Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 5065 deletions

diff --git a/gnu/llvm/tools/clang/lib/Sema/SemaDeclObjC.cpp b/gnu/llvm/tools/clang/lib/Sema/SemaDeclObjC.cpp
deleted file mode 100644
index 3746bdad035..00000000000
--- a/gnu/llvm/tools/clang/lib/Sema/SemaDeclObjC.cpp
+++ /dev/null
@@ -1,5065 +0,0 @@
-//===--- SemaDeclObjC.cpp - Semantic Analysis for ObjC Declarations -------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-//  This file implements semantic analysis for Objective C declarations.
-//
-//===----------------------------------------------------------------------===//
-
-#include "TypeLocBuilder.h"
-#include "clang/AST/ASTConsumer.h"
-#include "clang/AST/ASTContext.h"
-#include "clang/AST/ASTMutationListener.h"
-#include "clang/AST/DeclObjC.h"
-#include "clang/AST/Expr.h"
-#include "clang/AST/ExprObjC.h"
-#include "clang/AST/RecursiveASTVisitor.h"
-#include "clang/Basic/SourceManager.h"
-#include "clang/Sema/DeclSpec.h"
-#include "clang/Sema/Lookup.h"
-#include "clang/Sema/Scope.h"
-#include "clang/Sema/ScopeInfo.h"
-#include "clang/Sema/SemaInternal.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/DenseSet.h"
-
-using namespace clang;
-
-/// Check whether the given method, which must be in the 'init'
-/// family, is a valid member of that family.
-///
-/// \param receiverTypeIfCall - if null, check this as if declaring it;
-///   if non-null, check this as if making a call to it with the given
-///   receiver type
-///
-/// \return true to indicate that there was an error and appropriate
-///   actions were taken
-bool Sema::checkInitMethod(ObjCMethodDecl *method,
-                           QualType receiverTypeIfCall) {
-  if (method->isInvalidDecl()) return true;
-
-  // This castAs is safe: methods that don't return an object
-  // pointer won't be inferred as inits and will reject an explicit
-  // objc_method_family(init).
-
-  // We ignore protocols here.  Should we?  What about Class?
-
-  const ObjCObjectType *result =
-      method->getReturnType()->castAs<ObjCObjectPointerType>()->getObjectType();
-
-  if (result->isObjCId()) {
-    return false;
-  } else if (result->isObjCClass()) {
-    // fall through: always an error
-  } else {
-    ObjCInterfaceDecl *resultClass = result->getInterface();
-    assert(resultClass && "unexpected object type!");
-
-    // It's okay for the result type to still be a forward declaration
-    // if we're checking an interface declaration.
-    if (!resultClass->hasDefinition()) {
-      if (receiverTypeIfCall.isNull() &&
-          !isa<ObjCImplementationDecl>(method->getDeclContext()))
-        return false;
-
-    // Otherwise, we try to compare class types.
-    } else {
-      // If this method was declared in a protocol, we can't check
-      // anything unless we have a receiver type that's an interface.
-      const ObjCInterfaceDecl *receiverClass = nullptr;
-      if (isa<ObjCProtocolDecl>(method->getDeclContext())) {
-        if (receiverTypeIfCall.isNull())
-          return false;
-
-        receiverClass = receiverTypeIfCall->castAs<ObjCObjectPointerType>()
-          ->getInterfaceDecl();
-
-        // This can be null for calls to e.g. id<Foo>.
-        if (!receiverClass) return false;
-      } else {
-        receiverClass = method->getClassInterface();
-        assert(receiverClass && "method not associated with a class!");
-      }
-
-      // If either class is a subclass of the other, it's fine.
-      if (receiverClass->isSuperClassOf(resultClass) ||
-          resultClass->isSuperClassOf(receiverClass))
-        return false;
-    }
-  }
-
-  SourceLocation loc = method->getLocation();
-
-  // If we're in a system header, and this is not a call, just make
-  // the method unusable.
-  if (receiverTypeIfCall.isNull() && getSourceManager().isInSystemHeader(loc)) {
-    method->addAttr(UnavailableAttr::CreateImplicit(Context, "",
-                      UnavailableAttr::IR_ARCInitReturnsUnrelated, loc));
-    return true;
-  }
-
-  // Otherwise, it's an error.
-  Diag(loc, diag::err_arc_init_method_unrelated_result_type);
-  method->setInvalidDecl();
-  return true;
-}
-
-/// Issue a warning if the parameter of the overridden method is non-escaping
-/// but the parameter of the overriding method is not.
-static bool diagnoseNoescape(const ParmVarDecl *NewD, const ParmVarDecl *OldD,
-                             Sema &S) {
-  if (OldD->hasAttr<NoEscapeAttr>() && !NewD->hasAttr<NoEscapeAttr>()) {
-    S.Diag(NewD->getLocation(), diag::warn_overriding_method_missing_noescape);
-    S.Diag(OldD->getLocation(), diag::note_overridden_marked_noescape);
-    return false;
-  }
-
-  return true;
-}
-
-/// Produce additional diagnostics if a category conforms to a protocol that
-/// defines a method taking a non-escaping parameter.
-static void diagnoseNoescape(const ParmVarDecl *NewD, const ParmVarDecl *OldD,
-                             const ObjCCategoryDecl *CD,
-                             const ObjCProtocolDecl *PD, Sema &S) {
-  if (!diagnoseNoescape(NewD, OldD, S))
-    S.Diag(CD->getLocation(), diag::note_cat_conform_to_noescape_prot)
-        << CD->IsClassExtension() << PD
-        << cast<ObjCMethodDecl>(NewD->getDeclContext());
-}
-
-void Sema::CheckObjCMethodOverride(ObjCMethodDecl *NewMethod,
-                                   const ObjCMethodDecl *Overridden) {
-  if (Overridden->hasRelatedResultType() &&
-      !NewMethod->hasRelatedResultType()) {
-    // This can only happen when the method follows a naming convention that
-    // implies a related result type, and the original (overridden) method has
-    // a suitable return type, but the new (overriding) method does not have
-    // a suitable return type.
-    QualType ResultType = NewMethod->getReturnType();
-    SourceRange ResultTypeRange = NewMethod->getReturnTypeSourceRange();
-
-    // Figure out which class this method is part of, if any.
-    ObjCInterfaceDecl *CurrentClass
-      = dyn_cast<ObjCInterfaceDecl>(NewMethod->getDeclContext());
-    if (!CurrentClass) {
-      DeclContext *DC = NewMethod->getDeclContext();
-      if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(DC))
-        CurrentClass = Cat->getClassInterface();
-      else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(DC))
-        CurrentClass = Impl->getClassInterface();
-      else if (ObjCCategoryImplDecl *CatImpl
-               = dyn_cast<ObjCCategoryImplDecl>(DC))
-        CurrentClass = CatImpl->getClassInterface();
-    }
-
-    if (CurrentClass) {
-      Diag(NewMethod->getLocation(),
-           diag::warn_related_result_type_compatibility_class)
-        << Context.getObjCInterfaceType(CurrentClass)
-        << ResultType
-        << ResultTypeRange;
-    } else {
-      Diag(NewMethod->getLocation(),
-           diag::warn_related_result_type_compatibility_protocol)
-        << ResultType
-        << ResultTypeRange;
-    }
-
-    if (ObjCMethodFamily Family = Overridden->getMethodFamily())
-      Diag(Overridden->getLocation(),
-           diag::note_related_result_type_family)
-        << /*overridden method*/ 0
-        << Family;
-    else
-      Diag(Overridden->getLocation(),
-           diag::note_related_result_type_overridden);
-  }
-
-  if ((NewMethod->hasAttr<NSReturnsRetainedAttr>() !=
-       Overridden->hasAttr<NSReturnsRetainedAttr>())) {
-    Diag(NewMethod->getLocation(),
-         getLangOpts().ObjCAutoRefCount
-             ? diag::err_nsreturns_retained_attribute_mismatch
-             : diag::warn_nsreturns_retained_attribute_mismatch)
-        << 1;
-    Diag(Overridden->getLocation(), diag::note_previous_decl) << "method";
-  }
-  if ((NewMethod->hasAttr<NSReturnsNotRetainedAttr>() !=
-       Overridden->hasAttr<NSReturnsNotRetainedAttr>())) {
-    Diag(NewMethod->getLocation(),
-         getLangOpts().ObjCAutoRefCount
-             ? diag::err_nsreturns_retained_attribute_mismatch
-             : diag::warn_nsreturns_retained_attribute_mismatch)
-        << 0;
-    Diag(Overridden->getLocation(), diag::note_previous_decl)  << "method";
-  }
-
-  ObjCMethodDecl::param_const_iterator oi = Overridden->param_begin(),
-                                       oe = Overridden->param_end();
-  for (ObjCMethodDecl::param_iterator ni = NewMethod->param_begin(),
-                                      ne = NewMethod->param_end();
-       ni != ne && oi != oe; ++ni, ++oi) {
-    const ParmVarDecl *oldDecl = (*oi);
-    ParmVarDecl *newDecl = (*ni);
-    if (newDecl->hasAttr<NSConsumedAttr>() !=
-        oldDecl->hasAttr<NSConsumedAttr>()) {
-      Diag(newDecl->getLocation(),
-           getLangOpts().ObjCAutoRefCount
-               ? diag::err_nsconsumed_attribute_mismatch
-               : diag::warn_nsconsumed_attribute_mismatch);
-      Diag(oldDecl->getLocation(), diag::note_previous_decl) << "parameter";
-    }
-
-    diagnoseNoescape(newDecl, oldDecl, *this);
-  }
-}
-
-/// Check a method declaration for compatibility with the Objective-C
-/// ARC conventions.
-bool Sema::CheckARCMethodDecl(ObjCMethodDecl *method) {
-  ObjCMethodFamily family = method->getMethodFamily();
-  switch (family) {
-  case OMF_None:
-  case OMF_finalize:
-  case OMF_retain:
-  case OMF_release:
-  case OMF_autorelease:
-  case OMF_retainCount:
-  case OMF_self:
-  case OMF_initialize:
-  case OMF_performSelector:
-    return false;
-
-  case OMF_dealloc:
-    if (!Context.hasSameType(method->getReturnType(), Context.VoidTy)) {
-      SourceRange ResultTypeRange = method->getReturnTypeSourceRange();
-      if (ResultTypeRange.isInvalid())
-        Diag(method->getLocation(), diag::err_dealloc_bad_result_type)
-            << method->getReturnType()
-            << FixItHint::CreateInsertion(method->getSelectorLoc(0), "(void)");
-      else
-        Diag(method->getLocation(), diag::err_dealloc_bad_result_type)
-            << method->getReturnType()
-            << FixItHint::CreateReplacement(ResultTypeRange, "void");
-      return true;
-    }
-    return false;
-
-  case OMF_init:
-    // If the method doesn't obey the init rules, don't bother annotating it.
-    if (checkInitMethod(method, QualType()))
-      return true;
-
-    method->addAttr(NSConsumesSelfAttr::CreateImplicit(Context));
-
-    // Don't add a second copy of this attribute, but otherwise don't
-    // let it be suppressed.
-    if (method->hasAttr<NSReturnsRetainedAttr>())
-      return false;
-    break;
-
-  case OMF_alloc:
-  case OMF_copy:
-  case OMF_mutableCopy:
-  case OMF_new:
-    if (method->hasAttr<NSReturnsRetainedAttr>() ||
-        method->hasAttr<NSReturnsNotRetainedAttr>() ||
-        method->hasAttr<NSReturnsAutoreleasedAttr>())
-      return false;
-    break;
-  }
-
-  method->addAttr(NSReturnsRetainedAttr::CreateImplicit(Context));
-  return false;
-}
-
-static void DiagnoseObjCImplementedDeprecations(Sema &S, const NamedDecl *ND,
-                                                SourceLocation ImplLoc) {
-  if (!ND)
-    return;
-  bool IsCategory = false;
-  StringRef RealizedPlatform;
-  AvailabilityResult Availability = ND->getAvailability(
-      /*Message=*/nullptr, /*EnclosingVersion=*/VersionTuple(),
-      &RealizedPlatform);
-  if (Availability != AR_Deprecated) {
-    if (isa<ObjCMethodDecl>(ND)) {
-      if (Availability != AR_Unavailable)
-        return;
-      if (RealizedPlatform.empty())
-        RealizedPlatform = S.Context.getTargetInfo().getPlatformName();
-      // Warn about implementing unavailable methods, unless the unavailable
-      // is for an app extension.
-      if (RealizedPlatform.endswith("_app_extension"))
-        return;
-      S.Diag(ImplLoc, diag::warn_unavailable_def);
-      S.Diag(ND->getLocation(), diag::note_method_declared_at)
-          << ND->getDeclName();
-      return;
-    }
-    if (const auto *CD = dyn_cast<ObjCCategoryDecl>(ND)) {
-      if (!CD->getClassInterface()->isDeprecated())
-        return;
-      ND = CD->getClassInterface();
-      IsCategory = true;
-    } else
-      return;
-  }
-  S.Diag(ImplLoc, diag::warn_deprecated_def)
-      << (isa<ObjCMethodDecl>(ND)
-              ? /*Method*/ 0
-              : isa<ObjCCategoryDecl>(ND) || IsCategory ? /*Category*/ 2
-                                                        : /*Class*/ 1);
-  if (isa<ObjCMethodDecl>(ND))
-    S.Diag(ND->getLocation(), diag::note_method_declared_at)
-        << ND->getDeclName();
-  else
-    S.Diag(ND->getLocation(), diag::note_previous_decl)
-        << (isa<ObjCCategoryDecl>(ND) ? "category" : "class");
-}
-
-/// AddAnyMethodToGlobalPool - Add any method, instance or factory to global
-/// pool.
-void Sema::AddAnyMethodToGlobalPool(Decl *D) {
-  ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D);
-
-  // If we don't have a valid method decl, simply return.
-  if (!MDecl)
-    return;
-  if (MDecl->isInstanceMethod())
-    AddInstanceMethodToGlobalPool(MDecl, true);
-  else
-    AddFactoryMethodToGlobalPool(MDecl, true);
-}
-
-/// HasExplicitOwnershipAttr - returns true when pointer to ObjC pointer
-/// has explicit ownership attribute; false otherwise.
-static bool
-HasExplicitOwnershipAttr(Sema &S, ParmVarDecl *Param) {
-  QualType T = Param->getType();
-
-  if (const PointerType *PT = T->getAs<PointerType>()) {
-    T = PT->getPointeeType();
-  } else if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
-    T = RT->getPointeeType();
-  } else {
-    return true;
-  }
-
-  // If we have a lifetime qualifier, but it's local, we must have
-  // inferred it. So, it is implicit.
-  return !T.getLocalQualifiers().hasObjCLifetime();
-}
-
-/// ActOnStartOfObjCMethodDef - This routine sets up parameters; invisible
-/// and user declared, in the method definition's AST.
-void Sema::ActOnStartOfObjCMethodDef(Scope *FnBodyScope, Decl *D) {
-  assert((getCurMethodDecl() == nullptr) && "Methodparsing confused");
-  ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D);
-
-  PushExpressionEvaluationContext(ExprEvalContexts.back().Context);
-
-  // If we don't have a valid method decl, simply return.
-  if (!MDecl)
-    return;
-
-  QualType ResultType = MDecl->getReturnType();
-  if (!ResultType->isDependentType() && !ResultType->isVoidType() &&
-      !MDecl->isInvalidDecl() &&
-      RequireCompleteType(MDecl->getLocation(), ResultType,
-                          diag::err_func_def_incomplete_result))
-    MDecl->setInvalidDecl();
-
-  // Allow all of Sema to see that we are entering a method definition.
-  PushDeclContext(FnBodyScope, MDecl);
-  PushFunctionScope();
-
-  // Create Decl objects for each parameter, entrring them in the scope for
-  // binding to their use.
-
-  // Insert the invisible arguments, self and _cmd!
-  MDecl->createImplicitParams(Context, MDecl->getClassInterface());
-
-  PushOnScopeChains(MDecl->getSelfDecl(), FnBodyScope);
-  PushOnScopeChains(MDecl->getCmdDecl(), FnBodyScope);
-
-  // The ObjC parser requires parameter names so there's no need to check.
-  CheckParmsForFunctionDef(MDecl->parameters(),
-                           /*CheckParameterNames=*/false);
-
-  // Introduce all of the other parameters into this scope.
-  for (auto *Param : MDecl->parameters()) {
-    if (!Param->isInvalidDecl() &&
-        getLangOpts().ObjCAutoRefCount &&
-        !HasExplicitOwnershipAttr(*this, Param))
-      Diag(Param->getLocation(), diag::warn_arc_strong_pointer_objc_pointer) <<
-            Param->getType();
-
-    if (Param->getIdentifier())
-      PushOnScopeChains(Param, FnBodyScope);
-  }
-
-  // In ARC, disallow definition of retain/release/autorelease/retainCount
-  if (getLangOpts().ObjCAutoRefCount) {
-    switch (MDecl->getMethodFamily()) {
-    case OMF_retain:
-    case OMF_retainCount:
-    case OMF_release:
-    case OMF_autorelease:
-      Diag(MDecl->getLocation(), diag::err_arc_illegal_method_def)
-        << 0 << MDecl->getSelector();
-      break;
-
-    case OMF_None:
-    case OMF_dealloc:
-    case OMF_finalize:
-    case OMF_alloc:
-    case OMF_init:
-    case OMF_mutableCopy:
-    case OMF_copy:
-    case OMF_new:
-    case OMF_self:
-    case OMF_initialize:
-    case OMF_performSelector:
-      break;
-    }
-  }
-
-  // Warn on deprecated methods under -Wdeprecated-implementations,
-  // and prepare for warning on missing super calls.
-  if (ObjCInterfaceDecl *IC = MDecl->getClassInterface()) {
-    ObjCMethodDecl *IMD =
-      IC->lookupMethod(MDecl->getSelector(), MDecl->isInstanceMethod());
-
-    if (IMD) {
-      ObjCImplDecl *ImplDeclOfMethodDef =
-        dyn_cast<ObjCImplDecl>(MDecl->getDeclContext());
-      ObjCContainerDecl *ContDeclOfMethodDecl =
-        dyn_cast<ObjCContainerDecl>(IMD->getDeclContext());
-      ObjCImplDecl *ImplDeclOfMethodDecl = nullptr;
-      if (ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(ContDeclOfMethodDecl))
-        ImplDeclOfMethodDecl = OID->getImplementation();
-      else if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(ContDeclOfMethodDecl)) {
-        if (CD->IsClassExtension()) {
-          if (ObjCInterfaceDecl *OID = CD->getClassInterface())
-            ImplDeclOfMethodDecl = OID->getImplementation();
-        } else
-            ImplDeclOfMethodDecl = CD->getImplementation();
-      }
-      // No need to issue deprecated warning if deprecated mehod in class/category
-      // is being implemented in its own implementation (no overriding is involved).
-      if (!ImplDeclOfMethodDecl || ImplDeclOfMethodDecl != ImplDeclOfMethodDef)
-        DiagnoseObjCImplementedDeprecations(*this, IMD, MDecl->getLocation());
-    }
-
-    if (MDecl->getMethodFamily() == OMF_init) {
-      if (MDecl->isDesignatedInitializerForTheInterface()) {
-        getCurFunction()->ObjCIsDesignatedInit = true;
-        getCurFunction()->ObjCWarnForNoDesignatedInitChain =
-            IC->getSuperClass() != nullptr;
-      } else if (IC->hasDesignatedInitializers()) {
-        getCurFunction()->ObjCIsSecondaryInit = true;
-        getCurFunction()->ObjCWarnForNoInitDelegation = true;
-      }
-    }
-
-    // If this is "dealloc" or "finalize", set some bit here.
-    // Then in ActOnSuperMessage() (SemaExprObjC), set it back to false.
-    // Finally, in ActOnFinishFunctionBody() (SemaDecl), warn if flag is set.
-    // Only do this if the current class actually has a superclass.
-    if (const ObjCInterfaceDecl *SuperClass = IC->getSuperClass()) {
-      ObjCMethodFamily Family = MDecl->getMethodFamily();
-      if (Family == OMF_dealloc) {
-        if (!(getLangOpts().ObjCAutoRefCount ||
-              getLangOpts().getGC() == LangOptions::GCOnly))
-          getCurFunction()->ObjCShouldCallSuper = true;
-
-      } else if (Family == OMF_finalize) {
-        if (Context.getLangOpts().getGC() != LangOptions::NonGC)
-          getCurFunction()->ObjCShouldCallSuper = true;
-
-      } else {
-        const ObjCMethodDecl *SuperMethod =
-          SuperClass->lookupMethod(MDecl->getSelector(),
-                                   MDecl->isInstanceMethod());
-        getCurFunction()->ObjCShouldCallSuper =
-          (SuperMethod && SuperMethod->hasAttr<ObjCRequiresSuperAttr>());
-      }
-    }
-  }
-}
-
-namespace {
-
-// Callback to only accept typo corrections that are Objective-C classes.
-// If an ObjCInterfaceDecl* is given to the constructor, then the validation
-// function will reject corrections to that class.
-class ObjCInterfaceValidatorCCC : public CorrectionCandidateCallback {
- public:
-  ObjCInterfaceValidatorCCC() : CurrentIDecl(nullptr) {}
-  explicit ObjCInterfaceValidatorCCC(ObjCInterfaceDecl *IDecl)
-      : CurrentIDecl(IDecl) {}
-
-  bool ValidateCandidate(const TypoCorrection &candidate) override {
-    ObjCInterfaceDecl *ID = candidate.getCorrectionDeclAs<ObjCInterfaceDecl>();
-    return ID && !declaresSameEntity(ID, CurrentIDecl);
-  }
-
- private:
-  ObjCInterfaceDecl *CurrentIDecl;
-};
-
-} // end anonymous namespace
-
-static void diagnoseUseOfProtocols(Sema &TheSema,
-                                   ObjCContainerDecl *CD,
-                                   ObjCProtocolDecl *const *ProtoRefs,
-                                   unsigned NumProtoRefs,
-                                   const SourceLocation *ProtoLocs) {
-  assert(ProtoRefs);
-  // Diagnose availability in the context of the ObjC container.
-  Sema::ContextRAII SavedContext(TheSema, CD);
-  for (unsigned i = 0; i < NumProtoRefs; ++i) {
-    (void)TheSema.DiagnoseUseOfDecl(ProtoRefs[i], ProtoLocs[i],
-                                    /*UnknownObjCClass=*/nullptr,
-                                    /*ObjCPropertyAccess=*/false,
-                                    /*AvoidPartialAvailabilityChecks=*/true);
-  }
-}
-
-void Sema::
-ActOnSuperClassOfClassInterface(Scope *S,
-                                SourceLocation AtInterfaceLoc,
-                                ObjCInterfaceDecl *IDecl,
-                                IdentifierInfo *ClassName,
-                                SourceLocation ClassLoc,
-                                IdentifierInfo *SuperName,
-                                SourceLocation SuperLoc,
-                                ArrayRef<ParsedType> SuperTypeArgs,
-                                SourceRange SuperTypeArgsRange) {
-  // Check if a different kind of symbol declared in this scope.
-  NamedDecl *PrevDecl = LookupSingleName(TUScope, SuperName, SuperLoc,
-                                         LookupOrdinaryName);
-
-  if (!PrevDecl) {
-    // Try to correct for a typo in the superclass name without correcting
-    // to the class we're defining.
-    if (TypoCorrection Corrected = CorrectTypo(
-            DeclarationNameInfo(SuperName, SuperLoc),
-            LookupOrdinaryName, TUScope,
-            nullptr, llvm::make_unique<ObjCInterfaceValidatorCCC>(IDecl),
-            CTK_ErrorRecovery)) {
-      diagnoseTypo(Corrected, PDiag(diag::err_undef_superclass_suggest)
-                   << SuperName << ClassName);
-      PrevDecl = Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>();
-    }
-  }
-
-  if (declaresSameEntity(PrevDecl, IDecl)) {
-    Diag(SuperLoc, diag::err_recursive_superclass)
-      << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc);
-    IDecl->setEndOfDefinitionLoc(ClassLoc);
-  } else {
-    ObjCInterfaceDecl *SuperClassDecl =
-    dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
-    QualType SuperClassType;
-
-    // Diagnose classes that inherit from deprecated classes.
-    if (SuperClassDecl) {
-      (void)DiagnoseUseOfDecl(SuperClassDecl, SuperLoc);
-      SuperClassType = Context.getObjCInterfaceType(SuperClassDecl);
-    }
-
-    if (PrevDecl && !SuperClassDecl) {
-      // The previous declaration was not a class decl. Check if we have a
-      // typedef. If we do, get the underlying class type.
-      if (const TypedefNameDecl *TDecl =
-          dyn_cast_or_null<TypedefNameDecl>(PrevDecl)) {
-        QualType T = TDecl->getUnderlyingType();
-        if (T->isObjCObjectType()) {
-          if (NamedDecl *IDecl = T->getAs<ObjCObjectType>()->getInterface()) {
-            SuperClassDecl = dyn_cast<ObjCInterfaceDecl>(IDecl);
-            SuperClassType = Context.getTypeDeclType(TDecl);
-
-            // This handles the following case:
-            // @interface NewI @end
-            // typedef NewI DeprI __attribute__((deprecated("blah")))
-            // @interface SI : DeprI /* warn here */ @end
-            (void)DiagnoseUseOfDecl(const_cast<TypedefNameDecl*>(TDecl), SuperLoc);
-          }
-        }
-      }
-
-      // This handles the following case:
-      //
-      // typedef int SuperClass;
-      // @interface MyClass : SuperClass {} @end
-      //
-      if (!SuperClassDecl) {
-        Diag(SuperLoc, diag::err_redefinition_different_kind) << SuperName;
-        Diag(PrevDecl->getLocation(), diag::note_previous_definition);
-      }
-    }
-
-    if (!dyn_cast_or_null<TypedefNameDecl>(PrevDecl)) {
-      if (!SuperClassDecl)
-        Diag(SuperLoc, diag::err_undef_superclass)
-          << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc);
-      else if (RequireCompleteType(SuperLoc,
-                                   SuperClassType,
-                                   diag::err_forward_superclass,
-                                   SuperClassDecl->getDeclName(),
-                                   ClassName,
-                                   SourceRange(AtInterfaceLoc, ClassLoc))) {
-        SuperClassDecl = nullptr;
-        SuperClassType = QualType();
-      }
-    }
-
-    if (SuperClassType.isNull()) {
-      assert(!SuperClassDecl && "Failed to set SuperClassType?");
-      return;
-    }
-
-    // Handle type arguments on the superclass.
