1 files changed, 36 insertions, 16 deletions
diff --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp
index 2aadf89161c..9de46a689cd 100644
--- a/llvm/unittests/Support/Path.cpp
+++ b/llvm/unittests/Support/Path.cpp
@@ -8,6 +8,7 @@
 
 #include "llvm/Support/Path.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/ScopeExit.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/BinaryFormat/Magic.h"
@@ -1514,28 +1515,47 @@ TEST_F(FileSystemTest, ReadWriteFileCanReadOrWrite) {
   verifyWrite(FD, "Buzz", true);
 }
 
+TEST_F(FileSystemTest, readNativeFile) {
+  createFileWithData(NonExistantFile, false, fs::CD_CreateNew, "01234");
+  FileRemover Cleanup(NonExistantFile);
+  const auto &Read = [&](size_t ToRead) -> Expected<std::string> {
+    std::string Buf(ToRead, '?');
+    Expected<fs::file_t> FD = fs::openNativeFileForRead(NonExistantFile);
+    if (!FD)
+      return FD.takeError();
+    auto Close = make_scope_exit([&] { fs::closeFile(*FD); });
+    if (Expected<size_t> BytesRead = fs::readNativeFile(
+            *FD, makeMutableArrayRef(&*Buf.begin(), Buf.size())))
+      return Buf.substr(0, *BytesRead);
+    else
+      return BytesRead.takeError();
+  };
+  EXPECT_THAT_EXPECTED(Read(5), HasValue("01234"));
+  EXPECT_THAT_EXPECTED(Read(3), HasValue("012"));
+  EXPECT_THAT_EXPECTED(Read(6), HasValue("01234"));
+}
+
 TEST_F(FileSystemTest, readNativeFileSlice) {
-  char Data[10] = {'0', '1', '2', '3', '4', 0, 0, 0, 0, 0};
-  createFileWithData(NonExistantFile, false, fs::CD_CreateNew,
-                     StringRef(Data, 5));
+  createFileWithData(NonExistantFile, false, fs::CD_CreateNew, "01234");
   FileRemover Cleanup(NonExistantFile);
   Expected<fs::file_t> FD = fs::openNativeFileForRead(NonExistantFile);
   ASSERT_THAT_EXPECTED(FD, Succeeded());
-  char Buf[10];
+  auto Close = make_scope_exit([&] { fs::closeFile(*FD); });
   const auto &Read = [&](size_t Offset,
-                         size_t ToRead) -> Expected<ArrayRef<char>> {
-    std::memset(Buf, 0x47, sizeof(Buf));
-    if (std::error_code EC = fs::readNativeFileSlice(
-            *FD, makeMutableArrayRef(Buf, ToRead), Offset))
-      return errorCodeToError(EC);
-    return makeArrayRef(Buf, ToRead);
+                         size_t ToRead) -> Expected<std::string> {
+    std::string Buf(ToRead, '?');
+    if (Expected<size_t> BytesRead = fs::readNativeFileSlice(
+            *FD, makeMutableArrayRef(&*Buf.begin(), Buf.size()), Offset))
+      return Buf.substr(0, *BytesRead);
+    else
+      return BytesRead.takeError();
   };
-  EXPECT_THAT_EXPECTED(Read(0, 5), HasValue(makeArrayRef(Data + 0, 5)));
-  EXPECT_THAT_EXPECTED(Read(0, 3), HasValue(makeArrayRef(Data + 0, 3)));
-  EXPECT_THAT_EXPECTED(Read(2, 3), HasValue(makeArrayRef(Data + 2, 3)));
-  EXPECT_THAT_EXPECTED(Read(0, 6), HasValue(makeArrayRef(Data + 0, 6)));
-  EXPECT_THAT_EXPECTED(Read(2, 6), HasValue(makeArrayRef(Data + 2, 6)));
-  EXPECT_THAT_EXPECTED(Read(5, 5), HasValue(makeArrayRef(Data + 5, 5)));
+  EXPECT_THAT_EXPECTED(Read(0, 5), HasValue("01234"));
+  EXPECT_THAT_EXPECTED(Read(0, 3), HasValue("012"));
+  EXPECT_THAT_EXPECTED(Read(2, 3), HasValue("234"));
+  EXPECT_THAT_EXPECTED(Read(0, 6), HasValue("01234"));
+  EXPECT_THAT_EXPECTED(Read(2, 6), HasValue("234"));
+  EXPECT_THAT_EXPECTED(Read(5, 5), HasValue(""));
 }
 
 TEST_F(FileSystemTest, is_local) {