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=1):
  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=1):
 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 = 0)
 271         self.emit("%s _Py_%s(%s);" % (ctype, name, argstr), 0)
 272
 273     def visitProduct(self, prod, name):
 274         self.emit_function(name, get_c_type(name),
 275                            self.get_args(prod.fields), [], union=0)
 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=1):
 282         def emit(s, depth=0, reflow=1):
 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=0)
 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=1):
 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=1):
 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("", 0)
 371
 372     def sumTrailer(self, name):
 373         self.emit("", 0)
 374         self.emit("tmp = PyObject_Repr(obj);", 1)
 375         # there's really nothing more we can do if this fails ...
 376         self.emit("if (tmp == NULL) goto failed;", 1)
 377         error = "expected some sort of %s, but got %%.400s" % name
 378         format = "PyErr_Format(PyExc_TypeError, \"%s\", PyString_AS_STRING(tmp));"
 379         self.emit(format % error, 1, reflow=False)
 380         self.emit("failed:", 0)
 381         self.emit("Py_XDECREF(tmp);", 1)
 382         self.emit("return 1;", 1)
 383         self.emit("}", 0)
 384         self.emit("", 0)
 385
 386     def simpleSum(self, sum, name):
 387         self.funcHeader(name)
 388         for t in sum.types:
 389             self.emit("if (PyObject_IsInstance(obj, (PyObject*)%s_type)) {" % t.name, 1)
 390             self.emit("*out = %s;" % t.name, 2)
 391             self.emit("return 0;", 2)
 392             self.emit("}", 1)
 393         self.sumTrailer(name)
 394
 395     def buildArgs(self, fields):
 396         return ", ".join(fields + ["arena"])
 397
 398     def complexSum(self, sum, name):
 399         self.funcHeader(name)
 400         for a in sum.attributes:
 401             self.visitAttributeDeclaration(a, name, sum=sum)
 402         self.emit("", 0)
 403         # XXX: should we only do this for 'expr'?
 404         self.emit("if (obj == Py_None) {", 1)
 405         self.emit("*out = NULL;", 2)
 406         self.emit("return 0;", 2)
 407         self.emit("}", 1)
 408         for a in sum.attributes:
 409             self.visitField(a, name, sum=sum, depth=1)
 410         for t in sum.types:
 411             self.emit("if (PyObject_IsInstance(obj, (PyObject*)%s_type)) {" % t.name, 1)
 412             for f in t.fields:
 413                 self.visitFieldDeclaration(f, t.name, sum=sum, depth=2)
 414             self.emit("", 0)
 415             for f in t.fields:
 416                 self.visitField(f, t.name, sum=sum, depth=2)
 417             args = [f.name.value for f in t.fields] + [a.name.value for a in sum.attributes]
 418             self.emit("*out = %s(%s);" % (t.name, self.buildArgs(args)), 2)
 419             self.emit("if (*out == NULL) goto failed;", 2)
 420             self.emit("return 0;", 2)
 421             self.emit("}", 1)
 422         self.sumTrailer(name)
 423
 424     def visitAttributeDeclaration(self, a, name, sum=sum):
 425         ctype = get_c_type(a.type)
 426         self.emit("%s %s;" % (ctype, a.name), 1)
 427
 428     def visitSum(self, sum, name):
 429         if is_simple(sum):
 430             self.simpleSum(sum, name)
 431         else:
 432             self.complexSum(sum, name)
 433
 434     def visitProduct(self, prod, name):
 435         ctype = get_c_type(name)
 436         self.emit("int", 0)
 437         self.emit("obj2ast_%s(PyObject* obj, %s* out, PyArena* arena)" % (name, ctype), 0)
 438         self.emit("{", 0)
 439         self.emit("PyObject* tmp = NULL;", 1)
 440         for f in prod.fields:
 441             self.visitFieldDeclaration(f, name, prod=prod, depth=1)
 442         self.emit("", 0)
 443         for f in prod.fields:
 444             self.visitField(f, name, prod=prod, depth=1)
 445         args = [f.name.value for f in prod.fields]
 446         self.emit("*out = %s(%s);" % (name, self.buildArgs(args)), 1)
 447         self.emit("return 0;", 1)
 448         self.emit("failed:", 0)
 449         self.emit("Py_XDECREF(tmp);", 1)
 450         self.emit("return 1;", 1)
 451         self.emit("}", 0)
 452         self.emit("", 0)
 453
 454     def visitFieldDeclaration(self, field, name, sum=None, prod=None, depth=0):
 455         ctype = get_c_type(field.type)
 456         if field.seq:
 457             if self.isSimpleType(field):
 458                 self.emit("asdl_int_seq* %s;" % field.name, depth)
 459             else:
 460                 self.emit("asdl_seq* %s;" % field.name, depth)
 461         else:
 462             ctype = get_c_type(field.type)
 463             self.emit("%s %s;" % (ctype, field.name), depth)
 464
 465     def isSimpleSum(self, field):
 466         # XXX can the members of this list be determined automatically?
