Adding DIImportedModules to DIScopes.

This is just the basic groundwork for supporting DW_TAG_imported_module but I
wanted to commit this before pushing support further into Clang or LLVM so that
this rather churny change is isolated from the rest of the work. The major
churn here is obviously adding another field (within the common DIScope prefix)
to all DIScopes (files, classes, namespaces, lexical scopes, etc). This should
be the last big churny change needed for DW_TAG_imported_module/using directive
support/PR14606.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178099 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 163 insertions, 62 deletions

diff --git a/lib/IR/DIBuilder.cpp b/lib/IR/DIBuilder.cpp
index 0d18bed001..ee53dffed0 100644
--- a/lib/IR/DIBuilder.cpp
+++ b/lib/IR/DIBuilder.cpp
@@ -104,6 +104,7 @@ void DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_compile_unit),
     createFilePathPair(VMContext, Filename, Directory),
+    NULL, // Imported modules
     ConstantInt::get(Type::getInt32Ty(VMContext), Lang),
     MDString::get(VMContext, Producer),
     ConstantInt::get(Type::getInt1Ty(VMContext), isOptimized),
@@ -115,7 +116,9 @@ void DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
     TempGVs,
     MDString::get(VMContext, SplitName)
   };
-  TheCU = DICompileUnit(MDNode::get(VMContext, Elts));
+  DICompileUnit CU(MDNode::get(VMContext, Elts));
+  assert(CU.Verify() && "The compile unit should be valid");
+  TheCU = CU;
 
   // Create a named metadata so that it is easier to find cu in a module.
   NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
@@ -127,9 +130,12 @@ void DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
 DIFile DIBuilder::createFile(StringRef Filename, StringRef Directory) {
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_file_type),
-    createFilePathPair(VMContext, Filename, Directory)
+    createFilePathPair(VMContext, Filename, Directory),
+    NULL // Imported modules
   };
-  return DIFile(MDNode::get(VMContext, Elts));
+  DIFile F(MDNode::get(VMContext, Elts));
+  assert(F.Verify() && "The DIFile should be valid");
+  return F;
 }
 
 /// createEnumerator - Create a single enumerator value.
@@ -140,7 +146,9 @@ DIEnumerator DIBuilder::createEnumerator(StringRef Name, uint64_t Val) {
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt64Ty(VMContext), Val)
   };
-  return DIEnumerator(MDNode::get(VMContext, Elts));
+  DIEnumerator E(MDNode::get(VMContext, Elts));
+  assert(E.Verify() && "The enumerator should be valid");
+  return E;
 }
 
 /// createNullPtrType - Create C++0x nullptr type.
@@ -151,6 +159,7 @@ DIType DIBuilder::createNullPtrType(StringRef Name) {
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_unspecified_type),
     NULL, // Filename
+    Constant::getNullValue(Type::getInt32Ty(VMContext)), // Imported modules
     NULL, //TheCU,
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
@@ -160,7 +169,9 @@ DIType DIBuilder::createNullPtrType(StringRef Name) {
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags;
     ConstantInt::get(Type::getInt32Ty(VMContext), 0)  // Encoding
   };
-  return DIType(MDNode::get(VMContext, Elts));
+  DIType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The nullptr type should be valid");
+  return T;
 }
 
 /// createBasicType - Create debugging information entry for a basic
@@ -174,6 +185,7 @@ DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_base_type),
     NULL, // File/directory name
+    NULL, // Imported modules
     NULL, //TheCU,
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
@@ -183,7 +195,9 @@ DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags;
     ConstantInt::get(Type::getInt32Ty(VMContext), Encoding)
   };
-  return DIBasicType(MDNode::get(VMContext, Elts));
+  DIBasicType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The basic type should be valid");
+  return T;
 }
 
 /// createQualifiedType - Create debugging information entry for a qualified
@@ -193,6 +207,7 @@ DIDerivedType DIBuilder::createQualifiedType(unsigned Tag, DIType FromTy) {
   Value *Elts[] = {
     GetTagConstant(VMContext, Tag),
     NULL, // Filename
+    NULL, // Imported modules
     NULL, //TheCU,
     MDString::get(VMContext, StringRef()), // Empty name.
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
@@ -202,7 +217,9 @@ DIDerivedType DIBuilder::createQualifiedType(unsigned Tag, DIType FromTy) {
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags
     FromTy
   };
-  return DIDerivedType(MDNode::get(VMContext, Elts));
+  DIDerivedType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The derived type should be valid");
+  return T;
 }
 
