# Copyright 2015 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# ==============================================================================
# TEST SETUP
# ==============================================================================

import("//build/config/chromeos/args.gni")
import("//build/config/chromeos/ui_mode.gni")
import("//build/config/devtools.gni")
import("//build/config/gclient_args.gni")
import("//build/config/rts.gni")
import("//build/rust/rust_static_library.gni")
import("//build_overrides/build.gni")

declare_args() {
  # Some component repos (e.g. ANGLE) import //testing but do not have
  # "location_tags.json", and so we don't want to try and upload the tags
  # for their tests.
  # And, some build configs may simply turn off generation altogether.
  tests_have_location_tags = generate_location_tags

  # Build individual_fuzztest_wrapper if use_fuzztest_wrapper is set.
  # Some projects doesn't have //base and cannot build
  # individual_fuzztest_wrapper.
  use_fuzztest_wrapper = true
}

# On Fuchsia, the test executable has a suffix and is a dependency of the
# common |target_name| target. For `visibility`, the executable must be
# specified. Cross-platform targets that include `test` targets in their
# visibility lists, add `${exec_target_suffix}` immediately after the test
# target name. This is not necessary when the target is a `source_set`.
if (is_fuchsia) {
  exec_target_suffix = "__exec"
} else {
  exec_target_suffix = ""
}

if (is_android) {
  import("//build/android/test_wrapper/logdog_wrapper.gni")
  import("//build/config/android/config.gni")
  import("//build/config/android/create_unwind_table.gni")
  import("//build/config/android/extract_unwind_tables.gni")
  import("//build/config/android/rules.gni")
  import("//build/config/sanitizers/sanitizers.gni")
} else if (is_fuchsia) {
  import("//build/config/fuchsia/generate_runner_scripts.gni")
  import("//third_party/fuchsia-gn-sdk/src/cmc.gni")
  import("//third_party/fuchsia-gn-sdk/src/component.gni")
  import("//third_party/fuchsia-gn-sdk/src/package.gni")
} else if (is_chromeos && is_chromeos_device) {
  import("//build/config/chromeos/rules.gni")
  import("//build/config/sanitizers/sanitizers.gni")
  import("//build/util/generate_wrapper.gni")
} else if (is_ios) {
  import("//build/config/ios/ios_sdk.gni")
  import("//build/config/ios/ios_test_runner_wrapper.gni")
  import("//build/config/ios/rules.gni")
} else {
  import("//build/config/sanitizers/sanitizers.gni")
  import("//build/util/generate_wrapper.gni")
}

# This template represents the core common functionality of a test target
# on each platform. It includes:
# * the ability to generate a rust library that includes all .rs files found
#   in sources and depends on that from the test target.
# * the ability to recognize any declare fuzztests and build runners for them.
template("mixed_test") {
  assert(defined(invoker.target_type) && invoker.target_type != "")

  # The crate_root variable would transform the target into a Rust binary
  # which is incorrect. To not use a generated crate root set:
  # ```
  # test_crate_root = "path/to/root.rs"
  # ```
  assert(!defined(invoker.crate_root))

  _rs_vars = [
    "sources",  # We split this list into two.
    "crate_name",  # Android test template overrides the crate name.
  ]

  if (defined(invoker.sources)) {
    _rs_sources = filter_include(invoker.sources, [ "*.rs" ])
    _cc_sources = filter_exclude(invoker.sources, [ "*.rs" ])
  } else {
    _rs_sources = []
    _cc_sources = []
  }

  if (_rs_sources != []) {
    # Note: as a weak convention, __ is usually used before a suffix for
    # internally-generated targets. However, rust_target requires a strict
    # snake_case name.
    if (defined(invoker.crate_name)) {
      _rust_target_name = "${invoker.crate_name}_rust_objects"
    } else {
      _rust_target_name = "${target_name}_rust_objects"
    }

    # We could automatically add `deps += [ "//testing/rust_gtest_interop" ]`
    # if `rs_sources` is non-empty. But we don't automatically provide
    # //testing/gtest either so it would be asymmetric and could break in that
    # case. So, we act instead as if //testing/rust_gtest_interop is part of
    # the //testing/gtest dependency. If you add one, and have `rs_sources`
    # listed, you get both.
    _gtest_is_in_deps = false
    if (defined(invoker.deps) && invoker.deps != []) {
      foreach(dep, invoker.deps) {
        if (get_label_info(dep, "label_no_toolchain") ==
            "//testing/gtest:gtest") {
          _gtest_is_in_deps = true
        }
      }
    }

    # TODO(danakj): This could be a rust_source_set perhaps, the point being
    # that we need to link in all the .o object files inside the library,
    # instead of dropping unreachable ones during linking (which would drop the
    # tests). Alternatively we could use a special name suffix or other similar
    # trick perhaps to ensure that all object files are linked in here.
    rust_static_library(_rust_target_name) {
      forward_variables_from(invoker,
                             TESTONLY_AND_VISIBILITY + [
                                   "allow_unsafe",
                                   "deps",
                                   "generate_crate_root",
                                   "public_deps",
                                 ])
      configs += [ "//build/rust:test" ]
      if (defined(invoker.test_crate_root)) {
        crate_root = invoker.test_crate_root
      } else {
        generate_crate_root = true
      }
      sources = _rs_sources
      is_gtest_unittests = true

      if (_gtest_is_in_deps) {
        deps += [ "//testing/rust_gtest_interop" ]
      }
    }
  } else {
    not_needed(invoker, _rs_vars)
  }

  if (invoker.target_type == "shared_library_with_jni") {
    # Needed for shared_library_with_jni. Keeping this import guarded so
    # that projects who import //testing but not //third_party/jni_zero
    # don't have issues.
    import("//third_party/jni_zero/jni_zero.gni")
  }

