You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
122 lines
6.0 KiB
HTML
122 lines
6.0 KiB
HTML
4 years ago
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- Copyright (C) 1988-2019 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
Permission is granted to copy, distribute and/or modify this document
|
||
|
|
under the terms of the GNU Free Documentation License, Version 1.3 or
|
||
|
|
any later version published by the Free Software Foundation; with the
|
||
|
|
Invariant Sections being "Free Software" and "Free Software Needs
|
||
|
|
Free Documentation", with the Front-Cover Texts being "A GNU Manual,"
|
||
|
|
and with the Back-Cover Texts as in (a) below.
|
||
|
|
|
||
|
|
(a) The FSF's Back-Cover Text is: "You are free to copy and modify
|
||
|
|
this GNU Manual. Buying copies from GNU Press supports the FSF in
|
||
|
|
developing GNU and promoting software freedom." -->
|
||
|
|
<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>Compilation (Debugging with GDB)</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Compilation (Debugging with GDB)">
|
||
|
|
<meta name="keywords" content="Compilation (Debugging with GDB)">
|
||
|
|
<meta name="resource-type" content="document">
|
||
|
|
<meta name="distribution" content="global">
|
||
|
|
<meta name="Generator" content="makeinfo">
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<link href="index.html#Top" rel="start" title="Top">
|
||
|
|
<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="Running.html#Running" rel="up" title="Running">
|
||
|
|
<link href="Starting.html#Starting" rel="next" title="Starting">
|
||
|
|
<link href="Running.html#Running" rel="prev" title="Running">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.indentedblock {margin-right: 0em}
|
||
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
div.smalllisp {margin-left: 3.2em}
|
||
|
|
kbd {font-style: oblique}
|
||
|
|
pre.display {font-family: inherit}
|
||
|
|
pre.format {font-family: inherit}
|
||
|
|
pre.menu-comment {font-family: serif}
|
||
|
|
pre.menu-preformatted {font-family: serif}
|
||
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smallexample {font-size: smaller}
|
||
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smalllisp {font-size: smaller}
|
||
|
|
span.nolinebreak {white-space: nowrap}
|
||
|
|
span.roman {font-family: initial; font-weight: normal}
|
||
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en">
|
||
|
|
<a name="Compilation"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Starting.html#Starting" accesskey="n" rel="next">Starting</a>, Up: <a href="Running.html#Running" accesskey="u" rel="up">Running</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>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="Compiling-for-Debugging"></a>
|
||
|
|
<h3 class="section">4.1 Compiling for Debugging</h3>
|
||
|
|
|
||
|
|
<p>In order to debug a program effectively, you need to generate
|
||
|
|
debugging information when you compile it. This debugging information
|
||
|
|
is stored in the object file; it describes the data type of each
|
||
|
|
variable or function and the correspondence between source line numbers
|
||
|
|
and addresses in the executable code.
|
||
|
|
</p>
|
||
|
|
<p>To request debugging information, specify the ‘<samp>-g</samp>’ option when you run
|
||
|
|
the compiler.
|
||
|
|
</p>
|
||
|
|
<p>Programs that are to be shipped to your customers are compiled with
|
||
|
|
optimizations, using the ‘<samp>-O</samp>’ compiler option. However, some
|
||
|
|
compilers are unable to handle the ‘<samp>-g</samp>’ and ‘<samp>-O</samp>’ options
|
||
|
|
together. Using those compilers, you cannot generate optimized
|
||
|
|
executables containing debugging information.
|
||
|
|
</p>
|
||
|
|
<p><small>GCC</small>, the <small>GNU</small> C/C<tt>++</tt> compiler, supports ‘<samp>-g</samp>’ with or
|
||
|
|
without ‘<samp>-O</samp>’, making it possible to debug optimized code. We
|
||
|
|
recommend that you <em>always</em> use ‘<samp>-g</samp>’ whenever you compile a
|
||
|
|
program. You may think your program is correct, but there is no sense
|
||
|
|
in pushing your luck. For more information, see <a href="Optimized-Code.html#Optimized-Code">Optimized Code</a>.
|
||
|
|
</p>
|
||
|
|
<p>Older versions of the <small>GNU</small> C compiler permitted a variant option
|
||
|
|
‘<samp><span class="nolinebreak">-gg</span></samp>’<!-- /@w --> for debugging information. <small>GDB</small> no longer supports this
|
||
|
|
format; if your <small>GNU</small> C compiler has this option, do not use it.
|
||
|
|
</p>
|
||
|
|
<p><small>GDB</small> knows about preprocessor macros and can show you their
|
||
|
|
expansion (see <a href="Macros.html#Macros">Macros</a>). Most compilers do not include information
|
||
|
|
about preprocessor macros in the debugging information if you specify
|
||
|
|
the <samp>-g</samp> flag alone. Version 3.1 and later of <small>GCC</small>,
|
||
|
|
the <small>GNU</small> C compiler, provides macro information if you are using
|
||
|
|
the DWARF debugging format, and specify the option <samp>-g3</samp>.
|
||
|
|
</p>
|
||
|
|
<p>See <a href="http://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html#Debugging-Options">Options for Debugging Your Program or GCC</a> in <cite>Using the <small>GNU</small> Compiler Collection (GCC)</cite>, for more
|
||
|
|
information on <small>GCC</small> options affecting debug information.
|
||
|
|
</p>
|
||
|
|
<p>You will have the best debugging experience if you use the latest
|
||
|
|
version of the DWARF debugging format that your compiler supports.
|
||
|
|
DWARF is currently the most expressive and best supported debugging
|
||
|
|
format in <small>GDB</small>.
|
||
|
|
</p>
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Starting.html#Starting" accesskey="n" rel="next">Starting</a>, Up: <a href="Running.html#Running" accesskey="u" rel="up">Running</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>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|