 /// createPointerType - Create debugging information entry for a pointer.
@@ -213,6 +230,7 @@ DIBuilder::createPointerType(DIType PointeeTy, uint64_t SizeInBits,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_pointer_type),
     NULL, // Filename
+    NULL, // Imported modules
     NULL, //TheCU,
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
@@ -222,7 +240,9 @@ DIBuilder::createPointerType(DIType PointeeTy, uint64_t SizeInBits,
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags
     PointeeTy
   };
-  return DIDerivedType(MDNode::get(VMContext, Elts));
+  DIDerivedType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The pointer type should be valid");
+  return T;
 }
 
 DIDerivedType DIBuilder::createMemberPointerType(DIType PointeeTy, DIType Base) {
@@ -230,6 +250,7 @@ DIDerivedType DIBuilder::createMemberPointerType(DIType PointeeTy, DIType Base)
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_ptr_to_member_type),
     NULL, // Filename
+    NULL, // Imported modules
     NULL, //TheCU,
     NULL,
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
@@ -240,7 +261,9 @@ DIDerivedType DIBuilder::createMemberPointerType(DIType PointeeTy, DIType Base)
     PointeeTy,
     Base
   };
-  return DIDerivedType(MDNode::get(VMContext, Elts));
+  DIDerivedType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The member pointer type should be valid");
+  return T;
 }
 
 /// createReferenceType - Create debugging information entry for a reference
@@ -251,6 +274,7 @@ DIDerivedType DIBuilder::createReferenceType(unsigned Tag, DIType RTy) {
   Value *Elts[] = {
     GetTagConstant(VMContext, Tag),
     NULL, // Filename
+    NULL, // Imported modules
     NULL, // TheCU,
     NULL, // Name
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
@@ -260,7 +284,9 @@ DIDerivedType DIBuilder::createReferenceType(unsigned Tag, DIType RTy) {
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags
     RTy
   };
-  return DIDerivedType(MDNode::get(VMContext, Elts));
+  DIDerivedType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The reference type should be valid");
+  return T;
 }
 
 /// createTypedef - Create debugging information entry for a typedef.
@@ -271,6 +297,7 @@ DIDerivedType DIBuilder::createTypedef(DIType Ty, StringRef Name, DIFile File,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_typedef),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Context),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNo),
@@ -280,7 +307,9 @@ DIDerivedType DIBuilder::createTypedef(DIType Ty, StringRef Name, DIFile File,
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags
     Ty
   };
-  return DIDerivedType(MDNode::get(VMContext, Elts));
+  DIDerivedType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The typedef Type should be valid");
+  return T;
 }
 
 /// createFriend - Create debugging information entry for a 'friend'.
@@ -291,6 +320,7 @@ DIType DIBuilder::createFriend(DIType Ty, DIType FriendTy) {
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_friend),
     NULL,
+    NULL, // Imported modules
     Ty,
     NULL, // Name
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
@@ -300,7 +330,9 @@ DIType DIBuilder::createFriend(DIType Ty, DIType FriendTy) {
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags
     FriendTy
   };
-  return DIType(MDNode::get(VMContext, Elts));
+  DIType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The friend type should be valid");
+  return T;
 }
 
 /// createInheritance - Create debugging information entry to establish
@@ -312,6 +344,7 @@ DIDerivedType DIBuilder::createInheritance(
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_inheritance),
     NULL,
+    NULL, // Imported modules
     Ty,
     NULL, // Name
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Line
@@ -321,7 +354,9 @@ DIDerivedType DIBuilder::createInheritance(
     ConstantInt::get(Type::getInt32Ty(VMContext), Flags),
     BaseTy
   };
-  return DIDerivedType(MDNode::get(VMContext, Elts));
+  DIDerivedType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The inheritance type should be valid");
+  return T;
 }
 
