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Revert "[LLVM][DWARF] Add support for monolithic types in .debug_names (#68131)"
This reverts commit 9bbd2bf. Accidental commit: #68131 (comment)
1 parent 5181156 commit f320065

19 files changed

+126
-505
lines changed

‎llvm/include/llvm/CodeGen/AccelTable.h

+7-28
Original file line numberDiff line numberDiff line change
@@ -106,7 +106,6 @@ namespace llvm {
106106
class AsmPrinter;
107107
class DwarfCompileUnit;
108108
class DwarfDebug;
109-
class DwarfTypeUnit;
110109
class MCSymbol;
111110
class raw_ostream;
112111

@@ -198,9 +197,6 @@ template <typename DataT> class AccelTable : public AccelTableBase {
198197

199198
template <typename... Types>
200199
void addName(DwarfStringPoolEntryRef Name, Types &&... Args);
201-
void clear() { Entries.clear(); }
202-
void addEntries(AccelTable<DataT> &Table);
203-
const StringEntries getEntries() const { return Entries; }
204200
};
205201

206202
template <typename AccelTableDataT>
@@ -219,16 +215,6 @@ void AccelTable<AccelTableDataT>::addName(DwarfStringPoolEntryRef Name,
219215
AccelTableDataT(std::forward<Types>(Args)...));
220216
}
221217

222-
template <typename AccelTableDataT>
223-
void AccelTable<AccelTableDataT>::addEntries(
224-
AccelTable<AccelTableDataT> &Table) {
225-
for (auto &Entry : Table.getEntries()) {
226-
for (AccelTableData *Value : Entry.second.Values)
227-
addName(Entry.second.Name,
228-
static_cast<AccelTableDataT *>(Value)->getDie());
229-
}
230-
}
231-
232218
/// A base class for different implementations of Data classes for Apple
233219
/// Accelerator Tables. The columns in the table are defined by the static Atoms
234220
/// variable defined on the subclasses.
@@ -264,10 +250,6 @@ class AppleAccelTableData : public AccelTableData {
264250
/// emitDWARF5AccelTable function.
265251
class DWARF5AccelTableData : public AccelTableData {
266252
public:
267-
struct AttributeEncoding {
268-
dwarf::Index Index;
269-
dwarf::Form Form;
270-
};
271253
static uint32_t hash(StringRef Name) { return caseFoldingDjbHash(Name); }
272254

273255
DWARF5AccelTableData(const DIE &Die) : Die(Die) {}
@@ -327,20 +309,17 @@ void emitAppleAccelTable(AsmPrinter *Asm, AccelTable<DataT> &Contents,
327309
void emitDWARF5AccelTable(AsmPrinter *Asm,
328310
AccelTable<DWARF5AccelTableData> &Contents,
329311
const DwarfDebug &DD,
330-
ArrayRef<std::unique_ptr<DwarfCompileUnit>> CUs,
331-
ArrayRef<std::unique_ptr<DwarfTypeUnit>> TUs);
332-
using GetIndexForEntryReturnType =
333-
std::optional<std::pair<unsigned, DWARF5AccelTableData::AttributeEncoding>>;
312+
ArrayRef<std::unique_ptr<DwarfCompileUnit>> CUs);
313+
334314
/// Emit a DWARFv5 Accelerator Table consisting of entries in the specified
335315
/// AccelTable. The \p CUs contains either symbols keeping offsets to the
336316
/// start of compilation unit, either offsets to the start of compilation
337317
/// unit themselves.
338-
void emitDWARF5AccelTable(AsmPrinter *Asm,
339-
AccelTable<DWARF5AccelTableStaticData> &Contents,
340-
ArrayRef<std::variant<MCSymbol *, uint64_t>> CUs,
341-
llvm::function_ref<GetIndexForEntryReturnType(
342-
const DWARF5AccelTableStaticData &)>
343-
getIndexForEntry);
318+
void emitDWARF5AccelTable(
319+
AsmPrinter *Asm, AccelTable<DWARF5AccelTableStaticData> &Contents,
320+
ArrayRef<std::variant<MCSymbol *, uint64_t>> CUs,
321+
llvm::function_ref<unsigned(const DWARF5AccelTableStaticData &)>
322+
getCUIndexForEntry);
344323

345324
/// Accelerator table data implementation for simple Apple accelerator tables
346325
/// with just a DIE reference.

