1#! /usr/bin/env python
2"""Generate C code from an ASDL description."""
3
4# TO DO
5# handle fields that have a type but no name
6
7import os, sys
8
9import asdl
10
11TABSIZE = 8
12MAX_COL = 80
13
14def get_c_type(name):
15    """Return a string for the C name of the type.
16
17    This function special cases the default types provided by asdl:
18    identifier, string, int, bool.
19    """
20    # XXX ack!  need to figure out where Id is useful and where string
21    if isinstance(name, asdl.Id):
22        name = name.value
23    if name in asdl.builtin_types:
24        return name
25    else:
26        return "%s_ty" % name
27
28def reflow_lines(s, depth):
29    """Reflow the line s indented depth tabs.
30
31    Return a sequence of lines where no line extends beyond MAX_COL
32    when properly indented.  The first line is properly indented based
33    exclusively on depth * TABSIZE.  All following lines -- these are
34    the reflowed lines generated by this function -- start at the same
35    column as the first character beyond the opening { in the first
36    line.
37    """
38    size = MAX_COL - depth * TABSIZE
39    if len(s) < size:
40        return [s]
41
42    lines = []
43    cur = s
44    padding = ""
45    while len(cur) > size:
46        i = cur.rfind(' ', 0, size)
47        # XXX this should be fixed for real
48        if i == -1 and 'GeneratorExp' in cur:
49            i = size + 3
50        assert i != -1, "Impossible line %d to reflow: %r" % (size, s)
51        lines.append(padding + cur[:i])
52        if len(lines) == 1:
53            # find new size based on brace
54            j = cur.find('{', 0, i)
55            if j >= 0:
56                j += 2 # account for the brace and the space after it
57                size -= j
58                padding = " " * j
59            else:
60                j = cur.find('(', 0, i)
61                if j >= 0:
62                    j += 1 # account for the paren (no space after it)
63                    size -= j
64                    padding = " " * j
65        cur = cur[i+1:]
66    else:
67        lines.append(padding + cur)
68    return lines
69
70def is_simple(sum):
71    """Return True if a sum is a simple.
72
73    A sum is simple if its types have no fields, e.g.
74    unaryop = Invert | Not | UAdd | USub
75    """
76    for t in sum.types:
77        if t.fields:
78            return False
79    return True
80
81
82class EmitVisitor(asdl.VisitorBase):
83    """Visit that emits lines"""
84
85    def __init__(self, file):
86        self.file = file
87        super(EmitVisitor, self).__init__()
88
89    def emit(self, s, depth, reflow=True):
90        # XXX reflow long lines?
91        if reflow:
92            lines = reflow_lines(s, depth)
93        else:
94            lines = [s]
95        for line in lines:
96            line = (" " * TABSIZE * depth) + line + "\n"
97            self.file.write(line)
98
99
100class TypeDefVisitor(EmitVisitor):
101    def visitModule(self, mod):
102        for dfn in mod.dfns:
103            self.visit(dfn)
104
105    def visitType(self, type, depth=0):
106        self.visit(type.value, type.name, depth)
107
108    def visitSum(self, sum, name, depth):
109        if is_simple(sum):
110            self.simple_sum(sum, name, depth)
111        else:
112            self.sum_with_constructors(sum, name, depth)
113
114    def simple_sum(self, sum, name, depth):
115        enum = []
116        for i in range(len(sum.types)):
117            type = sum.types[i]
118            enum.append("%s=%d" % (type.name, i + 1))
119        enums = ", ".join(enum)
120        ctype = get_c_type(name)
121        s = "typedef enum _%s { %s } %s;" % (name, enums, ctype)
122        self.emit(s, depth)
123        self.emit("", depth)
124
125    def sum_with_constructors(self, sum, name, depth):
126        ctype = get_c_type(name)
127        s = "typedef struct _%(name)s *%(ctype)s;" % locals()
128        self.emit(s, depth)
129        self.emit("", depth)
130
131    def visitProduct(self, product, name, depth):
132        ctype = get_c_type(name)
133        s = "typedef struct _%(name)s *%(ctype)s;" % locals()
134        self.emit(s, depth)
135        self.emit("", depth)
136
137
138class StructVisitor(EmitVisitor):
139    """Visitor to generate typdefs for AST."""
140
141    def visitModule(self, mod):
142        for dfn in mod.dfns:
143            self.visit(dfn)
144
145    def visitType(self, type, depth=0):
146        self.visit(type.value, type.name, depth)
147
148    def visitSum(self, sum, name, depth):
149        if not is_simple(sum):
150            self.sum_with_constructors(sum, name, depth)
151
152    def sum_with_constructors(self, sum, name, depth):
153        def emit(s, depth=depth):
154            self.emit(s % sys._getframe(1).f_locals, depth)
155        enum = []
156        for i in range(len(sum.types)):
157            type = sum.types[i]
158            enum.append("%s_kind=%d" % (type.name, i + 1))
159
160        emit("enum _%(name)s_kind {" + ", ".join(enum) + "};")
161
162        emit("struct _%(name)s {")
163        emit("enum _%(name)s_kind kind;", depth + 1)
164        emit("union {", depth + 1)
165        for t in sum.types:
166            self.visit(t, depth + 2)
167        emit("} v;", depth + 1)
168        for field in sum.attributes:
169            # rudimentary attribute handling
170            type = str(field.type)
171            assert type in asdl.builtin_types, type
172            emit("%s %s;" % (type, field.name), depth + 1);
173        emit("};")
174        emit("")
175
176    def visitConstructor(self, cons, depth):
177        if cons.fields:
178            self.emit("struct {", depth)
179            for f in cons.fields:
180                self.visit(f, depth + 1)
181            self.emit("} %s;" % cons.name, depth)
182            self.emit("", depth)
183        else:
184            # XXX not sure what I want here, nothing is probably fine
185            pass
186
187    def visitField(self, field, depth):
188        # XXX need to lookup field.type, because it might be something
189        # like a builtin...
