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From: "jirislaby at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/65120] New: [gcc5] Wlogical-not-parentheses should not wanr about double exclamation !!
Date: Thu, 19 Feb 2015 13:39:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65120

            Bug ID: 65120
           Summary: [gcc5] Wlogical-not-parentheses should not wanr about
                    double exclamation !!
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jirislaby at gmail dot com

While warning about
  "if (!a == b)"
is perfectly fine and I like it, I do not like warning about
  "if (!!a = b)"
at all. It generates plenty of false positives (in the Linux kernel at least)
and I doubt it can warn about an error at all.

Better than papering over this as
  "if ((!aa) = b)"
or by -Wno-logical-not-parentheses does not make much sense to me (opposing to
the single ! case).

Note: this is all about:
"logical not is only applied to the left hand side of comparison"