[PATCH 2/6] hw/display/tcx: Add missing fall through comments

Philippe Mathieu-Daudé posted 6 patches 6 years, 1 month ago
Maintainers: Kevin Wolf <kwolf@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Joel Stanley <joel@jms.id.au>, Gerd Hoffmann <kraxel@redhat.com>, Peter Chubb <peter.chubb@nicta.com.au>, Andrew Jeffery <andrew@aj.id.au>, Hannes Reinecke <hare@suse.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Peter Maydell <peter.maydell@linaro.org>, Jason Wang <jasowang@redhat.com>, Fam Zheng <fam@euphon.net>, "Cédric Le Goater" <clg@kaod.org>, Max Reitz <mreitz@redhat.com>
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[PATCH 2/6] hw/display/tcx: Add missing fall through comments
Posted by Philippe Mathieu-Daudé 6 years, 1 month ago
GCC9 is confused by this comment when building with
CFLAG -Wimplicit-fallthrough=2:

  hw/display/tcx.c: In function ‘tcx_dac_writel’:
  hw/display/tcx.c:453:26: error: this statement may fall through [-Werror=implicit-fallthrough=]
    453 |             s->dac_index = (s->dac_index + 1) & 0xff; /* Index autoincrement */
        |             ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
  hw/display/tcx.c:454:9: note: here
    454 |         default:
        |         ^~~~~~~
  hw/display/tcx.c: In function ‘tcx_dac_readl’:
  hw/display/tcx.c:412:22: error: this statement may fall through [-Werror=implicit-fallthrough=]
    412 |         s->dac_index = (s->dac_index + 1) & 0xff; /* Index autoincrement */
        |         ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
  hw/display/tcx.c:413:5: note: here
    413 |     default:
        |     ^~~~~~~
  cc1: all warnings being treated as errors

Add the missing fall through comments.

Fixes: 55d7bfe22
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
Cc: Olivier Danet <odanet@caramail.com>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/display/tcx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/display/tcx.c b/hw/display/tcx.c
index 14e829d3fa..abbeb30284 100644
--- a/hw/display/tcx.c
+++ b/hw/display/tcx.c
@@ -410,6 +410,7 @@ static uint64_t tcx_dac_readl(void *opaque, hwaddr addr,
     case 2:
         val = s->b[s->dac_index] << 24;
         s->dac_index = (s->dac_index + 1) & 0xff; /* Index autoincrement */
+        /* fall through */
     default:
         s->dac_state = 0;
         break;
@@ -451,6 +452,7 @@ static void tcx_dac_writel(void *opaque, hwaddr addr, uint64_t val,
             s->b[index] = val >> 24;
             update_palette_entries(s, index, index + 1);
             s->dac_index = (s->dac_index + 1) & 0xff; /* Index autoincrement */
+            /* fall through */
         default:
             s->dac_state = 0;
             break;
-- 
2.21.0


Re: [PATCH 2/6] hw/display/tcx: Add missing fall through comments
Posted by Richard Henderson 6 years, 1 month ago
On 12/17/19 7:34 AM, Philippe Mathieu-Daudé wrote:
> GCC9 is confused by this comment when building with
> CFLAG -Wimplicit-fallthrough=2:
> 
>   hw/display/tcx.c: In function ‘tcx_dac_writel’:
>   hw/display/tcx.c:453:26: error: this statement may fall through [-Werror=implicit-fallthrough=]
>     453 |             s->dac_index = (s->dac_index + 1) & 0xff; /* Index autoincrement */
>         |             ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
>   hw/display/tcx.c:454:9: note: here
>     454 |         default:
>         |         ^~~~~~~
>   hw/display/tcx.c: In function ‘tcx_dac_readl’:
>   hw/display/tcx.c:412:22: error: this statement may fall through [-Werror=implicit-fallthrough=]
>     412 |         s->dac_index = (s->dac_index + 1) & 0xff; /* Index autoincrement */
>         |         ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
>   hw/display/tcx.c:413:5: note: here
>     413 |     default:
>         |     ^~~~~~~
>   cc1: all warnings being treated as errors
> 
> Add the missing fall through comments.
> 
> Fixes: 55d7bfe22
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> Cc: Olivier Danet <odanet@caramail.com>
> Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
>  hw/display/tcx.c | 2 ++
>  1 file changed, 2 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

Re: [PATCH 2/6] hw/display/tcx: Add missing fall through comments
Posted by Aleksandar Markovic 6 years, 1 month ago
On Tuesday, December 17, 2019, Philippe Mathieu-Daudé <philmd@redhat.com>
wrote:

