Don't apply the default %destructor/%printer to an unreferenced midrule

[bison.git] / src / symtab.c

diff --git a/src/symtab.c b/src/symtab.c
index afc0c1c8b52a0657ab0d072448164510bd75a60c..f4bf8032d13ca3907c8d77bdde9a8b0cd631094a 100644 (file)
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -1,5 +1,7 @@
-/* Symbol table manager for Bison,
-   Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
+/* Symbol table manager for Bison.
+
+   Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004, 2005, 2006 Free
+   Software Foundation, Inc.

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


@@ -15,39 +17,51 @@
 
    You should have received a copy of the GNU General Public License
    along with Bison; see the file COPYING.  If not, write to
 
    You should have received a copy of the GNU General Public License
    along with Bison; see the file COPYING.  If not, write to

-   the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
-
+   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */

 
 

+#include <config.h>

 #include "system.h"
 #include "system.h"

-#include "quotearg.h"
-#include "hash.h"
+
+#include <hash.h>
+#include <quotearg.h>
+

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

-#include "symtab.h"

 #include "gram.h"
 #include "gram.h"

+#include "symtab.h"

 
 /*------------------------.
 | Distinguished symbols.  |
 `------------------------*/
 
 
 /*------------------------.
 | Distinguished symbols.  |
 `------------------------*/
 

-symbol_t *errtoken = NULL;
-symbol_t *undeftoken = NULL;
-symbol_t *eoftoken = NULL;
-symbol_t *axiom = NULL;
-symbol_t *startsymbol = NULL;
-location_t startsymbol_location;
+symbol *errtoken = NULL;
+symbol *undeftoken = NULL;
+symbol *endtoken = NULL;
+symbol *accept = NULL;
+symbol *startsymbol = NULL;
+location startsymbol_location;
+
+/*-----------------------------------.
+| Default %destructor and %printer.  |
+`-----------------------------------*/
+
+static const char *default_destructor = NULL;
+static location default_destructor_location;
+static const char *default_printer = NULL;
+static location default_printer_location;

 
 /*---------------------------------.
 | Create a new symbol, named TAG.  |
 `---------------------------------*/
 
 
 /*---------------------------------.
 | Create a new symbol, named TAG.  |
 `---------------------------------*/
 

-static symbol_t *
-symbol_new (const char *tag, location_t location)
+static symbol *
+symbol_new (uniqstr tag, location loc)

 {
 {

-  symbol_t *res = XMALLOC (symbol_t, 1);
+  symbol *res = xmalloc (sizeof *res);

 
 

-  res->tag = xstrdup (tag);
-  res->location = location;
+  uniqstr_assert (tag);
+  res->tag = tag;
+  res->location = loc;

 
   res->type_name = NULL;
   res->destructor = NULL;
 
   res->type_name = NULL;
   res->destructor = NULL;


@@ -55,137 +69,336 @@ symbol_new (const char *tag, location_t location)
 
   res->number = NUMBER_UNDEFINED;
   res->prec = 0;
 
   res->number = NUMBER_UNDEFINED;
   res->prec = 0;

-  res->assoc = right_assoc;
+  res->assoc = undef_assoc;

   res->user_token_number = USER_NUMBER_UNDEFINED;
 
   res->alias = NULL;
   res->class = unknown_sym;
   res->user_token_number = USER_NUMBER_UNDEFINED;
 
   res->alias = NULL;
   res->class = unknown_sym;

+  res->declared = false;

 
 

+  if (nsyms == SYMBOL_NUMBER_MAXIMUM)
+    fatal (_("too many symbols in input grammar (limit is %d)"),
+          SYMBOL_NUMBER_MAXIMUM);

   nsyms++;
   return res;
 }
 
   nsyms++;
   return res;
 }
 

+/*----------------------------------------.
+| Create a new semantic type, named TAG.  |
+`----------------------------------------*/
+
+static semantic_type *
+semantic_type_new (uniqstr tag)
+{
+  semantic_type *res = xmalloc (sizeof *res);
+
+  uniqstr_assert (tag);
+  res->tag = tag;
+  res->destructor = NULL;
+  res->printer = NULL;
+
+  return res;
+}
+
+
+/*-----------------.
+| Print a symbol.  |
+`-----------------*/
+
+#define SYMBOL_ATTR_PRINT(Attr)                                \
+  if (s->Attr)                                         \
+    fprintf (f, " %s { %s }", #Attr, s->Attr)
+
+void
+symbol_print (symbol *s, FILE *f)
+{
+  if (s)
+    {
+      fprintf (f, "\"%s\"", s->tag);
+      SYMBOL_ATTR_PRINT (type_name);
+      SYMBOL_ATTR_PRINT (destructor);
+      SYMBOL_ATTR_PRINT (printer);
+    }
+  else
+    fprintf (f, "<NULL>");
+}
+
+#undef SYMBOL_ATTR_PRINT

