[PM] Lift the majority of the template boilerplate used to implement the

concept-based polymorphism in the pass manager to a separate header.

I got feedback from someone reading the code and trying to use it that
this was really making it hard to dive in and start using these APIs and
that makes a lot of sense.

This only requires a moderate amount of gymnastics to separate in this
way, namely rinsing the PreservedAnalysis object through a template
argument in a few places so that it is dependent and we only examine it
on instantiation.

llvm-svn: 225094

2 files changed, 343 insertions, 306 deletions

diff --git a/llvm/include/llvm/IR/PassManager.h b/llvm/include/llvm/IR/PassManager.h
index 5627a202556..04cc530aed7 100644
--- a/llvm/include/llvm/IR/PassManager.h
+++ b/llvm/include/llvm/IR/PassManager.h
@@ -43,6 +43,7 @@
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/PassManagerInternals.h"
 #include "llvm/Support/type_traits.h"
 #include <list>
 #include <memory>
@@ -152,312 +153,6 @@ private:
   SmallPtrSet<void *, 2> PreservedPassIDs;
 };
 
-/// \brief Implementation details of the pass manager interfaces.
-namespace detail {
-
-/// \brief Template for the abstract base class used to dispatch
-/// polymorphically over pass objects.
-template <typename IRUnitT, typename AnalysisManagerT> struct PassConcept {
-  // Boiler plate necessary for the container of derived classes.
-  virtual ~PassConcept() {}
-
-  /// \brief The polymorphic API which runs the pass over a given IR entity.
-  ///
-  /// Note that actual pass object can omit the analysis manager argument if
-  /// desired. Also that the analysis manager may be null if there is no
-  /// analysis manager in the pass pipeline.
-  virtual PreservedAnalyses run(IRUnitT IR, AnalysisManagerT *AM) = 0;
-
-  /// \brief Polymorphic method to access the name of a pass.
-  virtual StringRef name() = 0;
-};
-
-/// \brief SFINAE metafunction for computing whether \c PassT has a run method
-/// accepting an \c AnalysisManagerT.
-template <typename IRUnitT, typename AnalysisManagerT, typename PassT,
-          typename ResultT>
-class PassRunAcceptsAnalysisManager {
-  typedef char SmallType;
-  struct BigType {
-    char a, b;
-  };
-
-  template <typename T, ResultT (T::*)(IRUnitT, AnalysisManagerT *)>
-  struct Checker;
-
-  template <typename T> static SmallType f(Checker<T, &T::run> *);
-  template <typename T> static BigType f(...);
-
-public:
-  enum { Value = sizeof(f<PassT>(nullptr)) == sizeof(SmallType) };
-};
-
-/// \brief A template wrapper used to implement the polymorphic API.
-///
-/// Can be instantiated for any object which provides a \c run method accepting
-/// an \c IRUnitT. It requires the pass to be a copyable object. When the
-/// \c run method also accepts an \c AnalysisManagerT*, we pass it along.
-template <typename IRUnitT, typename AnalysisManagerT, typename PassT,
-          bool AcceptsAnalysisManager = PassRunAcceptsAnalysisManager<
-              IRUnitT, AnalysisManagerT, PassT, PreservedAnalyses>::Value>
-struct PassModel;
-
-/// \brief Specialization of \c PassModel for passes that accept an analyis
-/// manager.
-template <typename IRUnitT, typename AnalysisManagerT, typename PassT>
-struct PassModel<IRUnitT, AnalysisManagerT, PassT, true>
-    : PassConcept<IRUnitT, AnalysisManagerT> {
-  explicit PassModel(PassT Pass) : Pass(std::move(Pass)) {}
-  // We have to explicitly define all the special member functions because MSVC
-  // refuses to generate them.
-  PassModel(const PassModel &Arg) : Pass(Arg.Pass) {}
-  PassModel(PassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
-  friend void swap(PassModel &LHS, PassModel &RHS) {
-    using std::swap;
-    swap(LHS.Pass, RHS.Pass);
-  }
-  PassModel &operator=(PassModel RHS) {
-    swap(*this, RHS);
-    return *this;
-  }
-
-  PreservedAnalyses run(IRUnitT IR, AnalysisManagerT *AM) override {
-    return Pass.run(IR, AM);
-  }
-  StringRef name() override { return PassT::name(); }
-  PassT Pass;
-};
-
-/// \brief Specialization of \c PassModel for passes that accept an analyis
-/// manager.
