diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index f6c3aa1a3c1d2..8eb58b32ae172 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -3081,7 +3081,7 @@ Error ASTNodeImporter::ImportFunctionDeclBody(FunctionDecl *FromFD,
 
 // Returns true if the given D has a DeclContext up to the TranslationUnitDecl
 // which is equal to the given DC.
-bool isAncestorDeclContextOf(const DeclContext *DC, const Decl *D) {
+static bool isAncestorDeclContextOf(const DeclContext *DC, const Decl *D) {
   const DeclContext *DCi = D->getDeclContext();
   while (DCi != D->getTranslationUnitDecl()) {
     if (DCi == DC)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 7b2b0336c32ad..09fd3087b494a 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -14260,6 +14260,7 @@ CodeGenFunction::EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
   }
 }
 
+namespace {
 struct BuiltinAlignArgs {
   llvm::Value *Src = nullptr;
   llvm::Type *SrcType = nullptr;
@@ -14288,6 +14289,7 @@ struct BuiltinAlignArgs {
     Mask = CGF.Builder.CreateSub(Alignment, One, "mask");
   }
 };
+} // namespace
 
 /// Generate (x & (y-1)) == 0.
 RValue CodeGenFunction::EmitBuiltinIsAligned(const CallExpr *E) {
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 0d96c5a2f73f4..97b17799a03e5 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -1438,6 +1438,7 @@ CGOpenMPRuntime::getUserDefinedReduction(const OMPDeclareReductionDecl *D) {
   return UDRMap.lookup(D);
 }
 
+namespace {
 // Temporary RAII solution to perform a push/pop stack event on the OpenMP IR
 // Builder if one is present.
 struct PushAndPopStackRAII {
@@ -1481,6 +1482,7 @@ struct PushAndPopStackRAII {
   }
   llvm::OpenMPIRBuilder *OMPBuilder;
 };
+} // namespace
 
 static llvm::Function *emitParallelOrTeamsOutlinedFunction(
     CodeGenModule &CGM, const OMPExecutableDirective &D, const CapturedStmt *CS,
@@ -11122,8 +11124,8 @@ bool checkContext<OMP_CTX_SET_device, OMP_CTX_kind, CodeGenModule &>(
   return true;
 }
 
-bool matchesContext(CodeGenModule &CGM,
-                    const CompleteOMPContextSelectorData &ContextData) {
+static bool matchesContext(CodeGenModule &CGM,
+                           const CompleteOMPContextSelectorData &ContextData) {
   for (const OMPContextSelectorData &Data : ContextData) {
     switch (Data.Ctx) {
     case OMP_CTX_vendor:
diff --git a/clang/lib/Driver/ToolChains/Arch/ARM.cpp b/clang/lib/Driver/ToolChains/Arch/ARM.cpp
index ae1d7eaf7089f..a1923e731489e 100644
--- a/clang/lib/Driver/ToolChains/Arch/ARM.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/ARM.cpp
@@ -63,9 +63,9 @@ static void getARMHWDivFeatures(const Driver &D, const Arg *A,
 }
 
 // Handle -mfpu=.
-unsigned getARMFPUFeatures(const Driver &D, const Arg *A,
-                              const ArgList &Args, StringRef FPU,
-                              std::vector<StringRef> &Features) {
+static unsigned getARMFPUFeatures(const Driver &D, const Arg *A,
+                                  const ArgList &Args, StringRef FPU,
+                                  std::vector<StringRef> &Features) {
   unsigned FPUID = llvm::ARM::parseFPU(FPU);
   if (!llvm::ARM::getFPUFeatures(FPUID, Features))
     D.Diag(clang::diag::err_drv_clang_unsupported) << A->getAsString(Args);
diff --git a/clang/lib/StaticAnalyzer/Checkers/CheckPlacementNew.cpp b/clang/lib/StaticAnalyzer/Checkers/CheckPlacementNew.cpp
index 6fe3cb63cde9a..48fee4a0ffb74 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CheckPlacementNew.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CheckPlacementNew.cpp
@@ -6,6 +6,7 @@
 using namespace clang;
 using namespace ento;
 
+namespace {
 class PlacementNewChecker : public Checker<check::PreStmt<CXXNewExpr>> {
 public:
   void checkPreStmt(const CXXNewExpr *NE, CheckerContext &C) const;
@@ -22,6 +23,7 @@ class PlacementNewChecker : public Checker<check::PreStmt<CXXNewExpr>> {
   BugType BT{this, "Insufficient storage for placement new",
              categories::MemoryError};
 };
+} // namespace
 
 SVal PlacementNewChecker::getExtentSizeOfPlace(const Expr *Place,
                                                ProgramStateRef State,
diff --git a/clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp
index 861dfef02393a..3c04983df4438 100644
--- a/clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp
@@ -223,7 +223,8 @@ static const ExplodedNode *getAcquireSite(const ExplodedNode *N, SymbolRef Sym,
 
 /// Returns the symbols extracted from the argument or null if it cannot be
 /// found.
-SymbolRef getFuchsiaHandleSymbol(QualType QT, SVal Arg, ProgramStateRef State) {
+static SymbolRef getFuchsiaHandleSymbol(QualType QT, SVal Arg,
+                                        ProgramStateRef State) {
   int PtrToHandleLevel = 0;
   while (QT->isAnyPointerType() || QT->isReferenceType()) {
     ++PtrToHandleLevel;
diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
index 63ed91d67190b..076ca943788bf 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -1734,8 +1734,8 @@ static bool getHexUint(const MIToken &Token, APInt &Result) {
   return false;
 }
 
-bool getUnsigned(const MIToken &Token, unsigned &Result,
-                 ErrorCallbackType ErrCB) {
+static bool getUnsigned(const MIToken &Token, unsigned &Result,
+                        ErrorCallbackType ErrCB) {
   if (Token.hasIntegerValue()) {
     const uint64_t Limit = uint64_t(std::numeric_limits<unsigned>::max()) + 1;
     uint64_t Val64 = Token.integerValue().getLimitedValue(Limit);
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index c732106014e6c..7575d1a25e581 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -837,7 +837,7 @@ static bool isTargetDarwin(const MachineFunction &MF) {
 }
 
 // Convenience function to determine whether I is an SVE callee save.
-bool IsSVECalleeSave(MachineBasicBlock::iterator I) {
+static bool IsSVECalleeSave(MachineBasicBlock::iterator I) {
   switch (I->getOpcode()) {
   default:
     return false;
diff --git a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
index 39e53a75ac7e5..9645aa24dc058 100644
--- a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
@@ -341,9 +341,9 @@ static bool MSA3OpIntrinsicToGeneric(MachineInstr &MI, unsigned Opcode,
   return true;
 }
 
