[Bug c++/25322] New: ISO compliance of defining structs in anonymous unions

[Bug c++/25322] New: ISO compliance of defining structs in anonymous unions

[cfranz at aldon dot com]

$ cat testunion.cpp
// testunion.cpp

static union { struct n { int I2; } S2; }; // Case 1
static union { struct   { int I1; } S1; }; // Case 2

struct foo
{
       union { struct n { int I2; } S2; }; // Case 3
       union { struct   { int I1; } S1; }; // Case 4
};

void func()
{
       union { struct n { int I2; } S2; }; // Case 5
       union { struct   { int I1; } S1; }; // Case 6
}

$ g++ --version
g++ (GCC) 3.4.4 (cygming special) (gdc 0.12, using dmd 0.125)
Copyright (C) 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ g++ -c -pedantic testunion.cpp
testunion.cpp:8: error: `struct foo::<anonymous union>::n' invalid; an
anonymous
 union can only have non-static data members


g++ reports an error only in Case 3, regardless of the settings of -pedantic or
-pedantic-errors, but as I understand it all six cases violate the C++
standard.  Accordingly, Comeau and xlc++ reject all six cases in strict mode,
and accept them with warnings in relaxed mode.

This behavior is consistent for at least versions 3.4.4 and 3.3.2.


-- 
           Summary: ISO compliance of defining structs in anonymous unions
           Product: gcc
           Version: 3.4.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: cfranz at aldon dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25322

[Bug c++/25322] ISO compliance of defining structs in anonymous unions

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2005-12-08 23:36 -------
Hmm, I actually want to say that case 2, 4, and 6 are actually valid (But I
have not looked at the standard) as anonymous types are special.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |accepts-invalid
      Known to fail|                            |2.95.3 3.0.4 3.2.3 3.4.0
                   |                            |3.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25322

[Bug c++/25322] ISO compliance of defining structs in anonymous unions

[bangerth at dealii dot org]

------- Comment #2 from bangerth at dealii dot org  2005-12-09 05:20 -------
Confirmed. We should at least complain about cases 1, 3, 5. As does,
incidentally, icc with -Xc -ansi.

W.


-- 

bangerth at dealii dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-12-09 05:20:59
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25322

[Bug c++/25322] ISO compliance of defining structs in anonymous unions

[jvalenzu at infinite-monkeys dot org]

------- Comment #3 from jvalenzu at infinite-monkeys dot org  2006-03-10 16:25 -------
Would someone mind specifying what section of the standard this violates?  We
have a codebase that makes heavy use of (3). 


-- 

jvalenzu at infinite-monkeys dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jvalenzu at infinite-monkeys
                   |                            |dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25322

[Bug c++/25322] ISO compliance of defining structs in anonymous unions

[cfranz at aldon dot com]

------- Comment #4 from cfranz at aldon dot com  2006-05-11 23:27 -------
(In reply to comment #3)
> Would someone mind specifying what section of the standard this violates?  We
> have a codebase that makes heavy use of (3). 

Section 9.5.  Furthermore, I was basing cases 2, 4, and 6 on the following:
   http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_closed.html#359


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25322

[Bug c++/25322] ISO compliance of defining structs in anonymous unions

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25322

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED
   Target Milestone|---                         |12.0

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed for GCC 12 by r12-298; there is a testcase already.