From 8300034fbf60249e8d62a85d3a5d0d531347a248 Mon Sep 17 00:00:00 2001 From: Lysandros Nikolaou Date: Wed, 6 May 2020 19:13:07 +0300 Subject: [PATCH 1/5] bpo-40334: Fix error location upon parsing an invalid string literal When parsing a string with an invalid escape, the old parser used to point to the beginning of the invalid string. This PR changes the new parser to match that behavior, since it's currently pointing to the end of the string (or to be more precise, to the beginning of the next token). Closes we-like-parsers/cpython#64. --- Lib/test/test_string_literals.py | 6 ++---- Parser/pegen/parse_string.c | 33 +++++++++++++++++++------------- Parser/pegen/parse_string.h | 2 +- Parser/pegen/pegen.c | 2 +- 4 files changed, 24 insertions(+), 19 deletions(-) diff --git a/Lib/test/test_string_literals.py b/Lib/test/test_string_literals.py index 5b5477d14d467d..a65fba3c1b40be 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 +127,7 @@ 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) 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 d96303dc183fa7..c489d9647088fb 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); @@ -20,12 +20,19 @@ 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 a hack, in order for the SyntaxError to point to the token t, + since _PyPegen_raise_error always uses p->tokens[p->fill - 1] for the + error location. */ + Token *old_end = p->tokens[p->fill - 1]; + p->tokens[p->fill - 1] = t; RAISE_SYNTAX_ERROR("invalid escape sequence \\%c", first_invalid_escape_char); + p->tokens[p->fill - 1] = old_end; } Py_DECREF(msg); return -1; @@ -47,7 +54,7 @@ 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 +117,7 @@ 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 +130,7 @@ 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 +139,7 @@ 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; } @@ -147,7 +154,7 @@ decode_bytes_with_escapes(Parser *p, const char *s, Py_ssize_t len) 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) + const char **fstr, Py_ssize_t *fstrlen, Token *t) { size_t len; int quote = Py_CHARMASK(*s); @@ -245,7 +252,7 @@ _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 +260,7 @@ _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 +644,7 @@ 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 +667,7 @@ 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 +711,7 @@ 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 +1048,7 @@ 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 4f2aa94fc19b05..78a60d32fb922e 100644 --- a/Parser/pegen/parse_string.h +++ b/Parser/pegen/parse_string.h @@ -35,7 +35,7 @@ typedef struct { void _PyPegen_FstringParser_Init(FstringParser *); int _PyPegen_parsestr(Parser *, const char *, int *, int *, PyObject **, - const char **, Py_ssize_t *); + 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 c311593af70f58..e4f47583264ae5 100644 --- a/Parser/pegen/pegen.c +++ b/Parser/pegen/pegen.c @@ -1977,7 +1977,7 @@ _PyPegen_concatenate_strings(Parser *p, asdl_seq *strings) goto error; } - if (_PyPegen_parsestr(p, this_str, &this_bytesmode, &this_rawmode, &s, &fstr, &fstrlen) != 0) { + if (_PyPegen_parsestr(p, this_str, &this_bytesmode, &this_rawmode, &s, &fstr, &fstrlen, t) != 0) { goto error; } From 938f8e1a589bcf5051a795e8de359d4ddaa9c998 Mon Sep 17 00:00:00 2001 From: Lysandros Nikolaou Date: Wed, 6 May 2020 19:44:07 +0300 Subject: [PATCH 2/5] Update test_cmd_line_script as well --- Lib/test/test_cmd_line_script.