Use more ArrayRefs

No functional change is intended, just a small refactoring.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@273647 91177308-0d34-0410-b5e6-96231b3b80d8

39 files changed, 174 insertions, 238 deletions

diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index dbb44dfbc2..cd7d2538a1 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -1952,29 +1952,24 @@ public:
 
   unsigned getBuiltinID() const;
 
-  // Iterator access to formal parameters.
-  unsigned param_size() const { return getNumParams(); }
-  typedef ParmVarDecl **param_iterator;
-  typedef ParmVarDecl * const *param_const_iterator;
-  typedef llvm::iterator_range<param_iterator> param_range;
-  typedef llvm::iterator_range<param_const_iterator> param_const_range;
-
-  param_iterator param_begin() { return param_iterator(ParamInfo); }
-  param_iterator param_end() {
-    return param_iterator(ParamInfo + param_size());
-  }
-  param_range params() { return param_range(param_begin(), param_end()); }
-
-  param_const_iterator param_begin() const {
-    return param_const_iterator(ParamInfo);
-  }
-  param_const_iterator param_end() const {
-    return param_const_iterator(ParamInfo + param_size());
+  // ArrayRef interface to parameters.
+  ArrayRef<ParmVarDecl *> parameters() const {
+    return {ParamInfo, getNumParams()};
   }
-  param_const_range params() const {
-    return param_const_range(param_begin(), param_end());
+  MutableArrayRef<ParmVarDecl *> parameters() {
+    return {ParamInfo, getNumParams()};
   }
 
+  // Iterator access to formal parameters.
+  typedef MutableArrayRef<ParmVarDecl *>::iterator param_iterator;
+  typedef ArrayRef<ParmVarDecl *>::const_iterator param_const_iterator;
+  bool param_empty() const { return parameters().empty(); }
+  param_iterator param_begin() { return parameters().begin(); }
+  param_iterator param_end() { return parameters().end(); }
+  param_const_iterator param_begin() const { return parameters().begin(); }
+  param_const_iterator param_end() const { return parameters().end(); }
+  size_t param_size() const { return parameters().size(); }
+
   /// getNumParams - Return the number of parameters this function must have
   /// based on its FunctionType.  This is the length of the ParamInfo array
   /// after it has been created.
@@ -1992,12 +1987,6 @@ public:
     setParams(getASTContext(), NewParamInfo);
   }
 
-  // ArrayRef iterface to parameters.
-  // FIXME: Should one day replace iterator interface.
-  ArrayRef<ParmVarDecl*> parameters() const {
-    return llvm::makeArrayRef(ParamInfo, getNumParams());
-  }
-
   ArrayRef<NamedDecl *> getDeclsInPrototypeScope() const {
     return DeclsInPrototypeScope;
   }
@@ -2504,34 +2493,33 @@ class IndirectFieldDecl : public ValueDecl,
 
   IndirectFieldDecl(ASTContext &C, DeclContext *DC, SourceLocation L,
                     DeclarationName N, QualType T,
-                    NamedDecl **CH, unsigned CHS);
+                    MutableArrayRef<NamedDecl *> CH);
 
 public:
   static IndirectFieldDecl *Create(ASTContext &C, DeclContext *DC,
                                    SourceLocation L, IdentifierInfo *Id,
-                                   QualType T, NamedDecl **CH, unsigned CHS);
+                                   QualType T, llvm::MutableArrayRef<NamedDecl *> CH);
 
   static IndirectFieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);
-  
-  typedef NamedDecl * const *chain_iterator;
-  typedef llvm::iterator_range<chain_iterator> chain_range;
 
-  chain_range chain() const { return chain_range(chain_begin(), chain_end()); }
-  chain_iterator chain_begin() const { return chain_iterator(Chaining); }
-  chain_iterator chain_end() const {
-    return chain_iterator(Chaining + ChainingSize);
+  typedef ArrayRef<NamedDecl *>::const_iterator chain_iterator;
+
+  ArrayRef<NamedDecl *> chain() const {
+    return llvm::makeArrayRef(Chaining, ChainingSize);
   }
+  chain_iterator chain_begin() const { return chain().begin(); }
+  chain_iterator chain_end() const { return chain().end(); }
 
   unsigned getChainingSize() const { return ChainingSize; }
 
   FieldDecl *getAnonField() const {
-    assert(ChainingSize >= 2);
-    return cast<FieldDecl>(Chaining[ChainingSize - 1]);
+    assert(chain().size() >= 2);
+    return cast<FieldDecl>(chain().back());
   }
 
   VarDecl *getVarDecl() const {
-    assert(ChainingSize >= 2);
-    return dyn_cast<VarDecl>(*chain_begin());
+    assert(chain().size() >= 2);
+    return dyn_cast<VarDecl>(chain().front());
   }
 
   IndirectFieldDecl *getCanonicalDecl() override { return getFirstDecl(); }
@@ -3518,35 +3506,23 @@ public:
   void setSignatureAsWritten(TypeSourceInfo *Sig) { SignatureAsWritten = Sig; }
   TypeSourceInfo *getSignatureAsWritten() const { return SignatureAsWritten; }
 
-  // Iterator access to formal parameters.
-  unsigned param_size() const { return getNumParams(); }
-  typedef ParmVarDecl **param_iterator;
-  typedef ParmVarDecl * const *param_const_iterator;
-  typedef llvm::iterator_range<param_iterator> param_range;
-  typedef llvm::iterator_range<param_const_iterator> param_const_range;
-
   // ArrayRef access to formal parameters.
-  // FIXME: Should eventual replace iterator access.
-  ArrayRef<ParmVarDecl*> parameters() const {
-    return llvm::makeArrayRef(ParamInfo, param_size());
+  ArrayRef<ParmVarDecl *> parameters() const {
+    return {ParamInfo, getNumParams()};
   }
-
-  bool param_empty() const { return NumParams == 0; }
-  param_range params() { return param_range(param_begin(), param_end()); }
-  param_iterator param_begin() { return param_iterator(ParamInfo); }
-  param_iterator param_end() {
-    return param_iterator(ParamInfo + param_size());
+  MutableArrayRef<ParmVarDecl *> parameters() {
+    return {ParamInfo, getNumParams()};
   }
 
-  param_const_range params() const {
-    return param_const_range(param_begin(), param_end());
-  }
-  param_const_iterator param_begin() const {
-    return param_const_iterator(ParamInfo);
-  }
-  param_const_iterator param_end() const {
-    return param_const_iterator(ParamInfo + param_size());
-  }
+  // Iterator access to formal parameters.
+  typedef MutableArrayRef<ParmVarDecl *>::iterator param_iterator;
+  typedef ArrayRef<ParmVarDecl *>::const_iterator param_const_iterator;
+  bool param_empty() const { return parameters().empty(); }
+  param_iterator param_begin() { return parameters().begin(); }
+  param_iterator param_end() { return parameters().end(); }
+  param_const_iterator param_begin() const { return parameters().begin(); }
+  param_const_iterator param_end() const { return parameters().end(); }
+  size_t param_size() const { return parameters().size(); }
 
   unsigned getNumParams() const { return NumParams; }
   const ParmVarDecl *getParamDecl(unsigned i) const {
@@ -3567,22 +3543,12 @@ public:
   /// Does not include an entry for 'this'.
   unsigned getNumCaptures() const { return NumCaptures; }
 
