more semi random code, a checkpoint

lib/asm/string_literal.rb

@@ -1,4 +1,4 @@
-require_relative "code"
+require_relative "../vm/code"
 
 module Asm
   # The name really says it all.
@@ -6,7 +6,7 @@ module Asm
   # Currently string are stored "inline" , ie in the code segment. 
   # Mainly because that works an i aint no elf expert.
   
-  class StringLiteral < Code
+  class StringLiteral < Vm::Code
     
     # currently aligned to 4 (ie padded with 0) and off course 0 at the end
     def initialize(str)

lib/crystal.rb

@@ -5,3 +5,4 @@ require "elf/object_writer"
 require 'parser/composed'
 require 'parser/transform'
 require "vm/context"
+require "vm/machine"

lib/vm/block.rb

@@ -0,0 +1,41 @@
+require_relative "values"
+
+module Vm
+  
+  # Think flowcharts: blocks are the boxes. The smallest unit of linear code
+  
+  # Blocks must end in control instructions (jump/call/return). 
+  # And the only valid argument for a jump is a Block 
+  
+  # Blocks for a double linked list so one can traverse back and forth
+  
+  # There are four ways for a block to get data (to work on)
+  # - hard coded constants (embedded in code)
+  # - memory move
+  # - values passed in (from previous blocks. ie local variables)
+
+  # See Value description on how to create code/instructions
+  
+  class Block < Value
+
+    def initialize(name)
+      super()
+      @name = name.to_sym
+    end
+
+    attr_reader :name
+
+    def verify
+      raise "Empty #{self.inspect}" if @values.empty?
+    end
+    private 
+    
+    # possibly misguided ??
+    def add_arg value
+      # TODO check
+      @args << value
+    end
+
+  end
+
+end

lib/vm/code.rb

@@ -1,8 +1,7 @@
-
-module Asm
+module Vm
   # Base class for anything that we can assemble
 
-  # Derived classes include instrucitons, blocks and data(strings)
+  # Derived classes include instructions and data(strings)
   
   # The commonality abstracted here is the length and position
   # and the ability to assemble itself into the stream

lib/vm/context.rb

@@ -1,53 +1,32 @@
 require_relative "kernel"
+require_relative "program"
 
 module Vm
+  
+  #currently just holding the program in here so we can have global access
   class Context
-    def initialize 
-      @locals = {}
+    def initialize program
+      @attributes = {}
+      @attributes["program"] = program
     end
-    def get name
-      @locals[name]
-    end
-  end
-end
     
-# ast classes
-module Parser
-  Expression.class_eval do
-    def compile builder , context
-      raise "abstract #{self.inspect}"
-    end
-  end
-
-  IntegerExpression.class_eval do
-  end
-
-  NameExpression.class_eval do
-  end
-
-  StringExpression.class_eval do
-    def compile builder , context
-      return string
-    end
-  end
-
-  FuncallExpression.class_eval do
-    def compile builder , context
-      arguments = args.collect{|arg| arg.compile(builder , context) }
-      function = context.get(name)
-      unless function
-        function = Vm::Kernel.send(name)
-        context.add_function( name , function )
+    # map any function call to an attribute if possible
+    def method_missing name , *args , &block 
+      if args.length > 1 or block_given?
+        puts "NO -#{args.length} BLOCK #{block_given?}"
+        super 
+      else
+        name = name.to_s
+        if args.length == 1        #must be assignemnt for ir attr= val
+          if name.include? "="
+            return @attributes[name.chop] = args[0]
+          else 
+            super
+          end
+        else
+          return @attributes[name]
+        end
       end
-      
     end
   end
-
-  ConditionalExpression.class_eval do
-  end
-
-  AssignmentExpression.class_eval do
-  end
-  FunctionExpression.class_eval do
-  end
 end

lib/vm/conversion.rb

@@ -0,0 +1,26 @@
+module Vm
+  # Convert ast to vm-values via visitor pattern
+  # We do this (what would otherwise seem like foot-shuffling) to keep the layers seperated
+  # Ie towards the feature goal of reusing the same parse for several binary outputs 
+   
+  # scope of the funcitons is thus class scope ie self is the expression and all attributes work
+  # gets included into Value
+  module Conversion
+    def to_value
+      cl_name = self.class.name.to_s.split("::").last.gsub("Expression","").downcase
+      send "#{cl_name}_value"
+    end
+    def funcall_value
+      FunctionCall.new( name , args.collect{ |a| a.to_value } )
+    end
+    def string_value
+      ObjectReference.new( string )
+    end
+  end
+  
+end
+require_relative "../parser/nodes"
+
+Parser::Expression.class_eval do
+  include Vm::Conversion
+end

