llvm/clang/test/Modules/Inputs/PR20399/module.modulemap

module stdlib [system] {
    header "stl_map.h"
    header "vector"
 }

module libCore {
  header "SecondHeader.h"
    use stdlib
  export *
}

module libGdml {
  header "FirstHeader.h"
  use libCore
    use stdlib
  export *
}