MFC 261991:

Upgrade our copy of llvm/clang to 3.4 release.  This version supports
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.

The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3.  The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.

Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>

MFC 262121 (by emaste):

Update lldb for clang/llvm 3.4 import

This commit largely restores the lldb source to the upstream r196259
snapshot with the addition of threaded inferior support and a few bug
fixes.

Specific upstream lldb revisions restored include:
   SVN      git
  181387  779e6ac
  181703  7bef4e2
  182099  b31044e
  182650  f2dcf35
  182683  0d91b80
  183862  15c1774
  183929  99447a6
  184177  0b2934b
  184948  4dc3761
  184954  007e7bc
  186990  eebd175

Sponsored by:	DARPA, AFRL

MFC 262186 (by emaste):

Fix mismerge in r262121

A break statement was lost in the merge.  The error had no functional
impact, but restore it to reduce the diff against upstream.

MFC 262303:

Pull in r197521 from upstream clang trunk (by rdivacky):

  Use the integrated assembler by default on FreeBSD/ppc and ppc64.

Requested by:	jhibbits

MFC 262611:

Pull in r196874 from upstream llvm trunk:

  Fix a crash that occurs when PWD is invalid.

  MCJIT needs to be able to run in hostile environments, even when PWD
  is invalid. There's no need to crash MCJIT in this case.

  The obvious fix is to simply leave MCContext's CompilationDir empty
  when PWD can't be determined. This way, MCJIT clients,
  and other clients that link with LLVM don't need a valid working directory.

  If we do want to guarantee valid CompilationDir, that should be done
  only for clients of getCompilationDir(). This is as simple as checking
  for an empty string.

  The only current use of getCompilationDir is EmitGenDwarfInfo, which
  won't conceivably run with an invalid working dir. However, in the
  purely hypothetically and untestable case that this happens, the
  AT_comp_dir will be omitted from the compilation_unit DIE.

This should help fix assertions occurring with ports-mgmt/tinderbox,
when it is using jails, and sometimes invalidates clang's current
working directory.

Reported by:	decke

MFC 262809:

Pull in r203007 from upstream clang trunk:

  Don't produce an alias between destructors with different calling conventions.

  Fixes pr19007.

(Please note that is an LLVM PR identifier, not a FreeBSD one.)

This should fix Firefox and/or libxul crashes (due to problems with
regparm/stdcall calling conventions) on i386.

Reported by:	multiple users on freebsd-current
PR:		bin/187103

MFC 263048:

Repair recognition of "CC" as an alias for the C++ compiler, since it
was silently broken by upstream for a Windows-specific use-case.

Apparently some versions of CMake still rely on this archaic feature...

Reported by:	rakuco

MFC 263049:

Garbage collect the old way of adding the libstdc++ include directories
in clang's InitHeaderSearch.cpp.  This has been superseded by David
Chisnall's commit in r255321.

Moreover, if libc++ is used, the libstdc++ include directories should
not be in the search path at all.  These directories are now only used
if you pass -stdlib=libstdc++.

1 files changed, 528 insertions, 275 deletions

diff --git a/contrib/llvm/lib/IR/DebugInfo.cpp b/contrib/llvm/lib/IR/DebugInfo.cpp
index ec83dca..70a756f 100644
--- a/contrib/llvm/lib/IR/DebugInfo.cpp
+++ b/contrib/llvm/lib/IR/DebugInfo.cpp
@@ -34,24 +34,6 @@ using namespace llvm::dwarf;
 // DIDescriptor
 //===----------------------------------------------------------------------===//
 
-DIDescriptor::DIDescriptor(const DIFile F) : DbgNode(F.DbgNode) {
-}
-
-DIDescriptor::DIDescriptor(const DISubprogram F) : DbgNode(F.DbgNode) {
-}
-
-DIDescriptor::DIDescriptor(const DILexicalBlockFile F) : DbgNode(F.DbgNode) {
-}
-
-DIDescriptor::DIDescriptor(const DILexicalBlock F) : DbgNode(F.DbgNode) {
-}
-
-DIDescriptor::DIDescriptor(const DIVariable F) : DbgNode(F.DbgNode) {
-}
-
-DIDescriptor::DIDescriptor(const DIType F) : DbgNode(F.DbgNode) {
-}
-
 bool DIDescriptor::Verify() const {
   return DbgNode &&
          (DIDerivedType(DbgNode).Verify() ||
@@ -65,7 +47,7 @@ bool DIDescriptor::Verify() const {
           DIObjCProperty(DbgNode).Verify() ||
           DITemplateTypeParameter(DbgNode).Verify() ||
           DITemplateValueParameter(DbgNode).Verify() ||
-          DIImportedModule(DbgNode).Verify());
+          DIImportedEntity(DbgNode).Verify());
 }
 
 static Value *getField(const MDNode *DbgNode, unsigned Elt) {
@@ -74,10 +56,8 @@ static Value *getField(const MDNode *DbgNode, unsigned Elt) {
   return DbgNode->getOperand(Elt);
 }
 
-static const MDNode *getNodeField(const MDNode *DbgNode, unsigned Elt) {
-  if (const MDNode *R = dyn_cast_or_null<MDNode>(getField(DbgNode, Elt)))
-    return R;
-  return 0;
+static MDNode *getNodeField(const MDNode *DbgNode, unsigned Elt) {
+  return dyn_cast_or_null<MDNode>(getField(DbgNode, Elt));
 }
 
 static StringRef getStringField(const MDNode *DbgNode, unsigned Elt) {
@@ -95,8 +75,8 @@ uint64_t DIDescriptor::getUInt64Field(unsigned Elt) const {
     return 0;
 
   if (Elt < DbgNode->getNumOperands())
-    if (ConstantInt *CI
-        = dyn_cast_or_null<ConstantInt>(DbgNode->getOperand(Elt)))
+    if (ConstantInt *CI =
+            dyn_cast_or_null<ConstantInt>(DbgNode->getOperand(Elt)))
       return CI->getZExtValue();
 
   return 0;
@@ -107,21 +87,16 @@ int64_t DIDescriptor::getInt64Field(unsigned Elt) const {
     return 0;
 
   if (Elt < DbgNode->getNumOperands())
-    if (ConstantInt *CI
-        = dyn_cast_or_null<ConstantInt>(DbgNode->getOperand(Elt)))
+    if (ConstantInt *CI =
+            dyn_cast_or_null<ConstantInt>(DbgNode->getOperand(Elt)))
       return CI->getSExtValue();
 
   return 0;
 }
 
 DIDescriptor DIDescriptor::getDescriptorField(unsigned Elt) const {
-  if (DbgNode == 0)
-    return DIDescriptor();
-
-  if (Elt < DbgNode->getNumOperands())
-    return
-      DIDescriptor(dyn_cast_or_null<const MDNode>(DbgNode->getOperand(Elt)));
-  return DIDescriptor();
+  MDNode *Field = getNodeField(DbgNode, Elt);
+  return DIDescriptor(Field);
 }
 
 GlobalVariable *DIDescriptor::getGlobalVariableField(unsigned Elt) const {
@@ -129,7 +104,7 @@ GlobalVariable *DIDescriptor::getGlobalVariableField(unsigned Elt) const {
     return 0;
 
   if (Elt < DbgNode->getNumOperands())
-      return dyn_cast_or_null<GlobalVariable>(DbgNode->getOperand(Elt));
+    return dyn_cast_or_null<GlobalVariable>(DbgNode->getOperand(Elt));
   return 0;
 }
 
