X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FAsmPrinter%2FDwarfUnit.cpp;h=ccecb5be50bb90207fce0ce7739de7da1680547d;hb=9c9ef05445e4ebaf56e70f61e3fdcabc0ddcffc0;hp=693e37ffe8d557208d4e33403c62d70b3772bc8e;hpb=3955d288873e12d76b8b172321670728d8e026e0;p=oota-llvm.git

diff --git a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 693e37ffe8d..ccecb5be50b 100644
--- a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -17,20 +17,21 @@
 #include "DwarfAccelTable.h"
 #include "DwarfDebug.h"
 #include "llvm/ADT/APFloat.h"
-#include "llvm/DIBuilder.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instructions.h"
+#include "llvm/IR/Mangler.h"
 #include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCSection.h"
 #include "llvm/MC/MCStreamer.h"
-#include "llvm/Target/Mangler.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Target/TargetFrameLowering.h"
-#include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/Support/CommandLine.h"
 
 using namespace llvm;
 
@@ -42,8 +43,8 @@ GenerateDwarfTypeUnits("generate-type-units", cl::Hidden,
 /// Unit - Unit constructor.
 DwarfUnit::DwarfUnit(unsigned UID, DIE *D, DICompileUnit Node, AsmPrinter *A,
                      DwarfDebug *DW, DwarfFile *DWU)
-    : UniqueID(UID), Node(Node), UnitDie(D), DebugInfoOffset(0), Asm(A), DD(DW),
-      DU(DWU), IndexTyDie(0), Section(0) {
+    : UniqueID(UID), CUNode(Node), UnitDie(D), DebugInfoOffset(0), Asm(A),
+      DD(DW), DU(DWU), IndexTyDie(0), Section(0), Skeleton(0) {
   DIEIntegerOne = new (DIEValueAllocator) DIEInteger(1);
 }
 
@@ -54,14 +55,21 @@ DwarfCompileUnit::DwarfCompileUnit(unsigned UID, DIE *D, DICompileUnit Node,
   insertDIE(Node, D);
 }
 
-DwarfTypeUnit::DwarfTypeUnit(unsigned UID, DIE *D, uint16_t Language,
-                             AsmPrinter *A, DwarfDebug *DW, DwarfFile *DWU)
-    : DwarfUnit(UID, D, DICompileUnit(), A, DW, DWU), Language(Language) {}
+DwarfTypeUnit::DwarfTypeUnit(unsigned UID, DIE *D, DwarfCompileUnit &CU,
+                             AsmPrinter *A, DwarfDebug *DW, DwarfFile *DWU,
+                             MCDwarfDwoLineTable *SplitLineTable)
+    : DwarfUnit(UID, D, CU.getCUNode(), A, DW, DWU), CU(CU),
+      SplitLineTable(SplitLineTable) {
+  if (SplitLineTable)
+    addSectionOffset(UnitDie.get(), dwarf::DW_AT_stmt_list, 0);
+}
 
 /// ~Unit - Destructor for compile unit.
 DwarfUnit::~DwarfUnit() {
   for (unsigned j = 0, M = DIEBlocks.size(); j < M; ++j)
     DIEBlocks[j]->~DIEBlock();
+  for (unsigned j = 0, M = DIELocs.size(); j < M; ++j)
+    DIELocs[j]->~DIELoc();
 }
 
 /// createDIEEntry - Creates a new DIEEntry to be a proxy for a debug
@@ -169,7 +177,7 @@ void DwarfUnit::addUInt(DIE *Die, dwarf::Attribute Attribute,
   Die->addValue(Attribute, *Form, Value);
 }
 
-void DwarfUnit::addUInt(DIEBlock *Block, dwarf::Form Form, uint64_t Integer) {
+void DwarfUnit::addUInt(DIE *Block, dwarf::Form Form, uint64_t Integer) {
   addUInt(Block, (dwarf::Attribute)0, Form, Integer);
 }
 
@@ -183,7 +191,7 @@ void DwarfUnit::addSInt(DIE *Die, dwarf::Attribute Attribute,
   Die->addValue(Attribute, *Form, Value);
 }
 
-void DwarfUnit::addSInt(DIEBlock *Die, Optional<dwarf::Form> Form,
+void DwarfUnit::addSInt(DIELoc *Die, Optional<dwarf::Form> Form,
                         int64_t Integer) {
   addSInt(Die, (dwarf::Attribute)0, Form, Integer);
 }
@@ -195,24 +203,14 @@ void DwarfUnit::addSInt(DIEBlock *Die, Optional<dwarf::Form> Form,
 /// table.
 void DwarfUnit::addString(DIE *Die, dwarf::Attribute Attribute,
                           StringRef String) {
-  DIEValue *Value;
-  dwarf::Form Form;
-  if (!DD->useSplitDwarf()) {
-    MCSymbol *Symb = DU->getStringPoolEntry(String);
-    if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
-      Value = new (DIEValueAllocator) DIELabel(Symb);
-    else {
-      MCSymbol *StringPool = DU->getStringPoolSym();
-      Value = new (DIEValueAllocator) DIEDelta(Symb, StringPool);
-    }
-    Form = dwarf::DW_FORM_strp;
-  } else {
-    unsigned idx = DU->getStringPoolIndex(String);
-    Value = new (DIEValueAllocator) DIEInteger(idx);
-    Form = dwarf::DW_FORM_GNU_str_index;
-  }
+
+  if (!DD->useSplitDwarf())
+    return addLocalString(Die, Attribute, String);
+
+  unsigned idx = DU->getStringPoolIndex(String);
+  DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
   DIEValue *Str = new (DIEValueAllocator) DIEString(Value, String);
-  Die->addValue(Attribute, Form, Str);
+  Die->addValue(Attribute, dwarf::DW_FORM_GNU_str_index, Str);
 }
 
 /// addLocalString - Add a string attribute data and value. This is guaranteed
@@ -227,16 +225,27 @@ void DwarfUnit::addLocalString(DIE *Die, dwarf::Attribute Attribute,
     MCSymbol *StringPool = DU->getStringPoolSym();
     Value = new (DIEValueAllocator) DIEDelta(Symb, StringPool);
   }
-  Die->addValue(Attribute, dwarf::DW_FORM_strp, Value);
+  DIEValue *Str = new (DIEValueAllocator) DIEString(Value, String);
+  Die->addValue(Attribute, dwarf::DW_FORM_strp, Str);
 }
 
 /// addExpr - Add a Dwarf expression attribute data and value.
 ///
-void DwarfUnit::addExpr(DIEBlock *Die, dwarf::Form Form, const MCExpr *Expr) {
+void DwarfUnit::addExpr(DIELoc *Die, dwarf::Form Form, const MCExpr *Expr) {
   DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
   Die->addValue((dwarf::Attribute)0, Form, Value);
 }
 