  _building_fuzztest_fuzzer =
      defined(invoker.fuzztests) && use_fuzzing_engine && (is_linux || is_mac)

  # Fuzz tests are small fuzzers that do not require particularly-powerful
  # machines to run, so we do not build them when `high_end_fuzzer_targets`
  # is true and we are building fuzztests in fuzzing mode.
  if (_building_fuzztest_fuzzer && high_end_fuzzer_targets) {
    not_needed(invoker, "*")
    not_needed("*")

    # We still want a reachable target, so make it a no-op empty group. This
    # will let the fuzzer builders crawl the build graph and invoke ninja in
    # the same way regardless of GN args.
    group(target_name) {
    }
  } else {
    target(invoker.target_type, target_name) {
      forward_variables_from(invoker,
                             "*",
                             TESTONLY_AND_VISIBILITY + _rs_vars + [
                                   "fuzztests",
                                   "fuzztest_additional_args",
                                   "libfuzzer_options",
                                   "centipede_options",
                                   "asan_options",
                                   "msan_options",
                                   "ubsan_options",
                                   "environment_variables",
                                   "grammar_options",
                                 ])
      forward_variables_from(invoker, TESTONLY_AND_VISIBILITY)
      sources = _cc_sources
      if (!defined(deps)) {
        deps = []
      }
      if (!defined(ldflags)) {
        ldflags = []
      }

      if (_rs_sources != []) {
        deps += [ ":${_rust_target_name}" ]
      }
      if (defined(invoker.fuzztests)) {
        deps += [
          "//third_party/fuzztest",

          # The following target contains a static initializer which
          # will ensure that the code in base/test:test_support
          # ends up calling through to fuzztest::InitFuzzTest.
          "//testing/libfuzzer:confirm_fuzztest_init",
        ]
      }
    }
  }

  if (_building_fuzztest_fuzzer && !high_end_fuzzer_targets) {
    # This test contains fuzztests. We want to package them up in a way
    # which ClusterFuzz knows how to extract. We need to:
    # 1) make an executable for each individual fuzz test;
    # 2) check that the fuzztests variable is correct.
    # At present, all this is likely to work only if invoker.target_type
    # is 'executable', since we generate a wrapper script that assumes so.
    # At the moment, we aim to fuzz these fuzztests only on Linux so that's
    # fine. In future we may need to broaden this.

    # It makes no sense to have an empty fuzztests variable, let's forbid it.
    assert(invoker.fuzztests != [])
    if (defined(invoker.output_name)) {
      _output_name = invoker.output_name
    } else {
      _output_name = target_name
    }

    _fuzzer_binary_extension = ""
    if (is_win) {
      _fuzzer_binary_extension = ".exe"
    }

    # This will be the actual name of the fuzzer binary generated by
    # `target_name`.
    _fuzzer_binary_name = _output_name + _fuzzer_binary_extension
    _fuzztest_target_name = target_name

    # Additional command-line arguments passed to fuzzer executables, common to
    # all fuzz tests in this executable.
    _common_fuzzer_args = [ "--corpus_database=" ]

    if (defined(invoker.fuzztest_additional_args)) {
      _common_fuzzer_args += invoker.fuzztest_additional_args
    }

    # Confirming that the "fuzztests =" directive is correct can only
    # be done on builds where we can confidently run the fuzzing binary.
    # Let's be conservative about that -- so long as any failures are
    # spotted by at least one CI bot we should be good.
    confirm_fuzztest_contents = is_asan || !using_sanitizer

    if (confirm_fuzztest_contents) {
      # Confirm that the fuzztests GN variable matches with the
      # actual fuzztests in the binary. The output of this action is unused.
      # It just exists to fail the build if there's an error.
      # We only do this on Linux, and not for any sanitizers other than
      # ASAN, because that's specific for CI to show problems and there
      # may be unknown problems running the fuzztest binary on other
      # platforms.
      _fuzztest_check_action = target_name + "__fuzztest_check"
      action(_fuzztest_check_action) {
        deps = [ ":" + _fuzztest_target_name ]
        testonly = true
        script = "//testing/libfuzzer/confirm_fuzztests.py"
        _output_name = "$target_gen_dir/${target_name}__checked.txt"
        outputs = [ _output_name ]

        args = [
                 "--executable",
                 rebase_path(
                     get_label_info(_fuzztest_target_name, "root_out_dir") +
                     "/" + _fuzzer_binary_name),
                 "--output",
                 rebase_path(_output_name),
                 "--fuzztests",
               ] + invoker.fuzztests
      }
    }

    # Make a wrapper executable for each individual fuzz test
    if (use_fuzztest_wrapper) {
      foreach(fuzztest_unit, invoker.fuzztests) {
        _fuzzer_name = target_name + "_" +
                       string_replace(fuzztest_unit, ".", "_") + "_fuzzer"

        # We generate an actual executable because currently our fuzz
        # builder recipes use `gn refs --type=executable` to find things
        # to build. Otherwise we could use generate_wrapper or equivalent
        # to make a python script. We could alter the recipe, or rearrange
        # deps arragenements so that some other executable depends on these
        # scripts, but that seems worse. The executable might be more cross-
        # platform too.
        _fuzztest_generate_fuzzer = _fuzzer_name + "__generate"

        generated_file(_fuzztest_generate_fuzzer + "_constants") {
          outputs = [ "$target_gen_dir/$target_name/constants.cpp" ]

          _fuzzer_args = _common_fuzzer_args + [ "--fuzz=${fuzztest_unit}" ]

          fuzzer_args_joined = string_join(" ", _fuzzer_args)