@@ -138,7 +113,7 @@ Constant *DIDescriptor::getConstantField(unsigned Elt) const {
     return 0;
 
   if (Elt < DbgNode->getNumOperands())
-      return dyn_cast_or_null<Constant>(DbgNode->getOperand(Elt));
+    return dyn_cast_or_null<Constant>(DbgNode->getOperand(Elt));
   return 0;
 }
 
@@ -147,7 +122,7 @@ Function *DIDescriptor::getFunctionField(unsigned Elt) const {
     return 0;
 
   if (Elt < DbgNode->getNumOperands())
-      return dyn_cast_or_null<Function>(DbgNode->getOperand(Elt));
+    return dyn_cast_or_null<Function>(DbgNode->getOperand(Elt));
   return 0;
 }
 
@@ -156,19 +131,17 @@ void DIDescriptor::replaceFunctionField(unsigned Elt, Function *F) {
     return;
 
   if (Elt < DbgNode->getNumOperands()) {
-    MDNode *Node = const_cast<MDNode*>(DbgNode);
+    MDNode *Node = const_cast<MDNode *>(DbgNode);
     Node->replaceOperandWith(Elt, F);
   }
 }
 
 unsigned DIVariable::getNumAddrElements() const {
-  return DbgNode->getNumOperands()-8;
+  return DbgNode->getNumOperands() - 8;
 }
 
 /// getInlinedAt - If this variable is inlined then return inline location.
-MDNode *DIVariable::getInlinedAt() const {
-  return dyn_cast_or_null<MDNode>(DbgNode->getOperand(7));
-}
+MDNode *DIVariable::getInlinedAt() const { return getNodeField(DbgNode, 7); }
 
 //===----------------------------------------------------------------------===//
 // Predicates
@@ -177,7 +150,8 @@ MDNode *DIVariable::getInlinedAt() const {
 /// isBasicType - Return true if the specified tag is legal for
 /// DIBasicType.
 bool DIDescriptor::isBasicType() const {
-  if (!DbgNode) return false;
+  if (!DbgNode)
+    return false;
   switch (getTag()) {
   case dwarf::DW_TAG_base_type:
   case dwarf::DW_TAG_unspecified_type:
@@ -189,7 +163,8 @@ bool DIDescriptor::isBasicType() const {
 
 /// isDerivedType - Return true if the specified tag is legal for DIDerivedType.
 bool DIDescriptor::isDerivedType() const {
-  if (!DbgNode) return false;
+  if (!DbgNode)
+    return false;
   switch (getTag()) {
   case dwarf::DW_TAG_typedef:
   case dwarf::DW_TAG_pointer_type:
@@ -212,7 +187,8 @@ bool DIDescriptor::isDerivedType() const {
 /// isCompositeType - Return true if the specified tag is legal for
 /// DICompositeType.
 bool DIDescriptor::isCompositeType() const {
-  if (!DbgNode) return false;
+  if (!DbgNode)
+    return false;
   switch (getTag()) {
   case dwarf::DW_TAG_array_type:
   case dwarf::DW_TAG_structure_type:
@@ -228,7 +204,8 @@ bool DIDescriptor::isCompositeType() const {
 
 /// isVariable - Return true if the specified tag is legal for DIVariable.
 bool DIDescriptor::isVariable() const {
-  if (!DbgNode) return false;
+  if (!DbgNode)
+    return false;
   switch (getTag()) {
   case dwarf::DW_TAG_auto_variable:
   case dwarf::DW_TAG_arg_variable:
@@ -256,11 +233,6 @@ bool DIDescriptor::isGlobalVariable() const {
                      getTag() == dwarf::DW_TAG_constant);
 }
 
-/// isGlobal - Return true if the specified tag is legal for DIGlobal.
-bool DIDescriptor::isGlobal() const {
-  return isGlobalVariable();
-}
-
 /// isUnspecifiedParmeter - Return true if the specified tag is
 /// DW_TAG_unspecified_parameters.
 bool DIDescriptor::isUnspecifiedParameter() const {
@@ -270,17 +242,19 @@ bool DIDescriptor::isUnspecifiedParameter() const {
 /// isScope - Return true if the specified tag is one of the scope
 /// related tag.
 bool DIDescriptor::isScope() const {
-  if (!DbgNode) return false;
+  if (!DbgNode)
+    return false;
   switch (getTag()) {
   case dwarf::DW_TAG_compile_unit:
   case dwarf::DW_TAG_lexical_block:
   case dwarf::DW_TAG_subprogram:
   case dwarf::DW_TAG_namespace:
+  case dwarf::DW_TAG_file_type:
     return true;
   default:
     break;
   }
-  return false;
+  return isType();
 }
 
 /// isTemplateTypeParameter - Return true if the specified tag is
@@ -292,7 +266,9 @@ bool DIDescriptor::isTemplateTypeParameter() const {
 /// isTemplateValueParameter - Return true if the specified tag is
 /// DW_TAG_template_value_parameter.
 bool DIDescriptor::isTemplateValueParameter() const {
-  return DbgNode && getTag() == dwarf::DW_TAG_template_value_parameter;
+  return DbgNode && (getTag() == dwarf::DW_TAG_template_value_parameter ||
+                     getTag() == dwarf::DW_TAG_GNU_template_template_param ||
+                     getTag() == dwarf::DW_TAG_GNU_template_parameter_pack);
 }
 
 /// isCompileUnit - Return true if the specified tag is DW_TAG_compile_unit.
@@ -314,13 +290,13 @@ bool DIDescriptor::isNameSpace() const {
 /// lexical block with an extra file.
 bool DIDescriptor::isLexicalBlockFile() const {
   return DbgNode && getTag() == dwarf::DW_TAG_lexical_block &&
-    (DbgNode->getNumOperands() == 3);
+         (DbgNode->getNumOperands() == 3);
 }
 
 /// isLexicalBlock - Return true if the specified tag is DW_TAG_lexical_block.
 bool DIDescriptor::isLexicalBlock() const {
   return DbgNode && getTag() == dwarf::DW_TAG_lexical_block &&
-    (DbgNode->getNumOperands() > 3);
+         (DbgNode->getNumOperands() > 3);
 }
 
 /// isSubrange - Return true if the specified tag is DW_TAG_subrange_type.
@@ -338,33 +314,28 @@ bool DIDescriptor::isObjCProperty() const {
   return DbgNode && getTag() == dwarf::DW_TAG_APPLE_property;
 }
 
-/// \brief Return true if the specified tag is DW_TAG_imported_module.
-bool DIDescriptor::isImportedModule() const {
-  return DbgNode && getTag() == dwarf::DW_TAG_imported_module;
+/// \brief Return true if the specified tag is DW_TAG_imported_module or
+/// DW_TAG_imported_declaration.
+bool DIDescriptor::isImportedEntity() const {
+  return DbgNode && (getTag() == dwarf::DW_TAG_imported_module ||
+                     getTag() == dwarf::DW_TAG_imported_declaration);
 }
 
 //===----------------------------------------------------------------------===//
 // Simple Descriptor Constructors and other Methods
 //===----------------------------------------------------------------------===//
 
