Note when a decl is used in AST files.

When an AST file is built based on another AST file, it can use a decl from
the fist file, and therefore mark the "isUsed" bit.  We need to note this in
the AST file so that the bit is set correctly when the second AST file is
loaded.

This patch introduces the distinction between setIsUsed() and markUsed() so
that we don't call into the ASTMutationListener callback when it wouldn't
be appropriate.

Fixes PR16635.

llvm-svn: 190016

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/lib/Frontend/MultiplexConsumer.cpp b/clang/lib/Frontend/MultiplexConsumer.cpp
index f8ee36a50dc..9cf68a5e9b2 100644
--- a/clang/lib/Frontend/MultiplexConsumer.cpp
+++ b/clang/lib/Frontend/MultiplexConsumer.cpp
@@ -107,6 +107,8 @@ public:
   virtual void AddedObjCPropertyInClassExtension(const ObjCPropertyDecl *Prop,
                                             const ObjCPropertyDecl *OrigProp,
                                             const ObjCCategoryDecl *ClassExt);
+  void DeclarationMarkedUsed(const Decl *D) LLVM_OVERRIDE;
+
 private:
   std::vector<ASTMutationListener*> Listeners;
 };
@@ -175,6 +177,10 @@ void MultiplexASTMutationListener::AddedObjCPropertyInClassExtension(
   for (size_t i = 0, e = Listeners.size(); i != e; ++i)
     Listeners[i]->AddedObjCPropertyInClassExtension(Prop, OrigProp, ClassExt);
 }
+void MultiplexASTMutationListener::DeclarationMarkedUsed(const Decl *D) {
+  for (size_t i = 0, e = Listeners.size(); i != e; ++i)
+    Listeners[i]->DeclarationMarkedUsed(D);
+}
 
 }  // end namespace clang