From deaa06206291549075791e31e93f8613e12fa9b2 Mon Sep 17 00:00:00 2001
From: Torsten Ruger <torsten@villataika.fi>
Date: Sat, 30 May 2015 14:49:47 +0300
Subject: [PATCH] start to minimize

filter unused methods
Filter works, need to remove still
---
 lib/virtual.rb                  |  1 +
 lib/virtual/machine.rb          |  1 +
 lib/virtual/passes/minimizer.rb | 44 +++++++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+)
 create mode 100644 lib/virtual/passes/minimizer.rb

diff --git a/lib/virtual.rb b/lib/virtual.rb
index 6796e466..98c0bac3 100644
--- a/lib/virtual.rb
+++ b/lib/virtual.rb
@@ -7,6 +7,7 @@ require "virtual/compiled_method_info"
 require "virtual/slots/slot"
 require "virtual/type"
 # the passes _are_ order dependant
+require "virtual/passes/minimizer"
 require "virtual/passes/send_implementation"
 require "virtual/passes/get_implementation"
 require "virtual/passes/enter_implementation"
diff --git a/lib/virtual/machine.rb b/lib/virtual/machine.rb
index 6e51b65f..43615b32 100644
--- a/lib/virtual/machine.rb
+++ b/lib/virtual/machine.rb
@@ -42,6 +42,7 @@ module Virtual
     attr_reader :message , :passes , :space , :class_mappings , :init
 
     def run_passes
+      Minimizer.new.run
       @passes.each do |pass_class|
         blocks = [@init]
         @space.classes.values.each do |c|
diff --git a/lib/virtual/passes/minimizer.rb b/lib/virtual/passes/minimizer.rb
new file mode 100644
index 00000000..31a190c6
--- /dev/null
+++ b/lib/virtual/passes/minimizer.rb
@@ -0,0 +1,44 @@
+module Virtual
+
+  # Remove all functions that are not called
+  # Not called is approximated by the fact that the method name doesn't show up
+  # in any function reachable from main
+  class Minimizer
+    def run
+      @gonners = []
+      Parfait::Space.object_space.classes.values.each do |c|
+        c.instance_methods.each do |f|
+          @gonners << f
+        end
+      end
+      init= Parfait::Space.object_space.get_class_by_name("Kernel").get_instance_method "__init__"
+      remove init
+      dump_remaining
+    end
+
+    def remove function
+      index = @gonners.index function
+      unless index
+        puts "function was already removed #{ function.name}"
+        return
+      end
+      @gonners.delete function
+      function.info.blocks.each do |block|
+        block.codes.each do |code|
+          if code.is_a? Virtual::MessageSend
+            str_name = code.name.to_s
+            @gonners.each do |stay|
+              remove stay if(stay.name == str_name)
+            end
+          end
+          remove code.method if code.is_a? Virtual::MethodCall
+        end
+      end
+    end
+
+    def dump_remaining
+      names = @gonners.collect {|f| f.name }
+      puts "Dump #{names}"
+    end
+  end
+end