blob: 770c46ec84369a8c171a99b67b323f856722071b [file] [log] [blame]
//===- LiveDebugValues.cpp - Tracking Debug Value MIs ---------------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "LiveDebugValues.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Target/TargetMachine.h"
/// \file LiveDebugValues.cpp
/// The LiveDebugValues pass extends the range of variable locations
/// (specified by DBG_VALUE instructions) from single blocks to successors
/// and any other code locations where the variable location is valid.
/// There are currently two implementations: the "VarLoc" implementation
/// explicitly tracks the location of a variable, while the "InstrRef"
/// implementation tracks the values defined by instructions through locations.
/// This file implements neither; it merely registers the pass, allows the
/// user to pick which implementation will be used to propagate variable
/// locations.
#define DEBUG_TYPE "livedebugvalues"
using namespace llvm;
/// Generic LiveDebugValues pass. Calls through to VarLocBasedLDV or
/// InstrRefBasedLDV to perform location propagation, via the LDVImpl
/// base class.
class LiveDebugValues : public MachineFunctionPass {
static char ID;
~LiveDebugValues() {
if (TheImpl)
delete TheImpl;
/// Calculate the liveness information for the given machine function.
bool runOnMachineFunction(MachineFunction &MF) override;
MachineFunctionProperties getRequiredProperties() const override {
return MachineFunctionProperties().set(
void getAnalysisUsage(AnalysisUsage &AU) const override {
LDVImpl *TheImpl;
TargetPassConfig *TPC;
char LiveDebugValues::ID = 0;
char &llvm::LiveDebugValuesID = LiveDebugValues::ID;
INITIALIZE_PASS(LiveDebugValues, DEBUG_TYPE, "Live DEBUG_VALUE analysis", false,
/// Default construct and initialize the pass.
LiveDebugValues::LiveDebugValues() : MachineFunctionPass(ID) {
TheImpl = nullptr;
bool LiveDebugValues::runOnMachineFunction(MachineFunction &MF) {
if (!TheImpl) {
TPC = getAnalysisIfAvailable<TargetPassConfig>();
bool InstrRefBased = false;
if (TPC) {
auto &TM = TPC->getTM<TargetMachine>();
InstrRefBased = TM.Options.ValueTrackingVariableLocations;
if (InstrRefBased)
TheImpl = llvm::makeInstrRefBasedLiveDebugValues();
TheImpl = llvm::makeVarLocBasedLiveDebugValues();
return TheImpl->ExtendRanges(MF, TPC);