vendor/clang/clang-trunk-r366426

1 files changed, 310 insertions, 155 deletions

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 5536358b1ecf1..21cf9da18a8b2 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1,9 +1,8 @@
 //===- Decl.cpp - Declaration AST Node Implementation ---------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -568,7 +567,14 @@ static bool isSingleLineLanguageLinkage(const Decl &D) {
   return false;
 }
 
-static bool isExportedFromModuleIntefaceUnit(const NamedDecl *D) {
+/// Determine whether D is declared in the purview of a named module.
+static bool isInModulePurview(const NamedDecl *D) {
+  if (auto *M = D->getOwningModule())
+    return M->isModulePurview();
+  return false;
+}
+
+static bool isExportedFromModuleInterfaceUnit(const NamedDecl *D) {
   // FIXME: Handle isModulePrivate.
   switch (D->getModuleOwnershipKind()) {
   case Decl::ModuleOwnershipKind::Unowned:
@@ -576,8 +582,7 @@ static bool isExportedFromModuleIntefaceUnit(const NamedDecl *D) {
     return false;
   case Decl::ModuleOwnershipKind::Visible:
   case Decl::ModuleOwnershipKind::VisibleWhenImported:
-    if (auto *M = D->getOwningModule())
-      return M->Kind == Module::ModuleInterfaceUnit;
+    return isInModulePurview(D);
   }
   llvm_unreachable("unexpected module ownership kind");
 }
@@ -587,9 +592,8 @@ static LinkageInfo getInternalLinkageFor(const NamedDecl *D) {
   // as "module-internal linkage", which means that they have internal linkage
   // formally but can be indirectly accessed from outside the module via inline
   // functions and templates defined within the module.
-  if (auto *M = D->getOwningModule())
-    if (M->Kind == Module::ModuleInterfaceUnit)
-      return LinkageInfo(ModuleInternalLinkage, DefaultVisibility, false);
+  if (isInModulePurview(D))
+    return LinkageInfo(ModuleInternalLinkage, DefaultVisibility, false);
 
   return LinkageInfo::internal();
 }
@@ -599,15 +603,25 @@ static LinkageInfo getExternalLinkageFor(const NamedDecl *D) {
   //   - A name declared at namespace scope that does not have internal linkage
   //     by the previous rules and that is introduced by a non-exported
   //     declaration has module linkage.
-  if (auto *M = D->getOwningModule())
-    if (M->Kind == Module::ModuleInterfaceUnit)
-      if (!isExportedFromModuleIntefaceUnit(
-              cast<NamedDecl>(D->getCanonicalDecl())))
-        return LinkageInfo(ModuleLinkage, DefaultVisibility, false);
+  if (isInModulePurview(D) && !isExportedFromModuleInterfaceUnit(
+                                  cast<NamedDecl>(D->getCanonicalDecl())))
+    return LinkageInfo(ModuleLinkage, DefaultVisibility, false);
 
   return LinkageInfo::external();
 }
 
+static StorageClass getStorageClass(const Decl *D) {
+  if (auto *TD = dyn_cast<TemplateDecl>(D))
+    D = TD->getTemplatedDecl();
+  if (D) {
+    if (auto *VD = dyn_cast<VarDecl>(D))
+      return VD->getStorageClass();
+    if (auto *FD = dyn_cast<FunctionDecl>(D))
+      return FD->getStorageClass();
+  }
+  return SC_None;
+}
+
 LinkageInfo
 LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
                                             LVComputationKind computation,
@@ -619,24 +633,28 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
   // C++ [basic.link]p3:
   //   A name having namespace scope (3.3.6) has internal linkage if it
   //   is the name of
-  //     - an object, reference, function or function template that is
-  //       explicitly declared static; or,
-  // (This bullet corresponds to C99 6.2.2p3.)
+
+  if (getStorageClass(D->getCanonicalDecl()) == SC_Static) {
+    // - a variable, variable template, function, or function template
+    //   that is explicitly declared static; or
+    // (This bullet corresponds to C99 6.2.2p3.)
+    return getInternalLinkageFor(D);
+  }
+
   if (const auto *Var = dyn_cast<VarDecl>(D)) {
-    // Explicitly declared static.
-    if (Var->getStorageClass() == SC_Static)
-      return getInternalLinkageFor(Var);
-
-    // - a non-inline, non-volatile object or reference that is explicitly
-    //   declared const or constexpr and neither explicitly declared extern
-    //   nor previously declared to have external linkage; or (there is no
-    //   equivalent in C99)
-    // The C++ modules TS adds "non-exported" to this list.
+    // - a non-template variable of non-volatile const-qualified type, unless
+    //   - it is explicitly declared extern, or
+    //   - it is inline or exported, or
+    //   - it was previously declared and the prior declaration did not have
+    //     internal linkage
+    // (There is no equivalent in C99.)
     if (Context.getLangOpts().CPlusPlus &&
         Var->getType().isConstQualified() &&
         !Var->getType().isVolatileQualified() &&
         !Var->isInline() &&
-        !isExportedFromModuleIntefaceUnit(Var)) {
+        !isExportedFromModuleInterfaceUnit(Var) &&
+        !isa<VarTemplateSpecializationDecl>(Var) &&
+        !Var->getDescribedVarTemplate()) {
       const VarDecl *PrevVar = Var->getPreviousDecl();
       if (PrevVar)
         return getLVForDecl(PrevVar, computation);
@@ -656,14 +674,6 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
       if (PrevVar->getStorageClass() == SC_Static)
         return getInternalLinkageFor(Var);
     }
-  } else if (const FunctionDecl *Function = D->getAsFunction()) {
-    // C++ [temp]p4:
-    //   A non-member function template can have internal linkage; any
-    //   other template name shall have external linkage.
-
-    // Explicitly declared static.
-    if (Function->getCanonicalDecl()->getStorageClass() == SC_Static)
-      return getInternalLinkageFor(Function);
   } else if (const auto *IFD = dyn_cast<IndirectFieldDecl>(D)) {
     //   - a data member of an anonymous union.
     const VarDecl *VD = IFD->getVarDecl();
@@ -672,6 +682,8 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
   }
   assert(!isa<FieldDecl>(D) && "Didn't expect a FieldDecl!");
 
