vendor/clang/clang-release_39-r276489

1 files changed, 414 insertions, 234 deletions

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index d6a0ff7dc3d15..b025a397edca0 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -39,8 +39,8 @@ using namespace clang;
 using namespace sema;
 
 static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
-  return std::any_of(FD->param_begin(), FD->param_end(),
-                     std::mem_fn(&ParmVarDecl::hasAttr<PassObjectSizeAttr>));
+  return llvm::any_of(FD->parameters(),
+                      std::mem_fn(&ParmVarDecl::hasAttr<PassObjectSizeAttr>));
 }
 
 /// A convenience routine for creating a decayed reference to a function.
@@ -293,6 +293,13 @@ StandardConversionSequence::getNarrowingKind(ASTContext &Ctx,
   //   A narrowing conversion is an implicit conversion ...
   QualType FromType = getToType(0);
   QualType ToType = getToType(1);
+
+  // A conversion to an enumeration type is narrowing if the conversion to
+  // the underlying type is narrowing. This only arises for expressions of
+  // the form 'Enum{init}'.
+  if (auto *ET = ToType->getAs<EnumType>())
+    ToType = ET->getDecl()->getIntegerType();
+
   switch (Second) {
   // 'bool' is an integral type; dispatch to the right place to handle it.
   case ICK_Boolean_Conversion:
@@ -433,7 +440,7 @@ StandardConversionSequence::getNarrowingKind(ASTContext &Ctx,
 
 /// dump - Print this standard conversion sequence to standard
 /// error. Useful for debugging overloading issues.
-void StandardConversionSequence::dump() const {
+LLVM_DUMP_METHOD void StandardConversionSequence::dump() const {
   raw_ostream &OS = llvm::errs();
   bool PrintedSomething = false;
   if (First != ICK_Identity) {
@@ -985,7 +992,7 @@ Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
 }
 
 bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
-                      bool UseUsingDeclRules) {
+                      bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
   // C++ [basic.start.main]p2: This function shall not be overloaded.
   if (New->isMain())
     return false;
@@ -1041,7 +1048,7 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
   //
   // However, we don't consider either of these when deciding whether
   // a member introduced by a shadow declaration is hidden.
-  if (!UseUsingDeclRules && NewTemplate &&
+  if (!UseMemberUsingDeclRules && NewTemplate &&
       (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
                                        OldTemplate->getTemplateParameters(),
                                        false, TPL_TemplateMatch) ||
@@ -1061,7 +1068,7 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
   if (OldMethod && NewMethod &&
       !OldMethod->isStatic() && !NewMethod->isStatic()) {
     if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
-      if (!UseUsingDeclRules &&
+      if (!UseMemberUsingDeclRules &&
           (OldMethod->getRefQualifier() == RQ_None ||
            NewMethod->getRefQualifier() == RQ_None)) {
         // C++0x [over.load]p2:
@@ -1118,7 +1125,7 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
       return true;
   }
 
-  if (getLangOpts().CUDA && getLangOpts().CUDATargetOverloads) {
+  if (getLangOpts().CUDA && ConsiderCudaAttrs) {
     CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
                        OldTarget = IdentifyCUDATarget(Old);
     if (NewTarget == CFT_InvalidTarget || NewTarget == CFT_Global)
@@ -1129,7 +1136,10 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
     // Don't allow mixing of HD with other kinds. This guarantees that
     // we have only one viable function with this signature on any
     // side of CUDA compilation .
-    if ((NewTarget == CFT_HostDevice) || (OldTarget == CFT_HostDevice))
+    // __global__ functions can't be overloaded based on attribute
+    // difference because, like HD, they also exist on both sides.
+    if ((NewTarget == CFT_HostDevice) || (OldTarget == CFT_HostDevice) ||
+        (NewTarget == CFT_Global) || (OldTarget == CFT_Global))
       return false;
 
     // Allow overloading of functions with same signature, but
@@ -1147,7 +1157,16 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
 /// \returns true if \arg FD is unavailable and current context is inside
 /// an available function, false otherwise.
 bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
-  return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable();
+  if (!FD->isUnavailable())
+    return false;
+
+  // Walk up the context of the caller.
+  Decl *C = cast<Decl>(CurContext);
+  do {
+    if (C->isUnavailable())
+      return false;
+  } while ((C = cast_or_null<Decl>(C->getDeclContext())));
+  return true;
 }
 
 /// \brief Tries a user-defined conversion from From to ToType.
@@ -1199,11 +1218,13 @@ TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
            S.IsDerivedFrom(From->getLocStart(), FromCanon, ToCanon))) {
         // Turn this into a "standard" conversion sequence, so that it
         // gets ranked with standard conversion sequences.
+        DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
         ICS.setStandard();
         ICS.Standard.setAsIdentityConversion();
         ICS.Standard.setFromType(From->getType());
         ICS.Standard.setAllToTypes(ToType);
         ICS.Standard.CopyConstructor = Constructor;
+        ICS.Standard.FoundCopyConstructor = Found;
         if (ToCanon != FromCanon)
           ICS.Standard.Second = ICK_Derived_To_Base;
       }
@@ -1217,7 +1238,7 @@ TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
     for (OverloadCandidateSet::iterator Cand = Conversions.begin();
          Cand != Conversions.end(); ++Cand)
       if (Cand->Viable)
-        ICS.Ambiguous.addConversion(Cand->Function);
+        ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
     break;
 
     // Fall through.
@@ -1652,6 +1673,20 @@ static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
     SCS.Second = ICK_Complex_Real;
     FromType = ToType.getUnqualifiedType();
   } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
+    // FIXME: disable conversions between long double and __float128 if
+    // their representation is different until there is back end support
+    // We of course allow this conversion if long double is really double.
+    if (&S.Context.getFloatTypeSemantics(FromType) !=
+        &S.Context.getFloatTypeSemantics(ToType)) {
+      bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
+                                    ToType == S.Context.LongDoubleTy) ||
+                                   (FromType == S.Context.LongDoubleTy &&
+                                    ToType == S.Context.Float128Ty));
+      if (Float128AndLongDouble &&
+          (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) !=
+           &llvm::APFloat::IEEEdouble))
+        return false;
+    }
     // Floating point conversions (C++ 4.8).
     SCS.Second = ICK_Floating_Conversion;
     FromType = ToType.getUnqualifiedType();
@@ -1809,8 +1844,7 @@ bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
         (FromType->isSignedIntegerType() ||
          // We can promote any unsigned integer type whose size is
          // less than int to an int.
-         (!FromType->isSignedIntegerType() &&
-          Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) {
+         Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
       return To->getKind() == BuiltinType::Int;
     }
 
@@ -1955,7 +1989,8 @@ bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
       if (!getLangOpts().CPlusPlus &&
           (FromBuiltin->getKind() == BuiltinType::Float ||
            FromBuiltin->getKind() == BuiltinType::Double) &&
-          (ToBuiltin->getKind() == BuiltinType::LongDouble))
+          (ToBuiltin->getKind() == BuiltinType::LongDouble ||
+           ToBuiltin->getKind() == BuiltinType::Float128))
         return true;
 
       // Half can be promoted to float.
@@ -2538,9 +2573,8 @@ bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
        // Argument types are too different. Abort.
        return false;
    }
-   if (LangOpts.ObjCAutoRefCount && 
-       !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType, 
-                                                    ToFunctionType))
+   if (!Context.doFunctionTypesMatchOnExtParameterInfos(FromFunctionType,
+                                                        ToFunctionType))
      return false;
    
    ConvertedType = ToType;
@@ -2919,6 +2953,10 @@ Sema::IsQualificationConversion(QualType FromType, QualType ToType,
 
     Qualifiers FromQuals = FromType.getQualifiers();
     Qualifiers ToQuals = ToType.getQualifiers();
+
+    // Ignore __unaligned qualifier if this type is void.
+    if (ToType.getUnqualifiedType()->isVoidType())
+      FromQuals.removeUnaligned();
     
     // Objective-C ARC:
     //   Check Objective-C lifetime conversions.
@@ -3015,39 +3053,26 @@ IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
                                        UserDefinedConversionSequence &User,
                                        OverloadCandidateSet &CandidateSet,
                                        bool AllowExplicit) {
-  DeclContext::lookup_result R = S.LookupConstructors(To);
-  for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end();
-       Con != ConEnd; ++Con) {
-    NamedDecl *D = *Con;
-    DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
-
-    // Find the constructor (which may be a template).
-    CXXConstructorDecl *Constructor = nullptr;
-    FunctionTemplateDecl *ConstructorTmpl
-      = dyn_cast<FunctionTemplateDecl>(D);
-    if (ConstructorTmpl)
-      Constructor
-        = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
-    else
-      Constructor = cast<CXXConstructorDecl>(D);
+  for (auto *D : S.LookupConstructors(To)) {
+    auto Info = getConstructorInfo(D);
+    if (!Info)
+      continue;
 
-    bool Usable = !Constructor->isInvalidDecl() &&
-                  S.isInitListConstructor(Constructor) &&
-                  (AllowExplicit || !Constructor->isExplicit());
+    bool Usable = !Info.Constructor->isInvalidDecl() &&
+                  S.isInitListConstructor(Info.Constructor) &&
+                  (AllowExplicit || !Info.Constructor->isExplicit());
     if (Usable) {
       // If the first argument is (a reference to) the target type,
       // suppress conversions.
-      bool SuppressUserConversions =
-          isFirstArgumentCompatibleWithType(S.Context, Constructor, ToType);
-      if (ConstructorTmpl)
-        S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
-                                       /*ExplicitArgs*/ nullptr,
-                                       From, CandidateSet,
-                                       SuppressUserConversions);
+      bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
+          S.Context, Info.Constructor, ToType);
+      if (Info.ConstructorTmpl)
+        S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
+                                       /*ExplicitArgs*/ nullptr, From,
+                                       CandidateSet, SuppressUserConversions);
       else
-        S.AddOverloadCandidate(Constructor, FoundDecl,
-                               From, CandidateSet,
-                               SuppressUserConversions);
+        S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
+                               CandidateSet, SuppressUserConversions);
     }
   }
 
@@ -3147,27 +3172,17 @@ IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
         ListInitializing = true;
       }
 
-      DeclContext::lookup_result R = S.LookupConstructors(ToRecordDecl);
-      for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end();
-           Con != ConEnd; ++Con) {
-        NamedDecl *D = *Con;
-        DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
-
-        // Find the constructor (which may be a template).
-        CXXConstructorDecl *Constructor = nullptr;
-        FunctionTemplateDecl *ConstructorTmpl
-          = dyn_cast<FunctionTemplateDecl>(D);
-        if (ConstructorTmpl)
-          Constructor
-            = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
-        else
-          Constructor = cast<CXXConstructorDecl>(D);
+      for (auto *D : S.LookupConstructors(ToRecordDecl)) {
+        auto Info = getConstructorInfo(D);
+        if (!Info)
+          continue;
 
-        bool Usable = !Constructor->isInvalidDecl();
+        bool Usable = !Info.Constructor->isInvalidDecl();
         if (ListInitializing)
-          Usable = Usable && (AllowExplicit || !Constructor->isExplicit());
+          Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
         else
-          Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit);
+          Usable = Usable &&
+                   Info.Constructor->isConvertingConstructor(AllowExplicit);
         if (Usable) {
           bool SuppressUserConversions = !ConstructorsOnly;
           if (SuppressUserConversions && ListInitializing) {
@@ -3176,18 +3191,18 @@ IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
               // If the first argument is (a reference to) the target type,
               // suppress conversions.
               SuppressUserConversions = isFirstArgumentCompatibleWithType(
-                                                S.Context, Constructor, ToType);
+                  S.Context, Info.Constructor, ToType);
             }
           }
-          if (ConstructorTmpl)
-            S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
-                                           /*ExplicitArgs*/ nullptr,
-                                           llvm::makeArrayRef(Args, NumArgs),
-                                           CandidateSet, SuppressUserConversions);
+          if (Info.ConstructorTmpl)
+            S.AddTemplateOverloadCandidate(
+                Info.ConstructorTmpl, Info.FoundDecl,
+                /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
+                CandidateSet, SuppressUserConversions);
           else
             // Allow one user-defined conversion when user specifies a
             // From->ToType conversion via an static cast (c-style, etc).
-            S.AddOverloadCandidate(Constructor, FoundDecl,
+            S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
                                    llvm::makeArrayRef(Args, NumArgs),
                                    CandidateSet, SuppressUserConversions);
         }
@@ -4127,6 +4142,10 @@ Sema::CompareReferenceRelationship(SourceLocation Loc,
     T2Quals.removeObjCLifetime();    
   }
     
+  // MS compiler ignores __unaligned qualifier for references; do the same.
+  T1Quals.removeUnaligned();
+  T2Quals.removeUnaligned();
+
   if (T1Quals == T2Quals)
     return Ref_Compatible;
   else if (T1Quals.compatiblyIncludes(T2Quals))
@@ -4248,7 +4267,7 @@ FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
     for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
          Cand != CandidateSet.end(); ++Cand)
       if (Cand->Viable)
-        ICS.Ambiguous.addConversion(Cand->Function);
+        ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
     return true;
 
   case OR_No_Viable_Function:
@@ -4448,13 +4467,16 @@ TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
     // initialization fails.
     //
     // Note that we only want to check address spaces and cvr-qualifiers here.
-    // ObjC GC and lifetime qualifiers aren't important.
+    // ObjC GC, lifetime and unaligned qualifiers aren't important.
     Qualifiers T1Quals = T1.getQualifiers();
     Qualifiers T2Quals = T2.getQualifiers();
     T1Quals.removeObjCGCAttr();
     T1Quals.removeObjCLifetime();
     T2Quals.removeObjCGCAttr();
     T2Quals.removeObjCLifetime();
+    // MS compiler ignores __unaligned qualifier for references; do the same.
+    T1Quals.removeUnaligned();
+    T2Quals.removeUnaligned();
     if (!T1Quals.compatiblyIncludes(T2Quals))
       return ICS;
   }
@@ -5838,12 +5860,12 @@ Sema::AddOverloadCandidate(FunctionDecl *Function,
   }
 }
 
