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<title>GNU Compiler Collection (GCC) Internals: Fragments</title>

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Next: <a href="Collect2.html#Collect2" accesskey="n" rel="next">Collect2</a>, Previous: <a href="Host-Config.html#Host-Config" accesskey="p" rel="prev">Host Config</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Makefile-Fragments"></a>
<h2 class="chapter">19 Makefile Fragments</h2>
<a name="index-makefile-fragment"></a>

<p>When you configure GCC using the <samp>configure</samp> script, it will
construct the file <samp>Makefile</samp> from the template file
<samp>Makefile.in</samp>.  When it does this, it can incorporate makefile
fragments from the <samp>config</samp> directory.  These are used to set
Makefile parameters that are not amenable to being calculated by
autoconf.  The list of fragments to incorporate is set by
<samp>config.gcc</samp> (and occasionally <samp>config.build</samp>
and <samp>config.host</samp>); See <a href="System-Config.html#System-Config">System Config</a>.
</p>
<p>Fragments are named either <samp>t-<var>target</var></samp> or <samp>x-<var>host</var></samp>,
depending on whether they are relevant to configuring GCC to produce
code for a particular target, or to configuring GCC to run on a
particular host.  Here <var>target</var> and <var>host</var> are mnemonics
which usually have some relationship to the canonical system name, but
no formal connection.
</p>
<p>If these files do not exist, it means nothing needs to be added for a
given target or host.  Most targets need a few <samp>t-<var>target</var></samp>
fragments, but needing <samp>x-<var>host</var></samp> fragments is rare.
</p>
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<tr><td align="left" valign="top">&bull; <a href="Target-Fragment.html#Target-Fragment" accesskey="1">Target Fragment</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Writing <samp>t-<var>target</var></samp> files.
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<tr><td align="left" valign="top">&bull; <a href="Host-Fragment.html#Host-Fragment" accesskey="2">Host Fragment</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Writing <samp>x-<var>host</var></samp> files.
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