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// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "courgette/ensemble.h"
#include "base/basictypes.h"
#include "base/string_number_conversions.h"
#include "courgette/image_info.h"
#include "courgette/region.h"
#include "courgette/streams.h"
#include "courgette/simple_delta.h"
namespace courgette {
Element::Element(Kind kind, Ensemble* ensemble, const Region& region)
: kind_(kind), ensemble_(ensemble), region_(region) {
}
std::string Element::Name() const {
return ensemble_->name() + "("
+ base::IntToString(kind()) + ","
+ base::Uint64ToString(offset_in_ensemble()) + ","
+ base::Uint64ToString(region().length()) + ")";
}
// A subclass of Element that has a PEInfo.
class ElementWinPE : public Element {
public:
ElementWinPE(Kind kind, Ensemble* ensemble, const Region& region,
PEInfo* info)
: Element(kind, ensemble, region),
pe_info_(info) {
}
virtual PEInfo* GetPEInfo() const { return pe_info_; }
protected:
~ElementWinPE() { delete pe_info_; }
private:
PEInfo* pe_info_; // Owned by |this|.
};
// Scans the Ensemble's region, sniffing out Elements. We assume that the
// elements do not overlap.
Status Ensemble::FindEmbeddedElements() {
size_t length = region_.length();
const uint8* start = region_.start();
size_t position = 0;
while (position < length) {
// Quick test; Windows executables begin with 'MZ'.
if (start[position] == 'M' &&
position + 1 < length && start[position + 1] == 'Z') {
courgette::PEInfo *info = new courgette::PEInfo();
info->Init(start + position, length - position);
if (info->ParseHeader()) {
Region region(start + position, info->length());
if (info->has_text_section()) {
if (info->is_32bit()) {
Element* element = new ElementWinPE(Element::WIN32_X86_WITH_CODE,
this, region, info);
owned_elements_.push_back(element);
elements_.push_back(element);
position += region.length();
continue;
}
// TODO(sra): Extend to 64-bit executables.
}
// If we had a clever transformation for resource-only executables we
// should identify the suitable elements here:
if (!info->has_text_section() && false) {
Element* element = new ElementWinPE(Element::WIN32_NOCODE,
this, region, info);
owned_elements_.push_back(element);
elements_.push_back(element);
position += region.length();
continue;
}
}
delete info;
}
// This is where to add new formats, e.g. Linux executables, Dalvik
// executables etc.
// No Element found at current position.
++position;
}
return C_OK;
}
Ensemble::~Ensemble() {
for (size_t i = 0; i < owned_elements_.size(); ++i)
delete owned_elements_[i];
}
} // namespace
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