diff --git a/lib/CodeGen/MachineDebugInfoDesc.cpp b/lib/CodeGen/MachineDebugInfoDesc.cpp
new file mode 100644
index 0000000..e293609
--- /dev/null
+++ b/lib/CodeGen/MachineDebugInfoDesc.cpp
@@ -0,0 +1,588 @@
+//===-- llvm/CodeGen/MachineDebugInfoDesc.cpp -------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachineDebugInfoDesc.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/Constants.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/Streams.h"
+
+using namespace llvm;
+using namespace llvm::dwarf;
+
+/// getUIntOperand - Return ith operand if it is an unsigned integer.
+///
+static ConstantInt *getUIntOperand(const GlobalVariable *GV, unsigned i) {
+  // Make sure the GlobalVariable has an initializer.
+  if (!GV->hasInitializer()) return NULL;
+  
+  // Get the initializer constant.
+  ConstantStruct *CI = dyn_cast<ConstantStruct>(GV->getInitializer());
+  if (!CI) return NULL;
+  
+  // Check if there is at least i + 1 operands.
+  unsigned N = CI->getNumOperands();
+  if (i >= N) return NULL;
+
+  // Check constant.
+  return dyn_cast<ConstantInt>(CI->getOperand(i));
+}
+
+//===----------------------------------------------------------------------===//
+
+/// Supply a home for the DebugInfoDesc's v-table.
+DebugInfoDesc::~DebugInfoDesc() {}
+
+/// TagFromGlobal - Returns the tag number from a debug info descriptor
+/// GlobalVariable. Return DIIValid if operand is not an unsigned int.
+unsigned DebugInfoDesc::TagFromGlobal(GlobalVariable *GV) {
+  ConstantInt *C = getUIntOperand(GV, 0);
+  return C ? ((unsigned)C->getZExtValue() & ~LLVMDebugVersionMask) :
+             (unsigned)DW_TAG_invalid;
+}
+
+/// VersionFromGlobal - Returns the version number from a debug info
+/// descriptor GlobalVariable. Return DIIValid if operand is not an unsigned
+/// int.
+unsigned  DebugInfoDesc::VersionFromGlobal(GlobalVariable *GV) {
+  ConstantInt *C = getUIntOperand(GV, 0);
+  return C ? ((unsigned)C->getZExtValue() & LLVMDebugVersionMask) :
+             (unsigned)DW_TAG_invalid;
+}
+
+/// DescFactory - Create an instance of debug info descriptor based on Tag.
+/// Return NULL if not a recognized Tag.
+DebugInfoDesc *DebugInfoDesc::DescFactory(unsigned Tag) {
+  switch (Tag) {
+  case DW_TAG_anchor:           return new AnchorDesc();
+  case DW_TAG_compile_unit:     return new CompileUnitDesc();
+  case DW_TAG_variable:         return new GlobalVariableDesc();
+  case DW_TAG_subprogram:       return new SubprogramDesc();
+  case DW_TAG_lexical_block:    return new BlockDesc();
+  case DW_TAG_base_type:        return new BasicTypeDesc();
+  case DW_TAG_typedef:
+  case DW_TAG_pointer_type:        
+  case DW_TAG_reference_type:
+  case DW_TAG_const_type:
+  case DW_TAG_volatile_type:        
+  case DW_TAG_restrict_type:
+  case DW_TAG_member:
+  case DW_TAG_inheritance:      return new DerivedTypeDesc(Tag);
+  case DW_TAG_array_type:
+  case DW_TAG_structure_type:
+  case DW_TAG_union_type:
+  case DW_TAG_enumeration_type:
+  case DW_TAG_vector_type:
+  case DW_TAG_subroutine_type:  return new CompositeTypeDesc(Tag);
+  case DW_TAG_subrange_type:    return new SubrangeDesc();
+  case DW_TAG_enumerator:       return new EnumeratorDesc();
+  case DW_TAG_return_variable:
+  case DW_TAG_arg_variable:
+  case DW_TAG_auto_variable:    return new VariableDesc(Tag);
+  default: break;
+  }
+  return NULL;
+}
+
+/// getLinkage - get linkage appropriate for this type of descriptor.
