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;
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
};
};
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() {}
/// 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;
}
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
::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
::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,