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<a name="stacktrace.getting_started"></a><a class="link" href="getting_started.html" title="Getting Started">Getting Started</a>
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<div class="toc"><dl class="toc">
<dt><span class="section"><a href="getting_started.html#stacktrace.getting_started.how_to_print_current_call_stack">How
to print current call stack</a></span></dt>
<dt><span class="section"><a href="getting_started.html#stacktrace.getting_started.handle_terminates_aborts_and_seg">Handle
terminates, aborts and Segmentation Faults</a></span></dt>
<dt><span class="section"><a href="getting_started.html#stacktrace.getting_started.better_asserts">Better asserts</a></span></dt>
<dt><span class="section"><a href="getting_started.html#stacktrace.getting_started.exceptions_with_stacktrace">Exceptions
with stacktrace</a></span></dt>
<dt><span class="section"><a href="getting_started.html#stacktrace.getting_started.enabling_and_disabling_stacktrac">Enabling
and disabling stacktraces</a></span></dt>
<dt><span class="section"><a href="getting_started.html#stacktrace.getting_started.saving_stacktraces_by_specified_">Saving
stacktraces by specified format</a></span></dt>
<dt><span class="section"><a href="getting_started.html#stacktrace.getting_started.getting_function_information_fro">Getting
function information from pointer</a></span></dt>
<dt><span class="section"><a href="getting_started.html#stacktrace.getting_started.global_control_over_stacktrace_o">Global
control over stacktrace output format</a></span></dt>
</dl></div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="stacktrace.getting_started.how_to_print_current_call_stack"></a><a class="link" href="getting_started.html#stacktrace.getting_started.how_to_print_current_call_stack" title="How to print current call stack">How
to print current call stack</a>
</h3></div></div></div>
<p>
<code class="computeroutput"><a class="link" href="reference.html#boost.stacktrace.stacktrace">boost::stacktrace::stacktrace</a></code>
contains methods for working with call-stack/backtraces/stacktraces. Here's
a small example:
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">stacktrace</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="comment">// ... somewhere inside the `bar(int)` function that is called recursively:</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">();</span>
</pre>
<p>
In that example:
</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span></code>
is the namespace that has all the classes and functions to work with
stacktraces
</li>
<li class="listitem">
<code class="computeroutput"><a class="link" href="reference.html#boost.stacktrace.stacktrace">stacktrace()</a></code>
is the default constructor call; constructor stores the current function
call sequence inside the stacktrace class.
</li>
</ul></div>
<p>
Code from above will output something like this:
</p>
<pre class="programlisting"><span class="number">0</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">/</span><span class="identifier">path</span><span class="special">/</span><span class="identifier">to</span><span class="special">/</span><span class="identifier">source</span><span class="special">/</span><span class="identifier">file</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">70</span>
<span class="number">1</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">/</span><span class="identifier">path</span><span class="special">/</span><span class="identifier">to</span><span class="special">/</span><span class="identifier">source</span><span class="special">/</span><span class="identifier">file</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">70</span>
<span class="number">2</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">/</span><span class="identifier">path</span><span class="special">/</span><span class="identifier">to</span><span class="special">/</span><span class="identifier">source</span><span class="special">/</span><span class="identifier">file</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">70</span>
<span class="number">3</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">/</span><span class="identifier">path</span><span class="special">/</span><span class="identifier">to</span><span class="special">/</span><span class="identifier">source</span><span class="special">/</span><span class="identifier">file</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">70</span>
<span class="number">4</span><span class="special">#</span> <span class="identifier">main</span> <span class="identifier">at</span> <span class="special">/</span><span class="identifier">path</span><span class="special">/</span><span class="identifier">to</span><span class="special">/</span><span class="identifier">main</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">93</span>
<span class="number">5</span><span class="special">#</span> <span class="identifier">__libc_start_main</span> <span class="identifier">in</span> <span class="special">/</span><span class="identifier">lib</span><span class="special">/</span><span class="identifier">x86_64</span><span class="special">-</span><span class="identifier">linux</span><span class="special">-</span><span class="identifier">gnu</span><span class="special">/</span><span class="identifier">libc</span><span class="special">.</span><span class="identifier">so</span><span class="special">.</span><span class="number">6</span>
<span class="number">6</span><span class="special">#</span> <span class="identifier">_start</span>
</pre>
<div class="note"><table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../doc/src/images/note.png"></td>
<th align="left">Note</th>
</tr>
<tr><td align="left" valign="top"><p>
By default the Stacktrace library is very conservative in methods to decode
stacktrace. If your output does not look as fancy as in example from above,
see <a class="link" href="configuration_and_build.html" title="Configuration and Build">section "Configuration
and Build"</a> for allowing advanced features of the library.