+/// addLocationList - Add a Dwarf loclistptr attribute data and value.
+///
+void DwarfUnit::addLocationList(DIE *Die, dwarf::Attribute Attribute,
+                                unsigned Index) {
+  DIEValue *Value = new (DIEValueAllocator) DIELocList(Index);
+  dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
+                                                : dwarf::DW_FORM_data4;
+  Die->addValue(Attribute, Form, Value);
+}
+
 /// addLabel - Add a Dwarf label attribute data and value.
 ///
 void DwarfUnit::addLabel(DIE *Die, dwarf::Attribute Attribute, dwarf::Form Form,
@@ -245,8 +254,7 @@ void DwarfUnit::addLabel(DIE *Die, dwarf::Attribute Attribute, dwarf::Form Form,
   Die->addValue(Attribute, Form, Value);
 }
 
-void DwarfUnit::addLabel(DIEBlock *Die, dwarf::Form Form,
-                         const MCSymbol *Label) {
+void DwarfUnit::addLabel(DIELoc *Die, dwarf::Form Form, const MCSymbol *Label) {
   addLabel(Die, (dwarf::Attribute)0, Form, Label);
 }
 
@@ -274,29 +282,54 @@ void DwarfUnit::addSectionOffset(DIE *Die, dwarf::Attribute Attribute,
 /// DW_FORM_addr or DW_FORM_GNU_addr_index.
 ///
 void DwarfCompileUnit::addLabelAddress(DIE *Die, dwarf::Attribute Attribute,
-                                       MCSymbol *Label) {
+                                       const MCSymbol *Label) {
+
+  if (!DD->useSplitDwarf())
+    return addLocalLabelAddress(Die, Attribute, Label);
+
   if (Label)
     DD->addArangeLabel(SymbolCU(this, Label));
 
-  if (!DD->useSplitDwarf()) {
-    if (Label != NULL) {
-      DIEValue *Value = new (DIEValueAllocator) DIELabel(Label);
-      Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
-    } else {
-      DIEValue *Value = new (DIEValueAllocator) DIEInteger(0);
-      Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
-    }
+  unsigned idx = DU->getAddrPoolIndex(Label);
+  DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
+  Die->addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
+}
+
+void DwarfCompileUnit::addLocalLabelAddress(DIE *Die,
+                                            dwarf::Attribute Attribute,
+                                            const MCSymbol *Label) {
+  if (Label)
+    DD->addArangeLabel(SymbolCU(this, Label));
+
+  if (Label) {
+    DIEValue *Value = new (DIEValueAllocator) DIELabel(Label);
+    Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
   } else {
-    unsigned idx = DU->getAddrPoolIndex(Label);
-    DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
-    Die->addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
+    DIEValue *Value = new (DIEValueAllocator) DIEInteger(0);
+    Die->addValue(Attribute, dwarf::DW_FORM_addr, Value);
   }
 }
 
+unsigned DwarfCompileUnit::getOrCreateSourceID(StringRef FileName, StringRef DirName) {
+  // If we print assembly, we can't separate .file entries according to
+  // compile units. Thus all files will belong to the default compile unit.
+
+  // FIXME: add a better feature test than hasRawTextSupport. Even better,
+  // extend .file to support this.
+  return Asm->OutStreamer.EmitDwarfFileDirective(
+      0, DirName, FileName,
+      Asm->OutStreamer.hasRawTextSupport() ? 0 : getUniqueID());
+}
+
+unsigned DwarfTypeUnit::getOrCreateSourceID(StringRef FileName, StringRef DirName) {
+  return SplitLineTable ? SplitLineTable->getFile(DirName, FileName)
+                        : getCU().getOrCreateSourceID(FileName, DirName);
+}
+
 /// addOpAddress - Add a dwarf op address data and value using the
 /// form given and an op of either DW_FORM_addr or DW_FORM_GNU_addr_index.
 ///
-void DwarfUnit::addOpAddress(DIEBlock *Die, const MCSymbol *Sym) {
+void DwarfUnit::addOpAddress(DIELoc *Die, const MCSymbol *Sym) {
   if (!DD->useSplitDwarf()) {
     addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
     addLabel(Die, dwarf::DW_FORM_udata, Sym);
@@ -317,6 +350,12 @@ void DwarfUnit::addSectionDelta(DIE *Die, dwarf::Attribute Attribute,
     Die->addValue(Attribute, dwarf::DW_FORM_data4, Value);
 }
 
+void DwarfUnit::addLabelDelta(DIE *Die, dwarf::Attribute Attribute,
+                              const MCSymbol *Hi, const MCSymbol *Lo) {
+  DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo);
+  Die->addValue(Attribute, dwarf::DW_FORM_data4, Value);
+}
+
 /// addDIEEntry - Add a DIE attribute data and value.
 ///
 void DwarfUnit::addDIEEntry(DIE *Die, dwarf::Attribute Attribute, DIE *Entry) {
@@ -345,7 +384,9 @@ void DwarfUnit::addDIEEntry(DIE *Die, dwarf::Attribute Attribute,
 /// Create a DIE with the given Tag, add the DIE to its parent, and
 /// call insertDIE if MD is not null.
 DIE *DwarfUnit::createAndAddDIE(unsigned Tag, DIE &Parent, DIDescriptor N) {
-  DIE *Die = new DIE(Tag);
+  assert(Tag != dwarf::DW_TAG_auto_variable &&
+         Tag != dwarf::DW_TAG_arg_variable);
+  DIE *Die = new DIE((dwarf::Tag)Tag);
   Parent.addChild(Die);
   if (N)
     insertDIE(N, Die);
@@ -354,6 +395,12 @@ DIE *DwarfUnit::createAndAddDIE(unsigned Tag, DIE &Parent, DIDescriptor N) {
 
 /// addBlock - Add block data.
 ///
+void DwarfUnit::addBlock(DIE *Die, dwarf::Attribute Attribute, DIELoc *Loc) {
+  Loc->ComputeSize(Asm);
+  DIELocs.push_back(Loc); // Memoize so we can call the destructor later on.
+  Die->addValue(Attribute, Loc->BestForm(DD->getDwarfVersion()), Loc);
+}
+
 void DwarfUnit::addBlock(DIE *Die, dwarf::Attribute Attribute,
                          DIEBlock *Block) {
   Block->ComputeSize(Asm);
@@ -363,110 +410,66 @@ void DwarfUnit::addBlock(DIE *Die, dwarf::Attribute Attribute,
 
 /// addSourceLine - Add location information to specified debug information
 /// entry.
-void DwarfUnit::addSourceLine(DIE *Die, DIVariable V) {
-  // Verify variable.
-  if (!V.isVariable())
-    return;
-
-  unsigned Line = V.getLineNumber();
+void DwarfUnit::addSourceLine(DIE *Die, unsigned Line, StringRef File,
+                              StringRef Directory) {
   if (Line == 0)
     return;
-  unsigned FileID =
-      DD->getOrCreateSourceID(V.getContext().getFilename(),
-                              V.getContext().getDirectory(), getUniqueID());
+
+  unsigned FileID = getOrCreateSourceID(File, Directory);
   assert(FileID && "Invalid file id");
   addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
   addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
 }
 
