101 lines
4 KiB
HTML
101 lines
4 KiB
HTML
<html lang="en">
|
|
<head>
|
|
<title>Writing Symbols - 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="Symbols.html#Symbols" title="Symbols">
|
|
<link rel="prev" href="Reading-Symbols.html#Reading-Symbols" title="Reading Symbols">
|
|
<link rel="next" href="Mini-Symbols.html#Mini-Symbols" title="Mini Symbols">
|
|
<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="Writing-Symbols"></a>Next: <a rel="next" accesskey="n" href="Mini-Symbols.html#Mini-Symbols">Mini Symbols</a>,
|
|
Previous: <a rel="previous" accesskey="p" href="Reading-Symbols.html#Reading-Symbols">Reading Symbols</a>,
|
|
Up: <a rel="up" accesskey="u" href="Symbols.html#Symbols">Symbols</a>
|
|
<hr><br>
|
|
</div>
|
|
|
|
<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:
|
|
|
|
<pre class="example"> #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>
|
|
<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.
|
|
|
|
</body></html>
|
|
|