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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Windows x64 SEH __except filter continuing to __finally gets UD2"
href="https://llvm.org/bugs/show_bug.cgi?id=30747">30747</a>
</td>
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<th>Summary</th>
<td>Windows x64 SEH __except filter continuing to __finally gets UD2
</td>
</tr>
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<th>Product</th>
<td>new-bugs
</td>
</tr>
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<th>Version</th>
<td>3.8
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>new bugs
</td>
</tr>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>nb@ravenbrook.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=17465" name="attach_17465" title="C source with detailed disassembly in comment">attachment 17465</a> <a href="attachment.cgi?id=17465&action=edit" title="C source with detailed disassembly in comment">[details]</a></span>
C source with detailed disassembly in comment
Clang 3.8.0 on Windows 7, when compiling a __try { ... } __except (...) { ...}
inside a __try { ... } __finally { ... }, the __finally { ... } clause
generates a cleanup function which is garbled and includes a UD2. I believe
that the semantics of this are well-defined, and I get sensible behaviour with
Visual Studio compilers. Here's my code snippet, and attached is a detailed
disassembly in which I've picked apart the UNWIND_INFO and ScopeRecords and so
forth.
int f(void)
{
int x = 3;
__try {
__try {
g(3, &x);
} __except((x == 42) ? EXCEPTION_EXECUTE_HANDLER :
EXCEPTION_CONTINUE_SEARCH) {
x = 7;
}
} __finally {
++x;
}
return x;
}</pre>
</div>
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