Repository navigation
Expand file tree
/
Copy pathc_generator.py
More file actions
724 lines (649 loc) · 26.7 KB
/
Copy pathc_generator.py
File metadata and controls
724 lines (649 loc) · 26.7 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
import ast
from dataclasses import field, dataclass
import re
from typing import Any, Dict, IO, Optional, List, Text, Tuple, Set
from enum import Enum
from pegen import grammar
from pegen.grammar import (
Alt,
Cut,
Gather,
GrammarVisitor,
Group,
Lookahead,
NamedItem,
NameLeaf,
NegativeLookahead,
Opt,
PositiveLookahead,
Repeat0,
Repeat1,
Rhs,
Rule,
StringLeaf,
)
from pegen.parser_generator import ParserGenerator
EXTENSION_PREFIX = """\
#include "pegen.h"
"""
EXTENSION_SUFFIX = """
void *
_PyPegen_parse(Parser *p)
{
// Initialize keywords
p->keywords = reserved_keywords;
p->n_keyword_lists = n_keyword_lists;
return start_rule(p);
}
"""
class NodeTypes(Enum):
NAME_TOKEN = 0
NUMBER_TOKEN = 1
STRING_TOKEN = 2
GENERIC_TOKEN = 3
KEYWORD = 4
CUT_OPERATOR = 5
BASE_NODETYPES = {
"NAME": NodeTypes.NAME_TOKEN,
"NUMBER": NodeTypes.NUMBER_TOKEN,
"STRING": NodeTypes.STRING_TOKEN,
}
@dataclass
class FunctionCall:
function: str
arguments: List[Any] = field(default_factory=list)
assigned_variable: Optional[str] = None
return_type: Optional[str] = None
nodetype: Optional[NodeTypes] = None
force_true: bool = False
comment: Optional[str] = None
def __str__(self) -> str:
parts = []
parts.append(self.function)
if self.arguments:
parts.append(f"({', '.join(map(str, self.arguments))})")
if self.force_true:
parts.append(", 1")
if self.assigned_variable:
parts = ["(", self.assigned_variable, " = ", *parts, ")"]
if self.comment:
parts.append(f" // {self.comment}")
return "".join(parts)
class CCallMakerVisitor(GrammarVisitor):
def __init__(
self,
parser_generator: ParserGenerator,
exact_tokens: Dict[str, int],
non_exact_tokens: Set[str],
):
self.gen = parser_generator
self.exact_tokens = exact_tokens
self.non_exact_tokens = non_exact_tokens
self.cache: Dict[Any, FunctionCall] = {}
self.keyword_cache: Dict[str, int] = {}
def keyword_helper(self, keyword: str) -> FunctionCall:
if keyword not in self.keyword_cache:
self.keyword_cache[keyword] = self.gen.keyword_type()
return FunctionCall(
assigned_variable="_keyword",
function="_PyPegen_expect_token",
arguments=["p", self.keyword_cache[keyword]],
return_type="Token *",
nodetype=NodeTypes.KEYWORD,
comment=f"token='{keyword}'",
)
def visit_NameLeaf(self, node: NameLeaf) -> FunctionCall:
name = node.value
if name in self.non_exact_tokens:
if name in BASE_NODETYPES:
return FunctionCall(
assigned_variable=f"{name.lower()}_var",
function=f"_PyPegen_{name.lower()}_token",
arguments=["p"],
nodetype=BASE_NODETYPES[name],
return_type="expr_ty",
comment=name,
)
return FunctionCall(
assigned_variable=f"{name.lower()}_var",
function=f"_PyPegen_expect_token",
arguments=["p", name],
nodetype=NodeTypes.GENERIC_TOKEN,
return_type="Token *",
comment=f"token='{name}'",
)
type = None
rule = self.gen.all_rules.get(name.lower())
if rule is not None:
type = "asdl_seq *" if rule.is_loop() or rule.is_gather() else rule.type
return FunctionCall(
assigned_variable=f"{name}_var",
function=f"{name}_rule",
arguments=["p"],
return_type=type,
comment=f"{node}",
)
def visit_StringLeaf(self, node: StringLeaf) -> FunctionCall:
val = ast.literal_eval(node.value)
if re.match(r"[a-zA-Z_]\w*\Z", val): # This is a keyword
return self.keyword_helper(val)
else:
assert val in self.exact_tokens, f"{node.value} is not a known literal"
type = self.exact_tokens[val]
return FunctionCall(
assigned_variable="_literal",
