From 2f37c355ab0e9ec9c1753985d27c41fa0bd719b9 Mon Sep 17 00:00:00 2001 From: Lysandros Nikolaou Date: Thu, 7 May 2020 13:37:51 +0300 Subject: [PATCH] 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). --- Lib/test/test_cmd_line_script.py | 2 +- Lib/test/test_string_literals.py | 7 +++--- Parser/pegen/parse_string.c | 38 ++++++++++++++++++++------------ Parser/pegen/parse_string.h | 4 ++-- Parser/pegen/pegen.c | 10 +++------ Parser/pegen/pegen.h | 1 + 6 files changed, 34 insertions(+), 28 deletions(-) diff --git a/Lib/test/test_cmd_line_script.py b/Lib/test/test_cmd_line_script.py index 1fc9500738f..171340581af 100644 --- a/Lib/test/test_cmd_line_script.py +++ b/Lib/test/test_cmd_line_script.py @@ -648,7 +648,7 @@ def test_syntaxerror_invalid_escape_sequence_multi_line(self): self.assertEqual( stderr.splitlines()[-3:], [ b' foo = """\\q"""', - b' ^', + b' ^', b'SyntaxError: invalid escape sequence \\q' ], ) diff --git a/Lib/test/test_string_literals.py b/Lib/test/test_string_literals.py index 5b5477d14d4..9565ee2485a 100644 --- a/Lib/test/test_string_literals.py +++ b/Lib/test/test_string_literals.py @@ -118,8 +118,7 @@ def test_eval_str_invalid_escape(self): eval("'''\n\\z'''") self.assertEqual(len(w), 1) self.assertEqual(w[0].filename, '') - if use_old_parser(): - self.assertEqual(w[0].lineno, 1) + self.assertEqual(w[0].lineno, 1) with warnings.catch_warnings(record=True) as w: warnings.simplefilter('error', category=DeprecationWarning) @@ -128,8 +127,8 @@ def test_eval_str_invalid_escape(self): exc = cm.exception self.assertEqual(w, []) self.assertEqual(exc.filename, '') - if use_old_parser(): - self.assertEqual(exc.lineno, 1) + self.assertEqual(exc.lineno, 1) + self.assertEqual(exc.offset, 1) def test_eval_str_raw(self): self.assertEqual(eval(""" r'x' """), 'x') diff --git a/Parser/pegen/parse_string.c b/Parser/pegen/parse_string.c index d96303dc183..ca4b733c153 100644 --- a/Parser/pegen/parse_string.c +++ b/Parser/pegen/parse_string.c @@ -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 @@ fstring_compile_expr(Parser *p, const char *expr_start, const char *expr_end, */ 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 @@ fstring_find_literal(Parser *p, const char **str, const char *end, int raw, 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; diff --git a/Parser/pegen/parse_string.h b/Parser/pegen/parse_string.h index 4f2aa94fc19..cd85bd57d0a 100644 --- a/Parser/pegen/parse_string.h +++ b/Parser/pegen/parse_string.h @@ -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 *); diff --git a/Parser/pegen/pegen.c b/Parser/pegen/pegen.c index c311593af70..06af53b3597 100644 --- a/Parser/pegen/pegen.c +++ b/Parser/pegen/pegen.c @@ -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; } diff --git a/Parser/pegen/pegen.h b/Parser/pegen/pegen.h index cbe6f197ac7..ffb18e47e4a 100644 --- a/Parser/pegen/pegen.h +++ b/Parser/pegen/pegen.h @@ -71,6 +71,7 @@ typedef struct { int flags; int feature_version; growable_comment_array type_ignore_comments; + Token *known_err_token; } Parser; typedef struct {