qapi: Swap visit_* arguments for consistent 'name' placement

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.

Additional reason in favor of the swap: 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.

Later patches will then fix docs, 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').  The
movement of parameters is sufficient to provoke compiler errors
if any callers were missed.

    // 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 <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-19-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 5 insertions, 6 deletions

diff --git a/qemu-img.c b/qemu-img.c
index f121980707..163d8c1664 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -376,8 +376,8 @@ static void dump_json_image_check(ImageCheck *check, bool quiet)
     QString *str;
     QmpOutputVisitor *ov = qmp_output_visitor_new();
     QObject *obj;
-    visit_type_ImageCheck(qmp_output_get_visitor(ov),
-                          &check, NULL, &local_err);
+    visit_type_ImageCheck(qmp_output_get_visitor(ov), NULL, &check,
+                          &local_err);
     obj = qmp_output_get_qobject(ov);
     str = qobject_to_json_pretty(obj);
     assert(str != NULL);
@@ -1942,8 +1942,8 @@ static void dump_json_image_info_list(ImageInfoList *list)
     QString *str;
     QmpOutputVisitor *ov = qmp_output_visitor_new();
     QObject *obj;
-    visit_type_ImageInfoList(qmp_output_get_visitor(ov),
-                             &list, NULL, &local_err);
+    visit_type_ImageInfoList(qmp_output_get_visitor(ov), NULL, &list,
+                             &local_err);
     obj = qmp_output_get_qobject(ov);
     str = qobject_to_json_pretty(obj);
     assert(str != NULL);
@@ -1959,8 +1959,7 @@ static void dump_json_image_info(ImageInfo *info)
     QString *str;
     QmpOutputVisitor *ov = qmp_output_visitor_new();
     QObject *obj;
-    visit_type_ImageInfo(qmp_output_get_visitor(ov),
-                         &info, NULL, &local_err);
+    visit_type_ImageInfo(qmp_output_get_visitor(ov), NULL, &info, &local_err);
     obj = qmp_output_get_qobject(ov);
     str = qobject_to_json_pretty(obj);
     assert(str != NULL);