[llvm] [Support][test] Fix OpenDirectoryAsFileForRead test on AIX and z/OS (PR #216241)

[Daniel Chen via llvm-commits]

https://github.com/DanielCChen updated https://github.com/llvm/llvm-project/pull/216241

>From d2983e082141b8b2fbbf71c1b2952bd6fe9b7a5f Mon Sep 17 00:00:00 2001
From: Daniel Chen <cdchen at ca.ibm.com>
Date: Fri, 14 Aug 2026 00:09:01 -0400
Subject: [PATCH 1/2] [Support][test] Fix OpenDirectoryAsFileForRead test on
 AIX and z/OS

---
 llvm/unittests/Support/Path.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp
index b63ab426bb080..6e0cf878ac664 100644
--- a/llvm/unittests/Support/Path.cpp
+++ b/llvm/unittests/Support/Path.cpp
@@ -2042,6 +2042,10 @@ TEST_F(FileSystemTest, OpenDirectoryAsFileForRead) {
   Expected<fs::file_t> FD = fs::openNativeFileForRead(TestDirectory);
 #ifdef _WIN32
   EXPECT_EQ(errorToErrorCode(FD.takeError()), errc::is_a_directory);
+#elif defined(_AIX) || defined(__MVS__)
+  // On AIX and z/OS, open() on a directory with O_RDONLY fails immediately
+  // with EISDIR, unlike Linux where open() succeeds and read() returns EISDIR.
+  EXPECT_EQ(errorToErrorCode(FD.takeError()), errc::is_a_directory);
 #else
   ASSERT_THAT_EXPECTED(FD, Succeeded());
   scope_exit Close([&] { fs::closeFile(*FD); });

>From 32123bed31e364be0ef07a1ce1c2e7733c1739a6 Mon Sep 17 00:00:00 2001
From: Daniel Chen <cdchen at ca.ibm.com>
Date: Fri, 14 Aug 2026 10:36:59 -0400
Subject: [PATCH 2/2] To address review comments.

---
 llvm/unittests/Support/Path.cpp | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp
index 6e0cf878ac664..31599f6152e92 100644
--- a/llvm/unittests/Support/Path.cpp
+++ b/llvm/unittests/Support/Path.cpp
@@ -2040,11 +2040,7 @@ TEST_F(FileSystemTest, SetLastAccessAndModificationTimeDirectory) {
 TEST_F(FileSystemTest, OpenDirectoryAsFileForRead) {
   std::string Buf(5, '?');
   Expected<fs::file_t> FD = fs::openNativeFileForRead(TestDirectory);
-#ifdef _WIN32
-  EXPECT_EQ(errorToErrorCode(FD.takeError()), errc::is_a_directory);
-#elif defined(_AIX) || defined(__MVS__)
-  // On AIX and z/OS, open() on a directory with O_RDONLY fails immediately
-  // with EISDIR, unlike Linux where open() succeeds and read() returns EISDIR.
+#if defined(_WIN32) || defined(_AIX) || defined(__MVS__)
   EXPECT_EQ(errorToErrorCode(FD.takeError()), errc::is_a_directory);
 #else
   ASSERT_THAT_EXPECTED(FD, Succeeded());