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// -*- mode: C++ -*-
// Copyright (c) 2011, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Original author: Ted Mielczarek <ted.mielczarek@gmail.com>
// synth_elf.h: Interface to synth_elf::ELF: fake ELF generator.
#ifndef COMMON_LINUX_SYNTH_ELF_H_
#define COMMON_LINUX_SYNTH_ELF_H_
#include "common/test_assembler.h"
#include <list>
#include <vector>
#include <map>
#include <string>
#include <utility>
#include "common/using_std_string.h"
namespace google_breakpad {
namespace synth_elf {
using std::list;
using std::vector;
using std::map;
using std::pair;
using test_assembler::Endianness;
using test_assembler::kLittleEndian;
using test_assembler::kUnsetEndian;
using test_assembler::Label;
using test_assembler::Section;
// String tables are common in ELF headers, so subclass Section
// to make them easy to generate.
class StringTable : public Section {
public:
StringTable(Endianness endianness = kUnsetEndian)
: Section(endianness) {
start() = 0;
empty_string = Add("");
}
// Add the string s to the string table, and return
// a label containing the offset into the string table
// at which it was added.
Label Add(const string& s) {
if (strings_.find(s) != strings_.end())
return strings_[s];
Label string_label(Here());
AppendCString(s);
strings_[s] = string_label;
return string_label;
}
// All StringTables contain an empty string as their first
// entry.
Label empty_string;
// Avoid inserting duplicate strings.
map<string,Label> strings_;
};
// A Section representing an entire ELF file.
class ELF : public Section {
public:
ELF(uint16_t machine, // EM_386, etc
uint8_t file_class, // ELFCLASS{32,64}
Endianness endianness = kLittleEndian);
// Add the Section section to the section header table and append it
// to the file. Returns the index of the section in the section
// header table.
int AddSection(const string& name, const Section& section,
uint32_t type, uint32_t flags = 0, uint64_t addr = 0,
uint32_t link = 0, uint64_t entsize = 0, uint64_t offset = 0);
// Add a segment containing from section index start to section index end.
// The indexes must have been gotten from AddSection.
void AddSegment(int start, int end, uint32_t type, uint32_t flags = 0);
// Write out all data. GetContents may be used after this.
void Finish();
private:
// Size of an address, in bytes.
const size_t addr_size_;
// Offset to the program header table.
Label program_header_label_;
// Number of entries in the program header table.
int program_count_;
Label program_count_label_;
// The program header table itself.
Section program_header_table_;
// Offset to the section header table.
Label section_header_label_;
// Number of entries in the section header table.
int section_count_;
Label section_count_label_;
// The section header table itself.
Section section_header_table_;
// Index of the section header string table in the section
// header table.
Label section_header_string_index_;
// Section containing the names of section header table entries.
StringTable section_header_strings_;
// Record of an added section
struct ElfSection : public Section {
ElfSection(const Section& section, uint32_t type, uint32_t addr,
uint32_t offset, Label offset_label, uint32_t size)
: Section(section), type_(type), addr_(addr), offset_(offset)
, offset_label_(offset_label), size_(size) {
}
uint32_t type_;
uint32_t addr_;
uint32_t offset_;
Label offset_label_;
uint32_t size_;
};
vector<ElfSection> sections_;
void AppendSection(ElfSection& section);
};
// A class to build .symtab or .dynsym sections.
class SymbolTable : public Section {
public:
// table is the StringTable that contains symbol names. The caller
// must ensure that it remains alive for the life of the
// SymbolTable.
SymbolTable(Endianness endianness, size_t addr_size, StringTable& table);
// Add an Elf32_Sym.
void AddSymbol(const string& name, uint32_t value,
uint32_t size, unsigned info, uint16_t shndx);
// Add an Elf64_Sym.
void AddSymbol(const string& name, uint64_t value,
uint64_t size, unsigned info, uint16_t shndx);
private:
#ifndef NDEBUG
size_t addr_size_;
#endif
StringTable& table_;
};
// A class for note sections
class Notes : public Section {
public:
Notes(Endianness endianness)
: Section(endianness) {
}
// Add a note.
void AddNote(int type, const string& name, const uint8_t* desc_bytes,
size_t desc_size);
};
} // namespace synth_elf
} // namespace google_breakpad
#endif // COMMON_LINUX_SYNTH_ELF_H_