‎llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp

+60-112
Original file line numberDiff line numberDiff line change
@@ -13,6 +13,7 @@
1313
#include "llvm/CodeGen/AccelTable.h"
1414
#include "DwarfCompileUnit.h"
1515
#include "llvm/ADT/STLExtras.h"
16+
#include "llvm/ADT/StringMap.h"
1617
#include "llvm/ADT/Twine.h"
1718
#include "llvm/BinaryFormat/Dwarf.h"
1819
#include "llvm/CodeGen/AsmPrinter.h"
@@ -199,30 +200,32 @@ class Dwarf5AccelTableWriter : public AccelTableWriter {
199200
uint32_t AugmentationStringSize = sizeof(AugmentationString);
200201
char AugmentationString[8] = {'L', 'L', 'V', 'M', '0', '7', '0', '0'};
201202

202-
Header(uint32_t CompUnitCount, uint32_t LocalTypeUnitCount,
203-
uint32_t BucketCount, uint32_t NameCount)
204-
: CompUnitCount(CompUnitCount), LocalTypeUnitCount(LocalTypeUnitCount),
205-
BucketCount(BucketCount), NameCount(NameCount) {}
203+
Header(uint32_t CompUnitCount, uint32_t BucketCount, uint32_t NameCount)
204+
: CompUnitCount(CompUnitCount), BucketCount(BucketCount),
205+
NameCount(NameCount) {}
206206

207207
void emit(Dwarf5AccelTableWriter &Ctx);
208208
};
209+
struct AttributeEncoding {
210+
dwarf::Index Index;
211+
dwarf::Form Form;
212+
};
209213

210214
Header Header;
211-
DenseMap<uint32_t, SmallVector<DWARF5AccelTableData::AttributeEncoding, 2>>
212-
Abbreviations;
215+
DenseMap<uint32_t, SmallVector<AttributeEncoding, 2>> Abbreviations;
213216
ArrayRef<std::variant<MCSymbol *, uint64_t>> CompUnits;
214-
ArrayRef<std::variant<MCSymbol *, uint64_t>> TypeUnits;
215-
llvm::function_ref<GetIndexForEntryReturnType(const DataT &)>
216-
getIndexForEntry;
217+
llvm::function_ref<unsigned(const DataT &)> getCUIndexForEntry;
217218
MCSymbol *ContributionEnd = nullptr;
218219
MCSymbol *AbbrevStart = Asm->createTempSymbol("names_abbrev_start");
219220
MCSymbol *AbbrevEnd = Asm->createTempSymbol("names_abbrev_end");
220221
MCSymbol *EntryPool = Asm->createTempSymbol("names_entries");
221222

222-
void populateAbbrevsMap();
223+
DenseSet<uint32_t> getUniqueTags() const;
224+
225+
// Right now, we emit uniform attributes for all tags.
226+
SmallVector<AttributeEncoding, 2> getUniformAttributes() const;
223227

224228
void emitCUList() const;
225-
void emitTUList() const;
226229
void emitBuckets() const;
227230
void emitStringOffsets() const;
228231
void emitAbbrevs() const;
@@ -233,9 +236,7 @@ class Dwarf5AccelTableWriter : public AccelTableWriter {
233236
Dwarf5AccelTableWriter(
234237
AsmPrinter *Asm, const AccelTableBase &Contents,
235238
ArrayRef<std::variant<MCSymbol *, uint64_t>> CompUnits,
236-
ArrayRef<std::variant<MCSymbol *, uint64_t>> TypeUnits,
237-
llvm::function_ref<GetIndexForEntryReturnType(const DataT &)>
238-
getIndexForEntry);
239+
llvm::function_ref<unsigned(const DataT &)> GetCUIndexForEntry);
239240

240241
void emit();
241242
};
@@ -387,39 +388,31 @@ void Dwarf5AccelTableWriter<DataT>::Header::emit(Dwarf5AccelTableWriter &Ctx) {
387388
Asm->OutStreamer->emitBytes({AugmentationString, AugmentationStringSize});
388389
}
389390

