source: vendor/python/2.5/Python/symtable.c

Last change on this file was 3225, checked in by bird, 18 years ago

Python 2.5
File size: 36.9 KB
Line 
1#include "Python.h"
2#include "Python-ast.h"
3#include "code.h"
4#include "symtable.h"
5#include "structmember.h"
6
7/* error strings used for warnings */
8#define GLOBAL_AFTER_ASSIGN \
9"name '%.400s' is assigned to before global declaration"
10
11#define GLOBAL_AFTER_USE \
12"name '%.400s' is used prior to global declaration"
13
14#define IMPORT_STAR_WARNING "import * only allowed at module level"
15
16#define RETURN_VAL_IN_GENERATOR \
17 "'return' with argument inside generator"
18
19/* XXX(nnorwitz): change name since static? */
20static PySTEntryObject *
21PySTEntry_New(struct symtable *st, identifier name, _Py_block_ty block,
22 void *key, int lineno)
23{
24 PySTEntryObject *ste = NULL;
25 PyObject *k;
26
27 k = PyLong_FromVoidPtr(key);
28 if (k == NULL)
29 goto fail;
30 ste = (PySTEntryObject *)PyObject_New(PySTEntryObject,
31 &PySTEntry_Type);
32 ste->ste_table = st;
33 ste->ste_id = k;
34 ste->ste_tmpname = 0;
35
36 ste->ste_name = name;
37 Py_INCREF(name);
38
39 ste->ste_symbols = NULL;
40 ste->ste_varnames = NULL;
41 ste->ste_children = NULL;
42
43 ste->ste_symbols = PyDict_New();
44 if (ste->ste_symbols == NULL)
45 goto fail;
46
47 ste->ste_varnames = PyList_New(0);
48 if (ste->ste_varnames == NULL)
49 goto fail;
50
51 ste->ste_children = PyList_New(0);
52 if (ste->ste_children == NULL)
53 goto fail;
54
55 ste->ste_type = block;
56 ste->ste_unoptimized = 0;
57 ste->ste_nested = 0;
58 ste->ste_free = 0;
59 ste->ste_varargs = 0;
60 ste->ste_varkeywords = 0;
61 ste->ste_opt_lineno = 0;
62 ste->ste_tmpname = 0;
63 ste->ste_lineno = lineno;
64
65 if (st->st_cur != NULL &&
66 (st->st_cur->ste_nested ||
67 st->st_cur->ste_type == FunctionBlock))
68 ste->ste_nested = 1;
69 ste->ste_child_free = 0;
70 ste->ste_generator = 0;
71 ste->ste_returns_value = 0;
72
73 if (PyDict_SetItem(st->st_symbols, ste->ste_id, (PyObject *)ste) < 0)
74 goto fail;
75
76 return ste;
77 fail:
78 Py_XDECREF(ste);
79 return NULL;
80}
81
82static PyObject *
83ste_repr(PySTEntryObject *ste)
84{
85 char buf[256];
86
87 PyOS_snprintf(buf, sizeof(buf),
88 "<symtable entry %.100s(%ld), line %d>",
89 PyString_AS_STRING(ste->ste_name),
90 PyInt_AS_LONG(ste->ste_id), ste->ste_lineno);
91 return PyString_FromString(buf);
92}
93
94static void
95ste_dealloc(PySTEntryObject *ste)
96{
97 ste->ste_table = NULL;
98 Py_XDECREF(ste->ste_id);
99 Py_XDECREF(ste->ste_name);
100 Py_XDECREF(ste->ste_symbols);
101 Py_XDECREF(ste->ste_varnames);
102 Py_XDECREF(ste->ste_children);
103 PyObject_Del(ste);
104}
105
106#define OFF(x) offsetof(PySTEntryObject, x)
107
108static PyMemberDef ste_memberlist[] = {
109 {"id", T_OBJECT, OFF(ste_id), READONLY},
110 {"name", T_OBJECT, OFF(ste_name), READONLY},
111 {"symbols", T_OBJECT, OFF(ste_symbols), READONLY},
112 {"varnames", T_OBJECT, OFF(ste_varnames), READONLY},
113 {"children", T_OBJECT, OFF(ste_children), READONLY},
114 {"type", T_INT, OFF(ste_type), READONLY},
115 {"lineno", T_INT, OFF(ste_lineno), READONLY},
116 {NULL}
117};
118
119PyTypeObject PySTEntry_Type = {
120 PyObject_HEAD_INIT(&PyType_Type)
121 0,
122 "symtable entry",
123 sizeof(PySTEntryObject),
124 0,
125 (destructor)ste_dealloc, /* tp_dealloc */
126 0, /* tp_print */
127 0, /* tp_getattr */
128 0, /* tp_setattr */
129 0, /* tp_compare */
130 (reprfunc)ste_repr, /* tp_repr */
131 0, /* tp_as_number */
132 0, /* tp_as_sequence */
133 0, /* tp_as_mapping */
134 0, /* tp_hash */
135 0, /* tp_call */
136 0, /* tp_str */
137 PyObject_GenericGetAttr, /* tp_getattro */
138 0, /* tp_setattro */
139 0, /* tp_as_buffer */
140 Py_TPFLAGS_DEFAULT, /* tp_flags */
141 0, /* tp_doc */
142 0, /* tp_traverse */
143 0, /* tp_clear */
144 0, /* tp_richcompare */
145 0, /* tp_weaklistoffset */
146 0, /* tp_iter */
147 0, /* tp_iternext */
148 0, /* tp_methods */
149 ste_memberlist, /* tp_members */
150 0, /* tp_getset */
151 0, /* tp_base */
152 0, /* tp_dict */
153 0, /* tp_descr_get */
154 0, /* tp_descr_set */
155 0, /* tp_dictoffset */
156 0, /* tp_init */
157 0, /* tp_alloc */
158 0, /* tp_new */
159};
160
161static int symtable_analyze(struct symtable *st);
162static int symtable_warn(struct symtable *st, char *msg, int lineno);
163static int symtable_enter_block(struct symtable *st, identifier name,
164 _Py_block_ty block, void *ast, int lineno);
165static int symtable_exit_block(struct symtable *st, void *ast);
166static int symtable_visit_stmt(struct symtable *st, stmt_ty s);
167static int symtable_visit_expr(struct symtable *st, expr_ty s);
168static int symtable_visit_genexp(struct symtable *st, expr_ty s);
169static int symtable_visit_arguments(struct symtable *st, arguments_ty);
170static int symtable_visit_excepthandler(struct symtable *st, excepthandler_ty);
171static int symtable_visit_alias(struct symtable *st, alias_ty);
172static int symtable_visit_comprehension(struct symtable *st, comprehension_ty);
173static int symtable_visit_keyword(struct symtable *st, keyword_ty);
174static int symtable_visit_slice(struct symtable *st, slice_ty);
175static int symtable_visit_params(struct symtable *st, asdl_seq *args, int top);
176static int symtable_visit_params_nested(struct symtable *st, asdl_seq *args);
177static int symtable_implicit_arg(struct symtable *st, int pos);
178
179
