diff --git a/lib/Analysis/RegionPass.cpp b/lib/Analysis/RegionPass.cpp
index cd1e944d46a..5e1cdd48a78 100644
--- a/lib/Analysis/RegionPass.cpp
+++ b/lib/Analysis/RegionPass.cpp
@@ -199,7 +199,7 @@ public:
 
   bool runOnRegion(Region *R, RGPassManager &RGM) override {
     Out << Banner;
-    for (const auto &BB : R->blocks()) {
+    for (const auto *BB : R->blocks()) {
       if (BB)
         BB->print(Out);
       else
diff --git a/lib/CodeGen/WinEHPrepare.cpp b/lib/CodeGen/WinEHPrepare.cpp
index e5e6f250d3e..afe26ff8224 100644
--- a/lib/CodeGen/WinEHPrepare.cpp
+++ b/lib/CodeGen/WinEHPrepare.cpp
@@ -909,7 +909,7 @@ bool WinEHPrepare::outlineHandler(ActionHandler *Action, Function *SrcFn,
     // save the association of the blocks in LPadTargetBlocks.  The
     // return instructions which are created from these branches will be
     // replaced after all landing pads have been outlined.
-    for (const auto &MapEntry : VMap) {
+    for (const auto MapEntry : VMap) {
       // VMap maps all values and blocks that were just cloned, but dead
       // blocks which were pruned will map to nullptr.
       if (!isa<BasicBlock>(MapEntry.first) || MapEntry.second == nullptr)
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 87e7ed17e32..e9f685eb88f 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -803,7 +803,7 @@ static void EmitGenDwarfRanges(MCStreamer *MCOS) {
 
   MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfRangesSection());
 
-  for (const auto sec : Sections) {
+  for (const auto &sec : Sections) {
 
     MCSymbol *StartSymbol = sec.second.first;
     MCSymbol *EndSymbol = sec.second.second;
diff --git a/lib/Object/COFFObjectFile.cpp b/lib/Object/COFFObjectFile.cpp
index ad278a449e8..4c38b8fd2b0 100644
--- a/lib/Object/COFFObjectFile.cpp
+++ b/lib/Object/COFFObjectFile.cpp
@@ -262,7 +262,7 @@ std::error_code COFFObjectFile::getSymbolSize(DataRefImpl Ref,
   }
   const section_iterator SecEnd = section_end();
   uint64_t AfterAddr = UnknownAddressOrSize;
-  for (const symbol_iterator &SymbI : symbols()) {
+  for (const symbol_iterator SymbI : symbols()) {
     section_iterator SecI = SecEnd;
     if (std::error_code EC = SymbI->getSection(SecI))
       return EC;
diff --git a/lib/Target/AArch64/AArch64CollectLOH.cpp b/lib/Target/AArch64/AArch64CollectLOH.cpp
index 568f258c550..efdb2e33a36 100644
--- a/lib/Target/AArch64/AArch64CollectLOH.cpp
+++ b/lib/Target/AArch64/AArch64CollectLOH.cpp
@@ -328,7 +328,7 @@ static void initReachingDef(const MachineFunction &MF,
         const uint32_t *PreservedRegs = MO.getRegMask();
 
         // Set generated regs.
-        for (const auto Entry : RegToId) {
+        for (const auto &Entry : RegToId) {
           unsigned Reg = Entry.second;
           // Use the global register ID when querying APIs external to this
           // pass.
diff --git a/lib/Transforms/Scalar/StructurizeCFG.cpp b/lib/Transforms/Scalar/StructurizeCFG.cpp
index 6c3ce58c590..4f23e20d251 100644
--- a/lib/Transforms/Scalar/StructurizeCFG.cpp
+++ b/lib/Transforms/Scalar/StructurizeCFG.cpp
@@ -887,7 +887,7 @@ void StructurizeCFG::createFlow() {
 /// no longer dominate all their uses. Not sure if this is really nessasary
 void StructurizeCFG::rebuildSSA() {
   SSAUpdater Updater;
-  for (const auto &BB : ParentRegion->blocks())
+  for (auto *BB : ParentRegion->blocks())
     for (BasicBlock::iterator II = BB->begin(), IE = BB->end();
          II != IE; ++II) {
 
