source: branches/2922-DataCompletenessChartPerf/HeuristicLab.ExtLibs/HeuristicLab.Cecil/0.9.5/Mono.Cecil-0.9.5/Mono.Cecil/Mono.Cecil.PE/ImageWriter.cs @ 18242

//
// ImageWriter.cs
//
// Author:
//   Jb Evain (jbevain@gmail.com)
//
// Copyright (c) 2008 - 2011 Jb Evain
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.IO;

#if !READ_ONLY

using Mono.Cecil.Cil;
using Mono.Cecil.Metadata;

using RVA = System.UInt32;

namespace Mono.Cecil.PE {

  sealed class ImageWriter : BinaryStreamWriter {

    readonly ModuleDefinition module;
    readonly MetadataBuilder metadata;
    readonly TextMap text_map;

    ImageDebugDirectory debug_directory;
    byte [] debug_data;

    ByteBuffer win32_resources;

    const uint pe_header_size = 0x178u;
    const uint section_header_size = 0x28u;
    const uint file_alignment = 0x200;
    const uint section_alignment = 0x2000;
    const ulong image_base = 0x00400000;

    internal const RVA text_rva = 0x2000;

    readonly bool pe64;
    readonly uint time_stamp;

    internal Section text;
    internal Section rsrc;
    internal Section reloc;

    ushort sections;

    ImageWriter (ModuleDefinition module, MetadataBuilder metadata, Stream stream)
      : base (stream)
    {
      this.module = module;
      this.metadata = metadata;
      this.GetDebugHeader ();
      this.GetWin32Resources ();
      this.text_map = BuildTextMap ();
      this.sections = 2; // text + reloc
      this.pe64 = module.Architecture != TargetArchitecture.I386;
      this.time_stamp = (uint) DateTime.UtcNow.Subtract (new DateTime (1970, 1, 1)).TotalSeconds;
    }

    void GetDebugHeader ()
    {
      var symbol_writer = metadata.symbol_writer;
      if (symbol_writer == null)
        return;

      if (!symbol_writer.GetDebugHeader (out debug_directory, out debug_data))
        debug_data = Empty<byte>.Array;
    }

    void GetWin32Resources ()
    {
      var rsrc = GetImageResourceSection ();
      if (rsrc == null)
        return;

      var raw_resources = new byte [rsrc.Data.Length];
      Buffer.BlockCopy (rsrc.Data, 0, raw_resources, 0, rsrc.Data.Length);
      win32_resources = new ByteBuffer (raw_resources);
    }

    Section GetImageResourceSection ()
    {
      if (!module.HasImage)
        return null;

      const string rsrc_section = ".rsrc";

      return module.Image.GetSection (rsrc_section);
    }

    public static ImageWriter CreateWriter (ModuleDefinition module, MetadataBuilder metadata, Stream stream)
    {
      var writer = new ImageWriter (module, metadata, stream);
      writer.BuildSections ();
      return writer;
    }

    void BuildSections ()
    {
      var has_win32_resources = win32_resources != null;
      if (has_win32_resources)
        sections++;

      text = CreateSection (".text", text_map.GetLength (), null);
      var previous = text;

      if (has_win32_resources) {
        rsrc = CreateSection (".rsrc", (uint) win32_resources.length, previous);

        PatchWin32Resources (win32_resources);
        previous = rsrc;
      }

      reloc = CreateSection (".reloc", 12u, previous);
    }

    Section CreateSection (string name, uint size, Section previous)
    {
      return new Section {
        Name = name,
        VirtualAddress = previous != null
          ? previous.VirtualAddress + Align (previous.VirtualSize, section_alignment)
          : text_rva,
        VirtualSize = size,
        PointerToRawData = previous != null
          ? previous.PointerToRawData + previous.SizeOfRawData
          : Align (GetHeaderSize (), file_alignment),
        SizeOfRawData = Align (size, file_alignment)
      };
    }

    static uint Align (uint value, uint align)
    {
      align--;
      return (value + align) & ~align;
    }

