This repository was archived by the owner on Feb 13, 2025. It is now read-only.
forked from python/cpython
-
Notifications
You must be signed in to change notification settings - Fork 64
Expand file tree
/
Copy pathparsermodule.c
More file actions
3584 lines (3149 loc) · 103 KB
/
parsermodule.c
File metadata and controls
3584 lines (3149 loc) · 103 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* parsermodule.c
*
* Copyright 1995-1996 by Fred L. Drake, Jr. and Virginia Polytechnic
* Institute and State University, Blacksburg, Virginia, USA.
* Portions copyright 1991-1995 by Stichting Mathematisch Centrum,
* Amsterdam, The Netherlands. Copying is permitted under the terms
* associated with the main Python distribution, with the additional
* restriction that this additional notice be included and maintained
* on all distributed copies.
*
* This module serves to replace the original parser module written
* by Guido. The functionality is not matched precisely, but the
* original may be implemented on top of this. This is desirable
* since the source of the text to be parsed is now divorced from
* this interface.
*
* Unlike the prior interface, the ability to give a parse tree
* produced by Python code as a tuple to the compiler is enabled by
* this module. See the documentation for more details.
*
* I've added some annotations that help with the lint code-checking
* program, but they're not complete by a long shot. The real errors
* that lint detects are gone, but there are still warnings with
* Py_[X]DECREF() and Py_[X]INCREF() macros. The lint annotations
* look like "NOTE(...)".
*
* To debug parser errors like
* "parser.ParserError: Expected node type 12, got 333."
* decode symbol numbers using the automatically-generated files
* Lib/symbol.h and Include/token.h.
*/
#include "Python.h" /* general Python API */
#include "Python-ast.h" /* mod_ty */
#include "graminit.h" /* symbols defined in the grammar */
#include "node.h" /* internal parser structure */
#include "errcode.h" /* error codes for PyNode_*() */
#include "token.h" /* token definitions */
#include "grammar.h"
#include "parsetok.h"
/* ISTERMINAL() / ISNONTERMINAL() */
#undef Yield
#include "ast.h"
extern grammar _PyParser_Grammar; /* From graminit.c */
#ifdef lint
#include <note.h>
#else
#define NOTE(x)
#endif
/* String constants used to initialize module attributes.
*
*/
static char parser_copyright_string[] =
"Copyright 1995-1996 by Virginia Polytechnic Institute & State\n\
University, Blacksburg, Virginia, USA, and Fred L. Drake, Jr., Reston,\n\
Virginia, USA. Portions copyright 1991-1995 by Stichting Mathematisch\n\
Centrum, Amsterdam, The Netherlands.";
PyDoc_STRVAR(parser_doc_string,
"This is an interface to Python's internal parser.");
static char parser_version_string[] = "0.5";
typedef PyObject* (*SeqMaker) (Py_ssize_t length);
typedef int (*SeqInserter) (PyObject* sequence,
Py_ssize_t index,
PyObject* element);
/* The function below is copyrighted by Stichting Mathematisch Centrum. The
* original copyright statement is included below, and continues to apply
* in full to the function immediately following. All other material is
* original, copyrighted by Fred L. Drake, Jr. and Virginia Polytechnic
* Institute and State University. Changes were made to comply with the
* new naming conventions. Added arguments to provide support for creating
* lists as well as tuples, and optionally including the line numbers.
