[Bug libc/28182] New: _TIME_BITS=64 in C++ has issues with fcntl and ioctl

[Bug libc/28182] New: _TIME_BITS=64 in C++ has issues with fcntl and ioctl

[gerbilsoft at gerbilsoft dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28182

            Bug ID: 28182
           Summary: _TIME_BITS=64 in C++ has issues with fcntl and ioctl
           Product: glibc
           Version: 2.34
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libc
          Assignee: unassigned at sourceware dot org
          Reporter: gerbilsoft at gerbilsoft dot com
                CC: drepper.fsp at gmail dot com
  Target Milestone: ---

Attempting to compile a 32-bit C++ program that uses fcntl.h or sys/ioctl.h if
_TIME_BITS=64 results in an error related to exception handling.

Sample code:

#include <fcntl.h>

int main(void)
{
        return 0;
}

Compile with: g++ -m32 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
-D_LARGEFILE64_SOURCE -D_TIME_BITS=64 -c test.cpp

Results:

In file included from /usr/include/features.h:488,
                 from /usr/include/fcntl.h:25,
                 from test.cpp:1:
/usr/include/fcntl.h:191:41: error: expected initializer before ‘noexcept’
  191 |                        __fcntl_time64)  __THROW;
      |                                         ^~~~~~~
/usr/include/fcntl.h:193:41: error: expected initializer before ‘noexcept’
  193 |                        __fcntl_time64)  __THROW;
      |                                         ^~~~~~~

The same code does compile if built as C code instead of as C++.

Software versions:

OS: Gentoo Linux
Arch: amd64 (Intel Core i7-3520M)
Compiler: gcc-11.1.0
glibc: 2.34

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/28182] _TIME_BITS=64 in C++ has issues with fcntl, ioctl, prctl

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28182

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fweimer at redhat dot com
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-08-04
           Assignee|unassigned at sourceware dot org   |fweimer at redhat dot com
             Status|UNCONFIRMED                 |ASSIGNED
            Summary|_TIME_BITS=64 in C++ has    |_TIME_BITS=64 in C++ has
                   |issues with fcntl and ioctl |issues with fcntl, ioctl,
                   |                            |prctl
              Flags|                            |security-

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/28182] _TIME_BITS=64 in C++ has issues with fcntl, ioctl, prctl

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28182

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |2.35
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #1 from Florian Weimer <fweimer at redhat dot com> ---
Fixed for 2.35 via:

commit c87fcacc50505d550f1bb038382bcc7ea73a5926
Author: Florian Weimer <fweimer@redhat.com>
Date:   Fri Aug 6 09:51:38 2021 +0200

    Linux: Fix fcntl, ioctl, prctl redirects for _TIME_BITS=64 (bug 28182)

    __REDIRECT and __THROW are not compatible with C++ due to the ordering of
the
    __asm__ alias and the throw specifier. __REDIRECT_NTH has to be used
    instead.

    Fixes commit 8a40aff86ba5f64a3a84883e539cb67b ("io: Add time64 alias
    for fcntl"), commit 82c395d91ea4f69120d453aeec398e30 ("misc: Add
    time64 alias for ioctl"), commit b39ffab860cd743a82c91946619f1b8158
    ("Linux: Add time64 alias for prctl").

    Reviewed-by: Carlos O'Donell <carlos@redhat.com>

-- 
You are receiving this mail because:
You are on the CC list for the bug.