+/// addSourceLine - Add location information to specified debug information
+/// entry.
+void DwarfUnit::addSourceLine(DIE *Die, DIVariable V) {
+  assert(V.isVariable());
+
+  addSourceLine(Die, V.getLineNumber(), V.getContext().getFilename(),
+                V.getContext().getDirectory());
+}
+
 /// addSourceLine - Add location information to specified debug information
 /// entry.
 void DwarfUnit::addSourceLine(DIE *Die, DIGlobalVariable G) {
-  // Verify global variable.
-  if (!G.isGlobalVariable())
-    return;
+  assert(G.isGlobalVariable());
 
-  unsigned Line = G.getLineNumber();
-  if (Line == 0)
-    return;
-  unsigned FileID =
-      DD->getOrCreateSourceID(G.getFilename(), G.getDirectory(), getUniqueID());
-  assert(FileID && "Invalid file id");
-  addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
-  addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
+  addSourceLine(Die, G.getLineNumber(), G.getFilename(), G.getDirectory());
 }
 
 /// addSourceLine - Add location information to specified debug information
 /// entry.
 void DwarfUnit::addSourceLine(DIE *Die, DISubprogram SP) {
-  // Verify subprogram.
-  if (!SP.isSubprogram())
-    return;
-
-  // If the line number is 0, don't add it.
-  unsigned Line = SP.getLineNumber();
-  if (Line == 0)
-    return;
+  assert(SP.isSubprogram());
 
-  unsigned FileID = DD->getOrCreateSourceID(SP.getFilename(), SP.getDirectory(),
-                                            getUniqueID());
-  assert(FileID && "Invalid file id");
-  addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
-  addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
+  addSourceLine(Die, SP.getLineNumber(), SP.getFilename(), SP.getDirectory());
 }
 
 /// addSourceLine - Add location information to specified debug information
 /// entry.
 void DwarfUnit::addSourceLine(DIE *Die, DIType Ty) {
-  // Verify type.
-  if (!Ty.isType())
-    return;
+  assert(Ty.isType());
 
-  unsigned Line = Ty.getLineNumber();
-  if (Line == 0)
-    return;
-  unsigned FileID = DD->getOrCreateSourceID(Ty.getFilename(), Ty.getDirectory(),
-                                            getUniqueID());
-  assert(FileID && "Invalid file id");
-  addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
-  addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
+  addSourceLine(Die, Ty.getLineNumber(), Ty.getFilename(), Ty.getDirectory());
 }
 
 /// addSourceLine - Add location information to specified debug information
 /// entry.
 void DwarfUnit::addSourceLine(DIE *Die, DIObjCProperty Ty) {
-  // Verify type.
-  if (!Ty.isObjCProperty())
-    return;
+  assert(Ty.isObjCProperty());
 
-  unsigned Line = Ty.getLineNumber();
-  if (Line == 0)
-    return;
   DIFile File = Ty.getFile();
-  unsigned FileID = DD->getOrCreateSourceID(File.getFilename(),
-                                            File.getDirectory(), getUniqueID());
-  assert(FileID && "Invalid file id");
-  addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
-  addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
+  addSourceLine(Die, Ty.getLineNumber(), File.getFilename(),
+                File.getDirectory());
 }
 
 /// addSourceLine - Add location information to specified debug information
 /// entry.
 void DwarfUnit::addSourceLine(DIE *Die, DINameSpace NS) {
-  // Verify namespace.
-  if (!NS.Verify())
-    return;
+  assert(NS.Verify());
 
-  unsigned Line = NS.getLineNumber();
-  if (Line == 0)
-    return;
-  StringRef FN = NS.getFilename();
-
-  unsigned FileID =
-      DD->getOrCreateSourceID(FN, NS.getDirectory(), getUniqueID());
-  assert(FileID && "Invalid file id");
-  addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
-  addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
+  addSourceLine(Die, NS.getLineNumber(), NS.getFilename(), NS.getDirectory());
 }
 
 /// addVariableAddress - Add DW_AT_location attribute for a
@@ -483,19 +486,52 @@ void DwarfUnit::addVariableAddress(const DbgVariable &DV, DIE *Die,
 }
 
 /// addRegisterOp - Add register operand.
-void DwarfUnit::addRegisterOp(DIEBlock *TheDie, unsigned Reg) {
+void DwarfUnit::addRegisterOp(DIELoc *TheDie, unsigned Reg) {
   const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
-  unsigned DWReg = RI->getDwarfRegNum(Reg, false);
+  int DWReg = RI->getDwarfRegNum(Reg, false);
+  bool isSubRegister = DWReg < 0;
+
+  unsigned Idx = 0;
+
+  // Go up the super-register chain until we hit a valid dwarf register number.
+  for (MCSuperRegIterator SR(Reg, RI); SR.isValid() && DWReg < 0; ++SR) {
+    DWReg = RI->getDwarfRegNum(*SR, false);
+    if (DWReg >= 0)
+      Idx = RI->getSubRegIndex(*SR, Reg);
+  }
+
+  if (DWReg < 0) {
+    DEBUG(dbgs() << "Invalid Dwarf register number.\n");
+    addUInt(TheDie, dwarf::DW_FORM_data1, dwarf::DW_OP_nop);
+    return;
+  }
+
+  // Emit register
   if (DWReg < 32)
     addUInt(TheDie, dwarf::DW_FORM_data1, dwarf::DW_OP_reg0 + DWReg);
   else {
     addUInt(TheDie, dwarf::DW_FORM_data1, dwarf::DW_OP_regx);
     addUInt(TheDie, dwarf::DW_FORM_udata, DWReg);
   }
+
+  // Emit Mask
+  if (isSubRegister) {
+    unsigned Size = RI->getSubRegIdxSize(Idx);
+    unsigned Offset = RI->getSubRegIdxOffset(Idx);
+    if (Offset > 0) {
+      addUInt(TheDie, dwarf::DW_FORM_data1, dwarf::DW_OP_bit_piece);
+      addUInt(TheDie, dwarf::DW_FORM_data1, Size);
+      addUInt(TheDie, dwarf::DW_FORM_data1, Offset);
+    } else {
+      unsigned ByteSize = Size / 8; // Assuming 8 bits per byte.
+      addUInt(TheDie, dwarf::DW_FORM_data1, dwarf::DW_OP_piece);
+      addUInt(TheDie, dwarf::DW_FORM_data1, ByteSize);
+    }
+  }
 }
 
