+1 >= MAXINDENT) {
tok->done = E_TOODEEP;
tok->cur = tok->inp;
return MAKE_TOKEN(ERRORTOKEN);
}
if (altcol <= tok->altindstack[tok->indent]) {
return MAKE_TOKEN(_PyTokenizer_indenterror(tok));
}
tok->pendin++;
tok->indstack[++tok->indent] = col;
tok->altindstack[tok->indent] = altcol;
}
else /* col < tok->indstack[tok->indent] */ {
/* Dedent -- any number, must be consistent */
while (tok->indent > 0 &&
col < tok->indstack[tok->indent]) {
tok->pendin--;
tok->indent--;
}
if (col != tok->indstack[tok->indent]) {
tok->done = E_DEDENT;
tok->cur = tok->inp;
return MAKE_TOKEN(ERRORTOKEN);
}
if (altcol != tok->altindstack[tok->indent]) {
return MAKE_TOKEN(_PyTokenizer_indenterror(tok));
}
}
}
}
tok->start = tok->cur;
tok->starting_col_offset = tok->col_offset;
/* Return pending indents/dedents */
if (tok->pendin != 0) {
if (tok->pendin < 0) {
if (tok->tok_extra_tokens) {
p_start = tok->cur;
p_end = tok->cur;
}
tok->pendin++;
return MAKE_TOKEN(DEDENT);
}
else {
if (tok->tok_extra_tokens) {
p_start = tok->buf;
p_end = tok->cur;
}
tok->pendin--;
return MAKE_TOKEN(INDENT);
}
}
/* Peek ahead at the next character */
c = tok_nextc(tok);
tok_backup(tok, c);
again:
tok->start = NULL;
/* Skip spaces */
do {
c = tok_nextc(tok);
} while (c == ' ' || c == '\t' || c == '\014');
/* Set start of current token */
tok->start = tok->cur == NULL ? NULL : tok->cur - 1;
tok->starting_col_offset = tok->col_offset - 1;
/* Skip comment, unless it's a type comment */
if (c == '#') {
const char* p = NULL;
const char *prefix, *type_start;
int current_starting_col_offset;
while (c != EOF && c != '\n' && c != '\r') {
c = tok_nextc(tok);
}
if (tok->tok_extra_tokens) {
p = tok->start;
}
if (tok->type_comments) {
p = tok->start;
current_starting_col_offset = tok->starting_col_offset;
prefix = type_comment_prefix;
while (*prefix && p < tok->cur) {
if (*prefix == ' ') {
while (*p == ' ' || *p == '\t') {
p++;
current_starting_col_offset++;
}
} else if (*prefix == *p) {
p++;
current_starting_col_offset++;
} else {
break;
}
prefix++;
}
/* This is a type comment if we matched all of type_comment_prefix. */
if (!*prefix) {
int is_type_ignore = 1;
// +6 in order to skip the word 'ignore'
const char *ignore_end = p + 6;
const int ignore_end_col_offset = current_starting_col_offset + 6;
tok_backup(tok, c); /* don't eat the newline or EOF */
type_start = p;
/* A TYPE_IGNORE is "type: ignore" followed by the end of the token
* or anything ASCII and non-alphanumeric. */
is_type_ignore = (
tok->cur >= ignore_end && memcmp(p, "ignore", 6) == 0
&& !(tok->cur > ignore_end
&& ((unsigned char)ignore_end[0] >= 128 || Py_ISALNUM(ignore_end[0]))));
if (is_type_ignore) {
p_start = ignore_end;
p_end = tok->cur;
/* If this type ignore is the only thing on the line, consume the newline also. */
if (blankline) {
tok_nextc(tok);
tok->atbol = 1;
}
return MAKE_TYPE_COMMENT_TOKEN(TYPE_IGNORE, ignore_end_col_offset, tok->col_offset);
} else {
p_start = type_start;
p_end = tok->cur;
return MAKE_TYPE_COMMENT_TOKEN(TYPE_COMMENT, current_starting_col_offset, tok->col_offset);
}
}
}
if (tok->tok_extra_tokens) {
tok_backup(tok, c); /* don't eat the newline or EOF */
p_start = p;
p_end = tok->cur;
tok->comment_newline = blankline;
return MAKE_TOKEN(COMMENT);
}
}
if (tok->done == E_INTERACT_STOP) {
return MAKE_TOKEN(ENDMARKER);
}
/* Check for EOF and errors now */
