1 //===- GlobalTypeTableBuilder.h ----------------------------------*- C++-*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef LLVM_DEBUGINFO_CODEVIEW_GLOBALTYPETABLEBUILDER_H
11 #define LLVM_DEBUGINFO_CODEVIEW_GLOBALTYPETABLEBUILDER_H
12 
13 #include "llvm/ADT/ArrayRef.h"
14 #include "llvm/ADT/DenseSet.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/DebugInfo/CodeView/CodeView.h"
17 #include "llvm/DebugInfo/CodeView/SimpleTypeSerializer.h"
18 #include "llvm/DebugInfo/CodeView/TypeCollection.h"
19 #include "llvm/DebugInfo/CodeView/TypeHashing.h"
20 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
21 #include "llvm/Support/Allocator.h"
22 #include <cassert>
23 #include <cstdint>
24 #include <memory>
25 #include <vector>
26 
27 namespace llvm {
28 namespace codeview {
29 
30 class ContinuationRecordBuilder;
31 
32 class GlobalTypeTableBuilder : public TypeCollection {
33   /// Storage for records.  These need to outlive the TypeTableBuilder.
34   BumpPtrAllocator &RecordStorage;
35 
36   /// A serializer that can write non-continuation leaf types.  Only used as
37   /// a convenience function so that we can provide an interface method to
38   /// write an unserialized record.
39   SimpleTypeSerializer SimpleSerializer;
40 
41   /// Hash table.
42   DenseMap<GloballyHashedType, TypeIndex> HashedRecords;
43 
44   /// Contains a list of all records indexed by TypeIndex.toArrayIndex().
45   SmallVector<ArrayRef<uint8_t>, 2> SeenRecords;
46 
47   /// Contains a list of all hash values inexed by TypeIndex.toArrayIndex().
48   SmallVector<GloballyHashedType, 2> SeenHashes;
49 
50 public:
51   explicit GlobalTypeTableBuilder(BumpPtrAllocator &Storage);
52   ~GlobalTypeTableBuilder();
53 
54   // TypeTableCollection overrides
55   Optional<TypeIndex> getFirst() override;
56   Optional<TypeIndex> getNext(TypeIndex Prev) override;
57   CVType getType(TypeIndex Index) override;
58   StringRef getTypeName(TypeIndex Index) override;
59   bool contains(TypeIndex Index) override;
60   uint32_t size() override;
61   uint32_t capacity() override;
62 
63   // public interface
64   void reset();
65   TypeIndex nextTypeIndex() const;
66 
getAllocator()67   BumpPtrAllocator &getAllocator() { return RecordStorage; }
68 
69   ArrayRef<ArrayRef<uint8_t>> records() const;
70   ArrayRef<GloballyHashedType> hashes() const;
71 
72   template <typename CreateFunc>
insertRecordAs(GloballyHashedType Hash,size_t RecordSize,CreateFunc Create)73   TypeIndex insertRecordAs(GloballyHashedType Hash, size_t RecordSize,
74                            CreateFunc Create) {
75     auto Result = HashedRecords.try_emplace(Hash, nextTypeIndex());
76 
77     if (LLVM_UNLIKELY(Result.second)) {
78       uint8_t *Stable = RecordStorage.Allocate<uint8_t>(RecordSize);
79       MutableArrayRef<uint8_t> Data(Stable, RecordSize);
80       SeenRecords.push_back(Create(Data));
81       SeenHashes.push_back(Hash);
82     }
83 
84     // Update the caller's copy of Record to point a stable copy.
85     return Result.first->second;
86   }
87 
88   TypeIndex insertRecordBytes(ArrayRef<uint8_t> Data);
89   TypeIndex insertRecord(ContinuationRecordBuilder &Builder);
90 
writeLeafType(T & Record)91   template <typename T> TypeIndex writeLeafType(T &Record) {
92     ArrayRef<uint8_t> Data = SimpleSerializer.serialize(Record);
93     return insertRecordBytes(Data);
94   }
95 };
96 
97 } // end namespace codeview
98 } // end namespace llvm
99 
100 #endif // LLVM_DEBUGINFO_CODEVIEW_MERGINGTYPETABLEBUILDER_H
101