class OpRegGenImpl(transformer.CodeGenerator):
  """Visit the AST and generate C++ op registration functions."""

  def __init__(self, ctx):
    super(OpRegGenImpl, self).__init__(ctx)
    self.ctx = ctx

  def visit_Name(self, node):
    return node.id

  def visit_Constant(self, node):
    return node.value

  def visit_keyword(self, node):
    return node.arg, self.visit(node.value)

  def visit_List(self, node):

        '{}) : ({}) -> ({})'.format(arg_str, arg_ty_str, ret_ty_str), node)
    return list(zip(ret_ssa_values, ret_tys))

  def visit_If(self, node):
    raise NotImplementedError('If not supported.')

  def visit_Name(self, node):
    val_and_lookup_type = self.symbol_table.lookup(node.id)
    if val_and_lookup_type:
      (val, lookup_type) = val_and_lookup_type
    elif node.id in TFR_BUILTINS:
      val = node.id

                return super.visitAnnotation(remap(desc), visible);
            }

            @Override
            public void visitFrame(int type, int nLocal, Object[] local, int nStack, Object[] stack) {
                super.visitFrame(type, nLocal, remap(nLocal, local), nStack, remap(nStack, stack));
            }
        }
    }

        }
    }

    /**
     * @see org.objectweb.asm.Opcodes#F_SAME
     */
    public void _F_SAME() {
        super.visitFrame(F_SAME, 0, new Object[0], 0, new Object[0]);
    }

    public void _INVOKESPECIAL(Type owner, String name, String descriptor) {
        _INVOKESPECIAL(owner.getInternalName(), name, descriptor);
    }

                        // Must use an F_NEW frame, as we may encounter class versions <= V1_5, see ASM MethodWriter
                        mv.visitFrame(Opcodes.F_NEW, 1, locals, 1, new Object[]{"java/lang/Throwable"});

                        // finally block inlined before rethrowing a caught exception:
                        _ALOAD(0);

            methodVisitor.visitJumpInsn(Opcodes.IFNULL, lookup);
            methodVisitor.visitInsn(Opcodes.ARETURN);

            methodVisitor.visitLabel(lookup);
            methodVisitor.visitFrame(Opcodes.F_NEW, 1, new Object[]{className}, 1, new Object[]{META_CLASS_TYPE.getInternalName()});
            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0); // for storing to field