-    TypeSourceInfo *SuperClassTInfo = nullptr;
-    if (!SuperTypeArgs.empty()) {
-      TypeResult fullSuperClassType = actOnObjCTypeArgsAndProtocolQualifiers(
-                                        S,
-                                        SuperLoc,
-                                        CreateParsedType(SuperClassType,
-                                                         nullptr),
-                                        SuperTypeArgsRange.getBegin(),
-                                        SuperTypeArgs,
-                                        SuperTypeArgsRange.getEnd(),
-                                        SourceLocation(),
-                                        { },
-                                        { },
-                                        SourceLocation());
-      if (!fullSuperClassType.isUsable())
-        return;
-
-      SuperClassType = GetTypeFromParser(fullSuperClassType.get(),
-                                         &SuperClassTInfo);
-    }
-
-    if (!SuperClassTInfo) {
-      SuperClassTInfo = Context.getTrivialTypeSourceInfo(SuperClassType,
-                                                         SuperLoc);
-    }
-
-    IDecl->setSuperClass(SuperClassTInfo);
-    IDecl->setEndOfDefinitionLoc(SuperClassTInfo->getTypeLoc().getEndLoc());
-  }
-}
-
-DeclResult Sema::actOnObjCTypeParam(Scope *S,
-                                    ObjCTypeParamVariance variance,
-                                    SourceLocation varianceLoc,
-                                    unsigned index,
-                                    IdentifierInfo *paramName,
-                                    SourceLocation paramLoc,
-                                    SourceLocation colonLoc,
-                                    ParsedType parsedTypeBound) {
-  // If there was an explicitly-provided type bound, check it.
-  TypeSourceInfo *typeBoundInfo = nullptr;
-  if (parsedTypeBound) {
-    // The type bound can be any Objective-C pointer type.
-    QualType typeBound = GetTypeFromParser(parsedTypeBound, &typeBoundInfo);
-    if (typeBound->isObjCObjectPointerType()) {
-      // okay
-    } else if (typeBound->isObjCObjectType()) {
-      // The user forgot the * on an Objective-C pointer type, e.g.,
-      // "T : NSView".
-      SourceLocation starLoc = getLocForEndOfToken(
-                                 typeBoundInfo->getTypeLoc().getEndLoc());
-      Diag(typeBoundInfo->getTypeLoc().getBeginLoc(),
-           diag::err_objc_type_param_bound_missing_pointer)
-        << typeBound << paramName
-        << FixItHint::CreateInsertion(starLoc, " *");
-
-      // Create a new type location builder so we can update the type
-      // location information we have.
-      TypeLocBuilder builder;
-      builder.pushFullCopy(typeBoundInfo->getTypeLoc());
-
-      // Create the Objective-C pointer type.
-      typeBound = Context.getObjCObjectPointerType(typeBound);
-      ObjCObjectPointerTypeLoc newT
-        = builder.push<ObjCObjectPointerTypeLoc>(typeBound);
-      newT.setStarLoc(starLoc);
-
-      // Form the new type source information.
-      typeBoundInfo = builder.getTypeSourceInfo(Context, typeBound);
-    } else {
-      // Not a valid type bound.
-      Diag(typeBoundInfo->getTypeLoc().getBeginLoc(),
-           diag::err_objc_type_param_bound_nonobject)
-        << typeBound << paramName;
-
-      // Forget the bound; we'll default to id later.
-      typeBoundInfo = nullptr;
-    }
-
-    // Type bounds cannot have qualifiers (even indirectly) or explicit
-    // nullability.
-    if (typeBoundInfo) {
-      QualType typeBound = typeBoundInfo->getType();
-      TypeLoc qual = typeBoundInfo->getTypeLoc().findExplicitQualifierLoc();
-      if (qual || typeBound.hasQualifiers()) {
-        bool diagnosed = false;
-        SourceRange rangeToRemove;
-        if (qual) {
-          if (auto attr = qual.getAs<AttributedTypeLoc>()) {
-            rangeToRemove = attr.getLocalSourceRange();
-            if (attr.getTypePtr()->getImmediateNullability()) {
-              Diag(attr.getBeginLoc(),
-                   diag::err_objc_type_param_bound_explicit_nullability)
-                  << paramName << typeBound
-                  << FixItHint::CreateRemoval(rangeToRemove);
-              diagnosed = true;
-            }
-          }
-        }
-
-        if (!diagnosed) {
-          Diag(qual ? qual.getBeginLoc()
-                    : typeBoundInfo->getTypeLoc().getBeginLoc(),
-               diag::err_objc_type_param_bound_qualified)
-              << paramName << typeBound
-              << typeBound.getQualifiers().getAsString()
-              << FixItHint::CreateRemoval(rangeToRemove);
-        }
-
-        // If the type bound has qualifiers other than CVR, we need to strip
-        // them or we'll probably assert later when trying to apply new
-        // qualifiers.
-        Qualifiers quals = typeBound.getQualifiers();
-        quals.removeCVRQualifiers();
-        if (!quals.empty()) {
-          typeBoundInfo =
-             Context.getTrivialTypeSourceInfo(typeBound.getUnqualifiedType());
-        }
-      }
-    }
-  }
-
-  // If there was no explicit type bound (or we removed it due to an error),
-  // use 'id' instead.
-  if (!typeBoundInfo) {
-    colonLoc = SourceLocation();
-    typeBoundInfo = Context.getTrivialTypeSourceInfo(Context.getObjCIdType());
-  }
-
-  // Create the type parameter.
-  return ObjCTypeParamDecl::Create(Context, CurContext, variance, varianceLoc,
-                                   index, paramLoc, paramName, colonLoc,
-                                   typeBoundInfo);
-}
-
-ObjCTypeParamList *Sema::actOnObjCTypeParamList(Scope *S,
-                                                SourceLocation lAngleLoc,
-                                                ArrayRef<Decl *> typeParamsIn,
-                                                SourceLocation rAngleLoc) {
-  // We know that the array only contains Objective-C type parameters.
-  ArrayRef<ObjCTypeParamDecl *>
-    typeParams(
-      reinterpret_cast<ObjCTypeParamDecl * const *>(typeParamsIn.data()),
-      typeParamsIn.size());
-
-  // Diagnose redeclarations of type parameters.
-  // We do this now because Objective-C type parameters aren't pushed into
-  // scope until later (after the instance variable block), but we want the
-  // diagnostics to occur right after we parse the type parameter list.
-  llvm::SmallDenseMap<IdentifierInfo *, ObjCTypeParamDecl *> knownParams;
-  for (auto typeParam : typeParams) {
-    auto known = knownParams.find(typeParam->getIdentifier());
-    if (known != knownParams.end()) {
-      Diag(typeParam->getLocation(), diag::err_objc_type_param_redecl)
-        << typeParam->getIdentifier()
-        << SourceRange(known->second->getLocation());
-
-      typeParam->setInvalidDecl();
-    } else {
-      knownParams.insert(std::make_pair(typeParam->getIdentifier(), typeParam));
-
-      // Push the type parameter into scope.
-      PushOnScopeChains(typeParam, S, /*AddToContext=*/false);
-    }
-  }
-
-  // Create the parameter list.
-  return ObjCTypeParamList::create(Context, lAngleLoc, typeParams, rAngleLoc);
-}
-
-void Sema::popObjCTypeParamList(Scope *S, ObjCTypeParamList *typeParamList) {
-  for (auto typeParam : *typeParamList) {
-    if (!typeParam->isInvalidDecl()) {
-      S->RemoveDecl(typeParam);
-      IdResolver.RemoveDecl(typeParam);
-    }
-  }
-}
-
-namespace {
-  /// The context in which an Objective-C type parameter list occurs, for use
-  /// in diagnostics.
-  enum class TypeParamListContext {
-    ForwardDeclaration,
-    Definition,
-    Category,
-    Extension
-  };
-} // end anonymous namespace
-
-/// Check consistency between two Objective-C type parameter lists, e.g.,
-/// between a category/extension and an \@interface or between an \@class and an
-/// \@interface.
-static bool checkTypeParamListConsistency(Sema &S,
-                                          ObjCTypeParamList *prevTypeParams,
-                                          ObjCTypeParamList *newTypeParams,
-                                          TypeParamListContext newContext) {
-  // If the sizes don't match, complain about that.
-  if (prevTypeParams->size() != newTypeParams->size()) {
-    SourceLocation diagLoc;
-    if (newTypeParams->size() > prevTypeParams->size()) {
-      diagLoc = newTypeParams->begin()[prevTypeParams->size()]->getLocation();
-    } else {
-      diagLoc = S.getLocForEndOfToken(newTypeParams->back()->getEndLoc());
-    }
-
-    S.Diag(diagLoc, diag::err_objc_type_param_arity_mismatch)
-      << static_cast<unsigned>(newContext)
-      << (newTypeParams->size() > prevTypeParams->size())
-      << prevTypeParams->size()
-      << newTypeParams->size();
-
-    return true;
-  }
-
-  // Match up the type parameters.
-  for (unsigned i = 0, n = prevTypeParams->size(); i != n; ++i) {
-    ObjCTypeParamDecl *prevTypeParam = prevTypeParams->begin()[i];
-    ObjCTypeParamDecl *newTypeParam = newTypeParams->begin()[i];
-
-    // Check for consistency of the variance.
-    if (newTypeParam->getVariance() != prevTypeParam->getVariance()) {
-      if (newTypeParam->getVariance() == ObjCTypeParamVariance::Invariant &&
-          newContext != TypeParamListContext::Definition) {
-        // When the new type parameter is invariant and is not part
-        // of the definition, just propagate the variance.
-        newTypeParam->setVariance(prevTypeParam->getVariance());
-      } else if (prevTypeParam->getVariance()
-                   == ObjCTypeParamVariance::Invariant &&
-                 !(isa<ObjCInterfaceDecl>(prevTypeParam->getDeclContext()) &&
-                   cast<ObjCInterfaceDecl>(prevTypeParam->getDeclContext())
-                     ->getDefinition() == prevTypeParam->getDeclContext())) {
-        // When the old parameter is invariant and was not part of the
-        // definition, just ignore the difference because it doesn't
-        // matter.
-      } else {
-        {
-          // Diagnose the conflict and update the second declaration.
-          SourceLocation diagLoc = newTypeParam->getVarianceLoc();
-          if (diagLoc.isInvalid())
-            diagLoc = newTypeParam->getBeginLoc();
-
-          auto diag = S.Diag(diagLoc,
-                             diag::err_objc_type_param_variance_conflict)
-                        << static_cast<unsigned>(newTypeParam->getVariance())
-                        << newTypeParam->getDeclName()
-                        << static_cast<unsigned>(prevTypeParam->getVariance())
-                        << prevTypeParam->getDeclName();
-          switch (prevTypeParam->getVariance()) {
-          case ObjCTypeParamVariance::Invariant:
-            diag << FixItHint::CreateRemoval(newTypeParam->getVarianceLoc());
-            break;
-
-          case ObjCTypeParamVariance::Covariant:
-          case ObjCTypeParamVariance::Contravariant: {
-            StringRef newVarianceStr
-               = prevTypeParam->getVariance() == ObjCTypeParamVariance::Covariant
-                   ? "__covariant"
-                   : "__contravariant";
-            if (newTypeParam->getVariance()
-                  == ObjCTypeParamVariance::Invariant) {
-              diag << FixItHint::CreateInsertion(newTypeParam->getBeginLoc(),
-                                                 (newVarianceStr + " ").str());
-            } else {
-              diag << FixItHint::CreateReplacement(newTypeParam->getVarianceLoc(),
-                                               newVarianceStr);
-            }
-          }
-          }
-        }
-
-        S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here)
-          << prevTypeParam->getDeclName();
-
-        // Override the variance.
-        newTypeParam->setVariance(prevTypeParam->getVariance());
-      }
-    }
-
-    // If the bound types match, there's nothing to do.
-    if (S.Context.hasSameType(prevTypeParam->getUnderlyingType(),
-                              newTypeParam->getUnderlyingType()))
-      continue;
-
-    // If the new type parameter's bound was explicit, complain about it being
-    // different from the original.
-    if (newTypeParam->hasExplicitBound()) {
-      SourceRange newBoundRange = newTypeParam->getTypeSourceInfo()
-                                    ->getTypeLoc().getSourceRange();
-      S.Diag(newBoundRange.getBegin(), diag::err_objc_type_param_bound_conflict)
-        << newTypeParam->getUnderlyingType()
-        << newTypeParam->getDeclName()
-        << prevTypeParam->hasExplicitBound()
-        << prevTypeParam->getUnderlyingType()
-        << (newTypeParam->getDeclName() == prevTypeParam->getDeclName())
-        << prevTypeParam->getDeclName()
-        << FixItHint::CreateReplacement(
-             newBoundRange,
-             prevTypeParam->getUnderlyingType().getAsString(
-               S.Context.getPrintingPolicy()));
-
-      S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here)
-        << prevTypeParam->getDeclName();
-
-      // Override the new type parameter's bound type with the previous type,
-      // so that it's consistent.
-      newTypeParam->setTypeSourceInfo(
-        S.Context.getTrivialTypeSourceInfo(prevTypeParam->getUnderlyingType()));
-      continue;
-    }
-
-    // The new type parameter got the implicit bound of 'id'. That's okay for
-    // categories and extensions (overwrite it later), but not for forward
-    // declarations and @interfaces, because those must be standalone.
-    if (newContext == TypeParamListContext::ForwardDeclaration ||
-        newContext == TypeParamListContext::Definition) {
-      // Diagnose this problem for forward declarations and definitions.
-      SourceLocation insertionLoc
-        = S.getLocForEndOfToken(newTypeParam->getLocation());
-      std::string newCode
-        = " : " + prevTypeParam->getUnderlyingType().getAsString(
-                    S.Context.getPrintingPolicy());
-      S.Diag(newTypeParam->getLocation(),
-             diag::err_objc_type_param_bound_missing)
-        << prevTypeParam->getUnderlyingType()
-        << newTypeParam->getDeclName()
-        << (newContext == TypeParamListContext::ForwardDeclaration)
-        << FixItHint::CreateInsertion(insertionLoc, newCode);
-
-      S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here)
-        << prevTypeParam->getDeclName();
-    }
-
-    // Update the new type parameter's bound to match the previous one.
-    newTypeParam->setTypeSourceInfo(
-      S.Context.getTrivialTypeSourceInfo(prevTypeParam->getUnderlyingType()));
-  }
-
-  return false;
-}
-
-Decl *Sema::ActOnStartClassInterface(
-    Scope *S, SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
-    SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
-    IdentifierInfo *SuperName, SourceLocation SuperLoc,
-    ArrayRef<ParsedType> SuperTypeArgs, SourceRange SuperTypeArgsRange,
-    Decl *const *ProtoRefs, unsigned NumProtoRefs,
-    const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
-    const ParsedAttributesView &AttrList) {
-  assert(ClassName && "Missing class identifier");
-
-  // Check for another declaration kind with the same name.
-  NamedDecl *PrevDecl =
-      LookupSingleName(TUScope, ClassName, ClassLoc, LookupOrdinaryName,
-                       forRedeclarationInCurContext());
-
-  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
-    Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName;
-    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
-  }
-
-  // Create a declaration to describe this @interface.
-  ObjCInterfaceDecl* PrevIDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
-
-  if (PrevIDecl && PrevIDecl->getIdentifier() != ClassName) {
-    // A previous decl with a different name is because of
-    // @compatibility_alias, for example:
-    // \code
-    //   @class NewImage;
-    //   @compatibility_alias OldImage NewImage;
-    // \endcode
-    // A lookup for 'OldImage' will return the 'NewImage' decl.
-    //
-    // In such a case use the real declaration name, instead of the alias one,
-    // otherwise we will break IdentifierResolver and redecls-chain invariants.
-    // FIXME: If necessary, add a bit to indicate that this ObjCInterfaceDecl
-    // has been aliased.
-    ClassName = PrevIDecl->getIdentifier();
-  }
-
-  // If there was a forward declaration with type parameters, check
-  // for consistency.
-  if (PrevIDecl) {
-    if (ObjCTypeParamList *prevTypeParamList = PrevIDecl->getTypeParamList()) {
-      if (typeParamList) {
-        // Both have type parameter lists; check for consistency.
-        if (checkTypeParamListConsistency(*this, prevTypeParamList,
-                                          typeParamList,
-                                          TypeParamListContext::Definition)) {
-          typeParamList = nullptr;
-        }
-      } else {
-        Diag(ClassLoc, diag::err_objc_parameterized_forward_class_first)
-          << ClassName;
-        Diag(prevTypeParamList->getLAngleLoc(), diag::note_previous_decl)
-          << ClassName;
-
-        // Clone the type parameter list.
-        SmallVector<ObjCTypeParamDecl *, 4> clonedTypeParams;
-        for (auto typeParam : *prevTypeParamList) {
-          clonedTypeParams.push_back(
-            ObjCTypeParamDecl::Create(
-              Context,
-              CurContext,
-              typeParam->getVariance(),
-              SourceLocation(),
-              typeParam->getIndex(),
-              SourceLocation(),
-              typeParam->getIdentifier(),
-              SourceLocation(),
-              Context.getTrivialTypeSourceInfo(typeParam->getUnderlyingType())));
-        }
-
-        typeParamList = ObjCTypeParamList::create(Context,
-                                                  SourceLocation(),
-                                                  clonedTypeParams,
-                                                  SourceLocation());
-      }
-    }
-  }
-
-  ObjCInterfaceDecl *IDecl
-    = ObjCInterfaceDecl::Create(Context, CurContext, AtInterfaceLoc, ClassName,
-                                typeParamList, PrevIDecl, ClassLoc);
-  if (PrevIDecl) {
-    // Class already seen. Was it a definition?
-    if (ObjCInterfaceDecl *Def = PrevIDecl->getDefinition()) {
-      Diag(AtInterfaceLoc, diag::err_duplicate_class_def)
-        << PrevIDecl->getDeclName();
-      Diag(Def->getLocation(), diag::note_previous_definition);
-      IDecl->setInvalidDecl();
-    }
-  }
-
-  ProcessDeclAttributeList(TUScope, IDecl, AttrList);
-  AddPragmaAttributes(TUScope, IDecl);
-  PushOnScopeChains(IDecl, TUScope);
-
-  // Start the definition of this class. If we're in a redefinition case, there
-  // may already be a definition, so we'll end up adding to it.
-  if (!IDecl->hasDefinition())
-    IDecl->startDefinition();
-
-  if (SuperName) {
-    // Diagnose availability in the context of the @interface.
-    ContextRAII SavedContext(*this, IDecl);
-
-    ActOnSuperClassOfClassInterface(S, AtInterfaceLoc, IDecl,
-                                    ClassName, ClassLoc,
-                                    SuperName, SuperLoc, SuperTypeArgs,
-                                    SuperTypeArgsRange);
-  } else { // we have a root class.
-    IDecl->setEndOfDefinitionLoc(ClassLoc);
-  }
-
-  // Check then save referenced protocols.
-  if (NumProtoRefs) {
-    diagnoseUseOfProtocols(*this, IDecl, (ObjCProtocolDecl*const*)ProtoRefs,
-                           NumProtoRefs, ProtoLocs);
-    IDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
-                           ProtoLocs, Context);
-    IDecl->setEndOfDefinitionLoc(EndProtoLoc);
-  }
-
-  CheckObjCDeclScope(IDecl);
-  return ActOnObjCContainerStartDefinition(IDecl);
-}
-
-/// ActOnTypedefedProtocols - this action finds protocol list as part of the
-/// typedef'ed use for a qualified super class and adds them to the list
-/// of the protocols.
-void Sema::ActOnTypedefedProtocols(SmallVectorImpl<Decl *> &ProtocolRefs,
-                                  SmallVectorImpl<SourceLocation> &ProtocolLocs,
-                                   IdentifierInfo *SuperName,
-                                   SourceLocation SuperLoc) {
-  if (!SuperName)
-    return;
-  NamedDecl* IDecl = LookupSingleName(TUScope, SuperName, SuperLoc,
-                                      LookupOrdinaryName);
-  if (!IDecl)
-    return;
-
-  if (const TypedefNameDecl *TDecl = dyn_cast_or_null<TypedefNameDecl>(IDecl)) {
-    QualType T = TDecl->getUnderlyingType();
-    if (T->isObjCObjectType())
-      if (const ObjCObjectType *OPT = T->getAs<ObjCObjectType>()) {
-        ProtocolRefs.append(OPT->qual_begin(), OPT->qual_end());
-        // FIXME: Consider whether this should be an invalid loc since the loc
-        // is not actually pointing to a protocol name reference but to the
-        // typedef reference. Note that the base class name loc is also pointing
-        // at the typedef.
-        ProtocolLocs.append(OPT->getNumProtocols(), SuperLoc);
-      }
-  }
-}
-
-/// ActOnCompatibilityAlias - this action is called after complete parsing of
-/// a \@compatibility_alias declaration. It sets up the alias relationships.
-Decl *Sema::ActOnCompatibilityAlias(SourceLocation AtLoc,
-                                    IdentifierInfo *AliasName,
-                                    SourceLocation AliasLocation,
-                                    IdentifierInfo *ClassName,
-                                    SourceLocation ClassLocation) {
-  // Look for previous declaration of alias name
-  NamedDecl *ADecl =
-      LookupSingleName(TUScope, AliasName, AliasLocation, LookupOrdinaryName,
-                       forRedeclarationInCurContext());
-  if (ADecl) {
-    Diag(AliasLocation, diag::err_conflicting_aliasing_type) << AliasName;
-    Diag(ADecl->getLocation(), diag::note_previous_declaration);
-    return nullptr;
-  }
-  // Check for class declaration
-  NamedDecl *CDeclU =
-      LookupSingleName(TUScope, ClassName, ClassLocation, LookupOrdinaryName,
-                       forRedeclarationInCurContext());
-  if (const TypedefNameDecl *TDecl =
-        dyn_cast_or_null<TypedefNameDecl>(CDeclU)) {
-    QualType T = TDecl->getUnderlyingType();
-    if (T->isObjCObjectType()) {
-      if (NamedDecl *IDecl = T->getAs<ObjCObjectType>()->getInterface()) {
-        ClassName = IDecl->getIdentifier();
-        CDeclU = LookupSingleName(TUScope, ClassName, ClassLocation,
-                                  LookupOrdinaryName,
-                                  forRedeclarationInCurContext());
-      }
-    }
-  }
-  ObjCInterfaceDecl *CDecl = dyn_cast_or_null<ObjCInterfaceDecl>(CDeclU);
-  if (!CDecl) {
-    Diag(ClassLocation, diag::warn_undef_interface) << ClassName;
-    if (CDeclU)
-      Diag(CDeclU->getLocation(), diag::note_previous_declaration);
-    return nullptr;
-  }
-
-  // Everything checked out, instantiate a new alias declaration AST.
-  ObjCCompatibleAliasDecl *AliasDecl =
-    ObjCCompatibleAliasDecl::Create(Context, CurContext, AtLoc, AliasName, CDecl);
-
-  if (!CheckObjCDeclScope(AliasDecl))
-    PushOnScopeChains(AliasDecl, TUScope);
-
-  return AliasDecl;
-}
-
-bool Sema::CheckForwardProtocolDeclarationForCircularDependency(
-  IdentifierInfo *PName,
-  SourceLocation &Ploc, SourceLocation PrevLoc,
-  const ObjCList<ObjCProtocolDecl> &PList) {
-
-  bool res = false;
-  for (ObjCList<ObjCProtocolDecl>::iterator I = PList.begin(),
-       E = PList.end(); I != E; ++I) {
-    if (ObjCProtocolDecl *PDecl = LookupProtocol((*I)->getIdentifier(),
-                                                 Ploc)) {
-      if (PDecl->getIdentifier() == PName) {
-        Diag(Ploc, diag::err_protocol_has_circular_dependency);
-        Diag(PrevLoc, diag::note_previous_definition);
-        res = true;
-      }
-
-      if (!PDecl->hasDefinition())
-        continue;
-
-      if (CheckForwardProtocolDeclarationForCircularDependency(PName, Ploc,
-            PDecl->getLocation(), PDecl->getReferencedProtocols()))
-        res = true;
-    }
-  }
-  return res;
-}
-
-Decl *Sema::ActOnStartProtocolInterface(
-    SourceLocation AtProtoInterfaceLoc, IdentifierInfo *ProtocolName,
-    SourceLocation ProtocolLoc, Decl *const *ProtoRefs, unsigned NumProtoRefs,
-    const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
-    const ParsedAttributesView &AttrList) {
-  bool err = false;
-  // FIXME: Deal with AttrList.
-  assert(ProtocolName && "Missing protocol identifier");
-  ObjCProtocolDecl *PrevDecl = LookupProtocol(ProtocolName, ProtocolLoc,
-                                              forRedeclarationInCurContext());
-  ObjCProtocolDecl *PDecl = nullptr;
-  if (ObjCProtocolDecl *Def = PrevDecl? PrevDecl->getDefinition() : nullptr) {
-    // If we already have a definition, complain.
-    Diag(ProtocolLoc, diag::warn_duplicate_protocol_def) << ProtocolName;
-    Diag(Def->getLocation(), diag::note_previous_definition);
-
-    // Create a new protocol that is completely distinct from previous
-    // declarations, and do not make this protocol available for name lookup.
-    // That way, we'll end up completely ignoring the duplicate.
-    // FIXME: Can we turn this into an error?
-    PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
-                                     ProtocolLoc, AtProtoInterfaceLoc,
-                                     /*PrevDecl=*/nullptr);
-
-    // If we are using modules, add the decl to the context in order to
-    // serialize something meaningful.
-    if (getLangOpts().Modules)
-      PushOnScopeChains(PDecl, TUScope);
-    PDecl->startDefinition();
-  } else {
-    if (PrevDecl) {
-      // Check for circular dependencies among protocol declarations. This can
-      // only happen if this protocol was forward-declared.
-      ObjCList<ObjCProtocolDecl> PList;
-      PList.set((ObjCProtocolDecl *const*)ProtoRefs, NumProtoRefs, Context);
-      err = CheckForwardProtocolDeclarationForCircularDependency(
-              ProtocolName, ProtocolLoc, PrevDecl->getLocation(), PList);
-    }
-
-    // Create the new declaration.
-    PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
-                                     ProtocolLoc, AtProtoInterfaceLoc,
-                                     /*PrevDecl=*/PrevDecl);
-
-    PushOnScopeChains(PDecl, TUScope);
-    PDecl->startDefinition();
-  }
-
-  ProcessDeclAttributeList(TUScope, PDecl, AttrList);
-  AddPragmaAttributes(TUScope, PDecl);
-
-  // Merge attributes from previous declarations.
-  if (PrevDecl)
-    mergeDeclAttributes(PDecl, PrevDecl);
-
-  if (!err && NumProtoRefs ) {
-    /// Check then save referenced protocols.