+  // FIXME: This gives internal linkage to names that should have no linkage
+  // (those not covered by [basic.link]p6).
   if (D->isInAnonymousNamespace()) {
     const auto *Var = dyn_cast<VarDecl>(D);
     const auto *Func = dyn_cast<FunctionDecl>(D);
@@ -731,10 +743,20 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
 
   // C++ [basic.link]p4:
 
-  //   A name having namespace scope has external linkage if it is the
-  //   name of
+  //   A name having namespace scope that has not been given internal linkage
+  //   above and that is the name of
+  //   [...bullets...]
+  //   has its linkage determined as follows:
+  //     - if the enclosing namespace has internal linkage, the name has
+  //       internal linkage; [handled above]
+  //     - otherwise, if the declaration of the name is attached to a named
+  //       module and is not exported, the name has module linkage;
+  //     - otherwise, the name has external linkage.
+  // LV is currently set up to handle the last two bullets.
   //
-  //     - an object or reference, unless it has internal linkage; or
+  //   The bullets are:
+
+  //     - a variable; or
   if (const auto *Var = dyn_cast<VarDecl>(D)) {
     // GCC applies the following optimization to variables and static
     // data members, but not to functions:
@@ -780,7 +802,7 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
       mergeTemplateLV(LV, spec, computation);
     }
 
-  //     - a function, unless it has internal linkage; or
+  //     - a function; or
   } else if (const auto *Function = dyn_cast<FunctionDecl>(D)) {
     // In theory, we can modify the function's LV by the LV of its
     // type unless it has C linkage (see comment above about variables
@@ -834,7 +856,8 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
       mergeTemplateLV(LV, spec, computation);
     }
 
-  //     - an enumerator belonging to an enumeration with external linkage;
+  // FIXME: This is not part of the C++ standard any more.
+  //     - an enumerator belonging to an enumeration with external linkage; or
   } else if (isa<EnumConstantDecl>(D)) {
     LinkageInfo EnumLV = getLVForDecl(cast<NamedDecl>(D->getDeclContext()),
                                       computation);
@@ -842,16 +865,16 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
       return LinkageInfo::none();
     LV.merge(EnumLV);
 
-  //     - a template, unless it is a function template that has
-  //       internal linkage (Clause 14);
+  //     - a template
   } else if (const auto *temp = dyn_cast<TemplateDecl>(D)) {
     bool considerVisibility = !hasExplicitVisibilityAlready(computation);
     LinkageInfo tempLV =
       getLVForTemplateParameterList(temp->getTemplateParameters(), computation);
     LV.mergeMaybeWithVisibility(tempLV, considerVisibility);
 
-  //     - a namespace (7.3), unless it is declared within an unnamed
-  //       namespace.
+  //     An unnamed namespace or a namespace declared directly or indirectly
+  //     within an unnamed namespace has internal linkage. All other namespaces
+  //     have external linkage.
   //
   // We handled names in anonymous namespaces above.
   } else if (isa<NamespaceDecl>(D)) {
@@ -1508,6 +1531,11 @@ Module *Decl::getOwningModuleForLinkage(bool IgnoreLinkage) const {
     }
     return InternalLinkage ? M->Parent : nullptr;
   }
+
+  case Module::PrivateModuleFragment:
+    // The private module fragment is part of its containing module for linkage
+    // purposes.
+    return M->Parent;
   }
 
   llvm_unreachable("unknown module kind");
@@ -1532,10 +1560,16 @@ void NamedDecl::printQualifiedName(raw_ostream &OS,
                                    const PrintingPolicy &P) const {
   const DeclContext *Ctx = getDeclContext();
 
