pythonGH-97973: Return all necessary information from the tokenizer

Right now, the tokenizer only returns type and two pointers to the
start and end of the token. This PR modifies the tokenizer to return
the type and set all of the necessary information, so that the parser
does not have to this.

Parser/pegen.c

@@ -123,50 +123,45 @@ growable_comment_array_deallocate(growable_comment_array *arr) {
 }
 
 static int
-_get_keyword_or_name_type(Parser *p, const char *name, int name_len)
+_get_keyword_or_name_type(Parser *p, struct token new_token)
 {
+    int name_len = new_token.end_col_offset - new_token.col_offset;
     assert(name_len > 0);
+
     if (name_len >= p->n_keyword_lists ||
         p->keywords[name_len] == NULL ||
         p->keywords[name_len]->type == -1) {
         return NAME;
     }
     for (KeywordToken *k = p->keywords[name_len]; k != NULL && k->type != -1; k++) {
-        if (strncmp(k->str, name, name_len) == 0) {
+        if (strncmp(k->str, new_token.start, name_len) == 0) {
             return k->type;
         }
     }
     return NAME;
 }
 
 static int
-initialize_token(Parser *p, Token *token, const char *start, const char *end, int token_type) {
-    assert(token != NULL);
+initialize_token(Parser *p, Token *parser_token, struct token new_token, int token_type) {
+    assert(parser_token != NULL);
 
-    token->type = (token_type == NAME) ? _get_keyword_or_name_type(p, start, (int)(end - start)) : token_type;
-    token->bytes = PyBytes_FromStringAndSize(start, end - start);
-    if (token->bytes == NULL) {
+    parser_token->type = (token_type == NAME) ? _get_keyword_or_name_type(p, new_token) : token_type;
+    parser_token->bytes = PyBytes_FromStringAndSize(new_token.start, new_token.end - new_token.start);
+    if (parser_token->bytes == NULL) {
         return -1;
     }
-
-    if (_PyArena_AddPyObject(p->arena, token->bytes) < 0) {
-        Py_DECREF(token->bytes);
+    if (_PyArena_AddPyObject(p->arena, parser_token->bytes) < 0) {
+        Py_DECREF(parser_token->bytes);
         return -1;
     }
 
-    token->level = p->tok->level;
-
-    const char *line_start = token_type == STRING ? p->tok->multi_line_start : p->tok->line_start;
-    int lineno = token_type == STRING ? p->tok->first_lineno : p->tok->lineno;
-    int end_lineno = p->tok->lineno;
-
-    int col_offset = (start != NULL && start >= line_start) ? (int)(start - line_start) : -1;
-    int end_col_offset = (end != NULL && end >= p->tok->line_start) ? (int)(end - p->tok->line_start) : -1;
-
-    token->lineno = lineno;
-    token->col_offset = p->tok->lineno == p->starting_lineno ? p->starting_col_offset + col_offset : col_offset;
-    token->end_lineno = end_lineno;
-    token->end_col_offset = p->tok->lineno == p->starting_lineno ? p->starting_col_offset + end_col_offset : end_col_offset;
+    parser_token->level = new_token.level;
+    parser_token->lineno = new_token.lineno;
+    parser_token->col_offset = p->tok->lineno == p->starting_lineno ? p->starting_col_offset + new_token.col_offset
+                                                                    : new_token.col_offset;
+    parser_token->end_lineno = new_token.end_lineno;
+    parser_token->end_col_offset = p->tok->lineno == p->starting_lineno ? p->starting_col_offset + new_token.end_col_offset
+                                                                 : new_token.end_col_offset;
 
     p->fill += 1;
 
@@ -202,26 +197,25 @@ _resize_tokens_array(Parser *p) {
 int
 _PyPegen_fill_token(Parser *p)
 {
-    const char *start;
-    const char *end;
-    int type = _PyTokenizer_Get(p->tok, &start, &end);
+    struct token new_token;
+    int type = _PyTokenizer_Get(p->tok, &new_token);
 
     // Record and skip '# type: ignore' comments
     while (type == TYPE_IGNORE) {
-        Py_ssize_t len = end - start;
+        Py_ssize_t len = new_token.end_col_offset - new_token.col_offset;
         char *tag = PyMem_Malloc(len + 1);
         if (tag == NULL) {
             PyErr_NoMemory();
             return -1;
         }
-        strncpy(tag, start, len);
+        strncpy(tag, new_token.start, len);
         tag[len] = '\0';
         // Ownership of tag passes to the growable array
         if (!growable_comment_array_add(&p->type_ignore_comments, p->tok->lineno, tag)) {
             PyErr_NoMemory();
             return -1;
         }
-        type = _PyTokenizer_Get(p->tok, &start, &end);
+        type = _PyTokenizer_Get(p->tok, &new_token);
     }
 
     // If we have reached the end and we are in single input mode we need to insert a newline and reset the parsing
@@ -244,7 +238,7 @@ _PyPegen_fill_token(Parser *p)
     }
 
     Token *t = p->tokens[p->fill];
-    return initialize_token(p, t, start, end, type);
+    return initialize_token(p, t, new_token, type);
 }
 
 #if defined(Py_DEBUG)

Parser/pegen_errors.c

@@ -164,11 +164,10 @@ _PyPegen_tokenize_full_source_to_check_for_errors(Parser *p) {
     Py_ssize_t current_err_line = current_token->lineno;
 
     int ret = 0;
+    struct token new_token;
 
     for (;;) {
-        const char *start;
-        const char *end;
-        switch (_PyTokenizer_Get(p->tok, &start, &end)) {
+        switch (_PyTokenizer_Get(p->tok, &new_token)) {
             case ERRORTOKEN:
                 if (p->tok->level != 0) {
                     int error_lineno = p->tok->parenlinenostack[p->tok->level-1];