text: #! /usr/bin/env python
  """Generate C code from an ASDL description."""
  
  import os
  import sys
  
  from argparse import ArgumentParser
  from pathlib import Path
  
  import asdl
  
  TABSIZE = 4
  MAX_COL = 80
  AUTOGEN_MESSAGE = "/* File automatically generated by {}. */\n\n"
  
  def get_c_type(name):
      """Return a string for the C name of the type.
  
      This function special cases the default types provided by asdl.
      """
      if name in asdl.builtin_types:
          return name
      else:
          return "%s_ty" % name
  
  def reflow_lines(s, depth):
      """Reflow the line s indented depth tabs.
  
      Return a sequence of lines where no line extends beyond MAX_COL
      when properly indented.  The first line is properly indented based
      exclusively on depth * TABSIZE.  All following lines -- these are
      the reflowed lines generated by this function -- start at the same
      column as the first character beyond the opening { in the first
      line.
      """
      size = MAX_COL - depth * TABSIZE
      if len(s) < size:
          return [s]
  
      lines = []
      cur = s
      padding = ""
      while len(cur) > size:
          i = cur.rfind(' ', 0, size)
          # XXX this should be fixed for real
          if i == -1 and 'GeneratorExp' in cur:
              i = size + 3
          assert i != -1, "Impossible line %d to reflow: %r" % (size, s)
          lines.append(padding + cur[:i])
          if len(lines) == 1:
              # find new size based on brace
              j = cur.find('{', 0, i)
              if j >= 0:
                  j += 2 # account for the brace and the space after it
                  size -= j
                  padding = " " * j
              else:
                  j = cur.find('(', 0, i)
                  if j >= 0:
                      j += 1 # account for the paren (no space after it)
                      size -= j
                      padding = " " * j
          cur = cur[i+1:]
      else:
          lines.append(padding + cur)
      return lines
  
  def reflow_c_string(s, depth):
      return '"%s"' % s.replace('\n', '\\n"\n%s"' % (' ' * depth * TABSIZE))
  
  def is_simple(sum):
      """Return True if a sum is a simple.
  
      A sum is simple if its types have no fields, e.g.
      unaryop = Invert | Not | UAdd | USub
      """
      for t in sum.types:
          if t.fields:
              return False
      return True
  
  def asdl_of(name, obj):
      if isinstance(obj, asdl.Product) or isinstance(obj, asdl.Constructor):
          fields = ", ".join(map(str, obj.fields))
          if fields:
              fields = "({})".format(fields)
          return "{}{}".format(name, fields)
      else:
          if is_simple(obj):
              types = " | ".join(type.name for type in obj.types)
          else:
              sep = "\n{}| ".format(" " * (len(name) + 1))
              types = sep.join(
                  asdl_of(type.name, type) for type in obj.types
              )
          return "{} = {}".format(name, types)
  
  class EmitVisitor(asdl.VisitorBase):
      """Visit that emits lines"""
  
      def __init__(self, file):
          self.file = file
          self.identifiers = set()
          self.singletons = set()
          self.types = set()
          super(EmitVisitor, self).__init__()
  
      def emit_identifier(self, name):
          self.identifiers.add(str(name))
  
      def emit_singleton(self, name):
          self.singletons.add(str(name))
  
      def emit_type(self, name):
          self.types.add(str(name))
  
      def emit(self, s, depth, reflow=True):
          # XXX reflow long lines?
          if reflow:
              lines = reflow_lines(s, depth)
          else:
              lines = [s]
          for line in lines:
              if line:
                  line = (" " * TABSIZE * depth) + line
              self.file.write(line + "\n")
  
  
  class TypeDefVisitor(EmitVisitor):
      def visitModule(self, mod):
          for dfn in mod.dfns:
              self.visit(dfn)
  
      def visitType(self, type, depth=0):
          self.visit(type.value, type.name, depth)
  
      def visitSum(self, sum, name, depth):
          if is_simple(sum):
              self.simple_sum(sum, name, depth)
          else:
              self.sum_with_constructors(sum, name, depth)
  
      def simple_sum(self, sum, name, depth):
          enum = []
          for i in range(len(sum.types)):
              type = sum.types[i]
              enum.append("%s=%d" % (type.name, i + 1))
          enums = ", ".join(enum)
          ctype = get_c_type(name)
          s = "typedef enum _%s { %s } %s;" % (name, enums, ctype)
          self.emit(s, depth)
          self.emit("", depth)
  
      def sum_with_constructors(self, sum, name, depth):
          ctype = get_c_type(name)
          s = "typedef struct _%(name)s *%(ctype)s;" % locals()
          self.emit(s, depth)
          self.emit("", depth)
  
      def visitProduct(self, product, name, depth):
          ctype = get_c_type(name)
          s = "typedef struct _%(name)s *%(ctype)s;" % locals()
          self.emit(s, depth)
          self.emit("", depth)
  
  
  class StructVisitor(EmitVisitor):
      """Visitor to generate typedefs for AST."""
  
      def visitModule(self, mod):
          for dfn in mod.dfns:
              self.visit(dfn)
  
      def visitType(self, type, depth=0):
          self.visit(type.value, type.name, depth)
  
      def visitSum(self, sum, name, depth):
          if not is_simple(sum):
              self.sum_with_constructors(sum, name, depth)
  
      def sum_with_constructors(self, sum, name, depth):
          def emit(s, depth=depth):
              self.emit(s % sys._getframe(1).f_locals, depth)
          enum = []
          for i in range(len(sum.types)):
              type = sum.types[i]
              enum.append("%s_kind=%d" % (type.name, i + 1))
  
          emit("enum _%(name)s_kind {" + ", ".join(enum) + "};")
  
          emit("struct _%(name)s {")
          emit("enum _%(name)s_kind kind;", depth + 1)
          emit("union {", depth + 1)
          for t in sum.types:
              self.visit(t, depth + 2)
          emit("} v;", depth + 1)
          for field in sum.attributes:
              # rudimentary attribute handling
              type = str(field.type)
              assert type in asdl.builtin_types, type
              emit("%s %s;" % (type, field.name), depth + 1);
          emit("};")
          emit("")
  
      def visitConstructor(self, cons, depth):
          if cons.fields:
              self.emit("struct {", depth)
              for f in cons.fields:
                  self.visit(f, depth + 1)
              self.emit("} %s;" % cons.name, depth)
              self.emit("", depth)
  
