1 files changed, 152 insertions, 0 deletions
diff --git a/include/clang/AST/DeclGroup.h b/include/clang/AST/DeclGroup.h
new file mode 100644
index 000000000000..15a8adef8e57
--- /dev/null
+++ b/include/clang/AST/DeclGroup.h
@@ -0,0 +1,152 @@
+//===--- DeclGroup.h - Classes for representing groups of Decls -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the DeclGroup, DeclGroupRef, and OwningDeclGroup classes.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_DECLGROUP_H
+#define LLVM_CLANG_AST_DECLGROUP_H
+
+#include "llvm/Support/DataTypes.h"
+#include <cassert>
+
+namespace clang {
+  
+class ASTContext;
+class Decl;
+class DeclGroup;
+class DeclGroupIterator;
+
+class DeclGroup {
+  // FIXME: Include a TypeSpecifier object.
+  unsigned NumDecls;
+  
+private:
+  DeclGroup() : NumDecls(0) {}
+  DeclGroup(unsigned numdecls, Decl** decls);
+
+public:
+  static DeclGroup *Create(ASTContext &C, Decl **Decls, unsigned NumDecls);
+  void Destroy(ASTContext& C);
+
+  unsigned size() const { return NumDecls; }
+
+  Decl*& operator[](unsigned i) { 
+    assert (i < NumDecls && "Out-of-bounds access.");
+    return *((Decl**) (this+1));
+  }
+  
+  Decl* const& operator[](unsigned i) const { 
+    assert (i < NumDecls && "Out-of-bounds access.");
+    return *((Decl* const*) (this+1));
+  }
+};
+    
+class DeclGroupRef {
+  // Note this is not a PointerIntPair because we need the address of the
+  // non-group case to be valid as a Decl** for iteration.
+  enum Kind { SingleDeclKind=0x0, DeclGroupKind=0x1, Mask=0x1 };  
+  Decl* D;
+
+  Kind getKind() const {
+    return (Kind) (reinterpret_cast<uintptr_t>(D) & Mask);
+  }  
+  
+public:    
+  DeclGroupRef() : D(0) {}
+  
+  explicit DeclGroupRef(Decl* d) : D(d) {}
+  explicit DeclGroupRef(DeclGroup* dg)
+    : D((Decl*) (reinterpret_cast<uintptr_t>(dg) | DeclGroupKind)) {}
+  
+  static DeclGroupRef Create(ASTContext &C, Decl **Decls, unsigned NumDecls) {
+    if (NumDecls == 0)
+      return DeclGroupRef();
+    if (NumDecls == 1)
+      return DeclGroupRef(Decls[0]);
+    return DeclGroupRef(DeclGroup::Create(C, Decls, NumDecls));
+  }
+  
+  typedef Decl** iterator;
+  typedef Decl* const * const_iterator;
+  
+  bool isNull() const { return D == 0; }
+  bool isSingleDecl() const { return getKind() == SingleDeclKind; }
+  bool isDeclGroup() const { return getKind() == DeclGroupKind; }
+
+  Decl *getSingleDecl() {
+    assert(isSingleDecl() && "Isn't a declgroup");
+    return D;
+  }
+  const Decl *getSingleDecl() const {
+    return const_cast<DeclGroupRef*>(this)->getSingleDecl();
+  }
+  
+  DeclGroup &getDeclGroup() {
+    assert(isDeclGroup() && "Isn't a declgroup");
+    return *((DeclGroup*)(reinterpret_cast<uintptr_t>(D) & ~Mask));
+  }
+  const DeclGroup &getDeclGroup() const {
+    return const_cast<DeclGroupRef*>(this)->getDeclGroup();
+  }
+  
+  iterator begin() {
+    if (isSingleDecl())
+      return D ? &D : 0;
+    return &getDeclGroup()[0];
+  }
+
+  iterator end() {
+    if (isSingleDecl())
+      return D ? &D+1 : 0;
+    DeclGroup &G = getDeclGroup();
+    return &G[0] + G.size();
+  }
+  
+  const_iterator begin() const {
+    if (isSingleDecl())
+      return D ? &D : 0;
+    return &getDeclGroup()[0];
+  }
+  
+  const_iterator end() const {
+    if (isSingleDecl())
+      return D ? &D+1 : 0;
+    const DeclGroup &G = getDeclGroup();
+    return &G[0] + G.size();
+  }
+
+  void *getAsOpaquePtr() const { return D; }
+  static DeclGroupRef getFromOpaquePtr(void *Ptr) {
+    DeclGroupRef X;
+    X.D = static_cast<Decl*>(Ptr);
+    return X;
+  }
+};
+  
+} // end clang namespace
+
+namespace llvm {
+  // DeclGroupRef is "like a pointer", implement PointerLikeTypeTraits.
+  template <typename T>
+  class PointerLikeTypeTraits;
+  template <>
+  class PointerLikeTypeTraits<clang::DeclGroupRef> {
+  public:
+    static inline void *getAsVoidPointer(clang::DeclGroupRef P) {
+      return P.getAsOpaquePtr();
+    }
+    static inline clang::DeclGroupRef getFromVoidPointer(void *P) {
+      return clang::DeclGroupRef::getFromOpaquePtr(P);
+    }
+    enum { NumLowBitsAvailable = 0 };
+  };
+}
+#endif