llvm/llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp

//===- LiveDebugValues.cpp - Tracking Debug Value MIs ---------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "LiveDebugValues.h"

#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/PassRegistry.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/TargetParser/Triple.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 …

usingnamespacellvm;

static cl::opt<bool>
    ForceInstrRefLDV("force-instr-ref-livedebugvalues", cl::Hidden,
                     cl::desc("Use instruction-ref based LiveDebugValues with "
                              "normal DBG_VALUE inputs"),
                     cl::init(false));

static cl::opt<cl::boolOrDefault> ValueTrackingVariableLocations(
    "experimental-debug-variable-locations",
    cl::desc("Use experimental new value-tracking variable locations"));

// Options to prevent pathological compile-time behavior. If InputBBLimit and
// InputDbgValueLimit are both exceeded, range extension is disabled.
static cl::opt<unsigned> InputBBLimit(
    "livedebugvalues-input-bb-limit",
    cl::desc("Maximum input basic blocks before DBG_VALUE limit applies"),
    cl::init(10000), cl::Hidden);
static cl::opt<unsigned> InputDbgValueLimit(
    "livedebugvalues-input-dbg-value-limit",
    cl::desc(
        "Maximum input DBG_VALUE insts supported by debug range extension"),
    cl::init(50000), cl::Hidden);

namespace {
/// Generic LiveDebugValues pass. Calls through to VarLocBasedLDV or
/// InstrRefBasedLDV to perform location propagation, via the LDVImpl
/// base class.
class LiveDebugValues : public MachineFunctionPass { … };
} // namespace

char LiveDebugValues::ID = …;

char &llvm::LiveDebugValuesID = …;

INITIALIZE_PASS(…)

/// Default construct and initialize the pass.
LiveDebugValues::LiveDebugValues() : … { … }

bool LiveDebugValues::runOnMachineFunction(MachineFunction &MF) { … }

bool llvm::debuginfoShouldUseDebugInstrRef(const Triple &T) { … }