ELFIO/elfio/elfio_symbols.hpp
Serge Lamikhov-Center 9c739b49a0 Reformat sources by using clang-format
It is not perfect (and, probably, it is worser than it was before), but, it is automatic
2020-08-21 07:56:08 -07:00

450 lines
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C++

/*
Copyright (C) 2001-2020 by Serge Lamikhov-Center
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.
*/
#ifndef ELFIO_SYMBOLS_HPP
#define ELFIO_SYMBOLS_HPP
namespace ELFIO {
//------------------------------------------------------------------------------
template <class S> class symbol_section_accessor_template
{
public:
//------------------------------------------------------------------------------
symbol_section_accessor_template( const elfio& elf_file_,
S* symbol_section_ )
: elf_file( elf_file_ ), symbol_section( symbol_section_ )
{
find_hash_section();
}
//------------------------------------------------------------------------------
Elf_Xword get_symbols_num() const
{
Elf_Xword nRet = 0;
if ( 0 != symbol_section->get_entry_size() ) {
nRet =
symbol_section->get_size() / symbol_section->get_entry_size();
}
return nRet;
}
//------------------------------------------------------------------------------
bool get_symbol( Elf_Xword index,
std::string& name,
Elf64_Addr& value,
Elf_Xword& size,
unsigned char& bind,
unsigned char& type,
Elf_Half& section_index,
unsigned char& other ) const
{
bool ret = false;
if ( elf_file.get_class() == ELFCLASS32 ) {
ret = generic_get_symbol<Elf32_Sym>( index, name, value, size, bind,
type, section_index, other );
}
else {
ret = generic_get_symbol<Elf64_Sym>( index, name, value, size, bind,
type, section_index, other );
}
return ret;
}
//------------------------------------------------------------------------------
bool get_symbol( const std::string& name,
Elf64_Addr& value,
Elf_Xword& size,
unsigned char& bind,
unsigned char& type,
Elf_Half& section_index,
unsigned char& other ) const
{
bool ret = false;
if ( 0 != get_hash_table_index() ) {
Elf_Word nbucket = *(const Elf_Word*)hash_section->get_data();
Elf_Word nchain = *(const Elf_Word*)( hash_section->get_data() +
sizeof( Elf_Word ) );
Elf_Word val = elf_hash( (const unsigned char*)name.c_str() );
Elf_Word y = *(const Elf_Word*)( hash_section->get_data() +
( 2 + val % nbucket ) *
sizeof( Elf_Word ) );
std::string str;
get_symbol( y, str, value, size, bind, type, section_index, other );
while ( str != name && STN_UNDEF != y && y < nchain ) {
y = *(const Elf_Word*)( hash_section->get_data() +
( 2 + nbucket + y ) *
sizeof( Elf_Word ) );
get_symbol( y, str, value, size, bind, type, section_index,
other );
}
if ( str == name ) {
ret = true;
}
}
else {
for ( Elf_Xword i = 0; i < get_symbols_num() && !ret; i++ ) {
std::string symbol_name;
if ( get_symbol( i, symbol_name, value, size, bind, type,
section_index, other ) ) {
if ( symbol_name == name ) {
ret = true;
}
}
}
}
return ret;
}
//------------------------------------------------------------------------------
bool get_symbol( const Elf64_Addr& value,
std::string& name,
Elf_Xword& size,
unsigned char& bind,
unsigned char& type,
Elf_Half& section_index,
unsigned char& other ) const
{
const endianess_convertor& convertor = elf_file.get_convertor();
Elf_Xword idx = 0;
bool match = false;
Elf64_Addr v = 0;
if ( elf_file.get_class() == ELFCLASS32 ) {
match = generic_search_symbols<Elf32_Sym>(
[&]( const Elf32_Sym* sym ) {
return convertor( sym->st_value ) == value;
},
idx );
}
else {
match = generic_search_symbols<Elf64_Sym>(
[&]( const Elf64_Sym* sym ) {
return convertor( sym->st_value ) == value;
},
idx );
}
if ( match ) {
return get_symbol( idx, name, v, size, bind, type, section_index,
