Push DeclGroup much farther throughout the compiler.  Now the various
productions (except the already broken ObjC cases like @class X,Y;) in 
the parser that can produce more than one Decl return a DeclGroup instead
of a Decl, etc.

This allows elimination of the Decl::NextDeclarator field, and exposes
various clients that should look at all decls in a group, but which were
only looking at one (such as the dumper, printer, etc).  These have been
fixed.

Still TODO:

1) there are some FIXME's in the code about potentially using
DeclGroup for better location info.
2) ParseObjCAtDirectives should return a DeclGroup due to @class etc.
3) I'm not sure what is going on with StmtIterator.cpp, or if it can
   be radically simplified now.
4) I put a truly horrible hack in ParseTemplate.cpp.

I plan to bring up #3/4 on the mailing list, but don't plan to tackle
#1/2 in the short term.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68002 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTConsumer.cpp b/lib/AST/ASTConsumer.cpp
index 6c44d1a..f37cbde 100644
--- a/lib/AST/ASTConsumer.cpp
+++ b/lib/AST/ASTConsumer.cpp
@@ -12,7 +12,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/AST/ASTConsumer.h"
-#include "clang/AST/Decl.h"
+#include "clang/AST/DeclGroup.h"
 using namespace clang;
 
-ASTConsumer::~ASTConsumer() {}
+void ASTConsumer::HandleTopLevelDecl(DeclGroupRef D) {}
+
diff --git a/lib/AST/DeclGroup.cpp b/lib/AST/DeclGroup.cpp
index 36a7c2b..64b0399 100644
--- a/lib/AST/DeclGroup.cpp
+++ b/lib/AST/DeclGroup.cpp
@@ -19,13 +19,12 @@
 #include "llvm/Bitcode/Deserialize.h"
 using namespace clang;
 
-DeclGroup* DeclGroup::Create(ASTContext& C, unsigned numdecls, Decl** decls) {
-  assert (numdecls > 0);
-  unsigned size = sizeof(DeclGroup) + sizeof(Decl*) * numdecls;
-  unsigned alignment = llvm::AlignOf<DeclGroup>::Alignment;  
-  void* mem = C.Allocate(size, alignment);
-  new (mem) DeclGroup(numdecls, decls);
-  return static_cast<DeclGroup*>(mem);
+DeclGroup* DeclGroup::Create(ASTContext &C, Decl **Decls, unsigned NumDecls) {
+  assert(NumDecls > 1 && "Invalid DeclGroup");
+  unsigned Size = sizeof(DeclGroup) + sizeof(Decl*) * NumDecls;
+  void* Mem = C.Allocate(Size, llvm::AlignOf<DeclGroup>::Alignment);
+  new (Mem) DeclGroup(NumDecls, Decls);
+  return static_cast<DeclGroup*>(Mem);
 }
 
 /// Emit - Serialize a DeclGroup to Bitcode.
@@ -37,9 +36,9 @@
 /// Read - Deserialize a DeclGroup from Bitcode.
 DeclGroup* DeclGroup::Read(llvm::Deserializer& D, ASTContext& C) {
   unsigned NumDecls = (unsigned) D.ReadInt();
-  unsigned size = sizeof(DeclGroup) + sizeof(Decl*) * NumDecls;
+  unsigned Size = sizeof(DeclGroup) + sizeof(Decl*) * NumDecls;
   unsigned alignment = llvm::AlignOf<DeclGroup>::Alignment;  
-  DeclGroup* DG = (DeclGroup*) C.Allocate(size, alignment);
+  DeclGroup* DG = (DeclGroup*) C.Allocate(Size, alignment);
   new (DG) DeclGroup();
   DG->NumDecls = NumDecls;
   D.BatchReadOwnedPtrs(NumDecls, &(*DG)[0], C);
diff --git a/lib/AST/DeclSerialization.cpp b/lib/AST/DeclSerialization.cpp
index 8e3ef08..acaced2 100644
--- a/lib/AST/DeclSerialization.cpp
+++ b/lib/AST/DeclSerialization.cpp
@@ -39,7 +39,6 @@
   S.EmitInt(Access);
   S.EmitPtr(cast_or_null<Decl>(getDeclContext()));  // From Decl.
   S.EmitPtr(cast_or_null<Decl>(getLexicalDeclContext()));  // From Decl.
-  S.EmitPtr(NextDeclarator);
   if (const DeclContext *DC = dyn_cast<const DeclContext>(this))
     DC->EmitOutRec(S);
   
@@ -144,7 +143,6 @@
     D.ReadPtr(MDC->SemanticDC, SemaDCPtrID);
     D.ReadPtr(MDC->LexicalDC, LexicalDCPtrID);
   }
-  D.ReadPtr(Dcl->NextDeclarator);
   if (DeclContext *DC = dyn_cast<DeclContext>(Dcl))
     DC->ReadOutRec(D, C);
   bool OwnsNext = D.ReadBool();
diff --git a/lib/AST/StmtIterator.cpp b/lib/AST/StmtIterator.cpp
index 94829c0..20024f5 100644
--- a/lib/AST/StmtIterator.cpp
+++ b/lib/AST/StmtIterator.cpp
@@ -67,12 +67,11 @@
   if (inDecl()) {
     assert (decl);
     
+    // FIXME: SIMPLIFY AWAY.
     if (ImmediateAdvance)
-      decl = decl->getNextDeclarator();
-    
-    for ( ; decl ; decl = decl->getNextDeclarator())
-      if (HandleDecl(decl))
-        return;
+      decl = 0;
+    else if (HandleDecl(decl))
+      return;
   }
   else {
     assert (inDeclGroup());