 /// addRegisterOffset - Add register offset.
-void DwarfUnit::addRegisterOffset(DIEBlock *TheDie, unsigned Reg,
+void DwarfUnit::addRegisterOffset(DIELoc *TheDie, unsigned Reg,
                                   int64_t Offset) {
   const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
   unsigned DWReg = RI->getDwarfRegNum(Reg, false);
@@ -516,19 +552,19 @@ void DwarfUnit::addRegisterOffset(DIEBlock *TheDie, unsigned Reg,
 /// provided.
 void DwarfUnit::addAddress(DIE *Die, dwarf::Attribute Attribute,
                            const MachineLocation &Location, bool Indirect) {
-  DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
+  DIELoc *Loc = new (DIEValueAllocator) DIELoc();
 
   if (Location.isReg() && !Indirect)
-    addRegisterOp(Block, Location.getReg());
+    addRegisterOp(Loc, Location.getReg());
   else {
-    addRegisterOffset(Block, Location.getReg(), Location.getOffset());
+    addRegisterOffset(Loc, Location.getReg(), Location.getOffset());
     if (Indirect && !Location.isReg()) {
-      addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
+      addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
     }
   }
 
   // Now attach the location information to the DIE.
-  addBlock(Die, Attribute, Block);
+  addBlock(Die, Attribute, Loc);
 }
 
 /// addComplexAddress - Start with the address based on the location provided,
@@ -539,34 +575,34 @@ void DwarfUnit::addAddress(DIE *Die, dwarf::Attribute Attribute,
 void DwarfUnit::addComplexAddress(const DbgVariable &DV, DIE *Die,
                                   dwarf::Attribute Attribute,
                                   const MachineLocation &Location) {
-  DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
+  DIELoc *Loc = new (DIEValueAllocator) DIELoc();
   unsigned N = DV.getNumAddrElements();
   unsigned i = 0;
   if (Location.isReg()) {
     if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
       // If first address element is OpPlus then emit
       // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
-      addRegisterOffset(Block, Location.getReg(), DV.getAddrElement(1));
+      addRegisterOffset(Loc, Location.getReg(), DV.getAddrElement(1));
       i = 2;
     } else
-      addRegisterOp(Block, Location.getReg());
+      addRegisterOp(Loc, Location.getReg());
   } else
-    addRegisterOffset(Block, Location.getReg(), Location.getOffset());
+    addRegisterOffset(Loc, Location.getReg(), Location.getOffset());
 
   for (; i < N; ++i) {
     uint64_t Element = DV.getAddrElement(i);
     if (Element == DIBuilder::OpPlus) {
-      addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
-      addUInt(Block, dwarf::DW_FORM_udata, DV.getAddrElement(++i));
+      addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
+      addUInt(Loc, dwarf::DW_FORM_udata, DV.getAddrElement(++i));
     } else if (Element == DIBuilder::OpDeref) {
       if (!Location.isReg())
-        addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
+        addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
     } else
       llvm_unreachable("unknown DIBuilder Opcode");
   }
 
   // Now attach the location information to the DIE.
-  addBlock(Die, Attribute, Block);
+  addBlock(Die, Attribute, Loc);
 }
 
 /* Byref variables, in Blocks, are declared by the programmer as "SomeType
@@ -668,40 +704,40 @@ void DwarfUnit::addBlockByrefAddress(const DbgVariable &DV, DIE *Die,
 
   // Decode the original location, and use that as the start of the byref
   // variable's location.
-  DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
+  DIELoc *Loc = new (DIEValueAllocator) DIELoc();
 
   if (Location.isReg())
-    addRegisterOp(Block, Location.getReg());
+    addRegisterOp(Loc, Location.getReg());
   else
-    addRegisterOffset(Block, Location.getReg(), Location.getOffset());
+    addRegisterOffset(Loc, Location.getReg(), Location.getOffset());
 
   // If we started with a pointer to the __Block_byref... struct, then
   // the first thing we need to do is dereference the pointer (DW_OP_deref).
   if (isPointer)
-    addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
+    addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
 
   // Next add the offset for the '__forwarding' field:
   // DW_OP_plus_uconst ForwardingFieldOffset.  Note there's no point in
   // adding the offset if it's 0.
   if (forwardingFieldOffset > 0) {
-    addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
-    addUInt(Block, dwarf::DW_FORM_udata, forwardingFieldOffset);
+    addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
+    addUInt(Loc, dwarf::DW_FORM_udata, forwardingFieldOffset);
   }
 
   // Now dereference the __forwarding field to get to the real __Block_byref
   // struct:  DW_OP_deref.
-  addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
+  addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
 
   // Now that we've got the real __Block_byref... struct, add the offset
   // for the variable's field to get to the location of the actual variable:
   // DW_OP_plus_uconst varFieldOffset.  Again, don't add if it's 0.
   if (varFieldOffset > 0) {
-    addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
-    addUInt(Block, dwarf::DW_FORM_udata, varFieldOffset);
+    addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
+    addUInt(Loc, dwarf::DW_FORM_udata, varFieldOffset);
   }
 
   // Now attach the location information to the DIE.
-  addBlock(Die, Attribute, Block);
+  addBlock(Die, Attribute, Loc);
 }
 
 /// isTypeSigned - Return true if the type is signed.
@@ -746,8 +782,9 @@ static uint64_t getBaseTypeSize(DwarfDebug *DD, DIDerivedType Ty) {
 
   DIType BaseType = DD->resolve(Ty.getTypeDerivedFrom());
 
-  // If this type is not derived from any type then take conservative approach.
-  if (!BaseType.isValid())
+  // If this type is not derived from any type or the type is a declaration then
+  // take conservative approach.
+  if (!BaseType.isValid() || BaseType.isForwardDecl())
     return Ty.getSizeInBits();
 
   // If this is a derived type, go ahead and get the base type, unless it's a
@@ -937,41 +974,6 @@ DIE *DwarfUnit::createTypeDIE(DICompositeType Ty) {
   return TyDIE;
 }
 
-/// Return true if the type is appropriately scoped to be contained inside
-/// its own type unit.
-static bool isDwarfTypeUnitScoped(DIType Ty, const DwarfDebug *DD) {
-  DIScope Parent = DD->resolve(Ty.getContext());
-  while (Parent) {
-    // Don't generate a hash for anything scoped inside a function.
-    if (Parent.isSubprogram())
-      return false;
-    Parent = DD->resolve(Parent.getContext());
-  }
-  return true;
-}
-
-/// Return true if the type should be split out into a type unit.
-static bool shouldCreateDwarfTypeUnit(DICompositeType CTy,
-                                      const DwarfDebug *DD) {
-  if (!GenerateDwarfTypeUnits)
-    return false;
-
-  uint16_t Tag = CTy.getTag();
-
-  switch (Tag) {
-  case dwarf::DW_TAG_structure_type:
-  case dwarf::DW_TAG_union_type:
-  case dwarf::DW_TAG_enumeration_type:
-  case dwarf::DW_TAG_class_type:
-    // If this is a class, structure, union, or enumeration type
-    // that is a definition (not a declaration), and not scoped
-    // inside a function then separate this out as a type unit.
-    return !CTy.isForwardDecl() && isDwarfTypeUnitScoped(CTy, DD);
-  default:
-    return false;
-  }
-}
-
 /// getOrCreateTypeDIE - Find existing DIE or create new DIE for the
 /// given DIType.
 DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
@@ -980,6 +982,8 @@ DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
 
