[Buildroot] [PATCH v2, 1/1] package/python-rpi-ws281w: fix build with gcc 4.8

[Arnout Vandecappelle]

On 03/04/2021 14:36, Fabrice Fontaine wrote:
> Fix build failure with gcc 4.8 which is raised since bump to version
> 4.2.6 in commit f21d46bf99e2c3a86a86586bc3e82b214104cd30
> 
> Fixes:
>  - http://autobuild.buildroot.org/results/3d037922484bfc45d0f985f87b38f20c5a4ab064
> 
> Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>

 Applied to master, thanks.

 Regards,
 Arnout

> ---
> Changes v1 -> v2:
>  - Update upstream status
> 
>  ...0001-ws2811.c-fix-build-with-gcc-4.8.patch | 51 +++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 package/python-rpi-ws281x/0001-ws2811.c-fix-build-with-gcc-4.8.patch
> 
> diff --git a/package/python-rpi-ws281x/0001-ws2811.c-fix-build-with-gcc-4.8.patch b/package/python-rpi-ws281x/0001-ws2811.c-fix-build-with-gcc-4.8.patch
> new file mode 100644
> index 0000000000..9b534ac67a
> --- /dev/null
> +++ b/package/python-rpi-ws281x/0001-ws2811.c-fix-build-with-gcc-4.8.patch
> @@ -0,0 +1,51 @@
> +From 8faa5c2fb2b04b4fb062255aa807abafc50bff66 Mon Sep 17 00:00:00 2001
> +From: Fabrice Fontaine <fontaine.fabrice at gmail.com>
> +Date: Sat, 3 Apr 2021 10:27:20 +0200
> +Subject: [PATCH] ws2811.c: fix build with gcc 4.8
> +
> +Fix the following build failure with gcc 4.8 (which has been added by
> +commit 391f6e856d28510bd9ae4efd3a166da7f73613ab):
> +
> +lib/ws2811.c: In function 'ws2811_set_custom_gamma_factor':
> +lib/ws2811.c:1289:5: error: 'for' loop initial declarations are only allowed in C99 mode
> +     for (int chan = 0; chan < RPI_PWM_CHANNELS; chan++)
> +     ^
> +lib/ws2811.c:1289:5: note: use option -std=c99 or -std=gnu99 to compile your code
> +lib/ws2811.c:1295:11: error: 'for' loop initial declarations are only allowed in C99 mode
> +           for(int counter = 0; counter < 256; counter++)
> +           ^
> +
> +Fixes:
> + - http://autobuild.buildroot.org/results/3d037922484bfc45d0f985f87b38f20c5a4ab064
> +
> +Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>
> +[Retrieved from:
> +https://github.com/jgarff/rpi_ws281x/commit/0814bae544f0184ab1600bc2660486874eef5970]
> +---
> + ws2811.c | 5 +++--
> + 1 file changed, 3 insertions(+), 2 deletions(-)
> +
> +diff --git a/ws2811.c b/ws2811.c
> +index f5cdebd..6482796 100644
> +--- a/lib/ws2811.c
> ++++ b/lib/ws2811.c
> +@@ -1286,13 +1286,14 @@ const char * ws2811_get_return_t_str(const ws2811_return_t state)
> + 
> + void ws2811_set_custom_gamma_factor(ws2811_t *ws2811, double gamma_factor)
> + {
> +-    for (int chan = 0; chan < RPI_PWM_CHANNELS; chan++)
> ++    int chan, counter;
> ++    for (chan = 0; chan < RPI_PWM_CHANNELS; chan++)
> +     {
> +         ws2811_channel_t *channel = &ws2811->channel[chan];
> + 
> +         if (channel->gamma)
> +         {
> +-          for(int counter = 0; counter < 256; counter++)
> ++          for(counter = 0; counter < 256; counter++)
> +           {
> + 
> +              channel->gamma[counter] = (gamma_factor > 0)? (int)(pow((float)counter / (float)255.00, gamma_factor) * 255.00 + 0.5) : counter;
> +-- 
> +2.30.2
> +
>