    void WriteDOSHeader ()
    {
      Write (new byte [] {
        // dos header start
        0x4d, 0x5a, 0x90, 0x00, 0x03, 0x00, 0x00,
        0x00, 0x04, 0x00, 0x00, 0x00, 0xff, 0xff,
        0x00, 0x00, 0xb8, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00,
        // lfanew
        0x80, 0x00, 0x00, 0x00,
        // dos header end
        0x0e, 0x1f, 0xba, 0x0e, 0x00, 0xb4, 0x09,
        0xcd, 0x21, 0xb8, 0x01, 0x4c, 0xcd, 0x21,
        0x54, 0x68, 0x69, 0x73, 0x20, 0x70, 0x72,
        0x6f, 0x67, 0x72, 0x61, 0x6d, 0x20, 0x63,
        0x61, 0x6e, 0x6e, 0x6f, 0x74, 0x20, 0x62,
        0x65, 0x20, 0x72, 0x75, 0x6e, 0x20, 0x69,
        0x6e, 0x20, 0x44, 0x4f, 0x53, 0x20, 0x6d,
        0x6f, 0x64, 0x65, 0x2e, 0x0d, 0x0d, 0x0a,
        0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00
      });
    }

    void WritePEFileHeader ()
    {
      WriteUInt32 (0x00004550);   // Magic
      WriteUInt16 (GetMachine ());  // Machine
      WriteUInt16 (sections);     // NumberOfSections
      WriteUInt32 (time_stamp);
      WriteUInt32 (0);  // PointerToSymbolTable
      WriteUInt32 (0);  // NumberOfSymbols
      WriteUInt16 ((ushort) (!pe64 ? 0xe0 : 0xf0)); // SizeOfOptionalHeader

      // ExecutableImage | (pe64 ? 32BitsMachine : LargeAddressAware)
      var characteristics = (ushort) (0x0002 | (!pe64 ? 0x0100 : 0x0020));
      if (module.Kind == ModuleKind.Dll || module.Kind == ModuleKind.NetModule)
        characteristics |= 0x2000;
      WriteUInt16 (characteristics);  // Characteristics
    }

    ushort GetMachine ()
    {
      switch (module.Architecture) {
      case TargetArchitecture.I386:
        return 0x014c;
      case TargetArchitecture.AMD64:
        return 0x8664;
      case TargetArchitecture.IA64:
        return 0x0200;
      }

      throw new NotSupportedException ();
    }

    void WriteOptionalHeaders ()
    {
      WriteUInt16 ((ushort) (!pe64 ? 0x10b : 0x20b)); // Magic
      WriteByte (8);  // LMajor
      WriteByte (0);  // LMinor
      WriteUInt32 (text.SizeOfRawData); // CodeSize
      WriteUInt32 (reloc.SizeOfRawData
        + (rsrc != null ? rsrc.SizeOfRawData : 0)); // InitializedDataSize
      WriteUInt32 (0);  // UninitializedDataSize

      var entry_point_rva = text_map.GetRVA (TextSegment.StartupStub);
      if (module.Architecture == TargetArchitecture.IA64)
        entry_point_rva += 0x20;
      WriteUInt32 (entry_point_rva); // EntryPointRVA
      WriteUInt32 (text_rva); // BaseOfCode

      if (!pe64) {
        WriteUInt32 (0);  // BaseOfData
        WriteUInt32 ((uint) image_base);  // ImageBase
      } else {
        WriteUInt64 (image_base); // ImageBase
      }

      WriteUInt32 (section_alignment);  // SectionAlignment
      WriteUInt32 (file_alignment);   // FileAlignment

      WriteUInt16 (4);  // OSMajor
      WriteUInt16 (0);  // OSMinor
      WriteUInt16 (0);  // UserMajor
      WriteUInt16 (0);  // UserMinor
      WriteUInt16 (4);  // SubSysMajor
      WriteUInt16 (0);  // SubSysMinor
      WriteUInt32 (0);  // Reserved

