tools/reorder/elf_symbol_table.h

   1 /* -*- Mode: C++ -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is ``elf_symbol_table''
  16  *
  17  * The Initial Developer of the Original Code is Netscape
  18  * Communications Corp.  Portions created by the Initial Developer are
  19  * Copyright (C) 2001 the Initial Developer. All Rights Reserved.
  20  *
  21  * Contributor(s):
  22  *   Chris Waterson <waterson@netscape.com>
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either the GNU General Public License Version 2 or later (the "GPL"), or
  26  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  27  * in which case the provisions of the GPL or the LGPL are applicable instead
  28  * of those above. If you wish to allow use of your version of this file only
  29  * under the terms of either the GPL or the LGPL, and not to allow others to
  30  * use your version of this file under the terms of the MPL, indicate your
  31  * decision by deleting the provisions above and replace them with the notice
  32  * and other provisions required by the GPL or the LGPL. If you do not delete
  33  * the provisions above, a recipient may use your version of this file under
  34  * the terms of any one of the MPL, the GPL or the LGPL.
  35  *
  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #ifndef elf_symbol_table_h__
  39 #define elf_symbol_table_h__
  40
  41 /*
  42
  43   Utility class for reading ELF symbol tables.
  44
  45  */
  46
  47 #include <elf.h>
  48 #include <sys/mman.h>
  49
  50 #include "interval_map.h"
  51
  52 class elf_symbol_table {
  53 protected:
  54     int              m_fd;
  55     void            *m_mapping;
  56     size_t           m_size;
  57     const char      *m_strtab;
  58     const Elf32_Sym *m_symbols;
  59     int              m_nsymbols;
  60     int              m_text_shndx;
  61
  62     typedef interval_map<unsigned int, const Elf32_Sym *> rsymtab_t;
  63     rsymtab_t        m_rsymtab;
  64
  65     int verify_elf_header(const Elf32_Ehdr *hdr);
  66     int finish();
  67
  68 public:
  69     elf_symbol_table()
  70         : m_fd(-1),
  71           m_mapping(MAP_FAILED),
  72           m_size(0),
  73           m_strtab(0),
  74           m_symbols(0),
  75           m_nsymbols(0),
  76           m_text_shndx(0) {}
  77
  78     ~elf_symbol_table() { finish(); }
  79
  80     /**
  81      * Read the symbol table information from the specified file. (This will
  82      * memory-map the file.)
  83      *
  84      * Currently, only symbols from the `.text' section are loaded.
  85      */
  86     int init(const char *file);
  87
  88     /**
  89      * Determine what symbol the specified image address corresponds
  90      * to. Addresses need not refer to a symbol's start address:
  91      * symbol size information is used to reverse-map the address.
  92      */
  93     const Elf32_Sym *lookup(unsigned int addr) const;
  94
  95     /**
  96      * Determine the symbol name for the specified symbol.
  97      */
  98     const char *get_symbol_name(const Elf32_Sym *sym) const;
  99
 100     /**
 101      * Return `true' if the specified symbol is a function.
 102      */
 103     bool is_function(const Elf32_Sym *sym) const {
 104         return (sym->st_size > 0) &&
 105             (ELF32_ST_TYPE(sym->st_info) == STT_FUNC) &&
 106             (sym->st_shndx == m_text_shndx); }
 107
 108     typedef const Elf32_Sym *const_iterator;
 109
 110     const_iterator begin() const { return const_iterator(m_symbols); }
 111     const_iterator end() const { return const_iterator(m_symbols + m_nsymbols); }
 112 };
 113
 114 #endif // elf_symbol_table_h__