1//===- LiveDebugVariables.h - Tracking debug info variables ----*- c++ -*--===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file provides the interface to the LiveDebugVariables analysis.
11//
12// The analysis removes DBG_VALUE instructions for virtual registers and tracks
13// live user variables in a data structure that can be updated during register
14// allocation.
15//
16// After register allocation new DBG_VALUE instructions are emitted to reflect
17// the new locations of user variables.
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
22#define LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
23
24#include "llvm/ADT/ArrayRef.h"
25#include "llvm/IR/DebugInfo.h"
26#include "llvm/CodeGen/MachineFunctionPass.h"
27
28namespace llvm {
29
30class LiveInterval;
31class LiveIntervals;
32class VirtRegMap;
33
34class LiveDebugVariables : public MachineFunctionPass {
35  void *pImpl;
36  DenseMap<const Function*, DISubprogram> FunctionDIs;
37public:
38  static char ID; // Pass identification, replacement for typeid
39
40  LiveDebugVariables();
41  ~LiveDebugVariables();
42
43  /// renameRegister - Move any user variables in OldReg to NewReg:SubIdx.
44  /// @param OldReg Old virtual register that is going away.
45  /// @param NewReg New register holding the user variables.
46  /// @param SubIdx If NewReg is a virtual register, SubIdx may indicate a sub-
47  ///               register.
48  void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
49
50  /// splitRegister - Move any user variables in OldReg to the live ranges in
51  /// NewRegs where they are live. Mark the values as unavailable where no new
52  /// register is live.
53  void splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs,
54                     LiveIntervals &LIS);
55
56  /// emitDebugValues - Emit new DBG_VALUE instructions reflecting the changes
57  /// that happened during register allocation.
58  /// @param VRM Rename virtual registers according to map.
59  void emitDebugValues(VirtRegMap *VRM);
60
61  /// dump - Print data structures to dbgs().
62  void dump();
63
64private:
65
66  bool runOnMachineFunction(MachineFunction &) override;
67  void releaseMemory() override;
68  void getAnalysisUsage(AnalysisUsage &) const override;
69  bool doInitialization(Module &) override;
70
71};
72
73} // namespace llvm
74
75#endif // LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
76