diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 9b7ef07253a3..14ed0cc1836d 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -349,7 +349,7 @@ void codegen(const Config &Conf, TargetMachine *TM, AddStreamFn AddStream,
 
     DwoFile = Conf.DwoDir;
     sys::path::append(DwoFile, std::to_string(Task) + ".dwo");
-    TM->Options.MCOptions.SplitDwarfFile = DwoFile.str().str();
+    TM->Options.MCOptions.SplitDwarfFile = std::string(DwoFile);
   } else
     TM->Options.MCOptions.SplitDwarfFile = Conf.SplitDwarfFile;
 
diff --git a/llvm/lib/ProfileData/GCOV.cpp b/llvm/lib/ProfileData/GCOV.cpp
index e0f33fbbdb31..0c4006d867a6 100644
--- a/llvm/lib/ProfileData/GCOV.cpp
+++ b/llvm/lib/ProfileData/GCOV.cpp
@@ -693,7 +693,7 @@ std::string FileInfo::getCoveragePath(StringRef Filename,
     MD5::MD5Result Result;
     Hasher.update(Filename.str());
     Hasher.final(Result);
-    CoveragePath += "##" + Result.digest().str().str();
+    CoveragePath += "##" + std::string(Result.digest());
   }
   CoveragePath += ".gcov";
   return CoveragePath;
diff --git a/llvm/lib/Support/YAMLParser.cpp b/llvm/lib/Support/YAMLParser.cpp
index db1eb66ca26c..4f9feee4a8a0 100644
--- a/llvm/lib/Support/YAMLParser.cpp
+++ b/llvm/lib/Support/YAMLParser.cpp
@@ -1642,7 +1642,7 @@ bool Scanner::scanBlockScalar(bool IsLiteral) {
   Token T;
   T.Kind = Token::TK_BlockScalar;
   T.Range = StringRef(Start, Current - Start);
-  T.Value = Str.str().str();
+  T.Value = std::string(Str);
   TokenQueue.push_back(T);
   return true;
 }
diff --git a/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp b/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp
index 16b231f977aa..3ea53126d850 100644
--- a/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp
+++ b/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp
@@ -96,7 +96,7 @@ static std::string findInputFile(StringRef File, ArrayRef<StringRef> Paths) {
     SmallString<128> Path = Dir;
     sys::path::append(Path, File);
     if (sys::fs::exists(Path))
-      return Path.str().str();
+      return std::string(Path);
   }
   return "";
 }
diff --git a/llvm/tools/dsymutil/SymbolMap.cpp b/llvm/tools/dsymutil/SymbolMap.cpp
index 6a13efdf8e95..abf7557ca61e 100644
--- a/llvm/tools/dsymutil/SymbolMap.cpp
+++ b/llvm/tools/dsymutil/SymbolMap.cpp
@@ -96,7 +96,7 @@ SymbolMapTranslator SymbolMapLoader::Load(StringRef InputFile,
           StringRef UUID(CFStringGetCStringPtr(OldUUID, kCFStringEncodingUTF8));
           SmallString<256> BCSymbolMapPath(SymbolMapPath);
           sys::path::append(BCSymbolMapPath, UUID.str() + ".bcsymbolmap");
-          SymbolMapPath = BCSymbolMapPath.str().str();
+          SymbolMapPath = std::string(BCSymbolMapPath);
         }
         CFRelease(plist);
       }
diff --git a/llvm/tools/sancov/sancov.cpp b/llvm/tools/sancov/sancov.cpp
index d4046607edce..ffdf36f4e0bf 100644
--- a/llvm/tools/sancov/sancov.cpp
+++ b/llvm/tools/sancov/sancov.cpp
@@ -471,7 +471,7 @@ static std::unique_ptr<symbolize::LLVMSymbolizer> createSymbolizer() {
 static std::string normalizeFilename(const std::string &FileName) {
   SmallString<256> S(FileName);
   sys::path::remove_dots(S, /* remove_dot_dot */ true);
-  return stripPathPrefix(S.str().str());
+  return stripPathPrefix(std::string(S));
 }
 
 class Blacklists {
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index 6e87c70d5632..8191ec86e61f 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -1357,53 +1357,53 @@ TEST(APIntTest, toString) {
   bool isSigned;
 
