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/ADT/DenseSet.h"
12#include "llvm/ADT/STLExtras.h"
13#include "llvm/DebugInfo/CodeView/CodeView.h"
14#include "llvm/DebugInfo/CodeView/ContinuationRecordBuilder.h"
15#include "llvm/DebugInfo/CodeView/RecordSerialization.h"
16#include "llvm/DebugInfo/CodeView/TypeIndex.h"
17#include "llvm/Support/Allocator.h"
18#include "llvm/Support/BinaryByteStream.h"
19#include "llvm/Support/BinaryStreamWriter.h"
20#include "llvm/Support/Endian.h"
21#include "llvm/Support/Error.h"
22#include <algorithm>
23#include <cassert>
24#include <cstdint>
25#include <cstring>
26
27using namespace llvm;
28using namespace llvm::codeview;
29
30TypeIndex GlobalTypeTableBuilder::nextTypeIndex() const {
31  return TypeIndex::fromArrayIndex(SeenRecords.size());
32}
33
34GlobalTypeTableBuilder::GlobalTypeTableBuilder(BumpPtrAllocator &Storage)
35    : RecordStorage(Storage) {
36  SeenRecords.reserve(4096);
37}
38
39GlobalTypeTableBuilder::~GlobalTypeTableBuilder() = default;
40
41Optional<TypeIndex> GlobalTypeTableBuilder::getFirst() {
42  if (empty())
43    return None;
44
45  return TypeIndex(TypeIndex::FirstNonSimpleIndex);
46}
47
48Optional<TypeIndex> GlobalTypeTableBuilder::getNext(TypeIndex Prev) {
49  if (++Prev == nextTypeIndex())
50    return None;
51  return Prev;
52}
53
54CVType GlobalTypeTableBuilder::getType(TypeIndex Index) {
55  CVType Type(SeenRecords[Index.toArrayIndex()]);
56  return Type;
57}
58
59StringRef GlobalTypeTableBuilder::getTypeName(TypeIndex Index) {
60  llvm_unreachable("Method not implemented");
61}
62
63bool GlobalTypeTableBuilder::contains(TypeIndex Index) {
64  if (Index.isSimple() || Index.isNoneType())
65    return false;
66
67  return Index.toArrayIndex() < SeenRecords.size();
68}
69
70uint32_t GlobalTypeTableBuilder::size() { return SeenRecords.size(); }
71
72uint32_t GlobalTypeTableBuilder::capacity() { return SeenRecords.size(); }
73
74ArrayRef<ArrayRef<uint8_t>> GlobalTypeTableBuilder::records() const {
75  return SeenRecords;
76}
77
78ArrayRef<GloballyHashedType> GlobalTypeTableBuilder::hashes() const {
79  return SeenHashes;
80}
81
82void GlobalTypeTableBuilder::reset() {
83  HashedRecords.clear();
84  SeenRecords.clear();
85}
86
87static inline ArrayRef<uint8_t> stabilize(BumpPtrAllocator &Alloc,
88                                          ArrayRef<uint8_t> Data) {
89  uint8_t *Stable = Alloc.Allocate<uint8_t>(Data.size());
90  memcpy(Stable, Data.data(), Data.size());
91  return makeArrayRef(Stable, Data.size());
92}
93
94TypeIndex GlobalTypeTableBuilder::insertRecordBytes(ArrayRef<uint8_t> Record) {
95  GloballyHashedType GHT =
96      GloballyHashedType::hashType(Record, SeenHashes, SeenHashes);
97  return insertRecordAs(GHT, Record.size(),
98                        [Record](MutableArrayRef<uint8_t> Data) {
99                          assert(Data.size() == Record.size());
100                          ::memcpy(Data.data(), Record.data(), Record.size());
101                          return Data;
102                        });
103}
104
105TypeIndex
106GlobalTypeTableBuilder::insertRecord(ContinuationRecordBuilder &Builder) {
107  TypeIndex TI;
108  auto Fragments = Builder.end(nextTypeIndex());
109  assert(!Fragments.empty());
110  for (auto C : Fragments)
111    TI = insertRecordBytes(C.RecordData);
112  return TI;
113}
114
115bool GlobalTypeTableBuilder::replaceType(TypeIndex &Index, CVType Data,
116                                         bool Stabilize) {
117  assert(Index.toArrayIndex() < SeenRecords.size() &&
118         "This function cannot be used to insert records!");
119
120  ArrayRef<uint8_t> Record = Data.data();
121  assert(Record.size() < UINT32_MAX && "Record too big");
122  assert(Record.size() % 4 == 0 &&
123         "The type record size is not a multiple of 4 bytes which will cause "
124         "misalignment in the output TPI stream!");
125
126  GloballyHashedType Hash =
127      GloballyHashedType::hashType(Record, SeenHashes, SeenHashes);
128  auto Result = HashedRecords.try_emplace(Hash, Index.toArrayIndex());
129  if (!Result.second) {
130    Index = Result.first->second;
131    return false; // The record is already there, at a different location
132  }
133
134  if (Stabilize)
135    Record = stabilize(RecordStorage, Record);
136
137  SeenRecords[Index.toArrayIndex()] = Record;
138  SeenHashes[Index.toArrayIndex()] = Hash;
139  return true;
140}
141