Switch Sema::UnusedFileScopedDecls over to a LazyVector.

  - Added LazyVector::erase() to support this use case.
  - Factored out the LazyDecl-of-Decls to RecordData translation in
  the ASTWriter. There is still a pile of code duplication here to
  eliminate.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136270 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 3 deletions

diff --git a/include/clang/Sema/ExternalSemaSource.h b/include/clang/Sema/ExternalSemaSource.h
index 1bc479cf4d..e0c7b4f0f0 100644
--- a/include/clang/Sema/ExternalSemaSource.h
+++ b/include/clang/Sema/ExternalSemaSource.h
@@ -18,10 +18,11 @@
 
 namespace clang {
 
+class DeclaratorDecl;
+class LookupResult;
 struct ObjCMethodList;
-class Sema;
 class Scope;
-class LookupResult;
+class Sema;
 class VarDecl;
   
 /// \brief An abstract interface that should be implemented by
@@ -65,7 +66,7 @@ public:
   /// \return true to tell Sema to recover using the LookupResult.
   virtual bool LookupUnqualified(LookupResult &R, Scope *S) { return false; }
 
-  /// \brief Read the set of tentative definitions know to the external Sema
+  /// \brief Read the set of tentative definitions known to the external Sema
   /// source.
   ///
   /// The external source should append its own tentative definitions to the
@@ -75,6 +76,17 @@ public:
   virtual void ReadTentativeDefinitions(
                                   SmallVectorImpl<VarDecl *> &TentativeDefs) {}
   
+  /// \brief Read the set of unused file-scope declarations known to the
+  /// external Sema source.
+  ///
+  /// The external source should append its own unused, filed-scope to the
+  /// given vector of declarations. Note that this routine may be
+  /// invoked multiple times; the external source should take care not to
+  /// introduce the same declarations repeatedly.
+  virtual void ReadUnusedFileScopedDecls(
+                 SmallVectorImpl<const DeclaratorDecl *> &Decls) {}
+  
+  
   // isa/cast/dyn_cast support
   static bool classof(const ExternalASTSource *Source) {
     return Source->SemaSource;