-template <typename IRUnitT, typename AnalysisManagerT, typename PassT>
-struct PassModel<IRUnitT, AnalysisManagerT, PassT, false>
-    : PassConcept<IRUnitT, AnalysisManagerT> {
-  explicit PassModel(PassT Pass) : Pass(std::move(Pass)) {}
-  // We have to explicitly define all the special member functions because MSVC
-  // refuses to generate them.
-  PassModel(const PassModel &Arg) : Pass(Arg.Pass) {}
-  PassModel(PassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
-  friend void swap(PassModel &LHS, PassModel &RHS) {
-    using std::swap;
-    swap(LHS.Pass, RHS.Pass);
-  }
-  PassModel &operator=(PassModel RHS) {
-    swap(*this, RHS);
-    return *this;
-  }
-
-  PreservedAnalyses run(IRUnitT IR, AnalysisManagerT *AM) override {
-    return Pass.run(IR);
-  }
-  StringRef name() override { return PassT::name(); }
-  PassT Pass;
-};
-
-/// \brief Abstract concept of an analysis result.
-///
-/// This concept is parameterized over the IR unit that this result pertains
-/// to.
-template <typename IRUnitT> struct AnalysisResultConcept {
-  virtual ~AnalysisResultConcept() {}
-
-  /// \brief Method to try and mark a result as invalid.
-  ///
-  /// When the outer analysis manager detects a change in some underlying
-  /// unit of the IR, it will call this method on all of the results cached.
-  ///
-  /// This method also receives a set of preserved analyses which can be used
-  /// to avoid invalidation because the pass which changed the underlying IR
-  /// took care to update or preserve the analysis result in some way.
-  ///
-  /// \returns true if the result is indeed invalid (the default).
-  virtual bool invalidate(IRUnitT IR, const PreservedAnalyses &PA) = 0;
-};
-
-/// \brief SFINAE metafunction for computing whether \c ResultT provides an
-/// \c invalidate member function.
-template <typename IRUnitT, typename ResultT> class ResultHasInvalidateMethod {
-  typedef char SmallType;
-  struct BigType {
-    char a, b;
-  };
-
-  template <typename T, bool (T::*)(IRUnitT, const PreservedAnalyses &)>
-  struct Checker;
-
-  template <typename T> static SmallType f(Checker<T, &T::invalidate> *);
-  template <typename T> static BigType f(...);
-
-public:
-  enum { Value = sizeof(f<ResultT>(nullptr)) == sizeof(SmallType) };
-};
-
-/// \brief Wrapper to model the analysis result concept.
-///
-/// By default, this will implement the invalidate method with a trivial
-/// implementation so that the actual analysis result doesn't need to provide
-/// an invalidation handler. It is only selected when the invalidation handler
-/// is not part of the ResultT's interface.
-template <typename IRUnitT, typename PassT, typename ResultT,
-          bool HasInvalidateHandler =
-              ResultHasInvalidateMethod<IRUnitT, ResultT>::Value>
-struct AnalysisResultModel;
-
-/// \brief Specialization of \c AnalysisResultModel which provides the default
-/// invalidate functionality.
-template <typename IRUnitT, typename PassT, typename ResultT>
-struct AnalysisResultModel<IRUnitT, PassT, ResultT, false>
-    : AnalysisResultConcept<IRUnitT> {
-  explicit AnalysisResultModel(ResultT Result) : Result(std::move(Result)) {}
-  // We have to explicitly define all the special member functions because MSVC
-  // refuses to generate them.
-  AnalysisResultModel(const AnalysisResultModel &Arg) : Result(Arg.Result) {}
-  AnalysisResultModel(AnalysisResultModel &&Arg)
-      : Result(std::move(Arg.Result)) {}
-  friend void swap(AnalysisResultModel &LHS, AnalysisResultModel &RHS) {
-    using std::swap;
-    swap(LHS.Result, RHS.Result);
-  }
-  AnalysisResultModel &operator=(AnalysisResultModel RHS) {
-    swap(*this, RHS);
-    return *this;
-  }
-
-  /// \brief The model bases invalidation solely on being in the preserved set.