function=f"_PyPegen_expect_token",
arguments=["p", type],
nodetype=NodeTypes.GENERIC_TOKEN,
return_type="Token *",
comment=f"token='{val}'",
)
def visit_Rhs(self, node: Rhs) -> FunctionCall:
def can_we_inline(node: Rhs) -> int:
if len(node.alts) != 1 or len(node.alts[0].items) != 1:
return False
# If the alternative has an action we cannot inline
if getattr(node.alts[0], "action", None) is not None:
return False
return True
if node in self.cache:
return self.cache[node]
if can_we_inline(node):
self.cache[node] = self.generate_call(node.alts[0].items[0])
else:
name = self.gen.name_node(node)
self.cache[node] = FunctionCall(
assigned_variable=f"{name}_var",
function=f"{name}_rule",
arguments=["p"],
comment=f"{node}",
)
return self.cache[node]
def visit_NamedItem(self, node: NamedItem) -> FunctionCall:
call = self.generate_call(node.item)
if node.name:
call.assigned_variable = node.name
return call
def lookahead_call_helper(self, node: Lookahead, positive: int) -> FunctionCall:
call = self.generate_call(node.node)
if call.nodetype == NodeTypes.NAME_TOKEN:
return FunctionCall(
function=f"_PyPegen_lookahead_with_name",
arguments=[positive, call.function, *call.arguments],
return_type="int",
)
elif call.nodetype in {NodeTypes.GENERIC_TOKEN, NodeTypes.KEYWORD}:
return FunctionCall(
function=f"_PyPegen_lookahead_with_int",
arguments=[positive, call.function, *call.arguments],
return_type="int",
comment=f"token={node.node}",
)
else:
return FunctionCall(
function=f"_PyPegen_lookahead",
arguments=[positive, call.function, *call.arguments],
return_type="int",
)
def visit_PositiveLookahead(self, node: PositiveLookahead) -> FunctionCall:
return self.lookahead_call_helper(node, 1)
def visit_NegativeLookahead(self, node: NegativeLookahead) -> FunctionCall:
return self.lookahead_call_helper(node, 0)
def visit_Opt(self, node: Opt) -> FunctionCall:
call = self.generate_call(node.node)
return FunctionCall(
assigned_variable="_opt_var",
function=call.function,
arguments=call.arguments,
force_true=True,
comment=f"{node}",
)
def visit_Repeat0(self, node: Repeat0) -> FunctionCall:
if node in self.cache:
return self.cache[node]
name = self.gen.name_loop(node.node, False)
self.cache[node] = FunctionCall(
assigned_variable=f"{name}_var",
function=f"{name}_rule",
arguments=["p"],
return_type="asdl_seq *",
comment=f"{node}",
)
return self.cache[node]
def visit_Repeat1(self, node: Repeat1) -> FunctionCall:
if node in self.cache:
return self.cache[node]
name = self.gen.name_loop(node.node, True)
self.cache[node] = FunctionCall(
assigned_variable=f"{name}_var",
function=f"{name}_rule",
arguments=["p"],
return_type="asdl_seq *",
comment=f"{node}",
)
return self.cache[node]
def visit_Gather(self, node: Gather) -> FunctionCall:
if node in self.cache:
return self.cache[node]
name = self.gen.name_gather(node)
self.cache[node] = FunctionCall(
assigned_variable=f"{name}_var",
function=f"{name}_rule",
arguments=["p"],
return_type="asdl_seq *",
comment=f"{node}",
)
return self.cache[node]
def visit_Group(self, node: Group) -> FunctionCall:
return self.generate_call(node.rhs)
def visit_Cut(self, node: Cut) -> FunctionCall:
return FunctionCall(
assigned_variable="_cut_var",
return_type="int",
function="1",
nodetype=NodeTypes.CUT_OPERATOR,
)
def generate_call(self, node: Any) -> FunctionCall:
return super().visit(node)
class CParserGenerator(ParserGenerator, GrammarVisitor):
def __init__(
self,
grammar: grammar.Grammar,
tokens: Dict[int, str],
exact_tokens: Dict[str, int],
non_exact_tokens: Set[str],
file: Optional[IO[Text]],
debug: bool = False,
skip_actions: bool = False,
