[Mesa-dev] [PATCH 3/3] glsl/linker: Check that re-declared, inter-shader built-in blocks match

[Jordan Justen]

On 2017-03-05 11:28:43, Eduardo Lima Mitev wrote:
> From GLSL 4.5 spec, section "7.1 Built-In Language Variables", page 130 of
> the PDF states:
> 
>     "If multiple shaders using members of a built-in block belonging to
>      the same interface are linked together in the same program, they must
>      all redeclare the built-in block in the same way, as described in
>      section 4.3.9 “Interface Blocks” for interface-block matching, or a
>      link-time error will result."

We try to make sure that the interface matches for input variables in
the code just below where you added the additional check. What case is
it missing? Is there not an input variable being read in the test case
to trigger the interface match check?

-Jordan

> Fixes:
> * GL45-CTS.CommonBugs.CommonBug_PerVertexValidation
> ---
>  src/compiler/glsl/link_interface_blocks.cpp | 33 ++++++++++++++++++++++++++++-
>  1 file changed, 32 insertions(+), 1 deletion(-)
> 
> diff --git a/src/compiler/glsl/link_interface_blocks.cpp b/src/compiler/glsl/link_interface_blocks.cpp
> index 7037c7776de..4c0278661fa 100644
> --- a/src/compiler/glsl/link_interface_blocks.cpp
> +++ b/src/compiler/glsl/link_interface_blocks.cpp
> @@ -376,11 +376,42 @@ validate_interstage_inout_blocks(struct gl_shader_program *prog,
>     /* Verify that the consumer's input interfaces match. */
>     foreach_in_list(ir_instruction, node, consumer->ir) {
>        ir_variable *var = node->as_variable();
> -      if (!var || !var->get_interface_type() || var->data.mode != ir_var_shader_in)
> +      if (!var || !var->get_interface_type())
>           continue;
>  
>        ir_variable *producer_def = definitions.lookup(var);
>  
> +      /* Check that all built-in block re-declarations are compatible
> +       * across shaders: From OpenGL Shading Language 4.5, section
> +       * "7.1 Built-In Language Variables", page 130 of the PDF:
> +       *
> +       *    "If multiple shaders using members of a built-in block belonging
> +       *     to the same interface are linked together in the same program,
> +       *     they must all redeclare the built-in block in the same way, as
> +       *     described in section 4.3.9 “Interface Blocks” for interface-block
> +       *     matching, or a link-time error will result."
> +       */
> +      const glsl_type *consumer_iface =
> +         consumer->symbols->get_interface(var->get_interface_type()->name,
> +                                          ir_var_shader_in);
> +
> +      const glsl_type *producer_iface = NULL;
> +      if (producer_def && producer_def->get_interface_type()) {
> +         producer_iface =
> +            producer->symbols->get_interface(producer_def->get_interface_type()->name,
> +                                             ir_var_shader_out);
> +      }
> +
> +      if (producer_iface && consumer_iface &&
> +          interstage_member_mismatch(prog, consumer_iface, producer_iface)) {
> +         linker_error(prog, "Incompatible or missing gl_PerVertex re-declaration"
> +                      "in consecutive shaders");
> +         return;
> +      }
> +
> +      if (var->data.mode != ir_var_shader_in)
> +         continue;
> +
>        /* The producer doesn't generate this input: fail to link. Skip built-in
>         * 'gl_in[]' since that may not be present if the producer does not
>         * write to any of the pre-defined outputs (e.g. if the vertex shader
> -- 
> 2.11.0
> 
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev