Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>Hi
On Mon, Dec 21, 2015 at 6:08 PM, Eric Blake <ebl...@redhat.com> wrote:
> JSON uses "name":value, but many of our visitor interfaces were
> called with visit_type_FOO(v, &value, name, errp). This can be
> a bit confusing to have to mentally swap the parameter order to
> match JSON order. It's particularly bad for visit_start_struct(),
> where the 'name' parameter is smack in the middle of the
> otherwise-related group of 'obj, kind, size' parameters! It's
> time to do a global swap of the parameter ordering, so that the
> 'name' parameter is always immediately after the Visitor argument.
>
fwiw, I do agree.
> Additional reasons in favor of the swap: name is always an input
> parameter, while &value is sometimes an output parameter (depending
> on whether the caller is using an input visitor); and it is nicer
> to list input parameters first. Also, the existing include/qjson.h
> prefers listing 'name' first in json_prop_*(), and I have plans to
> unify that file with the qapi visitors; listing 'name' first in
> qapi will minimize churn to the (admittedly few) qjson.h clients.
>
> The next patches will then fix object.h, visitor-impl.h, and those
> clients to match.
>
> Done by first patching scripts/qapi*.py by hand to make generated
> files do what I want, then by running the following Coccinelle
> script to affect the rest of the code base:
> $ spatch --sp-file script `git grep -l '\bvisit_' -- '**/*.[ch]'`
> I then had to apply some touchups (Coccinelle insisted on TAB
> indentation in visitor.h, and botched the signature of
> visit_type_enum() by rewriting 'const char *const strings[]' to
> the syntactically invalid 'const char*const[] strings').
>
> // Part 1: Swap declaration order
> @@
> type TV, TErr, TObj, T1, T2;
> identifier OBJ, ARG1, ARG2;
> @@
> void visit_start_struct
> -(TV v, TObj OBJ, T1 ARG1, const char *name, T2 ARG2, TErr errp)
> +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
> { ... }
>
> @@
> type bool, TV, T1;
> identifier ARG1;
> @@
> bool visit_optional
> -(TV v, T1 ARG1, const char *name)
> +(TV v, const char *name, T1 ARG1)
> { ... }
>
> @@
> type TV, TErr, TObj, T1;
> identifier OBJ, ARG1;
> @@
> void visit_get_next_type
> -(TV v, TObj OBJ, T1 ARG1, const char *name, TErr errp)
> +(TV v, const char *name, TObj OBJ, T1 ARG1, TErr errp)
> { ... }
>
> @@
> type TV, TErr, TObj, T1, T2;
> identifier OBJ, ARG1, ARG2;
> @@
> void visit_type_enum
> -(TV v, TObj OBJ, T1 ARG1, T2 ARG2, const char *name, TErr errp)
> +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
> { ... }
>
> @@
> type TV, TErr, TObj;
> identifier OBJ;
> identifier VISIT_TYPE =~ "^visit_type_";
> @@
> void VISIT_TYPE
> -(TV v, TObj OBJ, const char *name, TErr errp)
> +(TV v, const char *name, TObj OBJ, TErr errp)
> { ... }
>
> // Part 2: swap caller order
> @@
> expression V, NAME, OBJ, ARG1, ARG2, ERR;
> identifier VISIT_TYPE =~ "^visit_type_";
> @@
> (
> -visit_start_struct(V, OBJ, ARG1, NAME, ARG2, ERR)
> +visit_start_struct(V, NAME, OBJ, ARG1, ARG2, ERR)
> |
> -visit_optional(V, ARG1, NAME)
> +visit_optional(V, NAME, ARG1)
> |
> -visit_get_next_type(V, OBJ, ARG1, NAME, ERR)
> +visit_get_next_type(V, NAME, OBJ, ARG1, ERR)
> |
> -visit_type_enum(V, OBJ, ARG1, ARG2, NAME, ERR)
> +visit_type_enum(V, NAME, OBJ, ARG1, ARG2, ERR)
> |
> -VISIT_TYPE(V, OBJ, NAME, ERR)
> +VISIT_TYPE(V, NAME, OBJ, ERR)
> )
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
The result looks good and passes the tests
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
However, docs/qapi-code-gen.txt should be updated in a follow-up patch.
--
Marc-André Lureau
