MFC r309124:

Upgrade our copies of clang, llvm, lldb, compiler-rt and libc++ to 3.9.0
release, and add lld 3.9.0.  Also completely revamp the build system for
clang, llvm, lldb and their related tools.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld are available here:
<http://llvm.org/releases/3.9.0/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/clang/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Bryan Drewery, Andrew Turner, Antoine Brodin and Jan
Beich for their help.

Relnotes:	yes

MFC r309147:

Pull in r282174 from upstream llvm trunk (by Krzysztof Parzyszek):

  [PPC] Set SP after loading data from stack frame, if no red zone is
  present

  Follow-up to r280705: Make sure that the SP is only restored after
  all data is loaded from the stack frame, if there is no red zone.

  This completes the fix for
  https://llvm.org/bugs/show_bug.cgi?id=26519.

  Differential Revision: https://reviews.llvm.org/D24466

Reported by:    Mark Millard
PR:             214433

MFC r309149:

Pull in r283060 from upstream llvm trunk (by Hal Finkel):

  [PowerPC] Refactor soft-float support, and enable PPC64 soft float

  This change enables soft-float for PowerPC64, and also makes
  soft-float disable all vector instruction sets for both 32-bit and
  64-bit modes. This latter part is necessary because the PPC backend
  canonicalizes many Altivec vector types to floating-point types, and
  so soft-float breaks scalarization support for many operations. Both
  for embedded targets and for operating-system kernels desiring
  soft-float support, it seems reasonable that disabling hardware
  floating-point also disables vector instructions (embedded targets
  without hardware floating point support are unlikely to have Altivec,
  etc. and operating system kernels desiring not to use floating-point
  registers to lower syscall cost are unlikely to want to use vector
  registers either). If someone needs this to work, we'll need to
  change the fact that we promote many Altivec operations to act on
  v4f32. To make it possible to disable Altivec when soft-float is
  enabled, hardware floating-point support needs to be expressed as a
  positive feature, like the others, and not a negative feature,
  because target features cannot have dependencies on the disabling of
  some other feature. So +soft-float has now become -hard-float.

  Fixes PR26970.

Pull in r283061 from upstream clang trunk (by Hal Finkel):

  [PowerPC] Enable soft-float for PPC64, and +soft-float -> -hard-float

  Enable soft-float support on PPC64, as the backend now supports it.
  Also, the backend now uses -hard-float instead of +soft-float, so set
  the target features accordingly.

  Fixes PR26970.

Reported by:	Mark Millard
PR:		214433

MFC r309212:

Add a few missed clang 3.9.0 files to OptionalObsoleteFiles.

MFC r309262:

Fix packaging for clang, lldb and lld 3.9.0

During the upgrade of clang/llvm etc to 3.9.0 in r309124, the PACKAGE
directive in the usr.bin/clang/*.mk files got dropped accidentally.

Restore it, with a few minor changes and additions:
* Correct license in clang.ucl to NCSA
* Add PACKAGE=clang for clang and most of the "ll" tools
* Put lldb in its own package
* Put lld in its own package

Reviewed by:	gjb, jmallett
Differential Revision: https://reviews.freebsd.org/D8666

MFC r309656:

During the bootstrap phase, when building the minimal llvm library on
PowerPC, add lib/Support/Atomic.cpp.  This is needed because upstream
llvm revision r271821 disabled the use of std::call_once, which causes
some fallback functions from Atomic.cpp to be used instead.

Reported by:	Mark Millard
PR:		214902

MFC r309835:

Tentatively apply https://reviews.llvm.org/D18730 to work around gcc PR
70528 (bogus error: constructor required before non-static data member).
This should fix buildworld with the external gcc package.

Reported by:	https://jenkins.freebsd.org/job/FreeBSD_HEAD_amd64_gcc/

MFC r310194:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
3.9.1 release.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/3.9.1/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/lld/docs/ReleaseNotes.html>

Relnotes:	yes

1 files changed, 178 insertions, 118 deletions

diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGObjCGNU.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGObjCGNU.cpp
index f0af3e9..caafef8 100644
--- a/contrib/llvm/tools/clang/lib/CodeGen/CGObjCGNU.cpp
+++ b/contrib/llvm/tools/clang/lib/CodeGen/CGObjCGNU.cpp
@@ -35,11 +35,9 @@
 #include "llvm/Support/Compiler.h"
 #include <cstdarg>
 
-
 using namespace clang;
 using namespace CodeGen;
 
-
 namespace {
 /// Class that lazily initialises the runtime function.  Avoids inserting the
 /// types and the function declaration into a module if they're not used, and
@@ -161,6 +159,7 @@ protected:
   /// runtime provides some LLVM passes that can use this to do things like
   /// automatic IMP caching and speculative inlining.
   unsigned msgSendMDKind;
+
   /// Helper function that generates a constant string and returns a pointer to
   /// the start of the string.  The result of this function can be used anywhere
   /// where the C code specifies const char*.  
@@ -170,6 +169,7 @@ protected:
     return llvm::ConstantExpr::getGetElementPtr(Array.getElementType(),
                                                 Array.getPointer(), Zeros);
   }
+
   /// Emits a linkonce_odr string, whose name is the prefix followed by the
   /// string value.  This allows the linker to combine the strings between
   /// different modules.  Used for EH typeinfo names, selector strings, and a
@@ -186,6 +186,7 @@ protected:
     return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
                                                 ConstStr, Zeros);
   }
+
   /// Generates a global structure, initialized by the elements in the vector.
   /// The element types must match the types of the structure elements in the
   /// first argument.
@@ -201,6 +202,7 @@ protected:
     GV->setAlignment(Align.getQuantity());
     return GV;
   }
+
   /// Generates a global array.  The vector must contain the same number of
   /// elements that the array type declares, of the type specified as the array
   /// element type.
@@ -216,6 +218,7 @@ protected:
     GV->setAlignment(Align.getQuantity());
     return GV;
   }
+
   /// Generates a global array, inferring the array type from the specified
   /// element type and the size of the initialiser.  
   llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty,
@@ -227,6 +230,7 @@ protected:
     llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size());
     return MakeGlobal(ArrayTy, V, Align, Name, linkage);
   }
+
   /// Returns a property name and encoding string.
   llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD,
                                              const Decl *Container) {
@@ -245,6 +249,7 @@ protected:
     }
     return MakeConstantString(PD->getNameAsString());
   }
+
   /// Push the property attributes into two structure fields. 
   void PushPropertyAttributes(std::vector<llvm::Constant*> &Fields,
       ObjCPropertyDecl *property, bool isSynthesized=true, bool
@@ -273,6 +278,7 @@ protected:
     Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0));
     Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0));
   }
+
   /// Ensures that the value has the required type, by inserting a bitcast if
   /// required.  This function lets us avoid inserting bitcasts that are
   /// redundant.
@@ -284,12 +290,14 @@ protected:
     if (V.getType() == Ty) return V;
     return B.CreateBitCast(V, Ty);
   }
+
   // Some zeros used for GEPs in lots of places.
   llvm::Constant *Zeros[2];
   /// Null pointer value.  Mainly used as a terminator in various arrays.
   llvm::Constant *NULLPtr;
   /// LLVM context.
   llvm::LLVMContext &VMContext;
+
 private:
   /// Placeholder for the class.  Lots of things refer to the class before we've
   /// actually emitted it.  We use this alias as a placeholder, and then replace
@@ -360,7 +368,6 @@ protected:
   LazyRuntimeFunction SyncExitFn;
 
 private:
-
   /// Function called if fast enumeration detects that the collection is
   /// modified during the update.
   LazyRuntimeFunction EnumerationMutationFn;
@@ -385,7 +392,7 @@ private:
   /// Objective-C 1 property structures when targeting the GCC runtime or it
   /// will abort.
   const int ProtocolVersion;
-private:
+
   /// Generates an instance variable list structure.  This is a structure
   /// containing a size and an array of structures containing instance variable
   /// metadata.  This is used purely for introspection in the fragile ABI.  In
@@ -393,6 +400,7 @@ private:
   llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
                                    ArrayRef<llvm::Constant *> IvarTypes,
                                    ArrayRef<llvm::Constant *> IvarOffsets);
+
   /// Generates a method list structure.  This is a structure containing a size
   /// and an array of structures containing method metadata.
   ///
@@ -403,23 +411,28 @@ private:
       ArrayRef<Selector> MethodSels,
       ArrayRef<llvm::Constant *> MethodTypes,
       bool isClassMethodList);
+
   /// Emits an empty protocol.  This is used for \@protocol() where no protocol
   /// is found.  The runtime will (hopefully) fix up the pointer to refer to the
   /// real protocol.
   llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName);
+
   /// Generates a list of property metadata structures.  This follows the same
   /// pattern as method and instance variable metadata lists.
   llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID,
         SmallVectorImpl<Selector> &InstanceMethodSels,
         SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes);
+
   /// Generates a list of referenced protocols.  Classes, categories, and
   /// protocols all use this structure.
   llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols);
+
   /// To ensure that all protocols are seen by the runtime, we add a category on
   /// a class defined in the runtime, declaring no methods, but adopting the
   /// protocols.  This is a horribly ugly hack, but it allows us to collect all
   /// of the protocols without changing the ABI.
   void GenerateProtocolHolderCategory();
+
   /// Generates a class structure.
   llvm::Constant *GenerateClassStructure(
       llvm::Constant *MetaClass,
@@ -436,25 +449,31 @@ private:
       llvm::Constant *StrongIvarBitmap,
       llvm::Constant *WeakIvarBitmap,
       bool isMeta=false);
+
   /// Generates a method list.  This is used by protocols to define the required
   /// and optional methods.
   llvm::Constant *GenerateProtocolMethodList(
       ArrayRef<llvm::Constant *> MethodNames,
       ArrayRef<llvm::Constant *> MethodTypes);
+
   /// Returns a selector with the specified type encoding.  An empty string is
   /// used to return an untyped selector (with the types field set to NULL).
   llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel,
                            const std::string &TypeEncoding);
+
   /// Returns the variable used to store the offset of an instance variable.
   llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
       const ObjCIvarDecl *Ivar);
   /// Emits a reference to a class.  This allows the linker to object if there
   /// is no class of the matching name.
+
 protected:
   void EmitClassRef(const std::string &className);
+
   /// Emits a pointer to the named class
   virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF,
                                      const std::string &Name, bool isWeak);
+
   /// Looks up the method for sending a message to the specified object.  This
   /// mechanism differs between the GCC and GNU runtimes, so this method must be
   /// overridden in subclasses.
@@ -463,6 +482,7 @@ protected:
                                  llvm::Value *cmd,
                                  llvm::MDNode *node,
                                  MessageSendInfo &MSI) = 0;
+
   /// Looks up the method for sending a message to a superclass.  This
   /// mechanism differs between the GCC and GNU runtimes, so this method must
   /// be overridden in subclasses.
@@ -470,6 +490,7 @@ protected:
                                       Address ObjCSuper,
                                       llvm::Value *cmd,
                                       MessageSendInfo &MSI) = 0;
+
   /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
   /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
   /// bits set to their values, LSB first, while larger ones are stored in a
@@ -482,6 +503,7 @@ protected:
   /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] },
   /// while a bitfield / with the 63rd bit set will be 1<<64.
   llvm::Constant *MakeBitField(ArrayRef<bool> bits);
+
 public:
   CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
       unsigned protocolClassVersion);
@@ -569,11 +591,12 @@ public:
     return NULLPtr;
   }
 
