blob: 40b5b1fa94c6aaa536b41a7ebec21263b78a6dcb [file] [log] [blame]
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- This file documents the GNU Assembler "as".
Copyright (C) 1991-2013 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 no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts. A copy of the license is included in the
section entitled "GNU Free Documentation License".
-->
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
<head>
<title>Using as: Previous</title>
<meta name="description" content="Using as: Previous">
<meta name="keywords" content="Using as: Previous">
<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="AS-Index.html#AS-Index" rel="index" title="AS Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Pseudo-Ops.html#Pseudo-Ops" rel="up" title="Pseudo Ops">
<link href="Print.html#Print" rel="next" title="Print">
<link href="PopSection.html#PopSection" rel="prev" title="PopSection">
<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="Previous"></a>
<div class="header">
<p>
Next: <a href="Print.html#Print" accesskey="n" rel="next">Print</a>, Previous: <a href="PopSection.html#PopSection" accesskey="p" rel="prev">PopSection</a>, Up: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="u" rel="up">Pseudo Ops</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="g_t_002eprevious"></a>
<h3 class="section">7.88 <code>.previous</code></h3>
<a name="index-previous-directive"></a>
<a name="index-Section-Stack-1"></a>
<p>This is one of the ELF section stack manipulation directives. The others are
<code>.section</code> (see <a href="Section.html#Section">Section</a>), <code>.subsection</code> (see <a href="SubSection.html#SubSection">SubSection</a>),
<code>.pushsection</code> (see <a href="PushSection.html#PushSection">PushSection</a>), and <code>.popsection</code>
(see <a href="PopSection.html#PopSection">PopSection</a>).
</p>
<p>This directive swaps the current section (and subsection) with most recently
referenced section/subsection pair prior to this one. Multiple
<code>.previous</code> directives in a row will flip between two sections (and their
subsections). For example:
</p>
<div class="smallexample">
<pre class="smallexample">.section A
.subsection 1
.word 0x1234
.subsection 2
.word 0x5678
.previous
.word 0x9abc
</pre></div>
<p>Will place 0x1234 and 0x9abc into subsection 1 and 0x5678 into subsection 2 of
section A. Whilst:
</p>
<div class="smallexample">
<pre class="smallexample">.section A
.subsection 1
# Now in section A subsection 1
.word 0x1234
.section B
.subsection 0
# Now in section B subsection 0
.word 0x5678
.subsection 1
# Now in section B subsection 1
.word 0x9abc
.previous
# Now in section B subsection 0
.word 0xdef0
</pre></div>
<p>Will place 0x1234 into section A, 0x5678 and 0xdef0 into subsection 0 of
section B and 0x9abc into subsection 1 of section B.
</p>
<p>In terms of the section stack, this directive swaps the current section with
the top section on the section stack.
</p>
</body>
</html>