if (c == EOF) {
if (tok->level) {
return MAKE_TOKEN(ERRORTOKEN);
}
return MAKE_TOKEN(tok->done == E_EOF ? ENDMARKER : ERRORTOKEN);
}
/* Identifier (most frequent token!) */
nonascii = 0;
if (is_potential_identifier_start(c)) {
/* Process the various legal combinations of b"", r"", u"", and f"". */
int saw_b = 0, saw_r = 0, saw_u = 0, saw_f = 0;
while (1) {
if (!(saw_b || saw_u || saw_f) && (c == 'b' || c == 'B'))
saw_b = 1;
/* Since this is a backwards compatibility support literal we don't
want to support it in arbitrary order like byte literals. */
else if (!(saw_b || saw_u || saw_r || saw_f)
&& (c == 'u'|| c == 'U')) {
saw_u = 1;
}
/* ur"" and ru"" are not supported */
else if (!(saw_r || saw_u) && (c == 'r' || c == 'R')) {
saw_r = 1;
}
else if (!(saw_f || saw_b || saw_u) && (c == 'f' || c == 'F')) {
saw_f = 1;
}
else {
break;
}
c = tok_nextc(tok);
if (c == '"' || c == '\'') {
if (saw_f) {
goto f_string_quote;
}
goto letter_quote;
}
}
while (is_potential_identifier_char(c)) {
if (c >= 128) {
nonascii = 1;
}
c = tok_nextc(tok);
}
tok_backup(tok, c);
if (nonascii && !verify_identifier(tok)) {
return MAKE_TOKEN(ERRORTOKEN);
}
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(NAME);
}
if (c == '\r') {
c = tok_nextc(tok);
}
/* Newline */
if (c == '\n') {
tok->atbol = 1;
if (blankline || tok->level > 0) {
if (tok->tok_extra_tokens) {
if (tok->comment_newline) {
tok->comment_newline = 0;
}
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(NL);
}
goto nextline;
}
if (tok->comment_newline && tok->tok_extra_tokens) {
tok->comment_newline = 0;
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(NL);
}
p_start = tok->start;
p_end = tok->cur - 1; /* Leave '\n' out of the string */
tok->cont_line = 0;
return MAKE_TOKEN(NEWLINE);
}
/* Period or number starting with period? */
if (c == '.') {
c = tok_nextc(tok);
if (Py_ISDIGIT(c)) {
goto fraction;
} else if (c == '.') {
c = tok_nextc(tok);
if (c == '.') {
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(ELLIPSIS);
}
else {
tok_backup(tok, c);
}
tok_backup(tok, '.');
}
else {
tok_backup(tok, c);
}
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(DOT);
}
/* Number */
if (Py_ISDIGIT(c)) {
if (c == '0') {
/* Hex, octal or binary -- maybe. */
c = tok_nextc(tok);
if (c == 'x' || c == 'X') {
/* Hex */
c = tok_nextc(tok);
do {
if (c == '_') {
c = tok_nextc(tok);
}
if (!Py_ISXDIGIT(c)) {
tok_backup(tok, c);
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "invalid hexadecimal literal"));
}
do {
c = tok_nextc(tok);
} while (Py_ISXDIGIT(c));
} while (c == '_');
if (!verify_end_of_number(tok, c, "hexadecimal")) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
else if (c == 'o' || c == 'O') {
/* Octal */
c = tok_nextc(tok);
do {
if (c == '_') {
c = tok_nextc(tok);
}
if (c < '0' || c >= '8') {
if (Py_ISDIGIT(c)) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok,
"invalid digit '%c' in octal literal", c));
}
else {
tok_backup(tok, c);
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "invalid octal literal"));
}
}
do {
c = tok_nextc(tok);
} while ('0' <= c && c < '8');
} while (c == '_');
if (Py_ISDIGIT(c)) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok,
"invalid digit '%c' in octal literal", c));
}
if (!verify_end_of_number(tok, c, "octal")) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
