rubyx/lib/register/block.rb
2015-10-23 14:08:12 +03:00

62 lines
1.7 KiB
Ruby

module Register
# 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 form a graph, which is managed by the method
class Block
def initialize(name , method )
super()
@method = method
raise "Method is not Method, but #{method.class}" unless method == :__init__ or method.is_a?(Parfait::Method)
@name = name.to_sym
@codes = []
end
attr_reader :name , :codes , :method , :position
def add_code kode
@codes << kode
self
end
# replace a code with an array of new codes. This is what happens in passes all the time
def replace code , new_codes
index = @codes.index code
raise "Code not found #{code} in #{self}" unless index
@codes.delete_at(index)
if( new_codes.is_a? Array)
new_codes.reverse.each {|c| @codes.insert(index , c)}
else
@codes.insert(index , new_codes)
end
end
# position is what another block uses to jump to. this is determined by the assembler
# the assembler allso assembles and assumes a linear instruction sequence
# Note: this will have to change for plocks and maybe anyway.
def set_position at
@position = at
@codes.each do |code|
begin
code.set_position( at)
rescue => e
puts "BLOCK #{self.to_s[0..5000]}"
raise e
end
raise code.inspect unless code.byte_length
at += code.byte_length
end
end
def byte_length
@codes.inject(0){|count , instruction| count += instruction.byte_length }
end
end
end