From 3cce23746edfc6c24f25b73bd8032582df03222c Mon Sep 17 00:00:00 2001
From: "David L. Jones" <dlj@google.com>
Date: Mon, 13 May 2019 20:32:53 +0000
Subject: [PATCH] [Support] Ensure redirected outputs don't contain output from
 previous tests.

stdout may be buffered, and may not flush on every write. Explicitly flushing
before redirecting the output ensures that the captured output does not contain
output from other tests.

llvm-svn: 360617
---
 llvm/unittests/Support/CommandLineTest.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/unittests/Support/CommandLineTest.cpp b/llvm/unittests/Support/CommandLineTest.cpp
index 2bf07e374940..4fb20b18d9bf 100644
--- a/llvm/unittests/Support/CommandLineTest.cpp
+++ b/llvm/unittests/Support/CommandLineTest.cpp
@@ -1085,6 +1085,7 @@ public:
   // Return std::string because the output of a failing EXPECT check is
   // unreadable for StringRef. It also avoids any lifetime issues.
   template <typename... Ts> std::string runTest(Ts... OptionAttributes) {
+    outs().flush();  // flush any output from previous tests
     AutoDeleteFile File;
     {
       OutputRedirector Stdout(fileno(stdout));