      WriteUInt32 (reloc.VirtualAddress + Align (reloc.VirtualSize, section_alignment));  // ImageSize
      WriteUInt32 (text.PointerToRawData);  // HeaderSize

      WriteUInt32 (0);  // Checksum
      WriteUInt16 (GetSubSystem ());  // SubSystem
      WriteUInt16 (0x8540); // DLLFlags

      const ulong stack_reserve = 0x100000;
      const ulong stack_commit = 0x1000;
      const ulong heap_reserve = 0x100000;
      const ulong heap_commit = 0x1000;

      if (!pe64) {
        WriteUInt32 ((uint) stack_reserve);
        WriteUInt32 ((uint) stack_commit);
        WriteUInt32 ((uint) heap_reserve);
        WriteUInt32 ((uint) heap_commit);
      } else {
        WriteUInt64 (stack_reserve);
        WriteUInt64 (stack_commit);
        WriteUInt64 (heap_reserve);
        WriteUInt64 (heap_commit);
      }

      WriteUInt32 (0);  // LoaderFlags
      WriteUInt32 (16); // NumberOfDataDir

      WriteZeroDataDirectory ();  // ExportTable
      WriteDataDirectory (text_map.GetDataDirectory (TextSegment.ImportDirectory)); // ImportTable
      if (rsrc != null) {             // ResourceTable
        WriteUInt32 (rsrc.VirtualAddress);
        WriteUInt32 (rsrc.VirtualSize);
      } else
        WriteZeroDataDirectory ();

      WriteZeroDataDirectory ();  // ExceptionTable
      WriteZeroDataDirectory ();  // CertificateTable
      WriteUInt32 (reloc.VirtualAddress);     // BaseRelocationTable
      WriteUInt32 (reloc.VirtualSize);

      if (text_map.GetLength (TextSegment.DebugDirectory) > 0) {
        WriteUInt32 (text_map.GetRVA (TextSegment.DebugDirectory));
        WriteUInt32 (28u);
      } else
        WriteZeroDataDirectory ();

      WriteZeroDataDirectory ();  // Copyright
      WriteZeroDataDirectory ();  // GlobalPtr
      WriteZeroDataDirectory ();  // TLSTable
      WriteZeroDataDirectory ();  // LoadConfigTable
      WriteZeroDataDirectory ();  // BoundImport
      WriteDataDirectory (text_map.GetDataDirectory (TextSegment.ImportAddressTable));  // IAT
      WriteZeroDataDirectory ();  // DelayImportDesc
      WriteDataDirectory (text_map.GetDataDirectory (TextSegment.CLIHeader)); // CLIHeader
      WriteZeroDataDirectory ();  // Reserved
    }

    void WriteZeroDataDirectory ()
    {
      WriteUInt32 (0);
      WriteUInt32 (0);
    }

    ushort GetSubSystem ()
    {
      switch (module.Kind) {
      case ModuleKind.Console:
      case ModuleKind.Dll:
      case ModuleKind.NetModule:
        return 0x3;
      case ModuleKind.Windows:
        return 0x2;
      default:
        throw new ArgumentOutOfRangeException ();
      }
    }

    void WriteSectionHeaders ()
    {
      WriteSection (text, 0x60000020);

      if (rsrc != null)
        WriteSection (rsrc, 0x40000040);

      WriteSection (reloc, 0x42000040);
    }

    void WriteSection (Section section, uint characteristics)
    {
      var name = new byte [8];
      var sect_name = section.Name;
      for (int i = 0; i < sect_name.Length; i++)
        name [i] = (byte) sect_name [i];

