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<a name="Process-Record-and-Replay"></a>
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<div class="header">
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<p>
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Next: <a href="Stack.html#Stack" accesskey="n" rel="next">Stack</a>, Previous: <a href="Reverse-Execution.html#Reverse-Execution" accesskey="p" rel="previous">Reverse Execution</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</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>
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</div>
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<hr>
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<a name="Recording-Inferior_0027s-Execution-and-Replaying-It"></a>
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<h2 class="chapter">7 Recording Inferior’s Execution and Replaying It</h2>
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<a name="index-process-record-and-replay"></a>
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<a name="index-recording-inferior_0027s-execution-and-replaying-it"></a>
|
|
<p>On some platforms, <small>GDB</small> provides a special <em>process record
|
and replay</em> target that can record a log of the process execution, and
|
replay it later with both forward and reverse execution commands.
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</p>
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<a name="index-replay-mode"></a>
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<p>When this target is in use, if the execution log includes the record
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for the next instruction, <small>GDB</small> will debug in <em>replay
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mode</em>. In the replay mode, the inferior does not really execute code
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instructions. Instead, all the events that normally happen during
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code execution are taken from the execution log. While code is not
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really executed in replay mode, the values of registers (including the
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program counter register) and the memory of the inferior are still
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changed as they normally would. Their contents are taken from the
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execution log.
|
</p>
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<a name="index-record-mode"></a>
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<p>If the record for the next instruction is not in the execution log,
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<small>GDB</small> will debug in <em>record mode</em>. In this mode, the
|
inferior executes normally, and <small>GDB</small> records the execution log
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for future replay.
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</p>
|
<p>The process record and replay target supports reverse execution
|
(see <a href="Reverse-Execution.html#Reverse-Execution">Reverse Execution</a>), even if the platform on which the
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inferior runs does not. However, the reverse execution is limited in
|
this case by the range of the instructions recorded in the execution
|
log. In other words, reverse execution on platforms that don’t
|
support it directly can only be done in the replay mode.
|
</p>
|
<p>When debugging in the reverse direction, <small>GDB</small> will work in
|
replay mode as long as the execution log includes the record for the
|
previous instruction; otherwise, it will work in record mode, if the
|
platform supports reverse execution, or stop if not.
|
</p>
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<p>Currently, process record and replay is supported on ARM, Aarch64,
|
Moxie, PowerPC, PowerPC64, S/390, and x86 (i386/amd64) running
|
GNU/Linux. Process record and replay can be used both when native
|
debugging, and when remote debugging via <code>gdbserver</code>.
|
</p>
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<p>For architecture environments that support process record and replay,
|
<small>GDB</small> provides the following commands:
|
</p>
|
<dl compact="compact">
|
<dd><a name="index-target-record"></a>
|
<a name="index-target-record_002dfull"></a>
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<a name="index-target-record_002dbtrace"></a>
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<a name="index-record"></a>
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<a name="index-record-full"></a>
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<a name="index-record-btrace"></a>
|
<a name="index-record-btrace-bts"></a>
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<a name="index-record-btrace-pt"></a>
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<a name="index-record-bts"></a>
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<a name="index-record-pt"></a>
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<a name="index-rec"></a>
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<a name="index-rec-full"></a>
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<a name="index-rec-btrace"></a>
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<a name="index-rec-btrace-bts"></a>
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<a name="index-rec-btrace-pt"></a>
|
<a name="index-rec-bts"></a>
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<a name="index-rec-pt"></a>
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</dd>
|
<dt><code>record <var>method</var></code></dt>
|
<dd><p>This command starts the process record and replay target. The
|
recording method can be specified as parameter. Without a parameter
|
the command uses the <code>full</code> recording method. The following
|
recording methods are available:
|
</p>
|
<dl compact="compact">
|
<dt><code>full</code></dt>
|
<dd><p>Full record/replay recording using <small>GDB</small>’s software record and
|
replay implementation. This method allows replaying and reverse
|
execution.