180static identifier top = NULL, lambda = NULL, genexpr = NULL;
181
182#define GET_IDENTIFIER(VAR) \
183 ((VAR) ? (VAR) : ((VAR) = PyString_InternFromString(# VAR)))
184
185#define DUPLICATE_ARGUMENT \
186"duplicate argument '%s' in function definition"
187
188static struct symtable *
189symtable_new(void)
190{
191 struct symtable *st;
192
193 st = (struct symtable *)PyMem_Malloc(sizeof(struct symtable));
194 if (st == NULL)
195 return NULL;
196
197 st->st_filename = NULL;
198 st->st_symbols = NULL;
199
200 if ((st->st_stack = PyList_New(0)) == NULL)
201 goto fail;
202 if ((st->st_symbols = PyDict_New()) == NULL)
203 goto fail;
204 st->st_cur = NULL;
205 st->st_tmpname = 0;
206 st->st_private = NULL;
207 return st;
208 fail:
209 PySymtable_Free(st);
210 return NULL;
211}
212
213struct symtable *
214PySymtable_Build(mod_ty mod, const char *filename, PyFutureFeatures *future)
215{
216 struct symtable *st = symtable_new();
217 asdl_seq *seq;
218 int i;
219
220 if (st == NULL)
221 return st;
222 st->st_filename = filename;
223 st->st_future = future;
224 if (!symtable_enter_block(st, GET_IDENTIFIER(top), ModuleBlock,
225 (void *)mod, 0)) {
226 PySymtable_Free(st);
227 return NULL;
228 }
229
230 st->st_top = st->st_cur;
231 st->st_cur->ste_unoptimized = OPT_TOPLEVEL;
232 /* Any other top-level initialization? */
233 switch (mod->kind) {
234 case Module_kind:
235 seq = mod->v.Module.body;
236 for (i = 0; i < asdl_seq_LEN(seq); i++)
237 if (!symtable_visit_stmt(st,
238 (stmt_ty)asdl_seq_GET(seq, i)))
239 goto error;
240 break;
241 case Expression_kind:
242 if (!symtable_visit_expr(st, mod->v.Expression.body))
243 goto error;
244 break;
245 case Interactive_kind:
246 seq = mod->v.Interactive.body;
247 for (i = 0; i < asdl_seq_LEN(seq); i++)
248 if (!symtable_visit_stmt(st,
249 (stmt_ty)asdl_seq_GET(seq, i)))
250 goto error;
251 break;
252 case Suite_kind:
253 PyErr_SetString(PyExc_RuntimeError,
254 "this compiler does not handle Suites");
255 goto error;
256 }
257 if (!symtable_exit_block(st, (void *)mod)) {
258 PySymtable_Free(st);
259 return NULL;
260 }
261 if (symtable_analyze(st))
262 return st;
263 PySymtable_Free(st);
264 return NULL;
265 error:
266 (void) symtable_exit_block(st, (void *)mod);
267 PySymtable_Free(st);
268 return NULL;
269}
270
271void
272PySymtable_Free(struct symtable *st)
273{
274 Py_XDECREF(st->st_symbols);
275 Py_XDECREF(st->st_stack);
276 PyMem_Free((void *)st);
277}
278
279PySTEntryObject *
280PySymtable_Lookup(struct symtable *st, void *key)
281{
282 PyObject *k, *v;
283
284 k = PyLong_FromVoidPtr(key);
285 if (k == NULL)
286 return NULL;
287 v = PyDict_GetItem(st->st_symbols, k);
288 if (v) {
289 assert(PySTEntry_Check(v));
290 Py_INCREF(v);
291 }
292 else {
293 PyErr_SetString(PyExc_KeyError,
294 "unknown symbol table entry");
295 }
296
297 Py_DECREF(k);
298 return (PySTEntryObject *)v;
299}
300
301int
302PyST_GetScope(PySTEntryObject *ste, PyObject *name)
303{
304 PyObject *v = PyDict_GetItem(ste->ste_symbols, name);
305 if (!v)
306 return 0;
307 assert(PyInt_Check(v));
308 return (PyInt_AS_LONG(v) >> SCOPE_OFF) & SCOPE_MASK;
309}
310
311
312/* Analyze raw symbol information to determine scope of each name.
313
314 The next several functions are helpers for PySymtable_Analyze(),
315 which determines whether a name is local, global, or free. In addition,
316 it determines which local variables are cell variables; they provide
317 bindings that are used for free variables in enclosed blocks.
318
319 There are also two kinds of free variables, implicit and explicit. An
320 explicit global is declared with the global statement. An implicit
321 global is a free variable for which the compiler has found no binding
322 in an enclosing function scope. The implicit global is either a global
323 or a builtin. Python's module and class blocks use the xxx_NAME opcodes
324 to handle these names to implement slightly odd semantics. In such a
325 block, the name is treated as global until it is assigned to; then it
326 is treated as a local.
327
328 The symbol table requires two passes to determine the scope of each name.
329 The first pass collects raw facts from the AST: the name is a parameter
330 here, the name is used by not defined here, etc. The second pass analyzes
331 these facts during a pass over the PySTEntryObjects created during pass 1.
332
333 When a function is entered during the second pass, the parent passes
334 the set of all name bindings visible to its children. These bindings
335 are used to determine if the variable is free or an implicit global.
336 After doing the local analysis, it analyzes each of its child blocks
337 using an updated set of name bindings.
338
339 The children update the free variable set. If a local variable is free
340 in a child, the variable is marked as a cell. The current function must
341 provide runtime storage for the variable that may outlive the function's
342 frame. Cell variables are removed from the free set before the analyze
343 function returns to its parent.
344
345 The sets of bound and free variables are implemented as dictionaries
346 mapping strings to None.
347*/
348
349#define SET_SCOPE(DICT, NAME, I) { \
350 PyObject *o = PyInt_FromLong(I); \
351 if (!o) \
352 return 0; \
353 if (PyDict_SetItem((DICT), (NAME), o) < 0) { \
354 Py_DECREF(o); \
355 return 0; \
356 } \
357 Py_DECREF(o); \
358}
359
360/* Decide on scope of name, given flags.