190        ctype = get_c_type(field.type)
191        name = field.name
192        if field.seq:
193            if field.type.value in ('cmpop',):
194                self.emit("asdl_int_seq *%(name)s;" % locals(), depth)
195            else:
196                self.emit("asdl_seq *%(name)s;" % locals(), depth)
197        else:
198            self.emit("%(ctype)s %(name)s;" % locals(), depth)
199
200    def visitProduct(self, product, name, depth):
201        self.emit("struct _%(name)s {" % locals(), depth)
202        for f in product.fields:
203            self.visit(f, depth + 1)
204        self.emit("};", depth)
205        self.emit("", depth)
206
207
208class PrototypeVisitor(EmitVisitor):
209    """Generate function prototypes for the .h file"""
210
211    def visitModule(self, mod):
212        for dfn in mod.dfns:
213            self.visit(dfn)
214
215    def visitType(self, type):
216        self.visit(type.value, type.name)
217
218    def visitSum(self, sum, name):
219        if is_simple(sum):
220            pass # XXX
221        else:
222            for t in sum.types:
223                self.visit(t, name, sum.attributes)
224
225    def get_args(self, fields):
226        """Return list of C argument into, one for each field.
227
228        Argument info is 3-tuple of a C type, variable name, and flag
229        that is true if type can be NULL.
230        """
231        args = []
232        unnamed = {}
233        for f in fields:
234            if f.name is None:
235                name = f.type
236                c = unnamed[name] = unnamed.get(name, 0) + 1
237                if c > 1:
238                    name = "name%d" % (c - 1)
239            else:
240                name = f.name
241            # XXX should extend get_c_type() to handle this
242            if f.seq:
243                if f.type.value in ('cmpop',):
244                    ctype = "asdl_int_seq *"
245                else:
246                    ctype = "asdl_seq *"
247            else:
248                ctype = get_c_type(f.type)
249            args.append((ctype, name, f.opt or f.seq))
250        return args
251
252    def visitConstructor(self, cons, type, attrs):
253        args = self.get_args(cons.fields)
254        attrs = self.get_args(attrs)
255        ctype = get_c_type(type)
256        self.emit_function(cons.name, ctype, args, attrs)
257
258    def emit_function(self, name, ctype, args, attrs, union=True):
259        args = args + attrs
260        if args:
261            argstr = ", ".join(["%s %s" % (atype, aname)
262                                for atype, aname, opt in args])
263            argstr += ", PyArena *arena"
264        else:
265            argstr = "PyArena *arena"
266        margs = "a0"
267        for i in range(1, len(args)+1):
268            margs += ", a%d" % i
269        self.emit("#define %s(%s) _Py_%s(%s)" % (name, margs, name, margs), 0,
270                reflow=False)
271        self.emit("%s _Py_%s(%s);" % (ctype, name, argstr), False)
272
273    def visitProduct(self, prod, name):
274        self.emit_function(name, get_c_type(name),
275                           self.get_args(prod.fields), [], union=False)
276
277
278class FunctionVisitor(PrototypeVisitor):
279    """Visitor to generate constructor functions for AST."""
280
281    def emit_function(self, name, ctype, args, attrs, union=True):
282        def emit(s, depth=0, reflow=True):
283            self.emit(s, depth, reflow)
284        argstr = ", ".join(["%s %s" % (atype, aname)
285                            for atype, aname, opt in args + attrs])
286        if argstr:
287            argstr += ", PyArena *arena"
288        else:
289            argstr = "PyArena *arena"
290        self.emit("%s" % ctype, 0)
291        emit("%s(%s)" % (name, argstr))
292        emit("{")
293        emit("%s p;" % ctype, 1)
294        for argtype, argname, opt in args:
295            # XXX hack alert: false is allowed for a bool
296            if not opt and not (argtype == "bool" or argtype == "int"):
297                emit("if (!%s) {" % argname, 1)
298                emit("PyErr_SetString(PyExc_ValueError,", 2)
299                msg = "field %s is required for %s" % (argname, name)
300                emit('                "%s");' % msg,
301                     2, reflow=False)
302                emit('return NULL;', 2)
303                emit('}', 1)
304
305        emit("p = (%s)PyArena_Malloc(arena, sizeof(*p));" % ctype, 1);
306        emit("if (!p)", 1)
307        emit("return NULL;", 2)
308        if union:
309            self.emit_body_union(name, args, attrs)
310        else:
311            self.emit_body_struct(name, args, attrs)
312        emit("return p;", 1)
313        emit("}")
314        emit("")
315
316    def emit_body_union(self, name, args, attrs):
317        def emit(s, depth=0, reflow=True):
318            self.emit(s, depth, reflow)
319        emit("p->kind = %s_kind;" % name, 1)
320        for argtype, argname, opt in args:
321            emit("p->v.%s.%s = %s;" % (name, argname, argname), 1)
322        for argtype, argname, opt in attrs:
323            emit("p->%s = %s;" % (argname, argname), 1)
324
325    def emit_body_struct(self, name, args, attrs):
326        def emit(s, depth=0, reflow=True):
327            self.emit(s, depth, reflow)
328        for argtype, argname, opt in args:
329            emit("p->%s = %s;" % (argname, argname), 1)
330        assert not attrs
331
332
333class PickleVisitor(EmitVisitor):
334
335    def visitModule(self, mod):
336        for dfn in mod.dfns:
337            self.visit(dfn)
338
339    def visitType(self, type):
340        self.visit(type.value, type.name)
341
342    def visitSum(self, sum, name):
343        pass
344
345    def visitProduct(self, sum, name):
346        pass
347
348    def visitConstructor(self, cons, name):
349        pass
350
351    def visitField(self, sum):
352        pass
353
354
355class Obj2ModPrototypeVisitor(PickleVisitor):
356    def visitProduct(self, prod, name):
357        code = "static int obj2ast_%s(PyObject* obj, %s* out, PyArena* arena);"
358        self.emit(code % (name, get_c_type(name)), 0)
359
360    visitSum = visitProduct
361
362
363class Obj2ModVisitor(PickleVisitor):
364    def funcHeader(self, name):
365        ctype = get_c_type(name)
366        self.emit("int", 0)
367        self.emit("obj2ast_%s(PyObject* obj, %s* out, PyArena* arena)" % (name, ctype), 0)
368        self.emit("{", 0)
369        self.emit("PyObject* tmp = NULL;", 1)
370        self.emit("int isinstance;", 1)
371        self.emit("", 0)
372
373    def sumTrailer(self, name):
374        self.emit("", 0)
375        self.emit("tmp = PyObject_Repr(obj);", 1)
376        # there's really nothing more we can do if this fails ...