|
</p>
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</dd>
|
<dt><code>btrace <var>format</var></code></dt>
|
<dd><p>Hardware-supported instruction recording, supported on Intel
|
processors. This method does not record data. Further, the data is
|
collected in a ring buffer so old data will be overwritten when the
|
buffer is full. It allows limited reverse execution. Variables and
|
registers are not available during reverse execution. In remote
|
debugging, recording continues on disconnect. Recorded data can be
|
inspected after reconnecting. The recording may be stopped using
|
<code>record stop</code>.
|
</p>
|
<p>The recording format can be specified as parameter. Without a parameter
|
the command chooses the recording format. The following recording
|
formats are available:
|
</p>
|
<dl compact="compact">
|
<dt><code>bts</code></dt>
|
<dd><a name="index-branch-trace-store"></a>
|
<p>Use the <em>Branch Trace Store</em> (<acronym>BTS</acronym>) recording format. In
|
this format, the processor stores a from/to record for each executed
|
branch in the btrace ring buffer.
|
</p>
|
</dd>
|
<dt><code>pt</code></dt>
|
<dd><a name="index-Intel-Processor-Trace"></a>
|
<p>Use the <em>Intel Processor Trace</em> recording format. In this
|
format, the processor stores the execution trace in a compressed form
|
that is afterwards decoded by <small>GDB</small>.
|
</p>
|
<p>The trace can be recorded with very low overhead. The compressed
|
trace format also allows small trace buffers to already contain a big
|
number of instructions compared to <acronym>BTS</acronym>.
|
</p>
|
<p>Decoding the recorded execution trace, on the other hand, is more
|
expensive than decoding <acronym>BTS</acronym> trace. This is mostly due to the
|
increased number of instructions to process. You should increase the
|
buffer-size with care.
|
</p></dd>
|
</dl>
|
|
<p>Not all recording formats may be available on all processors.
|
</p></dd>
|
</dl>
|
|
<p>The process record and replay target can only debug a process that is
|
already running. Therefore, you need first to start the process with
|
the <kbd>run</kbd> or <kbd>start</kbd> commands, and then start the recording
|
with the <kbd>record <var>method</var></kbd> command.
|
</p>
|
<a name="index-displaced-stepping_002c-and-process-record-and-replay"></a>
|
<p>Displaced stepping (see <a href="Maintenance-Commands.html#Maintenance-Commands">displaced stepping</a>)
|
will be automatically disabled when process record and replay target
|
is started. That’s because the process record and replay target
|
doesn’t support displaced stepping.
|
</p>
|
<a name="index-non_002dstop-mode_002c-and-process-record-and-replay"></a>
|
<a name="index-asynchronous-execution_002c-and-process-record-and-replay"></a>
|
<p>If the inferior is in the non-stop mode (see <a href="Non_002dStop-Mode.html#Non_002dStop-Mode">Non-Stop Mode</a>) or in
|
the asynchronous execution mode (see <a href="Background-Execution.html#Background-Execution">Background Execution</a>), not
|
all recording methods are available. The <code>full</code> recording method
|
does not support these two modes.
|
</p>
|
<a name="index-record-stop"></a>
|
<a name="index-rec-s"></a>
|
</dd>
|
<dt><code>record stop</code></dt>
|
<dd><p>Stop the process record and replay target. When process record and
|
replay target stops, the entire execution log will be deleted and the
|
inferior will either be terminated, or will remain in its final state.
|
</p>
|
<p>When you stop the process record and replay target in record mode (at
|
the end of the execution log), the inferior will be stopped at the
|
next instruction that would have been recorded. In other words, if
|
you record for a while and then stop recording, the inferior process
|
will be left in the same state as if the recording never happened.
|
</p>
|
<p>On the other hand, if the process record and replay target is stopped
|
while in replay mode (that is, not at the end of the execution log,
|
but at some earlier point), the inferior process will become “live”
|
at that earlier state, and it will then be possible to continue the
|
usual “live” debugging of the process from that state.
|
</p>
|
<p>When the inferior process exits, or <small>GDB</small> detaches from it,
|
process record and replay target will automatically stop itself.