-    diagnoseUseOfProtocols(*this, PDecl, (ObjCProtocolDecl*const*)ProtoRefs,
-                           NumProtoRefs, ProtoLocs);
-    PDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
-                           ProtoLocs, Context);
-  }
-
-  CheckObjCDeclScope(PDecl);
-  return ActOnObjCContainerStartDefinition(PDecl);
-}
-
-static bool NestedProtocolHasNoDefinition(ObjCProtocolDecl *PDecl,
-                                          ObjCProtocolDecl *&UndefinedProtocol) {
-  if (!PDecl->hasDefinition() || PDecl->getDefinition()->isHidden()) {
-    UndefinedProtocol = PDecl;
-    return true;
-  }
-
-  for (auto *PI : PDecl->protocols())
-    if (NestedProtocolHasNoDefinition(PI, UndefinedProtocol)) {
-      UndefinedProtocol = PI;
-      return true;
-    }
-  return false;
-}
-
-/// FindProtocolDeclaration - This routine looks up protocols and
-/// issues an error if they are not declared. It returns list of
-/// protocol declarations in its 'Protocols' argument.
-void
-Sema::FindProtocolDeclaration(bool WarnOnDeclarations, bool ForObjCContainer,
-                              ArrayRef<IdentifierLocPair> ProtocolId,
-                              SmallVectorImpl<Decl *> &Protocols) {
-  for (const IdentifierLocPair &Pair : ProtocolId) {
-    ObjCProtocolDecl *PDecl = LookupProtocol(Pair.first, Pair.second);
-    if (!PDecl) {
-      TypoCorrection Corrected = CorrectTypo(
-          DeclarationNameInfo(Pair.first, Pair.second),
-          LookupObjCProtocolName, TUScope, nullptr,
-          llvm::make_unique<DeclFilterCCC<ObjCProtocolDecl>>(),
-          CTK_ErrorRecovery);
-      if ((PDecl = Corrected.getCorrectionDeclAs<ObjCProtocolDecl>()))
-        diagnoseTypo(Corrected, PDiag(diag::err_undeclared_protocol_suggest)
-                                    << Pair.first);
-    }
-
-    if (!PDecl) {
-      Diag(Pair.second, diag::err_undeclared_protocol) << Pair.first;
-      continue;
-    }
-    // If this is a forward protocol declaration, get its definition.
-    if (!PDecl->isThisDeclarationADefinition() && PDecl->getDefinition())
-      PDecl = PDecl->getDefinition();
-
-    // For an objc container, delay protocol reference checking until after we
-    // can set the objc decl as the availability context, otherwise check now.
-    if (!ForObjCContainer) {
-      (void)DiagnoseUseOfDecl(PDecl, Pair.second);
-    }
-
-    // If this is a forward declaration and we are supposed to warn in this
-    // case, do it.
-    // FIXME: Recover nicely in the hidden case.
-    ObjCProtocolDecl *UndefinedProtocol;
-
-    if (WarnOnDeclarations &&
-        NestedProtocolHasNoDefinition(PDecl, UndefinedProtocol)) {
-      Diag(Pair.second, diag::warn_undef_protocolref) << Pair.first;
-      Diag(UndefinedProtocol->getLocation(), diag::note_protocol_decl_undefined)
-        << UndefinedProtocol;
-    }
-    Protocols.push_back(PDecl);
-  }
-}
-
-namespace {
-// Callback to only accept typo corrections that are either
-// Objective-C protocols or valid Objective-C type arguments.
-class ObjCTypeArgOrProtocolValidatorCCC : public CorrectionCandidateCallback {
-  ASTContext &Context;
-  Sema::LookupNameKind LookupKind;
- public:
-  ObjCTypeArgOrProtocolValidatorCCC(ASTContext &context,
-                                    Sema::LookupNameKind lookupKind)
-    : Context(context), LookupKind(lookupKind) { }
-
-  bool ValidateCandidate(const TypoCorrection &candidate) override {
-    // If we're allowed to find protocols and we have a protocol, accept it.
-    if (LookupKind != Sema::LookupOrdinaryName) {
-      if (candidate.getCorrectionDeclAs<ObjCProtocolDecl>())
-        return true;
-    }
-
-    // If we're allowed to find type names and we have one, accept it.
-    if (LookupKind != Sema::LookupObjCProtocolName) {
-      // If we have a type declaration, we might accept this result.
-      if (auto typeDecl = candidate.getCorrectionDeclAs<TypeDecl>()) {
-        // If we found a tag declaration outside of C++, skip it. This
-        // can happy because we look for any name when there is no
-        // bias to protocol or type names.
-        if (isa<RecordDecl>(typeDecl) && !Context.getLangOpts().CPlusPlus)
-          return false;
-
-        // Make sure the type is something we would accept as a type
-        // argument.
-        auto type = Context.getTypeDeclType(typeDecl);
-        if (type->isObjCObjectPointerType() ||
-            type->isBlockPointerType() ||
-            type->isDependentType() ||
-            type->isObjCObjectType())
-          return true;
-
-        return false;
-      }
-
-      // If we have an Objective-C class type, accept it; there will
-      // be another fix to add the '*'.
-      if (candidate.getCorrectionDeclAs<ObjCInterfaceDecl>())
-        return true;
-
-      return false;
-    }
-
-    return false;
-  }
-};
-} // end anonymous namespace
-
-void Sema::DiagnoseTypeArgsAndProtocols(IdentifierInfo *ProtocolId,
-                                        SourceLocation ProtocolLoc,
-                                        IdentifierInfo *TypeArgId,
-                                        SourceLocation TypeArgLoc,
-                                        bool SelectProtocolFirst) {
-  Diag(TypeArgLoc, diag::err_objc_type_args_and_protocols)
-      << SelectProtocolFirst << TypeArgId << ProtocolId
-      << SourceRange(ProtocolLoc);
-}
-
-void Sema::actOnObjCTypeArgsOrProtocolQualifiers(
-       Scope *S,
-       ParsedType baseType,
-       SourceLocation lAngleLoc,
-       ArrayRef<IdentifierInfo *> identifiers,
-       ArrayRef<SourceLocation> identifierLocs,
-       SourceLocation rAngleLoc,
-       SourceLocation &typeArgsLAngleLoc,
-       SmallVectorImpl<ParsedType> &typeArgs,
-       SourceLocation &typeArgsRAngleLoc,
-       SourceLocation &protocolLAngleLoc,
-       SmallVectorImpl<Decl *> &protocols,
-       SourceLocation &protocolRAngleLoc,
-       bool warnOnIncompleteProtocols) {
-  // Local function that updates the declaration specifiers with
-  // protocol information.
-  unsigned numProtocolsResolved = 0;
-  auto resolvedAsProtocols = [&] {
-    assert(numProtocolsResolved == identifiers.size() && "Unresolved protocols");
-
-    // Determine whether the base type is a parameterized class, in
-    // which case we want to warn about typos such as
-    // "NSArray<NSObject>" (that should be NSArray<NSObject *>).
-    ObjCInterfaceDecl *baseClass = nullptr;
-    QualType base = GetTypeFromParser(baseType, nullptr);
-    bool allAreTypeNames = false;
-    SourceLocation firstClassNameLoc;
-    if (!base.isNull()) {
-      if (const auto *objcObjectType = base->getAs<ObjCObjectType>()) {
-        baseClass = objcObjectType->getInterface();
-        if (baseClass) {
-          if (auto typeParams = baseClass->getTypeParamList()) {
-            if (typeParams->size() == numProtocolsResolved) {
-              // Note that we should be looking for type names, too.
-              allAreTypeNames = true;
-            }
-          }
-        }
-      }
-    }
-
-    for (unsigned i = 0, n = protocols.size(); i != n; ++i) {
-      ObjCProtocolDecl *&proto
-        = reinterpret_cast<ObjCProtocolDecl *&>(protocols[i]);
-      // For an objc container, delay protocol reference checking until after we
-      // can set the objc decl as the availability context, otherwise check now.
-      if (!warnOnIncompleteProtocols) {
-        (void)DiagnoseUseOfDecl(proto, identifierLocs[i]);
-      }
-
-      // If this is a forward protocol declaration, get its definition.
-      if (!proto->isThisDeclarationADefinition() && proto->getDefinition())
-        proto = proto->getDefinition();
-
-      // If this is a forward declaration and we are supposed to warn in this
-      // case, do it.
-      // FIXME: Recover nicely in the hidden case.
-      ObjCProtocolDecl *forwardDecl = nullptr;
-      if (warnOnIncompleteProtocols &&
-          NestedProtocolHasNoDefinition(proto, forwardDecl)) {
-        Diag(identifierLocs[i], diag::warn_undef_protocolref)
-          << proto->getDeclName();
-        Diag(forwardDecl->getLocation(), diag::note_protocol_decl_undefined)
-          << forwardDecl;
-      }
-
-      // If everything this far has been a type name (and we care
-      // about such things), check whether this name refers to a type
-      // as well.
-      if (allAreTypeNames) {
-        if (auto *decl = LookupSingleName(S, identifiers[i], identifierLocs[i],
-                                          LookupOrdinaryName)) {
-          if (isa<ObjCInterfaceDecl>(decl)) {
-            if (firstClassNameLoc.isInvalid())
-              firstClassNameLoc = identifierLocs[i];
-          } else if (!isa<TypeDecl>(decl)) {
-            // Not a type.
-            allAreTypeNames = false;
-          }
-        } else {
-          allAreTypeNames = false;
-        }
-      }
-    }
-
-    // All of the protocols listed also have type names, and at least
-    // one is an Objective-C class name. Check whether all of the
-    // protocol conformances are declared by the base class itself, in
-    // which case we warn.
-    if (allAreTypeNames && firstClassNameLoc.isValid()) {
-      llvm::SmallPtrSet<ObjCProtocolDecl*, 8> knownProtocols;
-      Context.CollectInheritedProtocols(baseClass, knownProtocols);
-      bool allProtocolsDeclared = true;
-      for (auto proto : protocols) {
-        if (knownProtocols.count(static_cast<ObjCProtocolDecl *>(proto)) == 0) {
-          allProtocolsDeclared = false;
-          break;
-        }
-      }
-
-      if (allProtocolsDeclared) {
-        Diag(firstClassNameLoc, diag::warn_objc_redundant_qualified_class_type)
-          << baseClass->getDeclName() << SourceRange(lAngleLoc, rAngleLoc)
-          << FixItHint::CreateInsertion(getLocForEndOfToken(firstClassNameLoc),
-                                        " *");
-      }
-    }
-
-    protocolLAngleLoc = lAngleLoc;
-    protocolRAngleLoc = rAngleLoc;
-    assert(protocols.size() == identifierLocs.size());
-  };
-
-  // Attempt to resolve all of the identifiers as protocols.
-  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
-    ObjCProtocolDecl *proto = LookupProtocol(identifiers[i], identifierLocs[i]);
-    protocols.push_back(proto);
-    if (proto)
-      ++numProtocolsResolved;
-  }
-
-  // If all of the names were protocols, these were protocol qualifiers.
-  if (numProtocolsResolved == identifiers.size())
-    return resolvedAsProtocols();
-
-  // Attempt to resolve all of the identifiers as type names or
-  // Objective-C class names. The latter is technically ill-formed,
-  // but is probably something like \c NSArray<NSView *> missing the
-  // \c*.
-  typedef llvm::PointerUnion<TypeDecl *, ObjCInterfaceDecl *> TypeOrClassDecl;
-  SmallVector<TypeOrClassDecl, 4> typeDecls;
-  unsigned numTypeDeclsResolved = 0;
-  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
-    NamedDecl *decl = LookupSingleName(S, identifiers[i], identifierLocs[i],
-                                       LookupOrdinaryName);
-    if (!decl) {
-      typeDecls.push_back(TypeOrClassDecl());
-      continue;
-    }
-
-    if (auto typeDecl = dyn_cast<TypeDecl>(decl)) {
-      typeDecls.push_back(typeDecl);
-      ++numTypeDeclsResolved;
-      continue;
-    }
-
-    if (auto objcClass = dyn_cast<ObjCInterfaceDecl>(decl)) {
-      typeDecls.push_back(objcClass);
-      ++numTypeDeclsResolved;
-      continue;
-    }
-
-    typeDecls.push_back(TypeOrClassDecl());
-  }
-
-  AttributeFactory attrFactory;
-
-  // Local function that forms a reference to the given type or
-  // Objective-C class declaration.
-  auto resolveTypeReference = [&](TypeOrClassDecl typeDecl, SourceLocation loc)
-                                -> TypeResult {
-    // Form declaration specifiers. They simply refer to the type.
-    DeclSpec DS(attrFactory);
-    const char* prevSpec; // unused
-    unsigned diagID; // unused
-    QualType type;
-    if (auto *actualTypeDecl = typeDecl.dyn_cast<TypeDecl *>())
-      type = Context.getTypeDeclType(actualTypeDecl);
-    else
-      type = Context.getObjCInterfaceType(typeDecl.get<ObjCInterfaceDecl *>());
-    TypeSourceInfo *parsedTSInfo = Context.getTrivialTypeSourceInfo(type, loc);
-    ParsedType parsedType = CreateParsedType(type, parsedTSInfo);
-    DS.SetTypeSpecType(DeclSpec::TST_typename, loc, prevSpec, diagID,
-                       parsedType, Context.getPrintingPolicy());
-    // Use the identifier location for the type source range.
-    DS.SetRangeStart(loc);
-    DS.SetRangeEnd(loc);
-
-    // Form the declarator.
-    Declarator D(DS, DeclaratorContext::TypeNameContext);
-
-    // If we have a typedef of an Objective-C class type that is missing a '*',
-    // add the '*'.
-    if (type->getAs<ObjCInterfaceType>()) {
-      SourceLocation starLoc = getLocForEndOfToken(loc);
-      D.AddTypeInfo(DeclaratorChunk::getPointer(/*typeQuals=*/0, starLoc,
-                                                SourceLocation(),
-                                                SourceLocation(),
-                                                SourceLocation(),
-                                                SourceLocation(),
-                                                SourceLocation()),
-                                                starLoc);
-
-      // Diagnose the missing '*'.
-      Diag(loc, diag::err_objc_type_arg_missing_star)
-        << type
-        << FixItHint::CreateInsertion(starLoc, " *");
-    }
-
-    // Convert this to a type.
-    return ActOnTypeName(S, D);
-  };
-
-  // Local function that updates the declaration specifiers with
-  // type argument information.
-  auto resolvedAsTypeDecls = [&] {
-    // We did not resolve these as protocols.
-    protocols.clear();
-
-    assert(numTypeDeclsResolved == identifiers.size() && "Unresolved type decl");
-    // Map type declarations to type arguments.
-    for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
-      // Map type reference to a type.
-      TypeResult type = resolveTypeReference(typeDecls[i], identifierLocs[i]);
-      if (!type.isUsable()) {
-        typeArgs.clear();
-        return;
-      }
-
-      typeArgs.push_back(type.get());
-    }
-
-    typeArgsLAngleLoc = lAngleLoc;
-    typeArgsRAngleLoc = rAngleLoc;
-  };
-
-  // If all of the identifiers can be resolved as type names or
-  // Objective-C class names, we have type arguments.
-  if (numTypeDeclsResolved == identifiers.size())
-    return resolvedAsTypeDecls();
-
-  // Error recovery: some names weren't found, or we have a mix of
-  // type and protocol names. Go resolve all of the unresolved names
-  // and complain if we can't find a consistent answer.
-  LookupNameKind lookupKind = LookupAnyName;
-  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
-    // If we already have a protocol or type. Check whether it is the
-    // right thing.
-    if (protocols[i] || typeDecls[i]) {
-      // If we haven't figured out whether we want types or protocols
-      // yet, try to figure it out from this name.
-      if (lookupKind == LookupAnyName) {
-        // If this name refers to both a protocol and a type (e.g., \c
-        // NSObject), don't conclude anything yet.
-        if (protocols[i] && typeDecls[i])
-          continue;
-
-        // Otherwise, let this name decide whether we'll be correcting
-        // toward types or protocols.
-        lookupKind = protocols[i] ? LookupObjCProtocolName
-                                  : LookupOrdinaryName;
-        continue;
-      }
-
-      // If we want protocols and we have a protocol, there's nothing
-      // more to do.
-      if (lookupKind == LookupObjCProtocolName && protocols[i])
-        continue;
-
-      // If we want types and we have a type declaration, there's
-      // nothing more to do.
-      if (lookupKind == LookupOrdinaryName && typeDecls[i])
-        continue;
-
-      // We have a conflict: some names refer to protocols and others
-      // refer to types.
-      DiagnoseTypeArgsAndProtocols(identifiers[0], identifierLocs[0],
-                                   identifiers[i], identifierLocs[i],
-                                   protocols[i] != nullptr);
-
-      protocols.clear();
-      typeArgs.clear();
-      return;
-    }
-
-    // Perform typo correction on the name.
-    TypoCorrection corrected = CorrectTypo(
-        DeclarationNameInfo(identifiers[i], identifierLocs[i]), lookupKind, S,
-        nullptr,
-        llvm::make_unique<ObjCTypeArgOrProtocolValidatorCCC>(Context,
-                                                             lookupKind),
-        CTK_ErrorRecovery);
-    if (corrected) {
-      // Did we find a protocol?
-      if (auto proto = corrected.getCorrectionDeclAs<ObjCProtocolDecl>()) {
-        diagnoseTypo(corrected,
-                     PDiag(diag::err_undeclared_protocol_suggest)
-                       << identifiers[i]);
-        lookupKind = LookupObjCProtocolName;
-        protocols[i] = proto;
-        ++numProtocolsResolved;
-        continue;
-      }
-
-      // Did we find a type?
-      if (auto typeDecl = corrected.getCorrectionDeclAs<TypeDecl>()) {
-        diagnoseTypo(corrected,
-                     PDiag(diag::err_unknown_typename_suggest)
-                       << identifiers[i]);
-        lookupKind = LookupOrdinaryName;
-        typeDecls[i] = typeDecl;
-        ++numTypeDeclsResolved;
-        continue;
-      }
-
-      // Did we find an Objective-C class?
-      if (auto objcClass = corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
-        diagnoseTypo(corrected,
-                     PDiag(diag::err_unknown_type_or_class_name_suggest)
-                       << identifiers[i] << true);
-        lookupKind = LookupOrdinaryName;
-        typeDecls[i] = objcClass;
-        ++numTypeDeclsResolved;
-        continue;
-      }
-    }
-
-    // We couldn't find anything.
-    Diag(identifierLocs[i],
-         (lookupKind == LookupAnyName ? diag::err_objc_type_arg_missing
-          : lookupKind == LookupObjCProtocolName ? diag::err_undeclared_protocol
-          : diag::err_unknown_typename))
-      << identifiers[i];
-    protocols.clear();
-    typeArgs.clear();
-    return;
-  }
-
-  // If all of the names were (corrected to) protocols, these were
-  // protocol qualifiers.
-  if (numProtocolsResolved == identifiers.size())
-    return resolvedAsProtocols();
-
-  // Otherwise, all of the names were (corrected to) types.
-  assert(numTypeDeclsResolved == identifiers.size() && "Not all types?");
-  return resolvedAsTypeDecls();
-}
-
-/// DiagnoseClassExtensionDupMethods - Check for duplicate declaration of
-/// a class method in its extension.
-///
-void Sema::DiagnoseClassExtensionDupMethods(ObjCCategoryDecl *CAT,
-                                            ObjCInterfaceDecl *ID) {
-  if (!ID)
-    return;  // Possibly due to previous error
-
-  llvm::DenseMap<Selector, const ObjCMethodDecl*> MethodMap;
-  for (auto *MD : ID->methods())
-    MethodMap[MD->getSelector()] = MD;
-
-  if (MethodMap.empty())
-    return;
-  for (const auto *Method : CAT->methods()) {
-    const ObjCMethodDecl *&PrevMethod = MethodMap[Method->getSelector()];
-    if (PrevMethod &&
-        (PrevMethod->isInstanceMethod() == Method->isInstanceMethod()) &&
-        !MatchTwoMethodDeclarations(Method, PrevMethod)) {
-      Diag(Method->getLocation(), diag::err_duplicate_method_decl)
-            << Method->getDeclName();
-      Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
-    }
-  }
-}
-
-/// ActOnForwardProtocolDeclaration - Handle \@protocol foo;
-Sema::DeclGroupPtrTy
-Sema::ActOnForwardProtocolDeclaration(SourceLocation AtProtocolLoc,
-                                      ArrayRef<IdentifierLocPair> IdentList,
-                                      const ParsedAttributesView &attrList) {
-  SmallVector<Decl *, 8> DeclsInGroup;
-  for (const IdentifierLocPair &IdentPair : IdentList) {
-    IdentifierInfo *Ident = IdentPair.first;
-    ObjCProtocolDecl *PrevDecl = LookupProtocol(Ident, IdentPair.second,
-                                                forRedeclarationInCurContext());
-    ObjCProtocolDecl *PDecl
-      = ObjCProtocolDecl::Create(Context, CurContext, Ident,
-                                 IdentPair.second, AtProtocolLoc,
-                                 PrevDecl);
-
-    PushOnScopeChains(PDecl, TUScope);
-    CheckObjCDeclScope(PDecl);
-
-    ProcessDeclAttributeList(TUScope, PDecl, attrList);
-    AddPragmaAttributes(TUScope, PDecl);
-
-    if (PrevDecl)
-      mergeDeclAttributes(PDecl, PrevDecl);
-
-    DeclsInGroup.push_back(PDecl);
-  }
-
-  return BuildDeclaratorGroup(DeclsInGroup);
-}
-
-Decl *Sema::ActOnStartCategoryInterface(
-    SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
-    SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
-    IdentifierInfo *CategoryName, SourceLocation CategoryLoc,
-    Decl *const *ProtoRefs, unsigned NumProtoRefs,
-    const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
-    const ParsedAttributesView &AttrList) {
-  ObjCCategoryDecl *CDecl;
-  ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
-
-  /// Check that class of this category is already completely declared.
-
-  if (!IDecl
-      || RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
-                             diag::err_category_forward_interface,
-                             CategoryName == nullptr)) {
-    // Create an invalid ObjCCategoryDecl to serve as context for
-    // the enclosing method declarations.  We mark the decl invalid
-    // to make it clear that this isn't a valid AST.
-    CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc,
-                                     ClassLoc, CategoryLoc, CategoryName,
-                                     IDecl, typeParamList);
-    CDecl->setInvalidDecl();
-    CurContext->addDecl(CDecl);
-
-    if (!IDecl)
-      Diag(ClassLoc, diag::err_undef_interface) << ClassName;
-    return ActOnObjCContainerStartDefinition(CDecl);
-  }
-
-  if (!CategoryName && IDecl->getImplementation()) {
-    Diag(ClassLoc, diag::err_class_extension_after_impl) << ClassName;
-    Diag(IDecl->getImplementation()->getLocation(),
-          diag::note_implementation_declared);
-  }
-
-  if (CategoryName) {
-    /// Check for duplicate interface declaration for this category
-    if (ObjCCategoryDecl *Previous
-          = IDecl->FindCategoryDeclaration(CategoryName)) {
-      // Class extensions can be declared multiple times, categories cannot.
-      Diag(CategoryLoc, diag::warn_dup_category_def)
-        << ClassName << CategoryName;
-      Diag(Previous->getLocation(), diag::note_previous_definition);
-    }
-  }
-
-  // If we have a type parameter list, check it.
-  if (typeParamList) {
-    if (auto prevTypeParamList = IDecl->getTypeParamList()) {
-      if (checkTypeParamListConsistency(*this, prevTypeParamList, typeParamList,
-                                        CategoryName
-                                          ? TypeParamListContext::Category
-                                          : TypeParamListContext::Extension))
-        typeParamList = nullptr;
-    } else {
-      Diag(typeParamList->getLAngleLoc(),
-           diag::err_objc_parameterized_category_nonclass)
-        << (CategoryName != nullptr)
-        << ClassName
-        << typeParamList->getSourceRange();
-
-      typeParamList = nullptr;
-    }
-  }
-
-  CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc,
-                                   ClassLoc, CategoryLoc, CategoryName, IDecl,
-                                   typeParamList);
-  // FIXME: PushOnScopeChains?
-  CurContext->addDecl(CDecl);
-
-  // Process the attributes before looking at protocols to ensure that the
-  // availability attribute is attached to the category to provide availability
-  // checking for protocol uses.
-  ProcessDeclAttributeList(TUScope, CDecl, AttrList);
-  AddPragmaAttributes(TUScope, CDecl);
-
-  if (NumProtoRefs) {
-    diagnoseUseOfProtocols(*this, CDecl, (ObjCProtocolDecl*const*)ProtoRefs,
-                           NumProtoRefs, ProtoLocs);
-    CDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
-                           ProtoLocs, Context);
-    // Protocols in the class extension belong to the class.
-    if (CDecl->IsClassExtension())
-     IDecl->mergeClassExtensionProtocolList((ObjCProtocolDecl*const*)ProtoRefs,
-                                            NumProtoRefs, Context);
-  }
-
-  CheckObjCDeclScope(CDecl);
-  return ActOnObjCContainerStartDefinition(CDecl);
-}
-
-/// ActOnStartCategoryImplementation - Perform semantic checks on the
-/// category implementation declaration and build an ObjCCategoryImplDecl
-/// object.
-Decl *Sema::ActOnStartCategoryImplementation(
-                      SourceLocation AtCatImplLoc,
-                      IdentifierInfo *ClassName, SourceLocation ClassLoc,
-                      IdentifierInfo *CatName, SourceLocation CatLoc) {
-  ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
-  ObjCCategoryDecl *CatIDecl = nullptr;
-  if (IDecl && IDecl->hasDefinition()) {
-    CatIDecl = IDecl->FindCategoryDeclaration(CatName);
-    if (!CatIDecl) {
-      // Category @implementation with no corresponding @interface.
-      // Create and install one.
-      CatIDecl = ObjCCategoryDecl::Create(Context, CurContext, AtCatImplLoc,
-                                          ClassLoc, CatLoc,
-                                          CatName, IDecl,
-                                          /*typeParamList=*/nullptr);
-      CatIDecl->setImplicit();
-    }
-  }
-
-  ObjCCategoryImplDecl *CDecl =
-    ObjCCategoryImplDecl::Create(Context, CurContext, CatName, IDecl,
-                                 ClassLoc, AtCatImplLoc, CatLoc);
-  /// Check that class of this category is already completely declared.
-  if (!IDecl) {
-    Diag(ClassLoc, diag::err_undef_interface) << ClassName;
-    CDecl->setInvalidDecl();
-  } else if (RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
-                                 diag::err_undef_interface)) {
-    CDecl->setInvalidDecl();
-  }
-
-  // FIXME: PushOnScopeChains?
-  CurContext->addDecl(CDecl);
-
-  // If the interface has the objc_runtime_visible attribute, we
-  // cannot implement a category for it.
-  if (IDecl && IDecl->hasAttr<ObjCRuntimeVisibleAttr>()) {
-    Diag(ClassLoc, diag::err_objc_runtime_visible_category)
-      << IDecl->getDeclName();
-  }
-
-  /// Check that CatName, category name, is not used in another implementation.
-  if (CatIDecl) {
-    if (CatIDecl->getImplementation()) {
-      Diag(ClassLoc, diag::err_dup_implementation_category) << ClassName
-        << CatName;
-      Diag(CatIDecl->getImplementation()->getLocation(),
-           diag::note_previous_definition);
-      CDecl->setInvalidDecl();
-    } else {
-      CatIDecl->setImplementation(CDecl);
-      // Warn on implementating category of deprecated class under
-      // -Wdeprecated-implementations flag.
-      DiagnoseObjCImplementedDeprecations(*this, CatIDecl,
-                                          CDecl->getLocation());
-    }
-  }
-
-  CheckObjCDeclScope(CDecl);
-  return ActOnObjCContainerStartDefinition(CDecl);
-}
-
-Decl *Sema::ActOnStartClassImplementation(
-                      SourceLocation AtClassImplLoc,
-                      IdentifierInfo *ClassName, SourceLocation ClassLoc,
-                      IdentifierInfo *SuperClassname,
-                      SourceLocation SuperClassLoc) {
-  ObjCInterfaceDecl *IDecl = nullptr;
-  // Check for another declaration kind with the same name.
-  NamedDecl *PrevDecl
-    = LookupSingleName(TUScope, ClassName, ClassLoc, LookupOrdinaryName,
-                       forRedeclarationInCurContext());
-  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
-    Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName;
-    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
-  } else if ((IDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl))) {
-    // FIXME: This will produce an error if the definition of the interface has
-    // been imported from a module but is not visible.
-    RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
-                        diag::warn_undef_interface);
-  } else {
-    // We did not find anything with the name ClassName; try to correct for
-    // typos in the class name.
-    TypoCorrection Corrected = CorrectTypo(
-        DeclarationNameInfo(ClassName, ClassLoc), LookupOrdinaryName, TUScope,
-        nullptr, llvm::make_unique<ObjCInterfaceValidatorCCC>(), CTK_NonError);
-    if (Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
-      // Suggest the (potentially) correct interface name. Don't provide a
-      // code-modification hint or use the typo name for recovery, because
-      // this is just a warning. The program may actually be correct.
-      diagnoseTypo(Corrected,
-                   PDiag(diag::warn_undef_interface_suggest) << ClassName,
-                   /*ErrorRecovery*/false);
-    } else {
-      Diag(ClassLoc, diag::warn_undef_interface) << ClassName;
-    }
-  }
-
-  // Check that super class name is valid class name
-  ObjCInterfaceDecl *SDecl = nullptr;
-  if (SuperClassname) {
-    // Check if a different kind of symbol declared in this scope.
-    PrevDecl = LookupSingleName(TUScope, SuperClassname, SuperClassLoc,
-                                LookupOrdinaryName);
-    if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
-      Diag(SuperClassLoc, diag::err_redefinition_different_kind)
-        << SuperClassname;
-      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
-    } else {
-      SDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
-      if (SDecl && !SDecl->hasDefinition())
-        SDecl = nullptr;
-      if (!SDecl)
-        Diag(SuperClassLoc, diag::err_undef_superclass)
-          << SuperClassname << ClassName;
-      else if (IDecl && !declaresSameEntity(IDecl->getSuperClass(), SDecl)) {
-        // This implementation and its interface do not have the same
-        // super class.
-        Diag(SuperClassLoc, diag::err_conflicting_super_class)
-          << SDecl->getDeclName();
-        Diag(SDecl->getLocation(), diag::note_previous_definition);
-      }
-    }
-  }
-
-  if (!IDecl) {
-    // Legacy case of @implementation with no corresponding @interface.
-    // Build, chain & install the interface decl into the identifier.
-
-    // FIXME: Do we support attributes on the @implementation? If so we should
-    // copy them over.
-    IDecl = ObjCInterfaceDecl::Create(Context, CurContext, AtClassImplLoc,
-                                      ClassName, /*typeParamList=*/nullptr,
-                                      /*PrevDecl=*/nullptr, ClassLoc,
-                                      true);
-    AddPragmaAttributes(TUScope, IDecl);
-    IDecl->startDefinition();
-    if (SDecl) {
-      IDecl->setSuperClass(Context.getTrivialTypeSourceInfo(
-                             Context.getObjCInterfaceType(SDecl),
-                             SuperClassLoc));
-      IDecl->setEndOfDefinitionLoc(SuperClassLoc);
-    } else {
-      IDecl->setEndOfDefinitionLoc(ClassLoc);
-    }
-
-    PushOnScopeChains(IDecl, TUScope);
-  } else {
-    // Mark the interface as being completed, even if it was just as
-    //   @class ....;
-    // declaration; the user cannot reopen it.
-    if (!IDecl->hasDefinition())
-      IDecl->startDefinition();
-  }
-
-  ObjCImplementationDecl* IMPDecl =
-    ObjCImplementationDecl::Create(Context, CurContext, IDecl, SDecl,
-                                   ClassLoc, AtClassImplLoc, SuperClassLoc);
-
-  if (CheckObjCDeclScope(IMPDecl))
-    return ActOnObjCContainerStartDefinition(IMPDecl);
-
-  // Check that there is no duplicate implementation of this class.
-  if (IDecl->getImplementation()) {
-    // FIXME: Don't leak everything!
-    Diag(ClassLoc, diag::err_dup_implementation_class) << ClassName;
-    Diag(IDecl->getImplementation()->getLocation(),
-         diag::note_previous_definition);
-    IMPDecl->setInvalidDecl();
-  } else { // add it to the list.
-    IDecl->setImplementation(IMPDecl);
-    PushOnScopeChains(IMPDecl, TUScope);
-    // Warn on implementating deprecated class under
-    // -Wdeprecated-implementations flag.
-    DiagnoseObjCImplementedDeprecations(*this, IDecl, IMPDecl->getLocation());
-  }
-
-  // If the superclass has the objc_runtime_visible attribute, we
-  // cannot implement a subclass of it.
-  if (IDecl->getSuperClass() &&
-      IDecl->getSuperClass()->hasAttr<ObjCRuntimeVisibleAttr>()) {
-    Diag(ClassLoc, diag::err_objc_runtime_visible_subclass)
-      << IDecl->getDeclName()
-      << IDecl->getSuperClass()->getDeclName();
-  }
-
-  return ActOnObjCContainerStartDefinition(IMPDecl);
-}
-
-Sema::DeclGroupPtrTy
-Sema::ActOnFinishObjCImplementation(Decl *ObjCImpDecl, ArrayRef<Decl *> Decls) {
-  SmallVector<Decl *, 64> DeclsInGroup;
-  DeclsInGroup.reserve(Decls.size() + 1);
-
-  for (unsigned i = 0, e = Decls.size(); i != e; ++i) {
-    Decl *Dcl = Decls[i];
-    if (!Dcl)
-      continue;
-    if (Dcl->getDeclContext()->isFileContext())
-      Dcl->setTopLevelDeclInObjCContainer();
-    DeclsInGroup.push_back(Dcl);
-  }
-
-  DeclsInGroup.push_back(ObjCImpDecl);
-
-  return BuildDeclaratorGroup(DeclsInGroup);
-}
-
-void Sema::CheckImplementationIvars(ObjCImplementationDecl *ImpDecl,
-                                    ObjCIvarDecl **ivars, unsigned numIvars,
-                                    SourceLocation RBrace) {
-  assert(ImpDecl && "missing implementation decl");
-  ObjCInterfaceDecl* IDecl = ImpDecl->getClassInterface();
-  if (!IDecl)
-    return;
-  /// Check case of non-existing \@interface decl.
-  /// (legacy objective-c \@implementation decl without an \@interface decl).
-  /// Add implementations's ivar to the synthesize class's ivar list.
-  if (IDecl->isImplicitInterfaceDecl()) {
-    IDecl->setEndOfDefinitionLoc(RBrace);
-    // Add ivar's to class's DeclContext.
-    for (unsigned i = 0, e = numIvars; i != e; ++i) {
-      ivars[i]->setLexicalDeclContext(ImpDecl);
-      IDecl->makeDeclVisibleInContext(ivars[i]);
-      ImpDecl->addDecl(ivars[i]);
-    }
-
-    return;
-  }
-  // If implementation has empty ivar list, just return.
-  if (numIvars == 0)
-    return;
-
-  assert(ivars && "missing @implementation ivars");
-  if (LangOpts.ObjCRuntime.isNonFragile()) {
-    if (ImpDecl->getSuperClass())
-      Diag(ImpDecl->getLocation(), diag::warn_on_superclass_use);
-    for (unsigned i = 0; i < numIvars; i++) {
-      ObjCIvarDecl* ImplIvar = ivars[i];
-      if (const ObjCIvarDecl *ClsIvar =
-            IDecl->getIvarDecl(ImplIvar->getIdentifier())) {
-        Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration);
-        Diag(ClsIvar->getLocation(), diag::note_previous_definition);
-        continue;
-      }
-      // Check class extensions (unnamed categories) for duplicate ivars.
-      for (const auto *CDecl : IDecl->visible_extensions()) {
-        if (const ObjCIvarDecl *ClsExtIvar =
-            CDecl->getIvarDecl(ImplIvar->getIdentifier())) {
-          Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration);
-          Diag(ClsExtIvar->getLocation(), diag::note_previous_definition);
-          continue;
-        }
-      }
-      // Instance ivar to Implementation's DeclContext.
-      ImplIvar->setLexicalDeclContext(ImpDecl);
-      IDecl->makeDeclVisibleInContext(ImplIvar);
-      ImpDecl->addDecl(ImplIvar);
-    }
-    return;
-  }
-  // Check interface's Ivar list against those in the implementation.
-  // names and types must match.
-  //
-  unsigned j = 0;
-  ObjCInterfaceDecl::ivar_iterator
-    IVI = IDecl->ivar_begin(), IVE = IDecl->ivar_end();
-  for (; numIvars > 0 && IVI != IVE; ++IVI) {
-    ObjCIvarDecl* ImplIvar = ivars[j++];
-    ObjCIvarDecl* ClsIvar = *IVI;
-    assert (ImplIvar && "missing implementation ivar");
-    assert (ClsIvar && "missing class ivar");
-
-    // First, make sure the types match.
-    if (!Context.hasSameType(ImplIvar->getType(), ClsIvar->getType())) {
-      Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_type)
-        << ImplIvar->getIdentifier()
-        << ImplIvar->getType() << ClsIvar->getType();
-      Diag(ClsIvar->getLocation(), diag::note_previous_definition);
-    } else if (ImplIvar->isBitField() && ClsIvar->isBitField() &&
-               ImplIvar->getBitWidthValue(Context) !=
-               ClsIvar->getBitWidthValue(Context)) {
-      Diag(ImplIvar->getBitWidth()->getBeginLoc(),
-           diag::err_conflicting_ivar_bitwidth)
-          << ImplIvar->getIdentifier();
-      Diag(ClsIvar->getBitWidth()->getBeginLoc(),
-           diag::note_previous_definition);
-    }
-    // Make sure the names are identical.
-    if (ImplIvar->getIdentifier() != ClsIvar->getIdentifier()) {
-      Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_name)
-        << ImplIvar->getIdentifier() << ClsIvar->getIdentifier();
-      Diag(ClsIvar->getLocation(), diag::note_previous_definition);
-    }
-    --numIvars;
-  }
-
-  if (numIvars > 0)
-    Diag(ivars[j]->getLocation(), diag::err_inconsistent_ivar_count);
-  else if (IVI != IVE)
-    Diag(IVI->getLocation(), diag::err_inconsistent_ivar_count);
-}
-
-static void WarnUndefinedMethod(Sema &S, SourceLocation ImpLoc,
-                                ObjCMethodDecl *method,
-                                bool &IncompleteImpl,
-                                unsigned DiagID,
-                                NamedDecl *NeededFor = nullptr) {
-  // No point warning no definition of method which is 'unavailable'.
-  if (method->getAvailability() == AR_Unavailable)
-    return;
-
-  // FIXME: For now ignore 'IncompleteImpl'.
-  // Previously we grouped all unimplemented methods under a single
-  // warning, but some users strongly voiced that they would prefer
-  // separate warnings.  We will give that approach a try, as that
-  // matches what we do with protocols.
-  {
-    const Sema::SemaDiagnosticBuilder &B = S.Diag(ImpLoc, DiagID);
-    B << method;
-    if (NeededFor)
-      B << NeededFor;
-  }
-
-  // Issue a note to the original declaration.
-  SourceLocation MethodLoc = method->getBeginLoc();
-  if (MethodLoc.isValid())
-    S.Diag(MethodLoc, diag::note_method_declared_at) << method;
-}
-
-/// Determines if type B can be substituted for type A.  Returns true if we can
-/// guarantee that anything that the user will do to an object of type A can
-/// also be done to an object of type B.  This is trivially true if the two
-/// types are the same, or if B is a subclass of A.  It becomes more complex
-/// in cases where protocols are involved.
-///
-/// Object types in Objective-C describe the minimum requirements for an
-/// object, rather than providing a complete description of a type.  For
-/// example, if A is a subclass of B, then B* may refer to an instance of A.
-/// The principle of substitutability means that we may use an instance of A
-/// anywhere that we may use an instance of B - it will implement all of the
-/// ivars of B and all of the methods of B.
-///
-/// This substitutability is important when type checking methods, because
-/// the implementation may have stricter type definitions than the interface.
-/// The interface specifies minimum requirements, but the implementation may
-/// have more accurate ones.  For example, a method may privately accept
-/// instances of B, but only publish that it accepts instances of A.  Any
-/// object passed to it will be type checked against B, and so will implicitly
-/// by a valid A*.  Similarly, a method may return a subclass of the class that
-/// it is declared as returning.
-///
-/// This is most important when considering subclassing.  A method in a
-/// subclass must accept any object as an argument that its superclass's
-/// implementation accepts.  It may, however, accept a more general type
-/// without breaking substitutability (i.e. you can still use the subclass
-/// anywhere that you can use the superclass, but not vice versa).  The
-/// converse requirement applies to return types: the return type for a
-/// subclass method must be a valid object of the kind that the superclass
-/// advertises, but it may be specified more accurately.  This avoids the need
-/// for explicit down-casting by callers.
-///
-/// Note: This is a stricter requirement than for assignment.
-static bool isObjCTypeSubstitutable(ASTContext &Context,
-                                    const ObjCObjectPointerType *A,
-                                    const ObjCObjectPointerType *B,
-                                    bool rejectId) {
-  // Reject a protocol-unqualified id.
-  if (rejectId && B->isObjCIdType()) return false;
-
-  // If B is a qualified id, then A must also be a qualified id and it must
-  // implement all of the protocols in B.  It may not be a qualified class.
-  // For example, MyClass<A> can be assigned to id<A>, but MyClass<A> is a
-  // stricter definition so it is not substitutable for id<A>.
-  if (B->isObjCQualifiedIdType()) {
-    return A->isObjCQualifiedIdType() &&
-           Context.ObjCQualifiedIdTypesAreCompatible(QualType(A, 0),
-                                                     QualType(B,0),
-                                                     false);
-  }
-
-  /*
-  // id is a special type that bypasses type checking completely.  We want a
-  // warning when it is used in one place but not another.
-  if (C.isObjCIdType(A) || C.isObjCIdType(B)) return false;
-
-
-  // If B is a qualified id, then A must also be a qualified id (which it isn't
-  // if we've got this far)
-  if (B->isObjCQualifiedIdType()) return false;
-  */
-
-  // Now we know that A and B are (potentially-qualified) class types.  The
-  // normal rules for assignment apply.
-  return Context.canAssignObjCInterfaces(A, B);
-}
-
-static SourceRange getTypeRange(TypeSourceInfo *TSI) {
-  return (TSI ? TSI->getTypeLoc().getSourceRange() : SourceRange());
-}
-
-/// Determine whether two set of Objective-C declaration qualifiers conflict.
-static bool objcModifiersConflict(Decl::ObjCDeclQualifier x,
-                                  Decl::ObjCDeclQualifier y) {
-  return (x & ~Decl::OBJC_TQ_CSNullability) !=
-         (y & ~Decl::OBJC_TQ_CSNullability);
-}
-
-static bool CheckMethodOverrideReturn(Sema &S,
-                                      ObjCMethodDecl *MethodImpl,
-                                      ObjCMethodDecl *MethodDecl,
-                                      bool IsProtocolMethodDecl,
-                                      bool IsOverridingMode,
-                                      bool Warn) {
-  if (IsProtocolMethodDecl &&
-      objcModifiersConflict(MethodDecl->getObjCDeclQualifier(),
-                            MethodImpl->getObjCDeclQualifier())) {
-    if (Warn) {
-      S.Diag(MethodImpl->getLocation(),
-             (IsOverridingMode
-                  ? diag::warn_conflicting_overriding_ret_type_modifiers
-                  : diag::warn_conflicting_ret_type_modifiers))
-          << MethodImpl->getDeclName()
-          << MethodImpl->getReturnTypeSourceRange();
-      S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration)
-          << MethodDecl->getReturnTypeSourceRange();
-    }
-    else
-      return false;
-  }
-  if (Warn && IsOverridingMode &&
-      !isa<ObjCImplementationDecl>(MethodImpl->getDeclContext()) &&
-      !S.Context.hasSameNullabilityTypeQualifier(MethodImpl->getReturnType(),
-                                                 MethodDecl->getReturnType(),
-                                                 false)) {
-    auto nullabilityMethodImpl =
-      *MethodImpl->getReturnType()->getNullability(S.Context);
-    auto nullabilityMethodDecl =
-      *MethodDecl->getReturnType()->getNullability(S.Context);
-      S.Diag(MethodImpl->getLocation(),
-             diag::warn_conflicting_nullability_attr_overriding_ret_types)
-        << DiagNullabilityKind(
-             nullabilityMethodImpl,
-             ((MethodImpl->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
-              != 0))
-        << DiagNullabilityKind(
-             nullabilityMethodDecl,
-             ((MethodDecl->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
-                != 0));
-      S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration);
-  }
-
-  if (S.Context.hasSameUnqualifiedType(MethodImpl->getReturnType(),
-                                       MethodDecl->getReturnType()))
-    return true;
-  if (!Warn)
-    return false;
-
-  unsigned DiagID =
-    IsOverridingMode ? diag::warn_conflicting_overriding_ret_types
-                     : diag::warn_conflicting_ret_types;
-
-  // Mismatches between ObjC pointers go into a different warning
-  // category, and sometimes they're even completely whitelisted.
-  if (const ObjCObjectPointerType *ImplPtrTy =
-          MethodImpl->getReturnType()->getAs<ObjCObjectPointerType>()) {
-    if (const ObjCObjectPointerType *IfacePtrTy =
-            MethodDecl->getReturnType()->getAs<ObjCObjectPointerType>()) {
-      // Allow non-matching return types as long as they don't violate
-      // the principle of substitutability.  Specifically, we permit
-      // return types that are subclasses of the declared return type,
-      // or that are more-qualified versions of the declared type.
-      if (isObjCTypeSubstitutable(S.Context, IfacePtrTy, ImplPtrTy, false))
-        return false;
-
-      DiagID =
-        IsOverridingMode ? diag::warn_non_covariant_overriding_ret_types
-                         : diag::warn_non_covariant_ret_types;
-    }
-  }
-
-  S.Diag(MethodImpl->getLocation(), DiagID)
-      << MethodImpl->getDeclName() << MethodDecl->getReturnType()
-      << MethodImpl->getReturnType()
-      << MethodImpl->getReturnTypeSourceRange();
-  S.Diag(MethodDecl->getLocation(), IsOverridingMode
-                                        ? diag::note_previous_declaration
-                                        : diag::note_previous_definition)
-      << MethodDecl->getReturnTypeSourceRange();
-  return false;
-}
-
-static bool CheckMethodOverrideParam(Sema &S,
-                                     ObjCMethodDecl *MethodImpl,
-                                     ObjCMethodDecl *MethodDecl,
-                                     ParmVarDecl *ImplVar,
-                                     ParmVarDecl *IfaceVar,
-                                     bool IsProtocolMethodDecl,
-                                     bool IsOverridingMode,
-                                     bool Warn) {
-  if (IsProtocolMethodDecl &&
-      objcModifiersConflict(ImplVar->getObjCDeclQualifier(),
-                            IfaceVar->getObjCDeclQualifier())) {
-    if (Warn) {
-      if (IsOverridingMode)
-        S.Diag(ImplVar->getLocation(),
-               diag::warn_conflicting_overriding_param_modifiers)
-            << getTypeRange(ImplVar->getTypeSourceInfo())
-            << MethodImpl->getDeclName();
-      else S.Diag(ImplVar->getLocation(),
-             diag::warn_conflicting_param_modifiers)
-          << getTypeRange(ImplVar->getTypeSourceInfo())
-          << MethodImpl->getDeclName();
-      S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration)
-          << getTypeRange(IfaceVar->getTypeSourceInfo());
-    }
-    else
-      return false;
-  }
-
-  QualType ImplTy = ImplVar->getType();
-  QualType IfaceTy = IfaceVar->getType();
-  if (Warn && IsOverridingMode &&
-      !isa<ObjCImplementationDecl>(MethodImpl->getDeclContext()) &&
-      !S.Context.hasSameNullabilityTypeQualifier(ImplTy, IfaceTy, true)) {
-    S.Diag(ImplVar->getLocation(),
-           diag::warn_conflicting_nullability_attr_overriding_param_types)
-      << DiagNullabilityKind(
-           *ImplTy->getNullability(S.Context),
-           ((ImplVar->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
-            != 0))
-      << DiagNullabilityKind(
-           *IfaceTy->getNullability(S.Context),
-           ((IfaceVar->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
-            != 0));
-    S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration);
-  }
-  if (S.Context.hasSameUnqualifiedType(ImplTy, IfaceTy))
-    return true;
-
-  if (!Warn)
-    return false;
-  unsigned DiagID =
-    IsOverridingMode ? diag::warn_conflicting_overriding_param_types
-                     : diag::warn_conflicting_param_types;
-
-  // Mismatches between ObjC pointers go into a different warning
-  // category, and sometimes they're even completely whitelisted.
-  if (const ObjCObjectPointerType *ImplPtrTy =
-        ImplTy->getAs<ObjCObjectPointerType>()) {
-    if (const ObjCObjectPointerType *IfacePtrTy =
-          IfaceTy->getAs<ObjCObjectPointerType>()) {
-      // Allow non-matching argument types as long as they don't
-      // violate the principle of substitutability.  Specifically, the
-      // implementation must accept any objects that the superclass
-      // accepts, however it may also accept others.
-      if (isObjCTypeSubstitutable(S.Context, ImplPtrTy, IfacePtrTy, true))
-        return false;
-
-      DiagID =
-      IsOverridingMode ? diag::warn_non_contravariant_overriding_param_types
-                       : diag::warn_non_contravariant_param_types;
-    }
-  }
-
-  S.Diag(ImplVar->getLocation(), DiagID)
-    << getTypeRange(ImplVar->getTypeSourceInfo())
-    << MethodImpl->getDeclName() << IfaceTy << ImplTy;
-  S.Diag(IfaceVar->getLocation(),
-         (IsOverridingMode ? diag::note_previous_declaration
-                           : diag::note_previous_definition))
-    << getTypeRange(IfaceVar->getTypeSourceInfo());
-  return false;
-}
-
-/// In ARC, check whether the conventional meanings of the two methods
-/// match.  If they don't, it's a hard error.
-static bool checkMethodFamilyMismatch(Sema &S, ObjCMethodDecl *impl,
-                                      ObjCMethodDecl *decl) {
-  ObjCMethodFamily implFamily = impl->getMethodFamily();
-  ObjCMethodFamily declFamily = decl->getMethodFamily();
-  if (implFamily == declFamily) return false;
-
-  // Since conventions are sorted by selector, the only possibility is
-  // that the types differ enough to cause one selector or the other
-  // to fall out of the family.
-  assert(implFamily == OMF_None || declFamily == OMF_None);
-
-  // No further diagnostics required on invalid declarations.
-  if (impl->isInvalidDecl() || decl->isInvalidDecl()) return true;
-
-  const ObjCMethodDecl *unmatched = impl;
-  ObjCMethodFamily family = declFamily;
-  unsigned errorID = diag::err_arc_lost_method_convention;
-  unsigned noteID = diag::note_arc_lost_method_convention;
-  if (declFamily == OMF_None) {
-    unmatched = decl;
-    family = implFamily;
-    errorID = diag::err_arc_gained_method_convention;
-    noteID = diag::note_arc_gained_method_convention;
-  }
-
-  // Indexes into a %select clause in the diagnostic.
-  enum FamilySelector {
-    F_alloc, F_copy, F_mutableCopy = F_copy, F_init, F_new
-  };
-  FamilySelector familySelector = FamilySelector();
-
-  switch (family) {
-  case OMF_None: llvm_unreachable("logic error, no method convention");
-  case OMF_retain:
-  case OMF_release:
-  case OMF_autorelease:
-  case OMF_dealloc:
-  case OMF_finalize:
-  case OMF_retainCount:
-  case OMF_self:
-  case OMF_initialize:
-  case OMF_performSelector:
-    // Mismatches for these methods don't change ownership
-    // conventions, so we don't care.
-    return false;
-
-  case OMF_init: familySelector = F_init; break;
-  case OMF_alloc: familySelector = F_alloc; break;
-  case OMF_copy: familySelector = F_copy; break;
-  case OMF_mutableCopy: familySelector = F_mutableCopy; break;
-  case OMF_new: familySelector = F_new; break;
-  }
-
-  enum ReasonSelector { R_NonObjectReturn, R_UnrelatedReturn };
-  ReasonSelector reasonSelector;
-
-  // The only reason these methods don't fall within their families is
-  // due to unusual result types.
