diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index 9694953..5cbaff9 100644
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -996,7 +996,7 @@
     for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(),
            ce = blockDecl->capture_end(); ci != ce; ++ci) {
       const VarDecl *variable = ci->getVariable();
-      DI->EmitLocation(Builder, variable->getLocation());
+      DI->setLocation(variable->getLocation());
 
       const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
       if (capture.isConstant()) {
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index c28ecc0..2ddb502 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -693,7 +693,7 @@
   // delegation optimization.
   if (CtorType == Ctor_Complete && IsConstructorDelegationValid(Ctor)) {
     if (CGDebugInfo *DI = getDebugInfo()) 
-      DI->EmitLocation(Builder, Ctor->getLocEnd());
+      DI->EmitLocation(Builder);
     EmitDelegateCXXConstructorCall(Ctor, Ctor_Base, Args);
     return;
   }
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 120486d..0902b94 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -55,37 +55,6 @@
   if (!Loc.isValid()) return;
 
   CurLoc = CGM.getContext().getSourceManager().getExpansionLoc(Loc);
-
-  // If we've changed files in the middle of a lexical scope go ahead
-  // and create a new lexical scope with file node if it's different
-  // from the one in the scope.
-  if (LexicalBlockStack.empty()) return;
-
-  SourceManager &SM = CGM.getContext().getSourceManager();
-  PresumedLoc PCLoc = SM.getPresumedLoc(CurLoc);
-  PresumedLoc PPLoc = SM.getPresumedLoc(PrevLoc);
-
-  if (PCLoc.isInvalid() || PPLoc.isInvalid() ||
-      !strcmp(PPLoc.getFilename(), PCLoc.getFilename()))
-    return;
-
-  llvm::MDNode *LB = LexicalBlockStack.back();
-  llvm::DIScope Scope = llvm::DIScope(LB);
-  if (Scope.isLexicalBlockFile()) {
-    llvm::DILexicalBlockFile LBF = llvm::DILexicalBlockFile(LB);
-    llvm::DIDescriptor D
-      = DBuilder.createLexicalBlockFile(LBF.getScope(),
-					getOrCreateFile(CurLoc));
-    llvm::MDNode *N = D;
-    LexicalBlockStack.pop_back();
-    LexicalBlockStack.push_back(N);
-  } else {
-    llvm::DIDescriptor D
-      = DBuilder.createLexicalBlockFile(Scope, getOrCreateFile(CurLoc));
-    llvm::MDNode *N = D;
-    LexicalBlockStack.pop_back();
-    LexicalBlockStack.push_back(N);
-  }
 }
 
 /// getContextDescriptor - Get context info for the decl.
@@ -236,7 +205,7 @@
 /// getLineNumber - Get line number for the location. If location is invalid
 /// then use current location.
 unsigned CGDebugInfo::getLineNumber(SourceLocation Loc) {
-  assert (Loc.isValid() || CurLoc.isValid() && "Invalid current location!");
+  assert (CurLoc.isValid() && "Invalid current location!");
   SourceManager &SM = CGM.getContext().getSourceManager();
   PresumedLoc PLoc = SM.getPresumedLoc(Loc.isValid() ? Loc : CurLoc);
   return PLoc.isValid()? PLoc.getLine() : 0;
@@ -245,7 +214,7 @@
 /// getColumnNumber - Get column number for the location. If location is 
 /// invalid then use current location.
 unsigned CGDebugInfo::getColumnNumber(SourceLocation Loc) {
-  assert (Loc.isValid() || CurLoc.isValid() && "Invalid current location!");
+  assert (CurLoc.isValid() && "Invalid current location!");
   SourceManager &SM = CGM.getContext().getSourceManager();
   PresumedLoc PLoc = SM.getPresumedLoc(Loc.isValid() ? Loc : CurLoc);
   return PLoc.isValid()? PLoc.getColumn() : 0;
@@ -1803,24 +1772,79 @@
   llvm::MDNode *SPN = SP;
   LexicalBlockStack.push_back(SPN);
   RegionMap[D] = llvm::WeakVH(SP);
+
+  // Clear stack used to keep track of #line directives.
+  LineDirectiveFiles.clear();
+}
+
+// UpdateLineDirectiveRegion - Update region stack only if #line directive
+// has introduced scope change.
+void CGDebugInfo::UpdateLineDirectiveRegion(CGBuilderTy &Builder) {
+  if (CurLoc.isInvalid() || CurLoc.isMacroID() ||
+      PrevLoc.isInvalid() || PrevLoc.isMacroID())
+    return;
+  SourceManager &SM = CGM.getContext().getSourceManager();
+  PresumedLoc PCLoc = SM.getPresumedLoc(CurLoc);
+  PresumedLoc PPLoc = SM.getPresumedLoc(PrevLoc);
+
+  if (PCLoc.isInvalid() || PPLoc.isInvalid() ||
+      !strcmp(PPLoc.getFilename(), PCLoc.getFilename()))
+    return;
+
+  // If #line directive stack is empty then we are entering a new scope.
+  if (LineDirectiveFiles.empty()) {
+    EmitLexicalBlockStart(Builder);
+    LineDirectiveFiles.push_back(PCLoc.getFilename());
+    return;
+  }
+
+  assert (LexicalBlockStack.size() >= LineDirectiveFiles.size()
+          && "error handling #line regions!");
+
+  bool SeenThisFile = false;
+  // Chek if current file is already seen earlier.
+  for(std::vector<const char *>::iterator I = LineDirectiveFiles.begin(),
+        E = LineDirectiveFiles.end(); I != E; ++I)
+    if (!strcmp(PCLoc.getFilename(), *I)) {
+      SeenThisFile = true;
+      break;
+    }
+
+  // If #line for this file is seen earlier then pop out #line regions.
+  if (SeenThisFile) {
+    while (!LineDirectiveFiles.empty()) {
+      const char *LastFile = LineDirectiveFiles.back();
+      LexicalBlockStack.pop_back();
+      LineDirectiveFiles.pop_back();
+      if (!strcmp(PPLoc.getFilename(), LastFile))
+        break;
+    }
+    return;
+  }
+
+  // .. otherwise insert new #line region.
+  EmitLexicalBlockStart(Builder);
+  LineDirectiveFiles.push_back(PCLoc.getFilename());
+
+  return;
 }
 
 /// EmitLocation - Emit metadata to indicate a change in line/column
 /// information in the source file.
-void CGDebugInfo::EmitLocation(CGBuilderTy &Builder, SourceLocation Loc) {
-  
-  // Update our current location
-  setLocation(Loc);
-
+void CGDebugInfo::EmitLocation(CGBuilderTy &Builder) {
   if (CurLoc.isInvalid() || CurLoc.isMacroID()) return;
 
   // Don't bother if things are the same as last time.
   SourceManager &SM = CGM.getContext().getSourceManager();
-  if (CurLoc == PrevLoc ||
+  if (CurLoc == PrevLoc || 
       SM.getExpansionLoc(CurLoc) == SM.getExpansionLoc(PrevLoc))
     // New Builder may not be in sync with CGDebugInfo.
     if (!Builder.getCurrentDebugLocation().isUnknown())
       return;
+
+  // The file may have had a line directive change. Process any of
+  // those before updating the state.
+  UpdateLineDirectiveRegion(Builder);
   
   // Update last state.
   PrevLoc = CurLoc;
@@ -1831,42 +1855,27 @@
                                                       Scope));
 }
 
