Undo googletest in .gn and replace it with a build variant

.gn

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 import("//build_overrides/build.gni")
-import("//build_overrides/googletest.gni")
 import("//build_overrides/pigweed.gni")
 
 # The location of the build configuration file.
@@ -34,11 +33,6 @@ default_args = {
   # GN target to use for the default Python build venv.
   pw_build_PYTHON_BUILD_VENV = "//:matter_build_venv"
 
-  # Use the GoogleTest backend for unit tests running on host.
-  pw_unit_test_BACKEND = "$dir_pw_unit_test:googletest"
-  pw_unit_test_MAIN = "$dir_pigweed/third_party/googletest:gmock_main"
-  dir_pw_third_party_googletest = "$dir_googletest"
-
   # Required for pw_unit_test
   pw_sys_io_BACKEND = "$dir_pw_sys_io_stdio"
   pw_assert_BACKEND = "$dir_pw_assert_log"

build/chip/chip_test_suite.gni

@@ -14,6 +14,7 @@
 
 import("//build_overrides/build.gni")
 import("//build_overrides/chip.gni")
+import("//build_overrides/googletest.gni")
 import("//build_overrides/pigweed.gni")
 
 import("${chip_root}/build/chip/tests.gni")
@@ -120,6 +121,10 @@ template("chip_test_suite") {
           # Link to the common lib for this suite so we get its `sources`.
           public_deps += [ ":${_suite_name}.lib" ]
 
+          if (pw_unit_test_BACKEND == "$dir_pw_unit_test:googletest") {
+            test_main = "$dir_pigweed/third_party/googletest:gmock_main"
+          }
+
           # Set variables that the platform executable may need.
           if (test_executable_output_name != "") {
             output_name = test_executable_output_name + _test_name +

scripts/build/build/targets.py

@@ -200,6 +200,7 @@ def BuildHostTarget():
     target.AppendModifier('data-model-disabled', data_model_interface="disabled").ExceptIfRe('-data-model-(check|enabled)')
     target.AppendModifier('data-model-enabled', data_model_interface="enabled").ExceptIfRe('-data-model-(check|disabled)')
     target.AppendModifier('check-failure-die', chip_data_model_check_die_on_failure=True).OnlyIfRe('-data-model-check')
+    target.AppendModifier('googletest', use_googletest=True).OnlyIfRe('-tests')
 
     return target
 

scripts/build/builders/host.py

@@ -336,7 +336,8 @@ def __init__(self, root, runner, app: HostApp, board=HostBoard.NATIVE,
                  chip_casting_simplified: Optional[bool] = None,
                  data_model_interface: Optional[str] = None,
                  chip_data_model_check_die_on_failure: Optional[bool] = None,
-                 disable_shell=False
+                 disable_shell=False,
+                 use_googletest=False,
                  ):
         super(HostBuilder, self).__init__(
             root=os.path.join(root, 'examples', app.ExamplePath()),
@@ -496,6 +497,12 @@ def __init__(self, root, runner, app: HostApp, board=HostBoard.NATIVE,
         if self.app == HostApp.TESTS and fuzzing_type == HostFuzzingType.PW_FUZZTEST:
             self.build_command = 'pw_fuzz_tests'
 
+        if self.app == HostApp.TESTS and use_googletest:
+            self.extra_gn_options.append('import("//build_overrides/pigweed.gni")')
+            self.extra_gn_options.append('import("//build_overrides/googletest.gni")')
+            self.extra_gn_options.append('pw_unit_test_BACKEND="$dir_pw_unit_test:googletest"')
+            self.extra_gn_options.append('dir_pw_third_party_googletest="$dir_googletest"')
+
     def GnBuildArgs(self):
         if self.board == HostBoard.NATIVE:
             return self.extra_gn_options

