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/CodeView.h"
  12 #include "llvm/DebugInfo/CodeView/ContinuationRecordBuilder.h"
  13 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
  14 #include "llvm/Support/Allocator.h"
  15 #include "llvm/Support/ErrorHandling.h"
  16 #include <cassert>
  17 #include <cstdint>
  18 #include <cstring>
  19
  20 using namespace llvm;
  21 using namespace llvm::codeview;
  22
  23 TypeIndex GlobalTypeTableBuilder::nextTypeIndex() const {
  24   return TypeIndex::fromArrayIndex(SeenRecords.size());
  25 }
  26
  27 GlobalTypeTableBuilder::GlobalTypeTableBuilder(BumpPtrAllocator &Storage)
  28     : RecordStorage(Storage) {
  29   SeenRecords.reserve(4096);
  30 }
  31
  32 GlobalTypeTableBuilder::~GlobalTypeTableBuilder() = default;
  33
  34 std::optional<TypeIndex> GlobalTypeTableBuilder::getFirst() {
  35   if (empty())
  36     return std::nullopt;
  37
  38   return TypeIndex(TypeIndex::FirstNonSimpleIndex);
  39 }
  40
  41 std::optional<TypeIndex> GlobalTypeTableBuilder::getNext(TypeIndex Prev) {
  42   if (++Prev == nextTypeIndex())
  43     return std::nullopt;
  44   return Prev;
  45 }
  46
  47 CVType GlobalTypeTableBuilder::getType(TypeIndex Index) {
  48   CVType Type(SeenRecords[Index.toArrayIndex()]);
  49   return Type;
  50 }
  51
  52 StringRef GlobalTypeTableBuilder::getTypeName(TypeIndex Index) {
  53   llvm_unreachable("Method not implemented");
  54 }
  55
  56 bool GlobalTypeTableBuilder::contains(TypeIndex Index) {
  57   if (Index.isSimple() || Index.isNoneType())
  58     return false;
  59
  60   return Index.toArrayIndex() < SeenRecords.size();
  61 }
  62
  63 uint32_t GlobalTypeTableBuilder::size() { return SeenRecords.size(); }
  64
  65 uint32_t GlobalTypeTableBuilder::capacity() { return SeenRecords.size(); }
  66
  67 ArrayRef<ArrayRef<uint8_t>> GlobalTypeTableBuilder::records() const {
  68   return SeenRecords;
  69 }
  70
  71 ArrayRef<GloballyHashedType> GlobalTypeTableBuilder::hashes() const {
  72   return SeenHashes;
  73 }
  74
  75 void GlobalTypeTableBuilder::reset() {
  76   HashedRecords.clear();
  77   SeenRecords.clear();
  78 }
  79
  80 static inline ArrayRef<uint8_t> stabilize(BumpPtrAllocator &Alloc,
  81                                           ArrayRef<uint8_t> Data) {
  82   uint8_t *Stable = Alloc.Allocate<uint8_t>(Data.size());
  83   memcpy(Stable, Data.data(), Data.size());
  84   return ArrayRef(Stable, Data.size());
  85 }
  86
  87 TypeIndex GlobalTypeTableBuilder::insertRecordBytes(ArrayRef<uint8_t> Record) {
  88   GloballyHashedType GHT =
  89       GloballyHashedType::hashType(Record, SeenHashes, SeenHashes);
  90   return insertRecordAs(GHT, Record.size(),
  91                         [Record](MutableArrayRef<uint8_t> Data) {
  92                           assert(Data.size() == Record.size());
  93                           ::memcpy(Data.data(), Record.data(), Record.size());
  94                           return Data;
  95                         });
  96 }
  97
  98 TypeIndex
  99 GlobalTypeTableBuilder::insertRecord(ContinuationRecordBuilder &Builder) {
 100   TypeIndex TI;
 101   auto Fragments = Builder.end(nextTypeIndex());
 102   assert(!Fragments.empty());
 103   for (auto C : Fragments)
 104     TI = insertRecordBytes(C.RecordData);
 105   return TI;
 106 }
 107
 108 bool GlobalTypeTableBuilder::replaceType(TypeIndex &Index, CVType Data,
 109                                          bool Stabilize) {
 110   assert(Index.toArrayIndex() < SeenRecords.size() &&
 111          "This function cannot be used to insert records!");
 112
 113   ArrayRef<uint8_t> Record = Data.data();
 114   assert(Record.size() < UINT32_MAX && "Record too big");
 115   assert(Record.size() % 4 == 0 &&
 116          "The type record size is not a multiple of 4 bytes which will cause "
 117          "misalignment in the output TPI stream!");
 118
 119   GloballyHashedType Hash =
 120       GloballyHashedType::hashType(Record, SeenHashes, SeenHashes);
 121   auto Result = HashedRecords.try_emplace(Hash, Index.toArrayIndex());
 122   if (!Result.second) {
 123     Index = Result.first->second;
 124     return false; // The record is already there, at a different location
 125   }
 126
 127   if (Stabilize)
 128     Record = stabilize(RecordStorage, Record);
 129
 130   SeenRecords[Index.toArrayIndex()] = Record;
 131   SeenHashes[Index.toArrayIndex()] = Hash;
 132   return true;
 133 }