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1 #include <Python.h>
2 #include <errcode.h>
3 #include "../tokenizer.h"
4 
5 #include "pegen.h"
6 #include "parse_string.h"
7 #include "ast.h"
8 
9 PyObject *
_PyPegen_new_type_comment(Parser * p,char * s)10 _PyPegen_new_type_comment(Parser *p, char *s)
11 {
12     PyObject *res = PyUnicode_DecodeUTF8(s, strlen(s), NULL);
13     if (res == NULL) {
14         return NULL;
15     }
16     if (PyArena_AddPyObject(p->arena, res) < 0) {
17         Py_DECREF(res);
18         return NULL;
19     }
20     return res;
21 }
22 
23 arg_ty
_PyPegen_add_type_comment_to_arg(Parser * p,arg_ty a,Token * tc)24 _PyPegen_add_type_comment_to_arg(Parser *p, arg_ty a, Token *tc)
25 {
26     if (tc == NULL) {
27         return a;
28     }
29     char *bytes = PyBytes_AsString(tc->bytes);
30     if (bytes == NULL) {
31         return NULL;
32     }
33     PyObject *tco = _PyPegen_new_type_comment(p, bytes);
34     if (tco == NULL) {
35         return NULL;
36     }
37     return arg(a->arg, a->annotation, tco,
38                a->lineno, a->col_offset, a->end_lineno, a->end_col_offset,
39                p->arena);
40 }
41 
42 static int
init_normalization(Parser * p)43 init_normalization(Parser *p)
44 {
45     if (p->normalize) {
46         return 1;
47     }
48     PyObject *m = PyImport_ImportModuleNoBlock("unicodedata");
49     if (!m)
50     {
51         return 0;
52     }
53     p->normalize = PyObject_GetAttrString(m, "normalize");
54     Py_DECREF(m);
55     if (!p->normalize)
56     {
57         return 0;
58     }
59     return 1;
60 }
61 
62 /* Checks if the NOTEQUAL token is valid given the current parser flags
63 0 indicates success and nonzero indicates failure (an exception may be set) */
64 int
_PyPegen_check_barry_as_flufl(Parser * p,Token * t)65 _PyPegen_check_barry_as_flufl(Parser *p, Token* t) {
66     assert(t->bytes != NULL);
67     assert(t->type == NOTEQUAL);
68 
69     char* tok_str = PyBytes_AS_STRING(t->bytes);
70     if (p->flags & PyPARSE_BARRY_AS_BDFL && strcmp(tok_str, "<>") != 0) {
71         RAISE_SYNTAX_ERROR("with Barry as BDFL, use '<>' instead of '!='");
72         return -1;
73     }
74     if (!(p->flags & PyPARSE_BARRY_AS_BDFL)) {
75         return strcmp(tok_str, "!=");
76     }
77     return 0;
78 }
79 
80 PyObject *
_PyPegen_new_identifier(Parser * p,char * n)81 _PyPegen_new_identifier(Parser *p, char *n)
82 {
83     PyObject *id = PyUnicode_DecodeUTF8(n, strlen(n), NULL);
84     if (!id) {
85         goto error;
86     }
87     /* PyUnicode_DecodeUTF8 should always return a ready string. */
88     assert(PyUnicode_IS_READY(id));
89     /* Check whether there are non-ASCII characters in the
90        identifier; if so, normalize to NFKC. */
91     if (!PyUnicode_IS_ASCII(id))
92     {
93         PyObject *id2;
94         if (!init_normalization(p))
95         {
96             Py_DECREF(id);
97             goto error;
98         }
99         PyObject *form = PyUnicode_InternFromString("NFKC");
100         if (form == NULL)
101         {
102             Py_DECREF(id);
103             goto error;
104         }
105         PyObject *args[2] = {form, id};
106         id2 = _PyObject_FastCall(p->normalize, args, 2);
107         Py_DECREF(id);
108         Py_DECREF(form);
109         if (!id2) {
110             goto error;
111         }
112         if (!PyUnicode_Check(id2))
113         {
114             PyErr_Format(PyExc_TypeError,
115                          "unicodedata.normalize() must return a string, not "
116                          "%.200s",
117                          _PyType_Name(Py_TYPE(id2)));
118             Py_DECREF(id2);
119             goto error;
120         }
121         id = id2;
122     }
123     PyUnicode_InternInPlace(&id);
124     if (PyArena_AddPyObject(p->arena, id) < 0)
125     {
126         Py_DECREF(id);
127         goto error;
128     }
129     return id;
130 
131 error:
132     p->error_indicator = 1;
133     return NULL;
134 }
135 
136 static PyObject *
_create_dummy_identifier(Parser * p)137 _create_dummy_identifier(Parser *p)
138 {
139     return _PyPegen_new_identifier(p, "");
140 }
141 
142 static inline Py_ssize_t
byte_offset_to_character_offset(PyObject * line,Py_ssize_t col_offset)143 byte_offset_to_character_offset(PyObject *line, Py_ssize_t col_offset)
144 {
145     const char *str = PyUnicode_AsUTF8(line);
146     if (!str) {
147         return 0;
148     }
149     assert(col_offset >= 0 && (unsigned long)col_offset <= strlen(str));
150     PyObject *text = PyUnicode_DecodeUTF8(str, col_offset, "replace");
151     if (!text) {
152         return 0;
153     }
154     Py_ssize_t size = PyUnicode_GET_LENGTH(text);
155     Py_DECREF(text);
156     return size;
157 }
158 
159 const char *
_PyPegen_get_expr_name(expr_ty e)160 _PyPegen_get_expr_name(expr_ty e)
161 {
162     assert(e != NULL);
163     switch (e->kind) {
164         case Attribute_kind:
165             return "attribute";
166         case Subscript_kind:
167             return "subscript";
168         case Starred_kind:
169             return "starred";
170         case Name_kind:
171             return "name";
172         case List_kind:
173             return "list";
174         case Tuple_kind:
175             return "tuple";
176         case Lambda_kind:
177             return "lambda";
178         case Call_kind:
179             return "function call";
180         case BoolOp_kind:
181         case BinOp_kind:
182         case UnaryOp_kind:
183             return "operator";
184         case GeneratorExp_kind:
185             return "generator expression";
186         case Yield_kind:
187         case YieldFrom_kind:
188             return "yield expression";
189         case Await_kind:
190             return "await expression";
191         case ListComp_kind:
192             return "list comprehension";
193         case SetComp_kind:
194             return "set comprehension";
195         case DictComp_kind:
196             return "dict comprehension";
197         case Dict_kind:
198             return "dict display";
199         case Set_kind:
200             return "set display";
201         case JoinedStr_kind:
202         case FormattedValue_kind:
203             return "f-string expression";
204         case Constant_kind: {
205             PyObject *value = e->v.Constant.value;
206             if (value == Py_None) {
207                 return "None";
208             }
209             if (value == Py_False) {
210                 return "False";
211             }
212             if (value == Py_True) {
213                 return "True";
214             }
215             if (value == Py_Ellipsis) {
216                 return "Ellipsis";
217             }
218             return "literal";
219         }
220         case Compare_kind:
221             return "comparison";
222         case IfExp_kind:
223             return "conditional expression";
224         case NamedExpr_kind:
225             return "named expression";
226         default:
227             PyErr_Format(PyExc_SystemError,
228                          "unexpected expression in assignment %d (line %d)",
229                          e->kind, e->lineno);
230             return NULL;
231     }
232 }
233 
234 static int
raise_decode_error(Parser * p)235 raise_decode_error(Parser *p)
236 {
237     assert(PyErr_Occurred());
238     const char *errtype = NULL;
239     if (PyErr_ExceptionMatches(PyExc_UnicodeError)) {
240         errtype = "unicode error";
241     }
242     else if (PyErr_ExceptionMatches(PyExc_ValueError)) {
243         errtype = "value error";
244     }
245     if (errtype) {
246         PyObject *type;
247         PyObject *value;
248         PyObject *tback;
249         PyObject *errstr;
250         PyErr_Fetch(&type, &value, &tback);
251         errstr = PyObject_Str(value);
252         if (errstr) {
253             RAISE_SYNTAX_ERROR("(%s) %U", errtype, errstr);
254             Py_DECREF(errstr);
255         }
256         else {
257             PyErr_Clear();
258             RAISE_SYNTAX_ERROR("(%s) unknown error", errtype);
259         }
260         Py_XDECREF(type);
261         Py_XDECREF(value);
262         Py_XDECREF(tback);
263     }
264 
265     return -1;
266 }
267 
268 static void
raise_tokenizer_init_error(PyObject * filename)269 raise_tokenizer_init_error(PyObject *filename)
270 {
271     if (!(PyErr_ExceptionMatches(PyExc_LookupError)
272           || PyErr_ExceptionMatches(PyExc_ValueError)
273           || PyErr_ExceptionMatches(PyExc_UnicodeDecodeError))) {
274         return;
275     }
276     PyObject *errstr = NULL;
277     PyObject *tuple = NULL;
278     PyObject *type;
279     PyObject *value;
280     PyObject *tback;
281     PyErr_Fetch(&type, &value, &tback);
282     errstr = PyObject_Str(value);
283     if (!errstr) {
284         goto error;
285     }
286 
287     PyObject *tmp = Py_BuildValue("(OiiO)", filename, 0, -1, Py_None);
288     if (!tmp) {
289         goto error;
290     }
291 
292     tuple = PyTuple_Pack(2, errstr, tmp);
293     Py_DECREF(tmp);
294     if (!value) {
295         goto error;
296     }
297     PyErr_SetObject(PyExc_SyntaxError, tuple);
298 
299 error:
300     Py_XDECREF(type);
301     Py_XDECREF(value);
302     Py_XDECREF(tback);
303     Py_XDECREF(errstr);
304     Py_XDECREF(tuple);
305 }
306 
307 static int
tokenizer_error(Parser * p)308 tokenizer_error(Parser *p)
309 {
310     if (PyErr_Occurred()) {
311         return -1;
312     }
313 
314     const char *msg = NULL;
315     PyObject* errtype = PyExc_SyntaxError;
316     switch (p->tok->done) {
317         case E_TOKEN:
318             msg = "invalid token";
319             break;
320         case E_EOFS:
321             RAISE_SYNTAX_ERROR("EOF while scanning triple-quoted string literal");
322             return -1;
323         case E_EOLS:
324             RAISE_SYNTAX_ERROR("EOL while scanning string literal");
325             return -1;
326         case E_EOF:
327             RAISE_SYNTAX_ERROR("unexpected EOF while parsing");
328             return -1;
329         case E_DEDENT:
330             RAISE_INDENTATION_ERROR("unindent does not match any outer indentation level");
331             return -1;
332         case E_INTR:
333             if (!PyErr_Occurred()) {
334                 PyErr_SetNone(PyExc_KeyboardInterrupt);
335             }
336             return -1;
337         case E_NOMEM:
338             PyErr_NoMemory();
339             return -1;
340         case E_TABSPACE:
341             errtype = PyExc_TabError;
342             msg = "inconsistent use of tabs and spaces in indentation";
343             break;
344         case E_TOODEEP:
345             errtype = PyExc_IndentationError;
346             msg = "too many levels of indentation";
347             break;
348         case E_LINECONT:
349             msg = "unexpected character after line continuation character";
350             break;
351         default:
352             msg = "unknown parsing error";
353     }
354 
355     PyErr_Format(errtype, msg);
356     // There is no reliable column information for this error
357     PyErr_SyntaxLocationObject(p->tok->filename, p->tok->lineno, 0);
358 
359     return -1;
360 }
361 
362 void *
_PyPegen_raise_error(Parser * p,PyObject * errtype,const char * errmsg,...)363 _PyPegen_raise_error(Parser *p, PyObject *errtype, const char *errmsg, ...)
