1 //===- GlobalsStream.cpp - PDB Index of Symbols by Name ---------*- C++ -*-===//
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 // The on-disk structores used in this file are based on the reference
11 // implementation which is available at
12 // https://github.com/Microsoft/microsoft-pdb/blob/master/PDB/dbi/gsi.h
13 //
14 // When you are reading the reference source code, you'd find the
15 // information below useful.
16 //
17 // - ppdb1->m_fMinimalDbgInfo seems to be always true.
18 // - SMALLBUCKETS macro is defined.
19 //
20 //===----------------------------------------------------------------------===//
21
22 #include "llvm/DebugInfo/PDB/Native/GlobalsStream.h"
23 #include "llvm/DebugInfo/PDB/Native/RawError.h"
24 #include "llvm/Support/BinaryStreamReader.h"
25 #include "llvm/Support/Error.h"
26 #include <algorithm>
27
28 using namespace llvm;
29 using namespace llvm::msf;
30 using namespace llvm::pdb;
31
GlobalsStream(std::unique_ptr<MappedBlockStream> Stream)32 GlobalsStream::GlobalsStream(std::unique_ptr<MappedBlockStream> Stream)
33 : Stream(std::move(Stream)) {}
34
35 GlobalsStream::~GlobalsStream() = default;
36
reload()37 Error GlobalsStream::reload() {
38 BinaryStreamReader Reader(*Stream);
39 if (auto E = GlobalsTable.read(Reader))
40 return E;
41 return Error::success();
42 }
43
checkHashHdrVersion(const GSIHashHeader * HashHdr)44 static Error checkHashHdrVersion(const GSIHashHeader *HashHdr) {
45 if (HashHdr->VerHdr != GSIHashHeader::HdrVersion)
46 return make_error<RawError>(
47 raw_error_code::feature_unsupported,
48 "Encountered unsupported globals stream version.");
49
50 return Error::success();
51 }
52
readGSIHashHeader(const GSIHashHeader * & HashHdr,BinaryStreamReader & Reader)53 static Error readGSIHashHeader(const GSIHashHeader *&HashHdr,
54 BinaryStreamReader &Reader) {
55 if (Reader.readObject(HashHdr))
56 return make_error<RawError>(raw_error_code::corrupt_file,
57 "Stream does not contain a GSIHashHeader.");
58
59 if (HashHdr->VerSignature != GSIHashHeader::HdrSignature)
60 return make_error<RawError>(
61 raw_error_code::feature_unsupported,
62 "GSIHashHeader signature (0xffffffff) not found.");
63
64 return Error::success();
65 }
66
readGSIHashRecords(FixedStreamArray<PSHashRecord> & HashRecords,const GSIHashHeader * HashHdr,BinaryStreamReader & Reader)67 static Error readGSIHashRecords(FixedStreamArray<PSHashRecord> &HashRecords,
68 const GSIHashHeader *HashHdr,
69 BinaryStreamReader &Reader) {
70 if (auto EC = checkHashHdrVersion(HashHdr))
71 return EC;
72
73 // HashHdr->HrSize specifies the number of bytes of PSHashRecords we have.
74 // Verify that we can read them all.
75 if (HashHdr->HrSize % sizeof(PSHashRecord))
76 return make_error<RawError>(raw_error_code::corrupt_file,
77 "Invalid HR array size.");
78 uint32_t NumHashRecords = HashHdr->HrSize / sizeof(PSHashRecord);
79 if (auto EC = Reader.readArray(HashRecords, NumHashRecords))
80 return joinErrors(std::move(EC),
81 make_error<RawError>(raw_error_code::corrupt_file,
82 "Error reading hash records."));
83
84 return Error::success();
85 }
86
87 static Error
readGSIHashBuckets(FixedStreamArray<support::ulittle32_t> & HashBuckets,ArrayRef<uint8_t> & HashBitmap,const GSIHashHeader * HashHdr,BinaryStreamReader & Reader)88 readGSIHashBuckets(FixedStreamArray<support::ulittle32_t> &HashBuckets,
89 ArrayRef<uint8_t> &HashBitmap, const GSIHashHeader *HashHdr,
90 BinaryStreamReader &Reader) {
91 if (auto EC = checkHashHdrVersion(HashHdr))
92 return EC;
93
94 // Before the actual hash buckets, there is a bitmap of length determined by
95 // IPHR_HASH.
96 size_t BitmapSizeInBits = alignTo(IPHR_HASH + 1, 32);
97 uint32_t NumBitmapEntries = BitmapSizeInBits / 8;
98 if (auto EC = Reader.readBytes(HashBitmap, NumBitmapEntries))
99 return joinErrors(std::move(EC),
100 make_error<RawError>(raw_error_code::corrupt_file,
101 "Could not read a bitmap."));
102 uint32_t NumBuckets = 0;
103 for (uint8_t B : HashBitmap)
104 NumBuckets += countPopulation(B);
105
106 // Hash buckets follow.
107 if (auto EC = Reader.readArray(HashBuckets, NumBuckets))
108 return joinErrors(std::move(EC),
109 make_error<RawError>(raw_error_code::corrupt_file,
110 "Hash buckets corrupted."));
111
112 return Error::success();
113 }
114
read(BinaryStreamReader & Reader)115 Error GSIHashTable::read(BinaryStreamReader &Reader) {
116 if (auto EC = readGSIHashHeader(HashHdr, Reader))
117 return EC;
118 if (auto EC = readGSIHashRecords(HashRecords, HashHdr, Reader))
119 return EC;
120 if (HashHdr->HrSize > 0)
121 if (auto EC = readGSIHashBuckets(HashBuckets, HashBitmap, HashHdr, Reader))
122 return EC;
123 return Error::success();
124 }
125