Vendor import of clang release_34 branch r197841 (effectively, 3.4 RC3):vendor/clang/clang-release_34-r197841

https://llvm.org/svn/llvm-project/cfe/branches/release_34@197841

1 files changed, 822 insertions, 533 deletions

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index ddcb931e46c5..fcb26f0da615 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -13,6 +13,7 @@
 
 #include "CGDebugInfo.h"
 #include "CGBlocks.h"
+#include "CGCXXABI.h"
 #include "CGObjCRuntime.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
@@ -36,12 +37,13 @@
 #include "llvm/IR/Module.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"

 using namespace clang;
 using namespace clang::CodeGen;
 
 CGDebugInfo::CGDebugInfo(CodeGenModule &CGM)
-  : CGM(CGM), DBuilder(CGM.getModule()),
-    BlockLiteralGenericSet(false) {
+    : CGM(CGM), DebugKind(CGM.getCodeGenOpts().getDebugInfo()),
+      DBuilder(CGM.getModule()) {
   CreateCompileUnit();
 }
 
@@ -50,9 +52,54 @@ CGDebugInfo::~CGDebugInfo() {
          "Region stack mismatch, stack not empty!");
 }
 
+
+NoLocation::NoLocation(CodeGenFunction &CGF, CGBuilderTy &B)
+  : DI(CGF.getDebugInfo()), Builder(B) {
+  if (DI) {
+    SavedLoc = DI->getLocation();
+    DI->CurLoc = SourceLocation();
+    Builder.SetCurrentDebugLocation(llvm::DebugLoc());
+  }
+}
+
+NoLocation::~NoLocation() {
+  if (DI) {
+    assert(Builder.getCurrentDebugLocation().isUnknown());
+    DI->CurLoc = SavedLoc;
+  }
+}
+
+ArtificialLocation::ArtificialLocation(CodeGenFunction &CGF, CGBuilderTy &B)
+  : DI(CGF.getDebugInfo()), Builder(B) {
+  if (DI) {
+    SavedLoc = DI->getLocation();
+    DI->CurLoc = SourceLocation();
+    Builder.SetCurrentDebugLocation(llvm::DebugLoc());
+  }
+}
+
+void ArtificialLocation::Emit() {
+  if (DI) {
+    // Sync the Builder.
+    DI->EmitLocation(Builder, SavedLoc);
+    DI->CurLoc = SourceLocation();
+    // Construct a location that has a valid scope, but no line info.
+    assert(!DI->LexicalBlockStack.empty());
+    llvm::DIDescriptor Scope(DI->LexicalBlockStack.back());
+    Builder.SetCurrentDebugLocation(llvm::DebugLoc::get(0, 0, Scope));
+  }
+}
+
+ArtificialLocation::~ArtificialLocation() {
+  if (DI) {
+    assert(Builder.getCurrentDebugLocation().getLine() == 0);
+    DI->CurLoc = SavedLoc;
+  }
+}
+
 void CGDebugInfo::setLocation(SourceLocation Loc) {
   // If the new location isn't valid return.
-  if (!Loc.isValid()) return;
+  if (Loc.isInvalid()) return;
 
   CurLoc = CGM.getContext().getSourceManager().getExpansionLoc(Loc);
 
@@ -112,7 +159,7 @@ llvm::DIScope CGDebugInfo::getContextDescriptor(const Decl *Context) {
 }
 
 /// getFunctionName - Get function name for the given FunctionDecl. If the
-/// name is constructred on demand (e.g. C++ destructor) then the name
+/// name is constructed on demand (e.g. C++ destructor) then the name
 /// is stored on the side.
 StringRef CGDebugInfo::getFunctionName(const FunctionDecl *FD) {
   assert (FD && "Invalid FunctionDecl!");
@@ -138,10 +185,7 @@ StringRef CGDebugInfo::getFunctionName(const FunctionDecl *FD) {
   }
 
   // Copy this name on the side and use its reference.
-  OS.flush();
-  char *StrPtr = DebugInfoNames.Allocate<char>(NS.size());
-  memcpy(StrPtr, NS.data(), NS.size());
-  return StringRef(StrPtr, NS.size());
+  return internString(OS.str());
 }
 
 StringRef CGDebugInfo::getObjCMethodName(const ObjCMethodDecl *OMD) {
@@ -149,35 +193,37 @@ StringRef CGDebugInfo::getObjCMethodName(const ObjCMethodDecl *OMD) {
   llvm::raw_svector_ostream OS(MethodName);
   OS << (OMD->isInstanceMethod() ? '-' : '+') << '[';
   const DeclContext *DC = OMD->getDeclContext();
-  if (const ObjCImplementationDecl *OID = 
+  if (const ObjCImplementationDecl *OID =
       dyn_cast<const ObjCImplementationDecl>(DC)) {
      OS << OID->getName();
-  } else if (const ObjCInterfaceDecl *OID = 
+  } else if (const ObjCInterfaceDecl *OID =
              dyn_cast<const ObjCInterfaceDecl>(DC)) {
       OS << OID->getName();
-  } else if (const ObjCCategoryImplDecl *OCD = 
+  } else if (const ObjCCategoryImplDecl *OCD =
              dyn_cast<const ObjCCategoryImplDecl>(DC)){
       OS << ((const NamedDecl *)OCD)->getIdentifier()->getNameStart() << '(' <<
           OCD->getIdentifier()->getNameStart() << ')';
+  } else if (isa<ObjCProtocolDecl>(DC)) {
+    // We can extract the type of the class from the self pointer.
+    if (ImplicitParamDecl* SelfDecl = OMD->getSelfDecl()) {
+      QualType ClassTy =
+        cast<ObjCObjectPointerType>(SelfDecl->getType())->getPointeeType();
+      ClassTy.print(OS, PrintingPolicy(LangOptions()));
+    }
   }
   OS << ' ' << OMD->getSelector().getAsString() << ']';
 
-  char *StrPtr = DebugInfoNames.Allocate<char>(OS.tell());
-  memcpy(StrPtr, MethodName.begin(), OS.tell());
-  return StringRef(StrPtr, OS.tell());
+  return internString(OS.str());
 }
 
 /// getSelectorName - Return selector name. This is used for debugging
 /// info.
 StringRef CGDebugInfo::getSelectorName(Selector S) {
-  const std::string &SName = S.getAsString();
-  char *StrPtr = DebugInfoNames.Allocate<char>(SName.size());
-  memcpy(StrPtr, SName.data(), SName.size());
-  return StringRef(StrPtr, SName.size());
+  return internString(S.getAsString());
 }
 
 /// getClassName - Get class name including template argument list.
-StringRef 
+StringRef
 CGDebugInfo::getClassName(const RecordDecl *RD) {
   const ClassTemplateSpecializationDecl *Spec
     = dyn_cast<ClassTemplateSpecializationDecl>(RD);
@@ -206,11 +252,7 @@ CGDebugInfo::getClassName(const RecordDecl *RD) {
   }
 
   // Copy this name on the side and use its reference.
-  size_t Length = Name.size() + TemplateArgList.size();
-  char *StrPtr = DebugInfoNames.Allocate<char>(Length);
-  memcpy(StrPtr, Name.data(), Name.size());
-  memcpy(StrPtr + Name.size(), TemplateArgList.data(), TemplateArgList.size());
-  return StringRef(StrPtr, Length);
+  return internString(Name, TemplateArgList);
 }
 
 /// getOrCreateFile - Get the file debug info descriptor for the input location.
@@ -280,9 +322,7 @@ StringRef CGDebugInfo::getCurrentDirname() {
     return CWDName;
   SmallString<256> CWD;
   llvm::sys::fs::current_path(CWD);
-  char *CompDirnamePtr = DebugInfoNames.Allocate<char>(CWD.size());
-  memcpy(CompDirnamePtr, CWD.data(), CWD.size());
-  return CWDName = StringRef(CompDirnamePtr, CWD.size());
+  return CWDName = internString(CWD);
 }
 
 /// CreateCompileUnit - Create new compile unit.
@@ -301,21 +341,20 @@ void CGDebugInfo::CreateCompileUnit() {
   std::string MainFileDir;
   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
     MainFileDir = MainFile->getDir()->getName();
-    if (MainFileDir != ".")
-      MainFileName = MainFileDir + "/" + MainFileName;
+    if (MainFileDir != ".") {
+      llvm::SmallString<1024> MainFileDirSS(MainFileDir);

+      llvm::sys::path::append(MainFileDirSS, MainFileName);

+      MainFileName = MainFileDirSS.str();

+    }
   }
 
   // Save filename string.
-  char *FilenamePtr = DebugInfoNames.Allocate<char>(MainFileName.length());
-  memcpy(FilenamePtr, MainFileName.c_str(), MainFileName.length());
-  StringRef Filename(FilenamePtr, MainFileName.length());
+  StringRef Filename = internString(MainFileName);
 
   // Save split dwarf file string.
   std::string SplitDwarfFile = CGM.getCodeGenOpts().SplitDwarfFile;
-  char *SplitDwarfPtr = DebugInfoNames.Allocate<char>(SplitDwarfFile.length());
-  memcpy(SplitDwarfPtr, SplitDwarfFile.c_str(), SplitDwarfFile.length());
-  StringRef SplitDwarfFilename(SplitDwarfPtr, SplitDwarfFile.length());
-  
+  StringRef SplitDwarfFilename = internString(SplitDwarfFile);
+
   unsigned LangTag;
   const LangOptions &LO = CGM.getLangOpts();
   if (LO.CPlusPlus) {
@@ -339,12 +378,11 @@ void CGDebugInfo::CreateCompileUnit() {
     RuntimeVers = LO.ObjCRuntime.isNonFragile() ? 2 : 1;
 
   // Create new compile unit.
-  DBuilder.createCompileUnit(LangTag, Filename, getCurrentDirname(),
-                             Producer, LO.Optimize,
-                             CGM.getCodeGenOpts().DwarfDebugFlags,
-                             RuntimeVers, SplitDwarfFilename);
   // FIXME - Eliminate TheCU.
-  TheCU = llvm::DICompileUnit(DBuilder.getCU());
+  TheCU = DBuilder.createCompileUnit(LangTag, Filename, getCurrentDirname(),
+                                     Producer, LO.Optimize,
+                                     CGM.getCodeGenOpts().DwarfDebugFlags,
+                                     RuntimeVers, SplitDwarfFilename);
 }
 
 /// CreateType - Get the Basic type from the cache or create a new
@@ -360,12 +398,11 @@ llvm::DIType CGDebugInfo::CreateType(const BuiltinType *BT) {
   case BuiltinType::Dependent:
     llvm_unreachable("Unexpected builtin type");
   case BuiltinType::NullPtr:
-    return DBuilder.
-      createNullPtrType(BT->getName(CGM.getLangOpts()));
+    return DBuilder.createNullPtrType();
   case BuiltinType::Void:
     return llvm::DIType();
   case BuiltinType::ObjCClass:
-    if (ClassTy.Verify())
+    if (ClassTy)
       return ClassTy;
     ClassTy = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
                                          "objc_class", TheCU,
@@ -377,16 +414,16 @@ llvm::DIType CGDebugInfo::CreateType(const BuiltinType *BT) {
     //  Class isa;
     // } *id;
 
-    if (ObjTy.Verify())
+    if (ObjTy)
       return ObjTy;
 
-    if (!ClassTy.Verify())
+    if (!ClassTy)
       ClassTy = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
                                            "objc_class", TheCU,
                                            getOrCreateMainFile(), 0);
 
     unsigned Size = CGM.getContext().getTypeSize(CGM.getContext().VoidPtrTy);
-    
+
     llvm::DIType ISATy = DBuilder.createPointerType(ClassTy, Size);
 
     ObjTy =
@@ -398,7 +435,7 @@ llvm::DIType CGDebugInfo::CreateType(const BuiltinType *BT) {
     return ObjTy;
   }
   case BuiltinType::ObjCSel: {
-    if (SelTy.Verify())
+    if (SelTy)
       return SelTy;
     SelTy =
       DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
@@ -411,7 +448,7 @@ llvm::DIType CGDebugInfo::CreateType(const BuiltinType *BT) {
     return getOrCreateStructPtrType("opencl_image1d_t",
                                     OCLImage1dDITy);
   case BuiltinType::OCLImage1dArray:
-    return getOrCreateStructPtrType("opencl_image1d_array_t", 
+    return getOrCreateStructPtrType("opencl_image1d_array_t",
                                     OCLImage1dArrayDITy);
   case BuiltinType::OCLImage1dBuffer:
     return getOrCreateStructPtrType("opencl_image1d_buffer_t",
@@ -471,7 +508,7 @@ llvm::DIType CGDebugInfo::CreateType(const BuiltinType *BT) {
   // Bit size, align and offset of the type.
   uint64_t Size = CGM.getContext().getTypeSize(BT);
   uint64_t Align = CGM.getContext().getTypeAlign(BT);
-  llvm::DIType DbgTy = 
+  llvm::DIType DbgTy =
     DBuilder.createBasicType(BTName, Size, Align, Encoding);
   return DbgTy;
 }
@@ -484,7 +521,7 @@ llvm::DIType CGDebugInfo::CreateType(const ComplexType *Ty) {
 
   uint64_t Size = CGM.getContext().getTypeSize(Ty);
   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
-  llvm::DIType DbgTy = 
+  llvm::DIType DbgTy =
     DBuilder.createBasicType("complex", Size, Align, Encoding);
 
   return DbgTy;
@@ -523,7 +560,7 @@ llvm::DIType CGDebugInfo::CreateQualifiedType(QualType Ty, llvm::DIFile Unit) {
   // No need to fill in the Name, Line, Size, Alignment, Offset in case of
   // CVR derived types.
   llvm::DIType DbgTy = DBuilder.createQualifiedType(Tag, FromTy);
-  
+
   return DbgTy;
 }
 
@@ -537,20 +574,48 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCObjectPointerType *Ty,
       return getOrCreateType(CGM.getContext().getObjCIdType(), Unit);
 
   llvm::DIType DbgTy =
-    CreatePointerLikeType(llvm::dwarf::DW_TAG_pointer_type, Ty, 
+    CreatePointerLikeType(llvm::dwarf::DW_TAG_pointer_type, Ty,
                           Ty->getPointeeType(), Unit);
   return DbgTy;
 }
 
 llvm::DIType CGDebugInfo::CreateType(const PointerType *Ty,
                                      llvm::DIFile Unit) {
-  return CreatePointerLikeType(llvm::dwarf::DW_TAG_pointer_type, Ty, 
+  return CreatePointerLikeType(llvm::dwarf::DW_TAG_pointer_type, Ty,
                                Ty->getPointeeType(), Unit);
 }
 
