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/ADT/iterator_range.h"
13 #include "llvm/DebugInfo/PDB/Native/Hash.h"
14 #include "llvm/DebugInfo/PDB/Native/HashTable.h"
15 #include "llvm/DebugInfo/PDB/Native/RawError.h"
16 #include "llvm/Support/BinaryStreamReader.h"
17 #include "llvm/Support/BinaryStreamRef.h"
18 #include "llvm/Support/BinaryStreamWriter.h"
19 #include "llvm/Support/Endian.h"
20 #include "llvm/Support/Error.h"
21 #include <algorithm>
22 #include <cassert>
23 #include <cstdint>
24 #include <tuple>
25 
26 using namespace llvm;
27 using namespace llvm::pdb;
28 
29 NamedStreamMapTraits::NamedStreamMapTraits(NamedStreamMap &NS) : NS(&NS) {}
30 
31 uint16_t NamedStreamMapTraits::hashLookupKey(StringRef S) const {
32   // In the reference implementation, this uses
33   // HASH Hasher<ULONG*, USHORT*>::hashPbCb(PB pb, size_t cb, ULONG ulMod).
34   // Here, the type HASH is a typedef of unsigned short.
35   // ** It is not a bug that we truncate the result of hashStringV1, in fact
36   //    it is a bug if we do not! **
37   // See NMTNI::hash() in the reference implementation.
38   return static_cast<uint16_t>(hashStringV1(S));
39 }
40 
41 StringRef NamedStreamMapTraits::storageKeyToLookupKey(uint32_t Offset) const {
42   return NS->getString(Offset);
43 }
44 
45 uint32_t NamedStreamMapTraits::lookupKeyToStorageKey(StringRef S) {
46   return NS->appendStringData(S);
47 }
48 
49 NamedStreamMap::NamedStreamMap()
50     : HashTraits(*this), OffsetIndexMap(1, HashTraits) {}
51 
52 Error NamedStreamMap::load(BinaryStreamReader &Stream) {
53   uint32_t StringBufferSize;
54   if (auto EC = Stream.readInteger(StringBufferSize))
55     return joinErrors(std::move(EC),
56                       make_error<RawError>(raw_error_code::corrupt_file,
57                                            "Expected string buffer size"));
58 
59   StringRef Buffer;
60   if (auto EC = Stream.readFixedString(Buffer, StringBufferSize))
61     return EC;
62   NamesBuffer.assign(Buffer.begin(), Buffer.end());
63 
64   return OffsetIndexMap.load(Stream);
65 }
66 
67 Error NamedStreamMap::commit(BinaryStreamWriter &Writer) const {
68   // The first field is the number of bytes of string data.
69   if (auto EC = Writer.writeInteger<uint32_t>(NamesBuffer.size()))
70     return EC;
71 
72   // Then the actual string data.
73   StringRef Data(NamesBuffer.data(), NamesBuffer.size());
74   if (auto EC = Writer.writeFixedString(Data))
75     return EC;
76 
77   // And finally the Offset Index map.
78   if (auto EC = OffsetIndexMap.commit(Writer))
79     return EC;
80 
81   return Error::success();
82 }
83 
84 uint32_t NamedStreamMap::calculateSerializedLength() const {
85   return sizeof(uint32_t)                              // String data size
86          + NamesBuffer.size()                          // String data
87          + OffsetIndexMap.calculateSerializedLength(); // Offset Index Map
88 }
89 
90 uint32_t NamedStreamMap::size() const { return OffsetIndexMap.size(); }
91 
92 StringRef NamedStreamMap::getString(uint32_t Offset) const {
93   assert(NamesBuffer.size() > Offset);
94   return StringRef(NamesBuffer.data() + Offset);
95 }
96 
97 uint32_t NamedStreamMap::hashString(uint32_t Offset) const {
98   return hashStringV1(getString(Offset));
99 }
100 
101 bool NamedStreamMap::get(StringRef Stream, uint32_t &StreamNo) const {
102   auto Iter = OffsetIndexMap.find_as(Stream);
103   if (Iter == OffsetIndexMap.end())
104     return false;
105   StreamNo = (*Iter).second;
106   return true;
107 }
108 
109 StringMap<uint32_t> NamedStreamMap::entries() const {
110   StringMap<uint32_t> Result;
111   for (const auto &Entry : OffsetIndexMap) {
112     StringRef Stream(NamesBuffer.data() + Entry.first);
113     Result.try_emplace(Stream, Entry.second);
114   }
115   return Result;
116 }
117 
118 uint32_t NamedStreamMap::appendStringData(StringRef S) {
119   uint32_t Offset = NamesBuffer.size();
120   NamesBuffer.insert(NamesBuffer.end(), S.begin(), S.end());
121   NamesBuffer.push_back('\0');
122   return Offset;
123 }
124 
125 void NamedStreamMap::set(StringRef Stream, uint32_t StreamNo) {
126   OffsetIndexMap.set_as(Stream, support::ulittle32_t(StreamNo));
127 }
128