      WriteBytes (name);
      WriteUInt32 (section.VirtualSize);
      WriteUInt32 (section.VirtualAddress);
      WriteUInt32 (section.SizeOfRawData);
      WriteUInt32 (section.PointerToRawData);
      WriteUInt32 (0);  // PointerToRelocations
      WriteUInt32 (0);  // PointerToLineNumbers
      WriteUInt16 (0);  // NumberOfRelocations
      WriteUInt16 (0);  // NumberOfLineNumbers
      WriteUInt32 (characteristics);
    }

    void MoveTo (uint pointer)
    {
      BaseStream.Seek (pointer, SeekOrigin.Begin);
    }

    void MoveToRVA (Section section, RVA rva)
    {
      BaseStream.Seek (section.PointerToRawData + rva - section.VirtualAddress, SeekOrigin.Begin);
    }

    void MoveToRVA (TextSegment segment)
    {
      MoveToRVA (text, text_map.GetRVA (segment));
    }

    void WriteRVA (RVA rva)
    {
      if (!pe64)
        WriteUInt32 (rva);
      else
        WriteUInt64 (rva);
    }

    void WriteText ()
    {
      MoveTo (text.PointerToRawData);

      // ImportAddressTable

      WriteRVA (text_map.GetRVA (TextSegment.ImportHintNameTable));
      WriteRVA (0);

      // CLIHeader

      WriteUInt32 (0x48);
      WriteUInt16 (2);
      WriteUInt16 ((ushort) ((module.Runtime <= TargetRuntime.Net_1_1) ? 0 : 5));

      WriteUInt32 (text_map.GetRVA (TextSegment.MetadataHeader));
      WriteUInt32 (GetMetadataLength ());
      WriteUInt32 ((uint) module.Attributes);
      WriteUInt32 (metadata.entry_point.ToUInt32 ());
      WriteDataDirectory (text_map.GetDataDirectory (TextSegment.Resources));
      WriteDataDirectory (text_map.GetDataDirectory (TextSegment.StrongNameSignature));
      WriteZeroDataDirectory ();  // CodeManagerTable
      WriteZeroDataDirectory ();  // VTableFixups
      WriteZeroDataDirectory ();  // ExportAddressTableJumps
      WriteZeroDataDirectory ();  // ManagedNativeHeader

      // Code

      MoveToRVA (TextSegment.Code);
      WriteBuffer (metadata.code);

      // Resources

      MoveToRVA (TextSegment.Resources);
      WriteBuffer (metadata.resources);

      // Data

      if (metadata.data.length > 0) {
        MoveToRVA (TextSegment.Data);
        WriteBuffer (metadata.data);
      }

      // StrongNameSignature
      // stays blank

      // MetadataHeader

      MoveToRVA (TextSegment.MetadataHeader);
      WriteMetadataHeader ();

      WriteMetadata ();

      // DebugDirectory
      if (text_map.GetLength (TextSegment.DebugDirectory) > 0) {
        MoveToRVA (TextSegment.DebugDirectory);
        WriteDebugDirectory ();
      }

      // ImportDirectory
      MoveToRVA (TextSegment.ImportDirectory);
      WriteImportDirectory ();

      // StartupStub
      MoveToRVA (TextSegment.StartupStub);
      WriteStartupStub ();
    }

    uint GetMetadataLength ()
    {
      return text_map.GetRVA (TextSegment.DebugDirectory) - text_map.GetRVA (TextSegment.MetadataHeader);
    }

    void WriteMetadataHeader ()
    {
      WriteUInt32 (0x424a5342); // Signature
      WriteUInt16 (1);  // MajorVersion
      WriteUInt16 (1);  // MinorVersion
      WriteUInt32 (0);  // Reserved

      var version = GetZeroTerminatedString (GetVersion ());
      WriteUInt32 ((uint) version.Length);
      WriteBytes (version);
      WriteUInt16 (0);  // Flags
      WriteUInt16 (GetStreamCount ());

      uint offset = text_map.GetRVA (TextSegment.TableHeap) - text_map.GetRVA (TextSegment.MetadataHeader);