lib/vm/function.rb

@@ -0,0 +1,52 @@
+require_relative "block"
+
+module Vm
+
+  # Functions are similar to Blocks. Where Blocks can be jumped to, Functions can be called.
+
+  # Functions also have arguments, though they are handled differently (in register allocation)
+  
+  # Functions have a minimum of two blocks, entry and exit, which are created for you
+  # but there is no branch created between them, this must be done by the programmer.
+  
+
+  class Function < Value
+
+    def initialize(name , args = [])
+      super()
+      @name = name
+      @args = args
+      @entry = Block.new("entry_#{name}")
+      @exit = Block.new("exit_#{name}")
+    end
+    attr_reader :name , :args , :entry , :exit
+    
+    def arity
+      @args.length
+    end
+
+    def compile function_expression ,  context
+      arguments = function_expression.args.collect do |arg|
+        add_arg arg.to_value
+      end
+      function = context.program.get_function(name)
+      unless function
+        function = Vm::Kernel.send(name)
+        context.program.get_or_create_function( name , function , arity )
+      end
+    end
+    
+    def verify
+      @entry.verify
+      @exit.verify
+    end
+
+    private 
+    def add_arg value
+      # TODO check
+      @args << value
+    end
+    
+  end
+
+end

lib/vm/function_call.rb

@@ -0,0 +1,33 @@
+module Vm
+
+  # name and args , return
+
+  class FunctionCall < Value
+
+    def initialize(name , args)
+      @name = name
+      @args = args
+      @function = nil
+    end
+    attr_reader :name , :args , :function
+    
+    def compile context
+      @function = context.program.get_function @name
+      if @function
+        raise "error #{self}" unless function.arity != @args.length
+      else
+        @function = context.program.get_or_create_function @name
+      end
+      args.each_with_index do |arg , index|
+        arg.load
+        arg.compile context
+      end
+      #puts "funcall #{self.inspect}"
+      self.call
+    end
+    
+    def call
+      Machine.instance.function_call self
+    end
+  end
+end

lib/vm/instruction.rb

@@ -1,6 +1,48 @@
 
 module Vm
-  class Instruction
+  # Instruction represent the actions that affect change on Values
+  # In an OO way of thinking the Value is data, Instruction the functionality
+
+  # But to allow flexibility, the value api bounces back to the machine api, so machines instantiate
+  # intructions.
+  
+  # When Instructions are instantiated the create a linked list of Values and Instructions.
+  # So Value links to Instruction and Instruction links to Value
+  # Also, because the idea of what one instruction does, does not always map one to one to real machine
+  # instructions, and instruction may link to another instruction thus creating an arbitrary list
+  # to get the job (the original instruciton) done
+  # Admittately it would be simpler just to create the (abstract) instructions and let the machine 
+  # encode them into what-ever is neccessary, but this approach leaves more possibility to 
+  # optimize the actual instruction stream (not just the crystal instruction stream). Makes sense?
+  
+  # We have basic classes (literally) of instructions
+  # - Memory
+  # - Stack
+  # - Logic
+  # - Math
+  # - Control/Compare
+  # - Move
+  # - Call
+  
+  # Instruction derives from Code, for the assembly api
+  class Code ; end
+
+  class Instruction < Code
+    
   end
   
+  class StackInstruction < Instruction
+  end
+  class MemoryInstruction < Instruction
+  end
+  class LogicInstruction < Instruction
+  end
+  class MathInstruction < Instruction
+  end
+  class CompareInstruction < Instruction
+  end
+  class MoveInstruction < Instruction
+  end
+  class CallInstruction < Instruction
+  end
 end

lib/vm/kernel.rb

@@ -1,5 +1,11 @@
 module Vm
   module Kernel
+    def self.start
+      #TODO extract args into array of strings
+    end
+    def self.exit
+      # Machine.exit swi 0 
+    end
     def self.puts
       "me"
     end

lib/vm/machine.rb

@@ -11,10 +11,18 @@ module Vm
   # * Note that register content is typed externally. Not as in mri, where int's are tagged. Floats can's
   #   be tagged and lambda should be it's own type, so tagging does not work
   
-  # Note: subclasses should/will be used once we have the basic architecture clear and working
+  # Programs are created by invoking methods on subclasses of Value. 
+  # But executable code is a sequence of Instructions and subclasses.
+  
+  # A Machines main responsibility in the framework is to instantiate Instruction
+  # Value functions are mapped to machines by concatenating the values class name + the methd name
+  # Example:  SignedValue.plus( value ) ->  Machine.signed_plus (value )
   
   class Machine
   
+    # hmm, not pretty but for now
+    @@instance = nil
+    
     attr_reader :registers
     attr_reader :scratch
     attr_reader :pc
@@ -23,5 +31,12 @@ module Vm
     # Still, using if to express tests makes sense, not just for 
     # consistency in this code, but also because that is what is actually done
     attr_reader :status  
+
+    def self.instance
+      @@instance
+    end
+    def self.instance= machine
+      @@instance = machine
+    end
   end
 end

