[Bug preprocessor/12258] -Wold-style-cast triggers on casts in macros from system headers

[Bug preprocessor/12258] -Wold-style-cast triggers on casts in macros from system headers

[hjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12258

--- Comment #3 from hjl at gcc dot gnu.org <hjl at gcc dot gnu.org> 2010-11-23 18:09:39 UTC ---
Author: hjl
Date: Tue Nov 23 18:09:34 2010
New Revision: 167090

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=167090
Log:
Properly check default linker.

2010-11-23  H.J. Lu  <hongjiu.lu@intel.com>

    PR binutils/12258
    * configure.ac: Correct comments for --enable-gold/--enable-ld.
    Properly check default linker.
    * configure: Regnerated.

Modified:
    trunk/ChangeLog
    trunk/configure
    trunk/configure.ac

[Bug preprocessor/12258] -Wold-style-cast triggers on casts in macros from system headers

[carlosgalvezp at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=12258

Carlos Galvez <carlosgalvezp at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |carlosgalvezp at gmail dot com

--- Comment #6 from Carlos Galvez <carlosgalvezp at gmail dot com> ---
Hi,

This problem seems to be back in GCC 9 and 11:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103862

[Bug preprocessor/12258] -Wold-style-cast triggers on casts in macros from system headers

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=12258

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Carlos Galvez from comment #6)
> This problem seems to be back in GCC 9 and 11:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103862

As pointed out in a comment there, it's a different case.

[Bug c++/12258] New: -Wold-style-cast triggers on casts in macros from system headers

[stl at caltech dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12258

           Summary: -Wold-style-cast triggers on casts in macros from system
                    headers
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: stl at caltech dot edu
                CC: gcc-bugs at gcc dot gnu dot org

See this thread:
http://gcc.gnu.org/ml/gcc/2003-09/msg00162.html

Basically, if something like

#pragma GCC system_header
#define NOTHING (int) 0

appears in something.h, and meow.cc consists of

#include <something.h>
int blah = NOTHING;

and meow.cc is compiled with -Wold-style-cast, the warning will trigger.

I originally encountered this using MinGW gcc 3.3, but Zack Weinberg's 
comments in the thread indicate that no version of gcc anywhere yet knows 
enough to not emit this warning.

[Bug preprocessor/12258] -Wold-style-cast triggers on casts in macros from system headers

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12258


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|c++                         |preprocessor
     Ever Confirmed|                            |1
           Keywords|                            |diagnostic
   Last reconfirmed|0000-00-00 00:00:00         |2003-09-17 05:14:26
               date|                            |


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-09-17 05:14 -------
This is reallly a preprocess failure (as the preprocessor does not tell the front-end that the code is 
from a system header).  It is also related to bug 11931 and bug 7263.

[Bug preprocessor/12258] -Wold-style-cast triggers on casts in macros from system headers

[stl at caltech dot edu]

------- Additional Comments From stl at caltech dot edu  2004-03-13 02:11 -------
My current workaround is similar to what Kai Henningsen proposed: I have my 
own const constants for #define'd constants, as well as my own functions for 
#define'd macros (e.g. FD_SET), in a separate header which I then mark as a 
GCC system header. This produces warning-free code. It's a dirty hack, though.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12258