source: BOOK/final-system/common/aboutdebug.xml@ 2ca4197

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<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. Additional information on system optimization can be found at
  <ulink url="&hints-root;optimization.txt"/>.</para>

</sect1>