   APInt(8, 0).toString(S, 2, true, true);
-  EXPECT_EQ(S.str().str(), "0b0");
+  EXPECT_EQ(std::string(S), "0b0");
   S.clear();
   APInt(8, 0).toString(S, 8, true, true);
-  EXPECT_EQ(S.str().str(), "00");
+  EXPECT_EQ(std::string(S), "00");
   S.clear();
   APInt(8, 0).toString(S, 10, true, true);
-  EXPECT_EQ(S.str().str(), "0");
+  EXPECT_EQ(std::string(S), "0");
   S.clear();
   APInt(8, 0).toString(S, 16, true, true);
-  EXPECT_EQ(S.str().str(), "0x0");
+  EXPECT_EQ(std::string(S), "0x0");
   S.clear();
   APInt(8, 0).toString(S, 36, true, false);
-  EXPECT_EQ(S.str().str(), "0");
+  EXPECT_EQ(std::string(S), "0");
   S.clear();
 
   isSigned = false;
   APInt(8, 255, isSigned).toString(S, 2, isSigned, true);
-  EXPECT_EQ(S.str().str(), "0b11111111");
+  EXPECT_EQ(std::string(S), "0b11111111");
   S.clear();
   APInt(8, 255, isSigned).toString(S, 8, isSigned, true);
-  EXPECT_EQ(S.str().str(), "0377");
+  EXPECT_EQ(std::string(S), "0377");
   S.clear();
   APInt(8, 255, isSigned).toString(S, 10, isSigned, true);
-  EXPECT_EQ(S.str().str(), "255");
+  EXPECT_EQ(std::string(S), "255");
   S.clear();
   APInt(8, 255, isSigned).toString(S, 16, isSigned, true);
-  EXPECT_EQ(S.str().str(), "0xFF");
+  EXPECT_EQ(std::string(S), "0xFF");
   S.clear();
   APInt(8, 255, isSigned).toString(S, 36, isSigned, false);
-  EXPECT_EQ(S.str().str(), "73");
+  EXPECT_EQ(std::string(S), "73");
   S.clear();
 
   isSigned = true;
   APInt(8, 255, isSigned).toString(S, 2, isSigned, true);
-  EXPECT_EQ(S.str().str(), "-0b1");
+  EXPECT_EQ(std::string(S), "-0b1");
   S.clear();
   APInt(8, 255, isSigned).toString(S, 8, isSigned, true);
-  EXPECT_EQ(S.str().str(), "-01");
+  EXPECT_EQ(std::string(S), "-01");
   S.clear();
   APInt(8, 255, isSigned).toString(S, 10, isSigned, true);
-  EXPECT_EQ(S.str().str(), "-1");
+  EXPECT_EQ(std::string(S), "-1");
   S.clear();
   APInt(8, 255, isSigned).toString(S, 16, isSigned, true);
-  EXPECT_EQ(S.str().str(), "-0x1");
+  EXPECT_EQ(std::string(S), "-0x1");
   S.clear();
   APInt(8, 255, isSigned).toString(S, 36, isSigned, false);
-  EXPECT_EQ(S.str().str(), "-1");
+  EXPECT_EQ(std::string(S), "-1");
   S.clear();
 }
 
diff --git a/llvm/unittests/Support/FileUtilitiesTest.cpp b/llvm/unittests/Support/FileUtilitiesTest.cpp
index 7fbb601eb786..cf1453b33d80 100644
--- a/llvm/unittests/Support/FileUtilitiesTest.cpp
+++ b/llvm/unittests/Support/FileUtilitiesTest.cpp
@@ -38,7 +38,8 @@ TEST(writeFileAtomicallyTest, Test) {
 
   SmallString<128> FinalTestfilePath(RootTestDirectory);
   sys::path::append(FinalTestfilePath, "foo.txt");
-  const std::string TempUniqTestFileModel = FinalTestfilePath.str().str() + "-%%%%%%%%";
+  const std::string TempUniqTestFileModel =
+      std::string(FinalTestfilePath) + "-%%%%%%%%";
   const std::string TestfileContent = "fooFOOfoo";
 
   llvm::Error Err = llvm::writeFileAtomically(TempUniqTestFileModel, FinalTestfilePath, TestfileContent);
diff --git a/llvm/unittests/Support/VirtualFileSystemTest.cpp b/llvm/unittests/Support/VirtualFileSystemTest.cpp
index ef92111cec70..7c0689745e26 100644
--- a/llvm/unittests/Support/VirtualFileSystemTest.cpp
+++ b/llvm/unittests/Support/VirtualFileSystemTest.cpp
@@ -1096,7 +1096,7 @@ TEST_F(InMemoryFileSystemTest, GetRealPath) {
     SmallString<16> Output;
     auto EC = FS.getRealPath(P, Output);
     EXPECT_FALSE(EC);
-    return Output.str().str();
+    return std::string(Output);
   };
 
   FS.setCurrentWorkingDirectory("a");