LCOV - code coverage report
Current view: top level - include/llvm/ADT - PointerUnion.h (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 72 72 100.0 %
Date: 2017-09-14 15:23:50 Functions: 1 1 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : //===- llvm/ADT/PointerUnion.h - Discriminated Union of 2 Ptrs --*- C++ -*-===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : // This file defines the PointerUnion class, which is a discriminated union of
      11             : // pointer types.
      12             : //
      13             : //===----------------------------------------------------------------------===//
      14             : 
      15             : #ifndef LLVM_ADT_POINTERUNION_H
      16             : #define LLVM_ADT_POINTERUNION_H
      17             : 
      18             : #include "llvm/ADT/DenseMapInfo.h"
      19             : #include "llvm/ADT/PointerIntPair.h"
      20             : #include "llvm/Support/PointerLikeTypeTraits.h"
      21             : #include <cassert>
      22             : #include <cstddef>
      23             : #include <cstdint>
      24             : 
      25             : namespace llvm {
      26             : 
      27             : template <typename T> struct PointerUnionTypeSelectorReturn {
      28             :   typedef T Return;
      29             : };
      30             : 
      31             : /// Get a type based on whether two types are the same or not.
      32             : ///
      33             : /// For:
      34             : ///
      35             : /// \code
      36             : ///   typedef typename PointerUnionTypeSelector<T1, T2, EQ, NE>::Return Ret;
      37             : /// \endcode
      38             : ///
      39             : /// Ret will be EQ type if T1 is same as T2 or NE type otherwise.
      40             : template <typename T1, typename T2, typename RET_EQ, typename RET_NE>
      41             : struct PointerUnionTypeSelector {
      42             :   typedef typename PointerUnionTypeSelectorReturn<RET_NE>::Return Return;
      43             : };
      44             : 
      45             : template <typename T, typename RET_EQ, typename RET_NE>
      46             : struct PointerUnionTypeSelector<T, T, RET_EQ, RET_NE> {
      47             :   typedef typename PointerUnionTypeSelectorReturn<RET_EQ>::Return Return;
      48             : };
      49             : 
      50             : template <typename T1, typename T2, typename RET_EQ, typename RET_NE>
      51             : struct PointerUnionTypeSelectorReturn<
      52             :     PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE>> {
      53             :   typedef
      54             :       typename PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE>::Return Return;
      55             : };
      56             : 
      57             : /// Provide PointerLikeTypeTraits for void* that is used by PointerUnion
      58             : /// for the two template arguments.
      59             : template <typename PT1, typename PT2> class PointerUnionUIntTraits {
      60             : public:
      61             :   static inline void *getAsVoidPointer(void *P) { return P; }
      62             :   static inline void *getFromVoidPointer(void *P) { return P; }
      63             : 
      64             :   enum {
      65             :     PT1BitsAv = (int)(PointerLikeTypeTraits<PT1>::NumLowBitsAvailable),
      66             :     PT2BitsAv = (int)(PointerLikeTypeTraits<PT2>::NumLowBitsAvailable),
      67             :     NumLowBitsAvailable = PT1BitsAv < PT2BitsAv ? PT1BitsAv : PT2BitsAv
      68             :   };
      69             : };
      70             : 
      71             : /// A discriminated union of two pointer types, with the discriminator in the
      72             : /// low bit of the pointer.
      73             : ///
      74             : /// This implementation is extremely efficient in space due to leveraging the
      75             : /// low bits of the pointer, while exposing a natural and type-safe API.
      76             : ///
      77             : /// Common use patterns would be something like this:
      78             : ///    PointerUnion<int*, float*> P;
      79             : ///    P = (int*)0;
      80             : ///    printf("%d %d", P.is<int*>(), P.is<float*>());  // prints "1 0"
      81             : ///    X = P.get<int*>();     // ok.
      82             : ///    Y = P.get<float*>();   // runtime assertion failure.
      83             : ///    Z = P.get<double*>();  // compile time failure.
      84             : ///    P = (float*)0;
      85             : ///    Y = P.get<float*>();   // ok.
