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.
  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             if not opt and argtype != "int":
 296                 emit("if (!%s) {" % argname, 1)
 297                 emit("PyErr_SetString(PyExc_ValueError,", 2)
 298                 msg = "field %s is required for %s" % (argname, name)
 299                 emit('                "%s");' % msg,
 300                      2, reflow=False)
 301                 emit('return NULL;', 2)
 302                 emit('}', 1)
 303
 304         emit("p = (%s)PyArena_Malloc(arena, sizeof(*p));" % ctype, 1);
 305         emit("if (!p)", 1)
 306         emit("return NULL;", 2)
 307         if union:
 308             self.emit_body_union(name, args, attrs)
 309         else:
 310             self.emit_body_struct(name, args, attrs)
 311         emit("return p;", 1)
 312         emit("}")
 313         emit("")
 314
 315     def emit_body_union(self, name, args, attrs):
 316         def emit(s, depth=0, reflow=True):
 317             self.emit(s, depth, reflow)
 318         emit("p->kind = %s_kind;" % name, 1)
 319         for argtype, argname, opt in args:
 320             emit("p->v.%s.%s = %s;" % (name, argname, argname), 1)
 321         for argtype, argname, opt in attrs:
 322             emit("p->%s = %s;" % (argname, argname), 1)
 323
 324     def emit_body_struct(self, name, args, attrs):
 325         def emit(s, depth=0, reflow=True):
 326             self.emit(s, depth, reflow)
 327         for argtype, argname, opt in args:
 328             emit("p->%s = %s;" % (argname, argname), 1)
 329         assert not attrs
 330
 331
 332 class PickleVisitor(EmitVisitor):
 333
 334     def visitModule(self, mod):
 335         for dfn in mod.dfns:
 336             self.visit(dfn)
 337
 338     def visitType(self, type):
 339         self.visit(type.value, type.name)
 340
 341     def visitSum(self, sum, name):
 342         pass
 343
 344     def visitProduct(self, sum, name):
 345         pass
 346
 347     def visitConstructor(self, cons, name):
 348         pass
 349
 350     def visitField(self, sum):
 351         pass
 352
 353
 354 class Obj2ModPrototypeVisitor(PickleVisitor):
 355     def visitProduct(self, prod, name):
 356         code = "static int obj2ast_%s(PyObject* obj, %s* out, PyArena* arena);"
 357         self.emit(code % (name, get_c_type(name)), 0)
 358
 359     visitSum = visitProduct
 360
 361
 362 class Obj2ModVisitor(PickleVisitor):
 363     def funcHeader(self, name):
 364         ctype = get_c_type(name)
 365         self.emit("int", 0)
 366         self.emit("obj2ast_%s(PyObject* obj, %s* out, PyArena* arena)" % (name, ctype), 0)
 367         self.emit("{", 0)
 368         self.emit("int isinstance;", 1)
 369         self.emit("", 0)
 370
 371     def sumTrailer(self, name, add_label=False):
 372         self.emit("", 0)
 373         # there's really nothing more we can do if this fails ...
 374         error = "expected some sort of %s, but got %%R" % name
 375         format = "PyErr_Format(PyExc_TypeError, \"%s\", obj);"
 376         self.emit(format % error, 1, reflow=False)
 377         if add_label:
 378             self.emit("failed:", 1)
 379         self.emit("return 1;", 1)
 380         self.emit("}", 0)
 381         self.emit("", 0)
 382
 383     def simpleSum(self, sum, name):
 384         self.funcHeader(name)
 385         for t in sum.types:
 386             line = ("isinstance = PyObject_IsInstance(obj, "
 387                     "(PyObject *)%s_type);")
 388             self.emit(line % (t.name,), 1)
 389             self.emit("if (isinstance == -1) {", 1)
 390             self.emit("return 1;", 2)
 391             self.emit("}", 1)
 392             self.emit("if (isinstance) {", 1)
 393             self.emit("*out = %s;" % t.name, 2)
 394             self.emit("return 0;", 2)
 395             self.emit("}", 1)
 396         self.sumTrailer(name)
 397
 398     def buildArgs(self, fields):
 399         return ", ".join(fields + ["arena"])
 400
 401     def complexSum(self, sum, name):
 402         self.funcHeader(name)
 403         self.emit("PyObject *tmp = NULL;", 1)
 404         for a in sum.attributes:
 405             self.visitAttributeDeclaration(a, name, sum=sum)
 406         self.emit("", 0)
 407         # XXX: should we only do this for 'expr'?