          NEWLINE = "$0x0A"

          contents =
              "const char* kFuzzerArgs = \"${fuzzer_args_joined}\";" + NEWLINE +
              "const char* kFuzzerBinary = \"${_fuzzer_binary_name}\";" +
              NEWLINE
        }

        _additional_fuzz_deps = []
        gen_fuzzer_config_args = []

        if (defined(invoker.libfuzzer_options)) {
          gen_fuzzer_config_args += [ "--libfuzzer_options" ]
          gen_fuzzer_config_args += invoker.libfuzzer_options
        }

        if (defined(invoker.centipede_options)) {
          gen_fuzzer_config_args += [ "--centipede_options" ]
          gen_fuzzer_config_args += invoker.centipede_options
        }

        if (defined(invoker.asan_options)) {
          gen_fuzzer_config_args += [ "--asan_options" ]
          gen_fuzzer_config_args += invoker.asan_options
        }

        if (defined(invoker.msan_options)) {
          gen_fuzzer_config_args += [ "--msan_options" ]
          gen_fuzzer_config_args += invoker.msan_options
        }

        if (defined(invoker.ubsan_options)) {
          gen_fuzzer_config_args += [ "--ubsan_options" ]
          gen_fuzzer_config_args += invoker.ubsan_options
        }

        if (defined(invoker.environment_variables)) {
          gen_fuzzer_config_args += [ "--environment_variables" ]
          gen_fuzzer_config_args += invoker.environment_variables
        }

        if (defined(invoker.grammar_options)) {
          gen_fuzzer_config_args += [ "--grammar_options" ]
          gen_fuzzer_config_args += invoker.grammar_options
        }

        if (gen_fuzzer_config_args != []) {
          _config_file_name = _fuzzer_name + ".options"
          _additional_fuzz_deps += [ ":" + _config_file_name ]

          # Generate .options file.
          action(_config_file_name) {
            script = "//testing/libfuzzer/gen_fuzzer_config.py"
            args = [
              "--config",
              rebase_path("$root_build_dir/" + _config_file_name,
                          root_build_dir),
            ]

            args += gen_fuzzer_config_args

            outputs = [ "$root_build_dir/$_config_file_name" ]
          }
        }

        _fuzzer_target_name = target_name
        executable(_fuzztest_generate_fuzzer) {
          testonly = true
          data_deps = [
                        ":" + _fuzztest_target_name,
                        ":" + _fuzzer_target_name,
                      ] + _additional_fuzz_deps
          deps = [
            "//testing/libfuzzer:individual_fuzztest_wrapper",
            ":" + _fuzztest_generate_fuzzer + "_constants",
          ]
          if (confirm_fuzztest_contents) {
            deps += [ ":" + _fuzztest_check_action ]
          }
          output_name = _fuzzer_name
          sources =
              get_target_outputs(":" + _fuzztest_generate_fuzzer + "_constants")
          write_runtime_deps = "$root_build_dir/${_fuzzer_name}.runtime_deps"
        }
      }
    } else {
      not_needed([
                   "_common_fuzzer_args",
                   "_fuzzer_binary_name",
                   "_fuzztest_target_name",
                 ])
    }
  }
}

# Define a test as an executable (or apk on Android) with the "testonly" flag
# set.
# Variable:
#   use_xvfb: (optional) whether to run the executable under Xvfb.
#   use_raw_android_executable: Use executable() rather than android_apk().
#   use_native_activity: Test implements ANativeActivity_onCreate().
#   test_runner_shard: (Fuchsia, optional): for CFv2 tests, use the given test
#      runner shard rather than the default shard for the ELF runner when
#      assembling the test component. This is useful, for example, to use the
#      elf_test_ambient_exec_runner for tests that require
#      job_policy_ambient_mark_vmo_exec.
#   fuchsia_package_deps: (Fuchsia, optional) List of fuchsia_component()
#      targets that this test package contains.
#   is_xctest: (iOS, optional) whether to build the executable as XCTest.
#      Similar to the GN arg 'enable_run_ios_unittests_with_xctest' but
#      for build targets.
#   allow_cleartext_traffic: (Android, optional) whether to allow cleartext
#      network requests during the test.
#   fuzztests: a list of instances of the FUZZ_TEST macro to
#      include fuzzing tests alongside unit tests. This introduces an
#      extra dependency and also creates additional metadata so that our
#      fuzzing infrastructure can find and run such tests.
#      This should be a list of the test names, for example
#      fuzztests = [ "MyTestClass.MyTestName" ]
#   fuzztest_additional_args: additional arguments to be forwarded to fuzztest.
template("test") {
  # Ensures a test filter file exists and if not, creates a dummy file.
  # The Regression Test Selection (rts) flag is passed in mb.py and used
  # to filter out test cases. Flag ensures that a file exists.
  if (use_rts) {
    action("${target_name}__rts_filters") {
      script = "//build/add_rts_filters.py"
      rts_file = "${root_build_dir}/gen/rts/${invoker.target_name}.filter"
      args = [ rebase_path(rts_file, root_build_dir) ]
      outputs = [ rts_file ]
    }
  }
  testonly = true
  if (!is_ios) {
    assert(!defined(invoker.is_xctest) || !invoker.is_xctest,
           "is_xctest can be set only for iOS builds")
  }
  if (!is_android) {
    assert(!defined(invoker.allow_cleartext_traffic),
           "allow_cleartext_traffic can be set only for Android tests")
  }

  if (is_android) {
    assert(!defined(invoker.use_xvfb) || !invoker.use_xvfb)

