QemuOpts: change opt->name|str from (const char *) to (char *)

qemu_opt_del() already assumes that all QemuOpt instances contain
malloc'd name and value; but it had to cast away const because
opts_start_struct() was doing its own thing and using static storage
instead.  By using the correct type and malloced strings everywhere, the
usage of this struct becomes clearer.
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NLeandro Dorileo <l@dorileo.org>
Signed-off-by: NChunyan Liu <cyliu@suse.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

include/qemu/option_int.h

@@ -30,8 +30,8 @@
 #include "qemu/error-report.h"
 
 struct QemuOpt {
-    const char   *name;
-    const char   *str;
+    char *name;
+    char *str;
 
     const QemuOptDesc *desc;
     union {

qapi/opts-visitor.c

@@ -143,8 +143,8 @@ opts_start_struct(Visitor *v, void **obj, const char *kind,
     if (ov->opts_root->id != NULL) {
         ov->fake_id_opt = g_malloc0(sizeof *ov->fake_id_opt);
 
-        ov->fake_id_opt->name = "id";
-        ov->fake_id_opt->str = ov->opts_root->id;
+        ov->fake_id_opt->name = g_strdup("id");
+        ov->fake_id_opt->str = g_strdup(ov->opts_root->id);
         opts_visitor_insert(ov->unprocessed_opts, ov->fake_id_opt);
     }
 }
@@ -177,7 +177,11 @@ opts_end_struct(Visitor *v, Error **errp)
     }
     g_hash_table_destroy(ov->unprocessed_opts);
     ov->unprocessed_opts = NULL;
-    g_free(ov->fake_id_opt);
+    if (ov->fake_id_opt) {
+        g_free(ov->fake_id_opt->name);
+        g_free(ov->fake_id_opt->str);
+        g_free(ov->fake_id_opt);
+    }
     ov->fake_id_opt = NULL;
 }
 

util/qemu-option.c

@@ -664,8 +664,8 @@ static void qemu_opt_parse(QemuOpt *opt, Error **errp)
 static void qemu_opt_del(QemuOpt *opt)
 {
     QTAILQ_REMOVE(&opt->opts->head, opt, next);
-    g_free((/* !const */ char*)opt->name);
-    g_free((/* !const */ char*)opt->str);
+    g_free(opt->name);
+    g_free(opt->str);
     g_free(opt);
 }