Module: BiteScript::Bytecode

Includes:

ASM, Signature

Included in:

MethodBuilder

Defined in:

lib/bitescript/bytecode.rb

Overview

Bytecode is a simple adapter around an ASM MethodVisitor that makes it look like JVM assembly code. Included classes must just provide a method_visitor accessor

Defined Under Namespace

Classes: SmartLabel

Constant Summary

JObject =

java.lang.Object

JSystem =

java.lang.System

JPrintStream =

java.io.PrintStream

JVoid =

java.lang.Void

JInteger =

java.lang.Integer

JFloat =

java.lang.Float

JLong =

java.lang.Long

JDobule =

java.lang.Double

OpcodeStackDeltas =

{}

OpcodeInstructions =

{}

Instance Method Summary

• #aprintln ⇒ Object
• #label(id = nil) ⇒ Object
• #labels ⇒ Object
• #line(num) ⇒ Object
• #println(type = JObject) ⇒ Object
• #push_int(num) ⇒ Object
• #start ⇒ Object
• #stop ⇒ Object
• #swap2 ⇒ Object
• #sym_to_label(id) ⇒ Object
• #trycatch(from, to, target, type) ⇒ Object

Methods included from Signature

ci, class_id, classname, path, sig, signature

Instance Method Details

#aprintln ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 378

def aprintln
  println
end

#label(id = nil) ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 364

def label(id = nil)
  if id
    label = labels[id]
    if label
      raise "Duplicate label '#{id}'"
    end
    label = labels[id] = SmartLabel.new(method_visitor)
    label.set!
    label
  else
    return SmartLabel.new(method_visitor)
  end
end

#labels ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 356

def labels
  @labels ||= {}
end

#line(num) ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 393

def line(num)
  if num && num != @line_num
    method_visitor.visit_line_number(num, label.set!.label)
  end
  @line_num = num
end

#println(type = JObject) ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 382

def println(type = JObject)
  getstatic JSystem, "out", JPrintStream
  swap
  invokevirtual JPrintStream, "println", [JVoid::TYPE, type]
end

#push_int(num) ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 400

def push_int(num)
  if (num <= Java::java.lang.Byte::MAX_VALUE && num >= Java::java.lang.Byte::MIN_VALUE)
    case num
    when -1
      iconst_m1
    when 0
      iconst_0
    when 1
      iconst_1
    when 2
      iconst_2
    when 3
      iconst_3
    when 4
      iconst_4
    when 5
      iconst_5
    else
      bipush(num)
    end
  elsif (num <= Java::java.lang.Short::MAX_VALUE && num >= Java::java.lang.Short::MIN_VALUE)
    sipush(num)
  elsif (num <= Java::java.lang.Integer::MAX_VALUE && num >= Java::java.lang.Integer::MIN_VALUE)
    ldc_int(num)
  else
    ldc_long(num)
  end
end

#start ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 320

def start
  method_visitor.visit_code
  @start_label.set!
end

#stop ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 325

def stop
  @end_label.set!
  @locals.each do |name, locals|
    local_debug_info(name, locals[-1], @end_label)
  end
  method_visitor.visit_maxs(1,1)
  method_visitor.visit_end
end

#swap2 ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 388

def swap2
  dup2_x2
  pop2
end

#sym_to_label(id) ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 360

def sym_to_label(id)
  lbl = labels[id] or raise "Unknown label '#{id}'"
end

#trycatch(from, to, target, type) ⇒ Object

# File 'lib/bitescript/bytecode.rb', line 334

def trycatch(from, to, target, type)
  from = sym_to_label(from) if Symbol === from
  to = sym_to_label(to) if Symbol === to
  target = sym_to_label(target) if Symbol === target
  
  method_visitor.visit_try_catch_block(from.label, to.label, target.label, type ? path(type) : nil)
end