C# BlobReader.ReadUInt32方法代码示例

        public static ILResult GetInstructions(BlobReader reader)
        {
            var instructions = ImmutableArray.CreateBuilder<Instruction>();
            List<int[]> switches = null;

            while (reader.RemainingBytes > 0)
            {
                ushort pos = (ushort)reader.Offset;
                byte op0 = reader.ReadByte();
                InstrCode code = (InstrCode)(op0 == 0xFE ? unchecked(0xFE00 + reader.ReadByte()) : op0);
                OperandType opType = code.GetOperandType();

                ulong operand = 0;
                if (code == InstrCode.Switch)
                {
                    if (switches == null)
                        switches = new List<int[]>();

                    operand = (ulong)switches.Count;
                    uint branchCount = reader.ReadUInt32();
                    int[] branches = new int[branchCount];
                    for (int i = 0; i < branchCount; i++)
                    {
                        branches[i] = reader.ReadInt32();
                    }
                    switches.Add(branches);
                }
                else
                {
                    byte operandSize = opType.GetOperandSize();
                    operand = operandSize == 8 ? reader.ReadUInt64()
                        : operandSize == 4 ? reader.ReadUInt32()
                        : operandSize == 2 ? reader.ReadUInt16()
                        : operandSize == 1 ? (ulong)reader.ReadByte()
                        : 0;
                }

                instructions.Add(new Instruction(pos, code, opType, operand));
            }

            return new ILResult
            {
                Instructions = instructions.ToImmutable(),
                Switches = switches?.ToArray()
            };
        }

        /// <summary>
        /// Reads stream headers described in Ecma-335 24.2.2 Stream header
        /// </summary>
        private StreamHeader[] ReadStreamHeaders(ref BlobReader memReader)
        {
            // storage header:
            memReader.ReadUInt16();
            int streamCount = memReader.ReadInt16();

            var streamHeaders = new StreamHeader[streamCount];
            for (int i = 0; i < streamHeaders.Length; i++)
            {
                if (memReader.RemainingBytes < COR20Constants.MinimumSizeofStreamHeader)
                {
                    throw new BadImageFormatException(MetadataResources.StreamHeaderTooSmall);
                }

                streamHeaders[i].Offset = memReader.ReadUInt32();
                streamHeaders[i].Size = memReader.ReadInt32();
                streamHeaders[i].Name = memReader.ReadUtf8NullTerminated();
                bool aligned = memReader.TryAlign(4);

                if (!aligned || memReader.RemainingBytes == 0)
                {
                    throw new BadImageFormatException(MetadataResources.NotEnoughSpaceForStreamHeaderName);
                }
            }

            return streamHeaders;
        }

        private void ReadMetadataTableHeader(ref BlobReader memReader, out uint[] metadataTableRowCounts)
        {
            if (memReader.RemainingBytes < MetadataStreamConstants.SizeOfMetadataTableHeader)
            {
                throw new BadImageFormatException(MetadataResources.MetadataTableHeaderTooSmall);
            }

            this.MetadataTableHeader.Reserved = memReader.ReadUInt32();
            this.MetadataTableHeader.MajorVersion = memReader.ReadByte();
            this.MetadataTableHeader.MinorVersion = memReader.ReadByte();
            this.MetadataTableHeader.HeapSizeFlags = (HeapSizeFlag)memReader.ReadByte();
            this.MetadataTableHeader.RowId = memReader.ReadByte();
            this.MetadataTableHeader.ValidTables = (TableMask)memReader.ReadUInt64();
            this.MetadataTableHeader.SortedTables = (TableMask)memReader.ReadUInt64();
            ulong presentTables = (ulong)this.MetadataTableHeader.ValidTables;

