grammar: introduce %empty

[bison.git] / src / reader.c

diff --git a/src/reader.c b/src/reader.c
index 14624df880b56ecd9d0d80425520e801e6cf5406..a83f11c1a8da97973efceeb873e62792d4b17027 100644 (file)
--- a/src/reader.c
+++ b/src/reader.c
@@ -1,7 +1,7 @@
 /* Input parser for Bison
 
 /* 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,
+   2009-2013 Free Software Foundation, Inc.

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


@@ -22,7 +22,6 @@
 #include "system.h"
 
 #include <quote.h>
 #include "system.h"
 
 #include <quote.h>

-#include <quotearg.h>

 
 #include "complain.h"
 #include "conflicts.h"
 
 #include "complain.h"
 #include "conflicts.h"


@@ -60,7 +59,7 @@ void
 grammar_start_symbol_set (symbol *sym, location loc)
 {
   if (start_flag)
 grammar_start_symbol_set (symbol *sym, location loc)
 {
   if (start_flag)

-    complain_at (loc, _("multiple %s declarations"), "%start");
+    complain (&loc, complaint, _("multiple %s declarations"), "%start");

   else
     {
       start_flag = true;
   else
     {
       start_flag = true;


@@ -95,7 +94,7 @@ get_merge_function (uniqstr name)
       syms->next = xmalloc (sizeof syms->next[0]);
       syms->next->name = uniqstr_new (name);
       /* After all symbol type declarations have been parsed, packgram invokes
       syms->next = xmalloc (sizeof syms->next[0]);
       syms->next->name = uniqstr_new (name);
       /* After all symbol type declarations have been parsed, packgram invokes

-        record_merge_function_type to set the type.  */
+         record_merge_function_type to set the type.  */

       syms->next->type = NULL;
       syms->next->next = NULL;
       merge_functions = head.next;
       syms->next->type = NULL;
       syms->next->next = NULL;
       merge_functions = head.next;


@@ -129,18 +128,23 @@ record_merge_function_type (int merger, uniqstr type, location declaration_loc)
   aver (merge_function != NULL && merger_find == merger);
   if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))
     {
   aver (merge_function != NULL && merger_find == merger);
   if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))
     {

-      complain_at (declaration_loc,
-                  _("result type clash on merge function `%s': <%s> != <%s>"),
-                  merge_function->name, type, merge_function->type);
-      complain_at (merge_function->type_declaration_location,
-                  _("previous declaration"));
+      unsigned indent = 0;
+      complain_indent (&declaration_loc, complaint, &indent,
+                       _("result type clash on merge function %s: "
+                         "<%s> != <%s>"),
+                       quote (merge_function->name), type,
+                       merge_function->type);
+      indent += SUB_INDENT;
+      complain_indent (&merge_function->type_declaration_location, complaint,
+                       &indent,
+                       _("previous declaration"));

     }
   merge_function->type = uniqstr_new (type);
   merge_function->type_declaration_location = declaration_loc;
 }
 
 /*--------------------------------------.
     }
   merge_function->type = uniqstr_new (type);
   merge_function->type_declaration_location = declaration_loc;
 }
 
 /*--------------------------------------.

-| Free all merge-function definitions. |
+| Free all merge-function definitions.  |

 `--------------------------------------*/
 
 void
 `--------------------------------------*/
 
 void


@@ -198,9 +202,9 @@ assign_named_ref (symbol_list *p, named_ref *name)
 
   if (name->id == sym->tag)
     {
 
   if (name->id == sym->tag)
     {

-      warn_at (name->loc,
-              _("duplicated symbol name for %s ignored"),
-              quote (sym->tag));
+      complain (&name->loc, Wother,
+                _("duplicated symbol name for %s ignored"),
+                quote (sym->tag));

       named_ref_free (name);
     }
   else
       named_ref_free (name);
     }
   else


@@ -221,7 +225,7 @@ static symbol_list *previous_rule_end = NULL;
 
 void
 grammar_current_rule_begin (symbol *lhs, location loc,
 
 void
 grammar_current_rule_begin (symbol *lhs, location loc,

-                           named_ref *lhs_name)
+                            named_ref *lhs_name)

 {
   symbol_list* p;
 
 {
   symbol_list* p;
 


@@ -231,7 +235,7 @@ grammar_current_rule_begin (symbol *lhs, location loc,
 
   p = grammar_symbol_append (lhs, loc);
   if (lhs_name)
 
   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;
 
 
   current_rule = grammar_end;
 