):
super().__init__(grammar, tokens, file)
self.callmakervisitor: CCallMakerVisitor = CCallMakerVisitor(
self, exact_tokens, non_exact_tokens
)
self._varname_counter = 0
self.debug = debug
self.skip_actions = skip_actions
def unique_varname(self, name: str = "tmpvar") -> str:
new_var = name + "_" + str(self._varname_counter)
self._varname_counter += 1
return new_var
def call_with_errorcheck_return(self, call_text: str, returnval: str) -> None:
error_var = self.unique_varname()
self.print(f"int {error_var} = {call_text};")
self.print(f"if ({error_var}) {{")
with self.indent():
self.print(f"return {returnval};")
self.print(f"}}")
def call_with_errorcheck_goto(self, call_text: str, goto_target: str) -> None:
error_var = self.unique_varname()
self.print(f"int {error_var} = {call_text};")
self.print(f"if ({error_var}) {{")
with self.indent():
self.print(f"goto {goto_target};")
self.print(f"}}")
def out_of_memory_return(self, expr: str, cleanup_code: Optional[str] = None,) -> None:
self.print(f"if ({expr}) {{")
with self.indent():
if cleanup_code is not None:
self.print(cleanup_code)
self.print("p->error_indicator = 1;")
self.print("PyErr_NoMemory();")
self.print("return NULL;")
self.print(f"}}")
def out_of_memory_goto(self, expr: str, goto_target: str) -> None:
self.print(f"if ({expr}) {{")
with self.indent():
self.print("PyErr_NoMemory();")
self.print(f"goto {goto_target};")
self.print(f"}}")
def generate(self, filename: str) -> None:
self.collect_todo()
self.print(f"// @generated by pegen.py from {filename}")
header = self.grammar.metas.get("header", EXTENSION_PREFIX)
if header:
self.print(header.rstrip("\n"))
subheader = self.grammar.metas.get("subheader", "")
if subheader:
self.print(subheader)
self._setup_keywords()
for i, (rulename, rule) in enumerate(self.todo.items(), 1000):
comment = " // Left-recursive" if rule.left_recursive else ""
self.print(f"#define {rulename}_type {i}{comment}")
self.print()
for rulename, rule in self.todo.items():
if rule.is_loop() or rule.is_gather():
type = "asdl_seq *"
elif rule.type:
type = rule.type + " "
else:
type = "void *"
self.print(f"static {type}{rulename}_rule(Parser *p);")
self.print()
while self.todo:
for rulename, rule in list(self.todo.items()):
del self.todo[rulename]
self.print()
if rule.left_recursive:
self.print("// Left-recursive")
self.visit(rule)
if self.skip_actions:
mode = 0
else:
mode = int(self.rules["start"].type == "mod_ty") if "start" in self.rules else 1
if mode == 1 and self.grammar.metas.get("bytecode"):
mode += 1
modulename = self.grammar.metas.get("modulename", "parse")
trailer = self.grammar.metas.get("trailer", EXTENSION_SUFFIX)
if trailer:
self.print(trailer.rstrip("\n") % dict(mode=mode, modulename=modulename))
def _group_keywords_by_length(self) -> Dict[int, List[Tuple[str, int]]]:
groups: Dict[int, List[Tuple[str, int]]] = {}
for keyword_str, keyword_type in self.callmakervisitor.keyword_cache.items():
length = len(keyword_str)
if length in groups:
groups[length].append((keyword_str, keyword_type))
else:
groups[length] = [(keyword_str, keyword_type)]
return groups
def _setup_keywords(self) -> None:
keyword_cache = self.callmakervisitor.keyword_cache
n_keyword_lists = (
len(max(keyword_cache.keys(), key=len)) + 1 if len(keyword_cache) > 0 else 0
)
self.print(f"static const int n_keyword_lists = {n_keyword_lists};")
groups = self._group_keywords_by_length()
self.print("static KeywordToken *reserved_keywords[] = {")
with self.indent():
num_groups = max(groups) + 1 if groups else 1
for keywords_length in range(num_groups):
if keywords_length not in groups.keys():