|
</p>
|
<a name="index-record-goto"></a>
|
</dd>
|
<dt><code>record goto</code></dt>
|
<dd><p>Go to a specific location in the execution log. There are several
|
ways to specify the location to go to:
|
</p>
|
<dl compact="compact">
|
<dt><code>record goto begin</code></dt>
|
<dt><code>record goto start</code></dt>
|
<dd><p>Go to the beginning of the execution log.
|
</p>
|
</dd>
|
<dt><code>record goto end</code></dt>
|
<dd><p>Go to the end of the execution log.
|
</p>
|
</dd>
|
<dt><code>record goto <var>n</var></code></dt>
|
<dd><p>Go to instruction number <var>n</var> in the execution log.
|
</p></dd>
|
</dl>
|
|
<a name="index-record-save"></a>
|
</dd>
|
<dt><code>record save <var>filename</var></code></dt>
|
<dd><p>Save the execution log to a file <samp><var>filename</var></samp>.
|
Default filename is <samp>gdb_record.<var>process_id</var></samp>, where
|
<var>process_id</var> is the process ID of the inferior.
|
</p>
|
<p>This command may not be available for all recording methods.
|
</p>
|
<a name="index-record-restore"></a>
|
</dd>
|
<dt><code>record restore <var>filename</var></code></dt>
|
<dd><p>Restore the execution log from a file <samp><var>filename</var></samp>.
|
File must have been created with <code>record save</code>.
|
</p>
|
<a name="index-set-record-full"></a>
|
</dd>
|
<dt><code>set record full insn-number-max <var>limit</var></code></dt>
|
<dt><code>set record full insn-number-max unlimited</code></dt>
|
<dd><p>Set the limit of instructions to be recorded for the <code>full</code>
|
recording method. Default value is 200000.
|
</p>
|
<p>If <var>limit</var> is a positive number, then <small>GDB</small> will start
|
deleting instructions from the log once the number of the record
|
instructions becomes greater than <var>limit</var>. For every new recorded
|
instruction, <small>GDB</small> will delete the earliest recorded
|
instruction to keep the number of recorded instructions at the limit.
|
(Since deleting recorded instructions loses information, <small>GDB</small>
|
lets you control what happens when the limit is reached, by means of
|
the <code>stop-at-limit</code> option, described below.)
|
</p>
|
<p>If <var>limit</var> is <code>unlimited</code> or zero, <small>GDB</small> will never
|
delete recorded instructions from the execution log. The number of
|
recorded instructions is limited only by the available memory.
|
</p>
|
<a name="index-show-record-full"></a>
|
</dd>
|
<dt><code>show record full insn-number-max</code></dt>
|
<dd><p>Show the limit of instructions to be recorded with the <code>full</code>
|
recording method.
|
</p>
|
</dd>
|
<dt><code>set record full stop-at-limit</code></dt>
|
<dd><p>Control the behavior of the <code>full</code> recording method when the
|
number of recorded instructions reaches the limit. If ON (the
|
default), <small>GDB</small> will stop when the limit is reached for the
|
first time and ask you whether you want to stop the inferior or
|
continue running it and recording the execution log. If you decide
|
to continue recording, each new recorded instruction will cause the
|
oldest one to be deleted.
|
</p>
|
<p>If this option is OFF, <small>GDB</small> will automatically delete the
|
oldest record to make room for each new one, without asking.
|
</p>
|
</dd>
|
<dt><code>show record full stop-at-limit</code></dt>
|
<dd><p>Show the current setting of <code>stop-at-limit</code>.
|
</p>
|
</dd>
|
<dt><code>set record full memory-query</code></dt>
|
<dd><p>Control the behavior when <small>GDB</small> is unable to record memory
|
changes caused by an instruction for the <code>full</code> recording method.
|
If ON, <small>GDB</small> will query whether to stop the inferior in that
|
case.
|
</p>
|
<p>If this option is OFF (the default), <small>GDB</small> will automatically
|
ignore the effect of such instructions on memory. Later, when
|
<small>GDB</small> replays this execution log, it will mark the log of this
|
instruction as not accessible, and it will not affect the replay
|
results.