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

-| Set the TYPE_NAME associated to SYMBOL.  Does nothing if passed 0 |
-| as TYPE_NAME.                                                     |
+| Complain that S's WHAT is redeclared at SECOND, and was first set |
+| at FIRST.                                                         |

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

+static void
+symbol_redeclaration (symbol *s, const char *what, location first,
+                      location second)
+{
+  complain_at (second, _("%s redeclaration for %s"), what, s->tag);
+  complain_at (first, _("previous declaration"));
+}
+
+static void
+semantic_type_redeclaration (semantic_type *s, const char *what, location first,
+                             location second)
+{
+  complain_at (second, _("%s redeclaration for <%s>"), what, s->tag);
+  complain_at (first, _("previous declaration"));
+}
+
+
+/*-----------------------------------------------------------------.
+| Set the TYPE_NAME associated with SYM.  Does nothing if passed 0 |
+| as TYPE_NAME.                                                    |
+`-----------------------------------------------------------------*/
+

 void
 void

-symbol_type_set (symbol_t *symbol, char *type_name, location_t location)
+symbol_type_set (symbol *sym, uniqstr type_name, location loc)

 {
   if (type_name)
     {
 {
   if (type_name)
     {

-      if (symbol->type_name)
-       complain_at (location,
-                    _("type redeclaration for %s"), symbol->tag);
-      symbol->type_name = type_name;
+      if (sym->type_name)
+       symbol_redeclaration (sym, "%type", sym->type_location, loc);
+      uniqstr_assert (type_name);
+      sym->type_name = type_name;
+      sym->type_location = loc;

     }
 }
 
 
     }
 }
 
 

+/*------------------------------------------------------------------.
+| Set the DESTRUCTOR associated with SYM.  Do nothing if passed 0.  |
+`------------------------------------------------------------------*/
+
+void
+symbol_destructor_set (symbol *sym, const char *destructor, location loc)
+{
+  if (destructor)
+    {
+      if (sym->destructor)
+       symbol_redeclaration (sym, "%destructor", sym->destructor_location,
+                              loc);
+      sym->destructor = destructor;
+      sym->destructor_location = loc;
+    }
+}
+

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

-| Set the DESTRUCTOR associated to SYMBOL.  Do nothing if passed 0.  |
+| Set the DESTRUCTOR associated with TYPE.  Do nothing if passed 0.  |

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

-symbol_destructor_set (symbol_t *symbol, char *destructor, location_t location)
+semantic_type_destructor_set (semantic_type *type, const char *destructor,
+                              location loc)

 {
   if (destructor)
     {
 {
   if (destructor)
     {

-      if (symbol->destructor)
-       complain_at (location,
-                    _("%s redeclaration for %s"),
-                    "%destructor", symbol->tag);
-      symbol->destructor = destructor;
-      symbol->destructor_location = location;
+      if (type->destructor)
+       semantic_type_redeclaration (type, "%destructor",
+                                     type->destructor_location, loc);
+      type->destructor = destructor;
+      type->destructor_location = loc;
+    }
+}
+
+/*---------------------------------------.
+| Get the computed %destructor for SYM.  |
+`---------------------------------------*/
+
+const char *
+symbol_destructor_get (symbol *sym)
+{
+  /* Per-symbol %destructor.  */
+  if (sym->destructor != NULL)
+    return sym->destructor;
+
+  /* Per-type %destructor.  */
+  if (sym->type_name)
+    {
+      semantic_type *type = semantic_type_get (sym->type_name);
+      if (type->destructor)
+        return type->destructor;

     }
     }

+
+  /* Apply the default %destructor only to user-defined symbols.  */
+  if (sym->tag[0] == '$' || sym == errtoken)
+    return NULL;
+  return default_destructor;

 }
 
 }
 

+/*---------------------------------------------------------------.
+| Get the grammar location of the %destructor computed for SYM.  |
+`---------------------------------------------------------------*/
+
+location
+symbol_destructor_location_get (symbol *sym)
+{
+  if (sym->destructor != NULL)
+    return sym->destructor_location;
+  if (sym->type_name)
+    {
+      semantic_type *type = semantic_type_get (sym->type_name);
+      if (type->destructor)
+        return type->destructor_location;
+    }
+  return default_destructor_location;
+}
+
+/*---------------------------------------------------------------.
+| Set the PRINTER associated with SYM.  Do nothing if passed 0.  |
+`---------------------------------------------------------------*/
+
+void
+symbol_printer_set (symbol *sym, const char *printer, location loc)
+{
+  if (printer)
+    {
+      if (sym->printer)
+       symbol_redeclaration (sym, "%printer", sym->printer_location, loc);
+      sym->printer = printer;
+      sym->printer_location = loc;
+    }
+}

