LLVM  10.0.0svn
Minidump.cpp
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1 //===- Minidump.cpp - Minidump object file implementation -----------------===//
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/Object/Minidump.h"
10 #include "llvm/Object/Error.h"
12 
13 using namespace llvm;
14 using namespace llvm::object;
15 using namespace llvm::minidump;
16 
19  auto It = StreamMap.find(Type);
20  if (It != StreamMap.end())
21  return getRawStream(Streams[It->second]);
22  return None;
23 }
24 
26  // Minidump strings consist of a 32-bit length field, which gives the size of
27  // the string in *bytes*. This is followed by the actual string encoded in
28  // UTF16.
29  auto ExpectedSize =
30  getDataSliceAs<support::ulittle32_t>(getData(), Offset, 1);
31  if (!ExpectedSize)
32  return ExpectedSize.takeError();
33  size_t Size = (*ExpectedSize)[0];
34  if (Size % 2 != 0)
35  return createError("String size not even");
36  Size /= 2;
37  if (Size == 0)
38  return "";
39 
40  Offset += sizeof(support::ulittle32_t);
41  auto ExpectedData =
42  getDataSliceAs<support::ulittle16_t>(getData(), Offset, Size);
43  if (!ExpectedData)
44  return ExpectedData.takeError();
45 
46  SmallVector<UTF16, 32> WStr(Size);
47  copy(*ExpectedData, WStr.begin());
48 
49  std::string Result;
50  if (!convertUTF16ToUTF8String(WStr, Result))
51  return createError("String decoding failed");
52 
53  return Result;
54 }
55 
56 template <typename T>
57 Expected<ArrayRef<T>> MinidumpFile::getListStream(StreamType Stream) const {
58  auto OptionalStream = getRawStream(Stream);
59  if (!OptionalStream)
60  return createError("No such stream");
61  auto ExpectedSize =
62  getDataSliceAs<support::ulittle32_t>(*OptionalStream, 0, 1);
63  if (!ExpectedSize)
64  return ExpectedSize.takeError();
65 
66  size_t ListSize = ExpectedSize.get()[0];
67 
68  size_t ListOffset = 4;
69  // Some producers insert additional padding bytes to align the list to an
70  // 8-byte boundary. Check for that by comparing the list size with the overall
71  // stream size.
72  if (ListOffset + sizeof(T) * ListSize < OptionalStream->size())
73  ListOffset = 8;
74 
75  return getDataSliceAs<T>(*OptionalStream, ListOffset, ListSize);
76 }
78  MinidumpFile::getListStream(StreamType) const;
80  MinidumpFile::getListStream(StreamType) const;
82  MinidumpFile::getListStream(StreamType) const;
83 
85 MinidumpFile::getDataSlice(ArrayRef<uint8_t> Data, size_t Offset, size_t Size) {
86  // Check for overflow.
87  if (Offset + Size < Offset || Offset + Size < Size ||
88  Offset + Size > Data.size())
89  return createEOFError();
90  return Data.slice(Offset, Size);
91 }
92 
96  auto ExpectedHeader = getDataSliceAs<minidump::Header>(Data, 0, 1);
97  if (!ExpectedHeader)
98  return ExpectedHeader.takeError();
99 
100  const minidump::Header &Hdr = (*ExpectedHeader)[0];
101  if (Hdr.Signature != Header::MagicSignature)
102  return createError("Invalid signature");
103  if ((Hdr.Version & 0xffff) != Header::MagicVersion)
104  return createError("Invalid version");
105 
106  auto ExpectedStreams = getDataSliceAs<Directory>(Data, Hdr.StreamDirectoryRVA,
107  Hdr.NumberOfStreams);
108  if (!ExpectedStreams)
109  return ExpectedStreams.takeError();
110 
112  for (const auto &Stream : llvm::enumerate(*ExpectedStreams)) {
113  StreamType Type = Stream.value().Type;
114  const LocationDescriptor &Loc = Stream.value().Location;
115 
116  auto ExpectedStream = getDataSlice(Data, Loc.RVA, Loc.DataSize);
117  if (!ExpectedStream)
118  return ExpectedStream.takeError();
119 
120  if (Type == StreamType::Unused && Loc.DataSize == 0) {
121  // Ignore dummy streams. This is technically ill-formed, but a number of
122  // existing minidumps seem to contain such streams.
123  continue;
124  }
125 
128  return createError("Cannot handle one of the minidump streams");
129 
130  // Update the directory map, checking for duplicate stream types.
131  if (!StreamMap.try_emplace(Type, Stream.index()).second)
132  return createError("Duplicate stream type");
133  }
134 
135  return std::unique_ptr<MinidumpFile>(
136  new MinidumpFile(Source, Hdr, *ExpectedStreams, std::move(StreamMap)));
137 }
const NoneType None
Definition: None.h:23
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Specifies the location (and size) of various objects in the minidump file.
Definition: Minidump.h:56
support::ulittle32_t NumberOfStreams
Definition: Minidump.h:37
support::ulittle32_t Signature
Definition: Minidump.h:33
ArrayRef< uint8_t > arrayRefFromStringRef(StringRef Input)
Construct a string ref from an array ref of unsigned chars.
Definition: StringExtras.h:60
unsigned second
Expected< std::string > getString(size_t Offset) const
Returns the minidump string at the given offset.
Definition: Minidump.cpp:25
StreamType
The type of a minidump stream identifies its contents.
Definition: Minidump.h:47
StringRef getBuffer() const
Definition: MemoryBuffer.h:272
Tagged union holding either a T or a Error.
Definition: CachePruning.h:22
The minidump header is the first part of a minidump file.
Definition: Minidump.h:29
support::ulittle32_t StreamDirectoryRVA
Definition: Minidump.h:38
static Error createError(const Twine &Err)
Definition: ELF.h:47
Type(LLVMContext &C, TypeID tid)
Definition: Type.h:90
static Expected< std::unique_ptr< MinidumpFile > > create(MemoryBufferRef Source)
Construct a new MinidumpFile object from the given memory buffer.
Definition: Minidump.cpp:94
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
detail::packed_endian_specific_integral< uint32_t, little, unaligned > ulittle32_t
Definition: Endian.h:274
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:148
ArrayRef< uint8_t > getRawStream(const minidump::Directory &Stream) const
Returns the raw contents of the stream given by the directory entry.
Definition: Minidump.h:38
support::ulittle32_t Version
Definition: Minidump.h:36
auto size(R &&Range, typename std::enable_if< std::is_same< typename std::iterator_traits< decltype(Range.begin())>::iterator_category, std::random_access_iterator_tag >::value, void >::type *=nullptr) -> decltype(std::distance(Range.begin(), Range.end()))
Get the size of a range.
Definition: STLExtras.h:1173
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:837
support::ulittle32_t RVA
Definition: Minidump.h:58
ArrayRef< T > slice(size_t N, size_t M) const
slice(n, m) - Chop off the first N elements of the array, and keep M elements in the array...
Definition: ArrayRef.h:178
bool convertUTF16ToUTF8String(ArrayRef< char > SrcBytes, std::string &Out)
Converts a stream of raw bytes assumed to be UTF16 into a UTF8 std::string.
support::ulittle32_t DataSize
Definition: Minidump.h:57
uint32_t Size
Definition: Profile.cpp:46
OutputIt copy(R &&Range, OutputIt Out)
Definition: STLExtras.h:1244
A class providing access to the contents of a minidump file.
Definition: Minidump.h:22
detail::enumerator< R > enumerate(R &&TheRange)
Given an input range, returns a new range whose values are are pair (A,B) such that A is the 0-based ...
Definition: STLExtras.h:1576