1<html lang="en"> 2<head> 3<title>Gcov Data Files - Using the GNU Compiler Collection (GCC)</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Using the GNU Compiler Collection (GCC)"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="Gcov.html#Gcov" title="Gcov"> 9<link rel="prev" href="Gcov-and-Optimization.html#Gcov-and-Optimization" title="Gcov and Optimization"> 10<link rel="next" href="Cross_002dprofiling.html#Cross_002dprofiling" title="Cross-profiling"> 11<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 12<!-- 13Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 141998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 152010 Free Software Foundation, Inc. 16 17Permission is granted to copy, distribute and/or modify this document 18under the terms of the GNU Free Documentation License, Version 1.3 or 19any later version published by the Free Software Foundation; with the 20Invariant Sections being ``Funding Free Software'', the Front-Cover 21Texts being (a) (see below), and with the Back-Cover Texts being (b) 22(see below). A copy of the license is included in the section entitled 23``GNU Free Documentation License''. 24 25(a) The FSF's Front-Cover Text is: 26 27 A GNU Manual 28 29(b) The FSF's Back-Cover Text is: 30 31 You have freedom to copy and modify this GNU Manual, like GNU 32 software. Copies published by the Free Software Foundation raise 33 funds for GNU development.--> 34<meta http-equiv="Content-Style-Type" content="text/css"> 35<style type="text/css"><!-- 36 pre.display { font-family:inherit } 37 pre.format { font-family:inherit } 38 pre.smalldisplay { font-family:inherit; font-size:smaller } 39 pre.smallformat { font-family:inherit; font-size:smaller } 40 pre.smallexample { font-size:smaller } 41 pre.smalllisp { font-size:smaller } 42 span.sc { font-variant:small-caps } 43 span.roman { font-family:serif; font-weight:normal; } 44 span.sansserif { font-family:sans-serif; font-weight:normal; } 45--></style> 46<link rel="stylesheet" type="text/css" href="../cs.css"> 47</head> 48<body> 49<div class="node"> 50<a name="Gcov-Data-Files"></a> 51<p> 52Next: <a rel="next" accesskey="n" href="Cross_002dprofiling.html#Cross_002dprofiling">Cross-profiling</a>, 53Previous: <a rel="previous" accesskey="p" href="Gcov-and-Optimization.html#Gcov-and-Optimization">Gcov and Optimization</a>, 54Up: <a rel="up" accesskey="u" href="Gcov.html#Gcov">Gcov</a> 55<hr> 56</div> 57 58<h3 class="section">10.4 Brief description of <samp><span class="command">gcov</span></samp> data files</h3> 59 60<p><samp><span class="command">gcov</span></samp> uses two files for profiling. The names of these files 61are derived from the original <em>object</em> file by substituting the 62file suffix with either <samp><span class="file">.gcno</span></samp>, or <samp><span class="file">.gcda</span></samp>. All of these files 63are placed in the same directory as the object file, and contain data 64stored in a platform-independent format. 65 66 <p>The <samp><span class="file">.gcno</span></samp> file is generated when the source file is compiled with 67the GCC <samp><span class="option">-ftest-coverage</span></samp> option. It contains information to 68reconstruct the basic block graphs and assign source line numbers to 69blocks. 70 71 <p>The <samp><span class="file">.gcda</span></samp> file is generated when a program containing object files 72built with the GCC <samp><span class="option">-fprofile-arcs</span></samp> option is executed. A 73separate <samp><span class="file">.gcda</span></samp> file is created for each object file compiled with 74this option. It contains arc transition counts, and some summary 75information. 76 77 <p>The full details of the file format is specified in <samp><span class="file">gcov-io.h</span></samp>, 78and functions provided in that header file should be used to access the 79coverage files. 80 81 </body></html> 82 83