1//===- NamedStreamMap.cpp - PDB Named Stream Map --------------------------===//
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/PDB/Native/NamedStreamMap.h"
10#include "llvm/ADT/StringMap.h"
11#include "llvm/ADT/StringRef.h"
12#include "llvm/DebugInfo/PDB/Native/Hash.h"
13#include "llvm/DebugInfo/PDB/Native/HashTable.h"
14#include "llvm/DebugInfo/PDB/Native/RawError.h"
15#include "llvm/Support/BinaryStreamReader.h"
16#include "llvm/Support/BinaryStreamWriter.h"
17#include "llvm/Support/Endian.h"
18#include "llvm/Support/Error.h"
19#include <cassert>
20#include <cstdint>
21
22using namespace llvm;
23using namespace llvm::pdb;
24
25NamedStreamMapTraits::NamedStreamMapTraits(NamedStreamMap &NS) : NS(&NS) {}
26
27uint16_t NamedStreamMapTraits::hashLookupKey(StringRef S) const {
28 // In the reference implementation, this uses
29 // HASH Hasher<ULONG*, USHORT*>::hashPbCb(PB pb, size_t cb, ULONG ulMod).
30 // Here, the type HASH is a typedef of unsigned short.
31 // ** It is not a bug that we truncate the result of hashStringV1, in fact
32 // it is a bug if we do not! **
33 // See NMTNI::hash() in the reference implementation.
34 return static_cast<uint16_t>(hashStringV1(Str: S));
35}
36
37StringRef NamedStreamMapTraits::storageKeyToLookupKey(uint32_t Offset) const {
38 return NS->getString(Offset);
39}
40
41uint32_t NamedStreamMapTraits::lookupKeyToStorageKey(StringRef S) {
42 return NS->appendStringData(S);
43}
44
45NamedStreamMap::NamedStreamMap() : HashTraits(*this), OffsetIndexMap(1) {}
46
47Error NamedStreamMap::load(BinaryStreamReader &Stream) {
48 uint32_t StringBufferSize;
49 if (auto EC = Stream.readInteger(Dest&: StringBufferSize))
50 return joinErrors(E1: std::move(EC),
51 E2: make_error<RawError>(Args: raw_error_code::corrupt_file,
52 Args: "Expected string buffer size"));
53
54 StringRef Buffer;
55 if (auto EC = Stream.readFixedString(Dest&: Buffer, Length: StringBufferSize))
56 return EC;
57 NamesBuffer.assign(first: Buffer.begin(), last: Buffer.end());
58
59 return OffsetIndexMap.load(Stream);
60}
61
62Error NamedStreamMap::commit(BinaryStreamWriter &Writer) const {
63 // The first field is the number of bytes of string data.
64 if (auto EC = Writer.writeInteger<uint32_t>(Value: NamesBuffer.size()))
65 return EC;
66
67 // Then the actual string data.
68 StringRef Data(NamesBuffer.data(), NamesBuffer.size());
69 if (auto EC = Writer.writeFixedString(Str: Data))
70 return EC;
71
72 // And finally the Offset Index map.
73 if (auto EC = OffsetIndexMap.commit(Writer))
74 return EC;
75
76 return Error::success();
77}
78
79uint32_t NamedStreamMap::calculateSerializedLength() const {
80 return sizeof(uint32_t) // String data size
81 + NamesBuffer.size() // String data
82 + OffsetIndexMap.calculateSerializedLength(); // Offset Index Map
83}
84
85uint32_t NamedStreamMap::size() const { return OffsetIndexMap.size(); }
86
87StringRef NamedStreamMap::getString(uint32_t Offset) const {
88 assert(NamesBuffer.size() > Offset);
89 return StringRef(NamesBuffer.data() + Offset);
90}
91
92uint32_t NamedStreamMap::hashString(uint32_t Offset) const {
93 return hashStringV1(Str: getString(Offset));
94}
95
96bool NamedStreamMap::get(StringRef Stream, uint32_t &StreamNo) const {
97 auto Iter = OffsetIndexMap.find_as(K: Stream, Traits: HashTraits);
98 if (Iter == OffsetIndexMap.end())
99 return false;
100 StreamNo = (*Iter).second;
101 return true;
102}
103
104StringMap<uint32_t> NamedStreamMap::entries() const {
105 StringMap<uint32_t> Result;
106 for (const auto &Entry : OffsetIndexMap) {
107 StringRef Stream(NamesBuffer.data() + Entry.first);
108 Result.try_emplace(Key: Stream, Args: Entry.second);
109 }
110 return Result;
111}
112
113uint32_t NamedStreamMap::appendStringData(StringRef S) {
114 uint32_t Offset = NamesBuffer.size();
115 llvm::append_range(C&: NamesBuffer, R&: S);
116 NamesBuffer.push_back(x: '\0');
117 return Offset;
118}
119
120void NamedStreamMap::set(StringRef Stream, uint32_t StreamNo) {
121 OffsetIndexMap.set_as(K: Stream, V: support::ulittle32_t(StreamNo), Traits&: HashTraits);
122}
123