      WriteStreamHeader (ref offset, TextSegment.TableHeap, "#~");
      WriteStreamHeader (ref offset, TextSegment.StringHeap, "#Strings");
      WriteStreamHeader (ref offset, TextSegment.UserStringHeap, "#US");
      WriteStreamHeader (ref offset, TextSegment.GuidHeap, "#GUID");
      WriteStreamHeader (ref offset, TextSegment.BlobHeap, "#Blob");
    }

    string GetVersion ()
    {
      switch (module.Runtime) {
      case TargetRuntime.Net_1_0:
        return "v1.0.3705";
      case TargetRuntime.Net_1_1:
        return "v1.1.4322";
      case TargetRuntime.Net_2_0:
        return "v2.0.50727";
      case TargetRuntime.Net_4_0:
      default:
        return "v4.0.30319";
      }
    }

    ushort GetStreamCount ()
    {
      return (ushort) (
        1 // #~
        + 1 // #Strings
        + (metadata.user_string_heap.IsEmpty ? 0 : 1) // #US
        + 1 // GUID
        + (metadata.blob_heap.IsEmpty ? 0 : 1));  // #Blob
    }

    void WriteStreamHeader (ref uint offset, TextSegment heap, string name)
    {
      var length = (uint) text_map.GetLength (heap);
      if (length == 0)
        return;

      WriteUInt32 (offset);
      WriteUInt32 (length);
      WriteBytes (GetZeroTerminatedString (name));
      offset += length;
    }

    static byte [] GetZeroTerminatedString (string @string)
    {
      return GetString (@string, (@string.Length + 1 + 3) & ~3);
    }

    static byte [] GetSimpleString (string @string)
    {
      return GetString (@string, @string.Length);
    }

    static byte [] GetString (string @string, int length)
    {
      var bytes = new byte [length];
      for (int i = 0; i < @string.Length; i++)
        bytes [i] = (byte) @string [i];

      return bytes;
    }

    void WriteMetadata ()
    {
      WriteHeap (TextSegment.TableHeap, metadata.table_heap);
      WriteHeap (TextSegment.StringHeap, metadata.string_heap);
      WriteHeap (TextSegment.UserStringHeap, metadata.user_string_heap);
      WriteGuidHeap ();
      WriteHeap (TextSegment.BlobHeap, metadata.blob_heap);
    }

    void WriteHeap (TextSegment heap, HeapBuffer buffer)
    {
      if (buffer.IsEmpty)
        return;

      MoveToRVA (heap);
      WriteBuffer (buffer);
    }

    void WriteGuidHeap ()
    {
      MoveToRVA (TextSegment.GuidHeap);
      WriteBytes (module.Mvid.ToByteArray ());
    }

    void WriteDebugDirectory ()
    {
      WriteInt32 (debug_directory.Characteristics);
      WriteUInt32 (time_stamp);
      WriteInt16 (debug_directory.MajorVersion);
      WriteInt16 (debug_directory.MinorVersion);
      WriteInt32 (debug_directory.Type);
      WriteInt32 (debug_directory.SizeOfData);
      WriteInt32 (debug_directory.AddressOfRawData);
      WriteInt32 ((int) BaseStream.Position + 4);

      WriteBytes (debug_data);
    }

    void WriteImportDirectory ()
    {
      WriteUInt32 (text_map.GetRVA (TextSegment.ImportDirectory) + 40); // ImportLookupTable
      WriteUInt32 (0);  // DateTimeStamp
      WriteUInt32 (0);  // ForwarderChain
      WriteUInt32 (text_map.GetRVA (TextSegment.ImportHintNameTable) + 14);
      WriteUInt32 (text_map.GetRVA (TextSegment.ImportAddressTable));
      Advance (20);

      // ImportLookupTable
      WriteUInt32 (text_map.GetRVA (TextSegment.ImportHintNameTable));

      // ImportHintNameTable
      MoveToRVA (TextSegment.ImportHintNameTable);

