diff --git a/include/llvm/Analysis/DebugInfo.h b/include/llvm/Analysis/DebugInfo.h
index d468b4e..41b8038 100644
--- a/include/llvm/Analysis/DebugInfo.h
+++ b/include/llvm/Analysis/DebugInfo.h
@@ -134,7 +134,7 @@
   public:
     explicit DICompileUnit(const MDNode *N = 0) : DIScope(N) {}
 
-    unsigned getLanguage() const     { return getUnsignedField(2); }
+    unsigned getLanguage() const   { return getUnsignedField(2); }
     StringRef getFilename() const  { return getStringField(3);   }
     StringRef getDirectory() const { return getStringField(4);   }
     StringRef getProducer() const  { return getStringField(5);   }
@@ -504,10 +504,18 @@
   public:
     explicit DILexicalBlock(const MDNode *N = 0) : DIScope(N) {}
     DIScope getContext() const       { return getFieldAs<DIScope>(1);      }
-    StringRef getDirectory() const   { return getContext().getDirectory(); }
-    StringRef getFilename() const    { return getContext().getFilename();  }
     unsigned getLineNumber() const   { return getUnsignedField(2);         }
     unsigned getColumnNumber() const { return getUnsignedField(3);         }
+    StringRef getDirectory() const {
+      DIFile F = getFieldAs<DIFile>(4);
+      StringRef dir = F.getDirectory();
+      return !dir.empty() ? dir : getContext().getDirectory();
+    }
+    StringRef getFilename() const {
+      DIFile F = getFieldAs<DIFile>(4);
+      StringRef filename = F.getFilename();
+      return !filename.empty() ? filename : getContext().getFilename();
+    }
   };
 
   /// DINameSpace - A wrapper for a C++ style name space.
@@ -693,8 +701,8 @@
 
     /// CreateLexicalBlock - This creates a descriptor for a lexical block
     /// with the specified parent context.
-    DILexicalBlock CreateLexicalBlock(DIDescriptor Context, unsigned Line = 0,
-                                      unsigned Col = 0);
+    DILexicalBlock CreateLexicalBlock(DIDescriptor Context, DIFile F,
+                                      unsigned Line = 0, unsigned Col = 0);
 
     /// CreateNameSpace - This creates new descriptor for a namespace
     /// with the specified parent context.
diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index c8d0d22..ca6c2e6 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -1107,14 +1107,19 @@
 /// CreateBlock - This creates a descriptor for a lexical block with the
 /// specified parent VMContext.
 DILexicalBlock DIFactory::CreateLexicalBlock(DIDescriptor Context,
-                                             unsigned LineNo, unsigned Col) {
+                                             DIFile F, unsigned LineNo,
+                                             unsigned Col) {
+  // Defeat MDNode uniqing for lexical blocks.
+  static unsigned int unique_id = 0;
   Value *Elts[] = {
     GetTagConstant(dwarf::DW_TAG_lexical_block),
     Context,
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNo),
-    ConstantInt::get(Type::getInt32Ty(VMContext), Col)
+    ConstantInt::get(Type::getInt32Ty(VMContext), Col),
+    F,
+    ConstantInt::get(Type::getInt32Ty(VMContext), unique_id++)
   };
-  return DILexicalBlock(MDNode::get(VMContext, &Elts[0], 4));
+  return DILexicalBlock(MDNode::get(VMContext, &Elts[0], 6));
 }
 
 /// CreateNameSpace - This creates new descriptor for a namespace
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 6f2634b..9596446 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2682,18 +2682,21 @@
   if (FDL.isUnknown()) return;
   
   const MDNode *Scope = FDL.getScope(MF->getFunction()->getContext());
+  const MDNode *TheScope = 0;
   
   DISubprogram SP = getDISubprogram(Scope);
   unsigned Line, Col;
   if (SP.Verify()) {
     Line = SP.getLineNumber();
     Col = 0;
+    TheScope = SP;
   } else {
     Line = FDL.getLine();
     Col = FDL.getCol();
+    TheScope = Scope;
   }
   
-  recordSourceLine(Line, Col, Scope);
+  recordSourceLine(Line, Col, TheScope);
 
   /// ProcessedArgs - Collection of arguments already processed.
   SmallPtrSet<const MDNode *, 8> ProcessedArgs;
@@ -2899,16 +2902,6 @@
     Src = GetOrCreateSourceID(Dir, Fn);
   }
 
-#if 0
-  if (!Lines.empty()) {
-    SrcLineInfo lastSrcLineInfo = Lines.back();
-    // Emitting sequential line records with the same line number (but
-    // different addresses) seems to confuse GDB.  Avoid this.
-    if (lastSrcLineInfo.getLine() == Line)
-      return NULL;
-  }
-#endif
-
   MCSymbol *Label = MMI->getContext().CreateTempSymbol();
   Lines.push_back(SrcLineInfo(Line, Col, Src, Label));