gn analyze output:
{
  "compile_targets": [],
  "status": "No dependency",
  "test_targets": []
}
gn analyze input:
{
  "files": [
    "//libcxx/include/CMakeLists.txt",
    "//libcxx/include/__atomic/atomic_sync_timed.h",
    "//libcxx/include/atomic",
    "//libcxx/include/module.modulemap.in",
    "//libcxx/include/semaphore",
    "//libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist",
    "//libcxx/lib/abi/i686-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist",
    "//libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist",
    "//libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist",
    "//libcxx/lib/abi/x86_64-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist",
    "//libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist",
    "//libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist",
    "//libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist",
    "//libcxx/src/atomic.cpp",
    "//libcxx/test/std/thread/thread.semaphore/lost_wakeup.timed.pass.cpp",
    "//llvm/utils/gn/secondary/libcxx/include/BUILD.gn"
  ],
  "test_targets": [
    "//clang-tools-extra/clangd/test:check-clangd",
    "//clang-tools-extra/test:check-clang-tools",
    "//clang/test:check-clang",
    "//compiler-rt/test/hwasan:check-hwasan",
    "//lld/test:check-lld",
    "//llvm/test:check-llvm"
  ],
  "additional_compile_targets": []
}
running all tests due to change to blacklisted file