blob: bacfd815441110944676661fe5e21c138dcc1b3b [file] [log] [blame]
#include <stdbool.h>
#include <Python.h>
#include "pycore_bytesobject.h" // _PyBytes_DecodeEscape()
#include "pycore_unicodeobject.h" // _PyUnicode_DecodeUnicodeEscapeInternal()
#include "lexer/state.h"
#include "pegen.h"
#include "string_parser.h"
//// STRING HANDLING FUNCTIONS ////
static int
warn_invalid_escape_sequence(Parser *p, const char *first_invalid_escape, Token *t)
{
if (p->call_invalid_rules) {
// Do not report warnings if we are in the second pass of the parser
// to avoid showing the warning twice.
return 0;
}
unsigned char c = *first_invalid_escape;
if ((t->type == FSTRING_MIDDLE || t->type == FSTRING_END) && (c == '{' || c == '}')) {
// in this case the tokenizer has already emitted a warning,
// see Parser/tokenizer/helpers.c:warn_invalid_escape_sequence
return 0;
}
int octal = ('4' <= c && c <= '7');
PyObject *msg =
octal
? PyUnicode_FromFormat("invalid octal escape sequence '\\%.3s'",
first_invalid_escape)
: PyUnicode_FromFormat("invalid escape sequence '\\%c'", c);
if (msg == NULL) {
return -1;
}
PyObject *category;
if (p->feature_version >= 12) {
category = PyExc_SyntaxWarning;
}
else {
category = PyExc_DeprecationWarning;
}
if (PyErr_WarnExplicitObject(category, msg, p->tok->filename,
t->lineno, NULL, NULL) < 0) {
if (PyErr_ExceptionMatches(category)) {
/* Replace the Syntax/DeprecationWarning exception with a SyntaxError
to get a more accurate error report */
PyErr_Clear();
/* This is needed, in order for the SyntaxError to point to the token t,
since _PyPegen_raise_error uses p->tokens[p->fill - 1] for the
error location, if p->known_err_token is not set. */
p->known_err_token = t;
if (octal) {
RAISE_SYNTAX_ERROR("invalid octal escape sequence '\\%.3s'",
first_invalid_escape);
}
else {
RAISE_SYNTAX_ERROR("invalid escape sequence '\\%c'", c);
}
}
Py_DECREF(msg);
return -1;
}
Py_DECREF(msg);
return 0;
}
static PyObject *
decode_utf8(const char **sPtr, const char *end)
{
const char *s;
const char *t;
t = s = *sPtr;
while (s < end && (*s & 0x80)) {
s++;
}
*sPtr = s;
return PyUnicode_DecodeUTF8(t, s - t, NULL);
}
static PyObject *
decode_unicode_with_escapes(Parser *parser, const char *s, size_t len, Token *t)
{
PyObject *v;
PyObject *u;
char *buf;
char *p;
const char *end;
/* check for integer overflow */
if (len > SIZE_MAX / 6) {
return NULL;
}
/* "ä" (2 bytes) may become "\U000000E4" (10 bytes), or 1:5
"\ä" (3 bytes) may become "\u005c\U000000E4" (16 bytes), or ~1:6 */
u = PyBytes_FromStringAndSize((char *)NULL, len * 6);
if (u == NULL) {
return NULL;
}
p = buf = PyBytes_AsString(u);
if (p == NULL) {
return NULL;
}
end = s + len;
while (s < end) {
if (*s == '\\') {
*p++ = *s++;
if (s >= end || *s & 0x80) {
strcpy(p, "u005c");
p += 5;
if (s >= end) {
break;
}
}
}
if (*s & 0x80) {
PyObject *w;
int kind;
const void *data;
Py_ssize_t w_len;
Py_ssize_t i;
w = decode_utf8(&s, end);
if (w == NULL) {
Py_DECREF(u);
return NULL;
}
kind = PyUnicode_KIND(w);
data = PyUnicode_DATA(w);
w_len = PyUnicode_GET_LENGTH(w);
for (i = 0; i < w_len; i++) {
Py_UCS4 chr = PyUnicode_READ(kind, data, i);
sprintf(p, "\\U%08x", chr);
p += 10;
}
/* Should be impossible to overflow */
assert(p - buf <= PyBytes_GET_SIZE(u));
Py_DECREF(w);
}
else {
*p++ = *s++;
}
}
len = p - buf;
s = buf;
const char *first_invalid_escape;
v = _PyUnicode_DecodeUnicodeEscapeInternal(s, len, NULL, NULL, &first_invalid_escape);
// HACK: later we can simply pass the line no, since we don't preserve the tokens
// when we are decoding the string but we preserve the line numbers.
