summaryrefslogtreecommitdiffstats
path: root/Parser/asdl_c.py
blob: fdbbeafa63e725c1dd5954b3e91f8667e973ff7c (plain)
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
#! /usr/bin/env python
"""Generate C code from an ASDL description."""

# TO DO
# handle fields that have a type but no name

import os, sys, traceback

import asdl

TABSIZE = 8
MAX_COL = 80

def get_c_type(name):
    """Return a string for the C name of the type.

    This function special cases the default types provided by asdl:
    identifier, string, int, bool.
    """
    # XXX ack!  need to figure out where Id is useful and where string
    if isinstance(name, asdl.Id):
        name = name.value
    if name in asdl.builtin_types:
        return name
    else:
        return "%s_ty" % name

def reflow_lines(s, depth):
    """Reflow the line s indented depth tabs.

    Return a sequence of lines where no line extends beyond MAX_COL
    when properly indented.  The first line is properly indented based
    exclusively on depth * TABSIZE.  All following lines -- these are
    the reflowed lines generated by this function -- start at the same
    column as the first character beyond the opening { in the first
    line.
    """
    size = MAX_COL - depth * TABSIZE
    if len(s) < size:
        return [s]

    lines = []
    cur = s
    padding = ""
    while len(cur) > size:
        i = cur.rfind(' ', 0, size)
        # XXX this should be fixed for real
        if i == -1 and 'GeneratorExp' in cur:
            i = size + 3
        assert i != -1, "Impossible line %d to reflow: %s" % (size, `s`)
        lines.append(padding + cur[:i])
        if len(lines) == 1:
            # find new size based on brace
            j = cur.find('{', 0, i)
            if j >= 0:
                j += 2 # account for the brace and the space after it
                size -= j
                padding = " " * j
            else:
                j = cur.find('(', 0, i)
                if j >= 0:
                    j += 1 # account for the paren (no space after it)
                    size -= j
                    padding = " " * j
        cur = cur[i+1:]
    else:
        lines.append(padding + cur)
    return lines

def is_simple(sum):
    """Return True if a sum is a simple.

    A sum is simple if its types have no fields, e.g.
    unaryop = Invert | Not | UAdd | USub
    """

    for t in sum.types:
        if t.fields:
            return False
    return True

class EmitVisitor(asdl.VisitorBase):
    """Visit that emits lines"""

    def __init__(self, file):
        self.file = file
        super(EmitVisitor, self).__init__()

    def emit(self, s, depth, reflow=1):
        # XXX reflow long lines?
        if reflow:
            lines = reflow_lines(s, depth)
        else:
            lines = [s]
        for line in lines:
            line = (" " * TABSIZE * depth) + line + "\n"
            self.file.write(line)

class TypeDefVisitor(EmitVisitor):
    def visitModule(self, mod):
        for dfn in mod.dfns:
            self.visit(dfn)

    def visitType(self, type, depth=0):
        self.visit(type.value, type.name, depth)

    def visitSum(self, sum, name, depth):
        if is_simple(sum):
            self.simple_sum(sum, name, depth)
        else:
            self.sum_with_constructors(sum, name, depth)

    def simple_sum(self, sum, name, depth):
        enum = []
        for i in range(len(sum.types)):
            type = sum.types[i]
            enum.append("%s=%d" % (type.name, i + 1))
        enums = ", ".join(enum)
        ctype = get_c_type(name)
        s = "typedef enum _%s { %s } %s;" % (name, enums, ctype)
        self.emit(s, depth)
        self.emit("", depth)

    def sum_with_constructors(self, sum, name, depth):
        ctype = get_c_type(name)
        s = "typedef struct _%(name)s *%(ctype)s;" % locals()
        self.emit(s, depth)
        self.emit("", depth)

    def visitProduct(self, product, name, depth):
        ctype = get_c_type(name)
        s = "typedef struct _%(name)s *%(ctype)s;" % locals()
        self.emit(s, depth)
        self.emit("", depth)

class StructVisitor(EmitVisitor):
    """Visitor to generate typdefs for AST."""

