doc: clean up references to `Tracking Locations'.

[bison.git] / src / reader.c

diff --git a/src/reader.c b/src/reader.c
index 3f00754131c1fe6e5e92f64ab919781aa094c61d..20f81d687fec8c4344bf70e70e293116845aada0 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,
-   2005, 2006, 2007, 2009 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000-2003, 2005-2007,
+   2009-2011 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -231,7 +231,7 @@ grammar_current_rule_begin (symbol *lhs, location loc,
 
   p = grammar_symbol_append (lhs, loc);
   if (lhs_name)
-    assign_named_ref(p, lhs_name);
+    assign_named_ref (p, named_ref_copy (lhs_name));
 
   current_rule = grammar_end;
 
@@ -250,22 +250,25 @@ grammar_current_rule_begin (symbol *lhs, location loc,
 /*----------------------------------------------------------------------.
 | 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; }".      |
+|   2. 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)
+symbol_should_be_used (symbol_list const *s, bool *midrule_warning)
 {
   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));
+  if ((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))
+    {
+      *midrule_warning = true;
+      return true;
+    }
   return false;
 }
 
@@ -309,16 +312,21 @@ grammar_rule_check (const symbol_list *r)
     symbol_list const *l = r;
     int n = 0;
     for (; l && l->content.sym; l = l->next, ++n)
-      if (! (l->action_props.is_value_used
-            || !symbol_should_be_used (l)
-            /* The default action, $$ = $1, `uses' both.  */
-            || (!r->action_props.code && (n == 0 || n == 1))))
-       {
-         if (n)
-           warn_at (r->location, _("unused value: $%d"), n);
-         else
-           warn_at (r->location, _("unset value: $$"));
-       }
+      {
+        bool midrule_warning = false;
+        if (!l->action_props.is_value_used
+            && symbol_should_be_used (l, &midrule_warning)
+            /* The default action, $$ = $1, `uses' both.  */
+            && (r->action_props.code || (n != 0 && n != 1)))
+          {
+            void (*warn_at_ptr)(location, char const*, ...) =
+              midrule_warning ? midrule_value_at : warn_at;
+            if (n)
+              warn_at_ptr (r->location, _("unused value: $%d"), n);
+            else
+              warn_at_ptr (r->location, _("unset value: $$"));
+          }
+      }
   }
 
   /* See comments in grammar_current_rule_prec_set for how POSIX
@@ -327,8 +335,8 @@ grammar_rule_check (const symbol_list *r)
   if (r->ruleprec
       && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"'
       && !r->ruleprec->declared && !r->ruleprec->prec)
-    complain_at (r->location, _("token for %%prec is not defined: %s"),
-                 r->ruleprec->tag);
+    warn_at (r->location, _("token for %%prec is not defined: %s"),
+             r->ruleprec->tag);
 }
 
 
@@ -377,7 +385,8 @@ grammar_midrule_action (void)
   code_props_rule_action_init (&midrule->action_props,
                                current_rule->action_props.code,
                                current_rule->action_props.location,
-                               midrule, 0);
+                               midrule, 0,
+                              current_rule->action_props.is_predicate);
   code_props_none_init (&current_rule->action_props);
 
   if (previous_rule_end)
@@ -468,14 +477,14 @@ grammar_current_rule_symbol_append (symbol *sym, location loc,
 
 void
 grammar_current_rule_action_append (const char *action, location loc,
-                                   named_ref *name)
+                                   named_ref *name, bool is_predicate)
 {
   if (current_rule->action_props.code)
     grammar_midrule_action ();
   /* After all symbol declarations have been parsed, packgram invokes
      code_props_translate_code.  */
   code_props_rule_action_init (&current_rule->action_props, action, loc,
-                               current_rule, name);
+                               current_rule, name, is_predicate);
 }
 
 \f
@@ -516,6 +525,7 @@ packgram (void)
       rules[ruleno].useful = true;
       rules[ruleno].action = p->action_props.code;
       rules[ruleno].action_location = p->action_props.location;
+      rules[ruleno].is_predicate = p->action_props.is_predicate;
 
       /* 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
@@ -630,7 +640,7 @@ prepare_percent_define_front_end_variables (void)
     muscle_percent_define_default ("lr.type", "lalr");
     lr_type = muscle_percent_define_get ("lr.type");
     if (0 != strcmp (lr_type, "canonical-lr"))
-      muscle_percent_define_default ("lr.default-reductions", "all");
+      muscle_percent_define_default ("lr.default-reductions", "most");
     else
       muscle_percent_define_default ("lr.default-reductions", "accepting");
     free (lr_type);
@@ -640,7 +650,7 @@ prepare_percent_define_front_end_variables (void)
   {
     static char const * const values[] = {
       "lr.type", "lalr", "ielr", "canonical-lr", NULL,
-      "lr.default-reductions", "all", "consistent", "accepting", NULL,
+      "lr.default-reductions", "most", "consistent", "accepting", NULL,
       NULL
     };
     muscle_percent_define_check_values (values);