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

-| Set the PRITNER associated to SYMBOL.  Do nothing if passed 0.  |
+| Set the PRINTER associated with TYPE.  Do nothing if passed 0.  |

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

-symbol_printer_set (symbol_t *symbol, char *printer, location_t location)
+semantic_type_printer_set (semantic_type *type, const char *printer,
+                           location loc)

 {
   if (printer)
     {
 {
   if (printer)
     {

-      if (symbol->printer)
-       complain_at (location,
-                    _("%s redeclaration for %s"),
-                    "%printer", symbol->tag);
-      symbol->printer = printer;
-      symbol->printer_location = location;
+      if (type->printer)
+       semantic_type_redeclaration (type, "%printer", type->printer_location,
+                                     loc);
+      type->printer = printer;
+      type->printer_location = loc;

     }
 }
 
     }
 }
 

+/*------------------------------------.
+| Get the computed %printer for SYM.  |
+`------------------------------------*/

 
 

-/*------------------------------------------------------------------.
-| Set the PRECEDENCE associated to SYMBOL.  Does nothing if invoked |
-| with UNDEF_ASSOC as ASSOC.                                        |
-`------------------------------------------------------------------*/
+const char *
+symbol_printer_get (symbol *sym)
+{
+  /* Per-symbol %printer.  */
+  if (sym->printer != NULL)
+    return sym->printer;
+
+  /* Per-type %printer.  */
+  if (sym->type_name)
+    {
+      semantic_type *type = semantic_type_get (sym->type_name);
+      if (type->printer)
+        return type->printer;
+    }
+
+  /* Apply the default %printer only to user-defined symbols.  */
+  if (sym->tag[0] == '$' || sym == errtoken)
+    return NULL;
+  return default_printer;
+}
+
+/*------------------------------------------------------------.
+| Get the grammar location of the %printer computed for SYM.  |
+`------------------------------------------------------------*/
+
+location
+symbol_printer_location_get (symbol *sym)
+{
+  if (sym->printer != NULL)
+    return sym->printer_location;
+  if (sym->type_name)
+    {
+      semantic_type *type = semantic_type_get (sym->type_name);
+      if (type->printer)
+        return type->printer_location;
+    }
+  return default_printer_location;
+}
+
+
+/*-----------------------------------------------------------------.
+| Set the PRECEDENCE associated with SYM.  Does nothing if invoked |
+| with UNDEF_ASSOC as ASSOC.                                       |
+`-----------------------------------------------------------------*/

 
 void
 
 void

-symbol_precedence_set (symbol_t *symbol,
-                      int prec, associativity assoc, location_t location)
+symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)

 {
 {

-  if (assoc != undef_assoc)
+  if (a != undef_assoc)

     {
     {

-      if (symbol->prec != 0)
-       complain_at (location,
-                    _("redefining precedence of %s"),
-                    symbol->tag);
-      symbol->prec = prec;
-      symbol->assoc = assoc;
+      if (sym->prec != 0)
+       symbol_redeclaration (sym, assoc_to_string (a), sym->prec_location,
+                              loc);
+      sym->prec = prec;
+      sym->assoc = a;
+      sym->prec_location = loc;

     }
 
   /* Only terminals have a precedence. */
     }
 
   /* Only terminals have a precedence. */

-  symbol_class_set (symbol, token_sym, location);
+  symbol_class_set (sym, token_sym, loc, false);

 }
 
 
 }
 
 

-/*-------------------------------------.
-| Set the CLASS associated to SYMBOL.  |
-`-------------------------------------*/
+/*------------------------------------.
+| Set the CLASS associated with SYM.  |
+`------------------------------------*/

 
 void
 
 void

-symbol_class_set (symbol_t *symbol, symbol_class class, location_t location)
+symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)

 {
 {

-  if (symbol->class != unknown_sym && symbol->class != class)
-    complain_at (location, _("symbol %s redefined"), symbol->tag);
+  if (sym->class != unknown_sym && sym->class != class)
+    {
+      complain_at (loc, _("symbol %s redefined"), sym->tag);
+      sym->declared = false;
+    }
+
+  if (class == nterm_sym && sym->class != nterm_sym)
+    sym->number = nvars++;
+  else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
+    sym->number = ntokens++;

 
 

-  if (class == nterm_sym && symbol->class != nterm_sym)
-    symbol->number = nvars++;
-  else if (class == token_sym && symbol->number == NUMBER_UNDEFINED)
-    symbol->number = ntokens++;
+  sym->class = class;

 
 

-  symbol->class = class;
+  if (declaring)
+    {
+      if (sym->declared)
+       warn_at (loc, _("symbol %s redeclared"), sym->tag);
+      sym->declared = true;
+    }

 }
 
 
 }
 
 