scripts/build/testdata/all_targets_linux_x64.txt

@@ -9,7 +9,7 @@ efr32-{brd2704b,brd4316a,brd4317a,brd4318a,brd4319a,brd4186a,brd4187a,brd2601b,b
 esp32-{m5stack,c3devkit,devkitc,qemu}-{all-clusters,all-clusters-minimal,energy-management,ota-provider,ota-requestor,shell,light,lock,bridge,temperature-measurement,ota-requestor,tests}[-rpc][-ipv6only][-tracing][-data-model-disabled][-data-model-enabled]
 genio-lighting-app
 linux-fake-tests[-mbedtls][-boringssl][-asan][-tsan][-ubsan][-libfuzzer][-ossfuzz][-pw-fuzztest][-coverage][-dmalloc][-clang]
-linux-{x64,arm64}-{rpc-console,all-clusters,all-clusters-minimal,chip-tool,thermostat,java-matter-controller,kotlin-matter-controller,minmdns,light,light-data-model-no-unique-id,lock,shell,ota-provider,ota-requestor,simulated-app1,simulated-app2,python-bindings,tv-app,tv-casting-app,bridge,fabric-admin,fabric-bridge,fabric-sync,tests,chip-cert,address-resolve-tool,contact-sensor,dishwasher,microwave-oven,refrigerator,rvc,air-purifier,lit-icd,air-quality-sensor,network-manager,energy-management,water-leak-detector}[-nodeps][-nlfaultinject][-platform-mdns][-minmdns-verbose][-libnl][-same-event-loop][-no-interactive][-ipv6only][-no-ble][-no-wifi][-no-thread][-no-shell][-mbedtls][-boringssl][-asan][-tsan][-ubsan][-libfuzzer][-ossfuzz][-pw-fuzztest][-coverage][-dmalloc][-clang][-test][-rpc][-with-ui][-evse-test-event][-enable-dnssd-tests][-disable-dnssd-tests][-chip-casting-simplified][-data-model-check][-data-model-disabled][-data-model-enabled][-check-failure-die]
+linux-{x64,arm64}-{rpc-console,all-clusters,all-clusters-minimal,chip-tool,thermostat,java-matter-controller,kotlin-matter-controller,minmdns,light,light-data-model-no-unique-id,lock,shell,ota-provider,ota-requestor,simulated-app1,simulated-app2,python-bindings,tv-app,tv-casting-app,bridge,fabric-admin,fabric-bridge,fabric-sync,tests,chip-cert,address-resolve-tool,contact-sensor,dishwasher,microwave-oven,refrigerator,rvc,air-purifier,lit-icd,air-quality-sensor,network-manager,energy-management,water-leak-detector}[-nodeps][-nlfaultinject][-platform-mdns][-minmdns-verbose][-libnl][-same-event-loop][-no-interactive][-ipv6only][-no-ble][-no-wifi][-no-thread][-no-shell][-mbedtls][-boringssl][-asan][-tsan][-ubsan][-libfuzzer][-ossfuzz][-pw-fuzztest][-coverage][-dmalloc][-clang][-test][-rpc][-with-ui][-evse-test-event][-enable-dnssd-tests][-disable-dnssd-tests][-chip-casting-simplified][-data-model-check][-data-model-disabled][-data-model-enabled][-check-failure-die][-googletest]
 linux-x64-efr32-test-runner[-clang]
 imx-{chip-tool,lighting-app,thermostat,all-clusters-app,all-clusters-minimal-app,ota-provider-app}[-release]
 infineon-psoc6-{lock,light,all-clusters,all-clusters-minimal}[-ota][-updateimage][-trustm]

src/test_driver/tizen/.gn

@@ -31,7 +31,6 @@ default_args = {
   pw_log_BACKEND = "$dir_pw_log_basic"
 
   pw_unit_test_BACKEND = "$dir_pw_unit_test:googletest"
-  pw_unit_test_MAIN = "$dir_pigweed/third_party/googletest:gmock_main"
   dir_pw_third_party_googletest = "$dir_googletest"
 
   # TODO: Make sure only unit tests link against this