/3rd_party/llvm/include/llvm/ADT/PointerUnion.h
https://code.google.com/p/softart/ · C++ Header · 460 lines · 326 code · 49 blank · 85 comment · 13 complexity · fc2fa3fd44f400d393cc7a45e1be774f MD5 · raw file
- //===- llvm/ADT/PointerUnion.h - Discriminated Union of 2 Ptrs --*- 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 PointerUnion class, which is a discriminated union of
- // pointer types.
- //
- //===----------------------------------------------------------------------===//
- #ifndef LLVM_ADT_POINTERUNION_H
- #define LLVM_ADT_POINTERUNION_H
- #include "llvm/Support/Compiler.h"
- #include "llvm/ADT/PointerIntPair.h"
- namespace llvm {
- template <typename T>
- struct PointerUnionTypeSelectorReturn {
- typedef T Return;
- };
- /// \brief Get a type based on whether two types are the same or not. For:
- /// @code
- /// typedef typename PointerUnionTypeSelector<T1, T2, EQ, NE>::Return Ret;
- /// @endcode
- /// Ret will be EQ type if T1 is same as T2 or NE type otherwise.
- template <typename T1, typename T2, typename RET_EQ, typename RET_NE>
- struct PointerUnionTypeSelector {
- typedef typename PointerUnionTypeSelectorReturn<RET_NE>::Return Return;
- };
- template <typename T, typename RET_EQ, typename RET_NE>
- struct PointerUnionTypeSelector<T, T, RET_EQ, RET_NE> {
- typedef typename PointerUnionTypeSelectorReturn<RET_EQ>::Return Return;
- };
- template <typename T1, typename T2, typename RET_EQ, typename RET_NE>
- struct PointerUnionTypeSelectorReturn<
- PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE> > {
- typedef typename PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE>::Return
- Return;
- };
- /// Provide PointerLikeTypeTraits for void* that is used by PointerUnion
- /// for the two template arguments.
- template <typename PT1, typename PT2>
- class PointerUnionUIntTraits {
- public:
- static inline void *getAsVoidPointer(void *P) { return P; }
- static inline void *getFromVoidPointer(void *P) { return P; }
- enum {
- PT1BitsAv = (int)(PointerLikeTypeTraits<PT1>::NumLowBitsAvailable),
- PT2BitsAv = (int)(PointerLikeTypeTraits<PT2>::NumLowBitsAvailable),
- NumLowBitsAvailable = PT1BitsAv < PT2BitsAv ? PT1BitsAv : PT2BitsAv
- };
- };
-
- /// PointerUnion - This implements a discriminated union of two pointer types,
- /// and keeps the discriminator bit-mangled into the low bits of the pointer.
- /// This allows the implementation to be extremely efficient in space, but
- /// permits a very natural and type-safe API.
- ///
- /// Common use patterns would be something like this:
- /// PointerUnion<int*, float*> P;
- /// P = (int*)0;
- /// printf("%d %d", P.is<int*>(), P.is<float*>()); // prints "1 0"
- /// X = P.get<int*>(); // ok.
- /// Y = P.get<float*>(); // runtime assertion failure.
- /// Z = P.get<double*>(); // compile time failure.
- /// P = (float*)0;
- /// Y = P.get<float*>(); // ok.
- /// X = P.get<int*>(); // runtime assertion failure.
- template <typename PT1, typename PT2>
- class PointerUnion {
- public:
- typedef PointerIntPair<void*, 1, bool,
- 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() {}
-
- PointerUnion(PT1 V) : Val(
- const_cast<void *>(PointerLikeTypeTraits<PT1>::getAsVoidPointer(V))) {
- }
- PointerUnion(PT2 V) : Val(
- const_cast<void *>(PointerLikeTypeTraits<PT2>::getAsVoidPointer(V)), 1) {
- }
-
- /// isNull - Return true if the pointer held in the union is null,
- /// regardless of which type it is.