</p></td></tr>
</table></div>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="stacktrace.getting_started.handle_terminates_aborts_and_seg"></a><a class="link" href="getting_started.html#stacktrace.getting_started.handle_terminates_aborts_and_seg" title="Handle terminates, aborts and Segmentation Faults">Handle
terminates, aborts and Segmentation Faults</a>
</h3></div></div></div>
<p>
Segmentation Faults and <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">terminate</span></code>
calls sometimes happen in programs. Programmers usually wish to get as much
information as possible on such incidents, so having a stacktrace will significantly
improve debugging and fixing.
</p>
<p>
<code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">terminate</span></code> calls <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">abort</span></code>,
so we need to capture stack traces on Segmentation Faults and Abort signals.
</p>
<div class="warning"><table border="0" summary="Warning">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../doc/src/images/warning.png"></td>
<th align="left">Warning</th>
</tr>
<tr><td align="left" valign="top"><p>
Writing a signal handler requires high attention! Only a few system calls
allowed in signal handlers, so there's no cross platform way to print a
stacktrace without a risk of deadlocking. The only way to deal with the
problem - <span class="bold"><strong>dump raw stacktrace into file/socket and
parse it on program restart</strong></span>.
</p></td></tr>
</table></div>
<div class="warning"><table border="0" summary="Warning">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../doc/src/images/warning.png"></td>
<th align="left">Warning</th>
</tr>
<tr><td align="left" valign="top"><p>
Not all the platforms provide means for even getting stacktrace in async
signal safe way. No stack trace will be saved on such platforms.
</p></td></tr>
</table></div>
<p>
Let's write a handler to safely dump stacktrace:
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">signal</span><span class="special">.</span><span class="identifier">h</span><span class="special">></span> <span class="comment">// ::signal, ::raise</span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">stacktrace</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="keyword">void</span> <span class="identifier">my_signal_handler</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">signum</span><span class="special">)</span> <span class="special">{</span>
<span class="special">::</span><span class="identifier">signal</span><span class="special">(</span><span class="identifier">signum</span><span class="special">,</span> <span class="identifier">SIG_DFL</span><span class="special">);</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">safe_dump_to</span><span class="special">(</span><span class="string">"./backtrace.dump"</span><span class="special">);</span>
<span class="special">::</span><span class="identifier">raise</span><span class="special">(</span><span class="identifier">SIGABRT</span><span class="special">);</span>
<span class="special">}</span>
</pre>
<p>
Registering our handler:
</p>
<pre class="programlisting"><span class="special">::</span><span class="identifier">signal</span><span class="special">(</span><span class="identifier">SIGSEGV</span><span class="special">,</span> <span class="special">&</span><span class="identifier">my_signal_handler</span><span class="special">);</span>
<span class="special">::</span><span class="identifier">signal</span><span class="special">(</span><span class="identifier">SIGABRT</span><span class="special">,</span> <span class="special">&</span><span class="identifier">my_signal_handler</span><span class="special">);</span>
</pre>
<p>
At program start we check for a file with stacktrace and if it exist - we're
writing it in human readable format:
</p>
<pre class="programlisting"><span class="keyword">if</span> <span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">filesystem</span><span class="special">::</span><span class="identifier">exists</span><span class="special">(</span><span class="string">"./backtrace.dump"</span><span class="special">))</span> <span class="special">{</span>
<span class="comment">// there is a backtrace</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">ifstream</span> <span class="identifier">ifs</span><span class="special">(</span><span class="string">"./backtrace.dump"</span><span class="special">);</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">stacktrace</span> <span class="identifier">st</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">from_dump</span><span class="special">(</span><span class="identifier">ifs</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Previous run crashed:\n"</span> <span class="special"><<</span> <span class="identifier">st</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
<span class="comment">// cleaning up</span>
<span class="identifier">ifs</span><span class="special">.</span><span class="identifier">close</span><span class="special">();</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">filesystem</span><span class="special">::</span><span class="identifier">remove</span><span class="special">(</span><span class="string">"./backtrace.dump"</span><span class="special">);</span>
<span class="special">}</span>
</pre>
<p>
Now we'll get the following output on <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">terminate</span></code>
call after the program restarts:
</p>
<pre class="programlisting"><span class="identifier">Previous</span> <span class="identifier">run</span> <span class="identifier">crashed</span><span class="special">:</span>
<span class="number">0</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F2EC0A6A8EF</span>