-  //
-  // FIXME: We should actually use two different concepts for analysis results
-  // rather than two different models, and avoid the indirect function call for
-  // ones that use the trivial behavior.
-  bool invalidate(IRUnitT, const PreservedAnalyses &PA) override {
-    return !PA.preserved(PassT::ID());
-  }
-
-  ResultT Result;
-};
-
-/// \brief Specialization of \c AnalysisResultModel which delegates invalidate
-/// handling to \c ResultT.
-template <typename IRUnitT, typename PassT, typename ResultT>
-struct AnalysisResultModel<IRUnitT, PassT, ResultT, true>
-    : AnalysisResultConcept<IRUnitT> {
-  explicit AnalysisResultModel(ResultT Result) : Result(std::move(Result)) {}
-  // We have to explicitly define all the special member functions because MSVC
-  // refuses to generate them.
-  AnalysisResultModel(const AnalysisResultModel &Arg) : Result(Arg.Result) {}
-  AnalysisResultModel(AnalysisResultModel &&Arg)
-      : Result(std::move(Arg.Result)) {}
-  friend void swap(AnalysisResultModel &LHS, AnalysisResultModel &RHS) {
-    using std::swap;
-    swap(LHS.Result, RHS.Result);
-  }
-  AnalysisResultModel &operator=(AnalysisResultModel RHS) {
-    swap(*this, RHS);
-    return *this;
-  }
-
-  /// \brief The model delegates to the \c ResultT method.
-  bool invalidate(IRUnitT IR, const PreservedAnalyses &PA) override {
-    return Result.invalidate(IR, PA);
-  }
-
-  ResultT Result;
-};
-
-/// \brief Abstract concept of an analysis pass.
-///
-/// This concept is parameterized over the IR unit that it can run over and
-/// produce an analysis result.
-template <typename IRUnitT, typename AnalysisManagerT>
-struct AnalysisPassConcept {
-  virtual ~AnalysisPassConcept() {}
-
-  /// \brief Method to run this analysis over a unit of IR.
-  /// \returns A unique_ptr to the analysis result object to be queried by
-  /// users.
-  virtual std::unique_ptr<AnalysisResultConcept<IRUnitT>>
-  run(IRUnitT IR, AnalysisManagerT *AM) = 0;
-};
-
-/// \brief Wrapper to model the analysis pass concept.
-///
-/// Can wrap any type which implements a suitable \c run method. The method
-/// must accept the IRUnitT as an argument and produce an object which can be
-/// wrapped in a \c AnalysisResultModel.
-template <typename IRUnitT, typename AnalysisManagerT, typename PassT,
-          bool AcceptsAnalysisManager = PassRunAcceptsAnalysisManager<
-              IRUnitT, AnalysisManagerT, PassT, typename PassT::Result>::Value>
-struct AnalysisPassModel;
-
-/// \brief Specialization of \c AnalysisPassModel which passes an
-/// \c AnalysisManager to PassT's run method.
-template <typename IRUnitT, typename AnalysisManagerT, typename PassT>
-struct AnalysisPassModel<IRUnitT, AnalysisManagerT, PassT, true>
-    : AnalysisPassConcept<IRUnitT, AnalysisManagerT> {
-  explicit AnalysisPassModel(PassT Pass) : Pass(std::move(Pass)) {}
-  // We have to explicitly define all the special member functions because MSVC
-  // refuses to generate them.
-  AnalysisPassModel(const AnalysisPassModel &Arg) : Pass(Arg.Pass) {}
-  AnalysisPassModel(AnalysisPassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
-  friend void swap(AnalysisPassModel &LHS, AnalysisPassModel &RHS) {
-    using std::swap;
-    swap(LHS.Pass, RHS.Pass);
-  }
-  AnalysisPassModel &operator=(AnalysisPassModel RHS) {
-    swap(*this, RHS);
-    return *this;
-  }
-
-  // FIXME: Replace PassT::Result with type traits when we use C++11.
-  typedef AnalysisResultModel<IRUnitT, PassT, typename PassT::Result>
-      ResultModelT;
-
-  /// \brief The model delegates to the \c PassT::run method.
-  ///
-  /// The return is wrapped in an \c AnalysisResultModel.