   DIType Ty(TyNode);
   assert(Ty.isType());
+  assert(Ty == resolve(Ty.getRef()) &&
+         "type was not uniqued, possible ODR violation.");
 
   // Construct the context before querying for the existence of the DIE in case
   // such construction creates the DIE.
@@ -994,23 +998,24 @@ DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
   // Create new type.
   TyDIE = createAndAddDIE(Ty.getTag(), *ContextDIE, Ty);
 
+  updateAcceleratorTables(Context, Ty, TyDIE);
+
   if (Ty.isBasicType())
     constructTypeDIE(*TyDIE, DIBasicType(Ty));
   else if (Ty.isCompositeType()) {
     DICompositeType CTy(Ty);
-    if (shouldCreateDwarfTypeUnit(CTy, DD)) {
-      DD->addDwarfTypeUnitType(getLanguage(), TyDIE, CTy);
-      // Skip updating the accellerator tables since this is not the full type
-      return TyDIE;
-    }
+    if (GenerateDwarfTypeUnits && !Ty.isForwardDecl())
+      if (MDString *TypeId = CTy.getIdentifier()) {
+        DD->addDwarfTypeUnitType(getCU(), TypeId->getString(), TyDIE, CTy);
+        // Skip updating the accelerator tables since this is not the full type.
+        return TyDIE;
+      }
     constructTypeDIE(*TyDIE, CTy);
   } else {
     assert(Ty.isDerivedType() && "Unknown kind of DIType");
     constructTypeDIE(*TyDIE, DIDerivedType(Ty));
   }
 
-  updateAcceleratorTables(Context, Ty, TyDIE);
-
   return TyDIE;
 }
 
@@ -1027,8 +1032,9 @@ void DwarfUnit::updateAcceleratorTables(DIScope Context, DIType Ty,
     unsigned Flags = IsImplementation ? dwarf::DW_FLAG_type_implementation : 0;
     addAccelType(Ty.getName(), std::make_pair(TyDIE, Flags));
 
-    if (!Context || Context.isCompileUnit() || Context.isFile() ||
-        Context.isNameSpace())
+    if ((!Context || Context.isCompileUnit() || Context.isFile() ||
+         Context.isNameSpace()) &&
+        getCUNode().getEmissionKind() != DIBuilder::LineTablesOnly)
       GlobalTypes[getParentContextString(Context) + Ty.getName().str()] = TyDIE;
   }
 }
@@ -1059,18 +1065,24 @@ void DwarfUnit::addType(DIE *Entity, DIType Ty, dwarf::Attribute Attribute) {
 // to reference is in the string table. We do this since the names we
 // add may not only be identical to the names in the DIE.
 void DwarfUnit::addAccelName(StringRef Name, const DIE *Die) {
+  if (!DD->useDwarfAccelTables())
+    return;
   DU->getStringPoolEntry(Name);
   std::vector<const DIE *> &DIEs = AccelNames[Name];
   DIEs.push_back(Die);
 }
 
 void DwarfUnit::addAccelObjC(StringRef Name, const DIE *Die) {
+  if (!DD->useDwarfAccelTables())
+    return;
   DU->getStringPoolEntry(Name);
   std::vector<const DIE *> &DIEs = AccelObjC[Name];
   DIEs.push_back(Die);
 }
 
 void DwarfUnit::addAccelNamespace(StringRef Name, const DIE *Die) {
+  if (!DD->useDwarfAccelTables())
+    return;
   DU->getStringPoolEntry(Name);
   std::vector<const DIE *> &DIEs = AccelNamespace[Name];
   DIEs.push_back(Die);
@@ -1078,6 +1090,8 @@ void DwarfUnit::addAccelNamespace(StringRef Name, const DIE *Die) {
 
 void DwarfUnit::addAccelType(StringRef Name,
                              std::pair<const DIE *, unsigned> Die) {
+  if (!DD->useDwarfAccelTables())
+    return;
   DU->getStringPoolEntry(Name);
   std::vector<std::pair<const DIE *, unsigned> > &DIEs = AccelTypes[Name];
   DIEs.push_back(Die);
@@ -1085,6 +1099,8 @@ void DwarfUnit::addAccelType(StringRef Name,
 
 /// addGlobalName - Add a new global name to the compile unit.
 void DwarfUnit::addGlobalName(StringRef Name, DIE *Die, DIScope Context) {
+  if (getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly)
+    return;
   std::string FullName = getParentContextString(Context) + Name.str();
   GlobalNames[FullName] = Die;
 }
@@ -1176,6 +1192,22 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, DIDerivedType DTy) {
     addSourceLine(&Buffer, DTy);
 }
 
+/// constructSubprogramArguments - Construct function argument DIEs.
+void DwarfUnit::constructSubprogramArguments(DIE &Buffer, DIArray Args) {
+  for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
+    DIDescriptor Ty = Args.getElement(i);
+    if (Ty.isUnspecifiedParameter()) {
+      assert(i == N-1 && "Unspecified parameter must be the last argument");
+      createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
+    } else {
+      DIE *Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
+      addType(Arg, DIType(Ty));
+      if (DIType(Ty).isArtificial())
+        addFlag(Arg, dwarf::DW_AT_artificial);
+    }
+  }
+}
+
 /// constructTypeDIE - Construct type DIE from DICompositeType.
 void DwarfUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
   // Add name if not anonymous or intermediate type.
@@ -1199,19 +1231,12 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
       addType(&Buffer, RTy);
 
