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 
26 namespace llvm {
27 
28 template <typename T> class ArrayRef;
29 class LiveIntervals;
30 class VirtRegMap;
31 
32 class LLVM_LIBRARY_VISIBILITY LiveDebugVariables : public MachineFunctionPass {
33   void *pImpl = nullptr;
34 
35 public:
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(Register OldReg, ArrayRef<Register> 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 
55 private:
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