1//===- LiveDebugVariables.h - Tracking debug info variables -----*- 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// This file provides the interface to the LiveDebugVariables analysis.
10//
11// The analysis removes DBG_VALUE instructions for virtual registers and tracks
12// live user variables in a data structure that can be updated during register
13// allocation.
14//
15// After register allocation new DBG_VALUE instructions are emitted to reflect
16// the new locations of user variables.
17//
18//===----------------------------------------------------------------------===//
19
20#ifndef LLVM_LIB_CODEGEN_LIVEDEBUGVARIABLES_H
21#define LLVM_LIB_CODEGEN_LIVEDEBUGVARIABLES_H
22
23#include "llvm/CodeGen/MachineFunctionPass.h"
24#include "llvm/Support/Compiler.h"
25
26namespace llvm {
27
28template <typename T> class ArrayRef;
29class LiveIntervals;
30class VirtRegMap;
31
32class LLVM_LIBRARY_VISIBILITY LiveDebugVariables : public MachineFunctionPass {
33  void *pImpl = nullptr;
34
35public:
36  static char ID; // Pass identification, replacement for typeid
37
38  LiveDebugVariables();
39  ~LiveDebugVariables() override;
40
41  /// splitRegister - Move any user variables in OldReg to the live ranges in
42  /// NewRegs where they are live. Mark the values as unavailable where no new
43  /// register is live.
44  void splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs,
45                     LiveIntervals &LIS);
46
47  /// emitDebugValues - Emit new DBG_VALUE instructions reflecting the changes
48  /// that happened during register allocation.
49  /// @param VRM Rename virtual registers according to map.
50  void emitDebugValues(VirtRegMap *VRM);
51
52  /// dump - Print data structures to dbgs().
53  void dump() const;
54
55private:
56  bool runOnMachineFunction(MachineFunction &) override;
57  void releaseMemory() override;
58  void getAnalysisUsage(AnalysisUsage &) const override;
59  bool doInitialization(Module &) override;
60};
61
62} // end namespace llvm
63
64#endif // LLVM_LIB_CODEGEN_LIVEDEBUGVARIABLES_H
65