83 lines
2.3 KiB
Ruby
83 lines
2.3 KiB
Ruby
require_relative "object"
|
|
|
|
module Virtual
|
|
# static description of a method
|
|
# name
|
|
# args (with defaults)
|
|
# code
|
|
# return arg (usually mystery, but for coded ones can be more specific)
|
|
# known local variable names
|
|
# temp variables (numbered)
|
|
#
|
|
class MethodDefinition < Virtual::Object
|
|
#return the main function (the top level) into which code is compiled
|
|
def MethodDefinition.main
|
|
MethodDefinition.new(:main , [] , Virtual::SelfReference )
|
|
end
|
|
def attributes
|
|
[:name , :args , :receiver , :return_type , :start]
|
|
end
|
|
def initialize name , args , receiver = Virtual::SelfReference.new , return_type = Virtual::Mystery , start = MethodEnter.new(MethodReturn.new)
|
|
@name = name.to_sym
|
|
@args = args
|
|
@locals = []
|
|
@tmps = []
|
|
@receiver = receiver
|
|
@return_type = return_type
|
|
@start = start
|
|
@current = @start
|
|
end
|
|
attr_reader :name , :args , :receiver , :start
|
|
attr_accessor :return_type , :current
|
|
|
|
# add an instruction after the current (insertion point)
|
|
# the added instruction will become the new insertion point
|
|
def add instruction
|
|
raise instruction.inspect unless instruction.is_a? Instruction
|
|
@current.insert(instruction) #insert after current
|
|
@current = instruction
|
|
end
|
|
|
|
# determine whether this method has a variable by the given name
|
|
# variables are locals and and arguments
|
|
# used to determine if a send must be issued
|
|
def has_var name
|
|
name = name.to_sym
|
|
var = @args.find {|a| a.name == name }
|
|
var = @locals.find {|a| a.name == name } unless var
|
|
var = @tmps.find {|a| a.name == name } unless var
|
|
var
|
|
end
|
|
|
|
# determine whether this method has an argument by the name
|
|
def has_arg name
|
|
name = name.to_sym
|
|
var = @args.find {|a| a.name == name }
|
|
var
|
|
end
|
|
|
|
def set_var name , var
|
|
v = has_var name
|
|
if( v )
|
|
v.type = var
|
|
else
|
|
v = Local.new(name , var)
|
|
@locals << v
|
|
end
|
|
v
|
|
end
|
|
|
|
def get_var name
|
|
var = has_var name
|
|
raise "no var #{name} in method #{self.name} , #{@locals} #{@args}" unless var
|
|
var
|
|
end
|
|
|
|
def get_tmp
|
|
name = "__tmp__#{@tmps.length}"
|
|
@tmps << name
|
|
Ast::NameExpression.new(name)
|
|
end
|
|
end
|
|
end
|