-bool MSA2OpIntrinsicToGeneric(MachineInstr &MI, unsigned Opcode,
-                              MachineIRBuilder &MIRBuilder,
-                              const MipsSubtarget &ST) {
+static bool MSA2OpIntrinsicToGeneric(MachineInstr &MI, unsigned Opcode,
+                                     MachineIRBuilder &MIRBuilder,
+                                     const MipsSubtarget &ST) {
   assert(ST.hasMSA() && "MSA intrinsic not supported on target without MSA.");
   MIRBuilder.buildInstr(Opcode)
       .add(MI.getOperand(0))
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index e31023607e807..801c09a317a7f 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1649,7 +1649,7 @@ Instruction *InstCombiner::narrowMathIfNoOverflow(BinaryOperator &BO) {
   return CastInst::Create(CastOpc, NarrowBO, BO.getType());
 }
 
-bool isMergedGEPInBounds(GEPOperator &GEP1, GEPOperator &GEP2) {
+static bool isMergedGEPInBounds(GEPOperator &GEP1, GEPOperator &GEP2) {
   // At least one GEP must be inbounds.
   if (!GEP1.isInBounds() && !GEP2.isInBounds())
     return false;
diff --git a/mlir/lib/Analysis/AffineAnalysis.cpp b/mlir/lib/Analysis/AffineAnalysis.cpp
index 2608452771fb3..5ea87f6bc56a9 100644
--- a/mlir/lib/Analysis/AffineAnalysis.cpp
+++ b/mlir/lib/Analysis/AffineAnalysis.cpp
@@ -117,6 +117,7 @@ static LogicalResult getInstIndexSet(Operation *op,
   return getIndexSet(loops, indexSet);
 }
 
+namespace {
 // ValuePositionMap manages the mapping from Values which represent dimension
 // and symbol identifiers from 'src' and 'dst' access functions to positions
 // in new space where some Values are kept separate (using addSrc/DstValue)
@@ -195,6 +196,7 @@ class ValuePositionMap {
   DenseMap<Value, unsigned> dstDimPosMap;
   DenseMap<Value, unsigned> symbolPosMap;
 };
+} // namespace
 
 // Builds a map from Value to identifier position in a new merged identifier
 // list, which is the result of merging dim/symbol lists from src/dst
@@ -240,12 +242,11 @@ static void buildDimAndSymbolPositionMaps(
 
 // Sets up dependence constraints columns appropriately, in the format:
 // [src-dim-ids, dst-dim-ids, symbol-ids, local-ids, const_term]
-void initDependenceConstraints(const FlatAffineConstraints &srcDomain,
-                               const FlatAffineConstraints &dstDomain,
-                               const AffineValueMap &srcAccessMap,
-                               const AffineValueMap &dstAccessMap,
-                               const ValuePositionMap &valuePosMap,
-                               FlatAffineConstraints *dependenceConstraints) {
+static void initDependenceConstraints(
+    const FlatAffineConstraints &srcDomain,
+    const FlatAffineConstraints &dstDomain, const AffineValueMap &srcAccessMap,
+    const AffineValueMap &dstAccessMap, const ValuePositionMap &valuePosMap,
+    FlatAffineConstraints *dependenceConstraints) {
   // Calculate number of equalities/inequalities and columns required to
   // initialize FlatAffineConstraints for 'dependenceDomain'.
   unsigned numIneq =
diff --git a/mlir/lib/Analysis/AffineStructures.cpp b/mlir/lib/Analysis/AffineStructures.cpp
index b5e314047b05f..97f534a727f88 100644
--- a/mlir/lib/Analysis/AffineStructures.cpp
+++ b/mlir/lib/Analysis/AffineStructures.cpp
@@ -1388,8 +1388,9 @@ static void getLowerAndUpperBoundIndices(const FlatAffineConstraints &cst,
 // Check if the pos^th identifier can be expressed as a floordiv of an affine
 // function of other identifiers (where the divisor is a positive constant).
 // For eg: 4q <= i + j <= 4q + 3   <=>   q = (i + j) floordiv 4.
-bool detectAsFloorDiv(const FlatAffineConstraints &cst, unsigned pos,
-                      SmallVectorImpl<AffineExpr> *memo, MLIRContext *context) {
+static bool detectAsFloorDiv(const FlatAffineConstraints &cst, unsigned pos,
+                             SmallVectorImpl<AffineExpr> *memo,
+                             MLIRContext *context) {
   assert(pos < cst.getNumIds() && "invalid position");
 
   SmallVector<unsigned, 4> lbIndices, ubIndices;
diff --git a/mlir/lib/Analysis/Liveness.cpp b/mlir/lib/Analysis/Liveness.cpp
index 26e152dcdf7a8..dbda9f5ba2899 100644
--- a/mlir/lib/Analysis/Liveness.cpp
+++ b/mlir/lib/Analysis/Liveness.cpp
@@ -21,6 +21,7 @@
 
 using namespace mlir;
 
+namespace {
 /// Builds and holds block information during the construction phase.
 struct BlockInfoBuilder {
   using ValueSetT = Liveness::ValueSetT;
@@ -107,6 +108,7 @@ struct BlockInfoBuilder {
   /// The set of all used values.
   ValueSetT useValues;
 };
+} // namespace
 
 /// Builds the internal liveness block mapping.
 static void buildBlockMapping(MutableArrayRef<Region> regions,
diff --git a/mlir/lib/Analysis/Utils.cpp b/mlir/lib/Analysis/Utils.cpp
index 4991e51d5f0dd..21ca17dce4238 100644
--- a/mlir/lib/Analysis/Utils.cpp
+++ b/mlir/lib/Analysis/Utils.cpp
@@ -471,8 +471,8 @@ static Operation *getInstAtPosition(ArrayRef<unsigned> positions,
 }
 