diff --git a/tools/llvm-cxxdump/llvm-cxxdump.cpp b/tools/llvm-cxxdump/llvm-cxxdump.cpp
index aeb977a5b42..dacb48ab01f 100644
--- a/tools/llvm-cxxdump/llvm-cxxdump.cpp
+++ b/tools/llvm-cxxdump/llvm-cxxdump.cpp
@@ -355,7 +355,8 @@ static void dumpCXXData(const ObjectFile *Obj) {
     StringRef SymName = VFTableEntry.second;
     outs() << VFTableName << '[' << Offset << "]: " << SymName << '\n';
   }
-  for (const std::pair<StringRef, ArrayRef<little32_t>> &VBTable : VBTables) {
+  for (const std::pair<const StringRef, ArrayRef<little32_t>> &VBTable :
+       VBTables) {
     StringRef VBTableName = VBTable.first;
     uint32_t Idx = 0;
     for (little32_t Offset : VBTable.second) {
@@ -363,7 +364,8 @@ static void dumpCXXData(const ObjectFile *Obj) {
       Idx += sizeof(Offset);
     }
   }
-  for (const std::pair<StringRef, CompleteObjectLocator> &COLPair : COLs) {
+  for (const std::pair<const StringRef, CompleteObjectLocator> &COLPair :
+       COLs) {
     StringRef COLName = COLPair.first;
     const CompleteObjectLocator &COL = COLPair.second;
     outs() << COLName << "[IsImageRelative]: " << COL.Data[0] << '\n';
@@ -373,7 +375,8 @@ static void dumpCXXData(const ObjectFile *Obj) {
     outs() << COLName << "[ClassHierarchyDescriptor]: " << COL.Symbols[1]
            << '\n';
   }
-  for (const std::pair<StringRef, ClassHierarchyDescriptor> &CHDPair : CHDs) {
+  for (const std::pair<const StringRef, ClassHierarchyDescriptor> &CHDPair :
+       CHDs) {
     StringRef CHDName = CHDPair.first;
     const ClassHierarchyDescriptor &CHD = CHDPair.second;
     outs() << CHDName << "[AlwaysZero]: " << CHD.Data[0] << '\n';
@@ -381,14 +384,14 @@ static void dumpCXXData(const ObjectFile *Obj) {
     outs() << CHDName << "[NumClasses]: " << CHD.Data[2] << '\n';
     outs() << CHDName << "[BaseClassArray]: " << CHD.Symbols[0] << '\n';
   }
-  for (const std::pair<std::pair<StringRef, uint64_t>, StringRef> &BCAEntry :
-       BCAEntries) {
+  for (const std::pair<const std::pair<StringRef, uint64_t>, StringRef>
+           &BCAEntry : BCAEntries) {
     StringRef BCAName = BCAEntry.first.first;
     uint64_t Offset = BCAEntry.first.second;
     StringRef SymName = BCAEntry.second;
     outs() << BCAName << '[' << Offset << "]: " << SymName << '\n';
   }
-  for (const std::pair<StringRef, BaseClassDescriptor> &BCDPair : BCDs) {
+  for (const std::pair<const StringRef, BaseClassDescriptor> &BCDPair : BCDs) {
     StringRef BCDName = BCDPair.first;
     const BaseClassDescriptor &BCD = BCDPair.second;
     outs() << BCDName << "[TypeDescriptor]: " << BCD.Symbols[0] << '\n';
@@ -400,7 +403,7 @@ static void dumpCXXData(const ObjectFile *Obj) {
     outs() << BCDName << "[ClassHierarchyDescriptor]: " << BCD.Symbols[1]
            << '\n';
   }
-  for (const std::pair<StringRef, TypeDescriptor> &TDPair : TDs) {
+  for (const std::pair<const StringRef, TypeDescriptor> &TDPair : TDs) {
     StringRef TDName = TDPair.first;
     const TypeDescriptor &TD = TDPair.second;
     outs() << TDName << "[VFPtr]: " << TD.Symbols[0] << '\n';
@@ -410,7 +413,7 @@ static void dumpCXXData(const ObjectFile *Obj) {
                          /*UseHexEscapes=*/true)
         << '\n';
   }
-  for (const std::pair<StringRef, ThrowInfo> &TIPair : TIs) {
+  for (const std::pair<const StringRef, ThrowInfo> &TIPair : TIs) {
     StringRef TIName = TIPair.first;
     const ThrowInfo &TI = TIPair.second;
     auto dumpThrowInfoFlag = [&](const char *Name, uint32_t Flag) {
@@ -429,7 +432,7 @@ static void dumpCXXData(const ObjectFile *Obj) {
     dumpThrowInfoSymbol("ForwardCompat", 8);
     dumpThrowInfoSymbol("CatchableTypeArray", 12);
   }
-  for (const std::pair<StringRef, CatchableTypeArray> &CTAPair : CTAs) {
+  for (const std::pair<const StringRef, CatchableTypeArray> &CTAPair : CTAs) {
     StringRef CTAName = CTAPair.first;
     const CatchableTypeArray &CTA = CTAPair.second;
 
