[reland][lit][unit] makes sure to print stderr when no test failures are found

In some situations, like running tests with sanitizers, all test
passes but the shard could still fail due to memory issues.

Relands 65769429c0

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

@@ -163,6 +163,8 @@ class GoogleTest(TestFormat):
                     res.append(l)
             assert False, f'gtest did not report the result for ' + test_name
 
+        found_failed_test = False
+
         with open(test.gtest_json_file, encoding='utf-8') as f:
             jf = json.load(f)
 
@@ -179,6 +181,7 @@ class GoogleTest(TestFormat):
                     header = f"Script:\n--\n%s --gtest_filter=%s\n--\n" % (
                         ' '.join(cmd), testname)
                     if 'failures' in testinfo:
+                        found_failed_test = True
                         output += header
                         test_out = get_test_stdout(testname)
                         if test_out:
@@ -189,6 +192,12 @@ class GoogleTest(TestFormat):
                     elif result != 'COMPLETED':
                         output += header
                         output += 'unresolved test result\n'
+
+        # In some situations, like running tests with sanitizers, all test passes but
+        # the shard could still fail due to memory issues.
+        if not found_failed_test:
+            output += f"\n{out}\n--\nexit: {exitCode}\n--\n"
+
         return lit.Test.FAIL, output
 
     def prepareCmd(self, cmd):
@@ -217,7 +226,11 @@ class GoogleTest(TestFormat):
         discovered_tests = remove_gtest(discovered_tests)
         gtests = [t for t in selected_tests if t.gtest_json_file]
         selected_tests = remove_gtest(selected_tests)
+        has_failure = False
         for test in gtests:
+            if test.isFailure():
+                has_failure = True
+
             # In case gtest has bugs such that no JSON file was emitted.
             if not os.path.exists(test.gtest_json_file):
                 selected_tests.append(test)
@@ -269,4 +282,4 @@ class GoogleTest(TestFormat):
                         discovered_tests.append(subtest)
             os.remove(test.gtest_json_file)
 
-        return selected_tests, discovered_tests
+        return selected_tests, discovered_tests, has_failure

llvm/utils/lit/lit/main.py

@@ -108,7 +108,7 @@ def main(builtin_params={}):
 
     record_test_times(selected_tests, lit_config)
 
-    selected_tests, discovered_tests = GoogleTest.post_process_shard_results(
+    selected_tests, discovered_tests, has_failure = GoogleTest.post_process_shard_results(
         selected_tests, discovered_tests)
 
     if opts.time_tests:
@@ -127,7 +127,7 @@ def main(builtin_params={}):
     if lit_config.numWarnings:
         sys.stderr.write('\n%d warning(s) in tests\n' % lit_config.numWarnings)
 
-    has_failure = any(t.isFailure() for t in discovered_tests)
+    has_failure = has_failure or any(t.isFailure() for t in discovered_tests)
     if has_failure:
         if opts.ignoreFail:
             sys.stderr.write("\nExiting with status 0 instead of 1 because "