@@ -243,29 +247,33 @@ grammar_current_rule_begin (symbol *lhs, location loc,
       ++nvars;
     }
   else if (lhs->class == token_sym)
       ++nvars;
     }
   else if (lhs->class == token_sym)

-    complain_at (loc, _("rule given for %s, which is a token"), lhs->tag);
+    complain (&loc, complaint, _("rule given for %s, which is a token"),
+              lhs->tag);

 }
 
 
 /*----------------------------------------------------------------------.
 | A symbol should be used if either:                                    |
 |   1. It has a destructor.                                             |
 }
 
 
 /*----------------------------------------------------------------------.
 | 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
 `----------------------------------------------------------------------*/
 
 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)
+  if (symbol_code_props_get (s->content.sym, destructor)->code)

     return true;
     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;
 }
 
   return false;
 }
 


@@ -289,19 +297,19 @@ grammar_rule_check (const symbol_list *r)
       symbol *first_rhs = r->next->content.sym;
       /* If $$ is being set in default way, report if any type mismatch.  */
       if (first_rhs)
       symbol *first_rhs = r->next->content.sym;
       /* If $$ is being set in default way, report if any type mismatch.  */
       if (first_rhs)

-       {
-         char const *lhs_type = r->content.sym->type_name;
-         const char *rhs_type =
-           first_rhs->type_name ? first_rhs->type_name : "";
-         if (!UNIQSTR_EQ (lhs_type, rhs_type))
-           warn_at (r->location,
-                    _("type clash on default action: <%s> != <%s>"),
-                    lhs_type, rhs_type);
-       }
+        {
+          char const *lhs_type = r->content.sym->type_name;
+          const char *rhs_type =
+            first_rhs->type_name ? first_rhs->type_name : "";
+          if (!UNIQSTR_EQ (lhs_type, rhs_type))
+            complain (&r->location, Wother,
+                      _("type clash on default action: <%s> != <%s>"),
+                      lhs_type, rhs_type);
+        }

       /* Warn if there is no default for $$ but we need one.  */
       else
       /* Warn if there is no default for $$ but we need one.  */
       else

-       warn_at (r->location,
-                _("empty rule for typed nonterminal, and no action"));
+        complain (&r->location, Wother,
+                  _("empty rule for typed nonterminal, and no action"));

     }
 
   /* Check that symbol values that should be used are in fact used.  */
     }
 
   /* Check that symbol values that should be used are in fact used.  */


@@ -309,17 +317,36 @@ 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->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, $$ = $1, `uses' both.  */
+            && (r->action_props.code || (n != 0 && n != 1)))
+          {
+            warnings warn_flag = midrule_warning ? Wmidrule_values : Wother;
+            if (n)
+              complain (&l->location, warn_flag, _("unused value: $%d"), n);
+            else
+              complain (&l->location, warn_flag, _("unset value: $$"));
+          }
+      }

   }
   }

+
+  /* Check that %empty => empty rule.  */
+  if (r->percent_empty_loc.start.file
+      && r->next && r->next->content.sym)
+    complain (&r->percent_empty_loc, complaint,
+              _("%%empty on non-empty rule"));
+
+  /* See comments in grammar_current_rule_prec_set for how POSIX
+     mandates this complaint.  It's only for identifiers, so skip
+     it for char literals and strings, which are always tokens.  */
+  if (r->ruleprec
+      && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"'
+      && r->ruleprec->status != declared && !r->ruleprec->prec)
+    complain (&r->location, Wother,
+              _("token for %%prec is not defined: %s"), r->ruleprec->tag);

 }
 
 
 }
 
 


@@ -368,7 +395,8 @@ grammar_midrule_action (void)
   code_props_rule_action_init (&midrule->action_props,
                                current_rule->action_props.code,
                                current_rule->action_props.location,
   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)
   code_props_none_init (&current_rule->action_props);
 
   if (previous_rule_end)


@@ -396,23 +424,46 @@ grammar_midrule_action (void)
 void
 grammar_current_rule_prec_set (symbol *precsym, location loc)
 {
 void
 grammar_current_rule_prec_set (symbol *precsym, location loc)
 {

+  /* POSIX says that any identifier is a nonterminal if it does not
+     appear on the LHS of a grammar rule and is not defined by %token
+     or by one of the directives that assigns precedence to a token.  We
+     ignore this here because the only kind of identifier that POSIX
+     allows to follow a %prec is a token and because assuming it's a
+     token now can produce more logical error messages.  Nevertheless,
+     grammar_rule_check does obey what we believe is the real intent of
+     POSIX here: that an error be reported for any identifier that
+     appears after %prec but that is not defined separately as a
+     token.  */

   symbol_class_set (precsym, token_sym, loc, false);
   if (current_rule->ruleprec)
   symbol_class_set (precsym, token_sym, loc, false);
   if (current_rule->ruleprec)