 467         return field.type.value in ('expr_context', 'boolop', 'operator',
 468                                     'unaryop', 'cmpop')
 469
 470     def isNumeric(self, field):
 471         return get_c_type(field.type) in ("int", "bool")
 472
 473     def isSimpleType(self, field):
 474         return self.isSimpleSum(field) or self.isNumeric(field)
 475
 476     def visitField(self, field, name, sum=None, prod=None, depth=0):
 477         ctype = get_c_type(field.type)
 478         self.emit("if (PyObject_HasAttrString(obj, \"%s\")) {" % field.name, depth)
 479         self.emit("int res;", depth+1)
 480         if field.seq:
 481             self.emit("Py_ssize_t len;", depth+1)
 482             self.emit("Py_ssize_t i;", depth+1)
 483         self.emit("tmp = PyObject_GetAttrString(obj, \"%s\");" % field.name, depth+1)
 484         self.emit("if (tmp == NULL) goto failed;", depth+1)
 485         if field.seq:
 486             self.emit("if (!PyList_Check(tmp)) {", depth+1)
 487             self.emit("PyErr_Format(PyExc_TypeError, \"%s field \\\"%s\\\" must "
 488                       "be a list, not a %%.200s\", tmp->ob_type->tp_name);" %
 489                       (name, field.name),
 490                       depth+2, reflow=False)
 491             self.emit("goto failed;", depth+2)
 492             self.emit("}", depth+1)
 493             self.emit("len = PyList_GET_SIZE(tmp);", depth+1)
 494             if self.isSimpleType(field):
 495                 self.emit("%s = asdl_int_seq_new(len, arena);" % field.name, depth+1)
 496             else:
 497                 self.emit("%s = asdl_seq_new(len, arena);" % field.name, depth+1)
 498             self.emit("if (%s == NULL) goto failed;" % field.name, depth+1)
 499             self.emit("for (i = 0; i < len; i++) {", depth+1)
 500             self.emit("%s value;" % ctype, depth+2)
 501             self.emit("res = obj2ast_%s(PyList_GET_ITEM(tmp, i), &value, arena);" %
 502                       field.type, depth+2, reflow=False)
 503             self.emit("if (res != 0) goto failed;", depth+2)
 504             self.emit("asdl_seq_SET(%s, i, value);" % field.name, depth+2)
 505             self.emit("}", depth+1)
 506         else:
 507             self.emit("res = obj2ast_%s(tmp, &%s, arena);" %
 508                       (field.type, field.name), depth+1)
 509             self.emit("if (res != 0) goto failed;", depth+1)
 510
 511         self.emit("Py_XDECREF(tmp);", depth+1)
 512         self.emit("tmp = NULL;", depth+1)
 513         self.emit("} else {", depth)
 514         if not field.opt:
 515             message = "required field \\\"%s\\\" missing from %s" % (field.name, name)
 516             format = "PyErr_SetString(PyExc_TypeError, \"%s\");"
 517             self.emit(format % message, depth+1, reflow=False)
 518             self.emit("return 1;", depth+1)
 519         else:
 520             if self.isNumeric(field):
 521                 self.emit("%s = 0;" % field.name, depth+1)
 522             elif not self.isSimpleType(field):
 523                 self.emit("%s = NULL;" % field.name, depth+1)
 524             else:
 525                 raise TypeError("could not determine the default value for %s" % field.name)
 526         self.emit("}", depth)
 527
 528
 529 class MarshalPrototypeVisitor(PickleVisitor):
 530
 531     def prototype(self, sum, name):
 532         ctype = get_c_type(name)
 533         self.emit("static int marshal_write_%s(PyObject **, int *, %s);"
 534                   % (name, ctype), 0)
 535
 536     visitProduct = visitSum = prototype
 537
 538
 539 class PyTypesDeclareVisitor(PickleVisitor):
 540
 541     def visitProduct(self, prod, name):
 542         self.emit("static PyTypeObject *%s_type;" % name, 0)
 543         self.emit("static PyObject* ast2obj_%s(void*);" % name, 0)
 544         if prod.fields:
 545             self.emit("static char *%s_fields[]={" % name,0)
 546             for f in prod.fields:
 547                 self.emit('"%s",' % f.name, 1)
 548             self.emit("};", 0)
