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/CodeGen/MachineFunctionPass.h"
25 
26 namespace llvm {
27 
28 class VirtRegMap;
29 
30 class LiveDebugVariables : public MachineFunctionPass {
31   void *pImpl;
32 public:
33   static char ID; // Pass identification, replacement for typeid
34 
35   LiveDebugVariables();
36   ~LiveDebugVariables();
37 
38   /// renameRegister - Move any user variables in OldReg to NewReg:SubIdx.
39   /// @param OldReg Old virtual register that is going away.
40   /// @param NewReg New register holding the user variables.
41   /// @param SubIdx If NewReg is a virtual register, SubIdx may indicate a sub-
42   ///               register.
43   void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
44 
45   /// emitDebugValues - Emit new DBG_VALUE instructions reflecting the changes
46   /// that happened during register allocation.
47   /// @param VRM Rename virtual registers according to map.
48   void emitDebugValues(VirtRegMap *VRM);
49 
50   /// dump - Print data structures to dbgs().
51   void dump();
52 
53 private:
54 
55   virtual bool runOnMachineFunction(MachineFunction &);
56   virtual void releaseMemory();
57   virtual void getAnalysisUsage(AnalysisUsage &) const;
58 
59 };
60 
61 } // namespace llvm
62 
63 #endif // LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
64