# File lib/mkmf.rb, line 602
def have_library(lib, func = nil, headers = nil, &b)
  func = "main" if !func or func.empty?
  lib = with_config(lib+'lib', lib)
  checking_for checking_message("#{func}()", LIBARG%lib) do
    if COMMON_LIBS.include?(lib)
      true
    else
      libs = append_library($libs, lib)
      if try_func(func, libs, headers, &b)
        $libs = libs
        true
      else
        false
      end
    end
  end
end