Index: cfe/trunk/include/clang/Edit/EditedSource.h
===================================================================
--- cfe/trunk/include/clang/Edit/EditedSource.h
+++ cfe/trunk/include/clang/Edit/EditedSource.h
@@ -41,9 +41,11 @@
   typedef std::map<FileOffset, FileEdit> FileEditsTy;
   FileEditsTy FileEdits;
 
-  llvm::DenseMap<unsigned, llvm::TinyPtrVector<IdentifierInfo*>>
+  // Location of argument use inside the macro body 
+  typedef std::pair<IdentifierInfo*, SourceLocation> MacroArgUse;
+  llvm::DenseMap<unsigned, SmallVector<MacroArgUse, 2>>
     ExpansionToArgMap;
-  SmallVector<std::pair<SourceLocation, IdentifierInfo*>, 2>
+  SmallVector<std::pair<SourceLocation, MacroArgUse>, 2>
     CurrCommitMacroArgExps;
 
   IdentifierTable IdentTable;
@@ -84,7 +86,7 @@
   FileEditsTy::iterator getActionForOffset(FileOffset Offs);
   void deconstructMacroArgLoc(SourceLocation Loc,
                               SourceLocation &ExpansionLoc,
-                              IdentifierInfo *&II);
+                              MacroArgUse &ArgUse);
 
   void startingCommit();
   void finishedCommit();
Index: cfe/trunk/lib/Edit/EditedSource.cpp
===================================================================
--- cfe/trunk/lib/Edit/EditedSource.cpp
+++ cfe/trunk/lib/Edit/EditedSource.cpp
@@ -25,17 +25,16 @@
 
 void EditedSource::deconstructMacroArgLoc(SourceLocation Loc,
                                           SourceLocation &ExpansionLoc,
-                                          IdentifierInfo *&II) {
+                                          MacroArgUse &ArgUse) {
   assert(SourceMgr.isMacroArgExpansion(Loc));
   SourceLocation DefArgLoc = SourceMgr.getImmediateExpansionRange(Loc).first;
   ExpansionLoc = SourceMgr.getImmediateExpansionRange(DefArgLoc).first;
   SmallString<20> Buf;
   StringRef ArgName = Lexer::getSpelling(SourceMgr.getSpellingLoc(DefArgLoc),
                                          Buf, SourceMgr, LangOpts);
-  II = nullptr;
-  if (!ArgName.empty()) {
-    II = &IdentTable.get(ArgName);
-  }
+  ArgUse = {nullptr, SourceLocation()};
+  if (!ArgName.empty())
+    ArgUse = {&IdentTable.get(ArgName), SourceMgr.getSpellingLoc(DefArgLoc)};
 }
 
 void EditedSource::startingCommit() {}
@@ -43,12 +42,11 @@
 void EditedSource::finishedCommit() {
   for (auto &ExpArg : CurrCommitMacroArgExps) {
     SourceLocation ExpLoc;
-    IdentifierInfo *II;
-    std::tie(ExpLoc, II) = ExpArg;
-    auto &ArgNames = ExpansionToArgMap[ExpLoc.getRawEncoding()];
-    if (std::find(ArgNames.begin(), ArgNames.end(), II) == ArgNames.end()) {
-      ArgNames.push_back(II);
-    }
+    MacroArgUse ArgUse;
+    std::tie(ExpLoc, ArgUse) = ExpArg;
+    auto &ArgUses = ExpansionToArgMap[ExpLoc.getRawEncoding()];
+    if (std::find(ArgUses.begin(), ArgUses.end(), ArgUse) == ArgUses.end())
+      ArgUses.push_back(ArgUse);
   }
   CurrCommitMacroArgExps.clear();
 }
@@ -66,12 +64,15 @@
   }
 