@@ -441,7 +444,7 @@ static void dumpCXXData(const ObjectFile *Obj) {
          I != E; ++I)
       outs() << CTAName << '[' << Idx++ << "]: " << I->second << '\n';
   }
-  for (const std::pair<StringRef, CatchableType> &CTPair : CTs) {
+  for (const std::pair<const StringRef, CatchableType> &CTPair : CTs) {
     StringRef CTName = CTPair.first;
     const CatchableType &CT = CTPair.second;
     auto dumpCatchableTypeFlag = [&](const char *Name, uint32_t Flag) {
@@ -464,14 +467,14 @@ static void dumpCXXData(const ObjectFile *Obj) {
            << "[CopyCtor]: " << (CT.Symbols[1].empty() ? "null" : CT.Symbols[1])
            << '\n';
   }
-  for (const std::pair<std::pair<StringRef, uint64_t>, StringRef> &VTTPair :
-       VTTEntries) {
+  for (const std::pair<const std::pair<StringRef, uint64_t>, StringRef>
+           &VTTPair : VTTEntries) {
     StringRef VTTName = VTTPair.first.first;
     uint64_t VTTOffset = VTTPair.first.second;
     StringRef VTTEntry = VTTPair.second;
     outs() << VTTName << '[' << VTTOffset << "]: " << VTTEntry << '\n';
   }
-  for (const std::pair<StringRef, StringRef> &TIPair : TINames) {
+  for (const std::pair<const StringRef, StringRef> &TIPair : TINames) {
     StringRef TIName = TIPair.first;
     outs() << TIName << ": " << TIPair.second << '\n';
   }
diff --git a/utils/TableGen/CodeGenRegisters.cpp b/utils/TableGen/CodeGenRegisters.cpp
index e36066adf7a..4dd76813575 100644
--- a/utils/TableGen/CodeGenRegisters.cpp
+++ b/utils/TableGen/CodeGenRegisters.cpp
@@ -1780,7 +1780,7 @@ void CodeGenRegBank::computeRegUnitLaneMasks() {
       const CodeGenRegister *SubRegister = S->second;
       unsigned LaneMask = SubRegIndex->LaneMask;
       // Distribute LaneMask to Register Units touched.
-      for (const auto &SUI : SubRegister->getRegUnits()) {
+      for (unsigned SUI : SubRegister->getRegUnits()) {
         bool Found = false;
         unsigned u = 0;
         for (unsigned RU : RegUnits) {