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