361
362 The dicts passed in as arguments are modified as necessary.
363 ste is passed so that flags can be updated.
364*/
365
366static int
367analyze_name(PySTEntryObject *ste, PyObject *dict, PyObject *name, long flags,
368 PyObject *bound, PyObject *local, PyObject *free,
369 PyObject *global)
370{
371 if (flags & DEF_GLOBAL) {
372 if (flags & DEF_PARAM) {
373 PyErr_Format(PyExc_SyntaxError,
374 "name '%s' is local and global",
375 PyString_AS_STRING(name));
376 return 0;
377 }
378 SET_SCOPE(dict, name, GLOBAL_EXPLICIT);
379 if (PyDict_SetItem(global, name, Py_None) < 0)
380 return 0;
381 if (bound && PyDict_GetItem(bound, name)) {
382 if (PyDict_DelItem(bound, name) < 0)
383 return 0;
384 }
385 return 1;
386 }
387 if (flags & DEF_BOUND) {
388 SET_SCOPE(dict, name, LOCAL);
389 if (PyDict_SetItem(local, name, Py_None) < 0)
390 return 0;
391 if (PyDict_GetItem(global, name)) {
392 if (PyDict_DelItem(global, name) < 0)
393 return 0;
394 }
395 return 1;
396 }
397 /* If an enclosing block has a binding for this name, it
398 is a free variable rather than a global variable.
399 Note that having a non-NULL bound implies that the block
400 is nested.
401 */
402 if (bound && PyDict_GetItem(bound, name)) {
403 SET_SCOPE(dict, name, FREE);
404 ste->ste_free = 1;
405 if (PyDict_SetItem(free, name, Py_None) < 0)
406 return 0;
407 return 1;
408 }
409 /* If a parent has a global statement, then call it global
410 explicit? It could also be global implicit.
411 */
412 else if (global && PyDict_GetItem(global, name)) {
413 SET_SCOPE(dict, name, GLOBAL_EXPLICIT);
414 return 1;
415 }
416 else {
417 if (ste->ste_nested)
418 ste->ste_free = 1;
419 SET_SCOPE(dict, name, GLOBAL_IMPLICIT);
420 return 1;
421 }
422 return 0; /* Can't get here */
423}
424
425#undef SET_SCOPE
426
427/* If a name is defined in free and also in locals, then this block
428 provides the binding for the free variable. The name should be
429 marked CELL in this block and removed from the free list.
430
431 Note that the current block's free variables are included in free.
432 That's safe because no name can be free and local in the same scope.
433*/
434
435static int
436analyze_cells(PyObject *scope, PyObject *free)
437{
438 PyObject *name, *v, *w;
439 int success = 0;
440 Py_ssize_t pos = 0;
441
442 w = PyInt_FromLong(CELL);
443 if (!w)
444 return 0;
445 while (PyDict_Next(scope, &pos, &name, &v)) {
446 long flags;
447 assert(PyInt_Check(v));
448 flags = PyInt_AS_LONG(v);
449 if (flags != LOCAL)
450 continue;
451 if (!PyDict_GetItem(free, name))
452 continue;
453 /* Replace LOCAL with CELL for this name, and remove
454 from free. It is safe to replace the value of name
455 in the dict, because it will not cause a resize.
456 */
457 if (PyDict_SetItem(scope, name, w) < 0)
458 goto error;
459 if (!PyDict_DelItem(free, name) < 0)
460 goto error;
461 }
462 success = 1;
463 error:
464 Py_DECREF(w);
465 return success;
466}
467
468/* Check for illegal statements in unoptimized namespaces */
469static int
470check_unoptimized(const PySTEntryObject* ste) {
471 char buf[300];
472 const char* trailer;
473
474 if (ste->ste_type != FunctionBlock || !ste->ste_unoptimized
475 || !(ste->ste_free || ste->ste_child_free))
476 return 1;
477
478 trailer = (ste->ste_child_free ?
479 "contains a nested function with free variables" :
480 "is a nested function");
481
482 switch (ste->ste_unoptimized) {
483 case OPT_TOPLEVEL: /* exec / import * at top-level is fine */
484 case OPT_EXEC: /* qualified exec is fine */
485 return 1;
486 case OPT_IMPORT_STAR:
487 PyOS_snprintf(buf, sizeof(buf),
488 "import * is not allowed in function '%.100s' "
489 "because it is %s",
490 PyString_AS_STRING(ste->ste_name), trailer);
491 break;
492 case OPT_BARE_EXEC:
493 PyOS_snprintf(buf, sizeof(buf),
494 "unqualified exec is not allowed in function "
495 "'%.100s' it %s",
496 PyString_AS_STRING(ste->ste_name), trailer);
497 break;
498 default:
499 PyOS_snprintf(buf, sizeof(buf),
500 "function '%.100s' uses import * and bare exec, "
501 "which are illegal because it %s",
502 PyString_AS_STRING(ste->ste_name), trailer);
503 break;
504 }
505
506 PyErr_SetString(PyExc_SyntaxError, buf);
507 PyErr_SyntaxLocation(ste->ste_table->st_filename,
508 ste->ste_opt_lineno);
509 return 0;
510}
511
512/* Enter the final scope information into the st_symbols dict.
513 *
514 * All arguments are dicts. Modifies symbols, others are read-only.
515*/
516static int
517update_symbols(PyObject *symbols, PyObject *scope,
518 PyObject *bound, PyObject *free, int classflag)
519{
520 PyObject *name, *v, *u, *w, *free_value = NULL;
521 Py_ssize_t pos = 0;
522
523 while (PyDict_Next(symbols, &pos, &name, &v)) {
524 long i, flags;
525 assert(PyInt_Check(v));
526 flags = PyInt_AS_LONG(v);
527 w = PyDict_GetItem(scope, name);
528 assert(w && PyInt_Check(w));
529 i = PyInt_AS_LONG(w);
530 flags |= (i << SCOPE_OFF);
531 u = PyInt_FromLong(flags);
532 if (!u)
533 return 0;
534 if (PyDict_SetItem(symbols, name, u) < 0) {
535 Py_DECREF(u);
536 return 0;
537 }
538 Py_DECREF(u);
539 }
540
541 free_value = PyInt_FromLong(FREE << SCOPE_OFF);
542 if (!free_value)
543 return 0;
544
545 /* add a free variable when it's only use is for creating a closure */
546 pos = 0;
547 while (PyDict_Next(free, &pos, &name, &v)) {
548 PyObject *o = PyDict_GetItem(symbols, name);
549
550 if (o) {
551 /* It could be a free variable in a method of
552 the class that has the same name as a local
553 or global in the class scope.
