diff --git a/include/llvm/LTO/Config.h b/include/llvm/LTO/Config.h
index c4bf370fa3d..1a7595d7540 100644
--- a/include/llvm/LTO/Config.h
+++ b/include/llvm/LTO/Config.h
@@ -114,10 +114,10 @@ struct Config {
   std::string SplitDwarfOutput;
 
   /// Optimization remarks file path.
-  std::string RemarksFilename = "";
+  std::string RemarksFilename;
 
   /// Optimization remarks pass filter.
-  std::string RemarksPasses = "";
+  std::string RemarksPasses;
 
   /// Whether to emit optimization remarks with hotness informations.
   bool RemarksWithHotness = false;
@@ -138,7 +138,7 @@ struct Config {
   llvm::Optional<uint64_t> RemarksHotnessThreshold = 0;
 
   /// The format used for serializing remarks (default: YAML).
-  std::string RemarksFormat = "";
+  std::string RemarksFormat;
 
   /// Whether to emit the pass manager debuggging informations.
   bool DebugPassManager = false;
diff --git a/lib/Analysis/CallPrinter.cpp b/lib/Analysis/CallPrinter.cpp
index c3922d55602..872a91ad7cb 100644
--- a/lib/Analysis/CallPrinter.cpp
+++ b/lib/Analysis/CallPrinter.cpp
@@ -196,7 +196,7 @@ struct DOTGraphTraits<CallGraphDOTInfo *> : public DefaultDOTGraphTraits {
     Function *F = Node->getFunction();
     if (F == nullptr)
       return "";
-    std::string attrs = "";
+    std::string attrs;
     if (ShowHeatColors) {
       uint64_t freq = CGInfo->getFreq(F);
       std::string color = getHeatColor(freq, CGInfo->getMaxFreq());
diff --git a/lib/Analysis/ConstraintSystem.cpp b/lib/Analysis/ConstraintSystem.cpp
index 1d582802f8e..9739c6af576 100644
--- a/lib/Analysis/ConstraintSystem.cpp
+++ b/lib/Analysis/ConstraintSystem.cpp
@@ -116,7 +116,7 @@ void ConstraintSystem::dump(ArrayRef<std::string> Names) const {
     for (unsigned I = 1, S = Row.size(); I < S; ++I) {
       if (Row[I] == 0)
         continue;
-      std::string Coefficient = "";
+      std::string Coefficient;
       if (Row[I] != 1)
         Coefficient = std::to_string(Row[I]) + " * ";
       Parts.push_back(Coefficient + Names[I - 1]);
diff --git a/lib/CodeGen/GlobalISel/InstructionSelect.cpp b/lib/CodeGen/GlobalISel/InstructionSelect.cpp
index f32278d0705..25fae548718 100644
--- a/lib/CodeGen/GlobalISel/InstructionSelect.cpp
+++ b/lib/CodeGen/GlobalISel/InstructionSelect.cpp
@@ -41,7 +41,7 @@ static cl::opt<std::string>
                    cl::desc("Record GlobalISel rule coverage files of this "
                             "prefix if instrumentation was generated"));
 #else
-static const std::string CoveragePrefix = "";
+static const std::string CoveragePrefix;
 #endif
 
 char InstructionSelect::ID = 0;
diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 7bc5c98b89b..32e8393a88e 100644
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -917,7 +917,7 @@ MCSection *TargetLoweringObjectFileELF::getSectionForMachineBasicBlock(
   }
 
   unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_EXECINSTR;
-  std::string GroupName = "";
+  std::string GroupName;
   if (F.hasComdat()) {
     Flags |= ELF::SHF_GROUP;
     GroupName = F.getComdat()->getName().str();
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
index e5e512672da..2fbe707ce8d 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
@@ -352,7 +352,7 @@ private:
     RemainingExpr = RemainingExpr.substr(1).ltrim();
 
     uint64_t StubAddr;
-    std::string ErrorMsg = "";
+    std::string ErrorMsg;
     std::tie(StubAddr, ErrorMsg) = Checker.getStubOrGOTAddrFor(
         StubContainerName, Symbol, PCtx.IsInsideLoad, IsStubAddr);
 