-ObjCMethodDecl *Sema::SelectBestMethod(Selector Sel, MultiExprArg Args,
-                                       bool IsInstance) {
-  SmallVector<ObjCMethodDecl*, 4> Methods;
-  if (!CollectMultipleMethodsInGlobalPool(Sel, Methods, IsInstance))
+ObjCMethodDecl *
+Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
+                       SmallVectorImpl<ObjCMethodDecl *> &Methods) {
+  if (Methods.size() <= 1)
     return nullptr;
-    
+
   for (unsigned b = 0, e = Methods.size(); b < e; b++) {
     bool Match = true;
     ObjCMethodDecl *Method = Methods[b];
@@ -5952,37 +5974,28 @@ EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
   SFINAETrap Trap(*this);
   SmallVector<Expr *, 16> ConvertedArgs;
   bool InitializationFailed = false;
-  bool ContainsValueDependentExpr = false;
 
   // Convert the arguments.
-  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
-    if (i == 0 && !MissingImplicitThis && isa<CXXMethodDecl>(Function) &&
+  for (unsigned I = 0, E = Args.size(); I != E; ++I) {
+    ExprResult R;
+    if (I == 0 && !MissingImplicitThis && isa<CXXMethodDecl>(Function) &&
         !cast<CXXMethodDecl>(Function)->isStatic() &&
         !isa<CXXConstructorDecl>(Function)) {
       CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
-      ExprResult R =
-        PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
-                                            Method, Method);
-      if (R.isInvalid()) {
-        InitializationFailed = true;
-        break;
-      }
-      ContainsValueDependentExpr |= R.get()->isValueDependent();
-      ConvertedArgs.push_back(R.get());
+      R = PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
+                                              Method, Method);
     } else {
-      ExprResult R =
-        PerformCopyInitialization(InitializedEntity::InitializeParameter(
-                                                Context,
-                                                Function->getParamDecl(i)),
-                                  SourceLocation(),
-                                  Args[i]);
-      if (R.isInvalid()) {
-        InitializationFailed = true;
-        break;
-      }
-      ContainsValueDependentExpr |= R.get()->isValueDependent();
-      ConvertedArgs.push_back(R.get());
+      R = PerformCopyInitialization(InitializedEntity::InitializeParameter(
+                                        Context, Function->getParamDecl(I)),
+                                    SourceLocation(), Args[I]);
     }
+
+    if (R.isInvalid()) {
+      InitializationFailed = true;
+      break;
+    }
+
+    ConvertedArgs.push_back(R.get());
   }
 
   if (InitializationFailed || Trap.hasErrorOccurred())
@@ -6002,7 +6015,6 @@ EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
         InitializationFailed = true;
         break;
       }
-      ContainsValueDependentExpr |= R.get()->isValueDependent();
       ConvertedArgs.push_back(R.get());
     }
 
@@ -6012,18 +6024,14 @@ EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
 
   for (auto *EIA : EnableIfAttrs) {
     APValue Result;
-    if (EIA->getCond()->isValueDependent()) {
-      // Don't even try now, we'll examine it after instantiation.
-      continue;
-    }
-
+    // FIXME: This doesn't consider value-dependent cases, because doing so is
+    // very difficult. Ideally, we should handle them more gracefully.
     if (!EIA->getCond()->EvaluateWithSubstitution(
-            Result, Context, Function, llvm::makeArrayRef(ConvertedArgs))) {
-      if (!ContainsValueDependentExpr)
-        return EIA;
-    } else if (!Result.isInt() || !Result.getInt().getBoolValue()) {
+            Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
+      return EIA;
+
+    if (!Result.isInt() || !Result.getInt().getBoolValue())
       return EIA;
-    }
   }
   return nullptr;
 }
@@ -6814,7 +6822,8 @@ namespace {
 /// enumeration types.
 class BuiltinCandidateTypeSet  {
   /// TypeSet - A set of types.
-  typedef llvm::SmallPtrSet<QualType, 8> TypeSet;
+  typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
+                          llvm::SmallPtrSet<QualType, 8>> TypeSet;
 
   /// PointerTypes - The set of pointer types that will be used in the
   /// built-in candidates.
@@ -6913,7 +6922,7 @@ BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
                                              const Qualifiers &VisibleQuals) {
 
   // Insert this type.
-  if (!PointerTypes.insert(Ty).second)
+  if (!PointerTypes.insert(Ty))
     return false;
 
   QualType PointeeTy;
@@ -6981,7 +6990,7 @@ bool
 BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
     QualType Ty) {
   // Insert this type.
-  if (!MemberPointerTypes.insert(Ty).second)
+  if (!MemberPointerTypes.insert(Ty))
     return false;
 
   const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
@@ -7187,13 +7196,13 @@ class BuiltinOperatorOverloadBuilder {
   // provided via the getArithmeticType() method below.
   // The "promoted arithmetic types" are the arithmetic
   // types are that preserved by promotion (C++ [over.built]p2).
-  static const unsigned FirstIntegralType = 3;
-  static const unsigned LastIntegralType = 20;
-  static const unsigned FirstPromotedIntegralType = 3,
-                        LastPromotedIntegralType = 11;
+  static const unsigned FirstIntegralType = 4;
+  static const unsigned LastIntegralType = 21;
+  static const unsigned FirstPromotedIntegralType = 4,
+                        LastPromotedIntegralType = 12;
   static const unsigned FirstPromotedArithmeticType = 0,
-                        LastPromotedArithmeticType = 11;
-  static const unsigned NumArithmeticTypes = 20;
+                        LastPromotedArithmeticType = 12;
+  static const unsigned NumArithmeticTypes = 21;
 
   /// \brief Get the canonical type for a given arithmetic type index.
   CanQualType getArithmeticType(unsigned index) {
@@ -7204,6 +7213,7 @@ class BuiltinOperatorOverloadBuilder {
       &ASTContext::FloatTy,
       &ASTContext::DoubleTy,
       &ASTContext::LongDoubleTy,
+      &ASTContext::Float128Ty,
 