-/// CreateLexicalBlock - Creates a new lexical block node and pushes it on
-/// the stack.
-void CGDebugInfo::CreateLexicalBlock(SourceLocation Loc) {
+/// EmitLexicalBlockStart - Constructs the debug code for entering a declarative
+/// region - beginning of a DW_TAG_lexical_block.
+void CGDebugInfo::EmitLexicalBlockStart(CGBuilderTy &Builder) {
   llvm::DIDescriptor D =
-    DBuilder.createLexicalBlock(LexicalBlockStack.empty() ?
-				llvm::DIDescriptor() :
-				llvm::DIDescriptor(LexicalBlockStack.back()),
-				getOrCreateFile(CurLoc),
-				getLineNumber(CurLoc),
-				getColumnNumber(CurLoc));
+    DBuilder.createLexicalBlock(LexicalBlockStack.empty() ? 
+                                llvm::DIDescriptor() : 
+                                llvm::DIDescriptor(LexicalBlockStack.back()),
+                                getOrCreateFile(CurLoc),
+                                getLineNumber(CurLoc), 
+                                getColumnNumber(CurLoc));
   llvm::MDNode *DN = D;
   LexicalBlockStack.push_back(DN);
 }
 
-/// EmitLexicalBlockStart - Constructs the debug code for entering a declarative
-/// region - beginning of a DW_TAG_lexical_block.
-void CGDebugInfo::EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc) {
-  // Set our current location.
-  setLocation(Loc);
-
-  // Create a new lexical block and push it on the stack.
-  CreateLexicalBlock(CurLoc);
-
-  // Emit a line table change for the current location inside the new scope.
-  Builder.SetCurrentDebugLocation(llvm::DebugLoc::get(getLineNumber(CurLoc),
-						      getColumnNumber(CurLoc),
-						      LexicalBlockStack.back()));
-}
-
 /// EmitLexicalBlockEnd - Constructs the debug code for exiting a declarative
 /// region - end of a DW_TAG_lexical_block.
-void CGDebugInfo::EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc) {
+void CGDebugInfo::EmitLexicalBlockEnd(CGBuilderTy &Builder) {
   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
 
-  // Provide an entry in the line table for the end of the block.
-  EmitLocation(Builder, Loc);
+  // Provide a region stop point.
+  EmitLocation(Builder);
 
   LexicalBlockStack.pop_back();
 }
@@ -1879,7 +1888,7 @@
 
   // Pop all regions for this function.
   while (LexicalBlockStack.size() != RCount)
-    EmitLexicalBlockEnd(Builder, CurLoc);
+    EmitLexicalBlockEnd(Builder);
   FnBeginRegionCount.pop_back();
 }
 
@@ -2018,9 +2027,9 @@
                                        addr, ArgNo);
       
       // Insert an llvm.dbg.declare into the current block.
-      // Insert an llvm.dbg.declare into the current block.
       llvm::Instruction *Call =
         DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
+      
       Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
       return;
     } 
@@ -2033,6 +2042,7 @@
     // Insert an llvm.dbg.declare into the current block.
     llvm::Instruction *Call =
       DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
+    
     Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
     return;
   }
@@ -2063,6 +2073,7 @@
         // Insert an llvm.dbg.declare into the current block.
         llvm::Instruction *Call =
           DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
+          
         Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
       }
     }
@@ -2127,10 +2138,11 @@
                                    llvm::DIDescriptor(LexicalBlockStack.back()),
                                    VD->getName(), Unit, Line, Ty, addr);
   // Insert an llvm.dbg.declare into the current block.
-  llvm::Instruction *Call =
+  llvm::Instruction *Call = 
     DBuilder.insertDeclare(Storage, D, Builder.GetInsertPoint());
-  Call->setDebugLoc(llvm::DebugLoc::get(Line, Column,
-                                        LexicalBlockStack.back()));
+  
+  llvm::MDNode *Scope = LexicalBlockStack.back();
+  Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
 }
 
 /// EmitDeclareOfArgVariable - Emit call to llvm.dbg.declare for an argument
@@ -2303,8 +2315,6 @@
   llvm::DIFile Unit = getOrCreateFile(D->getLocation());
   unsigned LineNo = getLineNumber(D->getLocation());
 
-  setLocation(D->getLocation());
-
   QualType T = D->getType();
   if (T->isIncompleteArrayType()) {
 
diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index a4533a8..e6c701a 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -64,6 +64,10 @@
   // the end of a function.
   std::vector<unsigned> FnBeginRegionCount;
 