|
</p>
|
</dd>
|
<dt><code>show record full memory-query</code></dt>
|
<dd><p>Show the current setting of <code>memory-query</code>.
|
</p>
|
<a name="index-set-record-btrace"></a>
|
<p>The <code>btrace</code> record target does not trace data. As a
|
convenience, when replaying, <small>GDB</small> reads read-only memory off
|
the live program directly, assuming that the addresses of the
|
read-only areas don’t change. This for example makes it possible to
|
disassemble code while replaying, but not to print variables.
|
In some cases, being able to inspect variables might be useful.
|
You can use the following command for that:
|
</p>
|
</dd>
|
<dt><code>set record btrace replay-memory-access</code></dt>
|
<dd><p>Control the behavior of the <code>btrace</code> recording method when
|
accessing memory during replay. If <code>read-only</code> (the default),
|
<small>GDB</small> will only allow accesses to read-only memory.
|
If <code>read-write</code>, <small>GDB</small> will allow accesses to read-only
|
and to read-write memory. Beware that the accessed memory corresponds
|
to the live target and not necessarily to the current replay
|
position.
|
</p>
|
</dd>
|
<dt><code>set record btrace cpu <var>identifier</var></code></dt>
|
<dd><p>Set the processor to be used for enabling workarounds for processor
|
errata when decoding the trace.
|
</p>
|
<p>Processor errata are defects in processor operation, caused by its
|
design or manufacture. They can cause a trace not to match the
|
specification. This, in turn, may cause trace decode to fail.
|
<small>GDB</small> can detect erroneous trace packets and correct them, thus
|
avoiding the decoding failures. These corrections are known as
|
<em>errata workarounds</em>, and are enabled based on the processor on
|
which the trace was recorded.
|
</p>
|
<p>By default, <small>GDB</small> attempts to detect the processor
|
automatically, and apply the necessary workarounds for it. However,
|
you may need to specify the processor if <small>GDB</small> does not yet
|
support it. This command allows you to do that, and also allows to
|
disable the workarounds.
|
</p>
|
<p>The argument <var>identifier</var> identifies the <small>CPU</small> and is of the
|
form: <code><var>vendor</var>:<var>processor identifier</var></code>. In addition,
|
there are two special identifiers, <code>none</code> and <code>auto</code>
|
(default).
|
</p>
|
<p>The following vendor identifiers and corresponding processor
|
identifiers are currently supported:
|
</p>
|
<table>
|
<tr><td width="10%"><code>intel</code></td><td width="90%"><var>family</var>/<var>model</var>[/<var>stepping</var>]</td></tr>
|
</table>
|
|
<p>On GNU/Linux systems, the processor <var>family</var>, <var>model</var>, and
|
<var>stepping</var> can be obtained from <code>/proc/cpuinfo</code>.
|
</p>
|
<p>If <var>identifier</var> is <code>auto</code>, enable errata workarounds for the
|
processor on which the trace was recorded. If <var>identifier</var> is
|
<code>none</code>, errata workarounds are disabled.
|
</p>
|
<p>For example, when using an old <small>GDB</small> on a new system, decode
|
may fail because <small>GDB</small> does not support the new processor. It
|
often suffices to specify an older processor that <small>GDB</small>
|
supports.
|
</p>
|
<div class="smallexample">
|
<pre class="smallexample">(gdb) info record
|
Active record target: record-btrace
|
Recording format: Intel Processor Trace.
|
Buffer size: 16kB.
|
Failed to configure the Intel Processor Trace decoder: unknown cpu.
|
(gdb) set record btrace cpu intel:6/158
|
(gdb) info record
|
Active record target: record-btrace
|
Recording format: Intel Processor Trace.
|
Buffer size: 16kB.
|
Recorded 84872 instructions in 3189 functions (0 gaps) for thread 1 (...).
