Parser/asdl_c.py

   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
   7 import os, sys
   8
   9 import asdl
  10
  11 TABSIZE = 8
  12 MAX_COL = 80
  13
  14 def 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
  28 def 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
  70 def 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
  82 class 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
 100 class 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
 138 class 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
 208 class 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
 278 class 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
 333 class 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
 355 class 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
 363 class 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
 541 class 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
 551 class 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
 589 class PyTypesVisitor(PickleVisitor):
 590
 591     def visitModule(self, mod):
 592         self.emit("""
 593 static int
 594 ast_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 */
 645 static PyObject *
 646 ast_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
 664 static PyMethodDef ast_type_methods[] = {
 665     {"__reduce__", ast_type_reduce, METH_NOARGS, NULL},
 666     {NULL}
 667 };
 668
 669 static 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
 712 static 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
 732 static 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) return 0;
 737     for(i = 0; i < num_fields; i++) {
 738         s = PyString_FromString(attrs[i]);
 739         if (!s) {
 740             Py_DECREF(l);
 741             return 0;
 742         }
 743         PyTuple_SET_ITEM(l, i, s);
 744     }
 745     result = PyObject_SetAttrString((PyObject*)type, "_attributes", l) >= 0;
 746     Py_DECREF(l);
 747     return result;
 748 }
 749
 750 /* Conversion AST -> Python */
 751
 752 static PyObject* ast2obj_list(asdl_seq *seq, PyObject* (*func)(void*))
 753 {
 754     int i, n = asdl_seq_LEN(seq);
 755     PyObject *result = PyList_New(n);
 756     PyObject *value;
 757     if (!result)
 758         return NULL;
 759     for (i = 0; i < n; i++) {
 760         value = func(asdl_seq_GET(seq, i));
 761         if (!value) {
 762             Py_DECREF(result);
 763             return NULL;
 764         }
 765         PyList_SET_ITEM(result, i, value);
 766     }
 767     return result;
 768 }
 769
 770 static PyObject* ast2obj_object(void *o)
 771 {
 772     if (!o)
 773         o = Py_None;
 774     Py_INCREF((PyObject*)o);
 775     return (PyObject*)o;
 776 }
 777 #define ast2obj_identifier ast2obj_object
 778 #define ast2obj_string ast2obj_object
 779 static PyObject* ast2obj_bool(bool b)
 780 {
 781     return PyBool_FromLong(b);
 782 }
 783
 784 static PyObject* ast2obj_int(long b)
 785 {
 786     return PyInt_FromLong(b);
 787 }
 788
 789 /* Conversion Python -> AST */
 790
 791 static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
 792 {
 793     if (obj == Py_None)
 794         obj = NULL;
 795     if (obj)
 796         PyArena_AddPyObject(arena, obj);
 797     Py_XINCREF(obj);
 798     *out = obj;
 799     return 0;
 800 }
 801
 802 #define obj2ast_identifier obj2ast_object
 803 #define obj2ast_string obj2ast_object
 804
 805 static int obj2ast_int(PyObject* obj, int* out, PyArena* arena)
 806 {
 807     int i;
 808     if (!PyInt_Check(obj) && !PyLong_Check(obj)) {
 809         PyObject *s = PyObject_Repr(obj);
 810         if (s == NULL) return 1;
 811         PyErr_Format(PyExc_ValueError, "invalid integer value: %.400s",
 812                      PyString_AS_STRING(s));
 813         Py_DECREF(s);
 814         return 1;
 815     }
 816
 817     i = (int)PyLong_AsLong(obj);
 818     if (i == -1 && PyErr_Occurred())
 819         return 1;
 820     *out = i;
 821     return 0;
 822 }
 823
 824 static int obj2ast_bool(PyObject* obj, bool* out, PyArena* arena)
 825 {
 826     if (!PyBool_Check(obj)) {
 827         PyObject *s = PyObject_Repr(obj);
 828         if (s == NULL) return 1;
 829         PyErr_Format(PyExc_ValueError, "invalid boolean value: %.400s",
 830                      PyString_AS_STRING(s));
 831         Py_DECREF(s);
 832         return 1;
 833     }
 834
 835     *out = (obj == Py_True);
 836     return 0;
 837 }
