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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Warning inconsistently reported on dead code"
href="https://bugs.llvm.org/show_bug.cgi?id=39938">39938</a>
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<th>Summary</th>
<td>Warning inconsistently reported on dead code
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>7.0
</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>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>C++
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>serge.guelton@telecom-bretagne.eu
</td>
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<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<p>
<div>
<pre>When compiled with -Wall, the following code reports a warning only on the live
path, as showcased in <a href="https://godbolt.org/z/3PD-eF">https://godbolt.org/z/3PD-eF</a>
int case0(int num) {
if(0)
return num / 0; << no warning
else
return 1;
}
int case1(int num) {
if(num)
return num / 0; << warning
else
return 1;
}
Yet, when the following code is compiled with -Wall -Wdouble-conversion, we
have a warning even in the dead path, as showcased in
<a href="https://godbolt.org/z/58Q5oA">https://godbolt.org/z/58Q5oA</a>
double foo(double);
int case0(float num) {
if(0)
return foo(num); << warning
else
return 1;
}
int case1(float num) {
if(num)
return foo(num); << warning
else
return 1;
}</pre>
</div>
</p>
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