377        self.emit("if (tmp == NULL) goto failed;", 1)
378        error = "expected some sort of %s, but got %%.400s" % name
379        format = "PyErr_Format(PyExc_TypeError, \"%s\", PyString_AS_STRING(tmp));"
380        self.emit(format % error, 1, reflow=False)
381        self.emit("failed:", 0)
382        self.emit("Py_XDECREF(tmp);", 1)
383        self.emit("return 1;", 1)
384        self.emit("}", 0)
385        self.emit("", 0)
386
387    def simpleSum(self, sum, name):
388        self.funcHeader(name)
389        for t in sum.types:
390            line = ("isinstance = PyObject_IsInstance(obj, "
391                    "(PyObject *)%s_type);")
392            self.emit(line % (t.name,), 1)
393            self.emit("if (isinstance == -1) {", 1)
394            self.emit("return 1;", 2)
395            self.emit("}", 1)
396            self.emit("if (isinstance) {", 1)
397            self.emit("*out = %s;" % t.name, 2)
398            self.emit("return 0;", 2)
399            self.emit("}", 1)
400        self.sumTrailer(name)
401
402    def buildArgs(self, fields):
403        return ", ".join(fields + ["arena"])
404
405    def complexSum(self, sum, name):
406        self.funcHeader(name)
407        for a in sum.attributes:
408            self.visitAttributeDeclaration(a, name, sum=sum)
409        self.emit("", 0)
410        # XXX: should we only do this for 'expr'?
411        self.emit("if (obj == Py_None) {", 1)
412        self.emit("*out = NULL;", 2)
413        self.emit("return 0;", 2)
414        self.emit("}", 1)
415        for a in sum.attributes:
416            self.visitField(a, name, sum=sum, depth=1)
417        for t in sum.types:
418            line = "isinstance = PyObject_IsInstance(obj, (PyObject*)%s_type);"
419            self.emit(line % (t.name,), 1)
420            self.emit("if (isinstance == -1) {", 1)
421            self.emit("return 1;", 2)
422            self.emit("}", 1)
423            self.emit("if (isinstance) {", 1)
424            for f in t.fields:
425                self.visitFieldDeclaration(f, t.name, sum=sum, depth=2)
426            self.emit("", 0)
427            for f in t.fields:
428                self.visitField(f, t.name, sum=sum, depth=2)
429            args = [f.name.value for f in t.fields] + [a.name.value for a in sum.attributes]
430            self.emit("*out = %s(%s);" % (t.name, self.buildArgs(args)), 2)
431            self.emit("if (*out == NULL) goto failed;", 2)
432            self.emit("return 0;", 2)
433            self.emit("}", 1)
434        self.sumTrailer(name)
435
436    def visitAttributeDeclaration(self, a, name, sum=sum):
437        ctype = get_c_type(a.type)
438        self.emit("%s %s;" % (ctype, a.name), 1)
439
440    def visitSum(self, sum, name):
441        if is_simple(sum):
442            self.simpleSum(sum, name)
443        else:
444            self.complexSum(sum, name)
445
446    def visitProduct(self, prod, name):
447        ctype = get_c_type(name)
448        self.emit("int", 0)
449        self.emit("obj2ast_%s(PyObject* obj, %s* out, PyArena* arena)" % (name, ctype), 0)
450        self.emit("{", 0)
451        self.emit("PyObject* tmp = NULL;", 1)
452        for f in prod.fields:
453            self.visitFieldDeclaration(f, name, prod=prod, depth=1)
454        self.emit("", 0)
455        for f in prod.fields:
456            self.visitField(f, name, prod=prod, depth=1)
457        args = [f.name.value for f in prod.fields]
458        self.emit("*out = %s(%s);" % (name, self.buildArgs(args)), 1)
459        self.emit("return 0;", 1)
460        self.emit("failed:", 0)
461        self.emit("Py_XDECREF(tmp);", 1)
462        self.emit("return 1;", 1)
463        self.emit("}", 0)
464        self.emit("", 0)
465
466    def visitFieldDeclaration(self, field, name, sum=None, prod=None, depth=0):
467        ctype = get_c_type(field.type)
468        if field.seq:
469            if self.isSimpleType(field):
470                self.emit("asdl_int_seq* %s;" % field.name, depth)
471            else:
472                self.emit("asdl_seq* %s;" % field.name, depth)
473        else:
474            ctype = get_c_type(field.type)
475            self.emit("%s %s;" % (ctype, field.name), depth)
476
477    def isSimpleSum(self, field):
478        # XXX can the members of this list be determined automatically?