 408         self.emit("if (obj == Py_None) {", 1)
 409         self.emit("*out = NULL;", 2)
 410         self.emit("return 0;", 2)
 411         self.emit("}", 1)
 412         for a in sum.attributes:
 413             self.visitField(a, name, sum=sum, depth=1)
 414         for t in sum.types:
 415             line = "isinstance = PyObject_IsInstance(obj, (PyObject*)%s_type);"
 416             self.emit(line % (t.name,), 1)
 417             self.emit("if (isinstance == -1) {", 1)
 418             self.emit("return 1;", 2)
 419             self.emit("}", 1)
 420             self.emit("if (isinstance) {", 1)
 421             for f in t.fields:
 422                 self.visitFieldDeclaration(f, t.name, sum=sum, depth=2)
 423             self.emit("", 0)
 424             for f in t.fields:
 425                 self.visitField(f, t.name, sum=sum, depth=2)
 426             args = [f.name.value for f in t.fields] + [a.name.value for a in sum.attributes]
 427             self.emit("*out = %s(%s);" % (t.name, self.buildArgs(args)), 2)
 428             self.emit("if (*out == NULL) goto failed;", 2)
 429             self.emit("return 0;", 2)
 430             self.emit("}", 1)
 431         self.sumTrailer(name, True)
 432
 433     def visitAttributeDeclaration(self, a, name, sum=sum):
 434         ctype = get_c_type(a.type)
 435         self.emit("%s %s;" % (ctype, a.name), 1)
 436
 437     def visitSum(self, sum, name):
 438         if is_simple(sum):
 439             self.simpleSum(sum, name)
 440         else:
 441             self.complexSum(sum, name)
 442
 443     def visitProduct(self, prod, name):
 444         ctype = get_c_type(name)
 445         self.emit("int", 0)
 446         self.emit("obj2ast_%s(PyObject* obj, %s* out, PyArena* arena)" % (name, ctype), 0)
 447         self.emit("{", 0)
 448         self.emit("PyObject* tmp = NULL;", 1)
 449         for f in prod.fields:
 450             self.visitFieldDeclaration(f, name, prod=prod, depth=1)
 451         self.emit("", 0)
 452         for f in prod.fields:
 453             self.visitField(f, name, prod=prod, depth=1)
 454         args = [f.name.value for f in prod.fields]
 455         self.emit("*out = %s(%s);" % (name, self.buildArgs(args)), 1)
 456         self.emit("return 0;", 1)
 457         self.emit("failed:", 0)
 458         self.emit("Py_XDECREF(tmp);", 1)
 459         self.emit("return 1;", 1)
 460         self.emit("}", 0)
 461         self.emit("", 0)
 462
 463     def visitFieldDeclaration(self, field, name, sum=None, prod=None, depth=0):
 464         ctype = get_c_type(field.type)
 465         if field.seq:
 466             if self.isSimpleType(field):
 467                 self.emit("asdl_int_seq* %s;" % field.name, depth)
 468             else:
 469                 self.emit("asdl_seq* %s;" % field.name, depth)
 470         else:
 471             ctype = get_c_type(field.type)
 472             self.emit("%s %s;" % (ctype, field.name), depth)
 473
 474     def isSimpleSum(self, field):
 475         # XXX can the members of this list be determined automatically?
 476         return field.type.value in ('expr_context', 'boolop', 'operator',
 477                                     'unaryop', 'cmpop')
 478
 479     def isNumeric(self, field):
 480         return get_c_type(field.type) in ("int", "bool")
 481
 482     def isSimpleType(self, field):
 483         return self.isSimpleSum(field) or self.isNumeric(field)
 484
 485     def visitField(self, field, name, sum=None, prod=None, depth=0):
 486         ctype = get_c_type(field.type)
 487         self.emit("if (PyObject_HasAttrString(obj, \"%s\")) {" % field.name, depth)
 488         self.emit("int res;", depth+1)
 489         if field.seq:
 490             self.emit("Py_ssize_t len;", depth+1)
 491             self.emit("Py_ssize_t i;", depth+1)
 492         self.emit("tmp = PyObject_GetAttrString(obj, \"%s\");" % field.name, depth+1)
 493         self.emit("if (tmp == NULL) goto failed;", depth+1)
 494         if field.seq:
 495             self.emit("if (!PyList_Check(tmp)) {", depth+1)
 496             self.emit("PyErr_Format(PyExc_TypeError, \"%s field \\\"%s\\\" must "
 497                       "be a list, not a %%.200s\", tmp->ob_type->tp_name);" %
 498                       (name, field.name),
 499                       depth+2, reflow=False)
 500             self.emit("goto failed;", depth+2)
 501             self.emit("}", depth+1)