-  if (unmatched->getReturnType()->isObjCObjectPointerType()) {
-    reasonSelector = R_UnrelatedReturn;
-  } else {
-    reasonSelector = R_NonObjectReturn;
-  }
-
-  S.Diag(impl->getLocation(), errorID) << int(familySelector) << int(reasonSelector);
-  S.Diag(decl->getLocation(), noteID) << int(familySelector) << int(reasonSelector);
-
-  return true;
-}
-
-void Sema::WarnConflictingTypedMethods(ObjCMethodDecl *ImpMethodDecl,
-                                       ObjCMethodDecl *MethodDecl,
-                                       bool IsProtocolMethodDecl) {
-  if (getLangOpts().ObjCAutoRefCount &&
-      checkMethodFamilyMismatch(*this, ImpMethodDecl, MethodDecl))
-    return;
-
-  CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl,
-                            IsProtocolMethodDecl, false,
-                            true);
-
-  for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(),
-       IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(),
-       EF = MethodDecl->param_end();
-       IM != EM && IF != EF; ++IM, ++IF) {
-    CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl, *IM, *IF,
-                             IsProtocolMethodDecl, false, true);
-  }
-
-  if (ImpMethodDecl->isVariadic() != MethodDecl->isVariadic()) {
-    Diag(ImpMethodDecl->getLocation(),
-         diag::warn_conflicting_variadic);
-    Diag(MethodDecl->getLocation(), diag::note_previous_declaration);
-  }
-}
-
-void Sema::CheckConflictingOverridingMethod(ObjCMethodDecl *Method,
-                                       ObjCMethodDecl *Overridden,
-                                       bool IsProtocolMethodDecl) {
-
-  CheckMethodOverrideReturn(*this, Method, Overridden,
-                            IsProtocolMethodDecl, true,
-                            true);
-
-  for (ObjCMethodDecl::param_iterator IM = Method->param_begin(),
-       IF = Overridden->param_begin(), EM = Method->param_end(),
-       EF = Overridden->param_end();
-       IM != EM && IF != EF; ++IM, ++IF) {
-    CheckMethodOverrideParam(*this, Method, Overridden, *IM, *IF,
-                             IsProtocolMethodDecl, true, true);
-  }
-
-  if (Method->isVariadic() != Overridden->isVariadic()) {
-    Diag(Method->getLocation(),
-         diag::warn_conflicting_overriding_variadic);
-    Diag(Overridden->getLocation(), diag::note_previous_declaration);
-  }
-}
-
-/// WarnExactTypedMethods - This routine issues a warning if method
-/// implementation declaration matches exactly that of its declaration.
-void Sema::WarnExactTypedMethods(ObjCMethodDecl *ImpMethodDecl,
-                                 ObjCMethodDecl *MethodDecl,
-                                 bool IsProtocolMethodDecl) {
-  // don't issue warning when protocol method is optional because primary
-  // class is not required to implement it and it is safe for protocol
-  // to implement it.
-  if (MethodDecl->getImplementationControl() == ObjCMethodDecl::Optional)
-    return;
-  // don't issue warning when primary class's method is
-  // depecated/unavailable.
-  if (MethodDecl->hasAttr<UnavailableAttr>() ||
-      MethodDecl->hasAttr<DeprecatedAttr>())
-    return;
-
-  bool match = CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl,
-                                      IsProtocolMethodDecl, false, false);
-  if (match)
-    for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(),
-         IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(),
-         EF = MethodDecl->param_end();
-         IM != EM && IF != EF; ++IM, ++IF) {
-      match = CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl,
-                                       *IM, *IF,
-                                       IsProtocolMethodDecl, false, false);
-      if (!match)
-        break;
-    }
-  if (match)
-    match = (ImpMethodDecl->isVariadic() == MethodDecl->isVariadic());
-  if (match)
-    match = !(MethodDecl->isClassMethod() &&
-              MethodDecl->getSelector() == GetNullarySelector("load", Context));
-
-  if (match) {
-    Diag(ImpMethodDecl->getLocation(),
-         diag::warn_category_method_impl_match);
-    Diag(MethodDecl->getLocation(), diag::note_method_declared_at)
-      << MethodDecl->getDeclName();
-  }
-}
-
-/// FIXME: Type hierarchies in Objective-C can be deep. We could most likely
-/// improve the efficiency of selector lookups and type checking by associating
-/// with each protocol / interface / category the flattened instance tables. If
-/// we used an immutable set to keep the table then it wouldn't add significant
-/// memory cost and it would be handy for lookups.
-
-typedef llvm::DenseSet<IdentifierInfo*> ProtocolNameSet;
-typedef std::unique_ptr<ProtocolNameSet> LazyProtocolNameSet;
-
-static void findProtocolsWithExplicitImpls(const ObjCProtocolDecl *PDecl,
-                                           ProtocolNameSet &PNS) {
-  if (PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
-    PNS.insert(PDecl->getIdentifier());
-  for (const auto *PI : PDecl->protocols())
-    findProtocolsWithExplicitImpls(PI, PNS);
-}
-
-/// Recursively populates a set with all conformed protocols in a class
-/// hierarchy that have the 'objc_protocol_requires_explicit_implementation'
-/// attribute.
-static void findProtocolsWithExplicitImpls(const ObjCInterfaceDecl *Super,
-                                           ProtocolNameSet &PNS) {
-  if (!Super)
-    return;
-
-  for (const auto *I : Super->all_referenced_protocols())
-    findProtocolsWithExplicitImpls(I, PNS);
-
-  findProtocolsWithExplicitImpls(Super->getSuperClass(), PNS);
-}
-
-/// CheckProtocolMethodDefs - This routine checks unimplemented methods
-/// Declared in protocol, and those referenced by it.
-static void CheckProtocolMethodDefs(Sema &S,
-                                    SourceLocation ImpLoc,
-                                    ObjCProtocolDecl *PDecl,
-                                    bool& IncompleteImpl,
-                                    const Sema::SelectorSet &InsMap,
-                                    const Sema::SelectorSet &ClsMap,
-                                    ObjCContainerDecl *CDecl,
-                                    LazyProtocolNameSet &ProtocolsExplictImpl) {
-  ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
-  ObjCInterfaceDecl *IDecl = C ? C->getClassInterface()
-                               : dyn_cast<ObjCInterfaceDecl>(CDecl);
-  assert (IDecl && "CheckProtocolMethodDefs - IDecl is null");
-
-  ObjCInterfaceDecl *Super = IDecl->getSuperClass();
-  ObjCInterfaceDecl *NSIDecl = nullptr;
-
-  // If this protocol is marked 'objc_protocol_requires_explicit_implementation'
-  // then we should check if any class in the super class hierarchy also
-  // conforms to this protocol, either directly or via protocol inheritance.
-  // If so, we can skip checking this protocol completely because we
-  // know that a parent class already satisfies this protocol.
-  //
-  // Note: we could generalize this logic for all protocols, and merely
-  // add the limit on looking at the super class chain for just
-  // specially marked protocols.  This may be a good optimization.  This
-  // change is restricted to 'objc_protocol_requires_explicit_implementation'
-  // protocols for now for controlled evaluation.
-  if (PDecl->hasAttr<ObjCExplicitProtocolImplAttr>()) {
-    if (!ProtocolsExplictImpl) {
-      ProtocolsExplictImpl.reset(new ProtocolNameSet);
-      findProtocolsWithExplicitImpls(Super, *ProtocolsExplictImpl);
-    }
-    if (ProtocolsExplictImpl->find(PDecl->getIdentifier()) !=
-        ProtocolsExplictImpl->end())
-      return;
-
-    // If no super class conforms to the protocol, we should not search
-    // for methods in the super class to implicitly satisfy the protocol.
-    Super = nullptr;
-  }
-
-  if (S.getLangOpts().ObjCRuntime.isNeXTFamily()) {
-    // check to see if class implements forwardInvocation method and objects
-    // of this class are derived from 'NSProxy' so that to forward requests
-    // from one object to another.
-    // Under such conditions, which means that every method possible is
-    // implemented in the class, we should not issue "Method definition not
-    // found" warnings.
-    // FIXME: Use a general GetUnarySelector method for this.
-    IdentifierInfo* II = &S.Context.Idents.get("forwardInvocation");
-    Selector fISelector = S.Context.Selectors.getSelector(1, &II);
-    if (InsMap.count(fISelector))
-      // Is IDecl derived from 'NSProxy'? If so, no instance methods
-      // need be implemented in the implementation.
-      NSIDecl = IDecl->lookupInheritedClass(&S.Context.Idents.get("NSProxy"));
-  }
-
-  // If this is a forward protocol declaration, get its definition.
-  if (!PDecl->isThisDeclarationADefinition() &&
-      PDecl->getDefinition())
-    PDecl = PDecl->getDefinition();
-
-  // If a method lookup fails locally we still need to look and see if
-  // the method was implemented by a base class or an inherited
-  // protocol. This lookup is slow, but occurs rarely in correct code
-  // and otherwise would terminate in a warning.
-
-  // check unimplemented instance methods.
-  if (!NSIDecl)
-    for (auto *method : PDecl->instance_methods()) {
-      if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
-          !method->isPropertyAccessor() &&
-          !InsMap.count(method->getSelector()) &&
-          (!Super || !Super->lookupMethod(method->getSelector(),
-                                          true /* instance */,
-                                          false /* shallowCategory */,
-                                          true /* followsSuper */,
-                                          nullptr /* category */))) {
-            // If a method is not implemented in the category implementation but
-            // has been declared in its primary class, superclass,
-            // or in one of their protocols, no need to issue the warning.
-            // This is because method will be implemented in the primary class
-            // or one of its super class implementation.
-
-            // Ugly, but necessary. Method declared in protocol might have
-            // have been synthesized due to a property declared in the class which
-            // uses the protocol.
-            if (ObjCMethodDecl *MethodInClass =
-                  IDecl->lookupMethod(method->getSelector(),
-                                      true /* instance */,
-                                      true /* shallowCategoryLookup */,
-                                      false /* followSuper */))
-              if (C || MethodInClass->isPropertyAccessor())
-                continue;
-            unsigned DIAG = diag::warn_unimplemented_protocol_method;
-            if (!S.Diags.isIgnored(DIAG, ImpLoc)) {
-              WarnUndefinedMethod(S, ImpLoc, method, IncompleteImpl, DIAG,
-                                  PDecl);
-            }
-          }
-    }
-  // check unimplemented class methods
-  for (auto *method : PDecl->class_methods()) {
-    if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
-        !ClsMap.count(method->getSelector()) &&
-        (!Super || !Super->lookupMethod(method->getSelector(),
-                                        false /* class method */,
-                                        false /* shallowCategoryLookup */,
-                                        true  /* followSuper */,
-                                        nullptr /* category */))) {
-      // See above comment for instance method lookups.
-      if (C && IDecl->lookupMethod(method->getSelector(),
-                                   false /* class */,
-                                   true /* shallowCategoryLookup */,
-                                   false /* followSuper */))
-        continue;
-
-      unsigned DIAG = diag::warn_unimplemented_protocol_method;
-      if (!S.Diags.isIgnored(DIAG, ImpLoc)) {
-        WarnUndefinedMethod(S, ImpLoc, method, IncompleteImpl, DIAG, PDecl);
-      }
-    }
-  }
-  // Check on this protocols's referenced protocols, recursively.
-  for (auto *PI : PDecl->protocols())
-    CheckProtocolMethodDefs(S, ImpLoc, PI, IncompleteImpl, InsMap, ClsMap,
-                            CDecl, ProtocolsExplictImpl);
-}
-
-/// MatchAllMethodDeclarations - Check methods declared in interface
-/// or protocol against those declared in their implementations.
-///
-void Sema::MatchAllMethodDeclarations(const SelectorSet &InsMap,
-                                      const SelectorSet &ClsMap,
-                                      SelectorSet &InsMapSeen,
-                                      SelectorSet &ClsMapSeen,
-                                      ObjCImplDecl* IMPDecl,
-                                      ObjCContainerDecl* CDecl,
-                                      bool &IncompleteImpl,
-                                      bool ImmediateClass,
-                                      bool WarnCategoryMethodImpl) {
-  // Check and see if instance methods in class interface have been
-  // implemented in the implementation class. If so, their types match.
-  for (auto *I : CDecl->instance_methods()) {
-    if (!InsMapSeen.insert(I->getSelector()).second)
-      continue;
-    if (!I->isPropertyAccessor() &&
-        !InsMap.count(I->getSelector())) {
-      if (ImmediateClass)
-        WarnUndefinedMethod(*this, IMPDecl->getLocation(), I, IncompleteImpl,
-                            diag::warn_undef_method_impl);
-      continue;
-    } else {
-      ObjCMethodDecl *ImpMethodDecl =
-        IMPDecl->getInstanceMethod(I->getSelector());
-      assert(CDecl->getInstanceMethod(I->getSelector(), true/*AllowHidden*/) &&
-             "Expected to find the method through lookup as well");
-      // ImpMethodDecl may be null as in a @dynamic property.
-      if (ImpMethodDecl) {
-        if (!WarnCategoryMethodImpl)
-          WarnConflictingTypedMethods(ImpMethodDecl, I,
-                                      isa<ObjCProtocolDecl>(CDecl));
-        else if (!I->isPropertyAccessor())
-          WarnExactTypedMethods(ImpMethodDecl, I, isa<ObjCProtocolDecl>(CDecl));
-      }
-    }
-  }
-
-  // Check and see if class methods in class interface have been
-  // implemented in the implementation class. If so, their types match.
-  for (auto *I : CDecl->class_methods()) {
-    if (!ClsMapSeen.insert(I->getSelector()).second)
-      continue;
-    if (!I->isPropertyAccessor() &&
-        !ClsMap.count(I->getSelector())) {
-      if (ImmediateClass)
-        WarnUndefinedMethod(*this, IMPDecl->getLocation(), I, IncompleteImpl,
-                            diag::warn_undef_method_impl);
-    } else {
-      ObjCMethodDecl *ImpMethodDecl =
-        IMPDecl->getClassMethod(I->getSelector());
-      assert(CDecl->getClassMethod(I->getSelector(), true/*AllowHidden*/) &&
-             "Expected to find the method through lookup as well");
-      // ImpMethodDecl may be null as in a @dynamic property.
-      if (ImpMethodDecl) {
-        if (!WarnCategoryMethodImpl)
-          WarnConflictingTypedMethods(ImpMethodDecl, I,
-                                      isa<ObjCProtocolDecl>(CDecl));
-        else if (!I->isPropertyAccessor())
-          WarnExactTypedMethods(ImpMethodDecl, I, isa<ObjCProtocolDecl>(CDecl));
-      }
-    }
-  }
-
-  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl> (CDecl)) {
-    // Also, check for methods declared in protocols inherited by
-    // this protocol.
-    for (auto *PI : PD->protocols())
-      MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
-                                 IMPDecl, PI, IncompleteImpl, false,
-                                 WarnCategoryMethodImpl);
-  }
-
-  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) {
-    // when checking that methods in implementation match their declaration,
-    // i.e. when WarnCategoryMethodImpl is false, check declarations in class
-    // extension; as well as those in categories.
-    if (!WarnCategoryMethodImpl) {
-      for (auto *Cat : I->visible_categories())
-        MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
-                                   IMPDecl, Cat, IncompleteImpl,
-                                   ImmediateClass && Cat->IsClassExtension(),
-                                   WarnCategoryMethodImpl);
-    } else {
-      // Also methods in class extensions need be looked at next.
-      for (auto *Ext : I->visible_extensions())
-        MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
-                                   IMPDecl, Ext, IncompleteImpl, false,
-                                   WarnCategoryMethodImpl);
-    }
-
-    // Check for any implementation of a methods declared in protocol.
-    for (auto *PI : I->all_referenced_protocols())
-      MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
-                                 IMPDecl, PI, IncompleteImpl, false,
-                                 WarnCategoryMethodImpl);
-
-    // FIXME. For now, we are not checking for exact match of methods
-    // in category implementation and its primary class's super class.
-    if (!WarnCategoryMethodImpl && I->getSuperClass())
-      MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
-                                 IMPDecl,
-                                 I->getSuperClass(), IncompleteImpl, false);
-  }
-}
-
-/// CheckCategoryVsClassMethodMatches - Checks that methods implemented in
-/// category matches with those implemented in its primary class and
-/// warns each time an exact match is found.
-void Sema::CheckCategoryVsClassMethodMatches(
-                                  ObjCCategoryImplDecl *CatIMPDecl) {
-  // Get category's primary class.
-  ObjCCategoryDecl *CatDecl = CatIMPDecl->getCategoryDecl();
-  if (!CatDecl)
-    return;
-  ObjCInterfaceDecl *IDecl = CatDecl->getClassInterface();
-  if (!IDecl)
-    return;
-  ObjCInterfaceDecl *SuperIDecl = IDecl->getSuperClass();
-  SelectorSet InsMap, ClsMap;
-
-  for (const auto *I : CatIMPDecl->instance_methods()) {
-    Selector Sel = I->getSelector();
-    // When checking for methods implemented in the category, skip over
-    // those declared in category class's super class. This is because
-    // the super class must implement the method.
-    if (SuperIDecl && SuperIDecl->lookupMethod(Sel, true))
-      continue;
-    InsMap.insert(Sel);
-  }
-
-  for (const auto *I : CatIMPDecl->class_methods()) {
-    Selector Sel = I->getSelector();
-    if (SuperIDecl && SuperIDecl->lookupMethod(Sel, false))
-      continue;
-    ClsMap.insert(Sel);
-  }
-  if (InsMap.empty() && ClsMap.empty())
-    return;
-
-  SelectorSet InsMapSeen, ClsMapSeen;
-  bool IncompleteImpl = false;
-  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
-                             CatIMPDecl, IDecl,
-                             IncompleteImpl, false,
-                             true /*WarnCategoryMethodImpl*/);
-}
-
-void Sema::ImplMethodsVsClassMethods(Scope *S, ObjCImplDecl* IMPDecl,
-                                     ObjCContainerDecl* CDecl,
-                                     bool IncompleteImpl) {
-  SelectorSet InsMap;
-  // Check and see if instance methods in class interface have been
-  // implemented in the implementation class.
-  for (const auto *I : IMPDecl->instance_methods())
-    InsMap.insert(I->getSelector());
-
-  // Add the selectors for getters/setters of @dynamic properties.
-  for (const auto *PImpl : IMPDecl->property_impls()) {
-    // We only care about @dynamic implementations.
-    if (PImpl->getPropertyImplementation() != ObjCPropertyImplDecl::Dynamic)
-      continue;
-
-    const auto *P = PImpl->getPropertyDecl();
-    if (!P) continue;
-
-    InsMap.insert(P->getGetterName());
-    if (!P->getSetterName().isNull())
-      InsMap.insert(P->getSetterName());
-  }
-
-  // Check and see if properties declared in the interface have either 1)
-  // an implementation or 2) there is a @synthesize/@dynamic implementation
-  // of the property in the @implementation.
-  if (const ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
-    bool SynthesizeProperties = LangOpts.ObjCDefaultSynthProperties &&
-                                LangOpts.ObjCRuntime.isNonFragile() &&
-                                !IDecl->isObjCRequiresPropertyDefs();
-    DiagnoseUnimplementedProperties(S, IMPDecl, CDecl, SynthesizeProperties);
-  }
-
-  // Diagnose null-resettable synthesized setters.
-  diagnoseNullResettableSynthesizedSetters(IMPDecl);
-
-  SelectorSet ClsMap;
-  for (const auto *I : IMPDecl->class_methods())
-    ClsMap.insert(I->getSelector());
-
-  // Check for type conflict of methods declared in a class/protocol and
-  // its implementation; if any.
-  SelectorSet InsMapSeen, ClsMapSeen;
-  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
-                             IMPDecl, CDecl,
-                             IncompleteImpl, true);
-
-  // check all methods implemented in category against those declared
-  // in its primary class.
-  if (ObjCCategoryImplDecl *CatDecl =
-        dyn_cast<ObjCCategoryImplDecl>(IMPDecl))
-    CheckCategoryVsClassMethodMatches(CatDecl);
-
-  // Check the protocol list for unimplemented methods in the @implementation
-  // class.
-  // Check and see if class methods in class interface have been
-  // implemented in the implementation class.
-
-  LazyProtocolNameSet ExplicitImplProtocols;
-
-  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) {
-    for (auto *PI : I->all_referenced_protocols())
-      CheckProtocolMethodDefs(*this, IMPDecl->getLocation(), PI, IncompleteImpl,
-                              InsMap, ClsMap, I, ExplicitImplProtocols);
-  } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
-    // For extended class, unimplemented methods in its protocols will
-    // be reported in the primary class.
-    if (!C->IsClassExtension()) {
-      for (auto *P : C->protocols())
-        CheckProtocolMethodDefs(*this, IMPDecl->getLocation(), P,
-                                IncompleteImpl, InsMap, ClsMap, CDecl,
-                                ExplicitImplProtocols);
-      DiagnoseUnimplementedProperties(S, IMPDecl, CDecl,
-                                      /*SynthesizeProperties=*/false);
-    }
-  } else
-    llvm_unreachable("invalid ObjCContainerDecl type.");
-}
-
-Sema::DeclGroupPtrTy
-Sema::ActOnForwardClassDeclaration(SourceLocation AtClassLoc,
-                                   IdentifierInfo **IdentList,
-                                   SourceLocation *IdentLocs,
-                                   ArrayRef<ObjCTypeParamList *> TypeParamLists,
-                                   unsigned NumElts) {
-  SmallVector<Decl *, 8> DeclsInGroup;
-  for (unsigned i = 0; i != NumElts; ++i) {
-    // Check for another declaration kind with the same name.
-    NamedDecl *PrevDecl
-      = LookupSingleName(TUScope, IdentList[i], IdentLocs[i],
-                         LookupOrdinaryName, forRedeclarationInCurContext());
-    if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
-      // GCC apparently allows the following idiom:
-      //
-      // typedef NSObject < XCElementTogglerP > XCElementToggler;
-      // @class XCElementToggler;
-      //
-      // Here we have chosen to ignore the forward class declaration
-      // with a warning. Since this is the implied behavior.
-      TypedefNameDecl *TDD = dyn_cast<TypedefNameDecl>(PrevDecl);
-      if (!TDD || !TDD->getUnderlyingType()->isObjCObjectType()) {
-        Diag(AtClassLoc, diag::err_redefinition_different_kind) << IdentList[i];
-        Diag(PrevDecl->getLocation(), diag::note_previous_definition);
-      } else {
-        // a forward class declaration matching a typedef name of a class refers
-        // to the underlying class. Just ignore the forward class with a warning
-        // as this will force the intended behavior which is to lookup the
-        // typedef name.
-        if (isa<ObjCObjectType>(TDD->getUnderlyingType())) {
-          Diag(AtClassLoc, diag::warn_forward_class_redefinition)
-              << IdentList[i];
-          Diag(PrevDecl->getLocation(), diag::note_previous_definition);
-          continue;
-        }
-      }
-    }
-
-    // Create a declaration to describe this forward declaration.
-    ObjCInterfaceDecl *PrevIDecl
-      = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
-
-    IdentifierInfo *ClassName = IdentList[i];
-    if (PrevIDecl && PrevIDecl->getIdentifier() != ClassName) {
-      // A previous decl with a different name is because of
-      // @compatibility_alias, for example:
-      // \code
-      //   @class NewImage;
-      //   @compatibility_alias OldImage NewImage;
-      // \endcode
-      // A lookup for 'OldImage' will return the 'NewImage' decl.
-      //
-      // In such a case use the real declaration name, instead of the alias one,
-      // otherwise we will break IdentifierResolver and redecls-chain invariants.
-      // FIXME: If necessary, add a bit to indicate that this ObjCInterfaceDecl
-      // has been aliased.
-      ClassName = PrevIDecl->getIdentifier();
-    }
-
-    // If this forward declaration has type parameters, compare them with the
-    // type parameters of the previous declaration.
-    ObjCTypeParamList *TypeParams = TypeParamLists[i];
-    if (PrevIDecl && TypeParams) {
-      if (ObjCTypeParamList *PrevTypeParams = PrevIDecl->getTypeParamList()) {
-        // Check for consistency with the previous declaration.
-        if (checkTypeParamListConsistency(
-              *this, PrevTypeParams, TypeParams,
-              TypeParamListContext::ForwardDeclaration)) {
-          TypeParams = nullptr;
-        }
-      } else if (ObjCInterfaceDecl *Def = PrevIDecl->getDefinition()) {
-        // The @interface does not have type parameters. Complain.
-        Diag(IdentLocs[i], diag::err_objc_parameterized_forward_class)
-          << ClassName
-          << TypeParams->getSourceRange();
-        Diag(Def->getLocation(), diag::note_defined_here)
-          << ClassName;
-
-        TypeParams = nullptr;
-      }
-    }
-
-    ObjCInterfaceDecl *IDecl
-      = ObjCInterfaceDecl::Create(Context, CurContext, AtClassLoc,
-                                  ClassName, TypeParams, PrevIDecl,
-                                  IdentLocs[i]);
-    IDecl->setAtEndRange(IdentLocs[i]);
-
-    PushOnScopeChains(IDecl, TUScope);
-    CheckObjCDeclScope(IDecl);
-    DeclsInGroup.push_back(IDecl);
-  }
-
-  return BuildDeclaratorGroup(DeclsInGroup);
-}
-
-static bool tryMatchRecordTypes(ASTContext &Context,
-                                Sema::MethodMatchStrategy strategy,
-                                const Type *left, const Type *right);
-
-static bool matchTypes(ASTContext &Context, Sema::MethodMatchStrategy strategy,
-                       QualType leftQT, QualType rightQT) {
-  const Type *left =
-    Context.getCanonicalType(leftQT).getUnqualifiedType().getTypePtr();
-  const Type *right =
-    Context.getCanonicalType(rightQT).getUnqualifiedType().getTypePtr();
-
-  if (left == right) return true;
-
-  // If we're doing a strict match, the types have to match exactly.
-  if (strategy == Sema::MMS_strict) return false;
-
-  if (left->isIncompleteType() || right->isIncompleteType()) return false;
-
-  // Otherwise, use this absurdly complicated algorithm to try to
-  // validate the basic, low-level compatibility of the two types.
-
-  // As a minimum, require the sizes and alignments to match.
-  TypeInfo LeftTI = Context.getTypeInfo(left);
-  TypeInfo RightTI = Context.getTypeInfo(right);
-  if (LeftTI.Width != RightTI.Width)
-    return false;
-
-  if (LeftTI.Align != RightTI.Align)
-    return false;
-
-  // Consider all the kinds of non-dependent canonical types:
-  // - functions and arrays aren't possible as return and parameter types
-
-  // - vector types of equal size can be arbitrarily mixed
-  if (isa<VectorType>(left)) return isa<VectorType>(right);
-  if (isa<VectorType>(right)) return false;
-
-  // - references should only match references of identical type
-  // - structs, unions, and Objective-C objects must match more-or-less
-  //   exactly
-  // - everything else should be a scalar
-  if (!left->isScalarType() || !right->isScalarType())
-    return tryMatchRecordTypes(Context, strategy, left, right);
-
-  // Make scalars agree in kind, except count bools as chars, and group
-  // all non-member pointers together.
