glsl: invariant qualifier is not valid for shader inputs in GLSL ES 3.00

GLSL ES 3.00 spec, chapter 4.6.1 "The Invariant Qualifier",

    Only variables output from a shader can be candidates for invariance. This
    includes user-defined output variables and the built-in output variables.
    As only outputs can be declared as invariant, an invariant output from one
    shader stage will still match an input of a subsequent stage without the
    input being declared as invariant.

This patch fixes the following dEQP tests:

dEQP-GLES3.functional.shaders.qualification_order.variables.valid.invariant_interp_storage_precision
dEQP-GLES3.functional.shaders.qualification_order.variables.valid.invariant_interp_storage
dEQP-GLES3.functional.shaders.qualification_order.variables.valid.invariant_storage_precision
dEQP-GLES3.functional.shaders.qualification_order.variables.valid.invariant_storage
dEQP-GLES3.functional.shaders.qualification_order.variables.invalid.invariant_interp_storage_precision_invariant_input
dEQP-GLES3.functional.shaders.qualification_order.variables.invalid.invariant_interp_storage_invariant_input
dEQP-GLES3.functional.shaders.qualification_order.variables.invalid.invariant_storage_precision_invariant_input
dEQP-GLES3.functional.shaders.qualification_order.variables.invalid.invariant_storage_invariant_input

No piglit regressions observed.

v2:
- Add spec content in the code

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
index 43da2c6..2261799 100644
--- a/src/glsl/link_varyings.cpp
+++ b/src/glsl/link_varyings.cpp
@@ -116,7 +116,7 @@ cross_validate_types_and_qualifiers(struct gl_shader_program *prog,
       return;
    }
 
-   if (input->data.invariant != output->data.invariant) {
+   if (!prog->IsES && input->data.invariant != output->data.invariant) {
       linker_error(prog,
                    "%s shader output `%s' %s invariant qualifier, "
                    "but %s shader input %s invariant qualifier\n",