Consolidate the 4 prologue alternative directives (%code, %requires,

[bison.git] / src / reader.c

diff --git a/src/reader.c b/src/reader.c
index 604c03b10eae59ffc0d9d28f64eab05c198edb8b..587a4f099886c75b4051712cd83300e2621bbc8b 100644 (file)
--- a/src/reader.c
+++ b/src/reader.c
@@ -1,7 +1,7 @@
 /* Input parser for Bison
 
    Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,
 /* Input parser for Bison
 
    Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,

-   2005, 2006 Free Software Foundation, Inc.
+   2005, 2006, 2007 Free Software Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    This file is part of Bison, the GNU Compiler Compiler.
 


@@ -243,19 +243,25 @@ grammar_current_rule_begin (symbol *lhs, location loc)
 
 
 /*----------------------------------------------------------------------.
 
 
 /*----------------------------------------------------------------------.

-| A symbol should be used if it has a destructor, or if it is a         |
-| mid-rule symbol (i.e., the generated LHS replacing a mid-rule         |
-| action) that was assigned to, as in "exp: { $$ = 1; } { $$ = $1; }".  |
+| A symbol should be used if either:                                    |
+|   1. It has a destructor.                                             |
+|   2. --warnings=midrule-values and the symbol is a mid-rule symbol    |
+|      (i.e., the generated LHS replacing a mid-rule action) that was   |
+|      assigned to or used, as in "exp: { $$ = 1; } { $$ = $1; }".      |

 `----------------------------------------------------------------------*/
 
 static bool
 symbol_should_be_used (symbol_list const *s)
 {
 `----------------------------------------------------------------------*/
 
 static bool
 symbol_should_be_used (symbol_list const *s)
 {

-  return (symbol_destructor_get (s->content.sym)
-         || (s->midrule && s->midrule->used)
-         || (s->midrule_parent_rule
-             && symbol_list_n_get (s->midrule_parent_rule,
-                                    s->midrule_parent_rhs_index)->used));
+  if (symbol_destructor_get (s->content.sym)->code)
+    return true;
+  if (warnings_flag & warnings_midrule_values)
+    return ((s->midrule && s->midrule->action_props.is_value_used)
+           || (s->midrule_parent_rule
+               && symbol_list_n_get (s->midrule_parent_rule,
+                                     s->midrule_parent_rhs_index)
+                     ->action_props.is_value_used));
+  return false;

 }
 
 /*----------------------------------------------------------------.
 }
 
 /*----------------------------------------------------------------.


@@ -273,7 +279,7 @@ grammar_rule_check (const symbol_list *r)
 
      Don't worry about the default action if $$ is untyped, since $$'s
      value can't be used.  */
 
      Don't worry about the default action if $$ is untyped, since $$'s
      value can't be used.  */

-  if (!r->action && r->content.sym->type_name)
+  if (!r->action_props.code && r->content.sym->type_name)

     {
       symbol *first_rhs = r->next->content.sym;
       /* If $$ is being set in default way, report if any type mismatch.  */
     {
       symbol *first_rhs = r->next->content.sym;
       /* If $$ is being set in default way, report if any type mismatch.  */


@@ -298,10 +304,10 @@ grammar_rule_check (const symbol_list *r)
     symbol_list const *l = r;
     int n = 0;
     for (; l && l->content.sym; l = l->next, ++n)
     symbol_list const *l = r;
     int n = 0;
     for (; l && l->content.sym; l = l->next, ++n)

-      if (! (l->used
+      if (! (l->action_props.is_value_used

             || !symbol_should_be_used (l)
             /* The default action, $$ = $1, `uses' both.  */
             || !symbol_should_be_used (l)
             /* The default action, $$ = $1, `uses' both.  */

-            || (!r->action && (n == 0 || n == 1))))
+            || (!r->action_props.code && (n == 0 || n == 1))))

        {
          if (n)
            warn_at (r->location, _("unused value: $%d"), n);
        {
          if (n)
            warn_at (r->location, _("unused value: $%d"), n);


@@ -341,7 +347,7 @@ grammar_midrule_action (void)
 
   /* Make a DUMMY nonterminal, whose location is that of the midrule
      action.  Create the MIDRULE.  */
 
   /* Make a DUMMY nonterminal, whose location is that of the midrule
      action.  Create the MIDRULE.  */

-  location dummy_location = current_rule->action_location;
+  location dummy_location = current_rule->action_props.location;

   symbol *dummy = dummy_symbol_get (dummy_location);
   symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
 
   symbol *dummy = dummy_symbol_get (dummy_location);
   symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
 


@@ -351,12 +357,11 @@ grammar_midrule_action (void)
   ++nritems;
   /* Attach its location and actions to that of the DUMMY.  */
   midrule->location = dummy_location;
   ++nritems;
   /* Attach its location and actions to that of the DUMMY.  */
   midrule->location = dummy_location;

