Re: [Qemu-devel] [PATCH v23 04/32] change opt->name and opt->str from (const char *) to (char *)

[Leandro Dorileo <l@dorileo.org>]

On Fri, Mar 21, 2014 at 06:12:15PM +0800, Chunyan Liu wrote:
> Signed-off-by: Chunyan Liu <cyliu@suse.com>
> ---
>  include/qemu/option_int.h |  4 ++--
>  qapi/opts-visitor.c       | 10 +++++++---
>  util/qemu-option.c        |  4 ++--
>  3 files changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/include/qemu/option_int.h b/include/qemu/option_int.h
> index 8212fa4..db9ed91 100644
> --- a/include/qemu/option_int.h
> +++ b/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;


I still don't see why you need this change. I understand you're strdup'ing name
and str, what I can't get is why you need this, and since the lack of description
in the patch itself I don't know what you're fixing here.

I saw the opts-visitor.c users and they're mostly controlling their QemuOpts instances,
their instances come after a qemu_opts_from_qdict() or qemu_opts_parse().

I haven't seen the users with too much inversion but I guess they follow the same
pattern.

I may be missing something completely obvious here but if you really need this change
could you introduce a test in the test-opts-visitor.c test suite so we can understand
the problem you're fixing here?

Regards...

-- 
Leandro Dorileo

>  
>      const QemuOptDesc *desc;
>      union {
> diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
> index 5d830a2..7a64f4e 100644
> --- a/qapi/opts-visitor.c
> +++ b/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;
>  }
>  
> diff --git a/util/qemu-option.c b/util/qemu-option.c
> index d5e80da..eab5102 100644
> --- a/util/qemu-option.c
> +++ b/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);
>  }
>  
> -- 
> 1.7.12.4
> 
>