lib/CodeGen/LiveDebugVariables.h

   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(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
  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