1 //===- GlobalsStream.h - PDB Index of Symbols by Name -----------*- C++ -*-===//
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 #ifndef LLVM_DEBUGINFO_PDB_NATIVE_GLOBALSSTREAM_H
10 #define LLVM_DEBUGINFO_PDB_NATIVE_GLOBALSSTREAM_H
11 
12 #include "llvm/ADT/iterator.h"
13 #include "llvm/DebugInfo/CodeView/CVRecord.h"
14 #include "llvm/DebugInfo/PDB/Native/RawTypes.h"
15 #include "llvm/Support/BinaryStreamArray.h"
16 #include "llvm/Support/Endian.h"
17 #include "llvm/Support/Error.h"
18 
19 namespace llvm {
20 class BinaryStreamReader;
21 namespace msf {
22 class MappedBlockStream;
23 }
24 namespace pdb {
25 class SymbolStream;
26 
27 /// Iterator over hash records producing symbol record offsets. Abstracts away
28 /// the fact that symbol record offsets on disk are off-by-one.
29 class GSIHashIterator
30     : public iterator_adaptor_base<
31           GSIHashIterator, FixedStreamArrayIterator<PSHashRecord>,
32           std::random_access_iterator_tag, const uint32_t> {
33 public:
34   template <typename T>
35   GSIHashIterator(T &&v)
36       : GSIHashIterator::iterator_adaptor_base(std::forward<T &&>(v)) {}
37 
38   uint32_t operator*() const {
39     uint32_t Off = this->I->Off;
40     return --Off;
41   }
42 };
43 
44 /// From https://github.com/Microsoft/microsoft-pdb/blob/master/PDB/dbi/gsi.cpp
45 enum : unsigned { IPHR_HASH = 4096 };
46 
47 /// A readonly view of a hash table used in the globals and publics streams.
48 /// Most clients will only want to iterate this to get symbol record offsets
49 /// into the PDB symbol stream.
50 class GSIHashTable {
51 public:
52   const GSIHashHeader *HashHdr;
53   FixedStreamArray<PSHashRecord> HashRecords;
54   FixedStreamArray<support::ulittle32_t> HashBitmap;
55   FixedStreamArray<support::ulittle32_t> HashBuckets;
56   std::array<int32_t, IPHR_HASH + 1> BucketMap;
57 
58   Error read(BinaryStreamReader &Reader);
59 
60   uint32_t getVerSignature() const { return HashHdr->VerSignature; }
61   uint32_t getVerHeader() const { return HashHdr->VerHdr; }
62   uint32_t getHashRecordSize() const { return HashHdr->HrSize; }
63   uint32_t getNumBuckets() const { return HashHdr->NumBuckets; }
64 
65   typedef GSIHashHeader iterator;
66   GSIHashIterator begin() const { return GSIHashIterator(HashRecords.begin()); }
67   GSIHashIterator end() const { return GSIHashIterator(HashRecords.end()); }
68 };
69 
70 class GlobalsStream {
71 public:
72   explicit GlobalsStream(std::unique_ptr<msf::MappedBlockStream> Stream);
73   ~GlobalsStream();
74   const GSIHashTable &getGlobalsTable() const { return GlobalsTable; }
75   Error reload();
76 
77   std::vector<std::pair<uint32_t, codeview::CVSymbol>>
78   findRecordsByName(StringRef Name, const SymbolStream &Symbols) const;
79 
80 private:
81   GSIHashTable GlobalsTable;
82   std::unique_ptr<msf::MappedBlockStream> Stream;
83 };
84 } // namespace pdb
85 }
86 
87 #endif
88