 838
 839 static int add_ast_fields(void)
 840 {
 841     PyObject *empty_tuple, *d;
 842     if (PyType_Ready(&AST_type) < 0)
 843         return -1;
 844     d = AST_type.tp_dict;
 845     empty_tuple = PyTuple_New(0);
 846     if (!empty_tuple ||
 847         PyDict_SetItemString(d, "_fields", empty_tuple) < 0 ||
 848         PyDict_SetItemString(d, "_attributes", empty_tuple) < 0) {
 849         Py_XDECREF(empty_tuple);
 850         return -1;
 851     }
 852     Py_DECREF(empty_tuple);
 853     return 0;
 854 }
 855
 856 """, 0, reflow=False)
 857
 858         self.emit("static int init_types(void)",0)
 859         self.emit("{", 0)
 860         self.emit("static int initialized;", 1)
 861         self.emit("if (initialized) return 1;", 1)
 862         self.emit("if (add_ast_fields() < 0) return 0;", 1)
 863         for dfn in mod.dfns:
 864             self.visit(dfn)
 865         self.emit("initialized = 1;", 1)
 866         self.emit("return 1;", 1);
 867         self.emit("}", 0)
 868
 869     def visitProduct(self, prod, name):
 870         if prod.fields:
 871             fields = name.value+"_fields"
 872         else:
 873             fields = "NULL"
 874         self.emit('%s_type = make_type("%s", &AST_type, %s, %d);' %
 875                         (name, name, fields, len(prod.fields)), 1)
 876         self.emit("if (!%s_type) return 0;" % name, 1)
 877
 878     def visitSum(self, sum, name):
 879         self.emit('%s_type = make_type("%s", &AST_type, NULL, 0);' %
 880                   (name, name), 1)
 881         self.emit("if (!%s_type) return 0;" % name, 1)
 882         if sum.attributes:
 883             self.emit("if (!add_attributes(%s_type, %s_attributes, %d)) return 0;" %
 884                             (name, name, len(sum.attributes)), 1)
 885         else:
 886             self.emit("if (!add_attributes(%s_type, NULL, 0)) return 0;" % name, 1)
 887         simple = is_simple(sum)
 888         for t in sum.types:
 889             self.visitConstructor(t, name, simple)
 890
 891     def visitConstructor(self, cons, name, simple):
 892         if cons.fields:
 893             fields = cons.name.value+"_fields"
 894         else:
 895             fields = "NULL"
 896         self.emit('%s_type = make_type("%s", %s_type, %s, %d);' %
 897                             (cons.name, cons.name, name, fields, len(cons.fields)), 1)
 898         self.emit("if (!%s_type) return 0;" % cons.name, 1)
 899         if simple:
 900             self.emit("%s_singleton = PyType_GenericNew(%s_type, NULL, NULL);" %
 901                              (cons.name, cons.name), 1)
 902             self.emit("if (!%s_singleton) return 0;" % cons.name, 1)
 903
 904
 905 def parse_version(mod):
 906     return mod.version.value[12:-3]
 907
 908 class ASTModuleVisitor(PickleVisitor):
 909
 910     def visitModule(self, mod):
 911         self.emit("PyMODINIT_FUNC", 0)
 912         self.emit("init_ast(void)", 0)
 913         self.emit("{", 0)
 914         self.emit("PyObject *m, *d;", 1)
 915         self.emit("if (!init_types()) return;", 1)
 916         self.emit('m = Py_InitModule3("_ast", NULL, NULL);', 1)
 917         self.emit("if (!m) return;", 1)
 918         self.emit("d = PyModule_GetDict(m);", 1)
 919         self.emit('if (PyDict_SetItemString(d, "AST", (PyObject*)&AST_type) < 0) return;', 1)
 920         self.emit('if (PyModule_AddIntConstant(m, "PyCF_ONLY_AST", PyCF_ONLY_AST) < 0)', 1)
 921         self.emit("return;", 2)
 922         # Value of version: "$Revision$"
 923         self.emit('if (PyModule_AddStringConstant(m, "__version__", "%s") < 0)'
 924                 % parse_version(mod), 1)
 925         self.emit("return;", 2)
 926         for dfn in mod.dfns:
 927             self.visit(dfn)
 928         self.emit("}", 0)
 929
 930     def visitProduct(self, prod, name):
 931         self.addObj(name)
 932
 933     def visitSum(self, sum, name):
 934         self.addObj(name)
 935         for t in sum.types:
 936             self.visitConstructor(t, name)
 937
 938     def visitConstructor(self, cons, name):
 939         self.addObj(cons.name)
 940
 941     def addObj(self, name):
 942         self.emit('if (PyDict_SetItemString(d, "%s", (PyObject*)%s_type) < 0) return;' % (name, name), 1)
 943
 944
 945 _SPECIALIZED_SEQUENCES = ('stmt', 'expr')
 946
 947 def find_sequence(fields, doing_specialization):
 948     """Return True if any field uses a sequence."""
