#    This file is part of Metasm, the Ruby assembly manipulation suite
#    Copyright (C) 2006-2009 Yoann GUILLOT
#
#    Licence is LGPL, see LICENCE in the top-level directory


require 'metasm/main'

module Metasm

# a Renderable element has a method #render that returns an array of [String or Renderable]
module Renderable
	def to_s
		render.join
	end

	# yields each Expr seen in #render (recursive)
	def each_expr
		r = proc { |e|
			case e
			when Expression
				yield e
				r[e.lexpr] ; r[e.rexpr]
			when Renderable
				e.render.each { |re| r[re] }
			end
		}
		r[self]
	end
end


class Instruction
	include Renderable
	def render
		@cpu.render_instruction(self)
	end
end

class Label
	include Renderable
	def render
		[@name + ':']
	end
end

class CPU
	# renders an instruction
	# may use instruction-global properties to render an argument (eg specify pointer size if not implicit)
	def render_instruction(i)
		r = []
		r << i.opname
		r << ' '
		i.args.each { |a| r << a << ', ' }
		r.pop
		r
	end

	# ease debugging in irb
	def inspect
		"#<#{self.class}:#{'%x' % object_id} ... >"
	end
end

class Expression
	include Renderable
	attr_accessor :render_info

	# this is an accessor to @@render_int, the lambda used to render integers > 10
	# usage: Expression.render_int = lambda { |e| '0x%x' % e }
	#  or    Expression.render_int { |e| '0x%x' % e }
	# XXX the returned string should be suitable for inclusion in a label name etc
	def self.render_int(&b)
		if b
			@@render_int = b
		else
			@@render_int
		end
	end
	def self.render_int=(p)
 		@@render_int = p
	end
	@@render_int = nil

	def render_integer(e)
		if render_info and @render_info[:char]
			ee = e
			v = []
			while ee > 0
				v << (ee & 0xff)
				ee >>= 8
			end
			v.reverse! if @render_info[:char] == :big
			if not v.empty? and v.all? { |c| c < 0x7f }
				# XXX endianness
				return "'" + v.pack('C*').inspect.gsub("'") { '\\\'' }[1...-1] + "'"
			end
		end
		if e < 0
			neg = true
			e = -e
		end
		if e < 10; e = e.to_s
		elsif @@render_int
			e = @@render_int[e]
		else
			e = '%xh' % e
			e = '0' << e unless (?0..?9).include? e[0]
		end
		e = '-' << e if neg
		e
	end

	NOSQ1 = NOSQ2 = {:* => [:*], :+ => [:+, :-, :*], :- => [:+, :-, :*]}
	NOSQ2[:-] = [:*]
	def render
		l = @lexpr.kind_of?(Integer) ? render_integer(@lexpr) : @lexpr
		r = @rexpr.kind_of?(Integer) ? render_integer(@rexpr) : @rexpr
		l = ['(', l, ')'] if @lexpr.kind_of? Expression and (not oa = NOSQ1[@op] or not oa.include?(@lexpr.op))
		r = ['(', r, ')'] if @rexpr.kind_of? Expression and (not oa = NOSQ2[@op] or not oa.include?(@rexpr.op))
		op = @op if l or @op != :+
		if op == :+
			r0 = [r].flatten.first
			r0 = r0.render.flatten.first while r0.kind_of? Renderable
			op = nil if (r0.kind_of? Integer and r0 < 0) or (r0.kind_of? String and r0[0] == ?-) or r0 == :-
		end
		[l, op, r].compact
	end
end
end