            // According to ECMA-335, MajorVersion and MinorVersion have fixed values and,
            // based on recommendation in 24.1 Fixed fields: When writing these fields it
            // is best that they be set to the value indicated, on reading they should be ignored.?
            // we will not be checking version values. We will continue checking that the set of
            // present tables is within the set we understand.
            ulong validTables = (ulong)TableMask.V2_0_TablesMask;

            if ((presentTables & ~validTables) != 0)
            {
                throw new BadImageFormatException(string.Format(MetadataResources.UnknownTables, presentTables));
            }

            if (this.metadataStreamKind == MetadataStreamKind.Compressed)
            {
                // In general Ptr tables and EnC tables are not allowed in a compressed stream.
                // However when asked for a snapshot of the current metadata after an EnC change has been applied
                // the CLR includes the EnCLog table into the snapshot. We need to be able to read the image,
                // so we'll allow the table here but pretend it's empty later.
                if ((presentTables & (ulong)(TableMask.PtrTables | TableMask.EnCMap)) != 0)
                {
                    throw new BadImageFormatException(MetadataResources.IllegalTablesInCompressedMetadataStream);
                }
            }

            int numberOfTables = this.MetadataTableHeader.GetNumberOfTablesPresent();
            if (memReader.RemainingBytes < numberOfTables * sizeof(int))
            {
                throw new BadImageFormatException(MetadataResources.TableRowCountSpaceTooSmall);
            }

            var rowCounts = new uint[numberOfTables];
            for (int i = 0; i < rowCounts.Length; i++)
            {
                rowCounts[i] = memReader.ReadUInt32();
            }

            metadataTableRowCounts = rowCounts;
        }

        /// <summary>
        /// Looks like this function reads beginning of the header described in
        /// Ecma-335 24.2.1 Metadata root
        /// </summary>
        private void ReadMetadataHeader(ref BlobReader memReader)
        {
            if (memReader.RemainingBytes < COR20Constants.MinimumSizeofMetadataHeader)
            {
                throw new BadImageFormatException(MetadataResources.MetadataHeaderTooSmall);
            }

            this.metadataHeader.Signature = memReader.ReadUInt32();
            if (this.metadataHeader.Signature != COR20Constants.COR20MetadataSignature)
            {
                throw new BadImageFormatException(MetadataResources.MetadataSignature);
            }

            this.metadataHeader.MajorVersion = memReader.ReadUInt16();
            this.metadataHeader.MinorVersion = memReader.ReadUInt16();
            this.metadataHeader.ExtraData = memReader.ReadUInt32();
            this.metadataHeader.VersionStringSize = memReader.ReadInt32();
            if (memReader.RemainingBytes < this.metadataHeader.VersionStringSize)
            {
                throw new BadImageFormatException(MetadataResources.NotEnoughSpaceForVersionString);
            }

            int numberOfBytesRead;
            this.metadataHeader.VersionString = memReader.GetMemoryBlockAt(0, this.metadataHeader.VersionStringSize).PeekUtf8NullTerminated(0, null, utf8Decoder, out numberOfBytesRead, '\0');
            memReader.SkipBytes(this.metadataHeader.VersionStringSize);
            this.metadataKind = GetMetadataKind(metadataHeader.VersionString);
        }

        internal static ImmutableArray<DebugDirectoryEntry> ReadDebugDirectoryEntries(BlobReader reader)
        {
            int entryCount = reader.Length / DebugDirectoryEntry.Size;
            var builder = ImmutableArray.CreateBuilder<DebugDirectoryEntry>(entryCount);
            for (int i = 0; i < entryCount; i++)
            {
                // Reserved, must be zero.
                int characteristics = reader.ReadInt32();
                if (characteristics != 0)
                {
                    throw new BadImageFormatException(SR.InvalidDebugDirectoryEntryCharacteristics);
                }

                uint stamp = reader.ReadUInt32();
                ushort majorVersion = reader.ReadUInt16();
                ushort minorVersion = reader.ReadUInt16();

                var type = (DebugDirectoryEntryType)reader.ReadInt32();

                int dataSize = reader.ReadInt32();
                int dataRva = reader.ReadInt32();
                int dataPointer = reader.ReadInt32();

                builder.Add(new DebugDirectoryEntry(stamp, majorVersion, minorVersion, type, dataSize, dataRva, dataPointer));
            }

            return builder.MoveToImmutable();
        }

        // internal for testing
        internal static void ReadStandalonePortablePdbStream(MemoryBlock block, out DebugMetadataHeader debugMetadataHeader, out int[] externalTableRowCounts)
        {
            var reader = new BlobReader(block);

            const int PdbIdSize = 20;
            byte[] pdbId = reader.ReadBytes(PdbIdSize);