|
</pre></div>
|
|
<a name="index-show-record-btrace"></a>
|
</dd>
|
<dt><code>show record btrace replay-memory-access</code></dt>
|
<dd><p>Show the current setting of <code>replay-memory-access</code>.
|
</p>
|
</dd>
|
<dt><code>show record btrace cpu</code></dt>
|
<dd><p>Show the processor to be used for enabling trace decode errata
|
workarounds.
|
</p>
|
<a name="index-set-record-btrace-bts"></a>
|
</dd>
|
<dt><code>set record btrace bts buffer-size <var>size</var></code></dt>
|
<dt><code>set record btrace bts buffer-size unlimited</code></dt>
|
<dd><p>Set the requested ring buffer size for branch tracing in <acronym>BTS</acronym>
|
format. Default is 64KB.
|
</p>
|
<p>If <var>size</var> is a positive number, then <small>GDB</small> will try to
|
allocate a buffer of at least <var>size</var> bytes for each new thread
|
that uses the btrace recording method and the <acronym>BTS</acronym> format.
|
The actually obtained buffer size may differ from the requested
|
<var>size</var>. Use the <code>info record</code> command to see the actual
|
buffer size for each thread that uses the btrace recording method and
|
the <acronym>BTS</acronym> format.
|
</p>
|
<p>If <var>limit</var> is <code>unlimited</code> or zero, <small>GDB</small> will try to
|
allocate a buffer of 4MB.
|
</p>
|
<p>Bigger buffers mean longer traces. On the other hand, <small>GDB</small> will
|
also need longer to process the branch trace data before it can be used.
|
</p>
|
</dd>
|
<dt><code>show record btrace bts buffer-size <var>size</var></code></dt>
|
<dd><p>Show the current setting of the requested ring buffer size for branch
|
tracing in <acronym>BTS</acronym> format.
|
</p>
|
<a name="index-set-record-btrace-pt"></a>
|
</dd>
|
<dt><code>set record btrace pt buffer-size <var>size</var></code></dt>
|
<dt><code>set record btrace pt buffer-size unlimited</code></dt>
|
<dd><p>Set the requested ring buffer size for branch tracing in Intel
|
Processor Trace format. Default is 16KB.
|
</p>
|
<p>If <var>size</var> is a positive number, then <small>GDB</small> will try to
|
allocate a buffer of at least <var>size</var> bytes for each new thread
|
that uses the btrace recording method and the Intel Processor Trace
|
format. The actually obtained buffer size may differ from the
|
requested <var>size</var>. Use the <code>info record</code> command to see the
|
actual buffer size for each thread.
|
</p>
|
<p>If <var>limit</var> is <code>unlimited</code> or zero, <small>GDB</small> will try to
|
allocate a buffer of 4MB.
|
</p>
|
<p>Bigger buffers mean longer traces. On the other hand, <small>GDB</small> will
|
also need longer to process the branch trace data before it can be used.
|
</p>
|
</dd>
|
<dt><code>show record btrace pt buffer-size <var>size</var></code></dt>
|
<dd><p>Show the current setting of the requested ring buffer size for branch
|
tracing in Intel Processor Trace format.
|
</p>
|
<a name="index-info-record"></a>
|
</dd>
|
<dt><code>info record</code></dt>
|
<dd><p>Show various statistics about the recording depending on the recording
|
method:
|
</p>
|
<dl compact="compact">
|
<dt><code>full</code></dt>
|
<dd><p>For the <code>full</code> recording method, it shows the state of process
|
record and its in-memory execution log buffer, including:
|
</p>
|
<ul>
|
<li> Whether in record mode or replay mode.
|
</li><li> Lowest recorded instruction number (counting from when the current execution log started recording instructions).
|
</li><li> Highest recorded instruction number.
|
</li><li> Current instruction about to be replayed (if in replay mode).
|
</li><li> Number of instructions contained in the execution log.
|
</li><li> Maximum number of instructions that may be contained in the execution log.
|
</li></ul>
|
|
</dd>
|
<dt><code>btrace</code></dt>
|
<dd><p>For the <code>btrace</code> recording method, it shows:
|
</p>
|
<ul>
|
<li> Recording format.
