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/*!A cross-platform build utility based on Lua
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright (C) 2015-present, Xmake Open Source Community.
*
* @author ruki
* @file readsyms.c
*
*/
/* //////////////////////////////////////////////////////////////////////////////////////
* trace
*/
#define TB_TRACE_MODULE_NAME "readsyms_elf"
#define TB_TRACE_MODULE_DEBUG (0)
/* //////////////////////////////////////////////////////////////////////////////////////
* includes
*/
#include "prefix.h"
/* //////////////////////////////////////////////////////////////////////////////////////
* private implementation
*/
tb_bool_t xm_binutils_elf_read_symbols_32(tb_stream_ref_t istream, tb_hize_t base_offset, lua_State *lua) {
tb_assert_and_check_return_val(istream && lua, tb_false);
// build context and ensure .symtab/.strtab are available
xm_elf_context_t ctx;
xm_binutils_elf_get_context_32(istream, base_offset, &ctx);
if (!ctx.symtab_offset || !ctx.symstr_offset) {
// no symbol table present: return empty result
lua_newtable(lua);
return tb_true;
}
// create result table
lua_newtable(lua);
// compute symbol count and seek to .symtab
tb_uint32_t sym_count = (tb_uint32_t)(ctx.symtab_size / sizeof(xm_elf32_symbol_t));
if (!tb_stream_seek(istream, base_offset + ctx.symtab_offset)) {
return tb_false;
}
tb_uint32_t result_count = 0;
for (tb_uint32_t i = 0; i < sym_count; i++) {
xm_elf32_symbol_t sym;
if (!tb_stream_bread(istream, (tb_byte_t*)&sym, sizeof(sym))) {
return tb_false;
}
// skip NULL symbol entries
if (sym.st_name == 0 && sym.st_value == 0 && sym.st_size == 0) {
continue;
}
// skip section/file symbols
tb_uint8_t type = sym.st_info & 0xf;
if (type == 3 || type == 4) {
continue;
}
// read symbol name from .strtab
tb_char_t name[256];
if (!xm_binutils_read_string(istream, base_offset + ctx.symstr_offset + sym.st_name, name, sizeof(name)) || !name[0]) {
continue;
}
// skip internal ('.', '$') and local-defined symbols
if (name[0] == '.' || name[0] == '$') {
continue;
}
tb_uint8_t bind = (sym.st_info >> 4) & 0xf;
if (bind == 0 && sym.st_shndx != 0) {
continue;
}
// push symbol entry: name + nm-style type
lua_pushinteger(lua, result_count + 1);
lua_newtable(lua);
lua_pushstring(lua, "name");
lua_pushstring(lua, name);
lua_settable(lua, -3);
tb_char_t type_char = xm_binutils_elf_get_symbol_type_char(sym.st_info, sym.st_shndx);
tb_char_t type_str[2] = {type_char, '\0'};
lua_pushstring(lua, "type");
lua_pushstring(lua, type_str);
lua_settable(lua, -3);
lua_settable(lua, -3);
result_count++;
}
return tb_true;
}
tb_bool_t xm_binutils_elf_read_symbols_64(tb_stream_ref_t istream, tb_hize_t base_offset, lua_State *lua) {
tb_assert_and_check_return_val(istream && lua, tb_false);
// build context and ensure .symtab/.strtab are available
xm_elf_context_t ctx;
xm_binutils_elf_get_context_64(istream, base_offset, &ctx);
if (!ctx.symtab_offset || !ctx.symstr_offset) {
// no symbol table present: return empty result
lua_newtable(lua);
return tb_true;
}
// create result table
lua_newtable(lua);
// compute symbol count and seek to .symtab
tb_uint32_t sym_count = (tb_uint32_t)(ctx.symtab_size / sizeof(xm_elf64_symbol_t));
if (!tb_stream_seek(istream, base_offset + ctx.symtab_offset)) {
return tb_false;
}
tb_uint32_t result_count = 0;
for (tb_uint32_t i = 0; i < sym_count; i++) {
xm_elf64_symbol_t sym;
if (!tb_stream_bread(istream, (tb_byte_t*)&sym, sizeof(sym))) {
return tb_false;
}
// skip NULL symbol entries
if (sym.st_name == 0 && sym.st_value == 0 && sym.st_size == 0) {
continue;
}
// skip section/file symbols
tb_uint8_t type = sym.st_info & 0xf;
if (type == 3 || type == 4) {
continue;
}
// read symbol name from .strtab
tb_char_t name[256];
if (!xm_binutils_read_string(istream, base_offset + ctx.symstr_offset + sym.st_name, name, sizeof(name)) || !name[0]) {
continue;
}
// skip internal ('.', '$') and local-defined symbols
if (name[0] == '.' || name[0] == '$') {
continue;
}
tb_uint8_t bind = (sym.st_info >> 4) & 0xf;
if (bind == 0 && sym.st_shndx != 0) {
continue;
}
// push symbol entry: name + nm-style type
lua_pushinteger(lua, result_count + 1);
lua_newtable(lua);
lua_pushstring(lua, "name");
lua_pushstring(lua, name);
lua_settable(lua, -3);
tb_char_t type_char = xm_binutils_elf_get_symbol_type_char(sym.st_info, sym.st_shndx);
tb_char_t type_str[2] = {type_char, '\0'};
lua_pushstring(lua, "type");
lua_pushstring(lua, type_str);
lua_settable(lua, -3);
lua_settable(lua, -3);
result_count++;
}
return tb_true;
}
tb_bool_t xm_binutils_elf_read_symbols(tb_stream_ref_t istream, tb_hize_t base_offset, lua_State *lua) {
tb_assert_and_check_return_val(istream && lua, tb_false);
// read and check ELF magic
tb_uint8_t magic[4];
if (!tb_stream_seek(istream, base_offset)) {
return tb_false;
}
if (!tb_stream_bread(istream, magic, 4)) {
return tb_false;
}
if (magic[0] != 0x7f || magic[1] != 'E' || magic[2] != 'L' || magic[3] != 'F') {
return tb_false;
}
// check ELF class (32-bit or 64-bit)
tb_uint8_t elf_class;
if (!tb_stream_seek(istream, base_offset + 4)) {
return tb_false;
}
if (!tb_stream_bread(istream, (tb_byte_t*)&elf_class, 1)) {
return tb_false;
}
if (elf_class == 1) {
return xm_binutils_elf_read_symbols_32(istream, base_offset, lua);
} else if (elf_class == 2) {
return xm_binutils_elf_read_symbols_64(istream, base_offset, lua);
}
return tb_false;
}
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