other );
}
return false;
}
//------------------------------------------------------------------------------
Elf_Word add_symbol( Elf_Word name,
Elf64_Addr value,
Elf_Xword size,
unsigned char info,
unsigned char other,
Elf_Half shndx )
{
Elf_Word nRet;
if ( symbol_section->get_size() == 0 ) {
if ( elf_file.get_class() == ELFCLASS32 ) {
nRet = generic_add_symbol<Elf32_Sym>( 0, 0, 0, 0, 0, 0 );
}
else {
nRet = generic_add_symbol<Elf64_Sym>( 0, 0, 0, 0, 0, 0 );
}
}
if ( elf_file.get_class() == ELFCLASS32 ) {
nRet = generic_add_symbol<Elf32_Sym>( name, value, size, info,
other, shndx );
}
else {
nRet = generic_add_symbol<Elf64_Sym>( name, value, size, info,
other, shndx );
}
return nRet;
}
//------------------------------------------------------------------------------
Elf_Word add_symbol( Elf_Word name,
Elf64_Addr value,
Elf_Xword size,
unsigned char bind,
unsigned char type,
unsigned char other,
Elf_Half shndx )
{
return add_symbol( name, value, size, ELF_ST_INFO( bind, type ), other,
shndx );
}
//------------------------------------------------------------------------------
Elf_Word add_symbol( string_section_accessor& pStrWriter,
const char* str,
Elf64_Addr value,
Elf_Xword size,
unsigned char info,
unsigned char other,
Elf_Half shndx )
{
Elf_Word index = pStrWriter.add_string( str );
return add_symbol( index, value, size, info, other, shndx );
}
//------------------------------------------------------------------------------
Elf_Word add_symbol( string_section_accessor& pStrWriter,
const char* str,
Elf64_Addr value,
Elf_Xword size,
unsigned char bind,
unsigned char type,
unsigned char other,
Elf_Half shndx )
{
return add_symbol( pStrWriter, str, value, size,
ELF_ST_INFO( bind, type ), other, shndx );
}
//------------------------------------------------------------------------------
Elf_Xword arrange_local_symbols(
std::function<void( Elf_Xword first, Elf_Xword second )> func =
nullptr )
{
int nRet = 0;
if ( elf_file.get_class() == ELFCLASS32 ) {
nRet = generic_arrange_local_symbols<Elf32_Sym>( func );
}
else {
nRet = generic_arrange_local_symbols<Elf64_Sym>( func );
}
return nRet;
}
//------------------------------------------------------------------------------
private:
//------------------------------------------------------------------------------
void find_hash_section()
{
hash_section = 0;
hash_section_index = 0;
Elf_Half nSecNo = elf_file.sections.size();
for ( Elf_Half i = 0; i < nSecNo && 0 == hash_section_index; ++i ) {
const section* sec = elf_file.sections[i];
if ( sec->get_link() == symbol_section->get_index() ) {
hash_section = sec;
hash_section_index = i;
}
}
}
//------------------------------------------------------------------------------
Elf_Half get_string_table_index() const
{
return (Elf_Half)symbol_section->get_link();
}
//------------------------------------------------------------------------------
Elf_Half get_hash_table_index() const { return hash_section_index; }
//------------------------------------------------------------------------------
template <class T> const T* generic_get_symbol_ptr( Elf_Xword index ) const
{
if ( 0 != symbol_section->get_data() && index < get_symbols_num() ) {
const T* pSym = reinterpret_cast<const T*>(
symbol_section->get_data() +
index * symbol_section->get_entry_size() );
return pSym;
}
return nullptr;
}
//------------------------------------------------------------------------------
template <class T>
bool generic_search_symbols( std::function<bool( const T* )> match,
Elf_Xword& idx ) const
{
for ( Elf_Xword i = 0; i < get_symbols_num(); i++ ) {
const T* symPtr = generic_get_symbol_ptr<T>( i );