      86             : ///    X = P.get<int*>();     // runtime assertion failure.
      87             : template <typename PT1, typename PT2> class PointerUnion {
      88             : public:
      89             :   typedef PointerIntPair<void *, 1, bool, PointerUnionUIntTraits<PT1, PT2>>
      90             :       ValTy;
      91             : 
      92             : private:
      93             :   ValTy Val;
      94             : 
      95             :   struct IsPT1 {
      96             :     static const int Num = 0;
      97             :   };
      98             :   struct IsPT2 {
      99             :     static const int Num = 1;
     100             :   };
     101             :   template <typename T> struct UNION_DOESNT_CONTAIN_TYPE {};
     102             : 
     103             : public:
     104  1675486163 :   PointerUnion() = default;
     105             : 
     106             :   PointerUnion(PT1 V)
     107             :       : Val(const_cast<void *>(
     108   698194958 :             PointerLikeTypeTraits<PT1>::getAsVoidPointer(V))) {}
     109             :   PointerUnion(PT2 V)
     110     9237815 :       : Val(const_cast<void *>(PointerLikeTypeTraits<PT2>::getAsVoidPointer(V)),
     111   224946802 :             1) {}
     112             : 
     113             :   /// Test if the pointer held in the union is null, regardless of
     114             :   /// which type it is.
     115             :   bool isNull() const {
     116             :     // Convert from the void* to one of the pointer types, to make sure that
     117             :     // we recursively strip off low bits if we have a nested PointerUnion.
     118   598007641 :     return !PointerLikeTypeTraits<PT1>::getFromVoidPointer(Val.getPointer());
     119             :   }
     120    16458774 :   explicit operator bool() const { return !isNull(); }
     121             : 
     122             :   /// Test if the Union currently holds the type matching T.
     123             :   template <typename T> int is() const {
     124             :     typedef typename ::llvm::PointerUnionTypeSelector<
     125             :         PT1, T, IsPT1, ::llvm::PointerUnionTypeSelector<
     126             :                            PT2, T, IsPT2, UNION_DOESNT_CONTAIN_TYPE<T>>>::Return
     127             :         Ty;
     128  1673619493 :     int TyNo = Ty::Num;
     129  3347238986 :     return static_cast<int>(Val.getInt()) == TyNo;
     130             :   }
     131             : 
     132             :   /// Returns the value of the specified pointer type.
     133             :   ///
     134             :   /// If the specified pointer type is incorrect, assert.
     135             :   template <typename T> T get() const {
     136             :     assert(is<T>() && "Invalid accessor called");
     137  2847623225 :     return PointerLikeTypeTraits<T>::getFromVoidPointer(Val.getPointer());
     138             :   }
     139             : 
     140             :   /// Returns the current pointer if it is of the specified pointer type,
     141             :   /// otherwises returns null.
     142             :   template <typename T> T dyn_cast() const {
     143   386468212 :     if (is<T>())
     144   157425809 :       return get<T>();
     145             :     return T();
     146             :   }
     147             : 
     148             :   /// If the union is set to the first pointer type get an address pointing to
     149             :   /// it.
     150             :   PT1 const *getAddrOfPtr1() const {
     151     8860111 :     return const_cast<PointerUnion *>(this)->getAddrOfPtr1();
     152             :   }
     153             : 
     154             :   /// If the union is set to the first pointer type get an address pointing to
     155             :   /// it.
     156             :   PT1 *getAddrOfPtr1() {
     157             :     assert(is<PT1>() && "Val is not the first pointer");
     158             :     assert(
     159             :         get<PT1>() == Val.getPointer() &&
     160             :         "Can't get the address because PointerLikeTypeTraits changes the ptr");
     161    16523979 :     return const_cast<PT1 *>(reinterpret_cast<const PT1 *>(Val.getAddrOfPointer()));
     162             :   }
     163             : 
     164             :   /// Assignment from nullptr which just clears the union.