 // Adds loop IV bounds to 'cst' for loop IVs not found in 'ivs'.
-LogicalResult addMissingLoopIVBounds(SmallPtrSet<Value, 8> &ivs,
-                                     FlatAffineConstraints *cst) {
+static LogicalResult addMissingLoopIVBounds(SmallPtrSet<Value, 8> &ivs,
+                                            FlatAffineConstraints *cst) {
   for (unsigned i = 0, e = cst->getNumDimIds(); i < e; ++i) {
     auto value = cst->getIdValue(i);
     if (ivs.count(value) == 0) {
diff --git a/mlir/lib/Conversion/LinalgToLLVM/LinalgToLLVM.cpp b/mlir/lib/Conversion/LinalgToLLVM/LinalgToLLVM.cpp
index 52549933f9d38..a88c9c493c58e 100644
--- a/mlir/lib/Conversion/LinalgToLLVM/LinalgToLLVM.cpp
+++ b/mlir/lib/Conversion/LinalgToLLVM/LinalgToLLVM.cpp
@@ -70,6 +70,8 @@ using urem = ValueBuilder<mlir::LLVM::URemOp>;
 using llvm_alloca = ValueBuilder<LLVM::AllocaOp>;
 using llvm_return = OperationBuilder<LLVM::ReturnOp>;
 
+namespace {
+
 template <typename T>
 static LLVMType getPtrToElementType(T containerType,
                                     LLVMTypeConverter &lowering) {
@@ -104,7 +106,6 @@ static Type convertLinalgType(Type t, LLVMTypeConverter &lowering) {
   return Type();
 }
 
-namespace {
 /// EDSC-compatible wrapper for MemRefDescriptor.
 class BaseViewConversionHelper {
 public:
@@ -139,7 +140,6 @@ class BaseViewConversionHelper {
 
   MemRefDescriptor d;
 };
-} // namespace
 
 // RangeOp creates a new range descriptor.
 class RangeOpConversion : public LLVMOpLowering {
@@ -421,12 +421,16 @@ static FlatSymbolRefAttr getLibraryCallSymbolRef(Operation *op,
   return fnNameAttr;
 }
 
+} // namespace
+
 Type LinalgTypeConverter::convertType(Type t) {
   if (auto result = LLVMTypeConverter::convertType(t))
     return result;
   return convertLinalgType(t, *this);
 }
 
+namespace {
+
 // LinalgOpConversion<LinalgOp> creates a new call to the
 // `LinalgOp::getLibraryCallName()` function.
 // The implementation of the function can be either in the same module or in an
@@ -552,6 +556,8 @@ populateLinalgToStandardConversionPatterns(OwningRewritePatternList &patterns,
       ctx);
 }
 
+} // namespace
+
 /// Populate the given list with patterns that convert from Linalg to LLVM.
 void mlir::populateLinalgToLLVMConversionPatterns(
     LinalgTypeConverter &converter, OwningRewritePatternList &patterns,
diff --git a/mlir/lib/Conversion/LoopsToGPU/LoopsToGPU.cpp b/mlir/lib/Conversion/LoopsToGPU/LoopsToGPU.cpp
index 3ea1f85d62f98..15633ac6d5027 100644
--- a/mlir/lib/Conversion/LoopsToGPU/LoopsToGPU.cpp
+++ b/mlir/lib/Conversion/LoopsToGPU/LoopsToGPU.cpp
@@ -98,7 +98,7 @@ static Value getOrEmitUpperBound(ForOp forOp, OpBuilder &) {
 // This roughly corresponds to the "matcher" part of the pattern-based
 // rewriting infrastructure.
 template <typename OpTy>
-LogicalResult checkLoopNestMappableImpl(OpTy forOp, unsigned numDims) {
+static LogicalResult checkLoopNestMappableImpl(OpTy forOp, unsigned numDims) {
   Region &limit = forOp.region();
   for (unsigned i = 0, e = numDims; i < e; ++i) {
     Operation *nested = &forOp.getBody()->front();
@@ -124,8 +124,8 @@ LogicalResult checkLoopNestMappableImpl(OpTy forOp, unsigned numDims) {
 }
 
 template <typename OpTy>
-LogicalResult checkLoopNestMappable(OpTy forOp, unsigned numBlockDims,
-                                    unsigned numThreadDims) {
+static LogicalResult checkLoopNestMappable(OpTy forOp, unsigned numBlockDims,
+                                           unsigned numThreadDims) {
   if (numBlockDims < 1 || numThreadDims < 1) {
     LLVM_DEBUG(llvm::dbgs() << "nothing to map");
     return success();
@@ -142,8 +142,8 @@ LogicalResult checkLoopNestMappable(OpTy forOp, unsigned numBlockDims,
 }
 
 template <typename OpTy>
-LogicalResult checkLoopOpMappable(OpTy forOp, unsigned numBlockDims,
-                                  unsigned numThreadDims) {
+static LogicalResult checkLoopOpMappable(OpTy forOp, unsigned numBlockDims,
+                                         unsigned numThreadDims) {
   if (numBlockDims < 1 || numThreadDims < 1) {
     LLVM_DEBUG(llvm::dbgs() << "nothing to map");
     return success();
@@ -265,8 +265,8 @@ Optional<OpTy> LoopToGpuConverter::collectBounds(OpTy forOp,
 /// `nids`. The innermost loop is mapped to the x-dimension, followed by the
 /// next innermost loop to y-dimension, followed by z-dimension.
 template <typename OpTy>
-OpTy createGPULaunchLoops(OpTy rootForOp, ArrayRef<Value> ids,
-                          ArrayRef<Value> nids) {
+static OpTy createGPULaunchLoops(OpTy rootForOp, ArrayRef<Value> ids,
+                                 ArrayRef<Value> nids) {
   auto nDims = ids.size();
   assert(nDims == nids.size());
   for (auto dim : llvm::seq<unsigned>(0, nDims)) {
@@ -285,9 +285,10 @@ OpTy createGPULaunchLoops(OpTy rootForOp, ArrayRef<Value> ids,
 /// Utility method to convert the gpu::KernelDim3 object for representing id of
 /// each workgroup/workitem and number of workgroup/workitems along a dimension
 /// of the launch into a container.
-void packIdAndNumId(gpu::KernelDim3 kernelIds, gpu::KernelDim3 kernelNids,
-                    unsigned nDims, SmallVectorImpl<Value> &ids,
-                    SmallVectorImpl<Value> &nids) {
+static void packIdAndNumId(gpu::KernelDim3 kernelIds,
+                           gpu::KernelDim3 kernelNids, unsigned nDims,
+                           SmallVectorImpl<Value> &ids,
+                           SmallVectorImpl<Value> &nids) {
   assert(nDims <= 3 && "invalid number of launch dimensions");
   SmallVector<Value, 3> allIds = {kernelIds.z, kernelIds.y, kernelIds.x};
   SmallVector<Value, 3> allNids = {kernelNids.z, kernelNids.y, kernelNids.x};
@@ -300,9 +301,9 @@ void packIdAndNumId(gpu::KernelDim3 kernelIds, gpu::KernelDim3 kernelNids,
 