-  typedef const Capture *capture_iterator;
-  typedef const Capture *capture_const_iterator;
-  typedef llvm::iterator_range<capture_iterator> capture_range;
-  typedef llvm::iterator_range<capture_const_iterator> capture_const_range;
+  typedef ArrayRef<Capture>::const_iterator capture_const_iterator;
 
-  capture_range captures() {
-    return capture_range(capture_begin(), capture_end());
-  }
-  capture_const_range captures() const {
-    return capture_const_range(capture_begin(), capture_end());
-  }
+  ArrayRef<Capture> captures() const { return {Captures, NumCaptures}; }
 
-  capture_iterator capture_begin() { return Captures; }
-  capture_iterator capture_end() { return Captures + NumCaptures; }
-  capture_const_iterator capture_begin() const { return Captures; }
-  capture_const_iterator capture_end() const { return Captures + NumCaptures; }
+  capture_const_iterator capture_begin() const { return captures().begin(); }
+  capture_const_iterator capture_end() const { return captures().end(); }
 
   bool capturesCXXThis() const { return CapturesCXXThis; }
   bool blockMissingReturnType() const { return BlockMissingReturnType; }
@@ -3693,9 +3659,6 @@ public:
   /// \brief Retrieve an iterator one past the last parameter decl.
   param_iterator param_end() const { return getParams() + NumParams; }
 
-  /// \brief Retrieve an iterator range for the parameter declarations.
-  param_range params() const { return param_range(param_begin(), param_end()); }
-
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) { return K == Captured; }
diff --git a/include/clang/AST/DeclObjC.h b/include/clang/AST/DeclObjC.h
index f89717f698..4e9682f3b3 100644
--- a/include/clang/AST/DeclObjC.h
+++ b/include/clang/AST/DeclObjC.h
@@ -351,11 +351,6 @@ public:
   typedef llvm::iterator_range<param_iterator> param_range;
   typedef llvm::iterator_range<param_const_iterator> param_const_range;
 
-  param_range params() { return param_range(param_begin(), param_end()); }
-  param_const_range params() const {
-    return param_const_range(param_begin(), param_end());
-  }
-
   param_const_iterator param_begin() const {
     return param_const_iterator(getParams());
   }
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 7063c6f706..5586298815 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -1827,16 +1827,14 @@ public:
 
   /// \brief Diagnose any unused parameters in the given sequence of
   /// ParmVarDecl pointers.
-  void DiagnoseUnusedParameters(ParmVarDecl * const *Begin,
-                                ParmVarDecl * const *End);
+  void DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters);
 
   /// \brief Diagnose whether the size of parameters or return value of a
   /// function or obj-c method definition is pass-by-value and larger than a
   /// specified threshold.
-  void DiagnoseSizeOfParametersAndReturnValue(ParmVarDecl * const *Begin,
-                                              ParmVarDecl * const *End,
-                                              QualType ReturnTy,
-                                              NamedDecl *D);
+  void
+  DiagnoseSizeOfParametersAndReturnValue(ArrayRef<ParmVarDecl *> Parameters,
+                                         QualType ReturnTy, NamedDecl *D);
 
   void DiagnoseInvalidJumps(Stmt *Body);
   Decl *ActOnFileScopeAsmDecl(Expr *expr,
@@ -2665,8 +2663,7 @@ public:
                            CallExpr *CE, FunctionDecl *FD);
 
   /// Helpers for dealing with blocks and functions.
-  bool CheckParmsForFunctionDef(ParmVarDecl *const *Param,
-                                ParmVarDecl *const *ParamEnd,
+  bool CheckParmsForFunctionDef(ArrayRef<ParmVarDecl *> Parameters,
                                 bool CheckParameterNames);
   void CheckCXXDefaultArguments(FunctionDecl *FD);
   void CheckExtraCXXDefaultArguments(Declarator &D);
@@ -7140,8 +7137,7 @@ public:
                                 int indexAdjustment,
                                 Optional<unsigned> NumExpansions,
                                 bool ExpectParameterPack);
-  bool SubstParmTypes(SourceLocation Loc,
-                      ParmVarDecl **Params, unsigned NumParams,
+  bool SubstParmTypes(SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
                       const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
                       const MultiLevelTemplateArgumentList &TemplateArgs,
                       SmallVectorImpl<QualType> &ParamTypes,
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 5fc7877322..572cebc681 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -5164,7 +5164,7 @@ std::string ASTContext::getObjCEncodingForBlock(const BlockExpr *Expr) const {
   SourceLocation Loc;
   CharUnits PtrSize = getTypeSizeInChars(VoidPtrTy);
   CharUnits ParmOffset = PtrSize;
-  for (auto PI : Decl->params()) {
+  for (auto PI : Decl->parameters()) {
     QualType PType = PI->getType();
     CharUnits sz = getObjCEncodingTypeSize(PType);
     if (sz.isZero())
@@ -5179,7 +5179,7 @@ std::string ASTContext::getObjCEncodingForBlock(const BlockExpr *Expr) const {
   
   // Argument types.
   ParmOffset = PtrSize;
-  for (auto PVDecl : Decl->params()) {
+  for (auto PVDecl : Decl->parameters()) {
     QualType PType = PVDecl->getOriginalType(); 
     if (const ArrayType *AT =
           dyn_cast<ArrayType>(PType->getCanonicalTypeInternal())) {
@@ -5207,7 +5207,7 @@ bool ASTContext::getObjCEncodingForFunctionDecl(const FunctionDecl *Decl,
   getObjCEncodingForType(Decl->getReturnType(), S);
   CharUnits ParmOffset;
   // Compute size of all parameters.
-  for (auto PI : Decl->params()) {
+  for (auto PI : Decl->parameters()) {
     QualType PType = PI->getType();
     CharUnits sz = getObjCEncodingTypeSize(PType);
     if (sz.isZero())
@@ -5221,7 +5221,7 @@ bool ASTContext::getObjCEncodingForFunctionDecl(const FunctionDecl *Decl,
   ParmOffset = CharUnits::Zero();
 
   // Argument types.
-  for (auto PVDecl : Decl->params()) {
+  for (auto PVDecl : Decl->parameters()) {
     QualType PType = PVDecl->getOriginalType();
     if (const ArrayType *AT =
           dyn_cast<ArrayType>(PType->getCanonicalTypeInternal())) {
diff --git a/lib/AST/ASTDumper.cpp b/lib/AST/ASTDumper.cpp
index da7e980c5a..e1d52eaf0d 100644
--- a/lib/AST/ASTDumper.cpp
+++ b/lib/AST/ASTDumper.cpp
@@ -1681,7 +1681,7 @@ void ASTDumper::VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D) {
 }
 
 void ASTDumper::VisitBlockDecl(const BlockDecl *D) {
-  for (auto I : D->params())
+  for (auto I : D->parameters())
     dumpDecl(I);
 
   if (D->isVariadic())
diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index 9a4e4a2894..4f79926481 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -3010,7 +3010,7 @@ Decl *ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
 