390-
static uint32_t constexpr LowerBitSize = dwarf::DW_IDX_type_hash;
391-
static uint32_t getTagFromAbbreviationTag(const uint32_t AbbrvTag) {
392-
return AbbrvTag >> LowerBitSize;
393-
}
394-
static uint32_t
395-
constructAbbreviationTag(const unsigned Tag,
396-
const GetIndexForEntryReturnType &EntryRet) {
397-
uint32_t AbbrvTag = 0;
398-
if (EntryRet)
399-
AbbrvTag |= 1 << EntryRet->second.Index;
400-
AbbrvTag |= 1 << dwarf::DW_IDX_die_offset;
401-
AbbrvTag |= Tag << LowerBitSize;
402-
return AbbrvTag;
403-
}
404391
template <typename DataT>
405-
void Dwarf5AccelTableWriter<DataT>::populateAbbrevsMap() {
392+
DenseSet<uint32_t> Dwarf5AccelTableWriter<DataT>::getUniqueTags() const {
393+
DenseSet<uint32_t> UniqueTags;
406394
for (auto &Bucket : Contents.getBuckets()) {
407395
for (auto *Hash : Bucket) {
408396
for (auto *Value : Hash->Values) {
409-
GetIndexForEntryReturnType EntryRet =
410-
getIndexForEntry(*static_cast<const DataT *>(Value));
411397
unsigned Tag = static_cast<const DataT *>(Value)->getDieTag();
412-
uint32_t AbbrvTag = constructAbbreviationTag(Tag, EntryRet);
413-
if (Abbreviations.count(AbbrvTag) == 0) {
414-
SmallVector<DWARF5AccelTableData::AttributeEncoding, 2> UA;
415-
if (EntryRet)
416-
UA.push_back(EntryRet->second);
417-
UA.push_back({dwarf::DW_IDX_die_offset, dwarf::DW_FORM_ref4});
418-
Abbreviations.try_emplace(AbbrvTag, UA);
419-
}
398+
UniqueTags.insert(Tag);
420399
}
421400
}
422401
}
402+
return UniqueTags;
403+
}
404+
405+
template <typename DataT>
406+
SmallVector<typename Dwarf5AccelTableWriter<DataT>::AttributeEncoding, 2>
407+
Dwarf5AccelTableWriter<DataT>::getUniformAttributes() const {
408+
SmallVector<AttributeEncoding, 2> UA;
409+
if (CompUnits.size() > 1) {
410+
size_t LargestCUIndex = CompUnits.size() - 1;
411+
dwarf::Form Form = DIEInteger::BestForm(/*IsSigned*/ false, LargestCUIndex);
412+
UA.push_back({dwarf::DW_IDX_compile_unit, Form});
413+
}
414+
UA.push_back({dwarf::DW_IDX_die_offset, dwarf::DW_FORM_ref4});
415+
return UA;
423416
}
424417

425418
template <typename DataT>
@@ -433,17 +426,6 @@ void Dwarf5AccelTableWriter<DataT>::emitCUList() const {
433426
}
434427
}
435428

436-
template <typename DataT>
437-
void Dwarf5AccelTableWriter<DataT>::emitTUList() const {
438-
for (const auto &TU : enumerate(TypeUnits)) {
439-
Asm->OutStreamer->AddComment("Type unit " + Twine(TU.index()));
440-
if (std::holds_alternative<MCSymbol *>(TU.value()))
441-
Asm->emitDwarfSymbolReference(std::get<MCSymbol *>(TU.value()));
442-
else
443-
Asm->emitDwarfLengthOrOffset(std::get<uint64_t>(TU.value()));
444-
}
445-
}
446-
447429
template <typename DataT>
448430
void Dwarf5AccelTableWriter<DataT>::emitBuckets() const {
449431
uint32_t Index = 1;
@@ -471,11 +453,10 @@ void Dwarf5AccelTableWriter<DataT>::emitAbbrevs() const {
471453
Asm->OutStreamer->emitLabel(AbbrevStart);
472454
for (const auto &Abbrev : Abbreviations) {
473455
Asm->OutStreamer->AddComment("Abbrev code");
474-
uint32_t Tag = getTagFromAbbreviationTag(Abbrev.first);
475-
assert(Tag != 0);
456+
assert(Abbrev.first != 0);
457+
Asm->emitULEB128(Abbrev.first);
458+
Asm->OutStreamer->AddComment(dwarf::TagString(Abbrev.first));
476459
Asm->emitULEB128(Abbrev.first);
477-
Asm->OutStreamer->AddComment(dwarf::TagString(Tag));
478-
Asm->emitULEB128(Tag);
479460
for (const auto &AttrEnc : Abbrev.second) {
480461
Asm->emitULEB128(AttrEnc.Index, dwarf::IndexString(AttrEnc.Index).data());
481462
Asm->emitULEB128(AttrEnc.Form,
@@ -490,21 +471,16 @@ void Dwarf5AccelTableWriter<DataT>::emitAbbrevs() const {
490471

