Re: [Qemu-devel] [PATCH 14/21] qemu-char: convert braille backend to data-driven creation

[Paolo Bonzini <pbonzini@redhat.com>]

On 12/10/2015 17:41, Samuel Thibault wrote:
> Eric Blake, le Mon 12 Oct 2015 09:30:12 -0600, a écrit :
>>  Also, I assume that brlapi_perror() adds additional information to
>> the error message it prints, such as conversion of a brlapi-specific
>> error message in the same manner in which perror() converts errno and in
>> which error_setg_errno() would be used.
> 
> Yes. Such additional information is really useful to debug brlapi
> issues.
> 
>> So I don't know if this
>> conversion is the best.  But I'm unfamiliar with brlapi_* in general, to
>> know if there is anything better to use,
> 
> brlapi_error_t * brlapi_error_location(void);
> const char * brlapi_strerror(const brlapi_error_t *error);
> 
> So brlapi_strerror(brlapi_error_location()) will return what you want,
> i.e. the string that brlapi_error() would have printed.

Is it okay to squash this?

diff --git a/backends/baum.c b/backends/baum.c
index 281be30..723c658 100644
--- a/backends/baum.c
+++ b/backends/baum.c
@@ -589,14 +589,16 @@ static CharDriverState *chr_baum_init(const char *id,
 
     baum->brlapi_fd = brlapi__openConnection(handle, NULL, NULL);
     if (baum->brlapi_fd == -1) {
-        error_setg(errp, "baum_init: brlapi_openConnection");
+        error_setg(errp, "brlapi__openConnection: %s",
+                   brlapi_strerror(brlapi_error_location()));
         goto fail_handle;
     }
 
     baum->cellCount_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, baum_cellCount_timer_cb, baum);
 
     if (brlapi__getDisplaySize(handle, &baum->x, &baum->y) == -1) {
-        error_setg(errp, "baum_init: brlapi_getDisplaySize");
+        error_setg(errp, "brlapi__getDisplaySize: %s",
+                   brlapi_strerror(brlapi_error_location()));
         goto fail;
     }
 
@@ -612,7 +614,8 @@ static CharDriverState *chr_baum_init(const char *id,
         tty = BRLAPI_TTY_DEFAULT;
 
     if (brlapi__enterTtyMode(handle, tty, NULL) == -1) {
-        error_setg(errp, "baum_init: brlapi_enterTtyMode");
+        error_setg(errp, "brlapi__enterTtyMode: %s",
+                   brlapi_strerror(brlapi_error_location()));
         goto fail;
     }
 

Thanks for the help,

Paolo