1 //===-- llvm/IR/ModuleSlotTracker.h -----------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_IR_MODULESLOTTRACKER_H 10 #define LLVM_IR_MODULESLOTTRACKER_H 11 12 #include <memory> 13 14 namespace llvm { 15 16 class Module; 17 class Function; 18 class SlotTracker; 19 class Value; 20 21 /// Manage lifetime of a slot tracker for printing IR. 22 /// 23 /// Wrapper around the \a SlotTracker used internally by \a AsmWriter. This 24 /// class allows callers to share the cost of incorporating the metadata in a 25 /// module or a function. 26 /// 27 /// If the IR changes from underneath \a ModuleSlotTracker, strings like 28 /// "<badref>" will be printed, or, worse, the wrong slots entirely. 29 class ModuleSlotTracker { 30 /// Storage for a slot tracker. 31 std::unique_ptr<SlotTracker> MachineStorage; 32 bool ShouldCreateStorage = false; 33 bool ShouldInitializeAllMetadata = false; 34 35 const Module *M = nullptr; 36 const Function *F = nullptr; 37 SlotTracker *Machine = nullptr; 38 39 public: 40 /// Wrap a preinitialized SlotTracker. 41 ModuleSlotTracker(SlotTracker &Machine, const Module *M, 42 const Function *F = nullptr); 43 44 /// Construct a slot tracker from a module. 45 /// 46 /// If \a M is \c nullptr, uses a null slot tracker. Otherwise, initializes 47 /// a slot tracker, and initializes all metadata slots. \c 48 /// ShouldInitializeAllMetadata defaults to true because this is expected to 49 /// be shared between multiple callers, and otherwise MDNode references will 50 /// not match up. 51 explicit ModuleSlotTracker(const Module *M, 52 bool ShouldInitializeAllMetadata = true); 53 54 /// Destructor to clean up storage. 55 ~ModuleSlotTracker(); 56 57 /// Lazily creates a slot tracker. 58 SlotTracker *getMachine(); 59 getModule()60 const Module *getModule() const { return M; } getCurrentFunction()61 const Function *getCurrentFunction() const { return F; } 62 63 /// Incorporate the given function. 64 /// 65 /// Purge the currently incorporated function and incorporate \c F. If \c F 66 /// is currently incorporated, this is a no-op. 67 void incorporateFunction(const Function &F); 68 69 /// Return the slot number of the specified local value. 70 /// 71 /// A function that defines this value should be incorporated prior to calling 72 /// this method. 73 /// Return -1 if the value is not in the function's SlotTracker. 74 int getLocalSlot(const Value *V); 75 }; 76 77 } // end namespace llvm 78 79 #endif 80