-  llvm::GlobalVariable *GetClassGlobal(const std::string &Name,
+  llvm::GlobalVariable *GetClassGlobal(StringRef Name,
                                        bool Weak = false) override {
     return nullptr;
   }
 };
+
 /// Class representing the legacy GCC Objective-C ABI.  This is the default when
 /// -fobjc-nonfragile-abi is not specified.
 ///
@@ -590,6 +613,7 @@ class CGObjCGCC : public CGObjCGNU {
   /// structure describing the receiver and the class, and a selector as
   /// arguments.  Returns the IMP for the corresponding method.
   LazyRuntimeFunction MsgLookupSuperFn;
+
 protected:
   llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
                          llvm::Value *cmd, llvm::MDNode *node,
@@ -602,23 +626,26 @@ protected:
     imp->setMetadata(msgSendMDKind, node);
     return imp.getInstruction();
   }
+
   llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
                               llvm::Value *cmd, MessageSendInfo &MSI) override {
-      CGBuilderTy &Builder = CGF.Builder;
-      llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
-          PtrToObjCSuperTy).getPointer(), cmd};
-      return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
-    }
-  public:
-    CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
-      // IMP objc_msg_lookup(id, SEL);
-      MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy,
-                       nullptr);
-      // IMP objc_msg_lookup_super(struct objc_super*, SEL);
-      MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
-              PtrToObjCSuperTy, SelectorTy, nullptr);
-    }
+    CGBuilderTy &Builder = CGF.Builder;
+    llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
+        PtrToObjCSuperTy).getPointer(), cmd};
+    return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
+  }
+
+public:
+  CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
+    // IMP objc_msg_lookup(id, SEL);
+    MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy,
+                     nullptr);
+    // IMP objc_msg_lookup_super(struct objc_super*, SEL);
+    MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
+                          PtrToObjCSuperTy, SelectorTy, nullptr);
+  }
 };
+
 /// Class used when targeting the new GNUstep runtime ABI.
 class CGObjCGNUstep : public CGObjCGNU {
     /// The slot lookup function.  Returns a pointer to a cacheable structure
@@ -646,8 +673,10 @@ class CGObjCGNUstep : public CGObjCGNU {
     /// Type of an slot structure pointer.  This is returned by the various
     /// lookup functions.
     llvm::Type *SlotTy;
+
   public:
     llvm::Constant *GetEHType(QualType T) override;
+
   protected:
     llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
                            llvm::Value *cmd, llvm::MDNode *node,
@@ -689,6 +718,7 @@ class CGObjCGNUstep : public CGObjCGNU {
       Receiver = Builder.CreateLoad(ReceiverPtr, true);
       return imp;
     }
+
     llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
                                 llvm::Value *cmd,
                                 MessageSendInfo &MSI) override {
@@ -702,6 +732,7 @@ class CGObjCGNUstep : public CGObjCGNU {
       return Builder.CreateAlignedLoad(Builder.CreateStructGEP(nullptr, slot, 4),
                                        CGF.getPointerAlign());
     }
+
   public:
     CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) {
       const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
@@ -753,6 +784,7 @@ class CGObjCGNUstep : public CGObjCGNU {
       CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy,
           PtrTy, PtrTy, nullptr);
     }
+
     llvm::Constant *GetCppAtomicObjectGetFunction() override {
       // The optimised functions were added in version 1.7 of the GNUstep
       // runtime.
@@ -760,6 +792,7 @@ class CGObjCGNUstep : public CGObjCGNU {
           VersionTuple(1, 7));
       return CxxAtomicObjectGetFn;
     }
+
     llvm::Constant *GetCppAtomicObjectSetFunction() override {
       // The optimised functions were added in version 1.7 of the GNUstep
       // runtime.
@@ -767,6 +800,7 @@ class CGObjCGNUstep : public CGObjCGNU {
           VersionTuple(1, 7));
       return CxxAtomicObjectSetFn;
     }
+
     llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
                                                     bool copy) override {
       // The optimised property functions omit the GC check, and so are not
@@ -821,32 +855,29 @@ protected:
 
   llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
                               llvm::Value *cmd, MessageSendInfo &MSI) override {
-      CGBuilderTy &Builder = CGF.Builder;
-      llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper.getPointer(),
-          PtrToObjCSuperTy), cmd};
+    CGBuilderTy &Builder = CGF.Builder;
+    llvm::Value *lookupArgs[] = {
+        EnforceType(Builder, ObjCSuper.getPointer(), PtrToObjCSuperTy), cmd,
+    };
 
-      if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
-        return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs);
-      else
-        return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
-    }
+    if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
+      return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs);
+    else
+      return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
+  }
 
-  llvm::Value *GetClassNamed(CodeGenFunction &CGF,
-                             const std::string &Name, bool isWeak) override {
+  llvm::Value *GetClassNamed(CodeGenFunction &CGF, const std::string &Name,
+                             bool isWeak) override {
     if (isWeak)
       return CGObjCGNU::GetClassNamed(CGF, Name, isWeak);
 
