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, 14 insertions, 14 deletions

diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index ba75667e03..35505acd98 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -29,7 +29,7 @@ def gen_visit_decl(name, scalar=False):
     if not scalar:
         c_type += '*'
     return mcgen('''
-void visit_type_%(c_name)s(Visitor *v, %(c_type)sobj, const char *name, Error **errp);
+void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **errp);
 ''',
                  c_name=c_name(name), c_type=c_type)
 
@@ -118,11 +118,11 @@ def gen_visit_struct(name, base, members):
     # call qapi_free_FOO() to avoid a memory leak of the partial FOO.
     ret += mcgen('''
 
-void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
+void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 {
     Error *err = NULL;
 
-    visit_start_struct(v, (void **)obj, "%(name)s", name, sizeof(%(c_name)s), &err);
+    visit_start_struct(v, name, (void **)obj, "%(name)s", sizeof(%(c_name)s), &err);
     if (err) {
         goto out;
     }
@@ -150,7 +150,7 @@ def gen_visit_list(name, element_type):
     # call qapi_free_FOOList() to avoid a memory leak of the partial FOOList.
     return mcgen('''
 
-void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
+void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 {
     Error *err = NULL;
     GenericList *i, **prev;
@@ -164,7 +164,7 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
          !err && (i = visit_next_list(v, prev, &err)) != NULL;
          prev = &i) {
         %(c_name)s *native_i = (%(c_name)s *)i;
-        visit_type_%(c_elt_type)s(v, &native_i->value, NULL, &err);
+        visit_type_%(c_elt_type)s(v, NULL, &native_i->value, &err);
     }
 
     error_propagate(errp, err);
@@ -180,10 +180,10 @@ out:
 def gen_visit_enum(name):
     return mcgen('''
 
-void visit_type_%(c_name)s(Visitor *v, %(c_name)s *obj, const char *name, Error **errp)
+void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s *obj, Error **errp)
 {
     int value = *obj;
-    visit_type_enum(v, &value, %(c_name)s_lookup, "%(name)s", name, errp);
+    visit_type_enum(v, name, &value, %(c_name)s_lookup, "%(name)s", errp);
     *obj = value;
 }
 ''',
@@ -198,7 +198,7 @@ def gen_visit_alternate(name, variants):
 
     ret = mcgen('''
 
-void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
+void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 {
     Error *err = NULL;
 
@@ -206,7 +206,7 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
     if (err) {
         goto out;
     }
-    visit_get_next_type(v, &(*obj)->type, %(promote_int)s, name, &err);
+    visit_get_next_type(v, name, &(*obj)->type, %(promote_int)s, &err);
     if (err) {
         goto out_obj;
     }
@@ -217,7 +217,7 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
     for var in variants.variants:
         ret += mcgen('''
     case %(case)s:
-        visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, name, &err);
+        visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, &err);
         break;
 ''',
                      case=var.type.alternate_qtype(),
@@ -255,11 +255,11 @@ def gen_visit_union(name, base, variants):
 
     ret += mcgen('''
 
-void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)
+void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error **errp)
 {
     Error *err = NULL;
 
-    visit_start_struct(v, (void **)obj, "%(name)s", name, sizeof(%(c_name)s), &err);
+    visit_start_struct(v, name, (void **)obj, "%(name)s", sizeof(%(c_name)s), &err);
     if (err) {
         goto out;
     }
@@ -276,7 +276,7 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
                      c_name=base.c_name())
     else:
         ret += mcgen('''
-    visit_type_%(c_type)s(v, &(*obj)->%(c_name)s, "%(name)s", &err);
+    visit_type_%(c_type)s(v, "%(name)s", &(*obj)->%(c_name)s, &err);
 ''',
                      c_type=variants.tag_member.type.c_name(),
                      c_name=c_name(variants.tag_member.name),
@@ -300,7 +300,7 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
                                        var.name))
         if simple_union_type:
             ret += mcgen('''
-        visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, "data", &err);
+        visit_type_%(c_type)s(v, "data", &(*obj)->u.%(c_name)s, &err);
 ''',
                          c_type=simple_union_type.c_name(),
                          c_name=c_name(var.name))