 502             self.emit("len = PyList_GET_SIZE(tmp);", depth+1)
 503             if self.isSimpleType(field):
 504                 self.emit("%s = asdl_int_seq_new(len, arena);" % field.name, depth+1)
 505             else:
 506                 self.emit("%s = asdl_seq_new(len, arena);" % field.name, depth+1)
 507             self.emit("if (%s == NULL) goto failed;" % field.name, depth+1)
 508             self.emit("for (i = 0; i < len; i++) {", depth+1)
 509             self.emit("%s value;" % ctype, depth+2)
 510             self.emit("res = obj2ast_%s(PyList_GET_ITEM(tmp, i), &value, arena);" %
 511                       field.type, depth+2, reflow=False)
 512             self.emit("if (res != 0) goto failed;", depth+2)
 513             self.emit("asdl_seq_SET(%s, i, value);" % field.name, depth+2)
 514             self.emit("}", depth+1)
 515         else:
 516             self.emit("res = obj2ast_%s(tmp, &%s, arena);" %
 517                       (field.type, field.name), depth+1)
 518             self.emit("if (res != 0) goto failed;", depth+1)
 519
 520         self.emit("Py_XDECREF(tmp);", depth+1)
 521         self.emit("tmp = NULL;", depth+1)
 522         self.emit("} else {", depth)
 523         if not field.opt:
 524             message = "required field \\\"%s\\\" missing from %s" % (field.name, name)
 525             format = "PyErr_SetString(PyExc_TypeError, \"%s\");"
 526             self.emit(format % message, depth+1, reflow=False)
 527             self.emit("return 1;", depth+1)
 528         else:
 529             if self.isNumeric(field):
 530                 self.emit("%s = 0;" % field.name, depth+1)
 531             elif not self.isSimpleType(field):
 532                 self.emit("%s = NULL;" % field.name, depth+1)
 533             else:
 534                 raise TypeError("could not determine the default value for %s" % field.name)
 535         self.emit("}", depth)
 536
 537
 538 class MarshalPrototypeVisitor(PickleVisitor):
 539
 540     def prototype(self, sum, name):
 541         ctype = get_c_type(name)
 542         self.emit("static int marshal_write_%s(PyObject **, int *, %s);"
 543                   % (name, ctype), 0)
 544
 545     visitProduct = visitSum = prototype
 546
 547
 548 class PyTypesDeclareVisitor(PickleVisitor):
 549
 550     def visitProduct(self, prod, name):
 551         self.emit("static PyTypeObject *%s_type;" % name, 0)
 552         self.emit("static PyObject* ast2obj_%s(void*);" % name, 0)
 553         if prod.fields:
 554             self.emit("static char *%s_fields[]={" % name,0)
 555             for f in prod.fields:
 556                 self.emit('"%s",' % f.name, 1)
 557             self.emit("};", 0)
 558
 559     def visitSum(self, sum, name):
 560         self.emit("static PyTypeObject *%s_type;" % name, 0)
 561         if sum.attributes:
 562             self.emit("static char *%s_attributes[] = {" % name, 0)
 563             for a in sum.attributes:
 564                 self.emit('"%s",' % a.name, 1)
 565             self.emit("};", 0)
 566         ptype = "void*"
 567         if is_simple(sum):
 568             ptype = get_c_type(name)
 569             tnames = []
 570             for t in sum.types:
 571                 tnames.append(str(t.name)+"_singleton")
 572             tnames = ", *".join(tnames)
 573             self.emit("static PyObject *%s;" % tnames, 0)
 574         self.emit("static PyObject* ast2obj_%s(%s);" % (name, ptype), 0)
 575         for t in sum.types:
 576             self.visitConstructor(t, name)
 577
 578     def visitConstructor(self, cons, name):
 579         self.emit("static PyTypeObject *%s_type;" % cons.name, 0)
 580         if cons.fields:
 581             self.emit("static char *%s_fields[]={" % cons.name, 0)
 582             for t in cons.fields:
 583                 self.emit('"%s",' % t.name, 1)
 584             self.emit("};",0)
 585
 586 class PyTypesVisitor(PickleVisitor):
 587
 588     def visitModule(self, mod):
 589         self.emit("""
 590 static int
 591 ast_type_init(PyObject *self, PyObject *args, PyObject *kw)
 592 {
 593     Py_ssize_t i, numfields = 0;
 594     int res = -1;
 595     PyObject *key, *value, *fields;
 596     fields = PyObject_GetAttrString((PyObject*)Py_TYPE(self), "_fields");
 597     if (!fields)
 598         PyErr_Clear();
 599     if (fields) {
 600         numfields = PySequence_Size(fields);
 601         if (numfields == -1)
 602             goto cleanup;
 603     }
