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<a name="File"></a>
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<p>
Next: <a href="Fill.html#Fill" accesskey="n" rel="next">Fill</a>, Previous: <a href="Fail.html#Fail" accesskey="p" rel="previous">Fail</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>
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<hr>
<a name="g_t_002efile"></a>
<h3 class="section">7.35 <code>.file</code></h3>
<a name="index-file-directive"></a>

<p>There are two different versions of the <code>.file</code> directive.  Targets
that support DWARF2 line number information use the DWARF2 version of
<code>.file</code>.  Other targets use the default version.
</p>
<a name="Default-Version"></a>
<h4 class="subheading">Default Version</h4>

<a name="index-logical-file-name"></a>
<a name="index-file-name_002c-logical"></a>
<p>This version of the <code>.file</code> directive tells <code>as</code> that we
are about to start a new logical file.  The syntax is:
</p>
<div class="smallexample">
<pre class="smallexample">.file <var>string</var>
</pre></div>

<p><var>string</var> is the new file name.  In general, the filename is
recognized whether or not it is surrounded by quotes &lsquo;<samp>&quot;</samp>&rsquo;; but if you wish
to specify an empty file name, you must give the quotes&ndash;<code>&quot;&quot;</code>.  This
statement may go away in future: it is only recognized to be compatible with
old <code>as</code> programs.
</p>
<a name="DWARF2-Version"></a>
<h4 class="subheading">DWARF2 Version</h4>

<p>When emitting DWARF2 line number information, <code>.file</code> assigns filenames
to the <code>.debug_line</code> file name table.  The syntax is:
</p>
<div class="smallexample">
<pre class="smallexample">.file <var>fileno</var> <var>filename</var>
</pre></div>

<p>The <var>fileno</var> operand should be a unique positive integer to use as the
index of the entry in the table.  The <var>filename</var> operand is a C string
literal enclosed in double quotes.  The <var>filename</var> can include directory
elements.  If it does, then the directory will be added to the directory table
and the basename will be added to the file table.
</p>
<p>The detail of filename indices is exposed to the user because the filename
table is shared with the <code>.debug_info</code> section of the DWARF2 debugging
information, and thus the user must know the exact indices that table
entries will have.
</p>
<p>If DWARF-5 support has been enabled via the <samp>-gdwarf-5</samp> option then
an extended version of the <code>file</code> is also allowed:
</p>
<div class="smallexample">
<pre class="smallexample">.file <var>fileno</var> [<var>dirname</var>] <var>filename</var> [md5 <var>value</var>]
</pre></div>

<p>With this version a separate directory name is allowed, although if this is
used then <var>filename</var> should not contain any directory components.  In
addtion an md5 hash value of the contents of <var>filename</var> can be provided.
This will be stored in the the file table as well, and can be used by tools
reading the debug information to verify that the contents of the source file
match the contents of the compiled file.
</p>
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Next: <a href="Fill.html#Fill" accesskey="n" rel="next">Fill</a>, Previous: <a href="Fail.html#Fail" accesskey="p" rel="previous">Fail</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>
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