<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- This file documents the BFD library.

Copyright (C) 1991-2015 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "GNU General Public License" and "Funding
Free Software", the Front-Cover texts being (a) (see below), and with
the Back-Cover Texts being (b) (see below).  A copy of the license is
included in the section entitled "GNU Free Documentation License".

(a) The FSF's Front-Cover Text is:

A GNU Manual

(b) The FSF's Back-Cover Text is:

You have freedom to copy and modify this GNU Manual, like GNU
     software.  Copies published by the Free Software Foundation raise
     funds for GNU development. -->
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
<head>
<title>Untitled Document: Write Other Derived Routines</title>

<meta name="description" content="Untitled Document: Write Other Derived Routines">
<meta name="keywords" content="Untitled Document: Write Other Derived Routines">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="BFD-Index.html#BFD-Index" rel="index" title="BFD Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Deriving-a-New-Hash-Table-Type.html#Deriving-a-New-Hash-Table-Type" rel="up" title="Deriving a New Hash Table Type">
<link href="BFD-back-ends.html#BFD-back-ends" rel="next" title="BFD back ends">
<link href="Write-the-Derived-Creation-Routine.html#Write-the-Derived-Creation-Routine" rel="prev" title="Write the Derived Creation Routine">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.indentedblock {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
div.smalllisp {margin-left: 3.2em}
kbd {font-style:oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space:nowrap}
span.nolinebreak {white-space:nowrap}
span.roman {font-family:serif; font-weight:normal}
span.sansserif {font-family:sans-serif; font-weight:normal}
ul.no-bullet {list-style: none}
-->
</style>


</head>

<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="Write-Other-Derived-Routines"></a>
<div class="header">
<p>
Previous: <a href="Write-the-Derived-Creation-Routine.html#Write-the-Derived-Creation-Routine" accesskey="p" rel="prev">Write the Derived Creation Routine</a>, Up: <a href="Deriving-a-New-Hash-Table-Type.html#Deriving-a-New-Hash-Table-Type" accesskey="u" rel="up">Deriving a New Hash Table Type</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="BFD-Index.html#BFD-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Write-other-derived-routines"></a>
<h4 class="subsubsection">2.18.4.3 Write other derived routines</h4>
<p>You will want to write other routines for your new hash table,
as well.
</p>
<p>You will want an initialization routine which calls the
initialization routine of the hash table you are deriving from
and initializes any other local fields.  For the linker hash
table, this is <code>_bfd_link_hash_table_init</code> in <code>linker.c</code>.
</p>
<p>You will want a lookup routine which calls the lookup routine
of the hash table you are deriving from and casts the result.
The linker hash table uses <code>bfd_link_hash_lookup</code> in
<code>linker.c</code> (this actually takes an additional argument which
it uses to decide how to return the looked up value).
</p>
<p>You may want a traversal routine.  This should just call the
traversal routine of the hash table you are deriving from with
appropriate casts.  The linker hash table uses
<code>bfd_link_hash_traverse</code> in <code>linker.c</code>.
</p>
<p>These routines may simply be defined as macros.  For example,
the a.out backend linker hash table, which is derived from the
linker hash table, uses macros for the lookup and traversal
routines.  These are <code>aout_link_hash_lookup</code> and
<code>aout_link_hash_traverse</code> in aoutx.h.
</p>


</body>
</html>