-  midrule->action = current_rule->action;
-  midrule->action_location = dummy_location;
-  current_rule->action = NULL;
-  /* The action has not been translated yet, so $$ use hasn't been
-     detected yet.  */
-  midrule->used = false;
+  code_props_rule_action_init (&midrule->action_props,
+                               current_rule->action_props.code,
+                               current_rule->action_props.location,
+                               midrule);
+  code_props_none_init (&current_rule->action_props);

 
   if (previous_rule_end)
     previous_rule_end->next = midrule;
 
   if (previous_rule_end)
     previous_rule_end->next = midrule;


@@ -382,6 +387,7 @@ grammar_midrule_action (void)
 void
 grammar_current_rule_prec_set (symbol *precsym, location loc)
 {
 void
 grammar_current_rule_prec_set (symbol *precsym, location loc)
 {

+  symbol_class_set (precsym, token_sym, loc, false);

   if (current_rule->ruleprec)
     complain_at (loc, _("only one %s allowed per rule"), "%prec");
   current_rule->ruleprec = precsym;
   if (current_rule->ruleprec)
     complain_at (loc, _("only one %s allowed per rule"), "%prec");
   current_rule->ruleprec = precsym;


@@ -421,7 +427,7 @@ grammar_current_rule_merge_set (uniqstr name, location loc)
 void
 grammar_current_rule_symbol_append (symbol *sym, location loc)
 {
 void
 grammar_current_rule_symbol_append (symbol *sym, location loc)
 {

-  if (current_rule->action)
+  if (current_rule->action_props.code)

     grammar_midrule_action ();
   grammar_symbol_append (sym, loc);
 }
     grammar_midrule_action ();
   grammar_symbol_append (sym, loc);
 }


@@ -431,12 +437,12 @@ grammar_current_rule_symbol_append (symbol *sym, location loc)
 void
 grammar_current_rule_action_append (const char *action, location loc)
 {
 void
 grammar_current_rule_action_append (const char *action, location loc)
 {

-  if (current_rule->action)
+  if (current_rule->action_props.code)

     grammar_midrule_action ();
   /* After all symbol declarations have been parsed, packgram invokes
     grammar_midrule_action ();
   /* After all symbol declarations have been parsed, packgram invokes

-     translate_rule_action.  */
-  current_rule->action = action;
-  current_rule->action_location = loc;
+     code_props_translate_code.  */
+  code_props_rule_action_init (&current_rule->action_props, action, loc,
+                               current_rule);

 }
 
 \f
 }
 
 \f


@@ -459,15 +465,15 @@ packgram (void)
 
   rules = xnmalloc (nrules, sizeof *rules);
 
 
   rules = xnmalloc (nrules, sizeof *rules);
 

-  /* Before invoking grammar_rule_check on any rule, make sure
-     all actions have already been scanned in order to set `used' flags.
-     Otherwise, checking that a midrule's $$ is set will not always work
-     properly because the midrule check must forward-reference the midrule's
-     parent rule.  */
+  /* Before invoking grammar_rule_check on any rule, make sure all actions have
+     already been scanned in order to set `used' flags.  Otherwise, checking
+     that a midrule's $$ should be set will not always work properly because
+     the check must forward-reference the midrule's parent rule.  For the same
+     reason, all the `used' flags must be set before checking whether to remove
+     `$' from any midrule symbol name.  */

   while (p)
     {
   while (p)
     {

-      if (p->action)
-        p->action = translate_rule_action (p);
+      code_props_translate_code (&p->action_props);

       if (p)
        p = p->next;
     }
       if (p)
        p = p->next;
     }


@@ -489,8 +495,18 @@ packgram (void)
       rules[ruleno].precsym = NULL;
       rules[ruleno].location = p->location;
       rules[ruleno].useful = true;
       rules[ruleno].precsym = NULL;
       rules[ruleno].location = p->location;
       rules[ruleno].useful = true;

-      rules[ruleno].action = p->action;
-      rules[ruleno].action_location = p->action_location;
+      rules[ruleno].action = p->action_props.code;
+      rules[ruleno].action_location = p->action_props.location;
+
+      /* If the midrule's $$ is set or its $n is used, remove the `$' from the
+        symbol name so that it's a user-defined symbol so that the default
+        %destructor and %printer apply.  */
+      if (p->midrule_parent_rule
+          && (p->action_props.is_value_used
+             || symbol_list_n_get (p->midrule_parent_rule,
+                                   p->midrule_parent_rhs_index)
+                   ->action_props.is_value_used))
+       p->content.sym->tag += 1;

 
       /* Don't check the generated rule 0.  It has no action, so some rhs
         symbols may appear unused, but the parsing algorithm ensures that
 
       /* Don't check the generated rule 0.  It has no action, so some rhs
         symbols may appear unused, but the parsing algorithm ensures that


@@ -656,5 +672,5 @@ check_and_convert_grammar (void)
   packgram ();
 
   /* The grammar as a symbol_list is no longer needed. */
   packgram ();
 
   /* The grammar as a symbol_list is no longer needed. */

-  LIST_FREE (symbol_list, grammar);
+  symbol_list_free (grammar);

 }
 }