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Add a comment about unreachable code, and fix a typo
[python.git] / Python / ast.c
blob3422c2e1b0dd51d714898b5ffb8ada59829139b3
1 /*
2 * This file includes functions to transform a concrete syntax tree (CST) to
3 * an abstract syntax tree (AST). The main function is PyAST_FromNode().
4 *
5 */
6 #include "Python.h"
7 #include "Python-ast.h"
8 #include "grammar.h"
9 #include "node.h"
10 #include "pyarena.h"
11 #include "ast.h"
12 #include "token.h"
13 #include "parsetok.h"
14 #include "graminit.h"
15
16 #include <assert.h>
17
18 /* Data structure used internally */
19 struct compiling {
20 char *c_encoding; /* source encoding */
21 int c_future_unicode; /* __future__ unicode literals flag */
22 PyArena *c_arena; /* arena for allocating memeory */
23 const char *c_filename; /* filename */
24 };
25
26 static asdl_seq *seq_for_testlist(struct compiling *, const node *);
27 static expr_ty ast_for_expr(struct compiling *, const node *);
28 static stmt_ty ast_for_stmt(struct compiling *, const node *);
29 static asdl_seq *ast_for_suite(struct compiling *, const node *);
30 static asdl_seq *ast_for_exprlist(struct compiling *, const node *,
31 expr_context_ty);
32 static expr_ty ast_for_testlist(struct compiling *, const node *);
33 static stmt_ty ast_for_classdef(struct compiling *, const node *, asdl_seq *);
34 static expr_ty ast_for_testlist_gexp(struct compiling *, const node *);
35
36 /* Note different signature for ast_for_call */
37 static expr_ty ast_for_call(struct compiling *, const node *, expr_ty);
38
39 static PyObject *parsenumber(struct compiling *, const char *);
40 static PyObject *parsestr(struct compiling *, const char *);
41 static PyObject *parsestrplus(struct compiling *, const node *n);
42
43 #ifndef LINENO
44 #define LINENO(n) ((n)->n_lineno)
45 #endif
46
47 static identifier
48 new_identifier(const char* n, PyArena *arena) {
49 PyObject* id = PyString_InternFromString(n);
50 if (id != NULL)
51 PyArena_AddPyObject(arena, id);
52 return id;
53 }
54
55 #define NEW_IDENTIFIER(n) new_identifier(STR(n), c->c_arena)
56
57 /* This routine provides an invalid object for the syntax error.
58 The outermost routine must unpack this error and create the
59 proper object. We do this so that we don't have to pass
60 the filename to everything function.
61
62 XXX Maybe we should just pass the filename...
63 */
64
65 static int
66 ast_error(const node *n, const char *errstr)
67 {
68 PyObject *u = Py_BuildValue("zi", errstr, LINENO(n));
69 if (!u)
70 return 0;
71 PyErr_SetObject(PyExc_SyntaxError, u);
72 Py_DECREF(u);
73 return 0;
74 }
75
76 static void
77 ast_error_finish(const char *filename)
78 {
79 PyObject *type, *value, *tback, *errstr, *loc, *tmp;
80 long lineno;
81
82 assert(PyErr_Occurred());
83 if (!PyErr_ExceptionMatches(PyExc_SyntaxError))
84 return;
85
86 PyErr_Fetch(&type, &value, &tback);
87 errstr = PyTuple_GetItem(value, 0);
88 if (!errstr)
89 return;
90 Py_INCREF(errstr);
91 lineno = PyInt_AsLong(PyTuple_GetItem(value, 1));
92 if (lineno == -1) {
93 Py_DECREF(errstr);
94 return;
95 }
96 Py_DECREF(value);
97
98 loc = PyErr_ProgramText(filename, lineno);
99 if (!loc) {
100 Py_INCREF(Py_None);
101 loc = Py_None;
102 }
103 tmp = Py_BuildValue("(zlOO)", filename, lineno, Py_None, loc);
104 Py_DECREF(loc);
105 if (!tmp) {
106 Py_DECREF(errstr);
107 return;
108 }
109 value = PyTuple_Pack(2, errstr, tmp);
110 Py_DECREF(errstr);
111 Py_DECREF(tmp);
112 if (!value)
113 return;
114 PyErr_Restore(type, value, tback);
115 }
116
117 static int
118 ast_warn(struct compiling *c, const node *n, char *msg)
119 {
120 if (PyErr_WarnExplicit(PyExc_SyntaxWarning, msg, c->c_filename, LINENO(n),
121 NULL, NULL) < 0) {
122 /* if -Werr, change it to a SyntaxError */
123 if (PyErr_Occurred() && PyErr_ExceptionMatches(PyExc_SyntaxWarning))
124 ast_error(n, msg);
125 return 0;
126 }
127 return 1;
128 }
129
130 static int
131 forbidden_check(struct compiling *c, const node *n, const char *x)
132 {
133 if (!strcmp(x, "None"))
134 return ast_error(n, "cannot assign to None");
135 if (!strcmp(x, "__debug__"))
136 return ast_error(n, "cannot assign to __debug__");
137 if (Py_Py3kWarningFlag) {
138 if (!(strcmp(x, "True") && strcmp(x, "False")) &&
139 !ast_warn(c, n, "assignment to True or False is forbidden in 3.x"))
140 return 0;
141 if (!strcmp(x, "nonlocal") &&
142 !ast_warn(c, n, "nonlocal is a keyword in 3.x"))
143 return 0;
144 }
145 return 1;
146 }
147
148 /* num_stmts() returns number of contained statements.
149
150 Use this routine to determine how big a sequence is needed for
151 the statements in a parse tree. Its raison d'etre is this bit of
152 grammar:
153
154 stmt: simple_stmt | compound_stmt
155 simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
156
157 A simple_stmt can contain multiple small_stmt elements joined
158 by semicolons. If the arg is a simple_stmt, the number of
159 small_stmt elements is returned.
160 */
161
162 static int
163 num_stmts(const node *n)
164 {
165 int i, l;
166 node *ch;
167
168 switch (TYPE(n)) {
169 case single_input:
170 if (TYPE(CHILD(n, 0)) == NEWLINE)
171 return 0;
172 else
173 return num_stmts(CHILD(n, 0));
174 case file_input:
175 l = 0;
176 for (i = 0; i < NCH(n); i++) {
177 ch = CHILD(n, i);
178 if (TYPE(ch) == stmt)
179 l += num_stmts(ch);
180 }
181 return l;
182 case stmt:
183 return num_stmts(CHILD(n, 0));
184 case compound_stmt:
185 return 1;
186 case simple_stmt:
187 return NCH(n) / 2; /* Divide by 2 to remove count of semi-colons */
188 case suite:
189 if (NCH(n) == 1)
190 return num_stmts(CHILD(n, 0));
191 else {
192 l = 0;
193 for (i = 2; i < (NCH(n) - 1); i++)
194 l += num_stmts(CHILD(n, i));
195 return l;
196 }
197 default: {
198 char buf[128];
199
200 sprintf(buf, "Non-statement found: %d %d",
201 TYPE(n), NCH(n));
202 Py_FatalError(buf);
203 }
204 }
205 assert(0);
206 return 0;
207 }
208
209 /* Transform the CST rooted at node * to the appropriate AST
210 */
211
212 mod_ty
213 PyAST_FromNode(const node *n, PyCompilerFlags *flags, const char *filename,
214 PyArena *arena)
215 {
216 int i, j, k, num;
217 asdl_seq *stmts = NULL;
218 stmt_ty s;
219 node *ch;
220 struct compiling c;
221
222 if (flags && flags->cf_flags & PyCF_SOURCE_IS_UTF8) {
223 c.c_encoding = "utf-8";
224 if (TYPE(n) == encoding_decl) {
225 ast_error(n, "encoding declaration in Unicode string");
226 goto error;
227 }
228 } else if (TYPE(n) == encoding_decl) {
229 c.c_encoding = STR(n);
230 n = CHILD(n, 0);
231 } else {
232 c.c_encoding = NULL;
233 }
234 c.c_future_unicode = flags && flags->cf_flags & CO_FUTURE_UNICODE_LITERALS;
235 c.c_arena = arena;
236 c.c_filename = filename;
237
238 k = 0;
239 switch (TYPE(n)) {
240 case file_input:
241 stmts = asdl_seq_new(num_stmts(n), arena);
242 if (!stmts)
243 return NULL;
244 for (i = 0; i < NCH(n) - 1; i++) {
245 ch = CHILD(n, i);
246 if (TYPE(ch) == NEWLINE)
247 continue;
248 REQ(ch, stmt);
249 num = num_stmts(ch);
250 if (num == 1) {
251 s = ast_for_stmt(&c, ch);
252 if (!s)
253 goto error;
254 asdl_seq_SET(stmts, k++, s);
255 }
256 else {
257 ch = CHILD(ch, 0);
258 REQ(ch, simple_stmt);
259 for (j = 0; j < num; j++) {
260 s = ast_for_stmt(&c, CHILD(ch, j * 2));
261 if (!s)
262 goto error;
263 asdl_seq_SET(stmts, k++, s);
264 }
265 }
266 }
267 return Module(stmts, arena);
268 case eval_input: {
269 expr_ty testlist_ast;
270
271 /* XXX Why not gen_for here? */
272 testlist_ast = ast_for_testlist(&c, CHILD(n, 0));
273 if (!testlist_ast)
274 goto error;
275 return Expression(testlist_ast, arena);
276 }
277 case single_input:
278 if (TYPE(CHILD(n, 0)) == NEWLINE) {
279 stmts = asdl_seq_new(1, arena);
280 if (!stmts)
281 goto error;
282 asdl_seq_SET(stmts, 0, Pass(n->n_lineno, n->n_col_offset,
283 arena));
284 if (!asdl_seq_GET(stmts, 0))
285 goto error;
286 return Interactive(stmts, arena);
287 }
288 else {
289 n = CHILD(n, 0);
290 num = num_stmts(n);
291 stmts = asdl_seq_new(num, arena);
292 if (!stmts)
293 goto error;
294 if (num == 1) {
295 s = ast_for_stmt(&c, n);
296 if (!s)
297 goto error;
298 asdl_seq_SET(stmts, 0, s);
299 }
300 else {
301 /* Only a simple_stmt can contain multiple statements. */
302 REQ(n, simple_stmt);
303 for (i = 0; i < NCH(n); i += 2) {
304 if (TYPE(CHILD(n, i)) == NEWLINE)
305 break;
306 s = ast_for_stmt(&c, CHILD(n, i));
307 if (!s)
308 goto error;
309 asdl_seq_SET(stmts, i / 2, s);
310 }
311 }
312
313 return Interactive(stmts, arena);
314 }
315 default:
316 PyErr_Format(PyExc_SystemError,
317 "invalid node %d for PyAST_FromNode", TYPE(n));
318 goto error;
319 }
320 error:
321 ast_error_finish(filename);
322 return NULL;
323 }
324
325 /* Return the AST repr. of the operator represented as syntax (|, ^, etc.)
326 */
327
328 static operator_ty
329 get_operator(const node *n)
330 {
331 switch (TYPE(n)) {
332 case VBAR:
333 return BitOr;
334 case CIRCUMFLEX:
335 return BitXor;
336 case AMPER:
337 return BitAnd;
338 case LEFTSHIFT:
339 return LShift;
340 case RIGHTSHIFT:
341 return RShift;
342 case PLUS:
343 return Add;
344 case MINUS:
345 return Sub;
346 case STAR:
347 return Mult;
348 case SLASH:
349 return Div;
350 case DOUBLESLASH:
351 return FloorDiv;
352 case PERCENT:
353 return Mod;
354 default:
355 return (operator_ty)0;
356 }
357 }
358
359 /* Set the context ctx for expr_ty e, recursively traversing e.
360
361 Only sets context for expr kinds that "can appear in assignment context"
362 (according to ../Parser/Python.asdl). For other expr kinds, it sets
363 an appropriate syntax error and returns false.
364 */
365
366 static int
367 set_context(struct compiling *c, expr_ty e, expr_context_ty ctx, const node *n)
368 {
369 asdl_seq *s = NULL;
370 /* If a particular expression type can't be used for assign / delete,
371 set expr_name to its name and an error message will be generated.
372 */
373 const char* expr_name = NULL;
374
375 /* The ast defines augmented store and load contexts, but the
376 implementation here doesn't actually use them. The code may be
377 a little more complex than necessary as a result. It also means
378 that expressions in an augmented assignment have a Store context.
379 Consider restructuring so that augmented assignment uses
380 set_context(), too.
381 */
382 assert(ctx != AugStore && ctx != AugLoad);
383
384 switch (e->kind) {
385 case Attribute_kind:
386 if (ctx == Store && !forbidden_check(c, n,
387 PyBytes_AS_STRING(e->v.Attribute.attr)))
388 return 0;
389 e->v.Attribute.ctx = ctx;
390 break;
391 case Subscript_kind:
392 e->v.Subscript.ctx = ctx;
393 break;
394 case Name_kind:
395 if (ctx == Store && !forbidden_check(c, n,
396 PyBytes_AS_STRING(e->v.Name.id)))
397 return 0;
398 e->v.Name.ctx = ctx;
399 break;
400 case List_kind:
401 e->v.List.ctx = ctx;
402 s = e->v.List.elts;
403 break;
404 case Tuple_kind:
405 if (asdl_seq_LEN(e->v.Tuple.elts)) {
406 e->v.Tuple.ctx = ctx;
407 s = e->v.Tuple.elts;
408 }
409 else {
410 expr_name = "()";
411 }
412 break;
413 case Lambda_kind:
414 expr_name = "lambda";
415 break;
416 case Call_kind:
417 expr_name = "function call";
418 break;
419 case BoolOp_kind:
420 case BinOp_kind:
421 case UnaryOp_kind:
422 expr_name = "operator";
423 break;
424 case GeneratorExp_kind:
425 expr_name = "generator expression";
426 break;
427 case Yield_kind:
428 expr_name = "yield expression";
429 break;
430 case ListComp_kind:
431 expr_name = "list comprehension";
432 break;
433 case Dict_kind:
434 case Num_kind:
435 case Str_kind:
436 expr_name = "literal";
437 break;
438 case Compare_kind:
439 expr_name = "comparison";
440 break;
441 case Repr_kind:
442 expr_name = "repr";
443 break;
444 case IfExp_kind:
445 expr_name = "conditional expression";
446 break;
447 default:
448 PyErr_Format(PyExc_SystemError,
449 "unexpected expression in assignment %d (line %d)",
450 e->kind, e->lineno);
451 return 0;
452 }
453 /* Check for error string set by switch */
454 if (expr_name) {
455 char buf[300];
456 PyOS_snprintf(buf, sizeof(buf),
457 "can't %s %s",
458 ctx == Store ? "assign to" : "delete",
459 expr_name);
460 return ast_error(n, buf);
461 }
462
463 /* If the LHS is a list or tuple, we need to set the assignment
464 context for all the contained elements.