-DIType::DIType(const MDNode *N) : DIScope(N) {
-  if (!N) return;
-  if (!isBasicType() && !isDerivedType() && !isCompositeType()) {
-    DbgNode = 0;
-  }
-}
-
 unsigned DIArray::getNumElements() const {
   if (!DbgNode)
     return 0;
   return DbgNode->getNumOperands();
 }
 
-/// replaceAllUsesWith - Replace all uses of debug info referenced by
-/// this descriptor.
+/// replaceAllUsesWith - Replace all uses of the MDNode used by this
+/// type with the one in the passed descriptor.
 void DIType::replaceAllUsesWith(DIDescriptor &D) {
-  if (!DbgNode)
-    return;
+
+  assert(DbgNode && "Trying to replace an unverified type!");
 
   // Since we use a TrackingVH for the node, its easy for clients to manufacture
   // legitimate situations where they want to replaceAllUsesWith() on something
@@ -372,19 +343,19 @@ void DIType::replaceAllUsesWith(DIDescriptor &D) {
   // this detail by allowing a value to be replaced with replaceAllUsesWith()
   // itself.
   if (DbgNode != D) {
-    MDNode *Node = const_cast<MDNode*>(DbgNode);
+    MDNode *Node = const_cast<MDNode *>(DbgNode);
     const MDNode *DN = D;
     const Value *V = cast_or_null<Value>(DN);
-    Node->replaceAllUsesWith(const_cast<Value*>(V));
+    Node->replaceAllUsesWith(const_cast<Value *>(V));
     MDNode::deleteTemporary(Node);
   }
 }
 
-/// replaceAllUsesWith - Replace all uses of debug info referenced by
-/// this descriptor.
+/// replaceAllUsesWith - Replace all uses of the MDNode used by this
+/// type with the one in D.
 void DIType::replaceAllUsesWith(MDNode *D) {
-  if (!DbgNode)
-    return;
+
+  assert(DbgNode && "Trying to replace an unverified type!");
 
   // Since we use a TrackingVH for the node, its easy for clients to manufacture
   // legitimate situations where they want to replaceAllUsesWith() on something
@@ -392,39 +363,24 @@ void DIType::replaceAllUsesWith(MDNode *D) {
   // this detail by allowing a value to be replaced with replaceAllUsesWith()
   // itself.
   if (DbgNode != D) {
-    MDNode *Node = const_cast<MDNode*>(DbgNode);
+    MDNode *Node = const_cast<MDNode *>(DbgNode);
     const MDNode *DN = D;
     const Value *V = cast_or_null<Value>(DN);
-    Node->replaceAllUsesWith(const_cast<Value*>(V));
+    Node->replaceAllUsesWith(const_cast<Value *>(V));
     MDNode::deleteTemporary(Node);
   }
 }
 
-/// isUnsignedDIType - Return true if type encoding is unsigned.
-bool DIType::isUnsignedDIType() {
-  DIDerivedType DTy(DbgNode);
-  if (DTy.Verify())
-    return DTy.getTypeDerivedFrom().isUnsignedDIType();
-
-  DIBasicType BTy(DbgNode);
-  if (BTy.Verify()) {
-    unsigned Encoding = BTy.getEncoding();
-    if (Encoding == dwarf::DW_ATE_unsigned ||
-        Encoding == dwarf::DW_ATE_unsigned_char ||
-        Encoding == dwarf::DW_ATE_boolean)
-      return true;
-  }
-  return false;
-}
-
 /// Verify - Verify that a compile unit is well formed.
 bool DICompileUnit::Verify() const {
   if (!isCompileUnit())
     return false;
-  StringRef N = getFilename();
-  if (N.empty())
+
+  // Don't bother verifying the compilation directory or producer string
+  // as those could be empty.
+  if (getFilename().empty())
     return false;
-  // It is possible that directory and produce string is empty.
+
   return DbgNode->getNumOperands() == 13;
 }
 
@@ -433,31 +389,85 @@ bool DIObjCProperty::Verify() const {
   if (!isObjCProperty())
     return false;
 
-  DIType Ty = getType();
-  if (!Ty.Verify()) return false;
-
   // Don't worry about the rest of the strings for now.
   return DbgNode->getNumOperands() == 8;
 }
 
+/// Check if a field at position Elt of a MDNode is a MDNode.
+/// We currently allow an empty string and an integer.
+/// But we don't allow a non-empty string in a MDNode field.
+static bool fieldIsMDNode(const MDNode *DbgNode, unsigned Elt) {
+  // FIXME: This function should return true, if the field is null or the field
+  // is indeed a MDNode: return !Fld || isa<MDNode>(Fld).
+  Value *Fld = getField(DbgNode, Elt);
+  if (Fld && isa<MDString>(Fld) && !cast<MDString>(Fld)->getString().empty())
+    return false;
+  return true;
+}
+
+/// Check if a field at position Elt of a MDNode is a MDString.
+static bool fieldIsMDString(const MDNode *DbgNode, unsigned Elt) {
+  Value *Fld = getField(DbgNode, Elt);
+  return !Fld || isa<MDString>(Fld);
+}
+
+/// Check if a value can be a reference to a type.
+static bool isTypeRef(const Value *Val) {
+  return !Val ||
+         (isa<MDString>(Val) && !cast<MDString>(Val)->getString().empty()) ||
+         (isa<MDNode>(Val) && DIType(cast<MDNode>(Val)).isType());
+}
+
+/// Check if a field at position Elt of a MDNode can be a reference to a type.
+static bool fieldIsTypeRef(const MDNode *DbgNode, unsigned Elt) {
+  Value *Fld = getField(DbgNode, Elt);
+  return isTypeRef(Fld);
+}
+
+/// Check if a value can be a ScopeRef.
+static bool isScopeRef(const Value *Val) {
+  return !Val ||
+         (isa<MDString>(Val) && !cast<MDString>(Val)->getString().empty()) ||
+         (isa<MDNode>(Val) && DIScope(cast<MDNode>(Val)).isScope());
+}
+
+/// Check if a field at position Elt of a MDNode can be a ScopeRef.
+static bool fieldIsScopeRef(const MDNode *DbgNode, unsigned Elt) {
+  Value *Fld = getField(DbgNode, Elt);
+  return isScopeRef(Fld);
+}
+
 /// Verify - Verify that a type descriptor is well formed.
 bool DIType::Verify() const {
   if (!isType())
     return false;
-  if (getContext() && !getContext().Verify())
+  // Make sure Context @ field 2 is MDNode.
+  if (!fieldIsScopeRef(DbgNode, 2))
     return false;
-  unsigned Tag = getTag();
+
+  // FIXME: Sink this into the various subclass verifies.
+  uint16_t Tag = getTag();
   if (!isBasicType() && Tag != dwarf::DW_TAG_const_type &&
       Tag != dwarf::DW_TAG_volatile_type && Tag != dwarf::DW_TAG_pointer_type &&
       Tag != dwarf::DW_TAG_ptr_to_member_type &&
       Tag != dwarf::DW_TAG_reference_type &&
       Tag != dwarf::DW_TAG_rvalue_reference_type &&
-      Tag != dwarf::DW_TAG_restrict_type &&
-      Tag != dwarf::DW_TAG_array_type &&
+      Tag != dwarf::DW_TAG_restrict_type && Tag != dwarf::DW_TAG_array_type &&
       Tag != dwarf::DW_TAG_enumeration_type &&
       Tag != dwarf::DW_TAG_subroutine_type &&
+      Tag != dwarf::DW_TAG_inheritance && Tag != dwarf::DW_TAG_friend &&
       getFilename().empty())
     return false;
+  // DIType is abstract, it should be a BasicType, a DerivedType or
+  // a CompositeType.
+  if (isBasicType())
+    DIBasicType(DbgNode).Verify();
+  else if (isCompositeType())
+    DICompositeType(DbgNode).Verify();
+  else if (isDerivedType())
+    DIDerivedType(DbgNode).Verify();
+  else
+    return false;
   return true;
 }
 
