From 0d43987005f1c44bbffb35919923a8110f134303 Mon Sep 17 00:00:00 2001
From: Torsten Ruger <torsten@villataika.fi>
Date: Sat, 15 Apr 2017 20:58:39 +0300
Subject: [PATCH] start to compile send

still very hacked version of simple call, but a start
---
 lib/mom/instruction.rb                |  1 +
 lib/mom/simple_call.rb                | 18 ++++++++
 lib/parfait/message.rb                |  4 +-
 lib/vool/ruby_compiler.rb             |  2 +-
 lib/vool/statements/send_statement.rb | 60 ++++++++++++++++++++++++++-
 stash/message.rb                      | 38 -----------------
 test/vool/to_mom/test_return.rb       | 13 ++++++
 test/vool/to_mom/test_send.rb         | 37 +++++++++++++++++
 8 files changed, 130 insertions(+), 43 deletions(-)
 create mode 100644 lib/mom/simple_call.rb
 delete mode 100644 stash/message.rb
 create mode 100644 test/vool/to_mom/test_send.rb

diff --git a/lib/mom/instruction.rb b/lib/mom/instruction.rb
index 0c3609cf..df1cce24 100644
--- a/lib/mom/instruction.rb
+++ b/lib/mom/instruction.rb
@@ -6,5 +6,6 @@ module Mom
 
 end
 
+require_relative "simple_call"
 require_relative "slot_load"
 require_relative "return_sequence"
diff --git a/lib/mom/simple_call.rb b/lib/mom/simple_call.rb
new file mode 100644
index 00000000..111ea94c
--- /dev/null
+++ b/lib/mom/simple_call.rb
@@ -0,0 +1,18 @@
+module Mom
+
+  # A SimpleCall is just that, a simple call. This could be called a function call too,
+  # meaning we managed to resolve the function at compile time and all we have to do is
+  # actually call it.
+  #
+  # As the call setup is done beforehand (for both simple and cached call), the
+  # calling really means just jumping to the address. Simple.
+  #
+  class SimpleCall < Instruction
+    attr_reader :method
+    
+    def initialize(method)
+      @method = method
+    end
+  end
+
+end
diff --git a/lib/parfait/message.rb b/lib/parfait/message.rb
index 32d34431..ba147e8c 100644
--- a/lib/parfait/message.rb
+++ b/lib/parfait/message.rb
@@ -1,6 +1,6 @@
 
-# A message is what is sent when you invoke a method. Args and stuff are packed up in to a Message
-# and the Message is sent to the receiver.
+# A message is what is created when a message is sent. Args and stuff are packed up in to a
+# Message and the Message is activated (by swapping it into the machine).
 
 # Part of the housekeeping (see attributes) makes messages a double linked list (next_message and
 #  caller) , and maybe surprisingly this means that we can create all messages at runtime
diff --git a/lib/vool/ruby_compiler.rb b/lib/vool/ruby_compiler.rb
index 2866d47a..d17c727e 100644
--- a/lib/vool/ruby_compiler.rb
+++ b/lib/vool/ruby_compiler.rb
@@ -167,7 +167,7 @@ module Vool
 
     # this is a call to super without args (z = zero arity)
     def on_zsuper exp
-      SendStatement.new( nil , SuperStatement.new )
+      SendStatement.new( nil , SuperStatement.new , nil)
     end
 
     # this is a call to super with args and
diff --git a/lib/vool/statements/send_statement.rb b/lib/vool/statements/send_statement.rb
index b0a5235d..a9900fe3 100644
--- a/lib/vool/statements/send_statement.rb
+++ b/lib/vool/statements/send_statement.rb
@@ -2,15 +2,71 @@ module Vool
   class SendStatement < Statement
     attr_reader :name , :receiver , :arguments
 
-    def initialize(name , receiver , arguments = [])
+    def initialize(name , receiver , arguments )
       @name , @receiver , @arguments = name , receiver , arguments
+      @arguments ||= []
     end
 
     def collect(arr)
       @receiver.collect(arr)
-      @arguments.collect(arr)
+      @arguments.each do |arg|
+        puts "ARG#{arg}"
+        arg.collect(arr)
+      end
       super
     end
 