465 */
466 if (s) {
467 int i;
468
469 for (i = 0; i < asdl_seq_LEN(s); i++) {
470 if (!set_context(c, (expr_ty)asdl_seq_GET(s, i), ctx, n))
471 return 0;
472 }
473 }
474 return 1;
475 }
476
477 static operator_ty
478 ast_for_augassign(struct compiling *c, const node *n)
479 {
480 REQ(n, augassign);
481 n = CHILD(n, 0);
482 switch (STR(n)[0]) {
483 case '+':
484 return Add;
485 case '-':
486 return Sub;
487 case '/':
488 if (STR(n)[1] == '/')
489 return FloorDiv;
490 else
491 return Div;
492 case '%':
493 return Mod;
494 case '<':
495 return LShift;
496 case '>':
497 return RShift;
498 case '&':
499 return BitAnd;
500 case '^':
501 return BitXor;
502 case '|':
503 return BitOr;
504 case '*':
505 if (STR(n)[1] == '*')
506 return Pow;
507 else
508 return Mult;
509 default:
510 PyErr_Format(PyExc_SystemError, "invalid augassign: %s", STR(n));
511 return (operator_ty)0;
512 }
513 }
514
515 static cmpop_ty
516 ast_for_comp_op(struct compiling *c, const node *n)
517 {
518 /* comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'
519 |'is' 'not'
520 */
521 REQ(n, comp_op);
522 if (NCH(n) == 1) {
523 n = CHILD(n, 0);
524 switch (TYPE(n)) {
525 case LESS:
526 return Lt;
527 case GREATER:
528 return Gt;
529 case EQEQUAL: /* == */
530 return Eq;
531 case LESSEQUAL:
532 return LtE;
533 case GREATEREQUAL:
534 return GtE;
535 case NOTEQUAL:
536 return NotEq;
537 case NAME:
538 if (strcmp(STR(n), "in") == 0)
539 return In;
540 if (strcmp(STR(n), "is") == 0)
541 return Is;
542 default:
543 PyErr_Format(PyExc_SystemError, "invalid comp_op: %s",
544 STR(n));
545 return (cmpop_ty)0;
546 }
547 }
548 else if (NCH(n) == 2) {
549 /* handle "not in" and "is not" */
550 switch (TYPE(CHILD(n, 0))) {
551 case NAME:
552 if (strcmp(STR(CHILD(n, 1)), "in") == 0)
553 return NotIn;
554 if (strcmp(STR(CHILD(n, 0)), "is") == 0)
555 return IsNot;
556 default:
557 PyErr_Format(PyExc_SystemError, "invalid comp_op: %s %s",
558 STR(CHILD(n, 0)), STR(CHILD(n, 1)));
559 return (cmpop_ty)0;
560 }
561 }
562 PyErr_Format(PyExc_SystemError, "invalid comp_op: has %d children",
563 NCH(n));
564 return (cmpop_ty)0;
565 }
566
567 static asdl_seq *
568 seq_for_testlist(struct compiling *c, const node *n)
569 {
570 /* testlist: test (',' test)* [','] */
571 asdl_seq *seq;
572 expr_ty expression;
573 int i;
574 assert(TYPE(n) == testlist ||
575 TYPE(n) == listmaker ||
576 TYPE(n) == testlist_gexp ||
577 TYPE(n) == testlist_safe ||
578 TYPE(n) == testlist1);
579
580 seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
581 if (!seq)
582 return NULL;
583
584 for (i = 0; i < NCH(n); i += 2) {
585 assert(TYPE(CHILD(n, i)) == test || TYPE(CHILD(n, i)) == old_test);
586
587 expression = ast_for_expr(c, CHILD(n, i));
588 if (!expression)
589 return NULL;
590
591 assert(i / 2 < seq->size);
592 asdl_seq_SET(seq, i / 2, expression);
593 }
594 return seq;
595 }
596
597 static expr_ty
598 compiler_complex_args(struct compiling *c, const node *n)
599 {
600 int i, len = (NCH(n) + 1) / 2;
601 expr_ty result;
602 asdl_seq *args = asdl_seq_new(len, c->c_arena);
603 if (!args)
604 return NULL;
605
606 /* fpdef: NAME | '(' fplist ')'
607 fplist: fpdef (',' fpdef)* [',']
608 */
609 REQ(n, fplist);
610 for (i = 0; i < len; i++) {
611 PyObject *arg_id;
612 const node *fpdef_node = CHILD(n, 2*i);
613 const node *child;
614 expr_ty arg;
615 set_name:
616 /* fpdef_node is either a NAME or an fplist */
617 child = CHILD(fpdef_node, 0);
618 if (TYPE(child) == NAME) {
619 if (!forbidden_check(c, n, STR(child)))
620 return NULL;
621 arg_id = NEW_IDENTIFIER(child);
622 if (!arg_id)
623 return NULL;
624 arg = Name(arg_id, Store, LINENO(child), child->n_col_offset,
625 c->c_arena);
626 }
627 else {
628 assert(TYPE(fpdef_node) == fpdef);
629 /* fpdef_node[0] is not a name, so it must be '(', get CHILD[1] */
630 child = CHILD(fpdef_node, 1);
631 assert(TYPE(child) == fplist);
632 /* NCH == 1 means we have (x), we need to elide the extra parens */
633 if (NCH(child) == 1) {
634 fpdef_node = CHILD(child, 0);
635 assert(TYPE(fpdef_node) == fpdef);
636 goto set_name;
637 }
638 arg = compiler_complex_args(c, child);
639 }
640 asdl_seq_SET(args, i, arg);
641 }
642
643 result = Tuple(args, Store, LINENO(n), n->n_col_offset, c->c_arena);
644 if (!set_context(c, result, Store, n))
645 return NULL;
646 return result;
647 }
648
649
650 /* Create AST for argument list. */
651
652 static arguments_ty
653 ast_for_arguments(struct compiling *c, const node *n)
654 {
655 /* parameters: '(' [varargslist] ')'
656 varargslist: (fpdef ['=' test] ',')* ('*' NAME [',' '**' NAME]
657 | '**' NAME) | fpdef ['=' test] (',' fpdef ['=' test])* [',']
658 */
659 int i, j, k, n_args = 0, n_defaults = 0, found_default = 0;
660 asdl_seq *args, *defaults;
661 identifier vararg = NULL, kwarg = NULL;
662 node *ch;
663
664 if (TYPE(n) == parameters) {
665 if (NCH(n) == 2) /* () as argument list */
666 return arguments(NULL, NULL, NULL, NULL, c->c_arena);
667 n = CHILD(n, 1);
668 }
669 REQ(n, varargslist);
670
671 /* first count the number of normal args & defaults */
672 for (i = 0; i < NCH(n); i++) {
673 ch = CHILD(n, i);
674 if (TYPE(ch) == fpdef)
675 n_args++;
676 if (TYPE(ch) == EQUAL)
677 n_defaults++;
678 }
679 args = (n_args ? asdl_seq_new(n_args, c->c_arena) : NULL);
680 if (!args && n_args)
681 return NULL; /* Don't need to goto error; no objects allocated */
682 defaults = (n_defaults ? asdl_seq_new(n_defaults, c->c_arena) : NULL);
683 if (!defaults && n_defaults)
684 return NULL; /* Don't need to goto error; no objects allocated */
685
686 /* fpdef: NAME | '(' fplist ')'
687 fplist: fpdef (',' fpdef)* [',']
688 */
689 i = 0;
690 j = 0; /* index for defaults */
691 k = 0; /* index for args */
692 while (i < NCH(n)) {
693 ch = CHILD(n, i);
694 switch (TYPE(ch)) {
695 case fpdef:
696 handle_fpdef:
697 /* XXX Need to worry about checking if TYPE(CHILD(n, i+1)) is
698 anything other than EQUAL or a comma? */
699 /* XXX Should NCH(n) check be made a separate check? */
700 if (i + 1 < NCH(n) && TYPE(CHILD(n, i + 1)) == EQUAL) {
701 expr_ty expression = ast_for_expr(c, CHILD(n, i + 2));
702 if (!expression)
703 goto error;
704 assert(defaults != NULL);
705 asdl_seq_SET(defaults, j++, expression);
706 i += 2;
707 found_default = 1;
708 }
709 else if (found_default) {
710 ast_error(n,
711 "non-default argument follows default argument");
712 goto error;
713 }
714 if (NCH(ch) == 3) {
715 ch = CHILD(ch, 1);
716 /* def foo((x)): is not complex, special case. */
717 if (NCH(ch) != 1) {
718 /* We have complex arguments, setup for unpacking. */
719 if (Py_Py3kWarningFlag && !ast_warn(c, ch,
720 "tuple parameter unpacking has been removed in 3.x"))
721 goto error;
722 asdl_seq_SET(args, k++, compiler_complex_args(c, ch));
723 if (!asdl_seq_GET(args, k-1))
724 goto error;
725 } else {
726 /* def foo((x)): setup for checking NAME below. */
727 /* Loop because there can be many parens and tuple
728 unpacking mixed in. */
729 ch = CHILD(ch, 0);
730 assert(TYPE(ch) == fpdef);
731 goto handle_fpdef;
732 }
733 }
734 if (TYPE(CHILD(ch, 0)) == NAME) {
735 PyObject *id;
736 expr_ty name;
737 if (!forbidden_check(c, n, STR(CHILD(ch, 0))))
738 goto error;
739 id = NEW_IDENTIFIER(CHILD(ch, 0));
740 if (!id)
741 goto error;
742 name = Name(id, Param, LINENO(ch), ch->n_col_offset,
743 c->c_arena);
744 if (!name)
745 goto error;
746 asdl_seq_SET(args, k++, name);
747
748 }
749 i += 2; /* the name and the comma */
750 break;
751 case STAR:
752 if (!forbidden_check(c, CHILD(n, i+1), STR(CHILD(n, i+1))))
753 goto error;
754 vararg = NEW_IDENTIFIER(CHILD(n, i+1));
755 if (!vararg)
756 goto error;
757 i += 3;
758 break;
759 case DOUBLESTAR:
760 if (!forbidden_check(c, CHILD(n, i+1), STR(CHILD(n, i+1))))
761 goto error;
762 kwarg = NEW_IDENTIFIER(CHILD(n, i+1));
763 if (!kwarg)
764 goto error;
765 i += 3;
766 break;
767 default:
768 PyErr_Format(PyExc_SystemError,
769 "unexpected node in varargslist: %d @ %d",
770 TYPE(ch), i);
771 goto error;
772 }
773 }
774
775 return arguments(args, vararg, kwarg, defaults, c->c_arena);
776
777 error:
778 Py_XDECREF(vararg);
779 Py_XDECREF(kwarg);
780 return NULL;
781 }
782
783 static expr_ty
784 ast_for_dotted_name(struct compiling *c, const node *n)
785 {
786 expr_ty e;
787 identifier id;
788 int lineno, col_offset;
789 int i;
790
791 REQ(n, dotted_name);
792
793 lineno = LINENO(n);
794 col_offset = n->n_col_offset;
795
796 id = NEW_IDENTIFIER(CHILD(n, 0));
797 if (!id)
798 return NULL;
799 e = Name(id, Load, lineno, col_offset, c->c_arena);
800 if (!e)
801 return NULL;
802
803 for (i = 2; i < NCH(n); i+=2) {
804 id = NEW_IDENTIFIER(CHILD(n, i));
805 if (!id)
806 return NULL;
807 e = Attribute(e, id, Load, lineno, col_offset, c->c_arena);
808 if (!e)
809 return NULL;
810 }
811
812 return e;
813 }
814
815 static expr_ty
816 ast_for_decorator(struct compiling *c, const node *n)
817 {
818 /* decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE */
819 expr_ty d = NULL;
820 expr_ty name_expr;
821
822 REQ(n, decorator);
823 REQ(CHILD(n, 0), AT);
824 REQ(RCHILD(n, -1), NEWLINE);
825
826 name_expr = ast_for_dotted_name(c, CHILD(n, 1));
827 if (!name_expr)
828 return NULL;
829
830 if (NCH(n) == 3) { /* No arguments */
831 d = name_expr;
832 name_expr = NULL;
833 }
834 else if (NCH(n) == 5) { /* Call with no arguments */
835 d = Call(name_expr, NULL, NULL, NULL, NULL, LINENO(n),
836 n->n_col_offset, c->c_arena);
837 if (!d)
838 return NULL;
839 name_expr = NULL;
840 }
841 else {
842 d = ast_for_call(c, CHILD(n, 3), name_expr);
843 if (!d)
844 return NULL;
845 name_expr = NULL;
846 }
847
848 return d;
849 }
850
851 static asdl_seq*
852 ast_for_decorators(struct compiling *c, const node *n)
853 {
854 asdl_seq* decorator_seq;
855 expr_ty d;
856 int i;
857
858 REQ(n, decorators);
859 decorator_seq = asdl_seq_new(NCH(n), c->c_arena);
860 if (!decorator_seq)
861 return NULL;
862
863 for (i = 0; i < NCH(n); i++) {
864 d = ast_for_decorator(c, CHILD(n, i));
865 if (!d)
866 return NULL;
867 asdl_seq_SET(decorator_seq, i, d);
868 }
869 return decorator_seq;
870 }
871
872 static stmt_ty
873 ast_for_funcdef(struct compiling *c, const node *n, asdl_seq *decorator_seq)
874 {
875 /* funcdef: 'def' NAME parameters ':' suite */
876 identifier name;
877 arguments_ty args;
878 asdl_seq *body;
879 int name_i = 1;
880
881 REQ(n, funcdef);
882
883 name = NEW_IDENTIFIER(CHILD(n, name_i));
884 if (!name)
885 return NULL;
886 else if (!forbidden_check(c, CHILD(n, name_i), STR(CHILD(n, name_i))))
887 return NULL;
888 args = ast_for_arguments(c, CHILD(n, name_i + 1));
889 if (!args)
890 return NULL;
891 body = ast_for_suite(c, CHILD(n, name_i + 3));
892 if (!body)
893 return NULL;
894
895 return FunctionDef(name, args, body, decorator_seq, LINENO(n),
896 n->n_col_offset, c->c_arena);
897 }
898
899 static stmt_ty
900 ast_for_decorated(struct compiling *c, const node *n)
901 {
902 /* decorated: decorators (classdef | funcdef) */
903 stmt_ty thing = NULL;
904 asdl_seq *decorator_seq = NULL;
905
906 REQ(n, decorated);
907
908 decorator_seq = ast_for_decorators(c, CHILD(n, 0));
909 if (!decorator_seq)
910 return NULL;
911
912 assert(TYPE(CHILD(n, 1)) == funcdef ||
913 TYPE(CHILD(n, 1)) == classdef);
914
915 if (TYPE(CHILD(n, 1)) == funcdef) {
916 thing = ast_for_funcdef(c, CHILD(n, 1), decorator_seq);
917 } else if (TYPE(CHILD(n, 1)) == classdef) {
918 thing = ast_for_classdef(c, CHILD(n, 1), decorator_seq);
919 }
920 /* we count the decorators in when talking about the class' or
921 function's line number */
922 if (thing) {
923 thing->lineno = LINENO(n);
924 thing->col_offset = n->n_col_offset;
925 }
926 return thing;
927 }
928
929 static expr_ty
930 ast_for_lambdef(struct compiling *c, const node *n)
931 {
932 /* lambdef: 'lambda' [varargslist] ':' test */
933 arguments_ty args;
934 expr_ty expression;
935
936 if (NCH(n) == 3) {
937 args = arguments(NULL, NULL, NULL, NULL, c->c_arena);
938 if (!args)
939 return NULL;
940 expression = ast_for_expr(c, CHILD(n, 2));
941 if (!expression)
942 return NULL;
943 }
944 else {
945 args = ast_for_arguments(c, CHILD(n, 1));
946 if (!args)
947 return NULL;
948 expression = ast_for_expr(c, CHILD(n, 3));
949 if (!expression)
950 return NULL;
951 }
952
953 return Lambda(args, expression, LINENO(n), n->n_col_offset, c->c_arena);
954 }
955
956 static expr_ty
957 ast_for_ifexpr(struct compiling *c, const node *n)
958 {
959 /* test: or_test 'if' or_test 'else' test */
960 expr_ty expression, body, orelse;
961
962 assert(NCH(n) == 5);
963 body = ast_for_expr(c, CHILD(n, 0));
964 if (!body)
965 return NULL;
966 expression = ast_for_expr(c, CHILD(n, 2));
967 if (!expression)
968 return NULL;
969 orelse = ast_for_expr(c, CHILD(n, 4));
970 if (!orelse)
971 return NULL;
972 return IfExp(expression, body, orelse, LINENO(n), n->n_col_offset,
973 c->c_arena);
974 }
975
976 /* XXX(nnorwitz): the listcomp and genexpr code should be refactored
977 so there is only a single version. Possibly for loops can also re-use
978 the code.
