You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
103 lines
4.9 KiB
HTML
103 lines
4.9 KiB
HTML
15 years ago
|
<html lang="en">
|
||
|
|
<head>
|
||
|
|
<title>Adding symbols from an archive - Untitled</title>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html">
|
||
|
|
<meta name="description" content="Untitled">
|
||
|
|
<meta name="generator" content="makeinfo 4.7">
|
||
|
|
<link title="Top" rel="start" href="index.html#Top">
|
||
|
|
<link rel="up" href="Adding-Symbols-to-the-Hash-Table.html#Adding-Symbols-to-the-Hash-Table" title="Adding Symbols to the Hash Table">
|
||
|
|
<link rel="prev" href="Adding-symbols-from-an-object-file.html#Adding-symbols-from-an-object-file" title="Adding symbols from an object file">
|
||
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
||
|
|
<!--
|
||
|
|
This file documents the BFD library.
|
||
|
|
|
||
|
|
Copyright (C) 1991, 2000, 2001, 2003, 2006, 2007 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 1.1 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.-->
|
||
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
||
|
|
<style type="text/css"><!--
|
||
|
|
pre.display { font-family:inherit }
|
||
|
|
pre.format { font-family:inherit }
|
||
|
|
pre.smalldisplay { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallformat { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallexample { font-size:smaller }
|
||
|
|
pre.smalllisp { font-size:smaller }
|
||
|
|
span.sc { font-variant:small-caps }
|
||
|
|
span.roman { font-family: serif; font-weight: normal; }
|
||
|
|
--></style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div class="node">
|
||
|
|
<p>
|
||
|
|
<a name="Adding-symbols-from-an-archive"></a>Previous: <a rel="previous" accesskey="p" href="Adding-symbols-from-an-object-file.html#Adding-symbols-from-an-object-file">Adding symbols from an object file</a>,
|
||
|
|
Up: <a rel="up" accesskey="u" href="Adding-Symbols-to-the-Hash-Table.html#Adding-Symbols-to-the-Hash-Table">Adding Symbols to the Hash Table</a>
|
||
|
|
<hr><br>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<h5 class="subsubsection">2.17.2.3 Adding symbols from an archive</h5>
|
||
|
|
|
||
|
|
<p>When the <code>_bfd_link_add_symbols</code> routine is passed an
|
||
|
|
archive, it must look through the symbols defined by the
|
||
|
|
archive and decide which elements of the archive should be
|
||
|
|
included in the link. For each such element it must call the
|
||
|
|
<code>add_archive_element</code> linker callback, and it must add the
|
||
|
|
symbols from the object file to the linker hash table.
|
||
|
|
|
||
|
|
<p><a name="index-_005fbfd_005fgeneric_005flink_005fadd_005farchive_005fsymbols-1374"></a>In most cases the work of looking through the symbols in the
|
||
|
|
archive should be done by the
|
||
|
|
<code>_bfd_generic_link_add_archive_symbols</code> function. This
|
||
|
|
function builds a hash table from the archive symbol table and
|
||
|
|
looks through the list of undefined symbols to see which
|
||
|
|
elements should be included.
|
||
|
|
<code>_bfd_generic_link_add_archive_symbols</code> is passed a function
|
||
|
|
to call to make the final decision about adding an archive
|
||
|
|
element to the link and to do the actual work of adding the
|
||
|
|
symbols to the linker hash table.
|
||
|
|
|
||
|
|
<p>The function passed to
|
||
|
|
<code>_bfd_generic_link_add_archive_symbols</code> must read the
|
||
|
|
symbols of the archive element and decide whether the archive
|
||
|
|
element should be included in the link. If the element is to
|
||
|
|
be included, the <code>add_archive_element</code> linker callback
|
||
|
|
routine must be called with the element as an argument, and
|
||
|
|
the elements symbols must be added to the linker hash table
|
||
|
|
just as though the element had itself been passed to the
|
||
|
|
<code>_bfd_link_add_symbols</code> function.
|
||
|
|
|
||
|
|
<p>When the a.out <code>_bfd_link_add_symbols</code> function receives an
|
||
|
|
archive, it calls <code>_bfd_generic_link_add_archive_symbols</code>
|
||
|
|
passing <code>aout_link_check_archive_element</code> as the function
|
||
|
|
argument. <code>aout_link_check_archive_element</code> calls
|
||
|
|
<code>aout_link_check_ar_symbols</code>. If the latter decides to add
|
||
|
|
the element (an element is only added if it provides a real,
|
||
|
|
non-common, definition for a previously undefined or common
|
||
|
|
symbol) it calls the <code>add_archive_element</code> callback and then
|
||
|
|
<code>aout_link_check_archive_element</code> calls
|
||
|
|
<code>aout_link_add_symbols</code> to actually add the symbols to the
|
||
|
|
linker hash table.
|
||
|
|
|
||
|
|
<p>The ECOFF back end is unusual in that it does not normally
|
||
|
|
call <code>_bfd_generic_link_add_archive_symbols</code>, because ECOFF
|
||
|
|
archives already contain a hash table of symbols. The ECOFF
|
||
|
|
back end searches the archive itself to avoid the overhead of
|
||
|
|
creating a new hash table.
|
||
|
|
|
||
|
|
</body></html>
|
||
|
|
|