104 lines
4.4 KiB
HTML
104 lines
4.4 KiB
HTML
<html lang="en">
|
|
<head>
|
|
<title>Branch Trace Format - Debugging with GDB</title>
|
|
<meta http-equiv="Content-Type" content="text/html">
|
|
<meta name="description" content="Debugging with GDB">
|
|
<meta name="generator" content="makeinfo 4.13">
|
|
<link title="Top" rel="start" href="index.html#Top">
|
|
<link rel="up" href="Remote-Protocol.html#Remote-Protocol" title="Remote Protocol">
|
|
<link rel="prev" href="Traceframe-Info-Format.html#Traceframe-Info-Format" title="Traceframe Info Format">
|
|
<link rel="next" href="Branch-Trace-Configuration-Format.html#Branch-Trace-Configuration-Format" title="Branch Trace Configuration Format">
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
|
<!--
|
|
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.''
|
|
-->
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
|
<style type="text/css"><!--
|
|
pre.display { font-family:inherit }
|
|
pre.format { font-family:inherit }
|
|
pre.smalldisplay { font-family:inherit; font-size:smaller }
|
|
pre.smallformat { font-family:inherit; font-size:smaller }
|
|
pre.smallexample { font-size:smaller }
|
|
pre.smalllisp { font-size:smaller }
|
|
span.sc { font-variant:small-caps }
|
|
span.roman { font-family:serif; font-weight:normal; }
|
|
span.sansserif { font-family:sans-serif; font-weight:normal; }
|
|
--></style>
|
|
</head>
|
|
<body>
|
|
<div class="node">
|
|
<a name="Branch-Trace-Format"></a>
|
|
<p>
|
|
Next: <a rel="next" accesskey="n" href="Branch-Trace-Configuration-Format.html#Branch-Trace-Configuration-Format">Branch Trace Configuration Format</a>,
|
|
Previous: <a rel="previous" accesskey="p" href="Traceframe-Info-Format.html#Traceframe-Info-Format">Traceframe Info Format</a>,
|
|
Up: <a rel="up" accesskey="u" href="Remote-Protocol.html#Remote-Protocol">Remote Protocol</a>
|
|
<hr>
|
|
</div>
|
|
|
|
<h3 class="section">E.19 Branch Trace Format</h3>
|
|
|
|
<p><a name="index-branch-trace-format-3636"></a>
|
|
In order to display the branch trace of an inferior thread,
|
|
<span class="sc">gdb</span> needs to obtain the list of branches. This list is
|
|
represented as list of sequential code blocks that are connected via
|
|
branches. The code in each block has been executed sequentially.
|
|
|
|
<p>This list is obtained using the ‘<samp><span class="samp">qXfer:btrace:read</span></samp>’
|
|
(see <a href="qXfer-btrace-read.html#qXfer-btrace-read">qXfer btrace read</a>) packet and is an XML document.
|
|
|
|
<p><span class="sc">gdb</span> must be linked with the Expat library to support XML
|
|
traceframe info discovery. See <a href="Expat.html#Expat">Expat</a>.
|
|
|
|
<p>The top-level structure of the document is shown below:
|
|
|
|
<pre class="smallexample"> <?xml version="1.0"?>
|
|
<!DOCTYPE btrace
|
|
PUBLIC "+//IDN gnu.org//DTD GDB Branch Trace V1.0//EN"
|
|
"http://sourceware.org/gdb/gdb-btrace.dtd">
|
|
<btrace>
|
|
block...
|
|
</btrace>
|
|
</pre>
|
|
<ul>
|
|
<li>A block of sequentially executed instructions starting at <var>begin</var>
|
|
and ending at <var>end</var>:
|
|
|
|
<pre class="smallexample"> <block begin="<var>begin</var>" end="<var>end</var>"/>
|
|
</pre>
|
|
</ul>
|
|
|
|
<p>The formal DTD for the branch trace format is given below:
|
|
|
|
<pre class="smallexample"> <!ELEMENT btrace (block* | pt) >
|
|
<!ATTLIST btrace version CDATA #FIXED "1.0">
|
|
|
|
<!ELEMENT block EMPTY>
|
|
<!ATTLIST block begin CDATA #REQUIRED
|
|
end CDATA #REQUIRED>
|
|
|
|
<!ELEMENT pt (pt-config?, raw?)>
|
|
|
|
<!ELEMENT pt-config (cpu?)>
|
|
|
|
<!ELEMENT cpu EMPTY>
|
|
<!ATTLIST cpu vendor CDATA #REQUIRED
|
|
family CDATA #REQUIRED
|
|
model CDATA #REQUIRED
|
|
stepping CDATA #REQUIRED>
|
|
|
|
<!ELEMENT raw (#PCDATA)>
|
|
</pre>
|
|
</body></html>
|
|
|