cpu: drop unnecessary NULL check and cpu_common_class_by_name()

both do nothing as for the first all callers
   parse_cpu_model() and qmp_query_cpu_model_()
should provide non NULL value, so just abort if it's not so.

While at it drop cpu_common_class_by_name() which is not need
any more as every target has CPUClass::class_by_name callback
by now, though abort in case a new arch will forget to define one.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Message-Id: <1518013857-4372-1-git-send-email-imammedo@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

qom/cpu.c

@@ -286,21 +286,12 @@ static bool cpu_common_has_work(CPUState *cs)
 
 ObjectClass *cpu_class_by_name(const char *typename, const char *cpu_model)
 {
-    CPUClass *cc;
-
-    if (!cpu_model) {
-        return NULL;
-    }
-    cc = CPU_CLASS(object_class_by_name(typename));
+    CPUClass *cc = CPU_CLASS(object_class_by_name(typename));
 
+    assert(cpu_model && cc->class_by_name);
     return cc->class_by_name(cpu_model);
 }
 
-static ObjectClass *cpu_common_class_by_name(const char *cpu_model)
-{
-    return NULL;
-}
-
 static void cpu_common_parse_features(const char *typename, char *features,
                                       Error **errp)
 {
@@ -418,7 +409,6 @@ static void cpu_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     CPUClass *k = CPU_CLASS(klass);
 
-    k->class_by_name = cpu_common_class_by_name;
     k->parse_features = cpu_common_parse_features;
     k->reset = cpu_common_reset;
     k->get_arch_id = cpu_common_get_arch_id;

target/i386/cpu.c

@@ -781,13 +781,7 @@ static char *x86_cpu_type_name(const char *model_name)
 static ObjectClass *x86_cpu_class_by_name(const char *cpu_model)
 {
     ObjectClass *oc;
-    char *typename;
-
-    if (cpu_model == NULL) {
-        return NULL;
-    }
-
-    typename = x86_cpu_type_name(cpu_model);
+    char *typename = x86_cpu_type_name(cpu_model);
     oc = object_class_by_name(typename);
     g_free(typename);
     return oc;