   // Import the function parameters.
   SmallVector<ParmVarDecl *, 8> Parameters;
-  for (auto P : D->params()) {
+  for (auto P : D->parameters()) {
     ParmVarDecl *ToP = cast_or_null<ParmVarDecl>(Importer.Import(P));
     if (!ToP)
       return nullptr;
@@ -3276,7 +3276,7 @@ Decl *ASTNodeImporter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
 
   IndirectFieldDecl *ToIndirectField = IndirectFieldDecl::Create(
       Importer.getToContext(), DC, Loc, Name.getAsIdentifierInfo(), T,
-      NamedChain, D->getChainingSize());
+      {NamedChain, D->getChainingSize()});
 
   for (const auto *Attr : D->attrs())
     ToIndirectField->addAttr(Attr->clone(Importer.getToContext()));
@@ -3619,7 +3619,7 @@ Decl *ASTNodeImporter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
 
   // Import the parameters
   SmallVector<ParmVarDecl *, 5> ToParams;
-  for (auto *FromP : D->params()) {
+  for (auto *FromP : D->parameters()) {
     ParmVarDecl *ToP = cast_or_null<ParmVarDecl>(Importer.Import(FromP));
     if (!ToP)
       return nullptr;
diff --git a/lib/AST/Comment.cpp b/lib/AST/Comment.cpp
index d05c5de543..893bdc5c17 100644
--- a/lib/AST/Comment.cpp
+++ b/lib/AST/Comment.cpp
@@ -157,7 +157,7 @@ void DeclInfo::fill() {
   case Decl::CXXConversion: {
     const FunctionDecl *FD = cast<FunctionDecl>(CommentDecl);
     Kind = FunctionKind;
-    ParamVars = llvm::makeArrayRef(FD->param_begin(), FD->getNumParams());
+    ParamVars = FD->parameters();
     ReturnType = FD->getReturnType();
     unsigned NumLists = FD->getNumTemplateParameterLists();
     if (NumLists != 0) {
@@ -177,7 +177,7 @@ void DeclInfo::fill() {
   case Decl::ObjCMethod: {
     const ObjCMethodDecl *MD = cast<ObjCMethodDecl>(CommentDecl);
     Kind = FunctionKind;
-    ParamVars = llvm::makeArrayRef(MD->param_begin(), MD->param_size());
+    ParamVars = MD->parameters();
     ReturnType = MD->getReturnType();
     IsObjCMethod = true;
     IsInstanceMethod = MD->isInstanceMethod();
@@ -189,7 +189,7 @@ void DeclInfo::fill() {
     Kind = FunctionKind;
     TemplateKind = Template;
     const FunctionDecl *FD = FTD->getTemplatedDecl();
-    ParamVars = llvm::makeArrayRef(FD->param_begin(), FD->getNumParams());
+    ParamVars = FD->parameters();
     ReturnType = FD->getReturnType();
     TemplateParameters = FTD->getTemplateParameters();
     break;
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 09ba90a3ea..d59c4b422b 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -2793,7 +2793,7 @@ unsigned FunctionDecl::getMinRequiredArguments() const {
     return getNumParams();
 
   unsigned NumRequiredArgs = 0;
-  for (auto *Param : params())
+  for (auto *Param : parameters())
     if (!Param->isParameterPack() && !Param->hasDefaultArg())
       ++NumRequiredArgs;
   return NumRequiredArgs;
@@ -4099,8 +4099,10 @@ void IndirectFieldDecl::anchor() { }
 
 IndirectFieldDecl::IndirectFieldDecl(ASTContext &C, DeclContext *DC,
                                      SourceLocation L, DeclarationName N,
-                                     QualType T, NamedDecl **CH, unsigned CHS)
-    : ValueDecl(IndirectField, DC, L, N, T), Chaining(CH), ChainingSize(CHS) {
+                                     QualType T,
+                                     MutableArrayRef<NamedDecl *> CH)
+    : ValueDecl(IndirectField, DC, L, N, T), Chaining(CH.data()),
+      ChainingSize(CH.size()) {
   // In C++, indirect field declarations conflict with tag declarations in the
   // same scope, so add them to IDNS_Tag so that tag redeclaration finds them.
   if (C.getLangOpts().CPlusPlus)
@@ -4109,16 +4111,15 @@ IndirectFieldDecl::IndirectFieldDecl(ASTContext &C, DeclContext *DC,
 
 IndirectFieldDecl *
 IndirectFieldDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
-                          IdentifierInfo *Id, QualType T, NamedDecl **CH,
-                          unsigned CHS) {
-  return new (C, DC) IndirectFieldDecl(C, DC, L, Id, T, CH, CHS);
+                          IdentifierInfo *Id, QualType T,
+                          llvm::MutableArrayRef<NamedDecl *> CH) {
+  return new (C, DC) IndirectFieldDecl(C, DC, L, Id, T, CH);
 }
 
 IndirectFieldDecl *IndirectFieldDecl::CreateDeserialized(ASTContext &C,
                                                          unsigned ID) {
   return new (C, ID) IndirectFieldDecl(C, nullptr, SourceLocation(),
-                                       DeclarationName(), QualType(), nullptr,
-                                       0);
+                                       DeclarationName(), QualType(), None);
 }
 
 SourceRange EnumConstantDecl::getSourceRange() const {
diff --git a/lib/AST/DeclPrinter.cpp b/lib/AST/DeclPrinter.cpp
index 9d76f65b62..6868ea2a6d 100644
--- a/lib/AST/DeclPrinter.cpp
+++ b/lib/AST/DeclPrinter.cpp
@@ -1055,7 +1055,7 @@ void DeclPrinter::VisitObjCMethodDecl(ObjCMethodDecl *OMD) {
 
   std::string name = OMD->getSelector().getAsString();
   std::string::size_type pos, lastPos = 0;
-  for (const auto *PI : OMD->params()) {
+  for (const auto *PI : OMD->parameters()) {
     // FIXME: selector is missing here!
     pos = name.find_first_of(':', lastPos);
     Out << " " << name.substr(lastPos, pos - lastPos) << ':';
diff --git a/lib/AST/StmtPrinter.cpp b/lib/AST/StmtPrinter.cpp
index d5b7e10839..311187b4b3 100644
--- a/lib/AST/StmtPrinter.cpp
+++ b/lib/AST/StmtPrinter.cpp
@@ -2054,7 +2054,7 @@ void StmtPrinter::VisitLambdaExpr(LambdaExpr *Node) {
     OS << " (";
     CXXMethodDecl *Method = Node->getCallOperator();
     NeedComma = false;
-    for (auto P : Method->params()) {
+    for (auto P : Method->parameters()) {
       if (NeedComma) {
         OS << ", ";
       } else {
diff --git a/lib/Analysis/Consumed.cpp b/lib/Analysis/Consumed.cpp
index f2a7d904a5..47bef1b927 100644
--- a/lib/Analysis/Consumed.cpp
+++ b/lib/Analysis/Consumed.cpp
@@ -1362,7 +1362,7 @@ void ConsumedAnalyzer::run(AnalysisDeclContext &AC) {
   ConsumedStmtVisitor Visitor(AC, *this, CurrStates.get());
 
