qapi: Support downstream alternates

Enhance the testsuite to cover downstream alternates, including
whether the branch name or type is downstream. Update the
generator to mangle alternate names in the appropriate places.

Backports commit d1f07c86c05706facf950b0b0dba370f71fd5ef6 from qemu

qemu/scripts/qapi-types.py

@@ -163,18 +163,18 @@ def generate_alternate_qtypes(expr):
     ret = mcgen('''
 const int %(name)s_qtypes[QTYPE_MAX] = {
 ''',
-    name=name)
+                name=c_name(name))
 
     for key in members:
         qtype = find_alternate_member_qtype(members[key])
         assert qtype, "Invalid alternate member"
 
         ret += mcgen('''
-    [ %(qtype)s ] = %(abbrev)s_KIND_%(enum)s,
+    [%(qtype)s] = %(enum_const)s,
 ''',
-        qtype = qtype,
-        abbrev = de_camel_case(name).upper(),
-        enum = c_name(de_camel_case(key),False).upper())
+                     qtype = qtype,
+                     enum_const = c_enum_const(name + 'Kind', key))
+
 
     ret += mcgen('''
 };

qemu/scripts/qapi-visit.py

@@ -203,11 +203,11 @@ void visit_type_%(name)s(Visitor *m, %(name)s **obj, const char *name, Error **e
     }
     switch ((*obj)->kind) {
 ''',
-    name=name)
+                name=c_name(name))
 
     # For alternate, always use the default enum type automatically generated
-    # as "'%sKind' % (name)"
-    disc_type = '%sKind' % (name)
+    # as name + 'Kind'
+    disc_type = c_name(name) + 'Kind'
 
     for key in members:
         assert (members[key] in builtin_types.keys()

qemu/scripts/qapi.py

@@ -728,17 +728,6 @@ def parse_args(typeinfo):
         # value of an optional argument.
         yield (argname, argentry, optional)
 
-def de_camel_case(name):
-    new_name = ''
-    for ch in name:
-        if ch.isupper() and new_name:
-            new_name += '_'
-        if ch == '-':
-            new_name += '_'
-        else:
-            new_name += ch.lower()
-    return new_name
-
 def camel_case(name):
     new_name = ''
     first = True