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Next: <a href="Show.html#Show" accesskey="n" rel="next">Show</a>, Up: <a href="Languages.html#Languages" accesskey="u" rel="up">Languages</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Switching-Between-Source-Languages"></a>
<h3 class="section">15.1 Switching Between Source Languages</h3>

<p>There are two ways to control the working language&mdash;either have <small>GDB</small>
set it automatically, or select it manually yourself.  You can use the
<code>set language</code> command for either purpose.  On startup, <small>GDB</small>
defaults to setting the language automatically.  The working language is
used to determine how expressions you type are interpreted, how values
are printed, etc.
</p>
<p>In addition to the working language, every source file that
<small>GDB</small> knows about has its own working language.  For some object
file formats, the compiler might indicate which language a particular
source file is in.  However, most of the time <small>GDB</small> infers the
language from the name of the file.  The language of a source file
controls whether C<tt>++</tt> names are demangled&mdash;this way <code>backtrace</code> can
show each frame appropriately for its own language.  There is no way to
set the language of a source file from within <small>GDB</small>, but you can
set the language associated with a filename extension.  See <a href="Show.html#Show">Displaying the Language</a>.
</p>
<p>This is most commonly a problem when you use a program, such
as <code>cfront</code> or <code>f2c</code>, that generates C but is written in
another language.  In that case, make the
program use <code>#line</code> directives in its C output; that way
<small>GDB</small> will know the correct language of the source code of the original
program, and will display that source code, not the generated C code.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">&bull; <a href="Filenames.html#Filenames" accesskey="1">Filenames</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Filename extensions and languages.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Manually.html#Manually" accesskey="2">Manually</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Setting the working language manually
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Automatically.html#Automatically" accesskey="3">Automatically</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Having <small>GDB</small> infer the source language
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