if ( symPtr == nullptr )
return false;
if ( match( symPtr ) ) {
idx = i;
return true;
}
}
return false;
}
//------------------------------------------------------------------------------
template <class T>
bool generic_get_symbol( Elf_Xword index,
std::string& name,
Elf64_Addr& value,
Elf_Xword& size,
unsigned char& bind,
unsigned char& type,
Elf_Half& section_index,
unsigned char& other ) const
{
bool ret = false;
if ( 0 != symbol_section->get_data() && index < get_symbols_num() ) {
const T* pSym = reinterpret_cast<const T*>(
symbol_section->get_data() +
index * symbol_section->get_entry_size() );
const endianess_convertor& convertor = elf_file.get_convertor();
section* string_section =
elf_file.sections[get_string_table_index()];
string_section_accessor str_reader( string_section );
const char* pStr =
str_reader.get_string( convertor( pSym->st_name ) );
if ( 0 != pStr ) {
name = pStr;
}
value = convertor( pSym->st_value );
size = convertor( pSym->st_size );
bind = ELF_ST_BIND( pSym->st_info );
type = ELF_ST_TYPE( pSym->st_info );
section_index = convertor( pSym->st_shndx );
other = pSym->st_other;
ret = true;
}
return ret;
}
//------------------------------------------------------------------------------
template <class T>
Elf_Word generic_add_symbol( Elf_Word name,
Elf64_Addr value,
Elf_Xword size,
unsigned char info,
unsigned char other,
Elf_Half shndx )
{
const endianess_convertor& convertor = elf_file.get_convertor();
T entry;
entry.st_name = convertor( name );
entry.st_value = value;
entry.st_value = convertor( entry.st_value );
entry.st_size = size;
entry.st_size = convertor( entry.st_size );
entry.st_info = convertor( info );
entry.st_other = convertor( other );
entry.st_shndx = convertor( shndx );
symbol_section->append_data( reinterpret_cast<char*>( &entry ),
sizeof( entry ) );
Elf_Word nRet = symbol_section->get_size() / sizeof( entry ) - 1;
return nRet;
}
//------------------------------------------------------------------------------
template <class T>
Elf_Xword generic_arrange_local_symbols(
std::function<void( Elf_Xword first, Elf_Xword second )> func )
{
const endianess_convertor& convertor = elf_file.get_convertor();
const Elf_Xword size = symbol_section->get_entry_size();
Elf_Xword first_not_local =
1; // Skip the first entry. It is always NOTYPE
Elf_Xword current = 0;
Elf_Xword count = get_symbols_num();
while ( true ) {
T* p1 = nullptr;
T* p2 = nullptr;
while ( first_not_local < count ) {
p1 = const_cast<T*>(
generic_get_symbol_ptr<T>( first_not_local ) );
if ( ELF_ST_BIND( convertor( p1->st_info ) ) != STB_LOCAL )
break;
++first_not_local;
}
current = first_not_local + 1;
while ( current < count ) {
p2 = const_cast<T*>( generic_get_symbol_ptr<T>( current ) );
if ( ELF_ST_BIND( convertor( p2->st_info ) ) == STB_LOCAL )
break;
++current;
}
if ( first_not_local < count && current < count ) {
if ( func )
func( first_not_local, current );
// Swap the symbols
T tmp;
std::copy( p1, p1 + 1, &tmp );
std::copy( p2, p2 + 1, p1 );
std::copy( &tmp, &tmp + 1, p2 );
}
else {
// Update 'info' field of the section
symbol_section->set_info( first_not_local );
break;
}
}
// Elf_Word nRet = symbol_section->get_size() / sizeof(entry) - 1;
return first_not_local;
}
//------------------------------------------------------------------------------
private:
const elfio& elf_file;
S* symbol_section;
Elf_Half hash_section_index;
const section* hash_section;
};
using symbol_section_accessor = symbol_section_accessor_template<section>;
using const_symbol_section_accessor =
symbol_section_accessor_template<const section>;
} // namespace ELFIO
#endif // ELFIO_SYMBOLS_HPP