-  // For ObjC methods, look through categories and use the interface as context.
+  // For ObjC methods and properties, look through categories and use the
+  // interface as context.
   if (auto *MD = dyn_cast<ObjCMethodDecl>(this))
     if (auto *ID = MD->getClassInterface())
       Ctx = ID;
+  if (auto *PD = dyn_cast<ObjCPropertyDecl>(this)) {
+    if (auto *MD = PD->getGetterMethodDecl())
+      if (auto *ID = MD->getClassInterface())
+        Ctx = ID;
+  }
 
   if (Ctx->isFunctionOrMethod()) {
     printName(OS);
@@ -2211,12 +2245,16 @@ void VarDecl::setInit(Expr *I) {
   Init = I;
 }
 
-bool VarDecl::isUsableInConstantExpressions(ASTContext &C) const {
+bool VarDecl::mightBeUsableInConstantExpressions(ASTContext &C) const {
   const LangOptions &Lang = C.getLangOpts();
 
   if (!Lang.CPlusPlus)
     return false;
 
+  // Function parameters are never usable in constant expressions.
+  if (isa<ParmVarDecl>(this))
+    return false;
+
   // In C++11, any variable of reference type can be used in a constant
   // expression if it is initialized by a constant expression.
   if (Lang.CPlusPlus11 && getType()->isReferenceType())
@@ -2238,6 +2276,22 @@ bool VarDecl::isUsableInConstantExpressions(ASTContext &C) const {
   return Lang.CPlusPlus11 && isConstexpr();
 }
 
+bool VarDecl::isUsableInConstantExpressions(ASTContext &Context) const {
+  // C++2a [expr.const]p3:
+  //   A variable is usable in constant expressions after its initializing
+  //   declaration is encountered...
+  const VarDecl *DefVD = nullptr;
+  const Expr *Init = getAnyInitializer(DefVD);
+  if (!Init || Init->isValueDependent() || getType()->isDependentType())
+    return false;
+  //   ... if it is a constexpr variable, or it is of reference type or of
+  //   const-qualified integral or enumeration type, ...
+  if (!DefVD->mightBeUsableInConstantExpressions(Context))
+    return false;
+  //   ... and its initializer is a constant initializer.
+  return DefVD->checkInitIsICE();
+}
+
 /// Convert the initializer for this declaration to the elaborated EvaluatedStmt
 /// form, which contains extra information on the evaluated value of the
 /// initializer.
@@ -2268,7 +2322,7 @@ APValue *VarDecl::evaluateValue(
   // first time it is evaluated. FIXME: The notes won't always be emitted the
   // first time we try evaluation, so might not be produced at all.
   if (Eval->WasEvaluated)
-    return Eval->Evaluated.isUninit() ? nullptr : &Eval->Evaluated;
+    return Eval->Evaluated.isAbsent() ? nullptr : &Eval->Evaluated;
 
   const auto *Init = cast<Expr>(Eval->Value);
   assert(!Init->isValueDependent());
@@ -2363,6 +2417,10 @@ bool VarDecl::checkInitIsICE() const {
   return Eval->IsICE;
 }
 
+bool VarDecl::isParameterPack() const {
+  return isa<PackExpansionType>(getType());
+}
+
 template<typename DeclT>
 static DeclT *getDefinitionOrSelf(DeclT *D) {
   assert(D);
@@ -2380,48 +2438,61 @@ bool VarDecl::isNonEscapingByref() const {
 }
 
 VarDecl *VarDecl::getTemplateInstantiationPattern() const {
-  // If it's a variable template specialization, find the template or partial
-  // specialization from which it was instantiated.
-  if (auto *VDTemplSpec = dyn_cast<VarTemplateSpecializationDecl>(this)) {
-    auto From = VDTemplSpec->getInstantiatedFrom();
-    if (auto *VTD = From.dyn_cast<VarTemplateDecl *>()) {
-      while (auto *NewVTD = VTD->getInstantiatedFromMemberTemplate()) {
-        if (NewVTD->isMemberSpecialization())
-          break;
-        VTD = NewVTD;
-      }
-      return getDefinitionOrSelf(VTD->getTemplatedDecl());
-    }
-    if (auto *VTPSD =
-            From.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
-      while (auto *NewVTPSD = VTPSD->getInstantiatedFromMember()) {
-        if (NewVTPSD->isMemberSpecialization())
-          break;
-        VTPSD = NewVTPSD;
-      }
-      return getDefinitionOrSelf<VarDecl>(VTPSD);
-    }
-  }
+  const VarDecl *VD = this;
 