479        return field.type.value in ('expr_context', 'boolop', 'operator',
480                                    'unaryop', 'cmpop')
481
482    def isNumeric(self, field):
483        return get_c_type(field.type) in ("int", "bool")
484
485    def isSimpleType(self, field):
486        return self.isSimpleSum(field) or self.isNumeric(field)
487
488    def visitField(self, field, name, sum=None, prod=None, depth=0):
489        ctype = get_c_type(field.type)
490        self.emit("if (PyObject_HasAttrString(obj, \"%s\")) {" % field.name, depth)
491        self.emit("int res;", depth+1)
492        if field.seq:
493            self.emit("Py_ssize_t len;", depth+1)
494            self.emit("Py_ssize_t i;", depth+1)
495        self.emit("tmp = PyObject_GetAttrString(obj, \"%s\");" % field.name, depth+1)
496        self.emit("if (tmp == NULL) goto failed;", depth+1)
497        if field.seq:
498            self.emit("if (!PyList_Check(tmp)) {", depth+1)
499            self.emit("PyErr_Format(PyExc_TypeError, \"%s field \\\"%s\\\" must "
500                      "be a list, not a %%.200s\", tmp->ob_type->tp_name);" %
501                      (name, field.name),
502                      depth+2, reflow=False)
503            self.emit("goto failed;", depth+2)
504            self.emit("}", depth+1)
505            self.emit("len = PyList_GET_SIZE(tmp);", depth+1)
506            if self.isSimpleType(field):
507                self.emit("%s = asdl_int_seq_new(len, arena);" % field.name, depth+1)
508            else:
509                self.emit("%s = asdl_seq_new(len, arena);" % field.name, depth+1)
510            self.emit("if (%s == NULL) goto failed;" % field.name, depth+1)
511            self.emit("for (i = 0; i < len; i++) {", depth+1)
512            self.emit("%s value;" % ctype, depth+2)
513            self.emit("res = obj2ast_%s(PyList_GET_ITEM(tmp, i), &value, arena);" %
514                      field.type, depth+2, reflow=False)
515            self.emit("if (res != 0) goto failed;", depth+2)
516            self.emit("asdl_seq_SET(%s, i, value);" % field.name, depth+2)
517            self.emit("}", depth+1)
518        else:
519            self.emit("res = obj2ast_%s(tmp, &%s, arena);" %
520                      (field.type, field.name), depth+1)
521            self.emit("if (res != 0) goto failed;", depth+1)
522
523        self.emit("Py_XDECREF(tmp);", depth+1)
524        self.emit("tmp = NULL;", depth+1)
525        self.emit("} else {", depth)
526        if not field.opt:
527            message = "required field \\\"%s\\\" missing from %s" % (field.name, name)
528            format = "PyErr_SetString(PyExc_TypeError, \"%s\");"
529            self.emit(format % message, depth+1, reflow=False)
530            self.emit("return 1;", depth+1)
531        else:
532            if self.isNumeric(field):
533                self.emit("%s = 0;" % field.name, depth+1)
534            elif not self.isSimpleType(field):
535                self.emit("%s = NULL;" % field.name, depth+1)
536            else:
537                raise TypeError("could not determine the default value for %s" % field.name)
538        self.emit("}", depth)
539
540
541class MarshalPrototypeVisitor(PickleVisitor):
542
543    def prototype(self, sum, name):
544        ctype = get_c_type(name)
545        self.emit("static int marshal_write_%s(PyObject **, int *, %s);"
546                  % (name, ctype), 0)
547
548    visitProduct = visitSum = prototype
549
550
551class PyTypesDeclareVisitor(PickleVisitor):
552
553    def visitProduct(self, prod, name):
554        self.emit("static PyTypeObject *%s_type;" % name, 0)
555        self.emit("static PyObject* ast2obj_%s(void*);" % name, 0)
556        if prod.fields:
557            self.emit("static char *%s_fields[]={" % name,0)
558            for f in prod.fields:
559                self.emit('"%s",' % f.name, 1)
560            self.emit("};", 0)
561
562    def visitSum(self, sum, name):
563        self.emit("static PyTypeObject *%s_type;" % name, 0)
564        if sum.attributes:
565            self.emit("static char *%s_attributes[] = {" % name, 0)
566            for a in sum.attributes:
567                self.emit('"%s",' % a.name, 1)
568            self.emit("};", 0)
569        ptype = "void*"
570        if is_simple(sum):
571            ptype = get_c_type(name)
572            tnames = []
573            for t in sum.types:
574                tnames.append(str(t.name)+"_singleton")
575            tnames = ", *".join(tnames)
576            self.emit("static PyObject *%s;" % tnames, 0)
577        self.emit("static PyObject* ast2obj_%s(%s);" % (name, ptype), 0)
578        for t in sum.types:
579            self.visitConstructor(t, name)
580
581    def visitConstructor(self, cons, name):
582        self.emit("static PyTypeObject *%s_type;" % cons.name, 0)
583        if cons.fields:
584            self.emit("static char *%s_fields[]={" % cons.name, 0)
585            for t in cons.fields:
586                self.emit('"%s",' % t.name, 1)
587            self.emit("};",0)
588
589class PyTypesVisitor(PickleVisitor):
590
591    def visitModule(self, mod):
592        self.emit("""
593static int
594ast_type_init(PyObject *self, PyObject *args, PyObject *kw)
595{
596    Py_ssize_t i, numfields = 0;
597    int res = -1;
598    PyObject *key, *value, *fields;
599    fields = PyObject_GetAttrString((PyObject*)Py_TYPE(self), "_fields");
600    if (!fields)
601        PyErr_Clear();
602    if (fields) {
603        numfields = PySequence_Size(fields);
604        if (numfields == -1)
605            goto cleanup;
606    }
607    res = 0; /* if no error occurs, this stays 0 to the end */
608    if (PyTuple_GET_SIZE(args) > 0) {
609        if (numfields != PyTuple_GET_SIZE(args)) {