<span class="number">1</span><span class="special">#</span> <span class="identifier">my_signal_handler</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">terminate_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">37</span>
<span class="number">2</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F2EBFD84CB0</span>
<span class="number">3</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F2EBFD84C37</span>
<span class="number">4</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F2EBFD88028</span>
<span class="number">5</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F2EC0395BBD</span>
<span class="number">6</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F2EC0393B96</span>
<span class="number">7</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F2EC0393BE1</span>
<span class="number">8</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">terminate_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">18</span>
<span class="number">9</span><span class="special">#</span> <span class="identifier">foo</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">terminate_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">22</span>
<span class="number">10</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">terminate_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">14</span>
<span class="number">11</span><span class="special">#</span> <span class="identifier">foo</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">terminate_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">22</span>
<span class="number">12</span><span class="special">#</span> <span class="identifier">main</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">terminate_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">84</span>
<span class="number">13</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F2EBFD6FF45</span>
<span class="number">14</span><span class="special">#</span> <span class="number">0x0000000000402209</span>
</pre>
<div class="note"><table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../doc/src/images/note.png"></td>
<th align="left">Note</th>
</tr>
<tr><td align="left" valign="top"><p>
Function names from shared libraries may not be decoded due to address
space layout randomization. Still better than nothing.
</p></td></tr>
</table></div>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="stacktrace.getting_started.better_asserts"></a><a class="link" href="getting_started.html#stacktrace.getting_started.better_asserts" title="Better asserts">Better asserts</a>
</h3></div></div></div>
<p>
Pretty often assertions provide not enough information to locate the problem.
For example you can see the following message on out-of-range access:
</p>
<pre class="programlisting"><span class="special">../../../</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">array</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">:</span><span class="number">123</span><span class="special">:</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">N</span><span class="special">>::</span><span class="keyword">operator</span><span class="special">[](</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">N</span><span class="special">>::</span><span class="identifier">size_type</span><span class="special">)</span> <span class="special">[</span><span class="identifier">with</span> <span class="identifier">T</span> <span class="special">=</span> <span class="keyword">int</span><span class="special">;</span> <span class="keyword">long</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">N</span> <span class="special">=</span> <span class="number">5ul</span><span class="special">]:</span> <span class="identifier">Assertion</span> <span class="char">'(i < N)&&("out of range")'</span> <span class="identifier">failed</span><span class="special">.</span>
<span class="identifier">Aborted</span> <span class="special">(</span><span class="identifier">core</span> <span class="identifier">dumped</span><span class="special">)</span>
</pre>
<p>
That's not enough to locate the problem without debugger. There may be thousand
code lines in real world examples and hundred places where that assertion
could happen. Let's try to improve the assertions, and make them more informative:
</p>
<pre class="programlisting"><span class="comment">// BOOST_ENABLE_ASSERT_DEBUG_HANDLER is defined for the whole project</span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">stdexcept</span><span class="special">></span> <span class="comment">// std::logic_error</span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> <span class="comment">// std::cerr</span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">stacktrace</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span>
<span class="keyword">inline</span> <span class="keyword">void</span> <span class="identifier">assertion_failed_msg</span><span class="special">(</span><span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">expr</span><span class="special">,</span> <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">msg</span><span class="special">,</span> <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="comment">/*file*/</span><span class="special">,</span> <span class="keyword">long</span> <span class="comment">/*line*/</span><span class="special">)</span> <span class="special">{</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cerr</span> <span class="special"><<</span> <span class="string">"Expression '"</span> <span class="special"><<</span> <span class="identifier">expr</span> <span class="special"><<</span> <span class="string">"' is false in function '"</span> <span class="special"><<</span> <span class="identifier">function</span> <span class="special"><<</span> <span class="string">"': "</span> <span class="special"><<</span> <span class="special">(</span><span class="identifier">msg</span> <span class="special">?</span> <span class="identifier">msg</span> <span class="special">:</span> <span class="string">"<...>"</span><span class="special">)</span> <span class="special"><<</span> <span class="string">".\n"</span>