    _use_default_launcher =
        !defined(invoker.use_default_launcher) || invoker.use_default_launcher
    if (!defined(invoker.use_raw_android_executable)) {
      # Checkouts where build_with_chromium == false often have a custom GN
      # template wrapper around test() which sets use_default_launcher == false.
      # Set the _use_raw_android_executable default so that test() targets which
      # do not use the custom wrapper
      # (1) Do not cause "gn gen" to fail
      # (2) Do not need to be moved into if(build_with_chromium) block.
      _use_raw_android_executable =
          !build_with_chromium && _use_default_launcher
    } else {
      not_needed([ "_use_default_launcher" ])
      _use_raw_android_executable = invoker.use_raw_android_executable
    }

    # output_name is used to allow targets with the same name but in different
    # packages to still produce unique runner scripts.
    _output_name = invoker.target_name
    if (defined(invoker.output_name)) {
      _output_name = invoker.output_name
    }

    _test_runner_target = "${_output_name}__test_runner_script"
    _wrapper_script_vars = [
      "additional_apks",
      "android_test_runner_script",
      "extra_args",
      "ignore_all_data_deps",
      "shard_timeout",
    ]

    assert(_use_raw_android_executable || enable_java_templates)

    if (_use_raw_android_executable) {
      not_needed(invoker, [ "add_unwind_tables_in_apk" ])

      _exec_target = "${target_name}__exec"
      _dist_target = "${target_name}__dist"
      _exec_output =
          "$target_out_dir/${invoker.target_name}/${invoker.target_name}"
      _crate_name = "${target_name}"

      mixed_test(_exec_target) {
        target_type = "executable"

        # Use a crate name that avoids creating a warning due to double
        # underscore (ie. `__`).
        crate_name = _crate_name

        # Configs will always be defined since we set_defaults in
        # BUILDCONFIG.gn.
        configs = []
        forward_variables_from(
            invoker,
            "*",
            TESTONLY_AND_VISIBILITY + _wrapper_script_vars + [
                  "data_deps",
                  "extra_dist_files",
                ])

        # Thanks to the set_defaults() for test(), configs are initialized with
        # the default shared_library configs rather than executable configs.
        configs -= [
          "//build/config:shared_library_config",
          "//build/config/android:hide_all_but_jni",
        ]
        configs += [ "//build/config:executable_config" ]

        if (defined(invoker.data_deps)) {
          data_deps = invoker.data_deps
        } else {
          data_deps = []
        }
        if (!defined(data)) {
          data = []
        }
        if (tests_have_location_tags) {
          data += [ "//testing/location_tags.json" ]
        }
        if (!defined(deps)) {
          deps = []
        }

        # Don't output to the root or else conflict with the group() below.
        output_name = rebase_path(_exec_output, root_out_dir)

        if (use_rts) {
          data_deps += [ ":${invoker.target_name}__rts_filters" ]
        }
      }

      create_native_executable_dist(_dist_target) {
        dist_dir = "$root_out_dir/$target_name"
        binary = _exec_output
        deps = [ ":$_exec_target" ]
        if (defined(invoker.extra_dist_files)) {
          extra_files = invoker.extra_dist_files
        }
        if (use_rts) {
          if (!defined(data_deps)) {
            data_deps = []
          }
          data_deps += [ ":${invoker.target_name}__rts_filters" ]
        }
      }
    } else {
      _library_target_name = "${target_name}__library"
      _library_crate_name = "${target_name}_library"
      _apk_target_name = "${target_name}__apk"
      _apk_specific_vars = [
        "allow_cleartext_traffic",
        "android_manifest",
        "android_manifest_dep",
        "android_manifest_template",
        "app_as_shared_lib",
        "keystore_name",
        "keystore_password",
        "keystore_path",
        "library_always_compress",
        "loadable_module_deps",
        "loadable_modules",
        "min_sdk_version",
        "product_config_java_packages",
        "proguard_configs",
        "proguard_enabled",
        "srcjar_deps",
        "target_sdk_version",
        "use_default_launcher",
        "use_native_activity",
      ]

      _add_unwind_tables_in_apk =
          defined(invoker.add_unwind_tables_in_apk) &&
          invoker.add_unwind_tables_in_apk && target_cpu == "arm"

      # Adds the unwind tables from unstripped binary as an asset file in the
      # apk, if |add_unwind_tables_in_apk| is specified by the test.
      if (_add_unwind_tables_in_apk) {
        # TODO(crbug.com/40833600): Remove generation of v1 unwind asset when
        # `CFIBacktraceAndroid` is replaced with `ChromeUnwinderAndroid`.
        _unwind_table_name = "${_library_target_name}_unwind_v1"
        unwind_table_v1(_unwind_table_name) {
          library_target = ":$_library_target_name"
        }

        if (use_android_unwinder_v2) {
          _unwind_table_v2_name = "${_library_target_name}_unwind_v2"
          unwind_table_v2(_unwind_table_v2_name) {
            library_target = ":$_library_target_name"
          }
        }

        _unwind_table_asset_name = "${target_name}__unwind_assets"
        android_assets(_unwind_table_asset_name) {
          sources = [ "$target_out_dir/$_unwind_table_name/$unwind_table_asset_v1_filename" ]
          disable_compression = true
          deps = [ ":$_unwind_table_name" ]
          if (use_android_unwinder_v2) {
            sources += [ "$target_out_dir/$_unwind_table_v2_name/$unwind_table_asset_v2_filename" ]
            deps += [ ":$_unwind_table_v2_name" ]
          }
        }
      }

      _generate_final_jni =
          !defined(invoker.generate_final_jni) || invoker.generate_final_jni
      mixed_test(_library_target_name) {
        if (_generate_final_jni) {
          target_type = "shared_library_with_jni"
          java_targets = [ ":$_apk_target_name" ]
        } else {
          target_type = "shared_library"
        }

        # Configs will always be defined since we set_defaults in
        # BUILDCONFIG.gn.
        configs = []  # Prevent list overwriting warning.
        configs = invoker.configs

        forward_variables_from(
            invoker,
            "*",
            [
                  "configs",
                  "deps",
                ] + _apk_specific_vars + _wrapper_script_vars +
                TESTONLY_AND_VISIBILITY)

