Re: [Mesa-dev] void operation in glsl

2013-08-26 Thread Liu Xin 

On 08/26/2013 02:42 PM, Matt Turner wrote:

On Sun, Aug 25, 2013 at 10:07 PM, Liu Xin  wrote:

HI, list,

i don't understand why glsl source  have  so many 'cast to void' operations,
like this.

ir_rvalue *
ast_node::hir(exec_list *instructions,
   struct _mesa_glsl_parse_state *state)
{
(void) instructions;
(void) state;

return NULL;
}

i think it's totally void operation, do you guy just make gcc compiler
happy?

Yes, the purpose is only to avoid unused variable warnings emitted by
the compiler.

yes it is. now i understood. clean code!
--lx

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Re: [Mesa-dev] void operation in glsl

2013-08-25 Thread Matt Turner 
On Sun, Aug 25, 2013 at 10:07 PM, Liu Xin  wrote:
> HI, list,
>
> i don't understand why glsl source  have  so many 'cast to void' operations,
> like this.
>
> ir_rvalue *
> ast_node::hir(exec_list *instructions,
>   struct _mesa_glsl_parse_state *state)
> {
>(void) instructions;
>(void) state;
>
>return NULL;
> }
>
> i think it's totally void operation, do you guy just make gcc compiler
> happy?

Yes, the purpose is only to avoid unused variable warnings emitted by
the compiler.
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Re: [Mesa-dev] void operation in glsl

2013-08-25 Thread Chris Forbes 
It's just a simple, portable way to make the `unused parameter`
warning shut up, when you're deliberately ignoring your parameters.

There are other ways [__attribute__(( unused )), etc] but they cease
to be simple or portable fairly quickly.

-- Chris

On Mon, Aug 26, 2013 at 5:07 PM, Liu Xin  wrote:
> HI, list,
>
> i don't understand why glsl source  have  so many 'cast to void' operations,
> like this.
>
> ir_rvalue *
> ast_node::hir(exec_list *instructions,
>   struct _mesa_glsl_parse_state *state)
> {
>(void) instructions;
>(void) state;
>
>return NULL;
> }
>
> i think it's totally void operation, do you guy just make gcc compiler
> happy?
>
> thanks,
> --lx
>
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> mesa-dev mailing list
> mesa-dev@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
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