      def visitField(self, field, depth):
          # XXX need to lookup field.type, because it might be something
          # like a builtin...
          ctype = get_c_type(field.type)
          name = field.name
          if field.seq:
              if field.type == 'cmpop':
                  self.emit("asdl_int_seq *%(name)s;" % locals(), depth)
              else:
                  self.emit("asdl_seq *%(name)s;" % locals(), depth)
          else:
              self.emit("%(ctype)s %(name)s;" % locals(), depth)
  
      def visitProduct(self, product, name, depth):
          self.emit("struct _%(name)s {" % locals(), depth)
          for f in product.fields:
              self.visit(f, depth + 1)
          for field in product.attributes:
              # rudimentary attribute handling
              type = str(field.type)
              assert type in asdl.builtin_types, type
              self.emit("%s %s;" % (type, field.name), depth + 1);
          self.emit("};", depth)
          self.emit("", depth)
  
  
  class PrototypeVisitor(EmitVisitor):
      """Generate function prototypes for the .h file"""
  
      def visitModule(self, mod):
          for dfn in mod.dfns:
              self.visit(dfn)
  
      def visitType(self, type):
          self.visit(type.value, type.name)
  
      def visitSum(self, sum, name):
          if is_simple(sum):
              pass # XXX
          else:
              for t in sum.types:
                  self.visit(t, name, sum.attributes)
  
      def get_args(self, fields):
          """Return list of C argument into, one for each field.
  
          Argument info is 3-tuple of a C type, variable name, and flag
          that is true if type can be NULL.
          """
          args = []
          unnamed = {}
          for f in fields:
              if f.name is None:
                  name = f.type
                  c = unnamed[name] = unnamed.get(name, 0) + 1
                  if c > 1:
                      name = "name%d" % (c - 1)
              else:
                  name = f.name
              # XXX should extend get_c_type() to handle this
              if f.seq:
                  if f.type == 'cmpop':
                      ctype = "asdl_int_seq *"
                  else:
                      ctype = "asdl_seq *"
              else:
                  ctype = get_c_type(f.type)
              args.append((ctype, name, f.opt or f.seq))
          return args
  
      def visitConstructor(self, cons, type, attrs):
          args = self.get_args(cons.fields)
          attrs = self.get_args(attrs)
          ctype = get_c_type(type)
          self.emit_function(cons.name, ctype, args, attrs)
  
      def emit_function(self, name, ctype, args, attrs, union=True):
          args = args + attrs
          if args:
              argstr = ", ".join(["%s %s" % (atype, aname)
                                  for atype, aname, opt in args])
          else:
              argstr = ""
          margs = "a0"
          for i in range(1, len(args)):
              margs += ", a%d" % i
          self.emit("#define %s(%s) _Py_%s(%s)" % (name, margs, name, margs), 0,
                  reflow=False)
          self.emit("%s _Py_%s(%s);" % (ctype, name, argstr), False)
  
      def visitProduct(self, prod, name):
          self.emit_function(name, get_c_type(name),
                             self.get_args(prod.fields),
                             self.get_args(prod.attributes),
                             union=False)
  
  
  class FunctionVisitor(PrototypeVisitor):
      """Visitor to generate constructor functions for AST."""
  
      def emit_function(self, name, ctype, args, attrs, union=True):
          def emit(s, depth=0, reflow=True):
              self.emit(s, depth, reflow)
          argstr = ", ".join(["%s %s" % (atype, aname)
                              for atype, aname, opt in args + attrs])
          if argstr:
              pass
          else:
              argstr = ""
          self.emit("%s" % ctype, 0)
          emit("%s(%s)" % (name, argstr))
          emit("{")
          emit("%s p;" % ctype, 1)
          for argtype, argname, opt in args:
              if not opt and argtype != "int":
                  emit("if (!%s) {" % argname, 1)
                  emit("PyErr_SetString(PyExc_ValueError,", 2)
                  msg = "field '%s' is required for %s" % (argname, name)
                  emit('                "%s");' % msg,
                       2, reflow=False)
                  emit('return NULL;', 2)
                  emit('}', 1)
  
          emit("p = (%s)malloc(sizeof(*p));" % ctype, 1);
          emit("if (!p)", 1)
          emit("return (%s) PyErr_NoMemory();" % ctype, 2)
          if union:
              self.emit_body_union(name, args, attrs)
          else:
              self.emit_body_struct(name, args, attrs)
          emit("return p;", 1)
          emit("}")
          emit("")
  
      def emit_body_union(self, name, args, attrs):
          def emit(s, depth=0, reflow=True):
              self.emit(s, depth, reflow)
          emit("p->kind = %s_kind;" % name, 1)
          for argtype, argname, opt in args:
              emit("p->v.%s.%s = %s;" % (name, argname, argname), 1)
          for argtype, argname, opt in attrs:
              emit("p->%s = %s;" % (argname, argname), 1)
  
      def emit_body_struct(self, name, args, attrs):
          def emit(s, depth=0, reflow=True):
              self.emit(s, depth, reflow)
          for argtype, argname, opt in args:
              emit("p->%s = %s;" % (argname, argname), 1)
          for argtype, argname, opt in attrs:
              emit("p->%s = %s;" % (argname, argname), 1)
  
  
  class PickleVisitor(EmitVisitor):
  
      def visitModule(self, mod):
          for dfn in mod.dfns:
              self.visit(dfn)
  
      def visitType(self, type):
          self.visit(type.value, type.name)
  
      def visitSum(self, sum, name):
          pass
  
      def visitProduct(self, sum, name):
          pass
  
      def visitConstructor(self, cons, name):
          pass
  
      def visitField(self, sum):
          pass
  
  
  class Obj2ModPrototypeVisitor(PickleVisitor):
      def visitProduct(self, prod, name):
          code = "static int obj2ast_%s(PyObject* obj, %s* out);"
          self.emit(code % (name, get_c_type(name)), 0)
  
      visitSum = visitProduct
  
  
  class Obj2ModVisitor(PickleVisitor):
      def funcHeader(self, name):
          ctype = get_c_type(name)
          self.emit("int", 0)
          self.emit("obj2ast_%s(PyObject* obj, %s* out)" % (name, ctype), 0)
          self.emit("{", 0)
          self.emit("int isinstance;", 1)
          self.emit("", 0)
  
      def sumTrailer(self, name, add_label=False):
          self.emit("", 0)
          # there's really nothing more we can do if this fails ...
          error = "expected some sort of %s, but got %%R" % name
          format = "PyErr_Format(PyExc_TypeError, \"%s\", obj);"
          self.emit(format % error, 1, reflow=False)
          if add_label:
              self.emit("failed:", 1)
              self.emit("Py_XDECREF(tmp);", 1)
          self.emit("return 1;", 1)
          self.emit("}", 0)
          self.emit("", 0)
  
