[PATCH v2] hw/rtc/twl92230: Silence warnings about missing fallthrough statements

[PATCH v2] hw/rtc/twl92230: Silence warnings about missing fallthrough statements

[Thomas Huth]

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.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 v2: Fixed copy-n-paste bug

 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..50b97a1fce 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_DCDC_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:
-- 
2.18.2

Re: [PATCH v2] hw/rtc/twl92230: Silence warnings about missing fallthrough statements

[Markus Armbruster]

Thomas Huth <thuth@redhat.com> writes:

> 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.
>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  v2: Fixed copy-n-paste bug
>
>  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..50b97a1fce 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];

Suggest to count up instead of down:

       case MENELAUS_VCORE_CTRL1:
  +    case MENELAUS_VCORE_CTRL2:
  +    case MENELAUS_VCORE_CTRL3:
  +    case MENELAUS_VCORE_CTRL4:
  +    case MENELAUS_VCORE_CTRL5:
  -        return s->vcore[reg];
  +        return s->vcore[addr - MENELAUS_VCORE_CTRL1];

[...]