src/llvm/include/llvm/IR/PassManagerInternal.h

   1 //===- PassManager internal APIs and implementation details -----*- 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 /// \file
  10 ///
  11 /// This header provides internal APIs and implementation details used by the
  12 /// pass management interfaces exposed in PassManager.h. To understand more
  13 /// context of why these particular interfaces are needed, see that header
  14 /// file. None of these APIs should be used elsewhere.
  15 ///
  16 //===----------------------------------------------------------------------===//
  17
  18 #ifndef LLVM_IR_PASSMANAGERINTERNAL_H
  19 #define LLVM_IR_PASSMANAGERINTERNAL_H
  20
  21 #include "llvm/ADT/StringRef.h"
  22
  23 namespace llvm {
  24
  25 template <typename IRUnitT> class AnalysisManager;
  26 class PreservedAnalyses;
  27
  28 /// \brief Implementation details of the pass manager interfaces.
  29 namespace detail {
  30
  31 /// \brief Template for the abstract base class used to dispatch
  32 /// polymorphically over pass objects.
  33 template <typename IRUnitT> struct PassConcept {
  34   // Boiler plate necessary for the container of derived classes.
  35   virtual ~PassConcept() {}
  36
  37   /// \brief The polymorphic API which runs the pass over a given IR entity.
  38   ///
  39   /// Note that actual pass object can omit the analysis manager argument if
  40   /// desired. Also that the analysis manager may be null if there is no
  41   /// analysis manager in the pass pipeline.
  42   virtual PreservedAnalyses run(IRUnitT &IR, AnalysisManager<IRUnitT> *AM) = 0;
  43
  44   /// \brief Polymorphic method to access the name of a pass.
  45   virtual StringRef name() = 0;
  46 };
  47
  48 /// \brief SFINAE metafunction for computing whether \c PassT has a run method
  49 /// accepting an \c AnalysisManager<IRUnitT>.
  50 template <typename IRUnitT, typename PassT, typename ResultT>
  51 class PassRunAcceptsAnalysisManager {
  52   typedef char SmallType;
  53   struct BigType {
  54     char a, b;
  55   };
  56
  57   template <typename T, ResultT (T::*)(IRUnitT &, AnalysisManager<IRUnitT> *)>
  58   struct Checker;
  59
  60   template <typename T> static SmallType f(Checker<T, &T::run> *);
  61   template <typename T> static BigType f(...);
  62
  63 public:
  64   enum { Value = sizeof(f<PassT>(nullptr)) == sizeof(SmallType) };
  65 };
  66
  67 /// \brief A template wrapper used to implement the polymorphic API.
  68 ///
  69 /// Can be instantiated for any object which provides a \c run method accepting
  70 /// an \c IRUnitT. It requires the pass to be a copyable object. When the
  71 /// \c run method also accepts an \c AnalysisManager<IRUnitT>*, we pass it
  72 /// along.
  73 template <typename IRUnitT, typename PassT,
  74           typename PreservedAnalysesT = PreservedAnalyses,
  75           bool AcceptsAnalysisManager = PassRunAcceptsAnalysisManager<
  76               IRUnitT, PassT, PreservedAnalysesT>::Value>
  77 struct PassModel;
  78
  79 /// \brief Specialization of \c PassModel for passes that accept an analyis
  80 /// manager.
  81 template <typename IRUnitT, typename PassT, typename PreservedAnalysesT>
  82 struct PassModel<IRUnitT, PassT, PreservedAnalysesT, true>
  83     : PassConcept<IRUnitT> {
  84   explicit PassModel(PassT Pass) : Pass(std::move(Pass)) {}
  85   // We have to explicitly define all the special member functions because MSVC
  86   // refuses to generate them.
