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universe.py 20.9 KB
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from rpython.rlib.rrandom import Random
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from rpython.rlib import jit
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from som.interpreter.interpreter import Interpreter
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from som.interpreter.bytecodes   import Bytecodes 
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from som.interpreter.frame       import Frame
 
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from som.vm.symbol_table         import SymbolTable
from som.vmobjects.object        import Object
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from som.vmobjects.clazz         import Class
from som.vmobjects.array         import Array
from som.vmobjects.symbol        import Symbol
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from som.vmobjects.method        import Method
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from som.vmobjects.integer       import Integer
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from som.vmobjects.string        import String
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from som.vmobjects.block         import Block, block_evaluation_primitive
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from som.vmobjects.biginteger    import BigInteger
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from som.vmobjects.double        import Double
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from som.vm.shell import Shell

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import som.compiler.sourcecode_compiler as sourcecode_compiler

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import os
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import time

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from rlib.exit  import Exit
from rlib.osext import path_split
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class Assoc(object):

    _immutable_fields_ = ["_global_name", "_value?"]

    def __init__(self, global_name, value):
        self._global_name = global_name
        self._value       = value

    def get_value(self):
        return self._value

    def set_value(self, value):
        self._value = value

    def __str__(self):
        return "(%s => %s)" % (self._global_name, self._value)

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class Universe(object):
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    CURRENT = None
    
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    _immutable_fields_ = [
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            "nilObject",
            "trueObject",
            "falseObject",
            "objectClass",
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            "classClass",
            "metaclassClass",
            "nilClass",
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            "integerClass",
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            "bigintegerClass",
            "arrayClass",
            "methodClass",
            "symbolClass",
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            "primitiveClass",
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            "systemClass",
            "blockClass",
            "blockClasses[*]",
            "stringClass",
            "doubleClass",
            "_symbol_table",
            "_globals"]
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    def __init__(self, avoid_exit = False):
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        self._interpreter    = Interpreter(self)
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        self._symbol_table   = {}
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        self._globals        = {}
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        self.nilObject      = None
        self.trueObject     = None
        self.falseObject    = None
        self.objectClass    = None
        self.classClass     = None
        self.metaclassClass = None
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        self.nilClass       = None
        self.integerClass   = None
        self.bigintegerClass= None
        self.arrayClass     = None
        self.methodClass    = None
        self.symbolClass    = None
        self.primitiveClass = None
        self.systemClass    = None
        self.blockClass     = None
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        self.blockClasses   = None
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        self.stringClass    = None
        self.doubleClass    = None
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        self._last_exit_code = 0
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        self._avoid_exit     = avoid_exit
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        self._dump_bytecodes = False
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        self.classpath       = None
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        self.start_time      = time.time() # a float of the time in seconds
        self.random          = Random(abs(int(time.clock() * time.time())))

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        CURRENT = self
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    def exit(self, error_code):
        if self._avoid_exit:
            self._last_exit_code = error_code
        else:
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            raise Exit(error_code)
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    def last_exit_code(self):
        return self._last_exit_code
    
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    def get_interpreter(self):
        return self._interpreter
    
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    def execute_method(self, class_name, selector):
        self._initialize_object_system()

        clazz = self.load_class(self.symbol_for(class_name))

        bootstrap_method = self._create_bootstrap_method()
        bootstrap_frame  = self._create_bootstrap_frame(bootstrap_method, clazz)
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        # Lookup the invokable on class
        invokable = clazz.get_class(self).lookup_invokable(self.symbol_for(selector))
        
        invokable.invoke(bootstrap_frame, self._interpreter)
        return bootstrap_frame.pop()
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    def _create_bootstrap_method(self):
        # Create a fake bootstrap method to simplify later frame traversal
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        bootstrap_method = self.new_method(self.symbol_for("bootstrap"), 1, [],
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                                           self.new_integer(0),
                                           self.new_integer(2))
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        bootstrap_method.set_bytecode(0, Bytecodes.halt)
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        bootstrap_method.set_holder(self.systemClass)
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        return bootstrap_method
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    def _create_bootstrap_frame(self, bootstrap_method, receiver, arguments = None):
        # Create a fake bootstrap frame with the system object on the stack
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        bootstrap_frame = self._interpreter.new_frame(None, bootstrap_method, None)
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        bootstrap_frame.push(receiver)
        