        # Use a crate name that avoids creating a warning due to double
        # underscore (ie. `__`).
        crate_name = _library_crate_name

        # Native targets do not need to depend on java targets. Filter them out
        # so that the shared library can be built without needing to wait for
        # dependent java targets.
        if (!defined(deps)) {
          deps = []
        }
        if (defined(invoker.deps)) {
          deps += filter_exclude(invoker.deps, java_target_patterns)
        }

        if (_use_default_launcher) {
          deps += [ "//testing/android/native_test:native_test_native_code" ]
        }
      }
      unittest_apk(_apk_target_name) {
        forward_variables_from(invoker, _apk_specific_vars)
        shared_library = ":$_library_target_name"
        if (_generate_final_jni) {
          srcjar_deps = [ "${shared_library}__jni_registration" ]
        }
        apk_name = invoker.target_name
        if (defined(invoker.output_name)) {
          apk_name = invoker.output_name
        }

        if (defined(invoker.deps)) {
          deps = invoker.deps
        } else {
          deps = []
        }
        if (defined(loadable_module_deps)) {
          deps += loadable_module_deps
        }

        # Add the Java classes so that each target does not have to do it.
        if (_use_default_launcher) {
          deps += [ "//base/test:test_support_java" ]
        }

        if (defined(_unwind_table_asset_name)) {
          deps += [ ":${_unwind_table_asset_name}" ]
        }

        if (use_rts) {
          data_deps = [ ":${invoker.target_name}__rts_filters" ]
        }
      }
    }

    test_runner_script(_test_runner_target) {
      forward_variables_from(invoker, _wrapper_script_vars)

      if (_use_raw_android_executable) {
        executable_dist_dir = "$root_out_dir/$_dist_target"
        data_deps = [ ":$_exec_target" ]
      } else {
        apk_target = ":$_apk_target_name"
        incremental_apk = incremental_install

        # Dep needed for the test runner .runtime_deps file to pick up data
        # deps from the forward_variables_from(invoker, "*") on the library.
        data_deps = [ ":$_library_target_name" ]
      }
      test_name = _output_name
      test_suite = _output_name
      test_type = "gtest"
      if (use_rts) {
        data_deps += [ ":${invoker.target_name}__rts_filters" ]
      }
    }

    # Create a wrapper script rather than using a group() in order to ensure
    # "ninja $target_name" always works. If this was a group(), then GN would
    # not create a top-level alias for it if a target exists in another
    # directory with the same $target_name.
    # Also - bots run this script directly for "components_perftests".
    generate_wrapper(target_name) {
      forward_variables_from(invoker, [ "visibility" ])
      executable = "$root_build_dir/bin/run_$_output_name"
      wrapper_script = "$root_build_dir/$_output_name"
      deps = [ ":$_test_runner_target" ]
      if (_use_raw_android_executable) {
        deps += [ ":$_dist_target" ]
      } else {
        # Dep needed for the swarming .isolate file to pick up data
        # deps from the forward_variables_from(invoker, "*") on the library.
        deps += [
          ":$_apk_target_name",
          ":$_library_target_name",
        ]
      }

      if (defined(invoker.data_deps)) {
        data_deps = invoker.data_deps
      } else {
        data_deps = []
      }

      data_deps += [ "//testing:test_scripts_shared" ]

      if (tests_have_location_tags) {
        data = [ "//testing/location_tags.json" ]
      }
      if (use_rts) {
        data_deps += [ ":${invoker.target_name}__rts_filters" ]
      }
    }
  } else if (is_fuchsia) {
    assert(!defined(invoker.use_xvfb) || !invoker.use_xvfb)

    _output_name = invoker.target_name
    _pkg_target = "${_output_name}_pkg"
    _exec_target = "${_output_name}__exec"
    _program_name = get_label_info(":${_exec_target}", "name")
    _crate_name = _output_name

    # Generate a CML fragment that provides the program name.
    _test_program_fragment_target = "${target_name}_program-fragment"
    _test_program_fragment = "${target_out_dir}/${target_name}_program.test-cml"
    generated_file(_test_program_fragment_target) {
      contents = {
        program = {
          binary = _program_name
        }
      }
      outputs = [ _test_program_fragment ]
      output_conversion = "json"
    }

    _test_runner_shard =
        "//build/config/fuchsia/test/elf_test_runner.shard.test-cml"
    if (defined(invoker.test_runner_shard)) {
      _test_runner_shard = invoker.test_runner_shard
    }

    # Collate the complete set of elements to include in the test component's
    # manifest.

    _manifest_fragments = [
      _test_program_fragment,
      _test_runner_shard,
    ]

    _subpackages = []

    # Select the Fuchsia test realm in which to run the test.
    if (defined(invoker.run_as_chromium_system_test) &&
        invoker.run_as_chromium_system_test) {
      _manifest_fragments += [
        "//build/config/fuchsia/test/chromium_system_test_facet.shard.test-cml",
        "//build/config/fuchsia/test/system_test_minimum.shard.test-cml",
      ]
    } else {
      _subpackages += [
        "//third_party/fuchsia-sdk/sdk/packages/fake-build-info:fake-build-info",
        "//third_party/fuchsia-sdk/sdk/packages/intl_property_manager:intl_property_manager",
      ]
      _manifest_fragments += [
        "//build/config/fuchsia/test/chromium_test_facet.shard.test-cml",
        "//build/config/fuchsia/test/minimum.shard.test-cml",
      ]
    }

    if (is_asan) {
      # TODO(crbug.com/40276216): Remove the extra cml segment for asan.
      _manifest_fragments +=
          [ "//build/config/fuchsia/test/asan_options.shard.test-cml" ]
    }

