lib: add ability to dump cli mode graph

The grammar sandbox has had the ability to dump individual commands as
DOT graphs, but now that generalized DOT support is present it's trivial
to extend this to entire submodes. This is quite useful for visualizing
the CLI space when debugging CLI errors.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/lib/command.c b/lib/command.c
index 2bff3b17a2..0720762da0 100644
--- a/lib/command.c
+++ b/lib/command.c
@@ -49,6 +49,29 @@ DEFINE_MTYPE(LIB, HOST, "Host config")
 DEFINE_MTYPE(LIB, STRVEC, "String vector")
 DEFINE_MTYPE(LIB, COMPLETION, "Completion item")
 
+#define item(x)                                                                \
+	{                                                                      \
+		x, #x                                                          \
+	}
+
+/* clang-format off */
+const struct message tokennames[] = {
+	item(WORD_TKN),
+	item(VARIABLE_TKN),
+	item(RANGE_TKN),
+	item(IPV4_TKN),
+	item(IPV4_PREFIX_TKN),
+	item(IPV6_TKN),
+	item(IPV6_PREFIX_TKN),
+	item(MAC_TKN),
+	item(MAC_PREFIX_TKN),
+	item(FORK_TKN),
+	item(JOIN_TKN),
+	item(START_TKN),
+	item(END_TKN),
+	{0},
+};
+
 const char *node_names[] = {
 	"auth",			    // AUTH_NODE,
 	"view",			    // VIEW_NODE,
@@ -121,6 +144,7 @@ const char *node_names[] = {
 	"bgp ipv6 flowspec",	    /* BGP_FLOWSPECV6_NODE
 				     */
 };
+/* clang-format on */
 
 /* Command vector which includes some level of command lists. Normally
    each daemon maintains each own cmdvec. */
@@ -1566,6 +1590,21 @@ DEFUN (show_commandtree,
 	return cmd_list_cmds(vty, argc == 3);
 }
 
+DEFUN_HIDDEN(show_cli_graph,
+             show_cli_graph_cmd,
+             "show cli graph",
+             SHOW_STR
+             "CLI reflection\n"
+             "Dump current command space as DOT graph\n")
+{
+	struct cmd_node *cn = vector_slot(cmdvec, vty->node);
+	char *dot = cmd_graph_dump_dot(cn->cmdgraph);
+
+	vty_out(vty, "%s\n", dot);
+	XFREE(MTYPE_TMP, dot);
+	return CMD_SUCCESS;
+}
+
 static int vty_write_config(struct vty *vty)
 {
 	size_t i;
@@ -2573,6 +2612,7 @@ void install_default(enum node_type node)
 	install_element(node, &config_end_cmd);
 	install_element(node, &config_help_cmd);
 	install_element(node, &config_list_cmd);
+	install_element(node, &show_cli_graph_cmd);
 	install_element(node, &find_cmd);
 
 	install_element(node, &config_write_cmd);