554 */
555 if (classflag &&
556 PyInt_AS_LONG(o) & (DEF_BOUND | DEF_GLOBAL)) {
557 long i = PyInt_AS_LONG(o) | DEF_FREE_CLASS;
558 o = PyInt_FromLong(i);
559 if (!o) {
560 Py_DECREF(free_value);
561 return 0;
562 }
563 if (PyDict_SetItem(symbols, name, o) < 0) {
564 Py_DECREF(o);
565 Py_DECREF(free_value);
566 return 0;
567 }
568 Py_DECREF(o);
569 }
570 /* else it's not free, probably a cell */
571 continue;
572 }
573 if (!PyDict_GetItem(bound, name))
574 continue; /* it's a global */
575
576 if (PyDict_SetItem(symbols, name, free_value) < 0) {
577 Py_DECREF(free_value);
578 return 0;
579 }
580 }
581 Py_DECREF(free_value);
582 return 1;
583}
584
585/* Make final symbol table decisions for block of ste.
586 Arguments:
587 ste -- current symtable entry (input/output)
588 bound -- set of variables bound in enclosing scopes (input)
589 free -- set of free variables in enclosed scopes (output)
590 globals -- set of declared global variables in enclosing scopes (input)
591*/
592
593static int
594analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free,
595 PyObject *global)
596{
597 PyObject *name, *v, *local = NULL, *scope = NULL, *newbound = NULL;
598 PyObject *newglobal = NULL, *newfree = NULL;
599 int i, success = 0;
600 Py_ssize_t pos = 0;
601
602 local = PyDict_New();
603 if (!local)
604 goto error;
605 scope = PyDict_New();
606 if (!scope)
607 goto error;
608 newglobal = PyDict_New();
609 if (!newglobal)
610 goto error;
611 newfree = PyDict_New();
612 if (!newfree)
613 goto error;
614 newbound = PyDict_New();
615 if (!newbound)
616 goto error;
617
618 if (ste->ste_type == ClassBlock) {
619 /* make a copy of globals before calling analyze_name(),
620 because global statements in the class have no effect
621 on nested functions.
622 */
623 if (PyDict_Update(newglobal, global) < 0)
624 goto error;
625 if (bound)
626 if (PyDict_Update(newbound, bound) < 0)
627 goto error;
628 }
629
630 assert(PySTEntry_Check(ste));
631 assert(PyDict_Check(ste->ste_symbols));
632 while (PyDict_Next(ste->ste_symbols, &pos, &name, &v)) {
633 long flags = PyInt_AS_LONG(v);
634 if (!analyze_name(ste, scope, name, flags, bound, local, free,
635 global))
636 goto error;
637 }
638
639 if (ste->ste_type != ClassBlock) {
640 if (ste->ste_type == FunctionBlock) {
641 if (PyDict_Update(newbound, local) < 0)
642 goto error;
643 }
644 if (bound) {
645 if (PyDict_Update(newbound, bound) < 0)
646 goto error;
647 }
648 if (PyDict_Update(newglobal, global) < 0)
649 goto error;
650 }
651
652 /* Recursively call analyze_block() on each child block */
653 for (i = 0; i < PyList_GET_SIZE(ste->ste_children); ++i) {
654 PyObject *c = PyList_GET_ITEM(ste->ste_children, i);
655 PySTEntryObject* entry;
656 assert(c && PySTEntry_Check(c));
657 entry = (PySTEntryObject*)c;
658 if (!analyze_block(entry, newbound, newfree, newglobal))
659 goto error;
660 if (entry->ste_free || entry->ste_child_free)
661 ste->ste_child_free = 1;
662 }
663
664 if (ste->ste_type == FunctionBlock && !analyze_cells(scope, newfree))
665 goto error;
666 if (!update_symbols(ste->ste_symbols, scope, bound, newfree,
667 ste->ste_type == ClassBlock))
668 goto error;
669 if (!check_unoptimized(ste))
670 goto error;
671
672 if (PyDict_Update(free, newfree) < 0)
673 goto error;
674 success = 1;
675 error:
676 Py_XDECREF(local);
677 Py_XDECREF(scope);
678 Py_XDECREF(newbound);
679 Py_XDECREF(newglobal);
680 Py_XDECREF(newfree);
681 if (!success)
682 assert(PyErr_Occurred());
683 return success;
684}
685
686static int
687symtable_analyze(struct symtable *st)
688{
689 PyObject *free, *global;
690 int r;
691
692 free = PyDict_New();
693 if (!free)
694 return 0;
695 global = PyDict_New();
696 if (!global) {
697 Py_DECREF(free);
698 return 0;
699 }
700 r = analyze_block(st->st_top, NULL, free, global);
701 Py_DECREF(free);
702 Py_DECREF(global);
703 return r;
704}
705
706
707static int
708symtable_warn(struct symtable *st, char *msg, int lineno)
709{
710 if (PyErr_WarnExplicit(PyExc_SyntaxWarning, msg, st->st_filename,
711 lineno, NULL, NULL) < 0) {
712 if (PyErr_ExceptionMatches(PyExc_SyntaxWarning)) {
713 PyErr_SetString(PyExc_SyntaxError, msg);
714 PyErr_SyntaxLocation(st->st_filename,
715 st->st_cur->ste_lineno);
716 }
717 return 0;
718 }
719 return 1;
720}
721
722/* symtable_enter_block() gets a reference via PySTEntry_New().
723 This reference is released when the block is exited, via the DECREF
724 in symtable_exit_block().