*/
static PyObject*
node2tuple(node *n, /* node to convert */
SeqMaker mkseq, /* create sequence */
SeqInserter addelem, /* func. to add elem. in seq. */
int lineno, /* include line numbers? */
int col_offset) /* include column offsets? */
{
PyObject *result = NULL, *w;
if (n == NULL) {
Py_INCREF(Py_None);
return Py_None;
}
if (ISNONTERMINAL(TYPE(n))) {
int i;
result = mkseq(1 + NCH(n) + (TYPE(n) == encoding_decl));
if (result == NULL)
goto error;
w = PyLong_FromLong(TYPE(n));
if (w == NULL)
goto error;
(void) addelem(result, 0, w);
for (i = 0; i < NCH(n); i++) {
w = node2tuple(CHILD(n, i), mkseq, addelem, lineno, col_offset);
if (w == NULL)
goto error;
(void) addelem(result, i+1, w);
}
if (TYPE(n) == encoding_decl) {
w = PyUnicode_FromString(STR(n));
if (w == NULL)
goto error;
(void) addelem(result, i+1, w);
}
}
else if (ISTERMINAL(TYPE(n))) {
result = mkseq(2 + lineno + col_offset);
if (result == NULL)
goto error;
w = PyLong_FromLong(TYPE(n));
if (w == NULL)
goto error;
(void) addelem(result, 0, w);
w = PyUnicode_FromString(STR(n));
if (w == NULL)
goto error;
(void) addelem(result, 1, w);
if (lineno == 1) {
w = PyLong_FromLong(n->n_lineno);
if (w == NULL)
goto error;
(void) addelem(result, 2, w);
}
if (col_offset == 1) {
w = PyLong_FromLong(n->n_col_offset);
if (w == NULL)
goto error;
(void) addelem(result, 3, w);
}
}
else {
PyErr_SetString(PyExc_SystemError,
"unrecognized parse tree node type");
return ((PyObject*) NULL);
}
return result;
error:
Py_XDECREF(result);
return NULL;
}
/*
* End of material copyrighted by Stichting Mathematisch Centrum.
*/
/* There are two types of intermediate objects we're interested in:
* 'eval' and 'exec' types. These constants can be used in the st_type
* field of the object type to identify which any given object represents.
* These should probably go in an external header to allow other extensions
* to use them, but then, we really should be using C++ too. ;-)
*/
#define PyST_EXPR 1
#define PyST_SUITE 2
/* These are the internal objects and definitions required to implement the
* ST type. Most of the internal names are more reminiscent of the 'old'
* naming style, but the code uses the new naming convention.
*/
static PyObject*
parser_error = 0;
typedef struct {
PyObject_HEAD /* standard object header */
node* st_node; /* the node* returned by the parser */
int st_type; /* EXPR or SUITE ? */
PyCompilerFlags st_flags; /* Parser and compiler flags */
} PyST_Object;
static void parser_free(PyST_Object *st);
static PyObject* parser_sizeof(PyST_Object *, void *);
static PyObject* parser_richcompare(PyObject *left, PyObject *right, int op);
static PyObject* parser_compilest(PyST_Object *, PyObject *, PyObject *);
static PyObject* parser_isexpr(PyST_Object *, PyObject *, PyObject *);
static PyObject* parser_issuite(PyST_Object *, PyObject *, PyObject *);
static PyObject* parser_st2list(PyST_Object *, PyObject *, PyObject *);
static PyObject* parser_st2tuple(PyST_Object *, PyObject *, PyObject *);
#define PUBLIC_METHOD_TYPE (METH_VARARGS|METH_KEYWORDS)
static PyMethodDef parser_methods[] = {
{"compile", (PyCFunction)parser_compilest, PUBLIC_METHOD_TYPE,
PyDoc_STR("Compile this ST object into a code object.")},
{"isexpr", (PyCFunction)parser_isexpr, PUBLIC_METHOD_TYPE,
PyDoc_STR("Determines if this ST object was created from an expression.")},
{"issuite", (PyCFunction)parser_issuite, PUBLIC_METHOD_TYPE,
PyDoc_STR("Determines if this ST object was created from a suite.")},
{"tolist", (PyCFunction)parser_st2list, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates a list-tree representation of this ST.")},
{"totuple", (PyCFunction)parser_st2tuple, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates a tuple-tree representation of this ST.")},
