Move the data that corresponds to the definition of a protocol into a

separately-allocated DefinitionData structure. Introduce various
functions that will help with the separation of declarations from
definitions (isThisDeclarationADefinition(), hasDefinition(),
getDefinition()).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147408 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 39 insertions, 25 deletions

diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp
index 72cc37ccdd..6843ca7e6c 100644
--- a/lib/Sema/SemaCodeComplete.cpp
+++ b/lib/Sema/SemaCodeComplete.cpp
@@ -4554,13 +4554,16 @@ static void AddObjCMethods(ObjCContainerDecl *Container,
   
   // Visit the protocols of protocols.
   if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Container)) {
-    const ObjCList<ObjCProtocolDecl> &Protocols
-      = Protocol->getReferencedProtocols();
-    for (ObjCList<ObjCProtocolDecl>::iterator I = Protocols.begin(),
-                                              E = Protocols.end(); 
-         I != E; ++I)
-      AddObjCMethods(*I, WantInstanceMethods, WantKind, SelIdents, NumSelIdents, 
-                     CurContext, Selectors, AllowSameLength, Results, false);    
+    if (Protocol->hasDefinition()) {
+      const ObjCList<ObjCProtocolDecl> &Protocols
+        = Protocol->getReferencedProtocols();
+      for (ObjCList<ObjCProtocolDecl>::iterator I = Protocols.begin(),
+                                                E = Protocols.end(); 
+           I != E; ++I)
+        AddObjCMethods(*I, WantInstanceMethods, WantKind, SelIdents, 
+                       NumSelIdents, CurContext, Selectors, AllowSameLength, 
+                       Results, false);
+    }
   }
   
   ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Container);
@@ -5417,7 +5420,7 @@ static void AddProtocolResults(DeclContext *Ctx, DeclContext *CurContext,
        D != DEnd; ++D) {
     // Record any protocols we find.
     if (ObjCProtocolDecl *Proto = dyn_cast<ObjCProtocolDecl>(*D))
-      if (!OnlyForwardDeclarations || Proto->isForwardDecl())
+      if (!OnlyForwardDeclarations || !Proto->hasDefinition())
         Results.AddResult(Result(Proto, 0), CurContext, 0, false);
 
     // Record any forward-declared protocols we find.
@@ -5427,7 +5430,7 @@ static void AddProtocolResults(DeclContext *Ctx, DeclContext *CurContext,
              P = Forward->protocol_begin(),
              PEnd = Forward->protocol_end();
            P != PEnd; ++P)
-        if (!OnlyForwardDeclarations || (*P)->isForwardDecl())
+        if (!OnlyForwardDeclarations || !(*P)->hasDefinition())
           Results.AddResult(Result(*P, 0), CurContext, 0, false);
     }
   }
@@ -5823,14 +5826,16 @@ static void FindImplementableMethods(ASTContext &Context,
   }
 
   if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Container)) {
-    // Recurse into protocols.
-    const ObjCList<ObjCProtocolDecl> &Protocols
-      = Protocol->getReferencedProtocols();
-    for (ObjCList<ObjCProtocolDecl>::iterator I = Protocols.begin(),
-           E = Protocols.end(); 
-         I != E; ++I)
-      FindImplementableMethods(Context, *I, WantInstanceMethods, ReturnType,
-                               KnownMethods, false);
+    if (Protocol->hasDefinition()) {
+      // Recurse into protocols.
+      const ObjCList<ObjCProtocolDecl> &Protocols
+        = Protocol->getReferencedProtocols();
+      for (ObjCList<ObjCProtocolDecl>::iterator I = Protocols.begin(),
+             E = Protocols.end(); 
+           I != E; ++I)
+        FindImplementableMethods(Context, *I, WantInstanceMethods, ReturnType,
+                                 KnownMethods, false);
+    }
   }
 
   // Add methods in this container. This operation occurs last because
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 168ccfc3f5..eb178612c8 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -545,6 +545,10 @@ bool Sema::CheckForwardProtocolDeclarationForCircularDependency(
         Diag(PrevLoc, diag::note_previous_definition);
         res = true;
       }
+      
+      if (!PDecl->hasDefinition())
+        continue;
+      
       if (CheckForwardProtocolDeclarationForCircularDependency(PName, Ploc,
             PDecl->getLocation(), PDecl->getReferencedProtocols()))
         res = true;
@@ -568,18 +572,18 @@ Sema::ActOnStartProtocolInterface(SourceLocation AtProtoInterfaceLoc,
   ObjCProtocolDecl *PDecl = LookupProtocol(ProtocolName, ProtocolLoc);
   if (PDecl) {
     // Protocol already seen. Better be a forward protocol declaration
-    if (!PDecl->isForwardDecl()) {
+    if (ObjCProtocolDecl *Def = PDecl->getDefinition()) {
       Diag(ProtocolLoc, diag::warn_duplicate_protocol_def) << ProtocolName;
-      Diag(PDecl->getLocation(), diag::note_previous_definition);
+      Diag(Def->getLocation(), diag::note_previous_definition);
 
-      // Create a new one; the other may be in a different DeclContex, (e.g.
-      // this one may be in a LinkageSpecDecl while the other is not) which
-      // will break invariants.
-      // We will not add it to scope chains to ignore it as the warning says.
+      // Create a new protocol that is completely distinct from previous
+      // declarations, and do not make this protocol available for name lookup.
+      // That way, we'll end up completely ignoring the duplicate.
+      // FIXME: Can we turn this into an error?
       PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
                                        ProtocolLoc, AtProtoInterfaceLoc,
                                        /*isForwardDecl=*/false);
-
+      PDecl->startDefinition();
     } else {
       ObjCList<ObjCProtocolDecl> PList;
       PList.set((ObjCProtocolDecl *const*)ProtoRefs, NumProtoRefs, Context);
@@ -600,7 +604,9 @@ Sema::ActOnStartProtocolInterface(SourceLocation AtProtoInterfaceLoc,
                                      ProtocolLoc, AtProtoInterfaceLoc,
                                      /*isForwardDecl=*/false);
     PushOnScopeChains(PDecl, TUScope);
+    PDecl->startDefinition();
   }
+  
   if (AttrList)
     ProcessDeclAttributeList(TUScope, PDecl, AttrList);
   if (!err && NumProtoRefs ) {
@@ -647,7 +653,7 @@ Sema::FindProtocolDeclaration(bool WarnOnDeclarations,
 
     // If this is a forward declaration and we are supposed to warn in this
     // case, do it.
-    if (WarnOnDeclarations && PDecl->isForwardDecl())
+    if (WarnOnDeclarations && !PDecl->hasDefinition())
       Diag(ProtocolId[i].second, diag::warn_undef_protocolref)
         << ProtocolId[i].first;
     Protocols.push_back(PDecl);
@@ -2497,6 +2503,9 @@ private:
   }
 
   void searchFrom(ObjCProtocolDecl *protocol) {
+    if (!protocol->hasDefinition())
+      return;
+    
     // A method in a protocol declaration overrides declarations from
     // referenced ("parent") protocols.
     search(protocol->getReferencedProtocols());