 /// createMemberType - Create debugging information entry for a member.
@@ -333,6 +368,7 @@ DIDerivedType DIBuilder::createMemberType(
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_member),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Scope),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
@@ -342,7 +378,9 @@ DIDerivedType DIBuilder::createMemberType(
     ConstantInt::get(Type::getInt32Ty(VMContext), Flags),
     Ty
   };
-  return DIDerivedType(MDNode::get(VMContext, Elts));
+  DIDerivedType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The member type should be valid");
+  return T;
 }
 
 /// createStaticMemberType - Create debugging information entry for a
@@ -356,6 +394,7 @@ DIType DIBuilder::createStaticMemberType(DIDescriptor Scope, StringRef Name,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_member),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Scope),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
@@ -366,7 +405,9 @@ DIType DIBuilder::createStaticMemberType(DIDescriptor Scope, StringRef Name,
     Ty,
     Val
   };
-  return DIType(MDNode::get(VMContext, Elts));
+  DIType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The static member type should be valid");
+  return T;
 }
 
 /// createObjCIVar - Create debugging information entry for Objective-C
@@ -382,6 +423,7 @@ DIType DIBuilder::createObjCIVar(StringRef Name,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_member),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(File),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
@@ -395,7 +437,9 @@ DIType DIBuilder::createObjCIVar(StringRef Name,
     MDString::get(VMContext, SetterName),
     ConstantInt::get(Type::getInt32Ty(VMContext), PropertyAttributes)
   };
-  return DIType(MDNode::get(VMContext, Elts));
+  DIType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The Objective-C IVar type should be valid");
+  return T;
 }
 
 /// createObjCIVar - Create debugging information entry for Objective-C
@@ -409,6 +453,7 @@ DIType DIBuilder::createObjCIVar(StringRef Name,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_member),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(File),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
@@ -419,7 +464,9 @@ DIType DIBuilder::createObjCIVar(StringRef Name,
     Ty,
     PropertyNode
   };
-  return DIType(MDNode::get(VMContext, Elts));
+  DIType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The Objective-C IVar type should be valid");
+  return T;
 }
 
 /// createObjCProperty - Create debugging information entry for Objective-C
@@ -440,7 +487,9 @@ DIObjCProperty DIBuilder::createObjCProperty(StringRef Name,
     ConstantInt::get(Type::getInt32Ty(VMContext), PropertyAttributes),
     Ty
   };
-  return DIObjCProperty(MDNode::get(VMContext, Elts));
+  DIObjCProperty P(MDNode::get(VMContext, Elts));
+  assert(P.Verify() && "The Objective-C property should be valid");
+  return P;
 }
 
 /// createTemplateTypeParameter - Create debugging information for template
@@ -458,7 +507,9 @@ DIBuilder::createTemplateTypeParameter(DIDescriptor Context, StringRef Name,
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNo),
     ConstantInt::get(Type::getInt32Ty(VMContext), ColumnNo)
   };
-  return DITemplateTypeParameter(MDNode::get(VMContext, Elts));
+  DITemplateTypeParameter P(MDNode::get(VMContext, Elts));
+  assert(P.Verify() && "The template type parameter should be valid");
+  return P;
 }
 
 /// createTemplateValueParameter - Create debugging information for template
@@ -478,7 +529,9 @@ DIBuilder::createTemplateValueParameter(DIDescriptor Context, StringRef Name,
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNo),
     ConstantInt::get(Type::getInt32Ty(VMContext), ColumnNo)
   };
-  return DITemplateValueParameter(MDNode::get(VMContext, Elts));
+  DITemplateValueParameter P(MDNode::get(VMContext, Elts));
+  assert(P.Verify() && "The template value parameter should be valid");
+  return P;
 }
 
 /// createClassType - Create debugging information entry for a class.
@@ -497,6 +550,7 @@ DICompositeType DIBuilder::createClassType(DIDescriptor Context, StringRef Name,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_class_type),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Context),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
@@ -529,6 +583,7 @@ DICompositeType DIBuilder::createStructType(DIDescriptor Context,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_structure_type),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Context),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
@@ -556,6 +611,7 @@ DICompositeType DIBuilder::createUnionType(
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_union_type),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Scope),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
@@ -568,7 +624,9 @@ DICompositeType DIBuilder::createUnionType(
     ConstantInt::get(Type::getInt32Ty(VMContext), RunTimeLang),
     Constant::getNullValue(Type::getInt32Ty(VMContext))
   };
-  return DICompositeType(MDNode::get(VMContext, Elts));
+  DICompositeType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The union type should be valid");
+  return T;
 }
 