610            PyErr_Format(PyExc_TypeError, "%.400s constructor takes %s"
611                         "%zd positional argument%s",
612                         Py_TYPE(self)->tp_name,
613                         numfields == 0 ? "" : "either 0 or ",
614                         numfields, numfields == 1 ? "" : "s");
615            res = -1;
616            goto cleanup;
617        }
618        for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
619            /* cannot be reached when fields is NULL */
620            PyObject *name = PySequence_GetItem(fields, i);
621            if (!name) {
622                res = -1;
623                goto cleanup;
624            }
625            res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
626            Py_DECREF(name);
627            if (res < 0)
628                goto cleanup;
629        }
630    }
631    if (kw) {
632        i = 0;  /* needed by PyDict_Next */
633        while (PyDict_Next(kw, &i, &key, &value)) {
634            res = PyObject_SetAttr(self, key, value);
635            if (res < 0)
636                goto cleanup;
637        }
638    }
639  cleanup:
640    Py_XDECREF(fields);
641    return res;
642}
643
644/* Pickling support */
645static PyObject *
646ast_type_reduce(PyObject *self, PyObject *unused)
647{
648    PyObject *res;
649    PyObject *dict = PyObject_GetAttrString(self, "__dict__");
650    if (dict == NULL) {
651        if (PyErr_ExceptionMatches(PyExc_AttributeError))
652            PyErr_Clear();
653        else
654            return NULL;
655    }
656    if (dict) {
657        res = Py_BuildValue("O()O", Py_TYPE(self), dict);
658        Py_DECREF(dict);
659        return res;
660    }
661    return Py_BuildValue("O()", Py_TYPE(self));
662}
663
664static PyMethodDef ast_type_methods[] = {
665    {"__reduce__", ast_type_reduce, METH_NOARGS, NULL},
666    {NULL}
667};
668
669static PyTypeObject AST_type = {
670    PyVarObject_HEAD_INIT(&PyType_Type, 0)
671    "_ast.AST",
672    sizeof(PyObject),
673    0,
674    0,                       /* tp_dealloc */
675    0,                       /* tp_print */
676    0,                       /* tp_getattr */
677    0,                       /* tp_setattr */
678    0,                       /* tp_compare */
679    0,                       /* tp_repr */
680    0,                       /* tp_as_number */
681    0,                       /* tp_as_sequence */
682    0,                       /* tp_as_mapping */
683    0,                       /* tp_hash */
684    0,                       /* tp_call */
685    0,                       /* tp_str */
686    PyObject_GenericGetAttr, /* tp_getattro */
687    PyObject_GenericSetAttr, /* tp_setattro */
688    0,                       /* tp_as_buffer */
689    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
690    0,                       /* tp_doc */
691    0,                       /* tp_traverse */
692    0,                       /* tp_clear */
693    0,                       /* tp_richcompare */
694    0,                       /* tp_weaklistoffset */
695    0,                       /* tp_iter */
696    0,                       /* tp_iternext */
697    ast_type_methods,        /* tp_methods */
698    0,                       /* tp_members */
699    0,                       /* tp_getset */
700    0,                       /* tp_base */
701    0,                       /* tp_dict */
702    0,                       /* tp_descr_get */
703    0,                       /* tp_descr_set */
704    0,                       /* tp_dictoffset */
705    (initproc)ast_type_init, /* tp_init */
706    PyType_GenericAlloc,     /* tp_alloc */
707    PyType_GenericNew,       /* tp_new */
708    PyObject_Del,            /* tp_free */
709};
710
711
712static PyTypeObject* make_type(char *type, PyTypeObject* base, char**fields, int num_fields)
713{
714    PyObject *fnames, *result;
715    int i;
716    fnames = PyTuple_New(num_fields);
717    if (!fnames) return NULL;
718    for (i = 0; i < num_fields; i++) {
719        PyObject *field = PyString_FromString(fields[i]);
720        if (!field) {
721            Py_DECREF(fnames);
722            return NULL;
723        }
724        PyTuple_SET_ITEM(fnames, i, field);
725    }
726    result = PyObject_CallFunction((PyObject*)&PyType_Type, "s(O){sOss}",
727                    type, base, "_fields", fnames, "__module__", "_ast");
728    Py_DECREF(fnames);
729    return (PyTypeObject*)result;
730}
731
732static int add_attributes(PyTypeObject* type, char**attrs, int num_fields)
733{
734    int i, result;
735    PyObject *s, *l = PyTuple_New(num_fields);
736    if (!l)
737        return 0;
738    for (i = 0; i < num_fields; i++) {
739        s = PyString_FromString(attrs[i]);
740        if (!s) {
741            Py_DECREF(l);
742            return 0;
743        }
744        PyTuple_SET_ITEM(l, i, s);
745    }
746    result = PyObject_SetAttrString((PyObject*)type, "_attributes", l) >= 0;
747    Py_DECREF(l);
748    return result;
749}
750
751/* Conversion AST -> Python */
752
753static PyObject* ast2obj_list(asdl_seq *seq, PyObject* (*func)(void*))
754{
755    int i, n = asdl_seq_LEN(seq);
756    PyObject *result = PyList_New(n);
757    PyObject *value;
758    if (!result)
759        return NULL;
760    for (i = 0; i < n; i++) {
761        value = func(asdl_seq_GET(seq, i));
762        if (!value) {
763            Py_DECREF(result);
764            return NULL;
765        }
766        PyList_SET_ITEM(result, i, value);
767    }
768    return result;
769}
770
771static PyObject* ast2obj_object(void *o)
772{
773    if (!o)
774        o = Py_None;
775    Py_INCREF((PyObject*)o);
776    return (PyObject*)o;
777}
778#define ast2obj_identifier ast2obj_object
779#define ast2obj_string ast2obj_object