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Lib/test/test_cmd_line_script.py b/Lib/test/test_cmd_line_script.py index 1fc9500738f352..171340581af228 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' ], ) From 8b5f2e8258b835cfed1b39fc5dd77686c6bf0e54 Mon Sep 17 00:00:00 2001 From: Lysandros Nikolaou Date: Wed, 6 May 2020 20:20:49 +0300 Subject: [PATCH 3/5] Call PyBytes_AsString in _PyPegen_parsestr instead of _PyPegen_concatenate_strings --- Parser/pegen/parse_string.c | 7 ++++++- Parser/pegen/parse_string.h | 4 ++-- Parser/pegen/pegen.c | 7 +------ 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/Parser/pegen/parse_string.c b/Parser/pegen/parse_string.c index c489d9647088fb..2ae3d0d3e08187 100644 --- a/Parser/pegen/parse_string.c +++ b/Parser/pegen/parse_string.c @@ -153,9 +153,14 @@ decode_bytes_with_escapes(Parser *p, const char *s, Py_ssize_t len, Token *t) 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, +_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; diff --git a/Parser/pegen/parse_string.h b/Parser/pegen/parse_string.h index 78a60d32fb922e..cd85bd57d0a383 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 *, Token *); +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 e4f47583264ae5..0d8e8db0ed6da9 100644 --- a/Parser/pegen/pegen.c +++ b/Parser/pegen/pegen.c @@ -1972,12 +1972,7 @@ _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, t) != 0) { + if (_PyPegen_parsestr(p, &this_bytesmode, &this_rawmode, &s, &fstr, &fstrlen, t) != 0) { goto error; } From 86b88a31d233eaf76cf28d7b73a1c0492fdd0cd3 Mon Sep 17 00:00:00 2001 From: Lysandros Nikolaou Date: Wed, 6 May 2020 20:34:16 +0300 Subject: [PATCH 4/5] Add a new field `known_err_token` to the `Parser` struct that has precedence over `p->tokens[p->fill - 1]` for the `SyntaxError` location and use it in `warn_invalid_escape_sequence`. --- Parser/pegen/parse_string.c | 10 ++++------ Parser/pegen/pegen.c | 3 ++- Parser/pegen/pegen.h | 1 + 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/Parser/pegen/parse_string.c b/Parser/pegen/parse_string.c index 2ae3d0d3e08187..ca4b733c153b57 100644 --- a/Parser/pegen/parse_string.c +++ b/Parser/pegen/parse_string.c @@ -26,13 +26,11 @@ warn_invalid_escape_sequence(Parser *p, unsigned char first_invalid_escape_char, to get a more accurate error report */ PyErr_Clear(); - /* This is a hack, in order for the SyntaxError to point to the token t, - since _PyPegen_raise_error always uses p->tokens[p->fill - 1] for the - error location. */ - Token *old_end = p->tokens[p->fill - 1]; - p->tokens[p->fill - 1] = t; + /* 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); - p->tokens[p->fill - 1] = old_end; } Py_DECREF(msg); return -1; diff --git a/Parser/pegen/pegen.c b/Parser/pegen/pegen.c index 0d8e8db0ed6da9..06af53b3597f74 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; } diff --git a/Parser/pegen/pegen.h b/Parser/pegen/pegen.h index cbe6f197ac7423..ffb18e47e4a9a8 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 { From 532a6c2d388be75cb19c899672f85d1879c54de1 Mon Sep 17 00:00:00 2001 From: Lysandros Nikolaou Date: Thu, 7 May 2020 02:52:23 +0300 Subject: [PATCH 5/5] Add assertion for column number --- Lib/test/test_string_literals.py | 1 + 1 file changed, 1 insertion(+) diff --git a/Lib/test/test_string_literals.py b/Lib/test/test_string_literals.py index a65fba3c1b40be..9565ee2485afd1 100644 --- a/Lib/test/test_string_literals.py +++ b/Lib/test/test_string_literals.py @@ -128,6 +128,7 @@ def test_eval_str_invalid_escape(self): self.assertEqual(w, []) self.assertEqual(exc.filename, '') self.assertEqual(exc.lineno, 1) + self.assertEqual(exc.offset, 1) def test_eval_str_raw(self): self.assertEqual(eval(""" r'x' """), 'x')