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. Buying copies from GNU Press supports the FSF in 14developing GNU and promoting software freedom." --> 15<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> 16<head> 17<title>Debugging with GDB: Manually</title> 18 19<meta name="description" content="Debugging with GDB: Manually"> 20<meta name="keywords" content="Debugging with GDB: Manually"> 21<meta name="resource-type" content="document"> 22<meta name="distribution" content="global"> 23<meta name="Generator" content="makeinfo"> 24<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 25<link href="index.html#Top" rel="start" title="Top"> 26<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> 27<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> 28<link href="Setting.html#Setting" rel="up" title="Setting"> 29<link href="Automatically.html#Automatically" rel="next" title="Automatically"> 30<link href="Filenames.html#Filenames" rel="previous" title="Filenames"> 31<style type="text/css"> 32<!-- 33a.summary-letter {text-decoration: none} 34blockquote.smallquotation {font-size: smaller} 35div.display {margin-left: 3.2em} 36div.example {margin-left: 3.2em} 37div.indentedblock {margin-left: 3.2em} 38div.lisp {margin-left: 3.2em} 39div.smalldisplay {margin-left: 3.2em} 40div.smallexample {margin-left: 3.2em} 41div.smallindentedblock {margin-left: 3.2em; font-size: smaller} 42div.smalllisp {margin-left: 3.2em} 43kbd {font-style:oblique} 44pre.display {font-family: inherit} 45pre.format {font-family: inherit} 46pre.menu-comment {font-family: serif} 47pre.menu-preformatted {font-family: serif} 48pre.smalldisplay {font-family: inherit; font-size: smaller} 49pre.smallexample {font-size: smaller} 50pre.smallformat {font-family: inherit; font-size: smaller} 51pre.smalllisp {font-size: smaller} 52span.nocodebreak {white-space:nowrap} 53span.nolinebreak {white-space:nowrap} 54span.roman {font-family:serif; font-weight:normal} 55span.sansserif {font-family:sans-serif; font-weight:normal} 56ul.no-bullet {list-style: none} 57--> 58</style> 59 60 61</head> 62 63<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> 64<a name="Manually"></a> 65<div class="header"> 66<p> 67Next: <a href="Automatically.html#Automatically" accesskey="n" rel="next">Automatically</a>, Previous: <a href="Filenames.html#Filenames" accesskey="p" rel="previous">Filenames</a>, Up: <a href="Setting.html#Setting" accesskey="u" rel="up">Setting</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> 68</div> 69<hr> 70<a name="Setting-the-Working-Language"></a> 71<h4 class="subsection">15.1.2 Setting the Working Language</h4> 72 73<p>If you allow <small>GDB</small> to set the language automatically, 74expressions are interpreted the same way in your debugging session and 75your program. 76</p> 77<a name="index-set-language"></a> 78<p>If you wish, you may set the language manually. To do this, issue the 79command ‘<samp>set language <var>lang</var></samp>’, where <var>lang</var> is the name of 80a language, such as 81<code>c</code> or <code>modula-2</code>. 82For a list of the supported languages, type ‘<samp>set language</samp>’. 83</p> 84<p>Setting the language manually prevents <small>GDB</small> from updating the working 85language automatically. This can lead to confusion if you try 86to debug a program when the working language is not the same as the 87source language, when an expression is acceptable to both 88languages—but means different things. For instance, if the current 89source file were written in C, and <small>GDB</small> was parsing Modula-2, a 90command such as: 91</p> 92<div class="smallexample"> 93<pre class="smallexample">print a = b + c 94</pre></div> 95 96<p>might not have the effect you intended. In C, this means to add 97<code>b</code> and <code>c</code> and place the result in <code>a</code>. The result 98printed would be the value of <code>a</code>. In Modula-2, this means to compare 99<code>a</code> to the result of <code>b+c</code>, yielding a <code>BOOLEAN</code> value. 100</p> 101 102 103 104</body> 105</html> 106