    def visitModule(self, mod):
        for dfn in mod.dfns:
            self.visit(dfn)

    def visitType(self, type, depth=0):
        self.visit(type.value, type.name, depth)

    def visitSum(self, sum, name, depth):
        if not is_simple(sum):
            self.sum_with_constructors(sum, name, depth)

    def sum_with_constructors(self, sum, name, depth):
        def emit(s, depth=depth):
            self.emit(s % sys._getframe(1).f_locals, depth)
        enum = []
        for i in range(len(sum.types)):
            type = sum.types[i]
            enum.append("%s_kind=%d" % (type.name, i + 1))

        emit("struct _%(name)s {")
        emit("enum { " + ", ".join(enum) + " } kind;", depth + 1)
        emit("union {", depth + 1)
        for t in sum.types:
            self.visit(t, depth + 2)
        emit("} v;", depth + 1)
        for field in sum.attributes:
            # rudimentary attribute handling
            type = str(field.type)
            assert type in asdl.builtin_types, type
            emit("%s %s;" % (type, field.name), depth + 1);
        emit("};")
        emit("")

    def visitConstructor(self, cons, depth):
        if cons.fields:
            self.emit("struct {", depth)
            for f in cons.fields:
                self.visit(f, depth + 1)
            self.emit("} %s;" % cons.name, depth)
            self.emit("", depth)
        else:
            # XXX not sure what I want here, nothing is probably fine
            pass

    def visitField(self, field, depth):
        # XXX need to lookup field.type, because it might be something
        # like a builtin...
        ctype = get_c_type(field.type)
        name = field.name
        if field.seq:
            self.emit("asdl_seq *%(name)s;" % locals(), depth)
        else:
            self.emit("%(ctype)s %(name)s;" % locals(), depth)

    def visitProduct(self, product, name, depth):
        self.emit("struct _%(name)s {" % locals(), depth)
        for f in product.fields:
            self.visit(f, depth + 1)
        self.emit("};", depth)
        self.emit("", depth)

class PrototypeVisitor(EmitVisitor):
    """Generate function prototypes for the .h file"""

    def visitModule(self, mod):
        for dfn in mod.dfns:
            self.visit(dfn)

    def visitType(self, type):
        self.visit(type.value, type.name)

    def visitSum(self, sum, name):
        if is_simple(sum):
            pass # XXX
        else:
            for t in sum.types:
                self.visit(t, name, sum.attributes)

    def get_args(self, fields):
        """Return list of C argument into, one for each field.

        Argument info is 3-tuple of a C type, variable name, and flag
        that is true if type can be NULL.
        """
        args = []
        unnamed = {}
        for f in fields:
            if f.name is None:
                name = f.type
                c = unnamed[name] = unnamed.get(name, 0) + 1
                if c > 1:
                    name = "name%d" % (c - 1)
            else:
                name = f.name
            # XXX should extend get_c_type() to handle this
            if f.seq:
                ctype = "asdl_seq *"
            else:
                ctype = get_c_type(f.type)
            args.append((ctype, name, f.opt or f.seq))
        return args

    def visitConstructor(self, cons, type, attrs):
        args = self.get_args(cons.fields)
        attrs = self.get_args(attrs)
        ctype = get_c_type(type)
        self.emit_function(cons.name, ctype, args, attrs)

    def emit_function(self, name, ctype, args, attrs, union=1):
        args = args + attrs
        if args:
            argstr = ", ".join(["%s %s" % (atype, aname)
                                for atype, aname, opt in args])
            argstr += ", PyArena *arena"
        else:
            argstr = "PyArena *arena"
        self.emit("%s %s(%s);" % (ctype, name, argstr), 0)

    def visitProduct(self, prod, name):
        self.emit_function(name, get_c_type(name),
                           self.get_args(prod.fields), [], union=0)

class FunctionVisitor(PrototypeVisitor):
    """Visitor to generate constructor functions for AST."""

    def emit_function(self, name, ctype, args, attrs, union=1):
        def emit(s, depth=0, reflow=1):
            self.emit(s, depth, reflow)
        argstr = ", ".join(["%s %s" % (atype, aname)
                            for atype, aname, opt in args + attrs])
        if argstr:
            argstr += ", PyArena *arena"
        else:
            argstr = "PyArena *arena"
        self.emit("%s" % ctype, 0)
        emit("%s(%s)" % (name, argstr))
        emit("{")
        emit("%s p;" % ctype, 1)
        for argtype, argname, opt in args:
            # XXX hack alert: false is allowed for a bool
            if not opt and not (argtype == "bool" or argtype == "int"):
                emit("if (!%s) {" % argname, 1)
                emit("PyErr_SetString(PyExc_ValueError,", 2)
                msg = "field %s is required for %s" % (argname, name)
                emit('                "%s");' % msg,
                     2, reflow=0)
                emit('return NULL;', 2)
                emit('}', 1)