       // Start of integral types.
       &ASTContext::IntTy,
@@ -7246,7 +7256,7 @@ class BuiltinOperatorOverloadBuilder {
     // (we could precompute SLL x UI for all known platforms, but it's
     // better not to make any assumptions).
     // We assume that int128 has a higher rank than long long on all platforms.
-    enum PromotedType {
+    enum PromotedType : int8_t {
             Dep=-1,
             Flt,  Dbl, LDbl,   SI,   SL,  SLL, S128,   UI,   UL,  ULL, U128
     };
@@ -8476,16 +8486,31 @@ Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
   }
 }
 
-// Determines whether Cand1 is "better" in terms of its enable_if attrs than
-// Cand2 for overloading. This function assumes that all of the enable_if attrs
-// on Cand1 and Cand2 have conditions that evaluate to true.
-//
-// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
-// Cand1's first N enable_if attributes have precisely the same conditions as
-// Cand2's first N enable_if attributes (where N = the number of enable_if
-// attributes on Cand2), and Cand1 has more than N enable_if attributes.
-static bool hasBetterEnableIfAttrs(Sema &S, const FunctionDecl *Cand1,
-                                   const FunctionDecl *Cand2) {
+namespace {
+enum class Comparison { Equal, Better, Worse };
+}
+
+/// Compares the enable_if attributes of two FunctionDecls, for the purposes of
+/// overload resolution.
+///
+/// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
+/// Cand1's first N enable_if attributes have precisely the same conditions as
+/// Cand2's first N enable_if attributes (where N = the number of enable_if
+/// attributes on Cand2), and Cand1 has more than N enable_if attributes.
+///
+/// Note that you can have a pair of candidates such that Cand1's enable_if
+/// attributes are worse than Cand2's, and Cand2's enable_if attributes are
+/// worse than Cand1's.
+static Comparison compareEnableIfAttrs(const Sema &S, const FunctionDecl *Cand1,
+                                       const FunctionDecl *Cand2) {
+  // Common case: One (or both) decls don't have enable_if attrs.
+  bool Cand1Attr = Cand1->hasAttr<EnableIfAttr>();
+  bool Cand2Attr = Cand2->hasAttr<EnableIfAttr>();
+  if (!Cand1Attr || !Cand2Attr) {
+    if (Cand1Attr == Cand2Attr)
+      return Comparison::Equal;
+    return Cand1Attr ? Comparison::Better : Comparison::Worse;
+  }
 
   // FIXME: The next several lines are just
   // specific_attr_iterator<EnableIfAttr> but going in declaration order,
@@ -8493,10 +8518,10 @@ static bool hasBetterEnableIfAttrs(Sema &S, const FunctionDecl *Cand1,
   auto Cand1Attrs = getOrderedEnableIfAttrs(Cand1);
   auto Cand2Attrs = getOrderedEnableIfAttrs(Cand2);
 
-  // Candidate 1 is better if it has strictly more attributes and
-  // the common sequence is identical.
-  if (Cand1Attrs.size() <= Cand2Attrs.size())
-    return false;
+  // It's impossible for Cand1 to be better than (or equal to) Cand2 if Cand1
+  // has fewer enable_if attributes than Cand2.
+  if (Cand1Attrs.size() < Cand2Attrs.size())
+    return Comparison::Worse;
 
   auto Cand1I = Cand1Attrs.begin();
   llvm::FoldingSetNodeID Cand1ID, Cand2ID;
@@ -8508,10 +8533,10 @@ static bool hasBetterEnableIfAttrs(Sema &S, const FunctionDecl *Cand1,
     Cand1A->getCond()->Profile(Cand1ID, S.getASTContext(), true);
     Cand2A->getCond()->Profile(Cand2ID, S.getASTContext(), true);
     if (Cand1ID != Cand2ID)
-      return false;
+      return Comparison::Worse;
   }
 
-  return true;
+  return Cand1I == Cand1Attrs.end() ? Comparison::Equal : Comparison::Better;
 }
 
 /// isBetterOverloadCandidate - Determines whether the first overload
@@ -8621,14 +8646,33 @@ bool clang::isBetterOverloadCandidate(Sema &S, const OverloadCandidate &Cand1,
       return BetterTemplate == Cand1.Function->getPrimaryTemplate();
   }
 
+  // FIXME: Work around a defect in the C++17 inheriting constructor wording.
+  // A derived-class constructor beats an (inherited) base class constructor.
+  bool Cand1IsInherited =
+      dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand1.FoundDecl.getDecl());
+  bool Cand2IsInherited =
+      dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand2.FoundDecl.getDecl());
+  if (Cand1IsInherited != Cand2IsInherited)
+    return Cand2IsInherited;
+  else if (Cand1IsInherited) {
+    assert(Cand2IsInherited);
+    auto *Cand1Class = cast<CXXRecordDecl>(Cand1.Function->getDeclContext());
+    auto *Cand2Class = cast<CXXRecordDecl>(Cand2.Function->getDeclContext());
+    if (Cand1Class->isDerivedFrom(Cand2Class))
+      return true;
+    if (Cand2Class->isDerivedFrom(Cand1Class))
+      return false;
+    // Inherited from sibling base classes: still ambiguous.
+  }
+
   // Check for enable_if value-based overload resolution.
-  if (Cand1.Function && Cand2.Function &&
-      (Cand1.Function->hasAttr<EnableIfAttr>() ||
-       Cand2.Function->hasAttr<EnableIfAttr>()))
-    return hasBetterEnableIfAttrs(S, Cand1.Function, Cand2.Function);
+  if (Cand1.Function && Cand2.Function) {
+    Comparison Cmp = compareEnableIfAttrs(S, Cand1.Function, Cand2.Function);
+    if (Cmp != Comparison::Equal)
+      return Cmp == Comparison::Better;
+  }
 
-  if (S.getLangOpts().CUDA && S.getLangOpts().CUDATargetOverloads &&
-      Cand1.Function && Cand2.Function) {
+  if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function) {
     FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
     return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
            S.IdentifyCUDAPreference(Caller, Cand2.Function);
@@ -8722,14 +8766,44 @@ OverloadingResult
 OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
                                          iterator &Best,
                                          bool UserDefinedConversion) {
+  llvm::SmallVector<OverloadCandidate *, 16> Candidates;
+  std::transform(begin(), end(), std::back_inserter(Candidates),
+                 [](OverloadCandidate &Cand) { return &Cand; });
+
+  // [CUDA] HD->H or HD->D calls are technically not allowed by CUDA
+  // but accepted by both clang and NVCC. However during a particular
+  // compilation mode only one call variant is viable. We need to
+  // exclude non-viable overload candidates from consideration based
+  // only on their host/device attributes. Specifically, if one
+  // candidate call is WrongSide and the other is SameSide, we ignore
+  // the WrongSide candidate.
+  if (S.getLangOpts().CUDA) {
+    const FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
+    bool ContainsSameSideCandidate =
+        llvm::any_of(Candidates, [&](OverloadCandidate *Cand) {
+          return Cand->Function &&
+                 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
+                     Sema::CFP_SameSide;
+        });
+    if (ContainsSameSideCandidate) {
+      auto IsWrongSideCandidate = [&](OverloadCandidate *Cand) {
+        return Cand->Function &&
+               S.IdentifyCUDAPreference(Caller, Cand->Function) ==
+                   Sema::CFP_WrongSide;
+      };
+      Candidates.erase(std::remove_if(Candidates.begin(), Candidates.end(),
+                                      IsWrongSideCandidate),
+                       Candidates.end());
+    }
+  }
+
   // Find the best viable function.
   Best = end();
-  for (iterator Cand = begin(); Cand != end(); ++Cand) {
+  for (auto *Cand : Candidates)
     if (Cand->Viable)
       if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc,
                                                      UserDefinedConversion))
         Best = Cand;
-  }
 
