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

2 files changed, 13 insertions, 0 deletions

diff --git a/lib/CodeGen/CGObjCGNU.cpp b/lib/CodeGen/CGObjCGNU.cpp
index 0a207ab76d..3a591e88dd 100644
--- a/lib/CodeGen/CGObjCGNU.cpp
+++ b/lib/CodeGen/CGObjCGNU.cpp
@@ -1529,6 +1529,11 @@ llvm::Constant *CGObjCGNU::GenerateEmptyProtocol(
 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
   ASTContext &Context = CGM.getContext();
   std::string ProtocolName = PD->getNameAsString();
+  
+  // Use the protocol definition, if there is one.
+  if (const ObjCProtocolDecl *Def = PD->getDefinition())
+    PD = Def;
+
   SmallVector<std::string, 16> Protocols;
   for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(),
        E = PD->protocol_end(); PI != E; ++PI)
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 121395676f..a782db76f6 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -1787,6 +1787,10 @@ llvm::Constant *CGObjCMac::GetOrEmitProtocol(const ObjCProtocolDecl *PD) {
   if (Entry && Entry->hasInitializer())
     return Entry;
 
+  // Use the protocol definition, if there is one.
+  if (const ObjCProtocolDecl *Def = PD->getDefinition())
+    PD = Def;
+
   // FIXME: I don't understand why gcc generates this, or where it is
   // resolved. Investigate. Its also wasteful to look this up over and over.
   LazySymbols.insert(&CGM.getContext().Idents.get("Protocol"));
@@ -5413,6 +5417,10 @@ llvm::Constant *CGObjCNonFragileABIMac::GetOrEmitProtocol(
   if (Entry && Entry->hasInitializer())
     return Entry;
 
+  // Use the protocol definition, if there is one.
+  if (const ObjCProtocolDecl *Def = PD->getDefinition())
+    PD = Def;
+  
   // Construct method lists.
   std::vector<llvm::Constant*> InstanceMethods, ClassMethods;
   std::vector<llvm::Constant*> OptInstanceMethods, OptClassMethods;