  87   PassModel(const PassModel &Arg) : Pass(Arg.Pass) {}
  88   PassModel(PassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
  89   friend void swap(PassModel &LHS, PassModel &RHS) {
  90     using std::swap;
  91     swap(LHS.Pass, RHS.Pass);
  92   }
  93   PassModel &operator=(PassModel RHS) {
  94     swap(*this, RHS);
  95     return *this;
  96   }
  97
  98   PreservedAnalysesT run(IRUnitT &IR, AnalysisManager<IRUnitT> *AM) override {
  99     return Pass.run(IR, AM);
 100   }
 101   StringRef name() override { return PassT::name(); }
 102   PassT Pass;
 103 };
 104
 105 /// \brief Specialization of \c PassModel for passes that accept an analyis
 106 /// manager.
 107 template <typename IRUnitT, typename PassT, typename PreservedAnalysesT>
 108 struct PassModel<IRUnitT, PassT, PreservedAnalysesT, false>
 109     : PassConcept<IRUnitT> {
 110   explicit PassModel(PassT Pass) : Pass(std::move(Pass)) {}
 111   // We have to explicitly define all the special member functions because MSVC
 112   // refuses to generate them.
 113   PassModel(const PassModel &Arg) : Pass(Arg.Pass) {}
 114   PassModel(PassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
 115   friend void swap(PassModel &LHS, PassModel &RHS) {
 116     using std::swap;
 117     swap(LHS.Pass, RHS.Pass);
 118   }
 119   PassModel &operator=(PassModel RHS) {
 120     swap(*this, RHS);
 121     return *this;
 122   }
 123
 124   PreservedAnalysesT run(IRUnitT &IR, AnalysisManager<IRUnitT> *AM) override {
 125     return Pass.run(IR);
 126   }
 127   StringRef name() override { return PassT::name(); }
 128   PassT Pass;
 129 };
 130
 131 /// \brief Abstract concept of an analysis result.
 132 ///
 133 /// This concept is parameterized over the IR unit that this result pertains
 134 /// to.
 135 template <typename IRUnitT> struct AnalysisResultConcept {
 136   virtual ~AnalysisResultConcept() {}
 137
 138   /// \brief Method to try and mark a result as invalid.
 139   ///
 140   /// When the outer analysis manager detects a change in some underlying
 141   /// unit of the IR, it will call this method on all of the results cached.
 142   ///
 143   /// This method also receives a set of preserved analyses which can be used
 144   /// to avoid invalidation because the pass which changed the underlying IR
 145   /// took care to update or preserve the analysis result in some way.
 146   ///
 147   /// \returns true if the result is indeed invalid (the default).
 148   virtual bool invalidate(IRUnitT &IR, const PreservedAnalyses &PA) = 0;
 149 };
 150
 151 /// \brief SFINAE metafunction for computing whether \c ResultT provides an
 152 /// \c invalidate member function.
 153 template <typename IRUnitT, typename ResultT> class ResultHasInvalidateMethod {
 154   typedef char SmallType;
 155   struct BigType {
 156     char a, b;
 157   };
 158
 159   template <typename T, bool (T::*)(IRUnitT &, const PreservedAnalyses &)>
 160   struct Checker;
 161
 162   template <typename T> static SmallType f(Checker<T, &T::invalidate> *);
 163   template <typename T> static BigType f(...);
 164
 165 public:
 166   enum { Value = sizeof(f<ResultT>(nullptr)) == sizeof(SmallType) };
 167 };
 168
 169 /// \brief Wrapper to model the analysis result concept.
 170 ///
 171 /// By default, this will implement the invalidate method with a trivial
 172 /// implementation so that the actual analysis result doesn't need to provide
 173 /// an invalidation handler. It is only selected when the invalidation handler
 174 /// is not part of the ResultT's interface.
 175 template <typename IRUnitT, typename PassT, typename ResultT,
 176           typename PreservedAnalysesT = PreservedAnalyses,
 177           bool HasInvalidateHandler =
 178               ResultHasInvalidateMethod<IRUnitT, ResultT>::Value>
 179 struct AnalysisResultModel;
 180
 181 /// \brief Specialization of \c AnalysisResultModel which provides the default
 182 /// invalidate functionality.