   // If we didn't find any viable functions, abort.
   if (Best == end())
@@ -8739,7 +8813,7 @@ OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
 
   // Make sure that this function is better than every other viable
   // function. If not, we have an ambiguity.
-  for (iterator Cand = begin(); Cand != end(); ++Cand) {
+  for (auto *Cand : Candidates) {
     if (Cand->Viable &&
         Cand != Best &&
         !isBetterOverloadCandidate(S, *Best, *Cand, Loc,
@@ -8782,10 +8856,12 @@ enum OverloadCandidateKind {
   oc_implicit_move_constructor,
   oc_implicit_copy_assignment,
   oc_implicit_move_assignment,
-  oc_implicit_inherited_constructor
+  oc_inherited_constructor,
+  oc_inherited_constructor_template
 };
 
 OverloadCandidateKind ClassifyOverloadCandidate(Sema &S,
+                                                NamedDecl *Found,
                                                 FunctionDecl *Fn,
                                                 std::string &Description) {
   bool isTemplate = false;
@@ -8797,11 +8873,13 @@ OverloadCandidateKind ClassifyOverloadCandidate(Sema &S,
   }
 
   if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
-    if (!Ctor->isImplicit())
-      return isTemplate ? oc_constructor_template : oc_constructor;
-
-    if (Ctor->getInheritedConstructor())
-      return oc_implicit_inherited_constructor;
+    if (!Ctor->isImplicit()) {
+      if (isa<ConstructorUsingShadowDecl>(Found))
+        return isTemplate ? oc_inherited_constructor_template
+                          : oc_inherited_constructor;
+      else
+        return isTemplate ? oc_constructor_template : oc_constructor;
+    }
 
     if (Ctor->isDefaultConstructor())
       return oc_implicit_default_constructor;
@@ -8833,14 +8911,13 @@ OverloadCandidateKind ClassifyOverloadCandidate(Sema &S,
   return isTemplate ? oc_function_template : oc_function;
 }
 
-void MaybeEmitInheritedConstructorNote(Sema &S, Decl *Fn) {
-  const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn);
-  if (!Ctor) return;
-
-  Ctor = Ctor->getInheritedConstructor();
-  if (!Ctor) return;
-
-  S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor);
+void MaybeEmitInheritedConstructorNote(Sema &S, Decl *FoundDecl) {
+  // FIXME: It'd be nice to only emit a note once per using-decl per overload
+  // set.
+  if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl))
+    S.Diag(FoundDecl->getLocation(),
+           diag::note_ovl_candidate_inherited_constructor)
+      << Shadow->getNominatedBaseClass();
 }
 
 } // end anonymous namespace
@@ -8879,8 +8956,8 @@ static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
     return false;
   }
 
-  auto I = std::find_if(FD->param_begin(), FD->param_end(),
-                        std::mem_fn(&ParmVarDecl::hasAttr<PassObjectSizeAttr>));
+  auto I = llvm::find_if(
+      FD->parameters(), std::mem_fn(&ParmVarDecl::hasAttr<PassObjectSizeAttr>));
   if (I == FD->param_end())
     return true;
 
@@ -8914,19 +8991,19 @@ bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
 }
 
 // Notes the location of an overload candidate.
-void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType,
-                                 bool TakingAddress) {
+void Sema::NoteOverloadCandidate(NamedDecl *Found, FunctionDecl *Fn,
+                                 QualType DestType, bool TakingAddress) {
   if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
     return;
 
   std::string FnDesc;
-  OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc);
+  OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Found, Fn, FnDesc);
   PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
                              << (unsigned) K << FnDesc;
 
   HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
   Diag(Fn->getLocation(), PD);
-  MaybeEmitInheritedConstructorNote(*this, Fn);
+  MaybeEmitInheritedConstructorNote(*this, Found);
 }
 
 // Notes the location of all overload candidates designated through
@@ -8943,11 +9020,11 @@ void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
        I != IEnd; ++I) {
     if (FunctionTemplateDecl *FunTmpl = 
                 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
-      NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType,
+      NoteOverloadCandidate(*I, FunTmpl->getTemplatedDecl(), DestType,
                             TakingAddress);
     } else if (FunctionDecl *Fun 
                       = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
-      NoteOverloadCandidate(Fun, DestType, TakingAddress);
+      NoteOverloadCandidate(*I, Fun, DestType, TakingAddress);
     }
   }
 }
@@ -8971,7 +9048,7 @@ void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
     if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
       break;
     ++CandsShown;
-    S.NoteOverloadCandidate(*I);
+    S.NoteOverloadCandidate(I->first, I->second);
   }
   if (I != E)
     S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
@@ -8996,7 +9073,8 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
   }
 
   std::string FnDesc;
-  OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc);
+  OverloadCandidateKind FnKind =
+      ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
 
   Expr *FromExpr = Conv.Bad.FromExpr;
   QualType FromTy = Conv.Bad.getFromType();
@@ -9013,7 +9091,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
       << (unsigned) FnKind << FnDesc
       << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
       << ToTy << Name << I+1;
-    MaybeEmitInheritedConstructorNote(S, Fn);
+    MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
     return;
   }
 
@@ -9026,8 +9104,10 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
   else {
     // TODO: detect and diagnose the full richness of const mismatches.
     if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
-      if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>())
-        CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType();
+      if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) {
+        CFromTy = FromPT->getPointeeType();
+        CToTy = ToPT->getPointeeType();
+      }
   }
 
   if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
@@ -9042,7 +9122,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
         << FromTy
         << FromQs.getAddressSpace() << ToQs.getAddressSpace()
         << (unsigned) isObjectArgument << I+1;
-      MaybeEmitInheritedConstructorNote(S, Fn);
+      MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
       return;
     }
 