@@ -389,7 +389,7 @@ private:
     RemainingExpr = RemainingExpr.substr(1).ltrim();
 
     uint64_t StubAddr;
-    std::string ErrorMsg = "";
+    std::string ErrorMsg;
     std::tie(StubAddr, ErrorMsg) = Checker.getSectionAddr(
         FileName, SectionName, PCtx.IsInsideLoad);
 
diff --git a/lib/Target/Mips/MipsRegisterBankInfo.h b/lib/Target/Mips/MipsRegisterBankInfo.h
index 55eeaf096b1..df51606e1e8 100644
--- a/lib/Target/Mips/MipsRegisterBankInfo.h
+++ b/lib/Target/Mips/MipsRegisterBankInfo.h
@@ -150,7 +150,7 @@ private:
 
   class TypeInfoForMF {
     /// MachineFunction name is used to recognise when MF changes.
-    std::string MFName = "";
+    std::string MFName;
     /// <key, value> : value is vector of all MachineInstrs that are waiting for
     /// key to figure out type of some of its ambiguous operands.
     DenseMap<const MachineInstr *, SmallVector<const MachineInstr *, 2>>
diff --git a/lib/Transforms/IPO/Attributor.cpp b/lib/Transforms/IPO/Attributor.cpp
index ab4ad7c784a..03ad4513500 100644
--- a/lib/Transforms/IPO/Attributor.cpp
+++ b/lib/Transforms/IPO/Attributor.cpp
@@ -2459,7 +2459,7 @@ template <> struct DOTGraphTraits<AADepGraph *> : public DefaultDOTGraphTraits {
 
   static std::string getNodeLabel(const AADepGraphNode *Node,
                                   const AADepGraph *DG) {
-    std::string AAString = "";
+    std::string AAString;
     raw_string_ostream O(AAString);
     Node->print(O);
     return AAString;
diff --git a/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp b/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
index 19173972879..9d856c85c3b 100644
--- a/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
+++ b/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
@@ -1596,7 +1596,7 @@ public:
         write(StringRef(Intrinsic::getName(II->getIntrinsicID(), {}))
                   .drop_front(StringRef("llvm.matrix.").size()));
         write(".");
-        std::string Tmp = "";
+        std::string Tmp;
         raw_string_ostream SS(Tmp);
 
         switch (II->getIntrinsicID()) {
diff --git a/tools/llvm-cov/SourceCoverageViewHTML.cpp b/tools/llvm-cov/SourceCoverageViewHTML.cpp
index 4db5624e34f..7ab1d6608cc 100644
--- a/tools/llvm-cov/SourceCoverageViewHTML.cpp
+++ b/tools/llvm-cov/SourceCoverageViewHTML.cpp
@@ -248,7 +248,7 @@ const char *ReportTitleTag = "h2";
 const char *CreatedTimeTag = "h4";
 
 std::string getPathToStyle(StringRef ViewPath) {
-  std::string PathToStyle = "";
+  std::string PathToStyle;
   std::string PathSep = std::string(sys::path::get_separator());
   unsigned NumSeps = ViewPath.count(PathSep);
   for (unsigned I = 0, E = NumSeps; I < E; ++I)
@@ -617,7 +617,7 @@ void SourceCoverageViewHTML::renderLine(raw_ostream &OS, LineRef L,
 
 void SourceCoverageViewHTML::renderLineCoverageColumn(
     raw_ostream &OS, const LineCoverageStats &Line) {
-  std::string Count = "";
+  std::string Count;
   if (Line.isMapped())
     Count = tag("pre", formatCount(Line.getExecutionCount()));
   std::string CoverageClass =
diff --git a/tools/llvm-ifs/llvm-ifs.cpp b/tools/llvm-ifs/llvm-ifs.cpp
index 8906300dca0..4d9a5c365a7 100644
--- a/tools/llvm-ifs/llvm-ifs.cpp
+++ b/tools/llvm-ifs/llvm-ifs.cpp
@@ -384,7 +384,7 @@ int main(int argc, char *argv[]) {
   IFSStub Stub;
   std::map<std::string, IFSSymbol> SymbolMap;
 
-  std::string PreviousInputFilePath = "";
+  std::string PreviousInputFilePath;
   for (const std::string &InputFilePath : InputFilenames) {
     Expected<std::unique_ptr<IFSStub>> StubOrErr = readInputFile(InputFilePath);
     if (!StubOrErr) {
diff --git a/tools/llvm-objdump/MachODump.cpp b/tools/llvm-objdump/MachODump.cpp
index 1fa9879c821..51212d52c18 100644
--- a/tools/llvm-objdump/MachODump.cpp
+++ b/tools/llvm-objdump/MachODump.cpp
@@ -2395,7 +2395,7 @@ void objdump::parseInputMachO(MachOUniversalBinary *UB) {
           ArchFound = true;
           Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
               I->getAsObjectFile();
-          std::string ArchitectureName = "";
+          std::string ArchitectureName;
           if (ArchFlags.size() > 1)
             ArchitectureName = I->getArchFlagName();
           if (ObjOrErr) {
@@ -2511,7 +2511,7 @@ void objdump::parseInputMachO(MachOUniversalBinary *UB) {
                                               E = UB->end_objects();
         I != E; ++I) {
     Expected<std::unique_ptr<ObjectFile>> ObjOrErr = I->getAsObjectFile();
-    std::string ArchitectureName = "";
+    std::string ArchitectureName;
     if (moreThanOneArch)
       ArchitectureName = I->getArchFlagName();
     if (ObjOrErr) {
diff --git a/utils/TableGen/CodeGenDAGPatterns.cpp b/utils/TableGen/CodeGenDAGPatterns.cpp
index 857d7f56ad7..1ca4a68eb15 100644
--- a/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -873,7 +873,7 @@ bool TreePredicateFn::hasPredCode() const {
 }
 
