MergingTypeTableBuilder.cpp revision 363496 
1//===- MergingTypeTableBuilder.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/MergingTypeTableBuilder.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 MergingTypeTableBuilder::nextTypeIndex() const {
31  return TypeIndex::fromArrayIndex(SeenRecords.size());
32}
33
34MergingTypeTableBuilder::MergingTypeTableBuilder(BumpPtrAllocator &Storage)
35    : RecordStorage(Storage) {
36  SeenRecords.reserve(4096);
37}
38
39MergingTypeTableBuilder::~MergingTypeTableBuilder() = default;
40
41Optional<TypeIndex> MergingTypeTableBuilder::getFirst() {
42  if (empty())
43    return None;
44
45  return TypeIndex(TypeIndex::FirstNonSimpleIndex);
46}
47
48Optional<TypeIndex> MergingTypeTableBuilder::getNext(TypeIndex Prev) {
49  if (++Prev == nextTypeIndex())
50    return None;
51  return Prev;
52}
53
54CVType MergingTypeTableBuilder::getType(TypeIndex Index) {
55  CVType Type(SeenRecords[Index.toArrayIndex()]);
56  return Type;
57}
58
59StringRef MergingTypeTableBuilder::getTypeName(TypeIndex Index) {
60  llvm_unreachable("Method not implemented");
61}
62
63bool MergingTypeTableBuilder::contains(TypeIndex Index) {
64  if (Index.isSimple() || Index.isNoneType())
65    return false;
66
67  return Index.toArrayIndex() < SeenRecords.size();
68}
69
70uint32_t MergingTypeTableBuilder::size() { return SeenRecords.size(); }
71
72uint32_t MergingTypeTableBuilder::capacity() { return SeenRecords.size(); }
73
74ArrayRef<ArrayRef<uint8_t>> MergingTypeTableBuilder::records() const {
75  return SeenRecords;
76}
77
78void MergingTypeTableBuilder::reset() {
79  HashedRecords.clear();
80  SeenRecords.clear();
81}
82
83static inline ArrayRef<uint8_t> stabilize(BumpPtrAllocator &Alloc,
84                                          ArrayRef<uint8_t> Data) {
85  uint8_t *Stable = Alloc.Allocate<uint8_t>(Data.size());
86  memcpy(Stable, Data.data(), Data.size());
87  return makeArrayRef(Stable, Data.size());
88}
89
90TypeIndex MergingTypeTableBuilder::insertRecordAs(hash_code Hash,
91                                                  ArrayRef<uint8_t> &Record) {
92  assert(Record.size() < UINT32_MAX && "Record too big");
93  assert(Record.size() % 4 == 0 &&
94         "The type record size is not a multiple of 4 bytes which will cause "
95         "misalignment in the output TPI stream!");
96
97  LocallyHashedType WeakHash{Hash, Record};
98  auto Result = HashedRecords.try_emplace(WeakHash, nextTypeIndex());
99
100  if (Result.second) {
101    ArrayRef<uint8_t> RecordData = stabilize(RecordStorage, Record);
102    Result.first->first.RecordData = RecordData;
103    SeenRecords.push_back(RecordData);
104  }
105
106  // Update the caller's copy of Record to point a stable copy.
107  TypeIndex ActualTI = Result.first->second;
108  Record = SeenRecords[ActualTI.toArrayIndex()];
109  return ActualTI;
110}
111
112TypeIndex
113MergingTypeTableBuilder::insertRecordBytes(ArrayRef<uint8_t> &Record) {
114  return insertRecordAs(hash_value(Record), Record);
115}
116
117TypeIndex
118MergingTypeTableBuilder::insertRecord(ContinuationRecordBuilder &Builder) {
119  TypeIndex TI;
120  auto Fragments = Builder.end(nextTypeIndex());
121  assert(!Fragments.empty());
122  for (auto C : Fragments)
123    TI = insertRecordBytes(C.RecordData);
124  return TI;
125}
126