gn analyze output:
{
  "compile_targets": [],
  "status": "No dependency",
  "test_targets": []
}
gn analyze input:
{
  "files": [
    "//clang/test/CMakeLists.txt",
    "//clang/test/Tooling/clang-linker-wrapper-spirv-elf.cpp",
    "//clang/test/Tooling/lit.local.cfg",
    "//flang/runtime/CMakeLists.txt",
    "//mlir/test/mlir-tblgen/gen-dialect-doc.td",
    "//mlir/test/mlir-tblgen/gen-pass-doc.td",
    "//mlir/tools/mlir-tblgen/OpDocGen.cpp",
    "//mlir/tools/mlir-tblgen/OpInterfacesGen.cpp",
    "//mlir/tools/mlir-tblgen/PassDocGen.cpp",
    "//utils/bazel/llvm-project-overlay/mlir/test/mlir-tblgen/BUILD.bazel"
  ],
  "test_targets": [
    "//clang-tools-extra/clangd/test:check-clangd",
    "//clang-tools-extra/test:check-clang-tools",
    "//clang/test:check-clang",
    "//lld/test:check-lld",
    "//llvm/test:check-llvm"
  ],
  "additional_compile_targets": []
}