            // ECMA-335 15.4.1.2:
            // The entry point to an application shall be static.
            // This entry point method can be a global method or it can appear inside a type. 
            // The entry point method shall either accept no arguments or a vector of strings.
            // The return type of the entry point method shall be void, int32, or unsigned int32. 
            // The entry point method cannot be defined in a generic class.
            uint entryPointToken = reader.ReadUInt32();
            int entryPointRowId = (int)(entryPointToken & TokenTypeIds.RIDMask);
            if (entryPointToken != 0 && ((entryPointToken & TokenTypeIds.TypeMask) != TokenTypeIds.MethodDef || entryPointRowId == 0))
            {
                throw new BadImageFormatException(string.Format(SR.InvalidEntryPointToken, entryPointToken));
            }

            ulong externalTableMask = reader.ReadUInt64();

            // EnC & Ptr tables can't be referenced from standalone PDB metadata:
            const ulong validTables = (ulong)TableMask.ValidPortablePdbExternalTables;

            if ((externalTableMask & ~validTables) != 0)
            {
                throw new BadImageFormatException(string.Format(SR.UnknownTables, (TableMask)externalTableMask));
            }

            externalTableRowCounts = ReadMetadataTableRowCounts(ref reader, externalTableMask);

            debugMetadataHeader = new DebugMetadataHeader(
                ImmutableByteArrayInterop.DangerousCreateFromUnderlyingArray(ref pdbId),
                MethodDefinitionHandle.FromRowId(entryPointRowId));
        }

        private static int[] ReadMetadataTableRowCounts(ref BlobReader memReader, ulong presentTableMask)
        {
            ulong currentTableBit = 1;

            var rowCounts = new int[MetadataTokens.TableCount];
            for (int i = 0; i < rowCounts.Length; i++)
            {
                if ((presentTableMask & currentTableBit) != 0)
                {
                    if (memReader.RemainingBytes < sizeof(uint))
                    {
                        throw new BadImageFormatException(SR.TableRowCountSpaceTooSmall);
                    }

                    uint rowCount = memReader.ReadUInt32();
                    if (rowCount > TokenTypeIds.RIDMask)
                    {
                        throw new BadImageFormatException(SR.Format(SR.InvalidRowCount, rowCount));
                    }

                    rowCounts[i] = (int)rowCount;
                }

                currentTableBit <<= 1;
            }

            return rowCounts;
        }

        private void ReadMetadataTableHeader(ref BlobReader reader, out HeapSizes heapSizes, out int[] metadataTableRowCounts, out TableMask sortedTables)
        {
            if (reader.RemainingBytes < MetadataStreamConstants.SizeOfMetadataTableHeader)
            {
                throw new BadImageFormatException(SR.MetadataTableHeaderTooSmall);
            }

            // reserved (shall be ignored):
            reader.ReadUInt32();

            // major version (shall be ignored):
            reader.ReadByte();

            // minor version (shall be ignored):
            reader.ReadByte();

            // heap sizes:
            heapSizes = (HeapSizes)reader.ReadByte();

            // reserved (shall be ignored):
            reader.ReadByte();

            ulong presentTables = reader.ReadUInt64();
            sortedTables = (TableMask)reader.ReadUInt64();

            // According to ECMA-335, MajorVersion and MinorVersion have fixed values and, 
            // based on recommendation in 24.1 Fixed fields: When writing these fields it 
            // is best that they be set to the value indicated, on reading they should be ignored.
            // We will not be checking version values. We will continue checking that the set of 
            // present tables is within the set we understand.

            ulong validTables = (ulong)(TableMask.TypeSystemTables | TableMask.DebugTables);

            if ((presentTables & ~validTables) != 0)
            {
                throw new BadImageFormatException(SR.Format(SR.UnknownTables, presentTables));
            }

            if (_metadataStreamKind == MetadataStreamKind.Compressed)
            {
                // In general Ptr tables and EnC tables are not allowed in a compressed stream.
                // However when asked for a snapshot of the current metadata after an EnC change has been applied 
                // the CLR includes the EnCLog table into the snapshot. We need to be able to read the image,
                // so we'll allow the table here but pretend it's empty later.
                if ((presentTables & (ulong)(TableMask.PtrTables | TableMask.EnCMap)) != 0)
                {
                    throw new BadImageFormatException(SR.IllegalTablesInCompressedMetadataStream);
                }
            }

            metadataTableRowCounts = ReadMetadataTableRowCounts(ref reader, presentTables);

            if ((heapSizes & HeapSizes.ExtraData) == HeapSizes.ExtraData)
            {
                // Skip "extra data" used by some obfuscators. Although it is not mentioned in the CLI spec,
                // it is honored by the native metadata reader.
                reader.ReadUInt32();
            }
        }