+/// In C++ mode, types have linkage, so we can rely on the ODR and
+/// on their mangled names, if they're external.
+static SmallString<256>
+getUniqueTagTypeName(const TagType *Ty, CodeGenModule &CGM,
+                     llvm::DICompileUnit TheCU) {
+  SmallString<256> FullName;
+  // FIXME: ODR should apply to ObjC++ exactly the same wasy it does to C++.
+  // For now, only apply ODR with C++.
+  const TagDecl *TD = Ty->getDecl();
+  if (TheCU.getLanguage() != llvm::dwarf::DW_LANG_C_plus_plus ||
+      !TD->isExternallyVisible())
+    return FullName;
+  // Microsoft Mangler does not have support for mangleCXXRTTIName yet.
+  if (CGM.getTarget().getCXXABI().isMicrosoft())
+    return FullName;
+
+  // TODO: This is using the RTTI name. Is there a better way to get
+  // a unique string for a type?
+  llvm::raw_svector_ostream Out(FullName);
+  CGM.getCXXABI().getMangleContext().mangleCXXRTTIName(QualType(Ty, 0), Out);
+  Out.flush();
+  return FullName;
+}
+
 // Creates a forward declaration for a RecordDecl in the given context.
-llvm::DIType CGDebugInfo::createRecordFwdDecl(const RecordDecl *RD,
-                                              llvm::DIDescriptor Ctx) {
+llvm::DICompositeType
+CGDebugInfo::getOrCreateRecordFwdDecl(const RecordType *Ty,
+                                      llvm::DIDescriptor Ctx) {
+  const RecordDecl *RD = Ty->getDecl();
+  if (llvm::DIType T = getTypeOrNull(CGM.getContext().getRecordType(RD)))
+    return llvm::DICompositeType(T);
   llvm::DIFile DefUnit = getOrCreateFile(RD->getLocation());
   unsigned Line = getLineNumber(RD->getLocation());
   StringRef RDName = getClassName(RD);
@@ -566,74 +631,18 @@ llvm::DIType CGDebugInfo::createRecordFwdDecl(const RecordDecl *RD,
   }
 
   // Create the type.
-  return DBuilder.createForwardDecl(Tag, RDName, Ctx, DefUnit, Line);
-}
-
-// Walk up the context chain and create forward decls for record decls,
-// and normal descriptors for namespaces.
-llvm::DIDescriptor CGDebugInfo::createContextChain(const Decl *Context) {
-  if (!Context)
-    return TheCU;
-
-  // See if we already have the parent.
-  llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator
-    I = RegionMap.find(Context);
-  if (I != RegionMap.end()) {
-    llvm::Value *V = I->second;
-    return llvm::DIDescriptor(dyn_cast_or_null<llvm::MDNode>(V));
-  }
-  
-  // Check namespace.
-  if (const NamespaceDecl *NSDecl = dyn_cast<NamespaceDecl>(Context))
-    return llvm::DIDescriptor(getOrCreateNameSpace(NSDecl));
-
-  if (const RecordDecl *RD = dyn_cast<RecordDecl>(Context)) {
-    if (!RD->isDependentType()) {
-      llvm::DIType Ty = getOrCreateLimitedType(CGM.getContext().getTypeDeclType(RD),
-                                               getOrCreateMainFile());
-      return llvm::DIDescriptor(Ty);
-    }
-  }
-  return TheCU;
-}
-
-/// CreatePointeeType - Create Pointee type. If Pointee is a record
-/// then emit record's fwd if debug info size reduction is enabled.
-llvm::DIType CGDebugInfo::CreatePointeeType(QualType PointeeTy,
-                                            llvm::DIFile Unit) {
-  if (CGM.getCodeGenOpts().getDebugInfo() != CodeGenOptions::LimitedDebugInfo)
-    return getOrCreateType(PointeeTy, Unit);
-
-  // Limit debug info for the pointee type.
-
-  // If we have an existing type, use that, it's still smaller than creating
-  // a new type.
-  llvm::DIType Ty = getTypeOrNull(PointeeTy);
-  if (Ty.Verify()) return Ty;
-
-  // Handle qualifiers.
-  if (PointeeTy.hasLocalQualifiers())
-    return CreateQualifiedType(PointeeTy, Unit);
-
-  if (const RecordType *RTy = dyn_cast<RecordType>(PointeeTy)) {
-    RecordDecl *RD = RTy->getDecl();
-    llvm::DIDescriptor FDContext =
-      getContextDescriptor(cast<Decl>(RD->getDeclContext()));
-    llvm::DIType RetTy = createRecordFwdDecl(RD, FDContext);
-    TypeCache[QualType(RTy, 0).getAsOpaquePtr()] = RetTy;
-    return RetTy;
-  }
-  return getOrCreateType(PointeeTy, Unit);
+  SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
+  return DBuilder.createForwardDecl(Tag, RDName, Ctx, DefUnit, Line, 0, 0, 0,
+                                    FullName);
 }
 
 llvm::DIType CGDebugInfo::CreatePointerLikeType(unsigned Tag,
-                                                const Type *Ty, 
+                                                const Type *Ty,
                                                 QualType PointeeTy,
                                                 llvm::DIFile Unit) {
   if (Tag == llvm::dwarf::DW_TAG_reference_type ||
       Tag == llvm::dwarf::DW_TAG_rvalue_reference_type)
-    return DBuilder.createReferenceType(Tag,
-                                        CreatePointeeType(PointeeTy, Unit));
+    return DBuilder.createReferenceType(Tag, getOrCreateType(PointeeTy, Unit));
 
   // Bit size, align and offset of the type.
   // Size is always the size of a pointer. We can't use getTypeSize here
@@ -642,25 +651,24 @@ llvm::DIType CGDebugInfo::CreatePointerLikeType(unsigned Tag,
   uint64_t Size = CGM.getTarget().getPointerWidth(AS);
   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
 
-  return DBuilder.createPointerType(CreatePointeeType(PointeeTy, Unit),
-                                    Size, Align);
+  return DBuilder.createPointerType(getOrCreateType(PointeeTy, Unit), Size,
+                                    Align);
 }
 
-llvm::DIType CGDebugInfo::getOrCreateStructPtrType(StringRef Name, llvm::DIType &Cache) {
-    if (Cache.Verify())
-      return Cache;
-    Cache =
-      DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
-                                 Name, TheCU, getOrCreateMainFile(),
-                                 0);
-    unsigned Size = CGM.getContext().getTypeSize(CGM.getContext().VoidPtrTy);
-    Cache = DBuilder.createPointerType(Cache, Size);
+llvm::DIType CGDebugInfo::getOrCreateStructPtrType(StringRef Name,
+                                                   llvm::DIType &Cache) {
+  if (Cache)
     return Cache;
+  Cache = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type, Name,
+                                     TheCU, getOrCreateMainFile(), 0);
+  unsigned Size = CGM.getContext().getTypeSize(CGM.getContext().VoidPtrTy);
+  Cache = DBuilder.createPointerType(Cache, Size);
+  return Cache;
 }
 
 llvm::DIType CGDebugInfo::CreateType(const BlockPointerType *Ty,
                                      llvm::DIFile Unit) {
-  if (BlockLiteralGenericSet)
+  if (BlockLiteralGeneric)
     return BlockLiteralGeneric;
 
   SmallVector<llvm::Value *, 8> EltTys;
@@ -716,7 +724,6 @@ llvm::DIType CGDebugInfo::CreateType(const BlockPointerType *Ty,
                                     Unit, LineNo, FieldOffset, 0,
                                     Flags, llvm::DIType(), Elements);
 
-  BlockLiteralGenericSet = true;
   BlockLiteralGeneric = DBuilder.createPointerType(EltTy, Size);
   return BlockLiteralGeneric;
 }
@@ -725,16 +732,16 @@ llvm::DIType CGDebugInfo::CreateType(const TypedefType *Ty, llvm::DIFile Unit) {
   // Typedefs are derived from some other type.  If we have a typedef of a
   // typedef, make sure to emit the whole chain.
   llvm::DIType Src = getOrCreateType(Ty->getDecl()->getUnderlyingType(), Unit);
-  if (!Src.Verify())
+  if (!Src)
     return llvm::DIType();
   // We don't set size information, but do specify where the typedef was
   // declared.
   unsigned Line = getLineNumber(Ty->getDecl()->getLocation());
   const TypedefNameDecl *TyDecl = Ty->getDecl();
-  
+
   llvm::DIDescriptor TypedefContext =
     getContextDescriptor(cast<Decl>(Ty->getDecl()->getDeclContext()));
-  
+
   return
     DBuilder.createTypedef(Src, TyDecl->getName(), Unit, Line, TypedefContext);
 }
@@ -767,7 +774,7 @@ llvm::DIType CGDebugInfo::createFieldType(StringRef name,
                                           AccessSpecifier AS,
                                           uint64_t offsetInBits,
                                           llvm::DIFile tunit,
-                                          llvm::DIDescriptor scope) {
+                                          llvm::DIScope scope) {
   llvm::DIType debugType = getOrCreateType(type, tunit);
 
   // Get the location for the field.
@@ -839,20 +846,15 @@ CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
   }
 }
 
-/// CollectRecordStaticField - Helper for CollectRecordFields.
-void CGDebugInfo::
-CollectRecordStaticField(const VarDecl *Var,
-                         SmallVectorImpl<llvm::Value *> &elements,
-                         llvm::DIType RecordTy) {
+/// Helper for CollectRecordFields.
+llvm::DIDerivedType
+CGDebugInfo::CreateRecordStaticField(const VarDecl *Var,
+                                     llvm::DIType RecordTy) {
   // Create the descriptor for the static variable, with or without
   // constant initializers.
   llvm::DIFile VUnit = getOrCreateFile(Var->getLocation());
   llvm::DIType VTy = getOrCreateType(Var->getType(), VUnit);
 
-  // Do not describe enums as static members.
-  if (VTy.getTag() == llvm::dwarf::DW_TAG_enumeration_type)
-    return;
-
   unsigned LineNumber = getLineNumber(Var->getLocation());
   StringRef VName = Var->getName();
   llvm::Constant *C = NULL;
@@ -873,10 +875,10 @@ CollectRecordStaticField(const VarDecl *Var,
   else if (Access == clang::AS_protected)
     Flags |= llvm::DIDescriptor::FlagProtected;
 
-  llvm::DIType GV = DBuilder.createStaticMemberType(RecordTy, VName, VUnit,
-                                                    LineNumber, VTy, Flags, C);
-  elements.push_back(GV);
+  llvm::DIDerivedType GV = DBuilder.createStaticMemberType(
+      RecordTy, VName, VUnit, LineNumber, VTy, Flags, C);
   StaticDataMemberCache[Var->getCanonicalDecl()] = llvm::WeakVH(GV);
+  return GV;
 }
 
 /// CollectRecordNormalField - Helper for CollectRecordFields.
@@ -908,10 +910,10 @@ CollectRecordNormalField(const FieldDecl *field, uint64_t OffsetInBits,
 
 /// CollectRecordFields - A helper function to collect debug info for
 /// record fields. This is used while creating debug info entry for a Record.
-void CGDebugInfo::
-CollectRecordFields(const RecordDecl *record, llvm::DIFile tunit,
-                    SmallVectorImpl<llvm::Value *> &elements,
-                    llvm::DIType RecordTy) {
+void CGDebugInfo::CollectRecordFields(const RecordDecl *record,
+                                      llvm::DIFile tunit,
+                                      SmallVectorImpl<llvm::Value *> &elements,
+                                      llvm::DICompositeType RecordTy) {
   const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(record);
 
   if (CXXDecl && CXXDecl->isLambda())
@@ -922,24 +924,22 @@ CollectRecordFields(const RecordDecl *record, llvm::DIFile tunit,
     // Field number for non-static fields.
     unsigned fieldNo = 0;
 
-    // Bookkeeping for an ms struct, which ignores certain fields.
-    bool IsMsStruct = record->isMsStruct(CGM.getContext());
-    const FieldDecl *LastFD = 0;
-
     // Static and non-static members should appear in the same order as
     // the corresponding declarations in the source program.
     for (RecordDecl::decl_iterator I = record->decls_begin(),
            E = record->decls_end(); I != E; ++I)
-      if (const VarDecl *V = dyn_cast<VarDecl>(*I))
-        CollectRecordStaticField(V, elements, RecordTy);
-      else if (FieldDecl *field = dyn_cast<FieldDecl>(*I)) {
-        if (IsMsStruct) {
-          // Zero-length bitfields following non-bitfield members are
-          // completely ignored; we don't even count them.
-          if (CGM.getContext().ZeroBitfieldFollowsNonBitfield((field), LastFD))
-            continue;
-          LastFD = field;
-        }
+      if (const VarDecl *V = dyn_cast<VarDecl>(*I)) {
+        // Reuse the existing static member declaration if one exists
+        llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator MI =
+            StaticDataMemberCache.find(V->getCanonicalDecl());
+        if (MI != StaticDataMemberCache.end()) {
+          assert(MI->second &&
+                 "Static data member declaration should still exist");
+          elements.push_back(
+              llvm::DIDerivedType(cast<llvm::MDNode>(MI->second)));
+        } else
+          elements.push_back(CreateRecordStaticField(V, RecordTy));
+      } else if (FieldDecl *field = dyn_cast<FieldDecl>(*I)) {
         CollectRecordNormalField(field, layout.getFieldOffset(fieldNo),
                                  tunit, elements, RecordTy);
 
@@ -952,17 +952,17 @@ CollectRecordFields(const RecordDecl *record, llvm::DIFile tunit,
 /// getOrCreateMethodType - CXXMethodDecl's type is a FunctionType. This
 /// function type is not updated to include implicit "this" pointer. Use this
 /// routine to get a method type which includes "this" pointer.
-llvm::DIType
+llvm::DICompositeType
 CGDebugInfo::getOrCreateMethodType(const CXXMethodDecl *Method,
                                    llvm::DIFile Unit) {
   const FunctionProtoType *Func = Method->getType()->getAs<FunctionProtoType>();
   if (Method->isStatic())
-    return getOrCreateType(QualType(Func, 0), Unit);
+    return llvm::DICompositeType(getOrCreateType(QualType(Func, 0), Unit));
   return getOrCreateInstanceMethodType(Method->getThisType(CGM.getContext()),
                                        Func, Unit);
 }
 
-llvm::DIType CGDebugInfo::getOrCreateInstanceMethodType(
+llvm::DICompositeType CGDebugInfo::getOrCreateInstanceMethodType(
     QualType ThisPtr, const FunctionProtoType *Func, llvm::DIFile Unit) {
   // Add "this" pointer.
   llvm::DIArray Args = llvm::DICompositeType(
@@ -984,7 +984,8 @@ llvm::DIType CGDebugInfo::getOrCreateInstanceMethodType(
     uint64_t Size = CGM.getTarget().getPointerWidth(AS);
     uint64_t Align = CGM.getContext().getTypeAlign(ThisPtrTy);
     llvm::DIType PointeeType = getOrCreateType(PointeeTy, Unit);
-    llvm::DIType ThisPtrType = DBuilder.createPointerType(PointeeType, Size, Align);
+    llvm::DIType ThisPtrType =
+      DBuilder.createPointerType(PointeeType, Size, Align);
     TypeCache[ThisPtr.getAsOpaquePtr()] = ThisPtrType;
     // TODO: This and the artificial type below are misleading, the
     // types aren't artificial the argument is, but the current
@@ -1007,7 +1008,7 @@ llvm::DIType CGDebugInfo::getOrCreateInstanceMethodType(
   return DBuilder.createSubroutineType(Unit, EltTypeArray);
 }
 
-/// isFunctionLocalClass - Return true if CXXRecordDecl is defined 
+/// isFunctionLocalClass - Return true if CXXRecordDecl is defined
 /// inside a function.
 static bool isFunctionLocalClass(const CXXRecordDecl *RD) {
   if (const CXXRecordDecl *NRD = dyn_cast<CXXRecordDecl>(RD->getDeclContext()))
@@ -1023,11 +1024,11 @@ llvm::DISubprogram
 CGDebugInfo::CreateCXXMemberFunction(const CXXMethodDecl *Method,
                                      llvm::DIFile Unit,
                                      llvm::DIType RecordTy) {
-  bool IsCtorOrDtor = 
+  bool IsCtorOrDtor =
     isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method);
-  
+
   StringRef MethodName = getFunctionName(Method);
-  llvm::DIType MethodTy = getOrCreateMethodType(Method, Unit);
+  llvm::DICompositeType MethodTy = getOrCreateMethodType(Method, Unit);
 
   // Since a single ctor/dtor corresponds to multiple functions, it doesn't
   // make sense to give a single ctor/dtor a linkage name.
@@ -1036,24 +1037,32 @@ CGDebugInfo::CreateCXXMemberFunction(const CXXMethodDecl *Method,
     MethodLinkageName = CGM.getMangledName(Method);
 
   // Get the location for the method.
-  llvm::DIFile MethodDefUnit = getOrCreateFile(Method->getLocation());
-  unsigned MethodLine = getLineNumber(Method->getLocation());
+  llvm::DIFile MethodDefUnit;
+  unsigned MethodLine = 0;
+  if (!Method->isImplicit()) {
+    MethodDefUnit = getOrCreateFile(Method->getLocation());
+    MethodLine = getLineNumber(Method->getLocation());
+  }
 
   // Collect virtual method info.
   llvm::DIType ContainingType;
-  unsigned Virtuality = 0; 
+  unsigned Virtuality = 0;
   unsigned VIndex = 0;
-  
+
   if (Method->isVirtual()) {
     if (Method->isPure())
       Virtuality = llvm::dwarf::DW_VIRTUALITY_pure_virtual;
     else
       Virtuality = llvm::dwarf::DW_VIRTUALITY_virtual;
-    
+
     // It doesn't make sense to give a virtual destructor a vtable index,
     // since a single destructor has two entries in the vtable.
-    if (!isa<CXXDestructorDecl>(Method))
-      VIndex = CGM.getVTableContext().getMethodVTableIndex(Method);
+    // FIXME: Add proper support for debug info for virtual calls in
+    // the Microsoft ABI, where we may use multiple vptrs to make a vftable
+    // lookup if we have multiple or virtual inheritance.
+    if (!isa<CXXDestructorDecl>(Method) &&
+        !CGM.getTarget().getCXXABI().isMicrosoft())
+      VIndex = CGM.getItaniumVTableContext().getMethodVTableIndex(Method);
     ContainingType = RecordTy;
   }
 
@@ -1068,7 +1077,7 @@ CGDebugInfo::CreateCXXMemberFunction(const CXXMethodDecl *Method,
   if (const CXXConstructorDecl *CXXC = dyn_cast<CXXConstructorDecl>(Method)) {
     if (CXXC->isExplicit())
       Flags |= llvm::DIDescriptor::FlagExplicit;
-  } else if (const CXXConversionDecl *CXXC = 
+  } else if (const CXXConversionDecl *CXXC =
              dyn_cast<CXXConversionDecl>(Method)) {
     if (CXXC->isExplicit())
       Flags |= llvm::DIDescriptor::FlagExplicit;
@@ -1078,21 +1087,21 @@ CGDebugInfo::CreateCXXMemberFunction(const CXXMethodDecl *Method,
 
   llvm::DIArray TParamsArray = CollectFunctionTemplateParams(Method, Unit);
   llvm::DISubprogram SP =
-    DBuilder.createMethod(RecordTy, MethodName, MethodLinkageName, 
+    DBuilder.createMethod(RecordTy, MethodName, MethodLinkageName,
                           MethodDefUnit, MethodLine,
-                          MethodTy, /*isLocalToUnit=*/false, 
+                          MethodTy, /*isLocalToUnit=*/false,
                           /* isDefinition=*/ false,
                           Virtuality, VIndex, ContainingType,
                           Flags, CGM.getLangOpts().Optimize, NULL,
                           TParamsArray);
-  
+
   SPCache[Method->getCanonicalDecl()] = llvm::WeakVH(SP);
 
   return SP;
 }
 
 /// CollectCXXMemberFunctions - A helper function to collect debug info for
-/// C++ member functions. This is used while creating debug info entry for 
+/// C++ member functions. This is used while creating debug info entry for
 /// a Record.
 void CGDebugInfo::
 CollectCXXMemberFunctions(const CXXRecordDecl *RD, llvm::DIFile Unit,
@@ -1104,40 +1113,42 @@ CollectCXXMemberFunctions(const CXXRecordDecl *RD, llvm::DIFile Unit,
   // the functions.
   for(DeclContext::decl_iterator I = RD->decls_begin(),
         E = RD->decls_end(); I != E; ++I) {
-    Decl *D = *I;
-    if (D->isImplicit() && !D->isUsed())
-      continue;
-
-    if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
-      EltTys.push_back(CreateCXXMemberFunction(Method, Unit, RecordTy));
-    else if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
+    if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*I)) {
+      // Reuse the existing member function declaration if it exists.
+      // It may be associated with the declaration of the type & should be
+      // reused as we're building the definition.
+      //
+      // This situation can arise in the vtable-based debug info reduction where
+      // implicit members are emitted in a non-vtable TU.
+      llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator MI =
+          SPCache.find(Method->getCanonicalDecl());
+      if (MI == SPCache.end()) {
+        // If the member is implicit, lazily create it when we see the
+        // definition, not before. (an ODR-used implicit default ctor that's
+        // never actually code generated should not produce debug info)
+        if (!Method->isImplicit())
+          EltTys.push_back(CreateCXXMemberFunction(Method, Unit, RecordTy));
+      } else
+        EltTys.push_back(MI->second);
+    } else if (const FunctionTemplateDecl *FTD =
+                   dyn_cast<FunctionTemplateDecl>(*I)) {
+      // Add any template specializations that have already been seen. Like
+      // implicit member functions, these may have been added to a declaration
+      // in the case of vtable-based debug info reduction.
       for (FunctionTemplateDecl::spec_iterator SI = FTD->spec_begin(),
-             SE = FTD->spec_end(); SI != SE; ++SI)
-        EltTys.push_back(CreateCXXMemberFunction(cast<CXXMethodDecl>(*SI), Unit,
-                                                 RecordTy));
-  }
-}                                 
-
-/// CollectCXXFriends - A helper function to collect debug info for
-/// C++ base classes. This is used while creating debug info entry for
-/// a Record.
-void CGDebugInfo::
-CollectCXXFriends(const CXXRecordDecl *RD, llvm::DIFile Unit,
-                SmallVectorImpl<llvm::Value *> &EltTys,
-                llvm::DIType RecordTy) {
-  for (CXXRecordDecl::friend_iterator BI = RD->friend_begin(),
-         BE = RD->friend_end(); BI != BE; ++BI) {
-    if ((*BI)->isUnsupportedFriend())
-      continue;
-    if (TypeSourceInfo *TInfo = (*BI)->getFriendType())
-      EltTys.push_back(DBuilder.createFriend(RecordTy, 
-                                             getOrCreateType(TInfo->getType(), 
-                                                             Unit)));
+                                               SE = FTD->spec_end();
+           SI != SE; ++SI) {
+        llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator MI =
+            SPCache.find(cast<CXXMethodDecl>(*SI)->getCanonicalDecl());
+        if (MI != SPCache.end())
+          EltTys.push_back(MI->second);
+      }
+    }
   }
 }
 
 /// CollectCXXBases - A helper function to collect debug info for
-/// C++ base classes. This is used while creating debug info entry for 
+/// C++ base classes. This is used while creating debug info entry for
 /// a Record.
 void CGDebugInfo::
 CollectCXXBases(const CXXRecordDecl *RD, llvm::DIFile Unit,
@@ -1149,30 +1160,30 @@ CollectCXXBases(const CXXRecordDecl *RD, llvm::DIFile Unit,
          BE = RD->bases_end(); BI != BE; ++BI) {
     unsigned BFlags = 0;
     uint64_t BaseOffset;
-    
+
     const CXXRecordDecl *Base =
       cast<CXXRecordDecl>(BI->getType()->getAs<RecordType>()->getDecl());
-    
+
     if (BI->isVirtual()) {
       // virtual base offset offset is -ve. The code generator emits dwarf
       // expression where it expects +ve number.
-      BaseOffset = 
-        0 - CGM.getVTableContext()
+      BaseOffset =
+        0 - CGM.getItaniumVTableContext()
                .getVirtualBaseOffsetOffset(RD, Base).getQuantity();
       BFlags = llvm::DIDescriptor::FlagVirtual;
     } else
       BaseOffset = CGM.getContext().toBits(RL.getBaseClassOffset(Base));
     // FIXME: Inconsistent units for BaseOffset. It is in bytes when
     // BI->isVirtual() and bits when not.
-    
+
     AccessSpecifier Access = BI->getAccessSpecifier();
     if (Access == clang::AS_private)
       BFlags |= llvm::DIDescriptor::FlagPrivate;
     else if (Access == clang::AS_protected)
       BFlags |= llvm::DIDescriptor::FlagProtected;
-    
-    llvm::DIType DTy = 
-      DBuilder.createInheritance(RecordTy,                                     
+
+    llvm::DIType DTy =
+      DBuilder.createInheritance(RecordTy,
                                  getOrCreateType(BI->getType(), Unit),
                                  BaseOffset, BFlags);
     EltTys.push_back(DTy);
@@ -1182,23 +1193,119 @@ CollectCXXBases(const CXXRecordDecl *RD, llvm::DIFile Unit,
 /// CollectTemplateParams - A helper function to collect template parameters.
 llvm::DIArray CGDebugInfo::
 CollectTemplateParams(const TemplateParameterList *TPList,
-                      const TemplateArgumentList &TAList,
+                      ArrayRef<TemplateArgument> TAList,
                       llvm::DIFile Unit) {
-  SmallVector<llvm::Value *, 16> TemplateParams;  
+  SmallVector<llvm::Value *, 16> TemplateParams;
   for (unsigned i = 0, e = TAList.size(); i != e; ++i) {
     const TemplateArgument &TA = TAList[i];
-    const NamedDecl *ND = TPList->getParam(i);
-    if (TA.getKind() == TemplateArgument::Type) {
+    StringRef Name;
+    if (TPList)
+      Name = TPList->getParam(i)->getName();
+    switch (TA.getKind()) {
+    case TemplateArgument::Type: {
       llvm::DIType TTy = getOrCreateType(TA.getAsType(), Unit);
       llvm::DITemplateTypeParameter TTP =
-        DBuilder.createTemplateTypeParameter(TheCU, ND->getName(), TTy);
+          DBuilder.createTemplateTypeParameter(TheCU, Name, TTy);
       TemplateParams.push_back(TTP);
-    } else if (TA.getKind() == TemplateArgument::Integral) {
+    } break;
+    case TemplateArgument::Integral: {
       llvm::DIType TTy = getOrCreateType(TA.getIntegralType(), Unit);
       llvm::DITemplateValueParameter TVP =
-        DBuilder.createTemplateValueParameter(TheCU, ND->getName(), TTy,
-                                             TA.getAsIntegral().getZExtValue());
-      TemplateParams.push_back(TVP);          
+          DBuilder.createTemplateValueParameter(
+              TheCU, Name, TTy,
+              llvm::ConstantInt::get(CGM.getLLVMContext(), TA.getAsIntegral()));
+      TemplateParams.push_back(TVP);
+    } break;
+    case TemplateArgument::Declaration: {
+      const ValueDecl *D = TA.getAsDecl();
+      bool InstanceMember = D->isCXXInstanceMember();
+      QualType T = InstanceMember
+                       ? CGM.getContext().getMemberPointerType(
+                             D->getType(), cast<RecordDecl>(D->getDeclContext())
+                                               ->getTypeForDecl())
+                       : CGM.getContext().getPointerType(D->getType());
+      llvm::DIType TTy = getOrCreateType(T, Unit);
+      llvm::Value *V = 0;
+      // Variable pointer template parameters have a value that is the address
+      // of the variable.
+      if (const VarDecl *VD = dyn_cast<VarDecl>(D))
+        V = CGM.GetAddrOfGlobalVar(VD);
+      // Member function pointers have special support for building them, though
+      // this is currently unsupported in LLVM CodeGen.
+      if (InstanceMember) {
+        if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(D))
+          V = CGM.getCXXABI().EmitMemberPointer(method);
+      } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
+        V = CGM.GetAddrOfFunction(FD);
+      // Member data pointers have special handling too to compute the fixed
+      // offset within the object.
+      if (isa<FieldDecl>(D)) {
+        // These five lines (& possibly the above member function pointer
+        // handling) might be able to be refactored to use similar code in
+        // CodeGenModule::getMemberPointerConstant
+        uint64_t fieldOffset = CGM.getContext().getFieldOffset(D);
+        CharUnits chars =
+            CGM.getContext().toCharUnitsFromBits((int64_t) fieldOffset);
+        V = CGM.getCXXABI().EmitMemberDataPointer(
+            cast<MemberPointerType>(T.getTypePtr()), chars);
+      }
+      llvm::DITemplateValueParameter TVP =
+          DBuilder.createTemplateValueParameter(TheCU, Name, TTy,
+                                                V->stripPointerCasts());
+      TemplateParams.push_back(TVP);
+    } break;
+    case TemplateArgument::NullPtr: {
+      QualType T = TA.getNullPtrType();
+      llvm::DIType TTy = getOrCreateType(T, Unit);
+      llvm::Value *V = 0;
+      // Special case member data pointer null values since they're actually -1
+      // instead of zero.
+      if (const MemberPointerType *MPT =
+              dyn_cast<MemberPointerType>(T.getTypePtr()))
+        // But treat member function pointers as simple zero integers because
+        // it's easier than having a special case in LLVM's CodeGen. If LLVM
+        // CodeGen grows handling for values of non-null member function
+        // pointers then perhaps we could remove this special case and rely on
+        // EmitNullMemberPointer for member function pointers.
+        if (MPT->isMemberDataPointer())
+          V = CGM.getCXXABI().EmitNullMemberPointer(MPT);
+      if (!V)
+        V = llvm::ConstantInt::get(CGM.Int8Ty, 0);
+      llvm::DITemplateValueParameter TVP =
+          DBuilder.createTemplateValueParameter(TheCU, Name, TTy, V);
+      TemplateParams.push_back(TVP);
+    } break;
+    case TemplateArgument::Template: {
+      llvm::DITemplateValueParameter TVP =
+          DBuilder.createTemplateTemplateParameter(
+              TheCU, Name, llvm::DIType(),
+              TA.getAsTemplate().getAsTemplateDecl()
+                  ->getQualifiedNameAsString());
+      TemplateParams.push_back(TVP);
+    } break;
+    case TemplateArgument::Pack: {
+      llvm::DITemplateValueParameter TVP =
+          DBuilder.createTemplateParameterPack(
+              TheCU, Name, llvm::DIType(),
+              CollectTemplateParams(NULL, TA.getPackAsArray(), Unit));
+      TemplateParams.push_back(TVP);
+    } break;
+    case TemplateArgument::Expression: {
+      const Expr *E = TA.getAsExpr();
+      QualType T = E->getType();
+      llvm::Value *V = CGM.EmitConstantExpr(E, T);
+      assert(V && "Expression in template argument isn't constant");
+      llvm::DIType TTy = getOrCreateType(T, Unit);
+      llvm::DITemplateValueParameter TVP =
+          DBuilder.createTemplateValueParameter(TheCU, Name, TTy,
+                                                V->stripPointerCasts());
+      TemplateParams.push_back(TVP);
+    } break;
+    // And the following should never occur:
+    case TemplateArgument::TemplateExpansion:
+    case TemplateArgument::Null:
+      llvm_unreachable(
+          "These argument types shouldn't exist in concrete types");
     }
   }
   return DBuilder.getOrCreateArray(TemplateParams);
@@ -1213,8 +1320,8 @@ CollectFunctionTemplateParams(const FunctionDecl *FD, llvm::DIFile Unit) {
     const TemplateParameterList *TList =
       FD->getTemplateSpecializationInfo()->getTemplate()
       ->getTemplateParameters();
-    return 
-      CollectTemplateParams(TList, *FD->getTemplateSpecializationArgs(), Unit);
+    return CollectTemplateParams(
+        TList, FD->getTemplateSpecializationArgs()->asArray(), Unit);
   }
   return llvm::DIArray();
 }
@@ -1227,12 +1334,12 @@ CollectCXXTemplateParams(const ClassTemplateSpecializationDecl *TSpecial,
   llvm::PointerUnion<ClassTemplateDecl *,
                      ClassTemplatePartialSpecializationDecl *>
     PU = TSpecial->getSpecializedTemplateOrPartial();
-  
+
   TemplateParameterList *TPList = PU.is<ClassTemplateDecl *>() ?
     PU.get<ClassTemplateDecl *>()->getTemplateParameters() :
     PU.get<ClassTemplatePartialSpecializationDecl *>()->getTemplateParameters();
   const TemplateArgumentList &TAList = TSpecial->getTemplateInstantiationArgs();
-  return CollectTemplateParams(TPList, TAList, Unit);
+  return CollectTemplateParams(TPList, TAList.asArray(), Unit);
 }
 