364 {
365     Token *t = p->known_err_token != NULL ? p->known_err_token : p->tokens[p->fill - 1];
366     Py_ssize_t col_offset;
367     if (t->col_offset == -1) {
368         col_offset = Py_SAFE_DOWNCAST(p->tok->cur - p->tok->buf,
369                                       intptr_t, int);
370     } else {
371         col_offset = t->col_offset + 1;
372     }
373 
374     va_list va;
375     va_start(va, errmsg);
376     _PyPegen_raise_error_known_location(p, errtype, t->lineno,
377                                         col_offset, errmsg, va);
378     va_end(va);
379 
380     return NULL;
381 }
382 
383 void *
_PyPegen_raise_error_known_location(Parser * p,PyObject * errtype,Py_ssize_t lineno,Py_ssize_t col_offset,const char * errmsg,va_list va)384 _PyPegen_raise_error_known_location(Parser *p, PyObject *errtype,
385                                     Py_ssize_t lineno, Py_ssize_t col_offset,
386                                     const char *errmsg, va_list va)
387 {
388     PyObject *value = NULL;
389     PyObject *errstr = NULL;
390     PyObject *error_line = NULL;
391     PyObject *tmp = NULL;
392     p->error_indicator = 1;
393 
394     if (p->start_rule == Py_fstring_input) {
395         const char *fstring_msg = "f-string: ";
396         Py_ssize_t len = strlen(fstring_msg) + strlen(errmsg);
397 
398         char *new_errmsg = PyMem_RawMalloc(len + 1); // Lengths of both strings plus NULL character
399         if (!new_errmsg) {
400             return (void *) PyErr_NoMemory();
401         }
402 
403         // Copy both strings into new buffer
404         memcpy(new_errmsg, fstring_msg, strlen(fstring_msg));
405         memcpy(new_errmsg + strlen(fstring_msg), errmsg, strlen(errmsg));
406         new_errmsg[len] = 0;
407         errmsg = new_errmsg;
408     }
409     errstr = PyUnicode_FromFormatV(errmsg, va);
410     if (!errstr) {
411         goto error;
412     }
413 
414     if (p->start_rule == Py_file_input) {
415         error_line = PyErr_ProgramTextObject(p->tok->filename, (int) lineno);
416     }
417 
418     if (!error_line) {
419         Py_ssize_t size = p->tok->inp - p->tok->buf;
420         error_line = PyUnicode_DecodeUTF8(p->tok->buf, size, "replace");
421         if (!error_line) {
422             goto error;
423         }
424     }
425 
426     if (p->start_rule == Py_fstring_input) {
427         col_offset -= p->starting_col_offset;
428     }
429     Py_ssize_t col_number = col_offset;
430 
431     if (p->tok->encoding != NULL) {
432         col_number = byte_offset_to_character_offset(error_line, col_offset);
433     }
434 
435     tmp = Py_BuildValue("(OiiN)", p->tok->filename, lineno, col_number, error_line);
436     if (!tmp) {
437         goto error;
438     }
439     value = PyTuple_Pack(2, errstr, tmp);
440     Py_DECREF(tmp);
441     if (!value) {
442         goto error;
443     }
444     PyErr_SetObject(errtype, value);
445 
446     Py_DECREF(errstr);
447     Py_DECREF(value);
448     if (p->start_rule == Py_fstring_input) {
449         PyMem_RawFree((void *)errmsg);
450     }
451     return NULL;
452 
453 error:
454     Py_XDECREF(errstr);
455     Py_XDECREF(error_line);
456     if (p->start_rule == Py_fstring_input) {
457         PyMem_RawFree((void *)errmsg);
458     }
459     return NULL;
460 }
461 
462 #if 0
463 static const char *
464 token_name(int type)
465 {
466     if (0 <= type && type <= N_TOKENS) {
467         return _PyParser_TokenNames[type];
468     }
469     return "<Huh?>";
470 }
471 #endif
472 
473 // Here, mark is the start of the node, while p->mark is the end.
474 // If node==NULL, they should be the same.
475 int
_PyPegen_insert_memo(Parser * p,int mark,int type,void * node)476 _PyPegen_insert_memo(Parser *p, int mark, int type, void *node)
477 {
478     // Insert in front
479     Memo *m = PyArena_Malloc(p->arena, sizeof(Memo));
480     if (m == NULL) {
481         return -1;
482     }
483     m->type = type;
484     m->node = node;
485     m->mark = p->mark;
486     m->next = p->tokens[mark]->memo;
487     p->tokens[mark]->memo = m;
488     return 0;
489 }
490 
491 // Like _PyPegen_insert_memo(), but updates an existing node if found.
492 int
_PyPegen_update_memo(Parser * p,int mark,int type,void * node)493 _PyPegen_update_memo(Parser *p, int mark, int type, void *node)
494 {
495     for (Memo *m = p->tokens[mark]->memo; m != NULL; m = m->next) {
496         if (m->type == type) {
497             // Update existing node.
498             m->node = node;
499             m->mark = p->mark;
500             return 0;
501         }
502     }
503     // Insert new node.
504     return _PyPegen_insert_memo(p, mark, type, node);
505 }
506 
507 // Return dummy NAME.
508 void *
_PyPegen_dummy_name(Parser * p,...)509 _PyPegen_dummy_name(Parser *p, ...)
510 {
511     static void *cache = NULL;
512 
513     if (cache != NULL) {
514         return cache;
515     }
516 
517     PyObject *id = _create_dummy_identifier(p);
518     if (!id) {
519         return NULL;
520     }
521     cache = Name(id, Load, 1, 0, 1, 0, p->arena);
522     return cache;
523 }
524 
525 static int
_get_keyword_or_name_type(Parser * p,const char * name,int name_len)526 _get_keyword_or_name_type(Parser *p, const char *name, int name_len)
527 {
528     assert(name_len > 0);
529     if (name_len >= p->n_keyword_lists ||
530         p->keywords[name_len] == NULL ||
531         p->keywords[name_len]->type == -1) {
532         return NAME;
533     }
534     for (KeywordToken *k = p->keywords[name_len]; k != NULL && k->type != -1; k++) {
535         if (strncmp(k->str, name, name_len) == 0) {
536             return k->type;
537         }
538     }
539     return NAME;
540 }
541 
542 static int
growable_comment_array_init(growable_comment_array * arr,size_t initial_size)543 growable_comment_array_init(growable_comment_array *arr, size_t initial_size) {
544     assert(initial_size > 0);
545     arr->items = PyMem_Malloc(initial_size * sizeof(*arr->items));
546     arr->size = initial_size;
547     arr->num_items = 0;
548 
549     return arr->items != NULL;
550 }
551 
552 static int
growable_comment_array_add(growable_comment_array * arr,int lineno,char * comment)553 growable_comment_array_add(growable_comment_array *arr, int lineno, char *comment) {
554     if (arr->num_items >= arr->size) {
555         size_t new_size = arr->size * 2;
556         void *new_items_array = PyMem_Realloc(arr->items, new_size * sizeof(*arr->items));
557         if (!new_items_array) {
558             return 0;
559         }
560         arr->items = new_items_array;
561         arr->size = new_size;
562     }
563 
564     arr->items[arr->num_items].lineno = lineno;
565     arr->items[arr->num_items].comment = comment;  // Take ownership
566     arr->num_items++;
567     return 1;
568 }
569 
570 static void
growable_comment_array_deallocate(growable_comment_array * arr)571 growable_comment_array_deallocate(growable_comment_array *arr) {
572     for (unsigned i = 0; i < arr->num_items; i++) {
573         PyMem_Free(arr->items[i].comment);
574     }
575     PyMem_Free(arr->items);
576 }
577 
578 int
_PyPegen_fill_token(Parser * p)579 _PyPegen_fill_token(Parser *p)
580 {
581     const char *start;
582     const char *end;
583     int type = PyTokenizer_Get(p->tok, &start, &end);
584 
585     // Record and skip '# type: ignore' comments
586     while (type == TYPE_IGNORE) {
587         Py_ssize_t len = end - start;
588         char *tag = PyMem_Malloc(len + 1);
589         if (tag == NULL) {
590             PyErr_NoMemory();
591             return -1;
592         }
593         strncpy(tag, start, len);
594         tag[len] = '\0';
595         // Ownership of tag passes to the growable array
596         if (!growable_comment_array_add(&p->type_ignore_comments, p->tok->lineno, tag)) {
597             PyErr_NoMemory();
598             return -1;
599         }
600         type = PyTokenizer_Get(p->tok, &start, &end);
601     }
602 
603     if (type == ENDMARKER && p->start_rule == Py_single_input && p->parsing_started) {
604         type = NEWLINE; /* Add an extra newline */
605         p->parsing_started = 0;
606 
607         if (p->tok->indent && !(p->flags & PyPARSE_DONT_IMPLY_DEDENT)) {
608             p->tok->pendin = -p->tok->indent;
609             p->tok->indent = 0;
610         }
611     }
612     else {
613         p->parsing_started = 1;
614     }
615 
616     if (p->fill == p->size) {
617         int newsize = p->size * 2;
618         Token **new_tokens = PyMem_Realloc(p->tokens, newsize * sizeof(Token *));
619         if (new_tokens == NULL) {
620             PyErr_NoMemory();
621             return -1;
622         }
623         p->tokens = new_tokens;
624 
625         for (int i = p->size; i < newsize; i++) {
626             p->tokens[i] = PyMem_Malloc(sizeof(Token));
627             if (p->tokens[i] == NULL) {
628                 p->size = i; // Needed, in order to cleanup correctly after parser fails
629                 PyErr_NoMemory();
630                 return -1;
631             }
632             memset(p->tokens[i], '\0', sizeof(Token));
633         }
634         p->size = newsize;
635     }
636 
637     Token *t = p->tokens[p->fill];
638     t->type = (type == NAME) ? _get_keyword_or_name_type(p, start, (int)(end - start)) : type;
639     t->bytes = PyBytes_FromStringAndSize(start, end - start);
640     if (t->bytes == NULL) {
641         return -1;
642     }
643     PyArena_AddPyObject(p->arena, t->bytes);
644 
645     int lineno = type == STRING ? p->tok->first_lineno : p->tok->lineno;
646     const char *line_start = type == STRING ? p->tok->multi_line_start : p->tok->line_start;
647     int end_lineno = p->tok->lineno;
648     int col_offset = -1;
649     int end_col_offset = -1;
650     if (start != NULL && start >= line_start) {
651         col_offset = (int)(start - line_start);
652     }
653     if (end != NULL && end >= p->tok->line_start) {
654         end_col_offset = (int)(end - p->tok->line_start);
655     }
656 
657     t->lineno = p->starting_lineno + lineno;
658     t->col_offset = p->tok->lineno == 1 ? p->starting_col_offset + col_offset : col_offset;
659     t->end_lineno = p->starting_lineno + end_lineno;
660     t->end_col_offset = p->tok->lineno == 1 ? p->starting_col_offset + end_col_offset : end_col_offset;
661 
662     p->fill += 1;
663 
664     if (type == ERRORTOKEN) {
665         if (p->tok->done == E_DECODE) {
666             return raise_decode_error(p);
667         }
668         return tokenizer_error(p);
669 
670     }
671 
672     return 0;
673 }
674 
675 // Instrumentation to count the effectiveness of memoization.
