bpo-40334: Fix error location upon parsing an invalid string literal (GH-19962)

When parsing a string with an invalid escape, the old parser used to
point to the beginning of the invalid string. This commit changes the new
parser to match that behaviour, since it's currently pointing to the
end of the string (or to be more precise, to the beginning of the next
token).
This commit is contained in:
Lysandros Nikolaou 2020-05-07 13:37:51 +03:00 committed by GitHub
parent 3466922320
commit 2f37c355ab
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 34 additions and 28 deletions

View File

@ -118,7 +118,6 @@ class TestLiterals(unittest.TestCase):
eval("'''\n\\z'''")
self.assertEqual(len(w), 1)
self.assertEqual(w[0].filename, '<string>')
if use_old_parser():
self.assertEqual(w[0].lineno, 1)
with warnings.catch_warnings(record=True) as w:
@ -128,8 +127,8 @@ class TestLiterals(unittest.TestCase):
exc = cm.exception
self.assertEqual(w, [])
self.assertEqual(exc.filename, '<string>')
if use_old_parser():
self.assertEqual(exc.lineno, 1)
self.assertEqual(exc.offset, 1)
def test_eval_str_raw(self):
self.assertEqual(eval(""" r'x' """), 'x')

View File

@ -12,7 +12,7 @@
// file (like "_PyPegen_raise_syntax_error").
static int
warn_invalid_escape_sequence(Parser *p, unsigned char first_invalid_escape_char)
warn_invalid_escape_sequence(Parser *p, unsigned char first_invalid_escape_char, Token *t)
{
PyObject *msg =
PyUnicode_FromFormat("invalid escape sequence \\%c", first_invalid_escape_char);
@ -20,11 +20,16 @@ warn_invalid_escape_sequence(Parser *p, unsigned char first_invalid_escape_char)
return -1;
}
if (PyErr_WarnExplicitObject(PyExc_DeprecationWarning, msg, p->tok->filename,
p->tok->lineno, NULL, NULL) < 0) {
t->lineno, NULL, NULL) < 0) {
if (PyErr_ExceptionMatches(PyExc_DeprecationWarning)) {
/* Replace the 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;
RAISE_SYNTAX_ERROR("invalid escape sequence \\%c", first_invalid_escape_char);
}
Py_DECREF(msg);
@ -47,7 +52,7 @@ decode_utf8(const char **sPtr, const char *end)
}
static PyObject *
decode_unicode_with_escapes(Parser *parser, const char *s, size_t len)
decode_unicode_with_escapes(Parser *parser, const char *s, size_t len, Token *t)
{
PyObject *v, *u;
char *buf;
@ -110,7 +115,7 @@ decode_unicode_with_escapes(Parser *parser, const char *s, size_t len)
v = _PyUnicode_DecodeUnicodeEscape(s, len, NULL, &first_invalid_escape);
if (v != NULL && first_invalid_escape != NULL) {
if (warn_invalid_escape_sequence(parser, *first_invalid_escape) < 0) {
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);
@ -123,7 +128,7 @@ decode_unicode_with_escapes(Parser *parser, const char *s, size_t len)
}
static PyObject *
decode_bytes_with_escapes(Parser *p, const char *s, Py_ssize_t len)
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);
@ -132,7 +137,7 @@ decode_bytes_with_escapes(Parser *p, const char *s, Py_ssize_t len)
}
if (first_invalid_escape != NULL) {
if (warn_invalid_escape_sequence(p, *first_invalid_escape) < 0) {
if (warn_invalid_escape_sequence(p, *first_invalid_escape, t) < 0) {
Py_DECREF(result);
return NULL;
}
@ -146,9 +151,14 @@ decode_bytes_with_escapes(Parser *p, const char *s, Py_ssize_t len)
If the string is an f-string, set *fstr and *fstrlen to the unparsed
string object. Return 0 if no errors occurred. */
int
_PyPegen_parsestr(Parser *p, const char *s, int *bytesmode, int *rawmode, PyObject **result,
const char **fstr, Py_ssize_t *fstrlen)
_PyPegen_parsestr(Parser *p, int *bytesmode, int *rawmode, PyObject **result,
const char **fstr, Py_ssize_t *fstrlen, Token *t)
{
const char *s = PyBytes_AsString(t->bytes);
if (s == NULL) {
return -1;
}
size_t len;
int quote = Py_CHARMASK(*s);
int fmode = 0;
@ -245,7 +255,7 @@ _PyPegen_parsestr(Parser *p, const char *s, int *bytesmode, int *rawmode, PyObje
*result = PyBytes_FromStringAndSize(s, len);
}
else {
*result = decode_bytes_with_escapes(p, s, len);
*result = decode_bytes_with_escapes(p, s, len, t);
}
}
else {
@ -253,7 +263,7 @@ _PyPegen_parsestr(Parser *p, const char *s, int *bytesmode, int *rawmode, PyObje
*result = PyUnicode_DecodeUTF8Stateful(s, len, NULL, NULL);
}
else {
*result = decode_unicode_with_escapes(p, s, len);
*result = decode_unicode_with_escapes(p, s, len, t);
}
}
return *result == NULL ? -1 : 0;
@ -637,7 +647,7 @@ exit:
*/
static int
fstring_find_literal(Parser *p, const char **str, const char *end, int raw,
PyObject **literal, int recurse_lvl)
PyObject **literal, int recurse_lvl, Token *t)
{
/* Get any literal string. It ends when we hit an un-doubled left
brace (which isn't part of a unicode name escape such as
@ -660,7 +670,7 @@ fstring_find_literal(Parser *p, const char **str, const char *end, int raw,
}
break;
}
if (ch == '{' && warn_invalid_escape_sequence(p, ch) < 0) {
if (ch == '{' && warn_invalid_escape_sequence(p, ch, t) < 0) {
return -1;
}
}
@ -704,7 +714,7 @@ done:
NULL, NULL);
else
*literal = decode_unicode_with_escapes(p, literal_start,
s - literal_start);
s - literal_start, t);
if (!*literal)
return -1;
}
@ -1041,7 +1051,7 @@ fstring_find_literal_and_expr(Parser *p, const char **str, const char *end, int
assert(*literal == NULL && *expression == NULL);
/* Get any literal string. */
result = fstring_find_literal(p, str, end, raw, literal, recurse_lvl);
result = fstring_find_literal(p, str, end, raw, literal, recurse_lvl, t);
if (result < 0)
goto error;