979 */
980
981 /* Count the number of 'for' loop in a list comprehension.
982
983 Helper for ast_for_listcomp().
984 */
985
986 static int
987 count_list_fors(struct compiling *c, const node *n)
988 {
989 int n_fors = 0;
990 node *ch = CHILD(n, 1);
991
992 count_list_for:
993 n_fors++;
994 REQ(ch, list_for);
995 if (NCH(ch) == 5)
996 ch = CHILD(ch, 4);
997 else
998 return n_fors;
999 count_list_iter:
1000 REQ(ch, list_iter);
1001 ch = CHILD(ch, 0);
1002 if (TYPE(ch) == list_for)
1003 goto count_list_for;
1004 else if (TYPE(ch) == list_if) {
1005 if (NCH(ch) == 3) {
1006 ch = CHILD(ch, 2);
1007 goto count_list_iter;
1008 }
1009 else
1010 return n_fors;
1011 }
1012
1013 /* Should never be reached */
1014 PyErr_SetString(PyExc_SystemError, "logic error in count_list_fors");
1015 return -1;
1016 }
1017
1018 /* Count the number of 'if' statements in a list comprehension.
1019
1020 Helper for ast_for_listcomp().
1021 */
1022
1023 static int
1024 count_list_ifs(struct compiling *c, const node *n)
1025 {
1026 int n_ifs = 0;
1027
1028 count_list_iter:
1029 REQ(n, list_iter);
1030 if (TYPE(CHILD(n, 0)) == list_for)
1031 return n_ifs;
1032 n = CHILD(n, 0);
1033 REQ(n, list_if);
1034 n_ifs++;
1035 if (NCH(n) == 2)
1036 return n_ifs;
1037 n = CHILD(n, 2);
1038 goto count_list_iter;
1039 }
1040
1041 static expr_ty
1042 ast_for_listcomp(struct compiling *c, const node *n)
1043 {
1044 /* listmaker: test ( list_for | (',' test)* [','] )
1045 list_for: 'for' exprlist 'in' testlist_safe [list_iter]
1046 list_iter: list_for | list_if
1047 list_if: 'if' test [list_iter]
1048 testlist_safe: test [(',' test)+ [',']]
1049 */
1050 expr_ty elt, first;
1051 asdl_seq *listcomps;
1052 int i, n_fors;
1053 node *ch;
1054
1055 REQ(n, listmaker);
1056 assert(NCH(n) > 1);
1057
1058 elt = ast_for_expr(c, CHILD(n, 0));
1059 if (!elt)
1060 return NULL;
1061
1062 n_fors = count_list_fors(c, n);
1063 if (n_fors == -1)
1064 return NULL;
1065
1066 listcomps = asdl_seq_new(n_fors, c->c_arena);
1067 if (!listcomps)
1068 return NULL;
1069
1070 ch = CHILD(n, 1);
1071 for (i = 0; i < n_fors; i++) {
1072 comprehension_ty lc;
1073 asdl_seq *t;
1074 expr_ty expression;
1075 node *for_ch;
1076
1077 REQ(ch, list_for);
1078
1079 for_ch = CHILD(ch, 1);
1080 t = ast_for_exprlist(c, for_ch, Store);
1081 if (!t)
1082 return NULL;
1083 expression = ast_for_testlist(c, CHILD(ch, 3));
1084 if (!expression)
1085 return NULL;
1086
1087 /* Check the # of children rather than the length of t, since
1088 [x for x, in ... ] has 1 element in t, but still requires a Tuple.
1089 */
1090 first = (expr_ty)asdl_seq_GET(t, 0);
1091 if (NCH(for_ch) == 1)
1092 lc = comprehension(first, expression, NULL, c->c_arena);
1093 else
1094 lc = comprehension(Tuple(t, Store, first->lineno, first->col_offset,
1095 c->c_arena),
1096 expression, NULL, c->c_arena);
1097 if (!lc)
1098 return NULL;
1099
1100 if (NCH(ch) == 5) {
1101 int j, n_ifs;
1102 asdl_seq *ifs;
1103 expr_ty list_for_expr;
1104
1105 ch = CHILD(ch, 4);
1106 n_ifs = count_list_ifs(c, ch);
1107 if (n_ifs == -1)
1108 return NULL;
1109
1110 ifs = asdl_seq_new(n_ifs, c->c_arena);
1111 if (!ifs)
1112 return NULL;
1113
1114 for (j = 0; j < n_ifs; j++) {
1115 REQ(ch, list_iter);
1116 ch = CHILD(ch, 0);
1117 REQ(ch, list_if);
1118
1119 list_for_expr = ast_for_expr(c, CHILD(ch, 1));
1120 if (!list_for_expr)
1121 return NULL;
1122
1123 asdl_seq_SET(ifs, j, list_for_expr);
1124 if (NCH(ch) == 3)
1125 ch = CHILD(ch, 2);
1126 }
1127 /* on exit, must guarantee that ch is a list_for */
1128 if (TYPE(ch) == list_iter)
1129 ch = CHILD(ch, 0);
1130 lc->ifs = ifs;
1131 }
1132 asdl_seq_SET(listcomps, i, lc);
1133 }
1134
1135 return ListComp(elt, listcomps, LINENO(n), n->n_col_offset, c->c_arena);
1136 }
1137
1138 /* Count the number of 'for' loops in a generator expression.
1139
1140 Helper for ast_for_genexp().
1141 */
1142
1143 static int
1144 count_gen_fors(struct compiling *c, const node *n)
1145 {
1146 int n_fors = 0;
1147 node *ch = CHILD(n, 1);
1148
1149 count_gen_for:
1150 n_fors++;
1151 REQ(ch, gen_for);
1152 if (NCH(ch) == 5)
1153 ch = CHILD(ch, 4);
1154 else
1155 return n_fors;
1156 count_gen_iter:
1157 REQ(ch, gen_iter);
1158 ch = CHILD(ch, 0);
1159 if (TYPE(ch) == gen_for)
1160 goto count_gen_for;
1161 else if (TYPE(ch) == gen_if) {
1162 if (NCH(ch) == 3) {
1163 ch = CHILD(ch, 2);
1164 goto count_gen_iter;
1165 }
1166 else
1167 return n_fors;
1168 }
1169
1170 /* Should never be reached */
1171 PyErr_SetString(PyExc_SystemError,
1172 "logic error in count_gen_fors");
1173 return -1;
1174 }
1175
1176 /* Count the number of 'if' statements in a generator expression.
1177
1178 Helper for ast_for_genexp().
1179 */
1180
1181 static int
1182 count_gen_ifs(struct compiling *c, const node *n)
1183 {
1184 int n_ifs = 0;
1185
1186 while (1) {
1187 REQ(n, gen_iter);
1188 if (TYPE(CHILD(n, 0)) == gen_for)
1189 return n_ifs;
1190 n = CHILD(n, 0);
1191 REQ(n, gen_if);
1192 n_ifs++;
1193 if (NCH(n) == 2)
1194 return n_ifs;
1195 n = CHILD(n, 2);
1196 }
1197 }
1198
1199 /* TODO(jhylton): Combine with list comprehension code? */
1200 static expr_ty
1201 ast_for_genexp(struct compiling *c, const node *n)
1202 {
1203 /* testlist_gexp: test ( gen_for | (',' test)* [','] )
1204 argument: [test '='] test [gen_for] # Really [keyword '='] test */
1205 expr_ty elt;
1206 asdl_seq *genexps;
1207 int i, n_fors;
1208 node *ch;
1209
1210 assert(TYPE(n) == (testlist_gexp) || TYPE(n) == (argument));
1211 assert(NCH(n) > 1);
1212
1213 elt = ast_for_expr(c, CHILD(n, 0));
1214 if (!elt)
1215 return NULL;
1216
1217 n_fors = count_gen_fors(c, n);
1218 if (n_fors == -1)
1219 return NULL;
1220
1221 genexps = asdl_seq_new(n_fors, c->c_arena);
1222 if (!genexps)
1223 return NULL;
1224
1225 ch = CHILD(n, 1);
1226 for (i = 0; i < n_fors; i++) {
1227 comprehension_ty ge;
1228 asdl_seq *t;
1229 expr_ty expression, first;
1230 node *for_ch;
1231
1232 REQ(ch, gen_for);
1233
1234 for_ch = CHILD(ch, 1);
1235 t = ast_for_exprlist(c, for_ch, Store);
1236 if (!t)
1237 return NULL;
1238 expression = ast_for_expr(c, CHILD(ch, 3));
1239 if (!expression)
1240 return NULL;
1241
1242 /* Check the # of children rather than the length of t, since
1243 (x for x, in ...) has 1 element in t, but still requires a Tuple. */
1244 first = (expr_ty)asdl_seq_GET(t, 0);
1245 if (NCH(for_ch) == 1)
1246 ge = comprehension(first, expression, NULL, c->c_arena);
1247 else
1248 ge = comprehension(Tuple(t, Store, first->lineno, first->col_offset,
1249 c->c_arena),
1250 expression, NULL, c->c_arena);
1251
1252 if (!ge)
1253 return NULL;
1254
1255 if (NCH(ch) == 5) {
1256 int j, n_ifs;
1257 asdl_seq *ifs;
1258
1259 ch = CHILD(ch, 4);
1260 n_ifs = count_gen_ifs(c, ch);
1261 if (n_ifs == -1)
1262 return NULL;
1263
1264 ifs = asdl_seq_new(n_ifs, c->c_arena);
1265 if (!ifs)
1266 return NULL;
1267
1268 for (j = 0; j < n_ifs; j++) {
1269 REQ(ch, gen_iter);
1270 ch = CHILD(ch, 0);
1271 REQ(ch, gen_if);
1272
1273 expression = ast_for_expr(c, CHILD(ch, 1));
1274 if (!expression)
1275 return NULL;
1276 asdl_seq_SET(ifs, j, expression);
1277 if (NCH(ch) == 3)
1278 ch = CHILD(ch, 2);
1279 }
1280 /* on exit, must guarantee that ch is a gen_for */
1281 if (TYPE(ch) == gen_iter)
1282 ch = CHILD(ch, 0);
1283 ge->ifs = ifs;
1284 }
1285 asdl_seq_SET(genexps, i, ge);
1286 }
1287
1288 return GeneratorExp(elt, genexps, LINENO(n), n->n_col_offset, c->c_arena);
1289 }
1290
1291 static expr_ty
1292 ast_for_atom(struct compiling *c, const node *n)
1293 {
1294 /* atom: '(' [yield_expr|testlist_gexp] ')' | '[' [listmaker] ']'
1295 | '{' [dictmaker] '}' | '`' testlist '`' | NAME | NUMBER | STRING+
1296 */
1297 node *ch = CHILD(n, 0);
1298
1299 switch (TYPE(ch)) {
1300 case NAME: {
1301 /* All names start in Load context, but may later be
1302 changed. */
1303 PyObject *name = NEW_IDENTIFIER(ch);
1304 if (!name)
1305 return NULL;
1306 return Name(name, Load, LINENO(n), n->n_col_offset, c->c_arena);
1307 }
1308 case STRING: {
1309 PyObject *str = parsestrplus(c, n);
1310 if (!str) {
1311 #ifdef Py_USING_UNICODE
1312 if (PyErr_ExceptionMatches(PyExc_UnicodeError)){
1313 PyObject *type, *value, *tback, *errstr;
1314 PyErr_Fetch(&type, &value, &tback);
1315 errstr = PyObject_Str(value);
1316 if (errstr) {
1317 char *s = "";
1318 char buf[128];
1319 s = PyString_AsString(errstr);
1320 PyOS_snprintf(buf, sizeof(buf), "(unicode error) %s", s);
1321 ast_error(n, buf);
1322 Py_DECREF(errstr);
1323 } else {
1324 ast_error(n, "(unicode error) unknown error");
1325 }
1326 Py_DECREF(type);
1327 Py_DECREF(value);
1328 Py_XDECREF(tback);
1329 }
1330 #endif
1331 return NULL;
1332 }
1333 PyArena_AddPyObject(c->c_arena, str);
1334 return Str(str, LINENO(n), n->n_col_offset, c->c_arena);
1335 }
1336 case NUMBER: {
1337 PyObject *pynum = parsenumber(c, STR(ch));
1338 if (!pynum)
1339 return NULL;
1340
1341 PyArena_AddPyObject(c->c_arena, pynum);
1342 return Num(pynum, LINENO(n), n->n_col_offset, c->c_arena);
1343 }
1344 case LPAR: /* some parenthesized expressions */
1345 ch = CHILD(n, 1);
1346
1347 if (TYPE(ch) == RPAR)
1348 return Tuple(NULL, Load, LINENO(n), n->n_col_offset, c->c_arena);
1349
1350 if (TYPE(ch) == yield_expr)
1351 return ast_for_expr(c, ch);
1352
1353 return ast_for_testlist_gexp(c, ch);
1354 case LSQB: /* list (or list comprehension) */
1355 ch = CHILD(n, 1);
1356
1357 if (TYPE(ch) == RSQB)
1358 return List(NULL, Load, LINENO(n), n->n_col_offset, c->c_arena);
1359
1360 REQ(ch, listmaker);
1361 if (NCH(ch) == 1 || TYPE(CHILD(ch, 1)) == COMMA) {
1362 asdl_seq *elts = seq_for_testlist(c, ch);
1363 if (!elts)
1364 return NULL;
1365
1366 return List(elts, Load, LINENO(n), n->n_col_offset, c->c_arena);
1367 }
1368 else
1369 return ast_for_listcomp(c, ch);
1370 case LBRACE: {
1371 /* dictmaker: test ':' test (',' test ':' test)* [','] */
1372 int i, size;
1373 asdl_seq *keys, *values;
1374
1375 ch = CHILD(n, 1);
1376 size = (NCH(ch) + 1) / 4; /* +1 in case no trailing comma */
1377 keys = asdl_seq_new(size, c->c_arena);
1378 if (!keys)
1379 return NULL;
1380
1381 values = asdl_seq_new(size, c->c_arena);
1382 if (!values)
1383 return NULL;
1384
1385 for (i = 0; i < NCH(ch); i += 4) {
1386 expr_ty expression;
1387
1388 expression = ast_for_expr(c, CHILD(ch, i));
1389 if (!expression)
1390 return NULL;
1391
1392 asdl_seq_SET(keys, i / 4, expression);
1393
1394 expression = ast_for_expr(c, CHILD(ch, i + 2));
1395 if (!expression)
1396 return NULL;
1397
1398 asdl_seq_SET(values, i / 4, expression);
1399 }
1400 return Dict(keys, values, LINENO(n), n->n_col_offset, c->c_arena);
1401 }
1402 case BACKQUOTE: { /* repr */
1403 expr_ty expression;
1404 if (Py_Py3kWarningFlag &&
1405 !ast_warn(c, n, "backquote not supported in 3.x; use repr()"))
1406 return NULL;
1407 expression = ast_for_testlist(c, CHILD(n, 1));
1408 if (!expression)
1409 return NULL;
1410
1411 return Repr(expression, LINENO(n), n->n_col_offset, c->c_arena);
1412 }
1413 default:
1414 PyErr_Format(PyExc_SystemError, "unhandled atom %d", TYPE(ch));
1415 return NULL;
1416 }
1417 }
1418
1419 static slice_ty
1420 ast_for_slice(struct compiling *c, const node *n)
1421 {
1422 node *ch;
1423 expr_ty lower = NULL, upper = NULL, step = NULL;
1424
1425 REQ(n, subscript);
1426
1427 /*
1428 subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
1429 sliceop: ':' [test]
1430 */
1431 ch = CHILD(n, 0);
1432 if (TYPE(ch) == DOT)
1433 return Ellipsis(c->c_arena);
1434
1435 if (NCH(n) == 1 && TYPE(ch) == test) {
1436 /* 'step' variable hold no significance in terms of being used over
1437 other vars */
1438 step = ast_for_expr(c, ch);
1439 if (!step)
1440 return NULL;
1441
1442 return Index(step, c->c_arena);
1443 }
1444
1445 if (TYPE(ch) == test) {
1446 lower = ast_for_expr(c, ch);
1447 if (!lower)
1448 return NULL;
1449 }
1450
1451 /* If there's an upper bound it's in the second or third position. */
1452 if (TYPE(ch) == COLON) {
1453 if (NCH(n) > 1) {
1454 node *n2 = CHILD(n, 1);
1455
1456 if (TYPE(n2) == test) {
1457 upper = ast_for_expr(c, n2);
1458 if (!upper)
1459 return NULL;
1460 }
1461 }
1462 } else if (NCH(n) > 2) {
1463 node *n2 = CHILD(n, 2);
1464
1465 if (TYPE(n2) == test) {
1466 upper = ast_for_expr(c, n2);
1467 if (!upper)
1468 return NULL;
1469 }
1470 }
1471
1472 ch = CHILD(n, NCH(n) - 1);
1473 if (TYPE(ch) == sliceop) {
1474 if (NCH(ch) == 1) {
1475 /*
1476 This is an extended slice (ie "x[::]") with no expression in the
1477 step field. We set this literally to "None" in order to
1478 disambiguate it from x[:]. (The interpreter might have to call
1479 __getslice__ for x[:], but it must call __getitem__ for x[::].)