else if (c == 'b' || c == 'B') {
/* Binary */
c = tok_nextc(tok);
do {
if (c == '_') {
c = tok_nextc(tok);
}
if (c != '0' && c != '1') {
if (Py_ISDIGIT(c)) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "invalid digit '%c' in binary literal", c));
}
else {
tok_backup(tok, c);
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "invalid binary literal"));
}
}
do {
c = tok_nextc(tok);
} while (c == '0' || c == '1');
} while (c == '_');
if (Py_ISDIGIT(c)) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "invalid digit '%c' in binary literal", c));
}
if (!verify_end_of_number(tok, c, "binary")) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
else {
int nonzero = 0;
/* maybe old-style octal; c is first char of it */
/* in any case, allow '0' as a literal */
while (1) {
if (c == '_') {
c = tok_nextc(tok);
if (!Py_ISDIGIT(c)) {
tok_backup(tok, c);
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "invalid decimal literal"));
}
}
if (c != '0') {
break;
}
c = tok_nextc(tok);
}
char* zeros_end = tok->cur;
if (Py_ISDIGIT(c)) {
nonzero = 1;
c = tok_decimal_tail(tok);
if (c == 0) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
if (c == '.') {
c = tok_nextc(tok);
goto fraction;
}
else if (c == 'e' || c == 'E') {
goto exponent;
}
else if (c == 'j' || c == 'J') {
goto imaginary;
}
else if (nonzero && !tok->tok_extra_tokens) {
/* Old-style octal: now disallowed. */
tok_backup(tok, c);
return MAKE_TOKEN(_PyTokenizer_syntaxerror_known_range(
tok, (int)(tok->start + 1 - tok->line_start),
(int)(zeros_end - tok->line_start),
"leading zeros in decimal integer "
"literals are not permitted; "
"use an 0o prefix for octal integers"));
}
if (!verify_end_of_number(tok, c, "decimal")) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
}
else {
/* Decimal */
c = tok_decimal_tail(tok);
if (c == 0) {
return MAKE_TOKEN(ERRORTOKEN);
}
{
/* Accept floating-point numbers. */
if (c == '.') {
c = tok_nextc(tok);
fraction:
/* Fraction */
if (Py_ISDIGIT(c)) {
c = tok_decimal_tail(tok);
if (c == 0) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
}
if (c == 'e' || c == 'E') {
int e;
exponent:
e = c;
/* Exponent part */
c = tok_nextc(tok);
if (c == '+' || c == '-') {
c = tok_nextc(tok);
if (!Py_ISDIGIT(c)) {
tok_backup(tok, c);
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "invalid decimal literal"));
}
} else if (!Py_ISDIGIT(c)) {
tok_backup(tok, c);
if (!verify_end_of_number(tok, e, "decimal")) {
return MAKE_TOKEN(ERRORTOKEN);
}
tok_backup(tok, e);
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(NUMBER);
}
c = tok_decimal_tail(tok);
if (c == 0) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
if (c == 'j' || c == 'J') {
/* Imaginary part */
imaginary:
c = tok_nextc(tok);
if (!verify_end_of_number(tok, c, "imaginary")) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
else if (!verify_end_of_number(tok, c, "decimal")) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
}
tok_backup(tok, c);
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(NUMBER);
}
f_string_quote:
if (((Py_TOLOWER(*tok->start) == 'f' || Py_TOLOWER(*tok->start) == 'r') && (c == '\'' || c == '"'))) {
int quote = c;
int quote_size = 1; /* 1 or 3 */
/* Nodes of type STRING, especially multi line strings
must be handled differently in order to get both
the starting line number and the column offset right.