   if (SourceMgr.isMacroArgExpansion(OrigLoc)) {
-    IdentifierInfo *II;
     SourceLocation ExpLoc;
-    deconstructMacroArgLoc(OrigLoc, ExpLoc, II);
+    MacroArgUse ArgUse;
+    deconstructMacroArgLoc(OrigLoc, ExpLoc, ArgUse);
     auto I = ExpansionToArgMap.find(ExpLoc.getRawEncoding());
     if (I != ExpansionToArgMap.end() &&
-        std::find(I->second.begin(), I->second.end(), II) != I->second.end()) {
+        std::find_if(
+            I->second.begin(), I->second.end(), [&](const MacroArgUse &U) {
+              return ArgUse.first == U.first && ArgUse.second != U.second;
+            }) != I->second.end()) {
       // Trying to write in a macro argument input that has already been
       // written by a previous commit for another expansion of the same macro
       // argument name. For example:
@@ -101,11 +102,11 @@
     return true;
 
   if (SourceMgr.isMacroArgExpansion(OrigLoc)) {
-    IdentifierInfo *II;
     SourceLocation ExpLoc;
-    deconstructMacroArgLoc(OrigLoc, ExpLoc, II);
-    if (II)
-      CurrCommitMacroArgExps.emplace_back(ExpLoc, II);
+    MacroArgUse ArgUse;
+    deconstructMacroArgLoc(OrigLoc, ExpLoc, ArgUse);
+    if (ArgUse.first)
+      CurrCommitMacroArgExps.emplace_back(ExpLoc, ArgUse);
   }
   
   FileEdit &FA = FileEdits[Offs];
Index: cfe/trunk/test/FixIt/fixit-format-darwin.m
===================================================================
--- cfe/trunk/test/FixIt/fixit-format-darwin.m
+++ cfe/trunk/test/FixIt/fixit-format-darwin.m
@@ -0,0 +1,59 @@
+// RUN: cp %s %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin9 -fsyntax-only -fblocks -Wformat -fixit %t
+// RUN: grep -v CHECK %t | FileCheck %s
+
+/* This is a test of code modifications created by darwin format fix-its hints 
+   that are provided as part of warning */
+
+int printf(const char * restrict, ...);
+
+#if __LP64__
+typedef long NSInteger;
+typedef unsigned long NSUInteger;
+#else
+typedef int NSInteger;
+typedef unsigned int NSUInteger;
+#endif
+NSInteger getNSInteger();
+NSUInteger getNSUInteger();
+
+#define Log1(...) \
+do { \
+  printf(__VA_ARGS__); \
+} while (0)
+
+#define Log2(...) \
+do { \
+  printf(__VA_ARGS__); \
+  printf(__VA_ARGS__); \
+} while (0) \
+
+#define Log3(X, Y, Z) \
+do { \
+  printf(X, Y); \
+  printf(X, Z); \
+} while (0) \
+
+void test() {
+  printf("test 1: %s", getNSInteger()); 
+  // CHECK: printf("test 1: %ld", (long)getNSInteger());
+  printf("test 2: %s %s", getNSInteger(), getNSInteger());
+  // CHECK: printf("test 2: %ld %ld", (long)getNSInteger(), (long)getNSInteger());
+  
+  Log1("test 3: %s", getNSInteger());
+  // CHECK: Log1("test 3: %ld", (long)getNSInteger());
+  Log1("test 4: %s %s", getNSInteger(), getNSInteger());
+  // CHECK: Log1("test 4: %ld %ld", (long)getNSInteger(), (long)getNSInteger());
+  
+  Log2("test 5: %s", getNSInteger());
+  // CHECK: Log2("test 5: %ld", (long)getNSInteger()); 
+  Log2("test 6: %s %s", getNSInteger(), getNSInteger());
+  // CHECK: Log2("test 6: %ld %ld", (long)getNSInteger(), (long)getNSInteger());
+  
+  // Artificial test to check that X (in Log3(X, Y, Z))
+  // is modified only according to the diagnostics
+  // for the first printf and the modification caused 
+  // by the second printf is dropped.
+  Log3("test 7: %s", getNSInteger(), getNSUInteger());
+  // CHECK: Log3("test 7: %ld", (long)getNSInteger(), (unsigned long)getNSUInteger());
+}