Re: [Qemu-devel] [PATCH 10/19] qemu-char: Chardev open error reporting, !_WIN32 part

[Markus Armbruster]

Kevin Wolf <address@hidden> writes:

> Am 07.02.2012 15:09, schrieb Markus Armbruster:
>> This part takes care of backends "file", "pipe", "pty" and "stdio".
>> Unlike many other backends, these leave open error reporting to their
>> caller.  Because the caller doesn't know what went wrong, this results
>> in a pretty useless error message.
>> 
>> Change them to report their errors.  Improves comically user-hostile
>> messages like this one for "-chardev file,id=foo,path=/x"
>> 
>>     chardev: opening backend "file" failed
>> 
>> to
>> 
>>     qemu-system-x86_64: -chardev file,id=foo,path=/x: Can't create file 
>> '/x': Permission denied
>>     chardev: opening backend "file" failed
>> 
>> The useless "opening backend failed" message will be cleaned up
>> shortly.
>> 
>> Signed-off-by: Markus Armbruster <address@hidden>
>> ---
>>  qemu-char.c |   19 +++++++++++++++----
>>  1 files changed, 15 insertions(+), 4 deletions(-)
>
>> @@ -1002,7 +1013,7 @@ static CharDriverState *qemu_chr_open_pty(QemuOpts 
>> *opts)
>>      chr->filename = g_malloc(len);
>>      snprintf(chr->filename, len, "pty:%s", q_ptsname(master_fd));
>>      qemu_opt_set(opts, "path", q_ptsname(master_fd));
>> -    fprintf(stderr, "char device redirected to %s\n", q_ptsname(master_fd));
>> +    error_printf("char device redirected to %s\n", q_ptsname(master_fd));
>>  
>>      s = g_malloc0(sizeof(PtyCharDriver));
>>      chr->opaque = s;
>
> Not really an error message. Does it make any sense at all to have this
> message?

error_printf() prints to the error channel (monitor or stderr), but not
necessarily an error message.  See for instance drive_init()'s use of it
to print format help.

Not sure whether it makes sense to have this message.  I guess it exists
because the pty is chosen automatically, but the user might still want
to know which one was chosen.