 549
 550     def visitSum(self, sum, name):
 551         self.emit("static PyTypeObject *%s_type;" % name, 0)
 552         if sum.attributes:
 553             self.emit("static char *%s_attributes[] = {" % name, 0)
 554             for a in sum.attributes:
 555                 self.emit('"%s",' % a.name, 1)
 556             self.emit("};", 0)
 557         ptype = "void*"
 558         if is_simple(sum):
 559             ptype = get_c_type(name)
 560             tnames = []
 561             for t in sum.types:
 562                 tnames.append(str(t.name)+"_singleton")
 563             tnames = ", *".join(tnames)
 564             self.emit("static PyObject *%s;" % tnames, 0)
 565         self.emit("static PyObject* ast2obj_%s(%s);" % (name, ptype), 0)
 566         for t in sum.types:
 567             self.visitConstructor(t, name)
 568
 569     def visitConstructor(self, cons, name):
 570         self.emit("static PyTypeObject *%s_type;" % cons.name, 0)
 571         if cons.fields:
 572             self.emit("static char *%s_fields[]={" % cons.name, 0)
 573             for t in cons.fields:
 574                 self.emit('"%s",' % t.name, 1)
 575             self.emit("};",0)
 576
 577 class PyTypesVisitor(PickleVisitor):
 578
 579     def visitModule(self, mod):
 580         self.emit("""
 581 static int
 582 ast_type_init(PyObject *self, PyObject *args, PyObject *kw)
 583 {
 584     Py_ssize_t i, numfields = 0;
 585     int res = -1;
 586     PyObject *key, *value, *fields;
 587     fields = PyObject_GetAttrString((PyObject*)Py_TYPE(self), "_fields");
 588     if (!fields)
 589         PyErr_Clear();
 590     if (fields) {
 591         numfields = PySequence_Size(fields);
 592         if (numfields == -1)
 593             goto cleanup;
 594     }
 595     res = 0; /* if no error occurs, this stays 0 to the end */
 596     if (PyTuple_GET_SIZE(args) > 0) {
 597         if (numfields != PyTuple_GET_SIZE(args)) {
 598             PyErr_Format(PyExc_TypeError, "%.400s constructor takes %s"
 599                          "%zd positional argument%s",
 600                          Py_TYPE(self)->tp_name,
 601                          numfields == 0 ? "" : "either 0 or ",
 602                          numfields, numfields == 1 ? "" : "s");
 603             res = -1;
 604             goto cleanup;
 605         }
 606         for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
 607             /* cannot be reached when fields is NULL */
 608             PyObject *name = PySequence_GetItem(fields, i);
 609             if (!name) {
 610                 res = -1;
 611                 goto cleanup;
 612             }
 613             res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
 614             Py_DECREF(name);
 615             if (res < 0)
 616                 goto cleanup;
 617         }
 618     }
 619     if (kw) {
 620         i = 0;  /* needed by PyDict_Next */
 621         while (PyDict_Next(kw, &i, &key, &value)) {
 622             res = PyObject_SetAttr(self, key, value);
 623             if (res < 0)
 624                 goto cleanup;
 625         }
 626     }
 627   cleanup:
 628     Py_XDECREF(fields);
 629     return res;
 630 }
 631
 632 /* Pickling support */
 633 static PyObject *
 634 ast_type_reduce(PyObject *self, PyObject *unused)
 635 {
 636     PyObject *res;
 637     PyObject *dict = PyObject_GetAttrString(self, "__dict__");
 638     if (dict == NULL) {
 639         if (PyErr_ExceptionMatches(PyExc_AttributeError))
 640             PyErr_Clear();
 641         else
 642             return NULL;
 643     }
 644     if (dict) {
 645         res = Py_BuildValue("O()O", Py_TYPE(self), dict);
 646         Py_DECREF(dict);
 647         return res;
 648     }
 649     return Py_BuildValue("O()", Py_TYPE(self));
 650 }
 651
 652 static PyMethodDef ast_type_methods[] = {
 653     {"__reduce__", ast_type_reduce, METH_NOARGS, NULL},
 654     {NULL}
 655 };
 656
 657 static PyTypeObject AST_type = {
 658     PyVarObject_HEAD_INIT(&PyType_Type, 0)
