- /**
- * Has this variable been statically assigned?
- *
- * This answers whether the variable was assigned in any path of
- * the shader during ast_to_hir. This doesn't answer whether it is
- * still written after dead code removal, nor is it maintained in
- * non-ast_to_hir.cpp (GLSL parsing) paths.
- */
- unsigned assigned:1;
-
- /**
- * Enum indicating how the variable was declared. See
- * ir_var_declaration_type.
- *
- * This is used to detect certain kinds of illegal variable redeclarations.
- */
- unsigned how_declared:2;
-
- /**
- * Storage class of the variable.
- *
- * \sa ir_variable_mode
- */
- unsigned mode:4;
-
- /**
- * Interpolation mode for shader inputs / outputs
- *
- * \sa ir_variable_interpolation
- */
- unsigned interpolation:2;
-
- /**
- * \name ARB_fragment_coord_conventions
- * @{
- */
- unsigned origin_upper_left:1;
- unsigned pixel_center_integer:1;
- /*@}*/
-
- /**
- * Was the location explicitly set in the shader?
- *
- * If the location is explicitly set in the shader, it \b cannot be changed
- * by the linker or by the API (e.g., calls to \c glBindAttribLocation have
- * no effect).
- */
- unsigned explicit_location:1;
- unsigned explicit_index:1;
-
- /**
- * Was an initial binding explicitly set in the shader?
- *
- * If so, constant_value contains an integer ir_constant representing the
- * initial binding point.
- */
- unsigned explicit_binding:1;
+ /**
+ * Is the variable read-only?
+ *
+ * This is set for variables declared as \c const, shader inputs,
+ * and uniforms.
+ */
+ unsigned read_only:1;
+ unsigned centroid:1;
+ unsigned sample:1;
+ unsigned invariant:1;
+
+ /**
+ * Has this variable been used for reading or writing?
+ *
+ * Several GLSL semantic checks require knowledge of whether or not a
+ * variable has been used. For example, it is an error to redeclare a
+ * variable as invariant after it has been used.
+ *
+ * This is only maintained in the ast_to_hir.cpp path, not in
+ * Mesa's fixed function or ARB program paths.
+ */
+ unsigned used:1;
+
+ /**
+ * Has this variable been statically assigned?
+ *
+ * This answers whether the variable was assigned in any path of
+ * the shader during ast_to_hir. This doesn't answer whether it is
+ * still written after dead code removal, nor is it maintained in
+ * non-ast_to_hir.cpp (GLSL parsing) paths.
+ */
+ unsigned assigned:1;