 604     res = 0; /* if no error occurs, this stays 0 to the end */
 605     if (PyTuple_GET_SIZE(args) > 0) {
 606         if (numfields != PyTuple_GET_SIZE(args)) {
 607             PyErr_Format(PyExc_TypeError, "%.400s constructor takes %s"
 608                          "%zd positional argument%s",
 609                          Py_TYPE(self)->tp_name,
 610                          numfields == 0 ? "" : "either 0 or ",
 611                          numfields, numfields == 1 ? "" : "s");
 612             res = -1;
 613             goto cleanup;
 614         }
 615         for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
 616             /* cannot be reached when fields is NULL */
 617             PyObject *name = PySequence_GetItem(fields, i);
 618             if (!name) {
 619                 res = -1;
 620                 goto cleanup;
 621             }
 622             res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
 623             Py_DECREF(name);
 624             if (res < 0)
 625                 goto cleanup;
 626         }
 627     }
 628     if (kw) {
 629         i = 0;  /* needed by PyDict_Next */
 630         while (PyDict_Next(kw, &i, &key, &value)) {
 631             res = PyObject_SetAttr(self, key, value);
 632             if (res < 0)
 633                 goto cleanup;
 634         }
 635     }
 636   cleanup:
 637     Py_XDECREF(fields);
 638     return res;
 639 }
 640
 641 /* Pickling support */
 642 static PyObject *
 643 ast_type_reduce(PyObject *self, PyObject *unused)
 644 {
 645     PyObject *res;
 646     PyObject *dict = PyObject_GetAttrString(self, "__dict__");
 647     if (dict == NULL) {
 648         if (PyErr_ExceptionMatches(PyExc_AttributeError))
 649             PyErr_Clear();
 650         else
 651             return NULL;
 652     }
 653     if (dict) {
 654         res = Py_BuildValue("O()O", Py_TYPE(self), dict);
 655         Py_DECREF(dict);
 656         return res;
 657     }
 658     return Py_BuildValue("O()", Py_TYPE(self));
 659 }
 660
 661 static PyMethodDef ast_type_methods[] = {
 662     {"__reduce__", ast_type_reduce, METH_NOARGS, NULL},
 663     {NULL}
 664 };
 665
 666 static PyTypeObject AST_type = {
 667     PyVarObject_HEAD_INIT(&PyType_Type, 0)
 668     "_ast.AST",
 669     sizeof(PyObject),
 670     0,
 671     0,                       /* tp_dealloc */
 672     0,                       /* tp_print */
 673     0,                       /* tp_getattr */
 674     0,                       /* tp_setattr */
 675     0,                       /* tp_reserved */
 676     0,                       /* tp_repr */
 677     0,                       /* tp_as_number */
 678     0,                       /* tp_as_sequence */
 679     0,                       /* tp_as_mapping */
 680     0,                       /* tp_hash */
 681     0,                       /* tp_call */
 682     0,                       /* tp_str */
 683     PyObject_GenericGetAttr, /* tp_getattro */
 684     PyObject_GenericSetAttr, /* tp_setattro */
 685     0,                       /* tp_as_buffer */
 686     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
 687     0,                       /* tp_doc */
 688     0,                       /* tp_traverse */
 689     0,                       /* tp_clear */
 690     0,                       /* tp_richcompare */
 691     0,                       /* tp_weaklistoffset */
 692     0,                       /* tp_iter */
 693     0,                       /* tp_iternext */
 694     ast_type_methods,        /* tp_methods */
 695     0,                       /* tp_members */
 696     0,                       /* tp_getset */
 697     0,                       /* tp_base */
 698     0,                       /* tp_dict */
 699     0,                       /* tp_descr_get */
 700     0,                       /* tp_descr_set */
 701     0,                       /* tp_dictoffset */
 702     (initproc)ast_type_init, /* tp_init */
 703     PyType_GenericAlloc,     /* tp_alloc */
 704     PyType_GenericNew,       /* tp_new */
 705     PyObject_Del,            /* tp_free */
 706 };
 707
 708
 709 static PyTypeObject* make_type(char *type, PyTypeObject* base, char**fields, int num_fields)
 710 {
 711     PyObject *fnames, *result;
 712     int i;
 713     fnames = PyTuple_New(num_fields);
 714     if (!fnames) return NULL;
 715     for (i = 0; i < num_fields; i++) {
 716         PyObject *field = PyUnicode_FromString(fields[i]);