780static PyObject* ast2obj_bool(bool b)
781{
782    return PyBool_FromLong(b);
783}
784
785static PyObject* ast2obj_int(long b)
786{
787    return PyInt_FromLong(b);
788}
789
790/* Conversion Python -> AST */
791
792static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
793{
794    if (obj == Py_None)
795        obj = NULL;
796    if (obj)
797        PyArena_AddPyObject(arena, obj);
798    Py_XINCREF(obj);
799    *out = obj;
800    return 0;
801}
802
803#define obj2ast_identifier obj2ast_object
804#define obj2ast_string obj2ast_object
805
806static int obj2ast_int(PyObject* obj, int* out, PyArena* arena)
807{
808    int i;
809    if (!PyInt_Check(obj) && !PyLong_Check(obj)) {
810        PyObject *s = PyObject_Repr(obj);
811        if (s == NULL) return 1;
812        PyErr_Format(PyExc_ValueError, "invalid integer value: %.400s",
813                     PyString_AS_STRING(s));
814        Py_DECREF(s);
815        return 1;
816    }
817
818    i = (int)PyLong_AsLong(obj);
819    if (i == -1 && PyErr_Occurred())
820        return 1;
821    *out = i;
822    return 0;
823}
824
825static int obj2ast_bool(PyObject* obj, bool* out, PyArena* arena)
826{
827    if (!PyBool_Check(obj)) {
828        PyObject *s = PyObject_Repr(obj);
829        if (s == NULL) return 1;
830        PyErr_Format(PyExc_ValueError, "invalid boolean value: %.400s",
831                     PyString_AS_STRING(s));
832        Py_DECREF(s);
833        return 1;
834    }
835
836    *out = (obj == Py_True);
837    return 0;
838}
839
840static int add_ast_fields(void)
841{
842    PyObject *empty_tuple, *d;
843    if (PyType_Ready(&AST_type) < 0)
844        return -1;
845    d = AST_type.tp_dict;
846    empty_tuple = PyTuple_New(0);
847    if (!empty_tuple ||
848        PyDict_SetItemString(d, "_fields", empty_tuple) < 0 ||
849        PyDict_SetItemString(d, "_attributes", empty_tuple) < 0) {
850        Py_XDECREF(empty_tuple);
851        return -1;
852    }
853    Py_DECREF(empty_tuple);
854    return 0;
855}
856
857""", 0, reflow=False)
858
859        self.emit("static int init_types(void)",0)
860        self.emit("{", 0)
861        self.emit("static int initialized;", 1)
862        self.emit("if (initialized) return 1;", 1)
863        self.emit("if (add_ast_fields() < 0) return 0;", 1)
864        for dfn in mod.dfns:
865            self.visit(dfn)
866        self.emit("initialized = 1;", 1)
867        self.emit("return 1;", 1);
868        self.emit("}", 0)
869
870    def visitProduct(self, prod, name):
871        if prod.fields:
872            fields = name.value+"_fields"
873        else:
874            fields = "NULL"
875        self.emit('%s_type = make_type("%s", &AST_type, %s, %d);' %
876                        (name, name, fields, len(prod.fields)), 1)
877        self.emit("if (!%s_type) return 0;" % name, 1)
878
879    def visitSum(self, sum, name):
880        self.emit('%s_type = make_type("%s", &AST_type, NULL, 0);' %
881                  (name, name), 1)
882        self.emit("if (!%s_type) return 0;" % name, 1)
883        if sum.attributes:
884            self.emit("if (!add_attributes(%s_type, %s_attributes, %d)) return 0;" %
885                            (name, name, len(sum.attributes)), 1)
886        else:
887            self.emit("if (!add_attributes(%s_type, NULL, 0)) return 0;" % name, 1)
888        simple = is_simple(sum)
889        for t in sum.types:
890            self.visitConstructor(t, name, simple)
891
892    def visitConstructor(self, cons, name, simple):
893        if cons.fields:
894            fields = cons.name.value+"_fields"
895        else:
896            fields = "NULL"
897        self.emit('%s_type = make_type("%s", %s_type, %s, %d);' %
898                            (cons.name, cons.name, name, fields, len(cons.fields)), 1)
899        self.emit("if (!%s_type) return 0;" % cons.name, 1)
900        if simple:
901            self.emit("%s_singleton = PyType_GenericNew(%s_type, NULL, NULL);" %
902                             (cons.name, cons.name), 1)
903            self.emit("if (!%s_singleton) return 0;" % cons.name, 1)
904
905
906def parse_version(mod):
907    return mod.version.value[12:-3]
908
909class ASTModuleVisitor(PickleVisitor):
910
911    def visitModule(self, mod):
912        self.emit("PyMODINIT_FUNC", 0)
913        self.emit("init_ast(void)", 0)
914        self.emit("{", 0)
915        self.emit("PyObject *m, *d;", 1)
916        self.emit("if (!init_types()) return;", 1)
917        self.emit('m = Py_InitModule3("_ast", NULL, NULL);', 1)
918        self.emit("if (!m) return;", 1)
919        self.emit("d = PyModule_GetDict(m);", 1)
920        self.emit('if (PyDict_SetItemString(d, "AST", (PyObject*)&AST_type) < 0) return;', 1)
921        self.emit('if (PyModule_AddIntConstant(m, "PyCF_ONLY_AST", PyCF_ONLY_AST) < 0)', 1)
922        self.emit("return;", 2)
923        # Value of version: "$Revision$"
924        self.emit('if (PyModule_AddStringConstant(m, "__version__", "%s") < 0)'
925                % parse_version(mod), 1)
926        self.emit("return;", 2)
927        for dfn in mod.dfns:
928            self.visit(dfn)
929        self.emit("}", 0)
930
931    def visitProduct(self, prod, name):
932        self.addObj(name)
933
934    def visitSum(self, sum, name):
935        self.addObj(name)
936        for t in sum.types:
937            self.visitConstructor(t, name)
938
939    def visitConstructor(self, cons, name):
940        self.addObj(cons.name)
941
942    def addObj(self, name):
943        self.emit('if (PyDict_SetItemString(d, "%s", (PyObject*)%s_type) < 0) return;' % (name, name), 1)
944
945
946_SPECIALIZED_SEQUENCES = ('stmt', 'expr')
947
948def find_sequence(fields, doing_specialization):
949    """Return True if any field uses a sequence."""