     bool isPrototyped = true;
-    // Add arguments.
-    for (unsigned i = 1, N = Elements.getNumElements(); i < N; ++i) {
-      DIDescriptor Ty = Elements.getElement(i);
-      if (Ty.isUnspecifiedParameter()) {
-        createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
-        isPrototyped = false;
-      } else {
-        DIE *Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
-        addType(Arg, DIType(Ty));
-        if (DIType(Ty).isArtificial())
-          addFlag(Arg, dwarf::DW_AT_artificial);
-      }
-    }
+    if (Elements.getNumElements() == 2 &&
+        Elements.getElement(1).isUnspecifiedParameter())
+      isPrototyped = false;
+
+    constructSubprogramArguments(Buffer, Elements);
+
     // Add prototype flag if we're dealing with a C language and the
     // function has been prototyped.
     uint16_t Language = getLanguage();
@@ -1234,21 +1259,9 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
     for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
       DIDescriptor Element = Elements.getElement(i);
       DIE *ElemDie = NULL;
-      if (Element.isSubprogram()) {
-        DISubprogram SP(Element);
-        ElemDie = getOrCreateSubprogramDIE(SP);
-        if (SP.isProtected())
-          addUInt(ElemDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
-                  dwarf::DW_ACCESS_protected);
-        else if (SP.isPrivate())
-          addUInt(ElemDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
-                  dwarf::DW_ACCESS_private);
-        else
-          addUInt(ElemDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
-                  dwarf::DW_ACCESS_public);
-        if (SP.isExplicit())
-          addFlag(ElemDie, dwarf::DW_AT_explicit);
-      } else if (Element.isDerivedType()) {
+      if (Element.isSubprogram())
+        ElemDie = getOrCreateSubprogramDIE(DISubprogram(Element));
+      else if (Element.isDerivedType()) {
         DIDerivedType DDTy(Element);
         if (DDTy.getTag() == dwarf::DW_TAG_friend) {
           ElemDie = createAndAddDIE(dwarf::DW_TAG_friend, Buffer);
@@ -1264,7 +1277,8 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
         ElemDie = createAndAddDIE(Property.getTag(), Buffer);
         StringRef PropertyName = Property.getObjCPropertyName();
         addString(ElemDie, dwarf::DW_AT_APPLE_property_name, PropertyName);
-        addType(ElemDie, Property.getType());
+        if (Property.getType())
+          addType(ElemDie, Property.getType());
         addSourceLine(ElemDie, Property);
         StringRef GetterName = Property.getObjCPropertyGetterName();
         if (!GetterName.empty())
@@ -1385,12 +1399,12 @@ DwarfUnit::constructTemplateValueParameterDIE(DIE &Buffer,
     else if (GlobalValue *GV = dyn_cast<GlobalValue>(Val)) {
       // For declaration non-type template parameters (such as global values and
       // functions)
-      DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
-      addOpAddress(Block, Asm->getSymbol(GV));
+      DIELoc *Loc = new (DIEValueAllocator) DIELoc();
+      addOpAddress(Loc, Asm->getSymbol(GV));
       // Emit DW_OP_stack_value to use the address as the immediate value of the
       // parameter, rather than a pointer to it.
-      addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
-      addBlock(ParamDIE, dwarf::DW_AT_location, Block);
+      addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
+      addBlock(ParamDIE, dwarf::DW_AT_location, Loc);
     } else if (VP.getTag() == dwarf::DW_TAG_GNU_template_template_param) {
       assert(isa<MDString>(Val));
       addString(ParamDIE, dwarf::DW_AT_GNU_template_name,
@@ -1429,7 +1443,12 @@ DIE *DwarfUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
   // Construct the context before querying for the existence of the DIE in case
   // such construction creates the DIE (as is the case for member function
   // declarations).
-  DIE *ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
+  DIScope Context = resolve(SP.getContext());
+  DIE *ContextDIE = getOrCreateContextDIE(Context);
+
+  // Unique declarations based on the ODR, where applicable.
+  SP = DISubprogram(DD->resolve(SP.getRef()));
+  assert(SP.Verify());
 
   DIE *SPDie = getDIE(SP);
   if (SPDie)
@@ -1450,20 +1469,25 @@ DIE *DwarfUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
   // Add function template parameters.
   addTemplateParams(*SPDie, SP.getTemplateParams());
 
-  // If this DIE is going to refer declaration info using AT_specification
-  // then there is no need to add other attributes.
-  if (DeclDie) {
+  if (DeclDie)
     // Refer function declaration directly.
     addDIEEntry(SPDie, dwarf::DW_AT_specification, DeclDie);
 
-    return SPDie;
+  // Add the linkage name if we have one and it isn't in the Decl.
+  StringRef LinkageName = SP.getLinkageName();
+  if (!LinkageName.empty()) {
+    if (SPDecl.isSubprogram() && !SPDecl.getLinkageName().empty())
+      assert(SPDecl.getLinkageName() == SP.getLinkageName() &&
+             "decl has a linkage name and it is different");
+    else
+      addString(SPDie, dwarf::DW_AT_MIPS_linkage_name,
+                GlobalValue::getRealLinkageName(LinkageName));
   }
 
-  // Add the linkage name if we have one.
-  StringRef LinkageName = SP.getLinkageName();
-  if (!LinkageName.empty())
-    addString(SPDie, dwarf::DW_AT_MIPS_linkage_name,
-              GlobalValue::getRealLinkageName(LinkageName));
+  // If this DIE is going to refer declaration info using AT_specification
+  // then there is no need to add other attributes.
+  if (DeclDie)
+    return SPDie;
 
   // Constructors and operators for anonymous aggregates do not have names.
   if (!SP.getName().empty())
@@ -1492,7 +1516,7 @@ DIE *DwarfUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
   unsigned VK = SP.getVirtuality();
   if (VK) {
     addUInt(SPDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1, VK);
-    DIEBlock *Block = getDIEBlock();
+    DIELoc *Block = getDIELoc();
     addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
     addUInt(Block, dwarf::DW_FORM_udata, SP.getVirtualIndex());
     addBlock(SPDie, dwarf::DW_AT_vtable_elem_location, Block);
@@ -1505,13 +1529,7 @@ DIE *DwarfUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
 
     // Add arguments. Do not add arguments for subprogram definition. They will
     // be handled while processing variables.
-    for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
-      DIE *Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, *SPDie);
-      DIType ATy(Args.getElement(i));
-      addType(Arg, ATy);
-      if (ATy.isArtificial())
-        addFlag(Arg, dwarf::DW_AT_artificial);
-    }
+    constructSubprogramArguments(*SPDie, Args);
   }
 
   if (SP.isArtificial())
@@ -1533,6 +1551,19 @@ DIE *DwarfUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
   if (SP.isRValueReference())
     addFlag(SPDie, dwarf::DW_AT_rvalue_reference);
 
+  if (SP.isProtected())
+    addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
+            dwarf::DW_ACCESS_protected);
+  else if (SP.isPrivate())
+    addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
+            dwarf::DW_ACCESS_private);
+  else
+    addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
+            dwarf::DW_ACCESS_public);
+
+  if (SP.isExplicit())
+    addFlag(SPDie, dwarf::DW_AT_explicit);
+
   return SPDie;
 }
 
@@ -1569,11 +1600,10 @@ void DwarfCompileUnit::createGlobalVariableDIE(DIGlobalVariable GV) {
   if (getDIE(GV))
     return;
 
-  if (!GV.isGlobalVariable())
-    return;
+  assert(GV.isGlobalVariable());
 
   DIScope GVContext = GV.getContext();
-  DIType GTy = GV.getType();
+  DIType GTy = DD->resolve(GV.getType());
 
