2 files changed, 34 insertions, 0 deletions
diff --git a/llvm/unittests/Support/CMakeLists.txt b/llvm/unittests/Support/CMakeLists.txt
index e2a6561089b..641163e39ed 100644
--- a/llvm/unittests/Support/CMakeLists.txt
+++ b/llvm/unittests/Support/CMakeLists.txt
@@ -21,6 +21,7 @@ add_llvm_unittest(SupportTests
   DebugTest.cpp
   EndianStreamTest.cpp
   EndianTest.cpp
+  ErrnoTest.cpp
   ErrorOrTest.cpp
   ErrorTest.cpp
   FileOutputBufferTest.cpp
diff --git a/llvm/unittests/Support/ErrnoTest.cpp b/llvm/unittests/Support/ErrnoTest.cpp
new file mode 100644
index 00000000000..72b52c01ee3
--- /dev/null
+++ b/llvm/unittests/Support/ErrnoTest.cpp
@@ -0,0 +1,33 @@
+//===- ErrnoTest.cpp - Error handling unit tests --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Errno.h"
+#include "gtest/gtest.h"
+
+using namespace llvm::sys;
+
+TEST(ErrnoTest, RetryAfterSignal) {
+  EXPECT_EQ(1, RetryAfterSignal(-1, [] { return 1; }));
+
+  EXPECT_EQ(-1, RetryAfterSignal(-1, [] {
+    errno = EAGAIN;
+    return -1;
+  }));
+  EXPECT_EQ(EAGAIN, errno);
+
+  unsigned calls = 0;
+  EXPECT_EQ(1, RetryAfterSignal(-1, [&calls] {
+              errno = EINTR;
+              ++calls;
+              return calls == 1 ? -1 : 1;
+            }));
+  EXPECT_EQ(2u, calls);
+
+  EXPECT_EQ(1, RetryAfterSignal(-1, [](int x) { return x; }, 1));
+}