1480 */
1481 identifier none = new_identifier("None", c->c_arena);
1482 if (!none)
1483 return NULL;
1484 ch = CHILD(ch, 0);
1485 step = Name(none, Load, LINENO(ch), ch->n_col_offset, c->c_arena);
1486 if (!step)
1487 return NULL;
1488 } else {
1489 ch = CHILD(ch, 1);
1490 if (TYPE(ch) == test) {
1491 step = ast_for_expr(c, ch);
1492 if (!step)
1493 return NULL;
1494 }
1495 }
1496 }
1497
1498 return Slice(lower, upper, step, c->c_arena);
1499 }
1500
1501 static expr_ty
1502 ast_for_binop(struct compiling *c, const node *n)
1503 {
1504 /* Must account for a sequence of expressions.
1505 How should A op B op C by represented?
1506 BinOp(BinOp(A, op, B), op, C).
1507 */
1508
1509 int i, nops;
1510 expr_ty expr1, expr2, result;
1511 operator_ty newoperator;
1512
1513 expr1 = ast_for_expr(c, CHILD(n, 0));
1514 if (!expr1)
1515 return NULL;
1516
1517 expr2 = ast_for_expr(c, CHILD(n, 2));
1518 if (!expr2)
1519 return NULL;
1520
1521 newoperator = get_operator(CHILD(n, 1));
1522 if (!newoperator)
1523 return NULL;
1524
1525 result = BinOp(expr1, newoperator, expr2, LINENO(n), n->n_col_offset,
1526 c->c_arena);
1527 if (!result)
1528 return NULL;
1529
1530 nops = (NCH(n) - 1) / 2;
1531 for (i = 1; i < nops; i++) {
1532 expr_ty tmp_result, tmp;
1533 const node* next_oper = CHILD(n, i * 2 + 1);
1534
1535 newoperator = get_operator(next_oper);
1536 if (!newoperator)
1537 return NULL;
1538
1539 tmp = ast_for_expr(c, CHILD(n, i * 2 + 2));
1540 if (!tmp)
1541 return NULL;
1542
1543 tmp_result = BinOp(result, newoperator, tmp,
1544 LINENO(next_oper), next_oper->n_col_offset,
1545 c->c_arena);
1546 if (!tmp_result)
1547 return NULL;
1548 result = tmp_result;
1549 }
1550 return result;
1551 }
1552
1553 static expr_ty
1554 ast_for_trailer(struct compiling *c, const node *n, expr_ty left_expr)
1555 {
1556 /* trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
1557 subscriptlist: subscript (',' subscript)* [',']
1558 subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
1559 */
1560 REQ(n, trailer);
1561 if (TYPE(CHILD(n, 0)) == LPAR) {
1562 if (NCH(n) == 2)
1563 return Call(left_expr, NULL, NULL, NULL, NULL, LINENO(n),
1564 n->n_col_offset, c->c_arena);
1565 else
1566 return ast_for_call(c, CHILD(n, 1), left_expr);
1567 }
1568 else if (TYPE(CHILD(n, 0)) == DOT ) {
1569 PyObject *attr_id = NEW_IDENTIFIER(CHILD(n, 1));
1570 if (!attr_id)
1571 return NULL;
1572 return Attribute(left_expr, attr_id, Load,
1573 LINENO(n), n->n_col_offset, c->c_arena);
1574 }
1575 else {
1576 REQ(CHILD(n, 0), LSQB);
1577 REQ(CHILD(n, 2), RSQB);
1578 n = CHILD(n, 1);
1579 if (NCH(n) == 1) {
1580 slice_ty slc = ast_for_slice(c, CHILD(n, 0));
1581 if (!slc)
1582 return NULL;
1583 return Subscript(left_expr, slc, Load, LINENO(n), n->n_col_offset,
1584 c->c_arena);
1585 }
1586 else {
1587 /* The grammar is ambiguous here. The ambiguity is resolved
1588 by treating the sequence as a tuple literal if there are
1589 no slice features.
1590 */
1591 int j;
1592 slice_ty slc;
1593 expr_ty e;
1594 bool simple = true;
1595 asdl_seq *slices, *elts;
1596 slices = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
1597 if (!slices)
1598 return NULL;
1599 for (j = 0; j < NCH(n); j += 2) {
1600 slc = ast_for_slice(c, CHILD(n, j));
1601 if (!slc)
1602 return NULL;
1603 if (slc->kind != Index_kind)
1604 simple = false;
1605 asdl_seq_SET(slices, j / 2, slc);
1606 }
1607 if (!simple) {
1608 return Subscript(left_expr, ExtSlice(slices, c->c_arena),
1609 Load, LINENO(n), n->n_col_offset, c->c_arena);
1610 }
1611 /* extract Index values and put them in a Tuple */
1612 elts = asdl_seq_new(asdl_seq_LEN(slices), c->c_arena);
1613 if (!elts)
1614 return NULL;
1615 for (j = 0; j < asdl_seq_LEN(slices); ++j) {
1616 slc = (slice_ty)asdl_seq_GET(slices, j);
1617 assert(slc->kind == Index_kind && slc->v.Index.value);
1618 asdl_seq_SET(elts, j, slc->v.Index.value);
1619 }
1620 e = Tuple(elts, Load, LINENO(n), n->n_col_offset, c->c_arena);
1621 if (!e)
1622 return NULL;
1623 return Subscript(left_expr, Index(e, c->c_arena),
1624 Load, LINENO(n), n->n_col_offset, c->c_arena);
1625 }
1626 }
1627 }
1628
1629 static expr_ty
1630 ast_for_factor(struct compiling *c, const node *n)
1631 {
1632 node *pfactor, *ppower, *patom, *pnum;
1633 expr_ty expression;
1634
1635 /* If the unary - operator is applied to a constant, don't generate
1636 a UNARY_NEGATIVE opcode. Just store the approriate value as a
1637 constant. The peephole optimizer already does something like
1638 this but it doesn't handle the case where the constant is
1639 (sys.maxint - 1). In that case, we want a PyIntObject, not a
1640 PyLongObject.
1641 */
1642 if (TYPE(CHILD(n, 0)) == MINUS &&
1643 NCH(n) == 2 &&
1644 TYPE((pfactor = CHILD(n, 1))) == factor &&
1645 NCH(pfactor) == 1 &&
1646 TYPE((ppower = CHILD(pfactor, 0))) == power &&
1647 NCH(ppower) == 1 &&
1648 TYPE((patom = CHILD(ppower, 0))) == atom &&
1649 TYPE((pnum = CHILD(patom, 0))) == NUMBER) {
1650 char *s = PyObject_MALLOC(strlen(STR(pnum)) + 2);
1651 if (s == NULL)
1652 return NULL;
1653 s[0] = '-';
1654 strcpy(s + 1, STR(pnum));
1655 PyObject_FREE(STR(pnum));
1656 STR(pnum) = s;
1657 return ast_for_atom(c, patom);
1658 }
1659
1660 expression = ast_for_expr(c, CHILD(n, 1));
1661 if (!expression)
1662 return NULL;
1663
1664 switch (TYPE(CHILD(n, 0))) {
1665 case PLUS:
1666 return UnaryOp(UAdd, expression, LINENO(n), n->n_col_offset,
1667 c->c_arena);
1668 case MINUS:
1669 return UnaryOp(USub, expression, LINENO(n), n->n_col_offset,
1670 c->c_arena);
1671 case TILDE:
1672 return UnaryOp(Invert, expression, LINENO(n),
1673 n->n_col_offset, c->c_arena);
1674 }
1675 PyErr_Format(PyExc_SystemError, "unhandled factor: %d",
1676 TYPE(CHILD(n, 0)));
1677 return NULL;
1678 }
1679
1680 static expr_ty
1681 ast_for_power(struct compiling *c, const node *n)
1682 {
1683 /* power: atom trailer* ('**' factor)*
1684 */
1685 int i;
1686 expr_ty e, tmp;
1687 REQ(n, power);
1688 e = ast_for_atom(c, CHILD(n, 0));
1689 if (!e)
1690 return NULL;
1691 if (NCH(n) == 1)
1692 return e;
1693 for (i = 1; i < NCH(n); i++) {
1694 node *ch = CHILD(n, i);
1695 if (TYPE(ch) != trailer)
1696 break;
1697 tmp = ast_for_trailer(c, ch, e);
1698 if (!tmp)
1699 return NULL;
1700 tmp->lineno = e->lineno;
1701 tmp->col_offset = e->col_offset;
1702 e = tmp;
1703 }
1704 if (TYPE(CHILD(n, NCH(n) - 1)) == factor) {
1705 expr_ty f = ast_for_expr(c, CHILD(n, NCH(n) - 1));
1706 if (!f)
1707 return NULL;
1708 tmp = BinOp(e, Pow, f, LINENO(n), n->n_col_offset, c->c_arena);
1709 if (!tmp)
1710 return NULL;
1711 e = tmp;
1712 }
1713 return e;
1714 }
1715
1716 /* Do not name a variable 'expr'! Will cause a compile error.
1717 */
1718
1719 static expr_ty
1720 ast_for_expr(struct compiling *c, const node *n)
1721 {
1722 /* handle the full range of simple expressions
1723 test: or_test ['if' or_test 'else' test] | lambdef
1724 or_test: and_test ('or' and_test)*
1725 and_test: not_test ('and' not_test)*
1726 not_test: 'not' not_test | comparison
1727 comparison: expr (comp_op expr)*
1728 expr: xor_expr ('|' xor_expr)*
1729 xor_expr: and_expr ('^' and_expr)*
1730 and_expr: shift_expr ('&' shift_expr)*
1731 shift_expr: arith_expr (('<<'|'>>') arith_expr)*
1732 arith_expr: term (('+'|'-') term)*
1733 term: factor (('*'|'/'|'%'|'//') factor)*
1734 factor: ('+'|'-'|'~') factor | power
1735 power: atom trailer* ('**' factor)*
1736
1737 As well as modified versions that exist for backward compatibility,
1738 to explicitly allow:
1739 [ x for x in lambda: 0, lambda: 1 ]
1740 (which would be ambiguous without these extra rules)
1741
1742 old_test: or_test | old_lambdef
1743 old_lambdef: 'lambda' [vararglist] ':' old_test
1744
1745 */
1746
1747 asdl_seq *seq;
1748 int i;
1749
1750 loop:
1751 switch (TYPE(n)) {
1752 case test:
1753 case old_test:
1754 if (TYPE(CHILD(n, 0)) == lambdef ||
1755 TYPE(CHILD(n, 0)) == old_lambdef)
1756 return ast_for_lambdef(c, CHILD(n, 0));
1757 else if (NCH(n) > 1)
1758 return ast_for_ifexpr(c, n);
1759 /* Fallthrough */
1760 case or_test:
1761 case and_test:
1762 if (NCH(n) == 1) {
1763 n = CHILD(n, 0);
1764 goto loop;
1765 }
1766 seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
1767 if (!seq)
1768 return NULL;
1769 for (i = 0; i < NCH(n); i += 2) {
1770 expr_ty e = ast_for_expr(c, CHILD(n, i));
1771 if (!e)
1772 return NULL;
1773 asdl_seq_SET(seq, i / 2, e);
1774 }
1775 if (!strcmp(STR(CHILD(n, 1)), "and"))
1776 return BoolOp(And, seq, LINENO(n), n->n_col_offset,
1777 c->c_arena);
1778 assert(!strcmp(STR(CHILD(n, 1)), "or"));
1779 return BoolOp(Or, seq, LINENO(n), n->n_col_offset, c->c_arena);
1780 case not_test:
1781 if (NCH(n) == 1) {
1782 n = CHILD(n, 0);
1783 goto loop;
1784 }
1785 else {
1786 expr_ty expression = ast_for_expr(c, CHILD(n, 1));
1787 if (!expression)
1788 return NULL;
1789
1790 return UnaryOp(Not, expression, LINENO(n), n->n_col_offset,
1791 c->c_arena);
1792 }
1793 case comparison:
1794 if (NCH(n) == 1) {
1795 n = CHILD(n, 0);
1796 goto loop;
1797 }
1798 else {
1799 expr_ty expression;
1800 asdl_int_seq *ops;
1801 asdl_seq *cmps;
1802 ops = asdl_int_seq_new(NCH(n) / 2, c->c_arena);
1803 if (!ops)
1804 return NULL;
1805 cmps = asdl_seq_new(NCH(n) / 2, c->c_arena);
1806 if (!cmps) {
1807 return NULL;
1808 }
1809 for (i = 1; i < NCH(n); i += 2) {
1810 cmpop_ty newoperator;
1811
1812 newoperator = ast_for_comp_op(c, CHILD(n, i));
1813 if (!newoperator) {
1814 return NULL;
1815 }
1816
1817 expression = ast_for_expr(c, CHILD(n, i + 1));
1818 if (!expression) {
1819 return NULL;
1820 }
1821
1822 asdl_seq_SET(ops, i / 2, newoperator);
1823 asdl_seq_SET(cmps, i / 2, expression);
1824 }
1825 expression = ast_for_expr(c, CHILD(n, 0));
1826 if (!expression) {
1827 return NULL;
1828 }
1829
1830 return Compare(expression, ops, cmps, LINENO(n),
1831 n->n_col_offset, c->c_arena);
1832 }
1833 break;
1834
1835 /* The next five cases all handle BinOps. The main body of code
1836 is the same in each case, but the switch turned inside out to
1837 reuse the code for each type of operator.
