+ /**
+ * Does this variable have an initializer?
+ *
+ * This is used by the linker to cross-validiate initializers of global
+ * variables.
+ */
+ unsigned has_initializer:1;
+
+ /**
+ * Is this variable a generic output or input that has not yet been matched
+ * up to a variable in another stage of the pipeline?
+ *
+ * This is used by the linker as scratch storage while assigning locations
+ * to generic inputs and outputs.
+ */
+ unsigned is_unmatched_generic_inout:1;
+
+ /**
+ * If non-zero, then this variable may be packed along with other variables
+ * into a single varying slot, so this offset should be applied when
+ * accessing components. For example, an offset of 1 means that the x
+ * component of this variable is actually stored in component y of the
+ * location specified by \c location.
+ */
+ unsigned location_frac:2;
+
+ /**
+ * Layout of the matrix. Uses glsl_matrix_layout values.
+ */
+ unsigned matrix_layout:2;
+
+ /**
+ * Non-zero if this variable was created by lowering a named interface
+ * block which was not an array.
+ *
+ * Note that this variable and \c from_named_ifc_block_array will never
+ * both be non-zero.
+ */
+ unsigned from_named_ifc_block_nonarray:1;
+
+ /**
+ * Non-zero if this variable was created by lowering a named interface
+ * block which was an array.
+ *
+ * Note that this variable and \c from_named_ifc_block_nonarray will never
+ * both be non-zero.
+ */
+ unsigned from_named_ifc_block_array:1;
+
+ /**
+ * Non-zero if the variable must be a shader input. This is useful for
+ * constraints on function parameters.
+ */
+ unsigned must_be_shader_input:1;
+
+ /**
+ * Output index for dual source blending.
+ *
+ * \note
+ * The GLSL spec only allows the values 0 or 1 for the index in \b dual
+ * source blending.
+ */
+ unsigned index:1;
+
+ /**
+ * Precision qualifier.
+ *
+ * In desktop GLSL we do not care about precision qualifiers at all, in
+ * fact, the spec says that precision qualifiers are ignored.
+ *
+ * To make things easy, we make it so that this field is always
+ * GLSL_PRECISION_NONE on desktop shaders. This way all the variables
+ * have the same precision value and the checks we add in the compiler
+ * for this field will never break a desktop shader compile.
+ */
+ unsigned precision:2;
+
+ /**
+ * \brief Layout qualifier for gl_FragDepth.
+ *
+ * This is not equal to \c ir_depth_layout_none if and only if this
+ * variable is \c gl_FragDepth and a layout qualifier is specified.
+ */
+ ir_depth_layout depth_layout:3;
+
+ /**
+ * ARB_shader_image_load_store qualifiers.
+ */
+ unsigned image_read_only:1; /**< "readonly" qualifier. */
+ unsigned image_write_only:1; /**< "writeonly" qualifier. */
+ unsigned image_coherent:1;
+ unsigned image_volatile:1;
+ unsigned image_restrict:1;
+
+ /**
+ * ARB_shader_storage_buffer_object
+ */
+ unsigned from_ssbo_unsized_array:1; /**< unsized array buffer variable. */
+
+ /**
+ * Emit a warning if this variable is accessed.
+ */
+ private:
+ uint8_t warn_extension_index;
+
+ public:
+ /** Image internal format if specified explicitly, otherwise GL_NONE. */
+ uint16_t image_format;
+
+ private:
+ /**
+ * Number of state slots used
+ *
+ * \note
+ * This could be stored in as few as 7-bits, if necessary. If it is made
+ * smaller, add an assertion to \c ir_variable::allocate_state_slots to
+ * be safe.
+ */
+ uint16_t _num_state_slots;
+
+ public:
+ /**
+ * Initial binding point for a sampler, atomic, or UBO.
+ *
+ * For array types, this represents the binding point for the first element.
+ */
+ int16_t binding;
+
+ /**
+ * Storage location of the base of this variable
+ *
+ * The precise meaning of this field depends on the nature of the variable.
+ *
+ * - Vertex shader input: one of the values from \c gl_vert_attrib.
+ * - Vertex shader output: one of the values from \c gl_varying_slot.
+ * - Geometry shader input: one of the values from \c gl_varying_slot.
+ * - Geometry shader output: one of the values from \c gl_varying_slot.
+ * - Fragment shader input: one of the values from \c gl_varying_slot.
+ * - Fragment shader output: one of the values from \c gl_frag_result.
+ * - Uniforms: Per-stage uniform slot number for default uniform block.
+ * - Uniforms: Index within the uniform block definition for UBO members.
+ * - Non-UBO Uniforms: explicit location until linking then reused to
+ * store uniform slot number.
+ * - Other: This field is not currently used.
+ *
+ * If the variable is a uniform, shader input, or shader output, and the
+ * slot has not been assigned, the value will be -1.
+ */
+ int location;
+
+ /**
+ * Vertex stream output identifier.
+ */
+ unsigned stream;
+
+ /**
+ * Location an atomic counter is stored at.
+ */
+ struct {
+ unsigned offset;
+ } atomic;
+
+ /**
+ * Highest element accessed with a constant expression array index
+ *
+ * Not used for non-array variables.
+ */
+ unsigned max_array_access;
+
+ /**
+ * Allow (only) ir_variable direct access private members.
+ */
+ friend class ir_variable;
+ } data;