 717         if (!field) {
 718             Py_DECREF(fnames);
 719             return NULL;
 720         }
 721         PyTuple_SET_ITEM(fnames, i, field);
 722     }
 723     result = PyObject_CallFunction((PyObject*)&PyType_Type, "U(O){sOss}",
 724                     type, base, "_fields", fnames, "__module__", "_ast");
 725     Py_DECREF(fnames);
 726     return (PyTypeObject*)result;
 727 }
 728
 729 static int add_attributes(PyTypeObject* type, char**attrs, int num_fields)
 730 {
 731     int i, result;
 732     PyObject *s, *l = PyTuple_New(num_fields);
 733     if (!l) return 0;
 734     for(i = 0; i < num_fields; i++) {
 735         s = PyUnicode_FromString(attrs[i]);
 736         if (!s) {
 737             Py_DECREF(l);
 738             return 0;
 739         }
 740         PyTuple_SET_ITEM(l, i, s);
 741     }
 742     result = PyObject_SetAttrString((PyObject*)type, "_attributes", l) >= 0;
 743     Py_DECREF(l);
 744     return result;
 745 }
 746
 747 /* Conversion AST -> Python */
 748
 749 static PyObject* ast2obj_list(asdl_seq *seq, PyObject* (*func)(void*))
 750 {
 751     int i, n = asdl_seq_LEN(seq);
 752     PyObject *result = PyList_New(n);
 753     PyObject *value;
 754     if (!result)
 755         return NULL;
 756     for (i = 0; i < n; i++) {
 757         value = func(asdl_seq_GET(seq, i));
 758         if (!value) {
 759             Py_DECREF(result);
 760             return NULL;
 761         }
 762         PyList_SET_ITEM(result, i, value);
 763     }
 764     return result;
 765 }
 766
 767 static PyObject* ast2obj_object(void *o)
 768 {
 769     if (!o)
 770         o = Py_None;
 771     Py_INCREF((PyObject*)o);
 772     return (PyObject*)o;
 773 }
 774 #define ast2obj_identifier ast2obj_object
 775 #define ast2obj_string ast2obj_object
 776
 777 static PyObject* ast2obj_int(long b)
 778 {
 779     return PyLong_FromLong(b);
 780 }
 781
 782 /* Conversion Python -> AST */
 783
 784 static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
 785 {
 786     if (obj == Py_None)
 787         obj = NULL;
 788     if (obj)
 789         PyArena_AddPyObject(arena, obj);
 790     Py_XINCREF(obj);
 791     *out = obj;
 792     return 0;
 793 }
 794
 795 #define obj2ast_identifier obj2ast_object
 796 #define obj2ast_string obj2ast_object
 797
 798 static int obj2ast_int(PyObject* obj, int* out, PyArena* arena)
 799 {
 800     int i;
 801     if (!PyLong_Check(obj)) {
 802         PyObject *s = PyObject_Repr(obj);
 803         if (s == NULL) return 1;
 804         PyErr_Format(PyExc_ValueError, "invalid integer value: %.400s",
 805                      PyBytes_AS_STRING(s));
 806         Py_DECREF(s);
 807         return 1;
 808     }
 809
 810     i = (int)PyLong_AsLong(obj);
 811     if (i == -1 && PyErr_Occurred())
 812         return 1;
 813     *out = i;
 814     return 0;
 815 }
 816
 817 static int add_ast_fields(void)
 818 {
 819     PyObject *empty_tuple, *d;
 820     if (PyType_Ready(&AST_type) < 0)
 821         return -1;
 822     d = AST_type.tp_dict;
 823     empty_tuple = PyTuple_New(0);
 824     if (!empty_tuple ||
 825         PyDict_SetItemString(d, "_fields", empty_tuple) < 0 ||
 826         PyDict_SetItemString(d, "_attributes", empty_tuple) < 0) {
 827         Py_XDECREF(empty_tuple);
 828         return -1;
 829     }
 830     Py_DECREF(empty_tuple);
 831     return 0;
 832 }
 833
 834 """, 0, reflow=False)
 835
 836         self.emit("static int init_types(void)",0)
 837         self.emit("{", 0)
 838         self.emit("static int initialized;", 1)
 839         self.emit("if (initialized) return 1;", 1)
 840         self.emit("if (add_ast_fields() < 0) return 0;", 1)
 841         for dfn in mod.dfns:
 842             self.visit(dfn)
 843         self.emit("initialized = 1;", 1)
 844         self.emit("return 1;", 1);
 845         self.emit("}", 0)
 846
 847     def visitProduct(self, prod, name):
 848         if prod.fields:
 849             fields = name.value+"_fields"
 850         else:
 851             fields = "NULL"
 852         self.emit('%s_type = make_type("%s", &AST_type, %s, %d);' %
 853                         (name, name, fields, len(prod.fields)), 1)
 854         self.emit("if (!%s_type) return 0;" % name, 1)
 855
 856     def visitSum(self, sum, name):
 857         self.emit('%s_type = make_type("%s", &AST_type, NULL, 0);' %
 858                   (name, name), 1)
 859         self.emit("if (!%s_type) return 0;" % name, 1)
