reduced label mess

lib/asm/arm_assembler.rb

@@ -1,6 +1,5 @@
 require 'asm/arm_assembler'
 require 'asm/instruction'
-require 'asm/generator_label'
 require 'asm/nodes'
 require 'stream_reader'
 require 'stringio'
@@ -38,9 +37,7 @@ module Asm
             arg_nodes << Asm::NumLiteral.new(arg)
           elsif (arg.is_a?(String))
             arg_nodes << add_string(arg)
-          elsif (arg.is_a?(Symbol))
-            arg_nodes << Asm::Label.new(arg.to_s)
-          elsif (arg.is_a?(Asm::GeneratorLabel))
+          elsif (arg.is_a?(Asm::Label))
             arg_nodes << arg
           else
             raise 'Invalid argument `%s\' for instruction' % arg.inspect
@@ -99,14 +96,14 @@ module Asm
         @values << val
       end
     
-      def label
-        label = Asm::GeneratorLabel.new(self)
+      def label name
+        label = Label.new(name , self)
         @labels << label
         label 
       end
 
-      def label!
-        label.set!
+      def label! name
+        label(name).set!
       end
 
       def assemble(io)

lib/asm/generator_label.rb

@@ -1,17 +0,0 @@
-require "asm/label_object"
-
-class Asm::GeneratorLabel < Asm::LabelObject
-  def initialize(asm)
-    @asm = asm
-  end
-  def at pos
-    @position = pos
-  end
-  def length 
-    0
-  end
-  def set!
-    @asm.add_value self
-    self
-  end
-end

lib/asm/instruction.rb

@@ -3,6 +3,7 @@ require "asm/instruction_tools"
 require "asm/normal_builder"
 require "asm/memory_access_builder"
 require "asm/stack_builder"
+require "asm/label"
 
 module Asm
 
@@ -91,18 +92,16 @@ module Asm
           builder.assemble io, as
         when :b, :bl
           arg = args[0]
+          if arg.is_a? Label
+            diff = arg.position - self.position - 8
+            arg = NumLiteral.new(diff)
+          end
           if (arg.is_a?(Asm::NumLiteral))
             jmp_val = arg.value >> 2
             packed = [jmp_val].pack('l')
             # signed 32-bit, condense to 24-bit
             # TODO add check that the value fits into 24 bits
             io << packed[0,3]
-          elsif (arg.is_a?(Asm::LabelObject) or arg.is_a?(Asm::Label))
-            #not yet tested/supported
-#            arg = @ast_asm.object_for_label(arg.label, self) if arg.is_a?(Asm::Label)
-            #write 0 "for now" and let relocation happen
-            raise "not coded #{arg.inspect}"
-            io << "\x00\x00\x00"
           else
             raise "else not coded #{arg.inspect}"
           end

lib/asm/label.rb

@@ -0,0 +1,37 @@
+module Asm
+
+  class Label
+    def initialize(name , asm)
+      @@oh = 1
+      @name = name
+      @asm = asm
+      @position = nil
+    end
+    
+    attr_writer :position , :name
+
+    def position
+      if (@position.nil?)
+        raise 'Tried to use label object that has not been set'
+      end
+      @position
+    end
+    def at pos
+      puts "called #{self}"
+      @position = pos
+    end
+    def length 
+      0
+    end
+
+    def assemble(io, as)
+      self.position = io.tell
+    end
+    def set!
+      @asm.add_value self
+      self
+    end
+
+  end
+
+end

lib/asm/label_object.rb

@@ -1,22 +0,0 @@
-module Asm
-  
-  class LabelObject
-    def initialize
-      @address = nil
-    end
-    attr_writer :address
-
-    def address
-      if (@address.nil?)
-        raise 'Tried to use label object that has not been set'
-      end
-      @address
-    end
-
-    def assemble(io, as)
-      self.address = io.tell
-    end
-
-  end
-
-end

lib/asm/nodes.rb

@@ -40,17 +40,4 @@ module Asm
     end
   end
 
-  class Label 
-    attr_accessor :label, :label_object
-    def initialize label , object = nil
-      @label = label
-      @label_object = object
-    end
-  end
-
-  class ParseError < StandardError
-    def initialize(message, s)
-      super(message)
-    end
-  end
 end

test/small_program_test.rb

@@ -15,9 +15,9 @@ class TestSmallProg < MiniTest::Test
   def test_loop
     @generator.instance_eval {
       mov r0, 5                #1
-      loop_start = label!
+      start = label!(:loop_start)
       subs r0, r0, 1          #2
-      bne loop_start          #3
+      bne start         #3
     	mov r7, 1               #4
     	swi 0                   #5  5 instructions
     }