glsl: add subroutine index qualifier support

ARB_explicit_uniform_location allows the index for subroutine functions
to be explicitly set in the shader.

This patch reduces the restriction on the index qualifier in
validate_layout_qualifiers() to allow it to be applied to subroutines
and adds the new subroutine qualifier validation to ast_function::hir().

ast_fully_specified_type::has_qualifiers() is updated to allow the
index qualifier on subroutine functions when explicit uniform locations
is available.

A new check is added to ast_type_qualifier::merge_qualifier() to stop
multiple function qualifiers from being defied, before this patch this
would cause a segfault.

Finally a new variable is added to ir_function_signature to store the
index. This value is validated and the non explicit values assigned in
link_assign_subroutine_types().

Reviewed-by: Tapani Pälli <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/glsl/ir_clone.cpp b/src/glsl/ir_clone.cpp
index 4484cc9d8a7..bee60a241e4 100644
--- a/src/glsl/ir_clone.cpp
+++ b/src/glsl/ir_clone.cpp
@@ -270,6 +270,7 @@ ir_function::clone(void *mem_ctx, struct hash_table *ht) const
    ir_function *copy = new(mem_ctx) ir_function(this->name);
 
    copy->is_subroutine = this->is_subroutine;
+   copy->subroutine_index = this->subroutine_index;
    copy->num_subroutine_types = this->num_subroutine_types;
    copy->subroutine_types = ralloc_array(mem_ctx, const struct glsl_type *, copy->num_subroutine_types);
    for (int i = 0; i < copy->num_subroutine_types; i++)