@@ -468,6 +478,14 @@ bool DIBasicType::Verify() const {
 
 /// Verify - Verify that a derived type descriptor is well formed.
 bool DIDerivedType::Verify() const {
+  // Make sure DerivedFrom @ field 9 is TypeRef.
+  if (!fieldIsTypeRef(DbgNode, 9))
+    return false;
+  if (getTag() == dwarf::DW_TAG_ptr_to_member_type)
+    // Make sure ClassType @ field 10 is a TypeRef.
+    if (!fieldIsTypeRef(DbgNode, 10))
+      return false;
+
   return isDerivedType() && DbgNode->getNumOperands() >= 10 &&
          DbgNode->getNumOperands() <= 14;
 }
@@ -476,10 +494,18 @@ bool DIDerivedType::Verify() const {
 bool DICompositeType::Verify() const {
   if (!isCompositeType())
     return false;
-  if (getContext() && !getContext().Verify())
+
+  // Make sure DerivedFrom @ field 9 and ContainingType @ field 12 are TypeRef.
+  if (!fieldIsTypeRef(DbgNode, 9))
+    return false;
+  if (!fieldIsTypeRef(DbgNode, 12))
+    return false;
+
+  // Make sure the type identifier at field 14 is MDString, it can be null.
+  if (!fieldIsMDString(DbgNode, 14))
     return false;
 
-  return DbgNode->getNumOperands() >= 10 && DbgNode->getNumOperands() <= 14;
+  return DbgNode->getNumOperands() == 15;
 }
 
 /// Verify - Verify that a subprogram descriptor is well formed.
@@ -487,11 +513,13 @@ bool DISubprogram::Verify() const {
   if (!isSubprogram())
     return false;
 
-  if (getContext() && !getContext().Verify())
+  // Make sure context @ field 2 is a ScopeRef and type @ field 7 is a MDNode.
+  if (!fieldIsScopeRef(DbgNode, 2))
     return false;
-
-  DICompositeType Ty = getType();
-  if (!Ty.Verify())
+  if (!fieldIsMDNode(DbgNode, 7))
+    return false;
+  // Containing type @ field 12.
+  if (!fieldIsTypeRef(DbgNode, 12))
     return false;
   return DbgNode->getNumOperands() == 20;
 }
@@ -503,15 +531,13 @@ bool DIGlobalVariable::Verify() const {
 
   if (getDisplayName().empty())
     return false;
-
-  if (getContext() && !getContext().Verify())
+  // Make sure context @ field 2 and type @ field 8 are MDNodes.
+  if (!fieldIsMDNode(DbgNode, 2))
     return false;
-
-  DIType Ty = getType();
-  if (!Ty.Verify())
+  if (!fieldIsMDNode(DbgNode, 8))
     return false;
-
-  if (!getGlobal() && !getConstant())
+  // Make sure StaticDataMemberDeclaration @ field 12 is MDNode.
+  if (!fieldIsMDNode(DbgNode, 12))
     return false;
 
   return DbgNode->getNumOperands() == 13;
@@ -522,13 +548,11 @@ bool DIVariable::Verify() const {
   if (!isVariable())
     return false;
 
-  if (getContext() && !getContext().Verify())
+  // Make sure context @ field 1 and type @ field 5 are MDNodes.
+  if (!fieldIsMDNode(DbgNode, 1))
     return false;
-
-  DIType Ty = getType();
-  if (!Ty.Verify())
+  if (!fieldIsMDNode(DbgNode, 5))
     return false;
-
   return DbgNode->getNumOperands() >= 8;
 }
 
@@ -548,9 +572,7 @@ bool DINameSpace::Verify() const {
 }
 
 /// \brief Retrieve the MDNode for the directory/file pair.
-MDNode *DIFile::getFileNode() const {
-  return const_cast<MDNode*>(getNodeField(DbgNode, 1));
-}
+MDNode *DIFile::getFileNode() const { return getNodeField(DbgNode, 1); }
 
 /// \brief Verify that the file descriptor is well formed.
 bool DIFile::Verify() const {
@@ -588,62 +610,82 @@ bool DITemplateValueParameter::Verify() const {
 }
 
 /// \brief Verify that the imported module descriptor is well formed.
-bool DIImportedModule::Verify() const {
-  return isImportedModule() && DbgNode->getNumOperands() == 4;
+bool DIImportedEntity::Verify() const {
+  return isImportedEntity() &&
+         (DbgNode->getNumOperands() == 4 || DbgNode->getNumOperands() == 5);
 }
 
-/// getOriginalTypeSize - If this type is derived from a base type then
-/// return base type size.
-uint64_t DIDerivedType::getOriginalTypeSize() const {
-  unsigned Tag = getTag();
-
-  if (Tag != dwarf::DW_TAG_member && Tag != dwarf::DW_TAG_typedef &&
-      Tag != dwarf::DW_TAG_const_type && Tag != dwarf::DW_TAG_volatile_type &&
-      Tag != dwarf::DW_TAG_restrict_type)
-    return getSizeInBits();
-
-  DIType BaseType = getTypeDerivedFrom();
-
-  // If this type is not derived from any type then take conservative approach.
-  if (!BaseType.isValid())
-    return getSizeInBits();
-
-  // If this is a derived type, go ahead and get the base type, unless it's a
-  // reference then it's just the size of the field. Pointer types have no need
-  // of this since they're a different type of qualification on the type.
-  if (BaseType.getTag() == dwarf::DW_TAG_reference_type ||
-      BaseType.getTag() == dwarf::DW_TAG_rvalue_reference_type)
-    return getSizeInBits();
-
-  if (BaseType.isDerivedType())
-    return DIDerivedType(BaseType).getOriginalTypeSize();
+/// getObjCProperty - Return property node, if this ivar is associated with one.
+MDNode *DIDerivedType::getObjCProperty() const {
+  return getNodeField(DbgNode, 10);
+}
 
-  return BaseType.getSizeInBits();
+MDString *DICompositeType::getIdentifier() const {
+  return cast_or_null<MDString>(getField(DbgNode, 14));
 }
 
-/// getObjCProperty - Return property node, if this ivar is associated with one.
-MDNode *DIDerivedType::getObjCProperty() const {
-  if (DbgNode->getNumOperands() <= 10)
-    return NULL;
-  return dyn_cast_or_null<MDNode>(DbgNode->getOperand(10));
+#ifndef NDEBUG
+static void VerifySubsetOf(const MDNode *LHS, const MDNode *RHS) {
+  for (unsigned i = 0; i != LHS->getNumOperands(); ++i) {
+    // Skip the 'empty' list (that's a single i32 0, rather than truly empty).
+    if (i == 0 && isa<ConstantInt>(LHS->getOperand(i)))
+      continue;
+    const MDNode *E = cast<MDNode>(LHS->getOperand(i));
+    bool found = false;
+    for (unsigned j = 0; !found && j != RHS->getNumOperands(); ++j)
+      found = E == RHS->getOperand(j);
+    assert(found && "Losing a member during member list replacement");
+  }
 }
+#endif
 