     EmitClassRef(Name);
-
     std::string SymbolName = "_OBJC_CLASS_" + Name;
-
     llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName);
-
     if (!ClassSymbol)
       ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
                                              llvm::GlobalValue::ExternalLinkage,
                                              nullptr, SymbolName);
-
     return ClassSymbol;
   }
 
@@ -865,7 +896,6 @@ public:
 };
 } // end anonymous namespace
 
-
 /// Emits a reference to a dummy variable which is emitted with each class.
 /// This ensures that a linker error will be generated when trying to link
 /// together modules where a referenced class is not defined.
@@ -1021,8 +1051,7 @@ CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
 }
 
 llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF,
-                                      const std::string &Name,
-                                      bool isWeak) {
+                                      const std::string &Name, bool isWeak) {
   llvm::Constant *ClassName = MakeConstantString(Name);
   // With the incompatible ABI, this will need to be replaced with a direct
   // reference to the class symbol.  For the compatible nonfragile ABI we are
@@ -1044,15 +1073,48 @@ llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF,
 // techniques can modify the name -> class mapping.
 llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF,
                                  const ObjCInterfaceDecl *OID) {
-  return GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported());
+  auto *Value =
+      GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported());
+  if (CGM.getTriple().isOSBinFormatCOFF()) {
+    if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value)) {
+      auto DLLStorage = llvm::GlobalValue::DefaultStorageClass;
+      if (OID->hasAttr<DLLExportAttr>())
+        DLLStorage = llvm::GlobalValue::DLLExportStorageClass;
+      else if (OID->hasAttr<DLLImportAttr>())
+        DLLStorage = llvm::GlobalValue::DLLImportStorageClass;
+      ClassSymbol->setDLLStorageClass(DLLStorage);
+    }
+  }
+  return Value;
 }
+
 llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
-  return GetClassNamed(CGF, "NSAutoreleasePool", false);
+  auto *Value  = GetClassNamed(CGF, "NSAutoreleasePool", false);
+  if (CGM.getTriple().isOSBinFormatCOFF()) {
+    if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value)) {
+      IdentifierInfo &II = CGF.CGM.getContext().Idents.get("NSAutoreleasePool");
+      TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
+      DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
+
+      const VarDecl *VD = nullptr;
+      for (const auto &Result : DC->lookup(&II))
+        if ((VD = dyn_cast<VarDecl>(Result)))
+          break;
+
+      auto DLLStorage = llvm::GlobalValue::DefaultStorageClass;
+      if (!VD || VD->hasAttr<DLLImportAttr>())
+        DLLStorage = llvm::GlobalValue::DLLImportStorageClass;
+      else if (VD->hasAttr<DLLExportAttr>())
+        DLLStorage = llvm::GlobalValue::DLLExportStorageClass;
+
+      ClassSymbol->setDLLStorageClass(DLLStorage);
+    }
+  }
+  return Value;
 }
 
 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel,
                                     const std::string &TypeEncoding) {
-
   SmallVectorImpl<TypedSelector> &Types = SelectorTable[Sel];
   llvm::GlobalAlias *SelValue = nullptr;
 
@@ -1247,8 +1309,6 @@ CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF,
   }
 
   llvm::Value *cmd = GetSelector(CGF, Sel);
-
-
   CallArgList ActualArgs;
 
   ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy);
@@ -1497,21 +1557,17 @@ GenerateMethodList(StringRef ClassName,
     IMPTy, //Method pointer
     nullptr);
   std::vector<llvm::Constant*> Methods;
-  std::vector<llvm::Constant*> Elements;
   for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) {
-    Elements.clear();
     llvm::Constant *Method =
       TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName,
                                                 MethodSels[i],
                                                 isClassMethodList));
     assert(Method && "Can't generate metadata for method that doesn't exist");
     llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString());
-    Elements.push_back(C);
-    Elements.push_back(MethodTypes[i]);
     Method = llvm::ConstantExpr::getBitCast(Method,
         IMPTy);
-    Elements.push_back(Method);
-    Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements));
+    Methods.push_back(
+        llvm::ConstantStruct::get(ObjCMethodTy, {C, MethodTypes[i], Method}));
   }
 