676 // The array counts the number of tokens skipped by memoization,
677 // indexed by type.
678 
679 #define NSTATISTICS 2000
680 static long memo_statistics[NSTATISTICS];
681 
682 void
_PyPegen_clear_memo_statistics()683 _PyPegen_clear_memo_statistics()
684 {
685     for (int i = 0; i < NSTATISTICS; i++) {
686         memo_statistics[i] = 0;
687     }
688 }
689 
690 PyObject *
_PyPegen_get_memo_statistics()691 _PyPegen_get_memo_statistics()
692 {
693     PyObject *ret = PyList_New(NSTATISTICS);
694     if (ret == NULL) {
695         return NULL;
696     }
697     for (int i = 0; i < NSTATISTICS; i++) {
698         PyObject *value = PyLong_FromLong(memo_statistics[i]);
699         if (value == NULL) {
700             Py_DECREF(ret);
701             return NULL;
702         }
703         // PyList_SetItem borrows a reference to value.
704         if (PyList_SetItem(ret, i, value) < 0) {
705             Py_DECREF(ret);
706             return NULL;
707         }
708     }
709     return ret;
710 }
711 
712 int  // bool
_PyPegen_is_memoized(Parser * p,int type,void * pres)713 _PyPegen_is_memoized(Parser *p, int type, void *pres)
714 {
715     if (p->mark == p->fill) {
716         if (_PyPegen_fill_token(p) < 0) {
717             p->error_indicator = 1;
718             return -1;
719         }
720     }
721 
722     Token *t = p->tokens[p->mark];
723 
724     for (Memo *m = t->memo; m != NULL; m = m->next) {
725         if (m->type == type) {
726             if (0 <= type && type < NSTATISTICS) {
727                 long count = m->mark - p->mark;
728                 // A memoized negative result counts for one.
729                 if (count <= 0) {
730                     count = 1;
731                 }
732                 memo_statistics[type] += count;
733             }
734             p->mark = m->mark;
735             *(void **)(pres) = m->node;
736             return 1;
737         }
738     }
739     return 0;
740 }
741 
742 int
_PyPegen_lookahead_with_name(int positive,expr_ty (func)(Parser *),Parser * p)743 _PyPegen_lookahead_with_name(int positive, expr_ty (func)(Parser *), Parser *p)
744 {
745     int mark = p->mark;
746     void *res = func(p);
747     p->mark = mark;
748     return (res != NULL) == positive;
749 }
750 
751 int
_PyPegen_lookahead_with_string(int positive,expr_ty (func)(Parser *,const char *),Parser * p,const char * arg)752 _PyPegen_lookahead_with_string(int positive, expr_ty (func)(Parser *, const char*), Parser *p, const char* arg)
753 {
754     int mark = p->mark;
755     void *res = func(p, arg);
756     p->mark = mark;
757     return (res != NULL) == positive;
758 }
759 
760 int
_PyPegen_lookahead_with_int(int positive,Token * (func)(Parser *,int),Parser * p,int arg)761 _PyPegen_lookahead_with_int(int positive, Token *(func)(Parser *, int), Parser *p, int arg)
762 {
763     int mark = p->mark;
764     void *res = func(p, arg);
765     p->mark = mark;
766     return (res != NULL) == positive;
767 }
768 
769 int
_PyPegen_lookahead(int positive,void * (func)(Parser *),Parser * p)770 _PyPegen_lookahead(int positive, void *(func)(Parser *), Parser *p)
771 {
772     int mark = p->mark;
773     void *res = (void*)func(p);
774     p->mark = mark;
775     return (res != NULL) == positive;
776 }
777 
778 Token *
_PyPegen_expect_token(Parser * p,int type)779 _PyPegen_expect_token(Parser *p, int type)
780 {
781     if (p->mark == p->fill) {
782         if (_PyPegen_fill_token(p) < 0) {
783             p->error_indicator = 1;
784             return NULL;
785         }
786     }
787     Token *t = p->tokens[p->mark];
788     if (t->type != type) {
789         return NULL;
790     }
791     p->mark += 1;
792     return t;
793 }
794 
795 expr_ty
_PyPegen_expect_soft_keyword(Parser * p,const char * keyword)796 _PyPegen_expect_soft_keyword(Parser *p, const char *keyword)
797 {
798     if (p->mark == p->fill) {
799         if (_PyPegen_fill_token(p) < 0) {
800             p->error_indicator = 1;
801             return NULL;
802         }
803     }
804     Token *t = p->tokens[p->mark];
805     if (t->type != NAME) {
806         return NULL;
807     }
808     char* s = PyBytes_AsString(t->bytes);
809     if (!s) {
810         p->error_indicator = 1;
811         return NULL;
812     }
813     if (strcmp(s, keyword) != 0) {
814         return NULL;
815     }
816     return _PyPegen_name_token(p);
817 }
818 
819 Token *
_PyPegen_get_last_nonnwhitespace_token(Parser * p)820 _PyPegen_get_last_nonnwhitespace_token(Parser *p)
821 {
822     assert(p->mark >= 0);
823     Token *token = NULL;
824     for (int m = p->mark - 1; m >= 0; m--) {
825         token = p->tokens[m];
826         if (token->type != ENDMARKER && (token->type < NEWLINE || token->type > DEDENT)) {
827             break;
828         }
829     }
830     return token;
831 }
832 
833 expr_ty
_PyPegen_name_token(Parser * p)834 _PyPegen_name_token(Parser *p)
835 {
836     Token *t = _PyPegen_expect_token(p, NAME);
837     if (t == NULL) {
838         return NULL;
839     }
840     char* s = PyBytes_AsString(t->bytes);
841     if (!s) {
842         p->error_indicator = 1;
843         return NULL;
844     }
845     PyObject *id = _PyPegen_new_identifier(p, s);
846     if (id == NULL) {
847         p->error_indicator = 1;
848         return NULL;
849     }
850     return Name(id, Load, t->lineno, t->col_offset, t->end_lineno, t->end_col_offset,
851                 p->arena);
852 }
853 
854 void *
_PyPegen_string_token(Parser * p)855 _PyPegen_string_token(Parser *p)
856 {
857     return _PyPegen_expect_token(p, STRING);
858 }
859 
860 static PyObject *
parsenumber_raw(const char * s)861 parsenumber_raw(const char *s)
862 {
863     const char *end;
864     long x;
865     double dx;
866     Py_complex compl;
867     int imflag;
868 
869     assert(s != NULL);
870     errno = 0;
871     end = s + strlen(s) - 1;
872     imflag = *end == 'j' || *end == 'J';
873     if (s[0] == '0') {
874         x = (long)PyOS_strtoul(s, (char **)&end, 0);
875         if (x < 0 && errno == 0) {
876             return PyLong_FromString(s, (char **)0, 0);
877         }
878     }
879     else {
880         x = PyOS_strtol(s, (char **)&end, 0);
881     }
882     if (*end == '\0') {
883         if (errno != 0) {
884             return PyLong_FromString(s, (char **)0, 0);
885         }
886         return PyLong_FromLong(x);
887     }
888     /* XXX Huge floats may silently fail */
889     if (imflag) {
890         compl.real = 0.;
891         compl.imag = PyOS_string_to_double(s, (char **)&end, NULL);
892         if (compl.imag == -1.0 && PyErr_Occurred()) {
893             return NULL;
894         }
895         return PyComplex_FromCComplex(compl);
896     }
897     dx = PyOS_string_to_double(s, NULL, NULL);
898     if (dx == -1.0 && PyErr_Occurred()) {
899         return NULL;
900     }
901     return PyFloat_FromDouble(dx);
902 }
903 
904 static PyObject *
parsenumber(const char * s)905 parsenumber(const char *s)
906 {
907     char *dup;
908     char *end;
909     PyObject *res = NULL;
910 
911     assert(s != NULL);
912 
913     if (strchr(s, '_') == NULL) {
914         return parsenumber_raw(s);
915     }
916     /* Create a duplicate without underscores. */
917     dup = PyMem_Malloc(strlen(s) + 1);
918     if (dup == NULL) {
919         return PyErr_NoMemory();
920     }
921     end = dup;
922     for (; *s; s++) {
923         if (*s != '_') {
924             *end++ = *s;
925         }
926     }
927     *end = '\0';
928     res = parsenumber_raw(dup);
929     PyMem_Free(dup);
930     return res;
931 }
932 
933 expr_ty
_PyPegen_number_token(Parser * p)934 _PyPegen_number_token(Parser *p)
935 {
936     Token *t = _PyPegen_expect_token(p, NUMBER);
937     if (t == NULL) {
938         return NULL;
939     }
940 
941     char *num_raw = PyBytes_AsString(t->bytes);
942     if (num_raw == NULL) {
943         p->error_indicator = 1;
944         return NULL;
945     }
946 
947     if (p->feature_version < 6 && strchr(num_raw, '_') != NULL) {
948         p->error_indicator = 1;
949         return RAISE_SYNTAX_ERROR("Underscores in numeric literals are only supported "
950                                   "in Python 3.6 and greater");
951     }
952 
953     PyObject *c = parsenumber(num_raw);
954 
955     if (c == NULL) {
956         p->error_indicator = 1;
957         PyObject *exc_type, *exc_value, *exc_tb;
958         PyErr_Fetch(&exc_type, &exc_value, &exc_tb);
959         // The only way a ValueError should happen in _this_ code is via
960         // PyLong_FromString hitting a length limit.
961         if (exc_type == PyExc_ValueError && exc_value != NULL) {
962             // The Fetch acted as PyErr_Clear(), we're replacing the exception.