-/*-------------------------------------------------.
-| Set the USER_TOKEN_NUMBER associated to SYMBOL.  |
-`-------------------------------------------------*/
+/*------------------------------------------------.
+| Set the USER_TOKEN_NUMBER associated with SYM.  |
+`------------------------------------------------*/

 
 void
 
 void

-symbol_user_token_number_set (symbol_t *symbol,
-                             int user_token_number, location_t location)
+symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)

 {
 {

-  assert (symbol->class == token_sym);
+  int *user_token_numberp;

 
 

-  if (symbol->user_token_number != USER_NUMBER_UNDEFINED
-      && symbol->user_token_number != user_token_number)
-    complain_at (location, _("redefining user token number of %s"),
-                symbol->tag);
+  aver (sym->class == token_sym);
+
+  if (sym->user_token_number != USER_NUMBER_ALIAS)
+    user_token_numberp = &sym->user_token_number;
+  else
+    user_token_numberp = &sym->alias->user_token_number;
+  if (*user_token_numberp != USER_NUMBER_UNDEFINED
+      && *user_token_numberp != user_token_number)
+    complain_at (loc, _("redefining user token number of %s"), sym->tag);

 
 

-  symbol->user_token_number = user_token_number;
-  /* User defined EOF token? */
+  *user_token_numberp = user_token_number;
+  /* User defined $end token? */

   if (user_token_number == 0)
     {
   if (user_token_number == 0)
     {

-      eoftoken = symbol;
-      eoftoken->number = 0;
+      endtoken = sym;
+      endtoken->number = 0;

       /* It is always mapped to 0, so it was already counted in
         NTOKENS.  */
       --ntokens;
       /* It is always mapped to 0, so it was already counted in
         NTOKENS.  */
       --ntokens;


@@ -193,72 +406,57 @@ symbol_user_token_number_set (symbol_t *symbol,
 }
 
 
 }
 
 

-/*------------.
-| Free THIS.  |
-`------------*/
+/*----------------------------------------------------------.
+| If SYM is not defined, report an error, and consider it a |
+| nonterminal.                                              |
+`----------------------------------------------------------*/

 
 

-static void
-symbol_free (symbol_t *this)
+static inline bool
+symbol_check_defined (symbol *sym)

 {
 {

-#if 0
-  /* This causes crashes because one string can appear more
-     than once.  */
-  XFREE (this->type_name);
-#endif
-  XFREE (this->tag);
-  XFREE (this);
-}
-
-
-/*-----------------------------------------------------------.
-| If THIS is not defined, report an error, and consider it a |
-| nonterminal.                                               |
-`-----------------------------------------------------------*/
-
-static bool
-symbol_check_defined (symbol_t *this)
-{
-  if (this->class == unknown_sym)
+  if (sym->class == unknown_sym)

     {
       complain_at
     {
       complain_at

-       (this->location,
+       (sym->location,

         _("symbol %s is used, but is not defined as a token and has no rules"),
         _("symbol %s is used, but is not defined as a token and has no rules"),

-        this->tag);
-      this->class = nterm_sym;
-      this->number = nvars++;
+        sym->tag);
+      sym->class = nterm_sym;
+      sym->number = nvars++;

     }
 
     }
 

-  return TRUE;
+  return true;

 }
 
 }
 

+static bool
+symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
+{
+  return symbol_check_defined (sym);
+}

 
 

-/*-------------------------------------------------------------------.
-| Declare the new SYMBOL.  Make it an alias of SYMVAL, and type them |
-| with TYPENAME.                                                     |
-`-------------------------------------------------------------------*/
+
+/*------------------------------------------------------------------.
+| Declare the new symbol SYM.  Make it an alias of SYMVAL, and type |
+| SYMVAL with SYM's type.                                           |
+`------------------------------------------------------------------*/

 
 void
 
 void

-symbol_make_alias (symbol_t *symbol, symbol_t *symval, location_t loc)
+symbol_make_alias (symbol *sym, symbol *symval, location loc)

 {
   if (symval->alias)
     warn_at (loc, _("symbol `%s' used more than once as a literal string"),
 {
   if (symval->alias)
     warn_at (loc, _("symbol `%s' used more than once as a literal string"),

-         symval->tag);
-  else if (symbol->alias)
+            symval->tag);
+  else if (sym->alias)

     warn_at (loc, _("symbol `%s' given more than one literal string"),
     warn_at (loc, _("symbol `%s' given more than one literal string"),

-         symbol->tag);
+            sym->tag);

   else
     {
       symval->class = token_sym;
   else
     {
       symval->class = token_sym;

-      symval->user_token_number = symbol->user_token_number;
-      symbol->user_token_number = USER_NUMBER_ALIAS;
-      symval->alias = symbol;
-      symbol->alias = symval;
-      /* symbol and symval combined are only one symbol */
-      nsyms--;
-      ntokens--;
-      assert (ntokens == symbol->number || ntokens == symval->number);
-      symbol->number = symval->number =
-       (symval->number < symbol->number) ? symval->number : symbol->number;
+      symval->user_token_number = sym->user_token_number;
+      sym->user_token_number = USER_NUMBER_ALIAS;
+      symval->alias = sym;
+      sym->alias = symval;
+      symval->number = sym->number;
+      symbol_type_set (symval, sym->type_name, loc);