- 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());
- }
- LLVM_EXPLICIT operator bool() const { return !isNull(); }
- /// is<T>() return true if the Union currently holds the type matching T.
- template<typename T>
- int is() const {
- 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;
- }
-
- /// get<T>() - Return the value of the specified pointer type. If the
- /// specified pointer type is incorrect, assert.
- template<typename T>
- T get() const {
- assert(is<T>() && "Invalid accessor called");
- return PointerLikeTypeTraits<T>::getFromVoidPointer(Val.getPointer());
- }
-
- /// dyn_cast<T>() - If the current value is of the specified pointer type,
- /// return it, otherwise return null.
- template<typename T>
- T dyn_cast() const {
- if (is<T>()) return get<T>();
- return T();
- }
- /// \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");
- return (PT1 *)Val.getAddrOfPointer();
- }
-
- /// Assignment operators - Allow assigning into this union from either
- /// pointer type, setting the discriminator to remember what it came from.
- const PointerUnion &operator=(const PT1 &RHS) {
- Val.initWithPointer(
- const_cast<void *>(PointerLikeTypeTraits<PT1>::getAsVoidPointer(RHS)));
- return *this;
- }
- const PointerUnion &operator=(const PT2 &RHS) {
- Val.setPointerAndInt(
- const_cast<void *>(PointerLikeTypeTraits<PT2>::getAsVoidPointer(RHS)),
- 1);
- return *this;
- }
-
- void *getOpaqueValue() const { return Val.getOpaqueValue(); }
- static inline PointerUnion getFromOpaqueValue(void *VP) {
- PointerUnion V;
- V.Val = ValTy::getFromOpaqueValue(VP);
- return V;
- }
- };
- template<typename PT1, typename PT2>
- static bool operator==(PointerUnion<PT1, PT2> lhs,
- PointerUnion<PT1, PT2> rhs) {
- return lhs.getOpaqueValue() == rhs.getOpaqueValue();
- }
- template<typename PT1, typename PT2>
- static bool operator!=(PointerUnion<PT1, PT2> lhs,
- PointerUnion<PT1, PT2> rhs) {
- return lhs.getOpaqueValue() != rhs.getOpaqueValue();
- }
- // Teach SmallPtrSet that PointerUnion is "basically a pointer", that has
- // # low bits available = min(PT1bits,PT2bits)-1.
- template<typename PT1, typename PT2>
- class PointerLikeTypeTraits<PointerUnion<PT1, PT2> > {
- public:
- static inline void *
- getAsVoidPointer(const PointerUnion<PT1, PT2> &P) {
- return P.getOpaqueValue();
- }
- static inline PointerUnion<PT1, PT2>
- getFromVoidPointer(void *P) {
- return PointerUnion<PT1, PT2>::getFromOpaqueValue(P);
- }
-
- // The number of bits available are the min of the two pointer types.
- enum {
- NumLowBitsAvailable =
- PointerLikeTypeTraits<typename PointerUnion<PT1,PT2>::ValTy>
- ::NumLowBitsAvailable
- };
- };
-
-
- /// PointerUnion3 - This is a pointer union of three pointer types. See
- /// documentation for PointerUnion for usage.
- template <typename PT1, typename PT2, typename PT3>
- class PointerUnion3 {
- public:
- typedef PointerUnion<PT1, PT2> InnerUnion;
- typedef PointerUnion<InnerUnion, PT3> ValTy;
- private:
- ValTy Val;
- struct IsInnerUnion {
- ValTy Val;
- IsInnerUnion(ValTy val) : Val(val) { }
- template<typename T>
- int is() const {
- return Val.template is<InnerUnion>() &&
- Val.template get<InnerUnion>().template is<T>();
- }
- template<typename T>
- T get() const {
- return Val.template get<InnerUnion>().template get<T>();
- }
- };
- struct IsPT3 {
- ValTy Val;
- IsPT3(ValTy val) : Val(val) { }
- template<typename T>
- int is() const {
- return Val.template is<T>();
- }
- template<typename T>
- T get() const {
- return Val.template get<T>();
- }
- };
- public:
- PointerUnion3() {}
-
- PointerUnion3(PT1 V) {
- Val = InnerUnion(V);
- }
- PointerUnion3(PT2 V) {
- Val = InnerUnion(V);
- }
- PointerUnion3(PT3 V) {
- Val = V;
- }
-
- /// isNull - Return true if the pointer held in the union is null,
- /// regardless of which type it is.