963             Py_XDECREF(exc_tb);
964             Py_DECREF(exc_type);
965             RAISE_ERROR_KNOWN_LOCATION(
966                 p, PyExc_SyntaxError,
967                 t->lineno, 0 /* col_offset */,
968                 "%S - Consider hexadecimal for huge integer literals "
969                 "to avoid decimal conversion limits.",
970                 exc_value);
971             Py_DECREF(exc_value);
972         } else {
973             PyErr_Restore(exc_type, exc_value, exc_tb);
974         }
975         return NULL;
976     }
977 
978     if (PyArena_AddPyObject(p->arena, c) < 0) {
979         Py_DECREF(c);
980         p->error_indicator = 1;
981         return NULL;
982     }
983 
984     return Constant(c, NULL, t->lineno, t->col_offset, t->end_lineno, t->end_col_offset,
985                     p->arena);
986 }
987 
988 static int // bool
newline_in_string(Parser * p,const char * cur)989 newline_in_string(Parser *p, const char *cur)
990 {
991     for (const char *c = cur; c >= p->tok->buf; c--) {
992         if (*c == '\'' || *c == '"') {
993             return 1;
994         }
995     }
996     return 0;
997 }
998 
999 /* Check that the source for a single input statement really is a single
1000    statement by looking at what is left in the buffer after parsing.
1001    Trailing whitespace and comments are OK. */
1002 static int // bool
bad_single_statement(Parser * p)1003 bad_single_statement(Parser *p)
1004 {
1005     const char *cur = strchr(p->tok->buf, '\n');
1006 
1007     /* Newlines are allowed if preceded by a line continuation character
1008        or if they appear inside a string. */
1009     if (!cur || (cur != p->tok->buf && *(cur - 1) == '\\')
1010              || newline_in_string(p, cur)) {
1011         return 0;
1012     }
1013     char c = *cur;
1014 
1015     for (;;) {
1016         while (c == ' ' || c == '\t' || c == '\n' || c == '\014') {
1017             c = *++cur;
1018         }
1019 
1020         if (!c) {
1021             return 0;
1022         }
1023 
1024         if (c != '#') {
1025             return 1;
1026         }
1027 
1028         /* Suck up comment. */
1029         while (c && c != '\n') {
1030             c = *++cur;
1031         }
1032     }
1033 }
1034 
1035 void
_PyPegen_Parser_Free(Parser * p)1036 _PyPegen_Parser_Free(Parser *p)
1037 {
1038     Py_XDECREF(p->normalize);
1039     for (int i = 0; i < p->size; i++) {
1040         PyMem_Free(p->tokens[i]);
1041     }
1042     PyMem_Free(p->tokens);
1043     growable_comment_array_deallocate(&p->type_ignore_comments);
1044     PyMem_Free(p);
1045 }
1046 
1047 static int
compute_parser_flags(PyCompilerFlags * flags)1048 compute_parser_flags(PyCompilerFlags *flags)
1049 {
1050     int parser_flags = 0;
1051     if (!flags) {
1052         return 0;
1053     }
1054     if (flags->cf_flags & PyCF_DONT_IMPLY_DEDENT) {
1055         parser_flags |= PyPARSE_DONT_IMPLY_DEDENT;
1056     }
1057     if (flags->cf_flags & PyCF_IGNORE_COOKIE) {
1058         parser_flags |= PyPARSE_IGNORE_COOKIE;
1059     }
1060     if (flags->cf_flags & CO_FUTURE_BARRY_AS_BDFL) {
1061         parser_flags |= PyPARSE_BARRY_AS_BDFL;
1062     }
1063     if (flags->cf_flags & PyCF_TYPE_COMMENTS) {
1064         parser_flags |= PyPARSE_TYPE_COMMENTS;
1065     }
1066     if ((flags->cf_flags & PyCF_ONLY_AST) && flags->cf_feature_version < 7) {
1067         parser_flags |= PyPARSE_ASYNC_HACKS;
1068     }
1069     return parser_flags;
1070 }
1071 
1072 Parser *
_PyPegen_Parser_New(struct tok_state * tok,int start_rule,int flags,int feature_version,int * errcode,PyArena * arena)1073 _PyPegen_Parser_New(struct tok_state *tok, int start_rule, int flags,
1074                     int feature_version, int *errcode, PyArena *arena)
1075 {
1076     Parser *p = PyMem_Malloc(sizeof(Parser));
1077     if (p == NULL) {
1078         return (Parser *) PyErr_NoMemory();
1079     }
1080     assert(tok != NULL);
1081     tok->type_comments = (flags & PyPARSE_TYPE_COMMENTS) > 0;
1082     tok->async_hacks = (flags & PyPARSE_ASYNC_HACKS) > 0;
1083     p->tok = tok;
1084     p->keywords = NULL;
1085     p->n_keyword_lists = -1;
1086     p->tokens = PyMem_Malloc(sizeof(Token *));
1087     if (!p->tokens) {
1088         PyMem_Free(p);
1089         return (Parser *) PyErr_NoMemory();
1090     }
1091     p->tokens[0] = PyMem_Calloc(1, sizeof(Token));
1092     if (!p->tokens) {
1093         PyMem_Free(p->tokens);
1094         PyMem_Free(p);
1095         return (Parser *) PyErr_NoMemory();
1096     }
1097     if (!growable_comment_array_init(&p->type_ignore_comments, 10)) {
1098         PyMem_Free(p->tokens[0]);
1099         PyMem_Free(p->tokens);
1100         PyMem_Free(p);
1101         return (Parser *) PyErr_NoMemory();
1102     }
1103 
1104     p->mark = 0;
1105     p->fill = 0;
1106     p->size = 1;
1107 
1108     p->errcode = errcode;
1109     p->arena = arena;
1110     p->start_rule = start_rule;
1111     p->parsing_started = 0;
1112     p->normalize = NULL;
1113     p->error_indicator = 0;
1114 
1115     p->starting_lineno = 0;
1116     p->starting_col_offset = 0;
1117     p->flags = flags;
1118     p->feature_version = feature_version;
1119     p->known_err_token = NULL;
1120     p->level = 0;
1121     p->call_invalid_rules = 0;
1122 
1123     return p;
1124 }
1125 
1126 static void
reset_parser_state(Parser * p)1127 reset_parser_state(Parser *p)
1128 {
1129     for (int i = 0; i < p->fill; i++) {
1130         p->tokens[i]->memo = NULL;
1131     }
1132     p->mark = 0;
1133     p->call_invalid_rules = 1;
1134 }
1135 
1136 void *
_PyPegen_run_parser(Parser * p)1137 _PyPegen_run_parser(Parser *p)
1138 {
1139     void *res = _PyPegen_parse(p);
1140     if (res == NULL) {
1141         reset_parser_state(p);
1142         _PyPegen_parse(p);
1143         if (PyErr_Occurred()) {
1144             return NULL;
1145         }
1146         if (p->fill == 0) {
1147             RAISE_SYNTAX_ERROR("error at start before reading any input");
1148         }
1149         else if (p->tok->done == E_EOF) {
1150             RAISE_SYNTAX_ERROR("unexpected EOF while parsing");
1151         }
1152         else {
1153             if (p->tokens[p->fill-1]->type == INDENT) {
1154                 RAISE_INDENTATION_ERROR("unexpected indent");
1155             }
1156             else if (p->tokens[p->fill-1]->type == DEDENT) {
1157                 RAISE_INDENTATION_ERROR("unexpected unindent");
1158             }
1159             else {
1160                 RAISE_SYNTAX_ERROR("invalid syntax");
1161             }
1162         }
1163         return NULL;
1164     }
1165 
1166     if (p->start_rule == Py_single_input && bad_single_statement(p)) {
1167         p->tok->done = E_BADSINGLE; // This is not necessary for now, but might be in the future
1168         return RAISE_SYNTAX_ERROR("multiple statements found while compiling a single statement");
1169     }
1170 
1171 #if defined(Py_DEBUG) && defined(Py_BUILD_CORE)
1172     if (p->start_rule == Py_single_input ||
1173         p->start_rule == Py_file_input ||
1174         p->start_rule == Py_eval_input)
1175     {
1176         assert(PyAST_Validate(res));
1177     }
1178 #endif
1179     return res;
1180 }
1181 
1182 mod_ty
_PyPegen_run_parser_from_file_pointer(FILE * fp,int start_rule,PyObject * filename_ob,const char * enc,const char * ps1,const char * ps2,PyCompilerFlags * flags,int * errcode,PyArena * arena)1183 _PyPegen_run_parser_from_file_pointer(FILE *fp, int start_rule, PyObject *filename_ob,
1184                              const char *enc, const char *ps1, const char *ps2,
1185                              PyCompilerFlags *flags, int *errcode, PyArena *arena)
1186 {
1187     struct tok_state *tok = PyTokenizer_FromFile(fp, enc, ps1, ps2);
1188     if (tok == NULL) {
1189         if (PyErr_Occurred()) {
1190             raise_tokenizer_init_error(filename_ob);
1191             return NULL;
1192         }
1193         return NULL;
1194     }
1195     // This transfers the ownership to the tokenizer
1196     tok->filename = filename_ob;
1197     Py_INCREF(filename_ob);
1198 
1199     // From here on we need to clean up even if there's an error
1200     mod_ty result = NULL;
1201 
1202     int parser_flags = compute_parser_flags(flags);
1203     Parser *p = _PyPegen_Parser_New(tok, start_rule, parser_flags, PY_MINOR_VERSION,
1204                                     errcode, arena);
1205     if (p == NULL) {
1206         goto error;
1207     }
1208 
1209     result = _PyPegen_run_parser(p);
1210     _PyPegen_Parser_Free(p);
1211 
1212 error:
1213     PyTokenizer_Free(tok);
1214     return result;
1215 }
1216 
1217 mod_ty
_PyPegen_run_parser_from_file(const char * filename,int start_rule,PyObject * filename_ob,PyCompilerFlags * flags,PyArena * arena)1218 _PyPegen_run_parser_from_file(const char *filename, int start_rule,
1219                      PyObject *filename_ob, PyCompilerFlags *flags, PyArena *arena)
1220 {
1221     FILE *fp = fopen(filename, "rb");
1222     if (fp == NULL) {
1223         PyErr_SetFromErrnoWithFilename(PyExc_OSError, filename);
1224         return NULL;
1225     }
1226 
1227     mod_ty result = _PyPegen_run_parser_from_file_pointer(fp, start_rule, filename_ob,
1228                                                  NULL, NULL, NULL, flags, NULL, arena);
1229 
1230     fclose(fp);
1231     return result;
1232 }
1233 
1234 mod_ty
_PyPegen_run_parser_from_string(const char * str,int start_rule,PyObject * filename_ob,PyCompilerFlags * flags,PyArena * arena)1235 _PyPegen_run_parser_from_string(const char *str, int start_rule, PyObject *filename_ob,
1236                        PyCompilerFlags *flags, PyArena *arena)
1237 {
1238     int exec_input = start_rule == Py_file_input;
1239 
1240     struct tok_state *tok;
1241     if (flags == NULL || flags->cf_flags & PyCF_IGNORE_COOKIE) {
1242         tok = PyTokenizer_FromUTF8(str, exec_input);
1243     } else {
1244         tok = PyTokenizer_FromString(str, exec_input);
1245     }
1246     if (tok == NULL) {
1247         if (PyErr_Occurred()) {
1248             raise_tokenizer_init_error(filename_ob);
1249         }
1250         return NULL;
1251     }
1252     // This transfers the ownership to the tokenizer
1253     tok->filename = filename_ob;
1254     Py_INCREF(filename_ob);
1255 
1256     // We need to clear up from here on
1257     mod_ty result = NULL;
1258 
1259     int parser_flags = compute_parser_flags(flags);
1260     int feature_version = flags && (flags->cf_flags & PyCF_ONLY_AST) ?