        if arguments:
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            bootstrap_frame.push(arguments)
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        return bootstrap_frame
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    def interpret(self, arguments):
        # Check for command line switches
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        arguments = self.handle_arguments(arguments)
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        # Initialize the known universe
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        system_object = self._initialize_object_system()
        bootstrap_method = self._create_bootstrap_method()
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        # Start the shell if no filename is given
        if len(arguments) == 0:
            shell = Shell(self, self._interpreter)
            shell.set_bootstrap_method(bootstrap_method)
            shell.start()
            return
        else:
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            # Convert the arguments into an array
            arguments_array = self.new_array_with_strings(arguments)
            bootstrap_frame = self._create_bootstrap_frame(bootstrap_method, system_object, arguments_array)
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            # Lookup the initialize invokable on the system class
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            initialize = self.systemClass.lookup_invokable(self.symbol_for("initialize:"))
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            return initialize.invoke(bootstrap_frame, self._interpreter)
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    def handle_arguments(self, arguments):
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        got_classpath  = False
        remaining_args = []

        i = 0
        while i < len(arguments):
            if arguments[i] == "-cp":
                if i + 1 >= len(arguments):
                    self._print_usage_and_exit()
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                self.setup_classpath(arguments[i + 1])
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                i += 1    # skip class path
                got_classpath = True
            elif arguments[i] == "-d":
                self._dump_bytecodes = True
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            elif arguments[i] in ["-h", "--help", "-?"]:
                self._print_usage_and_exit()
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            else:
                remaining_args.append(arguments[i])
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            i += 1
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        if not got_classpath:
            # Get the default class path of the appropriate size
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            self.classpath = self._default_classpath()
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        # check remaining args for class paths, and strip file extension
        i = 0
        while i < len(remaining_args):
            split = self._get_path_class_ext(remaining_args[i])

            if split[0] != "":  # there was a path
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                self.classpath.insert(0, split[0])
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            remaining_args[i] = split[1]
            i += 1
        
        return remaining_args
    
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    def setup_classpath(self, cp):
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        self.classpath = cp.split(os.pathsep)
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    @staticmethod
    def _default_classpath():
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        return ['.']
    
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    # take argument of the form "../foo/Test.som" and return
    # "../foo", "Test", "som"
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    @staticmethod
    def _get_path_class_ext(path):
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        return path_split(path)
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    def _print_usage_and_exit(self):
        # Print the usage
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        std_println("Usage: som [-options] [args...]                          ")
        std_println("                                                         ")
        std_println("where options include:                                   ")
        std_println("    -cp <directories separated by " + os.pathsep     + ">")
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        std_println("        set search path for application classes")
        std_println("    -d  enable disassembling")
        std_println("    -h  print this help")
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        # Exit
        self.exit(0)
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    def _initialize_object_system(self):
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        # Allocate the nil object
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        self.nilObject = Object(None)
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        # Allocate the Metaclass classes
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        self.metaclassClass = self.new_metaclass_class()
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        # Allocate the rest of the system classes
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        self.objectClass     = self.new_system_class()
        self.nilClass        = self.new_system_class()
        self.classClass      = self.new_system_class()
        self.arrayClass      = self.new_system_class()
        self.symbolClass     = self.new_system_class()
        self.methodClass     = self.new_system_class()
        self.integerClass    = self.new_system_class()
        self.bigintegerClass = self.new_system_class()
        self.primitiveClass  = self.new_system_class()
        self.stringClass     = self.new_system_class()
        self.doubleClass     = self.new_system_class()
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        # Setup the class reference for the nil object
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        self.nilObject.set_class(self.nilClass)
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        # Initialize the system classes
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        self._initialize_system_class(self.objectClass,                 None, "Object")
        self._initialize_system_class(self.classClass,      self.objectClass, "Class")
        self._initialize_system_class(self.metaclassClass,   self.classClass, "Metaclass")
        self._initialize_system_class(self.nilClass,        self.objectClass, "Nil")
        self._initialize_system_class(self.arrayClass,      self.objectClass, "Array")
        self._initialize_system_class(self.methodClass,      self.arrayClass, "Method")
        self._initialize_system_class(self.symbolClass,     self.objectClass, "Symbol")
        self._initialize_system_class(self.integerClass,    self.objectClass, "Integer")
        self._initialize_system_class(self.bigintegerClass, self.objectClass, "BigInteger")
        self._initialize_system_class(self.primitiveClass,  self.objectClass, "Primitive")
        self._initialize_system_class(self.stringClass,     self.objectClass, "String")
        self._initialize_system_class(self.doubleClass,     self.objectClass, "Double")
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        # Load methods and fields into the system classes
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        self._load_system_class(self.objectClass)
        self._load_system_class(self.classClass)
        self._load_system_class(self.metaclassClass)
        self._load_system_class(self.nilClass)
        self._load_system_class(self.arrayClass)
        self._load_system_class(self.methodClass)
        self._load_system_class(self.symbolClass)
        self._load_system_class(self.integerClass)
        self._load_system_class(self.bigintegerClass)
        self._load_system_class(self.primitiveClass)
        self._load_system_class(self.stringClass)
        self._load_system_class(self.doubleClass)
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        # Load the generic block class
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        self.blockClass = self.load_class(self.symbol_for("Block"))
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        # Setup the true and false objects
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        trueClassName    = self.symbol_for("True")
        trueClass        = self.load_class(trueClassName)
        self.trueObject  = self.new_instance(trueClass)
        
