fixing address resolution cleans up hello world

lib/asm/arm/instruction.rb

@@ -31,7 +31,7 @@ module Asm
         @opcode = opcode.downcase.to_sym
         @args = args
       end
-      attr_reader :opcode, :args
+      attr_reader :opcode, :args , :position
 
       def affect_status
         @s
@@ -55,7 +55,7 @@ module Asm
           builder.cond = COND_CODES[@cond]
           builder.rd = reg_ref(args[0])
           builder.rn = reg_ref(args[1])
-          builder.build_operand args[2]
+          builder.build_operand args[2] , self.position
           builder.assemble io, as
         when :cmn, :cmp, :teq, :tst
           builder = NormalBuilder.new(OPC_DATA_PROCESSING, OPCODES[opcode], 1)

lib/asm/arm/normal_builder.rb

@@ -43,7 +43,14 @@ module Asm
       end
 
       # Build representation for source value
-      def build_operand(arg)
+      def build_operand(arg , position = 0) 
+        #position only needed for calculating relative addresses to data objects
+        #there is a design stink here which makes my head ache. But shanti shanti
+        if arg.is_a?(Asm::DataObject)
+          # do pc relative addressing with the difference to the instuction
+          # 8 is for the funny pipeline adjustment (ie oc pointing to fetch and not execute)
+          arg = Asm::NumLiteralNode.new( arg.position - position - 8 )
+        end
         if (arg.is_a?(Asm::NumLiteralNode))
           if (arg.value.fits_u8?)
             # no shifting needed
@@ -82,10 +89,7 @@ module Asm
           end
       
           @operand = rm_ref | (shift_op << 4) | (shift_imm << 4+3)
-        elsif arg.is_a?(Asm::DataObject)
-          # do pc relative addressing with the difference to the instuction
         else
-          puts "#{self.inspect}"
           raise Asm::AssemblyError.new(Asm::ERRSTR_INVALID_ARG + " " + arg.inspect, arg)
         end
       end

lib/asm/data_object.rb

@@ -4,6 +4,10 @@ module Asm
       @data = data
     end
     
+    def position
+      throw "Not set" unless @address
+      @address 
+    end
     def at address
       @address = address
     end

test/label_test.rb

@@ -1,42 +0,0 @@
-require_relative 'helper'
-
-#try to call an extern function
-
-class TestExtern < MiniTest::Test
-  # need a code generator, for arm 
-  def setup
-    @generator = Asm::Arm::ArmAssembler.new
-  end
-
-  def test_extern
-    hello = "Hello Raisa"+ "\n\x00"
-    @generator.instance_eval {
-      mov r7, 4 #4 == write
-      mov r0 , 1     #stdout
-      add r1 , pc , hello   # address of "hello Raisa"
-      mov r2 , 12 # length of hello
-    	swi 0
-      mov r7, 1   #1 == exit
-    	swi 0
-    }
-    @generator.add_string(hello)
-    write(7 , 'label') 
-  end
-  #helper to write the file
-  def write len ,name
-    writer = Asm::ObjectWriter.new(Elf::Constants::TARGET_ARM)
-    assembly = @generator.assemble_to_string
-    #assert_equal len * 4 , assembly.length 
-    writer.set_text assembly
-    writer.save("#{name}_test.o")    
-  end
-end
-# _start copied from dietc
-#  	mov	fp, #0			@ clear the frame pointer
-#  	ldr	a1, [sp]		@ argc
-#  	add	a2, sp, #4		@ argv
-#  	ldr	ip, .L3
-#  	add	a3, a2, a1, lsl #2	@ &argv[argc]
-#  	add	a3, a3, #4		@ envp	
-#  	str	a3, [ip, #0]		@ environ = envp
-#  	bl	main

test/small_program_test.rb

@@ -12,7 +12,7 @@ class TestSmallProg < MiniTest::Test
     @generator = Asm::Arm::ArmAssembler.new
   end
 
-  def test_generate_small
+  def test_loop
     @generator.instance_eval {
       mov r0, 5                #1
       loop_start = label!
@@ -21,7 +21,21 @@ class TestSmallProg < MiniTest::Test
     	mov r7, 1               #4
     	swi 0                   #5  5 instructions
     }
-    write( 5 , "small" )
+    write( 5 , "loop" )
+  end
+
+  def test_hello
+    hello = "Hello Raisa"+ "\n\x00"
+    @generator.instance_eval {
+      mov r7, 4     # 4 == write
+      mov r0 , 1    # stdout
+      add r1 , pc , hello   # address of "hello Raisa"
+      mov r2 , hello.length
+    	swi 0         #software interupt, ie kernel syscall
+      mov r7, 1     # 1 == exit
+    	swi 0
+    }
+    write(7 , 'label') 
   end
 
   #test dropped along with functionality, didn't work and not needed (yet?) TODO
@@ -51,3 +65,12 @@ class TestSmallProg < MiniTest::Test
     writer.save("#{name}_test.o")    
   end
 end
+# _start copied from dietc
+#  	mov	fp, #0			@ clear the frame pointer
+#  	ldr	a1, [sp]		@ argc
+#  	add	a2, sp, #4		@ argv
+#  	ldr	ip, .L3
+#  	add	a3, a2, a1, lsl #2	@ &argv[argc]
+#  	add	a3, a3, #4		@ envp	
+#  	str	a3, [ip, #0]		@ environ = envp
+#  	bl	main