diff --git a/clang/include/clang/Analysis/FlowSensitive/StorageLocation.h b/clang/include/clang/Analysis/FlowSensitive/StorageLocation.h
--- a/clang/include/clang/Analysis/FlowSensitive/StorageLocation.h
+++ b/clang/include/clang/Analysis/FlowSensitive/StorageLocation.h
@@ -126,7 +126,7 @@
                      << " on StorageLocation " << this << " of type "
                      << getType() << "\n";
         llvm::dbgs() << "Existing children:\n";
-        for ([[maybe_unused]] auto [Field, Loc] : Children) {
+        for ([[maybe_unused]] auto &[Field, Loc] : Children) {
           llvm::dbgs() << Field->getNameAsString() << "\n";
         }
       }
diff --git a/clang/lib/AST/Interp/ByteCodeEmitter.cpp b/clang/lib/AST/Interp/ByteCodeEmitter.cpp
--- a/clang/lib/AST/Interp/ByteCodeEmitter.cpp
+++ b/clang/lib/AST/Interp/ByteCodeEmitter.cpp
@@ -61,7 +61,7 @@
 
       MD->getParent()->getCaptureFields(LC, LTC);
 
-      for (auto Cap : LC) {
+      for (auto &Cap : LC) {
         unsigned Offset = R->getField(Cap.second)->Offset;
         this->LambdaCaptures[Cap.first] = {
             Offset, Cap.second->getType()->isReferenceType()};
diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp
--- a/clang/lib/AST/RecordLayoutBuilder.cpp
+++ b/clang/lib/AST/RecordLayoutBuilder.cpp
@@ -3725,7 +3725,7 @@
   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
     OS << "  BaseOffsets: [";
     const CXXRecordDecl *Base = nullptr;
-    for (auto I : CXXRD->bases()) {
+    for (auto &I : CXXRD->bases()) {
       if (I.isVirtual())
         continue;
       if (Base)
diff --git a/clang/lib/Analysis/FlowSensitive/RecordOps.cpp b/clang/lib/Analysis/FlowSensitive/RecordOps.cpp
--- a/clang/lib/Analysis/FlowSensitive/RecordOps.cpp
+++ b/clang/lib/Analysis/FlowSensitive/RecordOps.cpp
@@ -35,7 +35,7 @@
   });
   assert(compatibleTypes);
 
-  for (auto [Field, DstFieldLoc] : Dst.children()) {
+  for (auto &[Field, DstFieldLoc] : Dst.children()) {
     StorageLocation *SrcFieldLoc = Src.getChild(*Field);
 
     assert(Field->getType()->isReferenceType() ||
@@ -83,7 +83,7 @@
   assert(Loc2.getType().getCanonicalType().getUnqualifiedType() ==
          Loc1.getType().getCanonicalType().getUnqualifiedType());
 
-  for (auto [Field, FieldLoc1] : Loc1.children()) {
+  for (auto &[Field, FieldLoc1] : Loc1.children()) {
     StorageLocation *FieldLoc2 = Loc2.getChild(*Field);
 
     assert(Field->getType()->isReferenceType() ||
diff --git a/clang/lib/Sema/SemaRISCVVectorLookup.cpp b/clang/lib/Sema/SemaRISCVVectorLookup.cpp
--- a/clang/lib/Sema/SemaRISCVVectorLookup.cpp
+++ b/clang/lib/Sema/SemaRISCVVectorLookup.cpp
@@ -302,7 +302,7 @@
         if (Record.MaskedPolicyScheme == PolicyScheme::SchemeNone)
           continue;
         // Create masked policy intrinsic.
-        for (auto P : SupportedMaskedPolicies) {
+        for (auto &P : SupportedMaskedPolicies) {
           llvm::SmallVector<PrototypeDescriptor> PolicyPrototype =
               RVVIntrinsic::computeBuiltinTypes(
                   BasicProtoSeq, /*IsMasked=*/true, Record.HasMaskedOffOperand,
diff --git a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -2618,7 +2618,7 @@
     return;
 
   CStringLengthTy::Factory &F = state->get_context<CStringLength>();
-  for (auto [Reg, Len] : Entries) {
+  for (auto &[Reg, Len] : Entries) {
     if (SymbolRef Sym = Len.getAsSymbol()) {
       if (SR.isDead(Sym))
         Entries = F.remove(Entries, Reg);
diff --git a/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
@@ -848,7 +848,8 @@
   if (argumentNumber < 0) { // There was no match in UIMethods
     if (const Decl *D = msg.getDecl()) {
       if (const ObjCMethodDecl *OMD = dyn_cast_or_null<ObjCMethodDecl>(D)) {
-        for (auto [Idx, FormalParam] : llvm::enumerate(OMD->parameters())) {
+        for (const auto &[Idx, FormalParam] :
+             llvm::enumerate(OMD->parameters())) {
           if (isAnnotatedAsTakingLocalized(FormalParam)) {
             argumentNumber = Idx;
             break;
diff --git a/clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp
@@ -531,7 +531,7 @@
   }
 
   if (ReturnSymbol)
-    for (auto [Sym, AllocState] : AMap) {
+    for (auto &[Sym, AllocState] : AMap) {
       if (ReturnSymbol == AllocState.Region)
         State = State->remove<AllocatedData>(Sym);
     }
diff --git a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -2818,7 +2818,7 @@
 