        emit("p = (%s)PyArena_Malloc(arena, sizeof(*p));" % ctype, 1);
        emit("if (!p) {", 1)
        emit("PyErr_NoMemory();", 2)
        emit("return NULL;", 2)
        emit("}", 1)
        if union:
            self.emit_body_union(name, args, attrs)
        else:
            self.emit_body_struct(name, args, attrs)
        emit("return p;", 1)
        emit("}")
        emit("")

    def emit_body_union(self, name, args, attrs):
        def emit(s, depth=0, reflow=1):
            self.emit(s, depth, reflow)
        emit("p->kind = %s_kind;" % name, 1)
        for argtype, argname, opt in args:
            emit("p->v.%s.%s = %s;" % (name, argname, argname), 1)
        for argtype, argname, opt in attrs:
            emit("p->%s = %s;" % (argname, argname), 1)

    def emit_body_struct(self, name, args, attrs):
        def emit(s, depth=0, reflow=1):
            self.emit(s, depth, reflow)
        for argtype, argname, opt in args:
            emit("p->%s = %s;" % (argname, argname), 1)
        assert not attrs

class PickleVisitor(EmitVisitor):

    def visitModule(self, mod):
        for dfn in mod.dfns:
            self.visit(dfn)

    def visitType(self, type):
        self.visit(type.value, type.name)

    def visitSum(self, sum, name):
        pass

    def visitProduct(self, sum, name):
        pass

    def visitConstructor(self, cons, name):
        pass

    def visitField(self, sum):
        pass

class MarshalPrototypeVisitor(PickleVisitor):

    def prototype(self, sum, name):
        ctype = get_c_type(name)
        self.emit("static int marshal_write_%s(PyObject **, int *, %s);"
                  % (name, ctype), 0)

    visitProduct = visitSum = prototype

class PyTypesDeclareVisitor(PickleVisitor):

    def visitProduct(self, prod, name):
        self.emit("static PyTypeObject *%s_type;" % name, 0)
        self.emit("static PyObject* ast2obj_%s(void*);" % name, 0)
        if prod.fields:
            self.emit("static char *%s_fields[]={" % name,0)
            for f in prod.fields:
                self.emit('"%s",' % f.name, 1)
            self.emit("};", 0)

    def visitSum(self, sum, name):
        self.emit("static PyTypeObject *%s_type;" % name, 0)
        if sum.attributes:
            self.emit("static char *%s_attributes[] = {" % name, 0)
            for a in sum.attributes:
                self.emit('"%s",' % a.name, 1)
            self.emit("};", 0)
        ptype = "void*"
        if is_simple(sum):
            ptype = get_c_type(name)
            tnames = []
            for t in sum.types:
                tnames.append(str(t.name)+"_singleton")
            tnames = ", *".join(tnames)
            self.emit("static PyObject *%s;" % tnames, 0)
        self.emit("static PyObject* ast2obj_%s(%s);" % (name, ptype), 0)
        for t in sum.types:
            self.visitConstructor(t, name)

    def visitConstructor(self, cons, name):
        self.emit("static PyTypeObject *%s_type;" % cons.name, 0)
        if cons.fields:
            self.emit("static char *%s_fields[]={" % cons.name, 0)
            for t in cons.fields:
                self.emit('"%s",' % t.name, 1)
            self.emit("};",0)

class PyTypesVisitor(PickleVisitor):

    def visitModule(self, mod):
        self.emit("""
static PyTypeObject* make_type(char *type, PyTypeObject* base, char**fields, int num_fields)
{
    PyObject *fnames, *result;
    int i;
    if (num_fields) {
        fnames = PyTuple_New(num_fields);
        if (!fnames) return NULL;
    } else {
        fnames = Py_None;
        Py_INCREF(Py_None);
    }
    for(i=0; i < num_fields; i++) {
        PyObject *field = PyString_FromString(fields[i]);
        if (!field) {
            Py_DECREF(fnames);
            return NULL;
        }
        PyTuple_SET_ITEM(fnames, i, field);
    }
    result = PyObject_CallFunction((PyObject*)&PyType_Type, "s(O){sOss}",
                    type, base, "_fields", fnames, "__module__", "_ast");
    Py_DECREF(fnames);
    return (PyTypeObject*)result;
}