-    complain_at (loc, _("only one %s allowed per rule"), "%prec");
+    complain (&loc, complaint, _("only one %s allowed per rule"), "%prec");

   current_rule->ruleprec = precsym;
 }
 
   current_rule->ruleprec = precsym;
 }
 

+/* Set %empty for the current rule. */
+
+void
+grammar_current_rule_empty_set (location loc)
+{
+  if (current_rule->percent_empty_loc.start.file)
+    complain (&loc, complaint, _("only one %s allowed per rule"), "%empty");
+  else
+    current_rule->percent_empty_loc = loc;
+}
+

 /* Attach dynamic precedence DPREC to the current rule. */
 
 void
 grammar_current_rule_dprec_set (int dprec, location loc)
 {
   if (! glr_parser)
 /* Attach dynamic precedence DPREC to the current rule. */
 
 void
 grammar_current_rule_dprec_set (int dprec, location loc)
 {
   if (! glr_parser)

-    warn_at (loc, _("%s affects only GLR parsers"), "%dprec");
+    complain (&loc, Wother, _("%s affects only GLR parsers"),
+              "%dprec");

   if (dprec <= 0)
   if (dprec <= 0)

-    complain_at (loc, _("%s must be followed by positive number"), "%dprec");
+    complain (&loc, complaint, _("%s must be followed by positive number"),
+              "%dprec");

   else if (current_rule->dprec != 0)
   else if (current_rule->dprec != 0)

-    complain_at (loc, _("only one %s allowed per rule"), "%dprec");
+    complain (&loc, complaint, _("only one %s allowed per rule"), "%dprec");

   current_rule->dprec = dprec;
 }
 
   current_rule->dprec = dprec;
 }
 


@@ -423,9 +474,10 @@ void
 grammar_current_rule_merge_set (uniqstr name, location loc)
 {
   if (! glr_parser)
 grammar_current_rule_merge_set (uniqstr name, location loc)
 {
   if (! glr_parser)

-    warn_at (loc, _("%s affects only GLR parsers"), "%merge");
+    complain (&loc, Wother, _("%s affects only GLR parsers"),
+              "%merge");

   if (current_rule->merger != 0)
   if (current_rule->merger != 0)

-    complain_at (loc, _("only one %s allowed per rule"), "%merge");
+    complain (&loc, complaint, _("only one %s allowed per rule"), "%merge");

   current_rule->merger = get_merge_function (name);
   current_rule->merger_declaration_location = loc;
 }
   current_rule->merger = get_merge_function (name);
   current_rule->merger_declaration_location = loc;
 }


@@ -435,7 +487,7 @@ 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,

-                                   named_ref *name)
+                                    named_ref *name)

 {
   symbol_list *p;
   if (current_rule->action_props.code)
 {
   symbol_list *p;
   if (current_rule->action_props.code)


@@ -443,20 +495,22 @@ grammar_current_rule_symbol_append (symbol *sym, location loc,
   p = grammar_symbol_append (sym, loc);
   if (name)
     assign_named_ref(p, name);
   p = grammar_symbol_append (sym, loc);
   if (name)
     assign_named_ref(p, name);

+  if (sym->status == undeclared || sym->status == used)
+    sym->status = needed;

 }
 
 /* Attach an ACTION to the current rule.  */
 
 void
 grammar_current_rule_action_append (const char *action, location loc,
 }
 
 /* Attach an ACTION to the current rule.  */
 
 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,
 {
   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
 }
 
 \f


@@ -470,7 +524,7 @@ packgram (void)
 {
   unsigned int itemno = 0;
   rule_number ruleno = 0;
 {
   unsigned int itemno = 0;
   rule_number ruleno = 0;

-  symbol_list *p = grammar;
+  symbol_list *p;

 
   ritem = xnmalloc (nritems + 1, sizeof *ritem);
 
 
   ritem = xnmalloc (nritems + 1, sizeof *ritem);
 


@@ -479,12 +533,11 @@ packgram (void)
 
   rules = xnmalloc (nrules, sizeof *rules);
 
 
   rules = xnmalloc (nrules, sizeof *rules);
 

-  while (p)
+  for (p = grammar; p; p = p->next)