 /// \brief Set the array of member DITypes.
 void DICompositeType::setTypeArray(DIArray Elements, DIArray TParams) {
-  assert((!TParams || DbgNode->getNumOperands() == 14) &&
+  assert((!TParams || DbgNode->getNumOperands() == 15) &&
          "If you're setting the template parameters this should include a slot "
          "for that!");
   TrackingVH<MDNode> N(*this);
-  N->replaceOperandWith(10, Elements);
+  if (Elements) {
+#ifndef NDEBUG
+    // Check that the new list of members contains all the old members as well.
+    if (const MDNode *El = cast_or_null<MDNode>(N->getOperand(10)))
+      VerifySubsetOf(El, Elements);
+#endif
+    N->replaceOperandWith(10, Elements);
+  }
   if (TParams)
     N->replaceOperandWith(13, TParams);
   DbgNode = N;
 }
 
+void DICompositeType::addMember(DIDescriptor D) {
+  SmallVector<llvm::Value *, 16> M;
+  DIArray OrigM = getTypeArray();
+  unsigned Elements = OrigM.getNumElements();
+  if (Elements == 1 && !OrigM.getElement(0))
+    Elements = 0;
+  M.reserve(Elements + 1);
+  for (unsigned i = 0; i != Elements; ++i)
+    M.push_back(OrigM.getElement(i));
+  M.push_back(D);
+  setTypeArray(DIArray(MDNode::get(DbgNode->getContext(), M)));
+}
+
+/// Generate a reference to this DIType. Uses the type identifier instead
+/// of the actual MDNode if possible, to help type uniquing.
+DIScopeRef DIScope::getRef() const {
+  if (!isCompositeType())
+    return DIScopeRef(*this);
+  DICompositeType DTy(DbgNode);
+  if (!DTy.getIdentifier())
+    return DIScopeRef(*this);
+  return DIScopeRef(DTy.getIdentifier());
+}
+
 /// \brief Set the containing type.
 void DICompositeType::setContainingType(DICompositeType ContainingType) {
   TrackingVH<MDNode> N(*this);
-  N->replaceOperandWith(12, ContainingType);
+  N->replaceOperandWith(12, ContainingType.getRef());
   DbgNode = N;
 }
 
@@ -673,24 +715,59 @@ bool DISubprogram::describes(const Function *F) {
 }
 
 unsigned DISubprogram::isOptimized() const {
-  assert (DbgNode && "Invalid subprogram descriptor!");
+  assert(DbgNode && "Invalid subprogram descriptor!");
   if (DbgNode->getNumOperands() == 15)
     return getUnsignedField(14);
   return 0;
 }
 
 MDNode *DISubprogram::getVariablesNodes() const {
-  if (!DbgNode || DbgNode->getNumOperands() <= 18)
-    return NULL;
-  return dyn_cast_or_null<MDNode>(DbgNode->getOperand(18));
+  return getNodeField(DbgNode, 18);
 }
 
 DIArray DISubprogram::getVariables() const {
-  if (!DbgNode || DbgNode->getNumOperands() <= 18)
-    return DIArray();
-  if (MDNode *T = dyn_cast_or_null<MDNode>(DbgNode->getOperand(18)))
-    return DIArray(T);
-  return DIArray();
+  return DIArray(getNodeField(DbgNode, 18));
+}
+
+Value *DITemplateValueParameter::getValue() const {
+  return getField(DbgNode, 4);
+}
+
+// If the current node has a parent scope then return that,
+// else return an empty scope.
+DIScopeRef DIScope::getContext() const {
+
+  if (isType())
+    return DIType(DbgNode).getContext();
+
+  if (isSubprogram())
+    return DIScopeRef(DISubprogram(DbgNode).getContext());
+
+  if (isLexicalBlock())
+    return DIScopeRef(DILexicalBlock(DbgNode).getContext());
+
+  if (isLexicalBlockFile())
+    return DIScopeRef(DILexicalBlockFile(DbgNode).getContext());
+
+  if (isNameSpace())
+    return DIScopeRef(DINameSpace(DbgNode).getContext());
+
+  assert((isFile() || isCompileUnit()) && "Unhandled type of scope.");
+  return DIScopeRef(NULL);
+}
+
+// If the scope node has a name, return that, else return an empty string.
+StringRef DIScope::getName() const {
+  if (isType())
+    return DIType(DbgNode).getName();
+  if (isSubprogram())
+    return DISubprogram(DbgNode).getName();
+  if (isNameSpace())
+    return DINameSpace(DbgNode).getName();
+  assert((isLexicalBlock() || isLexicalBlockFile() || isFile() ||
+          isCompileUnit()) &&
+         "Unhandled type of scope.");
+  return StringRef();
 }
 
 StringRef DIScope::getFilename() const {
@@ -709,54 +786,51 @@ DIArray DICompileUnit::getEnumTypes() const {
   if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(7)))
-    return DIArray(N);
-  return DIArray();
+  return DIArray(getNodeField(DbgNode, 7));
 }
 
 DIArray DICompileUnit::getRetainedTypes() const {
   if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(8)))
-    return DIArray(N);
-  return DIArray();
+  return DIArray(getNodeField(DbgNode, 8));
 }
 
 DIArray DICompileUnit::getSubprograms() const {
   if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(9)))
-    return DIArray(N);
-  return DIArray();
+  return DIArray(getNodeField(DbgNode, 9));
 }
 
-
 DIArray DICompileUnit::getGlobalVariables() const {
   if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(10)))
-    return DIArray(N);
-  return DIArray();
+  return DIArray(getNodeField(DbgNode, 10));
 }
 
-DIArray DICompileUnit::getImportedModules() const {
+DIArray DICompileUnit::getImportedEntities() const {
   if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(11)))
-    return DIArray(N);
-  return DIArray();
+  return DIArray(getNodeField(DbgNode, 11));
 }
 
-/// fixupObjcLikeName - Replace contains special characters used
+/// fixupSubprogramName - Replace contains special characters used
 /// in a typical Objective-C names with '.' in a given string.
-static void fixupObjcLikeName(StringRef Str, SmallVectorImpl<char> &Out) {
+static void fixupSubprogramName(DISubprogram Fn, SmallVectorImpl<char> &Out) {
+  StringRef FName =
+      Fn.getFunction() ? Fn.getFunction()->getName() : Fn.getName();
+  FName = Function::getRealLinkageName(FName);
+
+  StringRef Prefix("llvm.dbg.lv.");
+  Out.reserve(FName.size() + Prefix.size());
+  Out.append(Prefix.begin(), Prefix.end());
+
   bool isObjCLike = false;
-  for (size_t i = 0, e = Str.size(); i < e; ++i) {
-    char C = Str[i];
+  for (size_t i = 0, e = FName.size(); i < e; ++i) {
+    char C = FName[i];
     if (C == '[')
       isObjCLike = true;
 