725*/
726
727static int
728symtable_exit_block(struct symtable *st, void *ast)
729{
730 Py_ssize_t end;
731
732 Py_CLEAR(st->st_cur);
733 end = PyList_GET_SIZE(st->st_stack) - 1;
734 if (end >= 0) {
735 st->st_cur = (PySTEntryObject *)PyList_GET_ITEM(st->st_stack,
736 end);
737 if (st->st_cur == NULL)
738 return 0;
739 Py_INCREF(st->st_cur);
740 if (PySequence_DelItem(st->st_stack, end) < 0)
741 return 0;
742 }
743 return 1;
744}
745
746static int
747symtable_enter_block(struct symtable *st, identifier name, _Py_block_ty block,
748 void *ast, int lineno)
749{
750 PySTEntryObject *prev = NULL;
751
752 if (st->st_cur) {
753 prev = st->st_cur;
754 if (PyList_Append(st->st_stack, (PyObject *)st->st_cur) < 0) {
755 return 0;
756 }
757 Py_DECREF(st->st_cur);
758 }
759 st->st_cur = PySTEntry_New(st, name, block, ast, lineno);
760 if (st->st_cur == NULL)
761 return 0;
762 if (name == GET_IDENTIFIER(top))
763 st->st_global = st->st_cur->ste_symbols;
764 if (prev) {
765 if (PyList_Append(prev->ste_children,
766 (PyObject *)st->st_cur) < 0) {
767 return 0;
768 }
769 }
770 return 1;
771}
772
773static long
774symtable_lookup(struct symtable *st, PyObject *name)
775{
776 PyObject *o;
777 PyObject *mangled = _Py_Mangle(st->st_private, name);
778 if (!mangled)
779 return 0;
780 o = PyDict_GetItem(st->st_cur->ste_symbols, mangled);
781 Py_DECREF(mangled);
782 if (!o)
783 return 0;
784 return PyInt_AsLong(o);
785}
786
787static int
788symtable_add_def(struct symtable *st, PyObject *name, int flag)
789{
790 PyObject *o;
791 PyObject *dict;
792 long val;
793 PyObject *mangled = _Py_Mangle(st->st_private, name);
794
795 if (!mangled)
796 return 0;
797 dict = st->st_cur->ste_symbols;
798 if ((o = PyDict_GetItem(dict, mangled))) {
799 val = PyInt_AS_LONG(o);
800 if ((flag & DEF_PARAM) && (val & DEF_PARAM)) {
801 /* Is it better to use 'mangled' or 'name' here? */
802 PyErr_Format(PyExc_SyntaxError, DUPLICATE_ARGUMENT,
803 PyString_AsString(name));
804 PyErr_SyntaxLocation(st->st_filename,
805 st->st_cur->ste_lineno);
806 goto error;
807 }
808 val |= flag;
809 } else
810 val = flag;
811 o = PyInt_FromLong(val);
812 if (o == NULL)
813 goto error;
814 if (PyDict_SetItem(dict, mangled, o) < 0) {
815 Py_DECREF(o);
816 goto error;
817 }
818 Py_DECREF(o);
819
820 if (flag & DEF_PARAM) {
821 if (PyList_Append(st->st_cur->ste_varnames, mangled) < 0)
822 goto error;
823 } else if (flag & DEF_GLOBAL) {
824 /* XXX need to update DEF_GLOBAL for other flags too;
825 perhaps only DEF_FREE_GLOBAL */
826 val = flag;
827 if ((o = PyDict_GetItem(st->st_global, mangled))) {
828 val |= PyInt_AS_LONG(o);
829 }
830 o = PyInt_FromLong(val);
831 if (o == NULL)
832 goto error;
833 if (PyDict_SetItem(st->st_global, mangled, o) < 0) {
834 Py_DECREF(o);
835 goto error;
836 }
837 Py_DECREF(o);
838 }
839 Py_DECREF(mangled);
840 return 1;
841
842error:
843 Py_DECREF(mangled);
844 return 0;
845}
846
847/* VISIT, VISIT_SEQ and VIST_SEQ_TAIL take an ASDL type as their second argument.
848 They use the ASDL name to synthesize the name of the C type and the visit
849 function.
850
851 VISIT_SEQ_TAIL permits the start of an ASDL sequence to be skipped, which is
852 useful if the first node in the sequence requires special treatment.
853*/
854
855#define VISIT(ST, TYPE, V) \
856 if (!symtable_visit_ ## TYPE((ST), (V))) \
857 return 0;
858
859#define VISIT_IN_BLOCK(ST, TYPE, V, S) \
860 if (!symtable_visit_ ## TYPE((ST), (V))) { \
861 symtable_exit_block((ST), (S)); \
862 return 0; \
863 }
864
865#define VISIT_SEQ(ST, TYPE, SEQ) { \
866 int i; \
867 asdl_seq *seq = (SEQ); /* avoid variable capture */ \
868 for (i = 0; i < asdl_seq_LEN(seq); i++) { \
869 TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, i); \
870 if (!symtable_visit_ ## TYPE((ST), elt)) \
871 return 0; \
872 } \
873}
874
875#define VISIT_SEQ_IN_BLOCK(ST, TYPE, SEQ, S) { \
876 int i; \
877 asdl_seq *seq = (SEQ); /* avoid variable capture */ \
878 for (i = 0; i < asdl_seq_LEN(seq); i++) { \
879 TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, i); \
880 if (!symtable_visit_ ## TYPE((ST), elt)) { \
881 symtable_exit_block((ST), (S)); \
882 return 0; \
883 } \
884 } \
885}
886
887#define VISIT_SEQ_TAIL(ST, TYPE, SEQ, START) { \
888 int i; \
889 asdl_seq *seq = (SEQ); /* avoid variable capture */ \
890 for (i = (START); i < asdl_seq_LEN(seq); i++) { \
891 TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, i); \
892 if (!symtable_visit_ ## TYPE((ST), elt)) \
893 return 0; \
894 } \
895}
896
897#define VISIT_SEQ_TAIL_IN_BLOCK(ST, TYPE, SEQ, START, S) { \
898 int i; \
899 asdl_seq *seq = (SEQ); /* avoid variable capture */ \
900 for (i = (START); i < asdl_seq_LEN(seq); i++) { \
901 TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, i); \
902 if (!symtable_visit_ ## TYPE((ST), elt)) { \
903 symtable_exit_block((ST), (S)); \
904 return 0; \
905 } \
906 } \
907}
908
909static int
910symtable_new_tmpname(struct symtable *st)
911{
912 char tmpname[256];
913 identifier tmp;
914
915 PyOS_snprintf(tmpname, sizeof(tmpname), "_[%d]",
916 ++st->st_cur->ste_tmpname);
917 tmp = PyString_InternFromString(tmpname);
918 if (!tmp)
919 return 0;
920 if (!symtable_add_def(st, tmp, DEF_LOCAL))
