[unittest] Refactoring the gtest sharding option. (#69537)

This patch addresses the missed review comment from PR #67063. It
renames LIT flag "--disable-gtest-sharding" to "--no-gtest-sharding"
and corrects the code style issue.

llvm/utils/lit/lit/LitConfig.py

@@ -37,7 +37,7 @@ class LitConfig(object):
         maxIndividualTestTime=0,
         parallelism_groups={},
         per_test_coverage=False,
-        disableGTestSharding=False,
+        gtest_sharding=True,
     ):
         # The name of the test runner.
         self.progname = progname
@@ -88,7 +88,7 @@ class LitConfig(object):
         self.maxIndividualTestTime = maxIndividualTestTime
         self.parallelism_groups = parallelism_groups
         self.per_test_coverage = per_test_coverage
-        self.disableGTestSharding = bool(disableGTestSharding)
+        self.gtest_sharding = bool(gtest_sharding)
 
     @property
     def maxIndividualTestTime(self):

llvm/utils/lit/lit/cl_arguments.py

@@ -119,10 +119,16 @@ def parse_args():
 
     execution_group = parser.add_argument_group("Test Execution")
     execution_group.add_argument(
-        "--disable-gtest-sharding",
-        dest="disableGTestSharding",
-        help="Disable sharding for GoogleTest format",
+        "--gtest-sharding",
+        help="Enable sharding for GoogleTest format",
         action="store_true",
+        default=True,
+    )
+    execution_group.add_argument(
+        "--no-gtest-sharding",
+        dest="gtest_sharding",
+        help="Disable sharding for GoogleTest format",
+        action="store_false",
     )
     execution_group.add_argument(
         "--path",

llvm/utils/lit/lit/formats/googletest.py

@@ -68,7 +68,7 @@ class GoogleTest(TestFormat):
                     self.seen_executables.add(execpath)
                 num_tests = self.get_num_tests(execpath, litConfig, localConfig)
                 if num_tests is not None:
-                    if not litConfig.disableGTestSharding:
+                    if litConfig.gtest_sharding:
                         # Compute the number of shards.
                         shard_size = init_shard_size
                         nshard = int(math.ceil(num_tests / shard_size))
@@ -151,7 +151,7 @@ class GoogleTest(TestFormat):
             "GTEST_OUTPUT": "json:" + test.gtest_json_file,
             "GTEST_SHUFFLE": "1" if use_shuffle else "0",
         }
-        if not litConfig.disableGTestSharding:
+        if litConfig.gtest_sharding:
             testPath, testName = os.path.split(test.getSourcePath())
             while not os.path.exists(testPath):
                 # Handle GTest parameterized and typed tests, whose name includes

llvm/utils/lit/lit/main.py

@@ -41,7 +41,7 @@ def main(builtin_params={}):
         params=params,
         config_prefix=opts.configPrefix,
         per_test_coverage=opts.per_test_coverage,
-        disableGTestSharding=opts.disableGTestSharding,
+        gtest_sharding=opts.gtest_sharding,
     )
 
     discovered_tests = lit.discovery.find_tests_for_inputs(

llvm/utils/lit/tests/googletest-no-sharding.py

@@ -1,6 +1,6 @@
 # Check the various features of the GoogleTest format.
 
-# RUN: not %{lit} -v --disable-gtest-sharding --order=random %{inputs}/googletest-no-sharding > %t.out
+# RUN: not %{lit} -v --no-gtest-sharding --order=random %{inputs}/googletest-no-sharding > %t.out
 # FIXME: Temporarily dump test output so we can debug failing tests on
 # buildbots.
 # RUN: cat %t.out