<span class="special"><<</span> <span class="string">"Backtrace:\n"</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">()</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">abort</span><span class="special">();</span>
<span class="special">}</span>
<span class="keyword">inline</span> <span class="keyword">void</span> <span class="identifier">assertion_failed</span><span class="special">(</span><span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">expr</span><span class="special">,</span> <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">file</span><span class="special">,</span> <span class="keyword">long</span> <span class="identifier">line</span><span class="special">)</span> <span class="special">{</span>
<span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">assertion_failed_msg</span><span class="special">(</span><span class="identifier">expr</span><span class="special">,</span> <span class="number">0</span> <span class="comment">/*nullptr*/</span><span class="special">,</span> <span class="identifier">function</span><span class="special">,</span> <span class="identifier">file</span><span class="special">,</span> <span class="identifier">line</span><span class="special">);</span>
<span class="special">}</span>
<span class="special">}</span> <span class="comment">// namespace boost</span>
</pre>
<p>
We've defined the <code class="computeroutput"><span class="identifier">BOOST_ENABLE_ASSERT_DEBUG_HANDLER</span></code>
macro for the whole project. Now all the <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span></code>
and <code class="computeroutput"><span class="identifier">BOOST_ASSERT_MSG</span></code> will
call our functions <code class="computeroutput"><span class="identifier">assertion_failed</span></code>
and <code class="computeroutput"><span class="identifier">assertion_failed_msg</span></code>
in case of failure. In <code class="computeroutput"><span class="identifier">assertion_failed_msg</span></code>
we output information that was provided by the assertion macro and <code class="computeroutput"><a class="link" href="reference.html#boost.stacktrace.stacktrace">boost::stacktrace::stacktrace</a></code>:
</p>
<pre class="programlisting"><span class="identifier">Expression</span> <span class="char">'i < N'</span> <span class="identifier">is</span> <span class="keyword">false</span> <span class="identifier">in</span> <span class="identifier">function</span> <span class="char">'T& boost::array<T, N>::operator[](boost::array<T, N>::size_type) [with T = int; long unsigned int N = 5ul; boost::array<T, N>::reference = int&; boost::array<T, N>::size_type = long unsigned int]'</span><span class="special">:</span> <span class="identifier">out</span> <span class="identifier">of</span> <span class="identifier">range</span><span class="special">.</span>
<span class="identifier">Backtrace</span><span class="special">:</span>
<span class="number">0</span><span class="special">#</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">assertion_failed_msg</span><span class="special">(</span><span class="keyword">char</span> <span class="keyword">const</span><span class="special">*,</span> <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*,</span> <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*,</span> <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*,</span> <span class="keyword">long</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">assert_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">39</span>
<span class="number">1</span><span class="special">#</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="number">5ul</span><span class="special">>::</span><span class="keyword">operator</span><span class="special">[](</span><span class="keyword">unsigned</span> <span class="keyword">long</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../../../</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">array</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">:</span><span class="number">124</span>
<span class="number">2</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">assert_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">17</span>
<span class="number">3</span><span class="special">#</span> <span class="identifier">foo</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">assert_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">25</span>
<span class="number">4</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">assert_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">17</span>
<span class="number">5</span><span class="special">#</span> <span class="identifier">foo</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">assert_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">25</span>
<span class="number">6</span><span class="special">#</span> <span class="identifier">main</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">assert_handler</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">54</span>
<span class="number">7</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007F991FD69F45</span> <span class="identifier">in</span> <span class="special">/</span><span class="identifier">lib</span><span class="special">/</span><span class="identifier">x86_64</span><span class="special">-</span><span class="identifier">linux</span><span class="special">-</span><span class="identifier">gnu</span><span class="special">/</span><span class="identifier">libc</span><span class="special">.</span><span class="identifier">so</span><span class="special">.</span><span class="number">6</span>
<span class="number">8</span><span class="special">#</span> <span class="number">0x0000000000401139</span>
</pre>
<p>
Now we do know the steps that led to the assertion and can find the error
without debugger.
