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.
131 lines
5.1 KiB
HTML
131 lines
5.1 KiB
HTML
4 years ago
|
<!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) 1991-2019 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 6.4, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>Writing Symbols (Untitled Document)</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Writing Symbols (Untitled Document)">
|
||
|
|
<meta name="keywords" content="Writing Symbols (Untitled Document)">
|
||
|
|
<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="Symbols.html#Symbols" rel="up" title="Symbols">
|
||
|
|
<link href="Mini-Symbols.html#Mini-Symbols" rel="next" title="Mini Symbols">
|
||
|
|
<link href="Reading-Symbols.html#Reading-Symbols" rel="prev" title="Reading Symbols">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.indentedblock {margin-right: 0em}
|
||
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
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.nolinebreak {white-space: nowrap}
|
||
|
|
span.roman {font-family: initial; font-weight: normal}
|
||
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en">
|
||
|
|
<a name="Writing-Symbols"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Mini-Symbols.html#Mini-Symbols" accesskey="n" rel="next">Mini Symbols</a>, Previous: <a href="Reading-Symbols.html#Reading-Symbols" accesskey="p" rel="prev">Reading Symbols</a>, Up: <a href="Symbols.html#Symbols" accesskey="u" rel="up">Symbols</a> [<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="Writing-symbols"></a>
|
||
|
|
<h4 class="subsection">2.7.2 Writing symbols</h4>
|
||
|
|
<p>Writing of a symbol table is automatic when a BFD open for
|
||
|
|
writing is closed. The application attaches a vector of
|
||
|
|
pointers to pointers to symbols to the BFD being written, and
|
||
|
|
fills in the symbol count. The close and cleanup code reads
|
||
|
|
through the table provided and performs all the necessary
|
||
|
|
operations. The BFD output code must always be provided with an
|
||
|
|
“owned” symbol: one which has come from another BFD, or one
|
||
|
|
which has been created using <code>bfd_make_empty_symbol</code>. Here is an
|
||
|
|
example showing the creation of a symbol table with only one element:
|
||
|
|
</p>
|
||
|
|
<div class="example">
|
||
|
|
<pre class="example"> #include "sysdep.h"
|
||
|
|
#include "bfd.h"
|
||
|
|
int main (void)
|
||
|
|
{
|
||
|
|
bfd *abfd;
|
||
|
|
asymbol *ptrs[2];
|
||
|
|
asymbol *new;
|
||
|
|
|
||
|
|
abfd = bfd_openw ("foo","a.out-sunos-big");
|
||
|
|
bfd_set_format (abfd, bfd_object);
|
||
|
|
new = bfd_make_empty_symbol (abfd);
|
||
|
|
new->name = "dummy_symbol";
|
||
|
|
new->section = bfd_make_section_old_way (abfd, ".text");
|
||
|
|
new->flags = BSF_GLOBAL;
|
||
|
|
new->value = 0x12345;
|
||
|
|
|
||
|
|
ptrs[0] = new;
|
||
|
|
ptrs[1] = 0;
|
||
|
|
|
||
|
|
bfd_set_symtab (abfd, ptrs, 1);
|
||
|
|
bfd_close (abfd);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
./makesym
|
||
|
|
nm foo
|
||
|
|
00012345 A dummy_symbol
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>Many formats cannot represent arbitrary symbol information; for
|
||
|
|
instance, the <code>a.out</code> object format does not allow an
|
||
|
|
arbitrary number of sections. A symbol pointing to a section
|
||
|
|
which is not one of <code>.text</code>, <code>.data</code> or <code>.bss</code> cannot
|
||
|
|
be described.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|