      WriteUInt16 (0);  // Hint
      WriteBytes (GetRuntimeMain ());
      WriteByte (0);
      WriteBytes (GetSimpleString ("mscoree.dll"));
      WriteUInt16 (0);
    }

    byte [] GetRuntimeMain ()
    {
      return module.Kind == ModuleKind.Dll || module.Kind == ModuleKind.NetModule
        ? GetSimpleString ("_CorDllMain")
        : GetSimpleString ("_CorExeMain");
    }

    void WriteStartupStub ()
    {
      switch (module.Architecture) {
      case TargetArchitecture.I386:
        WriteUInt16 (0x25ff);
        WriteUInt32 ((uint) image_base + text_map.GetRVA (TextSegment.ImportAddressTable));
        return;
      case TargetArchitecture.AMD64:
        WriteUInt16 (0xa148);
        WriteUInt32 ((uint) image_base + text_map.GetRVA (TextSegment.ImportAddressTable));
        WriteUInt16 (0xe0ff);
        return;
      case TargetArchitecture.IA64:
        WriteBytes (new byte [] {
          0x0b, 0x48, 0x00, 0x02, 0x18, 0x10, 0xa0, 0x40, 0x24, 0x30, 0x28, 0x00, 0x00, 0x00, 0x04, 0x00,
          0x10, 0x08, 0x00, 0x12, 0x18, 0x10, 0x60, 0x50, 0x04, 0x80, 0x03, 0x00, 0x60, 0x00, 0x80, 0x00
        });
        WriteUInt32 ((uint) image_base + text_map.GetRVA (TextSegment.StartupStub));
        WriteUInt32 ((uint) image_base + text_rva);
        return;
      }
    }

    void WriteRsrc ()
    {
      MoveTo (rsrc.PointerToRawData);
      WriteBuffer (win32_resources);
    }

    void WriteReloc ()
    {
      MoveTo (reloc.PointerToRawData);

      var reloc_rva = text_map.GetRVA (TextSegment.StartupStub);
      reloc_rva += module.Architecture == TargetArchitecture.IA64 ? 0x20u : 2;
      var page_rva = reloc_rva & ~0xfffu;

      WriteUInt32 (page_rva); // PageRVA
      WriteUInt32 (0x000c); // Block Size

      switch (module.Architecture) {
      case TargetArchitecture.I386:
        WriteUInt32 (0x3000 + reloc_rva - page_rva);
        break;
      case TargetArchitecture.AMD64:
        WriteUInt32 (0xa000 + reloc_rva - page_rva);
        break;
      case TargetArchitecture.IA64:
        WriteUInt16 ((ushort) (0xa000 + reloc_rva - page_rva));
        WriteUInt16 ((ushort) (0xa000 + reloc_rva - page_rva + 8));
        break;
      }

      WriteBytes (new byte [file_alignment - reloc.VirtualSize]);
    }

    public void WriteImage ()
    {
      WriteDOSHeader ();
      WritePEFileHeader ();
      WriteOptionalHeaders ();
      WriteSectionHeaders ();
      WriteText ();
      if (rsrc != null)
        WriteRsrc ();
      WriteReloc ();
    }

    TextMap BuildTextMap ()
    {
      var map = metadata.text_map;

      map.AddMap (TextSegment.Code, metadata.code.length, !pe64 ? 4 : 16);
      map.AddMap (TextSegment.Resources, metadata.resources.length, 8);
      map.AddMap (TextSegment.Data, metadata.data.length, 4);
      if (metadata.data.length > 0)
        metadata.table_heap.FixupData (map.GetRVA (TextSegment.Data));
      map.AddMap (TextSegment.StrongNameSignature, GetStrongNameLength (), 4);

      map.AddMap (TextSegment.MetadataHeader, GetMetadataHeaderLength ());
      map.AddMap (TextSegment.TableHeap, metadata.table_heap.length, 4);
      map.AddMap (TextSegment.StringHeap, metadata.string_heap.length, 4);
      map.AddMap (TextSegment.UserStringHeap, metadata.user_string_heap.IsEmpty ? 0 : metadata.user_string_heap.length, 4);
      map.AddMap (TextSegment.GuidHeap, 16);
      map.AddMap (TextSegment.BlobHeap, metadata.blob_heap.IsEmpty ? 0 : metadata.blob_heap.length, 4);

      int debug_dir_len = 0;
      if (!debug_data.IsNullOrEmpty ()) {
        const int debug_dir_header_len = 28;

        debug_directory.AddressOfRawData = (int) map.GetNextRVA (TextSegment.BlobHeap) + debug_dir_header_len;
        debug_dir_len = debug_data.Length + debug_dir_header_len;
      }

      map.AddMap (TextSegment.DebugDirectory, debug_dir_len, 4);