    _test_component_manifest = "${target_out_dir}/${target_name}.cml"
    _merged_manifest_name = "${_output_name}.cml"

    if (defined(invoker.additional_manifest_fragments)) {
      _manifest_fragments += invoker.additional_manifest_fragments
    }

    # Generate the test component manifest from the specified elements.
    _test_component_manifest_target = "${target_name}_component-manifest"
    cmc_merge(_test_component_manifest_target) {
      sources = _manifest_fragments
      output_name = "${_merged_manifest_name}"
      deps = [ ":${_test_program_fragment_target}" ]
    }

    # Define the test component, dependent on the generated manifest, and the
    # test executable target.
    _test_component_target = "${target_name}_component"
    fuchsia_component(_test_component_target) {
      deps = [ ":$_test_component_manifest_target" ]
      data_deps = [ ":$_exec_target" ]
      manifest = _test_component_manifest
      visibility = [ ":*" ]
    }

    _test_component_targets = [ ":${_test_component_target}" ]

    # Define components for each entry in |additional_manifests|, if any. Since
    # manifests may themselves depend-on the outputs of |deps|, these components
    # must each individually depend on |invoker.deps|.
    if (defined(invoker.additional_manifests)) {
      foreach(filename, invoker.additional_manifests) {
        _additional_component_target =
            target_name + "_" + get_path_info(filename, "name")
        _test_component_targets += [ ":${_additional_component_target}" ]
        fuchsia_component(_additional_component_target) {
          forward_variables_from(invoker, [ "testonly" ])
          data_deps = [ ":$_exec_target" ]
          visibility = [ ":*" ]
          manifest = filename

          # Depend on |invoker.deps|, in case it includes a dependency that
          # creates this additional component's manifest.
          if (defined(invoker.deps)) {
            deps = invoker.deps
          }
        }
      }
    }

    # Define the package target that will bundle the test and additional
    # components and their data.
    fuchsia_package(_pkg_target) {
      forward_variables_from(invoker,
                             [
                               "excluded_files",
                               "excluded_dirs",
                               "excluded_paths",
                             ])
      package_name = _output_name
      deps = _test_component_targets

      if (defined(invoker.fuchsia_package_deps)) {
        deps += invoker.fuchsia_package_deps
      }
      if (!defined(excluded_paths)) {
        excluded_paths = []
      }
      excluded_paths += [
        "${devtools_root_location}/*",
        "*.git/*",
        "*.svn/*",
        "*.hg/*",
      ]
      if (devtools_root_location != "") {
        excluded_paths += [ "${devtools_root_location}/*" ]
      }

      subpackages = _subpackages
    }

    # |target_name| refers to the package-runner rule, so that building
    # "base_unittests" will build not only the executable, component, and
    # package, but also the script required to run them.
    fuchsia_test_runner(target_name) {
      forward_variables_from(invoker,
                             [
                               "data",
                               "data_deps",
                               "package_deps",
                               "use_test_server",
                             ])

      is_test_exe = true
      package = ":$_pkg_target"
      package_name = _output_name

      if (!defined(deps)) {
        deps = []
      }
      if (defined(invoker.deps)) {
        deps += invoker.deps
      }

      if (!defined(data)) {
        data = []
      }
      if (tests_have_location_tags) {
        data += [ "//testing/location_tags.json" ]
      }

      if (!defined(data_deps)) {
        data_deps = []
      }

      data_deps += [ "//testing:test_scripts_shared" ]
    }

    mixed_test(_exec_target) {
      target_type = "executable"
      forward_variables_from(invoker, "*", TESTONLY_AND_VISIBILITY)
      output_name = _exec_target

      if (!defined(deps)) {
        deps = []
      }

      # Use a crate name that avoids creating a warning due to double
      # underscore (ie. `__`).
      crate_name = _crate_name
    }
  } else if (is_ios) {
    assert(!defined(invoker.use_xvfb) || !invoker.use_xvfb)
    _runtime_deps_file = "$root_out_dir/${target_name}.runtime_deps"

    declare_args() {
      # Keep the unittest-as-xctest functionality defaulted to off for
      # local builds and test executions.
      enable_run_ios_unittests_with_xctest = false
    }

    _test_target = target_name

    _wrapper_output_name = "run_${target_name}"
    ios_test_runner_wrapper(_wrapper_output_name) {
      forward_variables_from(invoker,
                             [
                               "clones",
                               "data",
                               "deps",
                               "executable_args",
                               "retries",
                             ])

      _root_build_dir = rebase_path("${root_build_dir}", root_build_dir)

      if (!defined(executable_args)) {
        executable_args = []
      }
      executable_args += [
        "--app",
        "@WrappedPath(${_root_build_dir}/${_test_target}.app)",
      ]

      wrapper_output_name = "${_wrapper_output_name}"

      if (!defined(data)) {
        data = []
      }
      if (tests_have_location_tags) {
        data += [ "//testing/location_tags.json" ]
      }
    }

    _resources_bundle_data = target_name + "_resources_bundle_data"

    bundle_data(_resources_bundle_data) {
      visibility = [ ":$_test_target" ]
      sources = [ "//testing/gtest_ios/Default.png" ]
      outputs = [ "{{bundle_resources_dir}}/{{source_file_part}}" ]
    }

    force_xctest = enable_run_ios_unittests_with_xctest ||
                   (defined(invoker.is_xctest) && invoker.is_xctest)

    mixed_test(_test_target) {
      if (force_xctest) {
        target_type = "ios_xctest_test"
      } else {
        target_type = "ios_app_bundle"
      }
      testonly = true

      if (force_xctest && build_with_chromium) {
        xctest_module_target = "//base/test:google_test_runner"
      }

      forward_variables_from(invoker, "*", TESTONLY_AND_VISIBILITY)

