[libc++] Android temp dir is /data/local/tmp, enable Windows test

[libc++] Android temp dir is /data/local/tmp, enable Windows test

On Android, std::filesystem::temp_directory_path() should fall back to
/data/local/tmp when no environment variable is set. There is no /tmp
directory. Most apps can't access /data/local/tmp, but they do have a
"cache dir" (Context#getCacheDir()) that is usable for temporary files.
However, there is no obvious and reliable way for libc++ to query this
directory in contexts where it is available. The global fallback
/data/local/tmp is available for "adb shell", making it useful for test
suites.

On Windows, temp_directory_path falls back to the Windows directory
(e.g. "C:\Windows"), so call GetWindowsDirectoryW to do the test.

Reviewed By: ldionne, #libc, enh

Differential Revision: https://reviews.llvm.org/D137131

1 files changed, 6 insertions, 1 deletions

diff --git a/libcxx/src/filesystem/operations.cpp b/libcxx/src/filesystem/operations.cpp
index fc14778..af31fe0 100644
--- a/libcxx/src/filesystem/operations.cpp
+++ b/libcxx/src/filesystem/operations.cpp
@@ -1550,8 +1550,13 @@ path __temp_directory_path(error_code* ec) {
   for (auto& ep : env_paths)
     if ((ret = getenv(ep)))
       break;
-  if (ret == nullptr)
+  if (ret == nullptr) {
+#if defined(__ANDROID__)
+    ret = "/data/local/tmp";
+#else
     ret = "/tmp";
+#endif
+  }
 
   path p(ret);
 #endif