diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index db5a0cb..6df1610 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -189,6 +189,11 @@
   }
 }
 
+/// isType - Return true if the specified tag is legal for DIType.
+bool DIDescriptor::isType() const {
+  return isBasicType() || isCompositeType() || isDerivedType();
+}
+
 /// isSubprogram - Return true if the specified tag is legal for
 /// DISubprogram.
 bool DIDescriptor::isSubprogram() const {
@@ -207,6 +212,11 @@
   return Tag == dwarf::DW_TAG_variable;
 }
 
+/// isGlobal - Return true if the specified tag is legal for DIGlobal.
+bool DIDescriptor::isGlobal() const {
+  return isGlobalVariable();
+}
+
 /// isScope - Return true if the specified tag is one of the scope
 /// related tag.
 bool DIDescriptor::isScope() const {
@@ -240,6 +250,22 @@
   return Tag == dwarf::DW_TAG_lexical_block;
 }
 
+/// isSubrange - Return true if the specified tag is DW_TAG_subrange_type.
+bool DIDescriptor::isSubrange() const {
+  assert (!isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+
+  return Tag == dwarf::DW_TAG_subrange_type;
+}
+
+/// isEnumerator - Return true if the specified tag is DW_TAG_enumerator.
+bool DIDescriptor::isEnumerator() const {
+  assert (!isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+
+  return Tag == dwarf::DW_TAG_enumerator;
+}
+
 //===----------------------------------------------------------------------===//
 // Simple Descriptor Constructors and other Methods
 //===----------------------------------------------------------------------===//
@@ -392,6 +418,30 @@
   return false;
 }
 
+const char *DIScope::getFilename() const {
+  if (isLexicalBlock()) 
+    return DILexicalBlock(DbgNode).getFilename();
+  else if (isSubprogram())
+    return DISubprogram(DbgNode).getFilename();
+  else if (isCompileUnit())
+    return DICompileUnit(DbgNode).getFilename();
+  else 
+    assert (0 && "Invalid DIScope!");
+  return NULL;
+}
+
+const char *DIScope::getDirectory() const {
+  if (isLexicalBlock()) 
+    return DILexicalBlock(DbgNode).getDirectory();
+  else if (isSubprogram())
+    return DISubprogram(DbgNode).getDirectory();
+  else if (isCompileUnit())
+    return DICompileUnit(DbgNode).getDirectory();
+  else 
+    assert (0 && "Invalid DIScope!");
+  return NULL;
+}
+
 //===----------------------------------------------------------------------===//
 // DIDescriptor: dump routines for all descriptors.
 //===----------------------------------------------------------------------===//