921 return 0;
922 Py_DECREF(tmp);
923 return 1;
924}
925
926static int
927symtable_visit_stmt(struct symtable *st, stmt_ty s)
928{
929 switch (s->kind) {
930 case FunctionDef_kind:
931 if (!symtable_add_def(st, s->v.FunctionDef.name, DEF_LOCAL))
932 return 0;
933 if (s->v.FunctionDef.args->defaults)
934 VISIT_SEQ(st, expr, s->v.FunctionDef.args->defaults);
935 if (s->v.FunctionDef.decorators)
936 VISIT_SEQ(st, expr, s->v.FunctionDef.decorators);
937 if (!symtable_enter_block(st, s->v.FunctionDef.name,
938 FunctionBlock, (void *)s, s->lineno))
939 return 0;
940 VISIT_IN_BLOCK(st, arguments, s->v.FunctionDef.args, s);
941 VISIT_SEQ_IN_BLOCK(st, stmt, s->v.FunctionDef.body, s);
942 if (!symtable_exit_block(st, s))
943 return 0;
944 break;
945 case ClassDef_kind: {
946 PyObject *tmp;
947 if (!symtable_add_def(st, s->v.ClassDef.name, DEF_LOCAL))
948 return 0;
949 VISIT_SEQ(st, expr, s->v.ClassDef.bases);
950 if (!symtable_enter_block(st, s->v.ClassDef.name, ClassBlock,
951 (void *)s, s->lineno))
952 return 0;
953 tmp = st->st_private;
954 st->st_private = s->v.ClassDef.name;
955 VISIT_SEQ_IN_BLOCK(st, stmt, s->v.ClassDef.body, s);
956 st->st_private = tmp;
957 if (!symtable_exit_block(st, s))
958 return 0;
959 break;
960 }
961 case Return_kind:
962 if (s->v.Return.value) {
963 VISIT(st, expr, s->v.Return.value);
964 st->st_cur->ste_returns_value = 1;
965 if (st->st_cur->ste_generator) {
966 PyErr_SetString(PyExc_SyntaxError,
967 RETURN_VAL_IN_GENERATOR);
968 PyErr_SyntaxLocation(st->st_filename,
969 s->lineno);
970 return 0;
971 }
972 }
973 break;
974 case Delete_kind:
975 VISIT_SEQ(st, expr, s->v.Delete.targets);
976 break;
977 case Assign_kind:
978 VISIT_SEQ(st, expr, s->v.Assign.targets);
979 VISIT(st, expr, s->v.Assign.value);
980 break;
981 case AugAssign_kind:
982 VISIT(st, expr, s->v.AugAssign.target);
983 VISIT(st, expr, s->v.AugAssign.value);
984 break;
985 case Print_kind:
986 if (s->v.Print.dest)
987 VISIT(st, expr, s->v.Print.dest);
988 VISIT_SEQ(st, expr, s->v.Print.values);
989 break;
990 case For_kind:
991 VISIT(st, expr, s->v.For.target);
992 VISIT(st, expr, s->v.For.iter);
993 VISIT_SEQ(st, stmt, s->v.For.body);
994 if (s->v.For.orelse)
995 VISIT_SEQ(st, stmt, s->v.For.orelse);
996 break;
997 case While_kind:
998 VISIT(st, expr, s->v.While.test);
999 VISIT_SEQ(st, stmt, s->v.While.body);
1000 if (s->v.While.orelse)
1001 VISIT_SEQ(st, stmt, s->v.While.orelse);
1002 break;
1003 case If_kind:
1004 /* XXX if 0: and lookup_yield() hacks */
1005 VISIT(st, expr, s->v.If.test);
1006 VISIT_SEQ(st, stmt, s->v.If.body);
1007 if (s->v.If.orelse)
1008 VISIT_SEQ(st, stmt, s->v.If.orelse);
1009 break;
1010 case Raise_kind:
1011 if (s->v.Raise.type) {
1012 VISIT(st, expr, s->v.Raise.type);
1013 if (s->v.Raise.inst) {
1014 VISIT(st, expr, s->v.Raise.inst);
1015 if (s->v.Raise.tback)
1016 VISIT(st, expr, s->v.Raise.tback);
1017 }
1018 }
1019 break;
1020 case TryExcept_kind:
1021 VISIT_SEQ(st, stmt, s->v.TryExcept.body);
1022 VISIT_SEQ(st, stmt, s->v.TryExcept.orelse);
1023 VISIT_SEQ(st, excepthandler, s->v.TryExcept.handlers);
1024 break;
1025 case TryFinally_kind:
1026 VISIT_SEQ(st, stmt, s->v.TryFinally.body);
1027 VISIT_SEQ(st, stmt, s->v.TryFinally.finalbody);
1028 break;
1029 case Assert_kind:
1030 VISIT(st, expr, s->v.Assert.test);
1031 if (s->v.Assert.msg)
1032 VISIT(st, expr, s->v.Assert.msg);
1033 break;
1034 case Import_kind:
1035 VISIT_SEQ(st, alias, s->v.Import.names);
1036 /* XXX Don't have the lineno available inside
1037 visit_alias */
1038 if (st->st_cur->ste_unoptimized && !st->st_cur->ste_opt_lineno)
1039 st->st_cur->ste_opt_lineno = s->lineno;
1040 break;
1041 case ImportFrom_kind:
1042 VISIT_SEQ(st, alias, s->v.ImportFrom.names);
1043 /* XXX Don't have the lineno available inside
1044 visit_alias */
1045 if (st->st_cur->ste_unoptimized && !st->st_cur->ste_opt_lineno)
1046 st->st_cur->ste_opt_lineno = s->lineno;
1047 break;
1048 case Exec_kind:
1049 VISIT(st, expr, s->v.Exec.body);
1050 if (!st->st_cur->ste_opt_lineno)
1051 st->st_cur->ste_opt_lineno = s->lineno;
1052 if (s->v.Exec.globals) {
1053 st->st_cur->ste_unoptimized |= OPT_EXEC;
1054 VISIT(st, expr, s->v.Exec.globals);
1055 if (s->v.Exec.locals)
1056 VISIT(st, expr, s->v.Exec.locals);
1057 } else {
1058 st->st_cur->ste_unoptimized |= OPT_BARE_EXEC;
1059 }
1060 break;
1061 case Global_kind: {
1062 int i;
1063 asdl_seq *seq = s->v.Global.names;
1064 for (i = 0; i < asdl_seq_LEN(seq); i++) {
1065 identifier name = (identifier)asdl_seq_GET(seq, i);
1066 char *c_name = PyString_AS_STRING(name);
1067 long cur = symtable_lookup(st, name);
1068 if (cur < 0)
1069 return 0;
1070 if (cur & (DEF_LOCAL | USE)) {
1071 char buf[256];
1072 if (cur & DEF_LOCAL)
1073 PyOS_snprintf(buf, sizeof(buf),
1074 GLOBAL_AFTER_ASSIGN,
1075 c_name);
1076 else
1077 PyOS_snprintf(buf, sizeof(buf),
1078 GLOBAL_AFTER_USE,
1079 c_name);
1080 if (!symtable_warn(st, buf, s->lineno))
1081 return 0;
1082 }
1083 if (!symtable_add_def(st, name, DEF_GLOBAL))
1084 return 0;
1085 }
1086 break;
1087 }
1088 case Expr_kind:
1089 VISIT(st, expr, s->v.Expr.value);
1090 break;
1091 case Pass_kind:
1092 case Break_kind:
1093 case Continue_kind:
