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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Missing -Wparentheses warning for assignment withing assert()"
href="https://bugs.llvm.org/show_bug.cgi?id=47364">47364</a>
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<th>Summary</th>
<td>Missing -Wparentheses warning for assignment withing assert()
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<th>Product</th>
<td>clang
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<th>Version</th>
<td>10.0
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>enhancement
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>C
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>mpg@elzevir.fr
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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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<pre>Hi,
Consider the following example:
#include <assert.h>
extern int foo(void);
int main(void) {
int ret = foo();
assert(ret = 0); // oops
}
Compiled with `clang -Weverything -Werror -std=c99 -pedantic -c` (Clang
version: 10.0.0-4ubuntu1) it doesn't produce any warning.
The line marked "oops" is an actual typo I made in a project, and I would have
been grateful if Clang had given me a warning for it.
In fact, considering Clang warns about `if(ret = 0)` I was expecting to get a
warning for the same thing in the context of `assert()` too. I understand from
reading other bugs that `assert()` gets special treatment from `-Wparentheses`
to avoid warning on common idioms such as `assert(x && "failure message");`,
but I hope there's a way to still accept those idioms while warning about
relatively-obvious typos such as the above.
Fwiw, GCC gives the kind of warning I would expect here:
foo.c:7:12: warning: suggest parentheses around assignment used as truth value
[-Wparentheses]
Please consider making Clang produce a similar warning in this instance.
Thanks,
Manuel.</pre>
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