     165             :   const PointerUnion &operator=(std::nullptr_t) {
     166        2574 :     Val.initWithPointer(nullptr);
     167             :     return *this;
     168             :   }
     169             : 
     170             :   /// Assignment operators - Allow assigning into this union from either
     171             :   /// pointer type, setting the discriminator to remember what it came from.
     172             :   const PointerUnion &operator=(const PT1 &RHS) {
     173   182857927 :     Val.initWithPointer(
     174     5971622 :         const_cast<void *>(PointerLikeTypeTraits<PT1>::getAsVoidPointer(RHS)));
     175             :     return *this;
     176             :   }
     177             :   const PointerUnion &operator=(const PT2 &RHS) {
     178   141262597 :     Val.setPointerAndInt(
     179      101282 :         const_cast<void *>(PointerLikeTypeTraits<PT2>::getAsVoidPointer(RHS)),
     180             :         1);
     181             :     return *this;
     182             :   }
     183             : 
     184   224408242 :   void *getOpaqueValue() const { return Val.getOpaqueValue(); }
     185             :   static inline PointerUnion getFromOpaqueValue(void *VP) {
     186   748932613 :     PointerUnion V;
     187   748932613 :     V.Val = ValTy::getFromOpaqueValue(VP);
     188             :     return V;
     189             :   }
     190             : };
     191             : 
     192             : template <typename PT1, typename PT2>
     193             : bool operator==(PointerUnion<PT1, PT2> lhs, PointerUnion<PT1, PT2> rhs) {
     194      735164 :   return lhs.getOpaqueValue() == rhs.getOpaqueValue();
     195             : }
     196             : 
     197             : template <typename PT1, typename PT2>
     198             : bool operator!=(PointerUnion<PT1, PT2> lhs, PointerUnion<PT1, PT2> rhs) {
     199        7148 :   return lhs.getOpaqueValue() != rhs.getOpaqueValue();
     200             : }
     201             : 
     202             : template <typename PT1, typename PT2>
     203             : bool operator<(PointerUnion<PT1, PT2> lhs, PointerUnion<PT1, PT2> rhs) {
     204        2390 :   return lhs.getOpaqueValue() < rhs.getOpaqueValue();
     205             : }
     206             : 
     207             : // Teach SmallPtrSet that PointerUnion is "basically a pointer", that has
     208             : // # low bits available = min(PT1bits,PT2bits)-1.
     209             : template <typename PT1, typename PT2>
     210             : struct PointerLikeTypeTraits<PointerUnion<PT1, PT2>> {
     211             :   static inline void *getAsVoidPointer(const PointerUnion<PT1, PT2> &P) {
     212   199489251 :     return P.getOpaqueValue();
     213             :   }
     214             : 
     215             :   static inline PointerUnion<PT1, PT2> getFromVoidPointer(void *P) {
     216   648589677 :     return PointerUnion<PT1, PT2>::getFromOpaqueValue(P);
     217             :   }
     218             : 
     219             :   // The number of bits available are the min of the two pointer types.
     220             :   enum {
     221             :     NumLowBitsAvailable = PointerLikeTypeTraits<
     222             :         typename PointerUnion<PT1, PT2>::ValTy>::NumLowBitsAvailable
     223             :   };
     224             : };
     225             : 
     226             : /// A pointer union of three pointer types. See documentation for PointerUnion
     227             : /// for usage.
