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

Pedro Alves
2015-11-02T20:55:32Z

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