   // Add all trackable parameters to the state map.
-  for (const auto *PI : D->params())
+  for (const auto *PI : D->parameters())
     Visitor.VisitParmVarDecl(PI);
   
   // Visit all of the function's basic blocks.
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index dec071440a..c562602d96 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -402,7 +402,7 @@ CodeGenTypes::arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD,
   argTys.push_back(Context.getCanonicalParamType(receiverType));
   argTys.push_back(Context.getCanonicalParamType(Context.getObjCSelType()));
   // FIXME: Kill copy?
-  for (const auto *I : MD->params()) {
+  for (const auto *I : MD->parameters()) {
     argTys.push_back(Context.getCanonicalParamType(I->getType()));
   }
 
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index 768c2030a6..dc4455fbc7 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -2785,7 +2785,7 @@ void CodeGenFunction::EmitLambdaBlockInvokeBody() {
   CallArgs.add(RValue::get(ThisPtr.getPointer()), ThisType);
 
   // Add the rest of the parameters.
-  for (auto param : BD->params())
+  for (auto param : BD->parameters())
     EmitDelegateCallArg(CallArgs, param, param->getLocStart());
 
   assert(!Lambda->isGenericLambda() &&
@@ -2815,7 +2815,7 @@ void CodeGenFunction::EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD) {
   CallArgs.add(RValue::get(ThisPtr), ThisType);
 
   // Add the rest of the parameters.
-  for (auto Param : MD->params())
+  for (auto Param : MD->parameters())
     EmitDelegateCallArg(CallArgs, Param, Param->getLocStart());
 
   const CXXMethodDecl *CallOp = Lambda->getLambdaCallOperator();
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 5448d7b1c5..bfd9e8d3ba 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -2766,7 +2766,7 @@ llvm::DISubroutineType *CGDebugInfo::getOrCreateFunctionType(const Decl *D,
     Elts.push_back(DBuilder.createArtificialType(
         getOrCreateType(CGM.getContext().getObjCSelType(), F)));
     // Get rest of the arguments.
-    for (const auto *PI : OMethod->params())
+    for (const auto *PI : OMethod->parameters())
       Elts.push_back(getOrCreateType(PI->getType(), F));
     // Variadic methods need a special marker at the end of the type list.
     if (OMethod->isVariadic())
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 4f14f87275..019cfc601f 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -1943,7 +1943,7 @@ CGObjCCommonMac::EmitMessageSend(CodeGen::CodeGenFunction &CGF,
   // Emit a null-check if there's a consumed argument other than the receiver.
   bool RequiresNullCheck = false;
   if (ReceiverCanBeNull && CGM.getLangOpts().ObjCAutoRefCount && Method) {
-    for (const auto *ParamDecl : Method->params()) {
+    for (const auto *ParamDecl : Method->parameters()) {
       if (ParamDecl->hasAttr<NSConsumedAttr>()) {
         if (!nullReturn.NullBB)
           nullReturn.init(CGF, Arg0);
@@ -6828,7 +6828,7 @@ CGObjCNonFragileABIMac::EmitVTableMessageSend(CodeGenFunction &CGF,
   
   bool requiresnullCheck = false;
   if (CGM.getLangOpts().ObjCAutoRefCount && method)
-    for (const auto *ParamDecl : method->params()) {
+    for (const auto *ParamDecl : method->parameters()) {
       if (ParamDecl->hasAttr<NSConsumedAttr>()) {
         if (!nullReturn.NullBB)
           nullReturn.init(CGF, arg0);
diff --git a/lib/CodeGen/CGOpenMPRuntime.cpp b/lib/CodeGen/CGOpenMPRuntime.cpp
index 059492665d..6a0edbe0e7 100644
--- a/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -6405,7 +6405,7 @@ void CGOpenMPRuntime::emitDeclareSimdFunction(const FunctionDecl *FD,
   if (isa<CXXMethodDecl>(FD))
     ParamPositions.insert({FD, 0});
   unsigned ParamPos = ParamPositions.size();
-  for (auto *P : FD->params()) {
+  for (auto *P : FD->parameters()) {
     ParamPositions.insert({P->getCanonicalDecl(), ParamPos});
     ++ParamPos;
   }
diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index 38461446de..6f749056ad 100644
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -284,7 +284,7 @@ void CodeGenFunction::EmitCallAndReturnForThunk(llvm::Value *Callee,
     CGM.getCXXABI().adjustCallArgsForDestructorThunk(*this, CurGD, CallArgs);
 
   // Add the rest of the arguments.
-  for (const ParmVarDecl *PD : MD->params())
+  for (const ParmVarDecl *PD : MD->parameters())
     EmitDelegateCallArg(CallArgs, PD, PD->getLocStart());
 
   const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 2dc4c12ce2..e914d79355 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -949,7 +949,7 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
     CGM.getCXXABI().buildThisParam(*this, Args);
   }
 
-  for (auto *Param : FD->params()) {
+  for (auto *Param : FD->parameters()) {
     Args.push_back(Param);
     if (!Param->hasAttr<PassObjectSizeAttr>())
       continue;
diff --git a/lib/CodeGen/ObjectFilePCHContainerOperations.cpp b/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
index bdb4f67e73..2aa06062a5 100644
--- a/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
+++ b/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
@@ -105,7 +105,7 @@ class PCHContainerGenerator : public ASTConsumer {
         return true;
 
       SmallVector<QualType, 16> ArgTypes;
-      for (auto i : D->params())
+      for (auto i : D->parameters())
         ArgTypes.push_back(i->getType());
       QualType RetTy = D->getReturnType();
       QualType FnTy = Ctx.getFunctionType(RetTy, ArgTypes,
@@ -124,7 +124,7 @@ class PCHContainerGenerator : public ASTConsumer {
       ArgTypes.push_back(D->getSelfType(Ctx, D->getClassInterface(),
                                         selfIsPseudoStrong, selfIsConsumed));
       ArgTypes.push_back(Ctx.getObjCSelType());
-      for (auto i : D->params())
+      for (auto i : D->parameters())
         ArgTypes.push_back(i->getType());
       QualType RetTy = D->getReturnType();
       QualType FnTy = Ctx.getFunctionType(RetTy, ArgTypes,
diff --git a/lib/Frontend/ASTConsumers.cpp b/lib/Frontend/ASTConsumers.cpp
index 52776b6a84..d5fc289d3d 100644
--- a/lib/Frontend/ASTConsumers.cpp
+++ b/lib/Frontend/ASTConsumers.cpp
@@ -268,7 +268,7 @@ void DeclContextPrinter::PrintDeclContext(const DeclContext* DC,
     // Print the parameters.
     Out << "(";
     bool PrintComma = false;
-    for (auto I : FD->params()) {
+    for (auto I : FD->parameters()) {
       if (PrintComma)
         Out << ", ";
       else
diff --git a/lib/Frontend/Rewrite/RewriteModernObjC.cpp b/lib/Frontend/Rewrite/RewriteModernObjC.cpp
index b7b7078946..5538fd2835 100644
--- a/lib/Frontend/Rewrite/RewriteModernObjC.cpp
+++ b/lib/Frontend/Rewrite/RewriteModernObjC.cpp
@@ -1286,7 +1286,7 @@ void RewriteModernObjC::RewriteObjCMethodDecl(const ObjCInterfaceDecl *IDecl,
   ResultStr += " _cmd";
 