 659     "_ast.AST",
 660     sizeof(PyObject),
 661     0,
 662     0,                       /* tp_dealloc */
 663     0,                       /* tp_print */
 664     0,                       /* tp_getattr */
 665     0,                       /* tp_setattr */
 666     0,                       /* tp_compare */
 667     0,                       /* tp_repr */
 668     0,                       /* tp_as_number */
 669     0,                       /* tp_as_sequence */
 670     0,                       /* tp_as_mapping */
 671     0,                       /* tp_hash */
 672     0,                       /* tp_call */
 673     0,                       /* tp_str */
 674     PyObject_GenericGetAttr, /* tp_getattro */
 675     PyObject_GenericSetAttr, /* tp_setattro */
 676     0,                       /* tp_as_buffer */
 677     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
 678     0,                       /* tp_doc */
 679     0,                       /* tp_traverse */
 680     0,                       /* tp_clear */
 681     0,                       /* tp_richcompare */
 682     0,                       /* tp_weaklistoffset */
 683     0,                       /* tp_iter */
 684     0,                       /* tp_iternext */
 685     ast_type_methods,        /* tp_methods */
 686     0,                       /* tp_members */
 687     0,                       /* tp_getset */
 688     0,                       /* tp_base */
 689     0,                       /* tp_dict */
 690     0,                       /* tp_descr_get */
 691     0,                       /* tp_descr_set */
 692     0,                       /* tp_dictoffset */
 693     (initproc)ast_type_init, /* tp_init */
 694     PyType_GenericAlloc,     /* tp_alloc */
 695     PyType_GenericNew,       /* tp_new */
 696     PyObject_Del,            /* tp_free */
 697 };
 698
 699
 700 static PyTypeObject* make_type(char *type, PyTypeObject* base, char**fields, int num_fields)
 701 {
 702     PyObject *fnames, *result;
 703     int i;
 704     fnames = PyTuple_New(num_fields);
 705     if (!fnames) return NULL;
 706     for (i = 0; i < num_fields; i++) {
 707         PyObject *field = PyString_FromString(fields[i]);
 708         if (!field) {
 709             Py_DECREF(fnames);
 710             return NULL;
 711         }
 712         PyTuple_SET_ITEM(fnames, i, field);
 713     }
 714     result = PyObject_CallFunction((PyObject*)&PyType_Type, "s(O){sOss}",
 715                     type, base, "_fields", fnames, "__module__", "_ast");
 716     Py_DECREF(fnames);
 717     return (PyTypeObject*)result;
 718 }
 719
 720 static int add_attributes(PyTypeObject* type, char**attrs, int num_fields)
 721 {
 722     int i, result;
 723     PyObject *s, *l = PyTuple_New(num_fields);
 724     if (!l) return 0;
 725     for(i = 0; i < num_fields; i++) {
 726         s = PyString_FromString(attrs[i]);
 727         if (!s) {
 728             Py_DECREF(l);
 729             return 0;
 730         }
 731         PyTuple_SET_ITEM(l, i, s);
 732     }
 733     result = PyObject_SetAttrString((PyObject*)type, "_attributes", l) >= 0;
 734     Py_DECREF(l);
 735     return result;
 736 }
 737
 738 /* Conversion AST -> Python */
 739
 740 static PyObject* ast2obj_list(asdl_seq *seq, PyObject* (*func)(void*))
 741 {
 742     int i, n = asdl_seq_LEN(seq);
 743     PyObject *result = PyList_New(n);
 744     PyObject *value;
 745     if (!result)
 746         return NULL;
 747     for (i = 0; i < n; i++) {
 748         value = func(asdl_seq_GET(seq, i));
 749         if (!value) {
 750             Py_DECREF(result);
 751             return NULL;
 752         }
 753         PyList_SET_ITEM(result, i, value);
 754     }
 755     return result;
 756 }
 757
 758 static PyObject* ast2obj_object(void *o)
 759 {
 760     if (!o)
 761         o = Py_None;
 762     Py_INCREF((PyObject*)o);
 763     return (PyObject*)o;
 764 }
 765 #define ast2obj_identifier ast2obj_object
 766 #define ast2obj_string ast2obj_object
 767 static PyObject* ast2obj_bool(bool b)
 768 {