 /// createSubroutineType - Create subroutine type.
@@ -578,6 +636,7 @@ DIBuilder::createSubroutineType(DIFile File, DIArray ParameterTypes) {
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_subroutine_type),
     Constant::getNullValue(Type::getInt32Ty(VMContext)),
+    Constant::getNullValue(Type::getInt32Ty(VMContext)), // Imported modules
     Constant::getNullValue(Type::getInt32Ty(VMContext)),
     MDString::get(VMContext, ""),
     ConstantInt::get(Type::getInt32Ty(VMContext), 0),
@@ -590,7 +649,9 @@ DIBuilder::createSubroutineType(DIFile File, DIArray ParameterTypes) {
     ConstantInt::get(Type::getInt32Ty(VMContext), 0),
     Constant::getNullValue(Type::getInt32Ty(VMContext))
   };
-  return DICompositeType(MDNode::get(VMContext, Elts));
+  DICompositeType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The subroutine type should be valid");
+  return T;
 }
 
 /// createEnumerationType - Create debugging information entry for an
@@ -603,6 +664,7 @@ DICompositeType DIBuilder::createEnumerationType(
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_enumeration_type),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Scope),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
@@ -617,7 +679,9 @@ DICompositeType DIBuilder::createEnumerationType(
   };
   MDNode *Node = MDNode::get(VMContext, Elts);
   AllEnumTypes.push_back(Node);
-  return DICompositeType(Node);
+  DICompositeType T(Node);
+  assert(T.Verify() && "The enumeration type should be valid");
+  return T;
 }
 
 /// createArrayType - Create debugging information entry for an array.
@@ -627,6 +691,7 @@ DICompositeType DIBuilder::createArrayType(uint64_t Size, uint64_t AlignInBits,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_array_type),
     NULL, // Filename/Directory,
+    Constant::getNullValue(Type::getInt32Ty(VMContext)), // Imported modules
     NULL, //TheCU,
     MDString::get(VMContext, ""),
     ConstantInt::get(Type::getInt32Ty(VMContext), 0),
@@ -639,7 +704,9 @@ DICompositeType DIBuilder::createArrayType(uint64_t Size, uint64_t AlignInBits,
     ConstantInt::get(Type::getInt32Ty(VMContext), 0),
     Constant::getNullValue(Type::getInt32Ty(VMContext))
   };
-  return DICompositeType(MDNode::get(VMContext, Elts));
+  DICompositeType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The array type should be valid");
+  return T;
 }
 
 /// createVectorType - Create debugging information entry for a vector.
@@ -650,6 +717,7 @@ DIType DIBuilder::createVectorType(uint64_t Size, uint64_t AlignInBits,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_array_type),
     NULL, // Filename/Directory,
+    Constant::getNullValue(Type::getInt32Ty(VMContext)), // Imported modules
     NULL, //TheCU,
     MDString::get(VMContext, ""),
     ConstantInt::get(Type::getInt32Ty(VMContext), 0),
@@ -662,7 +730,9 @@ DIType DIBuilder::createVectorType(uint64_t Size, uint64_t AlignInBits,
     ConstantInt::get(Type::getInt32Ty(VMContext), 0),
     Constant::getNullValue(Type::getInt32Ty(VMContext))
   };
-  return DIType(MDNode::get(VMContext, Elts));
+  DIType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The vector type should be valid");
+  return T;
 }
 
 /// createArtificialType - Create a new DIType with "artificial" flag set.
@@ -684,9 +754,11 @@ DIType DIBuilder::createArtificialType(DIType Ty) {
   CurFlags = CurFlags | DIType::FlagArtificial;
 
   // Flags are stored at this slot.
-  Elts[8] =  ConstantInt::get(Type::getInt32Ty(VMContext), CurFlags);
+  Elts[9] =  ConstantInt::get(Type::getInt32Ty(VMContext), CurFlags);
 
-  return DIType(MDNode::get(VMContext, Elts));
+  DIType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The artificial type should be valid");
+  return T;
 }
 