     }
 }
 
     }
 }
 


@@ -268,41 +466,60 @@ symbol_make_alias (symbol_t *symbol, symbol_t *symval, location_t loc)
 | associativity.                                           |
 `---------------------------------------------------------*/
 
 | associativity.                                           |
 `---------------------------------------------------------*/
 

-static bool
-symbol_check_alias_consistence (symbol_t *this)
+static inline void
+symbol_check_alias_consistency (symbol *this)

 {
 {

-  /* Check only those who _are_ the aliases. */
-  if (this->alias && this->user_token_number == USER_NUMBER_ALIAS)
+  symbol *alias = this;
+  symbol *orig  = this->alias;
+
+  /* Check only those that _are_ the aliases.  */
+  if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
+    return;
+
+  if (orig->type_name != alias->type_name)

     {
     {

-      if (this->prec != this->alias->prec)
-       {
-         if (this->prec != 0 && this->alias->prec != 0)
-           complain_at (this->alias->location,
-                        _("conflicting precedences for %s and %s"),
-                        this->tag, this->alias->tag);
-         if (this->prec != 0)
-           this->alias->prec = this->prec;
-         else
-           this->prec = this->alias->prec;
-       }
+      if (orig->type_name)
+       symbol_type_set (alias, orig->type_name, orig->type_location);
+      else
+       symbol_type_set (orig, alias->type_name, alias->type_location);
+    }

 
 

-      if (this->assoc != this->alias->assoc)
-       {
-         /* FIXME: For some reason (probably the S/R => keep the S),
-            the right assoc is chosen has the ``not set''.  This is
-            not nice, fix this!  */
-         if (this->assoc != right_assoc
-             && this->alias->assoc != right_assoc)
-           complain_at (this->alias->location,
-                        _("conflicting associativities for %s and %s"),
-                        this->tag, this->alias->tag);
-         if (this->assoc != 0)
-           this->alias->assoc = this->assoc;
-         else
-           this->assoc = this->alias->assoc;
-       }
+
+  if (orig->destructor || alias->destructor)
+    {
+      if (orig->destructor)
+       symbol_destructor_set (alias, orig->destructor,
+                              orig->destructor_location);
+      else
+       symbol_destructor_set (orig, alias->destructor,
+                              alias->destructor_location);

     }
     }

-  return TRUE;
+
+  if (orig->printer || alias->printer)
+    {
+      if (orig->printer)
+       symbol_printer_set (alias, orig->printer, orig->printer_location);
+      else
+       symbol_printer_set (orig, alias->printer, alias->printer_location);
+    }
+
+  if (alias->prec || orig->prec)
+    {
+      if (orig->prec)
+       symbol_precedence_set (alias, orig->prec, orig->assoc,
+                              orig->prec_location);
+      else
+       symbol_precedence_set (orig, alias->prec, alias->assoc,
+                              alias->prec_location);
+    }
+}
+
+static bool
+symbol_check_alias_consistency_processor (void *this,
+                                         void *null ATTRIBUTE_UNUSED)
+{
+  symbol_check_alias_consistency (this);
+  return true;

 }
 
 
 }
 
 


@@ -311,8 +528,8 @@ symbol_check_alias_consistence (symbol_t *this)
 | into FDEFINES.  Put in SYMBOLS.                                    |
 `-------------------------------------------------------------------*/
 
 | into FDEFINES.  Put in SYMBOLS.                                    |
 `-------------------------------------------------------------------*/
 

-static bool
-symbol_pack (symbol_t *this)
+static inline bool
+symbol_pack (symbol *this)

 {
   if (this->class == nterm_sym)
     {
 {
   if (this->class == nterm_sym)
     {


@@ -325,25 +542,29 @@ symbol_pack (symbol_t *this)
         prec and assoc fields and make both the same */
       if (this->number == NUMBER_UNDEFINED)
        {
         prec and assoc fields and make both the same */
       if (this->number == NUMBER_UNDEFINED)
        {

-         if (this == eoftoken || this->alias == eoftoken)
+         if (this == endtoken || this->alias == endtoken)

            this->number = this->alias->number = 0;
          else
            {
            this->number = this->alias->number = 0;
          else
            {

-             assert (this->alias->number != NUMBER_UNDEFINED);
+             aver (this->alias->number != NUMBER_UNDEFINED);

              this->number = this->alias->number;
            }
        }
              this->number = this->alias->number;
            }
        }

