diff --git a/llvm/lib/CodeGen/FixupStatepointCallerSaved.cpp b/llvm/lib/CodeGen/FixupStatepointCallerSaved.cpp
index cdcac1f50db6..8a4877e8f43b 100644
--- a/llvm/lib/CodeGen/FixupStatepointCallerSaved.cpp
+++ b/llvm/lib/CodeGen/FixupStatepointCallerSaved.cpp
@@ -82,6 +82,7 @@ static unsigned getRegisterSize(const TargetRegisterInfo &TRI, Register Reg) {
   return TRI.getSpillSize(*RC);
 }
 
+namespace {
 // Cache used frame indexes during statepoint re-write to re-use them in
 // processing next statepoint instruction.
 // Two strategies. One is to preserve the size of spill slot while another one
@@ -282,6 +283,7 @@ public:
     return true;
   }
 };
+} // namespace
 
 bool FixupStatepointCallerSaved::runOnMachineFunction(MachineFunction &MF) {
   if (skipFunction(MF.getFunction()))
diff --git a/llvm/lib/CodeGen/GlobalISel/LostDebugLocObserver.cpp b/llvm/lib/CodeGen/GlobalISel/LostDebugLocObserver.cpp
index 29f56b167c66..6d606e5550f1 100644
--- a/llvm/lib/CodeGen/GlobalISel/LostDebugLocObserver.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LostDebugLocObserver.cpp
@@ -78,7 +78,7 @@ void LostDebugLocObserver::createdInstr(MachineInstr &MI) {
   PotentialMIsForDebugLocs.insert(&MI);
 }
 
-bool irTranslatorNeverAddsLocations(unsigned Opcode) {
+static bool irTranslatorNeverAddsLocations(unsigned Opcode) {
   switch (Opcode) {
   default:
     return false;
diff --git a/llvm/lib/Target/ARM/MVEGatherScatterLowering.cpp b/llvm/lib/Target/ARM/MVEGatherScatterLowering.cpp
index 580b5d5881f9..61ebf454aff3 100644
--- a/llvm/lib/Target/ARM/MVEGatherScatterLowering.cpp
+++ b/llvm/lib/Target/ARM/MVEGatherScatterLowering.cpp
@@ -515,7 +515,7 @@ void MVEGatherScatterLowering::pushOutMul(PHINode *&Phi,
 }
 
 // Return true if the given intrinsic is a gather or scatter
-bool isGatherScatter(IntrinsicInst *IntInst) {
+static bool isGatherScatter(IntrinsicInst *IntInst) {
   if (IntInst == nullptr)
     return false;
   unsigned IntrinsicID = IntInst->getIntrinsicID();
@@ -537,7 +537,7 @@ bool isGatherScatter(IntrinsicInst *IntInst) {
 
 // Check whether all usages of this instruction are as offsets of
 // gathers/scatters or simple arithmetics only used by gathers/scatters
-bool hasAllGatScatUsers(Instruction *I) {
+static bool hasAllGatScatUsers(Instruction *I) {
   if (I->hasNUses(0)) {
     return false;
   }
diff --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
index 1a3e59a3adb4..8573040a3fd4 100644
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -6016,6 +6016,7 @@ std::string AAMemoryLocation::getMemoryLocationsAsStr(
   return S;
 }
 
+namespace {
 struct AAMemoryLocationImpl : public AAMemoryLocation {
 
   AAMemoryLocationImpl(const IRPosition &IRP, Attributor &A)
@@ -6978,6 +6979,7 @@ struct AAValueConstantRangeCallSiteArgument : AAValueConstantRangeFloating {
     STATS_DECLTRACK_CSARG_ATTR(value_range)
   }
 };
+} // namespace
 
 const char AAReturnedValues::ID = 0;
 const char AANoUnwind::ID = 0;
diff --git a/llvm/lib/Transforms/Utils/FixIrreducible.cpp b/llvm/lib/Transforms/Utils/FixIrreducible.cpp
index df646b70a145..510c033f6474 100644
--- a/llvm/lib/Transforms/Utils/FixIrreducible.cpp
+++ b/llvm/lib/Transforms/Utils/FixIrreducible.cpp
@@ -241,8 +241,8 @@ template <> struct GraphTraits<Loop> : LoopBodyTraits {};
 } // namespace llvm
 
 // Overloaded wrappers to go with the function template below.
-BasicBlock *unwrapBlock(BasicBlock *B) { return B; }
-BasicBlock *unwrapBlock(LoopBodyTraits::NodeRef &N) { return N.second; }
+static BasicBlock *unwrapBlock(BasicBlock *B) { return B; }
+static BasicBlock *unwrapBlock(LoopBodyTraits::NodeRef &N) { return N.second; }
 
 static void createNaturalLoop(LoopInfo &LI, DominatorTree &DT, Function *F,
                               SetVector<BasicBlock *> &Blocks,
diff --git a/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp b/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
index 3d5c2a92b535..e4976aeaa346 100644
--- a/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
+++ b/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
@@ -199,10 +199,12 @@ static ParseResult parseGenericOp(OpAsmParser &parser, OperationState &result) {
                                 parser.getCurrentLocation(), result.operands);
 }
 
+namespace {
 template <typename GenericOpType>
 struct BlockArgsVerifier {
   static LogicalResult verify(GenericOpType op, Block &block);
 };
+} // namespace
 
 template <typename GenericOpType>
 LogicalResult BlockArgsVerifier<GenericOpType>::verify(GenericOpType op,
@@ -492,7 +494,8 @@ void mlir::linalg::ReshapeOp::build(
 // Common verifier for reshape-like types. Fills `expandedType` and
 // `collapsedType` with the proper `src` or `result` type.
 template <typename Op, typename T>
-LogicalResult verifyReshapeLikeTypes(Op op, T &expandedType, T &collapsedType) {
+static LogicalResult verifyReshapeLikeTypes(Op op, T &expandedType,
+                                            T &collapsedType) {
   expandedType = op.getSrcType();
   collapsedType = op.getResultType();
   unsigned expandedRank = expandedType.getRank();