(cf. issue 16806) */
tok->first_lineno = tok->lineno;
tok->multi_line_start = tok->line_start;
/* Find the quote size and start of string */
int after_quote = tok_nextc(tok);
if (after_quote == quote) {
int after_after_quote = tok_nextc(tok);
if (after_after_quote == quote) {
quote_size = 3;
}
else {
// TODO: Check this
tok_backup(tok, after_after_quote);
tok_backup(tok, after_quote);
}
}
if (after_quote != quote) {
tok_backup(tok, after_quote);
}
p_start = tok->start;
p_end = tok->cur;
if (tok->tok_mode_stack_index + 1 >= MAXFSTRINGLEVEL) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "too many nested f-strings"));
}
tokenizer_mode *the_current_tok = TOK_NEXT_MODE(tok);
the_current_tok->kind = TOK_FSTRING_MODE;
the_current_tok->f_string_quote = quote;
the_current_tok->f_string_quote_size = quote_size;
the_current_tok->f_string_start = tok->start;
the_current_tok->f_string_multi_line_start = tok->line_start;
the_current_tok->f_string_line_start = tok->lineno;
the_current_tok->f_string_start_offset = -1;
the_current_tok->f_string_multi_line_start_offset = -1;
the_current_tok->last_expr_buffer = NULL;
the_current_tok->last_expr_size = 0;
the_current_tok->last_expr_end = -1;
the_current_tok->in_format_spec = 0;
the_current_tok->f_string_debug = 0;
switch (*tok->start) {
case 'F':
case 'f':
the_current_tok->f_string_raw = Py_TOLOWER(*(tok->start + 1)) == 'r';
break;
case 'R':
case 'r':
the_current_tok->f_string_raw = 1;
break;
default:
Py_UNREACHABLE();
}
the_current_tok->curly_bracket_depth = 0;
the_current_tok->curly_bracket_expr_start_depth = -1;
return MAKE_TOKEN(FSTRING_START);
}
letter_quote:
/* String */
if (c == '\'' || c == '"') {
int quote = c;
int quote_size = 1; /* 1 or 3 */
int end_quote_size = 0;
int has_escaped_quote = 0;
/* Nodes of type STRING, especially multi line strings
must be handled differently in order to get both
the starting line number and the column offset right.
(cf. issue 16806) */
tok->first_lineno = tok->lineno;
tok->multi_line_start = tok->line_start;
/* Find the quote size and start of string */
c = tok_nextc(tok);
if (c == quote) {
c = tok_nextc(tok);
if (c == quote) {
quote_size = 3;
}
else {
end_quote_size = 1; /* empty string found */
}
}
if (c != quote) {
tok_backup(tok, c);
}
/* Get rest of string */
while (end_quote_size != quote_size) {
c = tok_nextc(tok);
if (tok->done == E_ERROR) {
return MAKE_TOKEN(ERRORTOKEN);
}
if (tok->done == E_DECODE) {
break;
}
if (c == EOF || (quote_size == 1 && c == '\n')) {
assert(tok->multi_line_start != NULL);
// shift the tok_state's location into
// the start of string, and report the error
// from the initial quote character
tok->cur = (char *)tok->start;
tok->cur++;
tok->line_start = tok->multi_line_start;
int start = tok->lineno;
tok->lineno = tok->first_lineno;
if (INSIDE_FSTRING(tok)) {
/* When we are in an f-string, before raising the
* unterminated string literal error, check whether
* does the initial quote matches with f-strings quotes
* and if it is, then this must be a missing '}' token
* so raise the proper error */
tokenizer_mode *the_current_tok = TOK_GET_MODE(tok);
if (the_current_tok->f_string_quote == quote &&
the_current_tok->f_string_quote_size == quote_size) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "f-string: expecting '}'", start));
}
}
if (quote_size == 3) {
_PyTokenizer_syntaxerror(tok, "unterminated triple-quoted string literal"
" (detected at line %d)", start);
if (c != '\n') {
tok->done = E_EOFS;
}
return MAKE_TOKEN(ERRORTOKEN);
}
else {
if (has_escaped_quote) {
_PyTokenizer_syntaxerror(