{"__sizeof__", (PyCFunction)parser_sizeof, METH_NOARGS,
PyDoc_STR("Returns size in memory, in bytes.")},
{NULL, NULL, 0, NULL}
};
static
PyTypeObject PyST_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
"parser.st", /* tp_name */
(int) sizeof(PyST_Object), /* tp_basicsize */
0, /* tp_itemsize */
(destructor)parser_free, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
0, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
/* Functions to access object as input/output buffer */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
/* __doc__ */
"Intermediate representation of a Python parse tree.",
0, /* tp_traverse */
0, /* tp_clear */
parser_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
parser_methods, /* tp_methods */
}; /* PyST_Type */
/* PyST_Type isn't subclassable, so just check ob_type */
#define PyST_Object_Check(v) ((v)->ob_type == &PyST_Type)
static int
parser_compare_nodes(node *left, node *right)
{
int j;
if (TYPE(left) < TYPE(right))
return (-1);
if (TYPE(right) < TYPE(left))
return (1);
if (ISTERMINAL(TYPE(left)))
return (strcmp(STR(left), STR(right)));
if (NCH(left) < NCH(right))
return (-1);
if (NCH(right) < NCH(left))
return (1);
for (j = 0; j < NCH(left); ++j) {
int v = parser_compare_nodes(CHILD(left, j), CHILD(right, j));
if (v != 0)
return (v);
}
return (0);
}
/* parser_richcompare(PyObject* left, PyObject* right, int op)
*
* Comparison function used by the Python operators ==, !=, <, >, <=, >=
* This really just wraps a call to parser_compare_nodes() with some easy
* checks and protection code.
*
*/
#define TEST_COND(cond) ((cond) ? Py_True : Py_False)
static PyObject *
parser_richcompare(PyObject *left, PyObject *right, int op)
{
int result;
PyObject *v;
/* neither argument should be NULL, unless something's gone wrong */
if (left == NULL || right == NULL) {
PyErr_BadInternalCall();
return NULL;
}
/* both arguments should be instances of PyST_Object */
if (!PyST_Object_Check(left) || !PyST_Object_Check(right)) {
v = Py_NotImplemented;
goto finished;
}
if (left == right)
/* if arguments are identical, they're equal */
result = 0;
else
result = parser_compare_nodes(((PyST_Object *)left)->st_node,
((PyST_Object *)right)->st_node);
/* Convert return value to a Boolean */
switch (op) {
case Py_EQ:
v = TEST_COND(result == 0);
break;
case Py_NE:
v = TEST_COND(result != 0);
break;
case Py_LE:
v = TEST_COND(result <= 0);
break;
case Py_GE:
v = TEST_COND(result >= 0);
break;
case Py_LT:
v = TEST_COND(result < 0);
break;
case Py_GT:
v = TEST_COND(result > 0);
break;
default:
PyErr_BadArgument();
return NULL;
}
finished:
Py_INCREF(v);
return v;
}
/* parser_newstobject(node* st)
*
* Allocates a new Python object representing an ST. This is simply the
* 'wrapper' object that holds a node* and allows it to be passed around in
* Python code.
*
*/
static PyObject*
parser_newstobject(node *st, int type)
{
PyST_Object* o = PyObject_New(PyST_Object, &PyST_Type);
if (o != 0) {
o->st_node = st;
o->st_type = type;
o->st_flags.cf_flags = 0;
}
else {
PyNode_Free(st);
}
return ((PyObject*)o);
}
/* void parser_free(PyST_Object* st)
*
* This is called by a del statement that reduces the reference count to 0.
*
*/
static void
parser_free(PyST_Object *st)
{
PyNode_Free(st->st_node);
PyObject_Del(st);
}
static PyObject *
parser_sizeof(PyST_Object *st, void *unused)
{
Py_ssize_t res;
res = _PyObject_SIZE(Py_TYPE(st)) + _PyNode_SizeOf(st->st_node);
return PyLong_FromSsize_t(res);
}
/* parser_st2tuple(PyObject* self, PyObject* args, PyObject* kw)
*
* This provides conversion from a node* to a tuple object that can be
* returned to the Python-level caller. The ST object is not modified.
