[v8,03/21] error: make Error **errp const where it is appropriate
diff mbox series

Message ID 20191205174635.18758-4-vsementsov@virtuozzo.com
State New
Headers show
Series
  • error: prepare for auto propagated local_err
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Commit Message

Vladimir Sementsov-Ogievskiy Dec. 5, 2019, 5:46 p.m. UTC
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>
---
 include/qapi/error.h | 6 +++---
 util/error.c         | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

Comments

Philippe Mathieu-Daudé Dec. 6, 2019, 7:28 a.m. UTC | #1
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;
>
Markus Armbruster Dec. 6, 2019, 3:49 p.m. UTC | #2
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> writes:

> 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: Markus Armbruster <armbru@redhat.com>

Patch
diff mbox series

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;