 769     return PyBool_FromLong(b);
 770 }
 771
 772 static PyObject* ast2obj_int(long b)
 773 {
 774     return PyInt_FromLong(b);
 775 }
 776
 777 /* Conversion Python -> AST */
 778
 779 static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
 780 {
 781     if (obj == Py_None)
 782         obj = NULL;
 783     if (obj)
 784         PyArena_AddPyObject(arena, obj);
 785     Py_XINCREF(obj);
 786     *out = obj;
 787     return 0;
 788 }
 789
 790 #define obj2ast_identifier obj2ast_object
 791 #define obj2ast_string obj2ast_object
 792
 793 static int obj2ast_int(PyObject* obj, int* out, PyArena* arena)
 794 {
 795     int i;
 796     if (!PyInt_Check(obj) && !PyLong_Check(obj)) {
 797         PyObject *s = PyObject_Repr(obj);
 798         if (s == NULL) return 1;
 799         PyErr_Format(PyExc_ValueError, "invalid integer value: %.400s",
 800                      PyString_AS_STRING(s));
 801         Py_DECREF(s);
 802         return 1;
 803     }
 804
 805     i = (int)PyLong_AsLong(obj);
 806     if (i == -1 && PyErr_Occurred())
 807         return 1;
 808     *out = i;
 809     return 0;
 810 }
 811
 812 static int obj2ast_bool(PyObject* obj, bool* out, PyArena* arena)
 813 {
 814     if (!PyBool_Check(obj)) {
 815         PyObject *s = PyObject_Repr(obj);
 816         if (s == NULL) return 1;
 817         PyErr_Format(PyExc_ValueError, "invalid boolean value: %.400s",
 818                      PyString_AS_STRING(s));
 819         Py_DECREF(s);
 820         return 1;
 821     }
 822
 823     *out = (obj == Py_True);
 824     return 0;
 825 }
 826
 827 static int add_ast_fields(void)
 828 {
 829     PyObject *empty_tuple, *d;
 830     if (PyType_Ready(&AST_type) < 0)
 831         return -1;
 832     d = AST_type.tp_dict;
 833     empty_tuple = PyTuple_New(0);
 834     if (!empty_tuple ||
 835         PyDict_SetItemString(d, "_fields", empty_tuple) < 0 ||
 836         PyDict_SetItemString(d, "_attributes", empty_tuple) < 0) {
 837         Py_XDECREF(empty_tuple);
 838         return -1;
 839     }
 840     Py_DECREF(empty_tuple);
 841     return 0;
 842 }
 843
 844 """, 0, reflow=False)
 845
 846         self.emit("static int init_types(void)",0)
 847         self.emit("{", 0)
 848         self.emit("static int initialized;", 1)
 849         self.emit("if (initialized) return 1;", 1)
 850         self.emit("if (add_ast_fields() < 0) return 0;", 1)
 851         for dfn in mod.dfns:
 852             self.visit(dfn)
 853         self.emit("initialized = 1;", 1)
 854         self.emit("return 1;", 1);
 855         self.emit("}", 0)
 856
 857     def visitProduct(self, prod, name):
 858         if prod.fields:
 859             fields = name.value+"_fields"
 860         else:
 861             fields = "NULL"
 862         self.emit('%s_type = make_type("%s", &AST_type, %s, %d);' %
 863                         (name, name, fields, len(prod.fields)), 1)
 864         self.emit("if (!%s_type) return 0;" % name, 1)
 865
 866     def visitSum(self, sum, name):
 867         self.emit('%s_type = make_type("%s", &AST_type, NULL, 0);' %
 868                   (name, name), 1)
 869         self.emit("if (!%s_type) return 0;" % name, 1)
 870         if sum.attributes:
 871             self.emit("if (!add_attributes(%s_type, %s_attributes, %d)) return 0;" %
 872                             (name, name, len(sum.attributes)), 1)
 873         else:
 874             self.emit("if (!add_attributes(%s_type, NULL, 0)) return 0;" % name, 1)
 875         simple = is_simple(sum)
 876         for t in sum.types:
 877             self.visitConstructor(t, name, simple)
 878
 879     def visitConstructor(self, cons, name, simple):
 880         if cons.fields:
 881             fields = cons.name.value+"_fields"
 882         else:
 883             fields = "NULL"
 884         self.emit('%s_type = make_type("%s", %s_type, %s, %d);' %
 885                             (cons.name, cons.name, name, fields, len(cons.fields)), 1)
 886         self.emit("if (!%s_type) return 0;" % cons.name, 1)
 887         if simple:
