Introduce the core infrastructure needed to model redeclaration chains

for Objective-C protocols, including:
  - Using the first declaration as the canonical declaration
  - Using the definition as the primary DeclContext
  - Making sure that all declarations have a pointer to the definition
  data, and that we know which declaration is the definition
  - Serialization support for redeclaration chains and for adding
  definitions to already-serialized declarations.

However, note that we're not taking advantage of much of this code
yet, because we're still re-using ObjCProtocolDecls.





git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147410 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 389abd5ec7..f7dd69a78a 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -1067,6 +1067,8 @@ static NamedDecl *getPreviousDeclaration(NamedDecl *D) {
     return TD->getPreviousDeclaration();
   if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
     return ID->getPreviousDeclaration();
+  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
+    return PD->getPreviousDeclaration();
   
   return 0;
 }