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<p class="MsoNormal"><span style="font-size:11.0pt">My proposal would change the examples following way:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">1. The simplest example seamlessly matching current model:</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">try { try { // enter the top and the nested regions at once</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">} } // leave both region at once<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">catch { // nested region handler (implicitly outside of any regions)
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> try { // enter the top region</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // here is the nested handler code<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> } // leave the top region</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">}</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">catch { // top region handler (implicitly outside of any regions)</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">// here is the top handler code</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">}</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">2. Example with split (the same as above, just with added gap in the middle)</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">try { try { // enter the top and the nested regions at once</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">} } // leave both region at once<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">... gap in the regions (may be a single instruction excluded from the exception regions)</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">try { try { // enter the top and the nested regions at once</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">} } // leave both region at once<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">catch { // nested region handler (implicitly outside of any regions)
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> try { // enter the top region</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // here is the nested handler code<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> } // leave the top region</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">}</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">catch { // top region handler (implicitly outside of any regions)</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">// here is the top handler code</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">}</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="color:black">From:
</span></b><span style="color:black">babylon-dev <babylon-dev-retn@openjdk.org> on behalf of Adam Sotona <adam.sotona@oracle.com><br>
<b>Date: </b>Wednesday, 9 October 2024 at 17:00<br>
<b>To: </b>Maurizio Cimadamore <maurizio.cimadamore@oracle.com>, babylon-dev@openjdk.org <babylon-dev@openjdk.org><br>
<b>Subject: </b>Re: ExceptionRegion modeling issues and proposed improvements<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">I would rather describe actual situation on examples:</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">1. The simplest example seamlessly matching current model:</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">try { // enter the top region</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> try { // enter the nested region</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> } // leave the nested region</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> catch { // handler implicitly a part of the top region
</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // here is the nested handler code</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> }</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">} // leave the top region</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">catch { // handler outside of any regions</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">// here is the top handler code</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">}</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">2. Example with split (the same as above, just with added gap in the middle)</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">try { // enter the top region part 1</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> try { // enter the nested region part 1</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> } catch { // handler implicitly a part of the top region part 1</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // we need to leave the top region part 1</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // and we cannot jump to the handler in the other top region part</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // so we jump to a synthetic isolated nested region exception handler</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> }</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">} // split - leave the top region part 1</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">catch { // handler outside of any regions</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // jump to common top region handler</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">}</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">... gap in the regions (may be a single instruction excluded from the exception regions)</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">try { // enter the top region part 2</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> try { // enter the nested region part 2</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> } // leave the nested region part 2</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> catch { // handler implicitly a part of the top region part 2</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // we need to leave the top region part 2</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // and jump to a synthetic isolated nested region exception handler</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> }</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">} // leave the top region part 2</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">catch { // handler outside of any regions</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // jump to common top region handler</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">}</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">// synthetic nested region handler</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">try { // enter the top region part 3
</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> // here is the nested handler code
</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas"> } // leave the top region part 3</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">catch { // common top region handler outside of any regions</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">// here is the common top handler code</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Consolas">}</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">3. And now add third level, jumps between the region fragments and jumps out of the regions (for example break or continue)... ;)</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="color:black">From:
</span></b><span style="color:black">Maurizio Cimadamore <maurizio.cimadamore@oracle.com><br>
<b>Date: </b>Wednesday, 9 October 2024 at 15:55<br>
<b>To: </b>Adam Sotona <adam.sotona@oracle.com>, babylon-dev@openjdk.org <babylon-dev@openjdk.org><br>
<b>Subject: </b>Re: ExceptionRegion modeling issues and proposed improvements</span><o:p></o:p></p>
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<p> <o:p></o:p></p>
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<p class="MsoNormal">On 09/10/2024 14:16, Adam Sotona wrote:<o:p></o:p></p>
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<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p>If we wanted to exit the region from block 27, then we'd also need to split, as we might need to exit either %1 or %5 from there, no?<o:p></o:p></p>
<p><span style="font-size:11.0pt">block 27 is the exception handler of the </span>
outer try region(s), so no need to exit it (them)<o:p></o:p></p>
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<p>Maybe this is the bit I'm missing: don't we need to exit exception regions explicitly, even inside catch handlers?<o:p></o:p></p>
<p>Maurizio<o:p></o:p></p>
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