02-grammar-rule-begin.patch

[Akim Demaille]

Index: ChangeLog
from  Akim Demaille  <address@hidden>

        * src/reader.c (grammar_rule_begin, previous_rule, current_rule):
        New.
        (readgram): Use them as replacement of inlined code, crule and
        crule1.

Index: src/reader.c
--- src/reader.c Mon, 10 Jun 2002 21:27:55 +0200 akim (bison/b/5_reader.c 
1.77.1.3.1.18.1.7.1.1 664)
+++ src/reader.c Mon, 10 Jun 2002 21:35:36 +0200 akim (bison/b/5_reader.c 
1.77.1.3.1.18.1.7.1.1 664)
@@ -1089,18 +1089,49 @@
   grammar_end = p;
 }

+/* The rule currently being defined, and the previous rule.  Point to
+   the first symbol of each list: their lhs.  */
+symbol_list *current_rule = NULL;
+symbol_list *previous_rule = NULL;
+
+
+/* Create a new rule for LHS in to the GRAMMAR. */
+
+static void
+grammar_rule_begin (symbol_t *lhs)
+{
+  if (!start_flag)
+    {
+      startsymbol = lhs;
+      start_flag = 1;
+    }
+
+  /* Start a new rule and record its lhs.  */
+  ++nrules;
+  ++nritems;
+
+  previous_rule = grammar_end;
+  grammar_symbol_append (lhs);
+  current_rule = grammar_end;
+
+  /* Mark the rule's lhs as a nonterminal if not already so.  */
+
+  if (lhs->class == unknown_sym)
+    {
+      lhs->class = nterm_sym;
+      lhs->number = nvars;
+      ++nvars;
+    }
+  else if (lhs->class == token_sym)
+    complain (_("rule given for %s, which is a token"), lhs->tag);
+}
+
 static void
 readgram (void)
 {
   token_t t;
   symbol_t *lhs = NULL;

-  /* Points to first symbol_list of current rule. its symbol is the
-     lhs of the rule.  */
-  symbol_list *crule = NULL;
-  /* Points to the symbol_list preceding crule.  */
-  symbol_list *crule1 = NULL;
-
   t = lex ();

   while (t != tok_two_percents && t != tok_eof)
@@ -1116,12 +1147,6 @@
          {
            lhs = symval;

-           if (!start_flag)
-             {
-               startsymbol = lhs;
-               start_flag = 1;
-             }
-
            t = lex ();
            if (t != tok_colon)
              {
@@ -1129,32 +1154,13 @@
                unlex (t);
              }
          }
-
        if (nrules == 0 && t == tok_bar)
          {
            complain (_("grammar starts with vertical bar"));
            lhs = symval;       /* BOGUS: use a random symval */
          }
-       /* start a new rule and record its lhs.  */
-
-       ++nrules;
-       ++nritems;
-
-       crule1 = grammar_end;
-       grammar_symbol_append (lhs);
-       crule = grammar_end;
-
-       /* mark the rule's lhs as a nonterminal if not already so.  */
-
-       if (lhs->class == unknown_sym)
-         {
-           lhs->class = nterm_sym;
-           lhs->number = nvars;
-           ++nvars;
-         }
-       else if (lhs->class == token_sym)
-         complain (_("rule given for %s, which is a token"), lhs->tag);

+       grammar_rule_begin (lhs);
        /* read the rhs of the rule.  */

        for (;;)
@@ -1163,7 +1169,7 @@
            if (t == tok_prec)
              {
                t = lex ();
-               crule->ruleprec = symval;
+               current_rule->ruleprec = symval;
                t = lex ();
              }

@@ -1212,21 +1218,21 @@
                ++nrules;
                ++nritems;
                /* Attach its lineno to that of the host rule. */
-               p->line = crule->line;
+               p->line = current_rule->line;
                /* Move the action from the host rule to this one. */
-               p->action = crule->action;
-               p->action_line = crule->action_line;
-               crule->action = NULL;
+               p->action = current_rule->action;
+               p->action_line = current_rule->action_line;
+               current_rule->action = NULL;

-               if (crule1)
-                 crule1->next = p;
+               if (previous_rule)
+                 previous_rule->next = p;
                else
                  grammar = p;
                /* End of the rule. */
-               crule1 = symbol_list_new (NULL);
-               crule1->next = crule;
+               previous_rule = symbol_list_new (NULL);
+               previous_rule->next = current_rule;

-               p->next = crule1;
+               p->next = previous_rule;

                /* Insert the dummy generated by that rule into this
                   rule.  */
@@ -1242,7 +1248,7 @@
              }
            else                /* handle an action.  */
              {
-               parse_action (crule, rulelength);
+               parse_action (current_rule, rulelength);
                action_flag = 1;
                ++xactions;     /* JF */
              }
@@ -1256,7 +1262,7 @@
          {
            complain (_("two @prec's in a row"));
            t = lex ();
-           crule->ruleprec = symval;
+           current_rule->ruleprec = symval;
            t = lex ();
          }

@@ -1265,7 +1271,7 @@
            /* This case never occurs -wjh */
            if (action_flag)
              complain (_("two actions at end of one rule"));
-           parse_action (crule, rulelength);
+           parse_action (current_rule, rulelength);
            action_flag = 1;
            ++xactions; /* -wjh */
            t = lex ();