 860         if sum.attributes:
 861             self.emit("if (!add_attributes(%s_type, %s_attributes, %d)) return 0;" %
 862                             (name, name, len(sum.attributes)), 1)
 863         else:
 864             self.emit("if (!add_attributes(%s_type, NULL, 0)) return 0;" % name, 1)
 865         simple = is_simple(sum)
 866         for t in sum.types:
 867             self.visitConstructor(t, name, simple)
 868
 869     def visitConstructor(self, cons, name, simple):
 870         if cons.fields:
 871             fields = cons.name.value+"_fields"
 872         else:
 873             fields = "NULL"
 874         self.emit('%s_type = make_type("%s", %s_type, %s, %d);' %
 875                             (cons.name, cons.name, name, fields, len(cons.fields)), 1)
 876         self.emit("if (!%s_type) return 0;" % cons.name, 1)
 877         if simple:
 878             self.emit("%s_singleton = PyType_GenericNew(%s_type, NULL, NULL);" %
 879                              (cons.name, cons.name), 1)
 880             self.emit("if (!%s_singleton) return 0;" % cons.name, 1)
 881
 882
 883 def parse_version(mod):
 884     return mod.version.value[12:-3]
 885
 886 class ASTModuleVisitor(PickleVisitor):
 887
 888     def visitModule(self, mod):
 889         self.emit("static struct PyModuleDef _astmodule = {", 0)
 890         self.emit('  PyModuleDef_HEAD_INIT, "_ast"', 0)
 891         self.emit("};", 0)
 892         self.emit("PyMODINIT_FUNC", 0)
 893         self.emit("PyInit__ast(void)", 0)
 894         self.emit("{", 0)
 895         self.emit("PyObject *m, *d;", 1)
 896         self.emit("if (!init_types()) return NULL;", 1)
 897         self.emit('m = PyModule_Create(&_astmodule);', 1)
 898         self.emit("if (!m) return NULL;", 1)
 899         self.emit("d = PyModule_GetDict(m);", 1)
 900         self.emit('if (PyDict_SetItemString(d, "AST", (PyObject*)&AST_type) < 0) return NULL;', 1)
 901         self.emit('if (PyModule_AddIntConstant(m, "PyCF_ONLY_AST", PyCF_ONLY_AST) < 0)', 1)
 902         self.emit("return NULL;", 2)
 903         # Value of version: "$Revision$"
 904         self.emit('if (PyModule_AddStringConstant(m, "__version__", "%s") < 0)'
 905                 % parse_version(mod), 1)
 906         self.emit("return NULL;", 2)
 907         for dfn in mod.dfns:
 908             self.visit(dfn)
 909         self.emit("return m;", 1)
 910         self.emit("}", 0)
 911
 912     def visitProduct(self, prod, name):
 913         self.addObj(name)
 914
 915     def visitSum(self, sum, name):
 916         self.addObj(name)
 917         for t in sum.types:
 918             self.visitConstructor(t, name)
 919
 920     def visitConstructor(self, cons, name):
 921         self.addObj(cons.name)
 922
 923     def addObj(self, name):
 924         self.emit('if (PyDict_SetItemString(d, "%s", (PyObject*)%s_type) < 0) return NULL;' % (name, name), 1)
 925
 926
 927 _SPECIALIZED_SEQUENCES = ('stmt', 'expr')
 928
 929 def find_sequence(fields, doing_specialization):
 930     """Return True if any field uses a sequence."""
 931     for f in fields:
 932         if f.seq:
 933             if not doing_specialization:
 934                 return True
 935             if str(f.type) not in _SPECIALIZED_SEQUENCES:
 936                 return True
 937     return False
 938
 939 def has_sequence(types, doing_specialization):
 940     for t in types:
 941         if find_sequence(t.fields, doing_specialization):
 942             return True
 943     return False
 944
 945
 946 class StaticVisitor(PickleVisitor):
 947     CODE = '''Very simple, always emit this static code.  Overide CODE'''
 948
 949     def visit(self, object):
 950         self.emit(self.CODE, 0, reflow=False)
 951
 952
 953 class ObjVisitor(PickleVisitor):
 954
 955     def func_begin(self, name):
 956         ctype = get_c_type(name)
 957         self.emit("PyObject*", 0)
 958         self.emit("ast2obj_%s(void* _o)" % (name), 0)
 959         self.emit("{", 0)
 960         self.emit("%s o = (%s)_o;" % (ctype, ctype), 1)
 961         self.emit("PyObject *result = NULL, *value = NULL;", 1)
 962         self.emit('if (!o) {', 1)
 963         self.emit("Py_INCREF(Py_None);", 2)
 964         self.emit('return Py_None;', 2)
 965         self.emit("}", 1)
 966         self.emit('', 0)
 967
 968     def func_end(self):
 969         self.emit("return result;", 1)
 970         self.emit("failed:", 0)
 971         self.emit("Py_XDECREF(value);", 1)