 949     for f in fields:
 950         if f.seq:
 951             if not doing_specialization:
 952                 return True
 953             if str(f.type) not in _SPECIALIZED_SEQUENCES:
 954                 return True
 955     return False
 956
 957 def has_sequence(types, doing_specialization):
 958     for t in types:
 959         if find_sequence(t.fields, doing_specialization):
 960             return True
 961     return False
 962
 963
 964 class StaticVisitor(PickleVisitor):
 965     CODE = '''Very simple, always emit this static code.  Overide CODE'''
 966
 967     def visit(self, object):
 968         self.emit(self.CODE, 0, reflow=False)
 969
 970
 971 class ObjVisitor(PickleVisitor):
 972
 973     def func_begin(self, name):
 974         ctype = get_c_type(name)
 975         self.emit("PyObject*", 0)
 976         self.emit("ast2obj_%s(void* _o)" % (name), 0)
 977         self.emit("{", 0)
 978         self.emit("%s o = (%s)_o;" % (ctype, ctype), 1)
 979         self.emit("PyObject *result = NULL, *value = NULL;", 1)
 980         self.emit('if (!o) {', 1)
 981         self.emit("Py_INCREF(Py_None);", 2)
 982         self.emit('return Py_None;', 2)
 983         self.emit("}", 1)
 984         self.emit('', 0)
 985
 986     def func_end(self):
 987         self.emit("return result;", 1)
 988         self.emit("failed:", 0)
 989         self.emit("Py_XDECREF(value);", 1)
 990         self.emit("Py_XDECREF(result);", 1)
 991         self.emit("return NULL;", 1)
 992         self.emit("}", 0)
 993         self.emit("", 0)
 994
 995     def visitSum(self, sum, name):
 996         if is_simple(sum):
 997             self.simpleSum(sum, name)
 998             return
 999         self.func_begin(name)
1000         self.emit("switch (o->kind) {", 1)
1001         for i in range(len(sum.types)):
1002             t = sum.types[i]
1003             self.visitConstructor(t, i + 1, name)
1004         self.emit("}", 1)
1005         for a in sum.attributes:
1006             self.emit("value = ast2obj_%s(o->%s);" % (a.type, a.name), 1)
1007             self.emit("if (!value) goto failed;", 1)
1008             self.emit('if (PyObject_SetAttrString(result, "%s", value) < 0)' % a.name, 1)
1009             self.emit('goto failed;', 2)
1010             self.emit('Py_DECREF(value);', 1)
1011         self.func_end()
1012
1013     def simpleSum(self, sum, name):
1014         self.emit("PyObject* ast2obj_%s(%s_ty o)" % (name, name), 0)
1015         self.emit("{", 0)
1016         self.emit("switch(o) {", 1)
1017         for t in sum.types:
1018             self.emit("case %s:" % t.name, 2)
1019             self.emit("Py_INCREF(%s_singleton);" % t.name, 3)
1020             self.emit("return %s_singleton;" % t.name, 3)
1021         self.emit("default:" % name, 2)
1022         self.emit('/* should never happen, but just in case ... */', 3)
1023         code = "PyErr_Format(PyExc_SystemError, \"unknown %s found\");" % name
1024         self.emit(code, 3, reflow=False)
1025         self.emit("return NULL;", 3)
1026         self.emit("}", 1)
1027         self.emit("}", 0)
1028
1029     def visitProduct(self, prod, name):
1030         self.func_begin(name)
1031         self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % name, 1);
1032         self.emit("if (!result) return NULL;", 1)
1033         for field in prod.fields:
1034             self.visitField(field, name, 1, True)
