rubyx/lib/register/assembler.rb
2015-05-28 21:10:27 +03:00

239 lines
8.2 KiB
Ruby

module Register
class LinkException < Exception
end
# Assmble the object space into a binary.
# Link first to get positions, then assemble
# link and assemble functions for each class are close to each other, so to get them the same.
# meaning: as the link function determines the length of an object and the assemble actually writes the bytes
# they are pretty much dependant. In an earlier version they were functions on the objects, but now it
# has gone to a visitor pattern.
class Assembler
TYPE_REF = 0
TYPE_INT = 1
TYPE_BITS = 4
TYPE_LENGTH = 6
def initialize space
@space = space
end
attr_reader :objects
def link
# want to have the methods first in the executable
# so first we determine the code length for the methods and set the
# binary code (array) to right length
@space.objects.each do |objekt|
next unless objekt.is_a? Parfait::Method
objekt.code.set_length(objekt.info.mem_length / 4 , 0)
end
at = 0
# then we make sure we really get the binary codes first
@space.objects.each do |objekt|
next unless objekt.is_a? Parfait::BinaryCode
objekt.set_position at
at += objekt.mem_length
end
# and then everything else
@space.objects.each do | objekt|
# have to tell the code that will be assembled where it is to
# get the jumps/calls right
if objekt.is_a? Parfait::Method
objekt.info.set_position( objekt.code.position )
end
next if objekt.is_a? Parfait::BinaryCode
objekt.set_position at
at += objekt.mem_length
end
end
def assemble
#slightly analogous to the link
begin
link
# first we need to create the binary code for the methods
@space.objects.each do |objekt|
next unless objekt.is_a? Parfait::Method
assemble_binary_method(objekt)
end
@stream = StringIO.new
#TODOmid , main = @objects.find{|k,objekt| objekt.is_a?(Virtual::CompiledMethod) and (objekt.name == :__init__ )}
# initial_jump = @space.init
# initial_jump.codes.each do |code|
# code.assemble( @stream )
# end
# then write the methods to file
@space.objects.each do |objekt|
next unless objekt.is_a? Parfait::BinaryCode
assemble_any( objekt )
end
# and then the rest of the object space
@space.objects.each do | objekt|
next if objekt.is_a? Parfait::BinaryCode
assemble_any( objekt )
end
rescue LinkException
# knowing that we fix the problem, we hope to get away with retry.
retry
end
puts "Assembled 0x#{@stream.length.to_s(16)}/#{@stream.length} bytes"
return @stream.string
end
# assemble the CompiledMethodInfo into a stringio
# and then plonk that binary data into the method.code array
def assemble_binary_method method
stream = StringIO.new
method.info.blocks.each do |block|
block.codes.each do |code|
code.assemble( stream )
end
end
method.code.fill_with 0
index = 1
stream.each_byte do |b|
method.set_char(index , b )
index = index + 1
raise "length error #{method.code.get_length}" if index > method.info.get_length
end
end
def assemble_any obj
puts "Assemble #{obj.class}(\n#{obj.to_s[0..500]}) at stream #{(@stream.length).to_s(16)} pos:#{obj.position.to_s(16)} , len:#{obj.mem_length}"
if @stream.length != obj.position
raise "Assemble #{obj.class} at #{@stream.length.to_s(16)} not #{obj.position.to_s(16)}"
end
clazz = obj.class.name.split("::").last
send("assemble_#{clazz}".to_sym , obj)
obj.position
end
def type_word array
word = 0
array.each_with_index do |var , index|
type = (var.class == Integer) ? TYPE_INT : TYPE_REF
word += type << (index * TYPE_BITS)
end
word += ( (array.length + 1 ) / 8 ) << TYPE_LENGTH * TYPE_BITS
word
end
# write type and layout of the instance, and the variables that are passed
# variables ar values, ie int or refs. For refs the object needs to save the object first
def assemble_self( object , variables )
raise "Object(#{object.object_id}) not linked #{object.inspect}" unless @objects[object.object_id]
type = type_word(variables)
@stream.write_uint32( type )
write_ref_for(object.layout[:names] )
variables.each do |var|
raise object.class.name unless var
write_ref_for(var)
end
pad_after( variables.length * 4 )
object.position
end
def assemble_List array
type = type_word(array)
@stream.write_uint32( type )
write_ref_for(array.layout[:names]) #ref
array.each do |var|
write_ref_for(var)
end
pad_after( array.length * 4 )
array.position
end
def assemble_Dictionary hash
# so here we can be sure to have _identical_ keys/values arrays
assemble_self( hash , [ hash.keys , hash.values ] )
end
def assemble_Space(space)
assemble_self(space , [space.classes,space.objects, space.symbols,space.messages,space.next_message,space.next_frame] )
end
def assemble_Class(clazz)
assemble_self( clazz , [clazz.name , clazz.super_class_name, clazz.instance_methods] )
end
def assemble_Message me
assemble_self(me , [])
end
def assemble_Frame me
assemble_self(me , [])
end
def assemble_Method(method)
count = method.info.blocks.inject(0) { |c , block| c += block.mem_length }
word = (count+7) / 32 # all object are multiple of 8 words (7 for header)
raise "Method too long, splitting not implemented #{method.name}/#{count}" if word > 15
# first line is integers, convention is that following lines are the same
TYPE_LENGTH.times { word = ((word << TYPE_BITS) + TYPE_INT) }
@stream.write_uint32( word )
write_ref_for(method.get_layout()) #ref of layout
# TODO the assembly may have to move to the object to be more extensible
method.blocks.each do |block|
block.codes.each do |code|
code.assemble( @stream )
end
end
pad_after( count )
end
def assemble_String( str )
str = str.string if str.is_a? Parfait::Word
str = str.to_s if str.is_a? Symbol
word = (str.length + 7) / 32 # all object are multiple of 8 words (7 for header)
raise "String too long (implement split string!) #{word}" if word > 15
# first line is integers, convention is that following lines are the same
TYPE_LENGTH.times { word = ((word << TYPE_BITS) + TYPE_INT) }
@stream.write_uint32( word )
write_ref_for( str.layout[:names] ) #ref
@stream.write str
pad_after(str.length)
#puts "String (#{slot.mem_length}) stream #{@stream.mem_length.to_s(16)}"
end
def assemble_Symbol(sym)
return assemble_String(sym)
end
def assemble_StringConstant( sc)
return assemble_String(sc)
end
private
# write means we write the resulting address straight into the assembler stream (ie don't return it)
# object means the object of which we write the address
# and we write the address into the self, given as second parameter
def write_ref_for object
@stream.write_sint32 object.position
end
# objects only come in lengths of multiple of 8 words
# but there is a constant overhead of 2 words, one for type, one for layout
# and as we would have to subtract 1 to make it work without overhead, we now have to add 7
def padded len
a = 32 * (1 + (len + 7)/32 )
#puts "#{a} for #{len}"
a
end
def padded_words words
padded(words*4) # 4 == word length, a constant waiting for a home
end
# pad_after is always in bytes and pads (writes 0's) up to the next 8 word boundary
def pad_after length
pad = padded(length) - length - 8 # for header, type and layout
pad.times do
@stream.write_uint8(0)
end
#puts "padded #{length} with #{pad} stream pos #{@stream.length.to_s(16)}"
end
end
Sof::Volotile.add(Register::Assembler , [:objects])
end