-  std::unique_ptr<AnalysisResultConcept<IRUnitT>>
-  run(IRUnitT IR, AnalysisManagerT *AM) override {
-    return make_unique<ResultModelT>(Pass.run(IR, AM));
-  }
-
-  PassT Pass;
-};
-
-/// \brief Specialization of \c AnalysisPassModel which does not pass an
-/// \c AnalysisManager to PassT's run method.
-template <typename IRUnitT, typename AnalysisManagerT, typename PassT>
-struct AnalysisPassModel<IRUnitT, AnalysisManagerT, PassT, false>
-    : AnalysisPassConcept<IRUnitT, AnalysisManagerT> {
-  explicit AnalysisPassModel(PassT Pass) : Pass(std::move(Pass)) {}
-  // We have to explicitly define all the special member functions because MSVC
-  // refuses to generate them.
-  AnalysisPassModel(const AnalysisPassModel &Arg) : Pass(Arg.Pass) {}
-  AnalysisPassModel(AnalysisPassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
-  friend void swap(AnalysisPassModel &LHS, AnalysisPassModel &RHS) {
-    using std::swap;
-    swap(LHS.Pass, RHS.Pass);
-  }
-  AnalysisPassModel &operator=(AnalysisPassModel RHS) {
-    swap(*this, RHS);
-    return *this;
-  }
-
-  // FIXME: Replace PassT::Result with type traits when we use C++11.
-  typedef AnalysisResultModel<IRUnitT, PassT, typename PassT::Result>
-      ResultModelT;
-
-  /// \brief The model delegates to the \c PassT::run method.
-  ///
-  /// The return is wrapped in an \c AnalysisResultModel.
-  std::unique_ptr<AnalysisResultConcept<IRUnitT>>
-  run(IRUnitT IR, AnalysisManagerT *) override {
-    return make_unique<ResultModelT>(Pass.run(IR));
-  }
-
-  PassT Pass;
-};
-
-} // End namespace detail
-
 class ModuleAnalysisManager;
 
 class ModulePassManager {
diff --git a/llvm/include/llvm/IR/PassManagerInternal.h b/llvm/include/llvm/IR/PassManagerInternal.h
new file mode 100644
index 00000000000..fb9c210dba2
--- /dev/null
+++ b/llvm/include/llvm/IR/PassManagerInternal.h
@@ -0,0 +1,342 @@
+//===- PassManager internal APIs and implementation details -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// This header provides internal APIs and implementation details used by the
+/// pass management interfaces exposed in PassManager.h. To understand more
+/// context of why these particular interfaces are needed, see that header
+/// file. None of these APIs should be used elsewhere.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_IR_PASSMANAGERINTERNAL_H
+#define LLVM_IR_PASSMANAGERINTERNAL_H
+
+#include "llvm/ADT/StringRef.h"
+
+namespace llvm {
+
+class Function;
+class Module;
+class PreservedAnalyses;
+
+/// \brief Implementation details of the pass manager interfaces.
+namespace detail {
+
+/// \brief Template for the abstract base class used to dispatch
+/// polymorphically over pass objects.
+template <typename IRUnitT, typename AnalysisManagerT> struct PassConcept {
+  // Boiler plate necessary for the container of derived classes.
+  virtual ~PassConcept() {}
+
+  /// \brief The polymorphic API which runs the pass over a given IR entity.
+  ///
+  /// Note that actual pass object can omit the analysis manager argument if
+  /// desired. Also that the analysis manager may be null if there is no
+  /// analysis manager in the pass pipeline.
+  virtual PreservedAnalyses run(IRUnitT IR, AnalysisManagerT *AM) = 0;
+
+  /// \brief Polymorphic method to access the name of a pass.
+  virtual StringRef name() = 0;
+};
+
+/// \brief SFINAE metafunction for computing whether \c PassT has a run method
+/// accepting an \c AnalysisManagerT.
+template <typename IRUnitT, typename AnalysisManagerT, typename PassT,
+          typename ResultT>
+class PassRunAcceptsAnalysisManager {
+  typedef char SmallType;
+  struct BigType {
+    char a, b;
+  };
+
+  template <typename T, ResultT (T::*)(IRUnitT, AnalysisManagerT *)>
+  struct Checker;
+
+  template <typename T> static SmallType f(Checker<T, &T::run> *);
+  template <typename T> static BigType f(...);
+
+public:
+  enum { Value = sizeof(f<PassT>(nullptr)) == sizeof(SmallType) };
+};
+
+/// \brief A template wrapper used to implement the polymorphic API.