950    for f in fields:
951        if f.seq:
952            if not doing_specialization:
953                return True
954            if str(f.type) not in _SPECIALIZED_SEQUENCES:
955                return True
956    return False
957
958def has_sequence(types, doing_specialization):
959    for t in types:
960        if find_sequence(t.fields, doing_specialization):
961            return True
962    return False
963
964
965class StaticVisitor(PickleVisitor):
966    CODE = '''Very simple, always emit this static code.  Overide CODE'''
967
968    def visit(self, object):
969        self.emit(self.CODE, 0, reflow=False)
970
971
972class ObjVisitor(PickleVisitor):
973
974    def func_begin(self, name):
975        ctype = get_c_type(name)
976        self.emit("PyObject*", 0)
977        self.emit("ast2obj_%s(void* _o)" % (name), 0)
978        self.emit("{", 0)
979        self.emit("%s o = (%s)_o;" % (ctype, ctype), 1)
980        self.emit("PyObject *result = NULL, *value = NULL;", 1)
981        self.emit('if (!o) {', 1)
982        self.emit("Py_INCREF(Py_None);", 2)
983        self.emit('return Py_None;', 2)
984        self.emit("}", 1)
985        self.emit('', 0)
986
987    def func_end(self):
988        self.emit("return result;", 1)
989        self.emit("failed:", 0)
990        self.emit("Py_XDECREF(value);", 1)
991        self.emit("Py_XDECREF(result);", 1)
992        self.emit("return NULL;", 1)
993        self.emit("}", 0)
994        self.emit("", 0)
995
996    def visitSum(self, sum, name):
997        if is_simple(sum):
998            self.simpleSum(sum, name)
999            return
1000        self.func_begin(name)
1001        self.emit("switch (o->kind) {", 1)
1002        for i in range(len(sum.types)):
1003            t = sum.types[i]
1004            self.visitConstructor(t, i + 1, name)
1005        self.emit("}", 1)
1006        for a in sum.attributes:
1007            self.emit("value = ast2obj_%s(o->%s);" % (a.type, a.name), 1)
1008            self.emit("if (!value) goto failed;", 1)
1009            self.emit('if (PyObject_SetAttrString(result, "%s", value) < 0)' % a.name, 1)
1010            self.emit('goto failed;', 2)
1011            self.emit('Py_DECREF(value);', 1)
1012        self.func_end()
1013
1014    def simpleSum(self, sum, name):
1015        self.emit("PyObject* ast2obj_%s(%s_ty o)" % (name, name), 0)
1016        self.emit("{", 0)
1017        self.emit("switch(o) {", 1)
1018        for t in sum.types:
1019            self.emit("case %s:" % t.name, 2)
1020            self.emit("Py_INCREF(%s_singleton);" % t.name, 3)
1021            self.emit("return %s_singleton;" % t.name, 3)
1022        self.emit("default:" % name, 2)
1023        self.emit('/* should never happen, but just in case ... */', 3)
1024        code = "PyErr_Format(PyExc_SystemError, \"unknown %s found\");" % name
1025        self.emit(code, 3, reflow=False)
1026        self.emit("return NULL;", 3)
1027        self.emit("}", 1)
1028        self.emit("}", 0)
1029
1030    def visitProduct(self, prod, name):
1031        self.func_begin(name)
1032        self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % name, 1);
1033        self.emit("if (!result) return NULL;", 1)
1034        for field in prod.fields:
1035            self.visitField(field, name, 1, True)
1036        self.func_end()
1037
1038    def visitConstructor(self, cons, enum, name):
1039        self.emit("case %s_kind:" % cons.name, 1)
1040        self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % cons.name, 2);
1041        self.emit("if (!result) goto failed;", 2)
1042        for f in cons.fields:
1043            self.visitField(f, cons.name, 2, False)
1044        self.emit("break;", 2)
1045
1046    def visitField(self, field, name, depth, product):
1047        def emit(s, d):
1048            self.emit(s, depth + d)
1049        if product:
1050            value = "o->%s" % field.name
1051        else:
1052            value = "o->v.%s.%s" % (name, field.name)
1053        self.set(field, value, depth)
1054        emit("if (!value) goto failed;", 0)
1055        emit('if (PyObject_SetAttrString(result, "%s", value) == -1)' % field.name, 0)
1056        emit("goto failed;", 1)
1057        emit("Py_DECREF(value);", 0)
1058
1059    def emitSeq(self, field, value, depth, emit):
1060        emit("seq = %s;" % value, 0)
1061        emit("n = asdl_seq_LEN(seq);", 0)
1062        emit("value = PyList_New(n);", 0)
1063        emit("if (!value) goto failed;", 0)
1064        emit("for (i = 0; i < n; i++) {", 0)
1065        self.set("value", field, "asdl_seq_GET(seq, i)", depth + 1)
1066        emit("if (!value1) goto failed;", 1)
1067        emit("PyList_SET_ITEM(value, i, value1);", 1)
1068        emit("value1 = NULL;", 1)
1069        emit("}", 0)
1070
1071    def set(self, field, value, depth):
1072        if field.seq:
1073            # XXX should really check for is_simple, but that requires a symbol table
1074            if field.type.value == "cmpop":
