Re: [PATCH v8 03/21] error: make Error **errp const where it is appropriate

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 12/5/19 6:46 PM, Vladimir Sementsov-Ogievskiy wrote:
> Mostly, Error ** is for returning error from the function, so the
> callee sets it. However these three functions get already filled errp
> parameter. They dont change the pointer itself, only change the
> internal state of referenced Error object. So we can make it
> Error *const * errp, to stress the behavior. It will also help
> coccinelle script (in future) to distinguish such cases from common
> errp usage.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
>   include/qapi/error.h | 6 +++---
>   util/error.c         | 6 +++---
>   2 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/include/qapi/error.h b/include/qapi/error.h
> index 3f95141a01..ad5b6e896d 100644
> --- a/include/qapi/error.h
> +++ b/include/qapi/error.h
> @@ -233,13 +233,13 @@ void error_propagate_prepend(Error **dst_errp, Error *local_err,
>    * Prepend some text to @errp's human-readable error message.
>    * The text is made by formatting @fmt, @ap like vprintf().
>    */
> -void error_vprepend(Error **errp, const char *fmt, va_list ap);
> +void error_vprepend(Error *const *errp, const char *fmt, va_list ap);
>   
>   /*
>    * Prepend some text to @errp's human-readable error message.
>    * The text is made by formatting @fmt, ... like printf().
>    */
> -void error_prepend(Error **errp, const char *fmt, ...)
> +void error_prepend(Error *const *errp, const char *fmt, ...)
>       GCC_FMT_ATTR(2, 3);
>   
>   /*
> @@ -256,7 +256,7 @@ void error_prepend(Error **errp, const char *fmt, ...)
>    * May be called multiple times.  The resulting hint should end with a
>    * newline.
>    */
> -void error_append_hint(Error **errp, const char *fmt, ...)
> +void error_append_hint(Error *const *errp, const char *fmt, ...)
>       GCC_FMT_ATTR(2, 3);
>   
>   /*
> diff --git a/util/error.c b/util/error.c
> index d4532ce318..b6c89d1412 100644
> --- a/util/error.c
> +++ b/util/error.c
> @@ -121,7 +121,7 @@ void error_setg_file_open_internal(Error **errp,
>                                 "Could not open '%s'", filename);
>   }
>   
> -void error_vprepend(Error **errp, const char *fmt, va_list ap)
> +void error_vprepend(Error *const *errp, const char *fmt, va_list ap)
>   {
>       GString *newmsg;
>   
> @@ -136,7 +136,7 @@ void error_vprepend(Error **errp, const char *fmt, va_list ap)
>       (*errp)->msg = g_string_free(newmsg, 0);
>   }
>   
> -void error_prepend(Error **errp, const char *fmt, ...)
> +void error_prepend(Error *const *errp, const char *fmt, ...)
>   {
>       va_list ap;
>   
> @@ -145,7 +145,7 @@ void error_prepend(Error **errp, const char *fmt, ...)
>       va_end(ap);
>   }
>   
> -void error_append_hint(Error **errp, const char *fmt, ...)
> +void error_append_hint(Error *const *errp, const char *fmt, ...)
>   {
>       va_list ap;
>       int saved_errno = errno;
>