*
*/
static PyObject*
parser_st2tuple(PyST_Object *self, PyObject *args, PyObject *kw)
{
int line_info = 0;
int col_info = 0;
PyObject *res = 0;
int ok;
static char *keywords[] = {"st", "line_info", "col_info", NULL};
if (self == NULL || PyModule_Check(self)) {
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|pp:st2tuple", keywords,
&PyST_Type, &self, &line_info,
&col_info);
}
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|pp:totuple", &keywords[1],
&line_info, &col_info);
if (ok != 0) {
/*
* Convert ST into a tuple representation. Use Guido's function,
* since it's known to work already.
*/
res = node2tuple(((PyST_Object*)self)->st_node,
PyTuple_New, PyTuple_SetItem, line_info, col_info);
}
return (res);
}
/* parser_st2list(PyObject* self, PyObject* args, PyObject* kw)
*
* This provides conversion from a node* to a list object that can be
* returned to the Python-level caller. The ST object is not modified.
*
*/
static PyObject*
parser_st2list(PyST_Object *self, PyObject *args, PyObject *kw)
{
int line_info = 0;
int col_info = 0;
PyObject *res = 0;
int ok;
static char *keywords[] = {"st", "line_info", "col_info", NULL};
if (self == NULL || PyModule_Check(self))
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|pp:st2list", keywords,
&PyST_Type, &self, &line_info,
&col_info);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|pp:tolist", &keywords[1],
&line_info, &col_info);
if (ok) {
/*
* Convert ST into a tuple representation. Use Guido's function,
* since it's known to work already.
*/
res = node2tuple(self->st_node,
PyList_New, PyList_SetItem, line_info, col_info);
}
return (res);
}
/* parser_compilest(PyObject* self, PyObject* args)
*
* This function creates code objects from the parse tree represented by
* the passed-in data object. An optional file name is passed in as well.
*
*/
static PyObject*
parser_compilest(PyST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = NULL;
PyArena* arena = NULL;
mod_ty mod;
PyObject* filename = NULL;
int ok;
static char *keywords[] = {"st", "filename", NULL};
if (self == NULL || PyModule_Check(self))
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|O&:compilest", keywords,
&PyST_Type, &self,
PyUnicode_FSDecoder, &filename);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|O&:compile", &keywords[1],
PyUnicode_FSDecoder, &filename);
if (!ok)
goto error;
if (filename == NULL) {
filename = PyUnicode_FromString("<syntax-tree>");
if (filename == NULL)
goto error;
}
arena = PyArena_New();
if (!arena)
goto error;
mod = PyAST_FromNodeObject(self->st_node, &self->st_flags,
filename, arena);
if (!mod)
goto error;
res = (PyObject *)PyAST_CompileObject(mod, filename,
&self->st_flags, -1, arena);
error:
Py_XDECREF(filename);
if (arena != NULL)
PyArena_Free(arena);
return res;
}
/* PyObject* parser_isexpr(PyObject* self, PyObject* args)
* PyObject* parser_issuite(PyObject* self, PyObject* args)
*
* Checks the passed-in ST object to determine if it is an expression or
* a statement suite, respectively. The return is a Python truth value.
*
*/
static PyObject*
parser_isexpr(PyST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = 0;
int ok;
static char *keywords[] = {"st", NULL};
if (self == NULL || PyModule_Check(self))
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!:isexpr", keywords,
&PyST_Type, &self);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, ":isexpr", &keywords[1]);
if (ok) {
/* Check to see if the ST represents an expression or not. */
res = (self->st_type == PyST_EXPR) ? Py_True : Py_False;
Py_INCREF(res);
}
return (res);
}
static PyObject*
parser_issuite(PyST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = 0;
int ok;
static char *keywords[] = {"st", NULL};
if (self == NULL || PyModule_Check(self))
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!:issuite", keywords,
&PyST_Type, &self);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, ":issuite", &keywords[1]);
if (ok) {
/* Check to see if the ST represents an expression or not. */
res = (self->st_type == PyST_EXPR) ? Py_False : Py_True;
Py_INCREF(res);
}
return (res);
}
/* err_string(char* message)
*
* Sets the error string for an exception of type ParserError.