-  if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo()) {
+  // If this is an instantiated member, walk back to the template from which
+  // it was instantiated.
+  if (MemberSpecializationInfo *MSInfo = VD->getMemberSpecializationInfo()) {
     if (isTemplateInstantiation(MSInfo->getTemplateSpecializationKind())) {
-      VarDecl *VD = getInstantiatedFromStaticDataMember();
+      VD = VD->getInstantiatedFromStaticDataMember();
       while (auto *NewVD = VD->getInstantiatedFromStaticDataMember())
         VD = NewVD;
-      return getDefinitionOrSelf(VD);
     }
   }
 
-  if (VarTemplateDecl *VarTemplate = getDescribedVarTemplate()) {
-    while (VarTemplate->getInstantiatedFromMemberTemplate()) {
-      if (VarTemplate->isMemberSpecialization())
+  // If it's an instantiated variable template specialization, find the
+  // template or partial specialization from which it was instantiated.
+  if (auto *VDTemplSpec = dyn_cast<VarTemplateSpecializationDecl>(VD)) {
+    if (isTemplateInstantiation(VDTemplSpec->getTemplateSpecializationKind())) {
+      auto From = VDTemplSpec->getInstantiatedFrom();
+      if (auto *VTD = From.dyn_cast<VarTemplateDecl *>()) {
+        while (!VTD->isMemberSpecialization()) {
+          auto *NewVTD = VTD->getInstantiatedFromMemberTemplate();
+          if (!NewVTD)
+            break;
+          VTD = NewVTD;
+        }
+        return getDefinitionOrSelf(VTD->getTemplatedDecl());
+      }
+      if (auto *VTPSD =
+              From.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
+        while (!VTPSD->isMemberSpecialization()) {
+          auto *NewVTPSD = VTPSD->getInstantiatedFromMember();
+          if (!NewVTPSD)
+            break;
+          VTPSD = NewVTPSD;
+        }
+        return getDefinitionOrSelf<VarDecl>(VTPSD);
+      }
+    }
+  }
+
+  // If this is the pattern of a variable template, find where it was
+  // instantiated from. FIXME: Is this necessary?
+  if (VarTemplateDecl *VarTemplate = VD->getDescribedVarTemplate()) {
+    while (!VarTemplate->isMemberSpecialization()) {
+      auto *NewVT = VarTemplate->getInstantiatedFromMemberTemplate();
+      if (!NewVT)
         break;
-      VarTemplate = VarTemplate->getInstantiatedFromMemberTemplate();
+      VarTemplate = NewVT;
     }
 
     return getDefinitionOrSelf(VarTemplate->getTemplatedDecl());
   }
-  return nullptr;
+
+  if (VD == this)
+    return nullptr;
+  return getDefinitionOrSelf(const_cast<VarDecl*>(VD));
 }
 
 VarDecl *VarDecl::getInstantiatedFromStaticDataMember() const {
@@ -2441,6 +2512,17 @@ TemplateSpecializationKind VarDecl::getTemplateSpecializationKind() const {
   return TSK_Undeclared;
 }
 
+TemplateSpecializationKind
+VarDecl::getTemplateSpecializationKindForInstantiation() const {
+  if (MemberSpecializationInfo *MSI = getMemberSpecializationInfo())
+    return MSI->getTemplateSpecializationKind();
+
+  if (const auto *Spec = dyn_cast<VarTemplateSpecializationDecl>(this))
+    return Spec->getSpecializationKind();
+
+  return TSK_Undeclared;
+}
+
 SourceLocation VarDecl::getPointOfInstantiation() const {
   if (const auto *Spec = dyn_cast<VarTemplateSpecializationDecl>(this))
     return Spec->getPointOfInstantiation();
@@ -2501,15 +2583,14 @@ void VarDecl::setTemplateSpecializationKind(TemplateSpecializationKind TSK,
   if (VarTemplateSpecializationDecl *Spec =
           dyn_cast<VarTemplateSpecializationDecl>(this)) {
     Spec->setSpecializationKind(TSK);
-    if (TSK != TSK_ExplicitSpecialization && PointOfInstantiation.isValid() &&
+    if (TSK != TSK_ExplicitSpecialization &&
+        PointOfInstantiation.isValid() &&
         Spec->getPointOfInstantiation().isInvalid()) {
       Spec->setPointOfInstantiation(PointOfInstantiation);
       if (ASTMutationListener *L = getASTContext().getASTMutationListener())
         L->InstantiationRequested(this);
     }
-  }
-
-  if (MemberSpecializationInfo *MSI = getMemberSpecializationInfo()) {
+  } else if (MemberSpecializationInfo *MSI = getMemberSpecializationInfo()) {
     MSI->setTemplateSpecializationKind(TSK);
     if (TSK != TSK_ExplicitSpecialization && PointOfInstantiation.isValid() &&
         MSI->getPointOfInstantiation().isInvalid()) {
@@ -2626,10 +2707,6 @@ bool ParmVarDecl::hasDefaultArg() const {
          !Init.isNull();
 }
 