 /// getOrCreateVTablePtrType - Return debug info descriptor for vtable.
@@ -1255,13 +1362,8 @@ llvm::DIType CGDebugInfo::getOrCreateVTablePtrType(llvm::DIFile Unit) {
 
 /// getVTableName - Get vtable name for the given Class.
 StringRef CGDebugInfo::getVTableName(const CXXRecordDecl *RD) {
-  // Construct gdb compatible name name.
-  std::string Name = "_vptr$" + RD->getNameAsString();
-
-  // Copy this name on the side and use its reference.
-  char *StrPtr = DebugInfoNames.Allocate<char>(Name.length());
-  memcpy(StrPtr, Name.data(), Name.length());
-  return StringRef(StrPtr, Name.length());
+  // Copy the gdb compatible name on the side and use its reference.
+  return internString("_vptr$", RD->getNameAsString());
 }
 
 
@@ -1283,15 +1385,16 @@ CollectVTableInfo(const CXXRecordDecl *RD, llvm::DIFile Unit,
   unsigned Size = CGM.getContext().getTypeSize(CGM.getContext().VoidPtrTy);
   llvm::DIType VPTR
     = DBuilder.createMemberType(Unit, getVTableName(RD), Unit,
-                                0, Size, 0, 0, llvm::DIDescriptor::FlagArtificial,
+                                0, Size, 0, 0,
+                                llvm::DIDescriptor::FlagArtificial,
                                 getOrCreateVTablePtrType(Unit));
   EltTys.push_back(VPTR);
 }
 
-/// getOrCreateRecordType - Emit record type's standalone debug info. 
-llvm::DIType CGDebugInfo::getOrCreateRecordType(QualType RTy, 
+/// getOrCreateRecordType - Emit record type's standalone debug info.
+llvm::DIType CGDebugInfo::getOrCreateRecordType(QualType RTy,
                                                 SourceLocation Loc) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   llvm::DIType T = getOrCreateType(RTy, getOrCreateFile(Loc));
   return T;
 }
@@ -1300,15 +1403,76 @@ llvm::DIType CGDebugInfo::getOrCreateRecordType(QualType RTy,
 /// debug info.
 llvm::DIType CGDebugInfo::getOrCreateInterfaceType(QualType D,
                                                    SourceLocation Loc) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   llvm::DIType T = getOrCreateType(D, getOrCreateFile(Loc));
   RetainedTypes.push_back(D.getAsOpaquePtr());
   return T;
 }
 
+void CGDebugInfo::completeType(const RecordDecl *RD) {
+  if (DebugKind > CodeGenOptions::LimitedDebugInfo ||
+      !CGM.getLangOpts().CPlusPlus)
+    completeRequiredType(RD);
+}
+
+void CGDebugInfo::completeRequiredType(const RecordDecl *RD) {
+  if (const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD))
+    if (CXXDecl->isDynamicClass())
+      return;
+
+  QualType Ty = CGM.getContext().getRecordType(RD);
+  llvm::DIType T = getTypeOrNull(Ty);
+  if (T && T.isForwardDecl())
+    completeClassData(RD);
+}
+
+void CGDebugInfo::completeClassData(const RecordDecl *RD) {
+  if (DebugKind <= CodeGenOptions::DebugLineTablesOnly)
+    return;
+  QualType Ty = CGM.getContext().getRecordType(RD);
+  void* TyPtr = Ty.getAsOpaquePtr();
+  if (CompletedTypeCache.count(TyPtr))
+    return;
+  llvm::DIType Res = CreateTypeDefinition(Ty->castAs<RecordType>());
+  assert(!Res.isForwardDecl());
+  CompletedTypeCache[TyPtr] = Res;
+  TypeCache[TyPtr] = Res;
+}
+
 /// CreateType - get structure or union type.
 llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty) {
   RecordDecl *RD = Ty->getDecl();
+  const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD);
+  // Always emit declarations for types that aren't required to be complete when
+  // in limit-debug-info mode. If the type is later found to be required to be
+  // complete this declaration will be upgraded to a definition by
+  // `completeRequiredType`.
+  // If the type is dynamic, only emit the definition in TUs that require class
+  // data. This is handled by `completeClassData`.
+  llvm::DICompositeType T(getTypeOrNull(QualType(Ty, 0)));
+  // If we've already emitted the type, just use that, even if it's only a
+  // declaration. The completeType, completeRequiredType, and completeClassData
+  // callbacks will handle promoting the declaration to a definition.
+  if (T ||
+      (DebugKind <= CodeGenOptions::LimitedDebugInfo &&
+       // Under -flimit-debug-info, emit only a declaration unless the type is
+       // required to be complete.
+       !RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) ||
+      // If the class is dynamic, only emit a declaration. A definition will be
+      // emitted whenever the vtable is emitted.
+      (CXXDecl && CXXDecl->hasDefinition() && CXXDecl->isDynamicClass()) || T) {
+    llvm::DIDescriptor FDContext =
+      getContextDescriptor(cast<Decl>(RD->getDeclContext()));
+    if (!T)
+      T = getOrCreateRecordFwdDecl(Ty, FDContext);
+    return T;
+  }
+
+  return CreateTypeDefinition(Ty);
+}
+
+llvm::DIType CGDebugInfo::CreateTypeDefinition(const RecordType *Ty) {
+  RecordDecl *RD = Ty->getDecl();
 
   // Get overall information about the record type for the debug info.
   llvm::DIFile DefUnit = getOrCreateFile(RD->getLocation());
@@ -1320,14 +1484,16 @@ llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty) {
   // may refer to the forward decl if the struct is recursive) and replace all
   // uses of the forward declaration with the final definition.
 
-  llvm::DICompositeType FwdDecl(
-      getOrCreateLimitedType(QualType(Ty, 0), DefUnit));
-  assert(FwdDecl.Verify() &&
-         "The debug type of a RecordType should be a DICompositeType");
+  llvm::DICompositeType FwdDecl(getOrCreateLimitedType(Ty, DefUnit));
+  assert(FwdDecl.isCompositeType() &&
+         "The debug type of a RecordType should be a llvm::DICompositeType");
 
   if (FwdDecl.isForwardDecl())
     return FwdDecl;
 
+  if (const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD))
+    CollectContainingType(CXXDecl, FwdDecl);
+
   // Push the struct on region stack.
   LexicalBlockStack.push_back(&*FwdDecl);
   RegionMap[Ty->getDecl()] = llvm::WeakVH(FwdDecl);
@@ -1337,6 +1503,7 @@ llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty) {
 
   // Convert all the elements.
   SmallVector<llvm::Value *, 16> EltTys;
+  // what about nested types?
 
   // Note: The split of CXXDecl information here is intentional, the
   // gdb tests will depend on a certain ordering at printout. The debug
@@ -1350,20 +1517,14 @@ llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty) {
 
   // Collect data fields (including static variables and any initializers).
   CollectRecordFields(RD, DefUnit, EltTys, FwdDecl);
-  llvm::DIArray TParamsArray;
-  if (CXXDecl) {
+  if (CXXDecl)
     CollectCXXMemberFunctions(CXXDecl, DefUnit, EltTys, FwdDecl);
-    CollectCXXFriends(CXXDecl, DefUnit, EltTys, FwdDecl);
-    if (const ClassTemplateSpecializationDecl *TSpecial
-        = dyn_cast<ClassTemplateSpecializationDecl>(RD))
-      TParamsArray = CollectCXXTemplateParams(TSpecial, DefUnit);
-  }
 
   LexicalBlockStack.pop_back();
   RegionMap.erase(Ty->getDecl());
 
   llvm::DIArray Elements = DBuilder.getOrCreateArray(EltTys);
-  FwdDecl.setTypeArray(Elements, TParamsArray);
+  FwdDecl.setTypeArray(Elements);
 
   RegionMap[Ty->getDecl()] = llvm::WeakVH(FwdDecl);
   return FwdDecl;
@@ -1376,6 +1537,31 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCObjectType *Ty,
   return getOrCreateType(Ty->getBaseType(), Unit);
 }
 
+
+/// \return true if Getter has the default name for the property PD.
+static bool hasDefaultGetterName(const ObjCPropertyDecl *PD,
+                                 const ObjCMethodDecl *Getter) {
+  assert(PD);
+  if (!Getter)
+    return true;
+
+  assert(Getter->getDeclName().isObjCZeroArgSelector());
+  return PD->getName() ==
+    Getter->getDeclName().getObjCSelector().getNameForSlot(0);
+}
+
+/// \return true if Setter has the default name for the property PD.
+static bool hasDefaultSetterName(const ObjCPropertyDecl *PD,
+                                 const ObjCMethodDecl *Setter) {
+  assert(PD);
+  if (!Setter)
+    return true;
+
+  assert(Setter->getDeclName().isObjCOneArgSelector());
+  return SelectorTable::constructSetterName(PD->getName()) ==
+    Setter->getDeclName().getObjCSelector().getNameForSlot(0);
+}
+
 /// CreateType - get objective-c interface type.
 llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
                                      llvm::DIFile Unit) {
@@ -1418,8 +1604,8 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
   // will find it and we're emitting the complete type.
   QualType QualTy = QualType(Ty, 0);
   CompletedTypeCache[QualTy.getAsOpaquePtr()] = RealDecl;
-  // Push the struct on region stack.
 