 183 template <typename IRUnitT, typename PassT, typename ResultT,
 184           typename PreservedAnalysesT>
 185 struct AnalysisResultModel<IRUnitT, PassT, ResultT, PreservedAnalysesT, false>
 186     : AnalysisResultConcept<IRUnitT> {
 187   explicit AnalysisResultModel(ResultT Result) : Result(std::move(Result)) {}
 188   // We have to explicitly define all the special member functions because MSVC
 189   // refuses to generate them.
 190   AnalysisResultModel(const AnalysisResultModel &Arg) : Result(Arg.Result) {}
 191   AnalysisResultModel(AnalysisResultModel &&Arg)
 192       : Result(std::move(Arg.Result)) {}
 193   friend void swap(AnalysisResultModel &LHS, AnalysisResultModel &RHS) {
 194     using std::swap;
 195     swap(LHS.Result, RHS.Result);
 196   }
 197   AnalysisResultModel &operator=(AnalysisResultModel RHS) {
 198     swap(*this, RHS);
 199     return *this;
 200   }
 201
 202   /// \brief The model bases invalidation solely on being in the preserved set.
 203   //
 204   // FIXME: We should actually use two different concepts for analysis results
 205   // rather than two different models, and avoid the indirect function call for
 206   // ones that use the trivial behavior.
 207   bool invalidate(IRUnitT &, const PreservedAnalysesT &PA) override {
 208     return !PA.preserved(PassT::ID());
 209   }
 210
 211   ResultT Result;
 212 };
 213
 214 /// \brief Specialization of \c AnalysisResultModel which delegates invalidate
 215 /// handling to \c ResultT.
 216 template <typename IRUnitT, typename PassT, typename ResultT,
 217           typename PreservedAnalysesT>
 218 struct AnalysisResultModel<IRUnitT, PassT, ResultT, PreservedAnalysesT, true>
 219     : AnalysisResultConcept<IRUnitT> {
 220   explicit AnalysisResultModel(ResultT Result) : Result(std::move(Result)) {}
 221   // We have to explicitly define all the special member functions because MSVC
 222   // refuses to generate them.
 223   AnalysisResultModel(const AnalysisResultModel &Arg) : Result(Arg.Result) {}
 224   AnalysisResultModel(AnalysisResultModel &&Arg)
 225       : Result(std::move(Arg.Result)) {}
 226   friend void swap(AnalysisResultModel &LHS, AnalysisResultModel &RHS) {
 227     using std::swap;
 228     swap(LHS.Result, RHS.Result);
 229   }
 230   AnalysisResultModel &operator=(AnalysisResultModel RHS) {
 231     swap(*this, RHS);
 232     return *this;
 233   }
 234
 235   /// \brief The model delegates to the \c ResultT method.
 236   bool invalidate(IRUnitT &IR, const PreservedAnalysesT &PA) override {
 237     return Result.invalidate(IR, PA);
 238   }
 239
 240   ResultT Result;
 241 };
 242
 243 /// \brief Abstract concept of an analysis pass.
 244 ///
 245 /// This concept is parameterized over the IR unit that it can run over and
 246 /// produce an analysis result.
 247 template <typename IRUnitT> struct AnalysisPassConcept {
 248   virtual ~AnalysisPassConcept() {}
 249
 250   /// \brief Method to run this analysis over a unit of IR.
 251   /// \returns A unique_ptr to the analysis result object to be queried by
 252   /// users.
 253   virtual std::unique_ptr<AnalysisResultConcept<IRUnitT>>
 254   run(IRUnitT &IR, AnalysisManager<IRUnitT> *AM) = 0;
 255
 256   /// \brief Polymorphic method to access the name of a pass.
 257   virtual StringRef name() = 0;
 258 };
 259
 260 /// \brief Wrapper to model the analysis pass concept.
 261 ///
 262 /// Can wrap any type which implements a suitable \c run method. The method
 263 /// must accept the IRUnitT as an argument and produce an object which can be
 264 /// wrapped in a \c AnalysisResultModel.