@@ -9053,7 +9133,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
         << FromTy
         << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
         << (unsigned) isObjectArgument << I+1;
-      MaybeEmitInheritedConstructorNote(S, Fn);
+      MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
       return;
     }
 
@@ -9064,7 +9144,16 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
       << FromTy
       << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
       << (unsigned) isObjectArgument << I+1;
-      MaybeEmitInheritedConstructorNote(S, Fn);
+      MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
+      return;
+    }
+
+    if (FromQs.hasUnaligned() != ToQs.hasUnaligned()) {
+      S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_unaligned)
+        << (unsigned) FnKind << FnDesc
+        << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
+        << FromTy << FromQs.hasUnaligned() << I+1;
+      MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
       return;
     }
 
@@ -9082,7 +9171,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
         << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
         << FromTy << (CVR - 1) << I+1;
     }
-    MaybeEmitInheritedConstructorNote(S, Fn);
+    MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
     return;
   }
 
@@ -9093,7 +9182,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
       << (unsigned) FnKind << FnDesc
       << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
       << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
-    MaybeEmitInheritedConstructorNote(S, Fn);
+    MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
     return;
   }
 
@@ -9104,11 +9193,14 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
   if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
     TempFromTy = PTy->getPointeeType();
   if (TempFromTy->isIncompleteType()) {
+    // Emit the generic diagnostic and, optionally, add the hints to it.
     S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
       << (unsigned) FnKind << FnDesc
       << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
-      << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
-    MaybeEmitInheritedConstructorNote(S, Fn);
+      << FromTy << ToTy << (unsigned) isObjectArgument << I+1
+      << (unsigned) (Cand->Fix.Kind);
+      
+    MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
     return;
   }
 
@@ -9147,7 +9239,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
         << (unsigned) FnKind << FnDesc
         << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
         << (unsigned) isObjectArgument << I + 1;
-      MaybeEmitInheritedConstructorNote(S, Fn);
+      MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
       return;
     }
   }
@@ -9159,7 +9251,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
       << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
       << (BaseToDerivedConversion - 1)
       << FromTy << ToTy << I+1;
-    MaybeEmitInheritedConstructorNote(S, Fn);
+    MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
     return;
   }
 
@@ -9172,7 +9264,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
         << (unsigned) FnKind << FnDesc
         << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
         << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
-        MaybeEmitInheritedConstructorNote(S, Fn);
+        MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
         return;
       }
   }
@@ -9194,7 +9286,7 @@ static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
     FDiag << *HI;
   S.Diag(Fn->getLocation(), FDiag);
 
-  MaybeEmitInheritedConstructorNote(S, Fn);
+  MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
 }
 
 /// Additional arity mismatch diagnosis specific to a function overload
@@ -9228,7 +9320,8 @@ static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
 }
 
 /// General arity mismatch diagnosis over a candidate in a candidate set.
-static void DiagnoseArityMismatch(Sema &S, Decl *D, unsigned NumFormalArgs) {
+static void DiagnoseArityMismatch(Sema &S, NamedDecl *Found, Decl *D,
+                                  unsigned NumFormalArgs) {
   assert(isa<FunctionDecl>(D) &&
       "The templated declaration should at least be a function"
       " when diagnosing bad template argument deduction due to too many"
@@ -9258,7 +9351,8 @@ static void DiagnoseArityMismatch(Sema &S, Decl *D, unsigned NumFormalArgs) {
   }
 
   std::string Description;
-  OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description);
+  OverloadCandidateKind FnKind =
+      ClassifyOverloadCandidate(S, Found, Fn, Description);
 
   if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
     S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
@@ -9268,28 +9362,25 @@ static void DiagnoseArityMismatch(Sema &S, Decl *D, unsigned NumFormalArgs) {
     S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
       << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
       << mode << modeCount << NumFormalArgs;
-  MaybeEmitInheritedConstructorNote(S, Fn);
+  MaybeEmitInheritedConstructorNote(S, Found);
 }
 
 /// Arity mismatch diagnosis specific to a function overload candidate.
 static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
                                   unsigned NumFormalArgs) {
   if (!CheckArityMismatch(S, Cand, NumFormalArgs))
-    DiagnoseArityMismatch(S, Cand->Function, NumFormalArgs);
+    DiagnoseArityMismatch(S, Cand->FoundDecl, Cand->Function, NumFormalArgs);
 }
 
 static TemplateDecl *getDescribedTemplate(Decl *Templated) {
-  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Templated))
-    return FD->getDescribedFunctionTemplate();
-  else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Templated))
-    return RD->getDescribedClassTemplate();
-
+  if (TemplateDecl *TD = Templated->getDescribedTemplate())
+    return TD;
   llvm_unreachable("Unsupported: Getting the described template declaration"
                    " for bad deduction diagnosis");
 }
 
 /// Diagnose a failed template-argument deduction.
-static void DiagnoseBadDeduction(Sema &S, Decl *Templated,
+static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
                                  DeductionFailureInfo &DeductionFailure,
                                  unsigned NumArgs,
                                  bool TakingCandidateAddress) {
@@ -9307,7 +9398,7 @@ static void DiagnoseBadDeduction(Sema &S, Decl *Templated,
     S.Diag(Templated->getLocation(),
            diag::note_ovl_candidate_incomplete_deduction)
         << ParamD->getDeclName();
-    MaybeEmitInheritedConstructorNote(S, Templated);
+    MaybeEmitInheritedConstructorNote(S, Found);
     return;
   }
 
@@ -9332,7 +9423,7 @@ static void DiagnoseBadDeduction(Sema &S, Decl *Templated,
 
     S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
         << ParamD->getDeclName() << Arg << NonCanonParam;
-    MaybeEmitInheritedConstructorNote(S, Templated);
+    MaybeEmitInheritedConstructorNote(S, Found);
     return;
   }
 
@@ -9351,7 +9442,7 @@ static void DiagnoseBadDeduction(Sema &S, Decl *Templated,
            diag::note_ovl_candidate_inconsistent_deduction)
         << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
         << *DeductionFailure.getSecondArg();
-    MaybeEmitInheritedConstructorNote(S, Templated);
+    MaybeEmitInheritedConstructorNote(S, Found);
     return;
   }
 