+  // Push the struct on region stack.
   LexicalBlockStack.push_back(static_cast<llvm::MDNode*>(RealDecl));
   RegionMap[Ty->getDecl()] = llvm::WeakVH(RealDecl);
 
@@ -1432,12 +1618,13 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
       getOrCreateType(CGM.getContext().getObjCInterfaceType(SClass), Unit);
     if (!SClassTy.isValid())
       return llvm::DIType();
-    
+
     llvm::DIType InhTag =
       DBuilder.createInheritance(RealDecl, SClassTy, 0, 0);
     EltTys.push_back(InhTag);
   }
 
+  // Create entries for all of the properties.
   for (ObjCContainerDecl::prop_iterator I = ID->prop_begin(),
          E = ID->prop_end(); I != E; ++I) {
     const ObjCPropertyDecl *PD = *I;
@@ -1449,9 +1636,9 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
     llvm::MDNode *PropertyNode =
       DBuilder.createObjCProperty(PD->getName(),
                                   PUnit, PLine,
-                                  (Getter && Getter->isImplicit()) ? "" :
+                                  hasDefaultGetterName(PD, Getter) ? "" :
                                   getSelectorName(PD->getGetterName()),
-                                  (Setter && Setter->isImplicit()) ? "" :
+                                  hasDefaultSetterName(PD, Setter) ? "" :
                                   getSelectorName(PD->getSetterName()),
                                   PD->getPropertyAttributes(),
                                   getOrCreateType(PD->getType(), PUnit));
@@ -1465,7 +1652,7 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
     llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);
     if (!FieldTy.isValid())
       return llvm::DIType();
-    
+
     StringRef FieldName = Field->getName();
 
     // Ignore unnamed fields.
@@ -1483,8 +1670,8 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
 
       // Bit size, align and offset of the type.
       FieldSize = Field->isBitField()
-        ? Field->getBitWidthValue(CGM.getContext())
-        : CGM.getContext().getTypeSize(FType);
+                      ? Field->getBitWidthValue(CGM.getContext())
+                      : CGM.getContext().getTypeSize(FType);
       FieldAlign = CGM.getContext().getTypeAlign(FType);
     }
 
@@ -1512,7 +1699,7 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
 
     llvm::MDNode *PropertyNode = NULL;
     if (ObjCImplementationDecl *ImpD = ID->getImplementation()) {
-      if (ObjCPropertyImplDecl *PImpD = 
+      if (ObjCPropertyImplDecl *PImpD =
           ImpD->FindPropertyImplIvarDecl(Field->getIdentifier())) {
         if (ObjCPropertyDecl *PD = PImpD->getPropertyDecl()) {
           SourceLocation Loc = PD->getLocation();
@@ -1523,9 +1710,9 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
           PropertyNode =
             DBuilder.createObjCProperty(PD->getName(),
                                         PUnit, PLine,
-                                        (Getter && Getter->isImplicit()) ? "" :
+                                        hasDefaultGetterName(PD, Getter) ? "" :
                                         getSelectorName(PD->getGetterName()),
-                                        (Setter && Setter->isImplicit()) ? "" :
+                                        hasDefaultSetterName(PD, Setter) ? "" :
                                         getSelectorName(PD->getSetterName()),
                                         PD->getPropertyAttributes(),
                                         getOrCreateType(PD->getType(), PUnit));
@@ -1547,7 +1734,7 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
   // private ivars that we would miss otherwise.
   if (ID->getImplementation() == 0)
     CompletedTypeCache.erase(QualTy.getAsOpaquePtr());
-  
+
   LexicalBlockStack.pop_back();
   return RealDecl;
 }
@@ -1585,7 +1772,7 @@ llvm::DIType CGDebugInfo::CreateType(const ArrayType *Ty,
       Align = 0;
     else
       Align = CGM.getContext().getTypeAlign(Ty->getElementType());
-  } else if (Ty->isDependentSizedArrayType() || Ty->isIncompleteType()) {
+  } else if (Ty->isIncompleteType()) {
     Size = 0;
     Align = 0;
   } else {
@@ -1610,7 +1797,7 @@ llvm::DIType CGDebugInfo::CreateType(const ArrayType *Ty,
     int64_t Count = -1;         // Count == -1 is an unbounded array.
     if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(Ty))
       Count = CAT->getSize().getZExtValue();
-    
+
     // FIXME: Verify this is right for VLAs.
     Subscripts.push_back(DBuilder.getOrCreateSubrange(0, Count));
     EltTy = Ty->getElementType();
@@ -1618,30 +1805,30 @@ llvm::DIType CGDebugInfo::CreateType(const ArrayType *Ty,
 
   llvm::DIArray SubscriptArray = DBuilder.getOrCreateArray(Subscripts);
 
-  llvm::DIType DbgTy = 
+  llvm::DIType DbgTy =
     DBuilder.createArrayType(Size, Align, getOrCreateType(EltTy, Unit),
                              SubscriptArray);
   return DbgTy;
 }
 
-llvm::DIType CGDebugInfo::CreateType(const LValueReferenceType *Ty, 
+llvm::DIType CGDebugInfo::CreateType(const LValueReferenceType *Ty,
                                      llvm::DIFile Unit) {
-  return CreatePointerLikeType(llvm::dwarf::DW_TAG_reference_type, 
+  return CreatePointerLikeType(llvm::dwarf::DW_TAG_reference_type,
                                Ty, Ty->getPointeeType(), Unit);
 }
 
-llvm::DIType CGDebugInfo::CreateType(const RValueReferenceType *Ty, 
+llvm::DIType CGDebugInfo::CreateType(const RValueReferenceType *Ty,
                                      llvm::DIFile Unit) {
-  return CreatePointerLikeType(llvm::dwarf::DW_TAG_rvalue_reference_type, 
+  return CreatePointerLikeType(llvm::dwarf::DW_TAG_rvalue_reference_type,
                                Ty, Ty->getPointeeType(), Unit);
 }
 
-llvm::DIType CGDebugInfo::CreateType(const MemberPointerType *Ty, 
+llvm::DIType CGDebugInfo::CreateType(const MemberPointerType *Ty,
                                      llvm::DIFile U) {
   llvm::DIType ClassType = getOrCreateType(QualType(Ty->getClass(), 0), U);
   if (!Ty->getPointeeType()->isFunctionType())
     return DBuilder.createMemberPointerType(
-        CreatePointeeType(Ty->getPointeeType(), U), ClassType);
+        getOrCreateType(Ty->getPointeeType(), U), ClassType);
   return DBuilder.createMemberPointerType(getOrCreateInstanceMethodType(
       CGM.getContext().getPointerType(
           QualType(Ty->getClass(), Ty->getPointeeType().getCVRQualifiers())),
@@ -1649,7 +1836,7 @@ llvm::DIType CGDebugInfo::CreateType(const MemberPointerType *Ty,
                                           ClassType);
 }
 
-llvm::DIType CGDebugInfo::CreateType(const AtomicType *Ty, 
+llvm::DIType CGDebugInfo::CreateType(const AtomicType *Ty,
                                      llvm::DIFile U) {
   // Ignore the atomic wrapping
   // FIXME: What is the correct representation?
@@ -1657,7 +1844,8 @@ llvm::DIType CGDebugInfo::CreateType(const AtomicType *Ty,
 }
 
 /// CreateEnumType - get enumeration type.
-llvm::DIType CGDebugInfo::CreateEnumType(const EnumDecl *ED) {
+llvm::DIType CGDebugInfo::CreateEnumType(const EnumType *Ty) {
+  const EnumDecl *ED = Ty->getDecl();
   uint64_t Size = 0;
   uint64_t Align = 0;
   if (!ED->getTypeForDecl()->isIncompleteType()) {
@@ -1665,6 +1853,8 @@ llvm::DIType CGDebugInfo::CreateEnumType(const EnumDecl *ED) {
     Align = CGM.getContext().getTypeAlign(ED->getTypeForDecl());
   }
 
+  SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
+
   // If this is just a forward declaration, construct an appropriately
   // marked node and just return it.
   if (!ED->getDefinition()) {
@@ -1675,7 +1865,7 @@ llvm::DIType CGDebugInfo::CreateEnumType(const EnumDecl *ED) {
     StringRef EDName = ED->getName();
     return DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_enumeration_type,
                                       EDName, EDContext, DefUnit, Line, 0,
-                                      Size, Align);
+                                      Size, Align, FullName);
   }
 
   // Create DIEnumerator elements for each enumerator.
@@ -1686,7 +1876,7 @@ llvm::DIType CGDebugInfo::CreateEnumType(const EnumDecl *ED) {
        Enum != EnumEnd; ++Enum) {
     Enumerators.push_back(
       DBuilder.createEnumerator(Enum->getName(),
-                                Enum->getInitVal().getZExtValue()));
+                                Enum->getInitVal().getSExtValue()));
   }
 
   // Return a CompositeType for the enum itself.
@@ -1694,21 +1884,25 @@ llvm::DIType CGDebugInfo::CreateEnumType(const EnumDecl *ED) {
 
   llvm::DIFile DefUnit = getOrCreateFile(ED->getLocation());
   unsigned Line = getLineNumber(ED->getLocation());
-  llvm::DIDescriptor EnumContext = 
+  llvm::DIDescriptor EnumContext =
     getContextDescriptor(cast<Decl>(ED->getDeclContext()));
   llvm::DIType ClassTy = ED->isFixed() ?
     getOrCreateType(ED->getIntegerType(), DefUnit) : llvm::DIType();
-  llvm::DIType DbgTy = 
+  llvm::DIType DbgTy =
     DBuilder.createEnumerationType(EnumContext, ED->getName(), DefUnit, Line,
                                    Size, Align, EltArray,
-                                   ClassTy);
+                                   ClassTy, FullName);
   return DbgTy;
 }
 
 static QualType UnwrapTypeForDebugInfo(QualType T, const ASTContext &C) {
   Qualifiers Quals;
   do {
-    Quals += T.getLocalQualifiers();
+    Qualifiers InnerQuals = T.getLocalQualifiers();
+    // Qualifiers::operator+() doesn't like it if you add a Qualifier
+    // that is already there.
+    Quals += Qualifiers::removeCommonQualifiers(Quals, InnerQuals);
+    Quals += InnerQuals;
     QualType LastT = T;
     switch (T->getTypeClass()) {
     default:
@@ -1741,21 +1935,25 @@ static QualType UnwrapTypeForDebugInfo(QualType T, const ASTContext &C) {
       T = cast<SubstTemplateTypeParmType>(T)->getReplacementType();
       break;
     case Type::Auto:
-      T = cast<AutoType>(T)->getDeducedType();
+      QualType DT = cast<AutoType>(T)->getDeducedType();
+      if (DT.isNull())
+        return T;
+      T = DT;
       break;
     }
-    
+
     assert(T != LastT && "Type unwrapping failed to unwrap!");
     (void)LastT;
   } while (true);
 }
 
-/// getType - Get the type from the cache or return null type if it doesn't exist.
+/// getType - Get the type from the cache or return null type if it doesn't
+/// exist.
 llvm::DIType CGDebugInfo::getTypeOrNull(QualType Ty) {
 
   // Unwrap the type as needed for debug information.
   Ty = UnwrapTypeForDebugInfo(Ty, CGM.getContext());
-  
+
   // Check for existing entry.
   if (Ty->getTypeClass() == Type::ObjCInterface) {
     llvm::Value *V = getCachedInterfaceTypeOrNull(Ty);
@@ -1793,10 +1991,7 @@ llvm::DIType CGDebugInfo::getCompletedTypeOrNull(QualType Ty) {
   }
 
   // Verify that any cached debug info still exists.
-  if (V != 0)
-    return llvm::DIType(cast<llvm::MDNode>(V));
-
-  return llvm::DIType();
+  return llvm::DIType(cast_or_null<llvm::MDNode>(V));
 }
 
 /// getCachedInterfaceTypeOrNull - Get the type from the interface
@@ -1824,9 +2019,7 @@ llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty, llvm::DIFile Unit) {
   // Unwrap the type as needed for debug information.
   Ty = UnwrapTypeForDebugInfo(Ty, CGM.getContext());
 
-  llvm::DIType T = getCompletedTypeOrNull(Ty);
-
-  if (T.Verify())
+  if (llvm::DIType T = getCompletedTypeOrNull(Ty))
     return T;
 
   // Otherwise create the type.
@@ -1836,29 +2029,33 @@ llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty, llvm::DIFile Unit) {
   // And update the type cache.
   TypeCache[TyPtr] = Res;
 
+  // FIXME: this getTypeOrNull call seems silly when we just inserted the type
+  // into the cache - but getTypeOrNull has a special case for cached interface
+  // types. We should probably just pull that out as a special case for the
+  // "else" block below & skip the otherwise needless lookup.
   llvm::DIType TC = getTypeOrNull(Ty);
-  if (TC.Verify() && TC.isForwardDecl())
+  if (TC && TC.isForwardDecl())
     ReplaceMap.push_back(std::make_pair(TyPtr, static_cast<llvm::Value*>(TC)));
   else if (ObjCInterfaceDecl* Decl = getObjCInterfaceDecl(Ty)) {
     // Interface types may have elements added to them by a
     // subsequent implementation or extension, so we keep them in
     // the ObjCInterfaceCache together with a checksum. Instead of
-    // the (possibly) incomplete interace type, we return a forward
+    // the (possibly) incomplete interface type, we return a forward
     // declaration that gets RAUW'd in CGDebugInfo::finalize().
-    llvm::DenseMap<void *, std::pair<llvm::WeakVH, unsigned > >
-      ::iterator it = ObjCInterfaceCache.find(TyPtr);
-    if (it != ObjCInterfaceCache.end())
-      TC = llvm::DIType(cast<llvm::MDNode>(it->second.first));
-    else
-      TC = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
-                                      Decl->getName(), TheCU, Unit,
-                                      getLineNumber(Decl->getLocation()),
-                                      TheCU.getLanguage());
+    std::pair<llvm::WeakVH, unsigned> &V = ObjCInterfaceCache[TyPtr];
+    if (V.first)
+      return llvm::DIType(cast<llvm::MDNode>(V.first));
+    TC = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
+                                    Decl->getName(), TheCU, Unit,
+                                    getLineNumber(Decl->getLocation()),
+                                    TheCU.getLanguage());
     // Store the forward declaration in the cache.
-    ObjCInterfaceCache[TyPtr] = std::make_pair(TC, Checksum(Decl));
+    V.first = TC;
+    V.second = Checksum(Decl);
 
     // Register the type for replacement in finalize().
     ReplaceMap.push_back(std::make_pair(TyPtr, static_cast<llvm::Value*>(TC)));
+
     return TC;
   }
 
@@ -1868,19 +2065,25 @@ llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty, llvm::DIFile Unit) {
   return Res;
 }
 
-/// Currently the checksum merely consists of the number of ivars.
-unsigned CGDebugInfo::Checksum(const ObjCInterfaceDecl
-                               *InterfaceDecl) {
-  unsigned IvarNo = 0;
-  for (const ObjCIvarDecl *Ivar = InterfaceDecl->all_declared_ivar_begin();
-       Ivar != 0; Ivar = Ivar->getNextIvar()) ++IvarNo;
-  return IvarNo;
+/// Currently the checksum of an interface includes the number of
+/// ivars and property accessors.
+unsigned CGDebugInfo::Checksum(const ObjCInterfaceDecl *ID) {
+  // The assumption is that the number of ivars can only increase
+  // monotonically, so it is safe to just use their current number as
+  // a checksum.
+  unsigned Sum = 0;
+  for (const ObjCIvarDecl *Ivar = ID->all_declared_ivar_begin();
+       Ivar != 0; Ivar = Ivar->getNextIvar())
+    ++Sum;
+
+  return Sum;
 }
 