@@ -771,33 +845,16 @@ static void fixupObjcLikeName(StringRef Str, SmallVectorImpl<char> &Out) {
 /// getFnSpecificMDNode - Return a NameMDNode, if available, that is
 /// suitable to hold function specific information.
 NamedMDNode *llvm::getFnSpecificMDNode(const Module &M, DISubprogram Fn) {
-  SmallString<32> Name = StringRef("llvm.dbg.lv.");
-  StringRef FName = "fn";
-  if (Fn.getFunction())
-    FName = Fn.getFunction()->getName();
-  else
-    FName = Fn.getName();
-  char One = '\1';
-  if (FName.startswith(StringRef(&One, 1)))
-    FName = FName.substr(1);
-  fixupObjcLikeName(FName, Name);
+  SmallString<32> Name;
+  fixupSubprogramName(Fn, Name);
   return M.getNamedMetadata(Name.str());
 }
 
 /// getOrInsertFnSpecificMDNode - Return a NameMDNode that is suitable
 /// to hold function specific information.
 NamedMDNode *llvm::getOrInsertFnSpecificMDNode(Module &M, DISubprogram Fn) {
-  SmallString<32> Name = StringRef("llvm.dbg.lv.");
-  StringRef FName = "fn";
-  if (Fn.getFunction())
-    FName = Fn.getFunction()->getName();
-  else
-    FName = Fn.getName();
-  char One = '\1';
-  if (FName.startswith(StringRef(&One, 1)))
-    FName = FName.substr(1);
-  fixupObjcLikeName(FName, Name);
-
+  SmallString<32> Name;
+  fixupSubprogramName(Fn, Name);
   return M.getOrInsertNamedMetadata(Name.str());
 }
 
@@ -810,8 +867,7 @@ DIVariable llvm::createInlinedVariable(MDNode *DV, MDNode *InlinedScope,
   SmallVector<Value *, 16> Elts;
   // Insert inlined scope as 7th element.
   for (unsigned i = 0, e = DV->getNumOperands(); i != e; ++i)
-    i == 7 ? Elts.push_back(InlinedScope) :
-             Elts.push_back(DV->getOperand(i));
+    i == 7 ? Elts.push_back(InlinedScope) : Elts.push_back(DV->getOperand(i));
   return DIVariable(MDNode::get(VMContext, Elts));
 }
 
@@ -820,9 +876,8 @@ DIVariable llvm::cleanseInlinedVariable(MDNode *DV, LLVMContext &VMContext) {
   SmallVector<Value *, 16> Elts;
   // Insert inlined scope as 7th element.
   for (unsigned i = 0, e = DV->getNumOperands(); i != e; ++i)
-    i == 7 ?
-      Elts.push_back(Constant::getNullValue(Type::getInt32Ty(VMContext))):
-      Elts.push_back(DV->getOperand(i));
+    i == 7 ? Elts.push_back(Constant::getNullValue(Type::getInt32Ty(VMContext)))
+           : Elts.push_back(DV->getOperand(i));
   return DIVariable(MDNode::get(VMContext, Elts));
 }
 
@@ -846,31 +901,70 @@ DICompositeType llvm::getDICompositeType(DIType T) {
   if (T.isCompositeType())
     return DICompositeType(T);
 
-  if (T.isDerivedType())
-    return getDICompositeType(DIDerivedType(T).getTypeDerivedFrom());
+  if (T.isDerivedType()) {
+    // This function is currently used by dragonegg and dragonegg does
+    // not generate identifier for types, so using an empty map to resolve
+    // DerivedFrom should be fine.
+    DITypeIdentifierMap EmptyMap;
+    return getDICompositeType(
+        DIDerivedType(T).getTypeDerivedFrom().resolve(EmptyMap));
+  }
 
   return DICompositeType();
 }
 
-/// isSubprogramContext - Return true if Context is either a subprogram
-/// or another context nested inside a subprogram.
-bool llvm::isSubprogramContext(const MDNode *Context) {
-  if (!Context)
-    return false;
-  DIDescriptor D(Context);
-  if (D.isSubprogram())
-    return true;
-  if (D.isType())
-    return isSubprogramContext(DIType(Context).getContext());
-  return false;
+/// Update DITypeIdentifierMap by going through retained types of each CU.
+DITypeIdentifierMap
+llvm::generateDITypeIdentifierMap(const NamedMDNode *CU_Nodes) {
+  DITypeIdentifierMap Map;
+  for (unsigned CUi = 0, CUe = CU_Nodes->getNumOperands(); CUi != CUe; ++CUi) {
+    DICompileUnit CU(CU_Nodes->getOperand(CUi));
+    DIArray Retain = CU.getRetainedTypes();
+    for (unsigned Ti = 0, Te = Retain.getNumElements(); Ti != Te; ++Ti) {
+      if (!Retain.getElement(Ti).isCompositeType())
+        continue;
+      DICompositeType Ty(Retain.getElement(Ti));
+      if (MDString *TypeId = Ty.getIdentifier()) {
+        // Definition has priority over declaration.
+        // Try to insert (TypeId, Ty) to Map.
+        std::pair<DITypeIdentifierMap::iterator, bool> P =
+            Map.insert(std::make_pair(TypeId, Ty));
+        // If TypeId already exists in Map and this is a definition, replace
+        // whatever we had (declaration or definition) with the definition.
+        if (!P.second && !Ty.isForwardDecl())
+          P.first->second = Ty;
+      }
+    }
+  }
+  return Map;
 }
 
 //===----------------------------------------------------------------------===//
 // DebugInfoFinder implementations.
 //===----------------------------------------------------------------------===//
 
+void DebugInfoFinder::reset() {
+  CUs.clear();
+  SPs.clear();
+  GVs.clear();
+  TYs.clear();
+  Scopes.clear();
+  NodesSeen.clear();
+  TypeIdentifierMap.clear();
+  TypeMapInitialized = false;
+}
+
+void DebugInfoFinder::InitializeTypeMap(const Module &M) {
+  if (!TypeMapInitialized)
+    if (NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu")) {
+      TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
+      TypeMapInitialized = true;
+    }
+}
+
 /// processModule - Process entire module and collect debug info.
 void DebugInfoFinder::processModule(const Module &M) {
+  InitializeTypeMap(M);
   if (NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu")) {
     for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
       DICompileUnit CU(CU_Nodes->getOperand(i));
@@ -878,8 +972,10 @@ void DebugInfoFinder::processModule(const Module &M) {
       DIArray GVs = CU.getGlobalVariables();
       for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i) {
         DIGlobalVariable DIG(GVs.getElement(i));
-        if (addGlobalVariable(DIG))
+        if (addGlobalVariable(DIG)) {
+          processScope(DIG.getContext());
           processType(DIG.getType());
+        }
       }
       DIArray SPs = CU.getSubprograms();
       for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
@@ -890,36 +986,38 @@ void DebugInfoFinder::processModule(const Module &M) {
       DIArray RetainedTypes = CU.getRetainedTypes();
       for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i)
         processType(DIType(RetainedTypes.getElement(i)));
-      // FIXME: We really shouldn't be bailing out after visiting just one CU
-      return;
+      DIArray Imports = CU.getImportedEntities();
+      for (unsigned i = 0, e = Imports.getNumElements(); i != e; ++i) {
+        DIImportedEntity Import = DIImportedEntity(Imports.getElement(i));
+        DIDescriptor Entity = Import.getEntity();
+        if (Entity.isType())
+          processType(DIType(Entity));
+        else if (Entity.isSubprogram())
+          processSubprogram(DISubprogram(Entity));
+        else if (Entity.isNameSpace())
+          processScope(DINameSpace(Entity).getContext());
+      }
     }
   }
 }
 