1094 /* nothing to do here */
1095 break;
1096 case With_kind:
1097 if (!symtable_new_tmpname(st))
1098 return 0;
1099 VISIT(st, expr, s->v.With.context_expr);
1100 if (s->v.With.optional_vars) {
1101 if (!symtable_new_tmpname(st))
1102 return 0;
1103 VISIT(st, expr, s->v.With.optional_vars);
1104 }
1105 VISIT_SEQ(st, stmt, s->v.With.body);
1106 break;
1107 }
1108 return 1;
1109}
1110
1111static int
1112symtable_visit_expr(struct symtable *st, expr_ty e)
1113{
1114 switch (e->kind) {
1115 case BoolOp_kind:
1116 VISIT_SEQ(st, expr, e->v.BoolOp.values);
1117 break;
1118 case BinOp_kind:
1119 VISIT(st, expr, e->v.BinOp.left);
1120 VISIT(st, expr, e->v.BinOp.right);
1121 break;
1122 case UnaryOp_kind:
1123 VISIT(st, expr, e->v.UnaryOp.operand);
1124 break;
1125 case Lambda_kind: {
1126 if (!symtable_add_def(st, GET_IDENTIFIER(lambda), DEF_LOCAL))
1127 return 0;
1128 if (e->v.Lambda.args->defaults)
1129 VISIT_SEQ(st, expr, e->v.Lambda.args->defaults);
1130 /* XXX how to get line numbers for expressions */
1131 if (!symtable_enter_block(st, GET_IDENTIFIER(lambda),
1132 FunctionBlock, (void *)e, 0))
1133 return 0;
1134 VISIT_IN_BLOCK(st, arguments, e->v.Lambda.args, (void*)e);
1135 VISIT_IN_BLOCK(st, expr, e->v.Lambda.body, (void*)e);
1136 if (!symtable_exit_block(st, (void *)e))
1137 return 0;
1138 break;
1139 }
1140 case IfExp_kind:
1141 VISIT(st, expr, e->v.IfExp.test);
1142 VISIT(st, expr, e->v.IfExp.body);
1143 VISIT(st, expr, e->v.IfExp.orelse);
1144 break;
1145 case Dict_kind:
1146 VISIT_SEQ(st, expr, e->v.Dict.keys);
1147 VISIT_SEQ(st, expr, e->v.Dict.values);
1148 break;
1149 case ListComp_kind:
1150 if (!symtable_new_tmpname(st))
1151 return 0;
1152 VISIT(st, expr, e->v.ListComp.elt);
1153 VISIT_SEQ(st, comprehension, e->v.ListComp.generators);
1154 break;
1155 case GeneratorExp_kind:
1156 if (!symtable_visit_genexp(st, e))
1157 return 0;
1158 break;
1159 case Yield_kind:
1160 if (e->v.Yield.value)
1161 VISIT(st, expr, e->v.Yield.value);
1162 st->st_cur->ste_generator = 1;
1163 if (st->st_cur->ste_returns_value) {
1164 PyErr_SetString(PyExc_SyntaxError,
1165 RETURN_VAL_IN_GENERATOR);
1166 PyErr_SyntaxLocation(st->st_filename,
1167 e->lineno);
1168 return 0;
1169 }
1170 break;
1171 case Compare_kind:
1172 VISIT(st, expr, e->v.Compare.left);
1173 VISIT_SEQ(st, expr, e->v.Compare.comparators);
1174 break;
1175 case Call_kind:
1176 VISIT(st, expr, e->v.Call.func);
1177 VISIT_SEQ(st, expr, e->v.Call.args);
1178 VISIT_SEQ(st, keyword, e->v.Call.keywords);
1179 if (e->v.Call.starargs)
1180 VISIT(st, expr, e->v.Call.starargs);
1181 if (e->v.Call.kwargs)
1182 VISIT(st, expr, e->v.Call.kwargs);
1183 break;
1184 case Repr_kind:
1185 VISIT(st, expr, e->v.Repr.value);
1186 break;
1187 case Num_kind:
1188 case Str_kind:
1189 /* Nothing to do here. */
1190 break;
1191 /* The following exprs can be assignment targets. */
1192 case Attribute_kind:
1193 VISIT(st, expr, e->v.Attribute.value);
1194 break;
1195 case Subscript_kind:
1196 VISIT(st, expr, e->v.Subscript.value);
1197 VISIT(st, slice, e->v.Subscript.slice);
1198 break;
1199 case Name_kind:
1200 if (!symtable_add_def(st, e->v.Name.id,
1201 e->v.Name.ctx == Load ? USE : DEF_LOCAL))
1202 return 0;
1203 break;
1204 /* child nodes of List and Tuple will have expr_context set */
1205 case List_kind:
1206 VISIT_SEQ(st, expr, e->v.List.elts);
1207 break;
1208 case Tuple_kind:
1209 VISIT_SEQ(st, expr, e->v.Tuple.elts);
1210 break;
1211 }
1212 return 1;
1213}
1214
1215static int
1216symtable_implicit_arg(struct symtable *st, int pos)
1217{
1218 PyObject *id = PyString_FromFormat(".%d", pos);
1219 if (id == NULL)
1220 return 0;
1221 if (!symtable_add_def(st, id, DEF_PARAM)) {
1222 Py_DECREF(id);
1223 return 0;
1224 }
1225 Py_DECREF(id);
1226 return 1;
1227}
1228
1229static int
1230symtable_visit_params(struct symtable *st, asdl_seq *args, int toplevel)
1231{
1232 int i;
1233
1234 /* go through all the toplevel arguments first */
1235 for (i = 0; i < asdl_seq_LEN(args); i++) {
1236 expr_ty arg = (expr_ty)asdl_seq_GET(args, i);
1237 if (arg->kind == Name_kind) {
1238 assert(arg->v.Name.ctx == Param ||
1239 (arg->v.Name.ctx == Store && !toplevel));
1240 if (!symtable_add_def(st, arg->v.Name.id, DEF_PARAM))
1241 return 0;
1242 }
1243 else if (arg->kind == Tuple_kind) {
1244 assert(arg->v.Tuple.ctx == Store);
1245 if (toplevel) {
1246 if (!symtable_implicit_arg(st, i))
1247 return 0;
1248 }
1249 }
1250 else {
1251 PyErr_SetString(PyExc_SyntaxError,
1252 "invalid expression in parameter list");
1253 PyErr_SyntaxLocation(st->st_filename,
1254 st->st_cur->ste_lineno);
1255 return 0;
1256 }
1257 }
1258
1259 if (!toplevel) {
1260 if (!symtable_visit_params_nested(st, args))
1261 return 0;
1262 }
1263
1264 return 1;
1265}
1266
1267static int
1268symtable_visit_params_nested(struct symtable *st, asdl_seq *args)
1269{
1270 int i;
1271 for (i = 0; i < asdl_seq_LEN(args); i++) {
1272 expr_ty arg = (expr_ty)asdl_seq_GET(args, i);
1273 if (arg->kind == Tuple_kind &&
1274 !symtable_visit_params(st, arg->v.Tuple.elts, 0))
1275 return 0;
1276 }
1277
1278 return 1;
1279}
1280
1281static int
1282symtable_visit_arguments(struct symtable *st, arguments_ty a)