> GCC9 is confused by this comment when building with
> CFLAG -Wimplicit-fallthrough=2:
>
>   hw/display/tcx.c: In function ‘tcx_dac_writel’:
>   hw/display/tcx.c:453:26: error: this statement may fall through
> [-Werror=implicit-fallthrough=]
>     453 |             s->dac_index = (s->dac_index + 1) & 0xff; /* Index
> autoincrement */
>         |             ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
>   hw/display/tcx.c:454:9: note: here
>     454 |         default:
>         |         ^~~~~~~
>   hw/display/tcx.c: In function ‘tcx_dac_readl’:
>   hw/display/tcx.c:412:22: error: this statement may fall through
> [-Werror=implicit-fallthrough=]
>     412 |         s->dac_index = (s->dac_index + 1) & 0xff; /* Index
> autoincrement */
>         |         ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
>   hw/display/tcx.c:413:5: note: here
>     413 |     default:
>         |     ^~~~~~~
>   cc1: all warnings being treated as errors
>
> Add the missing fall through comments.
>
> Fixes: 55d7bfe22
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> Cc: Olivier Danet <odanet@caramail.com>
> Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
>  hw/display/tcx.c | 2 ++
>  1 file changed, 2 insertions(+)
>
>
The content of the patch is fine, but the commit message is, I think,
inacurate: gcc is not confused at all, it does what it was told to.

The title is fine.


> diff --git a/hw/display/tcx.c b/hw/display/tcx.c
> index 14e829d3fa..abbeb30284 100644
> --- a/hw/display/tcx.c
> +++ b/hw/display/tcx.c
> @@ -410,6 +410,7 @@ static uint64_t tcx_dac_readl(void *opaque, hwaddr
> addr,
>      case 2:
>          val = s->b[s->dac_index] << 24;
>          s->dac_index = (s->dac_index + 1) & 0xff; /* Index autoincrement
> */
> +        /* fall through */
>      default:
>          s->dac_state = 0;
>          break;
> @@ -451,6 +452,7 @@ static void tcx_dac_writel(void *opaque, hwaddr addr,
> uint64_t val,
>              s->b[index] = val >> 24;
>              update_palette_entries(s, index, index + 1);
>              s->dac_index = (s->dac_index + 1) & 0xff; /* Index
> autoincrement */
> +            /* fall through */
>          default:
>              s->dac_state = 0;
>              break;
> --
> 2.21.0
>
>
>
Re: [PATCH 2/6] hw/display/tcx: Add missing fall through comments
Posted by Philippe Mathieu-Daudé 6 years, 1 month ago
On 12/18/19 8:54 AM, Aleksandar Markovic wrote:
> 
> 
> On Tuesday, December 17, 2019, Philippe Mathieu-Daudé <philmd@redhat.com 
> <mailto:philmd@redhat.com>> wrote:
> 
>     GCC9 is confused by this comment when building with
>     CFLAG -Wimplicit-fallthrough=2:
> 
>        hw/display/tcx.c: In function ‘tcx_dac_writel’:
>        hw/display/tcx.c:453:26: error: this statement may fall through
>     [-Werror=implicit-fallthrough=]
>          453 |             s->dac_index = (s->dac_index + 1) & 0xff; /*
>     Index autoincrement */
>              |             ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
>        hw/display/tcx.c:454:9: note: here
>          454 |         default:
>              |         ^~~~~~~
>        hw/display/tcx.c: In function ‘tcx_dac_readl’:
>        hw/display/tcx.c:412:22: error: this statement may fall through
>     [-Werror=implicit-fallthrough=]
>          412 |         s->dac_index = (s->dac_index + 1) & 0xff; /*
>     Index autoincrement */
>              |         ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
>        hw/display/tcx.c:413:5: note: here
>          413 |     default:
>              |     ^~~~~~~
>        cc1: all warnings being treated as errors
> 
>     Add the missing fall through comments.
> 
>     Fixes: 55d7bfe22
>     Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com
>     <mailto:philmd@redhat.com>>
>     ---
>     Cc: Olivier Danet <odanet@caramail.com <mailto:odanet@caramail.com>>
>     Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk
>     <mailto:mark.cave-ayland@ilande.co.uk>>
>     ---
>       hw/display/tcx.c | 2 ++
>       1 file changed, 2 insertions(+)
> 
> 
> The content of the patch is fine, but the commit message is, I think, 
> inacurate: gcc is not confused at all, it does what it was told to.

You are correct, I'll update the comment.

> The title is fine.
> 
>     diff --git a/hw/display/tcx.c b/hw/display/tcx.c
>     index 14e829d3fa..abbeb30284 100644
>     --- a/hw/display/tcx.c
>     +++ b/hw/display/tcx.c
>     @@ -410,6 +410,7 @@ static uint64_t tcx_dac_readl(void *opaque,
>     hwaddr addr,
>           case 2:
>               val = s->b[s->dac_index] << 24;
>               s->dac_index = (s->dac_index + 1) & 0xff; /* Index
>     autoincrement */
>     +        /* fall through */
>           default:
>               s->dac_state = 0;
>               break;
>     @@ -451,6 +452,7 @@ static void tcx_dac_writel(void *opaque, hwaddr
>     addr, uint64_t val,
>                   s->b[index] = val >> 24;
>                   update_palette_entries(s, index, index + 1);
>                   s->dac_index = (s->dac_index + 1) & 0xff; /* Index
>     autoincrement */
>     +            /* fall through */
>               default:
>                   s->dac_state = 0;
>                   break;
>     -- 
>     2.21.0
> 
>