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1//===- llvm/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.cpp -------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "llvm/CodeGen/DbgEntityHistoryCalculator.h"10#include "llvm/ADT/STLExtras.h"11#include "llvm/ADT/SmallSet.h"12#include "llvm/ADT/SmallVector.h"13#include "llvm/CodeGen/LexicalScopes.h"14#include "llvm/CodeGen/MachineBasicBlock.h"15#include "llvm/CodeGen/MachineFunction.h"16#include "llvm/CodeGen/MachineInstr.h"17#include "llvm/CodeGen/MachineOperand.h"18#include "llvm/CodeGen/TargetLowering.h"19#include "llvm/CodeGen/TargetRegisterInfo.h"20#include "llvm/CodeGen/TargetSubtargetInfo.h"21#include "llvm/IR/DebugInfoMetadata.h"22#include "llvm/IR/DebugLoc.h"23#include "llvm/MC/MCRegisterInfo.h"24#include "llvm/Support/Debug.h"25#include "llvm/Support/raw_ostream.h"26#include <cassert>27#include <map>28#include <optional>29 30using namespace llvm;31 32#define DEBUG_TYPE "dwarfdebug"33 34namespace {35using EntryIndex = DbgValueHistoryMap::EntryIndex;36}37 38void InstructionOrdering::initialize(const MachineFunction &MF) {39  // We give meta instructions the same ordinal as the preceding instruction40  // because this class is written for the task of comparing positions of41  // variable location ranges against scope ranges. To reflect what we'll see42  // in the binary, when we look at location ranges we must consider all43  // DBG_VALUEs between two real instructions at the same position. And a44  // scope range which ends on a meta instruction should be considered to end45  // at the last seen real instruction. E.g.46  //47  //  1 instruction p      Both the variable location for x and for y start48  //  1 DBG_VALUE for "x"  after instruction p so we give them all the same49  //  1 DBG_VALUE for "y"  number. If a scope range ends at DBG_VALUE for "y",50  //  2 instruction q      we should treat it as ending after instruction p51  //                       because it will be the last real instruction in the52  //                       range. DBG_VALUEs at or after this position for53  //                       variables declared in the scope will have no effect.54  clear();55  unsigned Position = 0;56  for (const MachineBasicBlock &MBB : MF)57    for (const MachineInstr &MI : MBB)58      InstNumberMap[&MI] = MI.isMetaInstruction() ? Position : ++Position;59}60 61bool InstructionOrdering::isBefore(const MachineInstr *A,62                                   const MachineInstr *B) const {63  assert(A->getParent() && B->getParent() && "Operands must have a parent");64  assert(A->getMF() == B->getMF() &&65         "Operands must be in the same MachineFunction");66  return InstNumberMap.lookup(A) < InstNumberMap.lookup(B);67}68 69bool DbgValueHistoryMap::startDbgValue(InlinedEntity Var,70                                       const MachineInstr &MI,71                                       EntryIndex &NewIndex) {72  // Instruction range should start with a DBG_VALUE instruction for the73  // variable.74  assert(MI.isDebugValue() && "not a DBG_VALUE");75  auto &Entries = VarEntries[Var];76  if (!Entries.empty() && Entries.back().isDbgValue() &&77      !Entries.back().isClosed() &&78      Entries.back().getInstr()->isEquivalentDbgInstr(MI)) {79    LLVM_DEBUG(dbgs() << "Coalescing identical DBG_VALUE entries:\n"80                      << "\t" << Entries.back().getInstr() << "\t" << MI81                      << "\n");82    return false;83  }84  Entries.emplace_back(&MI, Entry::DbgValue);85  NewIndex = Entries.size() - 1;86  return true;87}88 89EntryIndex DbgValueHistoryMap::startClobber(InlinedEntity Var,90                                            const MachineInstr &MI) {91  auto &Entries = VarEntries[Var];92  // If an instruction clobbers multiple registers that the variable is93  // described by, then we may have already created a clobbering instruction.94  if (Entries.back().isClobber() && Entries.back().getInstr() == &MI)95    return Entries.size() - 1;96  Entries.emplace_back(&MI, Entry::Clobber);97  return Entries.size() - 1;98}99 100void DbgValueHistoryMap::Entry::endEntry(EntryIndex Index) {101  // For now, instruction ranges are not allowed to cross basic block102  // boundaries.103  assert(isDbgValue() && "Setting end index for non-debug value");104  assert(!isClosed() && "End index has already been set");105  EndIndex = Index;106}107 108/// Check