1035         self.func_end()
1036
1037     def visitConstructor(self, cons, enum, name):
1038         self.emit("case %s_kind:" % cons.name, 1)
1039         self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % cons.name, 2);
1040         self.emit("if (!result) goto failed;", 2)
1041         for f in cons.fields:
1042             self.visitField(f, cons.name, 2, False)
1043         self.emit("break;", 2)
1044
1045     def visitField(self, field, name, depth, product):
1046         def emit(s, d):
1047             self.emit(s, depth + d)
1048         if product:
1049             value = "o->%s" % field.name
1050         else:
1051             value = "o->v.%s.%s" % (name, field.name)
1052         self.set(field, value, depth)
1053         emit("if (!value) goto failed;", 0)
1054         emit('if (PyObject_SetAttrString(result, "%s", value) == -1)' % field.name, 0)
1055         emit("goto failed;", 1)
1056         emit("Py_DECREF(value);", 0)
1057
1058     def emitSeq(self, field, value, depth, emit):
1059         emit("seq = %s;" % value, 0)
1060         emit("n = asdl_seq_LEN(seq);", 0)
1061         emit("value = PyList_New(n);", 0)
1062         emit("if (!value) goto failed;", 0)
1063         emit("for (i = 0; i < n; i++) {", 0)
1064         self.set("value", field, "asdl_seq_GET(seq, i)", depth + 1)
1065         emit("if (!value1) goto failed;", 1)
1066         emit("PyList_SET_ITEM(value, i, value1);", 1)
1067         emit("value1 = NULL;", 1)
1068         emit("}", 0)
1069
1070     def set(self, field, value, depth):
1071         if field.seq:
1072             # XXX should really check for is_simple, but that requires a symbol table
1073             if field.type.value == "cmpop":
1074                 # While the sequence elements are stored as void*,
1075                 # ast2obj_cmpop expects an enum
1076                 self.emit("{", depth)
1077                 self.emit("int i, n = asdl_seq_LEN(%s);" % value, depth+1)
1078                 self.emit("value = PyList_New(n);", depth+1)
1079                 self.emit("if (!value) goto failed;", depth+1)
1080                 self.emit("for(i = 0; i < n; i++)", depth+1)
1081                 # This cannot fail, so no need for error handling
1082                 self.emit("PyList_SET_ITEM(value, i, ast2obj_cmpop((cmpop_ty)asdl_seq_GET(%s, i)));" % value,
1083                           depth+2, reflow=False)
1084                 self.emit("}", depth)
1085             else:
1086                 self.emit("value = ast2obj_list(%s, ast2obj_%s);" % (value, field.type), depth)
1087         else:
1088             ctype = get_c_type(field.type)
1089             self.emit("value = ast2obj_%s(%s);" % (field.type, value), depth, reflow=False)
1090
1091
1092 class PartingShots(StaticVisitor):
1093
1094     CODE = """
1095 PyObject* PyAST_mod2obj(mod_ty t)
1096 {
1097     init_types();
1098     return ast2obj_mod(t);
1099 }
1100
1101 /* mode is 0 for "exec", 1 for "eval" and 2 for "single" input */
1102 mod_ty PyAST_obj2mod(PyObject* ast, PyArena* arena, int mode)
1103 {
1104     mod_ty res;
1105     PyObject *req_type[] = {(PyObject*)Module_type, (PyObject*)Expression_type,
1106                             (PyObject*)Interactive_type};
1107     char *req_name[] = {"Module", "Expression", "Interactive"};
1108     int isinstance;
1109     assert(0 <= mode && mode <= 2);
1110
1111     init_types();
1112
1113     isinstance = PyObject_IsInstance(ast, req_type[mode]);
