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.
119 lines
5.2 KiB
HTML
119 lines
5.2 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Copyright (C) 1988-2018 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 "Funding Free Software", the Front-Cover
|
|
Texts being (a) (see below), and with the Back-Cover Texts being (b)
|
|
(see below). A copy of the license is included in the section entitled
|
|
"GNU Free Documentation License".
|
|
|
|
(a) The FSF's Front-Cover Text is:
|
|
|
|
A GNU Manual
|
|
|
|
(b) The FSF's Back-Cover Text is:
|
|
|
|
You have freedom to copy and modify this GNU Manual, like GNU
|
|
software. Copies published by the Free Software Foundation raise
|
|
funds for GNU development. -->
|
|
<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<title>Cross-profiling (Using the GNU Compiler Collection (GCC))</title>
|
|
|
|
<meta name="description" content="Cross-profiling (Using the GNU Compiler Collection (GCC))">
|
|
<meta name="keywords" content="Cross-profiling (Using the GNU Compiler Collection (GCC))">
|
|
<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="Option-Index.html#Option-Index" rel="index" title="Option Index">
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
|
<link href="Gcov.html#Gcov" rel="up" title="Gcov">
|
|
<link href="Gcov_002dtool.html#Gcov_002dtool" rel="next" title="Gcov-tool">
|
|
<link href="Gcov-Data-Files.html#Gcov-Data-Files" rel="prev" title="Gcov Data Files">
|
|
<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="Cross_002dprofiling"></a>
|
|
<div class="header">
|
|
<p>
|
|
Previous: <a href="Gcov-Data-Files.html#Gcov-Data-Files" accesskey="p" rel="prev">Gcov Data Files</a>, Up: <a href="Gcov.html#Gcov" accesskey="u" rel="up">Gcov</a> [<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>
|
|
</div>
|
|
<hr>
|
|
<a name="Data-File-Relocation-to-Support-Cross_002dProfiling"></a>
|
|
<h3 class="section">10.5 Data File Relocation to Support Cross-Profiling</h3>
|
|
|
|
<p>Running the program will cause profile output to be generated. For each
|
|
source file compiled with <samp>-fprofile-arcs</samp>, an accompanying <samp>.gcda</samp>
|
|
file will be placed in the object file directory. That implicitly requires
|
|
running the program on the same system as it was built or having the same
|
|
absolute directory structure on the target system. The program will try
|
|
to create the needed directory structure, if it is not already present.
|
|
</p>
|
|
<p>To support cross-profiling, a program compiled with <samp>-fprofile-arcs</samp>
|
|
can relocate the data files based on two environment variables:
|
|
</p>
|
|
<ul>
|
|
<li> GCOV_PREFIX contains the prefix to add to the absolute paths
|
|
in the object file. Prefix can be absolute, or relative. The
|
|
default is no prefix.
|
|
|
|
</li><li> GCOV_PREFIX_STRIP indicates the how many initial directory names to strip off
|
|
the hardwired absolute paths. Default value is 0.
|
|
|
|
<p><em>Note:</em> If GCOV_PREFIX_STRIP is set without GCOV_PREFIX is undefined,
|
|
then a relative path is made out of the hardwired absolute paths.
|
|
</p></li></ul>
|
|
|
|
<p>For example, if the object file <samp>/user/build/foo.o</samp> was built with
|
|
<samp>-fprofile-arcs</samp>, the final executable will try to create the data file
|
|
<samp>/user/build/foo.gcda</samp> when running on the target system. This will
|
|
fail if the corresponding directory does not exist and it is unable to create
|
|
it. This can be overcome by, for example, setting the environment as
|
|
‘<samp>GCOV_PREFIX=/target/run</samp>’ and ‘<samp>GCOV_PREFIX_STRIP=1</samp>’. Such a
|
|
setting will name the data file <samp>/target/run/build/foo.gcda</samp>.
|
|
</p>
|
|
<p>You must move the data files to the expected directory tree in order to
|
|
use them for profile directed optimizations (<samp>-fprofile-use</samp>), or to
|
|
use the <code>gcov</code> tool.
|
|
</p>
|
|
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|