   // Array of method structures
@@ -1554,23 +1610,18 @@ GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
     IntTy,
     nullptr);
   std::vector<llvm::Constant*> Ivars;
-  std::vector<llvm::Constant*> Elements;
   for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) {
-    Elements.clear();
-    Elements.push_back(IvarNames[i]);
-    Elements.push_back(IvarTypes[i]);
-    Elements.push_back(IvarOffsets[i]);
-    Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements));
+    Ivars.push_back(llvm::ConstantStruct::get(
+        ObjCIvarTy, {IvarNames[i], IvarTypes[i], IvarOffsets[i]}));
   }
 
   // Array of method structures
   llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy,
       IvarNames.size());
 
-
-  Elements.clear();
-  Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size()));
-  Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars));
+  llvm::Constant *Elements[] = {
+      llvm::ConstantInt::get(IntTy, (int)IvarNames.size()),
+      llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)};
   // Structure containing array and array count
   llvm::StructType *ObjCIvarListTy = llvm::StructType::get(IntTy,
     ObjCIvarArrayTy,
@@ -1682,12 +1733,9 @@ GenerateProtocolMethodList(ArrayRef<llvm::Constant *> MethodNames,
     PtrToInt8Ty,
     nullptr);
   std::vector<llvm::Constant*> Methods;
-  std::vector<llvm::Constant*> Elements;
   for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) {
-    Elements.clear();
-    Elements.push_back(MethodNames[i]);
-    Elements.push_back(MethodTypes[i]);
-    Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements));
+    Methods.push_back(llvm::ConstantStruct::get(
+        ObjCMethodDescTy, {MethodNames[i], MethodTypes[i]}));
   }
   llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy,
       MethodNames.size());
@@ -1762,17 +1810,13 @@ llvm::Constant *CGObjCGNU::GenerateEmptyProtocol(
       MethodList->getType(),
       MethodList->getType(),
       nullptr);
-  std::vector<llvm::Constant*> Elements;
   // The isa pointer must be set to a magic number so the runtime knows it's
   // the correct layout.
-  Elements.push_back(llvm::ConstantExpr::getIntToPtr(
-        llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
-  Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name"));
-  Elements.push_back(ProtocolList);
-  Elements.push_back(MethodList);
-  Elements.push_back(MethodList);
-  Elements.push_back(MethodList);
-  Elements.push_back(MethodList);
+  llvm::Constant *Elements[] = {
+      llvm::ConstantExpr::getIntToPtr(
+          llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy),
+      MakeConstantString(ProtocolName, ".objc_protocol_name"), ProtocolList,
+      MethodList, MethodList, MethodList, MethodList};
   return MakeGlobal(ProtocolTy, Elements, CGM.getPointerAlign(),
                     ".objc_protocol");
 }
@@ -1849,7 +1893,7 @@ void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
 
   // Add all of the property methods need adding to the method list and to the
   // property metadata list.
-  for (auto *property : PD->properties()) {
+  for (auto *property : PD->instance_properties()) {
     std::vector<llvm::Constant*> Fields;
 
     Fields.push_back(MakePropertyEncodingString(property, nullptr));
@@ -1920,19 +1964,14 @@ void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
       PropertyList->getType(),
       OptionalPropertyList->getType(),
       nullptr);
-  std::vector<llvm::Constant*> Elements;
   // The isa pointer must be set to a magic number so the runtime knows it's
   // the correct layout.
-  Elements.push_back(llvm::ConstantExpr::getIntToPtr(
-        llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
-  Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name"));
-  Elements.push_back(ProtocolList);
-  Elements.push_back(InstanceMethodList);
-  Elements.push_back(ClassMethodList);
-  Elements.push_back(OptionalInstanceMethodList);
-  Elements.push_back(OptionalClassMethodList);
-  Elements.push_back(PropertyList);
-  Elements.push_back(OptionalPropertyList);
+  llvm::Constant *Elements[] = {
+      llvm::ConstantExpr::getIntToPtr(
+          llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy),
+      MakeConstantString(ProtocolName, ".objc_protocol_name"), ProtocolList,
+      InstanceMethodList, ClassMethodList, OptionalInstanceMethodList,
+      OptionalClassMethodList, PropertyList, OptionalPropertyList};
   ExistingProtocols[ProtocolName] =
     llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements,
           CGM.getPointerAlign(), ".objc_protocol"), IdTy);
@@ -2058,20 +2097,20 @@ void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
        E = Protos.end(); I != E; ++I)
     Protocols.push_back((*I)->getNameAsString());
 