+  /// LineDirectiveFiles - This stack is used to keep track of 
+  /// scopes introduced by #line directives.
+  std::vector<const char *> LineDirectiveFiles;
+
   /// DebugInfoNames - This is a storage for names that are
   /// constructed on demand. For example, C++ destructors, C++ operators etc..
   llvm::BumpPtrAllocator DebugInfoNames;
@@ -147,10 +151,10 @@
                          llvm::DIFile F,
                          SmallVectorImpl<llvm::Value *> &EltTys);
 
-  // CreateLexicalBlock - Create a new lexical block node and push it on
-  // the stack.
-  void CreateLexicalBlock(SourceLocation Loc);
-  
+  // UpdateLineDirectiveRegion - Update region stack only if #line directive
+  // has introduced scope change.
+  void UpdateLineDirectiveRegion(CGBuilderTy &Builder);
+
 public:
   CGDebugInfo(CodeGenModule &CGM);
   ~CGDebugInfo();
@@ -162,7 +166,7 @@
 
   /// EmitLocation - Emit metadata to indicate a change in line/column
   /// information in the source file.
-  void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
+  void EmitLocation(CGBuilderTy &Builder);
 
   /// EmitFunctionStart - Emit a call to llvm.dbg.function.start to indicate
   /// start of a new function.
@@ -178,11 +182,11 @@
 
   /// EmitLexicalBlockStart - Emit metadata to indicate the beginning of a
   /// new lexical block and push the block onto the stack.
-  void EmitLexicalBlockStart(CGBuilderTy &Builder, SourceLocation Loc);
+  void EmitLexicalBlockStart(CGBuilderTy &Builder);
 
   /// EmitLexicalBlockEnd - Emit metadata to indicate the end of a new lexical
   /// block and pop the current block.
-  void EmitLexicalBlockEnd(CGBuilderTy &Builder, SourceLocation Loc);
+  void EmitLexicalBlockEnd(CGBuilderTy &Builder);
 
   /// EmitDeclareOfAutoVariable - Emit call to llvm.dbg.declare for an automatic
   /// variable declaration.
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index ad27506..329dc5a 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -2180,8 +2180,10 @@
 
 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E, 
                                      ReturnValueSlot ReturnValue) {
-  if (CGDebugInfo *DI = getDebugInfo())
-    DI->EmitLocation(Builder, E->getLocStart());
+  if (CGDebugInfo *DI = getDebugInfo()) {
+    DI->setLocation(E->getLocStart());
+    DI->EmitLocation(Builder);
+  }
 
   // Builtins never have block type.
   if (E->getCallee()->getType()->isBlockPointerType())
diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index 51f2053..344c1ee 100644
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -1208,8 +1208,10 @@
   }
 
   CGDebugInfo *DI = getDebugInfo();
-  if (DI)
-    DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
+  if (DI) {
+    DI->setLocation(S.getSourceRange().getBegin());
+    DI->EmitLexicalBlockStart(Builder);
+  }
 
   // The local variable comes into scope immediately.
   AutoVarEmission variable = AutoVarEmission::invalid();
@@ -1463,8 +1465,10 @@
     EmitStoreThroughLValue(RValue::get(null), elementLValue);
   }
 
-  if (DI)
-    DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
+  if (DI) {
+    DI->setLocation(S.getSourceRange().getEnd());
+    DI->EmitLexicalBlockEnd(Builder);
+  }
 
   // Leave the cleanup we entered in ARC.
   if (getLangOptions().ObjCAutoRefCount)
@@ -2500,8 +2504,10 @@
   const CompoundStmt &S = cast<CompoundStmt>(*subStmt);
 
   CGDebugInfo *DI = getDebugInfo();
-  if (DI)
-    DI->EmitLexicalBlockStart(Builder, S.getLBracLoc());
+  if (DI) {
+    DI->setLocation(S.getLBracLoc());
+    DI->EmitLexicalBlockStart(Builder);
+  }
 