-      /* Do not do processing below for USER_NUMBER_ALIASs.  */
+      /* Do not do processing below for USER_NUMBER_ALIASes.  */

       if (this->user_token_number == USER_NUMBER_ALIAS)
       if (this->user_token_number == USER_NUMBER_ALIAS)

-       return TRUE;
+       return true;

     }
   else /* this->class == token_sym */
     }
   else /* this->class == token_sym */

-    {
-      assert (this->number != NUMBER_UNDEFINED);
-    }
+    aver (this->number != NUMBER_UNDEFINED);

 
   symbols[this->number] = this;
 
   symbols[this->number] = this;

-  return TRUE;
+  return true;
+}
+
+static bool
+symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
+{
+  return symbol_pack (this);

 }
 
 
 }
 
 


@@ -353,8 +574,8 @@ symbol_pack (symbol_t *this)
 | Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
 `--------------------------------------------------*/
 
 | Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
 `--------------------------------------------------*/
 

-static bool
-symbol_translation (symbol_t *this)
+static inline bool
+symbol_translation (symbol *this)

 {
   /* Non-terminal? */
   if (this->class == token_sym
 {
   /* Non-terminal? */
   if (this->class == token_sym


@@ -370,31 +591,77 @@ symbol_translation (symbol_t *this)
       token_translations[this->user_token_number] = this->number;
     }
 
       token_translations[this->user_token_number] = this->number;
     }
 

-  return TRUE;
+  return true;
+}
+
+static bool
+symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
+{
+  return symbol_translation (this);

 }
 
 
 }
 
 

-/*----------------------.
-| A symbol hash table.  |
-`----------------------*/
+/*---------------------------------------.
+| Symbol and semantic type hash tables.  |
+`---------------------------------------*/

 
 

-/* Initial capacity of symbols hash table.  */
+/* Initial capacity of symbol and semantic type hash table.  */

 #define HT_INITIAL_CAPACITY 257
 
 static struct hash_table *symbol_table = NULL;
 #define HT_INITIAL_CAPACITY 257
 
 static struct hash_table *symbol_table = NULL;

+static struct hash_table *semantic_type_table = NULL;
+
+static inline bool
+hash_compare_symbol (const symbol *m1, const symbol *m2)
+{
+  /* Since tags are unique, we can compare the pointers themselves.  */
+  return UNIQSTR_EQ (m1->tag, m2->tag);
+}
+
+static inline bool
+hash_compare_semantic_type (const semantic_type *m1, const semantic_type *m2)
+{
+  /* Since names are unique, we can compare the pointers themselves.  */
+  return UNIQSTR_EQ (m1->tag, m2->tag);
+}

 
 static bool
 
 static bool

-hash_compare_symbol_t (const symbol_t *m1, const symbol_t *m2)
+hash_symbol_comparator (void const *m1, void const *m2)

 {
 {

-  return strcmp (m1->tag, m2->tag) ? FALSE : TRUE;
+  return hash_compare_symbol (m1, m2);

 }
 
 }
 

-static unsigned int
-hash_symbol_t (const symbol_t *m, unsigned int tablesize)
+static bool
+hash_semantic_type_comparator (void const *m1, void const *m2)
+{
+  return hash_compare_semantic_type (m1, m2);
+}
+
+static inline size_t
+hash_symbol (const symbol *m, size_t tablesize)

 {
 {

-  return hash_string (m->tag, tablesize);
+  /* Since tags are unique, we can hash the pointer itself.  */
+  return ((uintptr_t) m->tag) % tablesize;

 }
 
 }
 

+static inline size_t
+hash_semantic_type (const semantic_type *m, size_t tablesize)
+{
+  /* Since names are unique, we can hash the pointer itself.  */
+  return ((uintptr_t) m->tag) % tablesize;
+}
+
+static size_t
+hash_symbol_hasher (void const *m, size_t tablesize)
+{
+  return hash_symbol (m, tablesize);
+}
+
+static size_t
+hash_semantic_type_hasher (void const *m, size_t tablesize)
+{
+  return hash_semantic_type (m, tablesize);
+}

 
 /*-------------------------------.
 | Create the symbol hash table.  |
 
 /*-------------------------------.
 | Create the symbol hash table.  |


@@ -405,9 +672,14 @@ symbols_new (void)
 {
   symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
                                  NULL,
 {
   symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
                                  NULL,

-                                 (Hash_hasher) hash_symbol_t,
-                                 (Hash_comparator) hash_compare_symbol_t,
-                                 (Hash_data_freer) symbol_free);
+                                 hash_symbol_hasher,
+                                 hash_symbol_comparator,
+                                 free);
+  semantic_type_table = hash_initialize (HT_INITIAL_CAPACITY,
+                                        NULL,
+                                        hash_semantic_type_hasher,
+                                        hash_semantic_type_comparator,
+                                        free);

 }
 
 
 }
 
 


