Class: Furnace::AVM2::Transform::NFNormalize

Inherits:
Object
  • Object
show all
Includes:
Visitor
Defined in:
lib/furnace-avm2/transform/nf_normalize.rb

Constant Summary collapse

COERCE_MAP = 
{
  :coerce_a => :any,
  :coerce_b => :bool,
  :coerce_s => :string,
}
CONVERT_MAP = 
{
  :convert_i => :integer,
  :convert_u => :unsigned,
  :convert_d => :double,
  :convert_s => :string,
  :convert_o => :object,
}
ForInMatcher = 
AST::Matcher.new do
  [:while,
    [:has_next2, capture(:object_reg), capture(:index_reg)],
    [:begin,
      [ either_multi[
          [ :set_local, capture(:value_reg) ],
          [ :set_slot, capture(:value_reg), [:get_scope_object, 1] ],
        ],
        [ either[:coerce, :convert], capture(:value_type),
          [ capture(:iterator),
            [:get_local, backref(:object_reg)],
            [:get_local, backref(:index_reg)]]]],
      capture_rest(:body)]]
end
ForInIndexMatcher = 
AST::Matcher.new do
  [:set_local, backref(:index_reg), [:integer, 0]]
end
ForInObjectMatcher = 
AST::Matcher.new do
  [:set_local, backref(:object_reg),
    [:coerce, :any,
      capture(:root)]]
end
SuperfluousContinueMatcher = 
AST::Matcher.new do
  [:continue]
end

Instance Method Summary collapse

Instance Method Details

#on_coerce_imm(node) ⇒ Object Also known as: on_coerce_a, on_coerce_b, on_coerce_s 



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# File 'lib/furnace-avm2/transform/nf_normalize.rb', line 31

def on_coerce_imm(node)
  expr, = node.children
  node.update(:coerce, [
    COERCE_MAP[node.type],
    expr
  ])
end

#on_convert_imm(node) ⇒ Object Also known as: on_convert_i, on_convert_u, on_convert_d, on_convert_s, on_convert_o 



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# File 'lib/furnace-avm2/transform/nf_normalize.rb', line 50

def on_convert_imm(node)
  expr, = node.children
  node.update(:convert, [
    CONVERT_MAP[node.type],
    expr
  ])
end

#on_nop(node) ⇒ Object 



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# File 'lib/furnace-avm2/transform/nf_normalize.rb', line 21

def on_nop(node)
  node.update(:remove)
end

#on_while(node) ⇒ Object 



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# File 'lib/furnace-avm2/transform/nf_normalize.rb', line 92

def on_while(node)
  *whatever, code = node.children
  if SuperfluousContinueMatcher.match code.children.last
    code.children.slice! -1
  end

  if captures = ForInMatcher.match(node)
    parent = node.parent

    case captures[:iterator]
    when :next_name
      type = :for_in
    when :next_value
      type = :for_each_in
    else
      return
    end

    index_node = object_node = nil

    loop_index = parent.children.index(node)
    parent.children[0..loop_index].reverse_each do |parent_node|
      if ForInIndexMatcher.match(parent_node, captures)
        index_node  = parent_node
      elsif ForInObjectMatcher.match(parent_node, captures)
        object_node = parent_node
      end

      break if index_node && object_node
    end

    return unless index_node && object_node

    index_node.update(:remove)
    object_node.update(:remove)

    node.update(type, [
      captures[:value_reg],
      captures[:value_type],
      captures[:object_reg],
      AST::Node.new(:begin, captures[:body])
    ])
  end
end

#remove_useless_return ⇒ Object 



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# File 'lib/furnace-avm2/transform/nf_normalize.rb', line 15

def remove_useless_return
  if @nf.children.last.type == :return_void
    @nf.children.slice! -1
  end
end

#transform(nf) ⇒ Object 



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# File 'lib/furnace-avm2/transform/nf_normalize.rb', line 6

def transform(nf)
  @nf = nf.normalize_hierarchy!

  remove_useless_return
  visit @nf

  @nf
end