   // Method arguments.
-  for (const auto *PDecl : OMD->params()) {
+  for (const auto *PDecl : OMD->parameters()) {
     ResultStr += ", ";
     if (PDecl->getType()->isObjCQualifiedIdType()) {
       ResultStr += "id ";
@@ -2785,7 +2785,7 @@ Stmt *RewriteModernObjC::RewriteObjCArrayLiteralExpr(ObjCArrayLiteral *Exp) {
   SmallVector<QualType, 4> ArgTypes;
   ArgTypes.push_back(Context->getObjCClassType());
   ArgTypes.push_back(Context->getObjCSelType());
-  for (const auto *PI : ArrayMethod->params())
+  for (const auto *PI : ArrayMethod->parameters())
     ArgTypes.push_back(PI->getType());
   
   QualType returnType = Exp->getType();
@@ -2932,7 +2932,7 @@ Stmt *RewriteModernObjC::RewriteObjCDictionaryLiteralExpr(ObjCDictionaryLiteral
   SmallVector<QualType, 8> ArgTypes;
   ArgTypes.push_back(Context->getObjCClassType());
   ArgTypes.push_back(Context->getObjCSelType());
-  for (const auto *PI : DictMethod->params()) {
+  for (const auto *PI : DictMethod->parameters()) {
     QualType T = PI->getType();
     if (const PointerType* PT = T->getAs<PointerType>()) {
       QualType PointeeTy = PT->getPointeeType();
@@ -3497,7 +3497,7 @@ Stmt *RewriteModernObjC::SynthMessageExpr(ObjCMessageExpr *Exp,
   ArgTypes.push_back(Context->getObjCSelType());
   if (ObjCMethodDecl *OMD = Exp->getMethodDecl()) {
     // Push any user argument types.
-    for (const auto *PI : OMD->params()) {
+    for (const auto *PI : OMD->parameters()) {
       QualType t = PI->getType()->isObjCQualifiedIdType()
                      ? Context->getObjCIdType()
                      : PI->getType();
diff --git a/lib/Frontend/Rewrite/RewriteObjC.cpp b/lib/Frontend/Rewrite/RewriteObjC.cpp
index 48c31b0314..fc938720d4 100644
--- a/lib/Frontend/Rewrite/RewriteObjC.cpp
+++ b/lib/Frontend/Rewrite/RewriteObjC.cpp
@@ -1118,7 +1118,7 @@ void RewriteObjC::RewriteObjCMethodDecl(const ObjCInterfaceDecl *IDecl,
   ResultStr += " _cmd";
 
   // Method arguments.
-  for (const auto *PDecl : OMD->params()) {
+  for (const auto *PDecl : OMD->parameters()) {
     ResultStr += ", ";
     if (PDecl->getType()->isObjCQualifiedIdType()) {
       ResultStr += "id ";
@@ -2917,7 +2917,7 @@ Stmt *RewriteObjC::SynthMessageExpr(ObjCMessageExpr *Exp,
   ArgTypes.push_back(Context->getObjCSelType());
   if (ObjCMethodDecl *OMD = Exp->getMethodDecl()) {
     // Push any user argument types.
-    for (const auto *PI : OMD->params()) {
+    for (const auto *PI : OMD->parameters()) {
       QualType t = PI->getType()->isObjCQualifiedIdType()
                      ? Context->getObjCIdType()
                      : PI->getType();
diff --git a/lib/Index/IndexDecl.cpp b/lib/Index/IndexDecl.cpp
index 5f5c49a2e3..eb3e151147 100644
--- a/lib/Index/IndexDecl.cpp
+++ b/lib/Index/IndexDecl.cpp
@@ -67,7 +67,7 @@ public:
         }
       } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
         if (FD->isThisDeclarationADefinition()) {
-          for (auto PI : FD->params()) {
+          for (auto PI : FD->parameters()) {
             IndexCtx.handleDecl(PI);
           }
         }
@@ -79,7 +79,7 @@ public:
     if (!IndexCtx.handleDecl(D, (unsigned)SymbolRole::Dynamic))
       return false;
     IndexCtx.indexTypeSourceInfo(D->getReturnTypeSourceInfo(), D);
-    for (const auto *I : D->params())
+    for (const auto *I : D->parameters())
       handleDeclarator(I, D);
 
     if (D->isThisDeclarationADefinition()) {
diff --git a/lib/Index/USRGeneration.cpp b/lib/Index/USRGeneration.cpp
index 40283dcd68..11ee873189 100644
--- a/lib/Index/USRGeneration.cpp
+++ b/lib/Index/USRGeneration.cpp
@@ -233,7 +233,7 @@ void USRGenerator::VisitFunctionDecl(const FunctionDecl *D) {
   }
 
   // Mangle in type information for the arguments.
-  for (auto PD : D->params()) {
+  for (auto PD : D->parameters()) {
     Out << '#';
     VisitType(PD->getType());
   }
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 5761ece2fa..49548608a6 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -9186,13 +9186,10 @@ static void diagnoseArrayStarInParamType(Sema &S, QualType PType,
 /// takes care of any checks that cannot be performed on the
 /// declaration itself, e.g., that the types of each of the function
 /// parameters are complete.
-bool Sema::CheckParmsForFunctionDef(ParmVarDecl *const *P,
-                                    ParmVarDecl *const *PEnd,
+bool Sema::CheckParmsForFunctionDef(ArrayRef<ParmVarDecl *> Parameters,
                                     bool CheckParameterNames) {
   bool HasInvalidParm = false;
-  for (; P != PEnd; ++P) {
-    ParmVarDecl *Param = *P;
-    
+  for (ParmVarDecl *Param : Parameters) {
     // C99 6.7.5.3p4: the parameters in a parameter type list in a
     // function declarator that is part of a function definition of
     // that function shall not have incomplete type.
diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp
index 2b226b8e75..d910c6f8ad 100644
--- a/lib/Sema/SemaCodeComplete.cpp
+++ b/lib/Sema/SemaCodeComplete.cpp
@@ -3208,7 +3208,7 @@ static void MaybeAddOverrideCalls(Sema &S, DeclContext *InContext,
   
   // We need to have names for all of the parameters, if we're going to 
   // generate a forwarding call.
-  for (auto P : Method->params())
+  for (auto P : Method->parameters())
     if (!P->getDeclName())
       return;
 
@@ -3240,7 +3240,7 @@ static void MaybeAddOverrideCalls(Sema &S, DeclContext *InContext,
                                          Overridden->getNameAsString()));
     Builder.AddChunk(CodeCompletionString::CK_LeftParen);
     bool FirstParam = true;
-    for (auto P : Method->params()) {
+    for (auto P : Method->parameters()) {
       if (FirstParam)
         FirstParam = false;
       else
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 0e9e9e55ff..c46e39dc9a 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -4134,7 +4134,7 @@ InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner,
 
         IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
             SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(),
-            VD->getType(), NamedChain, Chaining.size());
+            VD->getType(), {NamedChain, Chaining.size()});
 
         for (const auto *Attr : VD->attrs())
           IndirectField->addAttr(Attr->clone(SemaRef.Context));
@@ -8529,12 +8529,10 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
     }
 
     llvm::SmallPtrSet<const Type *, 16> ValidTypes;
-    for (auto Param : NewFD->params())
+    for (auto Param : NewFD->parameters())
       checkIsValidOpenCLKernelParameter(*this, D, Param, ValidTypes);
   }
-  for (FunctionDecl::param_iterator PI = NewFD->param_begin(),
-       PE = NewFD->param_end(); PI != PE; ++PI) {
-    ParmVarDecl *Param = *PI;
+  for (const ParmVarDecl *Param : NewFD->parameters()) {
     QualType PT = Param->getType();
 
     // OpenCL 2.0 pipe restrictions forbids pipe packet types to be non-value
@@ -10866,26 +10864,23 @@ ParmVarDecl *Sema::BuildParmVarDeclForTypedef(DeclContext *DC,
   return Param;
 }
 
-void Sema::DiagnoseUnusedParameters(ParmVarDecl * const *Param,
-                                    ParmVarDecl * const *ParamEnd) {
+void Sema::DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters) {
   // Don't diagnose unused-parameter errors in template instantiations; we
   // will already have done so in the template itself.
   if (!ActiveTemplateInstantiations.empty())
     return;
 
-  for (; Param != ParamEnd; ++Param) {
-    if (!(*Param)->isReferenced() && (*Param)->getDeclName() &&
-        !(*Param)->hasAttr<UnusedAttr>()) {
-      Diag((*Param)->getLocation(), diag::warn_unused_parameter)
-        << (*Param)->getDeclName();
+  for (const ParmVarDecl *Parameter : Parameters) {
+    if (!Parameter->isReferenced() && Parameter->getDeclName() &&
+        !Parameter->hasAttr<UnusedAttr>()) {
+      Diag(Parameter->getLocation(), diag::warn_unused_parameter)
+        << Parameter->getDeclName();
     }
   }
 }
 
-void Sema::DiagnoseSizeOfParametersAndReturnValue(ParmVarDecl * const *Param,
-                                                  ParmVarDecl * const *ParamEnd,
-                                                  QualType ReturnTy,
-                                                  NamedDecl *D) {
+void Sema::DiagnoseSizeOfParametersAndReturnValue(
+    ArrayRef<ParmVarDecl *> Parameters, QualType ReturnTy, NamedDecl *D) {
   if (LangOpts.NumLargeByValueCopy == 0) // No check.
     return;
 
@@ -10900,14 +10895,14 @@ void Sema::DiagnoseSizeOfParametersAndReturnValue(ParmVarDecl * const *Param,
 
   // Warn if any parameter is pass-by-value and larger than the specified
   // threshold.
-  for (; Param != ParamEnd; ++Param) {
-    QualType T = (*Param)->getType();
+  for (const ParmVarDecl *Parameter : Parameters) {
+    QualType T = Parameter->getType();
     if (T->isDependentType() || !T.isPODType(Context))
       continue;
     unsigned Size = Context.getTypeSizeInChars(T).getQuantity();
     if (Size > LangOpts.NumLargeByValueCopy)
-      Diag((*Param)->getLocation(), diag::warn_parameter_size)
-          << (*Param)->getDeclName() << Size;
+      Diag(Parameter->getLocation(), diag::warn_parameter_size)
+          << Parameter->getDeclName() << Size;
   }
 }
 
@@ -11249,11 +11244,11 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
     PushDeclContext(FnBodyScope, FD);
 
   // Check the validity of our function parameters
-  CheckParmsForFunctionDef(FD->param_begin(), FD->param_end(),
+  CheckParmsForFunctionDef(FD->parameters(),
                            /*CheckParameterNames=*/true);
 
   // Introduce our parameters into the function scope
-  for (auto Param : FD->params()) {
+  for (auto Param : FD->parameters()) {
     Param->setOwningFunction(FD);
 
     // If this has an identifier, add it to the scope stack.
@@ -11467,8 +11462,8 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
     if (!FD->isInvalidDecl()) {
       // Don't diagnose unused parameters of defaulted or deleted functions.
       if (!FD->isDeleted() && !FD->isDefaulted())
-        DiagnoseUnusedParameters(FD->param_begin(), FD->param_end());
-      DiagnoseSizeOfParametersAndReturnValue(FD->param_begin(), FD->param_end(),
+        DiagnoseUnusedParameters(FD->parameters());
+      DiagnoseSizeOfParametersAndReturnValue(FD->parameters(),
                                              FD->getReturnType(), FD);
 
       // If this is a structor, we need a vtable.
@@ -11539,8 +11534,8 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
     assert(MD == getCurMethodDecl() && "Method parsing confused");
     MD->setBody(Body);
     if (!MD->isInvalidDecl()) {
-      DiagnoseUnusedParameters(MD->param_begin(), MD->param_end());
-      DiagnoseSizeOfParametersAndReturnValue(MD->param_begin(), MD->param_end(),
+      DiagnoseUnusedParameters(MD->parameters());
+      DiagnoseSizeOfParametersAndReturnValue(MD->parameters(),
                                              MD->getReturnType(), MD);
 
       if (Body)
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 8eeaef7df5..8c0e9eaddf 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -11823,7 +11823,7 @@ bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
                   diag::err_operator_overload_static) << FnDecl->getDeclName();
   } else {
     bool ClassOrEnumParam = false;
-    for (auto Param : FnDecl->params()) {
+    for (auto Param : FnDecl->parameters()) {
       QualType ParamType = Param->getType().getNonReferenceType();
       if (ParamType->isDependentType() || ParamType->isRecordType() ||
           ParamType->isEnumeralType()) {
@@ -11845,7 +11845,7 @@ bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
   // Only the function-call operator allows default arguments
   // (C++ [over.call]p1).
   if (Op != OO_Call) {
-    for (auto Param : FnDecl->params()) {
+    for (auto Param : FnDecl->parameters()) {
       if (Param->hasDefaultArg())
         return Diag(Param->getLocation(),
                     diag::err_operator_overload_default_arg)
@@ -12110,7 +12110,7 @@ bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
 
   // A parameter-declaration-clause containing a default argument is not
   // equivalent to any of the permitted forms.
-  for (auto Param : FnDecl->params()) {
+  for (auto Param : FnDecl->parameters()) {
     if (Param->hasDefaultArg()) {
       Diag(Param->getDefaultArgRange().getBegin(),
            diag::err_literal_operator_default_argument)
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 41166960fa..f4d82b3c31 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -319,11 +319,11 @@ void Sema::ActOnStartOfObjCMethodDef(Scope *FnBodyScope, Decl *D) {
   PushOnScopeChains(MDecl->getCmdDecl(), FnBodyScope);
 
   // The ObjC parser requires parameter names so there's no need to check.
-  CheckParmsForFunctionDef(MDecl->param_begin(), MDecl->param_end(),
+  CheckParmsForFunctionDef(MDecl->parameters(),
                            /*CheckParameterNames=*/false);
 