1261         flags->cf_feature_version : PY_MINOR_VERSION;
1262     Parser *p = _PyPegen_Parser_New(tok, start_rule, parser_flags, feature_version,
1263                                     NULL, arena);
1264     if (p == NULL) {
1265         goto error;
1266     }
1267 
1268     result = _PyPegen_run_parser(p);
1269     _PyPegen_Parser_Free(p);
1270 
1271 error:
1272     PyTokenizer_Free(tok);
1273     return result;
1274 }
1275 
1276 void *
_PyPegen_interactive_exit(Parser * p)1277 _PyPegen_interactive_exit(Parser *p)
1278 {
1279     if (p->errcode) {
1280         *(p->errcode) = E_EOF;
1281     }
1282     return NULL;
1283 }
1284 
1285 /* Creates a single-element asdl_seq* that contains a */
1286 asdl_seq *
_PyPegen_singleton_seq(Parser * p,void * a)1287 _PyPegen_singleton_seq(Parser *p, void *a)
1288 {
1289     assert(a != NULL);
1290     asdl_seq *seq = _Py_asdl_seq_new(1, p->arena);
1291     if (!seq) {
1292         return NULL;
1293     }
1294     asdl_seq_SET(seq, 0, a);
1295     return seq;
1296 }
1297 
1298 /* Creates a copy of seq and prepends a to it */
1299 asdl_seq *
_PyPegen_seq_insert_in_front(Parser * p,void * a,asdl_seq * seq)1300 _PyPegen_seq_insert_in_front(Parser *p, void *a, asdl_seq *seq)
1301 {
1302     assert(a != NULL);
1303     if (!seq) {
1304         return _PyPegen_singleton_seq(p, a);
1305     }
1306 
1307     asdl_seq *new_seq = _Py_asdl_seq_new(asdl_seq_LEN(seq) + 1, p->arena);
1308     if (!new_seq) {
1309         return NULL;
1310     }
1311 
1312     asdl_seq_SET(new_seq, 0, a);
1313     for (Py_ssize_t i = 1, l = asdl_seq_LEN(new_seq); i < l; i++) {
1314         asdl_seq_SET(new_seq, i, asdl_seq_GET(seq, i - 1));
1315     }
1316     return new_seq;
1317 }
1318 
1319 /* Creates a copy of seq and appends a to it */
1320 asdl_seq *
_PyPegen_seq_append_to_end(Parser * p,asdl_seq * seq,void * a)1321 _PyPegen_seq_append_to_end(Parser *p, asdl_seq *seq, void *a)
1322 {
1323     assert(a != NULL);
1324     if (!seq) {
1325         return _PyPegen_singleton_seq(p, a);
1326     }
1327 
1328     asdl_seq *new_seq = _Py_asdl_seq_new(asdl_seq_LEN(seq) + 1, p->arena);
1329     if (!new_seq) {
1330         return NULL;
1331     }
1332 
1333     for (Py_ssize_t i = 0, l = asdl_seq_LEN(new_seq); i + 1 < l; i++) {
1334         asdl_seq_SET(new_seq, i, asdl_seq_GET(seq, i));
1335     }
1336     asdl_seq_SET(new_seq, asdl_seq_LEN(new_seq) - 1, a);
1337     return new_seq;
1338 }
1339 
1340 static Py_ssize_t
_get_flattened_seq_size(asdl_seq * seqs)1341 _get_flattened_seq_size(asdl_seq *seqs)
1342 {
1343     Py_ssize_t size = 0;
1344     for (Py_ssize_t i = 0, l = asdl_seq_LEN(seqs); i < l; i++) {
1345         asdl_seq *inner_seq = asdl_seq_GET(seqs, i);
1346         size += asdl_seq_LEN(inner_seq);
1347     }
1348     return size;
1349 }
1350 
1351 /* Flattens an asdl_seq* of asdl_seq*s */
1352 asdl_seq *
_PyPegen_seq_flatten(Parser * p,asdl_seq * seqs)1353 _PyPegen_seq_flatten(Parser *p, asdl_seq *seqs)
1354 {
1355     Py_ssize_t flattened_seq_size = _get_flattened_seq_size(seqs);
1356     assert(flattened_seq_size > 0);
1357 
1358     asdl_seq *flattened_seq = _Py_asdl_seq_new(flattened_seq_size, p->arena);
1359     if (!flattened_seq) {
1360         return NULL;
1361     }
1362 
1363     int flattened_seq_idx = 0;
1364     for (Py_ssize_t i = 0, l = asdl_seq_LEN(seqs); i < l; i++) {
1365         asdl_seq *inner_seq = asdl_seq_GET(seqs, i);
1366         for (Py_ssize_t j = 0, li = asdl_seq_LEN(inner_seq); j < li; j++) {
1367             asdl_seq_SET(flattened_seq, flattened_seq_idx++, asdl_seq_GET(inner_seq, j));
1368         }
1369     }
1370     assert(flattened_seq_idx == flattened_seq_size);
1371 
1372     return flattened_seq;
1373 }
1374 
1375 /* Creates a new name of the form <first_name>.<second_name> */
1376 expr_ty
_PyPegen_join_names_with_dot(Parser * p,expr_ty first_name,expr_ty second_name)1377 _PyPegen_join_names_with_dot(Parser *p, expr_ty first_name, expr_ty second_name)
1378 {
1379     assert(first_name != NULL && second_name != NULL);
1380     PyObject *first_identifier = first_name->v.Name.id;
1381     PyObject *second_identifier = second_name->v.Name.id;
1382 
1383     if (PyUnicode_READY(first_identifier) == -1) {
1384         return NULL;
1385     }
1386     if (PyUnicode_READY(second_identifier) == -1) {
1387         return NULL;
1388     }
1389     const char *first_str = PyUnicode_AsUTF8(first_identifier);
1390     if (!first_str) {
1391         return NULL;
1392     }
1393     const char *second_str = PyUnicode_AsUTF8(second_identifier);
1394     if (!second_str) {
1395         return NULL;
1396     }
1397     Py_ssize_t len = strlen(first_str) + strlen(second_str) + 1;  // +1 for the dot
1398 
1399     PyObject *str = PyBytes_FromStringAndSize(NULL, len);
1400     if (!str) {
1401         return NULL;
1402     }
1403 
1404     char *s = PyBytes_AS_STRING(str);
1405     if (!s) {
1406         return NULL;
1407     }
1408 
1409     strcpy(s, first_str);
1410     s += strlen(first_str);
1411     *s++ = '.';
1412     strcpy(s, second_str);
1413     s += strlen(second_str);
1414     *s = '\0';
1415 
1416     PyObject *uni = PyUnicode_DecodeUTF8(PyBytes_AS_STRING(str), PyBytes_GET_SIZE(str), NULL);
1417     Py_DECREF(str);
1418     if (!uni) {
1419         return NULL;
1420     }
1421     PyUnicode_InternInPlace(&uni);
1422     if (PyArena_AddPyObject(p->arena, uni) < 0) {
1423         Py_DECREF(uni);
1424         return NULL;
1425     }
1426 
1427     return _Py_Name(uni, Load, EXTRA_EXPR(first_name, second_name));
1428 }
1429 
1430 /* Counts the total number of dots in seq's tokens */
1431 int
_PyPegen_seq_count_dots(asdl_seq * seq)1432 _PyPegen_seq_count_dots(asdl_seq *seq)
1433 {
1434     int number_of_dots = 0;
1435     for (Py_ssize_t i = 0, l = asdl_seq_LEN(seq); i < l; i++) {
1436         Token *current_expr = asdl_seq_GET(seq, i);
1437         switch (current_expr->type) {
1438             case ELLIPSIS:
1439                 number_of_dots += 3;
1440                 break;
1441             case DOT:
1442                 number_of_dots += 1;
1443                 break;
1444             default:
1445                 Py_UNREACHABLE();
1446         }
1447     }
1448 
1449     return number_of_dots;
1450 }
1451 
1452 /* Creates an alias with '*' as the identifier name */
1453 alias_ty
_PyPegen_alias_for_star(Parser * p)1454 _PyPegen_alias_for_star(Parser *p)
1455 {
1456     PyObject *str = PyUnicode_InternFromString("*");
1457     if (!str) {
1458         return NULL;
1459     }
1460     if (PyArena_AddPyObject(p->arena, str) < 0) {
1461         Py_DECREF(str);
1462         return NULL;
1463     }
1464     return alias(str, NULL, p->arena);
1465 }
1466 
1467 /* Creates a new asdl_seq* with the identifiers of all the names in seq */
1468 asdl_seq *
_PyPegen_map_names_to_ids(Parser * p,asdl_seq * seq)1469 _PyPegen_map_names_to_ids(Parser *p, asdl_seq *seq)
1470 {
1471     Py_ssize_t len = asdl_seq_LEN(seq);
1472     assert(len > 0);
1473 
1474     asdl_seq *new_seq = _Py_asdl_seq_new(len, p->arena);
1475     if (!new_seq) {
1476         return NULL;
1477     }
1478     for (Py_ssize_t i = 0; i < len; i++) {
1479         expr_ty e = asdl_seq_GET(seq, i);
1480         asdl_seq_SET(new_seq, i, e->v.Name.id);
1481     }
1482     return new_seq;
1483 }
1484 
1485 /* Constructs a CmpopExprPair */
1486 CmpopExprPair *
_PyPegen_cmpop_expr_pair(Parser * p,cmpop_ty cmpop,expr_ty expr)1487 _PyPegen_cmpop_expr_pair(Parser *p, cmpop_ty cmpop, expr_ty expr)
1488 {
1489     assert(expr != NULL);
1490     CmpopExprPair *a = PyArena_Malloc(p->arena, sizeof(CmpopExprPair));
1491     if (!a) {
1492         return NULL;
1493     }
1494     a->cmpop = cmpop;
1495     a->expr = expr;
1496     return a;
1497 }
1498 
1499 asdl_int_seq *
_PyPegen_get_cmpops(Parser * p,asdl_seq * seq)1500 _PyPegen_get_cmpops(Parser *p, asdl_seq *seq)
1501 {
1502     Py_ssize_t len = asdl_seq_LEN(seq);
1503     assert(len > 0);
1504 
1505     asdl_int_seq *new_seq = _Py_asdl_int_seq_new(len, p->arena);
1506     if (!new_seq) {
1507         return NULL;
1508     }
1509     for (Py_ssize_t i = 0; i < len; i++) {
1510         CmpopExprPair *pair = asdl_seq_GET(seq, i);
1511         asdl_seq_SET(new_seq, i, pair->cmpop);
1512     }
1513     return new_seq;
1514 }
1515 
1516 asdl_seq *
_PyPegen_get_exprs(Parser * p,asdl_seq * seq)1517 _PyPegen_get_exprs(Parser *p, asdl_seq *seq)
1518 {
1519     Py_ssize_t len = asdl_seq_LEN(seq);
1520     assert(len > 0);
1521 
1522     asdl_seq *new_seq = _Py_asdl_seq_new(len, p->arena);
1523     if (!new_seq) {
1524         return NULL;
1525     }
1526     for (Py_ssize_t i = 0; i < len; i++) {
1527         CmpopExprPair *pair = asdl_seq_GET(seq, i);
1528         asdl_seq_SET(new_seq, i, pair->expr);
1529     }
1530     return new_seq;
1531 }
1532 
1533 /* Creates an asdl_seq* where all the elements have been changed to have ctx as context */
1534 static asdl_seq *
_set_seq_context(Parser * p,asdl_seq * seq,expr_context_ty ctx)1535 _set_seq_context(Parser *p, asdl_seq *seq, expr_context_ty ctx)
1536 {
1537     Py_ssize_t len = asdl_seq_LEN(seq);
1538     if (len == 0) {
1539         return NULL;
1540     }
1541 
1542     asdl_seq *new_seq = _Py_asdl_seq_new(len, p->arena);
1543     if (!new_seq) {
1544         return NULL;
1545     }
1546     for (Py_ssize_t i = 0; i < len; i++) {