      # Provide sensible defaults in case invoker did not define any of those
      # required variables.
      if (!defined(info_plist) && !defined(info_plist_target)) {
        info_plist = "//testing/gtest_ios/unittest-Info.plist"
      }

      bundle_identifier = shared_bundle_id_for_test_apps

      if (!defined(bundle_deps)) {
        bundle_deps = []
      }
      bundle_deps += [ ":$_resources_bundle_data" ]

      if (!defined(data_deps)) {
        data_deps = []
      }

      data_deps += [ "//testing:test_scripts_shared" ]

      # Include the generate_wrapper as part of data_deps
      data_deps += [ ":${_wrapper_output_name}" ]
      write_runtime_deps = _runtime_deps_file
      if (use_rts) {
        data_deps += [ ":${invoker.target_name}__rts_filters" ]
      }
      if (!defined(deps)) {
        deps = []
      }
    }
  } else if (is_chromeos && cros_board != "") {
    assert(!defined(invoker.use_xvfb) || !invoker.use_xvfb)

    # Building for a cros board (ie: not linux-chromeos).

    _gen_runner_target = "${target_name}__runner"
    _runtime_deps_file =
        "$root_out_dir/gen.runtime/" + get_label_info(target_name, "dir") +
        "/" + get_label_info(target_name, "name") + ".runtime_deps"

    if (is_skylab && (defined(tast_attr_expr) || defined(tast_tests) ||
                      defined(tast_disabled_tests))) {
      generate_skylab_tast_filter(_gen_runner_target) {
      }
    } else {
      generate_runner_script(_gen_runner_target) {
        generated_script = "$root_build_dir/bin/run_" + invoker.target_name
        test_exe = invoker.target_name
        runtime_deps_file = _runtime_deps_file

        if (tests_have_location_tags) {
          data = [ "//testing/location_tags.json" ]
        }
        if (use_rts) {
          data_deps = [ ":${invoker.target_name}__rts_filters" ]
        }
      }
    }

    mixed_test(target_name) {
      target_type = "executable"
      forward_variables_from(invoker, "*", TESTONLY_AND_VISIBILITY)
      forward_variables_from(invoker, [ "visibility" ])
      if (!defined(deps)) {
        deps = []
      }
      if (!defined(data)) {
        data = []
      }

      # We use a special trigger script for CrOS hardware tests.
      data += [ "//testing/trigger_scripts/chromeos_device_trigger.py" ]

      write_runtime_deps = _runtime_deps_file
      data += [ _runtime_deps_file ]
      deps += [ ":$_gen_runner_target" ]

      if (!defined(data_deps)) {
        data_deps = []
      }

      data_deps += [ "//testing:test_scripts_shared" ]
      if (use_rts) {
        data_deps += [ ":${invoker.target_name}__rts_filters" ]
      }
    }
  } else if (!is_nacl) {
    if (is_mac || is_win) {
      assert(!defined(invoker.use_xvfb) || !invoker.use_xvfb)
    }

    _runtime_deps_file = "$root_out_dir/${target_name}.runtime_deps"
    _executable = target_name
    _gen_runner_target = "${target_name}__runner"

    if ((is_linux || is_chromeos) && defined(invoker.use_xvfb)) {
      _use_xvfb = invoker.use_xvfb
    } else {
      _use_xvfb = false
    }

    generate_wrapper(_gen_runner_target) {
      wrapper_script = "$root_build_dir/bin/run_" + _executable

      data = []
      data_deps = [ "//testing:test_scripts_shared" ]

      if (_use_xvfb) {
        executable = "//testing/xvfb.py"
      } else {
        executable = "//testing/test_env.py"
      }
      if (tests_have_location_tags) {
        data += [ "//testing/location_tags.json" ]
      }

      executable_args = [
        "@WrappedPath(./${_executable})",
        "--test-launcher-bot-mode",
      ]
      if (is_asan) {
        executable_args += [ "--asan=1" ]
      }
      if (is_msan) {
        executable_args += [ "--msan=1" ]
      }
      if (is_tsan) {
        executable_args += [ "--tsan=1" ]
      }
      if (use_cfi_diag) {
        executable_args += [ "--cfi-diag=1" ]
      }
      if (fail_on_san_warnings) {
        executable_args += [ "--fail-san=1" ]
      }
      if (use_rts) {
        data_deps += [ ":${invoker.target_name}__rts_filters" ]
      }
    }

    mixed_test(target_name) {
      target_type = "executable"
      forward_variables_from(invoker,
                             "*",
                             TESTONLY_AND_VISIBILITY + [ "use_xvfb" ])
      forward_variables_from(invoker, [ "visibility" ])
      if (!defined(deps)) {
        deps = []
      }

      deps += [
        # Give tests the default manifest on Windows (a no-op elsewhere).
        "//build/win:default_exe_manifest",
      ]

      write_runtime_deps = _runtime_deps_file
      deps += [ ":$_gen_runner_target" ]

      if (!defined(data_deps)) {
        data_deps = []
      }

      data_deps += [ "//testing:test_scripts_shared" ]
      if (use_rts) {
        data_deps += [ ":${invoker.target_name}__rts_filters" ]
      }
    }
  } else {
    # This is a catch-all clause for NaCl toolchains and other random
    # configurations that might define tests; test() in these configs
    # will just define the underlying executables.
    assert(!defined(invoker.use_xvfb) || !invoker.use_xvfb,
           "use_xvfb should not be defined for a non-linux configuration")
    mixed_test(target_name) {
      target_type = "executable"
      forward_variables_from(invoker, "*", TESTONLY_AND_VISIBILITY)
      forward_variables_from(invoker, [ "visibility" ])
      if (!defined(deps)) {
        deps = []
      }

      if (!defined(data_deps)) {
        data_deps = []
      }

      data_deps += [ "//testing:test_scripts_shared" ]
      if (use_rts) {
        data_deps += [ ":${invoker.target_name}__rts_filters" ]
      }
    }
  }
}

