| 1 | <?xml version="1.0" encoding="ISO-8859-1"?> |
|---|
| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" |
|---|
| 3 | "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [ |
|---|
| 4 | <!ENTITY % general-entities SYSTEM "../../general.ent"> |
|---|
| 5 | %general-entities; |
|---|
| 6 | ]> |
|---|
| 7 | |
|---|
| 8 | <sect1 id="ch-system-aboutdebug"> |
|---|
| 9 | <?dbhtml filename="aboutdebug.html"?> |
|---|
| 10 | |
|---|
| 11 | <title>About Debugging Symbols</title> |
|---|
| 12 | |
|---|
| 13 | <para>Most programs and libraries are, by default, compiled with debugging |
|---|
| 14 | symbols included (with <command>gcc</command>'s <option>-g</option> option). |
|---|
| 15 | This means that when debugging a program or library that was compiled with |
|---|
| 16 | debugging information included, the debugger can provide not only memory |
|---|
| 17 | addresses, but also the names of the routines and variables.</para> |
|---|
| 18 | |
|---|
| 19 | <para>However, the inclusion of these debugging symbols enlarges a |
|---|
| 20 | program or library significantly. The following is an example of the |
|---|
| 21 | amount of space these symbols occupy:</para> |
|---|
| 22 | |
|---|
| 23 | <itemizedlist> |
|---|
| 24 | <listitem> |
|---|
| 25 | <para>a bash binary with debugging symbols: 1200 KB</para> |
|---|
| 26 | </listitem> |
|---|
| 27 | <listitem> |
|---|
| 28 | <para>a bash binary without debugging symbols: 480 KB</para> |
|---|
| 29 | </listitem> |
|---|
| 30 | <listitem> |
|---|
| 31 | <para>Glibc and GCC files (<filename class="directory">/lib</filename> |
|---|
| 32 | and <filename class="directory">/usr/lib</filename>) with debugging |
|---|
| 33 | symbols: 87 MB</para> |
|---|
| 34 | </listitem> |
|---|
| 35 | <listitem> |
|---|
| 36 | <para>Glibc and GCC files without debugging symbols: 16 MB</para> |
|---|
| 37 | </listitem> |
|---|
| 38 | </itemizedlist> |
|---|
| 39 | |
|---|
| 40 | <para>Sizes may vary depending on which compiler and C library were used, |
|---|
| 41 | but when comparing programs with and without debugging symbols, the |
|---|
| 42 | difference will usually be a factor between two and five.</para> |
|---|
| 43 | |
|---|
| 44 | <para>Because most users will never use a debugger on their system software, |
|---|
| 45 | a lot of disk space can be regained by removing these symbols. The next |
|---|
| 46 | section shows how to strip all debugging symbols from the programs and |
|---|
| 47 | libraries. Additional information on system optimization can be found at |
|---|
| 48 | <ulink url="&hints-root;optimization.txt"/>.</para> |
|---|
| 49 | |
|---|
| 50 | </sect1> |
|---|