if the instruction range [StartMI, EndMI] intersects any instruction109/// range in Ranges. EndMI can be nullptr to indicate that the range is110/// unbounded. Assumes Ranges is ordered and disjoint. Returns true and points111/// to the first intersecting scope range if one exists.112static std::optional<ArrayRef<InsnRange>::iterator>113intersects(const MachineInstr *StartMI, const MachineInstr *EndMI,114           ArrayRef<InsnRange> Ranges, const InstructionOrdering &Ordering) {115  for (auto RangesI = Ranges.begin(), RangesE = Ranges.end();116       RangesI != RangesE; ++RangesI) {117    if (EndMI && Ordering.isBefore(EndMI, RangesI->first))118      return std::nullopt;119    if (EndMI && !Ordering.isBefore(RangesI->second, EndMI))120      return RangesI;121    if (Ordering.isBefore(StartMI, RangesI->second))122      return RangesI;123  }124  return std::nullopt;125}126 127void DbgValueHistoryMap::trimLocationRanges(128    const MachineFunction &MF, LexicalScopes &LScopes,129    const InstructionOrdering &Ordering) {130  // The indices of the entries we're going to remove for each variable.131  SmallVector<EntryIndex, 4> ToRemove;132  // Entry reference count for each variable. Clobbers left with no references133  // will be removed.134  SmallVector<int, 4> ReferenceCount;135  // Entries reference other entries by index. Offsets is used to remap these136  // references if any entries are removed.137  SmallVector<size_t, 4> Offsets;138 139  LLVM_DEBUG(dbgs() << "Trimming location ranges for function '" << MF.getName()140                    << "'\n");141 142  for (auto &Record : VarEntries) {143    auto &HistoryMapEntries = Record.second;144    if (HistoryMapEntries.empty())145      continue;146 147    InlinedEntity Entity = Record.first;148    const DILocalVariable *LocalVar = cast<DILocalVariable>(Entity.first);149 150    LexicalScope *Scope = nullptr;151    if (const DILocation *InlinedAt = Entity.second) {152      Scope = LScopes.findInlinedScope(LocalVar->getScope(), InlinedAt);153    } else {154      Scope = LScopes.findLexicalScope(LocalVar->getScope());155      // Ignore variables for non-inlined function level scopes. The scope156      // ranges (from scope->getRanges()) will not include any instructions157      // before the first one with a debug-location, which could cause us to158      // incorrectly drop a location. We could introduce special casing for159      // these variables, but it doesn't seem worth it because no out-of-scope160      // locations have been observed for variables declared in function level161      // scopes.162      if (Scope &&163          (Scope->getScopeNode() == Scope->getScopeNode()->getSubprogram()) &&164          (Scope->getScopeNode() == LocalVar->getScope()))165        continue;166    }167 168    // If there is no scope for the variable then something has probably gone169    // wrong.170    if (!Scope)171      continue;172 173    ToRemove.clear();174    // Zero the reference counts.175    ReferenceCount.assign(HistoryMapEntries.size(), 0);176    // Index of the DBG_VALUE which marks the start of the current location177    // range.178    EntryIndex StartIndex = 0;179    ArrayRef<InsnRange> ScopeRanges(Scope->getRanges());180    for (auto EI = HistoryMapEntries.begin(), EE = HistoryMapEntries.end();181         EI != EE; ++EI, ++StartIndex) {182      // Only DBG_VALUEs can open location ranges so skip anything else.183      if (!EI->isDbgValue())184        continue;185 186      // Index of the entry which closes this range.187      EntryIndex EndIndex = EI->getEndIndex();188      // If this range is closed bump the reference count of the closing entry.189      if (EndIndex != NoEntry)190        ReferenceCount[EndIndex] += 1;191      // Skip this location range if the opening entry is still referenced. It192      // may close a location range which intersects a scope range.193      // TODO: We could be 'smarter' and trim these kinds of ranges such that194      // they do not leak out of the scope ranges if they partially overlap.195      if (ReferenceCount[StartIndex] > 0)196        continue;197 198      const MachineInstr *StartMI = EI->getInstr();199      const MachineInstr *EndMI = EndIndex != NoEntry200                                      ? HistoryMapEntries[EndIndex].getInstr()201                                      : nullptr;202      // Check if the location range [StartMI, EndMI] intersects with any scope203      // range for the variable.204      if (auto R = intersects(StartMI, EndMI, ScopeRanges, Ordering)) {205        // Adjust ScopeRanges to exclude ranges which subsequent location ranges206        // cannot possibly intersect.207        ScopeRanges = ArrayRef<InsnRange>(*R, ScopeRanges.end());208      } else {209        // If the location range does not intersect any scope range then the210        // DBG_VALUE which opened this location range is usless, mark it for211        // removal.212        ToRemove.push_back(StartIndex);213        // Because we'll be removing this entry we need to update the reference214        // count of the closing entry, if one exists.215        if (EndIndex != NoEntry)216          ReferenceCount[EndIndex] -= 1;217        LLVM_DEBUG(dbgs() << "Dropping value outside scope range of variable: ";218                   StartMI->print(llvm::dbgs()););219      }220    }221 222    // If there is nothing to remove then jump to next variable.223    if (ToRemove.empty())224      continue;225 226    // Mark clobbers that will no longer close any location ranges for removal.227    for (size_t i = 0; i < HistoryMapEntries.size(); ++i)228      if (ReferenceCount[i] <= 0 && HistoryMapEntries[i].isClobber())229        ToRemove.push_back(i);230 231    llvm::sort(ToRemove);232 233    // Build an offset map so we can update the EndIndex of the remaining234    // entries.235    // Zero the offsets.236    Offsets.assign(HistoryMapEntries.size(), 0);237    size_t CurOffset = 0;238    auto ToRemoveItr = ToRemove.begin();239    for (size_t EntryIdx = *ToRemoveItr; EntryIdx < HistoryMapEntries.size();240         ++EntryIdx) {241      // Check if this is an entry which will be removed.242      if (ToRemoveItr != ToRemove.end() && *ToRemoveItr == EntryIdx) {243        ++ToRemoveItr;244        ++CurOffset;245      }246      Offsets[EntryIdx] = CurOffset;247    }248 249    // Update the EndIndex of the entries to account for those which will be250    // removed.251    for (auto &Entry : HistoryMapEntries)252      if (Entry.isClosed())253        Entry.EndIndex -= Offsets[Entry.EndIndex];254 255    // Now actually remove the entries. Iterate backwards so that our remaining256    // ToRemove indices are valid after each erase.257    for (EntryIndex Idx : llvm::reverse(ToRemove))258      HistoryMapEntries.erase(HistoryMapEntries.begin() + Idx);259    LLVM_DEBUG(llvm::dbgs() << "New HistoryMap('" << LocalVar->getName()260                            << "') size: " << HistoryMapEntries.size() << "\n");261  }262}263 264bool DbgValueHistoryMap::hasNonEmptyLocation(const Entries &Entries) const {265  for (const auto &Entry : Entries) {266    if (!Entry.isDbgValue())267      continue;268 269    const MachineInstr *MI = Entry.getInstr();270    assert(MI->isDebugValue());271    // A DBG_VALUE $noreg is an empty variable location272    if (MI->isUndefDebugValue())273      continue;274 275    return true;276  }277 278  return false;279}280 281void DbgLabelInstrMap::addInstr(InlinedEntity Label, const MachineInstr &MI) {282  assert(MI.isDebugLabel() && "not a DBG_LABEL");283  LabelInstr[Label] = &MI;284}285 286namespace {287 288// Maps physreg numbers to the variables they describe.289using InlinedEntity = DbgValueHistoryMap::InlinedEntity;290using RegDescribedVarsMap = std::map<unsigned, SmallVector<InlinedEntity, 1>>;291 292// Keeps track of the debug value entries that are currently live for each293// inlined entity. As the history map entries are stored in a SmallVector, they294// may be moved at insertion of new entries, so store indices rather than295// pointers.296using DbgValueEntriesMap = std::map<InlinedEntity, SmallSet<EntryIndex, 1>>;297 298} // end anonymous namespace299 300// Claim that @Var is not described by @RegNo anymore.301static void dropRegDescribedVar(RegDescribedVarsMap &RegVars, unsigned RegNo,302                                InlinedEntity Var) {303  const auto &I = RegVars.find(RegNo);304  assert(RegNo != 0U && I != RegVars.end());305  auto &VarSet = I->second;306  const auto &VarPos = llvm::find(VarSet, Var);307  assert(VarPos != VarSet.end());308  VarSet.erase(VarPos);309  // Don't keep empty sets in a map to keep it as small as possible.310  if (VarSet.empty())311    RegVars.erase(I);312}313 314// Claim that @Var is now described by @RegNo.315static void