--- a/unittests/ADT/StringExtrasTest.cpp	Sun Dec 23 19:23:36 2018 +0900
+++ b/unittests/ADT/StringExtrasTest.cpp	Wed Aug 14 19:46:37 2019 +0900
@@ -1,9 +1,8 @@
 //===- StringExtrasTest.cpp - Unit tests for String extras ----------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
@@ -13,6 +12,17 @@
 
 using namespace llvm;
 
+TEST(StringExtrasTest, isPrint) {
+  EXPECT_FALSE(isPrint('\0'));
+  EXPECT_FALSE(isPrint('\t'));
+  EXPECT_TRUE(isPrint('0'));
+  EXPECT_TRUE(isPrint('a'));
+  EXPECT_TRUE(isPrint('A'));
+  EXPECT_TRUE(isPrint(' '));
+  EXPECT_TRUE(isPrint('~'));
+  EXPECT_TRUE(isPrint('?'));
+}
+
 TEST(StringExtrasTest, Join) {
   std::vector<std::string> Items;
   EXPECT_EQ("", join(Items.begin(), Items.end(), " <sep> "));
@@ -59,6 +69,7 @@
                     OddBytes.size());
   EXPECT_EQ(OddStr, toHex(OddData));
   EXPECT_EQ(OddData, fromHex(StringRef(OddStr).drop_front()));
+  EXPECT_EQ(StringRef(OddStr).lower(), toHex(OddData, true));
 
   std::vector<uint8_t> EvenBytes = {0xA5, 0xBD, 0x0D, 0x3E, 0xCD};
   std::string EvenStr = "A5BD0D3ECD";
@@ -66,6 +77,7 @@
                      EvenBytes.size());
   EXPECT_EQ(EvenStr, toHex(EvenData));
   EXPECT_EQ(EvenData, fromHex(EvenStr));
+  EXPECT_EQ(StringRef(EvenStr).lower(), toHex(EvenData, true));
 }
 
 TEST(StringExtrasTest, to_float) {
@@ -92,3 +104,17 @@
   printLowerCase("ABCdefg01234.,&!~`'}\"", OS);
   EXPECT_EQ("abcdefg01234.,&!~`'}\"", OS.str());
 }
+
+TEST(StringExtrasTest, printEscapedString) {
+  std::string str;
+  raw_string_ostream OS(str);
+  printEscapedString("ABCdef123&<>\\\"'\t", OS);
+  EXPECT_EQ("ABCdef123&<>\\5C\\22'\\09", OS.str());
+}
+
+TEST(StringExtrasTest, printHTMLEscaped) {
+  std::string str;
+  raw_string_ostream OS(str);
+  printHTMLEscaped("ABCdef123&<>\"'", OS);
+  EXPECT_EQ("ABCdef123&amp;&lt;&gt;&quot;&apos;", OS.str());
+}