</p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="stacktrace.getting_started.exceptions_with_stacktrace"></a><a class="link" href="getting_started.html#stacktrace.getting_started.exceptions_with_stacktrace" title="Exceptions with stacktrace">Exceptions
with stacktrace</a>
</h3></div></div></div>
<p>
You can provide more information along with exception by embedding stacktraces
into the exception. There are many ways to do that, here's how to doe that
using Boost.Exception:
</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
Declare a <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">error_info</span></code> typedef that holds the stacktrace:
</li></ul></div>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">stacktrace</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">exception</span><span class="special">/</span><span class="identifier">all</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">error_info</span><span class="special"><</span><span class="keyword">struct</span> <span class="identifier">tag_stacktrace</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">></span> <span class="identifier">traced</span><span class="special">;</span>
</pre>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
Write a helper class for throwing any exception with stacktrace:
</li></ul></div>
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">E</span><span class="special">></span>
<span class="keyword">void</span> <span class="identifier">throw_with_trace</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">E</span><span class="special">&</span> <span class="identifier">e</span><span class="special">)</span> <span class="special">{</span>
<span class="keyword">throw</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">enable_error_info</span><span class="special">(</span><span class="identifier">e</span><span class="special">)</span>
<span class="special"><<</span> <span class="identifier">traced</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">());</span>
<span class="special">}</span>
</pre>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
Use <code class="computeroutput"><span class="identifier">throw_with_trace</span><span class="special">(</span><span class="identifier">E</span><span class="special">);</span></code> instead of just <code class="computeroutput"><span class="keyword">throw</span>
<span class="identifier">E</span><span class="special">;</span></code>:
</li></ul></div>
<pre class="programlisting"><span class="keyword">if</span> <span class="special">(</span><span class="identifier">i</span> <span class="special">>=</span> <span class="number">4</span><span class="special">)</span>
<span class="identifier">throw_with_trace</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">out_of_range</span><span class="special">(</span><span class="string">"'i' must be less than 4 in oops()"</span><span class="special">));</span>
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">i</span> <span class="special"><=</span> <span class="number">0</span><span class="special">)</span>
<span class="identifier">throw_with_trace</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span><span class="special">(</span><span class="string">"'i' must not be greater than zero in oops()"</span><span class="special">));</span>
</pre>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
Process exceptions:
</li></ul></div>
<pre class="programlisting"><span class="keyword">try</span> <span class="special">{</span>
<span class="identifier">foo</span><span class="special">(</span><span class="number">5</span><span class="special">);</span> <span class="comment">// testing assert handler</span>
<span class="special">}</span> <span class="keyword">catch</span> <span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">exception</span><span class="special">&</span> <span class="identifier">e</span><span class="special">)</span> <span class="special">{</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cerr</span> <span class="special"><<</span> <span class="identifier">e</span><span class="special">.</span><span class="identifier">what</span><span class="special">()</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">;</span>
<span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">*</span> <span class="identifier">st</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">get_error_info</span><span class="special"><</span><span class="identifier">traced</span><span class="special">>(</span><span class="identifier">e</span><span class="special">);</span>
