Re: [PATCH] target/i386/cpu: add return value verification and ignore Error objects

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 9/4/20 3:45 PM, Pan Nengyuan wrote:
> 'err' is unnecessary in x86_cpu_class_check_missing_features(), we can change x86_cpu_expand_features()
> to return true on success, false on failure, then pass NULL here to remove it.
> 
> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
> Suggested-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
>  target/i386/cpu.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 49d8958528..c3d3766133 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -4883,7 +4883,7 @@ static void x86_cpu_parse_featurestr(const char *typename, char *features,
>      }
>  }
>  
> -static void x86_cpu_expand_features(X86CPU *cpu, Error **errp);
> +static bool x86_cpu_expand_features(X86CPU *cpu, Error **errp);
>  static void x86_cpu_filter_features(X86CPU *cpu, bool verbose);
>  
>  /* Build a list with the name of all features on a feature word array */
> @@ -4925,7 +4925,6 @@ static void x86_cpu_class_check_missing_features(X86CPUClass *xcc,
>                                                   strList **missing_feats)
>  {
>      X86CPU *xc;
> -    Error *err = NULL;
>      strList **next = missing_feats;
>  
>      if (xcc->host_cpuid_required && !accel_uses_host_cpuid()) {
> @@ -4937,8 +4936,7 @@ static void x86_cpu_class_check_missing_features(X86CPUClass *xcc,
>  
>      xc = X86_CPU(object_new_with_class(OBJECT_CLASS(xcc)));
>  
> -    x86_cpu_expand_features(xc, &err);
> -    if (err) {
> +    if (!x86_cpu_expand_features(xc, NULL)) {
>          /* Errors at x86_cpu_expand_features should never happen,
>           * but in case it does, just report the model as not
>           * runnable at all using the "type" property.
> @@ -4947,7 +4945,6 @@ static void x86_cpu_class_check_missing_features(X86CPUClass *xcc,
>          new->value = g_strdup("type");
>          *next = new;
>          next = &new->next;
> -        error_free(err);
>      }
>  
>      x86_cpu_filter_features(xc, false);
> @@ -6426,7 +6423,7 @@ static void x86_cpu_enable_xsave_components(X86CPU *cpu)
>  /* Expand CPU configuration data, based on configured features
>   * and host/accelerator capabilities when appropriate.
>   */
> -static void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
> +static bool x86_cpu_expand_features(X86CPU *cpu, Error **errp)
>  {
>      CPUX86State *env = &cpu->env;
>      FeatureWord w;
> @@ -6436,14 +6433,14 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
>      for (l = plus_features; l; l = l->next) {
>          const char *prop = l->data;
>          if (!object_property_set_bool(OBJECT(cpu), prop, true, errp)) {
> -            return;
> +            return false;
>          }
>      }
>  
>      for (l = minus_features; l; l = l->next) {
>          const char *prop = l->data;
>          if (!object_property_set_bool(OBJECT(cpu), prop, false, errp)) {
> -            return;
> +            return false;
>          }
>      }
>  
> @@ -6540,6 +6537,8 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
>      if (env->cpuid_xlevel2 == UINT32_MAX) {
>          env->cpuid_xlevel2 = env->cpuid_min_xlevel2;
>      }
> +
> +    return true;
>  }
>  
>  /*
>