|
</li><li> Number of instructions that have been recorded.
|
</li><li> Number of blocks of sequential control-flow formed by the recorded
|
instructions.
|
</li><li> Whether in record mode or replay mode.
|
</li></ul>
|
|
<p>For the <code>bts</code> recording format, it also shows:
|
</p><ul>
|
<li> Size of the perf ring buffer.
|
</li></ul>
|
|
<p>For the <code>pt</code> recording format, it also shows:
|
</p><ul>
|
<li> Size of the perf ring buffer.
|
</li></ul>
|
</dd>
|
</dl>
|
|
<a name="index-record-delete"></a>
|
<a name="index-rec-del"></a>
|
</dd>
|
<dt><code>record delete</code></dt>
|
<dd><p>When record target runs in replay mode (“in the past”), delete the
|
subsequent execution log and begin to record a new execution log starting
|
from the current address. This means you will abandon the previously
|
recorded “future” and begin recording a new “future”.
|
</p>
|
<a name="index-record-instruction_002dhistory"></a>
|
<a name="index-rec-instruction_002dhistory"></a>
|
</dd>
|
<dt><code>record instruction-history</code></dt>
|
<dd><p>Disassembles instructions from the recorded execution log. By
|
default, ten instructions are disassembled. This can be changed using
|
the <code>set record instruction-history-size</code> command. Instructions
|
are printed in execution order.
|
</p>
|
<p>It can also print mixed source+disassembly if you specify the the
|
<code>/m</code> or <code>/s</code> modifier, and print the raw instructions in hex
|
as well as in symbolic form by specifying the <code>/r</code> modifier.
|
</p>
|
<p>The current position marker is printed for the instruction at the
|
current program counter value. This instruction can appear multiple
|
times in the trace and the current position marker will be printed
|
every time. To omit the current position marker, specify the
|
<code>/p</code> modifier.
|
</p>
|
<p>To better align the printed instructions when the trace contains
|
instructions from more than one function, the function name may be
|
omitted by specifying the <code>/f</code> modifier.
|
</p>
|
<p>Speculatively executed instructions are prefixed with ‘<samp>?</samp>’. This
|
feature is not available for all recording formats.
|
</p>
|
<p>There are several ways to specify what part of the execution log to
|
disassemble:
|
</p>
|
<dl compact="compact">
|
<dt><code>record instruction-history <var>insn</var></code></dt>
|
<dd><p>Disassembles ten instructions starting from instruction number
|
<var>insn</var>.
|
</p>
|
</dd>
|
<dt><code>record instruction-history <var>insn</var>, +/-<var>n</var></code></dt>
|
<dd><p>Disassembles <var>n</var> instructions around instruction number
|
<var>insn</var>. If <var>n</var> is preceded with <code>+</code>, disassembles
|
<var>n</var> instructions after instruction number <var>insn</var>. If
|
<var>n</var> is preceded with <code>-</code>, disassembles <var>n</var>
|
instructions before instruction number <var>insn</var>.
|
</p>
|
</dd>
|
<dt><code>record instruction-history</code></dt>
|
<dd><p>Disassembles ten more instructions after the last disassembly.
|
</p>
|
</dd>
|
<dt><code>record instruction-history -</code></dt>
|
<dd><p>Disassembles ten more instructions before the last disassembly.
|
</p>
|
</dd>
|
<dt><code>record instruction-history <var>begin</var>, <var>end</var></code></dt>
|
<dd><p>Disassembles instructions beginning with instruction number
|
<var>begin</var> until instruction number <var>end</var>. The instruction
|
number <var>end</var> is included.
|
</p></dd>
|
</dl>
|
|
<p>This command may not be available for all recording methods.
|
</p>
|
<a name="index-set-record"></a>
|
</dd>
|
<dt><code>set record instruction-history-size <var>size</var></code></dt>
|
<dt><code>set record instruction-history-size unlimited</code></dt>
|
<dd><p>Define how many instructions to disassemble in the <code>record
|
instruction-history</code> command. The default value is 10.
