[Mesa-dev] [PATCH] nir: fix warning in nir_lower_io.c

[Lionel Landwerlin]

On 08/01/2019 17:33, Caio Marcelo de Oliveira Filho wrote:
> Add unreachable case for invalid deref type. Fixes the warning below
>
>      In file included from ../src/compiler/nir/nir_lower_io.c:34:
>      ../src/compiler/nir/nir_lower_io.c: In function ‘nir_lower_explicit_io’:
>      ../src/compiler/nir/nir.h:668:11: warning: ‘addr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
>          return src;
>                 ^~~
>      ../src/compiler/nir/nir_lower_io.c:735:17: note: ‘addr’ was declared here
>          nir_ssa_def *addr;
>                       ^~~~
> ---
>   src/compiler/nir/nir_lower_io.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/src/compiler/nir/nir_lower_io.c b/src/compiler/nir/nir_lower_io.c
> index bcbfebdfa3b..4a322da609e 100644
> --- a/src/compiler/nir/nir_lower_io.c
> +++ b/src/compiler/nir/nir_lower_io.c
> @@ -783,6 +783,10 @@ lower_explicit_io_deref(nir_builder *b, nir_deref_instr *deref,
>         /* Nothing to do here */
>         addr = parent_addr;
>         break;
> +
> +   default:
> +      unreachable("Invalid deref type");
> +      break;


Just a thought, but you could rather set the addr variable to NULL 
before the switch so that if a new deref type is ever added, the 
compiler can find all the places we need to update.


-

Lionel

>      }
>   
>      nir_instr_remove(&deref->instr);