*
*/
static void
err_string(char *message)
{
PyErr_SetString(parser_error, message);
}
/* PyObject* parser_do_parse(PyObject* args, int type)
*
* Internal function to actually execute the parse and return the result if
* successful or set an exception if not.
*
*/
static PyObject*
parser_do_parse(PyObject *args, PyObject *kw, char *argspec, int type)
{
char* string = 0;
PyObject* res = 0;
int flags = 0;
perrdetail err;
static char *keywords[] = {"source", NULL};
if (PyArg_ParseTupleAndKeywords(args, kw, argspec, keywords, &string)) {
node* n = PyParser_ParseStringFlagsFilenameEx(string, NULL,
&_PyParser_Grammar,
(type == PyST_EXPR)
? eval_input : file_input,
&err, &flags);
if (n) {
res = parser_newstobject(n, type);
if (res)
((PyST_Object *)res)->st_flags.cf_flags = flags & PyCF_MASK;
}
else {
PyParser_SetError(&err);
}
PyParser_ClearError(&err);
}
return (res);
}
/* PyObject* parser_expr(PyObject* self, PyObject* args)
* PyObject* parser_suite(PyObject* self, PyObject* args)
*
* External interfaces to the parser itself. Which is called determines if
* the parser attempts to recognize an expression ('eval' form) or statement
* suite ('exec' form). The real work is done by parser_do_parse() above.
*
*/
static PyObject*
parser_expr(PyST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
return (parser_do_parse(args, kw, "s:expr", PyST_EXPR));
}
static PyObject*
parser_suite(PyST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
return (parser_do_parse(args, kw, "s:suite", PyST_SUITE));
}
/* This is the messy part of the code. Conversion from a tuple to an ST
* object requires that the input tuple be valid without having to rely on
* catching an exception from the compiler. This is done to allow the
* compiler itself to remain fast, since most of its input will come from
* the parser directly, and therefore be known to be syntactically correct.
* This validation is done to ensure that we don't core dump the compile
* phase, returning an exception instead.
*
* Two aspects can be broken out in this code: creating a node tree from
* the tuple passed in, and verifying that it is indeed valid. It may be
* advantageous to expand the number of ST types to include funcdefs and
* lambdadefs to take advantage of the optimizer, recognizing those STs
* here. They are not necessary, and not quite as useful in a raw form.
* For now, let's get expressions and suites working reliably.
*/
static node* build_node_tree(PyObject *tuple);
static int validate_expr_tree(node *tree);
static int validate_file_input(node *tree);
static int validate_encoding_decl(node *tree);
/* PyObject* parser_tuple2st(PyObject* self, PyObject* args)
*
* This is the public function, called from the Python code. It receives a
* single tuple object from the caller, and creates an ST object if the
* tuple can be validated. It does this by checking the first code of the
* tuple, and, if acceptable, builds the internal representation. If this
* step succeeds, the internal representation is validated as fully as
* possible with the various validate_*() routines defined below.
*
* This function must be changed if support is to be added for PyST_FRAGMENT
* ST objects.
*
*/
static PyObject*
parser_tuple2st(PyST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
PyObject *st = 0;
PyObject *tuple;
node *tree;
static char *keywords[] = {"sequence", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kw, "O:sequence2st", keywords,
&tuple))
return (0);
if (!PySequence_Check(tuple)) {
PyErr_SetString(PyExc_ValueError,
"sequence2st() requires a single sequence argument");
return (0);
}
/*
* Convert the tree to the internal form before checking it.
