mingw/info/gdb/Create-and-Delete-Tracepoints.html

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  12 Node:<a name="Create%20and%20Delete%20Tracepoints">Create and Delete Tracepoints</a>,
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  18 <h4 class="subsection">Create and Delete Tracepoints</h4>
  19
  20      <dl>
  21 <dt><code>trace</code>
  22      <dd>The <code>trace</code> command is very similar to the <code>break</code> command.
  23 Its argument can be a source line, a function name, or an address in
  24 the target program.  See <a href="Set-Breaks.html#Set%20Breaks">Set Breaks</a>.  The <code>trace</code> command
  25 defines a tracepoint, which is a point in the target program where the
  26 debugger will briefly stop, collect some data, and then allow the
  27 program to continue.  Setting a tracepoint or changing its commands
  28 doesn't take effect until the next <code>tstart</code> command; thus, you
  29 cannot change the tracepoint attributes once a trace experiment is
  30 running.
  31
  32      <p>Here are some examples of using the <code>trace</code> command:
  33
  34      <pre class="smallexample">          (gdb) <b>trace foo.c:121</b>    // a source file and line number
  35
  36           (gdb) <b>trace +2</b>           // 2 lines forward
  37
  38           (gdb) <b>trace my_function</b>  // first source line of function
  39
  40           (gdb) <b>trace *my_function</b> // EXACT start address of function
  41
  42           (gdb) <b>trace *0x2117c4</b>    // an address
  43           </pre>
  44
  45      <p>You can abbreviate <code>trace</code> as <code>tr</code>.
  46
  47      <p>The convenience variable <code>$tpnum</code> records the tracepoint number
  48 of the most recently set tracepoint.
  49
  50      <br><dt><code>delete tracepoint </code>[<code></code><var>num</var><code></code>]<code></code>
  51      <dd>Permanently delete one or more tracepoints.  With no argument, the
  52 default is to delete all tracepoints.
  53
  54      <p>Examples:
  55
  56      <pre class="smallexample">          (gdb) <b>delete trace 1 2 3</b> // remove three tracepoints
  57
  58           (gdb) <b>delete trace</b>       // remove all tracepoints
  59           </pre>
  60
  61      <p>You can abbreviate this command as <code>del tr</code>.
  62 </dl>
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