[libcxx] Fix last_write_time test for filesystems that don't support very small times.
APFS minimum supported file write time is -2^63 nanoseconds, which doesn't go
as far as `file_time_type::min()` that is equal to -2^63 microseconds on macOS.
This change doesn't affect filesystems that support `file_time_type` range only
for in-memory file time representation but not for on-disk representation. Such
filesystems are considered as `SupportsMinTime`.
rdar://problem/35865151
Reviewers: EricWF, Hahnfeld
Subscribers: jkorous-apple, mclow.lists, cfe-commits, christof
Differential Revision: https://reviews.llvm.org/D42755
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@326383 91177308-0d34-0410-b5e6-96231b3b80d8
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 cdd1773..0ca82b2 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
@@ -116,12 +116,31 @@
return !ec && new_write_time > max_sec - 1;
}
+bool TestSupportsMinTime() {
+ using namespace std::chrono;
+ using Lim = std::numeric_limits<std::time_t>;
+ auto min_sec = duration_cast<seconds>(file_time_type::min().time_since_epoch()).count();
+ if (min_sec < Lim::min()) return false;
+ std::error_code ec;
+ std::time_t old_write_time, new_write_time;
+ { // WARNING: Do not assert in this scope.
+ scoped_test_env env;
+ const path file = env.create_file("file", 42);
+ old_write_time = LastWriteTime(file);
+ file_time_type tp = file_time_type::min();
+ fs::last_write_time(file, tp, ec);
+ new_write_time = LastWriteTime(file);
+ }
+ return !ec && new_write_time < min_sec + 1;
+}
+
#if defined(__clang__)
#pragma clang diagnostic pop
#endif
static const bool SupportsNegativeTimes = TestSupportsNegativeTimes();
static const bool SupportsMaxTime = TestSupportsMaxTime();
+static const bool SupportsMinTime = TestSupportsMinTime();
} // end namespace
@@ -140,6 +159,8 @@
// (B) 'tp' is non-negative or the filesystem supports negative times.
// (C) 'tp' is not 'file_time_type::max()' or the filesystem supports the max
// value.
+// (D) 'tp' is not 'file_time_type::min()' or the filesystem supports the min
+// value.
inline bool TimeIsRepresentableByFilesystem(file_time_type tp) {
using namespace std::chrono;
using Lim = std::numeric_limits<std::time_t>;
@@ -148,6 +169,7 @@
if (sec < Lim::min() || sec > Lim::max()) return false;
else if (microsec < 0 && !SupportsNegativeTimes) return false;
else if (tp == file_time_type::max() && !SupportsMaxTime) return false;
+ else if (tp == file_time_type::min() && !SupportsMinTime) return false;
return true;
}
@@ -355,20 +377,20 @@
TEST_CHECK(!ec);
TEST_CHECK(tt >= new_time);
TEST_CHECK(tt < new_time + Sec(1));
- }
- ec = GetTestEC();
- last_write_time(p, Clock::now());
+ ec = GetTestEC();
+ last_write_time(p, Clock::now());
- new_time = file_time_type::min() + MicroSec(1);
+ new_time = file_time_type::min() + MicroSec(1);
- last_write_time(p, new_time, ec);
- tt = last_write_time(p);
+ last_write_time(p, new_time, ec);
+ tt = last_write_time(p);
- if (TimeIsRepresentableByFilesystem(new_time)) {
- TEST_CHECK(!ec);
- TEST_CHECK(tt >= new_time);
- TEST_CHECK(tt < new_time + Sec(1));
+ if (TimeIsRepresentableByFilesystem(new_time)) {
+ TEST_CHECK(!ec);
+ TEST_CHECK(tt >= new_time);
+ TEST_CHECK(tt < new_time + Sec(1));
+ }
}
}