      def simpleSum(self, sum, name):
          self.funcHeader(name)
          for t in sum.types:
              line = ("isinstance = PyObject_IsInstance(obj, "
                      "astmodulestate_global->%s_type);")
              self.emit(line % (t.name,), 1)
              self.emit("if (isinstance == -1) {", 1)
              self.emit("return 1;", 2)
              self.emit("}", 1)
              self.emit("if (isinstance) {", 1)
              self.emit("*out = %s;" % t.name, 2)
              self.emit("return 0;", 2)
              self.emit("}", 1)
          self.sumTrailer(name)
  
      def buildArgs(self, fields):
          return ", ".join(fields)
  
      def complexSum(self, sum, name):
          self.funcHeader(name)
          self.emit("PyObject *tmp = NULL;", 1)
          self.emit("PyObject *tp;", 1)
          for a in sum.attributes:
              self.visitAttributeDeclaration(a, name, sum=sum)
          self.emit("", 0)
          # XXX: should we only do this for 'expr'?
          self.emit("if (obj == Py_None) {", 1)
          self.emit("*out = NULL;", 2)
          self.emit("return 0;", 2)
          self.emit("}", 1)
          for a in sum.attributes:
              self.visitField(a, name, sum=sum, depth=1)
          for t in sum.types:
              self.emit("tp = astmodulestate_global->%s_type;" % (t.name,), 1)
              self.emit("isinstance = PyObject_IsInstance(obj, tp);", 1)
              self.emit("if (isinstance == -1) {", 1)
              self.emit("return 1;", 2)
              self.emit("}", 1)
              self.emit("if (isinstance) {", 1)
              for f in t.fields:
                  self.visitFieldDeclaration(f, t.name, sum=sum, depth=2)
              self.emit("", 0)
              for f in t.fields:
                  self.visitField(f, t.name, sum=sum, depth=2)
              args = [f.name for f in t.fields] + [a.name for a in sum.attributes]
              self.emit("*out = %s(%s);" % (t.name, self.buildArgs(args)), 2)
              self.emit("if (*out == NULL) goto failed;", 2)
              self.emit("return 0;", 2)
              self.emit("}", 1)
          self.sumTrailer(name, True)
  
      def visitAttributeDeclaration(self, a, name, sum=sum):
          ctype = get_c_type(a.type)
          self.emit("%s %s;" % (ctype, a.name), 1)
  
      def visitSum(self, sum, name):
          if is_simple(sum):
              self.simpleSum(sum, name)
          else:
              self.complexSum(sum, name)
  
      def visitProduct(self, prod, name):
          ctype = get_c_type(name)
          self.emit("int", 0)
          self.emit("obj2ast_%s(PyObject* obj, %s* out)" % (name, ctype), 0)
          self.emit("{", 0)
          self.emit("PyObject* tmp = NULL;", 1)
          for f in prod.fields:
              self.visitFieldDeclaration(f, name, prod=prod, depth=1)
          for a in prod.attributes:
              self.visitFieldDeclaration(a, name, prod=prod, depth=1)
          self.emit("", 0)
          for f in prod.fields:
              self.visitField(f, name, prod=prod, depth=1)
          for a in prod.attributes:
              self.visitField(a, name, prod=prod, depth=1)
          args = [f.name for f in prod.fields]
          args.extend([a.name for a in prod.attributes])
          self.emit("*out = %s(%s);" % (name, self.buildArgs(args)), 1)
          self.emit("return 0;", 1)
          self.emit("failed:", 0)
          self.emit("Py_XDECREF(tmp);", 1)
          self.emit("return 1;", 1)
          self.emit("}", 0)
          self.emit("", 0)
  
      def visitFieldDeclaration(self, field, name, sum=None, prod=None, depth=0):
          ctype = get_c_type(field.type)
          if field.seq:
              if self.isSimpleType(field):
                  self.emit("asdl_int_seq* %s;" % field.name, depth)
              else:
                  self.emit("asdl_seq* %s;" % field.name, depth)
          else:
              ctype = get_c_type(field.type)
              self.emit("%s %s;" % (ctype, field.name), depth)
  
      def isSimpleSum(self, field):
          # XXX can the members of this list be determined automatically?
          return field.type in ('expr_context', 'boolop', 'operator',
                                'unaryop', 'cmpop')
  
      def isNumeric(self, field):
          return get_c_type(field.type) in ("int", "bool")
  
      def isSimpleType(self, field):
          return self.isSimpleSum(field) or self.isNumeric(field)
  
      def visitField(self, field, name, sum=None, prod=None, depth=0):
          ctype = get_c_type(field.type)
          line = "if (_PyObject_LookupAttr(obj, astmodulestate_global->%s, &tmp) < 0) {"
          self.emit(line % field.name, depth)
          self.emit("return 1;", depth+1)
          self.emit("}", depth)
          if not field.opt:
              self.emit("if (tmp == NULL) {", depth)
              message = "required field \\\"%s\\\" missing from %s" % (field.name, name)
              format = "PyErr_SetString(PyExc_TypeError, \"%s\");"
              self.emit(format % message, depth+1, reflow=False)
              self.emit("return 1;", depth+1)
          else:
              self.emit("if (tmp == NULL || tmp == Py_None) {", depth)
              self.emit("Py_CLEAR(tmp);", depth+1)
              if self.isNumeric(field):
                  self.emit("%s = 0;" % field.name, depth+1)
              elif not self.isSimpleType(field):
                  self.emit("%s = NULL;" % field.name, depth+1)
              else:
                  raise TypeError("could not determine the default value for %s" % field.name)
          self.emit("}", depth)
          self.emit("else {", depth)
  
