+ir_variable *
+builtin_variable_generator::add_index_variable(const char *name,
+ const glsl_type *type,
+ enum ir_variable_mode mode, int slot, int index)
+{
+ ir_variable *var = new(symtab) ir_variable(type, name, mode);
+ var->data.how_declared = ir_var_declared_implicitly;
+
+ switch (var->data.mode) {
+ case ir_var_auto:
+ case ir_var_shader_in:
+ case ir_var_uniform:
+ case ir_var_system_value:
+ var->data.read_only = true;
+ break;
+ case ir_var_shader_out:
+ case ir_var_shader_storage:
+ break;
+ default:
+ /* The only variables that are added using this function should be
+ * uniforms, shader storage, shader inputs, and shader outputs, constants
+ * (which use ir_var_auto), and system values.
+ */
+ assert(0);
+ break;
+ }
+
+ var->data.location = slot;
+ var->data.explicit_location = (slot >= 0);
+ var->data.explicit_index = 1;
+ var->data.index = index;
+
+ /* Once the variable is created an initialized, add it to the symbol table
+ * and add the declaration to the IR stream.
+ */
+ instructions->push_tail(var);
+
+ symtab->add_variable(var);
+ return var;
+}