+static char*
+get_top_level_name(const char *name)
+{
+ const char *first_dot = strchr(name, '.');
+ const char *first_square_bracket = strchr(name, '[');
+ int name_size = 0;
+
+ /* The ARB_program_interface_query spec says:
+ *
+ * "For the property TOP_LEVEL_ARRAY_SIZE, a single integer identifying
+ * the number of active array elements of the top-level shader storage
+ * block member containing to the active variable is written to
+ * <params>. If the top-level block member is not declared as an
+ * array, the value one is written to <params>. If the top-level block
+ * member is an array with no declared size, the value zero is written
+ * to <params>."
+ */
+
+ /* The buffer variable is on top level.*/
+ if (!first_square_bracket && !first_dot)
+ name_size = strlen(name);
+ else if ((!first_square_bracket ||
+ (first_dot && first_dot < first_square_bracket)))
+ name_size = first_dot - name;
+ else
+ name_size = first_square_bracket - name;
+
+ return strndup(name, name_size);
+}
+
+static char*
+get_var_name(const char *name)
+{
+ const char *first_dot = strchr(name, '.');
+
+ if (!first_dot)
+ return strdup(name);
+
+ return strndup(first_dot+1, strlen(first_dot) - 1);
+}
+
+static bool
+is_top_level_shader_storage_block_member(const char* name,
+ const char* interface_name,
+ const char* field_name)
+{
+ bool result = false;
+
+ /* If the given variable is already a top-level shader storage
+ * block member, then return array_size = 1.
+ * We could have two possibilities: if we have an instanced
+ * shader storage block or not instanced.
+ *
+ * For the first, we check create a name as it was in top level and
+ * compare it with the real name. If they are the same, then
+ * the variable is already at top-level.
+ *
+ * Full instanced name is: interface name + '.' + var name +
+ * NULL character
+ */
+ int name_length = strlen(interface_name) + 1 + strlen(field_name) + 1;
+ char *full_instanced_name = (char *) calloc(name_length, sizeof(char));
+ if (!full_instanced_name) {
+ fprintf(stderr, "%s: Cannot allocate space for name\n", __func__);
+ return false;
+ }
+
+ snprintf(full_instanced_name, name_length, "%s.%s",
+ interface_name, field_name);
+
+ /* Check if its top-level shader storage block member of an
+ * instanced interface block, or of a unnamed interface block.
+ */
+ if (strcmp(name, full_instanced_name) == 0 ||
+ strcmp(name, field_name) == 0)
+ result = true;
+
+ free(full_instanced_name);
+ return result;
+}
+
+static int
+get_array_size(struct gl_uniform_storage *uni, const glsl_struct_field *field,
+ char *interface_name, char *var_name)
+{
+ /* The ARB_program_interface_query spec says:
+ *
+ * "For the property TOP_LEVEL_ARRAY_SIZE, a single integer identifying
+ * the number of active array elements of the top-level shader storage
+ * block member containing to the active variable is written to
+ * <params>. If the top-level block member is not declared as an
+ * array, the value one is written to <params>. If the top-level block
+ * member is an array with no declared size, the value zero is written
+ * to <params>."
+ */
+ if (is_top_level_shader_storage_block_member(uni->name,
+ interface_name,
+ var_name))
+ return 1;
+ else if (field->type->is_array())
+ return field->type->length;
+
+ return 1;
+}
+
+static int
+get_array_stride(struct gl_uniform_storage *uni, const glsl_type *iface,
+ const glsl_struct_field *field, char *interface_name,
+ char *var_name, bool use_std430_as_default)
+{
+ /* The ARB_program_interface_query spec says:
+ *
+ * "For the property TOP_LEVEL_ARRAY_STRIDE, a single integer
+ * identifying the stride between array elements of the top-level
+ * shader storage block member containing the active variable is
+ * written to <params>. For top-level block members declared as
+ * arrays, the value written is the difference, in basic machine units,
+ * between the offsets of the active variable for consecutive elements
+ * in the top-level array. For top-level block members not declared as
+ * an array, zero is written to <params>."
+ */
+ if (field->type->is_array()) {
+ const enum glsl_matrix_layout matrix_layout =
+ glsl_matrix_layout(field->matrix_layout);
+ bool row_major = matrix_layout == GLSL_MATRIX_LAYOUT_ROW_MAJOR;
+ const glsl_type *array_type = field->type->fields.array;
+
+ if (is_top_level_shader_storage_block_member(uni->name,
+ interface_name,
+ var_name))
+ return 0;
+
+ if (GLSL_INTERFACE_PACKING_STD140 ==
+ iface->get_internal_ifc_packing(use_std430_as_default)) {
+ if (array_type->is_struct() || array_type->is_array())
+ return glsl_align(array_type->std140_size(row_major), 16);
+ else
+ return MAX2(array_type->std140_base_alignment(row_major), 16);
+ } else {
+ return array_type->std430_array_stride(row_major);
+ }
+ }
+ return 0;
+}
+
+static void
+calculate_array_size_and_stride(struct gl_shader_program *shProg,
+ struct gl_uniform_storage *uni,
+ bool use_std430_as_default)
+{
+ if (!uni->is_shader_storage)
+ return;
+
+ int block_index = uni->block_index;
+ int array_size = -1;
+ int array_stride = -1;
+ char *var_name = get_top_level_name(uni->name);
+ char *interface_name =
+ get_top_level_name(uni->is_shader_storage ?
+ shProg->data->ShaderStorageBlocks[block_index].Name :
+ shProg->data->UniformBlocks[block_index].Name);
+
+ if (strcmp(var_name, interface_name) == 0) {
+ /* Deal with instanced array of SSBOs */
+ char *temp_name = get_var_name(uni->name);
+ if (!temp_name) {
+ linker_error(shProg, "Out of memory during linking.\n");
+ goto write_top_level_array_size_and_stride;
+ }
+ free(var_name);
+ var_name = get_top_level_name(temp_name);
+ free(temp_name);
+ if (!var_name) {
+ linker_error(shProg, "Out of memory during linking.\n");
+ goto write_top_level_array_size_and_stride;
+ }
+ }
+
+ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
+ const gl_linked_shader *sh = shProg->_LinkedShaders[i];
+ if (sh == NULL)
+ continue;
+
+ foreach_in_list(ir_instruction, node, sh->ir) {
+ ir_variable *var = node->as_variable();
+ if (!var || !var->get_interface_type() ||
+ var->data.mode != ir_var_shader_storage)
+ continue;
+
+ const glsl_type *iface = var->get_interface_type();
+
+ if (strcmp(interface_name, iface->name) != 0)
+ continue;
+
+ for (unsigned i = 0; i < iface->length; i++) {
+ const glsl_struct_field *field = &iface->fields.structure[i];
+ if (strcmp(field->name, var_name) != 0)
+ continue;
+
+ array_stride = get_array_stride(uni, iface, field, interface_name,
+ var_name, use_std430_as_default);
+ array_size = get_array_size(uni, field, interface_name, var_name);
+ goto write_top_level_array_size_and_stride;
+ }
+ }
+ }
+write_top_level_array_size_and_stride:
+ free(interface_name);
+ free(var_name);
+ uni->top_level_array_stride = array_stride;
+ uni->top_level_array_size = array_size;
+}
+