lib/vm/program.rb

@@ -0,0 +1,75 @@
+require_relative "function"
+require_relative "function_call"
+require "arm/arm_machine"
+
+module Vm
+  # A Program represents an executable that we want to build
+  # it has a list of functions and (global) objects
+  
+  # The main entry is a function called (of all things) "main", This _must be supplied by the compling
+  # There is a start and exit block that call main, which receives an array of strings
+
+  # While data "ususally" would live in a .data section, we may also "inline" it into the code
+  # in an oo system all data is represented as objects
+
+  # in terms of variables and their visibility, things are simple. They are either local or global
+  
+  # throwing in a context for unspecified use (well one is to pass the programm/globals around)
+  
+   
+  class Program < Block
+    
+    # should init for a machine and pass that on to start/exit / register alloc and the like
+    def initialize 
+      super("start")
+      # this aint pretty. but i'll go soon enough
+      Machine.instance = Arm::ArmMachine.new
+      
+      @context = Context.new(self)
+      @functions = []
+      @objects = []
+      @entry = Vm::Kernel::start
+      @exit = Vm::Kernel::exit
+    end
+    attr_reader :context
+    
+    def add_object o
+      @objects << o # TODO check type , no basic values allowed (must be wrapped)
+    end
+    
+    def get_function name
+      @functions.detect{ |f| f.name == name }
+    end
+
+    # preferred way of creating new functions (also forward declarations, will flag unresolved later)
+    def get_or_create_function name 
+      fun = get_function name
+      unless fun
+        fun = Function.new(name)
+        @functions << fun
+      end
+      fun
+    end
+    
+    def compile
+      super
+      string_table
+    end
+    
+    def wrap_as_main value
+      
+    end
+    def verify
+      main = @functions.find{|f| f.name == "main"}
+      raise "No main in Program" unless main
+      @functions.each do |funct|
+        funct.verify
+      end
+    end
+    
+    private 
+    # the main function
+    def create_main
+    end
+  end
+end

lib/vm/values.rb

@@ -3,14 +3,15 @@ module Vm
   # Values represent the information as it is processed. Different subclasses for different types, 
   # each type with different operations.
   # The oprerations on values is what makes a machine do things.
-  # For compilation, values are mopped to the machines registers and the functions (on values) map
-  # to machine instructions
+  # For compilation, values are moved to the machines registers and the methods (on values) map
+  #     to machine instructions
   
   # Values are immutable! (that's why they are called values)
   # Operations on values _always_ produce new values (conceptionally)
   
-  # Values are a way to reason about (create/validate) instructions. The final executable is mostly 
-  # instrucions.
+  # Values are a way to reason about (create/validate) instructions. 
+  # In fact a linked lists of values is created by invoking instructions
+  # the linked list goes from value to instruction to value, backwards
   
   # Word Values are what fits in a register. Derived classes
   # Float, Reference , Integer(s) must fit the same registers
@@ -23,19 +24,18 @@ module Vm
     def byte_size
       raise "abstract method called #{self.inspect}"
     end
-    attr :register
     
-    def initialize reg = nil
-      @register = nil
-    end
   end
 
   class Word < Value
+    def load
+      Machine.instance.word_load self
+    end
   end
   
   class Unsigned < Word
     
-    def + unsigned
+    def plus unsigned
       unless unsigned.is_a? Unsigned
         unsigned = Conversion.new( unsigned , Unsigned )
       end
@@ -44,7 +44,7 @@ module Vm
   end
 
   class Signed < Word
-    def + signed
+    def plus signed
       unless signed.is_a? Signed
         signed = Conversion.new( signed , Signed )
       end
@@ -62,9 +62,22 @@ module Vm
   end
 
   class ObjectReference < Reference
-  end
+    def initialize obj
+      @object = obj
+    end
+    attr_reader :object
     
-  class Byte < Value
+    def compile context
+      if object.is_a? String
+        context.program.add_object object
+      else
+        #TODO define object layout more generally and let objects lay themselves out
+        # as it is the program does this (in the objectwriter/stringtable)
+        un.done
+      end
+    end
   end
 
 end
+
+require_relative "conversion"

test/test_runner.rb

@@ -1,5 +1,5 @@
 require_relative 'helper'
-
+require "yaml"
 class TestRunner < MiniTest::Test
 
   # this creates test methods dynamically , one for each file in runners directory
@@ -25,10 +25,14 @@ class TestRunner < MiniTest::Test
     #link
     # execute
     # check result ?
-    context = Vm::Context.new
-    builder = Asm::Assembler.new
-    compiled = tree.compile( builder , context )
-    puts compiled.inspect
+    program = Vm::Program.new
+    expression = tree.to_value
+    compiled = expression.compile( program.context )
+    # do some stuff with mains and what not ??
+    program.wrap_as_main compiled
+    puts program.to_yaml
+    program.verify
+    puts program.to_yaml
   end
 
 end