# Defines a type of test that invokes a script to run, rather than
# invoking an executable.
#
# The script must implement the
# [test executable API](//docs/testing/test_executable_api.md).
#
# The template must be passed the `script` parameter, which specifies the path
# to the script to run. It may optionally be passed a `args` parameter, which
# can be used to include a list of args to be specified by default. The
# template will produce a `$root_build_dir/run_$target_name` wrapper and write
# the runtime_deps for the target to
# $root_build_dir/${target_name}.runtime_deps, as per the conventions listed in
# the [test wrapper API](//docs/testing/test_wrapper_api.md).
#
# Variables:
#   script: Path to underlying test script.
#   args: Args to the test script.
#   enable_android_wrapper: (optional) If true, the test will get wrapped in the
#       logdog_wrapper on Android, which will stream logcats from the device.
#   enable_cros_wrapper: (optional) If true, the test will get wrapped by the
#       cros_test_wrapper on ChromeOS, which will prep the device for testing.
template("script_test") {
  _enable_logdog_wrapper = defined(invoker.enable_android_wrapper) &&
                           invoker.enable_android_wrapper && is_android
  _enable_cros_wrapper =
      defined(invoker.enable_cros_wrapper) && invoker.enable_cros_wrapper &&
      is_chromeos && is_chromeos_device
  assert(!(_enable_logdog_wrapper && _enable_cros_wrapper),
         "The logdog and cros_test wrappers are mutually exclusive")

  if (use_rts) {
    action("${target_name}__rts_filters") {
      script = "//build/add_rts_filters.py"
      rts_file = "${root_build_dir}/gen/rts/${invoker.target_name}.filter"
      args = [ rebase_path(rts_file, root_build_dir) ]
      outputs = [ rts_file ]
    }
  }

  _shared_data = [ invoker.script ]
  if (defined(invoker.data)) {
    _shared_data += invoker.data
  }
  if (tests_have_location_tags) {
    _shared_data += [ "//testing/location_tags.json" ]
  }

  _shared_data_deps = [ "//testing:test_scripts_shared" ]
  if (defined(invoker.data_deps)) {
    _shared_data_deps += invoker.data_deps
  }
  if (use_rts) {
    _shared_data_deps += [ ":${invoker.target_name}__rts_filters" ]
  }

  _wrapped_script =
      "@WrappedPath(" + rebase_path(invoker.script, root_build_dir) + ")"
  if (_enable_logdog_wrapper) {
    logdog_wrapper_script_test(target_name) {
      testonly = true
      args = [ _wrapped_script ]
      if (defined(invoker.args)) {
        args += invoker.args
      }
      data = _shared_data
      data_deps = _shared_data_deps

      forward_variables_from(invoker,
                             "*",
                             TESTONLY_AND_VISIBILITY + [
                                   "args",
                                   "data",
                                   "data_deps",
                                   "script",
                                 ])
    }
  } else if (_enable_cros_wrapper) {
    cros_test_wrapper_script_test(target_name) {
      args = [ _wrapped_script ]
      if (defined(invoker.args)) {
        args += invoker.args
      }
      data = _shared_data
      data_deps = _shared_data_deps

      forward_variables_from(invoker,
                             "*",
                             TESTONLY_AND_VISIBILITY + [
                                   "args",
                                   "data",
                                   "data_deps",
                                   "script",
                                 ])
    }
  } else {
    generate_wrapper(target_name) {
      testonly = true
      wrapper_script = "${root_build_dir}/bin/run_${target_name}"

      executable = "//testing/test_env.py"

      executable_args = [ _wrapped_script ]
      if (defined(invoker.args)) {
        executable_args += invoker.args
      }

      data = _shared_data
      data_deps = _shared_data_deps

      forward_variables_from(invoker,
                             "*",
                             TESTONLY_AND_VISIBILITY + [
                                   "args",
                                   "data",
                                   "data_deps",
                                   "script",
                                 ])
      forward_variables_from(invoker, [ "visibility" ])

      write_runtime_deps = "${root_build_dir}/${target_name}.runtime_deps"
    }
  }
}

# Defines a test target that uses exit code for pass/fail.
template("isolated_script_test") {
  script_test(target_name) {
    forward_variables_from(invoker,
                           "*",
                           TESTONLY_AND_VISIBILITY + [
                                 "args",
                                 "data",
                                 "deps",
                                 "script",
                               ])
    forward_variables_from(invoker, [ "visibility" ])
    deps = [ "//testing:run_isolated_script_test" ]
    if (defined(invoker.deps)) {
      deps += invoker.deps
    }
    script = "//testing/scripts/run_isolated_script_test.py"
    data = [ invoker.script ]
    if (defined(invoker.data)) {
      data += invoker.data
    }
    args = [
      rebase_path(invoker.script, root_build_dir),
      "--script-type=bare",
    ]
    if (defined(invoker.args)) {
      args += invoker.args
    }
  }
}

# Test defaults.
set_defaults("test") {
  if (is_android) {
    # Should be kept in sync with set_defaults("cronet_test") in
    # //components/cronet/android/cronet_test_templates.gni
    # LINT.IfChange
    configs = default_shared_library_configs
    configs -= [ "//build/config/android:hide_all_but_jni_onload" ]
    configs += [ "//build/config/android:hide_all_but_jni" ]

    # LINT.ThenChange(/components/cronet/android/cronet_test_templates.gni)
  } else {
    configs = default_executable_configs
  }
}