 /// Generate the body of the launch operation.
 template <typename OpTy>
-LogicalResult createLaunchBody(OpBuilder &builder, OpTy rootForOp,
-                               gpu::LaunchOp launchOp, unsigned numBlockDims,
-                               unsigned numThreadDims) {
+static LogicalResult
+createLaunchBody(OpBuilder &builder, OpTy rootForOp, gpu::LaunchOp launchOp,
+                 unsigned numBlockDims, unsigned numThreadDims) {
   OpBuilder::InsertionGuard bodyInsertionGuard(builder);
   builder.setInsertionPointToEnd(&launchOp.body().front());
   auto returnOp = builder.create<gpu::ReturnOp>(launchOp.getLoc());
@@ -337,8 +338,9 @@ LogicalResult createLaunchBody(OpBuilder &builder, OpTy rootForOp,
 // Convert the computation rooted at the `rootForOp`, into a GPU kernel with the
 // given workgroup size and number of workgroups.
 template <typename OpTy>
-LogicalResult createLaunchFromOp(OpTy rootForOp, ArrayRef<Value> numWorkGroups,
-                                 ArrayRef<Value> workGroupSizes) {
+static LogicalResult createLaunchFromOp(OpTy rootForOp,
+                                        ArrayRef<Value> numWorkGroups,
+                                        ArrayRef<Value> workGroupSizes) {
   OpBuilder builder(rootForOp.getOperation());
   if (numWorkGroups.size() > 3) {
     return rootForOp.emitError("invalid ")
diff --git a/mlir/lib/Conversion/StandardToSPIRV/ConvertStandardToSPIRV.cpp b/mlir/lib/Conversion/StandardToSPIRV/ConvertStandardToSPIRV.cpp
index 7e7b7ef6ea66c..cc535b938fb8e 100644
--- a/mlir/lib/Conversion/StandardToSPIRV/ConvertStandardToSPIRV.cpp
+++ b/mlir/lib/Conversion/StandardToSPIRV/ConvertStandardToSPIRV.cpp
@@ -139,10 +139,11 @@ class StoreOpConversion final : public SPIRVOpLowering<StoreOp> {
 
 // TODO(ravishankarm) : This method assumes that the `origBaseType` is a
 // MemRefType with AffineMap that has static strides. Handle dynamic strides
-spirv::AccessChainOp getElementPtr(OpBuilder &builder,
-                                   SPIRVTypeConverter &typeConverter,
-                                   Location loc, MemRefType origBaseType,
-                                   Value basePtr, ArrayRef<Value> indices) {
+static spirv::AccessChainOp getElementPtr(OpBuilder &builder,
+                                          SPIRVTypeConverter &typeConverter,
+                                          Location loc, MemRefType origBaseType,
+                                          Value basePtr,
+                                          ArrayRef<Value> indices) {
   // Get base and offset of the MemRefType and verify they are static.
   int64_t offset;
   SmallVector<int64_t, 4> strides;
diff --git a/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp b/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
index cc6636df00eed..8ec3212f7c0c9 100644
--- a/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
+++ b/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
@@ -34,6 +34,8 @@
 using namespace mlir;
 using namespace mlir::vector;
 
+namespace {
+
 template <typename T>
 static LLVM::LLVMType getPtrToElementType(T containerType,
                                           LLVMTypeConverter &lowering) {
@@ -948,6 +950,8 @@ class VectorStridedSliceOpConversion : public OpRewritePattern<StridedSliceOp> {
   }
 };
 
+} // namespace
+
 /// Populate the given list with patterns that convert from Vector to LLVM.
 void mlir::populateVectorToLLVMConversionPatterns(
     LLVMTypeConverter &converter, OwningRewritePatternList &patterns) {
diff --git a/mlir/lib/Dialect/AffineOps/AffineOps.cpp b/mlir/lib/Dialect/AffineOps/AffineOps.cpp
index 0da539ea9f08a..f846adaf4c42c 100644
--- a/mlir/lib/Dialect/AffineOps/AffineOps.cpp
+++ b/mlir/lib/Dialect/AffineOps/AffineOps.cpp
@@ -141,7 +141,8 @@ bool mlir::isValidDim(Value value) {
 /// Returns true if the 'index' dimension of the `memref` defined by
 /// `memrefDefOp` is a statically  shaped one or defined using a valid symbol.
 template <typename AnyMemRefDefOp>
-bool isMemRefSizeValidSymbol(AnyMemRefDefOp memrefDefOp, unsigned index) {
+static bool isMemRefSizeValidSymbol(AnyMemRefDefOp memrefDefOp,
+                                    unsigned index) {
   auto memRefType = memrefDefOp.getType();
   // Statically shaped.
   if (!ShapedType::isDynamic(memRefType.getDimSize(index)))
@@ -1620,7 +1621,8 @@ static LogicalResult verify(AffineIfOp op) {
   return success();
 }
 
-ParseResult parseAffineIfOp(OpAsmParser &parser, OperationState &result) {
+static ParseResult parseAffineIfOp(OpAsmParser &parser,
+                                   OperationState &result) {
   // Parse the condition attribute set.
   IntegerSetAttr conditionAttr;
   unsigned numDims;
@@ -1667,7 +1669,7 @@ ParseResult parseAffineIfOp(OpAsmParser &parser, OperationState &result) {
   return success();
 }
 
-void print(OpAsmPrinter &p, AffineIfOp op) {
+static void print(OpAsmPrinter &p, AffineIfOp op) {
   auto conditionAttr =
       op.getAttrOfType<IntegerSetAttr>(op.getConditionAttrName());
   p << "affine.if " << conditionAttr;
@@ -2057,7 +2059,7 @@ static ParseResult parseAffinePrefetchOp(OpAsmParser &parser,
   return success();
 }
 
-void print(OpAsmPrinter &p, AffinePrefetchOp op) {
+static void print(OpAsmPrinter &p, AffinePrefetchOp op) {
   p << AffinePrefetchOp::getOperationName() << " " << op.memref() << '[';
   AffineMapAttr mapAttr = op.getAttrOfType<AffineMapAttr>(op.getMapAttrName());
   if (mapAttr) {
@@ -2074,7 +2076,7 @@ void print(OpAsmPrinter &p, AffinePrefetchOp op) {
   p << " : " << op.getMemRefType();
 }
 