tok,
"unterminated string literal (detected at line %d); "
"perhaps you escaped the end quote?",
start
);
} else {
_PyTokenizer_syntaxerror(
tok, "unterminated string literal (detected at line %d)", start
);
}
if (c != '\n') {
tok->done = E_EOLS;
}
return MAKE_TOKEN(ERRORTOKEN);
}
}
if (c == quote) {
end_quote_size += 1;
}
else {
end_quote_size = 0;
if (c == '\\') {
c = tok_nextc(tok); /* skip escaped char */
if (c == quote) { /* but record whether the escaped char was a quote */
has_escaped_quote = 1;
}
if (c == '\r') {
c = tok_nextc(tok);
}
}
}
}
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(STRING);
}
/* Line continuation */
if (c == '\\') {
if ((c = tok_continuation_line(tok)) == -1) {
return MAKE_TOKEN(ERRORTOKEN);
}
tok->cont_line = 1;
goto again; /* Read next line */
}
/* Punctuation character */
int is_punctuation = (c == ':' || c == '}' || c == '!' || c == '{');
if (is_punctuation && INSIDE_FSTRING(tok) && INSIDE_FSTRING_EXPR(current_tok)) {
/* This code block gets executed before the curly_bracket_depth is incremented
* by the `{` case, so for ensuring that we are on the 0th level, we need
* to adjust it manually */
int cursor = current_tok->curly_bracket_depth - (c != '{');
int in_format_spec = current_tok->in_format_spec;
int cursor_in_format_with_debug =
cursor == 1 && (current_tok->f_string_debug || in_format_spec);
int cursor_valid = cursor == 0 || cursor_in_format_with_debug;
if ((cursor_valid) && !_PyLexer_update_fstring_expr(tok, c)) {
return MAKE_TOKEN(ENDMARKER);
}
if ((cursor_valid) && c != '{' && set_fstring_expr(tok, token, c)) {
return MAKE_TOKEN(ERRORTOKEN);
}
if (c == ':' && cursor == current_tok->curly_bracket_expr_start_depth) {
current_tok->kind = TOK_FSTRING_MODE;
current_tok->in_format_spec = 1;
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(_PyToken_OneChar(c));
}
}
/* Check for two-character token */
{
int c2 = tok_nextc(tok);
int current_token = _PyToken_TwoChars(c, c2);
if (current_token != OP) {
int c3 = tok_nextc(tok);
int current_token3 = _PyToken_ThreeChars(c, c2, c3);
if (current_token3 != OP) {
current_token = current_token3;
}
else {
tok_backup(tok, c3);
}
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(current_token);
}
tok_backup(tok, c2);
}
/* Keep track of parentheses nesting level */
switch (c) {
case '(':
case '[':
case '{':
if (tok->level >= MAXLEVEL) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "too many nested parentheses"));
}
tok->parenstack[tok->level] = c;
tok->parenlinenostack[tok->level] = tok->lineno;
tok->parencolstack[tok->level] = (int)(tok->start - tok->line_start);
tok->level++;
if (INSIDE_FSTRING(tok)) {
current_tok->curly_bracket_depth++;
}
break;
case ')':
case ']':
case '}':
if (INSIDE_FSTRING(tok) && !current_tok->curly_bracket_depth && c == '}') {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "f-string: single '}' is not allowed"));
}
if (!tok->tok_extra_tokens && !tok->level) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "unmatched '%c'", c));
}
if (tok->level > 0) {
tok->level--;
int opening = tok->parenstack[tok->level];
if (!tok->tok_extra_tokens && !((opening == '(' && c == ')') ||
(opening == '[' && c == ']') ||
(opening == '{' && c == '}'))) {
/* If the opening bracket belongs to an f-string's expression
part (e.g. f"{)}") and the closing bracket is an arbitrary
nested expression, then instead of matching a different
syntactical construct with it; we'll throw an unmatched
parentheses error. */
if (INSIDE_FSTRING(tok) && opening == '{') {
assert(current_tok->curly_bracket_depth >= 0);