 ObjCInterfaceDecl *CGDebugInfo::getObjCInterfaceDecl(QualType Ty) {
   switch (Ty->getTypeClass()) {
   case Type::ObjCObjectPointer:
-    return getObjCInterfaceDecl(cast<ObjCObjectPointerType>(Ty)->getPointeeType());
+    return getObjCInterfaceDecl(cast<ObjCObjectPointerType>(Ty)
+                                    ->getPointeeType());
   case Type::ObjCInterface:
     return cast<ObjCInterfaceType>(Ty)->getDecl();
   default:
@@ -1895,7 +2098,7 @@ llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
     return CreateQualifiedType(Ty, Unit);
 
   const char *Diag = 0;
-  
+
   // Work out details of type.
   switch (Ty->getTypeClass()) {
 #define TYPE(Class, Base)
@@ -1920,6 +2123,10 @@ llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
     return CreateType(cast<ComplexType>(Ty));
   case Type::Pointer:
     return CreateType(cast<PointerType>(Ty), Unit);
+  case Type::Decayed:
+    // Decayed types are just pointers in LLVM and DWARF.
+    return CreateType(
+        cast<PointerType>(cast<DecayedType>(Ty)->getDecayedType()), Unit);
   case Type::BlockPointer:
     return CreateType(cast<BlockPointerType>(Ty), Unit);
   case Type::Typedef:
@@ -1927,7 +2134,7 @@ llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
   case Type::Record:
     return CreateType(cast<RecordType>(Ty));
   case Type::Enum:
-    return CreateEnumType(cast<EnumType>(Ty)->getDecl());
+    return CreateEnumType(cast<EnumType>(Ty));
   case Type::FunctionProto:
   case Type::FunctionNoProto:
     return CreateType(cast<FunctionType>(Ty), Unit);
@@ -1956,10 +2163,13 @@ llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
   case Type::TypeOf:
   case Type::Decltype:
   case Type::UnaryTransform:
-  case Type::Auto:
+  case Type::PackExpansion:
     llvm_unreachable("type should have been unwrapped!");
+  case Type::Auto:
+    Diag = "auto";
+    break;
   }
-  
+
   assert(Diag && "Fall through without a diagnostic?");
   unsigned DiagID = CGM.getDiags().getCustomDiagID(DiagnosticsEngine::Error,
                                "debug information for %0 is not yet supported");
@@ -1970,117 +2180,119 @@ llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
 
 /// getOrCreateLimitedType - Get the type from the cache or create a new
 /// limited type if necessary.
-llvm::DIType CGDebugInfo::getOrCreateLimitedType(QualType Ty,
+llvm::DIType CGDebugInfo::getOrCreateLimitedType(const RecordType *Ty,
                                                  llvm::DIFile Unit) {
-  if (Ty.isNull())
-    return llvm::DIType();
+  QualType QTy(Ty, 0);
 
-  // Unwrap the type as needed for debug information.
-  Ty = UnwrapTypeForDebugInfo(Ty, CGM.getContext());
-
-  llvm::DIType T = getTypeOrNull(Ty);
+  llvm::DICompositeType T(getTypeOrNull(QTy));
 
   // We may have cached a forward decl when we could have created
   // a non-forward decl. Go ahead and create a non-forward decl
   // now.
-  if (T.Verify() && !T.isForwardDecl()) return T;
+  if (T && !T.isForwardDecl()) return T;
 
   // Otherwise create the type.
-  llvm::DIType Res = CreateLimitedTypeNode(Ty, Unit);
+  llvm::DICompositeType Res = CreateLimitedType(Ty);
 
-  if (T.Verify() && T.isForwardDecl())
-    ReplaceMap.push_back(std::make_pair(Ty.getAsOpaquePtr(),
-                                        static_cast<llvm::Value*>(T)));
+  // Propagate members from the declaration to the definition
+  // CreateType(const RecordType*) will overwrite this with the members in the
+  // correct order if the full type is needed.
+  Res.setTypeArray(T.getTypeArray());
+
+  if (T && T.isForwardDecl())
+    ReplaceMap.push_back(
+        std::make_pair(QTy.getAsOpaquePtr(), static_cast<llvm::Value *>(T)));
 
   // And update the type cache.
-  TypeCache[Ty.getAsOpaquePtr()] = Res;
+  TypeCache[QTy.getAsOpaquePtr()] = Res;
   return Res;
 }
 
 // TODO: Currently used for context chains when limiting debug info.
-llvm::DIType CGDebugInfo::CreateLimitedType(const RecordType *Ty) {
+llvm::DICompositeType CGDebugInfo::CreateLimitedType(const RecordType *Ty) {
   RecordDecl *RD = Ty->getDecl();
-  
+
   // Get overall information about the record type for the debug info.
   llvm::DIFile DefUnit = getOrCreateFile(RD->getLocation());
   unsigned Line = getLineNumber(RD->getLocation());
   StringRef RDName = getClassName(RD);
 
-  llvm::DIDescriptor RDContext;
-  if (CGM.getCodeGenOpts().getDebugInfo() == CodeGenOptions::LimitedDebugInfo)
-    RDContext = createContextChain(cast<Decl>(RD->getDeclContext()));
-  else
-    RDContext = getContextDescriptor(cast<Decl>(RD->getDeclContext()));
+  llvm::DIDescriptor RDContext =
+      getContextDescriptor(cast<Decl>(RD->getDeclContext()));
+
+  // If we ended up creating the type during the context chain construction,
+  // just return that.
+  // FIXME: this could be dealt with better if the type was recorded as
+  // completed before we started this (see the CompletedTypeCache usage in
+  // CGDebugInfo::CreateTypeDefinition(const RecordType*) - that would need to
+  // be pushed to before context creation, but after it was known to be
+  // destined for completion (might still have an issue if this caller only
+  // required a declaration but the context construction ended up creating a
+  // definition)
+  llvm::DICompositeType T(getTypeOrNull(CGM.getContext().getRecordType(RD)));
+  if (T && (!T.isForwardDecl() || !RD->getDefinition()))
+      return T;
 
   // If this is just a forward declaration, construct an appropriately
   // marked node and just return it.
   if (!RD->getDefinition())
-    return createRecordFwdDecl(RD, RDContext);
+    return getOrCreateRecordFwdDecl(Ty, RDContext);
 
   uint64_t Size = CGM.getContext().getTypeSize(Ty);
   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
-  const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD);
   llvm::DICompositeType RealDecl;
-  
+
+  SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
+
   if (RD->isUnion())
     RealDecl = DBuilder.createUnionType(RDContext, RDName, DefUnit, Line,
-                                        Size, Align, 0, llvm::DIArray());
+                                        Size, Align, 0, llvm::DIArray(), 0,
+                                        FullName);
   else if (RD->isClass()) {
     // FIXME: This could be a struct type giving a default visibility different
     // than C++ class type, but needs llvm metadata changes first.
     RealDecl = DBuilder.createClassType(RDContext, RDName, DefUnit, Line,
                                         Size, Align, 0, 0, llvm::DIType(),
                                         llvm::DIArray(), llvm::DIType(),
-                                        llvm::DIArray());
+                                        llvm::DIArray(), FullName);
   } else
     RealDecl = DBuilder.createStructType(RDContext, RDName, DefUnit, Line,
-                                         Size, Align, 0, llvm::DIType(), llvm::DIArray());
+                                         Size, Align, 0, llvm::DIType(),
+                                         llvm::DIArray(), 0, llvm::DIType(),
+                                         FullName);
 
   RegionMap[Ty->getDecl()] = llvm::WeakVH(RealDecl);
   TypeCache[QualType(Ty, 0).getAsOpaquePtr()] = RealDecl;
 
-  if (CXXDecl) {
-    // A class's primary base or the class itself contains the vtable.
-    llvm::DICompositeType ContainingType;
-    const ASTRecordLayout &RL = CGM.getContext().getASTRecordLayout(RD);
-    if (const CXXRecordDecl *PBase = RL.getPrimaryBase()) {
-      // Seek non virtual primary base root.
-      while (1) {
-        const ASTRecordLayout &BRL = CGM.getContext().getASTRecordLayout(PBase);
-        const CXXRecordDecl *PBT = BRL.getPrimaryBase();
-        if (PBT && !BRL.isPrimaryBaseVirtual())
-          PBase = PBT;
-        else
-          break;
-      }
-      ContainingType = llvm::DICompositeType(
-          getOrCreateType(QualType(PBase->getTypeForDecl(), 0), DefUnit));
-    } else if (CXXDecl->isDynamicClass())
-      ContainingType = RealDecl;
-
-    RealDecl.setContainingType(ContainingType);
-  }
-  return llvm::DIType(RealDecl);
+  if (const ClassTemplateSpecializationDecl *TSpecial =
+          dyn_cast<ClassTemplateSpecializationDecl>(RD))
+    RealDecl.setTypeArray(llvm::DIArray(),
+                          CollectCXXTemplateParams(TSpecial, DefUnit));
+  return RealDecl;
 }
 
-/// CreateLimitedTypeNode - Create a new debug type node, but only forward
-/// declare composite types that haven't been processed yet.
-llvm::DIType CGDebugInfo::CreateLimitedTypeNode(QualType Ty,llvm::DIFile Unit) {
-
-  // Work out details of type.
-  switch (Ty->getTypeClass()) {
-#define TYPE(Class, Base)
-#define ABSTRACT_TYPE(Class, Base)
-#define NON_CANONICAL_TYPE(Class, Base)
-#define DEPENDENT_TYPE(Class, Base) case Type::Class:
-        #include "clang/AST/TypeNodes.def"
-    llvm_unreachable("Dependent types cannot show up in debug information");
+void CGDebugInfo::CollectContainingType(const CXXRecordDecl *RD,
+                                        llvm::DICompositeType RealDecl) {
+  // A class's primary base or the class itself contains the vtable.
+  llvm::DICompositeType ContainingType;
+  const ASTRecordLayout &RL = CGM.getContext().getASTRecordLayout(RD);
+  if (const CXXRecordDecl *PBase = RL.getPrimaryBase()) {
+    // Seek non virtual primary base root.
+    while (1) {
+      const ASTRecordLayout &BRL = CGM.getContext().getASTRecordLayout(PBase);
+      const CXXRecordDecl *PBT = BRL.getPrimaryBase();
+      if (PBT && !BRL.isPrimaryBaseVirtual())
+        PBase = PBT;
+      else
+        break;
+    }
+    ContainingType = llvm::DICompositeType(
+        getOrCreateType(QualType(PBase->getTypeForDecl(), 0),
+                        getOrCreateFile(RD->getLocation())));
+  } else if (RD->isDynamicClass())
+    ContainingType = RealDecl;
 
-  case Type::Record:
-    return CreateLimitedType(cast<RecordType>(Ty));
-  default:
-    return CreateTypeNode(Ty, Unit);
-  }
+  RealDecl.setContainingType(ContainingType);
 }
 
 /// CreateMemberType - Create new member and increase Offset by FType's size.
@@ -2097,21 +2309,57 @@ llvm::DIType CGDebugInfo::CreateMemberType(llvm::DIFile Unit, QualType FType,
   return Ty;
 }
 
+llvm::DIDescriptor CGDebugInfo::getDeclarationOrDefinition(const Decl *D) {
+  // We only need a declaration (not a definition) of the type - so use whatever
+  // we would otherwise do to get a type for a pointee. (forward declarations in
+  // limited debug info, full definitions (if the type definition is available)
+  // in unlimited debug info)
+  if (const TypeDecl *TD = dyn_cast<TypeDecl>(D))
+    return getOrCreateType(CGM.getContext().getTypeDeclType(TD),
+                           getOrCreateFile(TD->getLocation()));
+  // Otherwise fall back to a fairly rudimentary cache of existing declarations.
+  // This doesn't handle providing declarations (for functions or variables) for
+  // entities without definitions in this TU, nor when the definition proceeds
+  // the call to this function.
+  // FIXME: This should be split out into more specific maps with support for
+  // emitting forward declarations and merging definitions with declarations,
+  // the same way as we do for types.
+  llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator I =
+      DeclCache.find(D->getCanonicalDecl());
+  if (I == DeclCache.end())
+    return llvm::DIDescriptor();
+  llvm::Value *V = I->second;
+  return llvm::DIDescriptor(dyn_cast_or_null<llvm::MDNode>(V));
+}
+
 /// getFunctionDeclaration - Return debug info descriptor to describe method
 /// declaration for the given method definition.
 llvm::DISubprogram CGDebugInfo::getFunctionDeclaration(const Decl *D) {
+  if (!D || DebugKind == CodeGenOptions::DebugLineTablesOnly)
+    return llvm::DISubprogram();
+
   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
   if (!FD) return llvm::DISubprogram();
 
   // Setup context.
-  getContextDescriptor(cast<Decl>(D->getDeclContext()));
+  llvm::DIScope S = getContextDescriptor(cast<Decl>(D->getDeclContext()));
 
   llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator
     MI = SPCache.find(FD->getCanonicalDecl());
+  if (MI == SPCache.end()) {
+    if (const CXXMethodDecl *MD =
+            dyn_cast<CXXMethodDecl>(FD->getCanonicalDecl())) {
+      llvm::DICompositeType T(S);
+      llvm::DISubprogram SP =
+          CreateCXXMemberFunction(MD, getOrCreateFile(MD->getLocation()), T);
+      T.addMember(SP);
+      return SP;
+    }
+  }
   if (MI != SPCache.end()) {
     llvm::Value *V = MI->second;
     llvm::DISubprogram SP(dyn_cast_or_null<llvm::MDNode>(V));
-    if (SP.isSubprogram() && !llvm::DISubprogram(SP).isDefinition())
+    if (SP.isSubprogram() && !SP.isDefinition())
       return SP;
   }
 
@@ -2123,7 +2371,7 @@ llvm::DISubprogram CGDebugInfo::getFunctionDeclaration(const Decl *D) {
     if (MI != SPCache.end()) {
       llvm::Value *V = MI->second;
       llvm::DISubprogram SP(dyn_cast_or_null<llvm::MDNode>(V));
-      if (SP.isSubprogram() && !llvm::DISubprogram(SP).isDefinition())
+      if (SP.isSubprogram() && !SP.isDefinition())
         return SP;
     }
   }
@@ -2132,9 +2380,15 @@ llvm::DISubprogram CGDebugInfo::getFunctionDeclaration(const Decl *D) {
 
 // getOrCreateFunctionType - Construct DIType. If it is a c++ method, include
 // implicit parameter "this".
-llvm::DIType CGDebugInfo::getOrCreateFunctionType(const Decl *D,
-                                                  QualType FnType,
-                                                  llvm::DIFile F) {
+llvm::DICompositeType CGDebugInfo::getOrCreateFunctionType(const Decl *D,
+                                                           QualType FnType,
+                                                           llvm::DIFile F) {
+  if (!D || DebugKind == CodeGenOptions::DebugLineTablesOnly)
+    // Create fake but valid subroutine type. Otherwise
+    // llvm::DISubprogram::Verify() would return false, and
+    // subprogram DIE will miss DW_AT_decl_file and
+    // DW_AT_decl_line fields.
+    return DBuilder.createSubroutineType(F, DBuilder.getOrCreateArray(None));
 
   if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
     return getOrCreateMethodType(Method, F);
@@ -2143,7 +2397,14 @@ llvm::DIType CGDebugInfo::getOrCreateFunctionType(const Decl *D,
     SmallVector<llvm::Value *, 16> Elts;
 