-LogicalResult verify(AffinePrefetchOp op) {
+static LogicalResult verify(AffinePrefetchOp op) {
   auto mapAttr = op.getAttrOfType<AffineMapAttr>(op.getMapAttrName());
   if (mapAttr) {
     AffineMap map = mapAttr.getValue();
diff --git a/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp b/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
index dbca1fb003a5d..083e282602015 100644
--- a/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
+++ b/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
@@ -258,7 +258,7 @@ iterator_range<Block::args_iterator> LaunchOp::getKernelArguments() {
   return llvm::drop_begin(args, LaunchOp::kNumConfigRegionAttributes);
 }
 
-LogicalResult verify(LaunchOp op) {
+static LogicalResult verify(LaunchOp op) {
   // Kernel launch takes kNumConfigOperands leading operands for grid/block
   // sizes and transforms them into kNumConfigRegionAttributes region arguments
   // for block/thread identifiers and grid/block sizes.
@@ -300,7 +300,7 @@ static void printSizeAssignment(OpAsmPrinter &p, KernelDim3 size,
   p << size.z << " = " << operands[2] << ')';
 }
 
-void printLaunchOp(OpAsmPrinter &p, LaunchOp op) {
+static void printLaunchOp(OpAsmPrinter &p, LaunchOp op) {
   ValueRange operands = op.getOperands();
 
   // Print the launch configuration.
@@ -370,7 +370,7 @@ parseSizeAssignment(OpAsmParser &parser,
 //                             (`args` ssa-reassignment `:` type-list)?
 //                             region attr-dict?
 // ssa-reassignment ::= `(` ssa-id `=` ssa-use (`,` ssa-id `=` ssa-use)* `)`
-ParseResult parseLaunchOp(OpAsmParser &parser, OperationState &result) {
+static ParseResult parseLaunchOp(OpAsmParser &parser, OperationState &result) {
   // Sizes of the grid and block.
   SmallVector<OpAsmParser::OperandType, LaunchOp::kNumConfigOperands> sizes(
       LaunchOp::kNumConfigOperands);
@@ -549,7 +549,7 @@ KernelDim3 LaunchFuncOp::getBlockSizeOperandValues() {
   return KernelDim3{getOperand(3), getOperand(4), getOperand(5)};
 }
 
-LogicalResult verify(LaunchFuncOp op) {
+static LogicalResult verify(LaunchFuncOp op) {
   auto module = op.getParentOfType<ModuleOp>();
   if (!module)
     return op.emitOpError("expected to belong to a module");
@@ -729,7 +729,7 @@ static void printAttributions(OpAsmPrinter &p, StringRef keyword,
 }
 
 /// Prints a GPU Func op.
-void printGPUFuncOp(OpAsmPrinter &p, GPUFuncOp op) {
+static void printGPUFuncOp(OpAsmPrinter &p, GPUFuncOp op) {
   p << GPUFuncOp::getOperationName() << ' ';
   p.printSymbolName(op.getName());
 
diff --git a/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp b/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
index a8be9b20b447b..384d24957f46d 100644
--- a/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
+++ b/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
@@ -109,7 +109,7 @@ static ParseResult parseGenericOp(OpAsmParser &parser, OperationState &result) {
 }
 
 template <typename GenericOpType>
-LogicalResult verifyBlockArgs(GenericOpType op, Block &block);
+static LogicalResult verifyBlockArgs(GenericOpType op, Block &block);
 
 template <> LogicalResult verifyBlockArgs(GenericOp op, Block &block) {
   auto nViews = op.getNumInputsAndOutputs();
@@ -158,7 +158,7 @@ template <> LogicalResult verifyBlockArgs(IndexedGenericOp op, Block &block) {
 }
 
 template <typename GenericOpType>
-LogicalResult verifyFuncArgs(GenericOpType op, FunctionType funType);
+static LogicalResult verifyFuncArgs(GenericOpType op, FunctionType funType);
 
 template <> LogicalResult verifyFuncArgs(GenericOp op, FunctionType funType) {
   auto nViews = op.getNumInputsAndOutputs();
@@ -228,7 +228,7 @@ LogicalResult verifyFuncArgs(IndexedGenericOp op, FunctionType funType) {
 }
 
 template <typename GenericOpType>
-LogicalResult verifyGenericOp(GenericOpType op) {
+static LogicalResult verifyGenericOp(GenericOpType op) {
   auto nInputViews = op.getNumInputs();
   auto nLoops = op.getNumLoops();
   auto nViews = op.getNumInputsAndOutputs();
@@ -729,7 +729,7 @@ static ParseResult parseYieldOp(OpAsmParser &parser, OperationState &result) {
 }
 
 template <typename GenericOpType>
-LogicalResult verifyYield(YieldOp op, GenericOpType genericOp) {
+static LogicalResult verifyYield(YieldOp op, GenericOpType genericOp) {
   // The operand number and types must match the view element types.
   auto nOutputViews = genericOp.getNumOutputs();
   if (op.getNumOperands() != nOutputViews)
diff --git a/mlir/lib/Dialect/Linalg/Transforms/LinalgToLoops.cpp b/mlir/lib/Dialect/Linalg/Transforms/LinalgToLoops.cpp
index c9f4b34ebc0e5..f5dac8aced151 100644
--- a/mlir/lib/Dialect/Linalg/Transforms/LinalgToLoops.cpp
+++ b/mlir/lib/Dialect/Linalg/Transforms/LinalgToLoops.cpp
@@ -37,6 +37,8 @@ using IndexedAffineValue = TemplatedIndexedValue<affine_load, affine_store>;
 using edsc::op::operator+;
 using edsc::op::operator==;
 
+namespace {
+
 static SmallVector<ValueHandle, 8>
 makeCanonicalAffineApplies(OpBuilder &b, Location loc, AffineMap map,
                            ArrayRef<Value> vals) {
@@ -379,7 +381,6 @@ class LinalgScopedEmitter<IndexedValueType, IndexedGenericOp> {
   }
 };
 
-namespace {
 // This struct is for factoring out the implementation and support template
 // instantiations in the following 2 cases:
 //   1. Appending to a list of patterns via RewritePatternList.
@@ -393,7 +394,6 @@ class LinalgOpToLoopsImpl {
 public:
   static LogicalResult doit(Operation *op, PatternRewriter &rewriter);
 };
-} // namespace
 
 template <typename LoopTy, typename IndexedValueTy, typename ConcreteOpTy>
 LogicalResult LinalgOpToLoopsImpl<LoopTy, IndexedValueTy, ConcreteOpTy>::doit(
@@ -538,6 +538,8 @@ void LowerLinalgToLoopsPass<LoopType, IndexedValueType>::runOnFunction() {
   applyPatternsGreedily(this->getFunction(), patterns);
 }
 