1114     if (isinstance == -1)
1115         return NULL;
1116     if (!isinstance) {
1117         PyErr_Format(PyExc_TypeError, "expected %s node, got %.400s",
1118                      req_name[mode], Py_TYPE(ast)->tp_name);
1119         return NULL;
1120     }
1121     if (obj2ast_mod(ast, &res, arena) != 0)
1122         return NULL;
1123     else
1124         return res;
1125 }
1126
1127 int PyAST_Check(PyObject* obj)
1128 {
1129     init_types();
1130     return PyObject_IsInstance(obj, (PyObject*)&AST_type);
1131 }
1132 """
1133
1134 class ChainOfVisitors:
1135     def __init__(self, *visitors):
1136         self.visitors = visitors
1137
1138     def visit(self, object):
1139         for v in self.visitors:
1140             v.visit(object)
1141             v.emit("", 0)
1142
1143 common_msg = "/* File automatically generated by %s. */\n\n"
1144
1145 c_file_msg = """
1146 /*
1147    __version__ %s.
1148
1149    This module must be committed separately after each AST grammar change;
1150    The __version__ number is set to the revision number of the commit
1151    containing the grammar change.
1152 */
1153
1154 """
1155
1156 def main(srcfile):
1157     argv0 = sys.argv[0]
1158     components = argv0.split(os.sep)
1159     argv0 = os.sep.join(components[-2:])
1160     auto_gen_msg = common_msg % argv0
1161     mod = asdl.parse(srcfile)
1162     if not asdl.check(mod):
1163         sys.exit(1)
1164     if INC_DIR:
1165         p = "%s/%s-ast.h" % (INC_DIR, mod.name)
1166         f = open(p, "wb")
1167         f.write(auto_gen_msg)
1168         f.write('#include "asdl.h"\n\n')
1169         c = ChainOfVisitors(TypeDefVisitor(f),
1170                             StructVisitor(f),
1171                             PrototypeVisitor(f),
1172                             )
1173         c.visit(mod)
1174         f.write("PyObject* PyAST_mod2obj(mod_ty t);\n")
1175         f.write("mod_ty PyAST_obj2mod(PyObject* ast, PyArena* arena, int mode);\n")
1176         f.write("int PyAST_Check(PyObject* obj);\n")
1177         f.close()
1178
1179     if SRC_DIR:
1180         p = os.path.join(SRC_DIR, str(mod.name) + "-ast.c")
1181         f = open(p, "wb")
1182         f.write(auto_gen_msg)
1183         f.write(c_file_msg % parse_version(mod))
1184         f.write('#include "Python.h"\n')
1185         f.write('#include "%s-ast.h"\n' % mod.name)
1186         f.write('\n')
1187         f.write("static PyTypeObject AST_type;\n")
1188         v = ChainOfVisitors(
1189             PyTypesDeclareVisitor(f),
1190             PyTypesVisitor(f),
1191             Obj2ModPrototypeVisitor(f),
1192             FunctionVisitor(f),
1193             ObjVisitor(f),
1194             Obj2ModVisitor(f),
1195             ASTModuleVisitor(f),
1196             PartingShots(f),
1197             )
1198         v.visit(mod)
1199         f.close()
1200
1201 if __name__ == "__main__":
1202     import sys
1203     import getopt
1204
1205     INC_DIR = ''
1206     SRC_DIR = ''
1207     opts, args = getopt.getopt(sys.argv[1:], "h:c:")
1208     if len(opts) != 1:
1209         print "Must specify exactly one output file"
1210         sys.exit(1)
1211     for o, v in opts:
1212         if o == '-h':
1213             INC_DIR = v
1214         if o == '-c':
1215             SRC_DIR = v
1216     if len(args) != 1:
1217         print "Must specify single input file"
1218         sys.exit(1)
1219     main(args[0])