+///
+/// Can be instantiated for any object which provides a \c run method accepting
+/// an \c IRUnitT. It requires the pass to be a copyable object. When the
+/// \c run method also accepts an \c AnalysisManagerT*, we pass it along.
+template <typename IRUnitT, typename AnalysisManagerT, typename PassT,
+          typename PreservedAnalysesT = PreservedAnalyses,
+          bool AcceptsAnalysisManager = PassRunAcceptsAnalysisManager<
+              IRUnitT, AnalysisManagerT, PassT, PreservedAnalysesT>::Value>
+struct PassModel;
+
+/// \brief Specialization of \c PassModel for passes that accept an analyis
+/// manager.
+template <typename IRUnitT, typename AnalysisManagerT, typename PassT,
+          typename PreservedAnalysesT>
+struct PassModel<IRUnitT, AnalysisManagerT, PassT, PreservedAnalysesT, true>
+    : PassConcept<IRUnitT, AnalysisManagerT> {
+  explicit PassModel(PassT Pass) : Pass(std::move(Pass)) {}
+  // We have to explicitly define all the special member functions because MSVC
+  // refuses to generate them.
+  PassModel(const PassModel &Arg) : Pass(Arg.Pass) {}
+  PassModel(PassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
+  friend void swap(PassModel &LHS, PassModel &RHS) {
+    using std::swap;
+    swap(LHS.Pass, RHS.Pass);
+  }
+  PassModel &operator=(PassModel RHS) {
+    swap(*this, RHS);
+    return *this;
+  }
+
+  PreservedAnalysesT run(IRUnitT IR, AnalysisManagerT *AM) override {
+    return Pass.run(IR, AM);
+  }
+  StringRef name() override { return PassT::name(); }
+  PassT Pass;
+};
+
+/// \brief Specialization of \c PassModel for passes that accept an analyis
+/// manager.
+template <typename IRUnitT, typename AnalysisManagerT, typename PassT,
+          typename PreservedAnalysesT>
+struct PassModel<IRUnitT, AnalysisManagerT, PassT, PreservedAnalysesT, false>
+    : PassConcept<IRUnitT, AnalysisManagerT> {
+  explicit PassModel(PassT Pass) : Pass(std::move(Pass)) {}
+  // We have to explicitly define all the special member functions because MSVC
+  // refuses to generate them.
+  PassModel(const PassModel &Arg) : Pass(Arg.Pass) {}
+  PassModel(PassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
+  friend void swap(PassModel &LHS, PassModel &RHS) {
+    using std::swap;
+    swap(LHS.Pass, RHS.Pass);
+  }
+  PassModel &operator=(PassModel RHS) {
+    swap(*this, RHS);
+    return *this;
+  }
+
+  PreservedAnalysesT run(IRUnitT IR, AnalysisManagerT *AM) override {
+    return Pass.run(IR);
+  }
+  StringRef name() override { return PassT::name(); }
+  PassT Pass;
+};
+
+/// \brief Abstract concept of an analysis result.
+///
+/// This concept is parameterized over the IR unit that this result pertains
+/// to.
+template <typename IRUnitT> struct AnalysisResultConcept {
+  virtual ~AnalysisResultConcept() {}
+
+  /// \brief Method to try and mark a result as invalid.
+  ///
+  /// When the outer analysis manager detects a change in some underlying
+  /// unit of the IR, it will call this method on all of the results cached.
+  ///
+  /// This method also receives a set of preserved analyses which can be used
+  /// to avoid invalidation because the pass which changed the underlying IR
+  /// took care to update or preserve the analysis result in some way.
+  ///
+  /// \returns true if the result is indeed invalid (the default).
+  virtual bool invalidate(IRUnitT IR, const PreservedAnalyses &PA) = 0;
+};
+
+/// \brief SFINAE metafunction for computing whether \c ResultT provides an
+/// \c invalidate member function.