 /// createObjectPointerType - Create a new type with both the object pointer
@@ -709,9 +781,11 @@ DIType DIBuilder::createObjectPointerType(DIType Ty) {
   CurFlags = CurFlags | (DIType::FlagObjectPointer | DIType::FlagArtificial);
 
   // Flags are stored at this slot.
-  Elts[8] = ConstantInt::get(Type::getInt32Ty(VMContext), CurFlags);
+  Elts[9] = ConstantInt::get(Type::getInt32Ty(VMContext), CurFlags);
 
-  return DIType(MDNode::get(VMContext, Elts));
+  DIType T(MDNode::get(VMContext, Elts));
+  assert(T.Verify() && "The object pointer type should be valid");
+  return T;
 }
 
 /// retainType - Retain DIType in a module even if it is not referenced
@@ -740,6 +814,7 @@ DIType DIBuilder::createForwardDecl(unsigned Tag, StringRef Name,
   Value *Elts[] = {
     GetTagConstant(VMContext, Tag),
     F.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Scope),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), Line),
@@ -911,6 +986,7 @@ DISubprogram DIBuilder::createFunction(DIDescriptor Context,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_subprogram),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Context),
     MDString::get(VMContext, Name),
     MDString::get(VMContext, Name),
@@ -958,6 +1034,7 @@ DISubprogram DIBuilder::createMethod(DIDescriptor Context,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_subprogram),
     F.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Context),
     MDString::get(VMContext, Name),
     MDString::get(VMContext, Name),
@@ -993,6 +1070,7 @@ DINameSpace DIBuilder::createNameSpace(DIDescriptor Scope, StringRef Name,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_namespace),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Scope),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNo)
@@ -1010,6 +1088,7 @@ DILexicalBlockFile DIBuilder::createLexicalBlockFile(DIDescriptor Scope,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_lexical_block),
     File.getFileNode(),
+    NULL, // Imported modules
     Scope
   };
   DILexicalBlockFile R(MDNode::get(VMContext, Elts));
@@ -1026,6 +1105,7 @@ DILexicalBlock DIBuilder::createLexicalBlock(DIDescriptor Scope, DIFile File,
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_lexical_block),
     File.getFileNode(),
+    NULL, // Imported modules
     getNonCompileUnitScope(Scope),
     ConstantInt::get(Type::getInt32Ty(VMContext), Line),
     ConstantInt::get(Type::getInt32Ty(VMContext), Col),
diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp
index b74522f8b7..80563e905f 100644
--- a/lib/IR/DebugInfo.cpp
+++ b/lib/IR/DebugInfo.cpp
@@ -64,7 +64,8 @@ bool DIDescriptor::Verify() const {
           DISubrange(DbgNode).Verify() || DIEnumerator(DbgNode).Verify() ||
           DIObjCProperty(DbgNode).Verify() ||
           DITemplateTypeParameter(DbgNode).Verify() ||
-          DITemplateValueParameter(DbgNode).Verify());
+          DITemplateValueParameter(DbgNode).Verify() ||
+          DIImportedModule(DbgNode).Verify());
 }
 
 static Value *getField(const MDNode *DbgNode, unsigned Elt) {
@@ -313,13 +314,13 @@ 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() == 4);
 }
 
 /// 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() > 4);
 }
 
 /// isSubrange - Return true if the specified tag is DW_TAG_subrange_type.
@@ -336,6 +337,12 @@ bool DIDescriptor::isEnumerator() const {
 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;
+}
+
 //===----------------------------------------------------------------------===//
 // Simple Descriptor Constructors and other Methods
 //===----------------------------------------------------------------------===//
@@ -418,7 +425,7 @@ bool DICompileUnit::Verify() const {
   if (N.empty())
     return false;
   // It is possible that directory and produce string is empty.
-  return DbgNode->getNumOperands() == 12;
+  return DbgNode->getNumOperands() == 13;
 }
 
 /// Verify - Verify that an ObjC property is well formed.
@@ -449,6 +456,7 @@ bool DIType::Verify() const {
       Tag != dwarf::DW_TAG_array_type &&
       Tag != dwarf::DW_TAG_enumeration_type &&
       Tag != dwarf::DW_TAG_subroutine_type &&
+      Tag != dwarf::DW_TAG_friend &&
       getFilename().empty())
     return false;
   return true;
@@ -456,13 +464,13 @@ bool DIType::Verify() const {
 