1838 */
1839 case expr:
1840 case xor_expr:
1841 case and_expr:
1842 case shift_expr:
1843 case arith_expr:
1844 case term:
1845 if (NCH(n) == 1) {
1846 n = CHILD(n, 0);
1847 goto loop;
1848 }
1849 return ast_for_binop(c, n);
1850 case yield_expr: {
1851 expr_ty exp = NULL;
1852 if (NCH(n) == 2) {
1853 exp = ast_for_testlist(c, CHILD(n, 1));
1854 if (!exp)
1855 return NULL;
1856 }
1857 return Yield(exp, LINENO(n), n->n_col_offset, c->c_arena);
1858 }
1859 case factor:
1860 if (NCH(n) == 1) {
1861 n = CHILD(n, 0);
1862 goto loop;
1863 }
1864 return ast_for_factor(c, n);
1865 case power:
1866 return ast_for_power(c, n);
1867 default:
1868 PyErr_Format(PyExc_SystemError, "unhandled expr: %d", TYPE(n));
1869 return NULL;
1870 }
1871 /* should never get here unless if error is set */
1872 return NULL;
1873 }
1874
1875 static expr_ty
1876 ast_for_call(struct compiling *c, const node *n, expr_ty func)
1877 {
1878 /*
1879 arglist: (argument ',')* (argument [',']| '*' test [',' '**' test]
1880 | '**' test)
1881 argument: [test '='] test [gen_for] # Really [keyword '='] test
1882 */
1883
1884 int i, nargs, nkeywords, ngens;
1885 asdl_seq *args;
1886 asdl_seq *keywords;
1887 expr_ty vararg = NULL, kwarg = NULL;
1888
1889 REQ(n, arglist);
1890
1891 nargs = 0;
1892 nkeywords = 0;
1893 ngens = 0;
1894 for (i = 0; i < NCH(n); i++) {
1895 node *ch = CHILD(n, i);
1896 if (TYPE(ch) == argument) {
1897 if (NCH(ch) == 1)
1898 nargs++;
1899 else if (TYPE(CHILD(ch, 1)) == gen_for)
1900 ngens++;
1901 else
1902 nkeywords++;
1903 }
1904 }
1905 if (ngens > 1 || (ngens && (nargs || nkeywords))) {
1906 ast_error(n, "Generator expression must be parenthesized "
1907 "if not sole argument");
1908 return NULL;
1909 }
1910
1911 if (nargs + nkeywords + ngens > 255) {
1912 ast_error(n, "more than 255 arguments");
1913 return NULL;
1914 }
1915
1916 args = asdl_seq_new(nargs + ngens, c->c_arena);
1917 if (!args)
1918 return NULL;
1919 keywords = asdl_seq_new(nkeywords, c->c_arena);
1920 if (!keywords)
1921 return NULL;
1922 nargs = 0;
1923 nkeywords = 0;
1924 for (i = 0; i < NCH(n); i++) {
1925 node *ch = CHILD(n, i);
1926 if (TYPE(ch) == argument) {
1927 expr_ty e;
1928 if (NCH(ch) == 1) {
1929 if (nkeywords) {
1930 ast_error(CHILD(ch, 0),
1931 "non-keyword arg after keyword arg");
1932 return NULL;
1933 }
1934 if (vararg) {
1935 ast_error(CHILD(ch, 0),
1936 "only named arguments may follow *expression");
1937 return NULL;
1938 }
1939 e = ast_for_expr(c, CHILD(ch, 0));
1940 if (!e)
1941 return NULL;
1942 asdl_seq_SET(args, nargs++, e);
1943 }
1944 else if (TYPE(CHILD(ch, 1)) == gen_for) {
1945 e = ast_for_genexp(c, ch);
1946 if (!e)
1947 return NULL;
1948 asdl_seq_SET(args, nargs++, e);
1949 }
1950 else {
1951 keyword_ty kw;
1952 identifier key;
1953 int k;
1954 char *tmp;
1955
1956 /* CHILD(ch, 0) is test, but must be an identifier? */
1957 e = ast_for_expr(c, CHILD(ch, 0));
1958 if (!e)
1959 return NULL;
1960 /* f(lambda x: x[0] = 3) ends up getting parsed with
1961 * LHS test = lambda x: x[0], and RHS test = 3.
1962 * SF bug 132313 points out that complaining about a keyword
1963 * then is very confusing.
1964 */
1965 if (e->kind == Lambda_kind) {
1966 ast_error(CHILD(ch, 0),
1967 "lambda cannot contain assignment");
1968 return NULL;
1969 } else if (e->kind != Name_kind) {
1970 ast_error(CHILD(ch, 0), "keyword can't be an expression");
1971 return NULL;
1972 }
1973 key = e->v.Name.id;
1974 if (!forbidden_check(c, CHILD(ch, 0), PyBytes_AS_STRING(key)))
1975 return NULL;
1976 for (k = 0; k < nkeywords; k++) {
1977 tmp = PyString_AS_STRING(
1978 ((keyword_ty)asdl_seq_GET(keywords, k))->arg);
1979 if (!strcmp(tmp, PyString_AS_STRING(key))) {
1980 ast_error(CHILD(ch, 0), "keyword argument repeated");
1981 return NULL;
1982 }
1983 }
1984 e = ast_for_expr(c, CHILD(ch, 2));
1985 if (!e)
1986 return NULL;
1987 kw = keyword(key, e, c->c_arena);
1988 if (!kw)
1989 return NULL;
1990 asdl_seq_SET(keywords, nkeywords++, kw);
1991 }
1992 }
1993 else if (TYPE(ch) == STAR) {
1994 vararg = ast_for_expr(c, CHILD(n, i+1));
1995 if (!vararg)
1996 return NULL;
1997 i++;
1998 }
1999 else if (TYPE(ch) == DOUBLESTAR) {
2000 kwarg = ast_for_expr(c, CHILD(n, i+1));
2001 if (!kwarg)
2002 return NULL;
2003 i++;
2004 }
2005 }
2006
2007 return Call(func, args, keywords, vararg, kwarg, func->lineno,
2008 func->col_offset, c->c_arena);
2009 }
2010
2011 static expr_ty
2012 ast_for_testlist(struct compiling *c, const node* n)
2013 {
2014 /* testlist_gexp: test (',' test)* [','] */
2015 /* testlist: test (',' test)* [','] */
2016 /* testlist_safe: test (',' test)+ [','] */
2017 /* testlist1: test (',' test)* */
2018 assert(NCH(n) > 0);
2019 if (TYPE(n) == testlist_gexp) {
2020 if (NCH(n) > 1)
2021 assert(TYPE(CHILD(n, 1)) != gen_for);
2022 }
2023 else {
2024 assert(TYPE(n) == testlist ||
2025 TYPE(n) == testlist_safe ||
2026 TYPE(n) == testlist1);
2027 }
2028 if (NCH(n) == 1)
2029 return ast_for_expr(c, CHILD(n, 0));
2030 else {
2031 asdl_seq *tmp = seq_for_testlist(c, n);
2032 if (!tmp)
2033 return NULL;
2034 return Tuple(tmp, Load, LINENO(n), n->n_col_offset, c->c_arena);
2035 }
2036 }
2037
2038 static expr_ty
2039 ast_for_testlist_gexp(struct compiling *c, const node* n)
2040 {
2041 /* testlist_gexp: test ( gen_for | (',' test)* [','] ) */
2042 /* argument: test [ gen_for ] */
2043 assert(TYPE(n) == testlist_gexp || TYPE(n) == argument);
2044 if (NCH(n) > 1 && TYPE(CHILD(n, 1)) == gen_for)
2045 return ast_for_genexp(c, n);
2046 return ast_for_testlist(c, n);
2047 }
2048
2049 /* like ast_for_testlist() but returns a sequence */
2050 static asdl_seq*
2051 ast_for_class_bases(struct compiling *c, const node* n)
2052 {
2053 /* testlist: test (',' test)* [','] */
2054 assert(NCH(n) > 0);
2055 REQ(n, testlist);
2056 if (NCH(n) == 1) {
2057 expr_ty base;
2058 asdl_seq *bases = asdl_seq_new(1, c->c_arena);
2059 if (!bases)
2060 return NULL;
2061 base = ast_for_expr(c, CHILD(n, 0));
2062 if (!base)
2063 return NULL;
2064 asdl_seq_SET(bases, 0, base);
2065 return bases;
2066 }
2067
2068 return seq_for_testlist(c, n);
2069 }
2070
2071 static stmt_ty
2072 ast_for_expr_stmt(struct compiling *c, const node *n)
2073 {
2074 REQ(n, expr_stmt);
2075 /* expr_stmt: testlist (augassign (yield_expr|testlist)
2076 | ('=' (yield_expr|testlist))*)
2077 testlist: test (',' test)* [',']
2078 augassign: '+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^='
2079 | '<<=' | '>>=' | '**=' | '//='
2080 test: ... here starts the operator precendence dance
2081 */
2082
2083 if (NCH(n) == 1) {
2084 expr_ty e = ast_for_testlist(c, CHILD(n, 0));
2085 if (!e)
2086 return NULL;
2087
2088 return Expr(e, LINENO(n), n->n_col_offset, c->c_arena);
2089 }
2090 else if (TYPE(CHILD(n, 1)) == augassign) {
2091 expr_ty expr1, expr2;
2092 operator_ty newoperator;
2093 node *ch = CHILD(n, 0);
2094
2095 expr1 = ast_for_testlist(c, ch);
2096 if (!expr1)
2097 return NULL;
2098 if(!set_context(c, expr1, Store, ch))
2099 return NULL;
2100 /* set_context checks that most expressions are not the left side.
2101 Augmented assignments can only have a name, a subscript, or an
2102 attribute on the left, though, so we have to explicitly check for
2103 those. */
2104 switch (expr1->kind) {
2105 case Name_kind:
2106 case Attribute_kind:
2107 case Subscript_kind:
2108 break;
2109 default:
2110 ast_error(ch, "illegal expression for augmented assignment");
2111 return NULL;
2112 }
2113
2114 ch = CHILD(n, 2);
2115 if (TYPE(ch) == testlist)
2116 expr2 = ast_for_testlist(c, ch);
2117 else
2118 expr2 = ast_for_expr(c, ch);
2119 if (!expr2)
2120 return NULL;
2121
2122 newoperator = ast_for_augassign(c, CHILD(n, 1));
2123 if (!newoperator)
2124 return NULL;
2125
2126 return AugAssign(expr1, newoperator, expr2, LINENO(n), n->n_col_offset,
2127 c->c_arena);
2128 }
2129 else {
2130 int i;
2131 asdl_seq *targets;
2132 node *value;
2133 expr_ty expression;
2134
2135 /* a normal assignment */
2136 REQ(CHILD(n, 1), EQUAL);
2137 targets = asdl_seq_new(NCH(n) / 2, c->c_arena);
2138 if (!targets)
2139 return NULL;
2140 for (i = 0; i < NCH(n) - 2; i += 2) {
2141 expr_ty e;
2142 node *ch = CHILD(n, i);
2143 if (TYPE(ch) == yield_expr) {
2144 ast_error(ch, "assignment to yield expression not possible");
2145 return NULL;
2146 }
2147 e = ast_for_testlist(c, ch);
2148
2149 /* set context to assign */
2150 if (!e)
2151 return NULL;
2152
2153 if (!set_context(c, e, Store, CHILD(n, i)))
2154 return NULL;
2155
2156 asdl_seq_SET(targets, i / 2, e);
2157 }
2158 value = CHILD(n, NCH(n) - 1);
2159 if (TYPE(value) == testlist)
2160 expression = ast_for_testlist(c, value);
2161 else
2162 expression = ast_for_expr(c, value);
2163 if (!expression)
2164 return NULL;
2165 return Assign(targets, expression, LINENO(n), n->n_col_offset,
2166 c->c_arena);
2167 }
2168 }
2169
2170 static stmt_ty
2171 ast_for_print_stmt(struct compiling *c, const node *n)
2172 {
2173 /* print_stmt: 'print' ( [ test (',' test)* [','] ]
2174 | '>>' test [ (',' test)+ [','] ] )
2175 */
2176 expr_ty dest = NULL, expression;
2177 asdl_seq *seq = NULL;
2178 bool nl;
2179 int i, j, values_count, start = 1;
2180
2181 REQ(n, print_stmt);
2182 if (NCH(n) >= 2 && TYPE(CHILD(n, 1)) == RIGHTSHIFT) {
2183 dest = ast_for_expr(c, CHILD(n, 2));
2184 if (!dest)
2185 return NULL;
2186 start = 4;
2187 }
2188 values_count = (NCH(n) + 1 - start) / 2;
2189 if (values_count) {
2190 seq = asdl_seq_new(values_count, c->c_arena);
2191 if (!seq)
2192 return NULL;
2193 for (i = start, j = 0; i < NCH(n); i += 2, ++j) {
2194 expression = ast_for_expr(c, CHILD(n, i));
2195 if (!expression)
2196 return NULL;
2197 asdl_seq_SET(seq, j, expression);
2198 }
2199 }
2200 nl = (TYPE(CHILD(n, NCH(n) - 1)) == COMMA) ? false : true;
2201 return Print(dest, seq, nl, LINENO(n), n->n_col_offset, c->c_arena);
2202 }
2203
2204 static asdl_seq *
2205 ast_for_exprlist(struct compiling *c, const node *n, expr_context_ty context)
2206 {
2207 asdl_seq *seq;
2208 int i;
2209 expr_ty e;
2210
2211 REQ(n, exprlist);
2212
2213 seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
2214 if (!seq)
2215 return NULL;
2216 for (i = 0; i < NCH(n); i += 2) {
2217 e = ast_for_expr(c, CHILD(n, i));
2218 if (!e)
2219 return NULL;
2220 asdl_seq_SET(seq, i / 2, e);
2221 if (context && !set_context(c, e, context, CHILD(n, i)))
2222 return NULL;
2223 }
2224 return seq;
2225 }
2226
2227 static stmt_ty
2228 ast_for_del_stmt(struct compiling *c, const node *n)
2229 {
2230 asdl_seq *expr_list;
2231
2232 /* del_stmt: 'del' exprlist */
2233 REQ(n, del_stmt);
2234
2235 expr_list = ast_for_exprlist(c, CHILD(n, 1), Del);
2236 if (!expr_list)
2237 return NULL;
2238 return Delete(expr_list, LINENO(n), n->n_col_offset, c->c_arena);
2239 }
2240
2241 static stmt_ty
2242 ast_for_flow_stmt(struct compiling *c, const node *n)
2243 {
2244 /*
2245 flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt
2246 | yield_stmt
2247 break_stmt: 'break'
2248 continue_stmt: 'continue'
2249 return_stmt: 'return' [testlist]
2250 yield_stmt: yield_expr
2251 yield_expr: 'yield' testlist
2252 raise_stmt: 'raise' [test [',' test [',' test]]]
2253 */
2254 node *ch;
2255
2256 REQ(n, flow_stmt);
2257 ch = CHILD(n, 0);
2258 switch (TYPE(ch)) {
2259 case break_stmt:
2260 return Break(LINENO(n), n->n_col_offset, c->c_arena);
2261 case continue_stmt:
2262 return Continue(LINENO(n), n->n_col_offset, c->c_arena);
2263 case yield_stmt: { /* will reduce to yield_expr */
2264 expr_ty exp = ast_for_expr(c, CHILD(ch, 0));
2265 if (!exp)
2266 return NULL;
2267 return Expr(exp, LINENO(n), n->n_col_offset, c->c_arena);
2268 }
2269 case return_stmt:
2270 if (NCH(ch) == 1)
2271 return Return(NULL, LINENO(n), n->n_col_offset, c->c_arena);
2272 else {
2273 expr_ty expression = ast_for_testlist(c, CHILD(ch, 1));
2274 if (!expression)
2275 return NULL;
2276 return Return(expression, LINENO(n), n->n_col_offset,
2277 c->c_arena);
2278 }
2279 case raise_stmt:
2280 if (NCH(ch) == 1)
2281 return Raise(NULL, NULL, NULL, LINENO(n), n->n_col_offset,
2282 c->c_arena);
2283 else if (NCH(ch) == 2) {
2284 expr_ty expression = ast_for_expr(c, CHILD(ch, 1));
2285 if (!expression)
2286 return NULL;
2287 return Raise(expression, NULL, NULL, LINENO(n),
2288 n->n_col_offset, c->c_arena);
2289 }
2290 else if (NCH(ch) == 4) {
2291 expr_ty expr1, expr2;
2292
2293 expr1 = ast_for_expr(c, CHILD(ch, 1));
2294 if (!expr1)
2295 return NULL;
2296 expr2 = ast_for_expr(c, CHILD(ch, 3));
2297 if (!expr2)
2298 return NULL;
2299
2300 return Raise(expr1, expr2, NULL, LINENO(n), n->n_col_offset,
2301 c->c_arena);
2302 }
2303 else if (NCH(ch) == 6) {
2304 expr_ty expr1, expr2, expr3;
2305
2306 expr1 = ast_for_expr(c, CHILD(ch, 1));
2307 if (!expr1)
2308 return NULL;
2309 expr2 = ast_for_expr(c, CHILD(ch, 3));
2310 if (!expr2)
2311 return NULL;
2312 expr3 = ast_for_expr(c, CHILD(ch, 5));
2313 if (!expr3)
2314 return NULL;
2315
2316 return Raise(expr1, expr2, expr3, LINENO(n), n->n_col_offset,
2317 c->c_arena);
2318 }
2319 default:
2320 PyErr_Format(PyExc_SystemError,
2321 "unexpected flow_stmt: %d", TYPE(ch));
2322 return NULL;
2323 }
2324
2325 PyErr_SetString(PyExc_SystemError, "unhandled flow statement");
2326 return NULL;
2327 }
2328
2329 static alias_ty
2330 alias_for_import_name(struct compiling *c, const node *n, int store)
2331 {
2332 /*
2333 import_as_name: NAME ['as' NAME]
2334 dotted_as_name: dotted_name ['as' NAME]
2335 dotted_name: NAME ('.' NAME)*
2336 */
2337 PyObject *str, *name;
2338
2339 loop:
2340 switch (TYPE(n)) {
2341 case import_as_name: {
2342 node *name_node = CHILD(n, 0);
2343 str = NULL;
2344 if (NCH(n) == 3) {
2345 node *str_node = CHILD(n, 2);
2346 if (store && !forbidden_check(c, str_node, STR(str_node)))
2347 return NULL;
2348 str = NEW_IDENTIFIER(str_node);
2349 if (!str)
2350 return NULL;
2351 }
2352 else {
2353 if (!forbidden_check(c, name_node, STR(name_node)))
2354 return NULL;
2355 }
2356 name = NEW_IDENTIFIER(name_node);
2357 if (!name)
2358 return NULL;
2359 return alias(name, str, c->c_arena);
2360 }
2361 case dotted_as_name:
2362 if (NCH(n) == 1) {
2363 n = CHILD(n, 0);
2364 goto loop;
2365 }
2366 else {
2367 node *asname_node = CHILD(n, 2);
2368 alias_ty a = alias_for_import_name(c, CHILD(n, 0), 0);
2369 if (!a)
2370 return NULL;
2371 assert(!a->asname);
2372 if (!forbidden_check(c, asname_node, STR(asname_node)))
2373 return NULL;
2374 a->asname = NEW_IDENTIFIER(asname_node);
2375 if (!a->asname)
2376 return NULL;
2377 return a;
2378 }
2379 break;
2380 case dotted_name:
2381 if (NCH(n) == 1) {
2382 node *name_node = CHILD(n, 0);
2383 if (store && !forbidden_check(c, name_node, STR(name_node)))
2384 return NULL;
2385 name = NEW_IDENTIFIER(name_node);
2386 if (!name)
2387 return NULL;
2388 return alias(name, NULL, c->c_arena);
2389 }
2390 else {
2391 /* Create a string of the form "a.b.c" */
2392 int i;
2393 size_t len;
2394 char *s;
2395
2396 len = 0;
2397 for (i = 0; i < NCH(n); i += 2)
2398 /* length of string plus one for the dot */
2399 len += strlen(STR(CHILD(n, i))) + 1;
2400 len--; /* the last name doesn't have a dot */
2401 str = PyString_FromStringAndSize(NULL, len);
2402 if (!str)
2403 return NULL;
2404 s = PyString_AS_STRING(str);
2405 if (!s)
2406 return NULL;
2407 for (i = 0; i < NCH(n); i += 2) {
2408 char *sch = STR(CHILD(n, i));
2409 strcpy(s, STR(CHILD(n, i)));
2410 s += strlen(sch);
2411 *s++ = '.';
2412 }
2413 --s;
2414 *s = '\0';
2415 PyString_InternInPlace(&str);
2416 PyArena_AddPyObject(c->c_arena, str);
2417 return alias(str, NULL, c->c_arena);
2418 }
2419 break;
2420 case STAR:
2421 str = PyString_InternFromString("*");
2422 PyArena_AddPyObject(c->c_arena, str);
2423 return alias(str, NULL, c->c_arena);
2424 default:
2425 PyErr_Format(PyExc_SystemError,
2426 "unexpected import name: %d", TYPE(n));
2427 return NULL;
2428 }
2429
2430 PyErr_SetString(PyExc_SystemError, "unhandled import name condition");
2431 return NULL;
2432 }
2433
2434 static stmt_ty
2435 ast_for_import_stmt(struct compiling *c, const node *n)
2436 {
2437 /*
2438 import_stmt: import_name | import_from
2439 import_name: 'import' dotted_as_names
2440 import_from: 'from' ('.'* dotted_name | '.') 'import'
2441 ('*' | '(' import_as_names ')' | import_as_names)
2442 */
2443 int lineno;
2444 int col_offset;
2445 int i;
2446 asdl_seq *aliases;
2447
2448 REQ(n, import_stmt);
2449 lineno = LINENO(n);
2450 col_offset = n->n_col_offset;
2451 n = CHILD(n, 0);
2452 if (TYPE(n) == import_name) {
2453 n = CHILD(n, 1);
2454 REQ(n, dotted_as_names);
2455 aliases = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
2456 if (!aliases)
2457 return NULL;
2458 for (i = 0; i < NCH(n); i += 2) {
2459 alias_ty import_alias = alias_for_import_name(c, CHILD(n, i), 1);
2460 if (!import_alias)
2461 return NULL;
2462 asdl_seq_SET(aliases, i / 2, import_alias);
2463 }
2464 return Import(aliases, lineno, col_offset, c->c_arena);
2465 }
2466 else if (TYPE(n) == import_from) {
2467 int n_children;
2468 int idx, ndots = 0;
2469 alias_ty mod = NULL;
2470 identifier modname = NULL;
2471
2472 /* Count the number of dots (for relative imports) and check for the
2473 optional module name */
2474 for (idx = 1; idx < NCH(n); idx++) {
2475 if (TYPE(CHILD(n, idx)) == dotted_name) {
2476 mod = alias_for_import_name(c, CHILD(n, idx), 0);
2477 if (!mod)
2478 return NULL;
2479 idx++;
2480 break;
2481 } else if (TYPE(CHILD(n, idx)) != DOT) {
2482 break;
2483 }
2484 ndots++;
2485 }
2486 idx++; /* skip over the 'import' keyword */
2487 switch (TYPE(CHILD(n, idx))) {
2488 case STAR:
2489 /* from ... import * */
2490 n = CHILD(n, idx);
2491 n_children = 1;
2492 break;
2493 case LPAR:
2494 /* from ... import (x, y, z) */
2495 n = CHILD(n, idx + 1);
2496 n_children = NCH(n);
2497 break;
2498 case import_as_names:
2499 /* from ... import x, y, z */
2500 n = CHILD(n, idx);
2501 n_children = NCH(n);
2502 if (n_children % 2 == 0) {
2503 ast_error(n, "trailing comma not allowed without"
2504 " surrounding parentheses");
2505 return NULL;
2506 }
2507 break;
2508 default:
2509 ast_error(n, "Unexpected node-type in from-import");
2510 return NULL;
2511 }
2512
2513 aliases = asdl_seq_new((n_children + 1) / 2, c->c_arena);
2514 if (!aliases)
2515 return NULL;
2516
2517 /* handle "from ... import *" special b/c there's no children */
2518 if (TYPE(n) == STAR) {
2519 alias_ty import_alias = alias_for_import_name(c, n, 1);
2520 if (!import_alias)
2521 return NULL;
2522 asdl_seq_SET(aliases, 0, import_alias);
2523 }
2524 else {
2525 for (i = 0; i < NCH(n); i += 2) {
2526 alias_ty import_alias = alias_for_import_name(c, CHILD(n, i), 1);
2527 if (!import_alias)
2528 return NULL;
2529 asdl_seq_SET(aliases, i / 2, import_alias);
2530 }
2531 }
2532 if (mod != NULL)
2533 modname = mod->name;
2534 return ImportFrom(modname, aliases, ndots, lineno, col_offset,
2535 c->c_arena);
2536 }
2537 PyErr_Format(PyExc_SystemError,
2538 "unknown import statement: starts with command '%s'",
2539 STR(CHILD(n, 0)));
2540 return NULL;
2541 }
2542
2543 static stmt_ty
2544 ast_for_global_stmt(struct compiling *c, const node *n)
2545 {
2546 /* global_stmt: 'global' NAME (',' NAME)* */
2547 identifier name;
2548 asdl_seq *s;
2549 int i;
2550
2551 REQ(n, global_stmt);
2552 s = asdl_seq_new(NCH(n) / 2, c->c_arena);
2553 if (!s)
2554 return NULL;