-bool ParmVarDecl::isParameterPack() const {
-  return isa<PackExpansionType>(getType());
-}
-
 void ParmVarDecl::setParameterIndexLarge(unsigned parameterIndex) {
   getASTContext().setParameterIndex(this, parameterIndex);
   ParmVarDeclBits.ParameterIndex = ParameterIndexSentinel;
@@ -2647,7 +2724,8 @@ FunctionDecl::FunctionDecl(Kind DK, ASTContext &C, DeclContext *DC,
                            SourceLocation StartLoc,
                            const DeclarationNameInfo &NameInfo, QualType T,
                            TypeSourceInfo *TInfo, StorageClass S,
-                           bool isInlineSpecified, bool isConstexprSpecified)
+                           bool isInlineSpecified,
+                           ConstexprSpecKind ConstexprKind)
     : DeclaratorDecl(DK, DC, NameInfo.getLoc(), NameInfo.getName(), T, TInfo,
                      StartLoc),
       DeclContext(DK), redeclarable_base(C), ODRHash(0),
@@ -2656,7 +2734,6 @@ FunctionDecl::FunctionDecl(Kind DK, ASTContext &C, DeclContext *DC,
   FunctionDeclBits.SClass = S;
   FunctionDeclBits.IsInline = isInlineSpecified;
   FunctionDeclBits.IsInlineSpecified = isInlineSpecified;
-  FunctionDeclBits.IsExplicitSpecified = false;
   FunctionDeclBits.IsVirtualAsWritten = false;
   FunctionDeclBits.IsPure = false;
   FunctionDeclBits.HasInheritedPrototype = false;
@@ -2668,7 +2745,7 @@ FunctionDecl::FunctionDecl(Kind DK, ASTContext &C, DeclContext *DC,
   FunctionDeclBits.IsExplicitlyDefaulted = false;
   FunctionDeclBits.HasImplicitReturnZero = false;
   FunctionDeclBits.IsLateTemplateParsed = false;
-  FunctionDeclBits.IsConstexpr = isConstexprSpecified;
+  FunctionDeclBits.ConstexprKind = ConstexprKind;
   FunctionDeclBits.InstantiationIsPending = false;
   FunctionDeclBits.UsesSEHTry = false;
   FunctionDeclBits.HasSkippedBody = false;
@@ -2904,6 +2981,8 @@ bool FunctionDecl::isExternC() const {
 }
 
 bool FunctionDecl::isInExternCContext() const {
+  if (hasAttr<OpenCLKernelAttr>())
+    return true;
   return getLexicalDeclContext()->isExternCContext();
 }
 
@@ -2982,16 +3061,20 @@ FunctionDecl::setPreviousDeclaration(FunctionDecl *PrevDecl) {
 
 FunctionDecl *FunctionDecl::getCanonicalDecl() { return getFirstDecl(); }
 
-/// Returns a value indicating whether this function
-/// corresponds to a builtin function.
+/// Returns a value indicating whether this function corresponds to a builtin
+/// function.
 ///
-/// The function corresponds to a built-in function if it is
-/// declared at translation scope or within an extern "C" block and
-/// its name matches with the name of a builtin. The returned value
-/// will be 0 for functions that do not correspond to a builtin, a
-/// value of type \c Builtin::ID if in the target-independent range
-/// \c [1,Builtin::First), or a target-specific builtin value.
-unsigned FunctionDecl::getBuiltinID() const {
+/// The function corresponds to a built-in function if it is declared at
+/// translation scope or within an extern "C" block and its name matches with
+/// the name of a builtin. The returned value will be 0 for functions that do
+/// not correspond to a builtin, a value of type \c Builtin::ID if in the
+/// target-independent range \c [1,Builtin::First), or a target-specific builtin
+/// value.
+///
+/// \param ConsiderWrapperFunctions If true, we should consider wrapper
+/// functions as their wrapped builtins. This shouldn't be done in general, but
+/// it's useful in Sema to diagnose calls to wrappers based on their semantics.
+unsigned FunctionDecl::getBuiltinID(bool ConsiderWrapperFunctions) const {
   if (!getIdentifier())
     return 0;
 
@@ -3019,7 +3102,7 @@ unsigned FunctionDecl::getBuiltinID() const {
 
   // If the function is marked "overloadable", it has a different mangled name
   // and is not the C library function.
-  if (hasAttr<OverloadableAttr>())
+  if (!ConsiderWrapperFunctions && hasAttr<OverloadableAttr>())
     return 0;
 
   if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
@@ -3030,7 +3113,7 @@ unsigned FunctionDecl::getBuiltinID() const {
   // function or whether it just has the same name.
 