 972         self.emit("Py_XDECREF(result);", 1)
 973         self.emit("return NULL;", 1)
 974         self.emit("}", 0)
 975         self.emit("", 0)
 976
 977     def visitSum(self, sum, name):
 978         if is_simple(sum):
 979             self.simpleSum(sum, name)
 980             return
 981         self.func_begin(name)
 982         self.emit("switch (o->kind) {", 1)
 983         for i in range(len(sum.types)):
 984             t = sum.types[i]
 985             self.visitConstructor(t, i + 1, name)
 986         self.emit("}", 1)
 987         for a in sum.attributes:
 988             self.emit("value = ast2obj_%s(o->%s);" % (a.type, a.name), 1)
 989             self.emit("if (!value) goto failed;", 1)
 990             self.emit('if (PyObject_SetAttrString(result, "%s", value) < 0)' % a.name, 1)
 991             self.emit('goto failed;', 2)
 992             self.emit('Py_DECREF(value);', 1)
 993         self.func_end()
 994
 995     def simpleSum(self, sum, name):
 996         self.emit("PyObject* ast2obj_%s(%s_ty o)" % (name, name), 0)
 997         self.emit("{", 0)
 998         self.emit("switch(o) {", 1)
 999         for t in sum.types:
1000             self.emit("case %s:" % t.name, 2)
1001             self.emit("Py_INCREF(%s_singleton);" % t.name, 3)
1002             self.emit("return %s_singleton;" % t.name, 3)
1003         self.emit("default:" % name, 2)
1004         self.emit('/* should never happen, but just in case ... */', 3)
1005         code = "PyErr_Format(PyExc_SystemError, \"unknown %s found\");" % name
1006         self.emit(code, 3, reflow=False)
1007         self.emit("return NULL;", 3)
1008         self.emit("}", 1)
1009         self.emit("}", 0)
1010
1011     def visitProduct(self, prod, name):
1012         self.func_begin(name)
1013         self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % name, 1);
1014         self.emit("if (!result) return NULL;", 1)
1015         for field in prod.fields:
1016             self.visitField(field, name, 1, True)
1017         self.func_end()
1018
1019     def visitConstructor(self, cons, enum, name):
1020         self.emit("case %s_kind:" % cons.name, 1)
1021         self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % cons.name, 2);
1022         self.emit("if (!result) goto failed;", 2)
1023         for f in cons.fields:
1024             self.visitField(f, cons.name, 2, False)
1025         self.emit("break;", 2)
1026
1027     def visitField(self, field, name, depth, product):
1028         def emit(s, d):
1029             self.emit(s, depth + d)
1030         if product:
1031             value = "o->%s" % field.name
1032         else:
1033             value = "o->v.%s.%s" % (name, field.name)
1034         self.set(field, value, depth)
1035         emit("if (!value) goto failed;", 0)
1036         emit('if (PyObject_SetAttrString(result, "%s", value) == -1)' % field.name, 0)
1037         emit("goto failed;", 1)
1038         emit("Py_DECREF(value);", 0)
1039
1040     def emitSeq(self, field, value, depth, emit):
1041         emit("seq = %s;" % value, 0)
1042         emit("n = asdl_seq_LEN(seq);", 0)
1043         emit("value = PyList_New(n);", 0)
1044         emit("if (!value) goto failed;", 0)
1045         emit("for (i = 0; i < n; i++) {", 0)
1046         self.set("value", field, "asdl_seq_GET(seq, i)", depth + 1)
1047         emit("if (!value1) goto failed;", 1)
1048         emit("PyList_SET_ITEM(value, i, value1);", 1)
1049         emit("value1 = NULL;", 1)
1050         emit("}", 0)
1051
1052     def set(self, field, value, depth):
1053         if field.seq:
1054             # XXX should really check for is_simple, but that requires a symbol table
1055             if field.type.value == "cmpop":
1056                 # While the sequence elements are stored as void*,
1057                 # ast2obj_cmpop expects an enum
1058                 self.emit("{", depth)
1059                 self.emit("int i, n = asdl_seq_LEN(%s);" % value, depth+1)
1060                 self.emit("value = PyList_New(n);", depth+1)
1061                 self.emit("if (!value) goto failed;", depth+1)
1062                 self.emit("for(i = 0; i < n; i++)", depth+1)
1063                 # This cannot fail, so no need for error handling
1064                 self.emit("PyList_SET_ITEM(value, i, ast2obj_cmpop((cmpop_ty)asdl_seq_GET(%s, i)));" % value,
1065                           depth+2, reflow=False)
1066                 self.emit("}", depth)