*/
tree = build_node_tree(tuple);
if (tree != 0) {
int start_sym = TYPE(tree);
if (start_sym == eval_input) {
/* Might be an eval form. */
if (validate_expr_tree(tree))
st = parser_newstobject(tree, PyST_EXPR);
else
PyNode_Free(tree);
}
else if (start_sym == file_input) {
/* This looks like an exec form so far. */
if (validate_file_input(tree))
st = parser_newstobject(tree, PyST_SUITE);
else
PyNode_Free(tree);
}
else if (start_sym == encoding_decl) {
/* This looks like an encoding_decl so far. */
if (validate_encoding_decl(tree))
st = parser_newstobject(tree, PyST_SUITE);
else
PyNode_Free(tree);
}
else {
/* This is a fragment, at best. */
PyNode_Free(tree);
err_string("parse tree does not use a valid start symbol");
}
}
/* Make sure we raise an exception on all errors. We should never
* get this, but we'd do well to be sure something is done.
*/
if (st == NULL && !PyErr_Occurred())
err_string("unspecified ST error occurred");
return st;
}
/* node* build_node_children()
*
* Iterate across the children of the current non-terminal node and build
* their structures. If successful, return the root of this portion of
* the tree, otherwise, 0. Any required exception will be specified already,
* and no memory will have been deallocated.
*
*/
static node*
build_node_children(PyObject *tuple, node *root, int *line_num)
{
Py_ssize_t len = PyObject_Size(tuple);
Py_ssize_t i;
int err;
if (len < 0) {
return NULL;
}
for (i = 1; i < len; ++i) {
/* elem must always be a sequence, however simple */
PyObject* elem = PySequence_GetItem(tuple, i);
int ok = elem != NULL;
int type = 0;
char *strn = 0;
if (ok)
ok = PySequence_Check(elem);
if (ok) {
PyObject *temp = PySequence_GetItem(elem, 0);
if (temp == NULL)
ok = 0;
else {
ok = PyLong_Check(temp);
if (ok) {
type = _PyLong_AsInt(temp);
if (type == -1 && PyErr_Occurred()) {
Py_DECREF(temp);
Py_DECREF(elem);
return NULL;
}
}
Py_DECREF(temp);
}
}
if (!ok) {
PyObject *err = Py_BuildValue("Os", elem,
"Illegal node construct.");
PyErr_SetObject(parser_error, err);
Py_XDECREF(err);
Py_XDECREF(elem);
return NULL;
}
if (ISTERMINAL(type)) {
Py_ssize_t len = PyObject_Size(elem);
PyObject *temp;
const char *temp_str;
if ((len != 2) && (len != 3)) {
err_string("terminal nodes must have 2 or 3 entries");
Py_DECREF(elem);
return NULL;
}
temp = PySequence_GetItem(elem, 1);
if (temp == NULL) {
Py_DECREF(elem);
return NULL;
}
if (!PyUnicode_Check(temp)) {
PyErr_Format(parser_error,
"second item in terminal node must be a string,"
" found %s",
Py_TYPE(temp)->tp_name);
Py_DECREF(temp);
Py_DECREF(elem);
return NULL;
}
if (len == 3) {
PyObject *o = PySequence_GetItem(elem, 2);
if (o == NULL) {
Py_DECREF(temp);
Py_DECREF(elem);
return NULL;
}
if (PyLong_Check(o)) {
int num = _PyLong_AsInt(o);
if (num == -1 && PyErr_Occurred()) {
Py_DECREF(o);
Py_DECREF(temp);
Py_DECREF(elem);
return NULL;
}
*line_num = num;
}
else {
PyErr_Format(parser_error,
"third item in terminal node must be an"
" integer, found %s",
Py_TYPE(temp)->tp_name);
Py_DECREF(o);
Py_DECREF(temp);
Py_DECREF(elem);
return NULL;
}
Py_DECREF(o);
}
temp_str = _PyUnicode_AsStringAndSize(temp, &len);
if (temp_str == NULL) {
Py_DECREF(temp);
Py_DECREF(elem);
return NULL;
}
strn = (char *)PyObject_MALLOC(len + 1);
if (strn == NULL) {
Py_DECREF(temp);
Py_DECREF(elem);
PyErr_NoMemory();
return NULL;
}
(void) memcpy(strn, temp_str, len + 1);
Py_DECREF(temp);
}
else if (!ISNONTERMINAL(type)) {
/*
* It has to be one or the other; this is an error.
