3 files changed, 34 insertions, 14 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index b3bac25a076..7d6565aac38 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -650,14 +650,14 @@ ASTSelectorLookupTrait::ReadData(Selector, const unsigned char* d,
 
   Result.ID = Reader.getGlobalSelectorID(
       F, endian::readNext<uint32_t, little, unaligned>(d));
-  unsigned NumInstanceMethodsAndBits =
-      endian::readNext<uint16_t, little, unaligned>(d);
-  unsigned NumFactoryMethodsAndBits =
-      endian::readNext<uint16_t, little, unaligned>(d);
-  Result.InstanceBits = NumInstanceMethodsAndBits & 0x3;
-  Result.FactoryBits = NumFactoryMethodsAndBits & 0x3;
-  unsigned NumInstanceMethods = NumInstanceMethodsAndBits >> 2;
-  unsigned NumFactoryMethods = NumFactoryMethodsAndBits >> 2;
+  unsigned FullInstanceBits = endian::readNext<uint16_t, little, unaligned>(d);
+  unsigned FullFactoryBits = endian::readNext<uint16_t, little, unaligned>(d);
+  Result.InstanceBits = FullInstanceBits & 0x3;
+  Result.InstanceHasMoreThanOneDecl = (FullInstanceBits >> 2) & 0x1;
+  Result.FactoryBits = FullFactoryBits & 0x3;
+  Result.FactoryHasMoreThanOneDecl = (FullFactoryBits >> 2) & 0x1;
+  unsigned NumInstanceMethods = FullInstanceBits >> 3;
+  unsigned NumFactoryMethods = FullFactoryBits >> 3;
 
   // Load instance methods
   for (unsigned I = 0; I != NumInstanceMethods; ++I) {
@@ -7061,6 +7061,8 @@ namespace clang { namespace serialization {
     unsigned PriorGeneration;
     unsigned InstanceBits;
     unsigned FactoryBits;
+    bool InstanceHasMoreThanOneDecl;
+    bool FactoryHasMoreThanOneDecl;
     SmallVector<ObjCMethodDecl *, 4> InstanceMethods;
     SmallVector<ObjCMethodDecl *, 4> FactoryMethods;
 
@@ -7068,7 +7070,8 @@ namespace clang { namespace serialization {
     ReadMethodPoolVisitor(ASTReader &Reader, Selector Sel,
                           unsigned PriorGeneration)
         : Reader(Reader), Sel(Sel), PriorGeneration(PriorGeneration),
-          InstanceBits(0), FactoryBits(0) {}
+          InstanceBits(0), FactoryBits(0), InstanceHasMoreThanOneDecl(false),
+          FactoryHasMoreThanOneDecl(false) {}
 
     static bool visit(ModuleFile &M, void *UserData) {
       ReadMethodPoolVisitor *This
@@ -7103,6 +7106,8 @@ namespace clang { namespace serialization {
       This->FactoryMethods.append(Data.Factory.begin(), Data.Factory.end());
       This->InstanceBits = Data.InstanceBits;
       This->FactoryBits = Data.FactoryBits;
+      This->InstanceHasMoreThanOneDecl = Data.InstanceHasMoreThanOneDecl;
+      This->FactoryHasMoreThanOneDecl = Data.FactoryHasMoreThanOneDecl;
       return true;
     }
     
@@ -7118,6 +7123,10 @@ namespace clang { namespace serialization {
 
     unsigned getInstanceBits() const { return InstanceBits; }
     unsigned getFactoryBits() const { return FactoryBits; }
+    bool instanceHasMoreThanOneDecl() const {
+      return InstanceHasMoreThanOneDecl;
+    }
+    bool factoryHasMoreThanOneDecl() const { return FactoryHasMoreThanOneDecl; }
   };
 } } // end namespace clang::serialization
 
@@ -7156,7 +7165,9 @@ void ASTReader::ReadMethodPool(Selector Sel) {
   addMethodsToPool(S, Visitor.getInstanceMethods(), Pos->second.first);
   addMethodsToPool(S, Visitor.getFactoryMethods(), Pos->second.second);
   Pos->second.first.setBits(Visitor.getInstanceBits());
+  Pos->second.first.setHasMoreThanOneDecl(Visitor.instanceHasMoreThanOneDecl());
   Pos->second.second.setBits(Visitor.getFactoryBits());
+  Pos->second.second.setHasMoreThanOneDecl(Visitor.factoryHasMoreThanOneDecl());
 }
 
 void ASTReader::ReadKnownNamespaces(
diff --git a/clang/lib/Serialization/ASTReaderInternals.h b/clang/lib/Serialization/ASTReaderInternals.h
index 2f0d37e77c9..d1b032b27ac 100644
--- a/clang/lib/Serialization/ASTReaderInternals.h
+++ b/clang/lib/Serialization/ASTReaderInternals.h
@@ -156,6 +156,8 @@ public:
     SelectorID ID;
     unsigned InstanceBits;
     unsigned FactoryBits;
+    bool InstanceHasMoreThanOneDecl;
+    bool FactoryHasMoreThanOneDecl;
     SmallVector<ObjCMethodDecl *, 2> Instance;
     SmallVector<ObjCMethodDecl *, 2> Factory;
   };
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index c5d5b984cd3..6c60d45503d 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -2940,13 +2940,20 @@ public:
 
     unsigned InstanceBits = Methods.Instance.getBits();
     assert(InstanceBits < 4);
-    unsigned NumInstanceMethodsAndBits =
-        (NumInstanceMethods << 2) | InstanceBits;
+    unsigned InstanceHasMoreThanOneDeclBit =
+        Methods.Instance.hasMoreThanOneDecl();
+    unsigned FullInstanceBits = (NumInstanceMethods << 3) |
+                                (InstanceHasMoreThanOneDeclBit << 2) |
+                                InstanceBits;
     unsigned FactoryBits = Methods.Factory.getBits();
     assert(FactoryBits < 4);
-    unsigned NumFactoryMethodsAndBits = (NumFactoryMethods << 2) | FactoryBits;
-    LE.write<uint16_t>(NumInstanceMethodsAndBits);
-    LE.write<uint16_t>(NumFactoryMethodsAndBits);
+    unsigned FactoryHasMoreThanOneDeclBit =
+        Methods.Factory.hasMoreThanOneDecl();
+    unsigned FullFactoryBits = (NumFactoryMethods << 3) |
+                               (FactoryHasMoreThanOneDeclBit << 2) |
+                               FactoryBits;
+    LE.write<uint16_t>(FullInstanceBits);
+    LE.write<uint16_t>(FullFactoryBits);
     for (const ObjCMethodList *Method = &Methods.Instance; Method;
          Method = Method->getNext())
       if (Method->getMethod())