 /// Verify - Verify that a basic type descriptor is well formed.
 bool DIBasicType::Verify() const {
-  return isBasicType() && DbgNode->getNumOperands() == 10;
+  return isBasicType() && DbgNode->getNumOperands() == 11;
 }
 
 /// Verify - Verify that a derived type descriptor is well formed.
 bool DIDerivedType::Verify() const {
-  return isDerivedType() && DbgNode->getNumOperands() >= 10 &&
-         DbgNode->getNumOperands() <= 14;
+  return isDerivedType() && DbgNode->getNumOperands() >= 11 &&
+         DbgNode->getNumOperands() <= 15;
 }
 
 /// Verify - Verify that a composite type descriptor is well formed.
@@ -472,7 +480,7 @@ bool DICompositeType::Verify() const {
   if (getContext() && !getContext().Verify())
     return false;
 
-  return DbgNode->getNumOperands() >= 10 && DbgNode->getNumOperands() <= 14;
+  return DbgNode->getNumOperands() >= 11 && DbgNode->getNumOperands() <= 15;
 }
 
 /// Verify - Verify that a subprogram descriptor is well formed.
@@ -486,7 +494,7 @@ bool DISubprogram::Verify() const {
   DICompositeType Ty = getType();
   if (!Ty.Verify())
     return false;
-  return DbgNode->getNumOperands() == 20;
+  return DbgNode->getNumOperands() == 21;
 }
 
 /// Verify - Verify that a global variable descriptor is well formed.
@@ -537,7 +545,7 @@ bool DILocation::Verify() const {
 bool DINameSpace::Verify() const {
   if (!isNameSpace())
     return false;
-  return DbgNode->getNumOperands() == 5;
+  return DbgNode->getNumOperands() == 6;
 }
 
 /// \brief Retrieve the MDNode for the directory/file pair.
@@ -547,7 +555,7 @@ MDNode *DIFile::getFileNode() const {
 
 /// \brief Verify that the file descriptor is well formed.
 bool DIFile::Verify() const {
-  return isFile() && DbgNode->getNumOperands() == 2;
+  return isFile() && DbgNode->getNumOperands() == 3;
 }
 
 /// \brief Verify that the enumerator descriptor is well formed.
@@ -562,12 +570,12 @@ bool DISubrange::Verify() const {
 
 /// \brief Verify that the lexical block descriptor is well formed.
 bool DILexicalBlock::Verify() const {
-  return isLexicalBlock() && DbgNode->getNumOperands() == 6;
+  return isLexicalBlock() && DbgNode->getNumOperands() == 7;
 }
 
 /// \brief Verify that the file-scoped lexical block descriptor is well formed.
 bool DILexicalBlockFile::Verify() const {
-  return isLexicalBlockFile() && DbgNode->getNumOperands() == 3;
+  return isLexicalBlockFile() && DbgNode->getNumOperands() == 4;
 }
 
 /// \brief Verify that the template type parameter descriptor is well formed.
@@ -580,6 +588,11 @@ bool DITemplateValueParameter::Verify() const {
   return isTemplateValueParameter() && DbgNode->getNumOperands() == 8;
 }
 
+/// \brief Verify that the imported module descriptor is well formed.
+bool DIImportedModule::Verify() const {
+  return isImportedModule() && DbgNode->getNumOperands() == 2;
+}
+
 /// getOriginalTypeSize - If this type is derived from a base type then
 /// return base type size.
 uint64_t DIDerivedType::getOriginalTypeSize() const {
@@ -611,25 +624,25 @@ uint64_t DIDerivedType::getOriginalTypeSize() const {
 
 /// getObjCProperty - Return property node, if this ivar is associated with one.
 MDNode *DIDerivedType::getObjCProperty() const {
-  if (DbgNode->getNumOperands() <= 10)
+  if (DbgNode->getNumOperands() <= 11)
     return NULL;
-  return dyn_cast_or_null<MDNode>(DbgNode->getOperand(10));
+  return dyn_cast_or_null<MDNode>(DbgNode->getOperand(11));
 }
 
