[Support] Add writeFileAtomically() to FileUtilities

Differential Revision: https://reviews.llvm.org/D66859

llvm-svn: 371103

2 files changed, 53 insertions, 0 deletions

diff --git a/llvm/unittests/Support/CMakeLists.txt b/llvm/unittests/Support/CMakeLists.txt
index b0a7cda7a47..161891517cf 100644
--- a/llvm/unittests/Support/CMakeLists.txt
+++ b/llvm/unittests/Support/CMakeLists.txt
@@ -33,6 +33,7 @@ add_llvm_unittest(SupportTests
   FileCheckTest.cpp
   FileCollectorTest.cpp
   FileOutputBufferTest.cpp
+  FileUtilitiesTest.cpp
   FormatVariadicTest.cpp
   GlobPatternTest.cpp
   Host.cpp
diff --git a/llvm/unittests/Support/FileUtilitiesTest.cpp b/llvm/unittests/Support/FileUtilitiesTest.cpp
new file mode 100644
index 00000000000..2bf9dc5eb8c
--- /dev/null
+++ b/llvm/unittests/Support/FileUtilitiesTest.cpp
@@ -0,0 +1,52 @@
+//===- llvm/unittest/Support/FileUtilitiesTest.cpp - unit tests -----------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/FileUtilities.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "gtest/gtest.h"
+#include <fstream>
+
+using namespace llvm;
+using namespace llvm::sys;
+
+#define ASSERT_NO_ERROR(x)                                                     \
+  if (std::error_code ASSERT_NO_ERROR_ec = x) {                                \
+    SmallString<128> MessageStorage;                                           \
+    raw_svector_ostream Message(MessageStorage);                               \
+    Message << #x ": did not return errc::success.\n"                          \
+            << "error number: " << ASSERT_NO_ERROR_ec.value() << "\n"          \
+            << "error message: " << ASSERT_NO_ERROR_ec.message() << "\n";      \
+    GTEST_FATAL_FAILURE_(MessageStorage.c_str());                              \
+  } else {                                                                     \
+  }
+
+namespace {
+TEST(writeFileAtomicallyTest, Test) {
+  // Create unique temporary directory for these tests
+  SmallString<128> RootTestDirectory;
+  ASSERT_NO_ERROR(
+    fs::createUniqueDirectory("writeFileAtomicallyTest", RootTestDirectory));
+
+  SmallString<128> FinalTestfilePath(RootTestDirectory);
+  sys::path::append(FinalTestfilePath, "foo.txt");
+  const std::string TempUniqTestFileModel = FinalTestfilePath.str().str() + "-%%%%%%%%";
+  const std::string TestfileContent = "fooFOOfoo";
+
+  llvm::Error Err = llvm::writeFileAtomically(TempUniqTestFileModel, FinalTestfilePath, TestfileContent);
+  ASSERT_FALSE(static_cast<bool>(Err));
+
+  std::ifstream FinalFileStream(FinalTestfilePath.str());
+  std::string FinalFileContent;
+  FinalFileStream >> FinalFileContent;
+  ASSERT_EQ(FinalFileContent, TestfileContent);
+}
+} // anonymous namespace