112 lines
6.1 KiB
HTML
112 lines
6.1 KiB
HTML
<html lang="en">
|
|
<head>
|
|
<title>Set Tracepoints - 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="Tracepoints.html#Tracepoints" title="Tracepoints">
|
|
<link rel="next" href="Analyze-Collected-Data.html#Analyze-Collected-Data" title="Analyze Collected Data">
|
|
<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="Set-Tracepoints"></a>
|
|
<p>
|
|
Next: <a rel="next" accesskey="n" href="Analyze-Collected-Data.html#Analyze-Collected-Data">Analyze Collected Data</a>,
|
|
Up: <a rel="up" accesskey="u" href="Tracepoints.html#Tracepoints">Tracepoints</a>
|
|
<hr>
|
|
</div>
|
|
|
|
<h3 class="section">13.1 Commands to Set Tracepoints</h3>
|
|
|
|
<p>Before running such a <dfn>trace experiment</dfn>, an arbitrary number of
|
|
tracepoints can be set. A tracepoint is actually a special type of
|
|
breakpoint (see <a href="Set-Breaks.html#Set-Breaks">Set Breaks</a>), so you can manipulate it using
|
|
standard breakpoint commands. For instance, as with breakpoints,
|
|
tracepoint numbers are successive integers starting from one, and many
|
|
of the commands associated with tracepoints take the tracepoint number
|
|
as their argument, to identify which tracepoint to work on.
|
|
|
|
<p>For each tracepoint, you can specify, in advance, some arbitrary set
|
|
of data that you want the target to collect in the trace buffer when
|
|
it hits that tracepoint. The collected data can include registers,
|
|
local variables, or global data. Later, you can use <span class="sc">gdb</span>
|
|
commands to examine the values these data had at the time the
|
|
tracepoint was hit.
|
|
|
|
<p>Tracepoints do not support every breakpoint feature. Ignore counts on
|
|
tracepoints have no effect, and tracepoints cannot run <span class="sc">gdb</span>
|
|
commands when they are hit. Tracepoints may not be thread-specific
|
|
either.
|
|
|
|
<p><a name="index-fast-tracepoints-859"></a>Some targets may support <dfn>fast tracepoints</dfn>, which are inserted in
|
|
a different way (such as with a jump instead of a trap), that is
|
|
faster but possibly restricted in where they may be installed.
|
|
|
|
<p><a name="index-static-tracepoints-860"></a><a name="index-markers_002c-static-tracepoints-861"></a><a name="index-probing-markers_002c-static-tracepoints-862"></a>Regular and fast tracepoints are dynamic tracing facilities, meaning
|
|
that they can be used to insert tracepoints at (almost) any location
|
|
in the target. Some targets may also support controlling <dfn>static
|
|
tracepoints</dfn> from <span class="sc">gdb</span>. With static tracing, a set of
|
|
instrumentation points, also known as <dfn>markers</dfn>, are embedded in
|
|
the target program, and can be activated or deactivated by name or
|
|
address. These are usually placed at locations which facilitate
|
|
investigating what the target is actually doing. <span class="sc">gdb</span>'s
|
|
support for static tracing includes being able to list instrumentation
|
|
points, and attach them with <span class="sc">gdb</span> defined high level
|
|
tracepoints that expose the whole range of convenience of
|
|
<span class="sc">gdb</span>'s tracepoints support. Namely, support for collecting
|
|
registers values and values of global or local (to the instrumentation
|
|
point) variables; tracepoint conditions and trace state variables.
|
|
The act of installing a <span class="sc">gdb</span> static tracepoint on an
|
|
instrumentation point, or marker, is referred to as <dfn>probing</dfn> a
|
|
static tracepoint marker.
|
|
|
|
<p><code>gdbserver</code> supports tracepoints on some target systems.
|
|
See <a href="Server.html#Server">Tracepoints support in <code>gdbserver</code></a>.
|
|
|
|
<p>This section describes commands to set tracepoints and associated
|
|
conditions and actions.
|
|
|
|
<ul class="menu">
|
|
<li><a accesskey="1" href="Create-and-Delete-Tracepoints.html#Create-and-Delete-Tracepoints">Create and Delete Tracepoints</a>
|
|
<li><a accesskey="2" href="Enable-and-Disable-Tracepoints.html#Enable-and-Disable-Tracepoints">Enable and Disable Tracepoints</a>
|
|
<li><a accesskey="3" href="Tracepoint-Passcounts.html#Tracepoint-Passcounts">Tracepoint Passcounts</a>
|
|
<li><a accesskey="4" href="Tracepoint-Conditions.html#Tracepoint-Conditions">Tracepoint Conditions</a>
|
|
<li><a accesskey="5" href="Trace-State-Variables.html#Trace-State-Variables">Trace State Variables</a>
|
|
<li><a accesskey="6" href="Tracepoint-Actions.html#Tracepoint-Actions">Tracepoint Actions</a>
|
|
<li><a accesskey="7" href="Listing-Tracepoints.html#Listing-Tracepoints">Listing Tracepoints</a>
|
|
<li><a accesskey="8" href="Listing-Static-Tracepoint-Markers.html#Listing-Static-Tracepoint-Markers">Listing Static Tracepoint Markers</a>
|
|
<li><a accesskey="9" href="Starting-and-Stopping-Trace-Experiments.html#Starting-and-Stopping-Trace-Experiments">Starting and Stopping Trace Experiments</a>
|
|
<li><a href="Tracepoint-Restrictions.html#Tracepoint-Restrictions">Tracepoint Restrictions</a>
|
|
</ul>
|
|
|
|
</body></html>
|
|
|