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/DebugInfo/CodeView/CodeView.h"
12 #include "llvm/DebugInfo/CodeView/ContinuationRecordBuilder.h"
13 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
14 #include "llvm/Support/Allocator.h"
15 #include "llvm/Support/ErrorHandling.h"
16 #include <cassert>
17 #include <cstdint>
18 #include <cstring>
19
20 using namespace llvm;
21 using namespace llvm::codeview;
22
nextTypeIndex() const23 TypeIndex GlobalTypeTableBuilder::nextTypeIndex() const {
24 return TypeIndex::fromArrayIndex(SeenRecords.size());
25 }
26
GlobalTypeTableBuilder(BumpPtrAllocator & Storage)27 GlobalTypeTableBuilder::GlobalTypeTableBuilder(BumpPtrAllocator &Storage)
28 : RecordStorage(Storage) {
29 SeenRecords.reserve(4096);
30 }
31
32 GlobalTypeTableBuilder::~GlobalTypeTableBuilder() = default;
33
getFirst()34 std::optional<TypeIndex> GlobalTypeTableBuilder::getFirst() {
35 if (empty())
36 return std::nullopt;
37
38 return TypeIndex(TypeIndex::FirstNonSimpleIndex);
39 }
40
getNext(TypeIndex Prev)41 std::optional<TypeIndex> GlobalTypeTableBuilder::getNext(TypeIndex Prev) {
42 if (++Prev == nextTypeIndex())
43 return std::nullopt;
44 return Prev;
45 }
46
getType(TypeIndex Index)47 CVType GlobalTypeTableBuilder::getType(TypeIndex Index) {
48 CVType Type(SeenRecords[Index.toArrayIndex()]);
49 return Type;
50 }
51
getTypeName(TypeIndex Index)52 StringRef GlobalTypeTableBuilder::getTypeName(TypeIndex Index) {
53 llvm_unreachable("Method not implemented");
54 }
55
contains(TypeIndex Index)56 bool GlobalTypeTableBuilder::contains(TypeIndex Index) {
57 if (Index.isSimple() || Index.isNoneType())
58 return false;
59
60 return Index.toArrayIndex() < SeenRecords.size();
61 }
62
size()63 uint32_t GlobalTypeTableBuilder::size() { return SeenRecords.size(); }
64
capacity()65 uint32_t GlobalTypeTableBuilder::capacity() { return SeenRecords.size(); }
66
records() const67 ArrayRef<ArrayRef<uint8_t>> GlobalTypeTableBuilder::records() const {
68 return SeenRecords;
69 }
70
hashes() const71 ArrayRef<GloballyHashedType> GlobalTypeTableBuilder::hashes() const {
72 return SeenHashes;
73 }
74
reset()75 void GlobalTypeTableBuilder::reset() {
76 HashedRecords.clear();
77 SeenRecords.clear();
78 }
79
stabilize(BumpPtrAllocator & Alloc,ArrayRef<uint8_t> Data)80 static inline ArrayRef<uint8_t> stabilize(BumpPtrAllocator &Alloc,
81 ArrayRef<uint8_t> Data) {
82 uint8_t *Stable = Alloc.Allocate<uint8_t>(Data.size());
83 memcpy(Stable, Data.data(), Data.size());
84 return ArrayRef(Stable, Data.size());
85 }
86
insertRecordBytes(ArrayRef<uint8_t> Record)87 TypeIndex GlobalTypeTableBuilder::insertRecordBytes(ArrayRef<uint8_t> Record) {
88 GloballyHashedType GHT =
89 GloballyHashedType::hashType(Record, SeenHashes, SeenHashes);
90 return insertRecordAs(GHT, Record.size(),
91 [Record](MutableArrayRef<uint8_t> Data) {
92 assert(Data.size() == Record.size());
93 ::memcpy(Data.data(), Record.data(), Record.size());
94 return Data;
95 });
96 }
97
98 TypeIndex
insertRecord(ContinuationRecordBuilder & Builder)99 GlobalTypeTableBuilder::insertRecord(ContinuationRecordBuilder &Builder) {
100 TypeIndex TI;
101 auto Fragments = Builder.end(nextTypeIndex());
102 assert(!Fragments.empty());
103 for (auto C : Fragments)
104 TI = insertRecordBytes(C.RecordData);
105 return TI;
106 }
107
replaceType(TypeIndex & Index,CVType Data,bool Stabilize)108 bool GlobalTypeTableBuilder::replaceType(TypeIndex &Index, CVType Data,
109 bool Stabilize) {
110 assert(Index.toArrayIndex() < SeenRecords.size() &&
111 "This function cannot be used to insert records!");
112
113 ArrayRef<uint8_t> Record = Data.data();
114 assert(Record.size() < UINT32_MAX && "Record too big");
115 assert(Record.size() % 4 == 0 &&
116 "The type record size is not a multiple of 4 bytes which will cause "
117 "misalignment in the output TPI stream!");
118
119 GloballyHashedType Hash =
120 GloballyHashedType::hashType(Record, SeenHashes, SeenHashes);
121 auto Result = HashedRecords.try_emplace(Hash, Index.toArrayIndex());
122 if (!Result.second) {
123 Index = Result.first->second;
124 return false; // The record is already there, at a different location
125 }
126
127 if (Stabilize)
128 Record = stabilize(RecordStorage, Record);
129
130 SeenRecords[Index.toArrayIndex()] = Record;
131 SeenHashes[Index.toArrayIndex()] = Hash;
132 return true;
133 }
134