[Mesa-dev] [PATCH 3/4] mesa/main: fix gl_buffer_index enum comparison

[Ian Romanick]

This patch is

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

On 05/30/2017 01:47 PM, Rob Herring wrote:
> For clang, enums are unsigned by default and gives the following warning:
> 
> external/mesa3d/src/mesa/main/buffers.c:764:21: warning: comparison of constant -1 with expression of type 'gl_buffer_index' is always false [-Wtautological-constant-out-of-range-compare]
>       if (srcBuffer == -1) {
>           ~~~~~~~~~ ^  ~~
> 
> Replace -1 with an enum value to fix this.
> 
> Signed-off-by: Rob Herring <robh at kernel.org>
> ---
>  src/mesa/main/buffers.c | 6 +++---
>  src/mesa/main/mtypes.h  | 3 ++-
>  2 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c
> index 7d17ae92de23..c5846e85c21d 100644
> --- a/src/mesa/main/buffers.c
> +++ b/src/mesa/main/buffers.c
> @@ -752,16 +752,16 @@ read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb,
>  
>     if (buffer == GL_NONE) {
>        /* This is legal--it means that no buffer should be bound for reading. */
> -      srcBuffer = -1;
> +      srcBuffer = BUFFER_NONE;
>     }
>     else {
>        /* general case / window-system framebuffer */
>        if (_mesa_is_gles3(ctx) && !is_legal_es3_readbuffer_enum(buffer))
> -         srcBuffer = -1;
> +         srcBuffer = BUFFER_NONE;
>        else
>           srcBuffer = read_buffer_enum_to_index(ctx, buffer);
>  
> -      if (srcBuffer == -1) {
> +      if (srcBuffer == BUFFER_NONE) {
>           _mesa_error(ctx, GL_INVALID_ENUM,
>                       "%s(invalid buffer %s)", caller,
>                       _mesa_enum_to_string(buffer));
> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
> index 29e4c67846a5..6b6937473054 100644
> --- a/src/mesa/main/mtypes.h
> +++ b/src/mesa/main/mtypes.h
> @@ -144,7 +144,8 @@ typedef enum
>     BUFFER_COLOR5,
>     BUFFER_COLOR6,
>     BUFFER_COLOR7,
> -   BUFFER_COUNT
> +   BUFFER_COUNT,
> +   BUFFER_NONE = -1,
>  } gl_buffer_index;
>  
>  /**
>