self.print("NULL,")
else:
self.print("(KeywordToken[]) {")
with self.indent():
for keyword_str, keyword_type in groups[keywords_length]:
self.print(f'{{"{keyword_str}", {keyword_type}}},')
self.print("{NULL, -1},")
self.print("},")
self.print("};")
def _set_up_token_start_metadata_extraction(self) -> None:
self.print("if (p->mark == p->fill && _PyPegen_fill_token(p) < 0) {")
with self.indent():
self.print("p->error_indicator = 1;")
self.print("return NULL;")
self.print("}")
self.print("int _start_lineno = p->tokens[_mark]->lineno;")
self.print("UNUSED(_start_lineno); // Only used by EXTRA macro")
self.print("int _start_col_offset = p->tokens[_mark]->col_offset;")
self.print("UNUSED(_start_col_offset); // Only used by EXTRA macro")
def _set_up_token_end_metadata_extraction(self) -> None:
self.print("Token *_token = _PyPegen_get_last_nonnwhitespace_token(p);")
self.print("if (_token == NULL) {")
with self.indent():
self.print("return NULL;")
self.print("}")
self.print("int _end_lineno = _token->end_lineno;")
self.print("UNUSED(_end_lineno); // Only used by EXTRA macro")
self.print("int _end_col_offset = _token->end_col_offset;")
self.print("UNUSED(_end_col_offset); // Only used by EXTRA macro")
def _check_for_errors(self) -> None:
self.print("if (p->error_indicator) {")
with self.indent():
self.print("return NULL;")
self.print("}")
def _set_up_rule_memoization(self, node: Rule, result_type: str) -> None:
self.print("{")
with self.indent():
self.print(f"{result_type} _res = NULL;")
self.print(f"if (_PyPegen_is_memoized(p, {node.name}_type, &_res))")
with self.indent():
self.print("return _res;")
self.print("int _mark = p->mark;")
self.print("int _resmark = p->mark;")
self.print("while (1) {")
with self.indent():
self.call_with_errorcheck_return(
f"_PyPegen_update_memo(p, _mark, {node.name}_type, _res)", "_res"
)
self.print("p->mark = _mark;")
self.print(f"void *_raw = {node.name}_raw(p);")
self.print("if (_raw == NULL || p->mark <= _resmark)")
with self.indent():
self.print("break;")
self.print(f"_resmark = p->mark;")
self.print("_res = _raw;")
self.print("}")
self.print(f"p->mark = _resmark;")
self.print("return _res;")
self.print("}")
self.print(f"static {result_type}")
self.print(f"{node.name}_raw(Parser *p)")
def _should_memoize(self, node: Rule) -> bool:
return node.memo and not node.left_recursive
def _handle_default_rule_body(self, node: Rule, rhs: Rhs, result_type: str) -> None:
memoize = self._should_memoize(node)
with self.indent():
self._check_for_errors()
self.print(f"{result_type} _res = NULL;")
if memoize:
self.print(f"if (_PyPegen_is_memoized(p, {node.name}_type, &_res))")
with self.indent():
self.print("return _res;")
self.print("int _mark = p->mark;")
if any(alt.action and "EXTRA" in alt.action for alt in rhs.alts):
self._set_up_token_start_metadata_extraction()
self.visit(
rhs, is_loop=False, is_gather=node.is_gather(), rulename=node.name,
)
if self.debug:
self.print(f'fprintf(stderr, "Fail at %d: {node.name}\\n", p->mark);')
self.print("_res = NULL;")
self.print(" done:")
with self.indent():
if memoize:
self.print(f"_PyPegen_insert_memo(p, _mark, {node.name}_type, _res);")
self.print("return _res;")
def _handle_loop_rule_body(self, node: Rule, rhs: Rhs) -> None:
memoize = self._should_memoize(node)
is_repeat1 = node.name.startswith("_loop1")
with self.indent():
self._check_for_errors()
self.print("void *_res = NULL;")
if memoize:
self.print(f"if (_PyPegen_is_memoized(p, {node.name}_type, &_res))")
with self.indent():
self.print("return _res;")
self.print("int _mark = p->mark;")
self.print("int _start_mark = p->mark;")