   // If this is a static function, it's not a builtin.
-  if (getStorageClass() == SC_Static)
+  if (!ConsiderWrapperFunctions && getStorageClass() == SC_Static)
     return 0;
 
   // OpenCL v1.2 s6.9.f - The library functions defined in
@@ -3337,7 +3420,13 @@ FunctionDecl *FunctionDecl::getInstantiatedFromMemberFunction() const {
 }
 
 MemberSpecializationInfo *FunctionDecl::getMemberSpecializationInfo() const {
-  return TemplateOrSpecialization.dyn_cast<MemberSpecializationInfo *>();
+  if (auto *MSI =
+          TemplateOrSpecialization.dyn_cast<MemberSpecializationInfo *>())
+    return MSI;
+  if (auto *FTSI = TemplateOrSpecialization
+                       .dyn_cast<FunctionTemplateSpecializationInfo *>())
+    return FTSI->getMemberSpecializationInfo();
+  return nullptr;
 }
 
 void
@@ -3356,6 +3445,8 @@ FunctionTemplateDecl *FunctionDecl::getDescribedFunctionTemplate() const {
 }
 
 void FunctionDecl::setDescribedFunctionTemplate(FunctionTemplateDecl *Template) {
+  assert(TemplateOrSpecialization.isNull() &&
+         "Member function is already a specialization");
   TemplateOrSpecialization = Template;
 }
 
@@ -3364,19 +3455,15 @@ bool FunctionDecl::isImplicitlyInstantiable() const {
   if (isInvalidDecl())
     return false;
 
-  switch (getTemplateSpecializationKind()) {
+  switch (getTemplateSpecializationKindForInstantiation()) {
   case TSK_Undeclared:
   case TSK_ExplicitInstantiationDefinition:
+  case TSK_ExplicitSpecialization:
     return false;
 
   case TSK_ImplicitInstantiation:
     return true;
 
-  // It is possible to instantiate TSK_ExplicitSpecialization kind
-  // if the FunctionDecl has a class scope specialization pattern.
-  case TSK_ExplicitSpecialization:
-    return getClassScopeSpecializationPattern() != nullptr;
-
   case TSK_ExplicitInstantiationDeclaration:
     // Handled below.
     break;
@@ -3399,26 +3486,12 @@ bool FunctionDecl::isImplicitlyInstantiable() const {
 }
 
 bool FunctionDecl::isTemplateInstantiation() const {
-  switch (getTemplateSpecializationKind()) {
-    case TSK_Undeclared:
-    case TSK_ExplicitSpecialization:
-      return false;
-    case TSK_ImplicitInstantiation:
-    case TSK_ExplicitInstantiationDeclaration:
-    case TSK_ExplicitInstantiationDefinition:
-      return true;
-  }
-  llvm_unreachable("All TSK values handled.");
+  // FIXME: Remove this, it's not clear what it means. (Which template
+  // specialization kind?)
+  return clang::isTemplateInstantiation(getTemplateSpecializationKind());
 }
 
 FunctionDecl *FunctionDecl::getTemplateInstantiationPattern() const {
-  // Handle class scope explicit specialization special case.
-  if (getTemplateSpecializationKind() == TSK_ExplicitSpecialization) {
-    if (auto *Spec = getClassScopeSpecializationPattern())
-      return getDefinitionOrSelf(Spec);
-    return nullptr;
-  }
-
   // If this is a generic lambda call operator specialization, its
   // instantiation pattern is always its primary template's pattern
   // even if its primary template was instantiated from another
@@ -3434,21 +3507,28 @@ FunctionDecl *FunctionDecl::getTemplateInstantiationPattern() const {
     return getDefinitionOrSelf(getPrimaryTemplate()->getTemplatedDecl());
   }
 
+  if (MemberSpecializationInfo *Info = getMemberSpecializationInfo()) {
+    if (!clang::isTemplateInstantiation(Info->getTemplateSpecializationKind()))
+      return nullptr;
+    return getDefinitionOrSelf(cast<FunctionDecl>(Info->getInstantiatedFrom()));
+  }
+
+  if (!clang::isTemplateInstantiation(getTemplateSpecializationKind()))
+    return nullptr;
+
   if (FunctionTemplateDecl *Primary = getPrimaryTemplate()) {
-    while (Primary->getInstantiatedFromMemberTemplate()) {
-      // If we have hit a point where the user provided a specialization of
-      // this template, we're done looking.
-      if (Primary->isMemberSpecialization())
+    // If we hit a point where the user provided a specialization of this
+    // template, we're done looking.
+    while (!Primary->isMemberSpecialization()) {
+      auto *NewPrimary = Primary->getInstantiatedFromMemberTemplate();
+      if (!NewPrimary)
         break;
-      Primary = Primary->getInstantiatedFromMemberTemplate();
+      Primary = NewPrimary;
     }
 
     return getDefinitionOrSelf(Primary->getTemplatedDecl());
   }
 
-  if (auto *MFD = getInstantiatedFromMemberFunction())
-    return getDefinitionOrSelf(MFD);
-
   return nullptr;
 }
 