1283{
1284 /* skip default arguments inside function block
1285 XXX should ast be different?
1286 */
1287 if (a->args && !symtable_visit_params(st, a->args, 1))
1288 return 0;
1289 if (a->vararg) {
1290 if (!symtable_add_def(st, a->vararg, DEF_PARAM))
1291 return 0;
1292 st->st_cur->ste_varargs = 1;
1293 }
1294 if (a->kwarg) {
1295 if (!symtable_add_def(st, a->kwarg, DEF_PARAM))
1296 return 0;
1297 st->st_cur->ste_varkeywords = 1;
1298 }
1299 if (a->args && !symtable_visit_params_nested(st, a->args))
1300 return 0;
1301 return 1;
1302}
1303
1304
1305static int
1306symtable_visit_excepthandler(struct symtable *st, excepthandler_ty eh)
1307{
1308 if (eh->type)
1309 VISIT(st, expr, eh->type);
1310 if (eh->name)
1311 VISIT(st, expr, eh->name);
1312 VISIT_SEQ(st, stmt, eh->body);
1313 return 1;
1314}
1315
1316
1317static int
1318symtable_visit_alias(struct symtable *st, alias_ty a)
1319{
1320 /* Compute store_name, the name actually bound by the import
1321 operation. It is diferent than a->name when a->name is a
1322 dotted package name (e.g. spam.eggs)
1323 */
1324 PyObject *store_name;
1325 PyObject *name = (a->asname == NULL) ? a->name : a->asname;
1326 const char *base = PyString_AS_STRING(name);
1327 char *dot = strchr(base, '.');
1328 if (dot) {
1329 store_name = PyString_FromStringAndSize(base, dot - base);
1330 if (!store_name)
1331 return 0;
1332 }
1333 else {
1334 store_name = name;
1335 Py_INCREF(store_name);
1336 }
1337 if (strcmp(PyString_AS_STRING(name), "*")) {
1338 int r = symtable_add_def(st, store_name, DEF_IMPORT);
1339 Py_DECREF(store_name);
1340 return r;
1341 }
1342 else {
1343 if (st->st_cur->ste_type != ModuleBlock) {
1344 int lineno = st->st_cur->ste_lineno;
1345 if (!symtable_warn(st, IMPORT_STAR_WARNING, lineno)) {
1346 Py_DECREF(store_name);
1347 return 0;
1348 }
1349 }
1350 st->st_cur->ste_unoptimized |= OPT_IMPORT_STAR;
1351 Py_DECREF(store_name);
1352 return 1;
1353 }
1354}
1355
1356
1357static int
1358symtable_visit_comprehension(struct symtable *st, comprehension_ty lc)
1359{
1360 VISIT(st, expr, lc->target);
1361 VISIT(st, expr, lc->iter);
1362 VISIT_SEQ(st, expr, lc->ifs);
1363 return 1;
1364}
1365
1366
1367static int
1368symtable_visit_keyword(struct symtable *st, keyword_ty k)
1369{
1370 VISIT(st, expr, k->value);
1371 return 1;
1372}
1373
1374
1375static int
1376symtable_visit_slice(struct symtable *st, slice_ty s)
1377{
1378 switch (s->kind) {
1379 case Slice_kind:
1380 if (s->v.Slice.lower)
1381 VISIT(st, expr, s->v.Slice.lower)
1382 if (s->v.Slice.upper)
1383 VISIT(st, expr, s->v.Slice.upper)
1384 if (s->v.Slice.step)
1385 VISIT(st, expr, s->v.Slice.step)
1386 break;
1387 case ExtSlice_kind:
1388 VISIT_SEQ(st, slice, s->v.ExtSlice.dims)
1389 break;
1390 case Index_kind:
1391 VISIT(st, expr, s->v.Index.value)
1392 break;
1393 case Ellipsis_kind:
1394 break;
1395 }
1396 return 1;
1397}
1398
1399static int
1400symtable_visit_genexp(struct symtable *st, expr_ty e)
1401{
1402 comprehension_ty outermost = ((comprehension_ty)
1403 (asdl_seq_GET(e->v.GeneratorExp.generators, 0)));
1404 /* Outermost iterator is evaluated in current scope */
1405 VISIT(st, expr, outermost->iter);
1406 /* Create generator scope for the rest */
1407 if (!symtable_enter_block(st, GET_IDENTIFIER(genexpr),
1408 FunctionBlock, (void *)e, 0)) {
1409 return 0;
1410 }
1411 st->st_cur->ste_generator = 1;
1412 /* Outermost iter is received as an argument */
1413 if (!symtable_implicit_arg(st, 0)) {
1414 symtable_exit_block(st, (void *)e);
1415 return 0;
1416 }
1417 VISIT_IN_BLOCK(st, expr, outermost->target, (void*)e);
1418 VISIT_SEQ_IN_BLOCK(st, expr, outermost->ifs, (void*)e);
1419 VISIT_SEQ_TAIL_IN_BLOCK(st, comprehension,
1420 e->v.GeneratorExp.generators, 1, (void*)e);
1421 VISIT_IN_BLOCK(st, expr, e->v.GeneratorExp.elt, (void*)e);
1422 if (!symtable_exit_block(st, (void *)e))
1423 return 0;
1424 return 1;
1425}
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