llvm/lib/DebugInfo/CodeView/GlobalTypeTableBuilder.cpp

   1 //===- GlobalTypeTableBuilder.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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/DebugInfo/CodeView/GlobalTypeTableBuilder.h"
  10 #include "llvm/ADT/ArrayRef.h"
  11 #include "llvm/DebugInfo/CodeView/ContinuationRecordBuilder.h"
  12 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
  13 #include "llvm/Support/Allocator.h"
  14 #include "llvm/Support/ErrorHandling.h"
  15 #include <cassert>
  16 #include <cstdint>
  17 #include <cstring>
  18
  19 using namespace llvm;
  20 using namespace llvm::codeview;
  21
  22 TypeIndex GlobalTypeTableBuilder::nextTypeIndex() const {
  23   return TypeIndex::fromArrayIndex(SeenRecords.size());
  24 }
  25
  26 GlobalTypeTableBuilder::GlobalTypeTableBuilder(BumpPtrAllocator &Storage)
  27     : RecordStorage(Storage) {
  28   SeenRecords.reserve(4096);
  29 }
  30
  31 GlobalTypeTableBuilder::~GlobalTypeTableBuilder() = default;
  32
  33 std::optional<TypeIndex> GlobalTypeTableBuilder::getFirst() {
  34   if (empty())
  35     return std::nullopt;
  36
  37   return TypeIndex(TypeIndex::FirstNonSimpleIndex);
  38 }
  39
  40 std::optional<TypeIndex> GlobalTypeTableBuilder::getNext(TypeIndex Prev) {
  41   if (++Prev == nextTypeIndex())
  42     return std::nullopt;
  43   return Prev;
  44 }
  45
  46 CVType GlobalTypeTableBuilder::getType(TypeIndex Index) {
  47   CVType Type(SeenRecords[Index.toArrayIndex()]);
  48   return Type;
  49 }
  50
  51 StringRef GlobalTypeTableBuilder::getTypeName(TypeIndex Index) {
  52   llvm_unreachable("Method not implemented");
  53 }
  54
  55 bool GlobalTypeTableBuilder::contains(TypeIndex Index) {
  56   if (Index.isSimple() || Index.isNoneType())
  57     return false;
  58
  59   return Index.toArrayIndex() < SeenRecords.size();
  60 }
  61
  62 uint32_t GlobalTypeTableBuilder::size() { return SeenRecords.size(); }
  63
  64 uint32_t GlobalTypeTableBuilder::capacity() { return SeenRecords.size(); }
  65
  66 ArrayRef<ArrayRef<uint8_t>> GlobalTypeTableBuilder::records() const {
  67   return SeenRecords;
  68 }
  69
  70 ArrayRef<GloballyHashedType> GlobalTypeTableBuilder::hashes() const {
  71   return SeenHashes;
  72 }
  73
  74 void GlobalTypeTableBuilder::reset() {
  75   HashedRecords.clear();
  76   SeenRecords.clear();
  77 }
  78
  79 static inline ArrayRef<uint8_t> stabilize(BumpPtrAllocator &Alloc,
  80                                           ArrayRef<uint8_t> Data) {
  81   uint8_t *Stable = Alloc.Allocate<uint8_t>(Data.size());
  82   memcpy(Stable, Data.data(), Data.size());
  83   return ArrayRef(Stable, Data.size());
  84 }
  85
  86 TypeIndex GlobalTypeTableBuilder::insertRecordBytes(ArrayRef<uint8_t> Record) {
  87   GloballyHashedType GHT =
  88       GloballyHashedType::hashType(Record, SeenHashes, SeenHashes);
  89   return insertRecordAs(GHT, Record.size(),
  90                         [Record](MutableArrayRef<uint8_t> Data) {
  91                           assert(Data.size() == Record.size());
  92                           ::memcpy(Data.data(), Record.data(), Record.size());
  93                           return Data;
  94                         });
  95 }
  96
  97 TypeIndex
  98 GlobalTypeTableBuilder::insertRecord(ContinuationRecordBuilder &Builder) {
  99   TypeIndex TI;
 100   auto Fragments = Builder.end(nextTypeIndex());
 101   assert(!Fragments.empty());
 102   for (auto C : Fragments)
 103     TI = insertRecordBytes(C.RecordData);
 104   return TI;
 105 }
 106
 107 bool GlobalTypeTableBuilder::replaceType(TypeIndex &Index, CVType Data,
 108                                          bool Stabilize) {
 109   assert(Index.toArrayIndex() < SeenRecords.size() &&
 110          "This function cannot be used to insert records!");
 111
 112   ArrayRef<uint8_t> Record = Data.data();
 113   assert(Record.size() < UINT32_MAX && "Record too big");
 114   assert(Record.size() % 4 == 0 &&
 115          "The type record size is not a multiple of 4 bytes which will cause "
 116          "misalignment in the output TPI stream!");
 117
 118   GloballyHashedType Hash =
 119       GloballyHashedType::hashType(Record, SeenHashes, SeenHashes);
 120   auto Result = HashedRecords.try_emplace(Hash, Index.toArrayIndex());
 121   if (!Result.second) {
 122     Index = Result.first->second;
 123     return false; // The record is already there, at a different location
 124   }
 125
 126   if (Stabilize)
 127     Record = stabilize(RecordStorage, Record);
 128
 129   SeenRecords[Index.toArrayIndex()] = Record;
 130   SeenHashes[Index.toArrayIndex()] = Hash;
 131   return true;
 132 }