static int add_attributes(PyTypeObject* type, char**attrs, int num_fields)
{
    int i, result;
    PyObject *s, *l = PyList_New(num_fields);
    if (!l) return 0;
    for(i = 0; i < num_fields; i++) {
        s = PyString_FromString(attrs[i]);
        if (!s) {
            Py_DECREF(l);
            return 0;
        }
        PyList_SET_ITEM(l, i, s);
    }
    result = PyObject_SetAttrString((PyObject*)type, "_attributes", l) >= 0;
    Py_DECREF(l);
    return result;
}

static PyObject* ast2obj_list(asdl_seq *seq, PyObject* (*func)(void*))
{
    int i, n = asdl_seq_LEN(seq);
    PyObject *result = PyList_New(n);
    PyObject *value;
    if (!result)
        return NULL;
    for (i = 0; i < n; i++) {
        value = func(asdl_seq_GET(seq, i));
        if (!value) {
            Py_DECREF(result);
            return NULL;
        }
        PyList_SET_ITEM(result, i, value);
    }
    return result;
}

static PyObject* ast2obj_object(void *o)
{
    if (!o)
        o = Py_None;
    Py_INCREF((PyObject*)o);
    return (PyObject*)o;
}
#define ast2obj_identifier ast2obj_object
#define ast2obj_string ast2obj_object
static PyObject* ast2obj_bool(bool b)
{
    return PyBool_FromLong(b);
}

static PyObject* ast2obj_int(bool b)
{
    return PyInt_FromLong(b);
}
""", 0, reflow=False)

        self.emit("static int init_types(void)",0)
        self.emit("{", 0)
        self.emit("static int initialized;", 1)
        self.emit("if (initialized) return 1;", 1)
        self.emit('AST_type = make_type("AST", &PyBaseObject_Type, NULL, 0);', 1)
        for dfn in mod.dfns:
            self.visit(dfn)
        self.emit("initialized = 1;", 1)
        self.emit("return 1;", 1);
        self.emit("}", 0)

    def visitProduct(self, prod, name):
        if prod.fields:
            fields = name.value+"_fields"
        else:
            fields = "NULL"
        self.emit('%s_type = make_type("%s", AST_type, %s, %d);' %
                        (name, name, fields, len(prod.fields)), 1)
        self.emit("if (!%s_type) return 0;" % name, 1)

    def visitSum(self, sum, name):
        self.emit('%s_type = make_type("%s", AST_type, NULL, 0);' % (name, name), 1)
        self.emit("if (!%s_type) return 0;" % name, 1)
        if sum.attributes:
            self.emit("if (!add_attributes(%s_type, %s_attributes, %d)) return 0;" %
                            (name, name, len(sum.attributes)), 1)
        else:
            self.emit("if (!add_attributes(%s_type, NULL, 0)) return 0;" % name, 1)
        simple = is_simple(sum)
        for t in sum.types:
            self.visitConstructor(t, name, simple)

    def visitConstructor(self, cons, name, simple):
        if cons.fields:
            fields = cons.name.value+"_fields"
        else:
            fields = "NULL"
        self.emit('%s_type = make_type("%s", %s_type, %s, %d);' %
                            (cons.name, cons.name, name, fields, len(cons.fields)), 1)
        self.emit("if (!%s_type) return 0;" % cons.name, 1)
        if simple:
            self.emit("%s_singleton = PyType_GenericNew(%s_type, NULL, NULL);" %
                             (cons.name, cons.name), 1)
            self.emit("if (!%s_singleton) return 0;" % cons.name, 1)

class ASTModuleVisitor(PickleVisitor):

    def visitModule(self, mod):
        self.emit("PyMODINIT_FUNC", 0)
        self.emit("init_ast(void)", 0)
        self.emit("{", 0)
        self.emit("PyObject *m, *d;", 1)
        self.emit("if (!init_types()) return;", 1)
        self.emit('m = Py_InitModule3("_ast", NULL, NULL);', 1)
        self.emit("if (!m) return;", 1)
        self.emit("d = PyModule_GetDict(m);", 1)
        self.emit('if (PyDict_SetItemString(d, "AST", (PyObject*)AST_type) < 0) return;', 1)
        self.emit('if (PyModule_AddIntConstant(m, "PyCF_ONLY_AST", PyCF_ONLY_AST) < 0)', 1)
        self.emit("return;", 2)
        # Value of version: "$Revision$"
        self.emit('if (PyModule_AddStringConstant(m, "__version__", "%s") < 0)' % mod.version.value[12:-3], 1)
        self.emit("return;", 2)
        for dfn in mod.dfns:
            self.visit(dfn)
        self.emit("}", 0)

