//===- Minidump.h - Minidump object file implementation ---------*- C++ -*-===//
 
//
 
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 
// See https://llvm.org/LICENSE.txt for license information.
 
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_OBJECT_MINIDUMP_H
 
#define LLVM_OBJECT_MINIDUMP_H
 
 
 
#include "llvm/ADT/DenseMap.h"
 
#include "llvm/ADT/StringExtras.h"
 
#include "llvm/ADT/iterator.h"
 
#include "llvm/BinaryFormat/Minidump.h"
 
#include "llvm/Object/Binary.h"
 
#include "llvm/Support/Error.h"
 
 
 
namespace llvm {
 
namespace object {
 
 
 
/// A class providing access to the contents of a minidump file.
 
class MinidumpFile : public Binary {
 
public:
 
  /// Construct a new MinidumpFile object from the given memory buffer. Returns
 
  /// an error if this file cannot be identified as a minidump file, or if its
 
  /// contents are badly corrupted (i.e. we cannot read the stream directory).
 
  static Expected<std::unique_ptr<MinidumpFile>> create(MemoryBufferRef Source);
 
 
 
  static bool classof(const Binary *B) { return B->isMinidump(); }
 
 
 
  /// Returns the contents of the minidump header.
 
  const minidump::Header &header() const { return Header; }
 
 
 
  /// Returns the list of streams (stream directory entries) in this file.
 
  ArrayRef<minidump::Directory> streams() const { return Streams; }
 
 
 
  /// Returns the raw contents of the stream given by the directory entry.
 
  ArrayRef<uint8_t> getRawStream(const minidump::Directory &Stream) const {
 
    return getData().slice(Stream.Location.RVA, Stream.Location.DataSize);
 
  }
 
 
 
  /// Returns the raw contents of the stream of the given type, or std::nullopt
 
  /// if the file does not contain a stream of this type.
 
  std::optional<ArrayRef<uint8_t>>
 
  getRawStream(minidump::StreamType Type) const;
 
 
 
  /// Returns the raw contents of an object given by the LocationDescriptor. An
 
  /// error is returned if the descriptor points outside of the minidump file.
 
  Expected<ArrayRef<uint8_t>>
 
  getRawData(minidump::LocationDescriptor Desc) const {
 
    return getDataSlice(getData(), Desc.RVA, Desc.DataSize);
 
  }
 
 
 
  /// Returns the minidump string at the given offset. An error is returned if
 
  /// we fail to parse the string, or the string is invalid UTF16.
 
  Expected<std::string> getString(size_t Offset) const;
 
 
 
  /// Returns the contents of the SystemInfo stream, cast to the appropriate
 
  /// type. An error is returned if the file does not contain this stream, or
 
  /// the stream is smaller than the size of the SystemInfo structure. The
 
  /// internal consistency of the stream is not checked in any way.
 
  Expected<const minidump::SystemInfo &> getSystemInfo() const {
 
    return getStream<minidump::SystemInfo>(minidump::StreamType::SystemInfo);
 
  }
 
 
 
  /// Returns the module list embedded in the ModuleList stream. An error is
 
  /// returned if the file does not contain this stream, or if the stream is
 
  /// not large enough to contain the number of modules declared in the stream
 
  /// header. The consistency of the Module entries themselves is not checked in
 
  /// any way.
 
  Expected<ArrayRef<minidump::Module>> getModuleList() const {
 
    return getListStream<minidump::Module>(minidump::StreamType::ModuleList);
 
  }
 
 
 
  /// Returns the thread list embedded in the ThreadList stream. An error is
 
  /// returned if the file does not contain this stream, or if the stream is
 
  /// not large enough to contain the number of threads declared in the stream
 
  /// header. The consistency of the Thread entries themselves is not checked in
 
  /// any way.
 
  Expected<ArrayRef<minidump::Thread>> getThreadList() const {
 
    return getListStream<minidump::Thread>(minidump::StreamType::ThreadList);
 
  }
 
 
 
  /// Returns the contents of the Exception stream.  An error is returned if the
 
  /// file does not contain this stream, or the stream is smaller than the size
 
  /// of the ExceptionStream structure.  The internal consistency of the stream
 
  /// is not checked in any way.
 
  Expected<const minidump::ExceptionStream &> getExceptionStream() const {
 
    return getStream<minidump::ExceptionStream>(
 
        minidump::StreamType::Exception);
 
  }
 
 
 
  /// Returns the list of descriptors embedded in the MemoryList stream. The
 
  /// descriptors provide the content of interesting regions of memory at the
 
  /// time the minidump was taken. An error is returned if the file does not
 
  /// contain this stream, or if the stream is not large enough to contain the
 
  /// number of memory descriptors declared in the stream header. The
 
  /// consistency of the MemoryDescriptor entries themselves is not checked in
 
  /// any way.
 