if (v != NULL && first_invalid_escape != NULL && t != NULL) {
if (warn_invalid_escape_sequence(parser, first_invalid_escape, t) < 0) {
/* We have not decref u before because first_invalid_escape points
inside u. */
Py_XDECREF(u);
Py_DECREF(v);
return NULL;
}
}
Py_XDECREF(u);
return v;
}
static PyObject *
decode_bytes_with_escapes(Parser *p, const char *s, Py_ssize_t len, Token *t)
{
const char *first_invalid_escape;
PyObject *result = _PyBytes_DecodeEscape(s, len, NULL, &first_invalid_escape);
if (result == NULL) {
return NULL;
}
if (first_invalid_escape != NULL) {
if (warn_invalid_escape_sequence(p, first_invalid_escape, t) < 0) {
Py_DECREF(result);
return NULL;
}
}
return result;
}
PyObject *
_PyPegen_decode_string(Parser *p, int raw, const char *s, size_t len, Token *t)
{
if (raw) {
return PyUnicode_DecodeUTF8Stateful(s, len, NULL, NULL);
}
return decode_unicode_with_escapes(p, s, len, t);
}
/* s must include the bracketing quote characters, and r, b &/or f prefixes
(if any), and embedded escape sequences (if any). (f-strings are handled by the parser)
_PyPegen_parse_string parses it, and returns the decoded Python string object. */
PyObject *
_PyPegen_parse_string(Parser *p, Token *t)
{
const char *s = PyBytes_AsString(t->bytes);
if (s == NULL) {
return NULL;
}
size_t len;
int quote = Py_CHARMASK(*s);
int bytesmode = 0;
int rawmode = 0;
if (Py_ISALPHA(quote)) {
while (!bytesmode || !rawmode) {
if (quote == 'b' || quote == 'B') {
quote =(unsigned char)*++s;
bytesmode = 1;
}
else if (quote == 'u' || quote == 'U') {
quote = (unsigned char)*++s;
}
else if (quote == 'r' || quote == 'R') {
quote = (unsigned char)*++s;
rawmode = 1;
}
else {
break;
}
}
}
if (quote != '\'' && quote != '\"') {
PyErr_BadInternalCall();
return NULL;
}
/* Skip the leading quote char. */
s++;
len = strlen(s);
if (len > INT_MAX) {
PyErr_SetString(PyExc_OverflowError, "string to parse is too long");
return NULL;
}
if (s[--len] != quote) {
/* Last quote char must match the first. */
PyErr_BadInternalCall();
return NULL;
}
if (len >= 4 && s[0] == quote && s[1] == quote) {
/* A triple quoted string. We've already skipped one quote at
the start and one at the end of the string. Now skip the
two at the start. */
s += 2;
len -= 2;
/* And check that the last two match. */
if (s[--len] != quote || s[--len] != quote) {
PyErr_BadInternalCall();
return NULL;
}
}
/* Avoid invoking escape decoding routines if possible. */
rawmode = rawmode || strchr(s, '\\') == NULL;
if (bytesmode) {
/* Disallow non-ASCII characters. */
const char *ch;
for (ch = s; *ch; ch++) {
if (Py_CHARMASK(*ch) >= 0x80) {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
t,
"bytes can only contain ASCII "
"literal characters");
return NULL;
}
}
if (rawmode) {
return PyBytes_FromStringAndSize(s, len);
}
return decode_bytes_with_escapes(p, s, len, t);
}
return _PyPegen_decode_string(p, rawmode, s, len, t);
}