* Raise an exception.
*/
PyObject *err = Py_BuildValue("Os", elem, "unknown node type.");
PyErr_SetObject(parser_error, err);
Py_XDECREF(err);
Py_DECREF(elem);
return NULL;
}
err = PyNode_AddChild(root, type, strn, *line_num, 0);
if (err == E_NOMEM) {
Py_DECREF(elem);
PyObject_FREE(strn);
PyErr_NoMemory();
return NULL;
}
if (err == E_OVERFLOW) {
Py_DECREF(elem);
PyObject_FREE(strn);
PyErr_SetString(PyExc_ValueError,
"unsupported number of child nodes");
return NULL;
}
if (ISNONTERMINAL(type)) {
node* new_child = CHILD(root, i - 1);
if (new_child != build_node_children(elem, new_child, line_num)) {
Py_DECREF(elem);
return NULL;
}
}
else if (type == NEWLINE) { /* It's true: we increment the */
++(*line_num); /* line number *after* the newline! */
}
Py_DECREF(elem);
}
return root;
}
static node*
build_node_tree(PyObject *tuple)
{
node* res = 0;
PyObject *temp = PySequence_GetItem(tuple, 0);
long num = -1;
if (temp != NULL)
num = PyLong_AsLong(temp);
Py_XDECREF(temp);
if (ISTERMINAL(num)) {
/*
* The tuple is simple, but it doesn't start with a start symbol.
* Raise an exception now and be done with it.
*/
tuple = Py_BuildValue("Os", tuple,
"Illegal syntax-tree; cannot start with terminal symbol.");
PyErr_SetObject(parser_error, tuple);
Py_XDECREF(tuple);
}
else if (ISNONTERMINAL(num)) {
/*
* Not efficient, but that can be handled later.
*/
int line_num = 0;
PyObject *encoding = NULL;
if (num == encoding_decl) {
encoding = PySequence_GetItem(tuple, 2);
if (encoding == NULL) {
PyErr_SetString(parser_error, "missed encoding");
return NULL;
}
if (!PyUnicode_Check(encoding)) {
PyErr_Format(parser_error,
"encoding must be a string, found %.200s",
Py_TYPE(encoding)->tp_name);
Py_DECREF(encoding);
return NULL;
}
/* tuple isn't borrowed anymore here, need to DECREF */
tuple = PySequence_GetSlice(tuple, 0, 2);
if (tuple == NULL) {
Py_DECREF(encoding);
return NULL;
}
}
res = PyNode_New(num);
if (res != NULL) {
if (res != build_node_children(tuple, res, &line_num)) {
PyNode_Free(res);
res = NULL;
}
if (res && encoding) {
Py_ssize_t len;
const char *temp;
temp = _PyUnicode_AsStringAndSize(encoding, &len);
if (temp == NULL) {
PyNode_Free(res);
Py_DECREF(encoding);
Py_DECREF(tuple);
return NULL;
}
res->n_str = (char *)PyObject_MALLOC(len + 1);
if (res->n_str == NULL) {
PyNode_Free(res);
Py_DECREF(encoding);
Py_DECREF(tuple);
PyErr_NoMemory();
return NULL;
}
(void) memcpy(res->n_str, temp, len + 1);
}
}
if (encoding != NULL) {
Py_DECREF(encoding);
Py_DECREF(tuple);
}
}
else {
/* The tuple is illegal -- if the number is neither TERMINAL nor
* NONTERMINAL, we can't use it. Not sure the implementation
* allows this condition, but the API doesn't preclude it.
*/
PyObject *err = Py_BuildValue("Os", tuple,
"Illegal component tuple.");