     228             : template <typename PT1, typename PT2, typename PT3> class PointerUnion3 {
     229             : public:
     230             :   typedef PointerUnion<PT1, PT2> InnerUnion;
     231             :   typedef PointerUnion<InnerUnion, PT3> ValTy;
     232             : 
     233             : private:
     234             :   ValTy Val;
     235             : 
     236             :   struct IsInnerUnion {
     237             :     ValTy Val;
     238             :     IsInnerUnion(ValTy val) : Val(val) {}
     239             :     template <typename T> int is() const {
     240     9458770 :       return Val.template is<InnerUnion>() &&
     241     6298480 :              Val.template get<InnerUnion>().template is<T>();
     242             :     }
     243             :     template <typename T> T get() const {
     244     5680002 :       return Val.template get<InnerUnion>().template get<T>();
     245             :     }
     246             :   };
     247             : 
     248             :   struct IsPT3 {
     249             :     ValTy Val;
     250             :     IsPT3(ValTy val) : Val(val) {}
     251     2747232 :     template <typename T> int is() const { return Val.template is<T>(); }
     252        4112 :     template <typename T> T get() const { return Val.template get<T>(); }
     253             :   };
     254             : 
     255             : public:
     256     2073814 :   PointerUnion3() = default;
     257             : 
     258     7965248 :   PointerUnion3(PT1 V) { Val = InnerUnion(V); }
     259      734420 :   PointerUnion3(PT2 V) { Val = InnerUnion(V); }
     260        1620 :   PointerUnion3(PT3 V) { Val = V; }
     261             : 
     262             :   /// Test if the pointer held in the union is null, regardless of
     263             :   /// which type it is.
     264    17551478 :   bool isNull() const { return Val.isNull(); }
     265             :   explicit operator bool() const { return !isNull(); }
     266             : 
     267             :   /// Test if the Union currently holds the type matching T.
     268             :   template <typename T> int is() const {
     269             :     // If T is PT1/PT2 choose IsInnerUnion otherwise choose IsPT3.
     270             :     typedef typename ::llvm::PointerUnionTypeSelector<
     271             :         PT1, T, IsInnerUnion,
     272             :         ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3>>::Return
     273             :         Ty;
     274     6546780 :     return Ty(Val).template is<T>();
     275             :   }
     276             : 
     277             :   /// Returns the value of the specified pointer type.
     278             :   ///
     279             :   /// If the specified pointer type is incorrect, assert.
     280             :   template <typename T> T get() const {
     281             :     assert(is<T>() && "Invalid accessor called");
     282             :     // If T is PT1/PT2 choose IsInnerUnion otherwise choose IsPT3.
     283             :     typedef typename ::llvm::PointerUnionTypeSelector<
     284             :         PT1, T, IsInnerUnion,
     285             :         ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3>>::Return
     286             :         Ty;
     287     3790780 :     return Ty(Val).template get<T>();
     288             :   }
     289             : 
     290             :   /// Returns the current pointer if it is of the specified pointer type,
     291             :   /// otherwises returns null.
     292             :   template <typename T> T dyn_cast() const {
     293     1435228 :     if (is<T>())
     294      141740 :       return get<T>();
     295             :     return T();
     296             :   }
     297             : 
     298             :   /// Assignment from nullptr which just clears the union.
     299             :   const PointerUnion3 &operator=(std::nullptr_t) {
     300             :     Val = nullptr;
     301             :     return *this;
     302             :   }
     303             : 
     304             :   /// Assignment operators - Allow assigning into this union from either
     305             :   /// pointer type, setting the discriminator to remember what it came from.
     306             :   const PointerUnion3 &operator=(const PT1 &RHS) {
     307      995439 :     Val = InnerUnion(RHS);
     308             :     return *this;
     309             :   }
     310             :   const PointerUnion3 &operator=(const PT2 &RHS) {
     311        8775 :     Val = InnerUnion(RHS);
     312             :     return *this;
     313             :   }
     314             :   const PointerUnion3 &operator=(const PT3 &RHS) {
     315         260 :     Val = RHS;
     316             :     return *this;
     317             :   }
     318             : 
     319       46168 :   void *getOpaqueValue() const { return Val.getOpaqueValue(); }
     320             :   static inline PointerUnion3 getFromOpaqueValue(void *VP) {
     321         510 :     PointerUnion3 V;
     322         510 :     V.Val = ValTy::getFromOpaqueValue(VP);
     323             :     return V;
     324             :   }
     325             : };
     326             : 
     327             : // Teach SmallPtrSet that PointerUnion3 is "basically a pointer", that has
     328             : // # low bits available = min(PT1bits,PT2bits,PT2bits)-2.