2555 for (i = 1; i < NCH(n); i += 2) {
2556 name = NEW_IDENTIFIER(CHILD(n, i));
2557 if (!name)
2558 return NULL;
2559 asdl_seq_SET(s, i / 2, name);
2560 }
2561 return Global(s, LINENO(n), n->n_col_offset, c->c_arena);
2562 }
2563
2564 static stmt_ty
2565 ast_for_exec_stmt(struct compiling *c, const node *n)
2566 {
2567 expr_ty expr1, globals = NULL, locals = NULL;
2568 int n_children = NCH(n);
2569 if (n_children != 2 && n_children != 4 && n_children != 6) {
2570 PyErr_Format(PyExc_SystemError,
2571 "poorly formed 'exec' statement: %d parts to statement",
2572 n_children);
2573 return NULL;
2574 }
2575
2576 /* exec_stmt: 'exec' expr ['in' test [',' test]] */
2577 REQ(n, exec_stmt);
2578 expr1 = ast_for_expr(c, CHILD(n, 1));
2579 if (!expr1)
2580 return NULL;
2581 if (n_children >= 4) {
2582 globals = ast_for_expr(c, CHILD(n, 3));
2583 if (!globals)
2584 return NULL;
2585 }
2586 if (n_children == 6) {
2587 locals = ast_for_expr(c, CHILD(n, 5));
2588 if (!locals)
2589 return NULL;
2590 }
2591
2592 return Exec(expr1, globals, locals, LINENO(n), n->n_col_offset,
2593 c->c_arena);
2594 }
2595
2596 static stmt_ty
2597 ast_for_assert_stmt(struct compiling *c, const node *n)
2598 {
2599 /* assert_stmt: 'assert' test [',' test] */
2600 REQ(n, assert_stmt);
2601 if (NCH(n) == 2) {
2602 expr_ty expression = ast_for_expr(c, CHILD(n, 1));
2603 if (!expression)
2604 return NULL;
2605 return Assert(expression, NULL, LINENO(n), n->n_col_offset,
2606 c->c_arena);
2607 }
2608 else if (NCH(n) == 4) {
2609 expr_ty expr1, expr2;
2610
2611 expr1 = ast_for_expr(c, CHILD(n, 1));
2612 if (!expr1)
2613 return NULL;
2614 expr2 = ast_for_expr(c, CHILD(n, 3));
2615 if (!expr2)
2616 return NULL;
2617
2618 return Assert(expr1, expr2, LINENO(n), n->n_col_offset, c->c_arena);
2619 }
2620 PyErr_Format(PyExc_SystemError,
2621 "improper number of parts to 'assert' statement: %d",
2622 NCH(n));
2623 return NULL;
2624 }
2625
2626 static asdl_seq *
2627 ast_for_suite(struct compiling *c, const node *n)
2628 {
2629 /* suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT */
2630 asdl_seq *seq;
2631 stmt_ty s;
2632 int i, total, num, end, pos = 0;
2633 node *ch;
2634
2635 REQ(n, suite);
2636
2637 total = num_stmts(n);
2638 seq = asdl_seq_new(total, c->c_arena);
2639 if (!seq)
2640 return NULL;
2641 if (TYPE(CHILD(n, 0)) == simple_stmt) {
2642 n = CHILD(n, 0);
2643 /* simple_stmt always ends with a NEWLINE,
2644 and may have a trailing SEMI
2645 */
2646 end = NCH(n) - 1;
2647 if (TYPE(CHILD(n, end - 1)) == SEMI)
2648 end--;
2649 /* loop by 2 to skip semi-colons */
2650 for (i = 0; i < end; i += 2) {
2651 ch = CHILD(n, i);
2652 s = ast_for_stmt(c, ch);
2653 if (!s)
2654 return NULL;
2655 asdl_seq_SET(seq, pos++, s);
2656 }
2657 }
2658 else {
2659 for (i = 2; i < (NCH(n) - 1); i++) {
2660 ch = CHILD(n, i);
2661 REQ(ch, stmt);
2662 num = num_stmts(ch);
2663 if (num == 1) {
2664 /* small_stmt or compound_stmt with only one child */
2665 s = ast_for_stmt(c, ch);
2666 if (!s)
2667 return NULL;
2668 asdl_seq_SET(seq, pos++, s);
2669 }
2670 else {
2671 int j;
2672 ch = CHILD(ch, 0);
2673 REQ(ch, simple_stmt);
2674 for (j = 0; j < NCH(ch); j += 2) {
2675 /* statement terminates with a semi-colon ';' */
2676 if (NCH(CHILD(ch, j)) == 0) {
2677 assert((j + 1) == NCH(ch));
2678 break;
2679 }
2680 s = ast_for_stmt(c, CHILD(ch, j));
2681 if (!s)
2682 return NULL;
2683 asdl_seq_SET(seq, pos++, s);
2684 }
2685 }
2686 }
2687 }
2688 assert(pos == seq->size);
2689 return seq;
2690 }
2691
2692 static stmt_ty
2693 ast_for_if_stmt(struct compiling *c, const node *n)
2694 {
2695 /* if_stmt: 'if' test ':' suite ('elif' test ':' suite)*
2696 ['else' ':' suite]
2697 */
2698 char *s;
2699
2700 REQ(n, if_stmt);
2701
2702 if (NCH(n) == 4) {
2703 expr_ty expression;
2704 asdl_seq *suite_seq;
2705
2706 expression = ast_for_expr(c, CHILD(n, 1));
2707 if (!expression)
2708 return NULL;
2709 suite_seq = ast_for_suite(c, CHILD(n, 3));
2710 if (!suite_seq)
2711 return NULL;
2712
2713 return If(expression, suite_seq, NULL, LINENO(n), n->n_col_offset,
2714 c->c_arena);
2715 }
2716
2717 s = STR(CHILD(n, 4));
2718 /* s[2], the third character in the string, will be
2719 's' for el_s_e, or
2720 'i' for el_i_f
2721 */
2722 if (s[2] == 's') {
2723 expr_ty expression;
2724 asdl_seq *seq1, *seq2;
2725
2726 expression = ast_for_expr(c, CHILD(n, 1));
2727 if (!expression)
2728 return NULL;
2729 seq1 = ast_for_suite(c, CHILD(n, 3));
2730 if (!seq1)
2731 return NULL;
2732 seq2 = ast_for_suite(c, CHILD(n, 6));
2733 if (!seq2)
2734 return NULL;
2735
2736 return If(expression, seq1, seq2, LINENO(n), n->n_col_offset,
2737 c->c_arena);
2738 }
2739 else if (s[2] == 'i') {
2740 int i, n_elif, has_else = 0;
2741 expr_ty expression;
2742 asdl_seq *suite_seq;
2743 asdl_seq *orelse = NULL;
2744 n_elif = NCH(n) - 4;
2745 /* must reference the child n_elif+1 since 'else' token is third,
2746 not fourth, child from the end. */
2747 if (TYPE(CHILD(n, (n_elif + 1))) == NAME
2748 && STR(CHILD(n, (n_elif + 1)))[2] == 's') {
2749 has_else = 1;
2750 n_elif -= 3;
2751 }
2752 n_elif /= 4;
2753
2754 if (has_else) {
2755 asdl_seq *suite_seq2;
2756
2757 orelse = asdl_seq_new(1, c->c_arena);
2758 if (!orelse)
2759 return NULL;
2760 expression = ast_for_expr(c, CHILD(n, NCH(n) - 6));
2761 if (!expression)
2762 return NULL;
2763 suite_seq = ast_for_suite(c, CHILD(n, NCH(n) - 4));
2764 if (!suite_seq)
2765 return NULL;
2766 suite_seq2 = ast_for_suite(c, CHILD(n, NCH(n) - 1));
2767 if (!suite_seq2)
2768 return NULL;
2769
2770 asdl_seq_SET(orelse, 0,
2771 If(expression, suite_seq, suite_seq2,
2772 LINENO(CHILD(n, NCH(n) - 6)),
2773 CHILD(n, NCH(n) - 6)->n_col_offset,
2774 c->c_arena));
2775 /* the just-created orelse handled the last elif */
2776 n_elif--;
2777 }
2778
2779 for (i = 0; i < n_elif; i++) {
2780 int off = 5 + (n_elif - i - 1) * 4;
2781 asdl_seq *newobj = asdl_seq_new(1, c->c_arena);
2782 if (!newobj)
2783 return NULL;
2784 expression = ast_for_expr(c, CHILD(n, off));
2785 if (!expression)
2786 return NULL;
2787 suite_seq = ast_for_suite(c, CHILD(n, off + 2));
2788 if (!suite_seq)
2789 return NULL;
2790
2791 asdl_seq_SET(newobj, 0,
2792 If(expression, suite_seq, orelse,
2793 LINENO(CHILD(n, off)),
2794 CHILD(n, off)->n_col_offset, c->c_arena));
2795 orelse = newobj;
2796 }
2797 expression = ast_for_expr(c, CHILD(n, 1));
2798 if (!expression)
2799 return NULL;
2800 suite_seq = ast_for_suite(c, CHILD(n, 3));
2801 if (!suite_seq)
2802 return NULL;
2803 return If(expression, suite_seq, orelse,
2804 LINENO(n), n->n_col_offset, c->c_arena);
2805 }
2806
2807 PyErr_Format(PyExc_SystemError,
2808 "unexpected token in 'if' statement: %s", s);
2809 return NULL;
2810 }
2811
2812 static stmt_ty
2813 ast_for_while_stmt(struct compiling *c, const node *n)
2814 {
2815 /* while_stmt: 'while' test ':' suite ['else' ':' suite] */
2816 REQ(n, while_stmt);
2817
2818 if (NCH(n) == 4) {
2819 expr_ty expression;
2820 asdl_seq *suite_seq;
2821
2822 expression = ast_for_expr(c, CHILD(n, 1));
2823 if (!expression)
2824 return NULL;
2825 suite_seq = ast_for_suite(c, CHILD(n, 3));
2826 if (!suite_seq)
2827 return NULL;
2828 return While(expression, suite_seq, NULL, LINENO(n), n->n_col_offset,
2829 c->c_arena);
2830 }
2831 else if (NCH(n) == 7) {
2832 expr_ty expression;
2833 asdl_seq *seq1, *seq2;
2834
2835 expression = ast_for_expr(c, CHILD(n, 1));
2836 if (!expression)
2837 return NULL;
2838 seq1 = ast_for_suite(c, CHILD(n, 3));
2839 if (!seq1)
2840 return NULL;
2841 seq2 = ast_for_suite(c, CHILD(n, 6));
2842 if (!seq2)
2843 return NULL;
2844
2845 return While(expression, seq1, seq2, LINENO(n), n->n_col_offset,
2846 c->c_arena);
2847 }
2848
2849 PyErr_Format(PyExc_SystemError,
2850 "wrong number of tokens for 'while' statement: %d",
2851 NCH(n));
2852 return NULL;
2853 }
2854
2855 static stmt_ty
2856 ast_for_for_stmt(struct compiling *c, const node *n)
2857 {
2858 asdl_seq *_target, *seq = NULL, *suite_seq;
2859 expr_ty expression;
2860 expr_ty target, first;
2861 const node *node_target;
2862 /* for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite] */
2863 REQ(n, for_stmt);
2864
2865 if (NCH(n) == 9) {
2866 seq = ast_for_suite(c, CHILD(n, 8));
2867 if (!seq)
2868 return NULL;
2869 }
2870
2871 node_target = CHILD(n, 1);
2872 _target = ast_for_exprlist(c, node_target, Store);
2873 if (!_target)
2874 return NULL;
2875 /* Check the # of children rather than the length of _target, since
2876 for x, in ... has 1 element in _target, but still requires a Tuple. */
2877 first = (expr_ty)asdl_seq_GET(_target, 0);
2878 if (NCH(node_target) == 1)
2879 target = first;
2880 else
2881 target = Tuple(_target, Store, first->lineno, first->col_offset, c->c_arena);
2882
2883 expression = ast_for_testlist(c, CHILD(n, 3));
2884 if (!expression)
2885 return NULL;
2886 suite_seq = ast_for_suite(c, CHILD(n, 5));
2887 if (!suite_seq)
2888 return NULL;
2889
2890 return For(target, expression, suite_seq, seq, LINENO(n), n->n_col_offset,
2891 c->c_arena);
2892 }
2893
2894 static excepthandler_ty
2895 ast_for_except_clause(struct compiling *c, const node *exc, node *body)
2896 {
2897 /* except_clause: 'except' [test [(',' | 'as') test]] */
2898 REQ(exc, except_clause);
2899 REQ(body, suite);
2900
2901 if (NCH(exc) == 1) {
2902 asdl_seq *suite_seq = ast_for_suite(c, body);
2903 if (!suite_seq)
2904 return NULL;
2905
2906 return ExceptHandler(NULL, NULL, suite_seq, LINENO(exc),
2907 exc->n_col_offset, c->c_arena);
2908 }
2909 else if (NCH(exc) == 2) {
2910 expr_ty expression;
2911 asdl_seq *suite_seq;
2912
2913 expression = ast_for_expr(c, CHILD(exc, 1));
2914 if (!expression)
2915 return NULL;
2916 suite_seq = ast_for_suite(c, body);
2917 if (!suite_seq)
2918 return NULL;
2919
2920 return ExceptHandler(expression, NULL, suite_seq, LINENO(exc),
2921 exc->n_col_offset, c->c_arena);
2922 }
2923 else if (NCH(exc) == 4) {
2924 asdl_seq *suite_seq;
2925 expr_ty expression;
2926 expr_ty e = ast_for_expr(c, CHILD(exc, 3));
2927 if (!e)
2928 return NULL;
2929 if (!set_context(c, e, Store, CHILD(exc, 3)))
2930 return NULL;
2931 expression = ast_for_expr(c, CHILD(exc, 1));
2932 if (!expression)
2933 return NULL;
2934 suite_seq = ast_for_suite(c, body);
2935 if (!suite_seq)
2936 return NULL;
2937
2938 return ExceptHandler(expression, e, suite_seq, LINENO(exc),
2939 exc->n_col_offset, c->c_arena);
2940 }
2941
2942 PyErr_Format(PyExc_SystemError,
2943 "wrong number of children for 'except' clause: %d",
2944 NCH(exc));
2945 return NULL;
2946 }
2947
2948 static stmt_ty
2949 ast_for_try_stmt(struct compiling *c, const node *n)
2950 {
2951 const int nch = NCH(n);
2952 int n_except = (nch - 3)/3;
2953 asdl_seq *body, *orelse = NULL, *finally = NULL;
2954
2955 REQ(n, try_stmt);
2956
2957 body = ast_for_suite(c, CHILD(n, 2));
2958 if (body == NULL)
2959 return NULL;
2960
2961 if (TYPE(CHILD(n, nch - 3)) == NAME) {
2962 if (strcmp(STR(CHILD(n, nch - 3)), "finally") == 0) {
2963 if (nch >= 9 && TYPE(CHILD(n, nch - 6)) == NAME) {
2964 /* we can assume it's an "else",
2965 because nch >= 9 for try-else-finally and
2966 it would otherwise have a type of except_clause */
2967 orelse = ast_for_suite(c, CHILD(n, nch - 4));
2968 if (orelse == NULL)
2969 return NULL;
2970 n_except--;
2971 }
2972
2973 finally = ast_for_suite(c, CHILD(n, nch - 1));
2974 if (finally == NULL)
2975 return NULL;
2976 n_except--;
2977 }
2978 else {
2979 /* we can assume it's an "else",
2980 otherwise it would have a type of except_clause */
2981 orelse = ast_for_suite(c, CHILD(n, nch - 1));
2982 if (orelse == NULL)
2983 return NULL;
2984 n_except--;
2985 }
2986 }
2987 else if (TYPE(CHILD(n, nch - 3)) != except_clause) {
2988 ast_error(n, "malformed 'try' statement");
2989 return NULL;
2990 }
2991
2992 if (n_except > 0) {
2993 int i;
2994 stmt_ty except_st;
2995 /* process except statements to create a try ... except */
2996 asdl_seq *handlers = asdl_seq_new(n_except, c->c_arena);
2997 if (handlers == NULL)
2998 return NULL;
2999
3000 for (i = 0; i < n_except; i++) {
3001 excepthandler_ty e = ast_for_except_clause(c, CHILD(n, 3 + i * 3),
3002 CHILD(n, 5 + i * 3));
3003 if (!e)
3004 return NULL;
3005 asdl_seq_SET(handlers, i, e);
3006 }
3007