1547         expr_ty e = asdl_seq_GET(seq, i);
1548         asdl_seq_SET(new_seq, i, _PyPegen_set_expr_context(p, e, ctx));
1549     }
1550     return new_seq;
1551 }
1552 
1553 static expr_ty
_set_name_context(Parser * p,expr_ty e,expr_context_ty ctx)1554 _set_name_context(Parser *p, expr_ty e, expr_context_ty ctx)
1555 {
1556     return _Py_Name(e->v.Name.id, ctx, EXTRA_EXPR(e, e));
1557 }
1558 
1559 static expr_ty
_set_tuple_context(Parser * p,expr_ty e,expr_context_ty ctx)1560 _set_tuple_context(Parser *p, expr_ty e, expr_context_ty ctx)
1561 {
1562     return _Py_Tuple(_set_seq_context(p, e->v.Tuple.elts, ctx), ctx, EXTRA_EXPR(e, e));
1563 }
1564 
1565 static expr_ty
_set_list_context(Parser * p,expr_ty e,expr_context_ty ctx)1566 _set_list_context(Parser *p, expr_ty e, expr_context_ty ctx)
1567 {
1568     return _Py_List(_set_seq_context(p, e->v.List.elts, ctx), ctx, EXTRA_EXPR(e, e));
1569 }
1570 
1571 static expr_ty
_set_subscript_context(Parser * p,expr_ty e,expr_context_ty ctx)1572 _set_subscript_context(Parser *p, expr_ty e, expr_context_ty ctx)
1573 {
1574     return _Py_Subscript(e->v.Subscript.value, e->v.Subscript.slice, ctx, EXTRA_EXPR(e, e));
1575 }
1576 
1577 static expr_ty
_set_attribute_context(Parser * p,expr_ty e,expr_context_ty ctx)1578 _set_attribute_context(Parser *p, expr_ty e, expr_context_ty ctx)
1579 {
1580     return _Py_Attribute(e->v.Attribute.value, e->v.Attribute.attr, ctx, EXTRA_EXPR(e, e));
1581 }
1582 
1583 static expr_ty
_set_starred_context(Parser * p,expr_ty e,expr_context_ty ctx)1584 _set_starred_context(Parser *p, expr_ty e, expr_context_ty ctx)
1585 {
1586     return _Py_Starred(_PyPegen_set_expr_context(p, e->v.Starred.value, ctx), ctx, EXTRA_EXPR(e, e));
1587 }
1588 
1589 /* Creates an `expr_ty` equivalent to `expr` but with `ctx` as context */
1590 expr_ty
_PyPegen_set_expr_context(Parser * p,expr_ty expr,expr_context_ty ctx)1591 _PyPegen_set_expr_context(Parser *p, expr_ty expr, expr_context_ty ctx)
1592 {
1593     assert(expr != NULL);
1594 
1595     expr_ty new = NULL;
1596     switch (expr->kind) {
1597         case Name_kind:
1598             new = _set_name_context(p, expr, ctx);
1599             break;
1600         case Tuple_kind:
1601             new = _set_tuple_context(p, expr, ctx);
1602             break;
1603         case List_kind:
1604             new = _set_list_context(p, expr, ctx);
1605             break;
1606         case Subscript_kind:
1607             new = _set_subscript_context(p, expr, ctx);
1608             break;
1609         case Attribute_kind:
1610             new = _set_attribute_context(p, expr, ctx);
1611             break;
1612         case Starred_kind:
1613             new = _set_starred_context(p, expr, ctx);
1614             break;
1615         default:
1616             new = expr;
1617     }
1618     return new;
1619 }
1620 
1621 /* Constructs a KeyValuePair that is used when parsing a dict's key value pairs */
1622 KeyValuePair *
_PyPegen_key_value_pair(Parser * p,expr_ty key,expr_ty value)1623 _PyPegen_key_value_pair(Parser *p, expr_ty key, expr_ty value)
1624 {
1625     KeyValuePair *a = PyArena_Malloc(p->arena, sizeof(KeyValuePair));
1626     if (!a) {
1627         return NULL;
1628     }
1629     a->key = key;
1630     a->value = value;
1631     return a;
1632 }
1633 
1634 /* Extracts all keys from an asdl_seq* of KeyValuePair*'s */
1635 asdl_seq *
_PyPegen_get_keys(Parser * p,asdl_seq * seq)1636 _PyPegen_get_keys(Parser *p, asdl_seq *seq)
1637 {
1638     Py_ssize_t len = asdl_seq_LEN(seq);
1639     asdl_seq *new_seq = _Py_asdl_seq_new(len, p->arena);
1640     if (!new_seq) {
1641         return NULL;
1642     }
1643     for (Py_ssize_t i = 0; i < len; i++) {
1644         KeyValuePair *pair = asdl_seq_GET(seq, i);
1645         asdl_seq_SET(new_seq, i, pair->key);
1646     }
1647     return new_seq;
1648 }
1649 
1650 /* Extracts all values from an asdl_seq* of KeyValuePair*'s */
1651 asdl_seq *
_PyPegen_get_values(Parser * p,asdl_seq * seq)1652 _PyPegen_get_values(Parser *p, asdl_seq *seq)
1653 {
1654     Py_ssize_t len = asdl_seq_LEN(seq);
1655     asdl_seq *new_seq = _Py_asdl_seq_new(len, p->arena);
1656     if (!new_seq) {
1657         return NULL;
1658     }
1659     for (Py_ssize_t i = 0; i < len; i++) {
1660         KeyValuePair *pair = asdl_seq_GET(seq, i);
1661         asdl_seq_SET(new_seq, i, pair->value);
1662     }
1663     return new_seq;
1664 }
1665 
1666 /* Constructs a NameDefaultPair */
1667 NameDefaultPair *
_PyPegen_name_default_pair(Parser * p,arg_ty arg,expr_ty value,Token * tc)1668 _PyPegen_name_default_pair(Parser *p, arg_ty arg, expr_ty value, Token *tc)
1669 {
1670     NameDefaultPair *a = PyArena_Malloc(p->arena, sizeof(NameDefaultPair));
1671     if (!a) {
1672         return NULL;
1673     }
1674     a->arg = _PyPegen_add_type_comment_to_arg(p, arg, tc);
1675     a->value = value;
1676     return a;
1677 }
1678 
1679 /* Constructs a SlashWithDefault */
1680 SlashWithDefault *
_PyPegen_slash_with_default(Parser * p,asdl_seq * plain_names,asdl_seq * names_with_defaults)1681 _PyPegen_slash_with_default(Parser *p, asdl_seq *plain_names, asdl_seq *names_with_defaults)
1682 {
1683     SlashWithDefault *a = PyArena_Malloc(p->arena, sizeof(SlashWithDefault));
1684     if (!a) {
1685         return NULL;
1686     }
1687     a->plain_names = plain_names;
1688     a->names_with_defaults = names_with_defaults;
1689     return a;
1690 }
1691 
1692 /* Constructs a StarEtc */
1693 StarEtc *
_PyPegen_star_etc(Parser * p,arg_ty vararg,asdl_seq * kwonlyargs,arg_ty kwarg)1694 _PyPegen_star_etc(Parser *p, arg_ty vararg, asdl_seq *kwonlyargs, arg_ty kwarg)
1695 {
1696     StarEtc *a = PyArena_Malloc(p->arena, sizeof(StarEtc));
1697     if (!a) {
1698         return NULL;
1699     }
1700     a->vararg = vararg;
1701     a->kwonlyargs = kwonlyargs;
1702     a->kwarg = kwarg;
1703     return a;
1704 }
1705 
1706 asdl_seq *
_PyPegen_join_sequences(Parser * p,asdl_seq * a,asdl_seq * b)1707 _PyPegen_join_sequences(Parser *p, asdl_seq *a, asdl_seq *b)
1708 {
1709     Py_ssize_t first_len = asdl_seq_LEN(a);
1710     Py_ssize_t second_len = asdl_seq_LEN(b);
1711     asdl_seq *new_seq = _Py_asdl_seq_new(first_len + second_len, p->arena);
1712     if (!new_seq) {
1713         return NULL;
1714     }
1715 
1716     int k = 0;
1717     for (Py_ssize_t i = 0; i < first_len; i++) {
1718         asdl_seq_SET(new_seq, k++, asdl_seq_GET(a, i));
1719     }
1720     for (Py_ssize_t i = 0; i < second_len; i++) {
1721         asdl_seq_SET(new_seq, k++, asdl_seq_GET(b, i));
1722     }
1723 
1724     return new_seq;
1725 }
1726 
1727 static asdl_seq *
_get_names(Parser * p,asdl_seq * names_with_defaults)1728 _get_names(Parser *p, asdl_seq *names_with_defaults)
1729 {
1730     Py_ssize_t len = asdl_seq_LEN(names_with_defaults);
1731     asdl_seq *seq = _Py_asdl_seq_new(len, p->arena);
1732     if (!seq) {
1733         return NULL;
1734     }
1735     for (Py_ssize_t i = 0; i < len; i++) {
1736         NameDefaultPair *pair = asdl_seq_GET(names_with_defaults, i);
1737         asdl_seq_SET(seq, i, pair->arg);
1738     }
1739     return seq;
1740 }
1741 
1742 static asdl_seq *
_get_defaults(Parser * p,asdl_seq * names_with_defaults)1743 _get_defaults(Parser *p, asdl_seq *names_with_defaults)
1744 {
1745     Py_ssize_t len = asdl_seq_LEN(names_with_defaults);
1746     asdl_seq *seq = _Py_asdl_seq_new(len, p->arena);
1747     if (!seq) {
1748         return NULL;
1749     }
1750     for (Py_ssize_t i = 0; i < len; i++) {
1751         NameDefaultPair *pair = asdl_seq_GET(names_with_defaults, i);
1752         asdl_seq_SET(seq, i, pair->value);
1753     }
1754     return seq;
1755 }
1756 
1757 /* Constructs an arguments_ty object out of all the parsed constructs in the parameters rule */
1758 arguments_ty
_PyPegen_make_arguments(Parser * p,asdl_seq * slash_without_default,SlashWithDefault * slash_with_default,asdl_seq * plain_names,asdl_seq * names_with_default,StarEtc * star_etc)1759 _PyPegen_make_arguments(Parser *p, asdl_seq *slash_without_default,
1760                         SlashWithDefault *slash_with_default, asdl_seq *plain_names,
1761                         asdl_seq *names_with_default, StarEtc *star_etc)
1762 {
1763     asdl_seq *posonlyargs;
1764     if (slash_without_default != NULL) {
1765         posonlyargs = slash_without_default;
1766     }
1767     else if (slash_with_default != NULL) {
1768         asdl_seq *slash_with_default_names =
1769             _get_names(p, slash_with_default->names_with_defaults);
1770         if (!slash_with_default_names) {
1771             return NULL;
1772         }
1773         posonlyargs = _PyPegen_join_sequences(p, slash_with_default->plain_names, slash_with_default_names);
1774         if (!posonlyargs) {
1775             return NULL;
1776         }
1777     }
1778     else {
1779         posonlyargs = _Py_asdl_seq_new(0, p->arena);
1780         if (!posonlyargs) {
1781             return NULL;
1782         }
1783     }
1784 
1785     asdl_seq *posargs;
1786     if (plain_names != NULL && names_with_default != NULL) {
1787         asdl_seq *names_with_default_names = _get_names(p, names_with_default);
1788         if (!names_with_default_names) {
1789             return NULL;
1790         }
1791         posargs = _PyPegen_join_sequences(p, plain_names, names_with_default_names);
