| <html lang="en"> |
| <head> |
| <title>Linkonce - Using as</title> |
| <meta http-equiv="Content-Type" content="text/html"> |
| <meta name="description" content="Using as"> |
| <meta name="generator" content="makeinfo 4.13"> |
| <link title="Top" rel="start" href="index.html#Top"> |
| <link rel="up" href="Pseudo-Ops.html#Pseudo-Ops" title="Pseudo Ops"> |
| <link rel="prev" href="Line.html#Line" title="Line"> |
| <link rel="next" href="List.html#List" title="List"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| This file documents the GNU Assembler "as". |
| |
| Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, |
| 2000, 2001, 2002, 2006, 2007, 2008, 2009, 2010 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''. |
| |
| --> |
| <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; } |
| span.sansserif { font-family:sans-serif; font-weight:normal; } |
| --></style> |
| <link rel="stylesheet" type="text/css" href="../cs.css"> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="Linkonce"></a> |
| <p> |
| Next: <a rel="next" accesskey="n" href="List.html#List">List</a>, |
| Previous: <a rel="previous" accesskey="p" href="Line.html#Line">Line</a>, |
| Up: <a rel="up" accesskey="u" href="Pseudo-Ops.html#Pseudo-Ops">Pseudo Ops</a> |
| <hr> |
| </div> |
| |
| <h3 class="section">7.70 <code>.linkonce [</code><var>type</var><code>]</code></h3> |
| |
| <p><a name="index-COMDAT-380"></a><a name="index-g_t_0040code_007blinkonce_007d-directive-381"></a><a name="index-common-sections-382"></a>Mark the current section so that the linker only includes a single copy of it. |
| This may be used to include the same section in several different object files, |
| but ensure that the linker will only include it once in the final output file. |
| The <code>.linkonce</code> pseudo-op must be used for each instance of the section. |
| Duplicate sections are detected based on the section name, so it should be |
| unique. |
| |
| <p>This directive is only supported by a few object file formats; as of this |
| writing, the only object file format which supports it is the Portable |
| Executable format used on Windows NT. |
| |
| <p>The <var>type</var> argument is optional. If specified, it must be one of the |
| following strings. For example: |
| <pre class="smallexample"> .linkonce same_size |
| </pre> |
| <p>Not all types may be supported on all object file formats. |
| |
| <dl> |
| <dt><code>discard</code><dd>Silently discard duplicate sections. This is the default. |
| |
| <br><dt><code>one_only</code><dd>Warn if there are duplicate sections, but still keep only one copy. |
| |
| <br><dt><code>same_size</code><dd>Warn if any of the duplicates have different sizes. |
| |
| <br><dt><code>same_contents</code><dd>Warn if any of the duplicates do not have exactly the same contents. |
| </dl> |
| |
| </body></html> |
| |