 std::string TreePredicateFn::getPredCode() const {
-  std::string Code = "";
+  std::string Code;
 
   if (!isLoad() && !isStore() && !isAtomic()) {
     Record *MemoryVT = getMemoryVT();
diff --git a/utils/TableGen/CodeGenInstruction.cpp b/utils/TableGen/CodeGenInstruction.cpp
index 1df5902b081..960fe08677f 100644
--- a/utils/TableGen/CodeGenInstruction.cpp
+++ b/utils/TableGen/CodeGenInstruction.cpp
@@ -472,7 +472,7 @@ HasOneImplicitDefWithKnownVT(const CodeGenTarget &TargetInfo) const {
 /// include text from the specified variant, returning the new string.
 std::string CodeGenInstruction::
 FlattenAsmStringVariants(StringRef Cur, unsigned Variant) {
-  std::string Res = "";
+  std::string Res;
 
   for (;;) {
     // Find the start of the next variant string.
diff --git a/utils/TableGen/CodeGenMapTable.cpp b/utils/TableGen/CodeGenMapTable.cpp
index ea53a2d3eee..289a20a96f0 100644
--- a/utils/TableGen/CodeGenMapTable.cpp
+++ b/utils/TableGen/CodeGenMapTable.cpp
@@ -374,7 +374,7 @@ unsigned MapTableEmitter::emitBinSearchTable(raw_ostream &OS) {
   for (unsigned i = 0; i < TotalNumInstr; i++) {
     Record *CurInstr = NumberedInstructions[i]->TheDef;
     std::vector<Record*> ColInstrs = MapTable[CurInstr];
-    std::string OutStr("");
+    std::string OutStr;
     unsigned RelExists = 0;
     if (!ColInstrs.empty()) {
       for (unsigned j = 0; j < NumCol; j++) {
diff --git a/utils/TableGen/GlobalISelEmitter.cpp b/utils/TableGen/GlobalISelEmitter.cpp
index 4be53930fc5..b238573be49 100644
--- a/utils/TableGen/GlobalISelEmitter.cpp
+++ b/utils/TableGen/GlobalISelEmitter.cpp
@@ -201,7 +201,7 @@ static Optional<LLTCodeGen> MVTToLLT(MVT::SimpleValueType SVT) {
 }
 
 static std::string explainPredicates(const TreePatternNode *N) {
-  std::string Explanation = "";
+  std::string Explanation;
   StringRef Separator = "";
   for (const TreePredicateCall &Call : N->getPredicateCalls()) {
     const TreePredicateFn &P = Call.Fn;
@@ -305,8 +305,8 @@ static Error failedImport(const Twine &Reason) {
 }
 
 static Error isTrivialOperatorNode(const TreePatternNode *N) {
-  std::string Explanation = "";
-  std::string Separator = "";
+  std::string Explanation;
+  std::string Separator;
 
   bool HasUnsupportedPredicate = false;
   for (const TreePredicateCall &Call : N->getPredicateCalls()) {
diff --git a/utils/TableGen/RISCVCompressInstEmitter.cpp b/utils/TableGen/RISCVCompressInstEmitter.cpp
index dcca207be7c..70f51816173 100644
--- a/utils/TableGen/RISCVCompressInstEmitter.cpp
+++ b/utils/TableGen/RISCVCompressInstEmitter.cpp
@@ -635,10 +635,10 @@ void RISCVCompressInstEmitter::emitCompressInstEmitter(raw_ostream &o,
     return;
   }
 
-  std::string CaseString("");
+  std::string CaseString;
   raw_string_ostream CaseStream(CaseString);
-  std::string PrevOp("");
-  std::string CurOp("");
+  std::string PrevOp;
+  std::string CurOp;
   CaseStream << "  switch (MI.getOpcode()) {\n";
   CaseStream << "    default: return false;\n";