+} // namespace
+
 /// Create a pass to convert Linalg operations to loop.for loops and
 /// std.load/std.store accesses.
 std::unique_ptr<OpPassBase<FuncOp>>
diff --git a/mlir/lib/Dialect/Linalg/Transforms/Tiling.cpp b/mlir/lib/Dialect/Linalg/Transforms/Tiling.cpp
index b77f658aa2fe0..bcf6576abbb36 100644
--- a/mlir/lib/Dialect/Linalg/Transforms/Tiling.cpp
+++ b/mlir/lib/Dialect/Linalg/Transforms/Tiling.cpp
@@ -170,7 +170,7 @@ struct TileCheck : public AffineExprVisitor<TileCheck> {
 //
 // TODO(pifon, ntv): Investigate whether mixing implicit and explicit indices
 // does not lead to losing information.
-void transformIndexedGenericOpIndices(
+static void transformIndexedGenericOpIndices(
     OpBuilder &b, LinalgOp op, ArrayRef<ValueHandle *> pivs,
     const LoopIndexToRangeIndexMap &loopIndexToRangeIndex) {
   auto indexedGenericOp = dyn_cast<IndexedGenericOp>(op.getOperation());
diff --git a/mlir/lib/Dialect/LoopOps/LoopOps.cpp b/mlir/lib/Dialect/LoopOps/LoopOps.cpp
index 7e3e286b842fa..8effe71088c12 100644
--- a/mlir/lib/Dialect/LoopOps/LoopOps.cpp
+++ b/mlir/lib/Dialect/LoopOps/LoopOps.cpp
@@ -68,7 +68,7 @@ void ForOp::build(Builder *builder, OperationState &result, Value lb, Value ub,
   bodyRegion->front().addArgument(builder->getIndexType());
 }
 
-LogicalResult verify(ForOp op) {
+static LogicalResult verify(ForOp op) {
   if (auto cst = dyn_cast_or_null<ConstantIndexOp>(op.step().getDefiningOp()))
     if (cst.getValue() <= 0)
       return op.emitOpError("constant step operand must be positive");
diff --git a/mlir/lib/Dialect/QuantOps/Transforms/ConvertSimQuant.cpp b/mlir/lib/Dialect/QuantOps/Transforms/ConvertSimQuant.cpp
index 2a4c14f2231fd..ffd7efb21bdb0 100644
--- a/mlir/lib/Dialect/QuantOps/Transforms/ConvertSimQuant.cpp
+++ b/mlir/lib/Dialect/QuantOps/Transforms/ConvertSimQuant.cpp
@@ -26,8 +26,6 @@ class ConvertSimulatedQuantPass
   void runOnFunction() override;
 };
 
-} // end anonymous namespace
-
 /// Base class rewrites ConstFakeQuant into a qbarrier/dbarrier pair.
 template <typename ConcreteRewriteClass, typename FakeQuantOp>
 class FakeQuantRewrite : public OpRewritePattern<FakeQuantOp> {
@@ -126,6 +124,8 @@ class ConstFakeQuantPerAxisRewrite
   }
 };
 
+} // namespace
+
 void ConvertSimulatedQuantPass::runOnFunction() {
   bool hadFailure = false;
   OwningRewritePatternList patterns;
diff --git a/mlir/lib/Dialect/SDBM/SDBMExpr.cpp b/mlir/lib/Dialect/SDBM/SDBMExpr.cpp
index 68e3e1c278ec9..ae2f447796e49 100644
--- a/mlir/lib/Dialect/SDBM/SDBMExpr.cpp
+++ b/mlir/lib/Dialect/SDBM/SDBMExpr.cpp
@@ -301,8 +301,9 @@ AffineExpr SDBMExpr::getAsAffineExpr() const {
 // expression is already a sum expression, update its constant and extract the
 // LHS if the constant becomes zero.  Otherwise, construct a sum expression.
 template <typename Result>
-Result addConstantAndSink(SDBMDirectExpr expr, int64_t constant, bool negated,
-                          function_ref<Result(SDBMDirectExpr)> builder) {
+static Result addConstantAndSink(SDBMDirectExpr expr, int64_t constant,
+                                 bool negated,
+                                 function_ref<Result(SDBMDirectExpr)> builder) {
   SDBMDialect *dialect = expr.getDialect();
   if (auto sumExpr = expr.dyn_cast<SDBMSumExpr>()) {
     if (negated)
diff --git a/mlir/lib/Dialect/SPIRV/SPIRVDialect.cpp b/mlir/lib/Dialect/SPIRV/SPIRVDialect.cpp
index 98c36fb9b0812..0e543df29b64d 100644
--- a/mlir/lib/Dialect/SPIRV/SPIRVDialect.cpp
+++ b/mlir/lib/Dialect/SPIRV/SPIRVDialect.cpp
@@ -375,6 +375,7 @@ Optional<uint64_t> parseAndVerify<uint64_t>(SPIRVDialect const &dialect,
   return parseAndVerifyInteger<uint64_t>(dialect, parser);
 }
 
+namespace {
 // Functor object to parse a comma separated list of specs. The function
 // parseAndVerify does the actual parsing and verification of individual
 // elements. This is a functor since parsing the last element of the list
@@ -407,6 +408,7 @@ template <typename ParseType> struct parseCommaSeparatedList<ParseType> {
     return llvm::None;
   }
 };
+} // namespace
 
 // dim ::= `1D` | `2D` | `3D` | `Cube` | <and other SPIR-V Dim specifiers...>
 //
diff --git a/mlir/lib/Dialect/SPIRV/Serialization/TranslateRegistration.cpp b/mlir/lib/Dialect/SPIRV/Serialization/TranslateRegistration.cpp
index 750710fa3d99a..46596741ea071 100644
--- a/mlir/lib/Dialect/SPIRV/Serialization/TranslateRegistration.cpp
+++ b/mlir/lib/Dialect/SPIRV/Serialization/TranslateRegistration.cpp
@@ -33,8 +33,8 @@ using namespace mlir;
 
 // Deserializes the SPIR-V binary module stored in the file named as
 // `inputFilename` and returns a module containing the SPIR-V module.
-OwningModuleRef deserializeModule(const llvm::MemoryBuffer *input,
-                                  MLIRContext *context) {
+static OwningModuleRef deserializeModule(const llvm::MemoryBuffer *input,
+                                         MLIRContext *context) {
   Builder builder(context);
 
   // Make sure the input stream can be treated as a stream of SPIR-V words
@@ -71,7 +71,7 @@ static TranslateToMLIRRegistration fromBinary(
 // Serialization registration
 //===----------------------------------------------------------------------===//
 