    def visitProduct(self, prod, name):
        self.addObj(name)

    def visitSum(self, sum, name):
        self.addObj(name)
        for t in sum.types:
            self.visitConstructor(t, name)

    def visitConstructor(self, cons, name):
        self.addObj(cons.name)

    def addObj(self, name):
        self.emit('if (PyDict_SetItemString(d, "%s", (PyObject*)%s_type) < 0) return;' % (name, name), 1)

_SPECIALIZED_SEQUENCES = ('stmt', 'expr')

def find_sequence(fields, doing_specialization):
    """Return True if any field uses a sequence."""
    for f in fields:
        if f.seq:
            if not doing_specialization:
                return True
            if str(f.type) not in _SPECIALIZED_SEQUENCES:
                return True
    return False

def has_sequence(types, doing_specialization):
    for t in types:
        if find_sequence(t.fields, doing_specialization):
            return True
    return False


class StaticVisitor(PickleVisitor):
    CODE = '''Very simple, always emit this static code.  Overide CODE'''

    def visit(self, object):
        self.emit(self.CODE, 0, reflow=False)

class ObjVisitor(PickleVisitor):

    def func_begin(self, name):
        ctype = get_c_type(name)
        self.emit("PyObject*", 0)
        self.emit("ast2obj_%s(void* _o)" % (name), 0)
        self.emit("{", 0)
        self.emit("%s o = (%s)_o;" % (ctype, ctype), 1)
        self.emit("PyObject *result = NULL, *value = NULL;", 1)
        self.emit('if (!o) {', 1)
        self.emit("Py_INCREF(Py_None);", 2)
        self.emit('return Py_None;', 2)
        self.emit("}", 1)
        self.emit('', 0)

    def func_end(self):
        self.emit("return result;", 1)
        self.emit("failed:", 0)
        self.emit("Py_XDECREF(value);", 1)
        self.emit("Py_XDECREF(result);", 1)
        self.emit("return NULL;", 1)
        self.emit("}", 0)
        self.emit("", 0)

    def visitSum(self, sum, name):
        if is_simple(sum):
            self.simpleSum(sum, name)
            return
        self.func_begin(name)
        self.emit("switch (o->kind) {", 1)
        for i in range(len(sum.types)):
            t = sum.types[i]
            self.visitConstructor(t, i + 1, name)
        self.emit("}", 1)
        for a in sum.attributes:
            self.emit("value = ast2obj_%s(o->%s);" % (a.type, a.name), 1)
            self.emit("if (!value) goto failed;", 1)
            self.emit('if (PyObject_SetAttrString(result, "%s", value) < 0)' % a.name, 1)
            self.emit('goto failed;', 2)
            self.emit('Py_DECREF(value);', 1)
        self.func_end()

    def simpleSum(self, sum, name):
        self.emit("PyObject* ast2obj_%s(%s_ty o)" % (name, name), 0)
        self.emit("{", 0)
        self.emit("switch(o) {", 1)
        for t in sum.types:
            self.emit("case %s:" % t.name, 2)
            self.emit("Py_INCREF(%s_singleton);" % t.name, 3)
            self.emit("return %s_singleton;" % t.name, 3)
        self.emit("}", 1)
        self.emit("return NULL; /* cannot happen */", 1)
        self.emit("}", 0)

    def visitProduct(self, prod, name):
        self.func_begin(name)
        self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % name, 1);
        self.emit("if (!result) return NULL;", 1)
        for field in prod.fields:
            self.visitField(field, name, 1, True)
        self.func_end()

    def visitConstructor(self, cons, enum, name):
        self.emit("case %s_kind:" % cons.name, 1)
        self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % cons.name, 2);
        self.emit("if (!result) goto failed;", 2)
        for f in cons.fields:
            self.visitField(f, cons.name, 2, False)
        self.emit("break;", 2)

