LLVM  8.0.0svn
PublicsStream.cpp
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1 //===- PublicsStream.cpp - PDB Public Symbol Stream -----------------------===//
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 data structures defined 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 // The reference doesn't compile, so I learned just by reading code.
21 // It's not guaranteed to be correct.
22 //
23 //===----------------------------------------------------------------------===//
24 
31 #include "llvm/Support/Endian.h"
32 #include "llvm/Support/Error.h"
33 #include <algorithm>
34 #include <cstdint>
35 
36 using namespace llvm;
37 using namespace llvm::msf;
38 using namespace llvm::support;
39 using namespace llvm::pdb;
40 
41 PublicsStream::PublicsStream(std::unique_ptr<MappedBlockStream> Stream)
42  : Stream(std::move(Stream)) {}
43 
45 
46 uint32_t PublicsStream::getSymHash() const { return Header->SymHash; }
48  return Header->ISectThunkTable;
49 }
51  return Header->OffThunkTable;
52 }
53 
54 // Publics stream contains fixed-size headers and a serialized hash table.
55 // This implementation is not complete yet. It reads till the end of the
56 // stream so that we verify the stream is at least not corrupted. However,
57 // we skip over the hash table which we believe contains information about
58 // public symbols.
60  BinaryStreamReader Reader(*Stream);
61 
62  // Check stream size.
63  if (Reader.bytesRemaining() <
64  sizeof(PublicsStreamHeader) + sizeof(GSIHashHeader))
65  return make_error<RawError>(raw_error_code::corrupt_file,
66  "Publics Stream does not contain a header.");
67 
68  // Read PSGSIHDR struct.
69  if (Reader.readObject(Header))
70  return make_error<RawError>(raw_error_code::corrupt_file,
71  "Publics Stream does not contain a header.");
72 
73  // Read the hash table.
74  if (auto E = PublicsTable.read(Reader))
75  return E;
76 
77  // Something called "address map" follows.
78  uint32_t NumAddressMapEntries = Header->AddrMap / sizeof(uint32_t);
79  if (auto EC = Reader.readArray(AddressMap, NumAddressMapEntries))
80  return joinErrors(std::move(EC),
81  make_error<RawError>(raw_error_code::corrupt_file,
82  "Could not read an address map."));
83 
84  // Something called "thunk map" follows.
85  if (auto EC = Reader.readArray(ThunkMap, Header->NumThunks))
86  return joinErrors(std::move(EC),
87  make_error<RawError>(raw_error_code::corrupt_file,
88  "Could not read a thunk map."));
89 
90  // Something called "section map" follows.
91  if (Reader.bytesRemaining() > 0) {
92  if (auto EC = Reader.readArray(SectionOffsets, Header->NumSections))
93  return joinErrors(std::move(EC),
94  make_error<RawError>(raw_error_code::corrupt_file,
95  "Could not read a section map."));
96  }
97 
98  if (Reader.bytesRemaining() > 0)
99  return make_error<RawError>(raw_error_code::corrupt_file,
100  "Corrupted publics stream.");
101  return Error::success();
102 }
uint32_t getThunkTableOffset() const
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
This provides a very simple, boring adaptor for a begin and end iterator into a range type...
Error readObject(const T *&Dest)
Get a pointer to an object of type T from the underlying stream, as if by memcpy, and store the resul...
support::ulittle32_t NumThunks
Definition: RawTypes.h:268
uint16_t getThunkTableSection() const
Definition: BitVector.h:938
Header of the hash tables found in the globals and publics sections.
Definition: RawTypes.h:29
support::ulittle16_t ISectThunkTable
Definition: RawTypes.h:270
uint32_t getSymHash() const
Error read(BinaryStreamReader &Reader)
support::ulittle32_t SymHash
Definition: RawTypes.h:266
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
support::ulittle32_t AddrMap
Definition: RawTypes.h:267
static ErrorSuccess success()
Create a success value.
Definition: Error.h:327
support::ulittle32_t OffThunkTable
Definition: RawTypes.h:272
Error joinErrors(Error E1, Error E2)
Concatenate errors.
Definition: Error.h:424
uint32_t bytesRemaining() const
Lightweight error class with error context and mandatory checking.
Definition: Error.h:158
Provides read only access to a subclass of BinaryStream.
support::ulittle32_t NumSections
Definition: RawTypes.h:273
Error readArray(ArrayRef< T > &Array, uint32_t NumElements)
Get a reference to a NumElements element array of objects of type T from the underlying stream as if ...