-  Type::ScalarTypeKind leftSK = left->getScalarTypeKind();
-  Type::ScalarTypeKind rightSK = right->getScalarTypeKind();
-  if (leftSK == Type::STK_Bool) leftSK = Type::STK_Integral;
-  if (rightSK == Type::STK_Bool) rightSK = Type::STK_Integral;
-  if (leftSK == Type::STK_CPointer || leftSK == Type::STK_BlockPointer)
-    leftSK = Type::STK_ObjCObjectPointer;
-  if (rightSK == Type::STK_CPointer || rightSK == Type::STK_BlockPointer)
-    rightSK = Type::STK_ObjCObjectPointer;
-
-  // Note that data member pointers and function member pointers don't
-  // intermix because of the size differences.
-
-  return (leftSK == rightSK);
-}
-
-static bool tryMatchRecordTypes(ASTContext &Context,
-                                Sema::MethodMatchStrategy strategy,
-                                const Type *lt, const Type *rt) {
-  assert(lt && rt && lt != rt);
-
-  if (!isa<RecordType>(lt) || !isa<RecordType>(rt)) return false;
-  RecordDecl *left = cast<RecordType>(lt)->getDecl();
-  RecordDecl *right = cast<RecordType>(rt)->getDecl();
-
-  // Require union-hood to match.
-  if (left->isUnion() != right->isUnion()) return false;
-
-  // Require an exact match if either is non-POD.
-  if ((isa<CXXRecordDecl>(left) && !cast<CXXRecordDecl>(left)->isPOD()) ||
-      (isa<CXXRecordDecl>(right) && !cast<CXXRecordDecl>(right)->isPOD()))
-    return false;
-
-  // Require size and alignment to match.
-  TypeInfo LeftTI = Context.getTypeInfo(lt);
-  TypeInfo RightTI = Context.getTypeInfo(rt);
-  if (LeftTI.Width != RightTI.Width)
-    return false;
-
-  if (LeftTI.Align != RightTI.Align)
-    return false;
-
-  // Require fields to match.
-  RecordDecl::field_iterator li = left->field_begin(), le = left->field_end();
-  RecordDecl::field_iterator ri = right->field_begin(), re = right->field_end();
-  for (; li != le && ri != re; ++li, ++ri) {
-    if (!matchTypes(Context, strategy, li->getType(), ri->getType()))
-      return false;
-  }
-  return (li == le && ri == re);
-}
-
-/// MatchTwoMethodDeclarations - Checks that two methods have matching type and
-/// returns true, or false, accordingly.
-/// TODO: Handle protocol list; such as id<p1,p2> in type comparisons
-bool Sema::MatchTwoMethodDeclarations(const ObjCMethodDecl *left,
-                                      const ObjCMethodDecl *right,
-                                      MethodMatchStrategy strategy) {
-  if (!matchTypes(Context, strategy, left->getReturnType(),
-                  right->getReturnType()))
-    return false;
-
-  // If either is hidden, it is not considered to match.
-  if (left->isHidden() || right->isHidden())
-    return false;
-
-  if (getLangOpts().ObjCAutoRefCount &&
-      (left->hasAttr<NSReturnsRetainedAttr>()
-         != right->hasAttr<NSReturnsRetainedAttr>() ||
-       left->hasAttr<NSConsumesSelfAttr>()
-         != right->hasAttr<NSConsumesSelfAttr>()))
-    return false;
-
-  ObjCMethodDecl::param_const_iterator
-    li = left->param_begin(), le = left->param_end(), ri = right->param_begin(),
-    re = right->param_end();
-
-  for (; li != le && ri != re; ++li, ++ri) {
-    assert(ri != right->param_end() && "Param mismatch");
-    const ParmVarDecl *lparm = *li, *rparm = *ri;
-
-    if (!matchTypes(Context, strategy, lparm->getType(), rparm->getType()))
-      return false;
-
-    if (getLangOpts().ObjCAutoRefCount &&
-        lparm->hasAttr<NSConsumedAttr>() != rparm->hasAttr<NSConsumedAttr>())
-      return false;
-  }
-  return true;
-}
-
-static bool isMethodContextSameForKindofLookup(ObjCMethodDecl *Method,
-                                               ObjCMethodDecl *MethodInList) {
-  auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext());
-  auto *MethodInListProtocol =
-      dyn_cast<ObjCProtocolDecl>(MethodInList->getDeclContext());
-  // If this method belongs to a protocol but the method in list does not, or
-  // vice versa, we say the context is not the same.
-  if ((MethodProtocol && !MethodInListProtocol) ||
-      (!MethodProtocol && MethodInListProtocol))
-    return false;
-
-  if (MethodProtocol && MethodInListProtocol)
-    return true;
-
-  ObjCInterfaceDecl *MethodInterface = Method->getClassInterface();
-  ObjCInterfaceDecl *MethodInListInterface =
-      MethodInList->getClassInterface();
-  return MethodInterface == MethodInListInterface;
-}
-
-void Sema::addMethodToGlobalList(ObjCMethodList *List,
-                                 ObjCMethodDecl *Method) {
-  // Record at the head of the list whether there were 0, 1, or >= 2 methods
-  // inside categories.
-  if (ObjCCategoryDecl *CD =
-          dyn_cast<ObjCCategoryDecl>(Method->getDeclContext()))
-    if (!CD->IsClassExtension() && List->getBits() < 2)
-      List->setBits(List->getBits() + 1);
-
-  // If the list is empty, make it a singleton list.
-  if (List->getMethod() == nullptr) {
-    List->setMethod(Method);
-    List->setNext(nullptr);
-    return;
-  }
-
-  // We've seen a method with this name, see if we have already seen this type
-  // signature.
-  ObjCMethodList *Previous = List;
-  ObjCMethodList *ListWithSameDeclaration = nullptr;
-  for (; List; Previous = List, List = List->getNext()) {
-    // If we are building a module, keep all of the methods.
-    if (getLangOpts().isCompilingModule())
-      continue;
-
-    bool SameDeclaration = MatchTwoMethodDeclarations(Method,
-                                                      List->getMethod());
-    // Looking for method with a type bound requires the correct context exists.
-    // We need to insert a method into the list if the context is different.
-    // If the method's declaration matches the list
-    // a> the method belongs to a different context: we need to insert it, in
-    //    order to emit the availability message, we need to prioritize over
-    //    availability among the methods with the same declaration.
-    // b> the method belongs to the same context: there is no need to insert a
-    //    new entry.
-    // If the method's declaration does not match the list, we insert it to the
-    // end.
-    if (!SameDeclaration ||
-        !isMethodContextSameForKindofLookup(Method, List->getMethod())) {
-      // Even if two method types do not match, we would like to say
-      // there is more than one declaration so unavailability/deprecated
-      // warning is not too noisy.
-      if (!Method->isDefined())
-        List->setHasMoreThanOneDecl(true);
-
-      // For methods with the same declaration, the one that is deprecated
-      // should be put in the front for better diagnostics.
-      if (Method->isDeprecated() && SameDeclaration &&
-          !ListWithSameDeclaration && !List->getMethod()->isDeprecated())
-        ListWithSameDeclaration = List;
-
-      if (Method->isUnavailable() && SameDeclaration &&
-          !ListWithSameDeclaration &&
-          List->getMethod()->getAvailability() < AR_Deprecated)
-        ListWithSameDeclaration = List;
-      continue;
-    }
-
-    ObjCMethodDecl *PrevObjCMethod = List->getMethod();
-
-    // Propagate the 'defined' bit.
-    if (Method->isDefined())
-      PrevObjCMethod->setDefined(true);
-    else {
-      // Objective-C doesn't allow an @interface for a class after its
-      // @implementation. So if Method is not defined and there already is
-      // an entry for this type signature, Method has to be for a different
-      // class than PrevObjCMethod.
-      List->setHasMoreThanOneDecl(true);
-    }
-
-    // If a method is deprecated, push it in the global pool.
-    // This is used for better diagnostics.
-    if (Method->isDeprecated()) {
-      if (!PrevObjCMethod->isDeprecated())
-        List->setMethod(Method);
-    }
-    // If the new method is unavailable, push it into global pool
-    // unless previous one is deprecated.
-    if (Method->isUnavailable()) {
-      if (PrevObjCMethod->getAvailability() < AR_Deprecated)
-        List->setMethod(Method);
-    }
-
-    return;
-  }
-
-  // We have a new signature for an existing method - add it.
-  // This is extremely rare. Only 1% of Cocoa selectors are "overloaded".
-  ObjCMethodList *Mem = BumpAlloc.Allocate<ObjCMethodList>();
-
-  // We insert it right before ListWithSameDeclaration.
-  if (ListWithSameDeclaration) {
-    auto *List = new (Mem) ObjCMethodList(*ListWithSameDeclaration);
-    // FIXME: should we clear the other bits in ListWithSameDeclaration?
-    ListWithSameDeclaration->setMethod(Method);
-    ListWithSameDeclaration->setNext(List);
-    return;
-  }
-
-  Previous->setNext(new (Mem) ObjCMethodList(Method));
-}
-
-/// Read the contents of the method pool for a given selector from
-/// external storage.
-void Sema::ReadMethodPool(Selector Sel) {
-  assert(ExternalSource && "We need an external AST source");
-  ExternalSource->ReadMethodPool(Sel);
-}
-
-void Sema::updateOutOfDateSelector(Selector Sel) {
-  if (!ExternalSource)
-    return;
-  ExternalSource->updateOutOfDateSelector(Sel);
-}
-
-void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl,
-                                 bool instance) {
-  // Ignore methods of invalid containers.
-  if (cast<Decl>(Method->getDeclContext())->isInvalidDecl())
-    return;
-
-  if (ExternalSource)
-    ReadMethodPool(Method->getSelector());
-
-  GlobalMethodPool::iterator Pos = MethodPool.find(Method->getSelector());
-  if (Pos == MethodPool.end())
-    Pos = MethodPool.insert(std::make_pair(Method->getSelector(),
-                                           GlobalMethods())).first;
-
-  Method->setDefined(impl);
-
-  ObjCMethodList &Entry = instance ? Pos->second.first : Pos->second.second;
-  addMethodToGlobalList(&Entry, Method);
-}
-
-/// Determines if this is an "acceptable" loose mismatch in the global
-/// method pool.  This exists mostly as a hack to get around certain
-/// global mismatches which we can't afford to make warnings / errors.
-/// Really, what we want is a way to take a method out of the global
-/// method pool.
-static bool isAcceptableMethodMismatch(ObjCMethodDecl *chosen,
-                                       ObjCMethodDecl *other) {
-  if (!chosen->isInstanceMethod())
-    return false;
-
-  Selector sel = chosen->getSelector();
-  if (!sel.isUnarySelector() || sel.getNameForSlot(0) != "length")
-    return false;
-
-  // Don't complain about mismatches for -length if the method we
-  // chose has an integral result type.
-  return (chosen->getReturnType()->isIntegerType());
-}
-
-/// Return true if the given method is wthin the type bound.
-static bool FilterMethodsByTypeBound(ObjCMethodDecl *Method,
-                                     const ObjCObjectType *TypeBound) {
-  if (!TypeBound)
-    return true;
-
-  if (TypeBound->isObjCId())
-    // FIXME: should we handle the case of bounding to id<A, B> differently?
-    return true;
-
-  auto *BoundInterface = TypeBound->getInterface();
-  assert(BoundInterface && "unexpected object type!");
-
-  // Check if the Method belongs to a protocol. We should allow any method
-  // defined in any protocol, because any subclass could adopt the protocol.
-  auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext());
-  if (MethodProtocol) {
-    return true;
-  }
-
-  // If the Method belongs to a class, check if it belongs to the class
-  // hierarchy of the class bound.
-  if (ObjCInterfaceDecl *MethodInterface = Method->getClassInterface()) {
-    // We allow methods declared within classes that are part of the hierarchy
-    // of the class bound (superclass of, subclass of, or the same as the class
-    // bound).
-    return MethodInterface == BoundInterface ||
-           MethodInterface->isSuperClassOf(BoundInterface) ||
-           BoundInterface->isSuperClassOf(MethodInterface);
-  }
-  llvm_unreachable("unknown method context");
-}
-
-/// We first select the type of the method: Instance or Factory, then collect
-/// all methods with that type.
-bool Sema::CollectMultipleMethodsInGlobalPool(
-    Selector Sel, SmallVectorImpl<ObjCMethodDecl *> &Methods,
-    bool InstanceFirst, bool CheckTheOther,
-    const ObjCObjectType *TypeBound) {
-  if (ExternalSource)
-    ReadMethodPool(Sel);
-
-  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
-  if (Pos == MethodPool.end())
-    return false;
-
-  // Gather the non-hidden methods.
-  ObjCMethodList &MethList = InstanceFirst ? Pos->second.first :
-                             Pos->second.second;
-  for (ObjCMethodList *M = &MethList; M; M = M->getNext())
-    if (M->getMethod() && !M->getMethod()->isHidden()) {
-      if (FilterMethodsByTypeBound(M->getMethod(), TypeBound))
-        Methods.push_back(M->getMethod());
-    }
-
-  // Return if we find any method with the desired kind.
-  if (!Methods.empty())
-    return Methods.size() > 1;
-
-  if (!CheckTheOther)
-    return false;
-
-  // Gather the other kind.
-  ObjCMethodList &MethList2 = InstanceFirst ? Pos->second.second :
-                              Pos->second.first;
-  for (ObjCMethodList *M = &MethList2; M; M = M->getNext())
-    if (M->getMethod() && !M->getMethod()->isHidden()) {
-      if (FilterMethodsByTypeBound(M->getMethod(), TypeBound))
-        Methods.push_back(M->getMethod());
-    }
-
-  return Methods.size() > 1;
-}
-
-bool Sema::AreMultipleMethodsInGlobalPool(
-    Selector Sel, ObjCMethodDecl *BestMethod, SourceRange R,
-    bool receiverIdOrClass, SmallVectorImpl<ObjCMethodDecl *> &Methods) {
-  // Diagnose finding more than one method in global pool.
-  SmallVector<ObjCMethodDecl *, 4> FilteredMethods;
-  FilteredMethods.push_back(BestMethod);
-
-  for (auto *M : Methods)
-    if (M != BestMethod && !M->hasAttr<UnavailableAttr>())
-      FilteredMethods.push_back(M);
-
-  if (FilteredMethods.size() > 1)
-    DiagnoseMultipleMethodInGlobalPool(FilteredMethods, Sel, R,
-                                       receiverIdOrClass);
-
-  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
-  // Test for no method in the pool which should not trigger any warning by
-  // caller.
-  if (Pos == MethodPool.end())
-    return true;
-  ObjCMethodList &MethList =
-    BestMethod->isInstanceMethod() ? Pos->second.first : Pos->second.second;
-  return MethList.hasMoreThanOneDecl();
-}
-
-ObjCMethodDecl *Sema::LookupMethodInGlobalPool(Selector Sel, SourceRange R,
-                                               bool receiverIdOrClass,
-                                               bool instance) {
-  if (ExternalSource)
-    ReadMethodPool(Sel);
-
-  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
-  if (Pos == MethodPool.end())
-    return nullptr;
-
-  // Gather the non-hidden methods.
-  ObjCMethodList &MethList = instance ? Pos->second.first : Pos->second.second;
-  SmallVector<ObjCMethodDecl *, 4> Methods;
-  for (ObjCMethodList *M = &MethList; M; M = M->getNext()) {
-    if (M->getMethod() && !M->getMethod()->isHidden())
-      return M->getMethod();
-  }
-  return nullptr;
-}
-
-void Sema::DiagnoseMultipleMethodInGlobalPool(SmallVectorImpl<ObjCMethodDecl*> &Methods,
-                                              Selector Sel, SourceRange R,
-                                              bool receiverIdOrClass) {
-  // We found multiple methods, so we may have to complain.
-  bool issueDiagnostic = false, issueError = false;
-
-  // We support a warning which complains about *any* difference in
-  // method signature.
-  bool strictSelectorMatch =
-  receiverIdOrClass &&
-  !Diags.isIgnored(diag::warn_strict_multiple_method_decl, R.getBegin());
-  if (strictSelectorMatch) {
-    for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
-      if (!MatchTwoMethodDeclarations(Methods[0], Methods[I], MMS_strict)) {
-        issueDiagnostic = true;
-        break;
-      }
-    }
-  }
-
-  // If we didn't see any strict differences, we won't see any loose
-  // differences.  In ARC, however, we also need to check for loose
-  // mismatches, because most of them are errors.
-  if (!strictSelectorMatch ||
-      (issueDiagnostic && getLangOpts().ObjCAutoRefCount))
-    for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
-      // This checks if the methods differ in type mismatch.
-      if (!MatchTwoMethodDeclarations(Methods[0], Methods[I], MMS_loose) &&
-          !isAcceptableMethodMismatch(Methods[0], Methods[I])) {
-        issueDiagnostic = true;
-        if (getLangOpts().ObjCAutoRefCount)
-          issueError = true;
-        break;
-      }
-    }
-
-  if (issueDiagnostic) {
-    if (issueError)
-      Diag(R.getBegin(), diag::err_arc_multiple_method_decl) << Sel << R;
-    else if (strictSelectorMatch)
-      Diag(R.getBegin(), diag::warn_strict_multiple_method_decl) << Sel << R;
-    else
-      Diag(R.getBegin(), diag::warn_multiple_method_decl) << Sel << R;
-
-    Diag(Methods[0]->getBeginLoc(),
-         issueError ? diag::note_possibility : diag::note_using)
-        << Methods[0]->getSourceRange();
-    for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
-      Diag(Methods[I]->getBeginLoc(), diag::note_also_found)
-          << Methods[I]->getSourceRange();
-    }
-  }
-}
-
-ObjCMethodDecl *Sema::LookupImplementedMethodInGlobalPool(Selector Sel) {
-  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
-  if (Pos == MethodPool.end())
-    return nullptr;
-
-  GlobalMethods &Methods = Pos->second;
-  for (const ObjCMethodList *Method = &Methods.first; Method;
-       Method = Method->getNext())
-    if (Method->getMethod() &&
-        (Method->getMethod()->isDefined() ||
-         Method->getMethod()->isPropertyAccessor()))
-      return Method->getMethod();
-
-  for (const ObjCMethodList *Method = &Methods.second; Method;
-       Method = Method->getNext())
-    if (Method->getMethod() &&
-        (Method->getMethod()->isDefined() ||
-         Method->getMethod()->isPropertyAccessor()))
-      return Method->getMethod();
-  return nullptr;
-}
-
-static void
-HelperSelectorsForTypoCorrection(
-                      SmallVectorImpl<const ObjCMethodDecl *> &BestMethod,
-                      StringRef Typo, const ObjCMethodDecl * Method) {
-  const unsigned MaxEditDistance = 1;
-  unsigned BestEditDistance = MaxEditDistance + 1;
-  std::string MethodName = Method->getSelector().getAsString();
-
-  unsigned MinPossibleEditDistance = abs((int)MethodName.size() - (int)Typo.size());
-  if (MinPossibleEditDistance > 0 &&
-      Typo.size() / MinPossibleEditDistance < 1)
-    return;
-  unsigned EditDistance = Typo.edit_distance(MethodName, true, MaxEditDistance);
-  if (EditDistance > MaxEditDistance)
-    return;
-  if (EditDistance == BestEditDistance)
-    BestMethod.push_back(Method);
-  else if (EditDistance < BestEditDistance) {
-    BestMethod.clear();
-    BestMethod.push_back(Method);
-  }
-}
-
-static bool HelperIsMethodInObjCType(Sema &S, Selector Sel,
-                                     QualType ObjectType) {
-  if (ObjectType.isNull())
-    return true;
-  if (S.LookupMethodInObjectType(Sel, ObjectType, true/*Instance method*/))
-    return true;
-  return S.LookupMethodInObjectType(Sel, ObjectType, false/*Class method*/) !=
-         nullptr;
-}
-
-const ObjCMethodDecl *
-Sema::SelectorsForTypoCorrection(Selector Sel,
-                                 QualType ObjectType) {
-  unsigned NumArgs = Sel.getNumArgs();
-  SmallVector<const ObjCMethodDecl *, 8> Methods;
-  bool ObjectIsId = true, ObjectIsClass = true;
-  if (ObjectType.isNull())
-    ObjectIsId = ObjectIsClass = false;
-  else if (!ObjectType->isObjCObjectPointerType())
-    return nullptr;
-  else if (const ObjCObjectPointerType *ObjCPtr =
-           ObjectType->getAsObjCInterfacePointerType()) {
-    ObjectType = QualType(ObjCPtr->getInterfaceType(), 0);
-    ObjectIsId = ObjectIsClass = false;
-  }
-  else if (ObjectType->isObjCIdType() || ObjectType->isObjCQualifiedIdType())
-    ObjectIsClass = false;
-  else if (ObjectType->isObjCClassType() || ObjectType->isObjCQualifiedClassType())
-    ObjectIsId = false;
-  else
-    return nullptr;
-
-  for (GlobalMethodPool::iterator b = MethodPool.begin(),
-       e = MethodPool.end(); b != e; b++) {
-    // instance methods
-    for (ObjCMethodList *M = &b->second.first; M; M=M->getNext())
-      if (M->getMethod() &&
-          (M->getMethod()->getSelector().getNumArgs() == NumArgs) &&
-          (M->getMethod()->getSelector() != Sel)) {
-        if (ObjectIsId)
-          Methods.push_back(M->getMethod());
-        else if (!ObjectIsClass &&
-                 HelperIsMethodInObjCType(*this, M->getMethod()->getSelector(),
-                                          ObjectType))
-          Methods.push_back(M->getMethod());
-      }
-    // class methods
-    for (ObjCMethodList *M = &b->second.second; M; M=M->getNext())
-      if (M->getMethod() &&
-          (M->getMethod()->getSelector().getNumArgs() == NumArgs) &&
-          (M->getMethod()->getSelector() != Sel)) {
-        if (ObjectIsClass)
-          Methods.push_back(M->getMethod());
-        else if (!ObjectIsId &&
-                 HelperIsMethodInObjCType(*this, M->getMethod()->getSelector(),
-                                          ObjectType))
-          Methods.push_back(M->getMethod());
-      }
-  }
-
-  SmallVector<const ObjCMethodDecl *, 8> SelectedMethods;
-  for (unsigned i = 0, e = Methods.size(); i < e; i++) {
-    HelperSelectorsForTypoCorrection(SelectedMethods,
-                                     Sel.getAsString(), Methods[i]);
-  }
-  return (SelectedMethods.size() == 1) ? SelectedMethods[0] : nullptr;
-}
-
-/// DiagnoseDuplicateIvars -
-/// Check for duplicate ivars in the entire class at the start of
-/// \@implementation. This becomes necesssary because class extension can
-/// add ivars to a class in random order which will not be known until
-/// class's \@implementation is seen.
-void Sema::DiagnoseDuplicateIvars(ObjCInterfaceDecl *ID,
-                                  ObjCInterfaceDecl *SID) {
-  for (auto *Ivar : ID->ivars()) {
-    if (Ivar->isInvalidDecl())
-      continue;
-    if (IdentifierInfo *II = Ivar->getIdentifier()) {
-      ObjCIvarDecl* prevIvar = SID->lookupInstanceVariable(II);
-      if (prevIvar) {
-        Diag(Ivar->getLocation(), diag::err_duplicate_member) << II;
-        Diag(prevIvar->getLocation(), diag::note_previous_declaration);
-        Ivar->setInvalidDecl();
-      }
-    }
-  }
-}
-
-/// Diagnose attempts to define ARC-__weak ivars when __weak is disabled.
-static void DiagnoseWeakIvars(Sema &S, ObjCImplementationDecl *ID) {
-  if (S.getLangOpts().ObjCWeak) return;
-
-  for (auto ivar = ID->getClassInterface()->all_declared_ivar_begin();
-         ivar; ivar = ivar->getNextIvar()) {
-    if (ivar->isInvalidDecl()) continue;
-    if (ivar->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
-      if (S.getLangOpts().ObjCWeakRuntime) {
-        S.Diag(ivar->getLocation(), diag::err_arc_weak_disabled);
-      } else {
-        S.Diag(ivar->getLocation(), diag::err_arc_weak_no_runtime);
-      }
-    }
-  }
-}
-
-/// Diagnose attempts to use flexible array member with retainable object type.
-static void DiagnoseRetainableFlexibleArrayMember(Sema &S,
-                                                  ObjCInterfaceDecl *ID) {
-  if (!S.getLangOpts().ObjCAutoRefCount)
-    return;
-
-  for (auto ivar = ID->all_declared_ivar_begin(); ivar;
-       ivar = ivar->getNextIvar()) {
-    if (ivar->isInvalidDecl())
-      continue;
-    QualType IvarTy = ivar->getType();
-    if (IvarTy->isIncompleteArrayType() &&
-        (IvarTy.getObjCLifetime() != Qualifiers::OCL_ExplicitNone) &&
-        IvarTy->isObjCLifetimeType()) {
-      S.Diag(ivar->getLocation(), diag::err_flexible_array_arc_retainable);
-      ivar->setInvalidDecl();
-    }
-  }
-}
-
-Sema::ObjCContainerKind Sema::getObjCContainerKind() const {
-  switch (CurContext->getDeclKind()) {
-    case Decl::ObjCInterface:
-      return Sema::OCK_Interface;
-    case Decl::ObjCProtocol:
-      return Sema::OCK_Protocol;
-    case Decl::ObjCCategory:
-      if (cast<ObjCCategoryDecl>(CurContext)->IsClassExtension())
-        return Sema::OCK_ClassExtension;
-      return Sema::OCK_Category;
-    case Decl::ObjCImplementation:
-      return Sema::OCK_Implementation;
-    case Decl::ObjCCategoryImpl:
-      return Sema::OCK_CategoryImplementation;
-
-    default:
-      return Sema::OCK_None;
-  }
-}
-
-static bool IsVariableSizedType(QualType T) {
-  if (T->isIncompleteArrayType())
-    return true;
-  const auto *RecordTy = T->getAs<RecordType>();
-  return (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember());
-}
-
-static void DiagnoseVariableSizedIvars(Sema &S, ObjCContainerDecl *OCD) {
-  ObjCInterfaceDecl *IntfDecl = nullptr;
-  ObjCInterfaceDecl::ivar_range Ivars = llvm::make_range(
-      ObjCInterfaceDecl::ivar_iterator(), ObjCInterfaceDecl::ivar_iterator());
-  if ((IntfDecl = dyn_cast<ObjCInterfaceDecl>(OCD))) {
-    Ivars = IntfDecl->ivars();
-  } else if (auto *ImplDecl = dyn_cast<ObjCImplementationDecl>(OCD)) {
-    IntfDecl = ImplDecl->getClassInterface();
-    Ivars = ImplDecl->ivars();
-  } else if (auto *CategoryDecl = dyn_cast<ObjCCategoryDecl>(OCD)) {
-    if (CategoryDecl->IsClassExtension()) {
-      IntfDecl = CategoryDecl->getClassInterface();
-      Ivars = CategoryDecl->ivars();
-    }
-  }
-
-  // Check if variable sized ivar is in interface and visible to subclasses.