@@ -416,48 +688,99 @@ symbols_new (void)
 | yet, create it.                                                 |
 `----------------------------------------------------------------*/
 
 | yet, create it.                                                 |
 `----------------------------------------------------------------*/
 

-symbol_t *
-symbol_get (const char *key, location_t location)
+symbol *
+symbol_from_uniqstr (const uniqstr key, location loc)

 {
 {

-  symbol_t probe;
-  symbol_t *entry;
+  symbol probe;
+  symbol *entry;

 
 

-  /* Keep the symbol in a printable form.  */
-  key = quotearg_style (escape_quoting_style, key);
-  (const char *) probe.tag = key;
+  probe.tag = key;

   entry = hash_lookup (symbol_table, &probe);
 
   if (!entry)
     {
       /* First insertion in the hash. */
   entry = hash_lookup (symbol_table, &probe);
 
   if (!entry)
     {
       /* First insertion in the hash. */

-      entry = symbol_new (key, location);
+      entry = symbol_new (key, loc);

       hash_insert (symbol_table, entry);
     }
   return entry;
 }
 
 
       hash_insert (symbol_table, entry);
     }
   return entry;
 }
 
 

+/*-----------------------------------------------------------------------.
+| Find the semantic type named KEY, and return it.  If it does not exist |
+| yet, create it.                                                        |
+`-----------------------------------------------------------------------*/
+
+semantic_type *
+semantic_type_from_uniqstr (const uniqstr key)
+{
+  semantic_type probe;
+  semantic_type *entry;
+
+  probe.tag = key;
+  entry = hash_lookup (semantic_type_table, &probe);
+
+  if (!entry)
+    {
+      /* First insertion in the hash. */
+      entry = semantic_type_new (key);
+      hash_insert (semantic_type_table, entry);
+    }
+  return entry;
+}
+
+
+/*----------------------------------------------------------------.
+| Find the symbol named KEY, and return it.  If it does not exist |
+| yet, create it.                                                 |
+`----------------------------------------------------------------*/
+
+symbol *
+symbol_get (const char *key, location loc)
+{
+  return symbol_from_uniqstr (uniqstr_new (key), loc);
+}
+
+
+/*-----------------------------------------------------------------------.
+| Find the semantic type named KEY, and return it.  If it does not exist |
+| yet, create it.                                                        |
+`-----------------------------------------------------------------------*/
+
+semantic_type *
+semantic_type_get (const char *key)
+{
+  return semantic_type_from_uniqstr (uniqstr_new (key));
+}
+
+

 /*------------------------------------------------------------------.
 | Generate a dummy nonterminal, whose name cannot conflict with the |
 | user's names.                                                     |
 `------------------------------------------------------------------*/
 
 /*------------------------------------------------------------------.
 | Generate a dummy nonterminal, whose name cannot conflict with the |
 | user's names.                                                     |
 `------------------------------------------------------------------*/
 

-symbol_t *
-dummy_symbol_get (location_t location)
+symbol *
+dummy_symbol_get (location loc)

 {
   /* Incremented for each generated symbol.  */
   static int dummy_count = 0;
   static char buf[256];
 
 {
   /* Incremented for each generated symbol.  */
   static int dummy_count = 0;
   static char buf[256];
 

-  symbol_t *sym;
+  symbol *sym;

 
 

-  sprintf (buf, "@%d", ++dummy_count);
-  sym = symbol_get (buf, location);
+  sprintf (buf, "$@%d", ++dummy_count);
+  sym = symbol_get (buf, loc);

   sym->class = nterm_sym;
   sym->number = nvars++;
   return sym;
 }
 
   sym->class = nterm_sym;
   sym->number = nvars++;
   return sym;
 }
 

+bool
+symbol_is_dummy (const symbol *sym)
+{
+  return sym->tag[0] == '@' || (sym->tag[0] == '$' && sym->tag[1] == '@');
+}

 
 /*-------------------.
 | Free the symbols.  |
 
 /*-------------------.
 | Free the symbols.  |


@@ -467,6 +790,7 @@ void
 symbols_free (void)
 {
   hash_free (symbol_table);
 symbols_free (void)
 {
   hash_free (symbol_table);

+  hash_free (semantic_type_table);

   free (symbols);
 }
 
   free (symbols);
 }
 


@@ -476,12 +800,10 @@ symbols_free (void)
 | terminals.                                                     |
 `---------------------------------------------------------------*/
 
 | terminals.                                                     |
 `---------------------------------------------------------------*/
 

-void
-symbols_do (symbol_processor processor, void *processor_data)
+static void
+symbols_do (Hash_processor processor, void *processor_data)

 {
 {

-  hash_do_for_each (symbol_table,
-                   (Hash_processor) processor,
-                   processor_data);
+  hash_do_for_each (symbol_table, processor, processor_data);

 }
 
 
 }
 
 