     // First element is always return type. For 'void' functions it is NULL.
-    Elts.push_back(getOrCreateType(OMethod->getResultType(), F));
+    QualType ResultTy = OMethod->getResultType();
+
+    // Replace the instancetype keyword with the actual type.
+    if (ResultTy == CGM.getContext().getObjCInstanceType())
+      ResultTy = CGM.getContext().getPointerType(
+        QualType(OMethod->getClassInterface()->getTypeForDecl(), 0));
+
+    Elts.push_back(getOrCreateType(ResultTy, F));
     // "self" pointer is always first argument.
     QualType SelfDeclTy = OMethod->getSelfDecl()->getType();
     llvm::DIType SelfTy = getOrCreateType(SelfDeclTy, F);
@@ -2152,14 +2413,14 @@ llvm::DIType CGDebugInfo::getOrCreateFunctionType(const Decl *D,
     llvm::DIType CmdTy = getOrCreateType(OMethod->getCmdDecl()->getType(), F);
     Elts.push_back(DBuilder.createArtificialType(CmdTy));
     // Get rest of the arguments.
-    for (ObjCMethodDecl::param_const_iterator PI = OMethod->param_begin(), 
+    for (ObjCMethodDecl::param_const_iterator PI = OMethod->param_begin(),
            PE = OMethod->param_end(); PI != PE; ++PI)
       Elts.push_back(getOrCreateType((*PI)->getType(), F));
 
     llvm::DIArray EltTypeArray = DBuilder.getOrCreateArray(Elts);
     return DBuilder.createSubroutineType(F, EltTypeArray);
   }
-  return getOrCreateType(FnType, F);
+  return llvm::DICompositeType(getOrCreateType(FnType, F));
 }
 
 /// EmitFunctionStart - Constructs the debug code for entering a function.
@@ -2187,7 +2448,7 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
   llvm::DIArray TParamsArray;
   if (!HasDecl) {
     // Use llvm function name.
-    Name = Fn->getName();
+    LinkageName = Fn->getName();
   } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
     // If there is a DISubprogram for this function available then use it.
     llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator
@@ -2214,16 +2475,16 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
     if (LinkageName == Name ||
         (!CGM.getCodeGenOpts().EmitGcovArcs &&
          !CGM.getCodeGenOpts().EmitGcovNotes &&
-         CGM.getCodeGenOpts().getDebugInfo() <= CodeGenOptions::DebugLineTablesOnly))
+         DebugKind <= CodeGenOptions::DebugLineTablesOnly))
       LinkageName = StringRef();
 
-    if (CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) {
+    if (DebugKind >= CodeGenOptions::LimitedDebugInfo) {
       if (const NamespaceDecl *NSDecl =
-          dyn_cast_or_null<NamespaceDecl>(FD->getDeclContext()))
+              dyn_cast_or_null<NamespaceDecl>(FD->getDeclContext()))
         FDContext = getOrCreateNameSpace(NSDecl);
       else if (const RecordDecl *RDecl =
-               dyn_cast_or_null<RecordDecl>(FD->getDeclContext()))
-        FDContext = getContextDescriptor(cast<Decl>(RDecl->getDeclContext()));
+                   dyn_cast_or_null<RecordDecl>(FD->getDeclContext()))
+        FDContext = getContextDescriptor(cast<Decl>(RDecl));
 
       // Collect template parameters.
       TParamsArray = CollectFunctionTemplateParams(FD, Unit);
@@ -2243,28 +2504,15 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
   if (!HasDecl || D->isImplicit())
     Flags |= llvm::DIDescriptor::FlagArtificial;
 
-  llvm::DIType DIFnType;
-  llvm::DISubprogram SPDecl;
-  if (HasDecl &&
-      CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) {
-    DIFnType = getOrCreateFunctionType(D, FnType, Unit);
-    SPDecl = getFunctionDeclaration(D);
-  } else {
-    // Create fake but valid subroutine type. Otherwise
-    // llvm::DISubprogram::Verify() would return false, and
-    // subprogram DIE will miss DW_AT_decl_file and
-    // DW_AT_decl_line fields.
-    SmallVector<llvm::Value*, 16> Elts;
-    llvm::DIArray EltTypeArray = DBuilder.getOrCreateArray(Elts);
-    DIFnType = DBuilder.createSubroutineType(Unit, EltTypeArray);
-  }
-  llvm::DISubprogram SP;
-  SP = DBuilder.createFunction(FDContext, Name, LinkageName, Unit,
-                               LineNo, DIFnType,
-                               Fn->hasInternalLinkage(), true/*definition*/,
-                               getLineNumber(CurLoc), Flags,
-                               CGM.getLangOpts().Optimize,
-                               Fn, TParamsArray, SPDecl);
+  llvm::DISubprogram SP =
+      DBuilder.createFunction(FDContext, Name, LinkageName, Unit, LineNo,
+                              getOrCreateFunctionType(D, FnType, Unit),
+                              Fn->hasInternalLinkage(), true /*definition*/,
+                              getLineNumber(CurLoc), Flags,
+                              CGM.getLangOpts().Optimize, Fn, TParamsArray,
+                              getFunctionDeclaration(D));
+  if (HasDecl)
+    DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(SP)));
 
   // Push function on region stack.
   llvm::MDNode *SPN = SP;
@@ -2274,10 +2522,10 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
 }
 
 /// EmitLocation - Emit metadata to indicate a change in line/column
-/// information in the source file.
+/// information in the source file. If the location is invalid, the
+/// previous location will be reused.
 void CGDebugInfo::EmitLocation(CGBuilderTy &Builder, SourceLocation Loc,
                                bool ForceColumnInfo) {
-  
   // Update our current location
   setLocation(Loc);
 
@@ -2292,7 +2540,7 @@ void CGDebugInfo::EmitLocation(CGBuilderTy &Builder, SourceLocation Loc,
         Builder.getCurrentDebugLocation().getScope(CGM.getLLVMContext()) ==
           LexicalBlockStack.back())
       return;
-  
+
   // Update last state.
   PrevLoc = CurLoc;
 
@@ -2319,7 +2567,8 @@ void CGDebugInfo::CreateLexicalBlock(SourceLocation Loc) {
 
 /// EmitLexicalBlockStart - Constructs the debug code for entering a declarative
 /// region - beginning of a DW_TAG_lexical_block.
-void CGDebugInfo::EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc) {
+void CGDebugInfo::EmitLexicalBlockStart(CGBuilderTy &Builder,
+                                        SourceLocation Loc) {
   // Set our current location.
   setLocation(Loc);
 
@@ -2334,7 +2583,8 @@ void CGDebugInfo::EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc
 
 /// EmitLexicalBlockEnd - Constructs the debug code for exiting a declarative
 /// region - end of a DW_TAG_lexical_block.
-void CGDebugInfo::EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc) {
+void CGDebugInfo::EmitLexicalBlockEnd(CGBuilderTy &Builder,
+                                      SourceLocation Loc) {
   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
 
   // Provide an entry in the line table for the end of the block.
@@ -2355,7 +2605,7 @@ void CGDebugInfo::EmitFunctionEnd(CGBuilderTy &Builder) {
   FnBeginRegionCount.pop_back();
 }
 
-// EmitTypeForVarWithBlocksAttr - Build up structure info for the byref.  
+// EmitTypeForVarWithBlocksAttr - Build up structure info for the byref.
 // See BuildByRefType.
 llvm::DIType CGDebugInfo::EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
                                                        uint64_t *XOffset) {
@@ -2364,9 +2614,9 @@ llvm::DIType CGDebugInfo::EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
   QualType FType;
   uint64_t FieldSize, FieldOffset;
   unsigned FieldAlign;
-  
+
   llvm::DIFile Unit = getOrCreateFile(VD->getLocation());
-  QualType Type = VD->getType();  
+  QualType Type = VD->getType();
 
   FieldOffset = 0;
   FType = CGM.getContext().getPointerType(CGM.getContext().VoidTy);
@@ -2388,21 +2638,23 @@ llvm::DIType CGDebugInfo::EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
   Qualifiers::ObjCLifetime Lifetime;
   if (CGM.getContext().getByrefLifetime(Type,
                                         Lifetime, HasByrefExtendedLayout)
-      && HasByrefExtendedLayout)
+      && HasByrefExtendedLayout) {
+    FType = CGM.getContext().getPointerType(CGM.getContext().VoidTy);
     EltTys.push_back(CreateMemberType(Unit, FType,
                                       "__byref_variable_layout",
                                       &FieldOffset));
-  
+  }
+
   CharUnits Align = CGM.getContext().getDeclAlign(VD);
   if (Align > CGM.getContext().toCharUnitsFromBits(
         CGM.getTarget().getPointerAlign(0))) {
-    CharUnits FieldOffsetInBytes 
+    CharUnits FieldOffsetInBytes
       = CGM.getContext().toCharUnitsFromBits(FieldOffset);
     CharUnits AlignedOffsetInBytes
       = FieldOffsetInBytes.RoundUpToAlignment(Align);
     CharUnits NumPaddingBytes
       = AlignedOffsetInBytes - FieldOffsetInBytes;
-    
+
     if (NumPaddingBytes.isPositive()) {
       llvm::APInt pad(32, NumPaddingBytes.getQuantity());
       FType = CGM.getContext().getConstantArrayType(CGM.getContext().CharTy,
@@ -2410,40 +2662,45 @@ llvm::DIType CGDebugInfo::EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
       EltTys.push_back(CreateMemberType(Unit, FType, "", &FieldOffset));
     }
   }
-  
+
   FType = Type;
   llvm::DIType FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
   FieldSize = CGM.getContext().getTypeSize(FType);
   FieldAlign = CGM.getContext().toBits(Align);
 
-  *XOffset = FieldOffset;  
+  *XOffset = FieldOffset;
   FieldTy = DBuilder.createMemberType(Unit, VD->getName(), Unit,
                                       0, FieldSize, FieldAlign,
                                       FieldOffset, 0, FieldTy);
   EltTys.push_back(FieldTy);
   FieldOffset += FieldSize;
-  
+
   llvm::DIArray Elements = DBuilder.getOrCreateArray(EltTys);
-  
+
   unsigned Flags = llvm::DIDescriptor::FlagBlockByrefStruct;
-  
+
   return DBuilder.createStructType(Unit, "", Unit, 0, FieldOffset, 0, Flags,
                                    llvm::DIType(), Elements);
 }
 
 /// EmitDeclare - Emit local variable declaration debug info.
 void CGDebugInfo::EmitDeclare(const VarDecl *VD, unsigned Tag,
-                              llvm::Value *Storage, 
+                              llvm::Value *Storage,
                               unsigned ArgNo, CGBuilderTy &Builder) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
 
-  llvm::DIFile Unit = getOrCreateFile(VD->getLocation());
+  bool Unwritten =
+      VD->isImplicit() || (isa<Decl>(VD->getDeclContext()) &&
+                           cast<Decl>(VD->getDeclContext())->isImplicit());
+  llvm::DIFile Unit;
+  if (!Unwritten)
+    Unit = getOrCreateFile(VD->getLocation());
   llvm::DIType Ty;
   uint64_t XOffset = 0;
   if (VD->hasAttr<BlocksAttr>())
     Ty = EmitTypeForVarWithBlocksAttr(VD, &XOffset);
-  else 
+  else
     Ty = getOrCreateType(VD->getType(), Unit);
 
   // If there is no debug info for this type then do not emit debug info
@@ -2451,24 +2708,13 @@ void CGDebugInfo::EmitDeclare(const VarDecl *VD, unsigned Tag,
   if (!Ty)
     return;
 
-  if (llvm::Argument *Arg = dyn_cast<llvm::Argument>(Storage)) {
-    // If Storage is an aggregate returned as 'sret' then let debugger know
-    // about this.
-    if (Arg->hasStructRetAttr())
-      Ty = DBuilder.createReferenceType(llvm::dwarf::DW_TAG_reference_type, Ty);
-    else if (CXXRecordDecl *Record = VD->getType()->getAsCXXRecordDecl()) {
-      // If an aggregate variable has non trivial destructor or non trivial copy
-      // constructor than it is pass indirectly. Let debug info know about this
-      // by using reference of the aggregate type as a argument type.
-      if (Record->hasNonTrivialCopyConstructor() ||
-          !Record->hasTrivialDestructor())
-        Ty = DBuilder.createReferenceType(llvm::dwarf::DW_TAG_reference_type, Ty);
-    }
-  }
-      
   // Get location information.
-  unsigned Line = getLineNumber(VD->getLocation());
-  unsigned Column = getColumnNumber(VD->getLocation());
+  unsigned Line = 0;
+  unsigned Column = 0;
+  if (!Unwritten) {
+    Line = getLineNumber(VD->getLocation());
+    Column = getColumnNumber(VD->getLocation());
+  }
   unsigned Flags = 0;
   if (VD->isImplicit())
     Flags |= llvm::DIDescriptor::FlagArtificial;
@@ -2479,6 +2725,10 @@ void CGDebugInfo::EmitDeclare(const VarDecl *VD, unsigned Tag,
   // otherwise it is 'self' or 'this'.
   if (isa<ImplicitParamDecl>(VD) && ArgNo == 1)
     Flags |= llvm::DIDescriptor::FlagObjectPointer;
+  if (llvm::Argument *Arg = dyn_cast<llvm::Argument>(Storage))
+    if (Arg->getType()->isPointerTy() && !Arg->hasByValAttr() &&
+        !VD->getType()->isPointerType())
+      Flags |= llvm::DIDescriptor::FlagIndirectVariable;
 
   llvm::MDNode *Scope = LexicalBlockStack.back();
 
@@ -2501,33 +2751,18 @@ void CGDebugInfo::EmitDeclare(const VarDecl *VD, unsigned Tag,
 
       // Create the descriptor for the variable.
       llvm::DIVariable D =
-        DBuilder.createComplexVariable(Tag, 
+        DBuilder.createComplexVariable(Tag,
                                        llvm::DIDescriptor(Scope),
                                        VD->getName(), Unit, Line, Ty,
                                        addr, ArgNo);
-      
-      // Insert an llvm.dbg.declare into the current block.
-      llvm::Instruction *Call =
-        DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
-      Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
-      return;
-    } else if (isa<VariableArrayType>(VD->getType())) {
-      // These are "complex" variables in that they need an op_deref.
-      // Create the descriptor for the variable.
-      llvm::Value *Addr = llvm::ConstantInt::get(CGM.Int64Ty,
-                                                 llvm::DIBuilder::OpDeref);
-      llvm::DIVariable D =
-        DBuilder.createComplexVariable(Tag,
-                                       llvm::DIDescriptor(Scope),
-                                       Name, Unit, Line, Ty,
-                                       Addr, ArgNo);
 