          self.emit("int res;", depth+1)
          if field.seq:
              self.emit("Py_ssize_t len;", depth+1)
              self.emit("Py_ssize_t i;", depth+1)
              self.emit("if (!PyList_Check(tmp)) {", depth+1)
              self.emit("PyErr_Format(PyExc_TypeError, \"%s field \\\"%s\\\" must "
                        "be a list, not a %%.200s\", _PyType_Name(Py_TYPE(tmp)));" %
                        (name, field.name),
                        depth+2, reflow=False)
              self.emit("goto failed;", depth+2)
              self.emit("}", depth+1)
              self.emit("len = PyList_GET_SIZE(tmp);", depth+1)
              if self.isSimpleType(field):
                  self.emit("%s = _Py_asdl_int_seq_new(len);" % field.name, depth+1)
              else:
                  self.emit("%s = _Py_asdl_seq_new(len);" % field.name, depth+1)
              self.emit("if (%s == NULL) goto failed;" % field.name, depth+1)
              self.emit("for (i = 0; i < len; i++) {", depth+1)
              self.emit("%s val;" % ctype, depth+2)
              self.emit("PyObject *tmp2 = PyList_GET_ITEM(tmp, i);", depth+2)
              self.emit("Py_INCREF(tmp2);", depth+2)
              self.emit("res = obj2ast_%s(tmp2, &val);" %
                        field.type, depth+2, reflow=False)
              self.emit("Py_DECREF(tmp2);", depth+2)
              self.emit("if (res != 0) goto failed;", depth+2)
              self.emit("if (len != PyList_GET_SIZE(tmp)) {", depth+2)
              self.emit("PyErr_SetString(PyExc_RuntimeError, \"%s field \\\"%s\\\" "
                        "changed size during iteration\");" %
                        (name, field.name),
                        depth+3, reflow=False)
              self.emit("goto failed;", depth+3)
              self.emit("}", depth+2)
              self.emit("asdl_seq_SET(%s, i, val);" % field.name, depth+2)
              self.emit("}", depth+1)
          else:
              self.emit("res = obj2ast_%s(tmp, &%s);" %
                        (field.type, field.name), depth+1)
              self.emit("if (res != 0) goto failed;", depth+1)
  
          self.emit("Py_CLEAR(tmp);", depth+1)
          self.emit("}", depth)
  
  
  class MarshalPrototypeVisitor(PickleVisitor):
  
      def prototype(self, sum, name):
          ctype = get_c_type(name)
          self.emit("static int marshal_write_%s(PyObject **, int *, %s);"
                    % (name, ctype), 0)
  
      visitProduct = visitSum = prototype
  
  
  class PyTypesDeclareVisitor(PickleVisitor):
  
      def visitProduct(self, prod, name):
          self.emit_type("%s_type" % name)
          self.emit("static PyObject* ast2obj_%s(void*);" % name, 0)
          if prod.attributes:
              for a in prod.attributes:
                  self.emit_identifier(a.name)
              self.emit("static const char * const %s_attributes[] = {" % name, 0)
              for a in prod.attributes:
                  self.emit('"%s",' % a.name, 1)
              self.emit("};", 0)
          if prod.fields:
              for f in prod.fields:
                  self.emit_identifier(f.name)
              self.emit("static const char * const %s_fields[]={" % name,0)
              for f in prod.fields:
                  self.emit('"%s",' % f.name, 1)
              self.emit("};", 0)
  
      def visitSum(self, sum, name):
          self.emit_type("%s_type" % name)
          if sum.attributes:
              for a in sum.attributes:
                  self.emit_identifier(a.name)
              self.emit("static const char * const %s_attributes[] = {" % name, 0)
              for a in sum.attributes:
                  self.emit('"%s",' % a.name, 1)
              self.emit("};", 0)
          ptype = "void*"
          if is_simple(sum):
              ptype = get_c_type(name)
              for t in sum.types:
                  self.emit_singleton("%s_singleton" % t.name)
          self.emit("static PyObject* ast2obj_%s(%s);" % (name, ptype), 0)
          for t in sum.types:
              self.visitConstructor(t, name)
  
      def visitConstructor(self, cons, name):
          if cons.fields:
              for t in cons.fields:
                  self.emit_identifier(t.name)
              self.emit("static const char * const %s_fields[]={" % cons.name, 0)
              for t in cons.fields:
                  self.emit('"%s",' % t.name, 1)
              self.emit("};",0)
  
  class PyTypesVisitor(PickleVisitor):
  
      def visitModule(self, mod):
          self.emit("""
  
  typedef struct {
      PyObject_HEAD
      PyObject *dict;
  } AST_object;
  
  static void
  ast_dealloc(AST_object *self)
  {
      /* bpo-31095: UnTrack is needed before calling any callbacks */
      PyTypeObject *tp = Py_TYPE(self);
      Py_CLEAR(self->dict);
      freefunc free_func = PyType_GetSlot(tp, Py_tp_free);
      assert(free_func != NULL);
      free_func(self);
      Py_DECREF(tp);
  }
  
  
  static int
  ast_clear(AST_object *self)
  {
      Py_CLEAR(self->dict);
      return 0;
  }
  
  static int
  ast_type_init(PyObject *self, PyObject *args, PyObject *kw)
  {
      Py_ssize_t i, numfields = 0;
      int res = -1;
      PyObject *key, *value, *fields;
      if (_PyObject_LookupAttr((PyObject*)Py_TYPE(self), astmodulestate_global->_fields, &fields) < 0) {
          goto cleanup;
      }
      if (fields) {
          numfields = PySequence_Size(fields);
          if (numfields == -1) {
              goto cleanup;
          }
      }
  
      res = 0; /* if no error occurs, this stays 0 to the end */
      if (numfields < PyTuple_GET_SIZE(args)) {
          PyErr_Format(PyExc_TypeError, "%.400s constructor takes at most "
                       "%zd positional argument%s",
                       _PyType_Name(Py_TYPE(self)),
                       numfields, numfields == 1 ? "" : "s");
          res = -1;
          goto cleanup;
      }
      for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
          /* cannot be reached when fields is NULL */
          PyObject *name = PySequence_GetItem(fields, i);
          if (!name) {
              res = -1;
              goto cleanup;
          }
          res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
          Py_DECREF(name);
          if (res < 0) {
              goto cleanup;
          }
      }
      if (kw) {
          i = 0;  /* needed by PyDict_Next */
          while (PyDict_Next(kw, &i, &key, &value)) {
              int contains = PySequence_Contains(fields, key);
              if (contains == -1) {
                  res = -1;
                  goto cleanup;
              } else if (contains == 1) {
                  Py_ssize_t p = PySequence_Index(fields, key);
                  if (p == -1) {
                      res = -1;
                      goto cleanup;
                  }
                  if (p < PyTuple_GET_SIZE(args)) {
                      PyErr_Format(PyExc_TypeError,
                          "%.400s got multiple values for argument '%U'",
                          Py_TYPE(self)->tp_name, key);
                      res = -1;
                      goto cleanup;
                  }
              }
              res = PyObject_SetAttr(self, key, value);
              if (res < 0) {
                  goto cleanup;
              }
          }
      }
    cleanup:
      Py_XDECREF(fields);
      return res;
  }
  