   // If this is a static data member definition, some attributes belong
   // to the declaration DIE.
@@ -1615,32 +1645,32 @@ void DwarfCompileUnit::createGlobalVariableDIE(DIGlobalVariable GV) {
   bool isGlobalVariable = GV.getGlobal() != NULL;
   if (isGlobalVariable) {
     addToAccelTable = true;
-    DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
+    DIELoc *Loc = new (DIEValueAllocator) DIELoc();
     const MCSymbol *Sym = Asm->getSymbol(GV.getGlobal());
     if (GV.getGlobal()->isThreadLocal()) {
       // FIXME: Make this work with -gsplit-dwarf.
       unsigned PointerSize = Asm->getDataLayout().getPointerSize();
       assert((PointerSize == 4 || PointerSize == 8) &&
              "Add support for other sizes if necessary");
-      const MCExpr *Expr =
-          Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym);
       // Based on GCC's support for TLS:
       if (!DD->useSplitDwarf()) {
         // 1) Start with a constNu of the appropriate pointer size
-        addUInt(Block, dwarf::DW_FORM_data1,
+        addUInt(Loc, dwarf::DW_FORM_data1,
                 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
         // 2) containing the (relocated) offset of the TLS variable
         //    within the module's TLS block.
-        addExpr(Block, dwarf::DW_FORM_udata, Expr);
+        addExpr(Loc, dwarf::DW_FORM_udata,
+                Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
       } else {
-        addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
-        addUInt(Block, dwarf::DW_FORM_udata, DU->getAddrPoolIndex(Expr));
+        addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
+        addUInt(Loc, dwarf::DW_FORM_udata,
+                DU->getAddrPoolIndex(Sym, /* TLS */ true));
       }
       // 3) followed by a custom OP to make the debugger do a TLS lookup.
-      addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_push_tls_address);
+      addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_push_tls_address);
     } else {
       DD->addArangeLabel(SymbolCU(this, Sym));
-      addOpAddress(Block, Sym);
+      addOpAddress(Loc, Sym);
     }
     // Do not create specification DIE if context is either compile unit
     // or a subprogram.
@@ -1649,12 +1679,12 @@ void DwarfCompileUnit::createGlobalVariableDIE(DIGlobalVariable GV) {
       // Create specification DIE.
       VariableSpecDIE = createAndAddDIE(dwarf::DW_TAG_variable, *UnitDie);
       addDIEEntry(VariableSpecDIE, dwarf::DW_AT_specification, VariableDIE);
-      addBlock(VariableSpecDIE, dwarf::DW_AT_location, Block);
+      addBlock(VariableSpecDIE, dwarf::DW_AT_location, Loc);
       // A static member's declaration is already flagged as such.
       if (!SDMDecl.Verify())
         addFlag(VariableDIE, dwarf::DW_AT_declaration);
     } else {
-      addBlock(VariableDIE, dwarf::DW_AT_location, Block);
+      addBlock(VariableDIE, dwarf::DW_AT_location, Loc);
     }
     // Add the linkage name.
     StringRef LinkageName = GV.getLinkageName();
@@ -1664,7 +1694,8 @@ void DwarfCompileUnit::createGlobalVariableDIE(DIGlobalVariable GV) {
       // TAG_variable.
       addString(IsStaticMember && VariableSpecDIE ? VariableSpecDIE
                                                   : VariableDIE,
-                dwarf::DW_AT_MIPS_linkage_name,
+                DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
+                                           : dwarf::DW_AT_MIPS_linkage_name,
                 GlobalValue::getRealLinkageName(LinkageName));
   } else if (const ConstantInt *CI =
                  dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
@@ -1676,17 +1707,17 @@ void DwarfCompileUnit::createGlobalVariableDIE(DIGlobalVariable GV) {
   } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV->getOperand(11))) {
     addToAccelTable = true;
     // GV is a merged global.
-    DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
+    DIELoc *Loc = new (DIEValueAllocator) DIELoc();
     Value *Ptr = CE->getOperand(0);
     MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
     DD->addArangeLabel(SymbolCU(this, Sym));
-    addOpAddress(Block, Sym);
-    addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
+    addOpAddress(Loc, Sym);
+    addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
     SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
-    addUInt(Block, dwarf::DW_FORM_udata,
+    addUInt(Loc, dwarf::DW_FORM_udata,
             Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
-    addUInt(Block, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
-    addBlock(VariableDIE, dwarf::DW_AT_location, Block);
+    addUInt(Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
+    addBlock(VariableDIE, dwarf::DW_AT_location, Loc);
   }
 
   if (addToAccelTable) {
@@ -1742,12 +1773,12 @@ void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, DICompositeType CTy) {
   // as different languages may have different sizes for indexes.
   DIE *IdxTy = getIndexTyDie();
   if (!IdxTy) {
-    // Construct an anonymous type for index type.
+    // Construct an integer type to use for indexes.
     IdxTy = createAndAddDIE(dwarf::DW_TAG_base_type, *UnitDie);
-    addString(IdxTy, dwarf::DW_AT_name, "int");
-    addUInt(IdxTy, dwarf::DW_AT_byte_size, None, sizeof(int32_t));
+    addString(IdxTy, dwarf::DW_AT_name, "sizetype");
+    addUInt(IdxTy, dwarf::DW_AT_byte_size, None, sizeof(int64_t));
     addUInt(IdxTy, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
-            dwarf::DW_ATE_signed);
+            dwarf::DW_ATE_unsigned);
     setIndexTyDie(IdxTy);
   }
 
@@ -1774,9 +1805,6 @@ void DwarfUnit::constructEnumTypeDIE(DIE &Buffer, DICompositeType CTy) {
       int64_t Value = Enum.getEnumValue();
       addSInt(Enumerator, dwarf::DW_AT_const_value, dwarf::DW_FORM_sdata,
               Value);
-
-      // Add the enumerator to the __apple_names accelerator table.
-      addAccelName(Name, Enumerator);
     }
   }
   DIType DTy = resolve(CTy.getTypeDerivedFrom());
@@ -1832,8 +1860,7 @@ DIE *DwarfUnit::constructVariableDIE(DbgVariable &DV, bool isScopeAbstract) {
 
   unsigned Offset = DV.getDotDebugLocOffset();
   if (Offset != ~0U) {
-    addSectionLabel(VariableDie, dwarf::DW_AT_location,
-                    Asm->GetTempSymbol("debug_loc", Offset));
+    addLocationList(VariableDie, dwarf::DW_AT_location, Offset);
     DV.setDIE(VariableDie);
     return VariableDie;
   }
@@ -1887,16 +1914,13 @@ void DwarfUnit::constructMemberDIE(DIE &Buffer, DIDerivedType DT) {
 
   addSourceLine(MemberDie, DT);
 
-  DIEBlock *MemLocationDie = new (DIEValueAllocator) DIEBlock();
-  addUInt(MemLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
-
   if (DT.getTag() == dwarf::DW_TAG_inheritance && DT.isVirtual()) {
 