 265 template <typename IRUnitT, typename PassT,
 266           bool AcceptsAnalysisManager = PassRunAcceptsAnalysisManager<
 267               IRUnitT, PassT, typename PassT::Result>::Value>
 268 struct AnalysisPassModel;
 269
 270 /// \brief Specialization of \c AnalysisPassModel which passes an
 271 /// \c AnalysisManager to PassT's run method.
 272 template <typename IRUnitT, typename PassT>
 273 struct AnalysisPassModel<IRUnitT, PassT, true> : AnalysisPassConcept<IRUnitT> {
 274   explicit AnalysisPassModel(PassT Pass) : Pass(std::move(Pass)) {}
 275   // We have to explicitly define all the special member functions because MSVC
 276   // refuses to generate them.
 277   AnalysisPassModel(const AnalysisPassModel &Arg) : Pass(Arg.Pass) {}
 278   AnalysisPassModel(AnalysisPassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
 279   friend void swap(AnalysisPassModel &LHS, AnalysisPassModel &RHS) {
 280     using std::swap;
 281     swap(LHS.Pass, RHS.Pass);
 282   }
 283   AnalysisPassModel &operator=(AnalysisPassModel RHS) {
 284     swap(*this, RHS);
 285     return *this;
 286   }
 287
 288   // FIXME: Replace PassT::Result with type traits when we use C++11.
 289   typedef AnalysisResultModel<IRUnitT, PassT, typename PassT::Result>
 290       ResultModelT;
 291
 292   /// \brief The model delegates to the \c PassT::run method.
 293   ///
 294   /// The return is wrapped in an \c AnalysisResultModel.
 295   std::unique_ptr<AnalysisResultConcept<IRUnitT>>
 296   run(IRUnitT &IR, AnalysisManager<IRUnitT> *AM) override {
 297     return make_unique<ResultModelT>(Pass.run(IR, AM));
 298   }
 299
 300   /// \brief The model delegates to a static \c PassT::name method.
 301   ///
 302   /// The returned string ref must point to constant immutable data!
 303   StringRef name() override { return PassT::name(); }
 304
 305   PassT Pass;
 306 };
 307
 308 /// \brief Specialization of \c AnalysisPassModel which does not pass an
 309 /// \c AnalysisManager to PassT's run method.
 310 template <typename IRUnitT, typename PassT>
 311 struct AnalysisPassModel<IRUnitT, PassT, false> : AnalysisPassConcept<IRUnitT> {
 312   explicit AnalysisPassModel(PassT Pass) : Pass(std::move(Pass)) {}
 313   // We have to explicitly define all the special member functions because MSVC
 314   // refuses to generate them.
 315   AnalysisPassModel(const AnalysisPassModel &Arg) : Pass(Arg.Pass) {}
 316   AnalysisPassModel(AnalysisPassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
 317   friend void swap(AnalysisPassModel &LHS, AnalysisPassModel &RHS) {
 318     using std::swap;
 319     swap(LHS.Pass, RHS.Pass);
 320   }
 321   AnalysisPassModel &operator=(AnalysisPassModel RHS) {
 322     swap(*this, RHS);
 323     return *this;
 324   }
 325
 326   // FIXME: Replace PassT::Result with type traits when we use C++11.
 327   typedef AnalysisResultModel<IRUnitT, PassT, typename PassT::Result>
 328       ResultModelT;
 329
 330   /// \brief The model delegates to the \c PassT::run method.
 331   ///
 332   /// The return is wrapped in an \c AnalysisResultModel.
 333   std::unique_ptr<AnalysisResultConcept<IRUnitT>>
 334   run(IRUnitT &IR, AnalysisManager<IRUnitT> *) override {
 335     return make_unique<ResultModelT>(Pass.run(IR));
 336   }
 337
 338   /// \brief The model delegates to a static \c PassT::name method.
 339   ///
 340   /// The returned string ref must point to constant immutable data!
 341   StringRef name() override { return PassT::name(); }
 342
 343   PassT Pass;
 344 };
 345
 346 } // End namespace detail
 347 }
 348
 349 #endif