class SyntaxTree::YARV::BasicBlock

This object represents a single basic block, wherein all contained instructions do not branch except for the last one.

Attributes

block_start [R]

This is the index into the list of instructions where this block starts.

id [R]

This is the unique identifier for this basic block.

incoming_blocks [R]

This is an array of basic blocks that lead into this block.

insns [R]

This is the set of instructions that this block contains.

outgoing_blocks [R]

This is an array of basic blocks that this block leads into.

Public Class Methods

new (block_start, insns)

Source

# File lib/syntax_tree/yarv/basic_block.rb, line 23
def initialize(block_start, insns)
  @id = "block_#{block_start}"

  @block_start = block_start
  @insns = insns

  @incoming_blocks = []
  @outgoing_blocks = []
end

Public Instance Methods

each_with_length () { |insn, length| ... }

Source

# File lib/syntax_tree/yarv/basic_block.rb, line 35
def each_with_length
  return enum_for(:each_with_length) unless block_given?

  length = block_start
  insns.each do |insn|
    yield insn, length
    length += insn.length
  end
end

Yield each instruction in this basic block along with its index from the original instruction sequence.

verify ()

Source

# File lib/syntax_tree/yarv/basic_block.rb, line 48
def verify
  insns[0...-1].each { |insn| raise unless insn.branch_targets.empty? }
end

This method is used to verify that the basic block is well formed. It checks that the only instruction in this basic block that branches is the last instruction.