<html>
<head>
<base href="http://llvm.org/bugs/" />
</head>
<body><span class="vcard"><a class="email" href="mailto:chengniansun@gmail.com" title="Chengnian Sun <chengniansun@gmail.com>"> <span class="fn">Chengnian Sun</span></a>
</span> changed
<a class="bz_bug_link
bz_status_REOPENED "
title="REOPENED --- - No -Wtautological-constant-out-of-range-compare warning"
href="http://llvm.org/bugs/show_bug.cgi?id=18691">bug 18691</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Status</td>
<td>RESOLVED
</td>
<td>REOPENED
</td>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>INVALID
</td>
<td>---
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_REOPENED "
title="REOPENED --- - No -Wtautological-constant-out-of-range-compare warning"
href="http://llvm.org/bugs/show_bug.cgi?id=18691#c2">Comment # 2</a>
on <a class="bz_bug_link
bz_status_REOPENED "
title="REOPENED --- - No -Wtautological-constant-out-of-range-compare warning"
href="http://llvm.org/bugs/show_bug.cgi?id=18691">bug 18691</a>
from <span class="vcard"><a class="email" href="mailto:chengniansun@gmail.com" title="Chengnian Sun <chengniansun@gmail.com>"> <span class="fn">Chengnian Sun</span></a>
</span></b>
<pre>I found another test case. I am not sure whether I should open another report,
so just reopen this one.
Wtautological-constant-out-of-range-compare does not warn on the following
case, which has a type conversion from bool to short type. If I remove the type
cast, Clang warns.
/////////////////////////////////////////////////////////
// test case on which clang does not warn
/////////////////////////////////////////////////////////
$: cat t.c
int f(int a) {
return 999 != (short)(a == 1);
}
$:
$: clang-trunk -Weverything -c t.c
t.c:1:5: warning: no previous prototype for function 'f' [-Wmissing-prototypes]
int f(int a) {
^
1 warning generated.
$:
$: gcc-trunk -c t.c -Wall
t.c: In function ‘f’:
t.c:2:14: warning: comparison of constant ‘999’ with boolean expression is
always true [-Wbool-compare]
return 999 != (short)(a == 1);
^
$:
/////////////////////////////////////////////////////////
// clang warns on the following case
/////////////////////////////////////////////////////////
$: cat t.c
int f(int a) {
return 999 != (a == 1);
}
$:
$: clang-trunk -Weverything -c t.c
t.c:1:5: warning: no previous prototype for function 'f' [-Wmissing-prototypes]
int f(int a) {
^
t.c:2:14: warning: comparison of constant 999 with boolean expression is always
true [-Wtautological-constant-out-of-range-compare]
return 999 != (a == 1);
~~~ ^ ~~~~~~~~
2 warnings generated.
$:
$: gcc-trunk -c t.c -Wall
t.c: In function ‘f’:
t.c:2:14: warning: comparison of constant ‘999’ with boolean expression is
always true [-Wbool-compare]
return 999 != (a == 1);
^
$:</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>