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4 If you are having difficulty with uncaught exceptions and want a
5 little bit of help debugging the causes of the core dumps, you can
6 make use of a GNU extension, the verbose terminate handler.
7 </p><pre class="programlisting">
8 #include <exception>
12 std::set_terminate(__gnu_cxx::__verbose_terminate_handler);
15 throw <em class="replaceable"><code>anything</code></em>;
18 The <code class="function">__verbose_terminate_handler</code> function
19 obtains the name of the current exception, attempts to demangle
20 it, and prints it to stderr. If the exception is derived from
21 <code class="classname">exception</code> then the output from
22 <code class="function">what()</code> will be included.
24 Any replacement termination function is required to kill the
25 program without returning; this one calls abort.
28 </p><pre class="programlisting">
29 #include <exception>
30 #include <stdexcept>
32 struct argument_error : public std::runtime_error
34 argument_error(const std::string& s): std::runtime_error(s) { }
39 std::set_terminate(__gnu_cxx::__verbose_terminate_handler);
41 throw argument_error(“<span class="quote">argc is greater than 5!</span>”);
46 With the verbose terminate handler active, this gives:
47 </p><pre class="screen">
48 <code class="computeroutput">
50 terminate called after throwing a `int'
52 % ./a.out f f f f f f f f f f f
53 terminate called after throwing an instance of `argument_error'
54 what(): argc is greater than 5!
58 The 'Aborted' line comes from the call to
59 <code class="function">abort()</code>, of course.
61 This is the default termination handler; nothing need be done to
62 use it. To go back to the previous “<span class="quote">silent death</span>”
63 method, simply include <code class="filename">exception</code> and
64 <code class="filename">cstdlib</code>, and call
65 </p><pre class="programlisting">
66 std::set_terminate(std::abort);
68 After this, all calls to <code class="function">terminate</code> will use
69 <code class="function">abort</code> as the terminate handler.
71 Note: the verbose terminate handler will attempt to write to
72 stderr. If your application closes stderr or redirects it to an
73 inappropriate location,
74 <code class="function">__verbose_terminate_handler</code> will behave in
75 an unspecified manner.
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