-  if (!isa<ObjCInterfaceDecl>(OCD)) {
-    for (auto ivar : Ivars) {
-      if (!ivar->isInvalidDecl() && IsVariableSizedType(ivar->getType())) {
-        S.Diag(ivar->getLocation(), diag::warn_variable_sized_ivar_visibility)
-            << ivar->getDeclName() << ivar->getType();
-      }
-    }
-  }
-
-  // Subsequent checks require interface decl.
-  if (!IntfDecl)
-    return;
-
-  // Check if variable sized ivar is followed by another ivar.
-  for (ObjCIvarDecl *ivar = IntfDecl->all_declared_ivar_begin(); ivar;
-       ivar = ivar->getNextIvar()) {
-    if (ivar->isInvalidDecl() || !ivar->getNextIvar())
-      continue;
-    QualType IvarTy = ivar->getType();
-    bool IsInvalidIvar = false;
-    if (IvarTy->isIncompleteArrayType()) {
-      S.Diag(ivar->getLocation(), diag::err_flexible_array_not_at_end)
-          << ivar->getDeclName() << IvarTy
-          << TTK_Class; // Use "class" for Obj-C.
-      IsInvalidIvar = true;
-    } else if (const RecordType *RecordTy = IvarTy->getAs<RecordType>()) {
-      if (RecordTy->getDecl()->hasFlexibleArrayMember()) {
-        S.Diag(ivar->getLocation(),
-               diag::err_objc_variable_sized_type_not_at_end)
-            << ivar->getDeclName() << IvarTy;
-        IsInvalidIvar = true;
-      }
-    }
-    if (IsInvalidIvar) {
-      S.Diag(ivar->getNextIvar()->getLocation(),
-             diag::note_next_ivar_declaration)
-          << ivar->getNextIvar()->getSynthesize();
-      ivar->setInvalidDecl();
-    }
-  }
-
-  // Check if ObjC container adds ivars after variable sized ivar in superclass.
-  // Perform the check only if OCD is the first container to declare ivars to
-  // avoid multiple warnings for the same ivar.
-  ObjCIvarDecl *FirstIvar =
-      (Ivars.begin() == Ivars.end()) ? nullptr : *Ivars.begin();
-  if (FirstIvar && (FirstIvar == IntfDecl->all_declared_ivar_begin())) {
-    const ObjCInterfaceDecl *SuperClass = IntfDecl->getSuperClass();
-    while (SuperClass && SuperClass->ivar_empty())
-      SuperClass = SuperClass->getSuperClass();
-    if (SuperClass) {
-      auto IvarIter = SuperClass->ivar_begin();
-      std::advance(IvarIter, SuperClass->ivar_size() - 1);
-      const ObjCIvarDecl *LastIvar = *IvarIter;
-      if (IsVariableSizedType(LastIvar->getType())) {
-        S.Diag(FirstIvar->getLocation(),
-               diag::warn_superclass_variable_sized_type_not_at_end)
-            << FirstIvar->getDeclName() << LastIvar->getDeclName()
-            << LastIvar->getType() << SuperClass->getDeclName();
-        S.Diag(LastIvar->getLocation(), diag::note_entity_declared_at)
-            << LastIvar->getDeclName();
-      }
-    }
-  }
-}
-
-// Note: For class/category implementations, allMethods is always null.
-Decl *Sema::ActOnAtEnd(Scope *S, SourceRange AtEnd, ArrayRef<Decl *> allMethods,
-                       ArrayRef<DeclGroupPtrTy> allTUVars) {
-  if (getObjCContainerKind() == Sema::OCK_None)
-    return nullptr;
-
-  assert(AtEnd.isValid() && "Invalid location for '@end'");
-
-  auto *OCD = cast<ObjCContainerDecl>(CurContext);
-  Decl *ClassDecl = OCD;
-
-  bool isInterfaceDeclKind =
-        isa<ObjCInterfaceDecl>(ClassDecl) || isa<ObjCCategoryDecl>(ClassDecl)
-         || isa<ObjCProtocolDecl>(ClassDecl);
-  bool checkIdenticalMethods = isa<ObjCImplementationDecl>(ClassDecl);
-
-  // FIXME: Remove these and use the ObjCContainerDecl/DeclContext.
-  llvm::DenseMap<Selector, const ObjCMethodDecl*> InsMap;
-  llvm::DenseMap<Selector, const ObjCMethodDecl*> ClsMap;
-
-  for (unsigned i = 0, e = allMethods.size(); i != e; i++ ) {
-    ObjCMethodDecl *Method =
-      cast_or_null<ObjCMethodDecl>(allMethods[i]);
-
-    if (!Method) continue;  // Already issued a diagnostic.
-    if (Method->isInstanceMethod()) {
-      /// Check for instance method of the same name with incompatible types
-      const ObjCMethodDecl *&PrevMethod = InsMap[Method->getSelector()];
-      bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod)
-                              : false;
-      if ((isInterfaceDeclKind && PrevMethod && !match)
-          || (checkIdenticalMethods && match)) {
-          Diag(Method->getLocation(), diag::err_duplicate_method_decl)
-            << Method->getDeclName();
-          Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
-        Method->setInvalidDecl();
-      } else {
-        if (PrevMethod) {
-          Method->setAsRedeclaration(PrevMethod);
-          if (!Context.getSourceManager().isInSystemHeader(
-                 Method->getLocation()))
-            Diag(Method->getLocation(), diag::warn_duplicate_method_decl)
-              << Method->getDeclName();
-          Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
-        }
-        InsMap[Method->getSelector()] = Method;
-        /// The following allows us to typecheck messages to "id".
-        AddInstanceMethodToGlobalPool(Method);
-      }
-    } else {
-      /// Check for class method of the same name with incompatible types
-      const ObjCMethodDecl *&PrevMethod = ClsMap[Method->getSelector()];
-      bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod)
-                              : false;
-      if ((isInterfaceDeclKind && PrevMethod && !match)
-          || (checkIdenticalMethods && match)) {
-        Diag(Method->getLocation(), diag::err_duplicate_method_decl)
-          << Method->getDeclName();
-        Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
-        Method->setInvalidDecl();
-      } else {
-        if (PrevMethod) {
-          Method->setAsRedeclaration(PrevMethod);
-          if (!Context.getSourceManager().isInSystemHeader(
-                 Method->getLocation()))
-            Diag(Method->getLocation(), diag::warn_duplicate_method_decl)
-              << Method->getDeclName();
-          Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
-        }
-        ClsMap[Method->getSelector()] = Method;
-        AddFactoryMethodToGlobalPool(Method);
-      }
-    }
-  }
-  if (isa<ObjCInterfaceDecl>(ClassDecl)) {
-    // Nothing to do here.
-  } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
-    // Categories are used to extend the class by declaring new methods.
-    // By the same token, they are also used to add new properties. No
-    // need to compare the added property to those in the class.
-
-    if (C->IsClassExtension()) {
-      ObjCInterfaceDecl *CCPrimary = C->getClassInterface();
-      DiagnoseClassExtensionDupMethods(C, CCPrimary);
-    }
-  }
-  if (ObjCContainerDecl *CDecl = dyn_cast<ObjCContainerDecl>(ClassDecl)) {
-    if (CDecl->getIdentifier())
-      // ProcessPropertyDecl is responsible for diagnosing conflicts with any
-      // user-defined setter/getter. It also synthesizes setter/getter methods
-      // and adds them to the DeclContext and global method pools.
-      for (auto *I : CDecl->properties())
-        ProcessPropertyDecl(I);
-    CDecl->setAtEndRange(AtEnd);
-  }
-  if (ObjCImplementationDecl *IC=dyn_cast<ObjCImplementationDecl>(ClassDecl)) {
-    IC->setAtEndRange(AtEnd);
-    if (ObjCInterfaceDecl* IDecl = IC->getClassInterface()) {
-      // Any property declared in a class extension might have user
-      // declared setter or getter in current class extension or one
-      // of the other class extensions. Mark them as synthesized as
-      // property will be synthesized when property with same name is
-      // seen in the @implementation.
-      for (const auto *Ext : IDecl->visible_extensions()) {
-        for (const auto *Property : Ext->instance_properties()) {
-          // Skip over properties declared @dynamic
-          if (const ObjCPropertyImplDecl *PIDecl
-              = IC->FindPropertyImplDecl(Property->getIdentifier(),
-                                         Property->getQueryKind()))
-            if (PIDecl->getPropertyImplementation()
-                  == ObjCPropertyImplDecl::Dynamic)
-              continue;
-
-          for (const auto *Ext : IDecl->visible_extensions()) {
-            if (ObjCMethodDecl *GetterMethod
-                  = Ext->getInstanceMethod(Property->getGetterName()))
-              GetterMethod->setPropertyAccessor(true);
-            if (!Property->isReadOnly())
-              if (ObjCMethodDecl *SetterMethod
-                    = Ext->getInstanceMethod(Property->getSetterName()))
-                SetterMethod->setPropertyAccessor(true);
-          }
-        }
-      }
-      ImplMethodsVsClassMethods(S, IC, IDecl);
-      AtomicPropertySetterGetterRules(IC, IDecl);
-      DiagnoseOwningPropertyGetterSynthesis(IC);
-      DiagnoseUnusedBackingIvarInAccessor(S, IC);
-      if (IDecl->hasDesignatedInitializers())
-        DiagnoseMissingDesignatedInitOverrides(IC, IDecl);
-      DiagnoseWeakIvars(*this, IC);
-      DiagnoseRetainableFlexibleArrayMember(*this, IDecl);
-
-      bool HasRootClassAttr = IDecl->hasAttr<ObjCRootClassAttr>();
-      if (IDecl->getSuperClass() == nullptr) {
-        // This class has no superclass, so check that it has been marked with
-        // __attribute((objc_root_class)).
-        if (!HasRootClassAttr) {
-          SourceLocation DeclLoc(IDecl->getLocation());
-          SourceLocation SuperClassLoc(getLocForEndOfToken(DeclLoc));
-          Diag(DeclLoc, diag::warn_objc_root_class_missing)
-            << IDecl->getIdentifier();
-          // See if NSObject is in the current scope, and if it is, suggest
-          // adding " : NSObject " to the class declaration.
-          NamedDecl *IF = LookupSingleName(TUScope,
-                                           NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject),
-                                           DeclLoc, LookupOrdinaryName);
-          ObjCInterfaceDecl *NSObjectDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
-          if (NSObjectDecl && NSObjectDecl->getDefinition()) {
-            Diag(SuperClassLoc, diag::note_objc_needs_superclass)
-              << FixItHint::CreateInsertion(SuperClassLoc, " : NSObject ");
-          } else {
-            Diag(SuperClassLoc, diag::note_objc_needs_superclass);
-          }
-        }
-      } else if (HasRootClassAttr) {
-        // Complain that only root classes may have this attribute.
-        Diag(IDecl->getLocation(), diag::err_objc_root_class_subclass);
-      }
-
-      if (const ObjCInterfaceDecl *Super = IDecl->getSuperClass()) {
-        // An interface can subclass another interface with a
-        // objc_subclassing_restricted attribute when it has that attribute as
-        // well (because of interfaces imported from Swift). Therefore we have
-        // to check if we can subclass in the implementation as well.
-        if (IDecl->hasAttr<ObjCSubclassingRestrictedAttr>() &&
-            Super->hasAttr<ObjCSubclassingRestrictedAttr>()) {
-          Diag(IC->getLocation(), diag::err_restricted_superclass_mismatch);
-          Diag(Super->getLocation(), diag::note_class_declared);
-        }
-      }
-
-      if (LangOpts.ObjCRuntime.isNonFragile()) {
-        while (IDecl->getSuperClass()) {
-          DiagnoseDuplicateIvars(IDecl, IDecl->getSuperClass());
-          IDecl = IDecl->getSuperClass();
-        }
-      }
-    }
-    SetIvarInitializers(IC);
-  } else if (ObjCCategoryImplDecl* CatImplClass =
-                                   dyn_cast<ObjCCategoryImplDecl>(ClassDecl)) {
-    CatImplClass->setAtEndRange(AtEnd);
-
-    // Find category interface decl and then check that all methods declared
-    // in this interface are implemented in the category @implementation.
-    if (ObjCInterfaceDecl* IDecl = CatImplClass->getClassInterface()) {
-      if (ObjCCategoryDecl *Cat
-            = IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier())) {
-        ImplMethodsVsClassMethods(S, CatImplClass, Cat);
-      }
-    }
-  } else if (const auto *IntfDecl = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
-    if (const ObjCInterfaceDecl *Super = IntfDecl->getSuperClass()) {
-      if (!IntfDecl->hasAttr<ObjCSubclassingRestrictedAttr>() &&
-          Super->hasAttr<ObjCSubclassingRestrictedAttr>()) {
-        Diag(IntfDecl->getLocation(), diag::err_restricted_superclass_mismatch);
-        Diag(Super->getLocation(), diag::note_class_declared);
-      }
-    }
-  }
-  DiagnoseVariableSizedIvars(*this, OCD);
-  if (isInterfaceDeclKind) {
-    // Reject invalid vardecls.
-    for (unsigned i = 0, e = allTUVars.size(); i != e; i++) {
-      DeclGroupRef DG = allTUVars[i].get();
-      for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
-        if (VarDecl *VDecl = dyn_cast<VarDecl>(*I)) {
-          if (!VDecl->hasExternalStorage())
-            Diag(VDecl->getLocation(), diag::err_objc_var_decl_inclass);
-        }
-    }
-  }
-  ActOnObjCContainerFinishDefinition();
-
-  for (unsigned i = 0, e = allTUVars.size(); i != e; i++) {
-    DeclGroupRef DG = allTUVars[i].get();
-    for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
-      (*I)->setTopLevelDeclInObjCContainer();
-    Consumer.HandleTopLevelDeclInObjCContainer(DG);
-  }
-
-  ActOnDocumentableDecl(ClassDecl);
-  return ClassDecl;
-}
-
-/// CvtQTToAstBitMask - utility routine to produce an AST bitmask for
-/// objective-c's type qualifier from the parser version of the same info.
-static Decl::ObjCDeclQualifier
-CvtQTToAstBitMask(ObjCDeclSpec::ObjCDeclQualifier PQTVal) {
-  return (Decl::ObjCDeclQualifier) (unsigned) PQTVal;
-}
-
-/// Check whether the declared result type of the given Objective-C
-/// method declaration is compatible with the method's class.
-///
-static Sema::ResultTypeCompatibilityKind
-CheckRelatedResultTypeCompatibility(Sema &S, ObjCMethodDecl *Method,
-                                    ObjCInterfaceDecl *CurrentClass) {
-  QualType ResultType = Method->getReturnType();
-
-  // If an Objective-C method inherits its related result type, then its
-  // declared result type must be compatible with its own class type. The
-  // declared result type is compatible if:
-  if (const ObjCObjectPointerType *ResultObjectType
-                                = ResultType->getAs<ObjCObjectPointerType>()) {
-    //   - it is id or qualified id, or
-    if (ResultObjectType->isObjCIdType() ||
-        ResultObjectType->isObjCQualifiedIdType())
-      return Sema::RTC_Compatible;
-
-    if (CurrentClass) {
-      if (ObjCInterfaceDecl *ResultClass
-                                      = ResultObjectType->getInterfaceDecl()) {
-        //   - it is the same as the method's class type, or
-        if (declaresSameEntity(CurrentClass, ResultClass))
-          return Sema::RTC_Compatible;
-
-        //   - it is a superclass of the method's class type
-        if (ResultClass->isSuperClassOf(CurrentClass))
-          return Sema::RTC_Compatible;
-      }
-    } else {
-      // Any Objective-C pointer type might be acceptable for a protocol
-      // method; we just don't know.
-      return Sema::RTC_Unknown;
-    }
-  }
-
-  return Sema::RTC_Incompatible;
-}
-
-namespace {
-/// A helper class for searching for methods which a particular method
-/// overrides.
-class OverrideSearch {
-public:
-  Sema &S;
-  ObjCMethodDecl *Method;
-  llvm::SmallSetVector<ObjCMethodDecl*, 4> Overridden;
-  bool Recursive;
-
-public:
-  OverrideSearch(Sema &S, ObjCMethodDecl *method) : S(S), Method(method) {
-    Selector selector = method->getSelector();
-
-    // Bypass this search if we've never seen an instance/class method
-    // with this selector before.
-    Sema::GlobalMethodPool::iterator it = S.MethodPool.find(selector);
-    if (it == S.MethodPool.end()) {
-      if (!S.getExternalSource()) return;
-      S.ReadMethodPool(selector);
-
-      it = S.MethodPool.find(selector);
-      if (it == S.MethodPool.end())
-        return;
-    }
-    ObjCMethodList &list =
-      method->isInstanceMethod() ? it->second.first : it->second.second;
-    if (!list.getMethod()) return;
-
-    ObjCContainerDecl *container
-      = cast<ObjCContainerDecl>(method->getDeclContext());
-
-    // Prevent the search from reaching this container again.  This is
-    // important with categories, which override methods from the
-    // interface and each other.
-    if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(container)) {
-      searchFromContainer(container);
-      if (ObjCInterfaceDecl *Interface = Category->getClassInterface())
-        searchFromContainer(Interface);
-    } else {
-      searchFromContainer(container);
-    }
-  }
-
-  typedef decltype(Overridden)::iterator iterator;
-  iterator begin() const { return Overridden.begin(); }
-  iterator end() const { return Overridden.end(); }
-
-private:
-  void searchFromContainer(ObjCContainerDecl *container) {
-    if (container->isInvalidDecl()) return;
-
-    switch (container->getDeclKind()) {
-#define OBJCCONTAINER(type, base) \
-    case Decl::type: \
-      searchFrom(cast<type##Decl>(container)); \
-      break;
-#define ABSTRACT_DECL(expansion)
-#define DECL(type, base) \
-    case Decl::type:
-#include "clang/AST/DeclNodes.inc"
-      llvm_unreachable("not an ObjC container!");
-    }
-  }
-
-  void searchFrom(ObjCProtocolDecl *protocol) {
-    if (!protocol->hasDefinition())
-      return;
-
-    // A method in a protocol declaration overrides declarations from
-    // referenced ("parent") protocols.
-    search(protocol->getReferencedProtocols());
-  }
-
-  void searchFrom(ObjCCategoryDecl *category) {
-    // A method in a category declaration overrides declarations from
-    // the main class and from protocols the category references.
-    // The main class is handled in the constructor.
-    search(category->getReferencedProtocols());
-  }
-
-  void searchFrom(ObjCCategoryImplDecl *impl) {
-    // A method in a category definition that has a category
-    // declaration overrides declarations from the category
-    // declaration.
-    if (ObjCCategoryDecl *category = impl->getCategoryDecl()) {
-      search(category);
-      if (ObjCInterfaceDecl *Interface = category->getClassInterface())
-        search(Interface);
-
-    // Otherwise it overrides declarations from the class.
-    } else if (ObjCInterfaceDecl *Interface = impl->getClassInterface()) {
-      search(Interface);
-    }
-  }
-
-  void searchFrom(ObjCInterfaceDecl *iface) {
-    // A method in a class declaration overrides declarations from
-    if (!iface->hasDefinition())
-      return;
-
-    //   - categories,
-    for (auto *Cat : iface->known_categories())
-      search(Cat);
-
-    //   - the super class, and
-    if (ObjCInterfaceDecl *super = iface->getSuperClass())
-      search(super);
-
-    //   - any referenced protocols.
-    search(iface->getReferencedProtocols());
-  }
-
-  void searchFrom(ObjCImplementationDecl *impl) {
-    // A method in a class implementation overrides declarations from
-    // the class interface.
-    if (ObjCInterfaceDecl *Interface = impl->getClassInterface())
-      search(Interface);
-  }
-
-  void search(const ObjCProtocolList &protocols) {
-    for (ObjCProtocolList::iterator i = protocols.begin(), e = protocols.end();
-         i != e; ++i)
-      search(*i);
-  }
-
-  void search(ObjCContainerDecl *container) {
-    // Check for a method in this container which matches this selector.
-    ObjCMethodDecl *meth = container->getMethod(Method->getSelector(),
-                                                Method->isInstanceMethod(),
-                                                /*AllowHidden=*/true);
-
-    // If we find one, record it and bail out.
-    if (meth) {
-      Overridden.insert(meth);
-      return;
-    }
-
-    // Otherwise, search for methods that a hypothetical method here
-    // would have overridden.
-
-    // Note that we're now in a recursive case.
-    Recursive = true;
-
-    searchFromContainer(container);
-  }
-};
-} // end anonymous namespace
-
-void Sema::CheckObjCMethodOverrides(ObjCMethodDecl *ObjCMethod,
-                                    ObjCInterfaceDecl *CurrentClass,
-                                    ResultTypeCompatibilityKind RTC) {
-  // Search for overridden methods and merge information down from them.
-  OverrideSearch overrides(*this, ObjCMethod);
-  // Keep track if the method overrides any method in the class's base classes,
-  // its protocols, or its categories' protocols; we will keep that info
-  // in the ObjCMethodDecl.
-  // For this info, a method in an implementation is not considered as
-  // overriding the same method in the interface or its categories.
-  bool hasOverriddenMethodsInBaseOrProtocol = false;
-  for (OverrideSearch::iterator
-         i = overrides.begin(), e = overrides.end(); i != e; ++i) {
-    ObjCMethodDecl *overridden = *i;
-
-    if (!hasOverriddenMethodsInBaseOrProtocol) {
-      if (isa<ObjCProtocolDecl>(overridden->getDeclContext()) ||
-          CurrentClass != overridden->getClassInterface() ||
-          overridden->isOverriding()) {
-        hasOverriddenMethodsInBaseOrProtocol = true;
-
-      } else if (isa<ObjCImplDecl>(ObjCMethod->getDeclContext())) {
-        // OverrideSearch will return as "overridden" the same method in the
-        // interface. For hasOverriddenMethodsInBaseOrProtocol, we need to
-        // check whether a category of a base class introduced a method with the
-        // same selector, after the interface method declaration.
-        // To avoid unnecessary lookups in the majority of cases, we use the
-        // extra info bits in GlobalMethodPool to check whether there were any
-        // category methods with this selector.
-        GlobalMethodPool::iterator It =
-            MethodPool.find(ObjCMethod->getSelector());
-        if (It != MethodPool.end()) {
-          ObjCMethodList &List =
-            ObjCMethod->isInstanceMethod()? It->second.first: It->second.second;
-          unsigned CategCount = List.getBits();
-          if (CategCount > 0) {
-            // If the method is in a category we'll do lookup if there were at
-            // least 2 category methods recorded, otherwise only one will do.
-            if (CategCount > 1 ||
-                !isa<ObjCCategoryImplDecl>(overridden->getDeclContext())) {
-              OverrideSearch overrides(*this, overridden);
-              for (OverrideSearch::iterator
-                     OI= overrides.begin(), OE= overrides.end(); OI!=OE; ++OI) {
-                ObjCMethodDecl *SuperOverridden = *OI;
-                if (isa<ObjCProtocolDecl>(SuperOverridden->getDeclContext()) ||
-                    CurrentClass != SuperOverridden->getClassInterface()) {
-                  hasOverriddenMethodsInBaseOrProtocol = true;
-                  overridden->setOverriding(true);
-                  break;
-                }
-              }
-            }
-          }
-        }
-      }
-    }
-
-    // Propagate down the 'related result type' bit from overridden methods.
-    if (RTC != Sema::RTC_Incompatible && overridden->hasRelatedResultType())
-      ObjCMethod->setRelatedResultType();
-
-    // Then merge the declarations.
-    mergeObjCMethodDecls(ObjCMethod, overridden);
-
-    if (ObjCMethod->isImplicit() && overridden->isImplicit())
-      continue; // Conflicting properties are detected elsewhere.
-
-    // Check for overriding methods
-    if (isa<ObjCInterfaceDecl>(ObjCMethod->getDeclContext()) ||
-        isa<ObjCImplementationDecl>(ObjCMethod->getDeclContext()))
-      CheckConflictingOverridingMethod(ObjCMethod, overridden,
-              isa<ObjCProtocolDecl>(overridden->getDeclContext()));
-
-    if (CurrentClass && overridden->getDeclContext() != CurrentClass &&
-        isa<ObjCInterfaceDecl>(overridden->getDeclContext()) &&
-        !overridden->isImplicit() /* not meant for properties */) {
-      ObjCMethodDecl::param_iterator ParamI = ObjCMethod->param_begin(),
-                                          E = ObjCMethod->param_end();
-      ObjCMethodDecl::param_iterator PrevI = overridden->param_begin(),
-                                     PrevE = overridden->param_end();
-      for (; ParamI != E && PrevI != PrevE; ++ParamI, ++PrevI) {
-        assert(PrevI != overridden->param_end() && "Param mismatch");
-        QualType T1 = Context.getCanonicalType((*ParamI)->getType());
-        QualType T2 = Context.getCanonicalType((*PrevI)->getType());
-        // If type of argument of method in this class does not match its
-        // respective argument type in the super class method, issue warning;
-        if (!Context.typesAreCompatible(T1, T2)) {
-          Diag((*ParamI)->getLocation(), diag::ext_typecheck_base_super)
-            << T1 << T2;
-          Diag(overridden->getLocation(), diag::note_previous_declaration);
-          break;
-        }
-      }
-    }
-  }
-
-  ObjCMethod->setOverriding(hasOverriddenMethodsInBaseOrProtocol);
-}
-
-/// Merge type nullability from for a redeclaration of the same entity,
-/// producing the updated type of the redeclared entity.
-static QualType mergeTypeNullabilityForRedecl(Sema &S, SourceLocation loc,
-                                              QualType type,
-                                              bool usesCSKeyword,
-                                              SourceLocation prevLoc,
-                                              QualType prevType,
-                                              bool prevUsesCSKeyword) {
-  // Determine the nullability of both types.
-  auto nullability = type->getNullability(S.Context);
-  auto prevNullability = prevType->getNullability(S.Context);
-
-  // Easy case: both have nullability.
-  if (nullability.hasValue() == prevNullability.hasValue()) {
-    // Neither has nullability; continue.
-    if (!nullability)
-      return type;
-
-    // The nullabilities are equivalent; do nothing.
-    if (*nullability == *prevNullability)
-      return type;
-
-    // Complain about mismatched nullability.
-    S.Diag(loc, diag::err_nullability_conflicting)
-      << DiagNullabilityKind(*nullability, usesCSKeyword)
-      << DiagNullabilityKind(*prevNullability, prevUsesCSKeyword);
-    return type;
-  }
-
-  // If it's the redeclaration that has nullability, don't change anything.
