source: BOOK/final-system/common/aboutdebug.xml@ 1274b62

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;
]>

<sect1 id="ch-system-aboutdebug">
  <?dbhtml filename="aboutdebug.html"?>

  <title>About Debugging Symbols</title>

  <para os="a">Most programs and libraries are, by default, compiled with debugging
  symbols included (with <command>gcc</command>'s <option>-g</option> option).
  This means that when debugging a program or library that was compiled with
  debugging information included, the debugger can provide not only memory
  addresses, but also the names of the routines and variables.</para>

  <para os="b">However, the inclusion of these debugging symbols enlarges a
  program or library significantly. The following is an example of the
  amount of space these symbols occupy:</para>

  <itemizedlist os="c">
    <listitem os="c1">
      <para>a bash binary with debugging symbols: 1200 KB</para>
    </listitem>
    <listitem os="c2">
      <para>a bash binary without debugging symbols: 480 KB</para>
    </listitem>
    <listitem os="c3">
      <para>Glibc and GCC files (<filename class="directory">/lib</filename>
      and <filename class="directory">/usr/lib</filename>) with debugging
      symbols: 87 MB</para>
    </listitem>
    <listitem os="c4">
      <para>Glibc and GCC files without debugging symbols: 16 MB</para>
    </listitem>
  </itemizedlist>

  <para os="d">Sizes may vary depending on which compiler and C library were used,
  but when comparing programs with and without debugging symbols, the
  difference will usually be a factor between two and five.</para>

  <para os="e">Because most users will never use a debugger on their system software,
  a lot of disk space can be regained by removing these symbols. The next
  section shows how to strip all debugging symbols from the programs and
  libraries.</para>

</sect1>