self.print("void **_children = PyMem_Malloc(sizeof(void *));")
self.out_of_memory_return(f"!_children")
self.print("ssize_t _children_capacity = 1;")
self.print("ssize_t _n = 0;")
if any(alt.action and "EXTRA" in alt.action for alt in rhs.alts):
self._set_up_token_start_metadata_extraction()
self.visit(
rhs, is_loop=True, is_gather=node.is_gather(), rulename=node.name,
)
if is_repeat1:
self.print("if (_n == 0 || p->error_indicator) {")
with self.indent():
self.print("PyMem_Free(_children);")
self.print("return NULL;")
self.print("}")
self.print("asdl_seq *_seq = _Py_asdl_seq_new(_n, p->arena);")
self.out_of_memory_return(f"!_seq", cleanup_code="PyMem_Free(_children);")
self.print("for (int i = 0; i < _n; i++) asdl_seq_SET(_seq, i, _children[i]);")
self.print("PyMem_Free(_children);")
if node.name:
self.print(f"_PyPegen_insert_memo(p, _start_mark, {node.name}_type, _seq);")
self.print("return _seq;")
def visit_Rule(self, node: Rule) -> None:
is_loop = node.is_loop()
is_gather = node.is_gather()
rhs = node.flatten()
if is_loop or is_gather:
result_type = "asdl_seq *"
elif node.type:
result_type = node.type
else:
result_type = "void *"
for line in str(node).splitlines():
self.print(f"// {line}")
if node.left_recursive and node.leader:
self.print(f"static {result_type} {node.name}_raw(Parser *);")
self.print(f"static {result_type}")
self.print(f"{node.name}_rule(Parser *p)")
if node.left_recursive and node.leader:
self._set_up_rule_memoization(node, result_type)
self.print("{")
if is_loop:
self._handle_loop_rule_body(node, rhs)
else:
self._handle_default_rule_body(node, rhs, result_type)
self.print("}")
def visit_NamedItem(self, node: NamedItem) -> None:
call = self.callmakervisitor.generate_call(node)
if call.assigned_variable:
call.assigned_variable = self.dedupe(call.assigned_variable)
self.print(call)
def visit_Rhs(
self, node: Rhs, is_loop: bool, is_gather: bool, rulename: Optional[str]
) -> None:
if is_loop:
assert len(node.alts) == 1
for alt in node.alts:
self.visit(alt, is_loop=is_loop, is_gather=is_gather, rulename=rulename)
def join_conditions(self, keyword: str, node: Any) -> None:
self.print(f"{keyword} (")
with self.indent():
first = True
for item in node.items:
if first:
first = False
else:
self.print("&&")
self.visit(item)
self.print(")")
def emit_action(self, node: Alt, cleanup_code: Optional[str] = None) -> None:
self.print(f"_res = {node.action};")
self.print("if (_res == NULL && PyErr_Occurred()) {")
with self.indent():
self.print("p->error_indicator = 1;")
if cleanup_code:
self.print(cleanup_code)
self.print("return NULL;")
self.print("}")
if self.debug:
self.print(
f'fprintf(stderr, "Hit with action [%d-%d]: %s\\n", _mark, p->mark, "{node}");'
)
def emit_default_action(self, is_gather: bool, node: Alt) -> None:
if len(self.local_variable_names) > 1:
if is_gather:
assert len(self.local_variable_names) == 2
self.print(
f"_res = _PyPegen_seq_insert_in_front(p, "
f"{self.local_variable_names[0]}, {self.local_variable_names[1]});"
)
else:
if self.debug:
self.print(
f'fprintf(stderr, "Hit without action [%d:%d]: %s\\n", _mark, p->mark, "{node}");'
)
self.print(
f"_res = _PyPegen_dummy_name(p, {', '.join(self.local_variable_names)});"
)
else:
if self.debug:
self.print(
f'fprintf(stderr, "Hit with default action [%d:%d]: %s\\n", _mark, p->mark, "{node}");'
)
self.print(f"_res = {self.local_variable_names[0]};")
def emit_dummy_action(self) -> None:
self.print("_res = _PyPegen_dummy_name(p);")
def handle_alt_normal(self, node: Alt, is_gather: bool) -> None:
self.join_conditions(keyword="if", node=node)
self.print("{")