491472
template <typename DataT>
492473
void Dwarf5AccelTableWriter<DataT>::emitEntry(const DataT &Entry) const {
493-
GetIndexForEntryReturnType EntryRet = getIndexForEntry(Entry);
494-
uint32_t AbbrvTag = constructAbbreviationTag(Entry.getDieTag(), EntryRet);
495-
auto AbbrevIt = Abbreviations.find(AbbrvTag);
474+
auto AbbrevIt = Abbreviations.find(Entry.getDieTag());
496475
assert(AbbrevIt != Abbreviations.end() &&
497476
"Why wasn't this abbrev generated?");
498-
assert(getTagFromAbbreviationTag(AbbrevIt->first) == Entry.getDieTag() &&
499-
"Invalid Tag");
500-
Asm->emitULEB128(AbbrevIt->first, "Abbreviation code");
501477

478+
Asm->emitULEB128(AbbrevIt->first, "Abbreviation code");
502479
for (const auto &AttrEnc : AbbrevIt->second) {
503480
Asm->OutStreamer->AddComment(dwarf::IndexString(AttrEnc.Index));
504481
switch (AttrEnc.Index) {
505-
case dwarf::DW_IDX_compile_unit:
506-
case dwarf::DW_IDX_type_unit: {
507-
DIEInteger ID(EntryRet->first);
482+
case dwarf::DW_IDX_compile_unit: {
483+
DIEInteger ID(getCUIndexForEntry(Entry));
508484
ID.emitValue(Asm, AttrEnc.Form);
509485
break;
510486
}
@@ -536,21 +512,22 @@ template <typename DataT>
536512
Dwarf5AccelTableWriter<DataT>::Dwarf5AccelTableWriter(
537513
AsmPrinter *Asm, const AccelTableBase &Contents,
538514
ArrayRef<std::variant<MCSymbol *, uint64_t>> CompUnits,
539-
ArrayRef<std::variant<MCSymbol *, uint64_t>> TypeUnits,
540-
llvm::function_ref<GetIndexForEntryReturnType(const DataT &)>
541-
getIndexForEntry)
515+
llvm::function_ref<unsigned(const DataT &)> getCUIndexForEntry)
542516
: AccelTableWriter(Asm, Contents, false),
543-
Header(CompUnits.size(), TypeUnits.size(), Contents.getBucketCount(),
517+
Header(CompUnits.size(), Contents.getBucketCount(),
544518
Contents.getUniqueNameCount()),
545-
CompUnits(CompUnits), TypeUnits(TypeUnits),
546-
getIndexForEntry(std::move(getIndexForEntry)) {
547-
populateAbbrevsMap();
519+
CompUnits(CompUnits), getCUIndexForEntry(std::move(getCUIndexForEntry)) {
520+
DenseSet<uint32_t> UniqueTags = getUniqueTags();
521+
SmallVector<AttributeEncoding, 2> UniformAttributes = getUniformAttributes();
522+
523+
Abbreviations.reserve(UniqueTags.size());
524+
for (uint32_t Tag : UniqueTags)
525+
Abbreviations.try_emplace(Tag, UniformAttributes);
548526
}
549527

550528
template <typename DataT> void Dwarf5AccelTableWriter<DataT>::emit() {
551529
Header.emit(*this);
552530
emitCUList();
553-
emitTUList();
554531
emitBuckets();
555532
emitHashes();
556533
emitStringOffsets();
@@ -568,17 +545,12 @@ void llvm::emitAppleAccelTableImpl(AsmPrinter *Asm, AccelTableBase &Contents,
568545
AppleAccelTableWriter(Asm, Contents, Atoms, SecBegin).emit();
569546
}
570547