  /* Pickling support */
  static PyObject *
  ast_type_reduce(PyObject *self, PyObject *unused)
  {
      PyObject *dict;
      if (_PyObject_LookupAttr(self, astmodulestate_global->__dict__, &dict) < 0) {
          return NULL;
      }
      if (dict) {
          return Py_BuildValue("O()N", Py_TYPE(self), dict);
      }
      return Py_BuildValue("O()", Py_TYPE(self));
  }
  
  static PyMemberDef ast_type_members[] = {
      {"__dictoffset__", T_PYSSIZET, offsetof(AST_object, dict), READONLY},
      {NULL}  /* Sentinel */
  };
  
  static PyMethodDef ast_type_methods[] = {
      {"__reduce__", ast_type_reduce, METH_NOARGS, NULL},
      {NULL}
  };
  
  static PyGetSetDef ast_type_getsets[] = {
      {"__dict__", PyObject_GenericGetDict, PyObject_GenericSetDict},
      {NULL}
  };
  
  static PyType_Slot AST_type_slots[] = {
      {Py_tp_dealloc, ast_dealloc},
      {Py_tp_getattro, PyObject_GenericGetAttr},
      {Py_tp_setattro, PyObject_GenericSetAttr},
      {Py_tp_clear, ast_clear},
      {Py_tp_members, ast_type_members},
      {Py_tp_methods, ast_type_methods},
      {Py_tp_getset, ast_type_getsets},
      {Py_tp_init, ast_type_init},
      {Py_tp_alloc, PyType_GenericAlloc},
      {Py_tp_new, PyType_GenericNew},
      {Py_tp_free, PyMem_Free},
      {0, 0},
  };
  
  static PyType_Spec AST_type_spec = {
      "ast.AST",
      sizeof(AST_object),
      0,
      Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
      AST_type_slots
  };
  
  static PyObject *
  make_type(const char *type, PyObject* base, const char* const* fields, int num_fields, const char *doc)
  {
      PyObject *fnames, *result;
      int i;
      fnames = PyTuple_New(num_fields);
      if (!fnames) return NULL;
      for (i = 0; i < num_fields; i++) {
          PyObject *field = PyUnicode_InternFromString(fields[i]);
          if (!field) {
              Py_DECREF(fnames);
              return NULL;
          }
          PyTuple_SET_ITEM(fnames, i, field);
      }
      result = PyObject_CallFunction((PyObject*)&PyType_Type, "s(O){OOOOOs}",
                      type, base,
                      astmodulestate_global->_fields, fnames,
                      astmodulestate_global->__module__,
                      astmodulestate_global->ast,
                      astmodulestate_global->__doc__, doc);
      Py_DECREF(fnames);
      return result;
  }
  
  static int
  add_attributes(PyObject *type, const char * const *attrs, int num_fields)
  {
      int i, result;
      PyObject *s, *l = PyTuple_New(num_fields);
      if (!l)
          return 0;
      for (i = 0; i < num_fields; i++) {
          s = PyUnicode_InternFromString(attrs[i]);
          if (!s) {
              Py_DECREF(l);
              return 0;
          }
          PyTuple_SET_ITEM(l, i, s);
      }
      result = PyObject_SetAttr(type, astmodulestate_global->_attributes, l) >= 0;
      Py_DECREF(l);
      return result;
  }
  
  /* Conversion AST -> Python */
  
  static PyObject* ast2obj_list(asdl_seq *seq, PyObject* (*func)(void*))
  {
      Py_ssize_t i, n = asdl_seq_LEN(seq);
      PyObject *result = PyList_New(n);
      PyObject *value;
      if (!result)
          return NULL;
      for (i = 0; i < n; i++) {
          value = func(asdl_seq_GET(seq, i));
          if (!value) {
              Py_DECREF(result);
              return NULL;
          }
          PyList_SET_ITEM(result, i, value);
      }
      return result;
  }
  
  static PyObject* ast2obj_object(void *o)
  {
      if (!o)
          o = Py_None;
      Py_INCREF((PyObject*)o);
      return (PyObject*)o;
  }
  #define ast2obj_constant ast2obj_object
  #define ast2obj_identifier ast2obj_object
  #define ast2obj_string ast2obj_object
  
  static PyObject* ast2obj_int(long b)
  {
      return PyLong_FromLong(b);
  }
  
  /* Conversion Python -> AST */
  
  static int obj2ast_object(PyObject* obj, PyObject** out)
  {
      if (obj == Py_None)
          obj = NULL;
      *out = obj;
      return 0;
  }
  
  static int obj2ast_constant(PyObject* obj, PyObject** out)
  {
      *out = obj;
      return 0;
  }
  
  static int obj2ast_identifier(PyObject* obj, PyObject** out)
  {
      if (!PyUnicode_CheckExact(obj) && obj != Py_None) {
          PyErr_SetString(PyExc_TypeError, "AST identifier must be of type str");
          return 1;
      }
      return obj2ast_object(obj, out);
  }
  
  static int obj2ast_string(PyObject* obj, PyObject** out)
  {
      if (!PyUnicode_CheckExact(obj)) {
          PyErr_SetString(PyExc_TypeError, "AST string must be of type str");
          return 1;
      }
      return obj2ast_object(obj, out);
  }
  
  static int obj2ast_int(PyObject* obj, int* out)
  {
      int i;
      if (!PyLong_Check(obj)) {
          PyErr_Format(PyExc_ValueError, "invalid integer value: %R", obj);
          return 1;
      }
  
      i = _PyLong_AsInt(obj);
      if (i == -1 && PyErr_Occurred())
          return 1;
      *out = i;
      return 0;
  }
  
  static int add_ast_fields(void)
  {
      PyObject *empty_tuple;
      empty_tuple = PyTuple_New(0);
      if (!empty_tuple ||
          PyObject_SetAttrString(astmodulestate_global->AST_type, "_fields", empty_tuple) < 0 ||
          PyObject_SetAttrString(astmodulestate_global->AST_type, "_attributes", empty_tuple) < 0) {
          Py_XDECREF(empty_tuple);
          return -1;
      }
      Py_DECREF(empty_tuple);
      return 0;
  }
  
