1//===- Minidump.h - Minidump object file implementation ---------*- 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_OBJECT_MINIDUMP_H
10#define LLVM_OBJECT_MINIDUMP_H
11
12#include "llvm/ADT/DenseMap.h"
13#include "llvm/ADT/StringExtras.h"
14#include "llvm/ADT/iterator.h"
15#include "llvm/BinaryFormat/Minidump.h"
16#include "llvm/Object/Binary.h"
17#include "llvm/Support/Error.h"
18
19namespace llvm {
20namespace object {
21
22/// A class providing access to the contents of a minidump file.
23class MinidumpFile : public Binary {
24public:
25  /// Construct a new MinidumpFile object from the given memory buffer. Returns
26  /// an error if this file cannot be identified as a minidump file, or if its
27  /// contents are badly corrupted (i.e. we cannot read the stream directory).
28  static Expected<std::unique_ptr<MinidumpFile>> create(MemoryBufferRef Source);
29
30  static bool classof(const Binary *B) { return B->isMinidump(); }
31
32  /// Returns the contents of the minidump header.
33  const minidump::Header &header() const { return Header; }
34
35  /// Returns the list of streams (stream directory entries) in this file.
36  ArrayRef<minidump::Directory> streams() const { return Streams; }
37
38  /// Returns the raw contents of the stream given by the directory entry.
39  ArrayRef<uint8_t> getRawStream(const minidump::Directory &Stream) const {
40    return getData().slice(Stream.Location.RVA, Stream.Location.DataSize);
41  }
42
43  /// Returns the raw contents of the stream of the given type, or None if the
44  /// file does not contain a stream of this type.
45  Optional<ArrayRef<uint8_t>> getRawStream(minidump::StreamType Type) const;
46
47  /// Returns the raw contents of an object given by the LocationDescriptor. An
48  /// error is returned if the descriptor points outside of the minidump file.
49  Expected<ArrayRef<uint8_t>>
50  getRawData(minidump::LocationDescriptor Desc) const {
51    return getDataSlice(getData(), Desc.RVA, Desc.DataSize);
52  }
53
54  /// Returns the minidump string at the given offset. An error is returned if
55  /// we fail to parse the string, or the string is invalid UTF16.
56  Expected<std::string> getString(size_t Offset) const;
57
58  /// Returns the contents of the SystemInfo stream, cast to the appropriate
59  /// type. An error is returned if the file does not contain this stream, or
60  /// the stream is smaller than the size of the SystemInfo structure. The
61  /// internal consistency of the stream is not checked in any way.
62  Expected<const minidump::SystemInfo &> getSystemInfo() const {
63    return getStream<minidump::SystemInfo>(minidump::StreamType::SystemInfo);
64  }
65
66  /// Returns the module list embedded in the ModuleList stream. An error is
67  /// returned if the file does not contain this stream, or if the stream is
68  /// not large enough to contain the number of modules declared in the stream
69  /// header. The consistency of the Module entries themselves is not checked in
70  /// any way.
71  Expected<ArrayRef<minidump::Module>> getModuleList() const {
72    return getListStream<minidump::Module>(minidump::StreamType::ModuleList);
73  }
74
75  /// Returns the thread list embedded in the ThreadList stream. An error is
76  /// returned if the file does not contain this stream, or if the stream is
77  /// not large enough to contain the number of threads declared in the stream
78  /// header. The consistency of the Thread entries themselves is not checked in
79  /// any way.
80  Expected<ArrayRef<minidump::Thread>> getThreadList() const {
81    return getListStream<minidump::Thread>(minidump::StreamType::ThreadList);
82  }
83
84  /// Returns the contents of the Exception stream.  An error is returned if the
85  /// file does not contain this stream, or the stream is smaller than the size
86  /// of the ExceptionStream structure.  The internal consistency of the stream
87  /// is not checked in any way.
88  Expected<const minidump::ExceptionStream &> getExceptionStream() const {
89    return getStream<minidump::ExceptionStream>(
90        minidump::StreamType::Exception);
91  }
92
93  /// Returns the list of descriptors embedded in the MemoryList stream. The
94  /// descriptors provide the content of interesting regions of memory at the
95  /// time the minidump was taken. An error is returned if the file does not
96  /// contain this stream, or if the stream is not large enough to contain the
97  /// number of memory descriptors declared in the stream header. The
98  /// consistency of the MemoryDescriptor entries themselves is not checked in
99  /// any way.
