class EnvUtil::Debugger

# File lib/envutil.rb, line 136
def command_file(file) "--command=#{file}"; end

# File lib/envutil.rb, line 98
def initialize(name, &block)
  @name = name
  instance_eval(&block)
end

# File lib/envutil.rb, line 94
def self.register(name, &block)
  @list << new(name, &block)
end

# File lib/envutil.rb, line 150
def self.search
  # Cache the result even when no debugger is available, not to probe
  # unusable debuggers repeatedly.
  return @debugger if defined?(@debugger)
  @debugger = @list.find(&:usable?)
end

# File lib/envutil.rb, line 133
def start(pid, *args, **opts)
  spawn(*%W[gdb --batch --quiet --pid #{pid}], *args, **opts)
end

# File lib/envutil.rb, line 132
def usable?; system(*%w[gdb --batch --quiet --nx -ex exit], out: IO::NULL, err: IO::NULL); end

# File lib/envutil.rb, line 107
def dump(pid, timeout: 60, reprieve: timeout&.div(4))
  dpid = start(pid, *command_file(File.join(__dir__, "dump.#{name}")), out: :err)
rescue Errno::ENOENT
  return
else
  return unless dpid
  [[timeout, :TERM], [reprieve, :KILL]].find do |t, sig|
    begin
      return EnvUtil.timeout(t) {Process.wait(dpid)}
    rescue Timeout::Error
      Process.kill(sig, dpid)
    end
  end
  true
end

# File lib/envutil.rb, line 126
def spawn(*args, **opts)
  super(*PRECOMMAND, *args, **opts)
end

# File lib/envutil.rb, line 105
def start(pid, *args) end

# File lib/envutil.rb, line 103
def usable?; false; end