@@ -9374,18 +9465,18 @@ static void DiagnoseBadDeduction(Sema &S, Decl *Templated,
              diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
           << (index + 1);
     }
-    MaybeEmitInheritedConstructorNote(S, Templated);
+    MaybeEmitInheritedConstructorNote(S, Found);
     return;
 
   case Sema::TDK_TooManyArguments:
   case Sema::TDK_TooFewArguments:
-    DiagnoseArityMismatch(S, Templated, NumArgs);
+    DiagnoseArityMismatch(S, Found, Templated, NumArgs);
     return;
 
   case Sema::TDK_InstantiationDepth:
     S.Diag(Templated->getLocation(),
            diag::note_ovl_candidate_instantiation_depth);
-    MaybeEmitInheritedConstructorNote(S, Templated);
+    MaybeEmitInheritedConstructorNote(S, Found);
     return;
 
   case Sema::TDK_SubstitutionFailure: {
@@ -9423,7 +9514,7 @@ static void DiagnoseBadDeduction(Sema &S, Decl *Templated,
     S.Diag(Templated->getLocation(),
            diag::note_ovl_candidate_substitution_failure)
         << TemplateArgString << SFINAEArgString << R;
-    MaybeEmitInheritedConstructorNote(S, Templated);
+    MaybeEmitInheritedConstructorNote(S, Found);
     return;
   }
 
@@ -9495,7 +9586,7 @@ static void DiagnoseBadDeduction(Sema &S, Decl *Templated,
   // note_ovl_candidate_bad_deduction, which is uselessly vague.
   case Sema::TDK_MiscellaneousDeductionFailure:
     S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
-    MaybeEmitInheritedConstructorNote(S, Templated);
+    MaybeEmitInheritedConstructorNote(S, Found);
     return;
   }
 }
@@ -9509,7 +9600,7 @@ static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
     if (CheckArityMismatch(S, Cand, NumArgs))
       return;
   }
-  DiagnoseBadDeduction(S, Cand->Function, // pattern
+  DiagnoseBadDeduction(S, Cand->FoundDecl, Cand->Function, // pattern
                        Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
 }
 
@@ -9522,7 +9613,8 @@ static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
                            CalleeTarget = S.IdentifyCUDATarget(Callee);
 
   std::string FnDesc;
-  OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc);
+  OverloadCandidateKind FnKind =
+      ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee, FnDesc);
 
   S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
       << (unsigned)FnKind << CalleeTarget << CallerTarget;
@@ -9599,18 +9691,19 @@ static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
   if (Cand->Viable && (Fn->isDeleted() ||
       S.isFunctionConsideredUnavailable(Fn))) {
     std::string FnDesc;
-    OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc);
+    OverloadCandidateKind FnKind =
+        ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
 
     S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
       << FnKind << FnDesc
       << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
-    MaybeEmitInheritedConstructorNote(S, Fn);
+    MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
     return;
   }
 
   // We don't really have anything else to say about viable candidates.
   if (Cand->Viable) {
-    S.NoteOverloadCandidate(Fn);
+    S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
     return;
   }
 
@@ -9620,19 +9713,20 @@ static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
     return DiagnoseArityMismatch(S, Cand, NumArgs);
 
   case ovl_fail_bad_deduction:
-    return DiagnoseBadDeduction(S, Cand, NumArgs, TakingCandidateAddress);
+    return DiagnoseBadDeduction(S, Cand, NumArgs,
+                                TakingCandidateAddress);
 
   case ovl_fail_illegal_constructor: {
     S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
       << (Fn->getPrimaryTemplate() ? 1 : 0);
-    MaybeEmitInheritedConstructorNote(S, Fn);
+    MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
     return;
   }
 
   case ovl_fail_trivial_conversion:
   case ovl_fail_bad_final_conversion:
   case ovl_fail_final_conversion_not_exact:
-    return S.NoteOverloadCandidate(Fn);
+    return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
 
   case ovl_fail_bad_conversion: {
     unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
@@ -9643,7 +9737,7 @@ static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
     // FIXME: this currently happens when we're called from SemaInit
     // when user-conversion overload fails.  Figure out how to handle
     // those conditions and diagnose them well.
-    return S.NoteOverloadCandidate(Fn);
+    return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
   }
 
   case ovl_fail_bad_target:
@@ -9691,7 +9785,6 @@ static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
 
   S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
     << FnType;
-  MaybeEmitInheritedConstructorNote(S, Cand->Surrogate);
 }
 
 static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
@@ -9721,8 +9814,8 @@ static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
     if (ICS.isBad()) break; // all meaningless after first invalid
     if (!ICS.isAmbiguous()) continue;
 
-    ICS.DiagnoseAmbiguousConversion(S, OpLoc,
-                              S.PDiag(diag::note_ambiguous_type_conversion));
+    ICS.DiagnoseAmbiguousConversion(
+        S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion));
   }
 }
 
@@ -10089,7 +10182,7 @@ struct CompareTemplateSpecCandidatesForDisplay {
 /// deductions.
 void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
                                                  bool ForTakingAddress) {
-  DiagnoseBadDeduction(S, Specialization, // pattern
+  DiagnoseBadDeduction(S, FoundDecl, Specialization, // pattern
                        DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
 }
 
@@ -10252,21 +10345,32 @@ public:
       }
     }
 
-    if (S.getLangOpts().CUDA && S.getLangOpts().CUDATargetOverloads &&
-        Matches.size() > 1)
+    if (S.getLangOpts().CUDA && Matches.size() > 1)
       EliminateSuboptimalCudaMatches();
   }
 
   bool hasComplained() const { return HasComplained; }
 
 private:
-  // Is A considered a better overload candidate for the desired type than B?
+  bool candidateHasExactlyCorrectType(const FunctionDecl *FD) {
+    QualType Discard;
+    return Context.hasSameUnqualifiedType(TargetFunctionType, FD->getType()) ||
+           S.IsNoReturnConversion(FD->getType(), TargetFunctionType, Discard);
+  }
+
+  /// \return true if A is considered a better overload candidate for the
+  /// desired type than B.
   bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
-    return hasBetterEnableIfAttrs(S, A, B);
+    // If A doesn't have exactly the correct type, we don't want to classify it
+    // as "better" than anything else. This way, the user is required to
+    // disambiguate for us if there are multiple candidates and no exact match.
+    return candidateHasExactlyCorrectType(A) &&
+           (!candidateHasExactlyCorrectType(B) ||
+            compareEnableIfAttrs(S, A, B) == Comparison::Better);
   }
 
-  // Returns true if we've eliminated any (read: all but one) candidates, false
-  // otherwise.
+  /// \return true if we were able to eliminate all but one overload candidate,
+  /// false otherwise.
   bool eliminiateSuboptimalOverloadCandidates() {
     // Same algorithm as overload resolution -- one pass to pick the "best",
     // another pass to be sure that nothing is better than the best.
@@ -10331,7 +10435,7 @@ private:
                                       Info, /*InOverloadResolution=*/true)) {
       // Make a note of the failed deduction for diagnostics.
       FailedCandidates.addCandidate()
-          .set(FunctionTemplate->getTemplatedDecl(),
+          .set(CurAccessFunPair, FunctionTemplate->getTemplatedDecl(),
                MakeDeductionFailureInfo(Context, Result, Info));
       return false;
     } 
@@ -10339,7 +10443,6 @@ private:
     // Template argument deduction ensures that we have an exact match or
     // compatible pointer-to-function arguments that would be adjusted by ICS.
     // This function template specicalization works.
-    Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl());
     assert(S.isSameOrCompatibleFunctionType(
               Context.getCanonicalType(Specialization->getType()),
               Context.getCanonicalType(TargetFunctionType)));
@@ -10380,12 +10483,9 @@ private:
       if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
         return false;
 