        falseClassName   = self.symbol_for("False")
        falseClass       = self.load_class(falseClassName)
        self.falseObject = self.new_instance(falseClass)
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        # Load the system class and create an instance of it
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        self.systemClass = self.load_class(self.symbol_for("System"))
        system_object = self.new_instance(self.systemClass)
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        # Put special objects and classes into the dictionary of globals
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        self.set_global(self.symbol_for("nil"),    self.nilObject)
        self.set_global(self.symbol_for("true"),   self.trueObject)
        self.set_global(self.symbol_for("false"),  self.falseObject)
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        self.set_global(self.symbol_for("system"), system_object)
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        self.set_global(self.symbol_for("System"), self.systemClass)
        self.set_global(self.symbol_for("Block"),  self.blockClass)
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        self.set_global(self.symbol_for("Nil"),    self.nilClass)
        
        self.set_global( trueClassName,  trueClass)
        self.set_global(falseClassName, falseClass)
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        self.blockClasses = [self.blockClass] + \
                [self._make_block_class(i) for i in [1, 2, 3]]

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        return system_object
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    @jit.elidable
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    def symbol_for(self, string):
        # Lookup the symbol in the symbol table
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        result = self._symbol_table.get(string, None)
        if result is not None:
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            return result
        
        # Create a new symbol and return it
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        result = self._new_symbol(string)
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        return result
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    def new_array_with_length(self, length):
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        return Array(self.nilObject, length)
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    def new_array_from_list(self, values):
        # Allocate a new array with the same length as the list
        result = self.new_array_with_length(len(values))

        # Copy all elements from the list into the array
        for i in range(len(values)):
            result.set_indexable_field(i, values[i])
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        return result
  
    def new_array_with_strings(self, strings):
        # Allocate a new array with the same length as the string array
        result = self.new_array_with_length(len(strings))

        # Copy all elements from the string array into the array
        for i in range(len(strings)):
            result.set_indexable_field(i, self.new_string(strings[i]))
    
        return result
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    @staticmethod
    def new_block(method, context_frame):
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        return Block(method, context_frame)
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    def new_class(self, class_class):
        # Allocate a new class and set its class to be the given class class
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        result = Class(self, class_class.get_number_of_instance_fields())
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        result.set_class(class_class)
        return result

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    @staticmethod
    def new_frame(previous_frame, method, context):
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        # Compute the maximum number of stack locations (including arguments,
        # locals and extra buffer to support doesNotUnderstand) and set the
        # number of indexable fields accordingly
        length = (method.get_number_of_arguments() +
                  method.get_number_of_locals().get_embedded_integer() +
                  method.get_maximum_number_of_stack_elements().get_embedded_integer() + 2)

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        return Frame(length, method, context, previous_frame)
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    @staticmethod
    def new_method(signature, num_bytecodes, literals,
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                   num_locals, maximum_number_of_stack_elements):
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        return Method(literals, num_locals, maximum_number_of_stack_elements,
                      num_bytecodes, signature)
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    def new_instance(self, instance_class):
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        result = Object(self.nilObject, instance_class.get_number_of_instance_fields())
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        result.set_class(instance_class)
        return result

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    @staticmethod
    def new_integer(value):
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        assert isinstance(value, int)
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        return Integer(value)
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    @staticmethod
    def new_biginteger(value):
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        return BigInteger(value)
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    @staticmethod
    def new_double(value):
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        return Double(value)
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    def new_metaclass_class(self):
        # Allocate the metaclass classes
        result = Class(self)
        result.set_class(Class(self))

        # Setup the metaclass hierarchy
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        result.get_class(self).set_class(result)
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        # Return the freshly allocated metaclass class
        return result
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    @staticmethod
    def new_string(embedded_string):
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        return String(embedded_string)
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    def _new_symbol(self, string):
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        result = Symbol(string)
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        # Insert the new symbol into the symbol table
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        self._symbol_table[string] = result
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        return result
      
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    def new_system_class(self):
        # Allocate the new system class
        system_class = Class(self)

