lib: parser: add named variables in CLI

struct cmd_token now has a "varname" field which is derived from the
DEFUN's string definition.  It can be manually specified with "$name"
after some token, e.g. "foo WORD$var".  A later commit adds code to
automatically fill the value if nothing is specified.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

1 files changed, 37 insertions, 5 deletions

diff --git a/lib/command_parse.y b/lib/command_parse.y
index 0c415af3aa..7e7a68ffdd 100644
--- a/lib/command_parse.y
+++ b/lib/command_parse.y
@@ -104,12 +104,15 @@
 %type <node> start
 %type <node> literal_token
 %type <node> placeholder_token
+%type <node> placeholder_token_real
 %type <node> simple_token
 %type <subgraph> selector
 %type <subgraph> selector_token
 %type <subgraph> selector_token_seq
 %type <subgraph> selector_seq_seq
 
+%type <string> varname_token
+
 %code {
 
   /* bison declarations */
@@ -184,6 +187,16 @@ start:
 }
 ;
 
+varname_token: '$' WORD
+{
+  $$ = XSTRDUP (MTYPE_LEX, $2);
+}
+| /* empty */
+{
+  $$ = NULL;
+}
+;
+
 cmd_token_seq:
   /* empty */
 | cmd_token_seq cmd_token
@@ -207,14 +220,16 @@ simple_token:
 | placeholder_token
 ;
 
-literal_token: WORD
+literal_token: WORD varname_token
 {
   $$ = new_token_node (ctx, WORD_TKN, $1, doc_next(ctx));
+  cmd_set_varname ($$->data, $2);
+  XFREE (MTYPE_LEX, $2);
   XFREE (MTYPE_LEX, $1);
 }
 ;
 
-placeholder_token:
+placeholder_token_real:
   IPV4
 {
   $$ = new_token_node (ctx, IPV4_TKN, $1, doc_next(ctx));
@@ -257,10 +272,22 @@ placeholder_token:
   XFREE (MTYPE_LEX, $1);
 }
 
+placeholder_token:
+  placeholder_token_real varname_token
+{
+  struct cmd_token *token = $$->data;
+  $$ = $1;
+  cmd_set_varname (token, $2);
+  XFREE (MTYPE_LEX, $2);
+};
+
+
 /* <selector|set> productions */
-selector: '<' selector_seq_seq '>'
+selector: '<' selector_seq_seq '>' varname_token
 {
   $$ = $2;
+  cmd_set_varname ($2.end->data, $4);
+  XFREE (MTYPE_LEX, $4);
 };
 
 selector_seq_seq:
@@ -283,7 +310,7 @@ selector_seq_seq:
 ;
 
 /* {keyword} productions */
-selector: '{' selector_seq_seq '}'
+selector: '{' selector_seq_seq '}' varname_token
 {
   $$ = $2;
   graph_add_edge ($$.end, $$.start);
@@ -293,6 +320,9 @@ selector: '{' selector_seq_seq '}'
    *    loop-avoidal fails to handle
    * just use [{a|b}] if neccessary, that will work perfectly fine, and reason
    * #1 is good enough to keep it this way. */
+
+  cmd_set_varname ($2.end->data, $4);
+  XFREE (MTYPE_LEX, $4);
 };
 
 
@@ -315,10 +345,12 @@ selector_token_seq:
 ;
 
 /* [option] productions */
-selector: '[' selector_seq_seq ']'
+selector: '[' selector_seq_seq ']' varname_token
 {
   $$ = $2;
   graph_add_edge ($$.start, $$.end);
+  cmd_set_varname ($2.end->data, $4);
+  XFREE (MTYPE_LEX, $4);
 }
 ;