1792         if (!posargs) {
1793             return NULL;
1794         }
1795     }
1796     else if (plain_names == NULL && names_with_default != NULL) {
1797         posargs = _get_names(p, names_with_default);
1798         if (!posargs) {
1799             return NULL;
1800         }
1801     }
1802     else if (plain_names != NULL && names_with_default == NULL) {
1803         posargs = plain_names;
1804     }
1805     else {
1806         posargs = _Py_asdl_seq_new(0, p->arena);
1807         if (!posargs) {
1808             return NULL;
1809         }
1810     }
1811 
1812     asdl_seq *posdefaults;
1813     if (slash_with_default != NULL && names_with_default != NULL) {
1814         asdl_seq *slash_with_default_values =
1815             _get_defaults(p, slash_with_default->names_with_defaults);
1816         if (!slash_with_default_values) {
1817             return NULL;
1818         }
1819         asdl_seq *names_with_default_values = _get_defaults(p, names_with_default);
1820         if (!names_with_default_values) {
1821             return NULL;
1822         }
1823         posdefaults = _PyPegen_join_sequences(p, slash_with_default_values, names_with_default_values);
1824         if (!posdefaults) {
1825             return NULL;
1826         }
1827     }
1828     else if (slash_with_default == NULL && names_with_default != NULL) {
1829         posdefaults = _get_defaults(p, names_with_default);
1830         if (!posdefaults) {
1831             return NULL;
1832         }
1833     }
1834     else if (slash_with_default != NULL && names_with_default == NULL) {
1835         posdefaults = _get_defaults(p, slash_with_default->names_with_defaults);
1836         if (!posdefaults) {
1837             return NULL;
1838         }
1839     }
1840     else {
1841         posdefaults = _Py_asdl_seq_new(0, p->arena);
1842         if (!posdefaults) {
1843             return NULL;
1844         }
1845     }
1846 
1847     arg_ty vararg = NULL;
1848     if (star_etc != NULL && star_etc->vararg != NULL) {
1849         vararg = star_etc->vararg;
1850     }
1851 
1852     asdl_seq *kwonlyargs;
1853     if (star_etc != NULL && star_etc->kwonlyargs != NULL) {
1854         kwonlyargs = _get_names(p, star_etc->kwonlyargs);
1855         if (!kwonlyargs) {
1856             return NULL;
1857         }
1858     }
1859     else {
1860         kwonlyargs = _Py_asdl_seq_new(0, p->arena);
1861         if (!kwonlyargs) {
1862             return NULL;
1863         }
1864     }
1865 
1866     asdl_seq *kwdefaults;
1867     if (star_etc != NULL && star_etc->kwonlyargs != NULL) {
1868         kwdefaults = _get_defaults(p, star_etc->kwonlyargs);
1869         if (!kwdefaults) {
1870             return NULL;
1871         }
1872     }
1873     else {
1874         kwdefaults = _Py_asdl_seq_new(0, p->arena);
1875         if (!kwdefaults) {
1876             return NULL;
1877         }
1878     }
1879 
1880     arg_ty kwarg = NULL;
1881     if (star_etc != NULL && star_etc->kwarg != NULL) {
1882         kwarg = star_etc->kwarg;
1883     }
1884 
1885     return _Py_arguments(posonlyargs, posargs, vararg, kwonlyargs, kwdefaults, kwarg,
1886                          posdefaults, p->arena);
1887 }
1888 
1889 /* Constructs an empty arguments_ty object, that gets used when a function accepts no
1890  * arguments. */
1891 arguments_ty
_PyPegen_empty_arguments(Parser * p)1892 _PyPegen_empty_arguments(Parser *p)
1893 {
1894     asdl_seq *posonlyargs = _Py_asdl_seq_new(0, p->arena);
1895     if (!posonlyargs) {
1896         return NULL;
1897     }
1898     asdl_seq *posargs = _Py_asdl_seq_new(0, p->arena);
1899     if (!posargs) {
1900         return NULL;
1901     }
1902     asdl_seq *posdefaults = _Py_asdl_seq_new(0, p->arena);
1903     if (!posdefaults) {
1904         return NULL;
1905     }
1906     asdl_seq *kwonlyargs = _Py_asdl_seq_new(0, p->arena);
1907     if (!kwonlyargs) {
1908         return NULL;
1909     }
1910     asdl_seq *kwdefaults = _Py_asdl_seq_new(0, p->arena);
1911     if (!kwdefaults) {
1912         return NULL;
1913     }
1914 
1915     return _Py_arguments(posonlyargs, posargs, NULL, kwonlyargs, kwdefaults, NULL, kwdefaults,
1916                          p->arena);
1917 }
1918 
1919 /* Encapsulates the value of an operator_ty into an AugOperator struct */
1920 AugOperator *
_PyPegen_augoperator(Parser * p,operator_ty kind)1921 _PyPegen_augoperator(Parser *p, operator_ty kind)
1922 {
1923     AugOperator *a = PyArena_Malloc(p->arena, sizeof(AugOperator));
1924     if (!a) {
1925         return NULL;
1926     }
1927     a->kind = kind;
1928     return a;
1929 }
1930 
1931 /* Construct a FunctionDef equivalent to function_def, but with decorators */
1932 stmt_ty
_PyPegen_function_def_decorators(Parser * p,asdl_seq * decorators,stmt_ty function_def)1933 _PyPegen_function_def_decorators(Parser *p, asdl_seq *decorators, stmt_ty function_def)
1934 {
1935     assert(function_def != NULL);
1936     if (function_def->kind == AsyncFunctionDef_kind) {
1937         return _Py_AsyncFunctionDef(
1938             function_def->v.FunctionDef.name, function_def->v.FunctionDef.args,
1939             function_def->v.FunctionDef.body, decorators, function_def->v.FunctionDef.returns,
1940             function_def->v.FunctionDef.type_comment, function_def->lineno,
1941             function_def->col_offset, function_def->end_lineno, function_def->end_col_offset,
1942             p->arena);
1943     }
1944 
1945     return _Py_FunctionDef(function_def->v.FunctionDef.name, function_def->v.FunctionDef.args,
1946                            function_def->v.FunctionDef.body, decorators,
1947                            function_def->v.FunctionDef.returns,
1948                            function_def->v.FunctionDef.type_comment, function_def->lineno,
1949                            function_def->col_offset, function_def->end_lineno,
1950                            function_def->end_col_offset, p->arena);
1951 }
1952 
1953 /* Construct a ClassDef equivalent to class_def, but with decorators */
1954 stmt_ty
_PyPegen_class_def_decorators(Parser * p,asdl_seq * decorators,stmt_ty class_def)1955 _PyPegen_class_def_decorators(Parser *p, asdl_seq *decorators, stmt_ty class_def)
1956 {
1957     assert(class_def != NULL);
1958     return _Py_ClassDef(class_def->v.ClassDef.name, class_def->v.ClassDef.bases,
1959                         class_def->v.ClassDef.keywords, class_def->v.ClassDef.body, decorators,
1960                         class_def->lineno, class_def->col_offset, class_def->end_lineno,
1961                         class_def->end_col_offset, p->arena);
1962 }
1963 
1964 /* Construct a KeywordOrStarred */
1965 KeywordOrStarred *
_PyPegen_keyword_or_starred(Parser * p,void * element,int is_keyword)1966 _PyPegen_keyword_or_starred(Parser *p, void *element, int is_keyword)
1967 {
1968     KeywordOrStarred *a = PyArena_Malloc(p->arena, sizeof(KeywordOrStarred));
1969     if (!a) {
1970         return NULL;
1971     }
1972     a->element = element;
1973     a->is_keyword = is_keyword;
1974     return a;
1975 }
1976 
1977 /* Get the number of starred expressions in an asdl_seq* of KeywordOrStarred*s */
1978 static int
_seq_number_of_starred_exprs(asdl_seq * seq)1979 _seq_number_of_starred_exprs(asdl_seq *seq)
1980 {
1981     int n = 0;
1982     for (Py_ssize_t i = 0, l = asdl_seq_LEN(seq); i < l; i++) {
1983         KeywordOrStarred *k = asdl_seq_GET(seq, i);
1984         if (!k->is_keyword) {
1985             n++;
1986         }
1987     }
1988     return n;
1989 }
1990 
1991 /* Extract the starred expressions of an asdl_seq* of KeywordOrStarred*s */
1992 asdl_seq *
_PyPegen_seq_extract_starred_exprs(Parser * p,asdl_seq * kwargs)1993 _PyPegen_seq_extract_starred_exprs(Parser *p, asdl_seq *kwargs)
1994 {
1995     int new_len = _seq_number_of_starred_exprs(kwargs);
1996     if (new_len == 0) {
1997         return NULL;
1998     }
1999     asdl_seq *new_seq = _Py_asdl_seq_new(new_len, p->arena);
2000     if (!new_seq) {
2001         return NULL;
2002     }
2003 
2004     int idx = 0;
2005     for (Py_ssize_t i = 0, len = asdl_seq_LEN(kwargs); i < len; i++) {
2006         KeywordOrStarred *k = asdl_seq_GET(kwargs, i);
2007         if (!k->is_keyword) {
2008             asdl_seq_SET(new_seq, idx++, k->element);
2009         }
2010     }
2011     return new_seq;
2012 }
2013 
2014 /* Return a new asdl_seq* with only the keywords in kwargs */
2015 asdl_seq *
_PyPegen_seq_delete_starred_exprs(Parser * p,asdl_seq * kwargs)2016 _PyPegen_seq_delete_starred_exprs(Parser *p, asdl_seq *kwargs)
2017 {
2018     Py_ssize_t len = asdl_seq_LEN(kwargs);
2019     Py_ssize_t new_len = len - _seq_number_of_starred_exprs(kwargs);
2020     if (new_len == 0) {
2021         return NULL;
2022     }
2023     asdl_seq *new_seq = _Py_asdl_seq_new(new_len, p->arena);
2024     if (!new_seq) {
2025         return NULL;
2026     }
2027 
2028     int idx = 0;
2029     for (Py_ssize_t i = 0; i < len; i++) {
2030         KeywordOrStarred *k = asdl_seq_GET(kwargs, i);
2031         if (k->is_keyword) {
2032             asdl_seq_SET(new_seq, idx++, k->element);
2033         }
2034     }
2035     return new_seq;
2036 }
2037 
2038 expr_ty
_PyPegen_concatenate_strings(Parser * p,asdl_seq * strings)2039 _PyPegen_concatenate_strings(Parser *p, asdl_seq *strings)
2040 {