int previous_bracket = current_tok->curly_bracket_depth - 1;
if (previous_bracket == current_tok->curly_bracket_expr_start_depth) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "f-string: unmatched '%c'", c));
}
}
if (tok->parenlinenostack[tok->level] != tok->lineno) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok,
"closing parenthesis '%c' does not match "
"opening parenthesis '%c' on line %d",
c, opening, tok->parenlinenostack[tok->level]));
}
else {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok,
"closing parenthesis '%c' does not match "
"opening parenthesis '%c'",
c, opening));
}
}
}
if (INSIDE_FSTRING(tok)) {
current_tok->curly_bracket_depth--;
if (current_tok->curly_bracket_depth < 0) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "f-string: unmatched '%c'", c));
}
if (c == '}' && current_tok->curly_bracket_depth == current_tok->curly_bracket_expr_start_depth) {
current_tok->curly_bracket_expr_start_depth--;
current_tok->kind = TOK_FSTRING_MODE;
current_tok->in_format_spec = 0;
current_tok->f_string_debug = 0;
}
}
break;
default:
break;
}
if (!Py_UNICODE_ISPRINTABLE(c)) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "invalid non-printable character U+%04X", c));
}
if( c == '=' && INSIDE_FSTRING_EXPR(current_tok)) {
current_tok->f_string_debug = 1;
}
/* Punctuation character */
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(_PyToken_OneChar(c));
}
static int
tok_get_fstring_mode(struct tok_state *tok, tokenizer_mode* current_tok, struct token *token)
{
const char *p_start = NULL;
const char *p_end = NULL;
int end_quote_size = 0;
int unicode_escape = 0;
tok->start = tok->cur;
tok->first_lineno = tok->lineno;
tok->starting_col_offset = tok->col_offset;
// If we start with a bracket, we defer to the normal mode as there is nothing for us to tokenize
// before it.
int start_char = tok_nextc(tok);
if (start_char == '{') {
int peek1 = tok_nextc(tok);
tok_backup(tok, peek1);
tok_backup(tok, start_char);
if (peek1 != '{') {
current_tok->curly_bracket_expr_start_depth++;
if (current_tok->curly_bracket_expr_start_depth >= MAX_EXPR_NESTING) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "f-string: expressions nested too deeply"));
}
TOK_GET_MODE(tok)->kind = TOK_REGULAR_MODE;
return tok_get_normal_mode(tok, current_tok, token);
}
}
else {
tok_backup(tok, start_char);
}
// Check if we are at the end of the string
for (int i = 0; i < current_tok->f_string_quote_size; i++) {
int quote = tok_nextc(tok);
if (quote != current_tok->f_string_quote) {
tok_backup(tok, quote);
goto f_string_middle;
}
}
if (current_tok->last_expr_buffer != NULL) {
PyMem_Free(current_tok->last_expr_buffer);
current_tok->last_expr_buffer = NULL;
current_tok->last_expr_size = 0;
current_tok->last_expr_end = -1;
}
p_start = tok->start;
p_end = tok->cur;
tok->tok_mode_stack_index--;
return MAKE_TOKEN(FSTRING_END);
f_string_middle:
// TODO: This is a bit of a hack, but it works for now. We need to find a better way to handle
// this.
tok->multi_line_start = tok->line_start;
while (end_quote_size != current_tok->f_string_quote_size) {
int c = tok_nextc(tok);
if (tok->done == E_ERROR || tok->done == E_DECODE) {
return MAKE_TOKEN(ERRORTOKEN);
}
int in_format_spec = (
current_tok->in_format_spec
&&
INSIDE_FSTRING_EXPR(current_tok)
);
if (c == EOF || (current_tok->f_string_quote_size == 1 && c == '\n')) {
if (tok->decoding_erred) {
return MAKE_TOKEN(ERRORTOKEN);
}
// If we are in a format spec and we found a newline,
// it means that the format spec ends here and we should
// return to the regular mode.