  """, 0, reflow=False)
  
          self.emit("static int init_types(void)",0)
          self.emit("{", 0)
          self.emit("PyObject *m;", 1)
          self.emit("if (PyState_FindModule(&_astmodule) == NULL) {", 1)
          self.emit("m = PyModule_Create(&_astmodule);", 2)
          self.emit("if (!m) return 0;", 2)
          self.emit("PyState_AddModule(m, &_astmodule);", 2)
          self.emit("}", 1)
          self.emit("astmodulestate *state = astmodulestate_global;", 1)
          self.emit("if (state->initialized) return 1;", 1)
          self.emit("if (init_identifiers() < 0) return 0;", 1)
          self.emit("state->AST_type = PyType_FromSpec(&AST_type_spec);", 1)
          self.emit("if (!state->AST_type) return 0;", 1)
          self.emit("if (add_ast_fields() < 0) return 0;", 1)
          for dfn in mod.dfns:
              self.visit(dfn)
          self.emit("state->initialized = 1;", 1)
          self.emit("return 1;", 1);
          self.emit("}", 0)
  
      def visitProduct(self, prod, name):
          if prod.fields:
              fields = name+"_fields"
          else:
              fields = "NULL"
          self.emit('state->%s_type = make_type("%s", state->AST_type, %s, %d,' %
                          (name, name, fields, len(prod.fields)), 1)
          self.emit('%s);' % reflow_c_string(asdl_of(name, prod), 2), 2, reflow=False)
          self.emit("if (!state->%s_type) return 0;" % name, 1)
          self.emit_type("AST_type")
          self.emit_type("%s_type" % name)
          if prod.attributes:
              self.emit("if (!add_attributes(state->%s_type, %s_attributes, %d)) return 0;" %
                              (name, name, len(prod.attributes)), 1)
          else:
              self.emit("if (!add_attributes(state->%s_type, NULL, 0)) return 0;" % name, 1)
          self.emit_defaults(name, prod.fields, 1)
          self.emit_defaults(name, prod.attributes, 1)
  
      def visitSum(self, sum, name):
          self.emit('state->%s_type = make_type("%s", state->AST_type, NULL, 0,' %
                    (name, name), 1)
          self.emit('%s);' % reflow_c_string(asdl_of(name, sum), 2), 2, reflow=False)
          self.emit_type("%s_type" % name)
          self.emit("if (!state->%s_type) return 0;" % name, 1)
          if sum.attributes:
              self.emit("if (!add_attributes(state->%s_type, %s_attributes, %d)) return 0;" %
                              (name, name, len(sum.attributes)), 1)
          else:
              self.emit("if (!add_attributes(state->%s_type, NULL, 0)) return 0;" % name, 1)
          self.emit_defaults(name, sum.attributes, 1)
          simple = is_simple(sum)
          for t in sum.types:
              self.visitConstructor(t, name, simple)
  
      def visitConstructor(self, cons, name, simple):
          if cons.fields:
              fields = cons.name+"_fields"
          else:
              fields = "NULL"
          self.emit('state->%s_type = make_type("%s", state->%s_type, %s, %d,' %
                              (cons.name, cons.name, name, fields, len(cons.fields)), 1)
          self.emit('%s);' % reflow_c_string(asdl_of(cons.name, cons), 2), 2, reflow=False)
          self.emit("if (!state->%s_type) return 0;" % cons.name, 1)
          self.emit_type("%s_type" % cons.name)
          self.emit_defaults(cons.name, cons.fields, 1)
          if simple:
              self.emit("state->%s_singleton = PyType_GenericNew((PyTypeObject *)"
                        "state->%s_type, NULL, NULL);" %
                               (cons.name, cons.name), 1)
              self.emit("if (!state->%s_singleton) return 0;" % cons.name, 1)
  
      def emit_defaults(self, name, fields, depth):
          for field in fields:
              if field.opt:
                  self.emit('if (PyObject_SetAttr(state->%s_type, state->%s, Py_None) == -1)' %
                              (name, field.name), depth)
                  self.emit("return 0;", depth+1)
  
  
  class ASTModuleVisitor(PickleVisitor):
  
      def visitModule(self, mod):
          self.emit("PyMODINIT_FUNC", 0)
          self.emit("PyInit__ast(void)", 0)
          self.emit("{", 0)
          self.emit("PyObject *m;", 1)
          self.emit("if (!init_types()) return NULL;", 1)
          self.emit('m = PyState_FindModule(&_astmodule);', 1)
          self.emit("if (!m) return NULL;", 1)
          self.emit('if (PyModule_AddObject(m, "AST", astmodulestate_global->AST_type) < 0) {', 1)
          self.emit('goto error;', 2)
          self.emit('}', 1)
          self.emit('Py_INCREF(astmodulestate(m)->AST_type);', 1)
          self.emit('if (PyModule_AddIntMacro(m, PyCF_ALLOW_TOP_LEVEL_AWAIT) < 0) {', 1)
          self.emit("goto error;", 2)
          self.emit('}', 1)
          self.emit('if (PyModule_AddIntMacro(m, PyCF_ONLY_AST) < 0) {', 1)
          self.emit("goto error;", 2)
          self.emit('}', 1)
          self.emit('if (PyModule_AddIntMacro(m, PyCF_TYPE_COMMENTS) < 0) {', 1)
          self.emit("goto error;", 2)
          self.emit('}', 1)
          for dfn in mod.dfns:
              self.visit(dfn)
          self.emit("return m;", 1)
          self.emit("error:", 0)
          self.emit("Py_DECREF(m);", 1)
          self.emit("return NULL;", 1)
          self.emit("}", 0)
  
      def visitProduct(self, prod, name):
          self.addObj(name)
  
      def visitSum(self, sum, name):
          self.addObj(name)
          for t in sum.types:
              self.visitConstructor(t, name)
  
      def visitConstructor(self, cons, name):
          self.addObj(cons.name)
  
      def addObj(self, name):
          self.emit("if (PyModule_AddObject(m, \"%s\", "
                    "astmodulestate_global->%s_type) < 0) {" % (name, name), 1)
          self.emit("goto error;", 2)
          self.emit('}', 1)
          self.emit("Py_INCREF(astmodulestate(m)->%s_type);" % name, 1)
  
