1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<!-- Copyright (C) 1988-2021 Free Software Foundation, Inc. 4 5Permission is granted to copy, distribute and/or modify this document 6under the terms of the GNU Free Documentation License, Version 1.3 or 7any later version published by the Free Software Foundation; with the 8Invariant Sections being "Free Software" and "Free Software Needs 9Free Documentation", with the Front-Cover Texts being "A GNU Manual," 10and with the Back-Cover Texts as in (a) below. 11 12(a) The FSF's Back-Cover Text is: "You are free to copy and modify 13this GNU Manual. 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You can use the 75<code>set language</code> command for either purpose. On startup, <small>GDB</small> 76defaults to setting the language automatically. The working language is 77used to determine how expressions you type are interpreted, how values 78are printed, etc. 79</p> 80<p>In addition to the working language, every source file that 81<small>GDB</small> knows about has its own working language. For some object 82file formats, the compiler might indicate which language a particular 83source file is in. However, most of the time <small>GDB</small> infers the 84language from the name of the file. The language of a source file 85controls whether C<tt>++</tt> names are demangled—this way <code>backtrace</code> can 86show each frame appropriately for its own language. There is no way to 87set the language of a source file from within <small>GDB</small>, but you can 88set the language associated with a filename extension. See <a href="Show.html#Show">Displaying the Language</a>. 89</p> 90<p>This is most commonly a problem when you use a program, such 91as <code>cfront</code> or <code>f2c</code>, that generates C but is written in 92another language. In that case, make the 93program use <code>#line</code> directives in its C output; that way 94<small>GDB</small> will know the correct language of the source code of the original 95program, and will display that source code, not the generated C code. 96</p> 97<table class="menu" border="0" cellspacing="0"> 98<tr><td align="left" valign="top">• <a href="Filenames.html#Filenames" accesskey="1">Filenames</a>:</td><td> </td><td align="left" valign="top">Filename extensions and languages. 99</td></tr> 100<tr><td align="left" valign="top">• <a href="Manually.html#Manually" accesskey="2">Manually</a>:</td><td> </td><td align="left" valign="top">Setting the working language manually 101</td></tr> 102<tr><td align="left" valign="top">• <a href="Automatically.html#Automatically" accesskey="3">Automatically</a>:</td><td> </td><td align="left" valign="top">Having <small>GDB</small> infer the source language 103</td></tr> 104</table> 105 106<hr> 107<div class="header"> 108<p> 109Next: <a href="Show.html#Show" accesskey="n" rel="next">Show</a>, Up: <a href="Languages.html#Languages" accesskey="u" rel="up">Languages</a> [<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> 110</div> 111 112 113 114</body> 115</html> 116