1 files changed, 28 insertions, 0 deletions
diff --git a/test/std/experimental/filesystem/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp b/test/std/experimental/filesystem/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp
index ed25649531b9..cdd177399aa7 100644
--- a/test/std/experimental/filesystem/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp
+++ b/test/std/experimental/filesystem/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp
@@ -88,6 +88,16 @@ bool TestSupportsNegativeTimes() {
     return !ec && new_write_time <= -5;
 }
 
+// In some configurations, the comparison is tautological and the test is valid.
+// We disable the warning so that we can actually test it regardless. Also, that
+// diagnostic is pretty new, so also don't fail if old clang does not support it
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunknown-warning-option"
+#pragma clang diagnostic ignored "-Wunknown-pragmas"
+#pragma clang diagnostic ignored "-Wtautological-constant-compare"
+#endif
+
 bool TestSupportsMaxTime() {
     using namespace std::chrono;
     using Lim = std::numeric_limits<std::time_t>;
@@ -106,11 +116,25 @@ bool TestSupportsMaxTime() {
     return !ec && new_write_time > max_sec - 1;
 }
 
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
 static const bool SupportsNegativeTimes = TestSupportsNegativeTimes();
 static const bool SupportsMaxTime = TestSupportsMaxTime();
 
 } // end namespace
 
+// In some configurations, the comparison is tautological and the test is valid.
+// We disable the warning so that we can actually test it regardless. Also, that
+// diagnostic is pretty new, so also don't fail if old clang does not support it
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunknown-warning-option"
+#pragma clang diagnostic ignored "-Wunknown-pragmas"
+#pragma clang diagnostic ignored "-Wtautological-constant-compare"
+#endif
+
 // Check if a time point is representable on a given filesystem. Check that:
 // (A) 'tp' is representable as a time_t
 // (B) 'tp' is non-negative or the filesystem supports negative times.
@@ -127,6 +151,10 @@ inline bool TimeIsRepresentableByFilesystem(file_time_type tp) {
     return true;
 }
 
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
 TEST_SUITE(exists_test_suite)
 
 TEST_CASE(signature_test)