+GlobalValue::LinkageTypes DebugInfoDesc::getLinkage() const {
+  return GlobalValue::InternalLinkage;
+}
+
+/// ApplyToFields - Target the vistor to the fields of the descriptor.
+void DebugInfoDesc::ApplyToFields(DIVisitor *Visitor) {
+  Visitor->Apply(Tag);
+}
+
+//===----------------------------------------------------------------------===//
+
+AnchorDesc::AnchorDesc()
+  : DebugInfoDesc(DW_TAG_anchor), AnchorTag(0){
+}
+AnchorDesc::AnchorDesc(AnchoredDesc *D)
+  : DebugInfoDesc(DW_TAG_anchor), AnchorTag(D->getTag()) {
+}
+
+// Implement isa/cast/dyncast.
+bool AnchorDesc::classof(const DebugInfoDesc *D) {
+  return D->getTag() == DW_TAG_anchor;
+}
+  
+/// getLinkage - get linkage appropriate for this type of descriptor.
+GlobalValue::LinkageTypes AnchorDesc::getLinkage() const {
+  return GlobalValue::LinkOnceLinkage;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the TransUnitDesc.
+void AnchorDesc::ApplyToFields(DIVisitor *Visitor) {
+  DebugInfoDesc::ApplyToFields(Visitor);
+  Visitor->Apply(AnchorTag);
+}
+
+/// getDescString - Return a string used to compose global names and labels. A
+/// global variable name needs to be defined for each debug descriptor that is
+/// anchored. NOTE: that each global variable named here also needs to be added
+/// to the list of names left external in the internalizer.
+///
+///   ExternalNames.insert("llvm.dbg.compile_units");
+///   ExternalNames.insert("llvm.dbg.global_variables");
+///   ExternalNames.insert("llvm.dbg.subprograms");
+const char *AnchorDesc::getDescString() const {
+  switch (AnchorTag) {
+  case DW_TAG_compile_unit: {
+    CompileUnitDesc CUD;
+    return CUD.getAnchorString();
+  }
+  case DW_TAG_variable: {
+    GlobalVariableDesc GVD;
+    return GVD.getAnchorString();
+  }
+  case DW_TAG_subprogram: {
+    SubprogramDesc SPD;
+    return SPD.getAnchorString();
+  }
+  default: break;
+  }
+
+  assert(0 && "Tag does not have a case for anchor string");
+  return "";
+}
+
+#ifndef NDEBUG
+void AnchorDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "AnchorTag(" << AnchorTag << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+AnchoredDesc::AnchoredDesc(unsigned T)
+  : DebugInfoDesc(T), Anchor(NULL) {
+}
+
+/// ApplyToFields - Target the visitor to the fields of the AnchoredDesc.
+void AnchoredDesc::ApplyToFields(DIVisitor *Visitor) {
+  DebugInfoDesc::ApplyToFields(Visitor);
+  Visitor->Apply(Anchor);
+}
+
+//===----------------------------------------------------------------------===//
+
+CompileUnitDesc::CompileUnitDesc()
+  : AnchoredDesc(DW_TAG_compile_unit), Language(0), FileName(""),
+    Directory(""), Producer("") {
+}
+
+// Implement isa/cast/dyncast.
+bool CompileUnitDesc::classof(const DebugInfoDesc *D) {
+  return D->getTag() == DW_TAG_compile_unit;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the CompileUnitDesc.
+///
+void CompileUnitDesc::ApplyToFields(DIVisitor *Visitor) {
+  AnchoredDesc::ApplyToFields(Visitor);
+  
+  // Handle cases out of sync with compiler.