addRegDescribedVar(RegDescribedVarsMap &RegVars, unsigned RegNo,316                               InlinedEntity Var) {317  assert(RegNo != 0U);318  auto &VarSet = RegVars[RegNo];319  assert(!is_contained(VarSet, Var));320  VarSet.push_back(Var);321}322 323/// Create a clobbering entry and end all open debug value entries324/// for \p Var that are described by \p RegNo using that entry. Inserts into \p325/// FellowRegisters the set of Registers that were also used to describe \p Var326/// alongside \p RegNo.327static void clobberRegEntries(InlinedEntity Var, unsigned RegNo,328                              const MachineInstr &ClobberingInstr,329                              DbgValueEntriesMap &LiveEntries,330                              DbgValueHistoryMap &HistMap,331                              SmallVectorImpl<Register> &FellowRegisters) {332  EntryIndex ClobberIndex = HistMap.startClobber(Var, ClobberingInstr);333  // Close all entries whose values are described by the register.334  SmallVector<EntryIndex, 4> IndicesToErase;335  // If a given register appears in a live DBG_VALUE_LIST for Var alongside the336  // clobbered register, and never appears in a live DBG_VALUE* for Var without337  // the clobbered register, then it is no longer linked to the variable.338  SmallSet<Register, 4> MaybeRemovedRegisters;339  SmallSet<Register, 4> KeepRegisters;340  for (auto Index : LiveEntries[Var]) {341    auto &Entry = HistMap.getEntry(Var, Index);342    assert(Entry.isDbgValue() && "Not a DBG_VALUE in LiveEntries");343    if (Entry.getInstr()->isDebugEntryValue())344      continue;345    if (Entry.getInstr()->hasDebugOperandForReg(RegNo)) {346      IndicesToErase.push_back(Index);347      Entry.endEntry(ClobberIndex);348      for (const auto &MO : Entry.getInstr()->debug_operands())349        if (MO.isReg() && MO.getReg() && MO.getReg() != RegNo)350          MaybeRemovedRegisters.insert(MO.getReg());351    } else {352      for (const auto &MO : Entry.getInstr()->debug_operands())353        if (MO.isReg() && MO.getReg())354          KeepRegisters.insert(MO.getReg());355    }356  }357 358  for (Register Reg : MaybeRemovedRegisters)359    if (!KeepRegisters.contains(Reg))360      FellowRegisters.push_back(Reg);361 362  // Drop all entries that have ended.363  auto &Entries = LiveEntries[Var];364  for (auto Index : IndicesToErase)365    Entries.erase(Index);366}367 368/// Add a new debug value for \p Var. Closes all overlapping debug values.369static void handleNewDebugValue(InlinedEntity Var, const MachineInstr &DV,370                                RegDescribedVarsMap &RegVars,371                                DbgValueEntriesMap &LiveEntries,372                                DbgValueHistoryMap &HistMap) {373  EntryIndex NewIndex;374  if (HistMap.startDbgValue(Var, DV, NewIndex)) {375    // As we already need to iterate all LiveEntries when handling a DbgValue,376    // we use this map to avoid a more expensive check against RegVars. There377    // is an assert that we handle this correctly in addRegDescribedVar.378    //379    // In other terms, the presence in this map indicates the presence of a380    // corresponding entry in RegVars.381    //382    // The bool value then tracks whether an entry is to be retained (true) or383    // removed (false); as we end previous entries we speculatively assume they384    // can be dropped from RegVars, but we then also visit the new entry whose385    // set of debug register operands may overlap and "save" a reg from being386    // dropped.387    SmallDenseMap<unsigned, bool, 4> TrackedRegs;388 389    // If we have created a new debug value entry, close all preceding390    // live entries that overlap.391    SmallVector<EntryIndex, 4> IndicesToErase;392    const DIExpression *DIExpr = DV.getDebugExpression();393    for (auto Index : LiveEntries[Var]) {394      auto &Entry = HistMap.getEntry(Var, Index);395      assert(Entry.isDbgValue() && "Not a DBG_VALUE in LiveEntries");396      const MachineInstr &DV = *Entry.getInstr();397      bool Overlaps = DIExpr->fragmentsOverlap(DV.getDebugExpression());398      if (Overlaps) {399        IndicesToErase.push_back(Index);400        Entry.endEntry(NewIndex);401      }402      if (!DV.isDebugEntryValue())403        for (const MachineOperand &Op : DV.debug_operands())404          if (Op.isReg() && Op.getReg())405            TrackedRegs[Op.getReg()] |= !Overlaps;406    }407 408    // If the new debug value is described by a register, add tracking of409    // that register if it is not already tracked.410    if (!DV.isDebugEntryValue()) {411      for (const MachineOperand &Op : DV.debug_operands()) {412        if (Op.isReg() && Op.getReg()) {413          Register NewReg = Op.getReg();414          if (TrackedRegs.insert_or_assign(NewReg, true).second)415            addRegDescribedVar(RegVars, NewReg, Var);416          LiveEntries[Var].insert(NewIndex);417        }418      }419    }420 421    // Drop tracking of registers that are no longer used.422    for (auto I : TrackedRegs)423      if (!I.second)424        dropRegDescribedVar(RegVars, I.first, Var);425 426    // Drop all entries that have ended, and mark the new entry as live.427    auto &Entries = LiveEntries[Var];428    for (auto Index : IndicesToErase)429      Entries.erase(Index);430    Entries.insert(NewIndex);431  }432}433 434// Terminate the location range for variables described by register at435// @I by inserting @ClobberingInstr to their history.436static void clobberRegisterUses(RegDescribedVarsMap &RegVars,437                                RegDescribedVarsMap::iterator I,438                                DbgValueHistoryMap &HistMap,439                                DbgValueEntriesMap &LiveEntries,440                                const MachineInstr &ClobberingInstr) {441  // Iterate over all variables described by this register and add this442  // instruction to their history, clobbering it. All registers that also443  // describe the clobbered variables (i.e. in variadic debug values) will have444  // those Variables removed from their DescribedVars.445  for (const auto &Var : I->second) {446    SmallVector<Register, 4> FellowRegisters;447    clobberRegEntries(Var, I->first, ClobberingInstr, LiveEntries, HistMap,448                      FellowRegisters);449    for (Register RegNo : FellowRegisters)450      dropRegDescribedVar(RegVars, RegNo, Var);451  }452  RegVars.erase(I);453}454 455// Terminate the location range for variables described by register456// @RegNo by inserting @ClobberingInstr to their history.457static void clobberRegisterUses(RegDescribedVarsMap &RegVars, unsigned RegNo,458                                DbgValueHistoryMap &HistMap,459                                DbgValueEntriesMap &LiveEntries,460                                const MachineInstr &ClobberingInstr) {461  const auto &I = RegVars.find(RegNo);462  if (I == RegVars.end())463    return;464  clobberRegisterUses(RegVars, I, HistMap, LiveEntries, ClobberingInstr);465}466 467void llvm::calculateDbgEntityHistory(const MachineFunction *MF,468                                     const TargetRegisterInfo *TRI,469                                     DbgValueHistoryMap &DbgValues,470                                     DbgLabelInstrMap &DbgLabels) {471  const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();472  Register SP = TLI->getStackPointerRegisterToSaveRestore();473  Register FrameReg = TRI->getFrameRegister(*MF);474  RegDescribedVarsMap RegVars;475  DbgValueEntriesMap LiveEntries;476  for (const auto &MBB : *MF) {477    for (const auto &MI : MBB) {478      if (MI.isDebugValue()) {479        assert(MI.getNumOperands() > 1 && "Invalid DBG_VALUE instruction!");480        const DILocalVariable *RawVar = MI.getDebugVariable();481        assert(RawVar->isValidLocationForIntrinsic(MI.getDebugLoc()) &&482               "Expected inlined-at fields to agree");483        InlinedEntity Var(RawVar, MI.getDebugLoc()->getInlinedAt());484 485        handleNewDebugValue(Var, MI, RegVars, LiveEntries, DbgValues);486      } else if (MI.isDebugLabel()) {487        assert(MI.getNumOperands() == 1 && "Invalid DBG_LABEL instruction!");488        const DILabel *RawLabel = MI.getDebugLabel();489        assert(RawLabel->isValidLocationForIntrinsic(MI.getDebugLoc()) &&490            "Expected inlined-at fields to agree");491        // When collecting debug information for labels, there is no MCSymbol492        // generated for it. So, we keep MachineInstr in DbgLabels in order493        // to query MCSymbol afterward.494        InlinedEntity L(RawLabel, MI.getDebugLoc()->getInlinedAt());495        DbgLabels.addInstr(L, MI);496      }497 498      // Meta Instructions have no output and do not change any values and so499      // can be safely