        # Setup the metaclass hierarchy
        system_class.set_class(Class(self))
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        system_class.get_class(self).set_class(self.metaclassClass)
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        # Return the freshly allocated system class
        return system_class
    
    def _initialize_system_class(self, system_class, super_class, name):
        # Initialize the superclass hierarchy
        if super_class:
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            system_class.set_super_class(super_class)
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            system_class.get_class(self).set_super_class(super_class.get_class(self))
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        else:
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            system_class.get_class(self).set_super_class(self.classClass)
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        # Initialize the array of instance fields
        system_class.set_instance_fields(self.new_array_with_length(0))
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        system_class.get_class(self).set_instance_fields(self.new_array_with_length(0))
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        # Initialize the array of instance invokables
        system_class.set_instance_invokables(self.new_array_with_length(0))
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        system_class.get_class(self).set_instance_invokables(self.new_array_with_length(0))
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        # Initialize the name of the system class
        system_class.set_name(self.symbol_for(name))
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        system_class.get_class(self).set_name(self.symbol_for(name + " class"))
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        # Insert the system class into the dictionary of globals
        self.set_global(system_class.get_name(), system_class)
    
    def get_global(self, name):
        # Return the global with the given name if it's in the dictionary of globals
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        # if not, return None
        jit.promote(self)
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        assoc = self._get_global(name)
        if assoc:
            return assoc.get_value()
        else:
            return None
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    @jit.elidable
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    def _get_global(self, name):
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        return self._globals.get(name, None)
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    def set_global(self, name, value):
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        self.get_globals_association(name).set_value(value)
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    def has_global(self, name):
        return name in self._globals
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    @jit.elidable_promote("all")
    def get_globals_association(self, name):
        assoc = self._globals.get(name, None)
        if assoc is None:
            assoc = Assoc(name, self.nilObject)
            self._globals[name] = assoc
        return assoc

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    def _get_block_class(self, number_of_arguments):
        return self.blockClasses[number_of_arguments]

    def _make_block_class(self, number_of_arguments):
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        # Compute the name of the block class with the given number of
        # arguments
        name = self.symbol_for("Block" + str(number_of_arguments))

        # Get the block class for blocks with the given number of arguments
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        result = self._load_class(name, None)
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        # Add the appropriate value primitive to the block class
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        result.add_instance_primitive(block_evaluation_primitive(number_of_arguments, self))
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        # Insert the block class into the dictionary of globals
        self.set_global(name, result)

        # Return the loaded block class
        return result

    def load_class(self, name):
        # Check if the requested class is already in the dictionary of globals
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        result = self.get_global(name)
        if result is not None:
            return result
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        # Load the class
        result = self._load_class(name, None)

        # Load primitives (if necessary) and return the resulting class
        if result and result.has_primitives():
            result.load_primitives()
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        self.set_global(name, result)
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        return result

    def _load_system_class(self, system_class):
        # Load the system class
        result = self._load_class(system_class.get_name(), system_class)

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        if not result:
            error_println(system_class.get_name().get_string()
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                   + " class could not be loaded. It is likely that the"
                   + " class path has not been initialized properly."
                   + " Please make sure that the '-cp' parameter is given on the command-line.")
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            self.exit(200)

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        # Load primitives if necessary
        if result.has_primitives():
            result.load_primitives()

    def _load_class(self, name, system_class):
        # Try loading the class from all different paths
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        for cpEntry in self.classpath:
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            try:
                # Load the class from a file and return the loaded class
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                result = sourcecode_compiler.compile_class_from_file(cpEntry, name.get_string(), system_class, self)
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                if self._dump_bytecodes:
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                    from som.compiler.disassembler import dump
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                    dump(result.get_class(self))
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                    dump(result)
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                return result
            except IOError:
                # Continue trying different paths
                pass

        # The class could not be found.
        return None
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    def load_shell_class(self, stmt):
        # Load the class from a stream and return the loaded class
        result = sourcecode_compiler.compile_class_from_string(stmt, None, self)
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        if self._dump_bytecodes:
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            from som.compiler.disassembler import dump
            dump(result)
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        return result

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def error_print(msg):
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    os.write(2, msg or "")
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def error_println(msg = ""):
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    os.write(2, msg + "\n")
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def std_print(msg):
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    os.write(1, msg or "")
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def std_println(msg = ""):
    os.write(1, msg + "\n")
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def main(args):
    u = Universe()
    u.interpret(args[1:])
    u.exit(0)

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def get_current():
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    return Universe.CURRENT
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if __name__ == '__main__':
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    import sys
    try:
        main(sys.argv)
    except Exit as e:
        sys.exit(e.code)