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* [Bug c++/105195] New: spurious warning label defined but not used with if constexpr
@ 2022-04-07 13:19 barry.revzin at gmail dot com
  2022-04-07 13:29 ` [Bug c++/105195] " mpolacek at gcc dot gnu.org
  2022-11-10 23:50 ` pinskia at gcc dot gnu.org
  0 siblings, 2 replies; 3+ messages in thread
From: barry.revzin at gmail dot com @ 2022-04-07 13:19 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105195

            Bug ID: 105195
           Summary: spurious warning label defined but not used with if
                    constexpr
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: barry.revzin at gmail dot com
  Target Milestone: ---

Similar to other "if constexpr" related warnings, gcc warns on this example:

void g();
void h();

template <bool B>
void f() {
    if constexpr (B) {
        goto label;
    }

    g();

label:
    h();
}

int main() {
    f<false>();
}

<source>:12:1: warning: label 'label' defined but not used [-Wunused-label]
   12 | label:
      | ^~~~~

But the label is used, just not in this particular instantiation.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [Bug c++/105195] spurious warning label defined but not used with if constexpr
  2022-04-07 13:19 [Bug c++/105195] New: spurious warning label defined but not used with if constexpr barry.revzin at gmail dot com
@ 2022-04-07 13:29 ` mpolacek at gcc dot gnu.org
  2022-11-10 23:50 ` pinskia at gcc dot gnu.org
  1 sibling, 0 replies; 3+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2022-04-07 13:29 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105195

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
           Keywords|                            |diagnostic
                 CC|                            |mpolacek at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2022-04-07

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [Bug c++/105195] spurious warning label defined but not used with if constexpr
  2022-04-07 13:19 [Bug c++/105195] New: spurious warning label defined but not used with if constexpr barry.revzin at gmail dot com
  2022-04-07 13:29 ` [Bug c++/105195] " mpolacek at gcc dot gnu.org
@ 2022-11-10 23:50 ` pinskia at gcc dot gnu.org
  1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-11-10 23:50 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105195

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
MSVC warns too:
<source>(12): warning C4102: 'label': unreferenced label
<source>(17): note: see reference to function template instantiation 'void
f<false>(void)' being compiled

clang does not though.
I think GCC should not warn either.

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2022-11-10 23:50 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2022-04-07 13:19 [Bug c++/105195] New: spurious warning label defined but not used with if constexpr barry.revzin at gmail dot com
2022-04-07 13:29 ` [Bug c++/105195] " mpolacek at gcc dot gnu.org
2022-11-10 23:50 ` pinskia at gcc dot gnu.org

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