     {
     {

-      int rule_length = 0;

       symbol *ruleprec = p->ruleprec;
       record_merge_function_type (p->merger, p->content.sym->type_name,
       symbol *ruleprec = p->ruleprec;
       record_merge_function_type (p->merger, p->content.sym->type_name,

-                                 p->merger_declaration_location);
+                                  p->merger_declaration_location);

       rules[ruleno].user_number = ruleno;
       rules[ruleno].number = ruleno;
       rules[ruleno].lhs = p->content.sym;
       rules[ruleno].user_number = ruleno;
       rules[ruleno].number = ruleno;
       rules[ruleno].lhs = p->content.sym;


@@ -497,57 +550,58 @@ packgram (void)
       rules[ruleno].useful = true;
       rules[ruleno].action = p->action_props.code;
       rules[ruleno].action_location = p->action_props.location;
       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
 
       /* 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.  */
+         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
       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;
+              || (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
 
       /* Don't check the generated rule 0.  It has no action, so some rhs

-        symbols may appear unused, but the parsing algorithm ensures that
-        %destructor's are invoked appropriately.  */
+         symbols may appear unused, but the parsing algorithm ensures that
+         %destructor's are invoked appropriately.  */

       if (p != grammar)
       if (p != grammar)

-       grammar_rule_check (p);
-
-      for (p = p->next; p && p->content.sym; p = p->next)
-       {
-         ++rule_length;
-
-         /* Don't allow rule_length == INT_MAX, since that might
-            cause confusion with strtol if INT_MAX == LONG_MAX.  */
-         if (rule_length == INT_MAX)
-             fatal_at (rules[ruleno].location, _("rule is too long"));
-
-         /* item_number = symbol_number.
-            But the former needs to contain more: negative rule numbers. */
-         ritem[itemno++] =
-            symbol_number_as_item_number (p->content.sym->number);
-         /* A rule gets by default the precedence and associativity
-            of its last token.  */
-         if (p->content.sym->class == token_sym && default_prec)
-           rules[ruleno].prec = p->content.sym;
-       }
+        grammar_rule_check (p);
+
+      {
+        size_t rule_length = 0;
+        for (p = p->next; p->content.sym; p = p->next)
+          {
+            ++rule_length;
+
+            /* Don't allow rule_length == INT_MAX, since that might
+               cause confusion with strtol if INT_MAX == LONG_MAX.  */
+            if (rule_length == INT_MAX)
+              complain (&rules[ruleno].location, fatal, _("rule is too long"));
+
+            /* item_number = symbol_number.
+               But the former needs to contain more: negative rule numbers. */
+            ritem[itemno++] =
+              symbol_number_as_item_number (p->content.sym->number);
+            /* A rule gets by default the precedence and associativity
+               of its last token.  */
+            if (p->content.sym->class == token_sym && default_prec)
+              rules[ruleno].prec = p->content.sym;
+          }
+      }

 
       /* If this rule has a %prec,
          the specified symbol's precedence replaces the default.  */
       if (ruleprec)
 
       /* If this rule has a %prec,
          the specified symbol's precedence replaces the default.  */
       if (ruleprec)

-       {
-         rules[ruleno].precsym = ruleprec;
-         rules[ruleno].prec = ruleprec;
-       }
+        {
+          rules[ruleno].precsym = ruleprec;
+          rules[ruleno].prec = ruleprec;
+        }

       /* An item ends by the rule number (negated).  */
       ritem[itemno++] = rule_number_as_item_number (ruleno);
       aver (itemno < ITEM_NUMBER_MAX);
       ++ruleno;
       aver (ruleno < RULE_NUMBER_MAX);
       /* An item ends by the rule number (negated).  */
       ritem[itemno++] = rule_number_as_item_number (ruleno);
       aver (itemno < ITEM_NUMBER_MAX);
       ++ruleno;
       aver (ruleno < RULE_NUMBER_MAX);

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

     }
 
   aver (itemno == nritems);
     }
 
   aver (itemno == nritems);


@@ -593,7 +647,7 @@ reader (void)
   gram_parse ();
   prepare_percent_define_front_end_variables ();
 
   gram_parse ();
   prepare_percent_define_front_end_variables ();
 

-  if (! complaint_issued)
+  if (complaint_status  < status_complaint)

     check_and_convert_grammar ();
 
   xfclose (gram_in);
     check_and_convert_grammar ();
 
   xfclose (gram_in);


@@ -603,25 +657,25 @@ static void
 prepare_percent_define_front_end_variables (void)
 {
   /* Set %define front-end variable defaults.  */
 prepare_percent_define_front_end_variables (void)
 {
   /* Set %define front-end variable defaults.  */

-  muscle_percent_define_default ("lr.keep-unreachable-states", "false");
+  muscle_percent_define_default ("lr.keep-unreachable-state", "false");

   {
     char *lr_type;
     /* IELR would be a better default, but LALR is historically the
        default.  */
   {
     char *lr_type;
     /* IELR would be a better default, but LALR is historically the
        default.  */

-    muscle_percent_define_default ("lr.type", "LALR");
+    muscle_percent_define_default ("lr.type", "lalr");

     lr_type = muscle_percent_define_get ("lr.type");
     lr_type = muscle_percent_define_get ("lr.type");

-    if (0 != strcmp (lr_type, "canonical LR"))
-      muscle_percent_define_default ("lr.default-reductions", "all");
+    if (STRNEQ (lr_type, "canonical-lr"))
+      muscle_percent_define_default ("lr.default-reduction", "most");

     else
     else

-      muscle_percent_define_default ("lr.default-reductions", "accepting");
+      muscle_percent_define_default ("lr.default-reduction", "accepting");

     free (lr_type);
   }
 
   /* Check %define front-end variables.  */
   {
     static char const * const values[] = {
     free (lr_type);
   }
 
   /* Check %define front-end variables.  */
   {
     static char const * const values[] = {

-      "lr.type", "LALR", "IELR", "canonical LR", NULL,
-      "lr.default-reductions", "all", "consistent", "accepting", NULL,
+      "lr.type", "lalr", "ielr", "canonical-lr", NULL,
+      "lr.default-reduction", "most", "consistent", "accepting", NULL,

       NULL
     };
     muscle_percent_define_check_values (values);
       NULL
     };
     muscle_percent_define_check_values (values);


@@ -631,7 +685,7 @@ prepare_percent_define_front_end_variables (void)
 
 /*-------------------------------------------------------------.
 | Check the grammar that has just been read, and convert it to |
 
 /*-------------------------------------------------------------.
 | Check the grammar that has just been read, and convert it to |

-| internal form.                                              |
+| internal form.                                               |

 `-------------------------------------------------------------*/
 
 static void
 `-------------------------------------------------------------*/
 
 static void


@@ -639,10 +693,7 @@ check_and_convert_grammar (void)
 {
   /* Grammar has been read.  Do some checking.  */
   if (nrules == 0)
 {
   /* Grammar has been read.  Do some checking.  */
   if (nrules == 0)

-    fatal (_("no rules in the input grammar"));
-
-  /* Report any undefined symbols and consider them nonterminals.  */
-  symbols_check_defined ();
+    complain (NULL, fatal, _("no rules in the input grammar"));

 
   /* If the user did not define her ENDTOKEN, do it now. */
   if (!endtoken)
 
   /* If the user did not define her ENDTOKEN, do it now. */
   if (!endtoken)


@@ -654,6 +705,9 @@ check_and_convert_grammar (void)
       endtoken->user_token_number = 0;
     }
 
       endtoken->user_token_number = 0;
     }
 

+  /* Report any undefined symbols and consider them nonterminals.  */
+  symbols_check_defined ();
+

   /* Find the start symbol if no %start.  */
   if (!start_flag)
     {
   /* Find the start symbol if no %start.  */
   if (!start_flag)
     {


@@ -675,7 +729,7 @@ check_and_convert_grammar (void)
   /* Insert the initial rule, whose line is that of the first rule
      (not that of the start symbol):
 
   /* Insert the initial rule, whose line is that of the first rule
      (not that of the start symbol):
 

-     accept: %start EOF.  */
+     $accept: %start $end.  */

   {
     symbol_list *p = symbol_list_sym_new (accept, empty_location);
     p->location = grammar->location;
   {
     symbol_list *p = symbol_list_sym_new (accept, empty_location);
     p->location = grammar->location;


@@ -688,7 +742,8 @@ check_and_convert_grammar (void)
     grammar = p;
   }
 
     grammar = p;
   }
 

-  aver (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);
+  aver (nsyms <= SYMBOL_NUMBER_MAXIMUM);
+  aver (nsyms == ntokens + nvars);

 
   /* Assign the symbols their symbol numbers.  Write #defines for the
      token symbols into FDEFINES if requested.  */
 
   /* Assign the symbols their symbol numbers.  Write #defines for the
      token symbols into FDEFINES if requested.  */