//===- LiveDebugVariables.h - Tracking debug info variables -----*- 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 provides the interface to the LiveDebugVariables analysis.

//

// The analysis removes DBG_VALUE instructions for virtual registers and tracks

// live user variables in a data structure that can be updated during register

// allocation.

//

// After register allocation new DBG_VALUE instructions are emitted to reflect

// the new locations of user variables.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_CODEGEN_LIVEDEBUGVARIABLES_H

#define LLVM_LIB_CODEGEN_LIVEDEBUGVARIABLES_H

#include "llvm/CodeGen/MachineFunctionPass.h"

#include "llvm/Support/Compiler.h"

namespace llvm {

template <typename T> class ArrayRef;

class LiveIntervals;

class VirtRegMap;

class LLVM_LIBRARY_VISIBILITY LiveDebugVariables : public MachineFunctionPass {

  void *pImpl = nullptr;

public:

  static char ID; // Pass identification, replacement for typeid

  LiveDebugVariables();

  ~LiveDebugVariables() override;

  /// splitRegister - Move any user variables in OldReg to the live ranges in

  /// NewRegs where they are live. Mark the values as unavailable where no new

  /// register is live.

  void splitRegister(Register OldReg, ArrayRef<Register> NewRegs,

                     LiveIntervals &LIS);

  /// emitDebugValues - Emit new DBG_VALUE instructions reflecting the changes

  /// that happened during register allocation.

  /// @param VRM Rename virtual registers according to map.

  void emitDebugValues(VirtRegMap *VRM);

  /// dump - Print data structures to dbgs().

  void dump() const;

private:

  bool runOnMachineFunction(MachineFunction &) override;

  void releaseMemory() override;

  void getAnalysisUsage(AnalysisUsage &) const override;

  MachineFunctionProperties getSetProperties() const override {

    return MachineFunctionProperties().set(

        MachineFunctionProperties::Property::TracksDebugUserValues);

  }

};

} // end namespace llvm

#endif // LLVM_LIB_CODEGEN_LIVEDEBUGVARIABLES_H