-  std::vector<llvm::Constant*> Elements;
-  Elements.push_back(MakeConstantString(CategoryName));
-  Elements.push_back(MakeConstantString(ClassName));
-  // Instance method list
-  Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
-          ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes,
-          false), PtrTy));
-  // Class method list
-  Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
-          ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true),
-        PtrTy));
-  // Protocol list
-  Elements.push_back(llvm::ConstantExpr::getBitCast(
-        GenerateProtocolList(Protocols), PtrTy));
+  llvm::Constant *Elements[] = {
+      MakeConstantString(CategoryName), MakeConstantString(ClassName),
+      // Instance method list
+      llvm::ConstantExpr::getBitCast(
+          GenerateMethodList(ClassName, CategoryName, InstanceMethodSels,
+                             InstanceMethodTypes, false),
+          PtrTy),
+      // Class method list
+      llvm::ConstantExpr::getBitCast(GenerateMethodList(ClassName, CategoryName,
+                                                        ClassMethodSels,
+                                                        ClassMethodTypes, true),
+                                     PtrTy),
+      // Protocol list
+      llvm::ConstantExpr::getBitCast(GenerateProtocolList(Protocols), PtrTy)};
   Categories.push_back(llvm::ConstantExpr::getBitCast(
         MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty,
             PtrTy, PtrTy, PtrTy, nullptr), Elements, CGM.getPointerAlign()),
@@ -2167,18 +2206,19 @@ void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
 
   // Get the class name
   ObjCInterfaceDecl *ClassDecl =
-    const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
+      const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
   std::string ClassName = ClassDecl->getNameAsString();
+
   // Emit the symbol that is used to generate linker errors if this class is
   // referenced in other modules but not declared.
   std::string classSymbolName = "__objc_class_name_" + ClassName;
-  if (llvm::GlobalVariable *symbol =
-      TheModule.getGlobalVariable(classSymbolName)) {
+  if (auto *symbol = TheModule.getGlobalVariable(classSymbolName)) {
     symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0));
   } else {
     new llvm::GlobalVariable(TheModule, LongTy, false,
-    llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0),
-    classSymbolName);
+                             llvm::GlobalValue::ExternalLinkage,
+                             llvm::ConstantInt::get(LongTy, 0),
+                             classSymbolName);
   }
 
   // Get the size of instances.
@@ -2256,7 +2296,6 @@ void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
     MakeGlobalArray(PtrToIntTy, IvarOffsetValues, CGM.getPointerAlign(),
                     ".ivar.offsets");
 
-
   // Collect information about instance methods
   SmallVector<Selector, 16> InstanceMethodSels;
   SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
@@ -2270,7 +2309,6 @@ void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
   llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels,
           InstanceMethodTypes);
 
-
   // Collect information about class methods
   SmallVector<Selector, 16> ClassMethodSels;
   SmallVector<llvm::Constant*, 16> ClassMethodTypes;
@@ -2343,19 +2381,35 @@ void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
       ++ivarIndex;
   }
   llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0);
+
   //Generate metaclass for class methods
-  llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr,
-      NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0], GenerateIvarList(
-        empty, empty, empty), ClassMethodList, NULLPtr,
-      NULLPtr, NULLPtr, ZeroPtr, ZeroPtr, true);
+  llvm::Constant *MetaClassStruct = GenerateClassStructure(
+      NULLPtr, NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0],
+      GenerateIvarList(empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr,
+      NULLPtr, ZeroPtr, ZeroPtr, true);
+  if (CGM.getTriple().isOSBinFormatCOFF()) {
+    auto Storage = llvm::GlobalValue::DefaultStorageClass;
+    if (OID->getClassInterface()->hasAttr<DLLImportAttr>())
+      Storage = llvm::GlobalValue::DLLImportStorageClass;
+    else if (OID->getClassInterface()->hasAttr<DLLExportAttr>())
+      Storage = llvm::GlobalValue::DLLExportStorageClass;
+    cast<llvm::GlobalValue>(MetaClassStruct)->setDLLStorageClass(Storage);
+  }
 