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">st</span><span class="special">)</span> <span class="special">{</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cerr</span> <span class="special"><<</span> <span class="special">*</span><span class="identifier">st</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">;</span>
<span class="special">}</span>
<span class="special">}</span>
</pre>
<p>
Code from above will output:
</p>
<pre class="programlisting"><span class="char">'i'</span> <span class="identifier">must</span> <span class="keyword">not</span> <span class="identifier">be</span> <span class="identifier">greater</span> <span class="identifier">than</span> <span class="identifier">zero</span> <span class="identifier">in</span> <span class="identifier">oops</span><span class="special">()</span>
<span class="number">0</span><span class="special">#</span> <span class="keyword">void</span> <span class="identifier">throw_with_trace</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span><span class="special">>(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span> <span class="keyword">const</span><span class="special">&)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">throwing_st</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">22</span>
<span class="number">1</span><span class="special">#</span> <span class="identifier">oops</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">throwing_st</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">38</span>
<span class="number">2</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">throwing_st</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">54</span>
<span class="number">3</span><span class="special">#</span> <span class="identifier">foo</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">throwing_st</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">59</span>
<span class="number">4</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">throwing_st</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">49</span>
<span class="number">5</span><span class="special">#</span> <span class="identifier">foo</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">throwing_st</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">59</span>
<span class="number">6</span><span class="special">#</span> <span class="identifier">main</span> <span class="identifier">at</span> <span class="special">../</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">throwing_st</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">76</span>
<span class="number">7</span><span class="special">#</span> <span class="number">0</span><span class="identifier">x00007FAC113BEF45</span> <span class="identifier">in</span> <span class="special">/</span><span class="identifier">lib</span><span class="special">/</span><span class="identifier">x86_64</span><span class="special">-</span><span class="identifier">linux</span><span class="special">-</span><span class="identifier">gnu</span><span class="special">/</span><span class="identifier">libc</span><span class="special">.</span><span class="identifier">so</span><span class="special">.</span><span class="number">6</span>
<span class="number">8</span><span class="special">#</span> <span class="number">0x0000000000402ED9</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="stacktrace.getting_started.enabling_and_disabling_stacktrac"></a><a class="link" href="getting_started.html#stacktrace.getting_started.enabling_and_disabling_stacktrac" title="Enabling and disabling stacktraces">Enabling
and disabling stacktraces</a>
</h3></div></div></div>
<p>
At some point arises a requirement to easily enable/disable stacktraces for
a whole project. That could be easily achieved.
</p>
<p>
Just define <span class="bold"><strong>BOOST_STACKTRACE_LINK</strong></span> for a
whole project. Now you can enable/disable stacktraces by just linking with
different libraries:
</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
link with <code class="computeroutput"><span class="identifier">boost_stacktrace_noop</span></code>
to disable backtracing
</li>
<li class="listitem">
link with other <code class="computeroutput"><span class="identifier">boost_stacktrace_</span><span class="special">*</span></code> libraries
</li>
</ul></div>
<p>
See <a class="link" href="configuration_and_build.html" title="Configuration and Build">section "Configuration
and Build"</a> for more info.
