toolchain/share/doc/gdb/tdump.html

120 lines
4.9 KiB
HTML

<html lang="en">
<head>
<title>tdump - 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="Analyze-Collected-Data.html#Analyze-Collected-Data" title="Analyze Collected Data">
<link rel="prev" href="tfind.html#tfind" title="tfind">
<link rel="next" href="save-tracepoints.html#save-tracepoints" title="save tracepoints">
<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="tdump"></a>
<p>
Next:&nbsp;<a rel="next" accesskey="n" href="save-tracepoints.html#save-tracepoints">save tracepoints</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="tfind.html#tfind">tfind</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="Analyze-Collected-Data.html#Analyze-Collected-Data">Analyze Collected Data</a>
<hr>
</div>
<h4 class="subsection">13.2.2 <code>tdump</code></h4>
<p><a name="index-tdump-930"></a><a name="index-dump-all-data-collected-at-tracepoint-931"></a><a name="index-tracepoint-data_002c-display-932"></a>
This command takes no arguments. It prints all the data collected at
the current trace snapshot.
<pre class="smallexample"> (gdb) <b>trace 444</b>
(gdb) <b>actions</b>
Enter actions for tracepoint #2, one per line:
&gt; collect $regs, $locals, $args, gdb_long_test
&gt; end
(gdb) <b>tstart</b>
(gdb) <b>tfind line 444</b>
#0 gdb_test (p1=0x11, p2=0x22, p3=0x33, p4=0x44, p5=0x55, p6=0x66)
at gdb_test.c:444
444 printp( "%s: arguments = 0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", )
(gdb) <b>tdump</b>
Data collected at tracepoint 2, trace frame 1:
d0 0xc4aa0085 -995491707
d1 0x18 24
d2 0x80 128
d3 0x33 51
d4 0x71aea3d 119204413
d5 0x22 34
d6 0xe0 224
d7 0x380035 3670069
a0 0x19e24a 1696330
a1 0x3000668 50333288
a2 0x100 256
a3 0x322000 3284992
a4 0x3000698 50333336
a5 0x1ad3cc 1758156
fp 0x30bf3c 0x30bf3c
sp 0x30bf34 0x30bf34
ps 0x0 0
pc 0x20b2c8 0x20b2c8
fpcontrol 0x0 0
fpstatus 0x0 0
fpiaddr 0x0 0
p = 0x20e5b4 "gdb-test"
p1 = (void *) 0x11
p2 = (void *) 0x22
p3 = (void *) 0x33
p4 = (void *) 0x44
p5 = (void *) 0x55
p6 = (void *) 0x66
gdb_long_test = 17 '\021'
(gdb)
</pre>
<p><code>tdump</code> works by scanning the tracepoint's current collection
actions and printing the value of each expression listed. So
<code>tdump</code> can fail, if after a run, you change the tracepoint's
actions to mention variables that were not collected during the run.
<p>Also, for tracepoints with <code>while-stepping</code> loops, <code>tdump</code>
uses the collected value of <code>$pc</code> to distinguish between trace
frames that were collected at the tracepoint hit, and frames that were
collected while stepping. This allows it to correctly choose whether
to display the basic list of collections, or the collections from the
body of the while-stepping loop. However, if <code>$pc</code> was not collected,
then <code>tdump</code> will always attempt to dump using the basic collection
list, and may fail if a while-stepping frame does not include all the
same data that is collected at the tracepoint hit.
<!-- This is getting pretty arcane, example would be good. -->
</body></html>