| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- Copyright (C) 1988-2015 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." --> |
| <!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>Debugging with GDB: Tracepoint Variables</title> |
| |
| <meta name="description" content="Debugging with GDB: Tracepoint Variables"> |
| <meta name="keywords" content="Debugging with GDB: Tracepoint Variables"> |
| <meta name="resource-type" content="document"> |
| <meta name="distribution" content="global"> |
| <meta name="Generator" content="makeinfo"> |
| <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> |
| <link href="index.html#Top" rel="start" title="Top"> |
| <link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> |
| <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> |
| <link href="Tracepoints.html#Tracepoints" rel="up" title="Tracepoints"> |
| <link href="Trace-Files.html#Trace-Files" rel="next" title="Trace Files"> |
| <link href="save-tracepoints.html#save-tracepoints" rel="prev" title="save tracepoints"> |
| <style type="text/css"> |
| <!-- |
| a.summary-letter {text-decoration: none} |
| blockquote.smallquotation {font-size: smaller} |
| div.display {margin-left: 3.2em} |
| div.example {margin-left: 3.2em} |
| div.indentedblock {margin-left: 3.2em} |
| div.lisp {margin-left: 3.2em} |
| div.smalldisplay {margin-left: 3.2em} |
| div.smallexample {margin-left: 3.2em} |
| div.smallindentedblock {margin-left: 3.2em; font-size: smaller} |
| div.smalllisp {margin-left: 3.2em} |
| kbd {font-style:oblique} |
| pre.display {font-family: inherit} |
| pre.format {font-family: inherit} |
| pre.menu-comment {font-family: serif} |
| pre.menu-preformatted {font-family: serif} |
| pre.smalldisplay {font-family: inherit; font-size: smaller} |
| pre.smallexample {font-size: smaller} |
| pre.smallformat {font-family: inherit; font-size: smaller} |
| pre.smalllisp {font-size: smaller} |
| span.nocodebreak {white-space:nowrap} |
| span.nolinebreak {white-space:nowrap} |
| span.roman {font-family:serif; font-weight:normal} |
| span.sansserif {font-family:sans-serif; font-weight:normal} |
| ul.no-bullet {list-style: none} |
| --> |
| </style> |
| |
| |
| </head> |
| |
| <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> |
| <a name="Tracepoint-Variables"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="Trace-Files.html#Trace-Files" accesskey="n" rel="next">Trace Files</a>, Previous: <a href="Analyze-Collected-Data.html#Analyze-Collected-Data" accesskey="p" rel="prev">Analyze Collected Data</a>, Up: <a href="Tracepoints.html#Tracepoints" accesskey="u" rel="up">Tracepoints</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> |
| </div> |
| <hr> |
| <a name="Convenience-Variables-for-Tracepoints"></a> |
| <h3 class="section">13.3 Convenience Variables for Tracepoints</h3> |
| <a name="index-tracepoint-variables"></a> |
| <a name="index-convenience-variables-for-tracepoints"></a> |
| |
| <dl compact="compact"> |
| <dd><a name="index-_0024trace_005fframe"></a> |
| </dd> |
| <dt><code>(int) $trace_frame</code></dt> |
| <dd><p>The current trace snapshot (a.k.a. <em>frame</em>) number, or -1 if no |
| snapshot is selected. |
| </p> |
| <a name="index-_0024tracepoint"></a> |
| </dd> |
| <dt><code>(int) $tracepoint</code></dt> |
| <dd><p>The tracepoint for the current trace snapshot. |
| </p> |
| <a name="index-_0024trace_005fline"></a> |
| </dd> |
| <dt><code>(int) $trace_line</code></dt> |
| <dd><p>The line number for the current trace snapshot. |
| </p> |
| <a name="index-_0024trace_005ffile"></a> |
| </dd> |
| <dt><code>(char []) $trace_file</code></dt> |
| <dd><p>The source file for the current trace snapshot. |
| </p> |
| <a name="index-_0024trace_005ffunc"></a> |
| </dd> |
| <dt><code>(char []) $trace_func</code></dt> |
| <dd><p>The name of the function containing <code>$tracepoint</code>. |
| </p></dd> |
| </dl> |
| |
| <p>Note: <code>$trace_file</code> is not suitable for use in <code>printf</code>, |
| use <code>output</code> instead. |
| </p> |
| <p>Here’s a simple example of using these convenience variables for |
| stepping through all the trace snapshots and printing some of their |
| data. Note that these are not the same as trace state variables, |
| which are managed by the target. |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample">(gdb) <b>tfind start</b> |
| |
| (gdb) <b>while $trace_frame != -1</b> |
| > output $trace_file |
| > printf ", line %d (tracepoint #%d)\n", $trace_line, $tracepoint |
| > tfind |
| > end |
| </pre></div> |
| |
| |
| |
| |
| </body> |
| </html> |