 /// \brief Set the array of member DITypes.
 void DICompositeType::setTypeArray(DIArray Elements, DIArray TParams) {
-  assert(!TParams || DbgNode->getNumOperands() == 14 && "If you're setting the template parameters this should include a slot for that");
+  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);
+  N->replaceOperandWith(11, Elements);
   if (TParams)
-    N->replaceOperandWith(13, TParams);
+    N->replaceOperandWith(14, TParams);
   DbgNode = N;
 }
 
 /// \brief Set the containing type.
 void DICompositeType::setContainingType(DICompositeType ContainingType) {
   TrackingVH<MDNode> N(*this);
-  N->replaceOperandWith(12, ContainingType);
+  N->replaceOperandWith(13, ContainingType);
   DbgNode = N;
 }
 
@@ -660,21 +673,21 @@ bool DISubprogram::describes(const Function *F) {
 
 unsigned DISubprogram::isOptimized() const {
   assert (DbgNode && "Invalid subprogram descriptor!");
-  if (DbgNode->getNumOperands() == 15)
-    return getUnsignedField(14);
+  if (DbgNode->getNumOperands() == 16)
+    return getUnsignedField(15);
   return 0;
 }
 
 MDNode *DISubprogram::getVariablesNodes() const {
-  if (!DbgNode || DbgNode->getNumOperands() <= 18)
+  if (!DbgNode || DbgNode->getNumOperands() <= 19)
     return NULL;
-  return dyn_cast_or_null<MDNode>(DbgNode->getOperand(18));
+  return dyn_cast_or_null<MDNode>(DbgNode->getOperand(19));
 }
 
 DIArray DISubprogram::getVariables() const {
-  if (!DbgNode || DbgNode->getNumOperands() <= 18)
+  if (!DbgNode || DbgNode->getNumOperands() <= 19)
     return DIArray();
-  if (MDNode *T = dyn_cast_or_null<MDNode>(DbgNode->getOperand(18)))
+  if (MDNode *T = dyn_cast_or_null<MDNode>(DbgNode->getOperand(19)))
     return DIArray(T);
   return DIArray();
 }
@@ -692,38 +705,38 @@ StringRef DIScope::getDirectory() const {
 }
 
 DIArray DICompileUnit::getEnumTypes() const {
-  if (!DbgNode || DbgNode->getNumOperands() < 12)
+  if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(7)))
+  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(8)))
     return DIArray(N);
   return DIArray();
 }
 
 DIArray DICompileUnit::getRetainedTypes() const {
-  if (!DbgNode || DbgNode->getNumOperands() < 12)
+  if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(8)))
+  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(9)))
     return DIArray(N);
   return DIArray();
 }
 
 DIArray DICompileUnit::getSubprograms() const {
-  if (!DbgNode || DbgNode->getNumOperands() < 12)
+  if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(9)))
+  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(10)))
     return DIArray(N);
   return DIArray();
 }
 
 
 DIArray DICompileUnit::getGlobalVariables() const {
-  if (!DbgNode || DbgNode->getNumOperands() < 12)
+  if (!DbgNode || DbgNode->getNumOperands() < 13)
     return DIArray();
 
-  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(10)))
+  if (MDNode *N = dyn_cast_or_null<MDNode>(DbgNode->getOperand(11)))
     return DIArray(N);
   return DIArray();
 }
@@ -1035,6 +1048,8 @@ void DIDescriptor::print(raw_ostream &OS) const {
     DINameSpace(DbgNode).printInternal(OS);
   } else if (this->isScope()) {
     DIScope(DbgNode).printInternal(OS);
+  } else if (this->isImportedModule()) {
+    DIImportedModule(DbgNode).printInternal(OS);
   }
 }
 
@@ -1170,6 +1185,12 @@ void DIObjCProperty::printInternal(raw_ostream &OS) const {
      << ", properties " << getUnsignedField(6) << ']';
 }
 
+void DIImportedModule::printInternal(raw_ostream &OS) const {
+  StringRef Name = getNameSpace().getName();
+  if (!Name.empty())
+    OS << " [" << Name << ']';
+}
+
 static void printDebugLoc(DebugLoc DL, raw_ostream &CommentOS,
                           const LLVMContext &Ctx) {
   if (!DL.isUnknown()) {          // Print source line info.