if (in_format_spec && c == '\n') {
tok_backup(tok, c);
TOK_GET_MODE(tok)->kind = TOK_REGULAR_MODE;
current_tok->in_format_spec = 0;
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(FSTRING_MIDDLE);
}
assert(tok->multi_line_start != NULL);
// shift the tok_state's location into
// the start of string, and report the error
// from the initial quote character
tok->cur = (char *)current_tok->f_string_start;
tok->cur++;
tok->line_start = current_tok->f_string_multi_line_start;
int start = tok->lineno;
tokenizer_mode *the_current_tok = TOK_GET_MODE(tok);
tok->lineno = the_current_tok->f_string_line_start;
if (current_tok->f_string_quote_size == 3) {
_PyTokenizer_syntaxerror(tok,
"unterminated triple-quoted f-string literal"
" (detected at line %d)", start);
if (c != '\n') {
tok->done = E_EOFS;
}
return MAKE_TOKEN(ERRORTOKEN);
}
else {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok,
"unterminated f-string literal (detected at"
" line %d)", start));
}
}
if (c == current_tok->f_string_quote) {
end_quote_size += 1;
continue;
} else {
end_quote_size = 0;
}
if (c == '{') {
if (!_PyLexer_update_fstring_expr(tok, c)) {
return MAKE_TOKEN(ENDMARKER);
}
int peek = tok_nextc(tok);
if (peek != '{' || in_format_spec) {
tok_backup(tok, peek);
tok_backup(tok, c);
current_tok->curly_bracket_expr_start_depth++;
if (current_tok->curly_bracket_expr_start_depth >= MAX_EXPR_NESTING) {
return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "f-string: expressions nested too deeply"));
}
TOK_GET_MODE(tok)->kind = TOK_REGULAR_MODE;
current_tok->in_format_spec = 0;
p_start = tok->start;
p_end = tok->cur;
} else {
p_start = tok->start;
p_end = tok->cur - 1;
}
return MAKE_TOKEN(FSTRING_MIDDLE);
} else if (c == '}') {
if (unicode_escape) {
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(FSTRING_MIDDLE);
}
int peek = tok_nextc(tok);
// The tokenizer can only be in the format spec if we have already completed the expression
// scanning (indicated by the end of the expression being set) and we are not at the top level
// of the bracket stack (-1 is the top level). Since format specifiers can't legally use double
// brackets, we can bypass it here.
int cursor = current_tok->curly_bracket_depth;
if (peek == '}' && !in_format_spec && cursor == 0) {
p_start = tok->start;
p_end = tok->cur - 1;
} else {
tok_backup(tok, peek);
tok_backup(tok, c);
TOK_GET_MODE(tok)->kind = TOK_REGULAR_MODE;
current_tok->in_format_spec = 0;
p_start = tok->start;
p_end = tok->cur;
}
return MAKE_TOKEN(FSTRING_MIDDLE);
} else if (c == '\\') {
int peek = tok_nextc(tok);
if (peek == '\r') {
peek = tok_nextc(tok);
}
// Special case when the backslash is right before a curly
// brace. We have to restore and return the control back
// to the loop for the next iteration.
if (peek == '{' || peek == '}') {
if (!current_tok->f_string_raw) {
if (_PyTokenizer_warn_invalid_escape_sequence(tok, peek)) {
return MAKE_TOKEN(ERRORTOKEN);
}
}
tok_backup(tok, peek);
continue;
}
if (!current_tok->f_string_raw) {
if (peek == 'N') {
/* Handle named unicode escapes (\N{BULLET}) */
peek = tok_nextc(tok);
if (peek == '{') {
unicode_escape = 1;
} else {
tok_backup(tok, peek);
}
}
} /* else {
skip the escaped character
}*/
}
}
// Backup the f-string quotes to emit a final FSTRING_MIDDLE and
// add the quotes to the FSTRING_END in the next tokenizer iteration.
for (int i = 0; i < current_tok->f_string_quote_size; i++) {
tok_backup(tok, current_tok->f_string_quote);
}
p_start = tok->start;
p_end = tok->cur;
return MAKE_TOKEN(FSTRING_MIDDLE);
}
static int
tok_get(struct tok_state *tok, struct token *token)
{
tokenizer_mode *current_tok = TOK_GET_MODE(tok);
if (current_tok->kind == TOK_REGULAR_MODE) {
return tok_get_normal_mode(tok, current_tok, token);
} else {
return tok_get_fstring_mode(tok, current_tok, token);
}
}
int
_PyTokenizer_Get(struct tok_state *tok, struct token *token)
{
int result = tok_get(tok, token);
if (tok->decoding_erred) {
result = ERRORTOKEN;
tok->done = E_DECODE;
}
return result;
}
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