[llvm] [BOLT][DWARF][NFC] Remove old GDB Index functions (PR #95019)
Sayhaan Siddiqui via llvm-commits
llvm-commits at lists.llvm.org
Mon Jun 10 11:24:22 PDT 2024
https://github.com/sayhaan updated https://github.com/llvm/llvm-project/pull/95019
>From 5283c9a6010a24cc3de3e2963cd5628083913b70 Mon Sep 17 00:00:00 2001
From: Sayhaan Siddiqui <sayhaan at meta.com>
Date: Tue, 4 Jun 2024 13:08:57 -0700
Subject: [PATCH] Remove old code for updating GDB Index
Summary:
Test Plan:
Reviewers:
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Tasks:
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Differential Revision: https://phabricator.intern.facebook.com/D58156979
---
bolt/include/bolt/Rewrite/DWARFRewriter.h | 11 --
bolt/lib/Rewrite/DWARFRewriter.cpp | 171 ----------------------
2 files changed, 182 deletions(-)
diff --git a/bolt/include/bolt/Rewrite/DWARFRewriter.h b/bolt/include/bolt/Rewrite/DWARFRewriter.h
index 3cc9d823c815b..4559ff5ff5159 100644
--- a/bolt/include/bolt/Rewrite/DWARFRewriter.h
+++ b/bolt/include/bolt/Rewrite/DWARFRewriter.h
@@ -150,9 +150,6 @@ class DWARFRewriter {
/// blocks) to be updated.
void updateDebugAddressRanges();
- /// Rewrite .gdb_index section if present.
- void updateGdbIndexSection(CUOffsetMap &CUMap, uint32_t NumCUs);
-
/// DWARFDie contains a pointer to a DIE and hence gets invalidated once the
/// embedded DIE is destroyed. This wrapper class stores a DIE internally and
/// could be cast to a DWARFDie that is valid even after the initial DIE is
@@ -194,14 +191,6 @@ class DWARFRewriter {
DwoRangesBase[DWOId] = RangesBase;
}
- /// Adds an GDBIndexTUEntry if .gdb_index seciton exists.
- void addGDBTypeUnitEntry(const GDBIndexTUEntry &&Entry);
-
- /// Returns all entries needed for Types CU list
- const GDBIndexTUEntryType &getGDBIndexTUEntryVector() const {
- return GDBIndexTUEntryVector;
- }
-
using OverriddenSectionsMap = std::unordered_map<DWARFSectionKind, StringRef>;
/// Output .dwo files.
void writeDWOFiles(DWARFUnit &, const OverriddenSectionsMap &,
diff --git a/bolt/lib/Rewrite/DWARFRewriter.cpp b/bolt/lib/Rewrite/DWARFRewriter.cpp
index 7b62999dfb2b6..04dc7e94e6031 100644
--- a/bolt/lib/Rewrite/DWARFRewriter.cpp
+++ b/bolt/lib/Rewrite/DWARFRewriter.cpp
@@ -2062,177 +2062,6 @@ void DWARFRewriter::writeDWOFiles(
TempOut->keep();
}
-void DWARFRewriter::addGDBTypeUnitEntry(const GDBIndexTUEntry &&Entry) {
- std::lock_guard<std::mutex> Lock(DWARFRewriterMutex);
- if (!BC.getGdbIndexSection())
- return;
- GDBIndexTUEntryVector.emplace_back(Entry);
-}
-
-void DWARFRewriter::updateGdbIndexSection(CUOffsetMap &CUMap, uint32_t NumCUs) {
- if (!BC.getGdbIndexSection())
- return;
-
- // See https://sourceware.org/gdb/onlinedocs/gdb/Index-Section-Format.html
- // for .gdb_index section format.
-
- StringRef GdbIndexContents = BC.getGdbIndexSection()->getContents();
-
- const char *Data = GdbIndexContents.data();
-
- // Parse the header.
- const uint32_t Version = read32le(Data);
- if (Version != 7 && Version != 8) {
- errs() << "BOLT-ERROR: can only process .gdb_index versions 7 and 8\n";
- exit(1);
- }
-
- // Some .gdb_index generators use file offsets while others use section
- // offsets. Hence we can only rely on offsets relative to each other,
- // and ignore their absolute values.
- const uint32_t CUListOffset = read32le(Data + 4);
- const uint32_t CUTypesOffset = read32le(Data + 8);
- const uint32_t AddressTableOffset = read32le(Data + 12);
- const uint32_t SymbolTableOffset = read32le(Data + 16);
- const uint32_t ConstantPoolOffset = read32le(Data + 20);
- Data += 24;
-
- // Map CUs offsets to indices and verify existing index table.
- std::map<uint32_t, uint32_t> OffsetToIndexMap;
- const uint32_t CUListSize = CUTypesOffset - CUListOffset;
- const uint32_t TUListSize = AddressTableOffset - CUTypesOffset;
- const unsigned NUmCUsEncoded = CUListSize / 16;
- unsigned MaxDWARFVersion = BC.DwCtx->getMaxVersion();
- unsigned NumDWARF5TUs =
- getGDBIndexTUEntryVector().size() - BC.DwCtx->getNumTypeUnits();
- bool SkipTypeUnits = false;
- // For DWARF5 Types are in .debug_info.
- // LLD doesn't generate Types CU List, and in CU list offset
- // only includes CUs.
- // GDB 11+ includes only CUs in CU list and generates Types
- // list.
- // GDB 9 includes CUs and TUs in CU list and generates TYpes
- // list. The NumCUs is CUs + TUs, so need to modify the check.
- // For split-dwarf
- // GDB-11, DWARF5: TU units from dwo are not included.