  
  _SPECIALIZED_SEQUENCES = ('stmt', 'expr')
  
  def find_sequence(fields, doing_specialization):
      """Return True if any field uses a sequence."""
      for f in fields:
          if f.seq:
              if not doing_specialization:
                  return True
              if str(f.type) not in _SPECIALIZED_SEQUENCES:
                  return True
      return False
  
  def has_sequence(types, doing_specialization):
      for t in types:
          if find_sequence(t.fields, doing_specialization):
              return True
      return False
  
  
  class StaticVisitor(PickleVisitor):
      CODE = '''Very simple, always emit this static code.  Override CODE'''
  
      def visit(self, object):
          self.emit(self.CODE, 0, reflow=False)
  
  
  class ObjVisitor(PickleVisitor):
  
      def func_begin(self, name):
          ctype = get_c_type(name)
          self.emit("PyObject*", 0)
          self.emit("ast2obj_%s(void* _o)" % (name), 0)
          self.emit("{", 0)
          self.emit("%s o = (%s)_o;" % (ctype, ctype), 1)
          self.emit("PyObject *result = NULL, *value = NULL;", 1)
          self.emit("PyTypeObject *tp;", 1)
          self.emit('if (!o) {', 1)
          self.emit("Py_RETURN_NONE;", 2)
          self.emit("}", 1)
          self.emit('', 0)
  
      def func_end(self):
          self.emit("return result;", 1)
          self.emit("failed:", 0)
          self.emit("Py_XDECREF(value);", 1)
          self.emit("Py_XDECREF(result);", 1)
          self.emit("return NULL;", 1)
          self.emit("}", 0)
          self.emit("", 0)
  
      def visitSum(self, sum, name):
          if is_simple(sum):
              self.simpleSum(sum, name)
              return
          self.func_begin(name)
          self.emit("switch (o->kind) {", 1)
          for i in range(len(sum.types)):
              t = sum.types[i]
              self.visitConstructor(t, i + 1, name)
          self.emit("}", 1)
          for a in sum.attributes:
              self.emit("value = ast2obj_%s(o->%s);" % (a.type, a.name), 1)
              self.emit("if (!value) goto failed;", 1)
              self.emit('if (PyObject_SetAttr(result, astmodulestate_global->%s, value) < 0)' % a.name, 1)
              self.emit('goto failed;', 2)
              self.emit('Py_DECREF(value);', 1)
          self.func_end()
  
      def simpleSum(self, sum, name):
          self.emit("PyObject* ast2obj_%s(%s_ty o)" % (name, name), 0)
          self.emit("{", 0)
          self.emit("switch(o) {", 1)
          for t in sum.types:
              self.emit("case %s:" % t.name, 2)
              self.emit("Py_INCREF(astmodulestate_global->%s_singleton);" % t.name, 3)
              self.emit("return astmodulestate_global->%s_singleton;" % t.name, 3)
          self.emit("}", 1)
          self.emit("Py_UNREACHABLE();", 1);
          self.emit("}", 0)
  
      def visitProduct(self, prod, name):
          self.func_begin(name)
          self.emit("tp = (PyTypeObject *)astmodulestate_global->%s_type;" % name, 1)
          self.emit("result = PyType_GenericNew(tp, NULL, NULL);", 1);
          self.emit("if (!result) return NULL;", 1)
          for field in prod.fields:
              self.visitField(field, name, 1, True)
          for a in prod.attributes:
              self.emit("value = ast2obj_%s(o->%s);" % (a.type, a.name), 1)
              self.emit("if (!value) goto failed;", 1)
              self.emit("if (PyObject_SetAttr(result, astmodulestate_global->%s, value) < 0)" % a.name, 1)
              self.emit('goto failed;', 2)
              self.emit('Py_DECREF(value);', 1)
          self.func_end()
  
      def visitConstructor(self, cons, enum, name):
          self.emit("case %s_kind:" % cons.name, 1)
          self.emit("tp = (PyTypeObject *)astmodulestate_global->%s_type;" % cons.name, 2)
          self.emit("result = PyType_GenericNew(tp, NULL, NULL);", 2);
          self.emit("if (!result) goto failed;", 2)
          for f in cons.fields:
              self.visitField(f, cons.name, 2, False)
          self.emit("break;", 2)
  
      def visitField(self, field, name, depth, product):
          def emit(s, d):
              self.emit(s, depth + d)
          if product:
              value = "o->%s" % field.name
          else:
              value = "o->v.%s.%s" % (name, field.name)
          self.set(field, value, depth)
          emit("if (!value) goto failed;", 0)
          emit("if (PyObject_SetAttr(result, astmodulestate_global->%s, value) == -1)" % field.name, 0)
          emit("goto failed;", 1)
          emit("Py_DECREF(value);", 0)
  
      def emitSeq(self, field, value, depth, emit):
          emit("seq = %s;" % value, 0)
          emit("n = asdl_seq_LEN(seq);", 0)
          emit("value = PyList_New(n);", 0)
          emit("if (!value) goto failed;", 0)
          emit("for (i = 0; i < n; i++) {", 0)
          self.set("value", field, "asdl_seq_GET(seq, i)", depth + 1)
          emit("if (!value1) goto failed;", 1)
          emit("PyList_SET_ITEM(value, i, value1);", 1)
          emit("value1 = NULL;", 1)
          emit("}", 0)
  
      def set(self, field, value, depth):
          if field.seq:
              # XXX should really check for is_simple, but that requires a symbol table
              if field.type == "cmpop":
                  # While the sequence elements are stored as void*,
                  # ast2obj_cmpop expects an enum
                  self.emit("{", depth)
                  self.emit("Py_ssize_t i, n = asdl_seq_LEN(%s);" % value, depth+1)
                  self.emit("value = PyList_New(n);", depth+1)
                  self.emit("if (!value) goto failed;", depth+1)
                  self.emit("for(i = 0; i < n; i++)", depth+1)
                  # This cannot fail, so no need for error handling
                  self.emit("PyList_SET_ITEM(value, i, ast2obj_cmpop((cmpop_ty)asdl_seq_GET(%s, i)));" % value,
                            depth+2, reflow=False)
                  self.emit("}", depth)
              else:
                  self.emit("value = ast2obj_list(%s, ast2obj_%s);" % (value, field.type), depth)
          else:
              ctype = get_c_type(field.type)
              self.emit("value = ast2obj_%s(%s);" % (field.type, value), depth, reflow=False)
  
  
  class PartingShots(StaticVisitor):
  
      CODE = """
  PyObject* PyAST_mod2obj(mod_ty t)
  {
      if (!init_types())
          return NULL;
      return ast2obj_mod(t);
  }
  