     329             : template <typename PT1, typename PT2, typename PT3>
     330             : struct PointerLikeTypeTraits<PointerUnion3<PT1, PT2, PT3>> {
     331             :   static inline void *getAsVoidPointer(const PointerUnion3<PT1, PT2, PT3> &P) {
     332             :     return P.getOpaqueValue();
     333             :   }
     334             : 
     335             :   static inline PointerUnion3<PT1, PT2, PT3> getFromVoidPointer(void *P) {
     336             :     return PointerUnion3<PT1, PT2, PT3>::getFromOpaqueValue(P);
     337             :   }
     338             : 
     339             :   // The number of bits available are the min of the two pointer types.
     340             :   enum {
     341             :     NumLowBitsAvailable = PointerLikeTypeTraits<
     342             :         typename PointerUnion3<PT1, PT2, PT3>::ValTy>::NumLowBitsAvailable
     343             :   };
     344             : };
     345             : 
     346             : /// A pointer union of four pointer types. See documentation for PointerUnion
     347             : /// for usage.
     348             : template <typename PT1, typename PT2, typename PT3, typename PT4>
     349             : class PointerUnion4 {
     350             : public:
     351             :   typedef PointerUnion<PT1, PT2> InnerUnion1;
     352             :   typedef PointerUnion<PT3, PT4> InnerUnion2;
     353             :   typedef PointerUnion<InnerUnion1, InnerUnion2> ValTy;
     354             : 
     355             : private:
     356             :   ValTy Val;
     357             : 
     358             : public:
     359    32456944 :   PointerUnion4() = default;
     360             : 
     361    16298540 :   PointerUnion4(PT1 V) { Val = InnerUnion1(V); }
     362       73924 :   PointerUnion4(PT2 V) { Val = InnerUnion1(V); }
     363      220560 :   PointerUnion4(PT3 V) { Val = InnerUnion2(V); }
     364       72132 :   PointerUnion4(PT4 V) { Val = InnerUnion2(V); }
     365             : 
     366             :   /// Test if the pointer held in the union is null, regardless of
     367             :   /// which type it is.
     368     5276632 :   bool isNull() const { return Val.isNull(); }
     369             :   explicit operator bool() const { return !isNull(); }
     370             : 
     371             :   /// Test if the Union currently holds the type matching T.
     372             :   template <typename T> int is() const {
     373             :     // If T is PT1/PT2 choose InnerUnion1 otherwise choose InnerUnion2.
     374             :     typedef typename ::llvm::PointerUnionTypeSelector<
     375             :         PT1, T, InnerUnion1, ::llvm::PointerUnionTypeSelector<
     376             :                                  PT2, T, InnerUnion1, InnerUnion2>>::Return Ty;
     377   267514078 :     return Val.template is<Ty>() && Val.template get<Ty>().template is<T>();
     378             :   }
     379             : 
     380             :   /// Returns the value of the specified pointer type.
     381             :   ///
     382             :   /// If the specified pointer type is incorrect, assert.
     383             :   template <typename T> T get() const {
     384             :     assert(is<T>() && "Invalid accessor called");
     385             :     // If T is PT1/PT2 choose InnerUnion1 otherwise choose InnerUnion2.
     386             :     typedef typename ::llvm::PointerUnionTypeSelector<
     387             :         PT1, T, InnerUnion1, ::llvm::PointerUnionTypeSelector<
     388             :                                  PT2, T, InnerUnion1, InnerUnion2>>::Return Ty;
     389   120013662 :     return Val.template get<Ty>().template get<T>();
     390             :   }
     391             : 
     392             :   /// Returns the current pointer if it is of the specified pointer type,
     393             :   /// otherwises returns null.
     394             :   template <typename T> T dyn_cast() const {
     395    39968317 :     if (is<T>())
     396    39968317 :       return get<T>();
     397             :     return T();
     398             :   }
     399             : 
     400             :   /// Assignment from nullptr which just clears the union.
     401             :   const PointerUnion4 &operator=(std::nullptr_t) {
     402             :     Val = nullptr;
     403             :     return *this;
     404             :   }
     405             : 
     406             :   /// Assignment operators - Allow assigning into this union from either
     407             :   /// pointer type, setting the discriminator to remember what it came from.
