1 files changed, 72 insertions, 0 deletions
diff --git a/src/compiler/nir/nir.c b/src/compiler/nir/nir.c
index 7ed93e1f409..1352d4cd3b4 100644
--- a/src/compiler/nir/nir.c
+++ b/src/compiler/nir/nir.c
@@ -324,6 +324,78 @@ nir_local_variable_create(nir_function_impl *impl,
 }
 
 nir_variable *
+nir_create_variable_with_location(nir_shader *shader, nir_variable_mode mode, int location,
+                                  const struct glsl_type *type)
+{
+   /* Only supporting non-array, or arrayed-io types, because otherwise we don't
+    * know how much to increment num_inputs/outputs
+    */
+   assert(glsl_get_length(type) <= 1);
+
+   const char *name;
+   switch (mode) {
+   case nir_var_shader_in:
+      if (shader->info.stage == MESA_SHADER_VERTEX)
+         name = gl_vert_attrib_name(location);
+      else
+         name = gl_varying_slot_name_for_stage(location, shader->info.stage);
+      break;
+
+   case nir_var_shader_out:
+      if (shader->info.stage == MESA_SHADER_FRAGMENT)
+         name = gl_frag_result_name(location);
+      else
+         name = gl_varying_slot_name_for_stage(location, shader->info.stage);
+      break;
+
+   case nir_var_system_value:
+      name = gl_system_value_name(location);
+      break;
+
+   default:
+      unreachable("Unsupported variable mode");
+   }
+
+   nir_variable *var = nir_variable_create(shader, mode, type, name);
+   var->data.location = location;
+
+   switch (mode) {
+   case nir_var_shader_in:
+      var->data.driver_location = shader->num_inputs++;
+      break;
+
+   case nir_var_shader_out:
+      var->data.driver_location = shader->num_outputs++;
+      break;
+
+   case nir_var_system_value:
+      break;
+
+   default:
+      unreachable("Unsupported variable mode");
+   }
+
+   return var;
+}
+
+nir_variable *
+nir_get_variable_with_location(nir_shader *shader, nir_variable_mode mode, int location,
+                               const struct glsl_type *type)
+{
+   nir_variable *var = nir_find_variable_with_location(shader, mode, location);
+   if (var) {
+      /* If this shader has location_fracs, this builder function is not suitable. */
+      assert(var->data.location_frac == 0);
+
+      /* The variable for the slot should match what we expected. */
+      assert(type == var->type);
+      return var;
+   }
+
+   return nir_create_variable_with_location(shader, mode, location, type);
+}
+
+nir_variable *
 nir_find_variable_with_location(nir_shader *shader,
                                 nir_variable_mode mode,
                                 unsigned location)