- //===-- llvm/IR/ModuleSlotTracker.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 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_IR_MODULESLOTTRACKER_H 
- #define LLVM_IR_MODULESLOTTRACKER_H 
-   
- #include <functional> 
- #include <memory> 
- #include <utility> 
- #include <vector> 
-   
- namespace llvm { 
-   
- class Module; 
- class Function; 
- class SlotTracker; 
- class Value; 
- class MDNode; 
-   
- /// Abstract interface of slot tracker storage. 
- class AbstractSlotTrackerStorage { 
- public: 
-   virtual ~AbstractSlotTrackerStorage(); 
-   
-   virtual unsigned getNextMetadataSlot() = 0; 
-   
-   virtual void createMetadataSlot(const MDNode *) = 0; 
-   virtual int getMetadataSlot(const MDNode *) = 0; 
- }; 
-   
- /// Manage lifetime of a slot tracker for printing IR. 
- /// 
- /// Wrapper around the \a SlotTracker used internally by \a AsmWriter.  This 
- /// class allows callers to share the cost of incorporating the metadata in a 
- /// module or a function. 
- /// 
- /// If the IR changes from underneath \a ModuleSlotTracker, strings like 
- /// "<badref>" will be printed, or, worse, the wrong slots entirely. 
- class ModuleSlotTracker { 
-   /// Storage for a slot tracker. 
-   std::unique_ptr<SlotTracker> MachineStorage; 
-   bool ShouldCreateStorage = false; 
-   bool ShouldInitializeAllMetadata = false; 
-   
-   const Module *M = nullptr; 
-   const Function *F = nullptr; 
-   SlotTracker *Machine = nullptr; 
-   
-   std::function<void(AbstractSlotTrackerStorage *, const Module *, bool)> 
-       ProcessModuleHookFn; 
-   std::function<void(AbstractSlotTrackerStorage *, const Function *, bool)> 
-       ProcessFunctionHookFn; 
-   
- public: 
-   /// Wrap a preinitialized SlotTracker. 
-   ModuleSlotTracker(SlotTracker &Machine, const Module *M, 
-                     const Function *F = nullptr); 
-   
-   /// Construct a slot tracker from a module. 
-   /// 
-   /// If \a M is \c nullptr, uses a null slot tracker.  Otherwise, initializes 
-   /// a slot tracker, and initializes all metadata slots.  \c 
-   /// ShouldInitializeAllMetadata defaults to true because this is expected to 
-   /// be shared between multiple callers, and otherwise MDNode references will 
-   /// not match up. 
-   explicit ModuleSlotTracker(const Module *M, 
-                              bool ShouldInitializeAllMetadata = true); 
-   
-   /// Destructor to clean up storage. 
-   virtual ~ModuleSlotTracker(); 
-   
-   /// Lazily creates a slot tracker. 
-   SlotTracker *getMachine(); 
-   
-   const Module *getModule() const { return M; } 
-   const Function *getCurrentFunction() const { return F; } 
-   
-   /// Incorporate the given function. 
-   /// 
-   /// Purge the currently incorporated function and incorporate \c F.  If \c F 
-   /// is currently incorporated, this is a no-op. 
-   void incorporateFunction(const Function &F); 
-   
-   /// Return the slot number of the specified local value. 
-   /// 
-   /// A function that defines this value should be incorporated prior to calling 
-   /// this method. 
-   /// Return -1 if the value is not in the function's SlotTracker. 
-   int getLocalSlot(const Value *V); 
-   
-   void setProcessHook( 
-       std::function<void(AbstractSlotTrackerStorage *, const Module *, bool)>); 
-   void setProcessHook(std::function<void(AbstractSlotTrackerStorage *, 
-                                          const Function *, bool)>); 
-   
-   using MachineMDNodeListType = 
-       std::vector<std::pair<unsigned, const MDNode *>>; 
-   
-   void collectMDNodes(MachineMDNodeListType &L, unsigned LB, unsigned UB) const; 
- }; 
-   
- } // end namespace llvm 
-   
- #endif 
-