[Mesa-dev] [PATCH 4/5] glsl: Consider active all elements of a shared/std140 block array

[Eduardo Lima Mitev]

From: Antia Puentes <apuentes at igalia.com>

Commmit 1ca25ab (glsl: Do not eliminate 'shared' or 'std140'
blocks or block members) considers active 'shared' and 'std140'
uniform blocks and uniform block arrays but did not include the
block array elements. It was possible to have an active uniform
block array without any elements marked as used, making the
assertion ((b->num_array_elements > 0) == b->type->is_array())
in link_uniform_blocks fail.

Fixes the following 5 dEQP tests:

 * dEQP-GLES3.functional.ubo.random.nested_structs_instance_arrays.18
 * dEQP-GLES3.functional.ubo.random.nested_structs_instance_arrays.24
 * dEQP-GLES3.functional.ubo.random.nested_structs_arrays_instance_arrays.19
 * dEQP-GLES3.functional.ubo.random.all_per_block_buffers.49
 * dEQP-GLES3.functional.ubo.random.all_shared_buffer.36
---
 src/glsl/link_uniform_block_active_visitor.cpp | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/src/glsl/link_uniform_block_active_visitor.cpp b/src/glsl/link_uniform_block_active_visitor.cpp
index 292cde3..8379750 100644
--- a/src/glsl/link_uniform_block_active_visitor.cpp
+++ b/src/glsl/link_uniform_block_active_visitor.cpp
@@ -105,6 +105,22 @@ link_uniform_block_active_visitor::visit(ir_variable *var)
    assert(b->num_array_elements == 0);
    assert(b->array_elements == NULL);
    assert(b->type != NULL);
+   assert(!b->type->is_array() || b->has_instance_name);
+
+   /* For uniform block arrays declared with a shared or std140 layout
+    * qualifier, mark all its instances as used.
+    */
+   if (b->type->is_array() && b->type->length > 0) {
+      b->num_array_elements = b->type->length;
+      b->array_elements = reralloc(this->mem_ctx,
+                                   b->array_elements,
+                                   unsigned,
+                                   b->num_array_elements);
+
+      for (unsigned i = 0; i < b->num_array_elements; i++) {
+         b->array_elements[i] = i;
+      }
+   }
 
    return visit_continue;
 }
@@ -146,6 +162,13 @@ link_uniform_block_active_visitor::visit_enter(ir_dereference_array *ir)
    assert((b->num_array_elements == 0) == (b->array_elements == NULL));
    assert(b->type != NULL);
 
+   /* If the block array was declared with a shared or std140 layout qualifier,
+    * all its instances have been already marked as used (see
+    * link_uniform_block_active_visitor::visit(ir_variable *) function).
+    */
+   if (var->type->interface_packing == GLSL_INTERFACE_PACKING_PACKED)
+      return visit_continue;
+
    ir_constant *c = ir->array_index->as_constant();
 
    if (c) {
-- 
2.1.3