[Mesa-dev] [PATCH 6/9] glsl: mark named uniform block arrays as active if defined with shared or std140 layout qualifier

[Eduardo Lima Mitev]

From: Samuel Iglesias Gonsalvez <siglesias at igalia.com>

If the named uniform block is an array declared with a shared or
std140 layout qualifier and no shader instruction has referenced it,
then it is never marked as active, then num_array_elements is zero.

Section 2.12.6 (Uniform Variables) of the OpenGL ES 3.0.4 spec says
that is should be considered active:

 "All members of a named uniform block declared with a shared or
  std140 layout qualifier are considered active, even if they are not
  referenced in any shader in the program. The uniform block itself is
  also considered active, even if no member of the block is
  referenced."

Fixes:

dEQP-GLES3.functional.ubo.random.basic_instance_arrays.18

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
---
 src/glsl/link_uniform_blocks.cpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/glsl/link_uniform_blocks.cpp b/src/glsl/link_uniform_blocks.cpp
index f5fc502..67a3f00 100644
--- a/src/glsl/link_uniform_blocks.cpp
+++ b/src/glsl/link_uniform_blocks.cpp
@@ -213,6 +213,32 @@ link_uniform_blocks(void *mem_ctx,
       const glsl_type *const block_type =
          b->type->is_array() ? b->type->fields.array : b->type;
 
+      /* Section 2.12.6 (Uniform Variables) of the OpenGL ES 3.0.4 spec says:
+       *
+       *   "All members of a named uniform block declared with a shared or
+       *   std140 layout qualifier are considered active, even if they are not
+       *   referenced in any shader in the program. The uniform block itself is
+       *   also considered active, even if no member of the block is
+       *   referenced."
+       *
+       * If the named uniform block is an array declared with a shared or
+       * std140 layout qualifier and no shader instruction has referenced it,
+       * then it is never marked as active, then num_array_elements is zero.
+       */
+      if (b->num_array_elements == 0 && b->type->is_array() &&
+          (b->type->interface_packing == GLSL_INTERFACE_PACKING_STD140 ||
+           b->type->interface_packing == GLSL_INTERFACE_PACKING_SHARED)) {
+         struct link_uniform_block_active *const block =
+            (struct link_uniform_block_active *) entry->data;
+         block->num_array_elements = block->type->length;
+         block->array_elements = reralloc(mem_ctx,
+                                          block->array_elements,
+                                          unsigned,
+                                          block->num_array_elements);
+         /* Mark the entire array as used. */
+         for (unsigned i = 0; i < block->num_array_elements; i++)
+            block->array_elements[i] = i;
+      }
       assert((b->num_array_elements > 0) == b->type->is_array());
 
       block_size.num_active_uniforms = 0;
-- 
2.1.3