1067             else:
1068                 self.emit("value = ast2obj_list(%s, ast2obj_%s);" % (value, field.type), depth)
1069         else:
1070             ctype = get_c_type(field.type)
1071             self.emit("value = ast2obj_%s(%s);" % (field.type, value), depth, reflow=False)
1072
1073
1074 class PartingShots(StaticVisitor):
1075
1076     CODE = """
1077 PyObject* PyAST_mod2obj(mod_ty t)
1078 {
1079     init_types();
1080     return ast2obj_mod(t);
1081 }
1082
1083 /* mode is 0 for "exec", 1 for "eval" and 2 for "single" input */
1084 mod_ty PyAST_obj2mod(PyObject* ast, PyArena* arena, int mode)
1085 {
1086     mod_ty res;
1087     PyObject *req_type[] = {(PyObject*)Module_type, (PyObject*)Expression_type,
1088                             (PyObject*)Interactive_type};
1089     char *req_name[] = {"Module", "Expression", "Interactive"};
1090     int isinstance;
1091     assert(0 <= mode && mode <= 2);
1092
1093     init_types();
1094
1095     isinstance = PyObject_IsInstance(ast, req_type[mode]);
1096     if (isinstance == -1)
1097         return NULL;
1098     if (!isinstance) {
1099         PyErr_Format(PyExc_TypeError, "expected %s node, got %.400s",
1100                      req_name[mode], Py_TYPE(ast)->tp_name);
1101         return NULL;
1102     }
1103     if (obj2ast_mod(ast, &res, arena) != 0)
1104         return NULL;
1105     else
1106         return res;
1107 }
1108
1109 int PyAST_Check(PyObject* obj)
1110 {
1111     init_types();
1112     return PyObject_IsInstance(obj, (PyObject*)&AST_type);
1113 }
1114 """
1115
1116 class ChainOfVisitors:
1117     def __init__(self, *visitors):
1118         self.visitors = visitors
1119
1120     def visit(self, object):
1121         for v in self.visitors:
1122             v.visit(object)
1123             v.emit("", 0)
1124
1125 common_msg = "/* File automatically generated by %s. */\n\n"
1126
1127 c_file_msg = """
1128 /*
1129    __version__ %s.
1130
1131    This module must be committed separately after each AST grammar change;
1132    The __version__ number is set to the revision number of the commit
1133    containing the grammar change.
1134 */
1135
1136 """
1137
1138 def main(srcfile):
1139     argv0 = sys.argv[0]
1140     components = argv0.split(os.sep)
1141     argv0 = os.sep.join(components[-2:])
1142     auto_gen_msg = common_msg % argv0
1143     mod = asdl.parse(srcfile)
1144     if not asdl.check(mod):
1145         sys.exit(1)
1146     if INC_DIR:
1147         p = "%s/%s-ast.h" % (INC_DIR, mod.name)
1148         f = open(p, "w")
1149         f.write(auto_gen_msg)
1150         f.write('#include "asdl.h"\n\n')
1151         c = ChainOfVisitors(TypeDefVisitor(f),
1152                             StructVisitor(f),
1153                             PrototypeVisitor(f),
1154                             )
1155         c.visit(mod)
1156         f.write("PyObject* PyAST_mod2obj(mod_ty t);\n")
1157         f.write("mod_ty PyAST_obj2mod(PyObject* ast, PyArena* arena, int mode);\n")
1158         f.write("int PyAST_Check(PyObject* obj);\n")
1159         f.close()
1160
1161     if SRC_DIR:
1162         p = os.path.join(SRC_DIR, str(mod.name) + "-ast.c")
1163         f = open(p, "w")
1164         f.write(auto_gen_msg)
1165         f.write(c_file_msg % parse_version(mod))
1166         f.write('#include "Python.h"\n')
1167         f.write('#include "%s-ast.h"\n' % mod.name)
1168         f.write('\n')
1169         f.write("static PyTypeObject AST_type;\n")
1170         v = ChainOfVisitors(
1171             PyTypesDeclareVisitor(f),
1172             PyTypesVisitor(f),
1173             Obj2ModPrototypeVisitor(f),
1174             FunctionVisitor(f),
1175             ObjVisitor(f),
1176             Obj2ModVisitor(f),
1177             ASTModuleVisitor(f),
1178             PartingShots(f),
1179             )
1180         v.visit(mod)
1181         f.close()
1182
1183 if __name__ == "__main__":
1184     import sys
1185     import getopt
1186
1187     INC_DIR = ''
1188     SRC_DIR = ''
1189     opts, args = getopt.getopt(sys.argv[1:], "h:c:")
1190     if len(opts) != 1:
1191         sys.stdout.write("Must specify exactly one output file\n")
1192         sys.exit(1)
1193     for o, v in opts:
1194         if o == '-h':
1195             INC_DIR = v
1196         if o == '-c':
1197             SRC_DIR = v
1198     if len(args) != 1:
1199         sys.stdout.write("Must specify single input file\n")
1200         sys.exit(1)
1201     main(args[0])