[Mesa-dev] [PATCH] glsl: reject samplers not declared as uniform/function parameters

[Timothy Arceri]

On 24/02/17 21:50, Samuel Pitoiset wrote:
> From section 4.1.7 of the GLSL 4.40 spec:
>
>    "The opaque types declare variables that are effectively opaque
>    handles to other objects.  These objects are accessed through
>    built-in functions, not through direct reading or writing of
>    the declared variable.  They  can only be declared as function
>    parameters or in uniform- qualified variables."
>
> Image variables and atomic counters are already rejected in this
> situation.
>
> Note that opaque variables can't be treated as l-values, which
> means only the 'in' function parameter is allowed.
>
> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>

Seems reasonable but can we have a few simple compile piglit tests to go 
with this?

Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>

> ---
>  src/compiler/glsl/ast_to_hir.cpp | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
> index 22803e89c7..3279149d34 100644
> --- a/src/compiler/glsl/ast_to_hir.cpp
> +++ b/src/compiler/glsl/ast_to_hir.cpp
> @@ -3601,6 +3601,15 @@ apply_layout_qualifier_to_variable(const struct ast_type_qualifier *qual,
>        }
>     }
>
> +   if (var->type->contains_sampler()) {
> +      if (var->data.mode != ir_var_uniform &&
> +          var->data.mode != ir_var_function_in) {
> +         _mesa_glsl_error(loc, state, "sampler variables may only be declared "
> +                          "as function parameters or uniform-qualified "
> +                          "global variables");
> +      }
> +   }
> +
>     /* Is the 'layout' keyword used with parameters that allow relaxed checking.
>      * Many implementations of GL_ARB_fragment_coord_conventions_enable and some
>      * implementations (only Mesa?) GL_ARB_explicit_attrib_location_enable
>