   // Cleanup the Realloc Pairs Map.
   ReallocPairsTy RP = state->get<ReallocPairs>();
-  for (auto [Sym, ReallocPair] : RP) {
+  for (auto &[Sym, ReallocPair] : RP) {
     if (SymReaper.isDead(Sym) || SymReaper.isDead(ReallocPair.ReallocatedSym)) {
       state = state->remove<ReallocPairs>(Sym);
     }
@@ -3078,7 +3078,7 @@
   // Realloc returns 0 when reallocation fails, which means that we should
   // restore the state of the pointer being reallocated.
   ReallocPairsTy RP = state->get<ReallocPairs>();
-  for (auto [Sym, ReallocPair] : RP) {
+  for (auto &[Sym, ReallocPair] : RP) {
     // If the symbol is assumed to be NULL, remove it from consideration.
     ConstraintManager &CMgr = state->getConstraintManager();
     ConditionTruthVal AllocFailed = CMgr.isNull(state, Sym);
@@ -3555,7 +3555,7 @@
 
   if (!RS.isEmpty()) {
     Out << Sep << "MallocChecker :" << NL;
-    for (auto [Sym, Data] : RS) {
+    for (auto &[Sym, Data] : RS) {
       const RefState *RefS = State->get<RegionState>(Sym);
       AllocationFamily Family = RefS->getAllocationFamily();
       std::optional<MallocChecker::CheckKind> CheckKind =
diff --git a/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
@@ -942,7 +942,7 @@
 ProgramStateRef NullabilityChecker::evalAssume(ProgramStateRef State, SVal Cond,
                                                bool Assumption) const {
   PropertyAccessesMapTy PropertyAccesses = State->get<PropertyAccessesMap>();
-  for (auto [PropKey, PropVal] : PropertyAccesses) {
+  for (auto &[PropKey, PropVal] : PropertyAccesses) {
     if (!PropVal.isConstrainedNonnull) {
       ConditionTruthVal IsNonNull = State->isNonNull(PropVal.Value);
       if (IsNonNull.isConstrainedTrue()) {
@@ -1370,7 +1370,7 @@
   if (!State->get<InvariantViolated>())
     Out << Sep << NL;
 
-  for (auto [Region, State] : B) {
+  for (auto &[Region, State] : B) {
     Out << Region << " : ";
     State.print(Out);
     Out << NL;
diff --git a/clang/lib/StaticAnalyzer/Checkers/ObjCSelfInitChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ObjCSelfInitChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/ObjCSelfInitChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ObjCSelfInitChecker.cpp
@@ -362,7 +362,7 @@
   }
 
   Out << NL;
-  for (auto [Sym, Flag] : FlagMap) {
+  for (auto &[Sym, Flag] : FlagMap) {
     Out << Sym << " : ";
 
     if (Flag == SelfFlag_None)
diff --git a/clang/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp
@@ -151,7 +151,7 @@
   Scan(M, D->getDeclContext(), SM.getFileID(D->getLocation()), SM);
 
   // Find ivars that are unused.
-  for (auto [Ivar, State] : M)
+  for (auto &[Ivar, State] : M)
     if (State == Unused) {
       std::string sbuf;
       llvm::raw_string_ostream os(sbuf);
diff --git a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
@@ -166,7 +166,7 @@
   const LocationContext *LC = C.getLocationContext();
   MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager();
 
-  for (auto Var : ReferencedVars) {
+  for (auto &Var : ReferencedVars) {
     const VarRegion *VR = Var.getCapturedRegion();
     if (VR->getSuperRegion() == R) {
       VR = MemMgr.getVarRegion(VR->getDecl(), LC);
diff --git a/clang/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp
@@ -163,7 +163,7 @@
   ProgramStateRef State = C.getState();
   SymbolVector LeakedStreams;
   StreamMapTy TrackedStreams = State->get<StreamMap>();
-  for (auto [Sym, StreamStatus] : TrackedStreams) {
+  for (auto &[Sym, StreamStatus] : TrackedStreams) {
     bool IsSymDead = SymReaper.isDead(Sym);
 