-  if (nullability)
-    return type;
-
-  // Otherwise, provide the result with the same nullability.
-  return S.Context.getAttributedType(
-           AttributedType::getNullabilityAttrKind(*prevNullability),
-           type, type);
-}
-
-/// Merge information from the declaration of a method in the \@interface
-/// (or a category/extension) into the corresponding method in the
-/// @implementation (for a class or category).
-static void mergeInterfaceMethodToImpl(Sema &S,
-                                       ObjCMethodDecl *method,
-                                       ObjCMethodDecl *prevMethod) {
-  // Merge the objc_requires_super attribute.
-  if (prevMethod->hasAttr<ObjCRequiresSuperAttr>() &&
-      !method->hasAttr<ObjCRequiresSuperAttr>()) {
-    // merge the attribute into implementation.
-    method->addAttr(
-      ObjCRequiresSuperAttr::CreateImplicit(S.Context,
-                                            method->getLocation()));
-  }
-
-  // Merge nullability of the result type.
-  QualType newReturnType
-    = mergeTypeNullabilityForRedecl(
-        S, method->getReturnTypeSourceRange().getBegin(),
-        method->getReturnType(),
-        method->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability,
-        prevMethod->getReturnTypeSourceRange().getBegin(),
-        prevMethod->getReturnType(),
-        prevMethod->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability);
-  method->setReturnType(newReturnType);
-
-  // Handle each of the parameters.
-  unsigned numParams = method->param_size();
-  unsigned numPrevParams = prevMethod->param_size();
-  for (unsigned i = 0, n = std::min(numParams, numPrevParams); i != n; ++i) {
-    ParmVarDecl *param = method->param_begin()[i];
-    ParmVarDecl *prevParam = prevMethod->param_begin()[i];
-
-    // Merge nullability.
-    QualType newParamType
-      = mergeTypeNullabilityForRedecl(
-          S, param->getLocation(), param->getType(),
-          param->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability,
-          prevParam->getLocation(), prevParam->getType(),
-          prevParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability);
-    param->setType(newParamType);
-  }
-}
-
-/// Verify that the method parameters/return value have types that are supported
-/// by the x86 target.
-static void checkObjCMethodX86VectorTypes(Sema &SemaRef,
-                                          const ObjCMethodDecl *Method) {
-  assert(SemaRef.getASTContext().getTargetInfo().getTriple().getArch() ==
-             llvm::Triple::x86 &&
-         "x86-specific check invoked for a different target");
-  SourceLocation Loc;
-  QualType T;
-  for (const ParmVarDecl *P : Method->parameters()) {
-    if (P->getType()->isVectorType()) {
-      Loc = P->getBeginLoc();
-      T = P->getType();
-      break;
-    }
-  }
-  if (Loc.isInvalid()) {
-    if (Method->getReturnType()->isVectorType()) {
-      Loc = Method->getReturnTypeSourceRange().getBegin();
-      T = Method->getReturnType();
-    } else
-      return;
-  }
-
-  // Vector parameters/return values are not supported by objc_msgSend on x86 in
-  // iOS < 9 and macOS < 10.11.
-  const auto &Triple = SemaRef.getASTContext().getTargetInfo().getTriple();
-  VersionTuple AcceptedInVersion;
-  if (Triple.getOS() == llvm::Triple::IOS)
-    AcceptedInVersion = VersionTuple(/*Major=*/9);
-  else if (Triple.isMacOSX())
-    AcceptedInVersion = VersionTuple(/*Major=*/10, /*Minor=*/11);
-  else
-    return;
-  if (SemaRef.getASTContext().getTargetInfo().getPlatformMinVersion() >=
-      AcceptedInVersion)
-    return;
-  SemaRef.Diag(Loc, diag::err_objc_method_unsupported_param_ret_type)
-      << T << (Method->getReturnType()->isVectorType() ? /*return value*/ 1
-                                                       : /*parameter*/ 0)
-      << (Triple.isMacOSX() ? "macOS 10.11" : "iOS 9");
-}
-
-Decl *Sema::ActOnMethodDeclaration(
-    Scope *S, SourceLocation MethodLoc, SourceLocation EndLoc,
-    tok::TokenKind MethodType, ObjCDeclSpec &ReturnQT, ParsedType ReturnType,
-    ArrayRef<SourceLocation> SelectorLocs, Selector Sel,
-    // optional arguments. The number of types/arguments is obtained
-    // from the Sel.getNumArgs().
-    ObjCArgInfo *ArgInfo, DeclaratorChunk::ParamInfo *CParamInfo,
-    unsigned CNumArgs, // c-style args
-    const ParsedAttributesView &AttrList, tok::ObjCKeywordKind MethodDeclKind,
-    bool isVariadic, bool MethodDefinition) {
-  // Make sure we can establish a context for the method.
-  if (!CurContext->isObjCContainer()) {
-    Diag(MethodLoc, diag::err_missing_method_context);
-    return nullptr;
-  }
-  Decl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
-  QualType resultDeclType;
-
-  bool HasRelatedResultType = false;
-  TypeSourceInfo *ReturnTInfo = nullptr;
-  if (ReturnType) {
-    resultDeclType = GetTypeFromParser(ReturnType, &ReturnTInfo);
-
-    if (CheckFunctionReturnType(resultDeclType, MethodLoc))
-      return nullptr;
-
-    QualType bareResultType = resultDeclType;
-    (void)AttributedType::stripOuterNullability(bareResultType);
-    HasRelatedResultType = (bareResultType == Context.getObjCInstanceType());
-  } else { // get the type for "id".
-    resultDeclType = Context.getObjCIdType();
-    Diag(MethodLoc, diag::warn_missing_method_return_type)
-      << FixItHint::CreateInsertion(SelectorLocs.front(), "(id)");
-  }
-
-  ObjCMethodDecl *ObjCMethod = ObjCMethodDecl::Create(
-      Context, MethodLoc, EndLoc, Sel, resultDeclType, ReturnTInfo, CurContext,
-      MethodType == tok::minus, isVariadic,
-      /*isPropertyAccessor=*/false,
-      /*isImplicitlyDeclared=*/false, /*isDefined=*/false,
-      MethodDeclKind == tok::objc_optional ? ObjCMethodDecl::Optional
-                                           : ObjCMethodDecl::Required,
-      HasRelatedResultType);
-
-  SmallVector<ParmVarDecl*, 16> Params;
-
-  for (unsigned i = 0, e = Sel.getNumArgs(); i != e; ++i) {
-    QualType ArgType;
-    TypeSourceInfo *DI;
-
-    if (!ArgInfo[i].Type) {
-      ArgType = Context.getObjCIdType();
-      DI = nullptr;
-    } else {
-      ArgType = GetTypeFromParser(ArgInfo[i].Type, &DI);
-    }
-
-    LookupResult R(*this, ArgInfo[i].Name, ArgInfo[i].NameLoc,
-                   LookupOrdinaryName, forRedeclarationInCurContext());
-    LookupName(R, S);
-    if (R.isSingleResult()) {
-      NamedDecl *PrevDecl = R.getFoundDecl();
-      if (S->isDeclScope(PrevDecl)) {
-        Diag(ArgInfo[i].NameLoc,
-             (MethodDefinition ? diag::warn_method_param_redefinition
-                               : diag::warn_method_param_declaration))
-          << ArgInfo[i].Name;
-        Diag(PrevDecl->getLocation(),
-             diag::note_previous_declaration);
-      }
-    }
-
-    SourceLocation StartLoc = DI
-      ? DI->getTypeLoc().getBeginLoc()
-      : ArgInfo[i].NameLoc;
-
-    ParmVarDecl* Param = CheckParameter(ObjCMethod, StartLoc,
-                                        ArgInfo[i].NameLoc, ArgInfo[i].Name,
-                                        ArgType, DI, SC_None);
-
-    Param->setObjCMethodScopeInfo(i);
-
-    Param->setObjCDeclQualifier(
-      CvtQTToAstBitMask(ArgInfo[i].DeclSpec.getObjCDeclQualifier()));
-
-    // Apply the attributes to the parameter.
-    ProcessDeclAttributeList(TUScope, Param, ArgInfo[i].ArgAttrs);
-    AddPragmaAttributes(TUScope, Param);
-
-    if (Param->hasAttr<BlocksAttr>()) {
-      Diag(Param->getLocation(), diag::err_block_on_nonlocal);
-      Param->setInvalidDecl();
-    }
-    S->AddDecl(Param);
-    IdResolver.AddDecl(Param);
-
-    Params.push_back(Param);
-  }
-
-  for (unsigned i = 0, e = CNumArgs; i != e; ++i) {
-    ParmVarDecl *Param = cast<ParmVarDecl>(CParamInfo[i].Param);
-    QualType ArgType = Param->getType();
-    if (ArgType.isNull())
-      ArgType = Context.getObjCIdType();
-    else
-      // Perform the default array/function conversions (C99 6.7.5.3p[7,8]).
-      ArgType = Context.getAdjustedParameterType(ArgType);
-
-    Param->setDeclContext(ObjCMethod);
-    Params.push_back(Param);
-  }
-
-  ObjCMethod->setMethodParams(Context, Params, SelectorLocs);
-  ObjCMethod->setObjCDeclQualifier(
-    CvtQTToAstBitMask(ReturnQT.getObjCDeclQualifier()));
-
-  ProcessDeclAttributeList(TUScope, ObjCMethod, AttrList);
-  AddPragmaAttributes(TUScope, ObjCMethod);
-
-  // Add the method now.
-  const ObjCMethodDecl *PrevMethod = nullptr;
-  if (ObjCImplDecl *ImpDecl = dyn_cast<ObjCImplDecl>(ClassDecl)) {
-    if (MethodType == tok::minus) {
-      PrevMethod = ImpDecl->getInstanceMethod(Sel);
-      ImpDecl->addInstanceMethod(ObjCMethod);
-    } else {
-      PrevMethod = ImpDecl->getClassMethod(Sel);
-      ImpDecl->addClassMethod(ObjCMethod);
-    }
-
-    // Merge information from the @interface declaration into the
-    // @implementation.
-    if (ObjCInterfaceDecl *IDecl = ImpDecl->getClassInterface()) {
-      if (auto *IMD = IDecl->lookupMethod(ObjCMethod->getSelector(),
-                                          ObjCMethod->isInstanceMethod())) {
-        mergeInterfaceMethodToImpl(*this, ObjCMethod, IMD);
-
-        // Warn about defining -dealloc in a category.
-        if (isa<ObjCCategoryImplDecl>(ImpDecl) && IMD->isOverriding() &&
-            ObjCMethod->getSelector().getMethodFamily() == OMF_dealloc) {
-          Diag(ObjCMethod->getLocation(), diag::warn_dealloc_in_category)
-            << ObjCMethod->getDeclName();
-        }
-      }
-
-      // Warn if a method declared in a protocol to which a category or
-      // extension conforms is non-escaping and the implementation's method is
-      // escaping.
-      for (auto *C : IDecl->visible_categories())
-        for (auto &P : C->protocols())
-          if (auto *IMD = P->lookupMethod(ObjCMethod->getSelector(),
-                                          ObjCMethod->isInstanceMethod())) {
-            assert(ObjCMethod->parameters().size() ==
-                       IMD->parameters().size() &&
-                   "Methods have different number of parameters");
-            auto OI = IMD->param_begin(), OE = IMD->param_end();
-            auto NI = ObjCMethod->param_begin();
-            for (; OI != OE; ++OI, ++NI)
-              diagnoseNoescape(*NI, *OI, C, P, *this);
-          }
-    }
-  } else {
-    cast<DeclContext>(ClassDecl)->addDecl(ObjCMethod);
-  }
-
-  if (PrevMethod) {
-    // You can never have two method definitions with the same name.
-    Diag(ObjCMethod->getLocation(), diag::err_duplicate_method_decl)
-      << ObjCMethod->getDeclName();
-    Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
-    ObjCMethod->setInvalidDecl();
-    return ObjCMethod;
-  }
-
-  // If this Objective-C method does not have a related result type, but we
-  // are allowed to infer related result types, try to do so based on the
-  // method family.
-  ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(ClassDecl);
-  if (!CurrentClass) {
-    if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl))
-      CurrentClass = Cat->getClassInterface();
-    else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(ClassDecl))
-      CurrentClass = Impl->getClassInterface();
-    else if (ObjCCategoryImplDecl *CatImpl
-                                   = dyn_cast<ObjCCategoryImplDecl>(ClassDecl))
-      CurrentClass = CatImpl->getClassInterface();
-  }
-
-  ResultTypeCompatibilityKind RTC
-    = CheckRelatedResultTypeCompatibility(*this, ObjCMethod, CurrentClass);
-
-  CheckObjCMethodOverrides(ObjCMethod, CurrentClass, RTC);
-
-  bool ARCError = false;
-  if (getLangOpts().ObjCAutoRefCount)
-    ARCError = CheckARCMethodDecl(ObjCMethod);
-
-  // Infer the related result type when possible.
-  if (!ARCError && RTC == Sema::RTC_Compatible &&
-      !ObjCMethod->hasRelatedResultType() &&
-      LangOpts.ObjCInferRelatedResultType) {
-    bool InferRelatedResultType = false;
-    switch (ObjCMethod->getMethodFamily()) {
-    case OMF_None:
-    case OMF_copy:
-    case OMF_dealloc:
-    case OMF_finalize:
-    case OMF_mutableCopy:
-    case OMF_release:
-    case OMF_retainCount:
-    case OMF_initialize:
-    case OMF_performSelector:
-      break;
-
-    case OMF_alloc:
-    case OMF_new:
-        InferRelatedResultType = ObjCMethod->isClassMethod();
-      break;
-
-    case OMF_init:
-    case OMF_autorelease:
-    case OMF_retain:
-    case OMF_self:
-      InferRelatedResultType = ObjCMethod->isInstanceMethod();
-      break;
-    }
-
-    if (InferRelatedResultType &&
-        !ObjCMethod->getReturnType()->isObjCIndependentClassType())
-      ObjCMethod->setRelatedResultType();
-  }
-
-  if (MethodDefinition &&
-      Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
-    checkObjCMethodX86VectorTypes(*this, ObjCMethod);
-
-  // + load method cannot have availability attributes. It get called on
-  // startup, so it has to have the availability of the deployment target.
-  if (const auto *attr = ObjCMethod->getAttr<AvailabilityAttr>()) {
-    if (ObjCMethod->isClassMethod() &&
-        ObjCMethod->getSelector().getAsString() == "load") {
-      Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
-          << 0;
-      ObjCMethod->dropAttr<AvailabilityAttr>();
-    }
-  }
-
-  ActOnDocumentableDecl(ObjCMethod);
-
-  return ObjCMethod;
-}
-
-bool Sema::CheckObjCDeclScope(Decl *D) {
-  // Following is also an error. But it is caused by a missing @end
-  // and diagnostic is issued elsewhere.
-  if (isa<ObjCContainerDecl>(CurContext->getRedeclContext()))
-    return false;
-
-  // If we switched context to translation unit while we are still lexically in
-  // an objc container, it means the parser missed emitting an error.
-  if (isa<TranslationUnitDecl>(getCurLexicalContext()->getRedeclContext()))
-    return false;
-
-  Diag(D->getLocation(), diag::err_objc_decls_may_only_appear_in_global_scope);
-  D->setInvalidDecl();
-
-  return true;
-}
-
-/// Called whenever \@defs(ClassName) is encountered in the source.  Inserts the
-/// instance variables of ClassName into Decls.
-void Sema::ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart,
-                     IdentifierInfo *ClassName,
-                     SmallVectorImpl<Decl*> &Decls) {
-  // Check that ClassName is a valid class
-  ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName, DeclStart);
-  if (!Class) {
-    Diag(DeclStart, diag::err_undef_interface) << ClassName;
-    return;
-  }
-  if (LangOpts.ObjCRuntime.isNonFragile()) {
-    Diag(DeclStart, diag::err_atdef_nonfragile_interface);
-    return;
-  }
-
-  // Collect the instance variables
-  SmallVector<const ObjCIvarDecl*, 32> Ivars;
-  Context.DeepCollectObjCIvars(Class, true, Ivars);
-  // For each ivar, create a fresh ObjCAtDefsFieldDecl.
-  for (unsigned i = 0; i < Ivars.size(); i++) {
-    const FieldDecl* ID = Ivars[i];
-    RecordDecl *Record = dyn_cast<RecordDecl>(TagD);
-    Decl *FD = ObjCAtDefsFieldDecl::Create(Context, Record,
-                                           /*FIXME: StartL=*/ID->getLocation(),
-                                           ID->getLocation(),
-                                           ID->getIdentifier(), ID->getType(),
-                                           ID->getBitWidth());
-    Decls.push_back(FD);
-  }
-
-  // Introduce all of these fields into the appropriate scope.
-  for (SmallVectorImpl<Decl*>::iterator D = Decls.begin();
-       D != Decls.end(); ++D) {
-    FieldDecl *FD = cast<FieldDecl>(*D);
-    if (getLangOpts().CPlusPlus)
-      PushOnScopeChains(FD, S);
-    else if (RecordDecl *Record = dyn_cast<RecordDecl>(TagD))
-      Record->addDecl(FD);
-  }
-}
-
-/// Build a type-check a new Objective-C exception variable declaration.
-VarDecl *Sema::BuildObjCExceptionDecl(TypeSourceInfo *TInfo, QualType T,
-                                      SourceLocation StartLoc,
-                                      SourceLocation IdLoc,
-                                      IdentifierInfo *Id,
-                                      bool Invalid) {
-  // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage
-  // duration shall not be qualified by an address-space qualifier."
-  // Since all parameters have automatic store duration, they can not have
-  // an address space.
-  if (T.getAddressSpace() != LangAS::Default) {
-    Diag(IdLoc, diag::err_arg_with_address_space);
-    Invalid = true;
-  }
-
-  // An @catch parameter must be an unqualified object pointer type;
-  // FIXME: Recover from "NSObject foo" by inserting the * in "NSObject *foo"?
-  if (Invalid) {
-    // Don't do any further checking.
-  } else if (T->isDependentType()) {
-    // Okay: we don't know what this type will instantiate to.
-  } else if (T->isObjCQualifiedIdType()) {
-    Invalid = true;
-    Diag(IdLoc, diag::err_illegal_qualifiers_on_catch_parm);
-  } else if (T->isObjCIdType()) {
-    // Okay: we don't know what this type will instantiate to.
-  } else if (!T->isObjCObjectPointerType()) {
-    Invalid = true;
-    Diag(IdLoc, diag::err_catch_param_not_objc_type);
-  } else if (!T->getAs<ObjCObjectPointerType>()->getInterfaceType()) {
-    Invalid = true;
-    Diag(IdLoc, diag::err_catch_param_not_objc_type);
-  }
-
-  VarDecl *New = VarDecl::Create(Context, CurContext, StartLoc, IdLoc, Id,
-                                 T, TInfo, SC_None);
-  New->setExceptionVariable(true);
-
-  // In ARC, infer 'retaining' for variables of retainable type.
-  if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(New))
-    Invalid = true;
-
-  if (Invalid)
-    New->setInvalidDecl();
-  return New;
-}
-
-Decl *Sema::ActOnObjCExceptionDecl(Scope *S, Declarator &D) {
-  const DeclSpec &DS = D.getDeclSpec();
-
-  // We allow the "register" storage class on exception variables because
-  // GCC did, but we drop it completely. Any other storage class is an error.
-  if (DS.getStorageClassSpec() == DeclSpec::SCS_register) {
-    Diag(DS.getStorageClassSpecLoc(), diag::warn_register_objc_catch_parm)
-      << FixItHint::CreateRemoval(SourceRange(DS.getStorageClassSpecLoc()));
-  } else if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
-    Diag(DS.getStorageClassSpecLoc(), diag::err_storage_spec_on_catch_parm)
-      << DeclSpec::getSpecifierName(SCS);
-  }
-  if (DS.isInlineSpecified())
-    Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
-        << getLangOpts().CPlusPlus17;
-  if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
-    Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
-         diag::err_invalid_thread)
-     << DeclSpec::getSpecifierName(TSCS);
-  D.getMutableDeclSpec().ClearStorageClassSpecs();
-
-  DiagnoseFunctionSpecifiers(D.getDeclSpec());
-
-  // Check that there are no default arguments inside the type of this
-  // exception object (C++ only).
-  if (getLangOpts().CPlusPlus)
-    CheckExtraCXXDefaultArguments(D);
-
-  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
-  QualType ExceptionType = TInfo->getType();
-
-  VarDecl *New = BuildObjCExceptionDecl(TInfo, ExceptionType,
-                                        D.getSourceRange().getBegin(),
-                                        D.getIdentifierLoc(),
-                                        D.getIdentifier(),
-                                        D.isInvalidType());
-
-  // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
-  if (D.getCXXScopeSpec().isSet()) {
-    Diag(D.getIdentifierLoc(), diag::err_qualified_objc_catch_parm)
-      << D.getCXXScopeSpec().getRange();
-    New->setInvalidDecl();
-  }
-
-  // Add the parameter declaration into this scope.
-  S->AddDecl(New);
-  if (D.getIdentifier())
-    IdResolver.AddDecl(New);
-
-  ProcessDeclAttributes(S, New, D);
-
-  if (New->hasAttr<BlocksAttr>())
-    Diag(New->getLocation(), diag::err_block_on_nonlocal);
-  return New;
-}
-
-/// CollectIvarsToConstructOrDestruct - Collect those ivars which require
-/// initialization.
-void Sema::CollectIvarsToConstructOrDestruct(ObjCInterfaceDecl *OI,
-                                SmallVectorImpl<ObjCIvarDecl*> &Ivars) {
-  for (ObjCIvarDecl *Iv = OI->all_declared_ivar_begin(); Iv;
-       Iv= Iv->getNextIvar()) {
-    QualType QT = Context.getBaseElementType(Iv->getType());
-    if (QT->isRecordType())
-      Ivars.push_back(Iv);
-  }
-}
-
-void Sema::DiagnoseUseOfUnimplementedSelectors() {
-  // Load referenced selectors from the external source.
-  if (ExternalSource) {
-    SmallVector<std::pair<Selector, SourceLocation>, 4> Sels;
-    ExternalSource->ReadReferencedSelectors(Sels);
-    for (unsigned I = 0, N = Sels.size(); I != N; ++I)
-      ReferencedSelectors[Sels[I].first] = Sels[I].second;
-  }
-
-  // Warning will be issued only when selector table is
-  // generated (which means there is at lease one implementation
-  // in the TU). This is to match gcc's behavior.
-  if (ReferencedSelectors.empty() ||
-      !Context.AnyObjCImplementation())
-    return;
-  for (auto &SelectorAndLocation : ReferencedSelectors) {
-    Selector Sel = SelectorAndLocation.first;
-    SourceLocation Loc = SelectorAndLocation.second;
-    if (!LookupImplementedMethodInGlobalPool(Sel))
-      Diag(Loc, diag::warn_unimplemented_selector) << Sel;
-  }
-}
-
-ObjCIvarDecl *
-Sema::GetIvarBackingPropertyAccessor(const ObjCMethodDecl *Method,
-                                     const ObjCPropertyDecl *&PDecl) const {
-  if (Method->isClassMethod())
-    return nullptr;
-  const ObjCInterfaceDecl *IDecl = Method->getClassInterface();
-  if (!IDecl)
-    return nullptr;
-  Method = IDecl->lookupMethod(Method->getSelector(), /*isInstance=*/true,
-                               /*shallowCategoryLookup=*/false,
-                               /*followSuper=*/false);
-  if (!Method || !Method->isPropertyAccessor())
-    return nullptr;
-  if ((PDecl = Method->findPropertyDecl()))
-    if (ObjCIvarDecl *IV = PDecl->getPropertyIvarDecl()) {
-      // property backing ivar must belong to property's class
-      // or be a private ivar in class's implementation.
-      // FIXME. fix the const-ness issue.
-      IV = const_cast<ObjCInterfaceDecl *>(IDecl)->lookupInstanceVariable(
-                                                        IV->getIdentifier());
-      return IV;
-    }
-  return nullptr;
-}
-
-namespace {
-  /// Used by Sema::DiagnoseUnusedBackingIvarInAccessor to check if a property
-  /// accessor references the backing ivar.
-  class UnusedBackingIvarChecker :
-      public RecursiveASTVisitor<UnusedBackingIvarChecker> {
-  public:
-    Sema &S;
-    const ObjCMethodDecl *Method;
-    const ObjCIvarDecl *IvarD;
-    bool AccessedIvar;
-    bool InvokedSelfMethod;
-
-    UnusedBackingIvarChecker(Sema &S, const ObjCMethodDecl *Method,
-                             const ObjCIvarDecl *IvarD)
-      : S(S), Method(Method), IvarD(IvarD),
-        AccessedIvar(false), InvokedSelfMethod(false) {
-      assert(IvarD);
-    }
-
-    bool VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
-      if (E->getDecl() == IvarD) {
-        AccessedIvar = true;
-        return false;
-      }
-      return true;
-    }
-
-    bool VisitObjCMessageExpr(ObjCMessageExpr *E) {
-      if (E->getReceiverKind() == ObjCMessageExpr::Instance &&
-          S.isSelfExpr(E->getInstanceReceiver(), Method)) {
-        InvokedSelfMethod = true;
-      }
-      return true;
-    }
-  };
-} // end anonymous namespace
-
-void Sema::DiagnoseUnusedBackingIvarInAccessor(Scope *S,
-                                          const ObjCImplementationDecl *ImplD) {
-  if (S->hasUnrecoverableErrorOccurred())
-    return;
-
-  for (const auto *CurMethod : ImplD->instance_methods()) {
-    unsigned DIAG = diag::warn_unused_property_backing_ivar;
-    SourceLocation Loc = CurMethod->getLocation();
-    if (Diags.isIgnored(DIAG, Loc))
-      continue;
-
-    const ObjCPropertyDecl *PDecl;
-    const ObjCIvarDecl *IV = GetIvarBackingPropertyAccessor(CurMethod, PDecl);
-    if (!IV)
-      continue;
-
-    UnusedBackingIvarChecker Checker(*this, CurMethod, IV);
-    Checker.TraverseStmt(CurMethod->getBody());
-    if (Checker.AccessedIvar)
-      continue;
-
-    // Do not issue this warning if backing ivar is used somewhere and accessor
-    // implementation makes a self call. This is to prevent false positive in
-    // cases where the ivar is accessed by another method that the accessor
-    // delegates to.
-    if (!IV->isReferenced() || !Checker.InvokedSelfMethod) {
-      Diag(Loc, DIAG) << IV;
-      Diag(PDecl->getLocation(), diag::note_property_declare);
-    }
-  }
-}