gecko/tools/reorder/elf_symbol_table.cpp

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/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is ``elf_symbol_table''
*
* The Initial Developer of the Original Code is Netscape
* Communications Corp. Portions created by the Initial Developer are
* Copyright (C) 2001 the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Chris Waterson <waterson@netscape.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include <string>
#include <fstream>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/stat.h>
#include "elf_symbol_table.h"
#include "elf_utils.h"
int
elf_symbol_table::init(const char *name)
{
// Open the file readonly.
m_fd = open(name, O_RDONLY);
if (m_fd < 0) {
perror(name);
return m_fd;
}
// Get its size.
struct stat statbuf;
if (fstat(m_fd, &statbuf) < 0) {
perror(name);
return -1;
}
m_size = statbuf.st_size;
// Memory map it.
m_mapping = mmap(0, m_size, PROT_READ, MAP_SHARED, m_fd, 0);
if (m_mapping == MAP_FAILED) {
perror(name);
return -1;
}
// Make sure it's an ELF header.
const Elf32_Ehdr *ehdr = reinterpret_cast<const Elf32_Ehdr *>(m_mapping);
if (elf_verify_header(ehdr) < 0)
return -1;
const char *mapping = reinterpret_cast<const char *>(m_mapping);
// Find the section headers
const Elf32_Shdr *shdrs
= reinterpret_cast<const Elf32_Shdr *>(mapping + ehdr->e_shoff);
// find the section header string table, .shstrtab
const Elf32_Shdr *shstrtabsh = shdrs + ehdr->e_shstrndx;
const char *shstrtab = mapping + shstrtabsh->sh_offset;
// parse the sections we care about
int shndx = 0;
const Elf32_Shdr *shlimit = shdrs + ehdr->e_shnum;
for (const Elf32_Shdr *shdr = shdrs; shdr < shlimit; ++shdr, ++shndx) {
basic_string<char> name(shstrtab + shdr->sh_name);
if (name == ".symtab") {
m_symbols = reinterpret_cast<const Elf32_Sym *>(mapping + shdr->sh_offset);
m_nsymbols = shdr->sh_size / sizeof(Elf32_Sym);
}
else if (name == ".strtab") {
m_strtab = mapping + shdr->sh_offset;
}
else if (name == ".text") {
m_text_shndx = shndx;
}
}
// Parse the symbol table
const Elf32_Sym *limit = m_symbols + m_nsymbols;
for (const Elf32_Sym *sym = m_symbols; sym < limit; ++sym) {
if (is_function(sym)) {
#ifdef DEBUG
hex(cout);
cout << sym->st_value << endl;
#endif
m_rsymtab.put(sym->st_value, sym->st_value + sym->st_size, sym);
}
}
return 0;
}
int
elf_symbol_table::finish()
{
if (m_mapping != MAP_FAILED) {
munmap(m_mapping, m_size);
m_mapping = MAP_FAILED;
}
if (m_fd >= 0) {
close(m_fd);
m_fd = -1;
}
return 0;
}
const Elf32_Sym *
elf_symbol_table::lookup(unsigned int addr) const
{
rsymtab_t::const_iterator result = m_rsymtab.get(addr);
return result != m_rsymtab.end() ? reinterpret_cast<const Elf32_Sym *>(*result) : 0;
}
const char *
elf_symbol_table::get_symbol_name(const Elf32_Sym *sym) const
{
return m_strtab + sym->st_name;
}