 888             self.emit("%s_singleton = PyType_GenericNew(%s_type, NULL, NULL);" %
 889                              (cons.name, cons.name), 1)
 890             self.emit("if (!%s_singleton) return 0;" % cons.name, 1)
 891
 892
 893 def parse_version(mod):
 894     return mod.version.value[12:-3]
 895
 896 class ASTModuleVisitor(PickleVisitor):
 897
 898     def visitModule(self, mod):
 899         self.emit("PyMODINIT_FUNC", 0)
 900         self.emit("init_ast(void)", 0)
 901         self.emit("{", 0)
 902         self.emit("PyObject *m, *d;", 1)
 903         self.emit("if (!init_types()) return;", 1)
 904         self.emit('m = Py_InitModule3("_ast", NULL, NULL);', 1)
 905         self.emit("if (!m) return;", 1)
 906         self.emit("d = PyModule_GetDict(m);", 1)
 907         self.emit('if (PyDict_SetItemString(d, "AST", (PyObject*)&AST_type) < 0) return;', 1)
 908         self.emit('if (PyModule_AddIntConstant(m, "PyCF_ONLY_AST", PyCF_ONLY_AST) < 0)', 1)
 909         self.emit("return;", 2)
 910         # Value of version: "$Revision$"
 911         self.emit('if (PyModule_AddStringConstant(m, "__version__", "%s") < 0)'
 912                 % parse_version(mod), 1)
 913         self.emit("return;", 2)
 914         for dfn in mod.dfns:
 915             self.visit(dfn)
 916         self.emit("}", 0)
 917
 918     def visitProduct(self, prod, name):
 919         self.addObj(name)
 920
 921     def visitSum(self, sum, name):
 922         self.addObj(name)
 923         for t in sum.types:
 924             self.visitConstructor(t, name)
 925
 926     def visitConstructor(self, cons, name):
 927         self.addObj(cons.name)
 928
 929     def addObj(self, name):
 930         self.emit('if (PyDict_SetItemString(d, "%s", (PyObject*)%s_type) < 0) return;' % (name, name), 1)
 931
 932
 933 _SPECIALIZED_SEQUENCES = ('stmt', 'expr')
 934
 935 def find_sequence(fields, doing_specialization):
 936     """Return True if any field uses a sequence."""
 937     for f in fields:
 938         if f.seq:
 939             if not doing_specialization:
 940                 return True
 941             if str(f.type) not in _SPECIALIZED_SEQUENCES:
 942                 return True
 943     return False
 944
 945 def has_sequence(types, doing_specialization):
 946     for t in types:
 947         if find_sequence(t.fields, doing_specialization):
 948             return True
 949     return False
 950
 951
 952 class StaticVisitor(PickleVisitor):
 953     CODE = '''Very simple, always emit this static code.  Overide CODE'''
 954
 955     def visit(self, object):
 956         self.emit(self.CODE, 0, reflow=False)
 957
 958
 959 class ObjVisitor(PickleVisitor):
 960
 961     def func_begin(self, name):
 962         ctype = get_c_type(name)
 963         self.emit("PyObject*", 0)
 964         self.emit("ast2obj_%s(void* _o)" % (name), 0)
 965         self.emit("{", 0)
 966         self.emit("%s o = (%s)_o;" % (ctype, ctype), 1)
 967         self.emit("PyObject *result = NULL, *value = NULL;", 1)
 968         self.emit('if (!o) {', 1)
 969         self.emit("Py_INCREF(Py_None);", 2)
 970         self.emit('return Py_None;', 2)
 971         self.emit("}", 1)
 972         self.emit('', 0)
 973
 974     def func_end(self):
 975         self.emit("return result;", 1)
 976         self.emit("failed:", 0)
 977         self.emit("Py_XDECREF(value);", 1)
 978         self.emit("Py_XDECREF(result);", 1)
 979         self.emit("return NULL;", 1)
 980         self.emit("}", 0)
 981         self.emit("", 0)
 982
 983     def visitSum(self, sum, name):
 984         if is_simple(sum):
 985             self.simpleSum(sum, name)
 986             return
 987         self.func_begin(name)
 988         self.emit("switch (o->kind) {", 1)
 989         for i in range(len(sum.types)):
 990             t = sum.types[i]
 991             self.visitConstructor(t, i + 1, name)
 992         self.emit("}", 1)
 993         for a in sum.attributes:
 994             self.emit("value = ast2obj_%s(o->%s);" % (a.type, a.name), 1)