+    # Sending in a dynamic language is off course not as simple as just calling.
+    # The function that needs to be called depends after all on the receiver,
+    # and no guarantees can be made on what that is.
+    #
+    # It helps to know that usually (>99%) the class of the receiver does not change.
+    # Our stategy then is to cache the functions and only dynamically determine it in
+    # case of a miss (the 1%, and first invocation)
+    #
+    # As cache key we must use the type of the object (which is the first word of _every_ object)
+    # as that is constant, and function implementations depend on the type (not class)
+    #
+    # A Send breaks down to 2 steps:
+    # - Setting up the next message, with receiver, arguments, and (importantly) return address
+    # - a CachedCall , or a SimpleCall, depending on weather the receiver type can be determined
+    #
+    # FIXME: we now presume direct (assignable) values for the arguments and receiver.
+    #        in a not so distant future, temporary variables will have to be created
+    #        and complex statements hoisted to assign to them. pps: same as in conditions
+    def to_mom( method )
+      message_setup + call_instruction
+    end
+
+    def message_setup
+      pops = [Mom::SlotConstant.new([:message , :next_message , :receiver] , @receiver) ]
+      @arguments.each_with_index do |arg , index|
+        arg_target = [:message , :next_message , :arguments]
+        pops << Mom::SlotConstant.new( arg_target + index , @arg)
+      end
+      pops
+    end
+
+    def call_instruction
+      if(receiver_type)
+        simple_call
+      else
+        cached_call
+      end
+    end
+
+    def receiver_type
+      Parfait.object_space.get_class_by_name(:Integer).instance_type
+    end
+    def simple_call
+      type = receiver_type
+      method = type.get_method(@name)
+      [Mom::SimpleCall.new( method) ]
+    end
+
+    def cached_call
+      [Mom::SlotConstant.new([:message , :next_message , :receiver] , @receiver) ]
+    end
+
   end
 end
diff --git a/stash/message.rb b/stash/message.rb
deleted file mode 100644
index 01c2c852..00000000
--- a/stash/message.rb
+++ /dev/null
@@ -1,38 +0,0 @@
-module Risc
-  # So when an object calls a method, or sends a message, this is what it sends: a Message
-
-  # A message contains the sender, return and exceptional return addresses,the arguments,
-  #  and a slot for the named_list.
-
-  # As such it is a very run-time object, deep in the machinery as it were, and does not have
-  # meaningful methods you could call at compile time.
-
-  # The methods that are there, are nevertheless meant to be called at compile time and generate
-  # code, rather than executing it.
-
-  # The caller creates the Message and passes control to the receiver's method
-
-  # The receiver create a new NamedList to hold local and temporary variables and (later) creates
-  # default values for arguments that were not passed
-
-  # How the actual finding of the method takes place (acording to the ruby rules) is not simple,
-  # but as there is a guaranteed result (be it method_missing) it does not matter to the passing
-  #  mechanism described
-
-  # During compilation Message and named_list objects are created to do type analysis
-
-  class Message
-
-    def initialize me , normal , exceptional
-      @me = me
-      @next_normal = normal
-      @next_exception = exceptional
-      @arguments = arguments
-      # a named_list represents the local and temporary variables at a point in the program.
-      @named_list = nil
-    end
-    attr_reader :me, :next_normal, :next_exception, :arguments , :locals
-
-    #
-  end
-end
diff --git a/test/vool/to_mom/test_return.rb b/test/vool/to_mom/test_return.rb
index 43a08259..6da63f43 100644
--- a/test/vool/to_mom/test_return.rb
+++ b/test/vool/to_mom/test_return.rb
@@ -34,4 +34,17 @@ module Vool
       assert_equal IntegerStatement ,  @stats.first.right.class
     end
   end
+  class TestReturnSendMom < MiniTest::Test
+    include MomCompile
+
+    def setup
+      Risc.machine.boot
+      @stats = compile_first_method( "return foo").first
+    end
+
+    def test_two_instructions_are_returned
+#need to implement send first
+#      assert_equal 2 ,  @stats.length
+    end
+  end
 end
diff --git a/test/vool/to_mom/test_send.rb b/test/vool/to_mom/test_send.rb
new file mode 100644
index 00000000..0c130321
--- /dev/null
+++ b/test/vool/to_mom/test_send.rb
@@ -0,0 +1,37 @@
+require_relative "helper"
+
+module Vool
+  class TestSendMom < MiniTest::Test
+    include MomCompile
+
+    def setup
+      Risc.machine.boot
+      @stats = compile_first_method( "5.mod4").first
+    end
+
+    def test_class_compiles
+      assert_equal Mom::SlotConstant , @stats.first.class , @stats
+    end
+    def test_slot_is_set
+      assert @stats.first.left
+    end
+    def test_two_instructions_are_returned
+      assert_equal 2 ,  @stats.length
+    end
+    def test_receiver_class
+      assert_equal Mom::SlotConstant,  @stats.first.class
+    end
+    def test_receiver_move
+      assert_equal :receiver,  @stats.first.left[2]
+    end
+    def test_call_is
+      assert_equal Mom::SimpleCall,  @stats[1].class
+    end
+    def test_call_has_method
+      assert_equal Parfait::TypedMethod,  @stats[1].method.class
+    end
+    def test_call_has_right_method
+      assert_equal :mod4,  @stats[1].method.name
+    end
+  end
+end