     // Collect leaked symbols.
diff --git a/clang/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp
@@ -138,7 +138,7 @@
 StackAddrEscapeChecker::getCapturedStackRegions(const BlockDataRegion &B,
                                                 CheckerContext &C) {
   SmallVector<const MemRegion *, 4> Regions;
-  for (auto Var : B.referenced_vars()) {
+  for (auto &Var : B.referenced_vars()) {
     SVal Val = C.getState()->getSVal(Var.getCapturedRegion());
     const MemRegion *Region = Val.getAsRegion();
     if (Region && isa<StackSpaceRegion>(Region->getMemorySpace()))
diff --git a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
@@ -991,7 +991,7 @@
   if (Ranges.empty())
     return;
 
-  for (auto [Start, End] : getRanges()) {
+  for (auto &[Start, End] : getRanges()) {
     const llvm::APSInt &Min = BVF.getValue(Start, ArgT);
     const llvm::APSInt &Max = BVF.getValue(End, ArgT);
     assert(Min <= Max);
@@ -1501,7 +1501,7 @@
   }
 
   // Check the argument types.
-  for (auto [Idx, ArgTy] : llvm::enumerate(ArgTys)) {
+  for (const auto &[Idx, ArgTy] : llvm::enumerate(ArgTys)) {
     if (isIrrelevant(ArgTy))
       continue;
     QualType FDArgTy =
diff --git a/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
@@ -57,7 +57,7 @@
   ProgramStateRef state = C.getState();
   auto *R = cast<BlockDataRegion>(C.getSVal(BE).getAsRegion());
 
-  for (auto Var : R->referenced_vars()) {
+  for (auto &Var : R->referenced_vars()) {
     // This VarRegion is the region associated with the block; we need
     // the one associated with the encompassing context.
     const VarRegion *VR = Var.getCapturedRegion();
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
@@ -211,7 +211,7 @@
     auto ReferencedVars = BDR->referenced_vars();
     auto CI = BD->capture_begin();
     auto CE = BD->capture_end();
-    for (auto Var : ReferencedVars) {
+    for (auto &Var : ReferencedVars) {
       const VarRegion *capturedR = Var.getCapturedRegion();
       const TypedValueRegion *originalR = Var.getOriginalRegion();
 
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
@@ -1193,7 +1193,7 @@
 
   // If we created a new MemRegion for the lambda, we should explicitly bind
   // the captures.
-  for (auto const [Idx, FieldForCapture, InitExpr] :
+  for (auto const &[Idx, FieldForCapture, InitExpr] :
        llvm::zip(llvm::seq<unsigned>(0, -1), LE->getLambdaClass()->fields(),
                  LE->capture_inits())) {
     SVal FieldLoc = State->getLValue(FieldForCapture, V);
diff --git a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
--- a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
+++ b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
@@ -492,7 +492,7 @@
 void BlockDataRegion::dumpToStream(raw_ostream &os) const {
   os << "block_data{" << BC;
   os << "; ";
-  for (auto Var : referenced_vars())
+  for (auto &Var : referenced_vars())
     os << "(" << Var.getCapturedRegion() << "<-" << Var.getOriginalRegion()
        << ") ";
   os << '}';
@@ -966,7 +966,7 @@
     if (const auto *BC = dyn_cast<BlockInvocationContext>(LC)) {
       const auto *BR = static_cast<const BlockDataRegion *>(BC->getData());
       // FIXME: This can be made more efficient.
-      for (auto Var : BR->referenced_vars()) {
+      for (auto &Var : BR->referenced_vars()) {
         const TypedValueRegion *OrigR = Var.getOriginalRegion();
         if (const auto *VR = dyn_cast<VarRegion>(OrigR)) {
           if (VR->getDecl() == VD)
diff --git a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
--- a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
@@ -627,7 +627,7 @@
 
   // Regions captured by a block are also implicitly reachable.
   if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(R)) {
-    for (auto Var : BDR->referenced_vars()) {
+    for (auto &Var : BDR->referenced_vars()) {
       if (!scan(Var.getCapturedRegion()))
         return false;
     }
diff --git a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
--- a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -1089,7 +1089,7 @@
   // BlockDataRegion?  If so, invalidate captured variables that are passed
   // by reference.
   if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
-    for (auto Var : BR->referenced_vars()) {
+    for (auto &Var : BR->referenced_vars()) {
       const VarRegion *VR = Var.getCapturedRegion();
       const VarDecl *VD = VR->getDecl();
       if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
@@ -2844,7 +2844,7 @@
 
     // All regions captured by a block are also live.
     if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
-      for (auto Var : BR->referenced_vars())
+      for (auto &Var : BR->referenced_vars())
         AddToWorkList(Var.getCapturedRegion());
     }
   }