X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FADT%2FPointerUnion.h;h=a9e86d22002de7f1b5c57b3a039ad2c809d6439e;hb=2430973fb657eb84dfbacb1e8886d3a29190e0b5;hp=975ba8a5f5277c11ea7eb71f00f145daaaadc203;hpb=128ccbb8e5e142d4ec6c9afb4160b74f76cb3064;p=oota-llvm.git

diff --git a/include/llvm/ADT/PointerUnion.h b/include/llvm/ADT/PointerUnion.h
index 975ba8a5f52..a9e86d22002 100644
--- a/include/llvm/ADT/PointerUnion.h
+++ b/include/llvm/ADT/PointerUnion.h
@@ -19,29 +19,6 @@
 
 namespace llvm {
 
-  /// \brief Statically get an integer for a type. For:
-  /// @code
-  /// PointerUnionTypeNum<PT1, PT2>::template NumFor<T>::Result
-  /// @endcode
-  /// Result will be 0 if T is PT1, 1 if it is PT2, and -1 otherwise.
-  template <typename PT1, typename PT2>
-  struct PointerUnionTypeNum {
-  private:
-    struct IsNeither { char x; };
-    struct IsPT1 { char x[2]; };
-    struct IsPT2 { char x[3]; };
-
-    static IsPT1 determine(PT1 *P);
-    static IsPT2 determine(PT2 *P);
-    static IsNeither determine(...);
-
-  public:
-    template <typename T>
-    struct NumFor {
-      static const int Result = (int)sizeof(determine((T*)0)) - 2;
-    };
-  };
-
   template <typename T>
   struct PointerUnionTypeSelectorReturn {
     typedef T Return;
@@ -77,8 +54,8 @@ namespace llvm {
     static inline void *getAsVoidPointer(void *P) { return P; }
     static inline void *getFromVoidPointer(void *P) { return P; }
     enum {
-      PT1BitsAv = PointerLikeTypeTraits<PT1>::NumLowBitsAvailable,
-      PT2BitsAv = PointerLikeTypeTraits<PT2>::NumLowBitsAvailable,
+      PT1BitsAv = (int)(PointerLikeTypeTraits<PT1>::NumLowBitsAvailable),
+      PT2BitsAv = (int)(PointerLikeTypeTraits<PT2>::NumLowBitsAvailable),
       NumLowBitsAvailable = PT1BitsAv < PT2BitsAv ? PT1BitsAv : PT2BitsAv
     };
   };
@@ -105,6 +82,16 @@ namespace llvm {
                            PointerUnionUIntTraits<PT1,PT2> > ValTy;
   private:
     ValTy Val;
+
+    struct IsPT1 {
+      static const int Num = 0;
+    };
+    struct IsPT2 {
+      static const int Num = 1;
+    };
+    template <typename T>
+    struct UNION_DOESNT_CONTAIN_TYPE { };
+
   public:
     PointerUnion() {}
     
@@ -121,16 +108,21 @@ namespace llvm {
     
     /// isNull - Return true if the pointer held in the union is null,
     /// regardless of which type it is.
-    bool isNull() const { return Val.getPointer() == 0; }
+    bool isNull() const {
+      // Convert from the void* to one of the pointer types, to make sure that
+      // we recursively strip off low bits if we have a nested PointerUnion.
+      return !PointerLikeTypeTraits<PT1>::getFromVoidPointer(Val.getPointer());
+    }
     operator bool() const { return !isNull(); }
 
     /// is<T>() return true if the Union currently holds the type matching T.
     template<typename T>
     int is() const {
-      static const int TyNo =
-              ::llvm::PointerUnionTypeNum<PT1, PT2>::template NumFor<T>::Result;
-      char TYPE_IS_NOT_IN_UNION[TyNo*2+1]; // statically check the type.
-      (void)TYPE_IS_NOT_IN_UNION;
+      typedef typename
+        ::llvm::PointerUnionTypeSelector<PT1, T, IsPT1,
+          ::llvm::PointerUnionTypeSelector<PT2, T, IsPT2,
+                                    UNION_DOESNT_CONTAIN_TYPE<T> > >::Return Ty;
+      int TyNo = Ty::Num;
       return static_cast<int>(Val.getInt()) == TyNo;
     }
     
@@ -150,16 +142,19 @@ namespace llvm {
       return T();
     }
 
-    /// \brief If the union is set to the first pointer type we can get an
-    /// address pointing to it.
-    template <typename T>
-    PT1 const *getAddrOf() const {
+    /// \brief If the union is set to the first pointer type get an address
+    /// pointing to it.
+    PT1 const *getAddrOfPtr1() const {
+      return const_cast<PointerUnion *>(this)->getAddrOfPtr1();
+    }
+
+    /// \brief If the union is set to the first pointer type get an address
+    /// pointing to it.
+    PT1 *getAddrOfPtr1() {
       assert(is<PT1>() && "Val is not the first pointer");
       assert(get<PT1>() == Val.getPointer() &&
          "Can't get the address because PointerLikeTypeTraits changes the ptr");
-      T const *can_only_get_address_of_first_pointer_type
-                        = reinterpret_cast<PT1 const *>(Val.getAddrOfPointer());
-      return can_only_get_address_of_first_pointer_type;
+      return (PT1 *)Val.getAddrOfPointer();
     }
     
     /// Assignment operators - Allow assigning into this union from either
@@ -271,7 +266,7 @@ namespace llvm {
         ::llvm::PointerUnionTypeSelector<PT1, T, IsInnerUnion,
           ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3 >
                                                                    >::Return Ty;
-      return Ty(Val).is<T>();
+      return Ty(Val).template is<T>();
     }
     
     /// get<T>() - Return the value of the specified pointer type. If the
@@ -284,7 +279,7 @@ namespace llvm {
         ::llvm::PointerUnionTypeSelector<PT1, T, IsInnerUnion,
           ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3 >
                                                                    >::Return Ty;
-      return Ty(Val).get<T>();
+      return Ty(Val).template get<T>();
     }
     
     /// dyn_cast<T>() - If the current value is of the specified pointer type,