Re: [PATCH 06/11] [C++/mingw] ser-tcp.c casts

[Pedro Alves <palves at redhat dot com>]

On 11/02/2015 08:40 PM, Simon Marchi wrote:
> On 15-11-02 02:36 PM, Pedro Alves wrote:
>> Fixes a few errors like these:
>>
>> ../../src/gdb/ser-tcp.c: In function 'int net_open(serial*, const char*)':
>> ../../src/gdb/ser-tcp.c:286:73: error: invalid conversion from 'void*' to 'char*' [-fpermissive]
>>      res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, (void *) &err, &len);
>>                                                                          ^
>>
>> gdb/ChangeLog:
>> 2015-11-01  Pedro Alves  <palves@redhat.com>
>>
>> 	* ser-tcp.c (net_open) [USE_WIN32API]: Cast getsockopt argument to
>> 	char * instead of void *.
>> 	(net_read_prim): Cast recv argument to
>> 	char * instead of void *.
>> 	(net_write_prim): Cast send argument to char * instead of void *.
>> ---
>>  gdb/ser-tcp.c | 19 +++++++++++++------
>>  1 file changed, 13 insertions(+), 6 deletions(-)
>>
>> diff --git a/gdb/ser-tcp.c b/gdb/ser-tcp.c
>> index ce40b61..507e0a1 100644
>> --- a/gdb/ser-tcp.c
>> +++ b/gdb/ser-tcp.c
>> @@ -280,10 +280,12 @@ net_open (struct serial *scb, const char *name)
>>  
>>      len = sizeof (err);
>>      /* On Windows, the fourth parameter to getsockopt is a "char *";
>> -       on UNIX systems it is generally "void *".  The cast to "void *"
>> -       is OK everywhere, since in C "void *" can be implicitly
>> -       converted to any pointer type.  */
>> +       on UNIX systems it is generally "void *".  */
>> +#ifdef USE_WIN32API
>> +    res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, (char *) &err, &len);
>> +#else
>>      res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, (void *) &err, &len);
>> +#endif
> 
> You could have done exactly the opposite of the old comment, that is cast to
> (char *).  It shouldn't generate any warning in either case.  But I think that
> your way is fine too.

Oh, good point.  I always forget that implicit cast to void* works.

I'll update the patch.

Thanks,
Pedro Alves