[waffle] [PATCH 2/6] wflinfo: Cleanup signature of wflinfo_try_create_context()

[Emil Velikov]

On 29/04/14 04:43, Chad Versace wrote:
> The function creates and returns two objects: a context and a config.
> The context is the function's return value, and the config is an out
> parameter.
> 
> Functions with asymmetric returns, I find awkard. Fix the signature to
> return both objects as out parameters.
> 
Hi Chad,

Rather silly question (as I'm getting through the codebase).

Wouldn't it be better if use return int over bool ? The function name does not
imply that a bool is returned, plus it gives us the flexibility of returning
appropriate (currently unneeded) errno.

Cheers,
Emil

> Signed-off-by: Chad Versace <chad.versace at linux.intel.com>
> ---
>  src/utils/wflinfo.c | 39 ++++++++++++++++++++-------------------
>  1 file changed, 20 insertions(+), 19 deletions(-)
> 
> diff --git a/src/utils/wflinfo.c b/src/utils/wflinfo.c
> index 4a105be..038deac 100644
> --- a/src/utils/wflinfo.c
> +++ b/src/utils/wflinfo.c
> @@ -600,19 +600,17 @@ removeXcodeArgs(int *argc, char **argv)
>  
>  #endif // __APPLE__
>  
> -static struct waffle_context *
> +static bool
>  wflinfo_try_create_context(const struct options *opts,
> -                           struct waffle_config **config,
>                             struct waffle_display *dpy,
> +                           struct waffle_context **out_ctx,
> +                           struct waffle_config **out_config,
>                             bool exit_on_fail)
>  {
>      int i;
>      int32_t config_attrib_list[64];
> -    struct waffle_context *ctx;
> -
> -    // Initialize outputs.
> -    ctx = NULL;
> -    *config = NULL;
> +    struct waffle_context *ctx = NULL;
> +    struct waffle_config *config = NULL;
>  
>      i = 0;
>      config_attrib_list[i++] = WAFFLE_CONTEXT_API;
> @@ -659,17 +657,19 @@ wflinfo_try_create_context(const struct options *opts,
>  
>      config_attrib_list[i++] = 0;
>  
> -    *config = waffle_config_choose(dpy, config_attrib_list);
> -    if (!*config) {
> +    config = waffle_config_choose(dpy, config_attrib_list);
> +    if (!config) {
>          goto fail;
>      }
>  
> -    ctx = waffle_context_create(*config, NULL);
> +    ctx = waffle_context_create(config, NULL);
>      if (!ctx) {
>          goto fail;
>      }
>  
> -    return ctx;
> +    *out_ctx = ctx;
> +    *out_config = config;
> +    return true;
>  
>  fail:
>      if (exit_on_fail) {
> @@ -678,11 +678,11 @@ fail:
>      if (ctx) {
>          waffle_context_destroy(ctx);
>      }
> -    if (*config) {
> -        waffle_config_destroy(*config);
> +    if (config) {
> +        waffle_config_destroy(config);
>      }
>  
> -    return NULL;
> +    return false;
>  }
>  
>  #define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
> @@ -692,7 +692,8 @@ wflinfo_create_context(const struct options *opts,
>                         struct waffle_config **config,
>                         struct waffle_display *dpy)
>  {
> -    struct waffle_context *ctx;
> +    struct waffle_context *ctx = NULL;
> +    bool ok = true;
>  
>      if (opts->context_profile != WAFFLE_NONE &&
>          opts->context_api == WAFFLE_CONTEXT_OPENGL &&
> @@ -709,13 +710,13 @@ wflinfo_create_context(const struct options *opts,
>  
>          for (int i = ARRAY_SIZE(known_gl_profile_versions) - 1; i >= 0; i--) {
>              tmp_opts.context_version = known_gl_profile_versions[i];
> -            ctx = wflinfo_try_create_context(&tmp_opts, config, dpy, false);
> -            if (ctx)
> +            ok = wflinfo_try_create_context(&tmp_opts, dpy, &ctx, config, false);
> +            if (!ok) {
>                  break;
> +            }
>          }
>      } else {
> -        ctx = wflinfo_try_create_context(opts, config, dpy, true);
> -
> +        wflinfo_try_create_context(opts, dpy, &ctx, config, true);
>      }
>  
>      return ctx;
>