     // For C++, virtual base classes are not at fixed offset. Use following
     // expression to extract appropriate offset from vtable.
     // BaseAddr = ObAddr + *((*ObAddr) - Offset)
 
-    DIEBlock *VBaseLocationDie = new (DIEValueAllocator) DIEBlock();
+    DIELoc *VBaseLocationDie = new (DIEValueAllocator) DIELoc();
     addUInt(VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_dup);
     addUInt(VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
     addUInt(VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
@@ -1912,10 +1936,9 @@ void DwarfUnit::constructMemberDIE(DIE &Buffer, DIDerivedType DT) {
     uint64_t OffsetInBytes;
 
     if (Size != FieldSize) {
-      // Handle bitfield.
-      addUInt(MemberDie, dwarf::DW_AT_byte_size, None,
-              getBaseTypeSize(DD, DT) >> 3);
-      addUInt(MemberDie, dwarf::DW_AT_bit_size, None, DT.getSizeInBits());
+      // Handle bitfield, assume bytes are 8 bits.
+      addUInt(MemberDie, dwarf::DW_AT_byte_size, None, FieldSize/8);
+      addUInt(MemberDie, dwarf::DW_AT_bit_size, None, Size);
 
       uint64_t Offset = DT.getOffsetInBits();
       uint64_t AlignMask = ~(DT.getAlignInBits() - 1);
@@ -1928,13 +1951,21 @@ void DwarfUnit::constructMemberDIE(DIE &Buffer, DIDerivedType DT) {
         Offset = FieldSize - (Offset + Size);
       addUInt(MemberDie, dwarf::DW_AT_bit_offset, None, Offset);
 
-      // Here WD_AT_data_member_location points to the anonymous
+      // Here DW_AT_data_member_location points to the anonymous
       // field that includes this bit field.
       OffsetInBytes = FieldOffset >> 3;
     } else
       // This is not a bitfield.
       OffsetInBytes = DT.getOffsetInBits() >> 3;
-    addUInt(MemberDie, dwarf::DW_AT_data_member_location, None, OffsetInBytes);
+
+    if (DD->getDwarfVersion() <= 2) {
+      DIELoc *MemLocationDie = new (DIEValueAllocator) DIELoc();
+      addUInt(MemLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
+      addUInt(MemLocationDie, dwarf::DW_FORM_udata, OffsetInBytes);
+      addBlock(MemberDie, dwarf::DW_AT_data_member_location, MemLocationDie);
+    } else
+      addUInt(MemberDie, dwarf::DW_AT_data_member_location, None,
+              OffsetInBytes);
   }
 
   if (DT.isProtected())
@@ -2006,29 +2037,76 @@ DIE *DwarfUnit::getOrCreateStaticMemberDIE(DIDerivedType DT) {
   return StaticMemberDIE;
 }
 
-void DwarfUnit::emitHeader(const MCSection *ASection,
-                           const MCSymbol *ASectionSym) const {
+void DwarfUnit::emitHeader(const MCSymbol *ASectionSym) const {
   Asm->OutStreamer.AddComment("DWARF version number");
   Asm->EmitInt16(DD->getDwarfVersion());
   Asm->OutStreamer.AddComment("Offset Into Abbrev. Section");
   // We share one abbreviations table across all units so it's always at the
   // start of the section. Use a relocatable offset where needed to ensure
   // linking doesn't invalidate that offset.
-  Asm->EmitSectionOffset(ASectionSym, ASectionSym);
+  if (ASectionSym)
+    Asm->EmitSectionOffset(ASectionSym, ASectionSym);
+  else
+    // Use a constant value when no symbol is provided.
+    Asm->EmitInt32(0);
   Asm->OutStreamer.AddComment("Address Size (in bytes)");
   Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
 }
 
-DwarfCompileUnit::~DwarfCompileUnit() {}
-DwarfTypeUnit::~DwarfTypeUnit() {}
+void DwarfUnit::addRange(RangeSpan Range) {
+  // Only add a range for this unit if we're emitting full debug.
+  if (getCUNode().getEmissionKind() == DIBuilder::FullDebug) {
+    // If we have no current ranges just add the range and return, otherwise,
+    // check the current section and CU against the previous section and CU we
+    // emitted into and the subprogram was contained within. If these are the
+    // same then extend our current range, otherwise add this as a new range.
+    if (CURanges.size() == 0 ||
+        this != DD->getPrevCU() ||
+        Asm->getCurrentSection() != DD->getPrevSection()) {
+      CURanges.push_back(Range);
+      return;
+    }
+
+    assert(&(CURanges.back().getEnd()->getSection()) ==
+               &(Range.getEnd()->getSection()) &&
+           "We can only append to a range in the same section!");
+    CURanges.back().setEnd(Range.getEnd());
+  }
+}
+
+void DwarfCompileUnit::initStmtList(MCSymbol *DwarfLineSectionSym) {
+  // Define start line table label for each Compile Unit.
+  MCSymbol *LineTableStartSym =
+      Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
+
+  stmtListIndex = UnitDie->getValues().size();
+
+  // DW_AT_stmt_list is a offset of line number information for this
+  // compile unit in debug_line section. For split dwarf this is
+  // left in the skeleton CU and so not included.
+  // The line table entries are not always emitted in assembly, so it
+  // is not okay to use line_table_start here.
+  if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
+    addSectionLabel(UnitDie.get(), dwarf::DW_AT_stmt_list, LineTableStartSym);
+  else
+    addSectionDelta(UnitDie.get(), dwarf::DW_AT_stmt_list, LineTableStartSym,
+                    DwarfLineSectionSym);
+}
+
+void DwarfCompileUnit::applyStmtList(DIE &D) {
+  D.addValue(dwarf::DW_AT_stmt_list,
+             UnitDie->getAbbrev().getData()[stmtListIndex].getForm(),
+             UnitDie->getValues()[stmtListIndex]);
+}
 
-void DwarfTypeUnit::emitHeader(const MCSection *ASection,
-                               const MCSymbol *ASectionSym) const {
-  DwarfUnit::emitHeader(ASection, ASectionSym);
+void DwarfTypeUnit::emitHeader(const MCSymbol *ASectionSym) const {
+  DwarfUnit::emitHeader(ASectionSym);
   Asm->OutStreamer.AddComment("Type Signature");
   Asm->OutStreamer.EmitIntValue(TypeSignature, sizeof(TypeSignature));
   Asm->OutStreamer.AddComment("Type DIE Offset");
-  Asm->OutStreamer.EmitIntValue(Ty->getOffset(), sizeof(Ty->getOffset()));
+  // In a skeleton type unit there is no type DIE so emit a zero offset.
+  Asm->OutStreamer.EmitIntValue(Ty ? Ty->getOffset() : 0,
+                                sizeof(Ty->getOffset()));
 }
 
 void DwarfTypeUnit::initSection(const MCSection *Section) {