     408             :   const PointerUnion4 &operator=(const PT1 &RHS) {
     409      634038 :     Val = InnerUnion1(RHS);
     410             :     return *this;
     411             :   }
     412             :   const PointerUnion4 &operator=(const PT2 &RHS) {
     413      851064 :     Val = InnerUnion1(RHS);
     414             :     return *this;
     415             :   }
     416             :   const PointerUnion4 &operator=(const PT3 &RHS) {
     417      251172 :     Val = InnerUnion2(RHS);
     418             :     return *this;
     419             :   }
     420             :   const PointerUnion4 &operator=(const PT4 &RHS) {
     421        4275 :     Val = InnerUnion2(RHS);
     422             :     return *this;
     423             :   }
     424             : 
     425    10052536 :   void *getOpaqueValue() const { return Val.getOpaqueValue(); }
     426             :   static inline PointerUnion4 getFromOpaqueValue(void *VP) {
     427     5605426 :     PointerUnion4 V;
     428     5605426 :     V.Val = ValTy::getFromOpaqueValue(VP);
     429             :     return V;
     430             :   }
     431             : };
     432             : 
     433             : // Teach SmallPtrSet that PointerUnion4 is "basically a pointer", that has
     434             : // # low bits available = min(PT1bits,PT2bits,PT2bits)-2.
     435             : template <typename PT1, typename PT2, typename PT3, typename PT4>
     436             : struct PointerLikeTypeTraits<PointerUnion4<PT1, PT2, PT3, PT4>> {
     437             :   static inline void *
     438             :   getAsVoidPointer(const PointerUnion4<PT1, PT2, PT3, PT4> &P) {
     439             :     return P.getOpaqueValue();
     440             :   }
     441             : 
     442             :   static inline PointerUnion4<PT1, PT2, PT3, PT4> getFromVoidPointer(void *P) {
     443             :     return PointerUnion4<PT1, PT2, PT3, PT4>::getFromOpaqueValue(P);
     444             :   }
     445             : 
     446             :   // The number of bits available are the min of the two pointer types.
     447             :   enum {
     448             :     NumLowBitsAvailable = PointerLikeTypeTraits<
     449             :         typename PointerUnion4<PT1, PT2, PT3, PT4>::ValTy>::NumLowBitsAvailable
     450             :   };
     451             : };
     452             : 
     453             : // Teach DenseMap how to use PointerUnions as keys.
     454             : template <typename T, typename U> struct DenseMapInfo<PointerUnion<T, U>> {
     455             :   typedef PointerUnion<T, U> Pair;
     456             :   typedef DenseMapInfo<T> FirstInfo;
     457             :   typedef DenseMapInfo<U> SecondInfo;
     458             : 
     459     9038734 :   static inline Pair getEmptyKey() { return Pair(FirstInfo::getEmptyKey()); }
     460             :   static inline Pair getTombstoneKey() {
     461     6926376 :     return Pair(FirstInfo::getTombstoneKey());
     462             :   }
     463             :   static unsigned getHashValue(const Pair &PairVal) {
     464     3447589 :     intptr_t key = (intptr_t)PairVal.getOpaqueValue();
     465     3447589 :     return DenseMapInfo<intptr_t>::getHashValue(key);
     466             :   }
     467    10688524 :   static bool isEqual(const Pair &LHS, const Pair &RHS) {
     468    42180074 :     return LHS.template is<T>() == RHS.template is<T>() &&
     469    31275718 :            (LHS.template is<T>() ? FirstInfo::isEqual(LHS.template get<T>(),
     470             :                                                       RHS.template get<T>())
     471      284716 :                                  : SecondInfo::isEqual(LHS.template get<U>(),
     472    10688524 :                                                        RHS.template get<U>()));
     473             :   }
     474             : };
     475             : 
     476             : } // end namespace llvm
     477             : 
     478             : #endif // LLVM_ADT_POINTERUNION_H

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