    def visitField(self, field, name, depth, product):
        def emit(s, d):
            self.emit(s, depth + d)
        if product:
            value = "o->%s" % field.name
        else:
            value = "o->v.%s.%s" % (name, field.name)
        self.set(field, value, depth)
        emit("if (!value) goto failed;", 0)
        emit('if (PyObject_SetAttrString(result, "%s", value) == -1)' % field.name, 0)
        emit("goto failed;", 1)
        emit("Py_DECREF(value);", 0)

    def emitSeq(self, field, value, depth, emit):
        emit("seq = %s;" % value, 0)
        emit("n = asdl_seq_LEN(seq);", 0)
        emit("value = PyList_New(n);", 0)
        emit("if (!value) goto failed;", 0)
        emit("for (i = 0; i < n; i++) {", 0)
        self.set("value", field, "asdl_seq_GET(seq, i)", depth + 1)
        emit("if (!value1) goto failed;", 1)
        emit("PyList_SET_ITEM(value, i, value1);", 1)
        emit("value1 = NULL;", 1)
        emit("}", 0)

    def set(self, field, value, depth):
        if field.seq:
            # XXX should really check for is_simple, but that requires a symbol table
            if field.type.value == "cmpop":
                # While the sequence elements are stored as void*,
                # ast2obj_cmpop expects an enum
                self.emit("{", depth)
                self.emit("int i, n = asdl_seq_LEN(%s);" % value, depth+1)
                self.emit("value = PyList_New(n);", depth+1)
                self.emit("if (!value) goto failed;", depth+1)
                self.emit("for(i = 0; i < n; i++)", depth+1)
                # This cannot fail, so no need for error handling
                self.emit("PyList_SET_ITEM(value, i, ast2obj_%s((%s_ty)asdl_seq_GET(%s, i)));" %
                                (field.type, field.type, value), depth+2, reflow=False)
                self.emit("}", depth)
            else:
                self.emit("value = ast2obj_list(%s, ast2obj_%s);" % (value, field.type), depth)
        else:
            ctype = get_c_type(field.type)
            self.emit("value = ast2obj_%s(%s);" % (field.type, value), depth, reflow=False)


class PartingShots(StaticVisitor):

    CODE = """
PyObject* PyAST_mod2obj(mod_ty t)
{
    init_types();
    return ast2obj_mod(t);
}
"""

class ChainOfVisitors:
    def __init__(self, *visitors):
        self.visitors = visitors

    def visit(self, object):
        for v in self.visitors:
            v.visit(object)
            v.emit("", 0)

def main(srcfile):
    argv0 = sys.argv[0]
    components = argv0.split(os.sep)
    argv0 = os.sep.join(components[-2:])
    auto_gen_msg = '/* File automatically generated by %s */\n' % argv0
    mod = asdl.parse(srcfile)
    if not asdl.check(mod):
        sys.exit(1)
    if INC_DIR:
        p = "%s/%s-ast.h" % (INC_DIR, mod.name)
    else:
        p = "%s-ast.h" % mod.name
    f = open(p, "wb")
    print >> f, auto_gen_msg
    print >> f, '#include "asdl.h"\n'
    c = ChainOfVisitors(TypeDefVisitor(f),
                        StructVisitor(f),
                        PrototypeVisitor(f),
                        )
    c.visit(mod)
    print >>f, "PyObject* PyAST_mod2obj(mod_ty t);"
    f.close()

    if SRC_DIR:
        p = os.path.join(SRC_DIR, str(mod.name) + "-ast.c")
    else:
        p = "%s-ast.c" % mod.name
    f = open(p, "wb")
    print >> f, auto_gen_msg
    print >> f, '#include "Python.h"'
    print >> f, '#include "%s-ast.h"' % mod.name
    print >> f
    print >>f, "static PyTypeObject* AST_type;"
    v = ChainOfVisitors(
                        PyTypesDeclareVisitor(f),
                        PyTypesVisitor(f),
                        FunctionVisitor(f),
                        ObjVisitor(f),
                        ASTModuleVisitor(f),
                        PartingShots(f),
                        )
    v.visit(mod)
    f.close()

if __name__ == "__main__":
    import sys
    import getopt

    INC_DIR = ''
    SRC_DIR = ''
    opts, args = getopt.getopt(sys.argv[1:], "h:c:")
    for o, v in opts:
        if o == '-h':
            INC_DIR = v
        if o == '-c':
            SRC_DIR = v
    if len(args) != 1:
        print "Must specify single input file"
    main(args[0])