make method creation class methods in MethodCompiler

and pass the wish to use main explicitly, which is really a test
feature

lib/register/builtin/compile_helper.rb

@@ -11,7 +11,7 @@ module Register
 
       def compiler_for( type , method_name , extra_args = {})
         args = {:index => :Integer}.merge( extra_args )
-        Vm::MethodCompiler.new.create_method(type , method_name , args ).init_method
+        Vm::MethodCompiler.create_method(type , method_name , args ).init_method
       end
 
       # Load the value

lib/register/builtin/integer.rb

@@ -6,18 +6,18 @@ module Register
         include AST::Sexp
 
         def mod4 context
-          compiler = Vm::MethodCompiler.new.create_method(:Integer,:mod4 ).init_method
+          compiler = Vm::MethodCompiler.create_method(:Integer,:mod4 ).init_method
           return compiler.method
         end
         def putint context
-          compiler = Vm::MethodCompiler.new.create_method(:Integer,:putint ).init_method
+          compiler = Vm::MethodCompiler.create_method(:Integer,:putint ).init_method
           return compiler.method
         end
 
 
         def div10 context
           s = "div_10"
-          compiler = Vm::MethodCompiler.new.create_method(:Integer,:div10 ).init_method
+          compiler = Vm::MethodCompiler.create_method(:Integer,:div10 ).init_method
           me = compiler.process( Vm::Tree::KnownName.new( :self) )
           tmp = compiler.process( Vm::Tree::KnownName.new( :self) )
           q = compiler.process( Vm::Tree::KnownName.new( :self) )

lib/register/builtin/kernel.rb

@@ -6,7 +6,7 @@ module Register
         # it isn't really a function, ie it is jumped to (not called), exits and may not return
         # so it is responsible for initial setup
         def __init__ context
-          compiler = Vm::MethodCompiler.new.create_method(:Kernel,:__init__ )
+          compiler = Vm::MethodCompiler.create_method(:Kernel,:__init__ )
           new_start = Register.label("__init__ start" , "__init__" )
           compiler.method.set_instructions( new_start)
           compiler.set_current new_start
@@ -29,7 +29,7 @@ module Register
         end
 
         def exit context
-          compiler = Vm::MethodCompiler.new.create_method(:Kernel,:exit ).init_method
+          compiler = Vm::MethodCompiler.create_method(:Kernel,:exit ).init_method
           emit_syscall( compiler , :exit )
           return compiler.method
         end

lib/register/builtin/space.rb

@@ -9,7 +9,7 @@ module Register
         # main entry point, ie __init__ calls this
         # defined here as empty, to be redefined
         def main context
-          compiler = Vm::MethodCompiler.new.create_method(:Space , :main ).init_method
+          compiler = Vm::MethodCompiler.create_method(:Space , :main ).init_method
           return compiler.method
         end
 

lib/register/builtin/word.rb

@@ -7,7 +7,7 @@ module Register
         include CompileHelper
 
         def putstring context
-          compiler = Vm::MethodCompiler.new.create_method(:Word , :putstring ).init_method
+          compiler = Vm::MethodCompiler.create_method(:Word , :putstring ).init_method
           compiler.add_slot_to_reg( "putstring" , :message , :receiver , :new_message )
           index = Parfait::Word.get_length_index
           reg = RegisterValue.new(:r2 , :Integer)

lib/vm/method_compiler.rb

@@ -56,7 +56,7 @@ module Vm
   # Helper function to create a new compiler and compie the statement(s)
   # Statement must be and AST::Node as generated by s expressions
   def self.compile_ast( statement )
-    compiler = MethodCompiler.new
+    compiler = MethodCompiler.new(:main)
     code = Vm.ast_to_code statement
     compiler.process code
   end
@@ -66,15 +66,15 @@ module Vm
       include Vm.const_get( mod.camelize )
     end
 
-    def initialize( method = nil )
+    def initialize( method )
       @regs = []
-      if method
+      if method == :main
-        @method = method
-        @type = method.for_type
-      else
         @type = Parfait.object_space.get_type()
         @method = @type.get_method( :main )
         @method = @type.create_method( :main ,{}) unless @method
+      else
+        @method = method
+        @type = method.for_type
       end
       @current = @method.instructions
     end
@@ -107,7 +107,7 @@ module Vm
 
     # create the method, do some checks and set it as the current method to be added to
     # class_name and method_name are pretty clear, args are given as a ruby array
-    def create_method( class_name , method_name , args = {})
+    def self.create_method( class_name , method_name , args = {})
       raise "create_method #{class_name}.#{class_name.class}" unless class_name.is_a? Symbol
       clazz = Parfait.object_space.get_class_by_name! class_name
       create_method_for( clazz.instance_type , method_name , args)
@@ -118,13 +118,12 @@ module Vm
     # args a hash that will be converted to a type
     # the created method is set as the current and the given type too
     # return the compiler (for chaining)
-    def create_method_for( type , method_name , args )
+    def self.create_method_for( type , method_name , args )
-      @type = type
       raise "create_method #{type.inspect} is not a Type" unless type.is_a? Parfait::Type
       raise "Args must be Hash #{args}" unless args.is_a?(Hash)
       raise "create_method #{method_name}.#{method_name.class}" unless method_name.is_a? Symbol
-      @method = type.create_method( method_name , args)
+      method = type.create_method( method_name , args)
-      self
+      self.new(method)
     end
 
     # add method entry and exit code. Mainly save_return for the enter and

test/helper.rb

@@ -22,7 +22,7 @@ require 'rubyx'
 
 module Compiling
   def clean_compile(clazz_name , method_name , args , statements)
-    compiler = Vm::MethodCompiler.new.create_method(clazz_name,method_name,args ).init_method
+    compiler = Vm::MethodCompiler.create_method(clazz_name,method_name,args ).init_method
     compiler.process( Vm.ast_to_code( statements ) )
   end
 

test/vm/method_compiler/helper.rb

@@ -41,7 +41,7 @@ module Register
     end
     def check_nil
       assert @expect , "No output given"
-      compiler = Vm::MethodCompiler.new
+      compiler = Vm::MethodCompiler.new(:main)
       code = Vm.ast_to_code( @input )
       assert code.to_s , @input
       produced = compiler.process( code )