[Bug c++/67048] New: GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[Bug c++/67048] New: GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[anders.granlund.0 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

            Bug ID: 67048
           Summary: GCC rejects well-formed program using empty anonymous
                    enum specifier in a variable declaration
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anders.granlund.0 at gmail dot com
  Target Milestone: ---

Consider the following well-formed program (prog.cc):

enum {} x;
int main() {}

Compile it with the following command line:

g++ prog.cc -std=c++14 -pedantic-errors

The following error message is given. I expected to get no error messages since
the program is well-formed.

prog.cc:1:6: error: ISO C++ forbids empty anonymous enum [-Wpedantic]
 enum {} x;
      ^

I have tried this with gcc HEAD 6.0.0 20150728 here:

http://melpon.org/wandbox/permlink/BXXfLL4WOU5lBOfk

[Bug c++/67048] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic, rejects-valid
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-07-29
     Ever confirmed|0                           |1

[Bug c++/67048] [9/10/11/12 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.8.5
   Target Milestone|---                         |9.5
      Known to fail|                            |10.1.0, 11.1.0, 4.9.0,
                   |                            |9.4.0
            Summary|GCC rejects well-formed     |[9/10/11/12 Regression] GCC
                   |program using empty         |rejects well-formed program
                   |anonymous enum specifier in |using empty anonymous enum
                   |a variable declaration      |specifier in a variable
                   |                            |declaration

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This was almost definitely caused by PR 54216 .

[Bug c++/67048] [9/10/11/12 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-bisection
           Priority|P3                          |P2
            Version|unknown                     |11.1.0

[Bug c++/67048] [9/10/11/12 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |marxin at gcc dot gnu.org

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
All releases I have (4.9.0) report the error.

[Bug c++/67048] [9/10/11/12/13 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

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

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

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Started with r197742.  I'll take a look.

[Bug c++/67048] [9/10/11/12/13 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:fd0d3e9121c5aa65150d242676be6bbdc8d4a92a

commit r13-51-gfd0d3e9121c5aa65150d242676be6bbdc8d4a92a
Author: Marek Polacek <polacek@redhat.com>
Date:   Thu Apr 28 16:50:06 2022 -0400

    c++: pedwarn for empty unnamed enum in decl [PR67048]

    [dcl.dcl]/5 says that

      enum { };

    is ill-formed, and since r197742 we issue a pedwarn.  However, the
    pedwarn also fires for

       enum { } x;

    which is well-formed.  So only warn when {} is followed by a ;.  This
    should be correct since you can't have "enum {}, <whatever>" -- that
    produces "expected unqualified-id before ',' token".

            PR c++/67048

    gcc/cp/ChangeLog:

            * parser.cc (cp_parser_enum_specifier): Warn about empty unnamed
enum
            only when it's followed by a semicolon.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/enum42.C: New test.

[Bug c++/67048] [9/10/11/12 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[9/10/11/12/13 Regression]  |[9/10/11/12 Regression] GCC
                   |GCC rejects well-formed     |rejects well-formed program
                   |program using empty         |using empty anonymous enum
                   |anonymous enum specifier in |specifier in a variable
                   |a variable declaration      |declaration

--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed for GCC 13 so far.

[Bug c++/67048] [10/11/12 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug c++/67048] [10/11/12 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug c++/67048] [10/11/12 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:60fed79c1e9a968eaedf292b298d19c9475ad37a

commit r12-8683-g60fed79c1e9a968eaedf292b298d19c9475ad37a
Author: Marek Polacek <polacek@redhat.com>
Date:   Thu Apr 28 16:50:06 2022 -0400

    c++: pedwarn for empty unnamed enum in decl [PR67048]

    [dcl.dcl]/5 says that

      enum { };

    is ill-formed, and since r197742 we issue a pedwarn.  However, the
    pedwarn also fires for

       enum { } x;

    which is well-formed.  So only warn when {} is followed by a ;.  This
    should be correct since you can't have "enum {}, <whatever>" -- that
    produces "expected unqualified-id before ',' token".

            PR c++/67048

    gcc/cp/ChangeLog:

            * parser.cc (cp_parser_enum_specifier): Warn about empty unnamed
enum
            only when it's followed by a semicolon.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/enum42.C: New test.

    (cherry picked from commit fd0d3e9121c5aa65150d242676be6bbdc8d4a92a)

[Bug c++/67048] [10/11 Regression] GCC rejects well-formed program using empty anonymous enum specifier in a variable declaration

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67048

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

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

--- Comment #9 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed.