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gh-104169: Refactor tokenizer into lexer and wrappers (#110684)
* The lexer, which include the actual lexeme producing logic, goes into the `lexer` directory. * The wrappers, one wrapper per input mode (file, string, utf-8, and readline), go into the `tokenizer` directory and include logic for creating a lexer instance and managing the buffer for different modes. --------- Co-authored-by: Pablo Galindo <pablogsal@gmail.com> Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
This commit is contained in:
Lysandros Nikolaou
GitHub
parent
eb50cd37ea
commit
01481f2dc1
29 changed files with 3185 additions and 2988 deletions
552
Parser/tokenizer/helpers.c
Normal file
552
Parser/tokenizer/helpers.c
Normal file
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@ -0,0 +1,552 @@
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#include "Python.h"
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#include "errcode.h"
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#include "pycore_token.h"
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#include "../lexer/state.h"
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/* ############## ERRORS ############## */
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static int
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_syntaxerror_range(struct tok_state *tok, const char *format,
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int col_offset, int end_col_offset,
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va_list vargs)
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{
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// In release builds, we don't want to overwrite a previous error, but in debug builds we
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// want to fail if we are not doing it so we can fix it.
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assert(tok->done != E_ERROR);
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if (tok->done == E_ERROR) {
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return ERRORTOKEN;
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}
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PyObject *errmsg, *errtext, *args;
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errmsg = PyUnicode_FromFormatV(format, vargs);
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if (!errmsg) {
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goto error;
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}
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errtext = PyUnicode_DecodeUTF8(tok->line_start, tok->cur - tok->line_start,
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"replace");
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if (!errtext) {
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goto error;
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}
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if (col_offset == -1) {
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col_offset = (int)PyUnicode_GET_LENGTH(errtext);
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}
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if (end_col_offset == -1) {
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end_col_offset = col_offset;
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}
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Py_ssize_t line_len = strcspn(tok->line_start, "\n");
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if (line_len != tok->cur - tok->line_start) {
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Py_DECREF(errtext);
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errtext = PyUnicode_DecodeUTF8(tok->line_start, line_len,
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"replace");
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}
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if (!errtext) {
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goto error;
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}
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args = Py_BuildValue("(O(OiiNii))", errmsg, tok->filename, tok->lineno,
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col_offset, errtext, tok->lineno, end_col_offset);
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if (args) {
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PyErr_SetObject(PyExc_SyntaxError, args);
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Py_DECREF(args);
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}
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error:
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Py_XDECREF(errmsg);
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tok->done = E_ERROR;
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return ERRORTOKEN;
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}
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int
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_PyTokenizer_syntaxerror(struct tok_state *tok, const char *format, ...)
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{
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// This errors are cleaned on startup. Todo: Fix it.
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va_list vargs;
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va_start(vargs, format);
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int ret = _syntaxerror_range(tok, format, -1, -1, vargs);
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va_end(vargs);
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return ret;
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}
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int
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_PyTokenizer_syntaxerror_known_range(struct tok_state *tok,
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int col_offset, int end_col_offset,
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const char *format, ...)
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{
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va_list vargs;
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va_start(vargs, format);
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int ret = _syntaxerror_range(tok, format, col_offset, end_col_offset, vargs);
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va_end(vargs);
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return ret;
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}
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int
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_PyTokenizer_indenterror(struct tok_state *tok)
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{
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tok->done = E_TABSPACE;
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tok->cur = tok->inp;
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return ERRORTOKEN;
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}
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char *
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_PyTokenizer_error_ret(struct tok_state *tok) /* XXX */
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{
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tok->decoding_erred = 1;
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if ((tok->fp != NULL || tok->readline != NULL) && tok->buf != NULL) {/* see _PyTokenizer_Free */
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PyMem_Free(tok->buf);
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}
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tok->buf = tok->cur = tok->inp = NULL;
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tok->start = NULL;
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tok->end = NULL;
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tok->done = E_DECODE;
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return NULL; /* as if it were EOF */
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}
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int
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_PyTokenizer_warn_invalid_escape_sequence(struct tok_state *tok, int first_invalid_escape_char)
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{
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if (!tok->report_warnings) {
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return 0;
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}
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PyObject *msg = PyUnicode_FromFormat(
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"invalid escape sequence '\\%c'",
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(char) first_invalid_escape_char
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);
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if (msg == NULL) {
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return -1;
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}
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if (PyErr_WarnExplicitObject(PyExc_SyntaxWarning, msg, tok->filename,
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tok->lineno, NULL, NULL) < 0) {
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Py_DECREF(msg);
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if (PyErr_ExceptionMatches(PyExc_SyntaxWarning)) {
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/* Replace the SyntaxWarning exception with a SyntaxError
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to get a more accurate error report */
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PyErr_Clear();
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return _PyTokenizer_syntaxerror(tok, "invalid escape sequence '\\%c'", (char) first_invalid_escape_char);
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}
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return -1;
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}
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Py_DECREF(msg);
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return 0;
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}
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int
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_PyTokenizer_parser_warn(struct tok_state *tok, PyObject *category, const char *format, ...)
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{
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if (!tok->report_warnings) {
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return 0;
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}
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PyObject *errmsg;
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va_list vargs;
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va_start(vargs, format);
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errmsg = PyUnicode_FromFormatV(format, vargs);
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va_end(vargs);
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if (!errmsg) {
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goto error;
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}
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if (PyErr_WarnExplicitObject(category, errmsg, tok->filename,
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tok->lineno, NULL, NULL) < 0) {
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if (PyErr_ExceptionMatches(category)) {
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/* Replace the DeprecationWarning exception with a SyntaxError
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to get a more accurate error report */
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PyErr_Clear();
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_PyTokenizer_syntaxerror(tok, "%U", errmsg);
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}
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goto error;
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}
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Py_DECREF(errmsg);
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return 0;
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error:
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Py_XDECREF(errmsg);
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tok->done = E_ERROR;
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return -1;
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}
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/* ############## STRING MANIPULATION ############## */
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char *
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_PyTokenizer_new_string(const char *s, Py_ssize_t len, struct tok_state *tok)
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{
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char* result = (char *)PyMem_Malloc(len + 1);
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if (!result) {
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tok->done = E_NOMEM;
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return NULL;
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}
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memcpy(result, s, len);
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result[len] = '\0';
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return result;
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}
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PyObject *
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_PyTokenizer_translate_into_utf8(const char* str, const char* enc) {
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PyObject *utf8;
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PyObject* buf = PyUnicode_Decode(str, strlen(str), enc, NULL);
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if (buf == NULL)
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return NULL;
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utf8 = PyUnicode_AsUTF8String(buf);
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Py_DECREF(buf);
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return utf8;
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}
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char *
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_PyTokenizer_translate_newlines(const char *s, int exec_input, int preserve_crlf,
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struct tok_state *tok) {
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int skip_next_lf = 0;
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size_t needed_length = strlen(s) + 2, final_length;
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char *buf, *current;
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char c = '\0';
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buf = PyMem_Malloc(needed_length);
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if (buf == NULL) {
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tok->done = E_NOMEM;
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return NULL;
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}
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for (current = buf; *s; s++, current++) {
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c = *s;
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if (skip_next_lf) {
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skip_next_lf = 0;
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if (c == '\n') {
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c = *++s;
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if (!c)
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break;
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}
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}
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if (!preserve_crlf && c == '\r') {
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skip_next_lf = 1;
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c = '\n';
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}
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*current = c;
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}
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/* If this is exec input, add a newline to the end of the string if
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there isn't one already. */
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if (exec_input && c != '\n' && c != '\0') {
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*current = '\n';
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current++;
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}
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*current = '\0';
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final_length = current - buf + 1;
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if (final_length < needed_length && final_length) {
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/* should never fail */
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char* result = PyMem_Realloc(buf, final_length);
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if (result == NULL) {
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PyMem_Free(buf);
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}
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buf = result;
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}
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return buf;
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}
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/* ############## ENCODING STUFF ############## */
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/* See whether the file starts with a BOM. If it does,
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invoke the set_readline function with the new encoding.
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Return 1 on success, 0 on failure. */
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int
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_PyTokenizer_check_bom(int get_char(struct tok_state *),
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void unget_char(int, struct tok_state *),
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int set_readline(struct tok_state *, const char *),
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struct tok_state *tok)
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{
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int ch1, ch2, ch3;
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ch1 = get_char(tok);
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tok->decoding_state = STATE_SEEK_CODING;
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if (ch1 == EOF) {
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return 1;
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} else if (ch1 == 0xEF) {
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ch2 = get_char(tok);
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if (ch2 != 0xBB) {
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unget_char(ch2, tok);
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unget_char(ch1, tok);
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return 1;
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}
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ch3 = get_char(tok);
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if (ch3 != 0xBF) {
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unget_char(ch3, tok);
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unget_char(ch2, tok);
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unget_char(ch1, tok);
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return 1;
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}
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} else {
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unget_char(ch1, tok);
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return 1;
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}
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if (tok->encoding != NULL)
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PyMem_Free(tok->encoding);
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tok->encoding = _PyTokenizer_new_string("utf-8", 5, tok);
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if (!tok->encoding)
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return 0;
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/* No need to set_readline: input is already utf-8 */
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return 1;
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}
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static const char *
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get_normal_name(const char *s) /* for utf-8 and latin-1 */
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{
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char buf[13];
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int i;
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for (i = 0; i < 12; i++) {
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int c = s[i];
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if (c == '\0')
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break;
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else if (c == '_')
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buf[i] = '-';
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else
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buf[i] = Py_TOLOWER(c);
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}
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buf[i] = '\0';
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if (strcmp(buf, "utf-8") == 0 ||
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strncmp(buf, "utf-8-", 6) == 0)
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return "utf-8";
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else if (strcmp(buf, "latin-1") == 0 ||
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strcmp(buf, "iso-8859-1") == 0 ||
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strcmp(buf, "iso-latin-1") == 0 ||
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strncmp(buf, "latin-1-", 8) == 0 ||
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strncmp(buf, "iso-8859-1-", 11) == 0 ||
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strncmp(buf, "iso-latin-1-", 12) == 0)
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return "iso-8859-1";
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else
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return s;
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}
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/* Return the coding spec in S, or NULL if none is found. */
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static int
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get_coding_spec(const char *s, char **spec, Py_ssize_t size, struct tok_state *tok)
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{
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Py_ssize_t i;
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*spec = NULL;
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/* Coding spec must be in a comment, and that comment must be
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* the only statement on the source code line. */
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for (i = 0; i < size - 6; i++) {
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if (s[i] == '#')
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break;
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if (s[i] != ' ' && s[i] != '\t' && s[i] != '\014')
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return 1;
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}
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for (; i < size - 6; i++) { /* XXX inefficient search */
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const char* t = s + i;
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if (memcmp(t, "coding", 6) == 0) {
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const char* begin = NULL;
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t += 6;
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if (t[0] != ':' && t[0] != '=')
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continue;
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do {
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t++;
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} while (t[0] == ' ' || t[0] == '\t');
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begin = t;
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while (Py_ISALNUM(t[0]) ||
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t[0] == '-' || t[0] == '_' || t[0] == '.')
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t++;
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if (begin < t) {
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char* r = _PyTokenizer_new_string(begin, t - begin, tok);
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const char* q;
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if (!r)
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return 0;
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q = get_normal_name(r);
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if (r != q) {
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PyMem_Free(r);
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r = _PyTokenizer_new_string(q, strlen(q), tok);
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if (!r)
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return 0;
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}
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*spec = r;
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break;
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}
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}
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}
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return 1;
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}
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/* Check whether the line contains a coding spec. If it does,
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invoke the set_readline function for the new encoding.
|
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This function receives the tok_state and the new encoding.
|
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Return 1 on success, 0 on failure. */
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int
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_PyTokenizer_check_coding_spec(const char* line, Py_ssize_t size, struct tok_state *tok,
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int set_readline(struct tok_state *, const char *))
|
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{
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char *cs;
|
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if (tok->cont_line) {
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/* It's a continuation line, so it can't be a coding spec. */
|
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tok->decoding_state = STATE_NORMAL;
|
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return 1;
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}
|
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if (!get_coding_spec(line, &cs, size, tok)) {
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return 0;
|
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}
|
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if (!cs) {
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Py_ssize_t i;
|
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for (i = 0; i < size; i++) {
|
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if (line[i] == '#' || line[i] == '\n' || line[i] == '\r')
|
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break;
|
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if (line[i] != ' ' && line[i] != '\t' && line[i] != '\014') {
|
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/* Stop checking coding spec after a line containing
|
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* anything except a comment. */
|
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tok->decoding_state = STATE_NORMAL;
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break;
|
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}
|
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}
|
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return 1;
|
||||
}
|
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tok->decoding_state = STATE_NORMAL;
|
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if (tok->encoding == NULL) {
|
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assert(tok->decoding_readline == NULL);
|
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if (strcmp(cs, "utf-8") != 0 && !set_readline(tok, cs)) {
|
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_PyTokenizer_error_ret(tok);
|
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PyErr_Format(PyExc_SyntaxError, "encoding problem: %s", cs);
|
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PyMem_Free(cs);
|
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return 0;
|
||||
}
|
||||
tok->encoding = cs;
|
||||
} else { /* then, compare cs with BOM */
|
||||
if (strcmp(tok->encoding, cs) != 0) {
|
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_PyTokenizer_error_ret(tok);
|
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PyErr_Format(PyExc_SyntaxError,
|
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"encoding problem: %s with BOM", cs);
|
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PyMem_Free(cs);
|
||||
return 0;
|
||||
}
|
||||
PyMem_Free(cs);
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* Check whether the characters at s start a valid
|
||||
UTF-8 sequence. Return the number of characters forming
|
||||
the sequence if yes, 0 if not. The special cases match
|
||||
those in stringlib/codecs.h:utf8_decode.
|
||||
*/
|
||||
static int
|
||||
valid_utf8(const unsigned char* s)
|
||||
{
|
||||
int expected = 0;
|
||||
int length;
|
||||
if (*s < 0x80) {
|
||||
/* single-byte code */
|
||||
return 1;
|
||||
}
|
||||
else if (*s < 0xE0) {
|
||||
/* \xC2\x80-\xDF\xBF -- 0080-07FF */
|
||||
if (*s < 0xC2) {
|
||||
/* invalid sequence
|
||||
\x80-\xBF -- continuation byte
|
||||
\xC0-\xC1 -- fake 0000-007F */
|
||||
return 0;
|
||||
}
|
||||
expected = 1;
|
||||
}
|
||||
else if (*s < 0xF0) {
|
||||
/* \xE0\xA0\x80-\xEF\xBF\xBF -- 0800-FFFF */
|
||||
if (*s == 0xE0 && *(s + 1) < 0xA0) {
|
||||
/* invalid sequence
|
||||
\xE0\x80\x80-\xE0\x9F\xBF -- fake 0000-0800 */
|
||||
return 0;
|
||||
}
|
||||
else if (*s == 0xED && *(s + 1) >= 0xA0) {
|
||||
/* Decoding UTF-8 sequences in range \xED\xA0\x80-\xED\xBF\xBF
|
||||
will result in surrogates in range D800-DFFF. Surrogates are
|
||||
not valid UTF-8 so they are rejected.
|
||||
See https://www.unicode.org/versions/Unicode5.2.0/ch03.pdf
|
||||
(table 3-7) and http://www.rfc-editor.org/rfc/rfc3629.txt */
|
||||
return 0;
|
||||
}
|
||||
expected = 2;
|
||||
}
|
||||
else if (*s < 0xF5) {
|
||||
/* \xF0\x90\x80\x80-\xF4\x8F\xBF\xBF -- 10000-10FFFF */
|
||||
if (*(s + 1) < 0x90 ? *s == 0xF0 : *s == 0xF4) {
|
||||
/* invalid sequence -- one of:
|
||||
\xF0\x80\x80\x80-\xF0\x8F\xBF\xBF -- fake 0000-FFFF
|
||||
\xF4\x90\x80\x80- -- 110000- overflow */
|
||||
return 0;
|
||||
}
|
||||
expected = 3;
|
||||
}
|
||||
else {
|
||||
/* invalid start byte */
|
||||
return 0;
|
||||
}
|
||||
length = expected + 1;
|
||||
for (; expected; expected--)
|
||||
if (s[expected] < 0x80 || s[expected] >= 0xC0)
|
||||
return 0;
|
||||
return length;
|
||||
}
|
||||
|
||||
int
|
||||
_PyTokenizer_ensure_utf8(char *line, struct tok_state *tok)
|
||||
{
|
||||
int badchar = 0;
|
||||
unsigned char *c;
|
||||
int length;
|
||||
for (c = (unsigned char *)line; *c; c += length) {
|
||||
if (!(length = valid_utf8(c))) {
|
||||
badchar = *c;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (badchar) {
|
||||
PyErr_Format(PyExc_SyntaxError,
|
||||
"Non-UTF-8 code starting with '\\x%.2x' "
|
||||
"in file %U on line %i, "
|
||||
"but no encoding declared; "
|
||||
"see https://peps.python.org/pep-0263/ for details",
|
||||
badchar, tok->filename, tok->lineno);
|
||||
return 0;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
|
||||
|
||||
/* ############## DEBUGGING STUFF ############## */
|
||||
|
||||
#ifdef Py_DEBUG
|
||||
void
|
||||
_PyTokenizer_print_escape(FILE *f, const char *s, Py_ssize_t size)
|
||||
{
|
||||
if (s == NULL) {
|
||||
fputs("NULL", f);
|
||||
return;
|
||||
}
|
||||
putc('"', f);
|
||||
while (size-- > 0) {
|
||||
unsigned char c = *s++;
|
||||
switch (c) {
|
||||
case '\n': fputs("\\n", f); break;
|
||||
case '\r': fputs("\\r", f); break;
|
||||
case '\t': fputs("\\t", f); break;
|
||||
case '\f': fputs("\\f", f); break;
|
||||
case '\'': fputs("\\'", f); break;
|
||||
case '"': fputs("\\\"", f); break;
|
||||
default:
|
||||
if (0x20 <= c && c <= 0x7f)
|
||||
putc(c, f);
|
||||
else
|
||||
fprintf(f, "\\x%02x", c);
|
||||
}
|
||||
}
|
||||
putc('"', f);
|
||||
}
|
||||
|
||||
void
|
||||
_PyTokenizer_tok_dump(int type, char *start, char *end)
|
||||
{
|
||||
fprintf(stderr, "%s", _PyParser_TokenNames[type]);
|
||||
if (type == NAME || type == NUMBER || type == STRING || type == OP)
|
||||
fprintf(stderr, "(%.*s)", (int)(end - start), start);
|
||||
}
|
||||
#endif
|
||||
Loading…
Add table
Add a link
Reference in a new issue