closure, gram: add missing const

* src/closure.h, src/closure.c, src/gram.h, src/gram.c: Add some missing
const where appropriate.

src/closure.c

@@ -52,7 +52,7 @@ static bitsetv firsts = NULL;
 `-----------------*/
 
 static void
-print_closure (char const *title, item_number *array, size_t size)
+print_closure (char const *title, item_number const *array, size_t size)
 {
   size_t i;
   fprintf (stderr, "Closure: %s\n", title);
@@ -189,7 +189,7 @@ new_closure (unsigned int n)
 
 
 void
-closure (item_number *core, size_t n)
+closure (item_number const *core, size_t n)
 {
   /* Index over CORE. */
   size_t c;

src/closure.h

@@ -44,7 +44,7 @@ void new_closure (unsigned int n);
    significant).  CLOSURE places there the indices of all items which
    represent units of input that could arrive next.  */
 
-void closure (item_number *items, size_t n);
+void closure (item_number const *items, size_t n);
 
 
 /* Frees ITEMSET, RULESET and internal data.  */

src/gram.c

@@ -47,25 +47,25 @@ symbol_number *token_translations = NULL;
 int max_user_token_number = 256;
 
 bool
-rule_useful_in_grammar_p (rule *r)
+rule_useful_in_grammar_p (rule const *r)
 {
   return r->number < nrules;
 }
 
 bool
-rule_useless_in_grammar_p (rule *r)
+rule_useless_in_grammar_p (rule const *r)
 {
   return !rule_useful_in_grammar_p (r);
 }
 
 bool
-rule_useless_in_parser_p (rule *r)
+rule_useless_in_parser_p (rule const *r)
 {
   return !r->useful && rule_useful_in_grammar_p (r);
 }
 
 void
-rule_lhs_print (rule *r, symbol *previous_lhs, FILE *out)
+rule_lhs_print (rule const *r, symbol const *previous_lhs, FILE *out)
 {
   fprintf (out, "  %3d ", r->number);
   if (previous_lhs != r->lhs)
@@ -82,13 +82,13 @@ rule_lhs_print (rule *r, symbol *previous_lhs, FILE *out)
 }
 
 void
-rule_lhs_print_xml (rule *r, FILE *out, int level)
+rule_lhs_print_xml (rule const *r, FILE *out, int level)
 {
   xml_printf (out, level, "<lhs>%s</lhs>", r->lhs->tag);
 }
 
 size_t
-rule_rhs_length (rule *r)
+rule_rhs_length (rule const *r)
 {
   size_t res = 0;
   item_number *rhsp;
@@ -98,7 +98,7 @@ rule_rhs_length (rule *r)
 }
 
 void
-rule_rhs_print (rule *r, FILE *out)
+rule_rhs_print (rule const *r, FILE *out)
 {
   if (*r->rhs >= 0)
     {
@@ -113,7 +113,7 @@ rule_rhs_print (rule *r, FILE *out)
 }
 
 static void
-rule_rhs_print_xml (rule *r, FILE *out, int level)
+rule_rhs_print_xml (rule const *r, FILE *out, int level)
 {
   if (*r->rhs >= 0)
     {
@@ -133,7 +133,7 @@ rule_rhs_print_xml (rule *r, FILE *out, int level)
 }
 
 static void
-rule_print (rule *r, FILE *out)
+rule_print (rule const *r, FILE *out)
 {
   fprintf (out, "%s:", r->lhs->tag);
   rule_rhs_print (r, out);
@@ -263,10 +263,12 @@ grammar_dump (FILE *out, const char *title)
   fprintf (out, "Rules\n-----\n\n");
   {
     rule_number i;
-    fprintf (out, "Num (Prec, Assoc, Useful, Ritem Range) Lhs -> Rhs (Ritem range) [Num]\n");
+    fprintf (out,
+             "Num (Prec, Assoc, Useful, Ritem Range) Lhs"
+             " -> Rhs (Ritem range) [Num]\n");
     for (i = 0; i < nrules + nuseless_productions; i++)
       {
-        rule *rule_i = &rules[i];
+        rule const *rule_i = &rules[i];
         item_number *rp = NULL;
         unsigned int rhs_itemno = rule_i->rhs - ritem;
         unsigned int rhs_count = 0;

src/gram.h

@@ -203,31 +203,31 @@ typedef struct
 extern rule *rules;
 
 /* A function that selects a rule.  */
-typedef bool (*rule_filter) (rule *);
+typedef bool (*rule_filter) (rule const *);
 
 /* Return true IFF the rule has a `number' smaller than NRULES.  That is, it is
    useful in the grammar.  */
-bool rule_useful_in_grammar_p (rule *r);
+bool rule_useful_in_grammar_p (rule const *r);
 
 /* Return true IFF the rule has a `number' higher than NRULES.  That is, it is
    useless in the grammar.  */
-bool rule_useless_in_grammar_p (rule *r);
+bool rule_useless_in_grammar_p (rule const *r);
 
 /* Return true IFF the rule is not flagged as useful but is useful in the
    grammar.  In other words, it was discarded because of conflicts.  */
-bool rule_useless_in_parser_p (rule *r);
+bool rule_useless_in_parser_p (rule const *r);
 
 /* Print this rule's number and lhs on OUT.  If a PREVIOUS_LHS was
    already displayed (by a previous call for another rule), avoid
    useless repetitions.  */
-void rule_lhs_print (rule *r, symbol *previous_lhs, FILE *out);
-void rule_lhs_print_xml (rule *r, FILE *out, int level);
+void rule_lhs_print (rule const *r, symbol const *previous_lhs, FILE *out);
+void rule_lhs_print_xml (rule const *r, FILE *out, int level);
 
 /* Return the length of the RHS.  */
-size_t rule_rhs_length (rule *r);
+size_t rule_rhs_length (rule const *r);
 
 /* Print this rule's RHS on OUT.  */
-void rule_rhs_print (rule *r, FILE *out);
+void rule_rhs_print (rule const *r, FILE *out);