rubyx/lib/risc/position.rb

48 lines
1.6 KiB
Ruby

module Risc
# Positions are very different during compilation and run-time.
# At run-time they are inherrent to the object, and fixed.
# While during compilation we can move things about, and do not use the
# objects memory position at all.
#
# Furthermore, there are differnet kind of positions during compilation.
# Off course the object position as hinted above, but also instruction
# positions, that do not reflect the position of the object, but of the
# assembled instruction in the binary.
#
# The Position class keeps a hash of all compile time positions.
#
# While the Position objects transmit the change that (re) positioning
# entails to affected objects.
class Position
@positions = {}
def self.positions
@positions
end
def self.position(object)
pos = self.positions[object]
if pos == nil
str = "position accessed but not set, "
str += "0x#{object.object_id.to_s(16)}\n"
str += "for #{object.class} byte_length #{object.byte_length if object.respond_to?(:byte_length)} for #{object.inspect[0...130]}"
raise str
end
pos
end
def self.set_position( object , pos )
raise "Position must be number not :#{pos}:" unless pos.is_a?(Numeric)
# resetting of position used to be error, but since relink and dynamic instruction size it is ok.
# in measures (of 32)
#puts "Setting #{pos} for #{self.class}"
old = Position.positions[object]
if old != nil and ((old - pos).abs > 10000)
raise "position set again #{pos}!=#{old} for #{object}"
end
self.positions[object] = pos
end
end
end