+  if (getVersion() == 0) {
+    unsigned DebugVersion;
+    Visitor->Apply(DebugVersion);
+  }
+
+  Visitor->Apply(Language);
+  Visitor->Apply(FileName);
+  Visitor->Apply(Directory);
+  Visitor->Apply(Producer);
+}
+
+#ifndef NDEBUG
+void CompileUnitDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Anchor(" << getAnchor() << "), "
+       << "Language(" << Language << "), "
+       << "FileName(\"" << FileName << "\"), "
+       << "Directory(\"" << Directory << "\"), "
+       << "Producer(\"" << Producer << "\")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+TypeDesc::TypeDesc(unsigned T)
+  : DebugInfoDesc(T), Context(NULL), Name(""), File(NULL), Line(0), Size(0),
+    Align(0), Offset(0), Flags(0) {
+}
+
+/// ApplyToFields - Target the visitor to the fields of the TypeDesc.
+///
+void TypeDesc::ApplyToFields(DIVisitor *Visitor) {
+  DebugInfoDesc::ApplyToFields(Visitor);
+  Visitor->Apply(Context);
+  Visitor->Apply(Name);
+  Visitor->Apply(File);
+  Visitor->Apply(Line);
+  Visitor->Apply(Size);
+  Visitor->Apply(Align);
+  Visitor->Apply(Offset);
+  if (getVersion() > LLVMDebugVersion4) Visitor->Apply(Flags);
+}
+
+#ifndef NDEBUG
+void TypeDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Context(" << Context << "), "
+       << "Name(\"" << Name << "\"), "
+       << "File(" << File << "), "
+       << "Line(" << Line << "), "
+       << "Size(" << Size << "), "
+       << "Align(" << Align << "), "
+       << "Offset(" << Offset << "), "
+       << "Flags(" << Flags << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+BasicTypeDesc::BasicTypeDesc()
+  : TypeDesc(DW_TAG_base_type), Encoding(0) {
+}
+
+// Implement isa/cast/dyncast.
+bool BasicTypeDesc::classof(const DebugInfoDesc *D) {
+  return D->getTag() == DW_TAG_base_type;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the BasicTypeDesc.
+void BasicTypeDesc::ApplyToFields(DIVisitor *Visitor) {
+  TypeDesc::ApplyToFields(Visitor);
+  Visitor->Apply(Encoding);
+}
+
+#ifndef NDEBUG
+void BasicTypeDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Context(" << getContext() << "), "
+       << "Name(\"" << getName() << "\"), "
+       << "Size(" << getSize() << "), "
+       << "Encoding(" << Encoding << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+DerivedTypeDesc::DerivedTypeDesc(unsigned T)
+  : TypeDesc(T), FromType(NULL) {
+}
+
+// Implement isa/cast/dyncast.
+bool DerivedTypeDesc::classof(const DebugInfoDesc *D) {
+  unsigned T =  D->getTag();
+  switch (T) {
+  case DW_TAG_typedef:
+  case DW_TAG_pointer_type:
+  case DW_TAG_reference_type:
+  case DW_TAG_const_type:
+  case DW_TAG_volatile_type:
+  case DW_TAG_restrict_type:
+  case DW_TAG_member:
+  case DW_TAG_inheritance:
+    return true;
+  default: break;
+  }
+  return false;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the DerivedTypeDesc.
+void DerivedTypeDesc::ApplyToFields(DIVisitor *Visitor) {
+  TypeDesc::ApplyToFields(Visitor);
+  Visitor->Apply(FromType);
+}
+
+#ifndef NDEBUG
+void DerivedTypeDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Context(" << getContext() << "), "
+       << "Name(\"" << getName() << "\"), "
+       << "Size(" << getSize() << "), "
+       << "File(" << getFile() << "), "
+       << "Line(" << getLine() << "), "
+       << "FromType(" << FromType << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+CompositeTypeDesc::CompositeTypeDesc(unsigned T)
+  : DerivedTypeDesc(T), Elements() {
+}
+  
+// Implement isa/cast/dyncast.