 /// processLocation - Process DILocation.
-void DebugInfoFinder::processLocation(DILocation Loc) {
-  if (!Loc.Verify()) return;
-  DIDescriptor S(Loc.getScope());
-  if (S.isCompileUnit())
-    addCompileUnit(DICompileUnit(S));
-  else if (S.isSubprogram())
-    processSubprogram(DISubprogram(S));
-  else if (S.isLexicalBlock())
-    processLexicalBlock(DILexicalBlock(S));
-  else if (S.isLexicalBlockFile()) {
-    DILexicalBlockFile DBF = DILexicalBlockFile(S);
-    processLexicalBlock(DILexicalBlock(DBF.getScope()));
-  }
-  processLocation(Loc.getOrigLocation());
+void DebugInfoFinder::processLocation(const Module &M, DILocation Loc) {
+  if (!Loc)
+    return;
+  InitializeTypeMap(M);
+  processScope(Loc.getScope());
+  processLocation(M, Loc.getOrigLocation());
 }
 
 /// processType - Process DIType.
 void DebugInfoFinder::processType(DIType DT) {
   if (!addType(DT))
     return;
+  processScope(DT.getContext().resolve(TypeIdentifierMap));
   if (DT.isCompositeType()) {
     DICompositeType DCT(DT);
-    processType(DCT.getTypeDerivedFrom());
+    processType(DCT.getTypeDerivedFrom().resolve(TypeIdentifierMap));
     DIArray DA = DCT.getTypeArray();
     for (unsigned i = 0, e = DA.getNumElements(); i != e; ++i) {
       DIDescriptor D = DA.getElement(i);
@@ -930,7 +1028,35 @@ void DebugInfoFinder::processType(DIType DT) {
     }
   } else if (DT.isDerivedType()) {
     DIDerivedType DDT(DT);
-    processType(DDT.getTypeDerivedFrom());
+    processType(DDT.getTypeDerivedFrom().resolve(TypeIdentifierMap));
+  }
+}
+
+void DebugInfoFinder::processScope(DIScope Scope) {
+  if (Scope.isType()) {
+    DIType Ty(Scope);
+    processType(Ty);
+    return;
+  }
+  if (Scope.isCompileUnit()) {
+    addCompileUnit(DICompileUnit(Scope));
+    return;
+  }
+  if (Scope.isSubprogram()) {
+    processSubprogram(DISubprogram(Scope));
+    return;
+  }
+  if (!addScope(Scope))
+    return;
+  if (Scope.isLexicalBlock()) {
+    DILexicalBlock LB(Scope);
+    processScope(LB.getContext());
+  } else if (Scope.isLexicalBlockFile()) {
+    DILexicalBlockFile LBF = DILexicalBlockFile(Scope);
+    processScope(LBF.getScope());
+  } else if (Scope.isNameSpace()) {
+    DINameSpace NS(Scope);
+    processScope(NS.getContext());
   }
 }
 
@@ -942,8 +1068,7 @@ void DebugInfoFinder::processLexicalBlock(DILexicalBlock LB) {
   else if (Context.isLexicalBlockFile()) {
     DILexicalBlockFile DBF = DILexicalBlockFile(Context);
     return processLexicalBlock(DILexicalBlock(DBF.getScope()));
-  }
-  else
+  } else
     return processSubprogram(DISubprogram(Context));
 }
 
@@ -951,13 +1076,30 @@ void DebugInfoFinder::processLexicalBlock(DILexicalBlock LB) {
 void DebugInfoFinder::processSubprogram(DISubprogram SP) {
   if (!addSubprogram(SP))
     return;
+  processScope(SP.getContext().resolve(TypeIdentifierMap));
   processType(SP.getType());
+  DIArray TParams = SP.getTemplateParams();
+  for (unsigned I = 0, E = TParams.getNumElements(); I != E; ++I) {
+    DIDescriptor Element = TParams.getElement(I);
+    if (Element.isTemplateTypeParameter()) {
+      DITemplateTypeParameter TType(Element);
+      processScope(TType.getContext().resolve(TypeIdentifierMap));
+      processType(TType.getType().resolve(TypeIdentifierMap));
+    } else if (Element.isTemplateValueParameter()) {
+      DITemplateValueParameter TVal(Element);
+      processScope(TVal.getContext().resolve(TypeIdentifierMap));
+      processType(TVal.getType().resolve(TypeIdentifierMap));
+    }
+  }
 }
 
 /// processDeclare - Process DbgDeclareInst.
-void DebugInfoFinder::processDeclare(const DbgDeclareInst *DDI) {
+void DebugInfoFinder::processDeclare(const Module &M,
+                                     const DbgDeclareInst *DDI) {
   MDNode *N = dyn_cast<MDNode>(DDI->getVariable());
-  if (!N) return;
+  if (!N)
+    return;
+  InitializeTypeMap(M);
 
   DIDescriptor DV(N);
   if (!DV.isVariable())
@@ -965,12 +1107,29 @@ void DebugInfoFinder::processDeclare(const DbgDeclareInst *DDI) {
 
   if (!NodesSeen.insert(DV))
     return;
+  processScope(DIVariable(N).getContext());
+  processType(DIVariable(N).getType());
+}
+
+void DebugInfoFinder::processValue(const Module &M, const DbgValueInst *DVI) {
+  MDNode *N = dyn_cast<MDNode>(DVI->getVariable());
+  if (!N)
+    return;
+  InitializeTypeMap(M);
+
+  DIDescriptor DV(N);
+  if (!DV.isVariable())
+    return;
+
+  if (!NodesSeen.insert(DV))
+    return;
+  processScope(DIVariable(N).getContext());
   processType(DIVariable(N).getType());
 }
 
 /// addType - Add type into Tys.
 bool DebugInfoFinder::addType(DIType DT) {
-  if (!DT.isValid())
+  if (!DT)
     return false;
 
   if (!NodesSeen.insert(DT))
@@ -982,9 +1141,8 @@ bool DebugInfoFinder::addType(DIType DT) {
 
 /// addCompileUnit - Add compile unit into CUs.
 bool DebugInfoFinder::addCompileUnit(DICompileUnit CU) {
-  if (!CU.Verify())
+  if (!CU)
     return false;
-
   if (!NodesSeen.insert(CU))
     return false;
 
@@ -994,7 +1152,7 @@ bool DebugInfoFinder::addCompileUnit(DICompileUnit CU) {
 
 /// addGlobalVariable - Add global variable into GVs.
 bool DebugInfoFinder::addGlobalVariable(DIGlobalVariable DIG) {
-  if (!DIDescriptor(DIG).isGlobalVariable())
+  if (!DIG)
     return false;
 
   if (!NodesSeen.insert(DIG))
@@ -1006,7 +1164,7 @@ bool DebugInfoFinder::addGlobalVariable(DIGlobalVariable DIG) {
 
 // addSubprogram - Add subprgoram into SPs.
 bool DebugInfoFinder::addSubprogram(DISubprogram SP) {
-  if (!DIDescriptor(SP).isSubprogram())
+  if (!SP)
     return false;
 
   if (!NodesSeen.insert(SP))
@@ -1016,18 +1174,33 @@ bool DebugInfoFinder::addSubprogram(DISubprogram SP) {
   return true;
 }
 
