Re: [PATCH v2] C++: dlsym casts in gdb/linux-thread-db.c and gdb/gdbserver/thread-db.c

[Pedro Alves <palves@redhat.com>]

On 08/05/2015 02:34 PM, Ulrich Weigand wrote:
> Pedro Alves wrote:
> 
>> gdb/ChangeLog:
>> 2015-08-03  Pedro Alves  <palves@redhat.com>
>>
>> 	* nat/gdb_thread_db.h (td_init_ftype, td_ta_new_ftype)
>> 	(td_ta_map_lwp2thr_ftype, td_ta_thr_iter_ftype)
>> 	(td_ta_event_addr_ftype, td_ta_set_event_ftype)
>> 	(td_ta_clear_event_ftype, td_ta_event_getmsg_ftype)
>> 	(td_thr_validate_ftype, td_thr_get_info_ftype)
>> 	(td_thr_event_enable_ftype, td_thr_tls_get_addr_ftype)
>> 	(td_thr_tlsbase_ftype, td_symbol_list_ftype, td_ta_delete_ftype):
>> 	New typedefs.
> 
> This breaks the build for me with:
> 
> In file included from /home/uweigand/dailybuild/spu-tc-2015-08-04/binutils-gdb-head/binutils-gdb/gdb/gdbserver/thread-db.c:31:                         
> /home/uweigand/dailybuild/spu-tc-2015-08-04/binutils-gdb-head/binutils-gdb/gdb/gdbserver/../nat/gdb_thread_db.h:20: error: redefinition of typedef ‘td_init_ftype’                                                                                                                                            
> /home/uweigand/dailybuild/spu-tc-2015-08-04/binutils-gdb-head/binutils-gdb/gdb/gdbserver/../nat/gdb_thread_db.h:20: error: previous declaration of ‘td_init_ftype’ was here                                                                                                                                   
> /home/uweigand/dailybuild/spu-tc-2015-08-04/binutils-gdb-head/binutils-gdb/gdb/gdbserver/../nat/gdb_thread_db.h:23: error: redefinition of typedef ‘td_ta_new_ftype’                                                                                                                                          
> /home/uweigand/dailybuild/spu-tc-2015-08-04/binutils-gdb-head/binutils-gdb/gdb/gdbserver/../nat/gdb_thread_db.h:23: error: previous declaration of ‘td_ta_new_ftype’ was here                                                                                                                                 
> [... etc for each of the typedefs ...]
> 
> It seems this is caused by the nat/gdb_thread_db.h header file
> being included twice into gdbserver/thread-db.c:
> 
> 1) via line 23:
> #include "linux-low.h"
> (which includes "nat/gdb_thread_db.h" at line 20)
> 
> 2) directly in line 30:
> #include "nat/gdb_thread_db.h"
> 
> and the file not being guarded against double inclusion.

Yeah, I think we should just add the guards.

Are you already taking care of that, or would you like me to?

> 
> (I'm not 100% sure whether an identical second typedef is supposed
> to be valid C or not, but at least my GCC 4.1 host compiler rejects
> it in this case.)

Thanks,
Pedro Alves