   // Introduce all of the other parameters into this scope.
-  for (auto *Param : MDecl->params()) {
+  for (auto *Param : MDecl->parameters()) {
     if (!Param->isInvalidDecl() &&
         getLangOpts().ObjCAutoRefCount &&
         !HasExplicitOwnershipAttr(*this, Param))
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index ab1180ed99..05aa18c633 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -12028,8 +12028,7 @@ void Sema::ActOnBlockArguments(SourceLocation CaretLoc, Declarator &ParamInfo,
   // Set the parameters on the block decl.
   if (!Params.empty()) {
     CurBlock->TheDecl->setParams(Params);
-    CheckParmsForFunctionDef(CurBlock->TheDecl->param_begin(),
-                             CurBlock->TheDecl->param_end(),
+    CheckParmsForFunctionDef(CurBlock->TheDecl->parameters(),
                              /*CheckParameterNames=*/false);
   }
   
@@ -12037,7 +12036,7 @@ void Sema::ActOnBlockArguments(SourceLocation CaretLoc, Declarator &ParamInfo,
   ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo);
 
   // Put the parameter variables in scope.
-  for (auto AI : CurBlock->TheDecl->params()) {
+  for (auto AI : CurBlock->TheDecl->parameters()) {
     AI->setOwningFunction(CurBlock->TheDecl);
 
     // If this has an identifier, add it to the scope stack.
@@ -12137,8 +12136,7 @@ ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc,
     BlockTy = Context.getFunctionType(RetTy, None, EPI);
   }
 
-  DiagnoseUnusedParameters(BSI->TheDecl->param_begin(),
-                           BSI->TheDecl->param_end());
+  DiagnoseUnusedParameters(BSI->TheDecl->parameters());
   BlockTy = Context.getBlockPointerType(BlockTy);
 
   // If needed, diagnose invalid gotos and switches in the block.
diff --git a/lib/Sema/SemaLambda.cpp b/lib/Sema/SemaLambda.cpp
index 1f5f63a414..73e0077d19 100644
--- a/lib/Sema/SemaLambda.cpp
+++ b/lib/Sema/SemaLambda.cpp
@@ -415,11 +415,10 @@ CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
   // Add parameters.
   if (!Params.empty()) {
     Method->setParams(Params);
-    CheckParmsForFunctionDef(const_cast<ParmVarDecl **>(Params.begin()),
-                             const_cast<ParmVarDecl **>(Params.end()),
+    CheckParmsForFunctionDef(Params,
                              /*CheckParameterNames=*/false);
-    
-    for (auto P : Method->params())
+
+    for (auto P : Method->parameters())
       P->setOwningFunction(Method);
   }
 
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index e5c24252ed..3bfa34c63f 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -2480,7 +2480,7 @@ Sema::SubstituteExplicitTemplateArguments(
   if (ExplicitTemplateArgs.size() == 0) {
     // No arguments to substitute; just copy over the parameter types and
     // fill in the function type.
-    for (auto P : Function->params())
+    for (auto P : Function->parameters())
       ParamTypes.push_back(P->getType());
 
     if (FunctionType)
@@ -2563,8 +2563,7 @@ Sema::SubstituteExplicitTemplateArguments(
   // return type, substitute it after the arguments to ensure we substitute
   // in lexical order.
   if (Proto->hasTrailingReturn()) {
-    if (SubstParmTypes(Function->getLocation(),
-                       Function->param_begin(), Function->getNumParams(),
+    if (SubstParmTypes(Function->getLocation(), Function->parameters(),
                        Proto->getExtParameterInfosOrNull(),
                        MultiLevelTemplateArgumentList(*ExplicitArgumentList),
                        ParamTypes, /*params*/ nullptr, ExtParamInfos))
@@ -2601,8 +2600,7 @@ Sema::SubstituteExplicitTemplateArguments(
   // Instantiate the types of each of the function parameters given the
   // explicitly-specified template arguments if we didn't do so earlier.
   if (!Proto->hasTrailingReturn() &&
-      SubstParmTypes(Function->getLocation(),
-                     Function->param_begin(), Function->getNumParams(),
+      SubstParmTypes(Function->getLocation(), Function->parameters(),
                      Proto->getExtParameterInfosOrNull(),
                      MultiLevelTemplateArgumentList(*ExplicitArgumentList),
                      ParamTypes, /*params*/ nullptr, ExtParamInfos))
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index 24a47d1942..10a3b865bc 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1714,23 +1714,21 @@ ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
 /// \brief Substitute the given template arguments into the given set of
 /// parameters, producing the set of parameter types that would be generated
 /// from such a substitution.
-bool Sema::SubstParmTypes(SourceLocation Loc, 
-                          ParmVarDecl **Params, unsigned NumParams,
-                    const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
-                          const MultiLevelTemplateArgumentList &TemplateArgs,
-                          SmallVectorImpl<QualType> &ParamTypes,
-                          SmallVectorImpl<ParmVarDecl *> *OutParams,
-                          ExtParameterInfoBuilder &ParamInfos) {
+bool Sema::SubstParmTypes(
+    SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
+    const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
+    const MultiLevelTemplateArgumentList &TemplateArgs,
+    SmallVectorImpl<QualType> &ParamTypes,
+    SmallVectorImpl<ParmVarDecl *> *OutParams,
+    ExtParameterInfoBuilder &ParamInfos) {
   assert(!ActiveTemplateInstantiations.empty() &&
          "Cannot perform an instantiation without some context on the "
          "instantiation stack");
   
   TemplateInstantiator Instantiator(*this, TemplateArgs, Loc, 
                                     DeclarationName());
-  return Instantiator.TransformFunctionTypeParams(Loc, Params, NumParams,
-                                                  nullptr, ExtParamInfos,
-                                                  ParamTypes, OutParams,
-                                                  ParamInfos);
+  return Instantiator.TransformFunctionTypeParams(
+      Loc, Params, nullptr, ExtParamInfos, ParamTypes, OutParams, ParamInfos);
 }
 
 /// \brief Perform substitution on the base class specifiers of the
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 78de86e49d..58c0ab027e 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -803,7 +803,7 @@ Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
   QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
   IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
       SemaRef.Context, Owner, D->getLocation(), D->getIdentifier(), T,
-      NamedChain, D->getChainingSize());
+      {NamedChain, D->getChainingSize()});
 
   for (const auto *Attr : D->attrs())
     IndirectField->addAttr(Attr->clone(SemaRef.Context));
@@ -3301,9 +3301,9 @@ TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
     // synthesized in the method declaration.
     SmallVector<QualType, 4> ParamTypes;
     Sema::ExtParameterInfoBuilder ExtParamInfos;
-    if (SemaRef.SubstParmTypes(D->getLocation(), D->param_begin(),
-                               D->getNumParams(), nullptr, TemplateArgs,
-                               ParamTypes, &Params, ExtParamInfos))
+    if (SemaRef.SubstParmTypes(D->getLocation(), D->parameters(), nullptr,
+                               TemplateArgs, ParamTypes, &Params,
+                               ExtParamInfos))
       return nullptr;
   }
 