-LogicalResult serializeModule(ModuleOp module, raw_ostream &output) {
+static LogicalResult serializeModule(ModuleOp module, raw_ostream &output) {
   if (!module)
     return failure();
 
@@ -104,8 +104,9 @@ static TranslateFromMLIRRegistration
 // Round-trip registration
 //===----------------------------------------------------------------------===//
 
-LogicalResult roundTripModule(llvm::SourceMgr &sourceMgr, raw_ostream &output,
-                              MLIRContext *context) {
+static LogicalResult roundTripModule(llvm::SourceMgr &sourceMgr,
+                                     raw_ostream &output,
+                                     MLIRContext *context) {
   // Parse an MLIR module from the source manager.
   auto srcModule = OwningModuleRef(parseSourceFile(sourceMgr, context));
   if (!srcModule)
diff --git a/mlir/lib/Dialect/VectorOps/VectorOps.cpp b/mlir/lib/Dialect/VectorOps/VectorOps.cpp
index f2742de8428fb..b26f70adbba56 100644
--- a/mlir/lib/Dialect/VectorOps/VectorOps.cpp
+++ b/mlir/lib/Dialect/VectorOps/VectorOps.cpp
@@ -918,9 +918,10 @@ static ParseResult parseInsertStridedSliceOp(OpAsmParser &parser,
 
 // TODO(ntv) Should be moved to Tablegen Confined attributes.
 template <typename OpType>
-LogicalResult isIntegerArrayAttrSmallerThanShape(OpType op, ArrayAttr arrayAttr,
-                                                 ArrayRef<int64_t> shape,
-                                                 StringRef attrName) {
+static LogicalResult isIntegerArrayAttrSmallerThanShape(OpType op,
+                                                        ArrayAttr arrayAttr,
+                                                        ArrayRef<int64_t> shape,
+                                                        StringRef attrName) {
   if (arrayAttr.size() > shape.size())
     return op.emitOpError("expected ")
            << attrName << " attribute of rank smaller than vector rank";
@@ -931,10 +932,10 @@ LogicalResult isIntegerArrayAttrSmallerThanShape(OpType op, ArrayAttr arrayAttr,
 // interval. If `halfOpen` is true then the admissible interval is [min, max).
 // Otherwise, the admissible interval is [min, max].
 template <typename OpType>
-LogicalResult isIntegerArrayAttrConfinedToRange(OpType op, ArrayAttr arrayAttr,
-                                                int64_t min, int64_t max,
-                                                StringRef attrName,
-                                                bool halfOpen = true) {
+static LogicalResult
+isIntegerArrayAttrConfinedToRange(OpType op, ArrayAttr arrayAttr, int64_t min,
+                                  int64_t max, StringRef attrName,
+                                  bool halfOpen = true) {
   for (auto attr : arrayAttr) {
     auto val = attr.cast<IntegerAttr>().getInt();
     auto upper = max;
@@ -951,7 +952,7 @@ LogicalResult isIntegerArrayAttrConfinedToRange(OpType op, ArrayAttr arrayAttr,
 // interval. If `halfOpen` is true then the admissible interval is [min, max).
 // Otherwise, the admissible interval is [min, max].
 template <typename OpType>
-LogicalResult
+static LogicalResult
 isIntegerArrayAttrConfinedToShape(OpType op, ArrayAttr arrayAttr,
                                   ArrayRef<int64_t> shape, StringRef attrName,
                                   bool halfOpen = true, int64_t min = 0) {
@@ -975,7 +976,7 @@ isIntegerArrayAttrConfinedToShape(OpType op, ArrayAttr arrayAttr,
 // interval. If `halfOpen` is true then the admissible interval is [min, max).
 // Otherwise, the admissible interval is [min, max].
 template <typename OpType>
-LogicalResult isSumOfIntegerArrayAttrConfinedToShape(
+static LogicalResult isSumOfIntegerArrayAttrConfinedToShape(
     OpType op, ArrayAttr arrayAttr1, ArrayAttr arrayAttr2,
     ArrayRef<int64_t> shape, StringRef attrName1, StringRef attrName2,
     bool halfOpen = true, int64_t min = 1) {
@@ -1470,7 +1471,8 @@ static void print(OpAsmPrinter &p, TransferReadOp op) {
   p << " : " << op.getMemRefType() << ", " << op.getVectorType();
 }
 
-ParseResult parseTransferReadOp(OpAsmParser &parser, OperationState &result) {
+static ParseResult parseTransferReadOp(OpAsmParser &parser,
+                                       OperationState &result) {
   llvm::SMLoc typesLoc;
   OpAsmParser::OperandType memrefInfo;
   SmallVector<OpAsmParser::OperandType, 8> indexInfo;
@@ -1545,7 +1547,8 @@ static void print(OpAsmPrinter &p, TransferWriteOp op) {
   p << " : " << op.getVectorType() << ", " << op.getMemRefType();
 }
 
-ParseResult parseTransferWriteOp(OpAsmParser &parser, OperationState &result) {
+static ParseResult parseTransferWriteOp(OpAsmParser &parser,
+                                        OperationState &result) {
   llvm::SMLoc typesLoc;
   OpAsmParser::OperandType storeValueInfo;
   OpAsmParser::OperandType memRefInfo;
@@ -1682,7 +1685,8 @@ static LogicalResult verify(TupleGetOp op) {
 // ConstantMaskOp
 //===----------------------------------------------------------------------===//
 
-ParseResult parseConstantMaskOp(OpAsmParser &parser, OperationState &result) {
+static ParseResult parseConstantMaskOp(OpAsmParser &parser,
+                                       OperationState &result) {
   Type resultType;
   ArrayAttr maskDimSizesAttr;
   StringRef attrName = ConstantMaskOp::getMaskDimSizesAttrName();
@@ -1729,7 +1733,8 @@ static LogicalResult verify(ConstantMaskOp &op) {
 // CreateMaskOp
 //===----------------------------------------------------------------------===//
 
-ParseResult parseCreateMaskOp(OpAsmParser &parser, OperationState &result) {
+static ParseResult parseCreateMaskOp(OpAsmParser &parser,
+                                     OperationState &result) {
   auto indexType = parser.getBuilder().getIndexType();
   Type resultType;
   SmallVector<OpAsmParser::OperandType, 4> operandInfo;
@@ -1758,7 +1763,7 @@ static LogicalResult verify(CreateMaskOp op) {
 // PrintOp
 //===----------------------------------------------------------------------===//
 
