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* [Bug c++/94505] New: Logical operator inside fold-expression: strange warning
@ 2020-04-06 18:57 frank.winklmeier at cern dot ch
  2020-04-06 20:04 ` [Bug c++/94505] " redi at gcc dot gnu.org
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: frank.winklmeier at cern dot ch @ 2020-04-06 18:57 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94505

            Bug ID: 94505
           Summary: Logical operator inside fold-expression: strange
                    warning
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: frank.winklmeier at cern dot ch
  Target Milestone: ---

This was first reported in [1] but I could not find any bug report. The
following code compiled with `gcc -Wall -std=c++17`:

template <bool... B>
bool foo () {
    return ((B && true) || ...);
}

int main () {
    foo<true, false, false, true> ();
} 

produces this warning:

t.cxx:7:38:   required from here
t.cxx:3:18: warning: suggest parentheses around '&&' within '||'
[-Wparentheses]
       return ((B && true) || ...);
               ~~~^~~~~~~~
t.cxx:3:18: warning: suggest parentheses around '&&' within '||'
[-Wparentheses]

Reproducible with any recent gcc version including gcc-trunk-20200406 (on
godbolt).


[1]
http://gcc.1065356.n8.nabble.com/Logical-operator-inside-fold-expression-strange-warning-td1627740.html

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/94505] Logical operator inside fold-expression: strange warning
  2020-04-06 18:57 [Bug c++/94505] New: Logical operator inside fold-expression: strange warning frank.winklmeier at cern dot ch
@ 2020-04-06 20:04 ` redi at gcc dot gnu.org
  2020-04-19 15:45 ` mpolacek at gcc dot gnu.org
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: redi at gcc dot gnu.org @ 2020-04-06 20:04 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94505

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-04-06
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
           Keywords|                            |diagnostic

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/94505] Logical operator inside fold-expression: strange warning
  2020-04-06 18:57 [Bug c++/94505] New: Logical operator inside fold-expression: strange warning frank.winklmeier at cern dot ch
  2020-04-06 20:04 ` [Bug c++/94505] " redi at gcc dot gnu.org
@ 2020-04-19 15:45 ` mpolacek at gcc dot gnu.org
  2020-04-20 19:35 ` cvs-commit at gcc dot gnu.org
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2020-04-19 15:45 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94505

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org
                 CC|                            |mpolacek at gcc dot gnu.org

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/94505] Logical operator inside fold-expression: strange warning
  2020-04-06 18:57 [Bug c++/94505] New: Logical operator inside fold-expression: strange warning frank.winklmeier at cern dot ch
  2020-04-06 20:04 ` [Bug c++/94505] " redi at gcc dot gnu.org
  2020-04-19 15:45 ` mpolacek at gcc dot gnu.org
@ 2020-04-20 19:35 ` cvs-commit at gcc dot gnu.org
  2020-04-20 19:45 ` cvs-commit at gcc dot gnu.org
  2020-04-20 19:46 ` mpolacek at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2020-04-20 19:35 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94505

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:5bdd4c5d3fc9c143e8edea3b10828e4b75d7a385

commit r10-7830-g5bdd4c5d3fc9c143e8edea3b10828e4b75d7a385
Author: Marek Polacek <polacek@redhat.com>
Date:   Sun Apr 19 12:12:01 2020 -0400

    c++: Fix bogus -Wparentheses warning with fold-expression [PR94505]

    We issue bogus -Wparentheses warnings (3 of them!) for this fold
expression:

      ((B && true) || ...)

    Firstly, issuing a warning for a compiler-generated expression is wrong
    and secondly, B && true must be wrapped in ( ) otherwise you'll get
    error: binary expression in operand of fold-expression.

            PR c++/94505 - bogus -Wparentheses warning with fold-expression.
            * pt.c (fold_expression): Add warning_sentinel for -Wparentheses
            before calling build_x_binary_op.

            * g++.dg/cpp1z/fold11.C: New test.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/94505] Logical operator inside fold-expression: strange warning
  2020-04-06 18:57 [Bug c++/94505] New: Logical operator inside fold-expression: strange warning frank.winklmeier at cern dot ch
                   ` (2 preceding siblings ...)
  2020-04-20 19:35 ` cvs-commit at gcc dot gnu.org
@ 2020-04-20 19:45 ` cvs-commit at gcc dot gnu.org
  2020-04-20 19:46 ` mpolacek at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2020-04-20 19:45 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94505

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Marek Polacek
<mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:83eeda5f004c3b9cbeccd3da1c3fe58b3015e55f

commit r9-8518-g83eeda5f004c3b9cbeccd3da1c3fe58b3015e55f
Author: Marek Polacek <polacek@redhat.com>
Date:   Mon Apr 20 15:43:49 2020 -0400

    c++: Fix bogus -Wparentheses warning with fold-expression [PR94505]

    We issue bogus -Wparentheses warnings (3 of them!) for this fold
expression:

      ((B && true) || ...)

    Firstly, issuing a warning for a compiler-generated expression is wrong
    and secondly, B && true must be wrapped in ( ) otherwise you'll get
    error: binary expression in operand of fold-expression.

            PR c++/94505 - bogus -Wparentheses warning with fold-expression.
            * pt.c (fold_expression): Add warning_sentinel for -Wparentheses
            before calling build_x_binary_op.

            * g++.dg/cpp1z/fold11.C: New test.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/94505] Logical operator inside fold-expression: strange warning
  2020-04-06 18:57 [Bug c++/94505] New: Logical operator inside fold-expression: strange warning frank.winklmeier at cern dot ch
                   ` (3 preceding siblings ...)
  2020-04-20 19:45 ` cvs-commit at gcc dot gnu.org
@ 2020-04-20 19:46 ` mpolacek at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2020-04-20 19:46 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94505

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed in GCC 9.4 and 10.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-04-20 19:46 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-04-06 18:57 [Bug c++/94505] New: Logical operator inside fold-expression: strange warning frank.winklmeier at cern dot ch
2020-04-06 20:04 ` [Bug c++/94505] " redi at gcc dot gnu.org
2020-04-19 15:45 ` mpolacek at gcc dot gnu.org
2020-04-20 19:35 ` cvs-commit at gcc dot gnu.org
2020-04-20 19:45 ` cvs-commit at gcc dot gnu.org
2020-04-20 19:46 ` mpolacek at gcc dot gnu.org

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