|
A <var>size</var> of <code>unlimited</code> means unlimited instructions.
|
</p>
|
<a name="index-show-record"></a>
|
</dd>
|
<dt><code>show record instruction-history-size</code></dt>
|
<dd><p>Show how many instructions to disassemble in the <code>record
|
instruction-history</code> command.
|
</p>
|
<a name="index-record-function_002dcall_002dhistory"></a>
|
<a name="index-rec-function_002dcall_002dhistory"></a>
|
</dd>
|
<dt><code>record function-call-history</code></dt>
|
<dd><p>Prints the execution history at function granularity. It prints one
|
line for each sequence of instructions that belong to the same
|
function giving the name of that function, the source lines
|
for this instruction sequence (if the <code>/l</code> modifier is
|
specified), and the instructions numbers that form the sequence (if
|
the <code>/i</code> modifier is specified). The function names are indented
|
to reflect the call stack depth if the <code>/c</code> modifier is
|
specified. The <code>/l</code>, <code>/i</code>, and <code>/c</code> modifiers can be
|
given together.
|
</p>
|
<div class="smallexample">
|
<pre class="smallexample">(gdb) <b>list 1, 10</b>
|
1 void foo (void)
|
2 {
|
3 }
|
4
|
5 void bar (void)
|
6 {
|
7 ...
|
8 foo ();
|
9 ...
|
10 }
|
(gdb) <b>record function-call-history /ilc</b>
|
1 bar inst 1,4 at foo.c:6,8
|
2 foo inst 5,10 at foo.c:2,3
|
3 bar inst 11,13 at foo.c:9,10
|
</pre></div>
|
|
<p>By default, ten lines are printed. This can be changed using the
|
<code>set record function-call-history-size</code> command. Functions are
|
printed in execution order. There are several ways to specify what
|
to print:
|
</p>
|
<dl compact="compact">
|
<dt><code>record function-call-history <var>func</var></code></dt>
|
<dd><p>Prints ten functions starting from function number <var>func</var>.
|
</p>
|
</dd>
|
<dt><code>record function-call-history <var>func</var>, +/-<var>n</var></code></dt>
|
<dd><p>Prints <var>n</var> functions around function number <var>func</var>. If
|
<var>n</var> is preceded with <code>+</code>, prints <var>n</var> functions after
|
function number <var>func</var>. If <var>n</var> is preceded with <code>-</code>,
|
prints <var>n</var> functions before function number <var>func</var>.
|
</p>
|
</dd>
|
<dt><code>record function-call-history</code></dt>
|
<dd><p>Prints ten more functions after the last ten-line print.
|
</p>
|
</dd>
|
<dt><code>record function-call-history -</code></dt>
|
<dd><p>Prints ten more functions before the last ten-line print.
|
</p>
|
</dd>
|
<dt><code>record function-call-history <var>begin</var>, <var>end</var></code></dt>
|
<dd><p>Prints functions beginning with function number <var>begin</var> until
|
function number <var>end</var>. The function number <var>end</var> is included.
|
</p></dd>
|
</dl>
|
|
<p>This command may not be available for all recording methods.
|
</p>
|
</dd>
|
<dt><code>set record function-call-history-size <var>size</var></code></dt>
|
<dt><code>set record function-call-history-size unlimited</code></dt>
|
<dd><p>Define how many lines to print in the
|
<code>record function-call-history</code> command. The default value is 10.
|
A size of <code>unlimited</code> means unlimited lines.
|
</p>
|
</dd>
|
<dt><code>show record function-call-history-size</code></dt>
|
<dd><p>Show how many lines to print in the
|
<code>record function-call-history</code> command.
|
</p></dd>
|
</dl>
|
|
|
<hr>
|
<div class="header">
|
<p>
|
Next: <a href="Stack.html#Stack" accesskey="n" rel="next">Stack</a>, Previous: <a href="Reverse-Execution.html#Reverse-Execution" accesskey="p" rel="previous">Reverse Execution</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</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>
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