        /// <summary>
        /// Looks like this function reads beginning of the header described in
        /// ECMA-335 24.2.1 Metadata root
        /// </summary>
        private void ReadMetadataHeader(ref BlobReader memReader, out string versionString)
        {
            if (memReader.RemainingBytes < COR20Constants.MinimumSizeofMetadataHeader)
            {
                throw new BadImageFormatException(SR.MetadataHeaderTooSmall);
            }

            uint signature = memReader.ReadUInt32();
            if (signature != COR20Constants.COR20MetadataSignature)
            {
                throw new BadImageFormatException(SR.MetadataSignature);
            }

            // major version
            memReader.ReadUInt16();

            // minor version
            memReader.ReadUInt16();

            // reserved:
            memReader.ReadUInt32();

            int versionStringSize = memReader.ReadInt32();
            if (memReader.RemainingBytes < versionStringSize)
            {
                throw new BadImageFormatException(SR.NotEnoughSpaceForVersionString);
            }

            int numberOfBytesRead;
            versionString = memReader.GetMemoryBlockAt(0, versionStringSize).PeekUtf8NullTerminated(0, null, UTF8Decoder, out numberOfBytesRead, '\0');
            memReader.SkipBytes(versionStringSize);
        }

        private object ReadAndTranslateValue(ref BlobReader sigReader, SignatureTypeCode typeCode, out bool isEnumTypeCode)
        {
            switch (typeCode)
            {
                case SignatureTypeCode.Boolean:
                    isEnumTypeCode = true;
                    return (short)(sigReader.ReadBoolean() ? 1 : 0);

                case SignatureTypeCode.Char:
                    isEnumTypeCode = true;
                    return (ushort)sigReader.ReadChar();

                case SignatureTypeCode.SByte:
                    isEnumTypeCode = true;
                    return (short)sigReader.ReadSByte();

                case SignatureTypeCode.Byte:
                    isEnumTypeCode = true;
                    return (short)sigReader.ReadByte();

                case SignatureTypeCode.Int16:
                    isEnumTypeCode = true;
                    return sigReader.ReadInt16();

                case SignatureTypeCode.UInt16:
                    isEnumTypeCode = true;
                    return sigReader.ReadUInt16();

                case SignatureTypeCode.Int32:
                    isEnumTypeCode = true;
                    return sigReader.ReadInt32();

                case SignatureTypeCode.UInt32:
                    isEnumTypeCode = true;
                    return sigReader.ReadUInt32();

                case SignatureTypeCode.Int64:
                    isEnumTypeCode = true;
                    return sigReader.ReadInt64();

                case SignatureTypeCode.UInt64:
                    isEnumTypeCode = true;
                    return sigReader.ReadUInt64();

                case SignatureTypeCode.Single:
                    isEnumTypeCode = false;
                    return sigReader.ReadSingle();

                case SignatureTypeCode.Double:
                    isEnumTypeCode = false;
                    return sigReader.ReadDouble();

                case SignatureTypeCode.String:
                    isEnumTypeCode = false;

                    if (sigReader.RemainingBytes == 1)
                    {
                        if (sigReader.ReadByte() != 0xff)
                        {
                            throw new BadImageFormatException();
                        }

                        return NullReferenceValue;
                    }

                    if (sigReader.RemainingBytes % 2 != 0)
                    {
                        throw new BadImageFormatException();
                    }

                    return sigReader.ReadUTF16(sigReader.RemainingBytes);

                case SignatureTypeCode.Object:
                    // null reference
                    isEnumTypeCode = false;
                    return NullReferenceValue;

                default:
                    throw new BadImageFormatException();
            }
        }