</p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="stacktrace.getting_started.saving_stacktraces_by_specified_"></a><a class="link" href="getting_started.html#stacktrace.getting_started.saving_stacktraces_by_specified_" title="Saving stacktraces by specified format">Saving
stacktraces by specified format</a>
</h3></div></div></div>
<p>
<code class="computeroutput"><a class="link" href="reference.html#boost.stacktrace.stacktrace">boost::stacktrace::stacktrace</a></code>
provides access to individual <code class="computeroutput"><a class="link" href="../boost/stacktrace/frame.html" title="Class frame">frames</a></code>
of the stacktrace, so that you could save stacktrace information in your
own format. Consider the example, that saves only function addresses of each
frame:
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">stacktrace</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> <span class="comment">// std::cout</span>
<span class="keyword">namespace</span> <span class="identifier">bs</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">;</span>
<span class="keyword">void</span> <span class="identifier">dump_compact</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">bs</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">&</span> <span class="identifier">st</span><span class="special">)</span> <span class="special">{</span>
<span class="keyword">for</span> <span class="special">(</span><span class="identifier">bs</span><span class="special">::</span><span class="identifier">frame</span> <span class="identifier">frame</span><span class="special">:</span> <span class="identifier">st</span><span class="special">)</span> <span class="special">{</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">frame</span><span class="special">.</span><span class="identifier">address</span><span class="special">()</span> <span class="special"><<</span> <span class="char">','</span><span class="special">;</span>
<span class="special">}</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
Code from above will output:
</p>
<pre class="programlisting"><span class="number">0</span><span class="identifier">x7fbcfd17f6b5</span><span class="special">,</span><span class="number">0x400d4a</span><span class="special">,</span><span class="number">0x400d61</span><span class="special">,</span><span class="number">0x400d61</span><span class="special">,</span><span class="number">0x400d61</span><span class="special">,</span><span class="number">0x400d61</span><span class="special">,</span><span class="number">0x400d77</span><span class="special">,</span><span class="number">0x400cbf</span><span class="special">,</span><span class="number">0x400dc0</span><span class="special">,</span><span class="number">0</span><span class="identifier">x7fbcfc82d830</span><span class="special">,</span><span class="number">0x400a79</span><span class="special">,</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="stacktrace.getting_started.getting_function_information_fro"></a><a class="link" href="getting_started.html#stacktrace.getting_started.getting_function_information_fro" title="Getting function information from pointer">Getting
function information from pointer</a>
</h3></div></div></div>
<p>
<code class="computeroutput"><a class="link" href="../boost/stacktrace/frame.html" title="Class frame">boost::stacktrace::frame</a></code>
provides information about functions. You may construct that class from function
pointer and get the function name at runtime:
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">signal</span><span class="special">.</span><span class="identifier">h</span><span class="special">></span> <span class="comment">// ::signal</span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">stacktrace</span><span class="special">/</span><span class="identifier">frame</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> <span class="comment">// std::cerr</span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cstdlib</span><span class="special">></span> <span class="comment">// std::exit</span>
<span class="keyword">void</span> <span class="identifier">print_signal_handler_and_exit</span><span class="special">()</span> <span class="special">{</span>
<span class="keyword">typedef</span> <span class="keyword">void</span><span class="special">(*</span><span class="identifier">function_t</span><span class="special">)(</span><span class="keyword">int</span><span class="special">);</span>
<span class="identifier">function_t</span> <span class="identifier">old_signal_function</span> <span class="special">=</span> <span class="special">::</span><span class="identifier">signal</span><span class="special">(</span><span class="identifier">SIGSEGV</span><span class="special">,</span> <span class="identifier">SIG_DFL</span><span class="special">);</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">stacktrace</span><span class="special">::</span><span class="identifier">frame</span> <span class="identifier">f</span><span class="special">(</span><span class="identifier">old_signal_function</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">f</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">exit</span><span class="special">(</span><span class="number">0</span><span class="special">);</span>
<span class="special">}</span>
</pre>
<p>
Code from above will output:
</p>
<pre class="programlisting"><span class="identifier">my_signal_handler</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="identifier">at</span> <span class="identifier">boost</span><span class="special">/</span><span class="identifier">libs</span><span class="special">/</span><span class="identifier">stacktrace</span><span class="special">/</span><span class="identifier">example</span><span class="special">/</span><span class="identifier">debug_function</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">21</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="stacktrace.getting_started.global_control_over_stacktrace_o"></a><a class="link" href="getting_started.html#stacktrace.getting_started.global_control_over_stacktrace_o" title="Global control over stacktrace output format">Global
control over stacktrace output format</a>
</h3></div></div></div>
<p>
