Conf: Allowing keyword redefinition

Some tokens are both keywords and symbols. For now, we allow only
specific keywords to be redefined; in future, more of the keywords may
be added to this category.

The redefinable keywords must be specified in any .Y file as follows:

  toksym: THE_KEYWORD ;

See proto/bgp/config.Y for an example.

Also dropped a lot of unused terminals.

4 files changed, 13 insertions, 13 deletions

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index e84e1d9d..11bcdb18 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -709,10 +709,7 @@ cf_lex_symbol(const char *data)
   struct symbol *sym = cf_get_symbol(data);
   cf_lval.s = sym;
 
-  if (sym->class != SYM_VOID)
-    return CF_SYM_KNOWN;
-
-  /* Is it a keyword? */
+  /* Is it a keyword? Prefer the keyword. */
   struct keyword *k = HASH_FIND(kw_hash, KW, data);
   if (k)
   {
@@ -725,9 +722,11 @@ cf_lex_symbol(const char *data)
     }
   }
 
-  /* OK, undefined symbol */
-  cf_lval.s = sym;
-  return CF_SYM_UNDEFINED;
+  /* OK, only a symbol. */
+  if (sym->class == SYM_VOID)
+    return CF_SYM_UNDEFINED;
+  else
+    return CF_SYM_KNOWN;
 }
 
 static void
diff --git a/conf/confbase.Y b/conf/confbase.Y
index 2286b257..8a27c3d5 100644
--- a/conf/confbase.Y
+++ b/conf/confbase.Y
@@ -116,7 +116,7 @@ CF_DECLS
 %type <mls> label_stack_start label_stack
 
 %type <t> text opttext
-%type <s> symbol
+%type <s> symbol symbol_known toksym 
 
 %nonassoc PREFIX_DUMMY
 %left AND OR
@@ -162,7 +162,7 @@ definition:
 expr:
    NUM
  | '(' term ')' { $$ = f_eval_int(f_linearize($2)); }
- | CF_SYM_KNOWN {
+ | symbol_known {
      if ($1->class != (SYM_CONSTANT | T_INT)) cf_error("Number constant expected");
      $$ = SYM_VAL($1).i; }
  ;
@@ -173,7 +173,9 @@ expr_us:
  | expr US { $$ = $1 US_; }
  ;
 
-symbol: CF_SYM_UNDEFINED | CF_SYM_KNOWN ;
+toksym: FROM ;
+symbol: CF_SYM_UNDEFINED | CF_SYM_KNOWN | toksym ;
+symbol_known: CF_SYM_KNOWN | toksym ;
 
 /* Switches */
 
diff --git a/conf/gen_keywords.m4 b/conf/gen_keywords.m4
index 0c1dc545..53226e4d 100644
--- a/conf/gen_keywords.m4
+++ b/conf/gen_keywords.m4
@@ -26,8 +26,7 @@ m4_define(CF_DEFINES, `m4_divert(-1)')
 m4_define(CF_handle_kw, `m4_divert(1){ "m4_translit($1,[[A-Z]],[[a-z]])", $1, NULL },
 m4_divert(-1)')
 m4_define(CF_keywd, `m4_ifdef([[CF_tok_$1]],,[[m4_define([[CF_tok_$1]],1)CF_handle_kw($1)]])')
-m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token[[]]CF_toks
-)DNL')
+m4_define(CF_KEYWORDS, `CF_iterate([[CF_keywd]], [[$@]])DNL')
 
 # CLI commands generate keywords as well
 m4_define(CF_CLI, `CF_KEYWORDS(m4_translit($1, [[ ]], [[,]]))
diff --git a/conf/gen_parser.m4 b/conf/gen_parser.m4
index 5b378a93..af4b1455 100644
--- a/conf/gen_parser.m4
+++ b/conf/gen_parser.m4
@@ -31,7 +31,7 @@ m4_define(CF_iterate, `m4_define([[CF_iter]], m4_defn([[$1]]))CF_itera($2)')
 
 # Keywords act as untyped %token
 m4_define(CF_keywd, `m4_ifdef([[CF_tok_$1]],,[[m4_define([[CF_tok_$1]],1)m4_define([[CF_toks]],CF_toks $1)]])')
-m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token[[]]CF_toks
+m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token<s>[[]]CF_toks
 )DNL')
 
 # CLI commands