<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Improve -Wparentheses for arbitrary bool contexts"
href="https://bugs.llvm.org/show_bug.cgi?id=34180">34180</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Improve -Wparentheses for arbitrary bool contexts
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Frontend
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>chisophugis@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre><a href="https://godbolt.org/g/Ca2Xtv">https://godbolt.org/g/Ca2Xtv</a>
bool f(int x) {
return x = 0;
}
GCC gives:
<source>:2:16: warning: suggest parentheses around assignment used as truth
value [-Wparentheses]
return x = 0;
^
This would have caught a bug in r310794 (<a href="https://reviews.llvm.org/rL310794">https://reviews.llvm.org/rL310794</a>)
I don't know for sure, but from the reduced test case, it seems that GCC is
just seeing when an assignment is used in a bool-typed context? E.g. just
`bool(x = 0)` seems to trigger it. <a href="https://godbolt.org/g/HyBZHM">https://godbolt.org/g/HyBZHM</a>
Looking at the two examples, it looks like ImplicitCastExpr to bool is probably
the thing to look for.
ImplicitCastExpr 0x4fce318 <col:12, col:16> '_Bool' <IntegralToBoolean>
ImplicitCastExpr 0x4fce578 <col:17, col:21> '_Bool' <IntegralToBoolean></pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>