[lit] Don't include tests skipped due to sharding in reports

When running multiple shards, don't include skipped tests in the xunit
output since merging the files will result in duplicates.
In our CHERI Jenkins CI, I configured the libc++ tests to run using sharding
(since we are testing using a single-CPU QEMU). We then merge the generated
XUnit xml files to produce a final result, but if the individual XMLs
report tests excluded due to sharding each test is included N times in the
final result. This also makes it difficult to find the tests that were
skipped due to missing REQUIRES: etc.

Reviewed By: yln

Differential Revision: https://reviews.llvm.org/D84235

llvm/utils/lit/lit/main.py

@@ -80,9 +80,13 @@ def main(builtin_params={}):
                              'error.\n')
             sys.exit(2)
 
+    # When running multiple shards, don't include skipped tests in the xunit
+    # output since merging the files will result in duplicates.
+    tests_for_report = discovered_tests
     if opts.shard:
         (run, shards) = opts.shard
         selected_tests = filter_by_shard(selected_tests, run, shards, lit_config)
+        tests_for_report = selected_tests
         if not selected_tests:
             sys.stderr.write('warning: shard does not contain any tests.  '
                              'Consider decreasing the number of shards.\n')
@@ -102,7 +106,7 @@ def main(builtin_params={}):
     print_results(discovered_tests, elapsed, opts)
 
     for report in opts.reports:
-        report.write_results(discovered_tests, elapsed)
+        report.write_results(tests_for_report, elapsed)
 
     if lit_config.numErrors:
         sys.stderr.write('\n%d error(s) in tests\n' % lit_config.numErrors)

llvm/utils/lit/lit/reports.py

@@ -127,7 +127,7 @@ class XunitReport(object):
     def _get_skip_reason(self, test):
         code = test.result.code
         if code == lit.Test.EXCLUDED:
-            return 'Test not selected (--filter, --max-tests, --run-shard)'
+            return 'Test not selected (--filter, --max-tests)'
         if code == lit.Test.SKIPPED:
             return 'User interrupt'
 

llvm/utils/lit/tests/xunit-output.py

@@ -14,7 +14,7 @@
 # CHECK-NEXT:   <failure><![CDATA[& < > ]]]]><![CDATA[> &"]]></failure>
 # CHECK-NEXT: </testcase>
 # CHECK-NEXT: <testcase classname="test-data.test-data" name="excluded.ini" time="{{[0-1]\.[0-9]+}}">
-# CHECK-NEXT:   <skipped message="Test not selected (--filter, --max-tests, --run-shard)"/>
+# CHECK-NEXT:   <skipped message="Test not selected (--filter, --max-tests)"/>
 # CHECK-NEXT: </testcase>
 # CHECK-NEXT: <testcase classname="test-data.test-data" name="missing_feature.ini" time="{{[0-1]\.[0-9]+}}">
 # CHECK-NEXT:   <skipped message="Missing required feature(s): dummy_feature"/>