GlobalTypeTableBuilder.h revision 363496 
1//===- GlobalTypeTableBuilder.h ----------------------------------*- C++-*-===//
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#ifndef LLVM_DEBUGINFO_CODEVIEW_GLOBALTYPETABLEBUILDER_H
10#define LLVM_DEBUGINFO_CODEVIEW_GLOBALTYPETABLEBUILDER_H
11
12#include "llvm/ADT/ArrayRef.h"
13#include "llvm/ADT/DenseSet.h"
14#include "llvm/ADT/SmallVector.h"
15#include "llvm/DebugInfo/CodeView/CodeView.h"
16#include "llvm/DebugInfo/CodeView/SimpleTypeSerializer.h"
17#include "llvm/DebugInfo/CodeView/TypeCollection.h"
18#include "llvm/DebugInfo/CodeView/TypeHashing.h"
19#include "llvm/DebugInfo/CodeView/TypeIndex.h"
20#include "llvm/Support/Allocator.h"
21#include <cassert>
22#include <cstdint>
23#include <memory>
24#include <vector>
25
26namespace llvm {
27namespace codeview {
28
29class ContinuationRecordBuilder;
30
31class GlobalTypeTableBuilder : public TypeCollection {
32  /// Storage for records.  These need to outlive the TypeTableBuilder.
33  BumpPtrAllocator &RecordStorage;
34
35  /// A serializer that can write non-continuation leaf types.  Only used as
36  /// a convenience function so that we can provide an interface method to
37  /// write an unserialized record.
38  SimpleTypeSerializer SimpleSerializer;
39
40  /// Hash table.
41  DenseMap<GloballyHashedType, TypeIndex> HashedRecords;
42
43  /// Contains a list of all records indexed by TypeIndex.toArrayIndex().
44  SmallVector<ArrayRef<uint8_t>, 2> SeenRecords;
45
46  /// Contains a list of all hash values indexed by TypeIndex.toArrayIndex().
47  SmallVector<GloballyHashedType, 2> SeenHashes;
48
49public:
50  explicit GlobalTypeTableBuilder(BumpPtrAllocator &Storage);
51  ~GlobalTypeTableBuilder();
52
53  // TypeTableCollection overrides
54  Optional<TypeIndex> getFirst() override;
55  Optional<TypeIndex> getNext(TypeIndex Prev) override;
56  CVType getType(TypeIndex Index) override;
57  StringRef getTypeName(TypeIndex Index) override;
58  bool contains(TypeIndex Index) override;
59  uint32_t size() override;
60  uint32_t capacity() override;
61
62  // public interface
63  void reset();
64  TypeIndex nextTypeIndex() const;
65
66  BumpPtrAllocator &getAllocator() { return RecordStorage; }
67
68  ArrayRef<ArrayRef<uint8_t>> records() const;
69  ArrayRef<GloballyHashedType> hashes() const;
70
71  template <typename CreateFunc>
72  TypeIndex insertRecordAs(GloballyHashedType Hash, size_t RecordSize,
73                           CreateFunc Create) {
74    assert(RecordSize < UINT32_MAX && "Record too big");
75    assert(RecordSize % 4 == 0 &&
76           "RecordSize is not a multiple of 4 bytes which will cause "
77           "misalignment in the output TPI stream!");
78
79    auto Result = HashedRecords.try_emplace(Hash, nextTypeIndex());
80
81    if (LLVM_UNLIKELY(Result.second /*inserted*/ ||
82                      Result.first->second.isSimple())) {
83      uint8_t *Stable = RecordStorage.Allocate<uint8_t>(RecordSize);
84      MutableArrayRef<uint8_t> Data(Stable, RecordSize);
85      ArrayRef<uint8_t> StableRecord = Create(Data);
86      if (StableRecord.empty()) {
87        // Records with forward references into the Type stream will be deferred
88        // for insertion at a later time, on the second pass.
89        Result.first->getSecond() = TypeIndex(SimpleTypeKind::NotTranslated);
90        return TypeIndex(SimpleTypeKind::NotTranslated);
91      }
92      if (Result.first->second.isSimple()) {
93        assert(Result.first->second.getIndex() ==
94               (uint32_t)SimpleTypeKind::NotTranslated);
95        // On the second pass, update with index to remapped record. The
96        // (initially misbehaved) record will now come *after* other records
97        // resolved in the first pass, with proper *back* references in the
98        // stream.
99        Result.first->second = nextTypeIndex();
100      }
101      SeenRecords.push_back(StableRecord);
102      SeenHashes.push_back(Hash);
103    }
104
105    return Result.first->second;
106  }
107
108  TypeIndex insertRecordBytes(ArrayRef<uint8_t> Data);
109  TypeIndex insertRecord(ContinuationRecordBuilder &Builder);
110
111  template <typename T> TypeIndex writeLeafType(T &Record) {
112    ArrayRef<uint8_t> Data = SimpleSerializer.serialize(Record);
113    return insertRecordBytes(Data);
114  }
115};
116
117} // end namespace codeview
118} // end namespace llvm
119
120#endif // LLVM_DEBUGINFO_CODEVIEW_MERGINGTYPETABLEBUILDER_H
121