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index a7b994d986..c90e0fa2ca 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -612,13 +612,12 @@ public:
   /// variables vector are acceptable.
   ///
   /// Return true on error.
-  bool TransformFunctionTypeParams(SourceLocation Loc,
-                                   ParmVarDecl **Params, unsigned NumParams,
-                                   const QualType *ParamTypes,
-                     const FunctionProtoType::ExtParameterInfo *ParamInfos,
-                                   SmallVectorImpl<QualType> &PTypes,
-                                   SmallVectorImpl<ParmVarDecl*> *PVars,
-                                   Sema::ExtParameterInfoBuilder &PInfos);
+  bool TransformFunctionTypeParams(
+      SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
+      const QualType *ParamTypes,
+      const FunctionProtoType::ExtParameterInfo *ParamInfos,
+      SmallVectorImpl<QualType> &PTypes, SmallVectorImpl<ParmVarDecl *> *PVars,
+      Sema::ExtParameterInfoBuilder &PInfos);
 
   /// \brief Transforms a single function-type parameter.  Return null
   /// on error.
@@ -4663,17 +4662,17 @@ ParmVarDecl *TreeTransform<Derived>::TransformFunctionTypeParam(
   return newParm;
 }
 
-template<typename Derived>
-bool TreeTransform<Derived>::
-  TransformFunctionTypeParams(SourceLocation Loc,
-                              ParmVarDecl **Params, unsigned NumParams,
-                              const QualType *ParamTypes,
-                        const FunctionProtoType::ExtParameterInfo *ParamInfos,
-                              SmallVectorImpl<QualType> &OutParamTypes,
-                              SmallVectorImpl<ParmVarDecl*> *PVars,
-                              Sema::ExtParameterInfoBuilder &PInfos) {
+template <typename Derived>
+bool TreeTransform<Derived>::TransformFunctionTypeParams(
+    SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
+    const QualType *ParamTypes,
+    const FunctionProtoType::ExtParameterInfo *ParamInfos,
+    SmallVectorImpl<QualType> &OutParamTypes,
+    SmallVectorImpl<ParmVarDecl *> *PVars,
+    Sema::ExtParameterInfoBuilder &PInfos) {
   int indexAdjustment = 0;
 
+  unsigned NumParams = Params.size();
   for (unsigned i = 0; i != NumParams; ++i) {
     if (ParmVarDecl *OldParm = Params[i]) {
       assert(OldParm->getFunctionScopeIndex() == i);
@@ -4908,7 +4907,7 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
 
   if (T->hasTrailingReturn()) {
     if (getDerived().TransformFunctionTypeParams(
-            TL.getBeginLoc(), TL.getParmArray(), TL.getNumParams(),
+            TL.getBeginLoc(), TL.getParams(),
             TL.getTypePtr()->param_type_begin(),
             T->getExtParameterInfosOrNull(),
             ParamTypes, &ParamDecls, ExtParamInfos))
@@ -4934,7 +4933,7 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
       return QualType();
 
     if (getDerived().TransformFunctionTypeParams(
-            TL.getBeginLoc(), TL.getParmArray(), TL.getNumParams(),
+            TL.getBeginLoc(), TL.getParams(),
             TL.getTypePtr()->param_type_begin(),
             T->getExtParameterInfosOrNull(),
             ParamTypes, &ParamDecls, ExtParamInfos))
@@ -11196,13 +11195,10 @@ TreeTransform<Derived>::TransformBlockExpr(BlockExpr *E) {
 
   // Parameter substitution.
   Sema::ExtParameterInfoBuilder extParamInfos;
-  if (getDerived().TransformFunctionTypeParams(E->getCaretLocation(),
-                                               oldBlock->param_begin(),
-                                               oldBlock->param_size(),
-                                               nullptr,
-                             exprFunctionType->getExtParameterInfosOrNull(),
-                                               paramTypes, &params,
-                                               extParamInfos)) {
+  if (getDerived().TransformFunctionTypeParams(
+          E->getCaretLocation(), oldBlock->parameters(), nullptr,
+          exprFunctionType->getExtParameterInfosOrNull(), paramTypes, &params,
+          extParamInfos)) {
     getSema().ActOnBlockError(E->getCaretLocation(), /*Scope=*/nullptr);
     return ExprError();
   }
diff --git a/lib/Serialization/ASTWriterDecl.cpp b/lib/Serialization/ASTWriterDecl.cpp
index 1e26f0f9c0..6a22f66981 100644
--- a/lib/Serialization/ASTWriterDecl.cpp
+++ b/lib/Serialization/ASTWriterDecl.cpp
@@ -597,7 +597,7 @@ void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
   }
 
   Record.push_back(D->param_size());
-  for (auto P : D->params())
+  for (auto P : D->parameters())
     Record.AddDeclRef(P);
   Code = serialization::DECL_FUNCTION;
 }
@@ -637,7 +637,7 @@ void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
   Record.AddTypeSourceInfo(D->getReturnTypeSourceInfo());
   Record.AddSourceLocation(D->getLocEnd());
   Record.push_back(D->param_size());
-  for (const auto *P : D->params())
+  for (const auto *P : D->parameters())
     Record.AddDeclRef(P);
 
   Record.push_back(D->SelLocsKind);
diff --git a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index cf4c011d5a..e06662b169 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -944,7 +944,7 @@ static bool treatUnusedNewEscaped(const CXXNewExpr *NE) {
   const CXXConstructorDecl *CtorD = ConstructE->getConstructor();
 
   // Iterate over the constructor parameters.
-  for (const auto *CtorParam : CtorD->params()) {
+  for (const auto *CtorParam : CtorD->parameters()) {
 
     QualType CtorParamPointeeT = CtorParam->getType()->getPointeeType();
     if (CtorParamPointeeT.isNull())
diff --git a/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp b/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp
index dab068b27e..559c75d7a5 100644
--- a/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp
@@ -61,7 +61,7 @@ void NSErrorMethodChecker::checkASTDecl(const ObjCMethodDecl *D,
     II = &D->getASTContext().Idents.get("NSError");
 
   bool hasNSError = false;
-  for (const auto *I : D->params())  {
+  for (const auto *I : D->parameters())  {
     if (IsNSError(I->getType(), II)) {
       hasNSError = true;
       break;
@@ -108,7 +108,7 @@ void CFErrorFunctionChecker::checkASTDecl(const FunctionDecl *D,
     II = &D->getASTContext().Idents.get("CFErrorRef");
 
   bool hasCFError = false;
-  for (auto I : D->params())  {
+  for (auto I : D->parameters())  {
     if (IsCFError(I->getType(), II)) {
       hasCFError = true;
       break;
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index dc95b599a7..a0bb7d52cb 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -935,7 +935,7 @@ bool CursorVisitor::VisitObjCMethodDecl(ObjCMethodDecl *ND) {
     if (Visit(TSInfo->getTypeLoc()))
       return true;
 
-  for (const auto *P : ND->params()) {
+  for (const auto *P : ND->parameters()) {
     if (Visit(MakeCXCursor(P, TU, RegionOfInterest)))
       return true;
   }
@@ -6278,7 +6278,7 @@ AnnotateTokensWorker::Visit(CXCursor cursor, CXCursor parent) {
         if (Method->getObjCDeclQualifier())
           HasContextSensitiveKeywords = true;
         else {
-          for (const auto *P : Method->params()) {
+          for (const auto *P : Method->parameters()) {
             if (P->getObjCDeclQualifier()) {
               HasContextSensitiveKeywords = true;
               break;