   // Keep track of the current cleanup stack depth.
   RunCleanupsScope Scope(*this);
@@ -2517,8 +2523,10 @@
        E = S.body_end(); I != E; ++I)
     EmitStmt(*I);
 
-  if (DI)
-    DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc());
+  if (DI) {
+    DI->setLocation(S.getRBracLoc());
+    DI->EmitLexicalBlockEnd(Builder);
+  }
 }
 
 /// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index c56931b..06a045f 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -31,12 +31,11 @@
 
 void CodeGenFunction::EmitStopPoint(const Stmt *S) {
   if (CGDebugInfo *DI = getDebugInfo()) {
-    SourceLocation Loc;
     if (isa<DeclStmt>(S))
-      Loc = S->getLocEnd();
+      DI->setLocation(S->getLocEnd());
     else
-      Loc = S->getLocStart();
-    DI->EmitLocation(Builder, Loc);
+      DI->setLocation(S->getLocStart());
+    DI->EmitLocation(Builder);
   }
 }
 
@@ -191,8 +190,10 @@
                              "LLVM IR generation of compound statement ('{}')");
 
   CGDebugInfo *DI = getDebugInfo();
-  if (DI)
-    DI->EmitLexicalBlockStart(Builder, S.getLBracLoc());
+  if (DI) {
+    DI->setLocation(S.getLBracLoc());
+    DI->EmitLexicalBlockStart(Builder);
+  }
 
   // Keep track of the current cleanup stack depth.
   RunCleanupsScope Scope(*this);
@@ -201,8 +202,10 @@
        E = S.body_end()-GetLast; I != E; ++I)
     EmitStmt(*I);
 
-  if (DI)
-    DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc());
+  if (DI) {
+    DI->setLocation(S.getRBracLoc());
+    DI->EmitLexicalBlockEnd(Builder);
+  }
 
   RValue RV;
   if (!GetLast)
@@ -567,8 +570,10 @@
   RunCleanupsScope ForScope(*this);
 
   CGDebugInfo *DI = getDebugInfo();
-  if (DI)
-    DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
+  if (DI) {
+    DI->setLocation(S.getSourceRange().getBegin());
+    DI->EmitLexicalBlockStart(Builder);
+  }
 
   // Evaluate the first part before the loop.
   if (S.getInit())
@@ -647,8 +652,10 @@
 
   ForScope.ForceCleanup();
 
-  if (DI)
-    DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
+  if (DI) {
+    DI->setLocation(S.getSourceRange().getEnd());
+    DI->EmitLexicalBlockEnd(Builder);
+  }
 
   // Emit the fall-through block.
   EmitBlock(LoopExit.getBlock(), true);
@@ -660,8 +667,10 @@
   RunCleanupsScope ForScope(*this);
 
   CGDebugInfo *DI = getDebugInfo();
-  if (DI)
-    DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
+  if (DI) {
+    DI->setLocation(S.getSourceRange().getBegin());
+    DI->EmitLexicalBlockStart(Builder);
+  }
 
   // Evaluate the first pieces before the loop.
   EmitStmt(S.getRangeStmt());
@@ -717,8 +726,10 @@
 
   ForScope.ForceCleanup();
 
-  if (DI)
-    DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
+  if (DI) {
+    DI->setLocation(S.getSourceRange().getEnd());
+    DI->EmitLexicalBlockEnd(Builder);
+  }
 
   // Emit the fall-through block.
   EmitBlock(LoopExit.getBlock(), true);
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 924ec84..aab513f 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1392,8 +1392,10 @@
     EmitCXXGlobalVarDeclInitFunc(D, GV);
 
   // Emit global variable debug information.
-  if (CGDebugInfo *DI = getModuleDebugInfo())
+  if (CGDebugInfo *DI = getModuleDebugInfo()) {
+    DI->setLocation(D->getLocation());
     DI->EmitGlobalVariable(GV, D);
+  }
 }
 
 llvm::GlobalValue::LinkageTypes