Index: cfe/trunk/include/clang/Basic/SourceManager.h
===================================================================
--- cfe/trunk/include/clang/Basic/SourceManager.h
+++ cfe/trunk/include/clang/Basic/SourceManager.h
@@ -1646,6 +1646,9 @@
     return getImmediateExpansionRange(Loc).first;
   }
 
+  /// \return Location of the top-level macro caller.
+  SourceLocation getTopMacroCallerLoc(SourceLocation Loc) const;
+
 private:
   friend class ASTReader;
   friend class ASTWriter;
Index: cfe/trunk/lib/Basic/SourceManager.cpp
===================================================================
--- cfe/trunk/lib/Basic/SourceManager.cpp
+++ cfe/trunk/lib/Basic/SourceManager.cpp
@@ -955,6 +955,12 @@
   return Expansion.getExpansionLocRange();
 }
 
+SourceLocation SourceManager::getTopMacroCallerLoc(SourceLocation Loc) const {
+  while (isMacroArgExpansion(Loc))
+    Loc = getImmediateSpellingLoc(Loc);
+  return Loc;
+}
+
 /// getExpansionRange - Given a SourceLocation object, return the range of
 /// tokens covered by the expansion in the ultimate file.
 std::pair<SourceLocation,SourceLocation>
Index: cfe/trunk/lib/Edit/Commit.cpp
===================================================================
--- cfe/trunk/lib/Edit/Commit.cpp
+++ cfe/trunk/lib/Edit/Commit.cpp
@@ -225,8 +225,7 @@
     isAtStartOfMacroExpansion(loc, &loc);
 
   const SourceManager &SM = SourceMgr;
-  while (SM.isMacroArgExpansion(loc))
-    loc = SM.getImmediateSpellingLoc(loc);
+  loc = SM.getTopMacroCallerLoc(loc);
 
   if (loc.isMacroID())
     if (!isAtStartOfMacroExpansion(loc, &loc))
@@ -256,8 +255,7 @@
     isAtEndOfMacroExpansion(loc, &loc);
 
   const SourceManager &SM = SourceMgr;
-  while (SM.isMacroArgExpansion(loc))
-    loc = SM.getImmediateSpellingLoc(loc);
+  loc = SM.getTopMacroCallerLoc(loc);
 
   if (loc.isMacroID())
     if (!isAtEndOfMacroExpansion(loc, &loc))
Index: cfe/trunk/lib/Sema/SemaChecking.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp
+++ cfe/trunk/lib/Sema/SemaChecking.cpp
@@ -9357,11 +9357,8 @@
   // Venture through the macro stacks to get to the source of macro arguments.
   // The new location is a better location than the complete location that was
   // passed in.
-  while (S.SourceMgr.isMacroArgExpansion(Loc))
-    Loc = S.SourceMgr.getImmediateMacroCallerLoc(Loc);
-
-  while (S.SourceMgr.isMacroArgExpansion(CC))
-    CC = S.SourceMgr.getImmediateMacroCallerLoc(CC);
+  Loc = S.SourceMgr.getTopMacroCallerLoc(Loc);
+  CC = S.SourceMgr.getTopMacroCallerLoc(CC);
 
   // __null is usually wrapped in a macro.  Go up a macro if that is the case.
   if (NullKind == Expr::NPCK_GNUNull && Loc.isMacroID()) {