3008 except_st = TryExcept(body, handlers, orelse, LINENO(n),
3009 n->n_col_offset, c->c_arena);
3010 if (!finally)
3011 return except_st;
3012
3013 /* if a 'finally' is present too, we nest the TryExcept within a
3014 TryFinally to emulate try ... except ... finally */
3015 body = asdl_seq_new(1, c->c_arena);
3016 if (body == NULL)
3017 return NULL;
3018 asdl_seq_SET(body, 0, except_st);
3019 }
3020
3021 /* must be a try ... finally (except clauses are in body, if any exist) */
3022 assert(finally != NULL);
3023 return TryFinally(body, finally, LINENO(n), n->n_col_offset, c->c_arena);
3024 }
3025
3026 /* with_item: test ['as' expr] */
3027 static stmt_ty
3028 ast_for_with_item(struct compiling *c, const node *n, asdl_seq *content)
3029 {
3030 expr_ty context_expr, optional_vars = NULL;
3031
3032 REQ(n, with_item);
3033 context_expr = ast_for_expr(c, CHILD(n, 0));
3034 if (!context_expr)
3035 return NULL;
3036 if (NCH(n) == 3) {
3037 optional_vars = ast_for_expr(c, CHILD(n, 2));
3038
3039 if (!optional_vars) {
3040 return NULL;
3041 }
3042 if (!set_context(c, optional_vars, Store, n)) {
3043 return NULL;
3044 }
3045 }
3046
3047 return With(context_expr, optional_vars, content, LINENO(n),
3048 n->n_col_offset, c->c_arena);
3049 }
3050
3051 /* with_stmt: 'with' with_item (',' with_item)* ':' suite */
3052 static stmt_ty
3053 ast_for_with_stmt(struct compiling *c, const node *n)
3054 {
3055 int i;
3056 stmt_ty ret;
3057 asdl_seq *inner;
3058
3059 REQ(n, with_stmt);
3060
3061 /* process the with items inside-out */
3062 i = NCH(n) - 1;
3063 /* the suite of the innermost with item is the suite of the with stmt */
3064 inner = ast_for_suite(c, CHILD(n, i));
3065 if (!inner)
3066 return NULL;
3067
3068 for (;;) {
3069 i -= 2;
3070 ret = ast_for_with_item(c, CHILD(n, i), inner);
3071 if (!ret)
3072 return NULL;
3073 /* was this the last item? */
3074 if (i == 1)
3075 break;
3076 /* if not, wrap the result so far in a new sequence */
3077 inner = asdl_seq_new(1, c->c_arena);
3078 if (!inner)
3079 return NULL;
3080 asdl_seq_SET(inner, 0, ret);
3081 }
3082
3083 return ret;
3084 }
3085
3086 static stmt_ty
3087 ast_for_classdef(struct compiling *c, const node *n, asdl_seq *decorator_seq)
3088 {
3089 /* classdef: 'class' NAME ['(' testlist ')'] ':' suite */
3090 PyObject *classname;
3091 asdl_seq *bases, *s;
3092
3093 REQ(n, classdef);
3094
3095 if (!forbidden_check(c, n, STR(CHILD(n, 1))))
3096 return NULL;
3097
3098 if (NCH(n) == 4) {
3099 s = ast_for_suite(c, CHILD(n, 3));
3100 if (!s)
3101 return NULL;
3102 classname = NEW_IDENTIFIER(CHILD(n, 1));
3103 if (!classname)
3104 return NULL;
3105 return ClassDef(classname, NULL, s, decorator_seq, LINENO(n),
3106 n->n_col_offset, c->c_arena);
3107 }
3108 /* check for empty base list */
3109 if (TYPE(CHILD(n,3)) == RPAR) {
3110 s = ast_for_suite(c, CHILD(n,5));
3111 if (!s)
3112 return NULL;
3113 classname = NEW_IDENTIFIER(CHILD(n, 1));
3114 if (!classname)
3115 return NULL;
3116 return ClassDef(classname, NULL, s, decorator_seq, LINENO(n),
3117 n->n_col_offset, c->c_arena);
3118 }
3119
3120 /* else handle the base class list */
3121 bases = ast_for_class_bases(c, CHILD(n, 3));
3122 if (!bases)
3123 return NULL;
3124
3125 s = ast_for_suite(c, CHILD(n, 6));
3126 if (!s)
3127 return NULL;
3128 classname = NEW_IDENTIFIER(CHILD(n, 1));
3129 if (!classname)
3130 return NULL;
3131 return ClassDef(classname, bases, s, decorator_seq,
3132 LINENO(n), n->n_col_offset, c->c_arena);
3133 }
3134
3135 static stmt_ty
3136 ast_for_stmt(struct compiling *c, const node *n)
3137 {
3138 if (TYPE(n) == stmt) {
3139 assert(NCH(n) == 1);
3140 n = CHILD(n, 0);
3141 }
3142 if (TYPE(n) == simple_stmt) {
3143 assert(num_stmts(n) == 1);
3144 n = CHILD(n, 0);
3145 }
3146 if (TYPE(n) == small_stmt) {
3147 n = CHILD(n, 0);
3148 /* small_stmt: expr_stmt | print_stmt | del_stmt | pass_stmt
3149 | flow_stmt | import_stmt | global_stmt | exec_stmt
3150 | assert_stmt
3151 */
3152 switch (TYPE(n)) {
3153 case expr_stmt:
3154 return ast_for_expr_stmt(c, n);
3155 case print_stmt:
3156 return ast_for_print_stmt(c, n);
3157 case del_stmt:
3158 return ast_for_del_stmt(c, n);
3159 case pass_stmt:
3160 return Pass(LINENO(n), n->n_col_offset, c->c_arena);
3161 case flow_stmt:
3162 return ast_for_flow_stmt(c, n);
3163 case import_stmt:
3164 return ast_for_import_stmt(c, n);
3165 case global_stmt:
3166 return ast_for_global_stmt(c, n);
3167 case exec_stmt:
3168 return ast_for_exec_stmt(c, n);
3169 case assert_stmt:
3170 return ast_for_assert_stmt(c, n);
3171 default:
3172 PyErr_Format(PyExc_SystemError,
3173 "unhandled small_stmt: TYPE=%d NCH=%d\n",
3174 TYPE(n), NCH(n));
3175 return NULL;
3176 }
3177 }
3178 else {
3179 /* compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt
3180 | funcdef | classdef | decorated
3181 */
3182 node *ch = CHILD(n, 0);
3183 REQ(n, compound_stmt);
3184 switch (TYPE(ch)) {
3185 case if_stmt:
3186 return ast_for_if_stmt(c, ch);
3187 case while_stmt:
3188 return ast_for_while_stmt(c, ch);
3189 case for_stmt:
3190 return ast_for_for_stmt(c, ch);
3191 case try_stmt:
3192 return ast_for_try_stmt(c, ch);
3193 case with_stmt:
3194 return ast_for_with_stmt(c, ch);
3195 case funcdef:
3196 return ast_for_funcdef(c, ch, NULL);
3197 case classdef:
3198 return ast_for_classdef(c, ch, NULL);
3199 case decorated:
3200 return ast_for_decorated(c, ch);
3201 default:
3202 PyErr_Format(PyExc_SystemError,
3203 "unhandled small_stmt: TYPE=%d NCH=%d\n",
3204 TYPE(n), NCH(n));
3205 return NULL;
3206 }
3207 }
3208 }
3209
3210 static PyObject *
3211 parsenumber(struct compiling *c, const char *s)
3212 {
3213 const char *end;
3214 long x;
3215 double dx;
3216 #ifndef WITHOUT_COMPLEX
3217 Py_complex complex;
3218 int imflag;
3219 #endif
3220
3221 assert(s != NULL);
3222 errno = 0;
3223 end = s + strlen(s) - 1;
3224 #ifndef WITHOUT_COMPLEX
3225 imflag = *end == 'j' || *end == 'J';
3226 #endif
3227 if (*end == 'l' || *end == 'L')
3228 return PyLong_FromString((char *)s, (char **)0, 0);
3229 x = PyOS_strtol((char *)s, (char **)&end, 0);
3230 if (*end == '\0') {
3231 if (errno != 0)
3232 return PyLong_FromString((char *)s, (char **)0, 0);
3233 return PyInt_FromLong(x);
3234 }
3235 /* XXX Huge floats may silently fail */
3236 #ifndef WITHOUT_COMPLEX
3237 if (imflag) {
3238 complex.real = 0.;
3239 PyFPE_START_PROTECT("atof", return 0)
3240 complex.imag = PyOS_ascii_atof(s);
3241 PyFPE_END_PROTECT(complex)
3242 return PyComplex_FromCComplex(complex);
3243 }
3244 else
3245 #endif
3246 {
3247 PyFPE_START_PROTECT("atof", return 0)
3248 dx = PyOS_ascii_atof(s);
3249 PyFPE_END_PROTECT(dx)
3250 return PyFloat_FromDouble(dx);
3251 }
3252 }
3253
3254 static PyObject *
3255 decode_utf8(struct compiling *c, const char **sPtr, const char *end, char* encoding)
3256 {
3257 #ifndef Py_USING_UNICODE
3258 Py_FatalError("decode_utf8 should not be called in this build.");
3259 return NULL;
3260 #else
3261 PyObject *u, *v;
3262 char *s, *t;
3263 t = s = (char *)*sPtr;
3264 /* while (s < end && *s != '\\') s++; */ /* inefficient for u".." */
3265 while (s < end && (*s & 0x80)) s++;
3266 *sPtr = s;
3267 u = PyUnicode_DecodeUTF8(t, s - t, NULL);
3268 if (u == NULL)
3269 return NULL;
3270 v = PyUnicode_AsEncodedString(u, encoding, NULL);
3271 Py_DECREF(u);
3272 return v;
3273 #endif
3274 }
3275
3276 #ifdef Py_USING_UNICODE
3277 static PyObject *
3278 decode_unicode(struct compiling *c, const char *s, size_t len, int rawmode, const char *encoding)
3279 {
3280 PyObject *v, *u;
3281 char *buf;
3282 char *p;
3283 const char *end;
3284 if (encoding == NULL) {
3285 buf = (char *)s;
3286 u = NULL;
3287 } else if (strcmp(encoding, "iso-8859-1") == 0) {
3288 buf = (char *)s;
3289 u = NULL;
3290 } else {
3291 /* check for integer overflow */
3292 if (len > PY_SIZE_MAX / 4)
3293 return NULL;
3294 /* "\XX" may become "\u005c\uHHLL" (12 bytes) */
3295 u = PyString_FromStringAndSize((char *)NULL, len * 4);
3296 if (u == NULL)
3297 return NULL;
3298 p = buf = PyString_AsString(u);
3299 end = s + len;
3300 while (s < end) {
3301 if (*s == '\\') {
3302 *p++ = *s++;
3303 if (*s & 0x80) {
3304 strcpy(p, "u005c");
3305 p += 5;
3306 }
3307 }
3308 if (*s & 0x80) { /* XXX inefficient */
3309 PyObject *w;
3310 char *r;
3311 Py_ssize_t rn, i;
3312 w = decode_utf8(c, &s, end, "utf-16-be");
3313 if (w == NULL) {
3314 Py_DECREF(u);
3315 return NULL;
3316 }
3317 r = PyString_AsString(w);
3318 rn = PyString_Size(w);
3319 assert(rn % 2 == 0);
3320 for (i = 0; i < rn; i += 2) {
3321 sprintf(p, "\\u%02x%02x",
3322 r[i + 0] & 0xFF,
3323 r[i + 1] & 0xFF);
3324 p += 6;
3325 }
3326 Py_DECREF(w);
3327 } else {
3328 *p++ = *s++;
3329 }
3330 }
3331 len = p - buf;
3332 s = buf;
3333 }
3334 if (rawmode)
3335 v = PyUnicode_DecodeRawUnicodeEscape(s, len, NULL);
3336 else
3337 v = PyUnicode_DecodeUnicodeEscape(s, len, NULL);
3338 Py_XDECREF(u);
3339 return v;
3340 }
3341 #endif
3342
3343 /* s is a Python string literal, including the bracketing quote characters,
3344 * and r &/or u prefixes (if any), and embedded escape sequences (if any).
3345 * parsestr parses it, and returns the decoded Python string object.
3346 */
3347 static PyObject *
3348 parsestr(struct compiling *c, const char *s)
3349 {
3350 size_t len;
3351 int quote = Py_CHARMASK(*s);
3352 int rawmode = 0;
3353 int need_encoding;
3354 int unicode = c->c_future_unicode;
3355
3356 if (isalpha(quote) || quote == '_') {
3357 if (quote == 'u' || quote == 'U') {
3358 quote = *++s;
3359 unicode = 1;
3360 }
3361 if (quote == 'b' || quote == 'B') {
3362 quote = *++s;
3363 unicode = 0;
3364 }
3365 if (quote == 'r' || quote == 'R') {
3366 quote = *++s;
3367 rawmode = 1;
3368 }
3369 }
3370 if (quote != '\'' && quote != '\"') {
3371 PyErr_BadInternalCall();
3372 return NULL;
3373 }
3374 s++;
3375 len = strlen(s);
3376 if (len > INT_MAX) {
3377 PyErr_SetString(PyExc_OverflowError,
3378 "string to parse is too long");
3379 return NULL;
3380 }
3381 if (s[--len] != quote) {
3382 PyErr_BadInternalCall();
3383 return NULL;
3384 }
3385 if (len >= 4 && s[0] == quote && s[1] == quote) {
3386 s += 2;
3387 len -= 2;
3388 if (s[--len] != quote || s[--len] != quote) {
3389 PyErr_BadInternalCall();
3390 return NULL;
3391 }
3392 }
3393 #ifdef Py_USING_UNICODE
3394 if (unicode || Py_UnicodeFlag) {
3395 return decode_unicode(c, s, len, rawmode, c->c_encoding);
3396 }
3397 #endif
3398 need_encoding = (c->c_encoding != NULL &&
3399 strcmp(c->c_encoding, "utf-8") != 0 &&
3400 strcmp(c->c_encoding, "iso-8859-1") != 0);
3401 if (rawmode || strchr(s, '\\') == NULL) {
3402 if (need_encoding) {
3403 #ifndef Py_USING_UNICODE
3404 /* This should not happen - we never see any other
3405 encoding. */
3406 Py_FatalError(
3407 "cannot deal with encodings in this build.");
3408 #else
3409 PyObject *v, *u = PyUnicode_DecodeUTF8(s, len, NULL);
3410 if (u == NULL)
3411 return NULL;
3412 v = PyUnicode_AsEncodedString(u, c->c_encoding, NULL);
3413 Py_DECREF(u);
3414 return v;
3415 #endif
3416 } else {
3417 return PyString_FromStringAndSize(s, len);
3418 }
3419 }
3420
3421 return PyString_DecodeEscape(s, len, NULL, unicode,
3422 need_encoding ? c->c_encoding : NULL);
3423 }
3424
3425 /* Build a Python string object out of a STRING atom. This takes care of
3426 * compile-time literal catenation, calling parsestr() on each piece, and
3427 * pasting the intermediate results together.
3428 */
3429 static PyObject *
3430 parsestrplus(struct compiling *c, const node *n)
3431 {
3432 PyObject *v;
3433 int i;
3434 REQ(CHILD(n, 0), STRING);
3435 if ((v = parsestr(c, STR(CHILD(n, 0)))) != NULL) {
3436 /* String literal concatenation */
3437 for (i = 1; i < NCH(n); i++) {
3438 PyObject *s;
3439 s = parsestr(c, STR(CHILD(n, i)));
3440 if (s == NULL)
3441 goto onError;
3442 if (PyString_Check(v) && PyString_Check(s)) {
3443 PyString_ConcatAndDel(&v, s);
3444 if (v == NULL)
3445 goto onError;
3446 }
3447 #ifdef Py_USING_UNICODE
3448 else {
3449 PyObject *temp = PyUnicode_Concat(v, s);
3450 Py_DECREF(s);
3451 Py_DECREF(v);
3452 v = temp;
3453 if (v == NULL)
3454 goto onError;
3455 }
3456 #endif
3457 }
3458 }
3459 return v;
3460
3461 onError:
3462 Py_XDECREF(v);
3463 return NULL;
3464 }
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