 995             self.emit("if (!value) goto failed;", 1)
 996             self.emit('if (PyObject_SetAttrString(result, "%s", value) < 0)' % a.name, 1)
 997             self.emit('goto failed;', 2)
 998             self.emit('Py_DECREF(value);', 1)
 999         self.func_end()
1000
1001     def simpleSum(self, sum, name):
1002         self.emit("PyObject* ast2obj_%s(%s_ty o)" % (name, name), 0)
1003         self.emit("{", 0)
1004         self.emit("switch(o) {", 1)
1005         for t in sum.types:
1006             self.emit("case %s:" % t.name, 2)
1007             self.emit("Py_INCREF(%s_singleton);" % t.name, 3)
1008             self.emit("return %s_singleton;" % t.name, 3)
1009         self.emit("default:" % name, 2)
1010         self.emit('/* should never happen, but just in case ... */', 3)
1011         code = "PyErr_Format(PyExc_SystemError, \"unknown %s found\");" % name
1012         self.emit(code, 3, reflow=False)
1013         self.emit("return NULL;", 3)
1014         self.emit("}", 1)
1015         self.emit("}", 0)
1016
1017     def visitProduct(self, prod, name):
1018         self.func_begin(name)
1019         self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % name, 1);
1020         self.emit("if (!result) return NULL;", 1)
1021         for field in prod.fields:
1022             self.visitField(field, name, 1, True)
1023         self.func_end()
1024
1025     def visitConstructor(self, cons, enum, name):
1026         self.emit("case %s_kind:" % cons.name, 1)
1027         self.emit("result = PyType_GenericNew(%s_type, NULL, NULL);" % cons.name, 2);
1028         self.emit("if (!result) goto failed;", 2)
1029         for f in cons.fields:
1030             self.visitField(f, cons.name, 2, False)
1031         self.emit("break;", 2)
1032
1033     def visitField(self, field, name, depth, product):
1034         def emit(s, d):
1035             self.emit(s, depth + d)
1036         if product:
1037             value = "o->%s" % field.name
1038         else:
1039             value = "o->v.%s.%s" % (name, field.name)
1040         self.set(field, value, depth)
1041         emit("if (!value) goto failed;", 0)
1042         emit('if (PyObject_SetAttrString(result, "%s", value) == -1)' % field.name, 0)
1043         emit("goto failed;", 1)
1044         emit("Py_DECREF(value);", 0)
1045
1046     def emitSeq(self, field, value, depth, emit):
1047         emit("seq = %s;" % value, 0)
1048         emit("n = asdl_seq_LEN(seq);", 0)
1049         emit("value = PyList_New(n);", 0)
1050         emit("if (!value) goto failed;", 0)
1051         emit("for (i = 0; i < n; i++) {", 0)
1052         self.set("value", field, "asdl_seq_GET(seq, i)", depth + 1)
1053         emit("if (!value1) goto failed;", 1)
1054         emit("PyList_SET_ITEM(value, i, value1);", 1)
1055         emit("value1 = NULL;", 1)
1056         emit("}", 0)
1057
1058     def set(self, field, value, depth):
1059         if field.seq:
1060             # XXX should really check for is_simple, but that requires a symbol table
1061             if field.type.value == "cmpop":
1062                 # While the sequence elements are stored as void*,
1063                 # ast2obj_cmpop expects an enum
1064                 self.emit("{", depth)
1065                 self.emit("int i, n = asdl_seq_LEN(%s);" % value, depth+1)
1066                 self.emit("value = PyList_New(n);", depth+1)
1067                 self.emit("if (!value) goto failed;", depth+1)
1068                 self.emit("for(i = 0; i < n; i++)", depth+1)
1069                 # This cannot fail, so no need for error handling
1070                 self.emit("PyList_SET_ITEM(value, i, ast2obj_cmpop((cmpop_ty)asdl_seq_GET(%s, i)));" % value,
1071                           depth+2, reflow=False)
1072                 self.emit("}", depth)
1073             else:
1074                 self.emit("value = ast2obj_list(%s, ast2obj_%s);" % (value, field.type), depth)
1075         else:
1076             ctype = get_c_type(field.type)
1077             self.emit("value = ast2obj_%s(%s);" % (field.type, value), depth, reflow=False)