@@ -3456,15 +3536,11 @@ FunctionTemplateDecl *FunctionDecl::getPrimaryTemplate() const {
   if (FunctionTemplateSpecializationInfo *Info
         = TemplateOrSpecialization
             .dyn_cast<FunctionTemplateSpecializationInfo*>()) {
-    return Info->Template.getPointer();
+    return Info->getTemplate();
   }
   return nullptr;
 }
 
-FunctionDecl *FunctionDecl::getClassScopeSpecializationPattern() const {
-    return getASTContext().getClassScopeSpecializationPattern(this);
-}
-
 FunctionTemplateSpecializationInfo *
 FunctionDecl::getTemplateSpecializationInfo() const {
   return TemplateOrSpecialization
@@ -3499,15 +3575,19 @@ FunctionDecl::setFunctionTemplateSpecialization(ASTContext &C,
                                                 TemplateSpecializationKind TSK,
                         const TemplateArgumentListInfo *TemplateArgsAsWritten,
                                           SourceLocation PointOfInstantiation) {
+  assert((TemplateOrSpecialization.isNull() ||
+          TemplateOrSpecialization.is<MemberSpecializationInfo *>()) &&
+         "Member function is already a specialization");
   assert(TSK != TSK_Undeclared &&
          "Must specify the type of function template specialization");
-  FunctionTemplateSpecializationInfo *Info
-    = TemplateOrSpecialization.dyn_cast<FunctionTemplateSpecializationInfo*>();
-  if (!Info)
-    Info = FunctionTemplateSpecializationInfo::Create(C, this, Template, TSK,
-                                                      TemplateArgs,
-                                                      TemplateArgsAsWritten,
-                                                      PointOfInstantiation);
+  assert((TemplateOrSpecialization.isNull() ||
+          TSK == TSK_ExplicitSpecialization) &&
+         "Member specialization must be an explicit specialization");
+  FunctionTemplateSpecializationInfo *Info =
+      FunctionTemplateSpecializationInfo::Create(
+          C, this, Template, TSK, TemplateArgs, TemplateArgsAsWritten,
+          PointOfInstantiation,
+          TemplateOrSpecialization.dyn_cast<MemberSpecializationInfo *>());
   TemplateOrSpecialization = Info;
   Template->addSpecialization(Info, InsertPos);
 }
@@ -3558,14 +3638,47 @@ DependentFunctionTemplateSpecializationInfo(const UnresolvedSetImpl &Ts,
 TemplateSpecializationKind FunctionDecl::getTemplateSpecializationKind() const {
   // For a function template specialization, query the specialization
   // information object.
-  FunctionTemplateSpecializationInfo *FTSInfo
-    = TemplateOrSpecialization.dyn_cast<FunctionTemplateSpecializationInfo*>();
-  if (FTSInfo)
+  if (FunctionTemplateSpecializationInfo *FTSInfo =
+          TemplateOrSpecialization
+              .dyn_cast<FunctionTemplateSpecializationInfo *>())
+    return FTSInfo->getTemplateSpecializationKind();
+
+  if (MemberSpecializationInfo *MSInfo =
+          TemplateOrSpecialization.dyn_cast<MemberSpecializationInfo *>())
+    return MSInfo->getTemplateSpecializationKind();
+
+  return TSK_Undeclared;
+}
+
+TemplateSpecializationKind
+FunctionDecl::getTemplateSpecializationKindForInstantiation() const {
+  // This is the same as getTemplateSpecializationKind(), except that for a
+  // function that is both a function template specialization and a member
+  // specialization, we prefer the member specialization information. Eg:
+  //
+  // template<typename T> struct A {
+  //   template<typename U> void f() {}
+  //   template<> void f<int>() {}
+  // };
+  //
+  // For A<int>::f<int>():
+  // * getTemplateSpecializationKind() will return TSK_ExplicitSpecialization
+  // * getTemplateSpecializationKindForInstantiation() will return
+  //       TSK_ImplicitInstantiation
+  //
+  // This reflects the facts that A<int>::f<int> is an explicit specialization
+  // of A<int>::f, and that A<int>::f<int> should be implicitly instantiated
+  // from A::f<int> if a definition is needed.
+  if (FunctionTemplateSpecializationInfo *FTSInfo =
+          TemplateOrSpecialization
+              .dyn_cast<FunctionTemplateSpecializationInfo *>()) {
+    if (auto *MSInfo = FTSInfo->getMemberSpecializationInfo())
+      return MSInfo->getTemplateSpecializationKind();
     return FTSInfo->getTemplateSpecializationKind();
+  }
 
-  MemberSpecializationInfo *MSInfo
-    = TemplateOrSpecialization.dyn_cast<MemberSpecializationInfo*>();
-  if (MSInfo)
+  if (MemberSpecializationInfo *MSInfo =
+          TemplateOrSpecialization.dyn_cast<MemberSpecializationInfo *>())
     return MSInfo->getTemplateSpecializationKind();
 
   return TSK_Undeclared;
@@ -3673,6 +3786,10 @@ unsigned FunctionDecl::getMemoryFunctionKind() const {
   case Builtin::BImemcmp:
     return Builtin::BImemcmp;
 