+bool DebugInfoFinder::addScope(DIScope Scope) {
+  if (!Scope)
+    return false;
+  // FIXME: Ocaml binding generates a scope with no content, we treat it
+  // as null for now.
+  if (Scope->getNumOperands() == 0)
+    return false;
+  if (!NodesSeen.insert(Scope))
+    return false;
+  Scopes.push_back(Scope);
+  return true;
+}
+
 //===----------------------------------------------------------------------===//
 // DIDescriptor: dump routines for all descriptors.
 //===----------------------------------------------------------------------===//
 
 /// dump - Print descriptor to dbgs() with a newline.
 void DIDescriptor::dump() const {
-  print(dbgs()); dbgs() << '\n';
+  print(dbgs());
+  dbgs() << '\n';
 }
 
 /// print - Print descriptor.
 void DIDescriptor::print(raw_ostream &OS) const {
-  if (!DbgNode) return;
+  if (!DbgNode)
+    return;
 
   if (const char *Tag = dwarf::TagString(getTag()))
     OS << "[ " << Tag << " ]";
@@ -1089,7 +1262,8 @@ void DIEnumerator::printInternal(raw_ostream &OS) const {
 }
 
 void DIType::printInternal(raw_ostream &OS) const {
-  if (!DbgNode) return;
+  if (!DbgNode)
+    return;
 
   StringRef Res = getName();
   if (!Res.empty())
@@ -1097,13 +1271,11 @@ void DIType::printInternal(raw_ostream &OS) const {
 
   // TODO: Print context?
 
-  OS << " [line " << getLineNumber()
-     << ", size " << getSizeInBits()
-     << ", align " << getAlignInBits()
-     << ", offset " << getOffsetInBits();
+  OS << " [line " << getLineNumber() << ", size " << getSizeInBits()
+     << ", align " << getAlignInBits() << ", offset " << getOffsetInBits();
   if (isBasicType())
     if (const char *Enc =
-        dwarf::AttributeEncodingString(DIBasicType(DbgNode).getEncoding()))
+            dwarf::AttributeEncodingString(DIBasicType(DbgNode).getEncoding()))
       OS << ", enc " << Enc;
   OS << "]";
 
@@ -1116,7 +1288,12 @@ void DIType::printInternal(raw_ostream &OS) const {
     OS << " [artificial]";
 
   if (isForwardDecl())
-    OS << " [fwd]";
+    OS << " [decl]";
+  else if (getTag() == dwarf::DW_TAG_structure_type ||
+           getTag() == dwarf::DW_TAG_union_type ||
+           getTag() == dwarf::DW_TAG_enumeration_type ||
+           getTag() == dwarf::DW_TAG_class_type)
+    OS << " [def]";
   if (isVector())
     OS << " [vector]";
   if (isStaticMember())
@@ -1194,19 +1371,17 @@ void DIObjCProperty::printInternal(raw_ostream &OS) const {
   if (!Name.empty())
     OS << " [" << Name << ']';
 
-  OS << " [line " << getLineNumber()
-     << ", properties " << getUnsignedField(6) << ']';
+  OS << " [line " << getLineNumber() << ", properties " << getUnsignedField(6)
+     << ']';
 }
 
 static void printDebugLoc(DebugLoc DL, raw_ostream &CommentOS,
                           const LLVMContext &Ctx) {
-  if (!DL.isUnknown()) {          // Print source line info.
+  if (!DL.isUnknown()) { // Print source line info.
     DIScope Scope(DL.getScope(Ctx));
+    assert(Scope.isScope() && "Scope of a DebugLoc should be a DIScope.");
     // Omit the directory, because it's likely to be long and uninteresting.
-    if (Scope.Verify())
-      CommentOS << Scope.getFilename();
-    else
-      CommentOS << "<unknown>";
+    CommentOS << Scope.getFilename();
     CommentOS << ':' << DL.getLine();
     if (DL.getCol() != 0)
       CommentOS << ':' << DL.getCol();
@@ -1233,3 +1408,81 @@ void DIVariable::printExtendedName(raw_ostream &OS) const {
     }
   }
 }
+
+/// Specialize constructor to make sure it has the correct type.
+template <> DIRef<DIScope>::DIRef(const Value *V) : Val(V) {
+  assert(isScopeRef(V) && "DIScopeRef should be a MDString or MDNode");
+}
+template <> DIRef<DIType>::DIRef(const Value *V) : Val(V) {
+  assert(isTypeRef(V) && "DITypeRef should be a MDString or MDNode");
+}
+
+/// Specialize getFieldAs to handle fields that are references to DIScopes.
+template <>
+DIScopeRef DIDescriptor::getFieldAs<DIScopeRef>(unsigned Elt) const {
+  return DIScopeRef(getField(DbgNode, Elt));
+}
+/// Specialize getFieldAs to handle fields that are references to DITypes.
+template <> DITypeRef DIDescriptor::getFieldAs<DITypeRef>(unsigned Elt) const {
+  return DITypeRef(getField(DbgNode, Elt));
+}
+
+/// Strip debug info in the module if it exists.
+/// To do this, we remove all calls to the debugger intrinsics and any named
+/// metadata for debugging. We also remove debug locations for instructions.
+/// Return true if module is modified.
+bool llvm::StripDebugInfo(Module &M) {
+
+  bool Changed = false;
+
+  // Remove all of the calls to the debugger intrinsics, and remove them from
+  // the module.
+  if (Function *Declare = M.getFunction("llvm.dbg.declare")) {
+    while (!Declare->use_empty()) {
+      CallInst *CI = cast<CallInst>(Declare->use_back());
+      CI->eraseFromParent();
+    }
+    Declare->eraseFromParent();
+    Changed = true;
+  }
+
+  if (Function *DbgVal = M.getFunction("llvm.dbg.value")) {
+    while (!DbgVal->use_empty()) {
+      CallInst *CI = cast<CallInst>(DbgVal->use_back());
+      CI->eraseFromParent();
+    }
+    DbgVal->eraseFromParent();
+    Changed = true;
+  }
+
+  for (Module::named_metadata_iterator NMI = M.named_metadata_begin(),
+         NME = M.named_metadata_end(); NMI != NME;) {
+    NamedMDNode *NMD = NMI;
+    ++NMI;
+    if (NMD->getName().startswith("llvm.dbg.")) {
+      NMD->eraseFromParent();
+      Changed = true;
+    }
+  }
+
+  for (Module::iterator MI = M.begin(), ME = M.end(); MI != ME; ++MI)
+    for (Function::iterator FI = MI->begin(), FE = MI->end(); FI != FE;
+         ++FI)
+      for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE;
+           ++BI) {
+        if (!BI->getDebugLoc().isUnknown()) {
+          Changed = true;
+          BI->setDebugLoc(DebugLoc());
+        }
+      }
+
+  return Changed;
+}
+
+/// Return Debug Info Metadata Version by checking module flags.
+unsigned llvm::getDebugMetadataVersionFromModule(const Module &M) {
+  Value *Val = M.getModuleFlag("Debug Info Version");
+  if (!Val)
+    return 0;
+  return cast<ConstantInt>(Val)->getZExtValue();
+}