1078
1079
1080 class PartingShots(StaticVisitor):
1081
1082     CODE = """
1083 PyObject* PyAST_mod2obj(mod_ty t)
1084 {
1085     init_types();
1086     return ast2obj_mod(t);
1087 }
1088
1089 /* mode is 0 for "exec", 1 for "eval" and 2 for "single" input */
1090 mod_ty PyAST_obj2mod(PyObject* ast, PyArena* arena, int mode)
1091 {
1092     mod_ty res;
1093     PyObject *req_type[] = {(PyObject*)Module_type, (PyObject*)Expression_type,
1094                             (PyObject*)Interactive_type};
1095     char *req_name[] = {"Module", "Expression", "Interactive"};
1096     assert(0 <= mode && mode <= 2);
1097
1098     init_types();
1099
1100     if (!PyObject_IsInstance(ast, req_type[mode])) {
1101         PyErr_Format(PyExc_TypeError, "expected %s node, got %.400s",
1102                      req_name[mode], Py_TYPE(ast)->tp_name);
1103         return NULL;
1104     }
1105     if (obj2ast_mod(ast, &res, arena) != 0)
1106         return NULL;
1107     else
1108         return res;
1109 }
1110
1111 int PyAST_Check(PyObject* obj)
1112 {
1113     init_types();
1114     return PyObject_IsInstance(obj, (PyObject*)&AST_type);
1115 }
1116 """
1117
1118 class ChainOfVisitors:
1119     def __init__(self, *visitors):
1120         self.visitors = visitors
1121
1122     def visit(self, object):
1123         for v in self.visitors:
1124             v.visit(object)
1125             v.emit("", 0)
1126
1127 common_msg = "/* File automatically generated by %s. */\n\n"
1128
1129 c_file_msg = """
1130 /*
1131    __version__ %s.
1132
1133    This module must be committed separately after each AST grammar change;
1134    The __version__ number is set to the revision number of the commit
1135    containing the grammar change.
1136 */
1137
1138 """
1139
1140 def main(srcfile):
1141     argv0 = sys.argv[0]
1142     components = argv0.split(os.sep)
1143     argv0 = os.sep.join(components[-2:])
1144     auto_gen_msg = common_msg % argv0
1145     mod = asdl.parse(srcfile)
1146     if not asdl.check(mod):
1147         sys.exit(1)
1148     if INC_DIR:
1149         p = "%s/%s-ast.h" % (INC_DIR, mod.name)
1150         f = open(p, "wb")
1151         f.write(auto_gen_msg)
1152         f.write('#include "asdl.h"\n\n')
1153         c = ChainOfVisitors(TypeDefVisitor(f),
1154                             StructVisitor(f),
1155                             PrototypeVisitor(f),
1156                             )
1157         c.visit(mod)
1158         f.write("PyObject* PyAST_mod2obj(mod_ty t);\n")
1159         f.write("mod_ty PyAST_obj2mod(PyObject* ast, PyArena* arena, int mode);\n")
1160         f.write("int PyAST_Check(PyObject* obj);\n")
1161         f.close()
1162
1163     if SRC_DIR:
1164         p = os.path.join(SRC_DIR, str(mod.name) + "-ast.c")
1165         f = open(p, "wb")
1166         f.write(auto_gen_msg)
1167         f.write(c_file_msg % parse_version(mod))
1168         f.write('#include "Python.h"\n')
1169         f.write('#include "%s-ast.h"\n' % mod.name)
1170         f.write('\n')
1171         f.write("static PyTypeObject AST_type;\n")
1172         v = ChainOfVisitors(
1173             PyTypesDeclareVisitor(f),
1174             PyTypesVisitor(f),
1175             Obj2ModPrototypeVisitor(f),
1176             FunctionVisitor(f),
1177             ObjVisitor(f),
1178             Obj2ModVisitor(f),
1179             ASTModuleVisitor(f),
1180             PartingShots(f),
1181             )
1182         v.visit(mod)
1183         f.close()
1184
1185 if __name__ == "__main__":
1186     import sys
1187     import getopt
1188
1189     INC_DIR = ''
1190     SRC_DIR = ''
1191     opts, args = getopt.getopt(sys.argv[1:], "h:c:")
1192     if len(opts) != 1:
1193         print "Must specify exactly one output file"
1194         sys.exit(1)
1195     for o, v in opts:
1196         if o == '-h':
1197             INC_DIR = v
1198         if o == '-c':
1199             SRC_DIR = v
1200     if len(args) != 1:
1201         print "Must specify single input file"
1202         sys.exit(1)
1203     main(args[0])