- bool isNull() const { return Val.isNull(); }
- LLVM_EXPLICIT operator bool() const { return !isNull(); }
-
- /// is<T>() return true if the Union currently holds the type matching T.
- template<typename T>
- int is() const {
- // If T is PT1/PT2 choose IsInnerUnion otherwise choose IsPT3.
- typedef typename
- ::llvm::PointerUnionTypeSelector<PT1, T, IsInnerUnion,
- ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3 >
- >::Return Ty;
- return Ty(Val).template is<T>();
- }
-
- /// get<T>() - Return the value of the specified pointer type. If the
- /// specified pointer type is incorrect, assert.
- template<typename T>
- T get() const {
- assert(is<T>() && "Invalid accessor called");
- // If T is PT1/PT2 choose IsInnerUnion otherwise choose IsPT3.
- typedef typename
- ::llvm::PointerUnionTypeSelector<PT1, T, IsInnerUnion,
- ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3 >
- >::Return Ty;
- return Ty(Val).template get<T>();
- }
-
- /// dyn_cast<T>() - If the current value is of the specified pointer type,
- /// return it, otherwise return null.
- template<typename T>
- T dyn_cast() const {
- if (is<T>()) return get<T>();
- return T();
- }
-
- /// Assignment operators - Allow assigning into this union from either
- /// pointer type, setting the discriminator to remember what it came from.
- const PointerUnion3 &operator=(const PT1 &RHS) {
- Val = InnerUnion(RHS);
- return *this;
- }
- const PointerUnion3 &operator=(const PT2 &RHS) {
- Val = InnerUnion(RHS);
- return *this;
- }
- const PointerUnion3 &operator=(const PT3 &RHS) {
- Val = RHS;
- return *this;
- }
-
- void *getOpaqueValue() const { return Val.getOpaqueValue(); }
- static inline PointerUnion3 getFromOpaqueValue(void *VP) {
- PointerUnion3 V;
- V.Val = ValTy::getFromOpaqueValue(VP);
- return V;
- }
- };
-
- // Teach SmallPtrSet that PointerUnion3 is "basically a pointer", that has
- // # low bits available = min(PT1bits,PT2bits,PT2bits)-2.
- template<typename PT1, typename PT2, typename PT3>
- class PointerLikeTypeTraits<PointerUnion3<PT1, PT2, PT3> > {
- public:
- static inline void *
- getAsVoidPointer(const PointerUnion3<PT1, PT2, PT3> &P) {
- return P.getOpaqueValue();
- }
- static inline PointerUnion3<PT1, PT2, PT3>
- getFromVoidPointer(void *P) {
- return PointerUnion3<PT1, PT2, PT3>::getFromOpaqueValue(P);
- }
-
- // The number of bits available are the min of the two pointer types.
- enum {
- NumLowBitsAvailable =
- PointerLikeTypeTraits<typename PointerUnion3<PT1, PT2, PT3>::ValTy>
- ::NumLowBitsAvailable
- };
- };
- /// PointerUnion4 - This is a pointer union of four pointer types. See
- /// documentation for PointerUnion for usage.