571-
void llvm::emitDWARF5AccelTable(AsmPrinter *Asm,
572-
AccelTable<DWARF5AccelTableData> &Contents,
573-
const DwarfDebug &DD,
574-
ArrayRef<std::unique_ptr<DwarfCompileUnit>> CUs,
575-
ArrayRef<std::unique_ptr<DwarfTypeUnit>> TUs) {
548+
void llvm::emitDWARF5AccelTable(
549+
AsmPrinter *Asm, AccelTable<DWARF5AccelTableData> &Contents,
550+
const DwarfDebug &DD, ArrayRef<std::unique_ptr<DwarfCompileUnit>> CUs) {
576551
std::vector<std::variant<MCSymbol *, uint64_t>> CompUnits;
577-
std::vector<std::variant<MCSymbol *, uint64_t>> TypeUnits;
578552
SmallVector<unsigned, 1> CUIndex(CUs.size());
579-
DenseMap<const DIE *, unsigned> TUIndex(TUs.size());
580-
int CUCount = 0;
581-
int TUCount = 0;
553+
int Count = 0;
582554
for (const auto &CU : enumerate(CUs)) {
583555
switch (CU.value()->getCUNode()->getNameTableKind()) {
584556
case DICompileUnit::DebugNameTableKind::Default:
@@ -587,61 +559,37 @@ void llvm::emitDWARF5AccelTable(AsmPrinter *Asm,
587559
default:
588560
continue;
589561
}
590-
CUIndex[CU.index()] = CUCount++;
562+
CUIndex[CU.index()] = Count++;
591563
assert(CU.index() == CU.value()->getUniqueID());
592564
const DwarfCompileUnit *MainCU =
593565
DD.useSplitDwarf() ? CU.value()->getSkeleton() : CU.value().get();
594566
CompUnits.push_back(MainCU->getLabelBegin());
595567
}
596568

597-
for (const auto &TU : enumerate(TUs)) {
598-
switch (TU.value()->getCUNode()->getNameTableKind()) {
599-
case DICompileUnit::DebugNameTableKind::Default:
600-
break;
601-
default:
602-
continue;
603-
}
604-
TUIndex[&TU.value()->getUnitDie()] = TUCount++;
605-
const DwarfTypeUnit *MainTU = TU.value().get();
606-
TypeUnits.push_back(MainTU->getLabelBegin());
607-
}
608-
609569
if (CompUnits.empty())
610570
return;
611571

612572
Asm->OutStreamer->switchSection(
613573
Asm->getObjFileLowering().getDwarfDebugNamesSection());
614574

615575
Contents.finalize(Asm, "names");
616-
dwarf::Form CUIndexForm =
617-
DIEInteger::BestForm(/*IsSigned*/ false, CompUnits.size() - 1);
618-
dwarf::Form TUIndexForm =
619-
DIEInteger::BestForm(/*IsSigned*/ false, TypeUnits.size() - 1);
620576
Dwarf5AccelTableWriter<DWARF5AccelTableData>(
621-
Asm, Contents, CompUnits, TypeUnits,
622-
[&](const DWARF5AccelTableData &Entry) -> GetIndexForEntryReturnType {
577+
Asm, Contents, CompUnits,
578+
[&](const DWARF5AccelTableData &Entry) {
623579
const DIE *CUDie = Entry.getDie().getUnitDie();
624-
GetIndexForEntryReturnType Index = std::nullopt;
625-
if (CUDie->getTag() == dwarf::DW_TAG_type_unit)
626-
Index = {TUIndex[CUDie], {dwarf::DW_IDX_type_unit, TUIndexForm}};
627-
else if (CUIndex.size() > 1)
628-
Index = {CUIndex[DD.lookupCU(CUDie)->getUniqueID()],
629-
{dwarf::DW_IDX_compile_unit, CUIndexForm}};
630-
return Index;
580+
return CUIndex[DD.lookupCU(CUDie)->getUniqueID()];
631581
})
632582
.emit();
633583
}
634584

635585
void llvm::emitDWARF5AccelTable(
636586
AsmPrinter *Asm, AccelTable<DWARF5AccelTableStaticData> &Contents,
637587
ArrayRef<std::variant<MCSymbol *, uint64_t>> CUs,
638-
llvm::function_ref<
639-
GetIndexForEntryReturnType(const DWARF5AccelTableStaticData &)>
640-
getIndexForEntry) {
641-
std::vector<std::variant<MCSymbol *, uint64_t>> TypeUnits;
588+
llvm::function_ref<unsigned(const DWARF5AccelTableStaticData &)>
589+
getCUIndexForEntry) {
642590
Contents.finalize(Asm, "names");
643-
Dwarf5AccelTableWriter<DWARF5AccelTableStaticData>(
644-
Asm, Contents, CUs, TypeUnits, getIndexForEntry)
591+
Dwarf5AccelTableWriter<DWARF5AccelTableStaticData>(Asm, Contents, CUs,
592+
getCUIndexForEntry)
645593
.emit();
646594
}
647595

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