Re: [PATCH] hw/rtc/twl92230: Silence warnings about missing fallthrough statements

[Laurent Vivier <laurent@vivier.eu>]

Le 01/10/2020 à 20:21, Thomas Huth a écrit :
> When compiling with -Werror=implicit-fallthrough, gcc complains about
> missing fallthrough annotations in this file. Looking at the code,
> the fallthrough is indeed wanted here, but instead of adding the
> annotations, it can be done more efficiently by simply calculating
> the offset with a subtraction instead of increasing a local variable
> one by one.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  hw/rtc/twl92230.c | 50 +++++++++++++++++++++++------------------------
>  1 file changed, 24 insertions(+), 26 deletions(-)
> 
> diff --git a/hw/rtc/twl92230.c b/hw/rtc/twl92230.c
> index f838913b37..499f421932 100644
> --- a/hw/rtc/twl92230.c
> +++ b/hw/rtc/twl92230.c
> @@ -271,37 +271,36 @@ static void menelaus_gpio_set(void *opaque, int line, int level)
>  static uint8_t menelaus_read(void *opaque, uint8_t addr)
>  {
>      MenelausState *s = (MenelausState *) opaque;
> -    int reg = 0;
>  
>      switch (addr) {
>      case MENELAUS_REV:
>          return 0x22;
>  
> -    case MENELAUS_VCORE_CTRL5: reg ++;
> -    case MENELAUS_VCORE_CTRL4: reg ++;
> -    case MENELAUS_VCORE_CTRL3: reg ++;
> -    case MENELAUS_VCORE_CTRL2: reg ++;
> +    case MENELAUS_VCORE_CTRL5:
> +    case MENELAUS_VCORE_CTRL4:
> +    case MENELAUS_VCORE_CTRL3:
> +    case MENELAUS_VCORE_CTRL2:
>      case MENELAUS_VCORE_CTRL1:
> -        return s->vcore[reg];
> +        return s->vcore[addr - MENELAUS_VCORE_CTRL1];
>  
> -    case MENELAUS_DCDC_CTRL3: reg ++;
> -    case MENELAUS_DCDC_CTRL2: reg ++;
> +    case MENELAUS_DCDC_CTRL3:
> +    case MENELAUS_DCDC_CTRL2:
>      case MENELAUS_DCDC_CTRL1:
> -        return s->dcdc[reg];
> -
> -    case MENELAUS_LDO_CTRL8: reg ++;
> -    case MENELAUS_LDO_CTRL7: reg ++;
> -    case MENELAUS_LDO_CTRL6: reg ++;
> -    case MENELAUS_LDO_CTRL5: reg ++;
> -    case MENELAUS_LDO_CTRL4: reg ++;
> -    case MENELAUS_LDO_CTRL3: reg ++;
> -    case MENELAUS_LDO_CTRL2: reg ++;
> +        return s->dcdc[addr - MENELAUS_VCORE_CTRL1];
> +
> +    case MENELAUS_LDO_CTRL8:
> +    case MENELAUS_LDO_CTRL7:
> +    case MENELAUS_LDO_CTRL6:
> +    case MENELAUS_LDO_CTRL5:
> +    case MENELAUS_LDO_CTRL4:
> +    case MENELAUS_LDO_CTRL3:
> +    case MENELAUS_LDO_CTRL2:
>      case MENELAUS_LDO_CTRL1:
> -        return s->ldo[reg];
> +        return s->ldo[addr - MENELAUS_LDO_CTRL1];
>  
> -    case MENELAUS_SLEEP_CTRL2: reg ++;
> +    case MENELAUS_SLEEP_CTRL2:
>      case MENELAUS_SLEEP_CTRL1:
> -        return s->sleep[reg];
> +        return s->sleep[addr - MENELAUS_SLEEP_CTRL1];
>  
>      case MENELAUS_DEVICE_OFF:
>          return 0;
> @@ -395,10 +394,10 @@ static uint8_t menelaus_read(void *opaque, uint8_t addr)
>      case MENELAUS_S2_PULL_DIR:
>          return s->pull[3];
>  
> -    case MENELAUS_MCT_CTRL3: reg ++;
> -    case MENELAUS_MCT_CTRL2: reg ++;
> +    case MENELAUS_MCT_CTRL3:
> +    case MENELAUS_MCT_CTRL2:
>      case MENELAUS_MCT_CTRL1:
> -        return s->mmc_ctrl[reg];
> +        return s->mmc_ctrl[addr - MENELAUS_MCT_CTRL1];
>      case MENELAUS_MCT_PIN_ST:
>          /* TODO: return the real Card Detect */
>          return 0;
> @@ -418,7 +417,6 @@ static void menelaus_write(void *opaque, uint8_t addr, uint8_t value)
>  {
>      MenelausState *s = (MenelausState *) opaque;
>      int line;
> -    int reg = 0;
>      struct tm tm;
>  
>      switch (addr) {
> @@ -496,9 +494,9 @@ static void menelaus_write(void *opaque, uint8_t addr, uint8_t value)
>          s->ldo[7] = value & 3;
>          break;
>  
> -    case MENELAUS_SLEEP_CTRL2: reg ++;
> +    case MENELAUS_SLEEP_CTRL2:
>      case MENELAUS_SLEEP_CTRL1:
> -        s->sleep[reg] = value;
> +        s->sleep[addr - MENELAUS_SLEEP_CTRL1] = value;
>          break;
>  
>      case MENELAUS_DEVICE_OFF:
> 

pplied to my trivial-patches branch.

Thanks,
Laurent