       // Insert an llvm.dbg.declare into the current block.
       llvm::Instruction *Call =
         DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
       Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
       return;
-    }
+    } else if (isa<VariableArrayType>(VD->getType()))
+      Flags |= llvm::DIDescriptor::FlagIndirectVariable;
   } else if (const RecordType *RT = dyn_cast<RecordType>(VD->getType())) {
     // If VD is an anonymous union then Storage represents value for
     // all union fields.
@@ -2539,18 +2774,18 @@ void CGDebugInfo::EmitDeclare(const VarDecl *VD, unsigned Tag,
         FieldDecl *Field = *I;
         llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);
         StringRef FieldName = Field->getName();
-          
+
         // Ignore unnamed fields. Do not ignore unnamed records.
         if (FieldName.empty() && !isa<RecordType>(Field->getType()))
           continue;
-          
+
         // Use VarDecl's Tag, Scope and Line number.
         llvm::DIVariable D =
           DBuilder.createLocalVariable(Tag, llvm::DIDescriptor(Scope),
-                                       FieldName, Unit, Line, FieldTy, 
+                                       FieldName, Unit, Line, FieldTy,
                                        CGM.getLangOpts().Optimize, Flags,
                                        ArgNo);
-          
+
         // Insert an llvm.dbg.declare into the current block.
         llvm::Instruction *Call =
           DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
@@ -2575,7 +2810,7 @@ void CGDebugInfo::EmitDeclare(const VarDecl *VD, unsigned Tag,
 void CGDebugInfo::EmitDeclareOfAutoVariable(const VarDecl *VD,
                                             llvm::Value *Storage,
                                             CGBuilderTy &Builder) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   EmitDeclare(VD, llvm::dwarf::DW_TAG_auto_variable, Storage, 0, Builder);
 }
 
@@ -2585,9 +2820,10 @@ void CGDebugInfo::EmitDeclareOfAutoVariable(const VarDecl *VD,
 /// never happen though, since creating a type for the implicit self
 /// argument implies that we already parsed the interface definition
 /// and the ivar declarations in the implementation.
-llvm::DIType CGDebugInfo::CreateSelfType(const QualType &QualTy, llvm::DIType Ty) {
+llvm::DIType CGDebugInfo::CreateSelfType(const QualType &QualTy,
+                                         llvm::DIType Ty) {
   llvm::DIType CachedTy = getTypeOrNull(QualTy);
-  if (CachedTy.Verify()) Ty = CachedTy;
+  if (CachedTy) Ty = CachedTy;
   else DEBUG(llvm::dbgs() << "No cached type for self.");
   return DBuilder.createObjectPointerType(Ty);
 }
@@ -2596,20 +2832,20 @@ void CGDebugInfo::EmitDeclareOfBlockDeclRefVariable(const VarDecl *VD,
                                                     llvm::Value *Storage,
                                                     CGBuilderTy &Builder,
                                                  const CGBlockInfo &blockInfo) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
-  
+
   if (Builder.GetInsertBlock() == 0)
     return;
-  
+
   bool isByRef = VD->hasAttr<BlocksAttr>();
-  
+
   uint64_t XOffset = 0;
   llvm::DIFile Unit = getOrCreateFile(VD->getLocation());
   llvm::DIType Ty;
   if (isByRef)
     Ty = EmitTypeForVarWithBlocksAttr(VD, &XOffset);
-  else 
+  else
     Ty = getOrCreateType(VD->getType(), Unit);
 
   // Self is passed along as an implicit non-arg variable in a
@@ -2649,7 +2885,7 @@ void CGDebugInfo::EmitDeclareOfBlockDeclRefVariable(const VarDecl *VD,
 
   // Create the descriptor for the variable.
   llvm::DIVariable D =
-    DBuilder.createComplexVariable(llvm::dwarf::DW_TAG_auto_variable, 
+    DBuilder.createComplexVariable(llvm::dwarf::DW_TAG_auto_variable,
                                    llvm::DIDescriptor(LexicalBlockStack.back()),
                                    VD->getName(), Unit, Line, Ty, addr);
 
@@ -2665,7 +2901,7 @@ void CGDebugInfo::EmitDeclareOfBlockDeclRefVariable(const VarDecl *VD,
 void CGDebugInfo::EmitDeclareOfArgVariable(const VarDecl *VD, llvm::Value *AI,
                                            unsigned ArgNo,
                                            CGBuilderTy &Builder) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   EmitDeclare(VD, llvm::dwarf::DW_TAG_arg_variable, AI, ArgNo, Builder);
 }
 
@@ -2683,7 +2919,7 @@ void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
                                                        llvm::Value *Arg,
                                                        llvm::Value *LocalAddr,
                                                        CGBuilderTy &Builder) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   ASTContext &C = CGM.getContext();
   const BlockDecl *blockDecl = block.getBlockDecl();
 
@@ -2692,7 +2928,7 @@ void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
   llvm::DIFile tunit = getOrCreateFile(loc);
   unsigned line = getLineNumber(loc);
   unsigned column = getColumnNumber(loc);
-  
+
   // Build the debug-info type for the block literal.
   getContextDescriptor(cast<Decl>(blockDecl->getDeclContext()));
 
@@ -2812,7 +3048,7 @@ void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
   // Create the descriptor for the parameter.
   llvm::DIVariable debugVar =
     DBuilder.createLocalVariable(llvm::dwarf::DW_TAG_arg_variable,
-                                 llvm::DIDescriptor(scope), 
+                                 llvm::DIDescriptor(scope),
                                  Arg->getName(), tunit, line, type,
                                  CGM.getLangOpts().Optimize, flags,
                                  cast<llvm::Argument>(Arg)->getArgNo() + 1);
@@ -2831,25 +3067,32 @@ void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
   DbgDecl->setDebugLoc(llvm::DebugLoc::get(line, column, scope));
 }
 
-/// getStaticDataMemberDeclaration - If D is an out-of-class definition of
-/// a static data member of a class, find its corresponding in-class
-/// declaration.
-llvm::DIDerivedType CGDebugInfo::getStaticDataMemberDeclaration(const Decl *D) {
-  if (cast<VarDecl>(D)->isStaticDataMember()) {
-    llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator
-      MI = StaticDataMemberCache.find(D->getCanonicalDecl());
-    if (MI != StaticDataMemberCache.end())
-      // Verify the info still exists.
-      if (llvm::Value *V = MI->second)
-        return llvm::DIDerivedType(cast<llvm::MDNode>(V));
-  }
-  return llvm::DIDerivedType();
+/// If D is an out-of-class definition of a static data member of a class, find
+/// its corresponding in-class declaration.
+llvm::DIDerivedType
+CGDebugInfo::getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D) {
+  if (!D->isStaticDataMember())
+    return llvm::DIDerivedType();
+  llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator MI =
+      StaticDataMemberCache.find(D->getCanonicalDecl());
+  if (MI != StaticDataMemberCache.end()) {
+    assert(MI->second && "Static data member declaration should still exist");
+    return llvm::DIDerivedType(cast<llvm::MDNode>(MI->second));
+  }
+
+  // If the member wasn't found in the cache, lazily construct and add it to the
+  // type (used when a limited form of the type is emitted).
+  llvm::DICompositeType Ctxt(
+      getContextDescriptor(cast<Decl>(D->getDeclContext())));
+  llvm::DIDerivedType T = CreateRecordStaticField(D, Ctxt);
+  Ctxt.addMember(T);
+  return T;
 }
 
 /// EmitGlobalVariable - Emit information about a global variable.
 void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
                                      const VarDecl *D) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   // Create global variable debug descriptor.
   llvm::DIFile Unit = getOrCreateFile(D->getLocation());
   unsigned LineNo = getLineNumber(D->getLocation());
@@ -2873,18 +3116,19 @@ void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
     LinkageName = Var->getName();
   if (LinkageName == DeclName)
     LinkageName = StringRef();
-  llvm::DIDescriptor DContext = 
+  llvm::DIDescriptor DContext =
     getContextDescriptor(dyn_cast<Decl>(D->getDeclContext()));
-  DBuilder.createStaticVariable(DContext, DeclName, LinkageName,
-                                Unit, LineNo, getOrCreateType(T, Unit),
-                                Var->hasInternalLinkage(), Var,
-                                getStaticDataMemberDeclaration(D));
+  llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
+      DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
+      Var->hasInternalLinkage(), Var,
+      getOrCreateStaticDataMemberDeclarationOrNull(D));
+  DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(GV)));
 }
 
 /// EmitGlobalVariable - Emit information about an objective-c interface.
 void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
                                      ObjCInterfaceDecl *ID) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   // Create global variable debug descriptor.
   llvm::DIFile Unit = getOrCreateFile(ID->getLocation());
   unsigned LineNo = getLineNumber(ID->getLocation());
@@ -2908,9 +3152,9 @@ void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
 }
 
 /// EmitGlobalVariable - Emit global variable's debug info.
-void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD, 
+void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD,
                                      llvm::Constant *Init) {
-  assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
+  assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
   // Create the descriptor for the variable.
   llvm::DIFile Unit = getOrCreateFile(VD->getLocation());
   StringRef Name = VD->getName();
@@ -2923,34 +3167,79 @@ void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD,
   // Do not use DIGlobalVariable for enums.
   if (Ty.getTag() == llvm::dwarf::DW_TAG_enumeration_type)
     return;
-  DBuilder.createStaticVariable(Unit, Name, Name, Unit,
-                                getLineNumber(VD->getLocation()),
-                                Ty, true, Init,
-                                getStaticDataMemberDeclaration(VD));
+  llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
+      Unit, Name, Name, Unit, getLineNumber(VD->getLocation()), Ty, true, Init,
+      getOrCreateStaticDataMemberDeclarationOrNull(cast<VarDecl>(VD)));
+  DeclCache.insert(std::make_pair(VD->getCanonicalDecl(), llvm::WeakVH(GV)));
+}
+
+llvm::DIScope CGDebugInfo::getCurrentContextDescriptor(const Decl *D) {
+  if (!LexicalBlockStack.empty())
+    return llvm::DIScope(LexicalBlockStack.back());
+  return getContextDescriptor(D);
 }
 
 void CGDebugInfo::EmitUsingDirective(const UsingDirectiveDecl &UD) {
-  llvm::DIScope Scope =
-      LexicalBlockStack.empty()
-          ? getContextDescriptor(cast<Decl>(UD.getDeclContext()))
-          : llvm::DIScope(LexicalBlockStack.back());
+  if (CGM.getCodeGenOpts().getDebugInfo() < CodeGenOptions::LimitedDebugInfo)
+    return;
   DBuilder.createImportedModule(
-      Scope, getOrCreateNameSpace(UD.getNominatedNamespace()),
+      getCurrentContextDescriptor(cast<Decl>(UD.getDeclContext())),
+      getOrCreateNameSpace(UD.getNominatedNamespace()),
       getLineNumber(UD.getLocation()));
 }
 
+void CGDebugInfo::EmitUsingDecl(const UsingDecl &UD) {
+  if (CGM.getCodeGenOpts().getDebugInfo() < CodeGenOptions::LimitedDebugInfo)
+    return;
+  assert(UD.shadow_size() &&
+         "We shouldn't be codegening an invalid UsingDecl containing no decls");
+  // Emitting one decl is sufficient - debuggers can detect that this is an
+  // overloaded name & provide lookup for all the overloads.
+  const UsingShadowDecl &USD = **UD.shadow_begin();
+  if (llvm::DIDescriptor Target =
+          getDeclarationOrDefinition(USD.getUnderlyingDecl()))
+    DBuilder.createImportedDeclaration(
+        getCurrentContextDescriptor(cast<Decl>(USD.getDeclContext())), Target,
+        getLineNumber(USD.getLocation()));
+}
+
+llvm::DIImportedEntity
+CGDebugInfo::EmitNamespaceAlias(const NamespaceAliasDecl &NA) {
+  if (CGM.getCodeGenOpts().getDebugInfo() < CodeGenOptions::LimitedDebugInfo)
+    return llvm::DIImportedEntity(0);
+  llvm::WeakVH &VH = NamespaceAliasCache[&NA];
+  if (VH)
+    return llvm::DIImportedEntity(cast<llvm::MDNode>(VH));
+  llvm::DIImportedEntity R(0);
+  if (const NamespaceAliasDecl *Underlying =
+          dyn_cast<NamespaceAliasDecl>(NA.getAliasedNamespace()))
+    // This could cache & dedup here rather than relying on metadata deduping.
+    R = DBuilder.createImportedModule(
+        getCurrentContextDescriptor(cast<Decl>(NA.getDeclContext())),
+        EmitNamespaceAlias(*Underlying), getLineNumber(NA.getLocation()),
+        NA.getName());
+  else
+    R = DBuilder.createImportedModule(
+        getCurrentContextDescriptor(cast<Decl>(NA.getDeclContext())),
+        getOrCreateNameSpace(cast<NamespaceDecl>(NA.getAliasedNamespace())),
+        getLineNumber(NA.getLocation()), NA.getName());
+  VH = R;
+  return R;
+}
+
 /// getOrCreateNamesSpace - Return namespace descriptor for the given
 /// namespace decl.
-llvm::DINameSpace 
+llvm::DINameSpace
 CGDebugInfo::getOrCreateNameSpace(const NamespaceDecl *NSDecl) {
-  llvm::DenseMap<const NamespaceDecl *, llvm::WeakVH>::iterator I = 
+  NSDecl = NSDecl->getCanonicalDecl();
+  llvm::DenseMap<const NamespaceDecl *, llvm::WeakVH>::iterator I =
     NameSpaceCache.find(NSDecl);
   if (I != NameSpaceCache.end())
     return llvm::DINameSpace(cast<llvm::MDNode>(I->second));
-  
+
   unsigned LineNo = getLineNumber(NSDecl->getLocation());
   llvm::DIFile FileD = getOrCreateFile(NSDecl->getLocation());
-  llvm::DIDescriptor Context = 
+  llvm::DIDescriptor Context =
     getContextDescriptor(dyn_cast<Decl>(NSDecl->getDeclContext()));
   llvm::DINameSpace NS =
     DBuilder.createNameSpace(Context, NSDecl->getName(), FileD, LineNo);
@@ -2965,7 +3254,7 @@ void CGDebugInfo::finalize() {
     // Verify that the debug info still exists.
     if (llvm::Value *V = VI->second)
       Ty = llvm::DIType(cast<llvm::MDNode>(V));
-    
+
     llvm::DenseMap<void *, llvm::WeakVH>::iterator it =
       TypeCache.find(VI->first);
     if (it != TypeCache.end()) {
@@ -2974,7 +3263,7 @@ void CGDebugInfo::finalize() {
         RepTy = llvm::DIType(cast<llvm::MDNode>(V));
     }
 
-    if (Ty.Verify() && Ty.isForwardDecl() && RepTy.Verify())
+    if (Ty && Ty.isForwardDecl() && RepTy)
       Ty.replaceAllUsesWith(RepTy);
   }