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/None.h"
12 #include "llvm/DebugInfo/CodeView/CodeView.h"
13 #include "llvm/DebugInfo/CodeView/ContinuationRecordBuilder.h"
14 #include "llvm/DebugInfo/CodeView/TypeHashing.h"
15 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
16 #include "llvm/Support/Allocator.h"
17 #include "llvm/Support/ErrorHandling.h"
18 #include <cassert>
19 #include <cstdint>
20 #include <cstring>
21
22 using namespace llvm;
23 using namespace llvm::codeview;
24
nextTypeIndex() const25 TypeIndex MergingTypeTableBuilder::nextTypeIndex() const {
26 return TypeIndex::fromArrayIndex(SeenRecords.size());
27 }
28
MergingTypeTableBuilder(BumpPtrAllocator & Storage)29 MergingTypeTableBuilder::MergingTypeTableBuilder(BumpPtrAllocator &Storage)
30 : RecordStorage(Storage) {
31 SeenRecords.reserve(4096);
32 }
33
34 MergingTypeTableBuilder::~MergingTypeTableBuilder() = default;
35
getFirst()36 Optional<TypeIndex> MergingTypeTableBuilder::getFirst() {
37 if (empty())
38 return None;
39
40 return TypeIndex(TypeIndex::FirstNonSimpleIndex);
41 }
42
getNext(TypeIndex Prev)43 Optional<TypeIndex> MergingTypeTableBuilder::getNext(TypeIndex Prev) {
44 if (++Prev == nextTypeIndex())
45 return None;
46 return Prev;
47 }
48
getType(TypeIndex Index)49 CVType MergingTypeTableBuilder::getType(TypeIndex Index) {
50 CVType Type(SeenRecords[Index.toArrayIndex()]);
51 return Type;
52 }
53
getTypeName(TypeIndex Index)54 StringRef MergingTypeTableBuilder::getTypeName(TypeIndex Index) {
55 llvm_unreachable("Method not implemented");
56 }
57
contains(TypeIndex Index)58 bool MergingTypeTableBuilder::contains(TypeIndex Index) {
59 if (Index.isSimple() || Index.isNoneType())
60 return false;
61
62 return Index.toArrayIndex() < SeenRecords.size();
63 }
64
size()65 uint32_t MergingTypeTableBuilder::size() { return SeenRecords.size(); }
66
capacity()67 uint32_t MergingTypeTableBuilder::capacity() { return SeenRecords.size(); }
68
records() const69 ArrayRef<ArrayRef<uint8_t>> MergingTypeTableBuilder::records() const {
70 return SeenRecords;
71 }
72
reset()73 void MergingTypeTableBuilder::reset() {
74 HashedRecords.clear();
75 SeenRecords.clear();
76 }
77
stabilize(BumpPtrAllocator & Alloc,ArrayRef<uint8_t> Data)78 static inline ArrayRef<uint8_t> stabilize(BumpPtrAllocator &Alloc,
79 ArrayRef<uint8_t> Data) {
80 uint8_t *Stable = Alloc.Allocate<uint8_t>(Data.size());
81 memcpy(Stable, Data.data(), Data.size());
82 return makeArrayRef(Stable, Data.size());
83 }
84
insertRecordAs(hash_code Hash,ArrayRef<uint8_t> & Record)85 TypeIndex MergingTypeTableBuilder::insertRecordAs(hash_code Hash,
86 ArrayRef<uint8_t> &Record) {
87 assert(Record.size() < UINT32_MAX && "Record too big");
88 assert(Record.size() % 4 == 0 &&
89 "The type record size is not a multiple of 4 bytes which will cause "
90 "misalignment in the output TPI stream!");
91
92 LocallyHashedType WeakHash{Hash, Record};
93 auto Result = HashedRecords.try_emplace(WeakHash, nextTypeIndex());
94
95 if (Result.second) {
96 ArrayRef<uint8_t> RecordData = stabilize(RecordStorage, Record);
97 Result.first->first.RecordData = RecordData;
98 SeenRecords.push_back(RecordData);
99 }
100
101 // Update the caller's copy of Record to point a stable copy.
102 TypeIndex ActualTI = Result.first->second;
103 Record = SeenRecords[ActualTI.toArrayIndex()];
104 return ActualTI;
105 }
106
107 TypeIndex
insertRecordBytes(ArrayRef<uint8_t> & Record)108 MergingTypeTableBuilder::insertRecordBytes(ArrayRef<uint8_t> &Record) {
109 return insertRecordAs(hash_value(Record), Record);
110 }
111
112 TypeIndex
insertRecord(ContinuationRecordBuilder & Builder)113 MergingTypeTableBuilder::insertRecord(ContinuationRecordBuilder &Builder) {
114 TypeIndex TI;
115 auto Fragments = Builder.end(nextTypeIndex());
116 assert(!Fragments.empty());
117 for (auto C : Fragments)
118 TI = insertRecordBytes(C.RecordData);
119 return TI;
120 }
121
replaceType(TypeIndex & Index,CVType Data,bool Stabilize)122 bool MergingTypeTableBuilder::replaceType(TypeIndex &Index, CVType Data,
123 bool Stabilize) {
124 assert(Index.toArrayIndex() < SeenRecords.size() &&
125 "This function cannot be used to insert records!");
126
127 ArrayRef<uint8_t> Record = Data.data();
128 assert(Record.size() < UINT32_MAX && "Record too big");
129 assert(Record.size() % 4 == 0 &&
130 "The type record size is not a multiple of 4 bytes which will cause "
131 "misalignment in the output TPI stream!");
132
133 LocallyHashedType WeakHash{hash_value(Record), Record};
134 auto Result = HashedRecords.try_emplace(WeakHash, Index.toArrayIndex());
135 if (!Result.second) {
136 Index = Result.first->second;
137 return false; // The record is already there, at a different location
138 }
139
140 if (Stabilize) {
141 Record = stabilize(RecordStorage, Record);
142 Result.first->first.RecordData = Record;
143 }
144
145 SeenRecords[Index.toArrayIndex()] = Record;
146 return true;
147 }
148