contrib/llvm/lib/Object/WindowsResource.cpp

   1 //===-- WindowsResource.cpp -------------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the .res file class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Object/WindowsResource.h"
  15 #include "llvm/Object/Error.h"
  16 #include <system_error>
  17
  18 namespace llvm {
  19 namespace object {
  20
  21 static const size_t ResourceMagicSize = 16;
  22
  23 static const size_t NullEntrySize = 16;
  24
  25 #define RETURN_IF_ERROR(X)                                                     \
  26   if (auto EC = X)                                                             \
  27     return EC;
  28
  29 WindowsResource::WindowsResource(MemoryBufferRef Source)
  30     : Binary(Binary::ID_WinRes, Source) {
  31   size_t LeadingSize = ResourceMagicSize + NullEntrySize;
  32   BBS = BinaryByteStream(Data.getBuffer().drop_front(LeadingSize),
  33                          support::little);
  34 }
  35
  36 WindowsResource::~WindowsResource() = default;
  37
  38 Expected<std::unique_ptr<WindowsResource>>
  39 WindowsResource::createWindowsResource(MemoryBufferRef Source) {
  40   if (Source.getBufferSize() < ResourceMagicSize + NullEntrySize)
  41     return make_error<GenericBinaryError>(
  42         "File too small to be a resource file",
  43         object_error::invalid_file_type);
  44   std::unique_ptr<WindowsResource> Ret(new WindowsResource(Source));
  45   return std::move(Ret);
  46 }
  47
  48 Expected<ResourceEntryRef> WindowsResource::getHeadEntry() {
  49   Error Err = Error::success();
  50   auto Ref = ResourceEntryRef(BinaryStreamRef(BBS), this, Err);
  51   if (Err)
  52     return std::move(Err);
  53   return Ref;
  54 }
  55
  56 ResourceEntryRef::ResourceEntryRef(BinaryStreamRef Ref,
  57                                    const WindowsResource *Owner, Error &Err)
  58     : Reader(Ref), OwningRes(Owner) {
  59   if (loadNext())
  60     Err = make_error<GenericBinaryError>("Could not read first entry.",
  61                                          object_error::unexpected_eof);
  62 }
  63
  64 Error ResourceEntryRef::moveNext(bool &End) {
  65   // Reached end of all the entries.
  66   if (Reader.bytesRemaining() == 0) {
  67     End = true;
  68     return Error::success();
  69   }
  70   RETURN_IF_ERROR(loadNext());
  71
  72   return Error::success();
  73 }
  74
  75 Error ResourceEntryRef::loadNext() {
  76   uint32_t DataSize;
  77   RETURN_IF_ERROR(Reader.readInteger(DataSize));
  78   uint32_t HeaderSize;
  79   RETURN_IF_ERROR(Reader.readInteger(HeaderSize));
  80   // The data and header size ints are themselves part of the header, so we must
  81   // subtract them from the size.
  82   RETURN_IF_ERROR(
  83       Reader.readStreamRef(HeaderBytes, HeaderSize - 2 * sizeof(uint32_t)));
  84   RETURN_IF_ERROR(Reader.readStreamRef(DataBytes, DataSize));
  85   RETURN_IF_ERROR(Reader.padToAlignment(sizeof(uint32_t)));
  86   return Error::success();
  87 }
  88
  89 } // namespace object
  90 } // namespace llvm