# We have parsed successfully all the conditions for the option.
with self.indent():
# Prepare to emmit the rule action and do so
if node.action and "EXTRA" in node.action:
self._set_up_token_end_metadata_extraction()
if self.skip_actions:
self.emit_dummy_action()
elif node.action:
self.emit_action(node)
else:
self.emit_default_action(is_gather, node)
# As the current option has parsed correctly, do not continue with the rest.
self.print(f"goto done;")
self.print("}")
def handle_alt_loop(self, node: Alt, is_gather: bool, rulename: Optional[str]) -> None:
# Condition of the main body of the alternative
self.join_conditions(keyword="while", node=node)
self.print("{")
# We have parsed successfully one item!
with self.indent():
# Prepare to emit the rule action and do so
if node.action and "EXTRA" in node.action:
self._set_up_token_end_metadata_extraction()
if self.skip_actions:
self.emit_dummy_action()
elif node.action:
self.emit_action(node, cleanup_code="PyMem_Free(_children);")
else:
self.emit_default_action(is_gather, node)
# Add the result of rule to the temporary buffer of children. This buffer
# will populate later an asdl_seq with all elements to return.
self.print("if (_n == _children_capacity) {")
with self.indent():
self.print("_children_capacity *= 2;")
self.print(
"void **_new_children = PyMem_Realloc(_children, _children_capacity*sizeof(void *));"
)
self.out_of_memory_return(f"!_new_children")
self.print("_children = _new_children;")
self.print("}")
self.print("_children[_n++] = _res;")
self.print("_mark = p->mark;")
self.print("}")
def visit_Alt(
self, node: Alt, is_loop: bool, is_gather: bool, rulename: Optional[str]
) -> None:
self.print(f"{{ // {node}")
with self.indent():
self._check_for_errors()
# Prepare variable declarations for the alternative
vars = self.collect_vars(node)
for v, var_type in sorted(item for item in vars.items() if item[0] is not None):
if not var_type:
var_type = "void *"
else:
var_type += " "
if v == "_cut_var":
v += " = 0" # cut_var must be initialized
self.print(f"{var_type}{v};")
if v.startswith("_opt_var"):
self.print(f"UNUSED({v}); // Silence compiler warnings")
with self.local_variable_context():
if is_loop:
self.handle_alt_loop(node, is_gather, rulename)
else:
self.handle_alt_normal(node, is_gather)
self.print("p->mark = _mark;")
if "_cut_var" in vars:
self.print("if (_cut_var) return NULL;")
self.print("}")
def collect_vars(self, node: Alt) -> Dict[Optional[str], Optional[str]]:
types = {}
with self.local_variable_context():
for item in node.items:
name, type = self.add_var(item)
types[name] = type
return types
def add_var(self, node: NamedItem) -> Tuple[Optional[str], Optional[str]]:
call = self.callmakervisitor.generate_call(node.item)
name = node.name if node.name else call.assigned_variable
if name is not None:
name = self.dedupe(name)
return name, call.return_type