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PODoes this code contain a hidden bug?
 

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  1. PODoes this code contain a hidden bug?
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    <p>The following code :</p> <ul> <li>Runs fine when compiled with gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5/32bits)</li> <li>Runs fine when compiled with MSVC10 (Win7/32bits)</li> <li>Crashes when running with gcc version 4.5.2 (MinGW on Win7/32bits)</li> </ul> <p><strong>main.cpp</strong> :</p> <pre><code># include &lt;iostream&gt; # include &lt;csetjmp&gt; # include &lt;stdexcept&gt; using namespace std ; void do_work(jmp_buf context) { try { throw runtime_error("Ouch !") ; } catch(exception &amp; e) { } longjmp(context, -1) ; //BP1 } int main(int, char *[]) { jmp_buf context ; try { if( setjmp(context) != 0 ) { throw runtime_error("Oops !") ; //BP2 } do_work(context) ; } catch(exception &amp; e) { cout &lt;&lt; "Caught an exception saying : " &lt;&lt; e.what() &lt;&lt; endl ; } } </code></pre> <p>I tried debugging it but the program behaves strangely. Sometimes I could get past the first breakpoint (BP1), then crash at BP2, and sometimes control never reachs BP1, like if the program is stuck in an infinite loop. I cannot say more with my debugging skills. </p> <p>This code is the minimal I could get that exhibits the strange behavior with MinGW 4.5. I also noticed that :</p> <ul> <li>If I replace the <code>do_work</code> function call by its content, the program runs fine.</li> <li>If I remove the <code>try{ ... } catch(...){ }</code> block inside <code>do_work</code>, the program runs fine.</li> <li>Optimization flags have no effect (always crashing).</li> </ul> <p>I'm aware of the <code>setjmp/longjmp</code> issues in C++ code, but I'm forced to use it to interface with some legacy C code.</p> <p>My question :</p> <ul> <li>Is this a faulty/buggy/erroneous code ? Or is MinGW 4.5 mishandling the code ? (It is harsh and presumptuous to blame the tool, but I suspect some settings in it).</li> </ul> <p>Thanks for any advice.</p> <p><sub>Please retag if necessary.</sub></p>
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