        /// <summary>
        /// Reads all Debug Directory table entries.
        /// </summary>
        /// <exception cref="BadImageFormatException">Bad format of the entry.</exception>
        public unsafe ImmutableArray<DebugDirectoryEntry> ReadDebugDirectory()
        {
            var debugDirectory = PEHeaders.PEHeader.DebugTableDirectory;
            if (debugDirectory.Size == 0)
            {
                return ImmutableArray<DebugDirectoryEntry>.Empty;
            }

            int position;
            if (!PEHeaders.TryGetDirectoryOffset(debugDirectory, out position))
            {
                throw new BadImageFormatException(SR.InvalidDirectoryRVA);
            }

            const int entrySize = 0x1c;

            if (debugDirectory.Size % entrySize != 0)
            {
                throw new BadImageFormatException(SR.InvalidDirectorySize);
            }

            using (AbstractMemoryBlock block = _peImage.GetMemoryBlock(position, debugDirectory.Size))
            {
                var reader = new BlobReader(block.Pointer, block.Size);

                int entryCount = debugDirectory.Size / entrySize;
                var builder = ImmutableArray.CreateBuilder<DebugDirectoryEntry>(entryCount);
                for (int i = 0; i < entryCount; i++)
                {
                    // Reserved, must be zero.
                    int characteristics = reader.ReadInt32();
                    if (characteristics != 0)
                    {
                        throw new BadImageFormatException(SR.InvalidDebugDirectoryEntryCharacteristics);
                    }

                    uint stamp = reader.ReadUInt32();
                    ushort majorVersion = reader.ReadUInt16();
                    ushort minorVersion = reader.ReadUInt16();

                    var type = (DebugDirectoryEntryType)reader.ReadInt32();

                    int dataSize = reader.ReadInt32();
                    int dataRva = reader.ReadInt32();
                    int dataPointer = reader.ReadInt32();

                    builder.Add(new DebugDirectoryEntry(stamp, majorVersion, minorVersion, type, dataSize, dataRva, dataPointer));
                }

                return builder.MoveToImmutable();
            }
        }

        private static ImmutableArray<ExceptionRegion> ReadFatExceptionHandlers(ref BlobReader memReader, int count)
        {
            var result = new ExceptionRegion[count];
            for (int i = 0; i < result.Length; i++)
            {
                var sehFlags = (ExceptionRegionKind)memReader.ReadUInt32();
                int tryOffset = memReader.ReadInt32();
                int tryLength = memReader.ReadInt32();
                int handlerOffset = memReader.ReadInt32();
                int handlerLength = memReader.ReadInt32();
                int classTokenOrFilterOffset = memReader.ReadInt32();
                result[i] = new ExceptionRegion(sehFlags, tryOffset, tryLength, handlerOffset, handlerLength, classTokenOrFilterOffset);
            }

            return ImmutableArray.Create(result);
        }

        // internal for testing
        internal static unsafe ImmutableArray<byte> DecodeEmbeddedPortablePdbDebugDirectoryData(AbstractMemoryBlock block)
        {
            byte[] decompressed;
            
            const int headerSize = 2 * sizeof(int);

            var headerReader = new BlobReader(block.Pointer, headerSize);

            if (headerReader.ReadUInt32() != PortablePdbVersions.DebugDirectoryEmbeddedSignature)
            {
                throw new BadImageFormatException(SR.UnexpectedEmbeddedPortablePdbDataSignature);
            }

            int decompressedSize = headerReader.ReadInt32();

            try
            {
                decompressed = new byte[decompressedSize];
            }
            catch
            {
                throw new BadImageFormatException(SR.DataTooBig);
            }

            var compressed = new ReadOnlyUnmanagedMemoryStream(block.Pointer + headerSize, block.Size - headerSize);
            var deflate = new DeflateStream(compressed, CompressionMode.Decompress, leaveOpen: true);

            if (decompressedSize > 0)
            {
                int actualLength;

                try
                {
                    actualLength = deflate.TryReadAll(decompressed, 0, decompressed.Length);
                }
                catch (InvalidDataException e)
                {
                    throw new BadImageFormatException(e.Message, e.InnerException);
                }

                if (actualLength != decompressed.Length)
                {
                    throw new BadImageFormatException(SR.SizeMismatch);
                }
            }

            // Check that there is no more compressed data left, 
            // in case the decompressed size specified in the header is smaller 
            // than the actual decompressed size of the data.
            if (deflate.ReadByte() != -1)
            {
                throw new BadImageFormatException(SR.SizeMismatch);
            }

            return ImmutableByteArrayInterop.DangerousCreateFromUnderlyingArray(ref decompressed);
        }