courgette/ensemble.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "courgette/ensemble.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/string_number_conversions.h"
   9
  10 #include "courgette/image_info.h"
  11 #include "courgette/region.h"
  12 #include "courgette/streams.h"
  13 #include "courgette/simple_delta.h"
  14
  15 namespace courgette {
  16
  17 Element::Element(ExecutableType kind,
  18                  Ensemble* ensemble,
  19                  const Region& region,
  20                  PEInfo* info)
  21     : kind_(kind), ensemble_(ensemble), region_(region), info_(info) {
  22 }
  23
  24 Element::~Element() {
  25   delete info_;
  26 }
  27
  28 std::string Element::Name() const {
  29   return ensemble_->name() + "("
  30       + base::IntToString(kind()) + ","
  31       + base::Uint64ToString(offset_in_ensemble()) + ","
  32       + base::Uint64ToString(region().length()) + ")";
  33 }
  34
  35 // Scans the Ensemble's region, sniffing out Elements.  We assume that the
  36 // elements do not overlap.
  37 Status Ensemble::FindEmbeddedElements() {
  38
  39   size_t length = region_.length();
  40   const uint8* start = region_.start();
  41
  42   size_t position = 0;
  43   while (position < length) {
  44     ExecutableType type = DetectExecutableType(start + position,
  45                                                length - position);
  46
  47     //
  48     // TODO(dgarrett) This switch can go away totally after two things.
  49     //
  50     // Make ImageInfo generic for all executable types.
  51     // Find a generic way to handle length detection for executables.
  52     //
  53     // When this switch is gone, that's one less piece of code that is
  54     // executable type aware.
  55     //
  56     switch (type) {
  57       case UNKNOWN: {
  58         // No Element found at current position.
  59         ++position;
  60         break;
  61       }
  62       case WIN32_X86: {
  63         // The Info is only created to detect the length of the executable
  64         courgette::PEInfo* info(new courgette::PEInfo());
  65         info->Init(start + position, length - position);
  66         if (!info->ParseHeader()) {
  67           delete info;
  68           position++;
  69           break;
  70         }
  71         Region region(start + position, info->length());
  72
  73         Element* element = new Element(type, this, region, info);
  74         owned_elements_.push_back(element);
  75         elements_.push_back(element);
  76         position += region.length();
  77         break;
  78       }
  79     }
  80   }
  81   return C_OK;
  82 }
  83
  84 Ensemble::~Ensemble() {
  85   for (size_t i = 0;  i < owned_elements_.size();  ++i)
  86     delete owned_elements_[i];
  87 }
  88
  89 }  // namespace