1075                # While the sequence elements are stored as void*,
1076                # ast2obj_cmpop expects an enum
1077                self.emit("{", depth)
1078                self.emit("int i, n = asdl_seq_LEN(%s);" % value, depth+1)
1079                self.emit("value = PyList_New(n);", depth+1)
1080                self.emit("if (!value) goto failed;", depth+1)
1081                self.emit("for(i = 0; i < n; i++)", depth+1)
1082                # This cannot fail, so no need for error handling
1083                self.emit("PyList_SET_ITEM(value, i, ast2obj_cmpop((cmpop_ty)asdl_seq_GET(%s, i)));" % value,
1084                          depth+2, reflow=False)
1085                self.emit("}", depth)
1086            else:
1087                self.emit("value = ast2obj_list(%s, ast2obj_%s);" % (value, field.type), depth)
1088        else:
1089            ctype = get_c_type(field.type)
1090            self.emit("value = ast2obj_%s(%s);" % (field.type, value), depth, reflow=False)
1091
1092
1093class PartingShots(StaticVisitor):
1094
1095    CODE = """
1096PyObject* PyAST_mod2obj(mod_ty t)
1097{
1098    init_types();
1099    return ast2obj_mod(t);
1100}
1101
1102/* mode is 0 for "exec", 1 for "eval" and 2 for "single" input */
1103mod_ty PyAST_obj2mod(PyObject* ast, PyArena* arena, int mode)
1104{
1105    mod_ty res;
1106    PyObject *req_type[] = {(PyObject*)Module_type, (PyObject*)Expression_type,
1107                            (PyObject*)Interactive_type};
1108    char *req_name[] = {"Module", "Expression", "Interactive"};
1109    int isinstance;
1110    assert(0 <= mode && mode <= 2);
1111
1112    init_types();
1113
1114    isinstance = PyObject_IsInstance(ast, req_type[mode]);
1115    if (isinstance == -1)
1116        return NULL;
1117    if (!isinstance) {
1118        PyErr_Format(PyExc_TypeError, "expected %s node, got %.400s",
1119                     req_name[mode], Py_TYPE(ast)->tp_name);
1120        return NULL;
1121    }
1122    if (obj2ast_mod(ast, &res, arena) != 0)
1123        return NULL;
1124    else
1125        return res;
1126}
1127
1128int PyAST_Check(PyObject* obj)
1129{
1130    init_types();
1131    return PyObject_IsInstance(obj, (PyObject*)&AST_type);
1132}
1133"""
1134
1135class ChainOfVisitors:
1136    def __init__(self, *visitors):
1137        self.visitors = visitors
1138
1139    def visit(self, object):
1140        for v in self.visitors:
1141            v.visit(object)
1142            v.emit("", 0)
1143
1144common_msg = "/* File automatically generated by %s. */\n\n"
1145
1146c_file_msg = """
1147/*
1148   __version__ %s.
1149
1150   This module must be committed separately after each AST grammar change;
1151   The __version__ number is set to the revision number of the commit
1152   containing the grammar change.
1153*/
1154
1155"""
1156
1157def main(srcfile):
1158    argv0 = sys.argv[0]
1159    components = argv0.split(os.sep)
1160    argv0 = os.sep.join(components[-2:])
1161    auto_gen_msg = common_msg % argv0
1162    mod = asdl.parse(srcfile)
1163    if not asdl.check(mod):
1164        sys.exit(1)
1165    if INC_DIR:
1166        p = "%s/%s-ast.h" % (INC_DIR, mod.name)
1167        f = open(p, "wb")
1168        f.write(auto_gen_msg)
1169        f.write('#include "asdl.h"\n\n')
1170        c = ChainOfVisitors(TypeDefVisitor(f),
1171                            StructVisitor(f),
1172                            PrototypeVisitor(f),
1173                            )
1174        c.visit(mod)
1175        f.write("PyObject* PyAST_mod2obj(mod_ty t);\n")
1176        f.write("mod_ty PyAST_obj2mod(PyObject* ast, PyArena* arena, int mode);\n")
1177        f.write("int PyAST_Check(PyObject* obj);\n")
1178        f.close()
1179
1180    if SRC_DIR:
1181        p = os.path.join(SRC_DIR, str(mod.name) + "-ast.c")
1182        f = open(p, "wb")
1183        f.write(auto_gen_msg)
1184        f.write(c_file_msg % parse_version(mod))
1185        f.write('#include "Python.h"\n')
1186        f.write('#include "%s-ast.h"\n' % mod.name)
1187        f.write('\n')
1188        f.write("static PyTypeObject AST_type;\n")
1189        v = ChainOfVisitors(
1190            PyTypesDeclareVisitor(f),
1191            PyTypesVisitor(f),
1192            Obj2ModPrototypeVisitor(f),
1193            FunctionVisitor(f),
1194            ObjVisitor(f),
1195            Obj2ModVisitor(f),
1196            ASTModuleVisitor(f),
1197            PartingShots(f),
1198            )
1199        v.visit(mod)
1200        f.close()
1201
1202if __name__ == "__main__":
1203    import sys
1204    import getopt
1205
1206    INC_DIR = ''
1207    SRC_DIR = ''
1208    opts, args = getopt.getopt(sys.argv[1:], "h:c:")
1209    if len(opts) != 1:
1210        print "Must specify exactly one output file"
1211        sys.exit(1)
1212    for o, v in opts:
1213        if o == '-h':
1214            INC_DIR = v
1215        if o == '-c':
1216            SRC_DIR = v
1217    if len(args) != 1:
1218        print "Must specify single input file"
1219        sys.exit(1)
1220    main(args[0])
1221