100  Expected<ArrayRef<minidump::MemoryDescriptor>> getMemoryList() const {
101    return getListStream<minidump::MemoryDescriptor>(
102        minidump::StreamType::MemoryList);
103  }
104
105  class MemoryInfoIterator
106      : public iterator_facade_base<MemoryInfoIterator,
107                                    std::forward_iterator_tag,
108                                    minidump::MemoryInfo> {
109  public:
110    MemoryInfoIterator(ArrayRef<uint8_t> Storage, size_t Stride)
111        : Storage(Storage), Stride(Stride) {
112      assert(Storage.size() % Stride == 0);
113    }
114
115    bool operator==(const MemoryInfoIterator &R) const {
116      return Storage.size() == R.Storage.size();
117    }
118
119    const minidump::MemoryInfo &operator*() const {
120      assert(Storage.size() >= sizeof(minidump::MemoryInfo));
121      return *reinterpret_cast<const minidump::MemoryInfo *>(Storage.data());
122    }
123
124    MemoryInfoIterator &operator++() {
125      Storage = Storage.drop_front(Stride);
126      return *this;
127    }
128
129  private:
130    ArrayRef<uint8_t> Storage;
131    size_t Stride;
132  };
133
134  /// Returns the list of descriptors embedded in the MemoryInfoList stream. The
135  /// descriptors provide properties (e.g. permissions) of interesting regions
136  /// of memory at the time the minidump was taken. An error is returned if the
137  /// file does not contain this stream, or if the stream is not large enough to
138  /// contain the number of memory descriptors declared in the stream header.
139  /// The consistency of the MemoryInfoList entries themselves is not checked
140  /// in any way.
141  Expected<iterator_range<MemoryInfoIterator>> getMemoryInfoList() const;
142
143private:
144  static Error createError(StringRef Str) {
145    return make_error<GenericBinaryError>(Str, object_error::parse_failed);
146  }
147
148  static Error createEOFError() {
149    return make_error<GenericBinaryError>("Unexpected EOF",
150                                          object_error::unexpected_eof);
151  }
152
153  /// Return a slice of the given data array, with bounds checking.
154  static Expected<ArrayRef<uint8_t>> getDataSlice(ArrayRef<uint8_t> Data,
155                                                  size_t Offset, size_t Size);
156
157  /// Return the slice of the given data array as an array of objects of the
158  /// given type. The function checks that the input array is large enough to
159  /// contain the correct number of objects of the given type.
160  template <typename T>
161  static Expected<ArrayRef<T>> getDataSliceAs(ArrayRef<uint8_t> Data,
162                                              size_t Offset, size_t Count);
163
164  MinidumpFile(MemoryBufferRef Source, const minidump::Header &Header,
165               ArrayRef<minidump::Directory> Streams,
166               DenseMap<minidump::StreamType, std::size_t> StreamMap)
167      : Binary(ID_Minidump, Source), Header(Header), Streams(Streams),
168        StreamMap(std::move(StreamMap)) {}
169
170  ArrayRef<uint8_t> getData() const {
171    return arrayRefFromStringRef(Data.getBuffer());
172  }
173
174  /// Return the stream of the given type, cast to the appropriate type. Checks
175  /// that the stream is large enough to hold an object of this type.
176  template <typename T>
177  Expected<const T &> getStream(minidump::StreamType Stream) const;
178
179  /// Return the contents of a stream which contains a list of fixed-size items,
180  /// prefixed by the list size.
181  template <typename T>
182  Expected<ArrayRef<T>> getListStream(minidump::StreamType Stream) const;
183
184  const minidump::Header &Header;
185  ArrayRef<minidump::Directory> Streams;
186  DenseMap<minidump::StreamType, std::size_t> StreamMap;
187};
188
189template <typename T>
190Expected<const T &> MinidumpFile::getStream(minidump::StreamType Type) const {
191  if (Optional<ArrayRef<uint8_t>> Stream = getRawStream(Type)) {
192    if (Stream->size() >= sizeof(T))
193      return *reinterpret_cast<const T *>(Stream->data());
194    return createEOFError();
195  }
196  return createError("No such stream");
197}
198
199template <typename T>
200Expected<ArrayRef<T>> MinidumpFile::getDataSliceAs(ArrayRef<uint8_t> Data,
201                                                   size_t Offset,
202                                                   size_t Count) {
203  // Check for overflow.
204  if (Count > std::numeric_limits<size_t>::max() / sizeof(T))
205    return createEOFError();
206  Expected<ArrayRef<uint8_t>> Slice =
207      getDataSlice(Data, Offset, sizeof(T) * Count);
208  if (!Slice)
209    return Slice.takeError();
210  return ArrayRef<T>(reinterpret_cast<const T *>(Slice->data()), Count);
211}
212
213} // end namespace object
214} // end namespace llvm
215
216#endif // LLVM_OBJECT_MINIDUMP_H
217