ZJIT.exit_locations

# File tmp/rubies/ruby-4.0.0/zjit.rb, line 51
def exit_locations
  return unless trace_exit_locations_enabled?

  results = Primitive.rb_zjit_get_exit_locations
  raw_samples = results[:raw]
  line_samples = results[:lines]
  frames = results[:frames]
  samples_count = 0

  # Use nonexistent.def as a dummy file name.
  frame_template = { samples: 0, total_samples: 0, edges: {}, name: name, file: "nonexistent.def", line: nil, lines: {} }

  # Loop through all possible instructions and setup the frame hash.
  RubyVM::INSTRUCTION_NAMES.each_with_index do |name, frame_id|
    frames[frame_id] = frame_template.dup.tap { |h| h[:name] = name }
  end

  # Loop through the raw_samples and build the hashes for StackProf.
  # The loop is based off an example in the StackProf documentation and therefore
  # this functionality can only work with that library.
  #
  # Raw Samples:
  # [ length, frame1, frame2, frameN, ..., instruction, count
  #
  # Line Samples
  # [ length, line_1, line_2, line_n, ..., dummy value, count
  i = 0
  while i < raw_samples.length
    stack_length = raw_samples[i]
    i += 1 # consume the stack length

    sample_count = raw_samples[i + stack_length]

    prev_frame_id = nil
    stack_length.times do |idx|
      idx += i
      frame_id = raw_samples[idx]

      if prev_frame_id
        prev_frame = frames[prev_frame_id]
        prev_frame[:edges][frame_id] ||= 0
        prev_frame[:edges][frame_id] += sample_count
      end

      frame_info = frames[frame_id]
      frame_info[:total_samples] += sample_count

      frame_info[:lines][line_samples[idx]] ||= [0, 0]
      frame_info[:lines][line_samples[idx]][0] += sample_count

      prev_frame_id = frame_id
    end

    i += stack_length # consume the stack

    top_frame_id = prev_frame_id
    top_frame_line = 1

    frames[top_frame_id][:samples] += sample_count
    frames[top_frame_id][:lines] ||= {}
    frames[top_frame_id][:lines][top_frame_line] ||= [0, 0]
    frames[top_frame_id][:lines][top_frame_line][1] += sample_count

    samples_count += sample_count
    i += 1
  end

  results[:samples] = samples_count

  # These values are mandatory to include for stackprof, but we don't use them.
  results[:missed_samples] = 0
  results[:gc_samples] = 0
  results
end