+typedef enum _node_verification_t {
+ NODE_VERIFICATION_OFF = 0, /**< do not verify nodes at all */
+ NODE_VERIFICATION_ON = 1, /**< do node verification and assert on error in debug version */
+ NODE_VERIFICATION_REPORT = 2, /**< do node verification, but report to stderr only */
+ NODE_VERIFICATION_ERROR_ONLY = 3 /**< do node verification, but NEVER do assert nor report */
+} node_verification_t;
+
+/** Select verification of nodes.
+ *
+ * Per default the verification is in mode NODE_VERIFICATION_ASSERT.
+ * Turn the verification off during development to check partial implementations.
+ */
+void do_node_verification(node_verification_t mode);
+
+/**
+ * Tests the modes of checknode and its predecessors.
+ * Checknode must be in current_ir_graph.
+ *
+ * \return
+ * NON-zero on success
+ */
+int irn_vrfy(struct ir_node *checknode);
+
+/**
+ * Tests the modes of checknode and its predecessors.
+ * Checknode must be in given ir_graph.
+ *
+ * \return
+ * NON-zero on success
+ */
+int irn_vrfy_irg(struct ir_node *checknode, ir_graph *irg);
+
+/**
+ * Same as irn_vrfy_irg, but temporary sets verification mode to
+ * NODE_VERIFICATION_ERROR_ONLY.
+ * \return
+ * NON-zero on success
+ */
+int irn_vrfy_irg_dump(struct ir_node *checknode, ir_graph *irg, const char **bad_string);
+
+/**
+ * Calls irn_vrfy for each node in irg.
+ * Graph must be in state "op_pin_state_pinned".
+ *
+ * \return
+ * NON-zero on success.
+ */
+int irg_vrfy(ir_graph *irg);
+
+/**
+ * Possible flags for irg_vrfy_bads().
+ */
+enum verify_bad_flags_t {
+ BAD_CF = 1, /**< Bad nodes are allowed as predecessors of Blocks and Phis. */
+ BAD_DF = 2, /**< Bad nodes are allowed as dataflow predecessors. */
+ BAD_BLOCK = 4, /**< Bad nodes are allowed as Block input. */
+ TUPLE = 8 /**< Tuple nodes are allowed. */
+};