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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - break in statement expression results in -Wunreachable-code"
href="https://bugs.llvm.org/show_bug.cgi?id=36075">36075</a>
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<th>Summary</th>
<td>break in statement expression results in -Wunreachable-code
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>5.0
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Frontend
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
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<th>Reporter</th>
<td>wielkiegie@gmail.com
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<p>
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<pre>The following code results in -Wunreachable-code on clang 5.0 and trunk:
--------------------------------
int main()
{
while (true)
{
({ break; });
}
}
--------------------------------
prog.cc:5:9: warning: code will never be executed [-Wunreachable-code]
({ break; });
^~~~~~~~~~~~
--------------------------------
It seems the trigger is an unconditional "break" statement as the last one of
the expression statement.
The warning goes away after putting the expression statement inside a macro
which might be related to a fix for <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [linux kernel] -Wunused-value should not warn about unused statement expression result expanded from a macro"
href="show_bug.cgi?id=13747">bug 13747</a>, but the warning shouldn't be
generated regardless.</pre>
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