- template <typename PT1, typename PT2, typename PT3, typename PT4>
- class PointerUnion4 {
- public:
- typedef PointerUnion<PT1, PT2> InnerUnion1;
- typedef PointerUnion<PT3, PT4> InnerUnion2;
- typedef PointerUnion<InnerUnion1, InnerUnion2> ValTy;
- private:
- ValTy Val;
- public:
- PointerUnion4() {}
-
- PointerUnion4(PT1 V) {
- Val = InnerUnion1(V);
- }
- PointerUnion4(PT2 V) {
- Val = InnerUnion1(V);
- }
- PointerUnion4(PT3 V) {
- Val = InnerUnion2(V);
- }
- PointerUnion4(PT4 V) {
- Val = InnerUnion2(V);
- }
-
- /// isNull - Return true if the pointer held in the union is null,
- /// regardless of which type it is.
- bool isNull() const { return Val.isNull(); }
- LLVM_EXPLICIT operator bool() const { return !isNull(); }
-
- /// is<T>() return true if the Union currently holds the type matching T.
- template<typename T>
- int is() const {
- // If T is PT1/PT2 choose InnerUnion1 otherwise choose InnerUnion2.
- typedef typename
- ::llvm::PointerUnionTypeSelector<PT1, T, InnerUnion1,
- ::llvm::PointerUnionTypeSelector<PT2, T, InnerUnion1, InnerUnion2 >
- >::Return Ty;
- return Val.template is<Ty>() &&
- Val.template get<Ty>().template is<T>();
- }
-
- /// get<T>() - Return the value of the specified pointer type. If the
- /// specified pointer type is incorrect, assert.
- template<typename T>
- T get() const {
- assert(is<T>() && "Invalid accessor called");
- // If T is PT1/PT2 choose InnerUnion1 otherwise choose InnerUnion2.
- typedef typename
- ::llvm::PointerUnionTypeSelector<PT1, T, InnerUnion1,
- ::llvm::PointerUnionTypeSelector<PT2, T, InnerUnion1, InnerUnion2 >
- >::Return Ty;
- return Val.template get<Ty>().template get<T>();
- }
-
- /// dyn_cast<T>() - If the current value is of the specified pointer type,
- /// return it, otherwise return null.
- template<typename T>
- T dyn_cast() const {
- if (is<T>()) return get<T>();
- return T();
- }
-
- /// Assignment operators - Allow assigning into this union from either
- /// pointer type, setting the discriminator to remember what it came from.
- const PointerUnion4 &operator=(const PT1 &RHS) {
- Val = InnerUnion1(RHS);
- return *this;
- }
- const PointerUnion4 &operator=(const PT2 &RHS) {
- Val = InnerUnion1(RHS);
- return *this;
- }
- const PointerUnion4 &operator=(const PT3 &RHS) {
- Val = InnerUnion2(RHS);
- return *this;
- }
- const PointerUnion4 &operator=(const PT4 &RHS) {
- Val = InnerUnion2(RHS);
- return *this;
- }
-
- void *getOpaqueValue() const { return Val.getOpaqueValue(); }
- static inline PointerUnion4 getFromOpaqueValue(void *VP) {
- PointerUnion4 V;
- V.Val = ValTy::getFromOpaqueValue(VP);
- return V;
- }
- };
-
- // Teach SmallPtrSet that PointerUnion4 is "basically a pointer", that has
- // # low bits available = min(PT1bits,PT2bits,PT2bits)-2.
- template<typename PT1, typename PT2, typename PT3, typename PT4>
- class PointerLikeTypeTraits<PointerUnion4<PT1, PT2, PT3, PT4> > {
- public:
- static inline void *
- getAsVoidPointer(const PointerUnion4<PT1, PT2, PT3, PT4> &P) {
- return P.getOpaqueValue();
- }
- static inline PointerUnion4<PT1, PT2, PT3, PT4>
- getFromVoidPointer(void *P) {
- return PointerUnion4<PT1, PT2, PT3, PT4>::getFromOpaqueValue(P);
- }
-
- // The number of bits available are the min of the two pointer types.
- enum {
- NumLowBitsAvailable =
- PointerLikeTypeTraits<typename PointerUnion4<PT1, PT2, PT3, PT4>::ValTy>
- ::NumLowBitsAvailable
- };
- };
- }
- #endif