2 files changed, 22 insertions, 0 deletions
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 910f5dcf779..aa672b3a7ec 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3606,6 +3606,9 @@ ASTReader::ASTReadResult ASTReader::ReadAST(StringRef FileName,
          Id != IdEnd; ++Id)
       Id->second->setOutOfDate(true);
   }
+  // Mark selectors as out of date.
+  for (auto Sel : SelectorGeneration)
+    SelectorOutOfDate[Sel.first] = true;
   
   // Resolve any unresolved module exports.
   for (unsigned I = 0, N = UnresolvedModuleRefs.size(); I != N; ++I) {
@@ -7139,6 +7142,7 @@ void ASTReader::ReadMethodPool(Selector Sel) {
   unsigned &Generation = SelectorGeneration[Sel];
   unsigned PriorGeneration = Generation;
   Generation = getGeneration();
+  SelectorOutOfDate[Sel] = false;
   
   // Search for methods defined with this selector.
   ++NumMethodPoolLookups;
@@ -7170,6 +7174,11 @@ void ASTReader::ReadMethodPool(Selector Sel) {
   addMethodsToPool(S, Visitor.getFactoryMethods(), Pos->second.second);
 }
 
+void ASTReader::updateOutOfDateSelector(Selector Sel) {
+  if (SelectorOutOfDate[Sel])
+    ReadMethodPool(Sel);
+}
+
 void ASTReader::ReadKnownNamespaces(
                           SmallVectorImpl<NamespaceDecl *> &Namespaces) {
   Namespaces.clear();
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 32c9c4787c4..606228af753 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -4387,6 +4387,19 @@ uint64_t ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
     }
   }
 
+  // For method pool in the module, if it contains an entry for a selector,
+  // the entry should be complete, containing everything introduced by that
+  // module and all modules it imports. It's possible that the entry is out of
+  // date, so we need to pull in the new content here.
+
+  // It's possible that updateOutOfDateSelector can update SelectorIDs. To be
+  // safe, we copy all selectors out.
+  llvm::SmallVector<Selector, 256> AllSelectors;
+  for (auto &SelectorAndID : SelectorIDs)
+    AllSelectors.push_back(SelectorAndID.first);
+  for (auto &Selector : AllSelectors)
+    SemaRef.updateOutOfDateSelector(Selector);
+
   // Form the record of special types.
   RecordData SpecialTypes;
   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);