View File

@ -34,8 +34,8 @@ typedef struct {
} FstringParser;
void _PyPegen_FstringParser_Init(FstringParser *);
int _PyPegen_parsestr(Parser *, const char *, int *, int *, PyObject **,
const char **, Py_ssize_t *);
int _PyPegen_parsestr(Parser *, int *, int *, PyObject **,
const char **, Py_ssize_t *, Token *);
int _PyPegen_FstringParser_ConcatFstring(Parser *, FstringParser *, const char **,
const char *, int, int, Token *, Token *,
Token *);

View File

@ -383,7 +383,7 @@ _PyPegen_raise_error(Parser *p, PyObject *errtype, int with_col_number, const ch
PyObject *errstr = NULL;
PyObject *loc = NULL;
PyObject *tmp = NULL;
Token *t = p->tokens[p->fill - 1];
Token *t = p->known_err_token != NULL ? p->known_err_token : p->tokens[p->fill - 1];
Py_ssize_t col_number = !with_col_number;
va_list va;
p->error_indicator = 1;
@ -1053,6 +1053,7 @@ _PyPegen_Parser_New(struct tok_state *tok, int start_rule, int flags,
p->starting_col_offset = 0;
p->flags = flags;
p->feature_version = feature_version;
p->known_err_token = NULL;
return p;
}
@ -1972,12 +1973,7 @@ _PyPegen_concatenate_strings(Parser *p, asdl_seq *strings)
const char *fstr;
Py_ssize_t fstrlen = -1;
char *this_str = PyBytes_AsString(t->bytes);
if (!this_str) {
goto error;
}
if (_PyPegen_parsestr(p, this_str, &this_bytesmode, &this_rawmode, &s, &fstr, &fstrlen) != 0) {
if (_PyPegen_parsestr(p, &this_bytesmode, &this_rawmode, &s, &fstr, &fstrlen, t) != 0) {
goto error;
}

View File

@ -71,6 +71,7 @@ typedef struct {
int flags;
int feature_version;
growable_comment_array type_ignore_comments;
Token *known_err_token;
} Parser;
typedef struct {