Re: [Qemu-block] [PATCH v11 18/28] qerror: more error_setg() usage

[Andreas Färber]

Am 11.11.2015 um 07:51 schrieb Eric Blake:
> A few uses of error_set(ERROR_CLASS_GENERIC_ERROR) have snuck in
> since c6bd8c706.  Nuke them.
> 
> Signed-off-by: Eric Blake 
[...]
> diff --git a/qom/object.c b/qom/object.c
> index fc6e161..c0decb6 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -1330,8 +1330,8 @@ static Object *object_resolve_link(Object *obj, const 
> char *name,
>  target = object_resolve_path_type(path, target_type, );
> 
>  if (ambiguous) {
> -error_set(errp, ERROR_CLASS_GENERIC_ERROR,
> -  "Path '%s' does not uniquely identify an object", path);
> +error_setg(errp, "Path '%s' does not uniquely identify an object",
> +   path);
>  } else if (!target) {
>  target = object_resolve_path(path, );
>  if (target || ambiguous) {

Acked-by: Andreas Färber 

No idea why it's this way, maybe predated the function?

Regards,
Andreas

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GF: Felix Imendörffer, Jane Smithard, Graham Norton; HRB 21284 (AG Nürnberg)

[Qemu-block] [PATCH v11 18/28] qerror: more error_setg() usage

[Eric Blake]

A few uses of error_set(ERROR_CLASS_GENERIC_ERROR) have snuck in
since c6bd8c706.  Nuke them.

Signed-off-by: Eric Blake 

---
v11: new patch
---
 block.c   |  3 +--
 docs/writing-qmp-commands.txt | 20 +---
 hw/i386/pc.c  |  2 +-
 hw/net/rocker/rocker.c|  6 ++
 hw/net/rocker/rocker_of_dpa.c | 12 
 qom/object.c  |  4 ++--
 6 files changed, 19 insertions(+), 28 deletions(-)

diff --git a/block.c b/block.c
index e9f40dc..53a978a 100644
--- a/block.c
+++ b/block.c
@@ -1795,8 +1795,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, 
BlockReopenQueue *queue,

 ret = bdrv_flush(reopen_state->bs);
 if (ret) {
-error_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive",
-  strerror(-ret));
+error_setg_errno(errp, -ret, "Error flushing drive");
 goto error;
 }

diff --git a/docs/writing-qmp-commands.txt b/docs/writing-qmp-commands.txt
index 8647cac..59aa77a 100644
--- a/docs/writing-qmp-commands.txt
+++ b/docs/writing-qmp-commands.txt
@@ -210,7 +210,7 @@ if you don't see these strings, then something went wrong.
 === Errors ===

 QMP commands should use the error interface exported by the error.h header
-file. Basically, errors are set by calling the error_set() function.
+file. Basically, most errors are set by calling the error_setg() function.

 Let's say we don't accept the string "message" to contain the word "love". If
 it does contain it, we want the "hello-world" command to return an error:
@@ -219,8 +219,7 @@ void qmp_hello_world(bool has_message, const char *message, 
Error **errp)
 {
 if (has_message) {
 if (strstr(message, "love")) {
-error_set(errp, ERROR_CLASS_GENERIC_ERROR,
-  "the word 'love' is not allowed");
+error_setg(errp, "the word 'love' is not allowed");
 return;
 }
 printf("%s\n", message);
@@ -229,10 +228,8 @@ void qmp_hello_world(bool has_message, const char 
*message, Error **errp)
 }
 }

-The first argument to the error_set() function is the Error pointer to pointer,
-which is passed to all QMP functions. The second argument is a ErrorClass
-value, which should be ERROR_CLASS_GENERIC_ERROR most of the time (more
-details about error classes are given below). The third argument is a human
+The first argument to the error_setg() function is the Error pointer
+to pointer, which is passed to all QMP functions. The next argument is a human
 description of the error, this is a free-form printf-like string.

 Let's test the example above. Build qemu, run it as defined in the "Testing"
@@ -249,8 +246,9 @@ The QMP server's response should be:
 }
 }

-As a general rule, all QMP errors should use ERROR_CLASS_GENERIC_ERROR. There
-are two exceptions to this rule:
+As a general rule, all QMP errors should use ERROR_CLASS_GENERIC_ERROR
+(done by default when using error_setg()). There are two exceptions to
+this rule:

  1. A non-generic ErrorClass value exists* for the failure you want to report
 (eg. DeviceNotFound)
@@ -259,8 +257,8 @@ are two exceptions to this rule:
 want to report, hence you have to add a new ErrorClass value so that they
 can check for it

-If the failure you want to report doesn't fall in one of the two cases above,
-just report ERROR_CLASS_GENERIC_ERROR.
+If the failure you want to report falls into one of the two cases above,
+use error_set() with a second argument of an ErrorClass value.

  * All existing ErrorClass values are defined in the qapi-schema.json file

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 0cb8afd..dfb57a8 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1795,7 +1795,7 @@ static void pc_machine_set_max_ram_below_4g(Object *obj, 
Visitor *v,
 return;
 }
 if (value > (1ULL << 32)) {
-error_set(, ERROR_CLASS_GENERIC_ERROR,
+error_setg(,
   "Machine option 'max-ram-below-4g=%"PRIu64
   "' expects size less than or equal to 4G", value);
 error_propagate(errp, error);
diff --git a/hw/net/rocker/rocker.c b/hw/net/rocker/rocker.c
index bb6fdc3..c57f1a6 100644
--- a/hw/net/rocker/rocker.c
+++ b/hw/net/rocker/rocker.c
@@ -101,8 +101,7 @@ RockerSwitch *qmp_query_rocker(const char *name, Error 
**errp)

 r = rocker_find(name);
 if (!r) {
-error_set(errp, ERROR_CLASS_GENERIC_ERROR,
-  "rocker %s not found", name);
+error_setg(errp, "rocker %s not found", name);
 return NULL;
 }

@@ -122,8 +121,7 @@ RockerPortList *qmp_query_rocker_ports(const char *name, 
Error **errp)

 r = rocker_find(name);
 if (!r) {
-error_set(errp, ERROR_CLASS_GENERIC_ERROR,
-  "rocker %s not found", name);
+error_setg(errp, "rocker %s not found", name);
 return NULL;
 }

diff --git a/hw/net/rocker/rocker_of_dpa.c