xref: /external/llvm/lib/CodeGen/LiveDebugVariables.cpp

//===- LiveDebugVariables.cpp - Tracking debug info variables -------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the LiveDebugVariables analysis.
//
// Remove all DBG_VALUE instructions referencing virtual registers and replace
// them with a data structure tracking where live user variables are kept - in a
// virtual register or in a stack slot.
//
// Allow the data structure to be updated during register allocation when values
// are moved between registers and stack slots. Finally emit new DBG_VALUE
// instructions after register allocation is complete.
//
//===----------------------------------------------------------------------===//

#include "LiveDebugVariables.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Target/TargetMachine.h"

using namespace llvm;

char LiveDebugVariables::ID = 0;

INITIALIZE_PASS_BEGIN(LiveDebugVariables, "livedebugvars",
                "Debug Variable Analysis", false, false)
INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
INITIALIZE_PASS_END(LiveDebugVariables, "livedebugvars",
                "Debug Variable Analysis", false, false)

void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const {
  AU.addRequiredTransitive<LiveIntervals>();
  AU.setPreservesAll();
  MachineFunctionPass::getAnalysisUsage(AU);
}

LiveDebugVariables::LiveDebugVariables() : MachineFunctionPass(ID) {
  initializeLiveDebugVariablesPass(*PassRegistry::getPassRegistry());
}

bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
  return false;
}