-ParseResult parsePrintOp(OpAsmParser &parser, OperationState &result) {
+static ParseResult parsePrintOp(OpAsmParser &parser, OperationState &result) {
   OpAsmParser::OperandType source;
   Type sourceType;
   return failure(parser.parseOperand(source) ||
diff --git a/mlir/lib/Dialect/VectorOps/VectorTransforms.cpp b/mlir/lib/Dialect/VectorOps/VectorTransforms.cpp
index d98f41e3d63ec..c86c4325d794a 100644
--- a/mlir/lib/Dialect/VectorOps/VectorTransforms.cpp
+++ b/mlir/lib/Dialect/VectorOps/VectorTransforms.cpp
@@ -522,6 +522,7 @@ generateTransferOpSlices(VectorType vectorType, TupleType tupleType,
   }
 }
 
+namespace {
 // Splits vector TransferReadOp into smaller TransferReadOps based on slicing
 // scheme of its unique ExtractSlicesOp user.
 struct SplitTransferReadOp : public OpRewritePattern<vector::TransferReadOp> {
@@ -657,6 +658,8 @@ struct TupleGetFolderOp : public OpRewritePattern<vector::TupleGetOp> {
   }
 };
 
+} // namespace
+
 // TODO(andydavis) Add pattern to rewrite ExtractSlices(ConstantMaskOp).
 // TODO(andydavis) Add this as DRR pattern.
 void mlir::vector::populateVectorToVectorTransformationPatterns(
diff --git a/mlir/lib/ExecutionEngine/ExecutionEngine.cpp b/mlir/lib/ExecutionEngine/ExecutionEngine.cpp
index 1537018076ab4..651c90a87d71b 100644
--- a/mlir/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/mlir/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -122,7 +122,7 @@ static std::string makePackedFunctionName(StringRef name) {
 // For each function in the LLVM module, define an interface function that wraps
 // all the arguments of the original function and all its results into an i8**
 // pointer to provide a unified invocation interface.
-void packFunctionArguments(Module *module) {
+static void packFunctionArguments(Module *module) {
   auto &ctx = module->getContext();
   llvm::IRBuilder<> builder(ctx);
   DenseSet<llvm::Function *> interfaceFunctions;
diff --git a/mlir/lib/IR/SymbolTable.cpp b/mlir/lib/IR/SymbolTable.cpp
index ed9de48c400b3..ee4bc9ad57a46 100644
--- a/mlir/lib/IR/SymbolTable.cpp
+++ b/mlir/lib/IR/SymbolTable.cpp
@@ -674,8 +674,8 @@ static Attribute rebuildAttrAfterRAUW(
 }
 
 /// Generates a new symbol reference attribute with a new leaf reference.
-SymbolRefAttr generateNewRefAttr(SymbolRefAttr oldAttr,
-                                 FlatSymbolRefAttr newLeafAttr) {
+static SymbolRefAttr generateNewRefAttr(SymbolRefAttr oldAttr,
+                                        FlatSymbolRefAttr newLeafAttr) {
   if (oldAttr.isa<FlatSymbolRefAttr>())
     return newLeafAttr;
   auto nestedRefs = llvm::to_vector<2>(oldAttr.getNestedReferences());
diff --git a/mlir/lib/Pass/PassStatistics.cpp b/mlir/lib/Pass/PassStatistics.cpp
index 0ab656c20547c..7ad11f012f750 100644
--- a/mlir/lib/Pass/PassStatistics.cpp
+++ b/mlir/lib/Pass/PassStatistics.cpp
@@ -135,7 +135,7 @@ static void printResultsAsPipeline(raw_ostream &os, OpPassManager &pm) {
     printPass(/*indent=*/0, &pass);
 }
 
-void printStatistics(OpPassManager &pm, PassDisplayMode displayMode) {
+static void printStatistics(OpPassManager &pm, PassDisplayMode displayMode) {
   auto os = llvm::CreateInfoOutputFile();
 
   // Print the stats header.
diff --git a/mlir/lib/Transforms/Utils/LoopUtils.cpp b/mlir/lib/Transforms/Utils/LoopUtils.cpp
index 9d7e7cddb05e8..441d95fa698c0 100644
--- a/mlir/lib/Transforms/Utils/LoopUtils.cpp
+++ b/mlir/lib/Transforms/Utils/LoopUtils.cpp
@@ -351,7 +351,7 @@ LogicalResult mlir::instBodySkew(AffineForOp forOp, ArrayRef<uint64_t> shifts,
 // in the parent loop.  Collect at most `maxLoops` loops and append them to
 // `forOps`.
 template <typename T>
-void getPerfectlyNestedLoopsImpl(
+static void getPerfectlyNestedLoopsImpl(
     SmallVectorImpl<T> &forOps, T rootForOp,
     unsigned maxLoops = std::numeric_limits<unsigned>::max()) {
   for (unsigned i = 0; i < maxLoops; ++i) {
diff --git a/mlir/test/lib/TestDialect/TestPatterns.cpp b/mlir/test/lib/TestDialect/TestPatterns.cpp
index 62ee89e0fe4c0..bbeb2c6276171 100644
--- a/mlir/test/lib/TestDialect/TestPatterns.cpp
+++ b/mlir/test/lib/TestDialect/TestPatterns.cpp
@@ -21,7 +21,8 @@ static void createOpI(PatternRewriter &rewriter, Value input) {
   rewriter.create<OpI>(rewriter.getUnknownLoc(), input);
 }
 
-void handleNoResultOp(PatternRewriter &rewriter, OpSymbolBindingNoResult op) {
+static void handleNoResultOp(PatternRewriter &rewriter,
+                             OpSymbolBindingNoResult op) {
   // Turn the no result op to a one-result op.
   rewriter.create<OpSymbolBindingB>(op.getLoc(), op.operand().getType(),
                                     op.operand());
@@ -56,6 +57,7 @@ static mlir::PassRegistration<TestPatternDriver>
 // ReturnType Driver.
 //===----------------------------------------------------------------------===//
 
+namespace {
 struct ReturnTypeOpMatch : public RewritePattern {
   ReturnTypeOpMatch(MLIRContext *ctx)
       : RewritePattern(OpWithInferTypeInterfaceOp::getOperationName(), 1, ctx) {
@@ -94,7 +96,6 @@ struct ReturnTypeOpMatch : public RewritePattern {
   }
 };
 
-namespace {
 struct TestReturnTypeDriver : public FunctionPass<TestReturnTypeDriver> {
   void runOnFunction() override {
     mlir::OwningRewritePatternList patterns;