2041     Py_ssize_t len = asdl_seq_LEN(strings);
2042     assert(len > 0);
2043 
2044     Token *first = asdl_seq_GET(strings, 0);
2045     Token *last = asdl_seq_GET(strings, len - 1);
2046 
2047     int bytesmode = 0;
2048     PyObject *bytes_str = NULL;
2049 
2050     FstringParser state;
2051     _PyPegen_FstringParser_Init(&state);
2052 
2053     for (Py_ssize_t i = 0; i < len; i++) {
2054         Token *t = asdl_seq_GET(strings, i);
2055 
2056         int this_bytesmode;
2057         int this_rawmode;
2058         PyObject *s;
2059         const char *fstr;
2060         Py_ssize_t fstrlen = -1;
2061 
2062         if (_PyPegen_parsestr(p, &this_bytesmode, &this_rawmode, &s, &fstr, &fstrlen, t) != 0) {
2063             goto error;
2064         }
2065 
2066         /* Check that we are not mixing bytes with unicode. */
2067         if (i != 0 && bytesmode != this_bytesmode) {
2068             RAISE_SYNTAX_ERROR("cannot mix bytes and nonbytes literals");
2069             Py_XDECREF(s);
2070             goto error;
2071         }
2072         bytesmode = this_bytesmode;
2073 
2074         if (fstr != NULL) {
2075             assert(s == NULL && !bytesmode);
2076 
2077             int result = _PyPegen_FstringParser_ConcatFstring(p, &state, &fstr, fstr + fstrlen,
2078                                                      this_rawmode, 0, first, t, last);
2079             if (result < 0) {
2080                 goto error;
2081             }
2082         }
2083         else {
2084             /* String or byte string. */
2085             assert(s != NULL && fstr == NULL);
2086             assert(bytesmode ? PyBytes_CheckExact(s) : PyUnicode_CheckExact(s));
2087 
2088             if (bytesmode) {
2089                 if (i == 0) {
2090                     bytes_str = s;
2091                 }
2092                 else {
2093                     PyBytes_ConcatAndDel(&bytes_str, s);
2094                     if (!bytes_str) {
2095                         goto error;
2096                     }
2097                 }
2098             }
2099             else {
2100                 /* This is a regular string. Concatenate it. */
2101                 if (_PyPegen_FstringParser_ConcatAndDel(&state, s) < 0) {
2102                     goto error;
2103                 }
2104             }
2105         }
2106     }
2107 
2108     if (bytesmode) {
2109         if (PyArena_AddPyObject(p->arena, bytes_str) < 0) {
2110             goto error;
2111         }
2112         return Constant(bytes_str, NULL, first->lineno, first->col_offset, last->end_lineno,
2113                         last->end_col_offset, p->arena);
2114     }
2115 
2116     return _PyPegen_FstringParser_Finish(p, &state, first, last);
2117 
2118 error:
2119     Py_XDECREF(bytes_str);
2120     _PyPegen_FstringParser_Dealloc(&state);
2121     if (PyErr_Occurred()) {
2122         raise_decode_error(p);
2123     }
2124     return NULL;
2125 }
2126 
2127 mod_ty
_PyPegen_make_module(Parser * p,asdl_seq * a)2128 _PyPegen_make_module(Parser *p, asdl_seq *a) {
2129     asdl_seq *type_ignores = NULL;
2130     Py_ssize_t num = p->type_ignore_comments.num_items;
2131     if (num > 0) {
2132         // Turn the raw (comment, lineno) pairs into TypeIgnore objects in the arena
2133         type_ignores = _Py_asdl_seq_new(num, p->arena);
2134         if (type_ignores == NULL) {
2135             return NULL;
2136         }
2137         for (int i = 0; i < num; i++) {
2138             PyObject *tag = _PyPegen_new_type_comment(p, p->type_ignore_comments.items[i].comment);
2139             if (tag == NULL) {
2140                 return NULL;
2141             }
2142             type_ignore_ty ti = TypeIgnore(p->type_ignore_comments.items[i].lineno, tag, p->arena);
2143             if (ti == NULL) {
2144                 return NULL;
2145             }
2146             asdl_seq_SET(type_ignores, i, ti);
2147         }
2148     }
2149     return Module(a, type_ignores, p->arena);
2150 }
2151 
2152 // Error reporting helpers
2153 
2154 expr_ty
_PyPegen_get_invalid_target(expr_ty e,TARGETS_TYPE targets_type)2155 _PyPegen_get_invalid_target(expr_ty e, TARGETS_TYPE targets_type)
2156 {
2157     if (e == NULL) {
2158         return NULL;
2159     }
2160 
2161 #define VISIT_CONTAINER(CONTAINER, TYPE) do { \
2162         Py_ssize_t len = asdl_seq_LEN(CONTAINER->v.TYPE.elts);\
2163         for (Py_ssize_t i = 0; i < len; i++) {\
2164             expr_ty other = asdl_seq_GET(CONTAINER->v.TYPE.elts, i);\
2165             expr_ty child = _PyPegen_get_invalid_target(other, targets_type);\
2166             if (child != NULL) {\
2167                 return child;\
2168             }\
2169         }\
2170     } while (0)
2171 
2172     // We only need to visit List and Tuple nodes recursively as those
2173     // are the only ones that can contain valid names in targets when
2174     // they are parsed as expressions. Any other kind of expression
2175     // that is a container (like Sets or Dicts) is directly invalid and
2176     // we don't need to visit it recursively.
2177 
2178     switch (e->kind) {
2179         case List_kind:
2180             VISIT_CONTAINER(e, List);
2181             return NULL;
2182         case Tuple_kind:
2183             VISIT_CONTAINER(e, Tuple);
2184             return NULL;
2185         case Starred_kind:
2186             if (targets_type == DEL_TARGETS) {
2187                 return e;
2188             }
2189             return _PyPegen_get_invalid_target(e->v.Starred.value, targets_type);
2190         case Compare_kind:
2191             // This is needed, because the `a in b` in `for a in b` gets parsed
2192             // as a comparison, and so we need to search the left side of the comparison
2193             // for invalid targets.
2194             if (targets_type == FOR_TARGETS) {
2195                 cmpop_ty cmpop = (cmpop_ty) asdl_seq_GET(e->v.Compare.ops, 0);
2196                 if (cmpop == In) {
2197                     return _PyPegen_get_invalid_target(e->v.Compare.left, targets_type);
2198                 }
2199                 return NULL;
2200             }
2201             return e;
2202         case Name_kind:
2203         case Subscript_kind:
2204         case Attribute_kind:
2205             return NULL;
2206         default:
2207             return e;
2208     }
2209 }
2210 
_PyPegen_arguments_parsing_error(Parser * p,expr_ty e)2211 void *_PyPegen_arguments_parsing_error(Parser *p, expr_ty e) {
2212     int kwarg_unpacking = 0;
2213     for (Py_ssize_t i = 0, l = asdl_seq_LEN(e->v.Call.keywords); i < l; i++) {
2214         keyword_ty keyword = asdl_seq_GET(e->v.Call.keywords, i);
2215         if (!keyword->arg) {
2216             kwarg_unpacking = 1;
2217         }
2218     }
2219 
2220     const char *msg = NULL;
2221     if (kwarg_unpacking) {
2222         msg = "positional argument follows keyword argument unpacking";
2223     } else {
2224         msg = "positional argument follows keyword argument";
2225     }
2226 
2227     return RAISE_SYNTAX_ERROR(msg);
2228 }
2229 
2230 void *
_PyPegen_nonparen_genexp_in_call(Parser * p,expr_ty args)2231 _PyPegen_nonparen_genexp_in_call(Parser *p, expr_ty args)
2232 {
2233     /* The rule that calls this function is 'args for_if_clauses'.
2234        For the input f(L, x for x in y), L and x are in args and
2235        the for is parsed as a for_if_clause. We have to check if
2236        len <= 1, so that input like dict((a, b) for a, b in x)
2237        gets successfully parsed and then we pass the last
2238        argument (x in the above example) as the location of the
2239        error */
2240     Py_ssize_t len = asdl_seq_LEN(args->v.Call.args);
2241     if (len <= 1) {
2242         return NULL;
2243     }
2244 
2245     return RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
2246         (expr_ty) asdl_seq_GET(args->v.Call.args, len - 1),
2247         "Generator expression must be parenthesized"
2248     );
2249 }
2250 
2251 
_PyPegen_collect_call_seqs(Parser * p,asdl_seq * a,asdl_seq * b,int lineno,int col_offset,int end_lineno,int end_col_offset,PyArena * arena)2252 expr_ty _PyPegen_collect_call_seqs(Parser *p, asdl_seq *a, asdl_seq *b,
2253                      int lineno, int col_offset, int end_lineno,
2254                      int end_col_offset, PyArena *arena) {
2255     Py_ssize_t args_len = asdl_seq_LEN(a);
2256     Py_ssize_t total_len = args_len;
2257 
2258     if (b == NULL) {
2259         return _Py_Call(_PyPegen_dummy_name(p), a, NULL, lineno, col_offset,
2260                         end_lineno, end_col_offset, arena);
2261 
2262     }
2263 
2264     asdl_seq *starreds = _PyPegen_seq_extract_starred_exprs(p, b);
2265     asdl_seq *keywords = _PyPegen_seq_delete_starred_exprs(p, b);
2266 
2267     if (starreds) {
2268         total_len += asdl_seq_LEN(starreds);
2269     }
2270 
2271     asdl_seq *args = _Py_asdl_seq_new(total_len, arena);
2272 
2273     Py_ssize_t i = 0;
2274     for (i = 0; i < args_len; i++) {
2275         asdl_seq_SET(args, i, asdl_seq_GET(a, i));
2276     }
2277     for (; i < total_len; i++) {
2278         asdl_seq_SET(args, i, asdl_seq_GET(starreds, i - args_len));
2279     }
2280 
2281     return _Py_Call(_PyPegen_dummy_name(p), args, keywords, lineno,
2282                     col_offset, end_lineno, end_col_offset, arena);
2283 
2284 
2285 }
2286