You may override the behavior of default stacktrace output operator by defining
the macro from Boost.Config <code class="computeroutput">BOOST_USER_CONFIG</code>
to point to a file like following:
</p>
<pre class="programlisting"><span class="preprocessor">#ifndef</span> <span class="identifier">USER_CONFIG_HPP</span>
<span class="preprocessor">#define</span> <span class="identifier">USER_CONFIG_HPP</span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">stacktrace</span><span class="special">/</span><span class="identifier">stacktrace_fwd</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iosfwd</span><span class="special">></span>
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">stacktrace</span> <span class="special">{</span>
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">TraitsT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">TraitsT</span><span class="special">>&</span> <span class="identifier">do_stream_st</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">TraitsT</span><span class="special">>&</span> <span class="identifier">os</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">basic_stacktrace</span><span class="special"><</span><span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">bt</span><span class="special">);</span>
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">TraitsT</span><span class="special">></span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">TraitsT</span><span class="special">>&</span> <span class="keyword">operator</span><span class="special"><<(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">TraitsT</span><span class="special">>&</span> <span class="identifier">os</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">stacktrace</span><span class="special">&</span> <span class="identifier">bt</span><span class="special">)</span> <span class="special">{</span>
<span class="keyword">return</span> <span class="identifier">do_stream_st</span><span class="special">(</span><span class="identifier">os</span><span class="special">,</span> <span class="identifier">bt</span><span class="special">);</span>
<span class="special">}</span>
<span class="special">}}</span> <span class="comment">// namespace boost::stacktrace</span>
<span class="preprocessor">#endif</span> <span class="comment">// USER_CONFIG_HPP</span>
</pre>
<p>
Implementation of <code class="computeroutput"><span class="identifier">do_stream_st</span></code>
may be the following:
</p>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">stacktrace</span> <span class="special">{</span>
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">TraitsT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">></span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">TraitsT</span><span class="special">>&</span> <span class="identifier">do_stream_st</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">TraitsT</span><span class="special">>&</span> <span class="identifier">os</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">basic_stacktrace</span><span class="special"><</span><span class="identifier">Allocator</span><span class="special">>&</span> <span class="identifier">bt</span><span class="special">)</span> <span class="special">{</span>
<span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">streamsize</span> <span class="identifier">w</span> <span class="special">=</span> <span class="identifier">os</span><span class="special">.</span><span class="identifier">width</span><span class="special">();</span>
<span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">frames</span> <span class="special">=</span> <span class="identifier">bt</span><span class="special">.</span><span class="identifier">size</span><span class="special">();</span>
<span class="keyword">for</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">i</span> <span class="special"><</span> <span class="identifier">frames</span><span class="special">;</span> <span class="special">++</span><span class="identifier">i</span><span class="special">)</span> <span class="special">{</span>
<span class="identifier">os</span><span class="special">.</span><span class="identifier">width</span><span class="special">(</span><span class="number">2</span><span class="special">);</span>
<span class="identifier">os</span> <span class="special"><<</span> <span class="identifier">i</span><span class="special">;</span>
<span class="identifier">os</span><span class="special">.</span><span class="identifier">width</span><span class="special">(</span><span class="identifier">w</span><span class="special">);</span>
<span class="identifier">os</span> <span class="special"><<</span> <span class="string">"# "</span><span class="special">;</span>
<span class="identifier">os</span> <span class="special"><<</span> <span class="identifier">bt</span><span class="special">[</span><span class="identifier">i</span><span class="special">].</span><span class="identifier">name</span><span class="special">();</span>
<span class="identifier">os</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">;</span>
<span class="special">}</span>
<span class="keyword">return</span> <span class="identifier">os</span><span class="special">;</span>
<span class="special">}</span>
<span class="special">}}</span> <span class="comment">// namespace boost::stacktrace</span>
</pre>
<p>
Code from above will output:
</p>
<pre class="programlisting"><span class="identifier">Terminate</span> <span class="identifier">called</span><span class="special">:</span>
<span class="number">0</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span>
<span class="number">1</span><span class="special">#</span> <span class="identifier">foo</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span>
<span class="number">2</span><span class="special">#</span> <span class="identifier">bar</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span>
<span class="number">3</span><span class="special">#</span> <span class="identifier">foo</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span>
</pre>
</div>
</div>
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<td align="right"><div class="copyright-footer">Copyright © 2016, 2017 Antony Polukhin<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
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