- // GDB-11, DWARF4: TU units from dwo are included.
- if (MaxDWARFVersion >= 5)
- SkipTypeUnits = !TUListSize ? true
- : ((NUmCUsEncoded + NumDWARF5TUs) ==
- BC.DwCtx->getNumCompileUnits());
-
- if (!((CUListSize == NumCUs * 16) ||
- (CUListSize == (NumCUs + NumDWARF5TUs) * 16))) {
- errs() << "BOLT-ERROR: .gdb_index: CU count mismatch\n";
- exit(1);
- }
- DenseSet<uint64_t> OriginalOffsets;
- for (unsigned Index = 0, Units = BC.DwCtx->getNumCompileUnits();
- Index < Units; ++Index) {
- const DWARFUnit *CU = BC.DwCtx->getUnitAtIndex(Index);
- if (SkipTypeUnits && CU->isTypeUnit())
- continue;
- const uint64_t Offset = read64le(Data);
- Data += 16;
- if (CU->getOffset() != Offset) {
- errs() << "BOLT-ERROR: .gdb_index CU offset mismatch\n";
- exit(1);
- }
-
- OriginalOffsets.insert(Offset);
- OffsetToIndexMap[Offset] = Index;
- }
-
- // Ignore old address table.
- const uint32_t OldAddressTableSize = SymbolTableOffset - AddressTableOffset;
- // Move Data to the beginning of symbol table.
- Data += SymbolTableOffset - CUTypesOffset;
-
- // Calculate the size of the new address table.
- uint32_t NewAddressTableSize = 0;
- for (const auto &CURangesPair : ARangesSectionWriter->getCUAddressRanges()) {
- const SmallVector<DebugAddressRange, 2> &Ranges = CURangesPair.second;
- NewAddressTableSize += Ranges.size() * 20;
- }
-
- // Difference between old and new table (and section) sizes.
- // Could be negative.
- int32_t Delta = NewAddressTableSize - OldAddressTableSize;
-
- size_t NewGdbIndexSize = GdbIndexContents.size() + Delta;
-
- // Free'd by ExecutableFileMemoryManager.
- auto *NewGdbIndexContents = new uint8_t[NewGdbIndexSize];
- uint8_t *Buffer = NewGdbIndexContents;
-
- write32le(Buffer, Version);
- write32le(Buffer + 4, CUListOffset);
- write32le(Buffer + 8, CUTypesOffset);
- write32le(Buffer + 12, AddressTableOffset);
- write32le(Buffer + 16, SymbolTableOffset + Delta);
- write32le(Buffer + 20, ConstantPoolOffset + Delta);
- Buffer += 24;
-
- using MapEntry = std::pair<uint32_t, CUInfo>;
- std::vector<MapEntry> CUVector(CUMap.begin(), CUMap.end());
- // Need to sort since we write out all of TUs in .debug_info before CUs.
- std::sort(CUVector.begin(), CUVector.end(),
- [](const MapEntry &E1, const MapEntry &E2) -> bool {
- return E1.second.Offset < E2.second.Offset;
- });
- // Writing out CU List <Offset, Size>
- for (auto &CUInfo : CUVector) {
- // Skipping TU for DWARF5 when they are not included in CU list.
- if (!OriginalOffsets.count(CUInfo.first))
- continue;
- write64le(Buffer, CUInfo.second.Offset);
- // Length encoded in CU doesn't contain first 4 bytes that encode length.
- write64le(Buffer + 8, CUInfo.second.Length + 4);
- Buffer += 16;
- }
-
- // Rewrite TU CU List, since abbrevs can be different.
- // Entry example:
- // 0: offset = 0x00000000, type_offset = 0x0000001e, type_signature =
- // 0x418503b8111e9a7b Spec says " triplet, the first value is the CU offset,
- // the second value is the type offset in the CU, and the third value is the
- // type signature" Looking at what is being generated by gdb-add-index. The
- // first entry is TU offset, second entry is offset from it, and third entry
- // is the type signature.
- if (TUListSize)
- for (const GDBIndexTUEntry &Entry : getGDBIndexTUEntryVector()) {
- write64le(Buffer, Entry.UnitOffset);
- write64le(Buffer + 8, Entry.TypeDIERelativeOffset);
- write64le(Buffer + 16, Entry.TypeHash);
- Buffer += sizeof(GDBIndexTUEntry);
- }
-
- // Generate new address table.
- for (const std::pair<const uint64_t, DebugAddressRangesVector> &CURangesPair :
- ARangesSectionWriter->getCUAddressRanges()) {
- const uint32_t CUIndex = OffsetToIndexMap[CURangesPair.first];
- const DebugAddressRangesVector &Ranges = CURangesPair.second;
- for (const DebugAddressRange &Range : Ranges) {
- write64le(Buffer, Range.LowPC);
- write64le(Buffer + 8, Range.HighPC);
- write32le(Buffer + 16, CUIndex);
- Buffer += 20;
- }
- }
-
- const size_t TrailingSize =
- GdbIndexContents.data() + GdbIndexContents.size() - Data;
- assert(Buffer + TrailingSize == NewGdbIndexContents + NewGdbIndexSize &&
- "size calculation error");
-
- // Copy over the rest of the original data.
- memcpy(Buffer, Data, TrailingSize);
-
- // Register the new section.
- BC.registerOrUpdateNoteSection(".gdb_index", NewGdbIndexContents,
- NewGdbIndexSize);
-}
-
std::unique_ptr<DebugBufferVector>
DWARFRewriter::makeFinalLocListsSection(DWARFVersion Version) {
auto LocBuffer = std::make_unique<DebugBufferVector>();
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