1<html lang="en"> 2<head> 3<title>Bug Reporting - GNU Binary Utilities</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="GNU Binary Utilities"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="Reporting-Bugs.html#Reporting-Bugs" title="Reporting Bugs"> 9<link rel="prev" href="Bug-Criteria.html#Bug-Criteria" title="Bug Criteria"> 10<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 11<!-- 12Copyright (C) 1991-2013 Free Software Foundation, Inc. 13 14Permission is granted to copy, distribute and/or modify this document 15under the terms of the GNU Free Documentation License, Version 1.3 16or any later version published by the Free Software Foundation; 17with no Invariant Sections, with no Front-Cover Texts, and with no 18Back-Cover Texts. A copy of the license is included in the 19section entitled ``GNU Free Documentation License''. 20 21--> 22<meta http-equiv="Content-Style-Type" content="text/css"> 23<style type="text/css"><!-- 24 pre.display { font-family:inherit } 25 pre.format { font-family:inherit } 26 pre.smalldisplay { font-family:inherit; font-size:smaller } 27 pre.smallformat { font-family:inherit; font-size:smaller } 28 pre.smallexample { font-size:smaller } 29 pre.smalllisp { font-size:smaller } 30 span.sc { font-variant:small-caps } 31 span.roman { font-family:serif; font-weight:normal; } 32 span.sansserif { font-family:sans-serif; font-weight:normal; } 33--></style> 34<link rel="stylesheet" type="text/css" href="../cs.css"> 35</head> 36<body> 37<div class="node"> 38<a name="Bug-Reporting"></a> 39<p> 40Previous: <a rel="previous" accesskey="p" href="Bug-Criteria.html#Bug-Criteria">Bug Criteria</a>, 41Up: <a rel="up" accesskey="u" href="Reporting-Bugs.html#Reporting-Bugs">Reporting Bugs</a> 42<hr> 43</div> 44 45<h3 class="section">19.2 How to Report Bugs</h3> 46 47<p><a name="index-bug-reports-171"></a><a name="index-bugs_002c-reporting-172"></a> 48A number of companies and individuals offer support for <span class="sc">gnu</span> 49products. If you obtained the binary utilities from a support 50organization, we recommend you contact that organization first. 51 52 <p>You can find contact information for many support companies and 53individuals in the file <samp><span class="file">etc/SERVICE</span></samp> in the <span class="sc">gnu</span> Emacs 54distribution. 55 56 <p>In any event, we also recommend that you send bug reports for the binary 57utilities to <a href="https://sourcery.mentor.com/GNUToolchain/">https://sourcery.mentor.com/GNUToolchain/</a>. 58 59 <p>The fundamental principle of reporting bugs usefully is this: 60<strong>report all the facts</strong>. If you are not sure whether to state a 61fact or leave it out, state it! 62 63 <p>Often people omit facts because they think they know what causes the 64problem and assume that some details do not matter. Thus, you might 65assume that the name of a file you use in an example does not matter. 66Well, probably it does not, but one cannot be sure. Perhaps the bug is 67a stray memory reference which happens to fetch from the location where 68that pathname is stored in memory; perhaps, if the pathname were 69different, the contents of that location would fool the utility into 70doing the right thing despite the bug. Play it safe and give a 71specific, complete example. That is the easiest thing for you to do, 72and the most helpful. 73 74 <p>Keep in mind that the purpose of a bug report is to enable us to fix the bug if 75it is new to us. Therefore, always write your bug reports on the assumption 76that the bug has not been reported previously. 77 78 <p>Sometimes people give a few sketchy facts and ask, “Does this ring a 79bell?” This cannot help us fix a bug, so it is basically useless. We 80respond by asking for enough details to enable us to investigate. 81You might as well expedite matters by sending them to begin with. 82 83 <p>To enable us to fix the bug, you should include all these things: 84 85 <ul> 86<li>The version of the utility. Each utility announces it if you start it 87with the <samp><span class="option">--version</span></samp> argument. 88 89 <p>Without this, we will not know whether there is any point in looking for 90the bug in the current version of the binary utilities. 91 92 <li>Any patches you may have applied to the source, including any patches 93made to the <code>BFD</code> library. 94 95 <li>The type of machine you are using, and the operating system name and 96version number. 97 98 <li>What compiler (and its version) was used to compile the utilities—e.g. 99“<code>gcc-2.7</code>”. 100 101 <li>The command arguments you gave the utility to observe the bug. To 102guarantee you will not omit something important, list them all. A copy 103of the Makefile (or the output from make) is sufficient. 104 105 <p>If we were to try to guess the arguments, we would probably guess wrong 106and then we might not encounter the bug. 107 108 <li>A complete input file, or set of input files, that will reproduce the 109bug. If the utility is reading an object file or files, then it is 110generally most helpful to send the actual object files. 111 112 <p>If the source files were produced exclusively using <span class="sc">gnu</span> programs 113(e.g., <samp><span class="command">gcc</span></samp>, <samp><span class="command">gas</span></samp>, and/or the <span class="sc">gnu</span> <samp><span class="command">ld</span></samp>), then it 114may be OK to send the source files rather than the object files. In 115this case, be sure to say exactly what version of <samp><span class="command">gcc</span></samp>, or 116whatever, was used to produce the object files. Also say how 117<samp><span class="command">gcc</span></samp>, or whatever, was configured. 118 119 <li>A description of what behavior you observe that you believe is 120incorrect. For example, “It gets a fatal signal.” 121 122 <p>Of course, if the bug is that the utility gets a fatal signal, then we 123will certainly notice it. But if the bug is incorrect output, we might 124not notice unless it is glaringly wrong. You might as well not give us 125a chance to make a mistake. 126 127 <p>Even if the problem you experience is a fatal signal, you should still 128say so explicitly. Suppose something strange is going on, such as your 129copy of the utility is out of sync, or you have encountered a bug in 130the C library on your system. (This has happened!) Your copy might 131crash and ours would not. If you told us to expect a crash, then when 132ours fails to crash, we would know that the bug was not happening for 133us. If you had not told us to expect a crash, then we would not be able 134to draw any conclusion from our observations. 135 136 <li>If you wish to suggest changes to the source, send us context diffs, as 137generated by <samp><span class="command">diff</span></samp> with the <samp><span class="option">-u</span></samp>, <samp><span class="option">-c</span></samp>, or <samp><span class="option">-p</span></samp> 138option. Always send diffs from the old file to the new file. If you 139wish to discuss something in the <samp><span class="command">ld</span></samp> source, refer to it by 140context, not by line number. 141 142 <p>The line numbers in our development sources will not match those in your 143sources. Your line numbers would convey no useful information to us. 144</ul> 145 146 <p>Here are some things that are not necessary: 147 148 <ul> 149<li>A description of the envelope of the bug. 150 151 <p>Often people who encounter a bug spend a lot of time investigating 152which changes to the input file will make the bug go away and which 153changes will not affect it. 154 155 <p>This is often time consuming and not very useful, because the way we 156will find the bug is by running a single example under the debugger 157with breakpoints, not by pure deduction from a series of examples. 158We recommend that you save your time for something else. 159 160 <p>Of course, if you can find a simpler example to report <em>instead</em> 161of the original one, that is a convenience for us. Errors in the 162output will be easier to spot, running under the debugger will take 163less time, and so on. 164 165 <p>However, simplification is not vital; if you do not want to do this, 166report the bug anyway and send us the entire test case you used. 167 168 <li>A patch for the bug. 169 170 <p>A patch for the bug does help us if it is a good one. But do not omit 171the necessary information, such as the test case, on the assumption that 172a patch is all we need. We might see problems with your patch and decide 173to fix the problem another way, or we might not understand it at all. 174 175 <p>Sometimes with programs as complicated as the binary utilities it is 176very hard to construct an example that will make the program follow a 177certain path through the code. If you do not send us the example, we 178will not be able to construct one, so we will not be able to verify that 179the bug is fixed. 180 181 <p>And if we cannot understand what bug you are trying to fix, or why your 182patch should be an improvement, we will not install it. A test case will 183help us to understand. 184 185 <li>A guess about what the bug is or what it depends on. 186 187 <p>Such guesses are usually wrong. Even we cannot guess right about such 188things without first using the debugger to find the facts. 189</ul> 190 191 </body></html> 192 193