46 lines
1.5 KiB
Ruby
46 lines
1.5 KiB
Ruby
module Risc
|
|
module Position
|
|
|
|
# Instructions are also a linked list, but their position is not really
|
|
# the position of the object.
|
|
# Rather it is the position of the assembled code in the binary.
|
|
# (Luckily arm is sane, so this is realtively simple)
|
|
#
|
|
# Really we only need to calculate Positions at a jump, so between the
|
|
# Jump and the label it jumps too. The other instructions are "just" fill.
|
|
# But off course we need to propagate positions to get it right.
|
|
#
|
|
# Assembled instructions are kept in BinaryCode objects.
|
|
# When propagating positions we have to see that the next position assembles into
|
|
# the same BinaryCode, or else move it and the code along
|
|
#
|
|
class InstructionPosition < ObjectPosition
|
|
attr_reader :instruction , :binary
|
|
def initialize(instruction, pos , binary)
|
|
raise "not set " unless binary
|
|
super(pos, instruction)
|
|
@instruction = instruction
|
|
@binary = binary
|
|
end
|
|
def init(at)
|
|
diff = at - Position.get(@binary).at
|
|
if( diff % 60 == 12*4)
|
|
@binary.extend_one unless @binary.next
|
|
@binary = @binary.next
|
|
raise "end of line " unless @binary
|
|
at = Position.get(@binary).at + 3*4
|
|
end
|
|
return unless instruction.next
|
|
at += instruction.byte_length
|
|
Position.set(instruction.next, at , binary)
|
|
end
|
|
|
|
def reset_to(pos)
|
|
super(pos)
|
|
#puts "Reset (#{changed}) #{instruction}"
|
|
init(pos)
|
|
end
|
|
end
|
|
end
|
|
end
|