+template <typename IRUnitT, typename ResultT> class ResultHasInvalidateMethod {
+  typedef char SmallType;
+  struct BigType {
+    char a, b;
+  };
+
+  template <typename T, bool (T::*)(IRUnitT, const PreservedAnalyses &)>
+  struct Checker;
+
+  template <typename T> static SmallType f(Checker<T, &T::invalidate> *);
+  template <typename T> static BigType f(...);
+
+public:
+  enum { Value = sizeof(f<ResultT>(nullptr)) == sizeof(SmallType) };
+};
+
+/// \brief Wrapper to model the analysis result concept.
+///
+/// By default, this will implement the invalidate method with a trivial
+/// implementation so that the actual analysis result doesn't need to provide
+/// an invalidation handler. It is only selected when the invalidation handler
+/// is not part of the ResultT's interface.
+template <typename IRUnitT, typename PassT, typename ResultT,
+          typename PreservedAnalysesT = PreservedAnalyses,
+          bool HasInvalidateHandler =
+              ResultHasInvalidateMethod<IRUnitT, ResultT>::Value>
+struct AnalysisResultModel;
+
+/// \brief Specialization of \c AnalysisResultModel which provides the default
+/// invalidate functionality.
+template <typename IRUnitT, typename PassT, typename ResultT,
+          typename PreservedAnalysesT>
+struct AnalysisResultModel<IRUnitT, PassT, ResultT, PreservedAnalysesT, false>
+    : AnalysisResultConcept<IRUnitT> {
+  explicit AnalysisResultModel(ResultT Result) : Result(std::move(Result)) {}
+  // We have to explicitly define all the special member functions because MSVC
+  // refuses to generate them.
+  AnalysisResultModel(const AnalysisResultModel &Arg) : Result(Arg.Result) {}
+  AnalysisResultModel(AnalysisResultModel &&Arg)
+      : Result(std::move(Arg.Result)) {}
+  friend void swap(AnalysisResultModel &LHS, AnalysisResultModel &RHS) {
+    using std::swap;
+    swap(LHS.Result, RHS.Result);
+  }
+  AnalysisResultModel &operator=(AnalysisResultModel RHS) {
+    swap(*this, RHS);
+    return *this;
+  }
+
+  /// \brief The model bases invalidation solely on being in the preserved set.
+  //
+  // FIXME: We should actually use two different concepts for analysis results
+  // rather than two different models, and avoid the indirect function call for
+  // ones that use the trivial behavior.
+  bool invalidate(IRUnitT, const PreservedAnalysesT &PA) override {
+    return !PA.preserved(PassT::ID());
+  }
+
+  ResultT Result;
+};
+
+/// \brief Specialization of \c AnalysisResultModel which delegates invalidate
+/// handling to \c ResultT.
+template <typename IRUnitT, typename PassT, typename ResultT,
+          typename PreservedAnalysesT>
+struct AnalysisResultModel<IRUnitT, PassT, ResultT, PreservedAnalysesT, true>
+    : AnalysisResultConcept<IRUnitT> {
+  explicit AnalysisResultModel(ResultT Result) : Result(std::move(Result)) {}
+  // We have to explicitly define all the special member functions because MSVC
+  // refuses to generate them.
+  AnalysisResultModel(const AnalysisResultModel &Arg) : Result(Arg.Result) {}
+  AnalysisResultModel(AnalysisResultModel &&Arg)
+      : Result(std::move(Arg.Result)) {}
+  friend void swap(AnalysisResultModel &LHS, AnalysisResultModel &RHS) {
+    using std::swap;
+    swap(LHS.Result, RHS.Result);
+  }
+  AnalysisResultModel &operator=(AnalysisResultModel RHS) {
+    swap(*this, RHS);
+    return *this;
+  }
+
+  /// \brief The model delegates to the \c ResultT method.
+  bool invalidate(IRUnitT IR, const PreservedAnalysesT &PA) override {
+    return Result.invalidate(IR, PA);
+  }
+
+  ResultT Result;
+};
+
+/// \brief Abstract concept of an analysis pass.
+///
+/// This concept is parameterized over the IR unit that it can run over and
+/// produce an analysis result.
+template <typename IRUnitT, typename AnalysisManagerT>
+struct AnalysisPassConcept {
+  virtual ~AnalysisPassConcept() {}
+
+  /// \brief Method to run this analysis over a unit of IR.
+  /// \returns A unique_ptr to the analysis result object to be queried by
+  /// users.
+  virtual std::unique_ptr<AnalysisResultConcept<IRUnitT>>
+  run(IRUnitT IR, AnalysisManagerT *AM) = 0;
+};
+
+/// \brief Wrapper to model the analysis pass concept.
+///
+/// Can wrap any type which implements a suitable \c run method. The method
+/// must accept the IRUnitT as an argument and produce an object which can be
+/// wrapped in a \c AnalysisResultModel.
+template <typename IRUnitT, typename AnalysisManagerT, typename PassT,
+          bool AcceptsAnalysisManager = PassRunAcceptsAnalysisManager<
+              IRUnitT, AnalysisManagerT, PassT, typename PassT::Result>::Value>
+struct AnalysisPassModel;
+
+/// \brief Specialization of \c AnalysisPassModel which passes an
+/// \c AnalysisManager to PassT's run method.
+template <typename IRUnitT, typename AnalysisManagerT, typename PassT>
+struct AnalysisPassModel<IRUnitT, AnalysisManagerT, PassT, true>
+    : AnalysisPassConcept<IRUnitT, AnalysisManagerT> {
+  explicit AnalysisPassModel(PassT Pass) : Pass(std::move(Pass)) {}
+  // We have to explicitly define all the special member functions because MSVC
+  // refuses to generate them.
+  AnalysisPassModel(const AnalysisPassModel &Arg) : Pass(Arg.Pass) {}
+  AnalysisPassModel(AnalysisPassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
+  friend void swap(AnalysisPassModel &LHS, AnalysisPassModel &RHS) {
+    using std::swap;
+    swap(LHS.Pass, RHS.Pass);
+  }
+  AnalysisPassModel &operator=(AnalysisPassModel RHS) {
+    swap(*this, RHS);
+    return *this;
+  }
+
+  // FIXME: Replace PassT::Result with type traits when we use C++11.
+  typedef AnalysisResultModel<IRUnitT, PassT, typename PassT::Result>
+      ResultModelT;
+
+  /// \brief The model delegates to the \c PassT::run method.
+  ///
+  /// The return is wrapped in an \c AnalysisResultModel.
+  std::unique_ptr<AnalysisResultConcept<IRUnitT>>
+  run(IRUnitT IR, AnalysisManagerT *AM) override {
+    return make_unique<ResultModelT>(Pass.run(IR, AM));
+  }
+
+  PassT Pass;
+};
+
+/// \brief Specialization of \c AnalysisPassModel which does not pass an
+/// \c AnalysisManager to PassT's run method.
+template <typename IRUnitT, typename AnalysisManagerT, typename PassT>
+struct AnalysisPassModel<IRUnitT, AnalysisManagerT, PassT, false>
+    : AnalysisPassConcept<IRUnitT, AnalysisManagerT> {
+  explicit AnalysisPassModel(PassT Pass) : Pass(std::move(Pass)) {}
+  // We have to explicitly define all the special member functions because MSVC
+  // refuses to generate them.
+  AnalysisPassModel(const AnalysisPassModel &Arg) : Pass(Arg.Pass) {}
+  AnalysisPassModel(AnalysisPassModel &&Arg) : Pass(std::move(Arg.Pass)) {}
+  friend void swap(AnalysisPassModel &LHS, AnalysisPassModel &RHS) {
+    using std::swap;
+    swap(LHS.Pass, RHS.Pass);
+  }
+  AnalysisPassModel &operator=(AnalysisPassModel RHS) {
+    swap(*this, RHS);
+    return *this;
+  }
+
+  // FIXME: Replace PassT::Result with type traits when we use C++11.
+  typedef AnalysisResultModel<IRUnitT, PassT, typename PassT::Result>
+      ResultModelT;
+
+  /// \brief The model delegates to the \c PassT::run method.
+  ///
+  /// The return is wrapped in an \c AnalysisResultModel.
+  std::unique_ptr<AnalysisResultConcept<IRUnitT>>
+  run(IRUnitT IR, AnalysisManagerT *) override {
+    return make_unique<ResultModelT>(Pass.run(IR));
+  }
+
+  PassT Pass;
+};
+
+} // End namespace detail
+}
+
+#endif