Class: CodeTools::AST::Ensure

Inherits:
Node
  • Object
show all
Defined in:
lib/rubinius/code/ast/exceptions.rb

Instance Attribute Summary collapse

Attributes inherited from Node

#line

Instance Method Summary collapse

Methods inherited from Node

#ascii_graph, #attributes, #children, #defined, match_arguments?, match_send?, #new_block_generator, #new_generator, #node_name, #or_bytecode, #pos, #set_child, #transform, transform, transform_comment, transform_kind, transform_kind=, transform_name, #value_defined, #visit, #walk

Constructor Details

#initialize(line, body, ensr) ⇒ Ensure

Returns a new instance of Ensure.



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# File 'lib/rubinius/code/ast/exceptions.rb', line 32

def initialize(line, body, ensr)
  @line = line
  @body = body || NilLiteral.new(line)
  @ensure = ensr
end

Instance Attribute Details

#body ⇒ Object

Returns the value of attribute body.



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# File 'lib/rubinius/code/ast/exceptions.rb', line 30

def body
  @body
end

#ensure ⇒ Object

Returns the value of attribute ensure.



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# File 'lib/rubinius/code/ast/exceptions.rb', line 30

def ensure
  @ensure
end

Instance Method Details

#bytecode(g) ⇒ Object 



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# File 'lib/rubinius/code/ast/exceptions.rb', line 38

def bytecode(g)
  pos(g)

  ok = g.new_label
  ex = g.new_label
  g.setup_unwind ex, EnsureType

  # TODO: ?
  g.new_label.set!

  g.push_exception_state
  outer_exc_state = g.new_stack_local
  g.set_stack_local outer_exc_state
  g.pop

  old_break = g.break
  new_break = g.new_label
  g.break = new_break

  old_next = g.next
  new_next = g.new_label
  g.next = new_next

  g.state.push_ensure
  @body.bytecode(g)
  g.state.pop_ensure

  g.break = old_break
  g.next = old_next

  g.pop_unwind
  g.goto ok

  check_break = nil

  if new_break.used?
    used_break_local = g.new_stack_local
    check_break = g.new_label

    new_break.set!
    g.pop_unwind

    g.push_true
    g.set_stack_local used_break_local
    g.pop

    g.goto check_break
  end

  check_next = nil

  if new_next.used?
    used_next_local = g.new_stack_local
    check_next = g.new_label

    new_next.set!
    g.pop_unwind

    g.push_true
    g.set_stack_local used_next_local
    g.pop

    g.goto check_next
  end

  ex.set!

  g.push_exception_state

  g.state.push_inside_ensure
  g.state.push_rescue(outer_exc_state)
  @ensure.bytecode(g)
  g.state.pop_rescue
  g.pop

  g.restore_exception_state

  # Re-raise the exception
  g.reraise

  # There is no mapping to the original source here, so
  # reflect that in the lines table to try and make it
  # more accurate.
  g.set_line 0

  ok.set!

  if check_break
    g.push_false
    g.set_stack_local used_break_local
    g.pop

    check_break.set!
  end

  if check_next
    g.push_false
    g.set_stack_local used_next_local
    g.pop

    check_next.set!
  end

  # Now, re-emit the code for the ensure which will run if there was no
  # exception generated.
  @ensure.bytecode(g)
  g.pop

  if check_break
    post = g.new_label

    g.push_stack_local used_break_local
    g.goto_if_false post

    if g.break
      g.goto g.break
    else
      g.raise_break
    end
    post.set!
  end

  if check_next
    post = g.new_label

    g.push_stack_local used_next_local
    g.goto_if_false post

    g.next ? g.goto(g.next) : g.ret
    post.set!
  end
  g.state.pop_inside_ensure
end

#to_sexp ⇒ Object 



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# File 'lib/rubinius/code/ast/exceptions.rb', line 172

def to_sexp
  [:ensure, @body.to_sexp, @ensure.to_sexp]
end