ignored.500      if (MI.isMetaInstruction())501        continue;502 503      // Other instructions may clobber registers which describe some variables.504      for (const MachineOperand &MO : MI.operands()) {505        if (MO.isReg() && MO.isDef() && MO.getReg()) {506          // Ignore call instructions that claim to clobber SP. The AArch64507          // backend does this for aggregate function arguments.508          if (MI.isCall() && MO.getReg() == SP)509            continue;510          // If this is a virtual register, only clobber it since it doesn't511          // have aliases.512          if (MO.getReg().isVirtual())513            clobberRegisterUses(RegVars, MO.getReg(), DbgValues, LiveEntries,514                                MI);515          // If this is a register def operand, it may end a debug value516          // range. Ignore frame-register defs in the epilogue and prologue,517          // we expect debuggers to understand that stack-locations are518          // invalid outside of the function body.519          else if (MO.getReg() != FrameReg ||520                   (!MI.getFlag(MachineInstr::FrameDestroy) &&521                   !MI.getFlag(MachineInstr::FrameSetup))) {522            for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid();523                 ++AI)524              clobberRegisterUses(RegVars, *AI, DbgValues, LiveEntries, MI);525          }526        } else if (MO.isRegMask()) {527          // If this is a register mask operand, clobber all debug values in528          // non-CSRs.529          SmallVector<unsigned, 32> RegsToClobber;530          // Don't consider SP to be clobbered by register masks.531          for (auto It : RegVars) {532            unsigned int Reg = It.first;533            if (Reg != SP && Register::isPhysicalRegister(Reg) &&534                MO.clobbersPhysReg(Reg))535              RegsToClobber.push_back(Reg);536          }537 538          for (unsigned Reg : RegsToClobber) {539            clobberRegisterUses(RegVars, Reg, DbgValues, LiveEntries, MI);540          }541        }542      } // End MO loop.543    }   // End instr loop.544 545    // Make sure locations for all variables are valid only until the end of546    // the basic block (unless it's the last basic block, in which case let547    // their liveness run off to the end of the function).548    if (!MBB.empty() && &MBB != &MF->back()) {549      // Iterate over all variables that have open debug values.550      for (auto &Pair : LiveEntries) {551        if (Pair.second.empty())552          continue;553 554        // Create a clobbering entry.555        EntryIndex ClobIdx = DbgValues.startClobber(Pair.first, MBB.back());556 557        // End all entries.558        for (EntryIndex Idx : Pair.second) {559          DbgValueHistoryMap::Entry &Ent = DbgValues.getEntry(Pair.first, Idx);560          assert(Ent.isDbgValue() && !Ent.isClosed());561          Ent.endEntry(ClobIdx);562        }563      }564 565      LiveEntries.clear();566      RegVars.clear();567    }568  }569}570 571#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)572LLVM_DUMP_METHOD void DbgValueHistoryMap::dump(StringRef FuncName) const {573  dbgs() << "DbgValueHistoryMap('" << FuncName << "'):\n";574  for (const auto &VarRangePair : *this) {575    const InlinedEntity &Var = VarRangePair.first;576    const Entries &Entries = VarRangePair.second;577 578    const DILocalVariable *LocalVar = cast<DILocalVariable>(Var.first);579    const DILocation *Location = Var.second;580 581    dbgs() << " - " << LocalVar->getName() << " at ";582 583    if (Location)584      dbgs() << Location->getFilename() << ":" << Location->getLine() << ":"585             << Location->getColumn();586    else587      dbgs() << "<unknown location>";588 589    dbgs() << " --\n";590 591    for (const auto &E : enumerate(Entries)) {592      const auto &Entry = E.value();593      dbgs() << "  Entry[" << E.index() << "]: ";594      if (Entry.isDbgValue())595        dbgs() << "Debug value\n";596      else597        dbgs() << "Clobber\n";598      dbgs() << "   Instr: " << *Entry.getInstr();599      if (Entry.isDbgValue()) {600        if (Entry.getEndIndex() == NoEntry)601          dbgs() << "   - Valid until end of function\n";602        else603          dbgs() << "   - Closed by Entry[" << Entry.getEndIndex() << "]\n";604      }605      dbgs() << "\n";606    }607  }608}609#endif610