+bool CompositeTypeDesc::classof(const DebugInfoDesc *D) {
+  unsigned T =  D->getTag();
+  switch (T) {
+  case DW_TAG_array_type:
+  case DW_TAG_structure_type:
+  case DW_TAG_union_type:
+  case DW_TAG_enumeration_type:
+  case DW_TAG_vector_type:
+  case DW_TAG_subroutine_type:
+    return true;
+  default: break;
+  }
+  return false;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the CompositeTypeDesc.
+///
+void CompositeTypeDesc::ApplyToFields(DIVisitor *Visitor) {
+  DerivedTypeDesc::ApplyToFields(Visitor);  
+  Visitor->Apply(Elements);
+}
+
+#ifndef NDEBUG
+void CompositeTypeDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Context(" << getContext() << "), "
+       << "Name(\"" << getName() << "\"), "
+       << "Size(" << getSize() << "), "
+       << "File(" << getFile() << "), "
+       << "Line(" << getLine() << "), "
+       << "FromType(" << getFromType() << "), "
+       << "Elements.size(" << Elements.size() << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+SubrangeDesc::SubrangeDesc()
+  : DebugInfoDesc(DW_TAG_subrange_type), Lo(0), Hi(0) {
+}
+
+// Implement isa/cast/dyncast.
+bool SubrangeDesc::classof(const DebugInfoDesc *D) {
+  return D->getTag() == DW_TAG_subrange_type;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the SubrangeDesc.
+void SubrangeDesc::ApplyToFields(DIVisitor *Visitor) {
+  DebugInfoDesc::ApplyToFields(Visitor);
+  Visitor->Apply(Lo);
+  Visitor->Apply(Hi);
+}
+
+#ifndef NDEBUG
+void SubrangeDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Lo(" << Lo << "), "
+       << "Hi(" << Hi << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+EnumeratorDesc::EnumeratorDesc()
+  : DebugInfoDesc(DW_TAG_enumerator), Name(""), Value(0) {
+}
+
+// Implement isa/cast/dyncast.
+bool EnumeratorDesc::classof(const DebugInfoDesc *D) {
+  return D->getTag() == DW_TAG_enumerator;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the EnumeratorDesc.
+void EnumeratorDesc::ApplyToFields(DIVisitor *Visitor) {
+  DebugInfoDesc::ApplyToFields(Visitor);
+  Visitor->Apply(Name);
+  Visitor->Apply(Value);
+}
+
+#ifndef NDEBUG
+void EnumeratorDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Name(" << Name << "), "
+       << "Value(" << Value << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+VariableDesc::VariableDesc(unsigned T)
+  : DebugInfoDesc(T), Context(NULL), Name(""), File(NULL), Line(0), TyDesc(0) {
+}
+
+// Implement isa/cast/dyncast.
+bool VariableDesc::classof(const DebugInfoDesc *D) {
+  unsigned T =  D->getTag();
+  switch (T) {
+  case DW_TAG_auto_variable:
+  case DW_TAG_arg_variable:
+  case DW_TAG_return_variable:
+    return true;
+  default: break;
+  }
+  return false;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the VariableDesc.
+void VariableDesc::ApplyToFields(DIVisitor *Visitor) {
+  DebugInfoDesc::ApplyToFields(Visitor);
+  Visitor->Apply(Context);
+  Visitor->Apply(Name);
+  Visitor->Apply(File);
+  Visitor->Apply(Line);
+  Visitor->Apply(TyDesc);
+}
+
+#ifndef NDEBUG
+void VariableDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Context(" << Context << "), "
+       << "Name(\"" << Name << "\"), "
+       << "File(" << File << "), "
+       << "Line(" << Line << "), "
+       << "TyDesc(" << TyDesc << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+GlobalDesc::GlobalDesc(unsigned T)
+  : AnchoredDesc(T), Context(0), Name(""), FullName(""), LinkageName(""),
+    File(NULL), Line(0), TyDesc(NULL), IsStatic(false), IsDefinition(false) {
+}
+
+/// ApplyToFields - Target the visitor to the fields of the global.