  /* mode is 0 for "exec", 1 for "eval" and 2 for "single" input */
  mod_ty PyAST_obj2mod(PyObject* ast, int mode)
  {
      PyObject *req_type[3];
      const char * const req_name[] = {"Module", "Expression", "Interactive"};
      int isinstance;
  
      req_type[0] = astmodulestate_global->Module_type;
      req_type[1] = astmodulestate_global->Expression_type;
      req_type[2] = astmodulestate_global->Interactive_type;
  
      assert(0 <= mode && mode <= 2);
  
      if (!init_types())
          return NULL;
  
      isinstance = PyObject_IsInstance(ast, req_type[mode]);
      if (isinstance == -1)
          return NULL;
      if (!isinstance) {
          PyErr_Format(PyExc_TypeError, "expected %s node, got %.400s",
                       req_name[mode], _PyType_Name(Py_TYPE(ast)));
          return NULL;
      }
  
      mod_ty res = NULL;
      if (obj2ast_mod(ast, &res) != 0)
          return NULL;
      else
          return res;
  }
  
  int PyAST_Check(PyObject* obj)
  {
      if (!init_types())
          return -1;
      return PyObject_IsInstance(obj, astmodulestate_global->AST_type);
  }
  """
  
  class ChainOfVisitors:
      def __init__(self, *visitors):
          self.visitors = visitors
  
      def visit(self, object):
          for v in self.visitors:
              v.visit(object)
              v.emit("", 0)
  
  
  def generate_module_def(f, mod):
      # Gather all the data needed for ModuleSpec
      visitor_list = set()
      with open(os.devnull, "w") as devnull:
          visitor = PyTypesDeclareVisitor(devnull)
          visitor.visit(mod)
          visitor_list.add(visitor)
          visitor = PyTypesVisitor(devnull)
          visitor.visit(mod)
          visitor_list.add(visitor)
  
      state_strings = {
          "ast",
          "_fields",
          "__doc__",
          "__dict__",
          "__module__",
          "_attributes",
      }
      module_state = state_strings.copy()
      for visitor in visitor_list:
          for identifier in visitor.identifiers:
              module_state.add(identifier)
              state_strings.add(identifier)
          for singleton in visitor.singletons:
              module_state.add(singleton)
          for tp in visitor.types:
              module_state.add(tp)
      state_strings = sorted(state_strings)
      module_state = sorted(module_state)
      f.write('typedef struct {\n')
      f.write('    int initialized;\n')
      for s in module_state:
          f.write('    PyObject *' + s + ';\n')
      f.write('} astmodulestate;\n\n')
      f.write("""
  #define astmodulestate(o) ((astmodulestate *)PyModule_GetState(o))
  
  static int astmodule_clear(PyObject *module)
  {
  """)
      for s in module_state:
          f.write("    Py_CLEAR(astmodulestate(module)->" + s + ');\n')
      f.write("""
      return 0;
  }
  
  static void astmodule_free(void* module) {
      astmodule_clear((PyObject*)module);
  }
  
  static struct PyModuleDef _astmodule = {
      PyModuleDef_HEAD_INIT,
      "_ast",
      NULL,
      sizeof(astmodulestate),
      NULL,
      NULL,
      NULL,
      astmodule_clear,
      astmodule_free,
  };
  
  #define astmodulestate_global ((astmodulestate *)PyModule_GetState(PyState_FindModule(&_astmodule)))
  
  """)
      f.write('static int init_identifiers(void)\n')
      f.write('{\n')
      f.write('    astmodulestate *state = astmodulestate_global;\n')
      for identifier in state_strings:
          f.write('    if ((state->' + identifier)
          f.write(' = PyUnicode_InternFromString("')
          f.write(identifier + '")) == NULL) return 0;\n')
      f.write('    return 1;\n')
      f.write('};\n\n')
  
  def write_header(f, mod):
      f.write('#ifndef Py_PYTHON_AST_H\n')
      f.write('#define Py_PYTHON_AST_H\n')
      f.write('#ifdef __cplusplus\n')
      f.write('extern "C" {\n')
      f.write('#endif\n')
      f.write('\n')
      f.write('#ifndef Py_LIMITED_API\n')
      f.write('#include "asdl.h"\n')
      f.write('\n')
      f.write('#undef Yield   /* undefine macro conflicting with <winbase.h> */\n')
      f.write('\n')
      c = ChainOfVisitors(TypeDefVisitor(f),
                          StructVisitor(f))
      c.visit(mod)
      f.write("// Note: these macros affect function definitions, not only call sites.\n")
      PrototypeVisitor(f).visit(mod)
      f.write("\n")
      f.write("PyObject* PyAST_mod2obj(mod_ty t);\n")
      f.write("mod_ty PyAST_obj2mod(PyObject* ast, int mode);\n")
      f.write("int PyAST_Check(PyObject* obj);\n")
      f.write("#endif /* !Py_LIMITED_API */\n")
      f.write('\n')
      f.write('#ifdef __cplusplus\n')
      f.write('}\n')
      f.write('#endif\n')
      f.write('#endif /* !Py_PYTHON_AST_H */\n')
  
  def write_source(f, mod):
      f.write('#include <stddef.h>\n')
      f.write('\n')
      f.write('#include "Python.h"\n')
      f.write('#include "%s-ast.h"\n' % mod.name)
      f.write('#include "structmember.h"         // PyMemberDef\n')
      f.write('\n')
  
      generate_module_def(f, mod)
  
      v = ChainOfVisitors(
          PyTypesDeclareVisitor(f),
          PyTypesVisitor(f),
          Obj2ModPrototypeVisitor(f),
          FunctionVisitor(f),
          ObjVisitor(f),
          Obj2ModVisitor(f),
          ASTModuleVisitor(f),
          PartingShots(f),
      )
      v.visit(mod)
  
  def main(input_file, c_file, h_file, dump_module=False):
      auto_gen_msg = AUTOGEN_MESSAGE.format("/".join(Path(__file__).parts[-2:]))
      mod = asdl.parse(input_file)
      if dump_module:
          print('Parsed Module:')
          print(mod)
      if not asdl.check(mod):
          sys.exit(1)
      for file, writer in (c_file, write_source), (h_file, write_header):
          if file is not None:
              with file.open("w") as f:
                  f.write(auto_gen_msg)
                  writer(f, mod)
              print(file, "regenerated.")
  
  if __name__ == "__main__":
      parser = ArgumentParser()
      parser.add_argument("input_file", type=Path)
      parser.add_argument("-C", "--c-file", type=Path, default=None)
      parser.add_argument("-H", "--h-file", type=Path, default=None)
      parser.add_argument("-d", "--dump-module", action="store_true")
  
      options = parser.parse_args()
      main(**vars(options))
  