-      QualType ResultTy;
-      if (Context.hasSameUnqualifiedType(TargetFunctionType, 
-                                         FunDecl->getType()) ||
-          S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType,
-                                 ResultTy) ||
-          (!S.getLangOpts().CPlusPlus && TargetType->isVoidPointerType())) {
+      // If we're in C, we need to support types that aren't exactly identical.
+      if (!S.getLangOpts().CPlusPlus ||
+          candidateHasExactlyCorrectType(FunDecl)) {
         Matches.push_back(std::make_pair(
             CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
         FoundNonTemplateFunction = true;
@@ -10451,9 +10551,10 @@ private:
     UnresolvedSetIterator Result = S.getMostSpecialized(
         MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
         SourceExpr->getLocStart(), S.PDiag(),
-        S.PDiag(diag::err_addr_ovl_ambiguous) << Matches[0]
-                                                     .second->getDeclName(),
-        S.PDiag(diag::note_ovl_candidate) << (unsigned)oc_function_template,
+        S.PDiag(diag::err_addr_ovl_ambiguous)
+          << Matches[0].second->getDeclName(),
+        S.PDiag(diag::note_ovl_candidate)
+          << (unsigned)oc_function_template,
         Complain, TargetFunctionType);
 
     if (Result != MatchesCopy.end()) {
@@ -10501,7 +10602,7 @@ public:
         if (FunctionDecl *Fun =
                 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
           if (!functionHasPassObjectSizeParams(Fun))
-            S.NoteOverloadCandidate(Fun, TargetFunctionType,
+            S.NoteOverloadCandidate(*I, Fun, TargetFunctionType,
                                     /*TakingAddress=*/true);
       FailedCandidates.NoteCandidates(S, OvlExpr->getLocStart());
     }
@@ -10614,6 +10715,72 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
 }
 
 /// \brief Given an expression that refers to an overloaded function, try to
+/// resolve that function to a single function that can have its address taken.
+/// This will modify `Pair` iff it returns non-null.
+///
+/// This routine can only realistically succeed if all but one candidates in the
+/// overload set for SrcExpr cannot have their addresses taken.
+FunctionDecl *
+Sema::resolveAddressOfOnlyViableOverloadCandidate(Expr *E,
+                                                  DeclAccessPair &Pair) {
+  OverloadExpr::FindResult R = OverloadExpr::find(E);
+  OverloadExpr *Ovl = R.Expression;
+  FunctionDecl *Result = nullptr;
+  DeclAccessPair DAP;
+  // Don't use the AddressOfResolver because we're specifically looking for
+  // cases where we have one overload candidate that lacks
+  // enable_if/pass_object_size/...
+  for (auto I = Ovl->decls_begin(), E = Ovl->decls_end(); I != E; ++I) {
+    auto *FD = dyn_cast<FunctionDecl>(I->getUnderlyingDecl());
+    if (!FD)
+      return nullptr;
+
+    if (!checkAddressOfFunctionIsAvailable(FD))
+      continue;
+
+    // We have more than one result; quit.
+    if (Result)
+      return nullptr;
+    DAP = I.getPair();
+    Result = FD;
+  }
+
+  if (Result)
+    Pair = DAP;
+  return Result;
+}
+
+/// \brief Given an overloaded function, tries to turn it into a non-overloaded
+/// function reference using resolveAddressOfOnlyViableOverloadCandidate. This
+/// will perform access checks, diagnose the use of the resultant decl, and, if
+/// necessary, perform a function-to-pointer decay.
+///
+/// Returns false if resolveAddressOfOnlyViableOverloadCandidate fails.
+/// Otherwise, returns true. This may emit diagnostics and return true.
+bool Sema::resolveAndFixAddressOfOnlyViableOverloadCandidate(
+    ExprResult &SrcExpr) {
+  Expr *E = SrcExpr.get();
+  assert(E->getType() == Context.OverloadTy && "SrcExpr must be an overload");
+
+  DeclAccessPair DAP;
+  FunctionDecl *Found = resolveAddressOfOnlyViableOverloadCandidate(E, DAP);
+  if (!Found)
+    return false;
+
+  // Emitting multiple diagnostics for a function that is both inaccessible and
+  // unavailable is consistent with our behavior elsewhere. So, always check
+  // for both.
+  DiagnoseUseOfDecl(Found, E->getExprLoc());
+  CheckAddressOfMemberAccess(E, DAP);
+  Expr *Fixed = FixOverloadedFunctionReference(E, DAP, Found);
+  if (Fixed->getType()->isFunctionType())
+    SrcExpr = DefaultFunctionArrayConversion(Fixed, /*Diagnose=*/false);
+  else
+    SrcExpr = Fixed;
+  return true;
+}
+
+/// \brief Given an expression that refers to an overloaded function, try to
 /// resolve that overloaded function expression down to a single function.
 ///
 /// This routine can only resolve template-ids that refer to a single function
@@ -10671,7 +10838,7 @@ Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
       // Make a note of the failed deduction for diagnostics.
       // TODO: Actually use the failed-deduction info?
       FailedCandidates.addCandidate()
-          .set(FunctionTemplate->getTemplatedDecl(),
+          .set(I.getPair(), FunctionTemplate->getTemplatedDecl(),
                MakeDeductionFailureInfo(Context, Result, Info));
       continue;
     }
@@ -12236,6 +12403,16 @@ Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
              << MD->getDeclName();
     }
   }
+
+  if (CXXDestructorDecl *DD =
+          dyn_cast<CXXDestructorDecl>(TheCall->getMethodDecl())) {
+    // a->A::f() doesn't go through the vtable, except in AppleKext mode.
+    bool CallCanBeVirtual = !MemExpr->hasQualifier() || getLangOpts().AppleKext;
+    CheckVirtualDtorCall(DD, MemExpr->getLocStart(), /*IsDelete=*/false,
+                         CallCanBeVirtual, /*WarnOnNonAbstractTypes=*/true,
+                         MemExpr->getMemberLoc());
+  }
+
   return MaybeBindToTemporary(TheCall);
 }
 
@@ -12843,6 +13020,9 @@ Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
           = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
         QualType MemPtrType
           = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
+        // Under the MS ABI, lock down the inheritance model now.
+        if (Context.getTargetInfo().getCXXABI().isMicrosoft())
+          (void)isCompleteType(UnOp->getOperatorLoc(), MemPtrType);
 
         return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType,
                                            VK_RValue, OK_Ordinary,