   // Generate the class structure
-  llvm::Constant *ClassStruct =
-    GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L,
-                           ClassName.c_str(), nullptr,
-      llvm::ConstantInt::get(LongTy, instanceSize), IvarList,
-      MethodList, GenerateProtocolList(Protocols), IvarOffsetArray,
-      Properties, StrongIvarBitmap, WeakIvarBitmap);
+  llvm::Constant *ClassStruct = GenerateClassStructure(
+      MetaClassStruct, SuperClass, 0x11L, ClassName.c_str(), nullptr,
+      llvm::ConstantInt::get(LongTy, instanceSize), IvarList, MethodList,
+      GenerateProtocolList(Protocols), IvarOffsetArray, Properties,
+      StrongIvarBitmap, WeakIvarBitmap);
+  if (CGM.getTriple().isOSBinFormatCOFF()) {
+    auto Storage = llvm::GlobalValue::DefaultStorageClass;
+    if (OID->getClassInterface()->hasAttr<DLLImportAttr>())
+      Storage = llvm::GlobalValue::DLLImportStorageClass;
+    else if (OID->getClassInterface()->hasAttr<DLLExportAttr>())
+      Storage = llvm::GlobalValue::DLLExportStorageClass;
+    cast<llvm::GlobalValue>(ClassStruct)->setDLLStorageClass(Storage);
+  }
 
   // Resolve the class aliases, if they exist.
   if (ClassPtrAlias) {
@@ -2376,7 +2430,6 @@ void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
   Classes.push_back(ClassStruct);
 }
 
-
 llvm::Function *CGObjCGNU::ModuleInitFunction() {
   // Only emit an ObjC load function if no Objective-C stuff has been called
   if (Classes.empty() && Categories.empty() && ConstantStrings.empty() &&
@@ -2651,12 +2704,15 @@ llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic,
 llvm::Constant *CGObjCGNU::GetGetStructFunction() {
   return GetStructPropertyFn;
 }
+
 llvm::Constant *CGObjCGNU::GetSetStructFunction() {
   return SetStructPropertyFn;
 }
+
 llvm::Constant *CGObjCGNU::GetCppAtomicObjectGetFunction() {
   return nullptr;
 }
+
 llvm::Constant *CGObjCGNU::GetCppAtomicObjectSetFunction() {
   return nullptr;
 }
@@ -2685,7 +2741,6 @@ void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF,
   // In Objective-C++ mode, we actually emit something equivalent to the C++
   // exception handler. 
   EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn);
-  return ;
 }
 
 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
@@ -2800,7 +2855,7 @@ llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable(
     // to replace it with the real version for a library.  In non-PIC code you
     // must compile with the fragile ABI if you want to use ivars from a
     // GCC-compiled class.
-    if (CGM.getLangOpts().PICLevel || CGM.getLangOpts().PIELevel) {
+    if (CGM.getLangOpts().PICLevel) {
       llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule,
             Int32Ty, false,
             llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess");
@@ -2848,7 +2903,12 @@ llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF,
                          const ObjCIvarDecl *Ivar) {
   if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
     Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);
-    if (RuntimeVersion < 10)
+
+    // The MSVC linker cannot have a single global defined as LinkOnceAnyLinkage
+    // and ExternalLinkage, so create a reference to the ivar global and rely on
+    // the definition being created as part of GenerateClass.
+    if (RuntimeVersion < 10 ||
+        CGF.CGM.getTarget().getTriple().isKnownWindowsMSVCEnvironment())
       return CGF.Builder.CreateZExtOrBitCast(
           CGF.Builder.CreateDefaultAlignedLoad(CGF.Builder.CreateAlignedLoad(
                   ObjCIvarOffsetVariable(Interface, Ivar),