+  case Builtin::BI__builtin_bcmp:
+  case Builtin::BIbcmp:
+    return Builtin::BIbcmp;
+
   case Builtin::BI__builtin_strncpy:
   case Builtin::BI__builtin___strncpy_chk:
   case Builtin::BIstrncpy:
@@ -3713,6 +3830,8 @@ unsigned FunctionDecl::getMemoryFunctionKind() const {
         return Builtin::BImemmove;
       else if (FnInfo->isStr("memcmp"))
         return Builtin::BImemcmp;
+      else if (FnInfo->isStr("bcmp"))
+        return Builtin::BIbcmp;
       else if (FnInfo->isStr("strncpy"))
         return Builtin::BIstrncpy;
       else if (FnInfo->isStr("strncmp"))
@@ -3794,6 +3913,39 @@ bool FieldDecl::isZeroLengthBitField(const ASTContext &Ctx) const {
          getBitWidthValue(Ctx) == 0;
 }
 
+bool FieldDecl::isZeroSize(const ASTContext &Ctx) const {
+  if (isZeroLengthBitField(Ctx))
+    return true;
+
+  // C++2a [intro.object]p7:
+  //   An object has nonzero size if it
+  //     -- is not a potentially-overlapping subobject, or
+  if (!hasAttr<NoUniqueAddressAttr>())
+    return false;
+
+  //     -- is not of class type, or
+  const auto *RT = getType()->getAs<RecordType>();
+  if (!RT)
+    return false;
+  const RecordDecl *RD = RT->getDecl()->getDefinition();
+  if (!RD) {
+    assert(isInvalidDecl() && "valid field has incomplete type");
+    return false;
+  }
+
+  //     -- [has] virtual member functions or virtual base classes, or
+  //     -- has subobjects of nonzero size or bit-fields of nonzero length
+  const auto *CXXRD = cast<CXXRecordDecl>(RD);
+  if (!CXXRD->isEmpty())
+    return false;
+
+  // Otherwise, [...] the circumstances under which the object has zero size
+  // are implementation-defined.
+  // FIXME: This might be Itanium ABI specific; we don't yet know what the MS
+  // ABI will do.
+  return true;
+}
+
 unsigned FieldDecl::getFieldIndex() const {
   const FieldDecl *Canonical = getCanonicalDecl();
   if (Canonical != this)
@@ -4100,6 +4252,9 @@ RecordDecl::RecordDecl(Kind DK, TagKind TK, const ASTContext &C,
   setNonTrivialToPrimitiveDefaultInitialize(false);
   setNonTrivialToPrimitiveCopy(false);
   setNonTrivialToPrimitiveDestroy(false);
+  setHasNonTrivialToPrimitiveDefaultInitializeCUnion(false);
+  setHasNonTrivialToPrimitiveDestructCUnion(false);
+  setHasNonTrivialToPrimitiveCopyCUnion(false);
   setParamDestroyedInCallee(false);
   setArgPassingRestrictions(APK_CanPassInRegs);
 }
@@ -4260,6 +4415,7 @@ BlockDecl::BlockDecl(DeclContext *DC, SourceLocation CaretLoc)
   setBlockMissingReturnType(true);
   setIsConversionFromLambda(false);
   setDoesNotEscape(false);
+  setCanAvoidCopyToHeap(false);
 }
 
 void BlockDecl::setParams(ArrayRef<ParmVarDecl *> NewParamInfo) {
@@ -4422,13 +4578,12 @@ FunctionDecl *FunctionDecl::Create(ASTContext &C, DeclContext *DC,
                                    SourceLocation StartLoc,
                                    const DeclarationNameInfo &NameInfo,
                                    QualType T, TypeSourceInfo *TInfo,
-                                   StorageClass SC,
-                                   bool isInlineSpecified,
+                                   StorageClass SC, bool isInlineSpecified,
                                    bool hasWrittenPrototype,
-                                   bool isConstexprSpecified) {
+                                   ConstexprSpecKind ConstexprKind) {
   FunctionDecl *New =
       new (C, DC) FunctionDecl(Function, C, DC, StartLoc, NameInfo, T, TInfo,
-                               SC, isInlineSpecified, isConstexprSpecified);
+                               SC, isInlineSpecified, ConstexprKind);
   New->setHasWrittenPrototype(hasWrittenPrototype);
   return New;
 }
@@ -4436,7 +4591,7 @@ FunctionDecl *FunctionDecl::Create(ASTContext &C, DeclContext *DC,
 FunctionDecl *FunctionDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
   return new (C, ID) FunctionDecl(Function, C, nullptr, SourceLocation(),
                                   DeclarationNameInfo(), QualType(), nullptr,
-                                  SC_None, false, false);
+                                  SC_None, false, CSK_unspecified);
 }
 
 BlockDecl *BlockDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L) {