  Expected<ArrayRef<minidump::MemoryDescriptor>> getMemoryList() const {
 
    return getListStream<minidump::MemoryDescriptor>(
 
        minidump::StreamType::MemoryList);
 
  }
 
 
 
  class MemoryInfoIterator
 
      : public iterator_facade_base<MemoryInfoIterator,
 
                                    std::forward_iterator_tag,
 
                                    minidump::MemoryInfo> {
 
  public:
 
    MemoryInfoIterator(ArrayRef<uint8_t> Storage, size_t Stride)
 
        : Storage(Storage), Stride(Stride) {
 
      assert(Storage.size() % Stride == 0);
 
    }
 
 
 
    bool operator==(const MemoryInfoIterator &R) const {
 
      return Storage.size() == R.Storage.size();
 
    }
 
 
 
    const minidump::MemoryInfo &operator*() const {
 
      assert(Storage.size() >= sizeof(minidump::MemoryInfo));
 
      return *reinterpret_cast<const minidump::MemoryInfo *>(Storage.data());
 
    }
 
 
 
    MemoryInfoIterator &operator++() {
 
      Storage = Storage.drop_front(Stride);
 
      return *this;
 
    }
 
 
 
  private:
 
    ArrayRef<uint8_t> Storage;
 
    size_t Stride;
 
  };
 
 
 
  /// Returns the list of descriptors embedded in the MemoryInfoList stream. The
 
  /// descriptors provide properties (e.g. permissions) of interesting regions
 
  /// of memory at the time the minidump was taken. An error is returned if the
 
  /// file does not contain this stream, or if the stream is not large enough to
 
  /// contain the number of memory descriptors declared in the stream header.
 
  /// The consistency of the MemoryInfoList entries themselves is not checked
 
  /// in any way.
 
  Expected<iterator_range<MemoryInfoIterator>> getMemoryInfoList() const;
 
 
 
private:
 
  static Error createError(StringRef Str) {
 
    return make_error<GenericBinaryError>(Str, object_error::parse_failed);
 
  }
 
 
 
  static Error createEOFError() {
 
    return make_error<GenericBinaryError>("Unexpected EOF",
 
                                          object_error::unexpected_eof);
 
  }
 
 
 
  /// Return a slice of the given data array, with bounds checking.
 
  static Expected<ArrayRef<uint8_t>> getDataSlice(ArrayRef<uint8_t> Data,
 
                                                  size_t Offset, size_t Size);
 
 
 
  /// Return the slice of the given data array as an array of objects of the
 
  /// given type. The function checks that the input array is large enough to
 
  /// contain the correct number of objects of the given type.
 
  template <typename T>
 
  static Expected<ArrayRef<T>> getDataSliceAs(ArrayRef<uint8_t> Data,
 
                                              size_t Offset, size_t Count);
 
 
 
  MinidumpFile(MemoryBufferRef Source, const minidump::Header &Header,
 
               ArrayRef<minidump::Directory> Streams,
 
               DenseMap<minidump::StreamType, std::size_t> StreamMap)
 
      : Binary(ID_Minidump, Source), Header(Header), Streams(Streams),
 
        StreamMap(std::move(StreamMap)) {}
 
 
 
  ArrayRef<uint8_t> getData() const {
 
    return arrayRefFromStringRef(Data.getBuffer());
 
  }
 
 
 
  /// Return the stream of the given type, cast to the appropriate type. Checks
 
  /// that the stream is large enough to hold an object of this type.
 
  template <typename T>
 
  Expected<const T &> getStream(minidump::StreamType Stream) const;
 
 
 
  /// Return the contents of a stream which contains a list of fixed-size items,
 
  /// prefixed by the list size.
 
  template <typename T>
 
  Expected<ArrayRef<T>> getListStream(minidump::StreamType Stream) const;
 
 
 
  const minidump::Header &Header;
 
  ArrayRef<minidump::Directory> Streams;
 
  DenseMap<minidump::StreamType, std::size_t> StreamMap;
 
};
 
 
 
template <typename T>
 
Expected<const T &> MinidumpFile::getStream(minidump::StreamType Type) const {
 
  if (std::optional<ArrayRef<uint8_t>> Stream = getRawStream(Type)) {
 
    if (Stream->size() >= sizeof(T))
 
      return *reinterpret_cast<const T *>(Stream->data());
 
    return createEOFError();
 
  }
 
  return createError("No such stream");
 
}
 
 
 
template <typename T>
 
Expected<ArrayRef<T>> MinidumpFile::getDataSliceAs(ArrayRef<uint8_t> Data,
 
                                                   size_t Offset,
 
                                                   size_t Count) {
 
  // Check for overflow.
 
  if (Count > std::numeric_limits<size_t>::max() / sizeof(T))
 
    return createEOFError();
 
  Expected<ArrayRef<uint8_t>> Slice =
 
      getDataSlice(Data, Offset, sizeof(T) * Count);
 
  if (!Slice)
 
    return Slice.takeError();
 
  return ArrayRef<T>(reinterpret_cast<const T *>(Slice->data()), Count);
 
}
 
 
 
} // end namespace object
 
} // end namespace llvm
 
 
 
#endif // LLVM_OBJECT_MINIDUMP_H