+///
+void GlobalDesc::ApplyToFields(DIVisitor *Visitor) {
+  AnchoredDesc::ApplyToFields(Visitor);
+  Visitor->Apply(Context);
+  Visitor->Apply(Name);
+  Visitor->Apply(FullName);
+  Visitor->Apply(LinkageName);
+  Visitor->Apply(File);
+  Visitor->Apply(Line);
+  Visitor->Apply(TyDesc);
+  Visitor->Apply(IsStatic);
+  Visitor->Apply(IsDefinition);
+}
+
+//===----------------------------------------------------------------------===//
+
+GlobalVariableDesc::GlobalVariableDesc()
+  : GlobalDesc(DW_TAG_variable), Global(NULL) {
+}
+
+// Implement isa/cast/dyncast.
+bool GlobalVariableDesc::classof(const DebugInfoDesc *D) {
+  return D->getTag() == DW_TAG_variable; 
+}
+
+/// ApplyToFields - Target the visitor to the fields of the GlobalVariableDesc.
+void GlobalVariableDesc::ApplyToFields(DIVisitor *Visitor) {
+  GlobalDesc::ApplyToFields(Visitor);
+  Visitor->Apply(Global);
+}
+
+#ifndef NDEBUG
+void GlobalVariableDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Anchor(" << getAnchor() << "), "
+       << "Name(\"" << getName() << "\"), "
+       << "FullName(\"" << getFullName() << "\"), "
+       << "LinkageName(\"" << getLinkageName() << "\"), "
+       << "File(" << getFile() << "),"
+       << "Line(" << getLine() << "),"
+       << "Type(" << getType() << "), "
+       << "IsStatic(" << (isStatic() ? "true" : "false") << "), "
+       << "IsDefinition(" << (isDefinition() ? "true" : "false") << "), "
+       << "Global(" << Global << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+SubprogramDesc::SubprogramDesc()
+  : GlobalDesc(DW_TAG_subprogram) {
+}
+
+// Implement isa/cast/dyncast.
+bool SubprogramDesc::classof(const DebugInfoDesc *D) {
+  return D->getTag() == DW_TAG_subprogram;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the SubprogramDesc.
+void SubprogramDesc::ApplyToFields(DIVisitor *Visitor) {
+  GlobalDesc::ApplyToFields(Visitor);
+}
+
+#ifndef NDEBUG
+void SubprogramDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "), "
+       << "Anchor(" << getAnchor() << "), "
+       << "Name(\"" << getName() << "\"), "
+       << "FullName(\"" << getFullName() << "\"), "
+       << "LinkageName(\"" << getLinkageName() << "\"), "
+       << "File(" << getFile() << "),"
+       << "Line(" << getLine() << "),"
+       << "Type(" << getType() << "), "
+       << "IsStatic(" << (isStatic() ? "true" : "false") << "), "
+       << "IsDefinition(" << (isDefinition() ? "true" : "false") << ")\n";
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+
+BlockDesc::BlockDesc()
+  : DebugInfoDesc(DW_TAG_lexical_block), Context(NULL) {
+}
+
+// Implement isa/cast/dyncast.
+bool BlockDesc::classof(const DebugInfoDesc *D) {
+  return D->getTag() == DW_TAG_lexical_block;
+}
+
+/// ApplyToFields - Target the visitor to the fields of the BlockDesc.
+void BlockDesc::ApplyToFields(DIVisitor *Visitor) {
+  DebugInfoDesc::ApplyToFields(Visitor);
+
+  Visitor->Apply(Context);
+}
+
+#ifndef NDEBUG
+void BlockDesc::dump() {
+  cerr << getDescString() << " "
+       << "Version(" << getVersion() << "), "
+       << "Tag(" << getTag() << "),"
+       << "Context(" << Context << ")\n";
+}
+#endif