- //===- llvm/CodeGen/MachinePassRegistry.h -----------------------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- // This file contains the mechanics for machine function pass registries.  A 
- // function pass registry (MachinePassRegistry) is auto filled by the static 
- // constructors of MachinePassRegistryNode.  Further there is a command line 
- // parser (RegisterPassParser) which listens to each registry for additions 
- // and deletions, so that the appropriate command option is updated. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_CODEGEN_MACHINEPASSREGISTRY_H 
- #define LLVM_CODEGEN_MACHINEPASSREGISTRY_H 
-   
- #include "llvm/ADT/StringRef.h" 
- #include "llvm/CodeGen/Passes.h" 
- #include "llvm/Support/CommandLine.h" 
-   
- namespace llvm { 
-   
- //===----------------------------------------------------------------------===// 
- /// 
- /// MachinePassRegistryListener - Listener to adds and removals of nodes in 
- /// registration list. 
- /// 
- //===----------------------------------------------------------------------===// 
- template <class PassCtorTy> class MachinePassRegistryListener { 
-   virtual void anchor() {} 
-   
- public: 
-   MachinePassRegistryListener() = default; 
-   virtual ~MachinePassRegistryListener() = default; 
-   
-   virtual void NotifyAdd(StringRef N, PassCtorTy C, StringRef D) = 0; 
-   virtual void NotifyRemove(StringRef N) = 0; 
- }; 
-   
- //===----------------------------------------------------------------------===// 
- /// 
- /// MachinePassRegistryNode - Machine pass node stored in registration list. 
- /// 
- //===----------------------------------------------------------------------===// 
- template <typename PassCtorTy> class MachinePassRegistryNode { 
- private: 
-   MachinePassRegistryNode *Next = nullptr; // Next function pass in list. 
-   StringRef Name;                       // Name of function pass. 
-   StringRef Description;                // Description string. 
-   PassCtorTy Ctor;                      // Pass creator. 
-   
- public: 
-   MachinePassRegistryNode(const char *N, const char *D, PassCtorTy C) 
-       : Name(N), Description(D), Ctor(C) {} 
-   
-   // Accessors 
-   MachinePassRegistryNode *getNext()      const { return Next; } 
-   MachinePassRegistryNode **getNextAddress()    { return &Next; } 
-   StringRef getName()                   const { return Name; } 
-   StringRef getDescription()            const { return Description; } 
-   PassCtorTy getCtor() const { return Ctor; } 
-   void setNext(MachinePassRegistryNode *N)      { Next = N; } 
- }; 
-   
- //===----------------------------------------------------------------------===// 
- /// 
- /// MachinePassRegistry - Track the registration of machine passes. 
- /// 
- //===----------------------------------------------------------------------===// 
- template <typename PassCtorTy> class MachinePassRegistry { 
- private: 
-   MachinePassRegistryNode<PassCtorTy> *List; // List of registry nodes. 
-   PassCtorTy Default;                        // Default function pass creator. 
-   MachinePassRegistryListener<PassCtorTy> 
-       *Listener; // Listener for list adds are removes. 
-   
- public: 
-   // NO CONSTRUCTOR - we don't want static constructor ordering to mess 
-   // with the registry. 
-   
-   // Accessors. 
-   // 
-   MachinePassRegistryNode<PassCtorTy> *getList() { return List; } 
-   PassCtorTy getDefault() { return Default; } 
-   void setDefault(PassCtorTy C) { Default = C; } 
-   /// setDefault - Set the default constructor by name. 
-   void setDefault(StringRef Name) { 
-     PassCtorTy Ctor = nullptr; 
-     for (MachinePassRegistryNode<PassCtorTy> *R = getList(); R; 
-          R = R->getNext()) { 
-       if (R->getName() == Name) { 
-         Ctor = R->getCtor(); 
-         break; 
-       } 
-     } 
-     assert(Ctor && "Unregistered pass name"); 
-     setDefault(Ctor); 
-   } 
-   void setListener(MachinePassRegistryListener<PassCtorTy> *L) { Listener = L; } 
-   
-   /// Add - Adds a function pass to the registration list. 
-   /// 
-   void Add(MachinePassRegistryNode<PassCtorTy> *Node) { 
-     Node->setNext(List); 
-     List = Node; 
-     if (Listener) 
-       Listener->NotifyAdd(Node->getName(), Node->getCtor(), 
-                           Node->getDescription()); 
-   } 
-   
-   /// Remove - Removes a function pass from the registration list. 
-   /// 
-   void Remove(MachinePassRegistryNode<PassCtorTy> *Node) { 
-     for (MachinePassRegistryNode<PassCtorTy> **I = &List; *I; 
-          I = (*I)->getNextAddress()) { 
-       if (*I == Node) { 
-         if (Listener) 
-           Listener->NotifyRemove(Node->getName()); 
-         *I = (*I)->getNext(); 
-         break; 
-       } 
-     } 
-   } 
- }; 
-   
- //===----------------------------------------------------------------------===// 
- /// 
- /// RegisterPassParser class - Handle the addition of new machine passes. 
- /// 
- //===----------------------------------------------------------------------===// 
- template <class RegistryClass> 
- class RegisterPassParser 
-     : public MachinePassRegistryListener< 
-           typename RegistryClass::FunctionPassCtor>, 
-       public cl::parser<typename RegistryClass::FunctionPassCtor> { 
- public: 
-   RegisterPassParser(cl::Option &O) 
-       : cl::parser<typename RegistryClass::FunctionPassCtor>(O) {} 
-   ~RegisterPassParser() override { RegistryClass::setListener(nullptr); } 
-   
-   void initialize() { 
-     cl::parser<typename RegistryClass::FunctionPassCtor>::initialize(); 
-   
-     // Add existing passes to option. 
-     for (RegistryClass *Node = RegistryClass::getList(); 
-          Node; Node = Node->getNext()) { 
-       this->addLiteralOption(Node->getName(), 
-                       (typename RegistryClass::FunctionPassCtor)Node->getCtor(), 
-                              Node->getDescription()); 
-     } 
-   
-     // Make sure we listen for list changes. 
-     RegistryClass::setListener(this); 
-   } 
-   
-   // Implement the MachinePassRegistryListener callbacks. 
-   void NotifyAdd(StringRef N, typename RegistryClass::FunctionPassCtor C, 
-                  StringRef D) override { 
-     this->addLiteralOption(N, C, D); 
-   } 
-   void NotifyRemove(StringRef N) override { 
-     this->removeLiteralOption(N); 
-   } 
- }; 
-   
- } // end namespace llvm 
-   
- #endif // LLVM_CODEGEN_MACHINEPASSREGISTRY_H 
-