      RVA import_dir_rva = map.GetNextRVA (TextSegment.DebugDirectory);
      RVA import_hnt_rva = import_dir_rva + (!pe64 ? 48u : 52u);
      import_hnt_rva = (import_hnt_rva + 15u) & ~15u;
      uint import_dir_len = (import_hnt_rva - import_dir_rva) + 27u;

      RVA startup_stub_rva = import_dir_rva + import_dir_len;
      startup_stub_rva = module.Architecture == TargetArchitecture.IA64
        ? (startup_stub_rva + 15u) & ~15u
        : 2 + ((startup_stub_rva + 3u) & ~3u);

      map.AddMap (TextSegment.ImportDirectory, new Range (import_dir_rva, import_dir_len));
      map.AddMap (TextSegment.ImportHintNameTable, new Range (import_hnt_rva, 0));
      map.AddMap (TextSegment.StartupStub, new Range (startup_stub_rva, GetStartupStubLength ()));

      return map;
    }

    uint GetStartupStubLength ()
    {
      switch (module.Architecture) {
      case TargetArchitecture.I386:
        return 6;
      case TargetArchitecture.AMD64:
        return 12;
      case TargetArchitecture.IA64:
        return 48;
      default:
        throw new InvalidOperationException ();
      }
    }

    int GetMetadataHeaderLength ()
    {
      return
        // MetadataHeader
        40
        // #~ header
        + 12
        // #Strings header
        + 20
        // #US header
        + (metadata.user_string_heap.IsEmpty ? 0 : 12)
        // #GUID header
        + 16
        // #Blob header
        + (metadata.blob_heap.IsEmpty ? 0 : 16);
    }

    int GetStrongNameLength ()
    {
      if ((module.Attributes & ModuleAttributes.StrongNameSigned) == 0)
        return 0;

      if (module.Assembly == null)
        throw new InvalidOperationException ();

      var public_key = module.Assembly.Name.PublicKey;

      if (public_key != null) {
        // in fx 2.0 the key may be from 384 to 16384 bits
        // so we must calculate the signature size based on
        // the size of the public key (minus the 32 byte header)
        int size = public_key.Length;
        if (size > 32)
          return size - 32;
        // note: size == 16 for the ECMA "key" which is replaced
        // by the runtime with a 1024 bits key (128 bytes)
      }

      return 128; // default strongname signature size
    }

    public DataDirectory GetStrongNameSignatureDirectory ()
    {
      return text_map.GetDataDirectory (TextSegment.StrongNameSignature);
    }

    public uint GetHeaderSize ()
    {
      return pe_header_size + (sections * section_header_size);
    }

    void PatchWin32Resources (ByteBuffer resources)
    {
      PatchResourceDirectoryTable (resources);
    }

    void PatchResourceDirectoryTable (ByteBuffer resources)
    {
      resources.Advance (12);

      var entries = resources.ReadUInt16 () + resources.ReadUInt16 ();

      for (int i = 0; i < entries; i++)
        PatchResourceDirectoryEntry (resources);
    }

    void PatchResourceDirectoryEntry (ByteBuffer resources)
    {
      resources.Advance (4);
      var child = resources.ReadUInt32 ();

      var position = resources.position;
      resources.position = (int) child & 0x7fffffff;

      if ((child & 0x80000000) != 0)
        PatchResourceDirectoryTable (resources);
      else
        PatchResourceDataEntry (resources);

      resources.position = position;
    }

    void PatchResourceDataEntry (ByteBuffer resources)
    {
      var old_rsrc = GetImageResourceSection ();
      var rva = resources.ReadUInt32 ();
      resources.position -= 4;
      resources.WriteUInt32 (rva - old_rsrc.VirtualAddress + rsrc.VirtualAddress);
    }
  }
}

#endif