@@ -493,7 +815,7 @@ symbols_do (symbol_processor processor, void *processor_data)
 void
 symbols_check_defined (void)
 {
 void
 symbols_check_defined (void)
 {

-  symbols_do (symbol_check_defined, NULL);
+  symbols_do (symbol_check_defined_processor, NULL);

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


@@ -504,7 +826,7 @@ symbols_check_defined (void)
 static void
 symbols_token_translations_init (void)
 {
 static void
 symbols_token_translations_init (void)
 {

-  int num_256_available_p = TRUE;
+  bool num_256_available_p = true;

   int i;
 
   /* Find the highest user token number, and whether 256, the POSIX
   int i;
 
   /* Find the highest user token number, and whether 256, the POSIX


@@ -512,13 +834,13 @@ symbols_token_translations_init (void)
   max_user_token_number = 0;
   for (i = 0; i < ntokens; ++i)
     {
   max_user_token_number = 0;
   for (i = 0; i < ntokens; ++i)
     {

-      symbol_t *this = symbols[i];
+      symbol *this = symbols[i];

       if (this->user_token_number != USER_NUMBER_UNDEFINED)
        {
          if (this->user_token_number > max_user_token_number)
            max_user_token_number = this->user_token_number;
          if (this->user_token_number == 256)
       if (this->user_token_number != USER_NUMBER_UNDEFINED)
        {
          if (this->user_token_number > max_user_token_number)
            max_user_token_number = this->user_token_number;
          if (this->user_token_number == 256)

-           num_256_available_p = FALSE;
+           num_256_available_p = false;

        }
     }
 
        }
     }
 


@@ -533,21 +855,22 @@ symbols_token_translations_init (void)
 
   for (i = 0; i < ntokens; ++i)
     {
 
   for (i = 0; i < ntokens; ++i)
     {

-      symbol_t *this = symbols[i];
+      symbol *this = symbols[i];

       if (this->user_token_number == USER_NUMBER_UNDEFINED)
        this->user_token_number = ++max_user_token_number;
       if (this->user_token_number > max_user_token_number)
        max_user_token_number = this->user_token_number;
     }
 
       if (this->user_token_number == USER_NUMBER_UNDEFINED)
        this->user_token_number = ++max_user_token_number;
       if (this->user_token_number > max_user_token_number)
        max_user_token_number = this->user_token_number;
     }
 

-  token_translations = XCALLOC (symbol_number_t, max_user_token_number + 1);
+  token_translations = xnmalloc (max_user_token_number + 1,
+                                sizeof *token_translations);

 
   /* Initialize all entries for literal tokens to 2, the internal
 
   /* Initialize all entries for literal tokens to 2, the internal

-     token number for $undefined., which represents all invalid
-     inputs.  */
+     token number for $undefined, which represents all invalid inputs.
+     */

   for (i = 0; i < max_user_token_number + 1; i++)
     token_translations[i] = undeftoken->number;
   for (i = 0; i < max_user_token_number + 1; i++)
     token_translations[i] = undeftoken->number;

-  symbols_do (symbol_translation, NULL);
+  symbols_do (symbol_translation_processor, NULL);

 }
 
 
 }
 
 


@@ -559,10 +882,34 @@ symbols_token_translations_init (void)
 void
 symbols_pack (void)
 {
 void
 symbols_pack (void)
 {

-  symbols = XCALLOC (symbol_t *, nsyms);
-
-  symbols_do (symbol_check_alias_consistence, NULL);
-  symbols_do (symbol_pack, NULL);
+  symbols_do (symbol_check_alias_consistency_processor, NULL);
+
+  symbols = xcalloc (nsyms, sizeof *symbols);
+  symbols_do (symbol_pack_processor, NULL);
+
+  /* Aliases leave empty slots in symbols, so remove them.  */
+  {
+    int writei;
+    int readi;
+    int nsyms_old = nsyms;
+    for (writei = 0, readi = 0; readi < nsyms_old; readi += 1)
+      {
+        if (symbols[readi] == NULL)
+          {
+            nsyms -= 1;
+            ntokens -= 1;
+          }
+        else
+          {
+            symbols[writei] = symbols[readi];
+            symbols[writei]->number = writei;
+            if (symbols[writei]->alias)
+              symbols[writei]->alias->number = writei;
+            writei += 1;
+          }
+      }
+  }
+  symbols = xnrealloc (symbols, nsyms, sizeof *symbols);

 
   symbols_token_translations_init ();
 
 
   symbols_token_translations_init ();
 


@@ -575,3 +922,32 @@ symbols_pack (void)
              _("the start symbol %s is a token"),
              startsymbol->tag);
 }
              _("the start symbol %s is a token"),
              startsymbol->tag);
 }

+
+
+/*-----------------------------------.
+| Set default %destructor/%printer.  |
+`-----------------------------------*/
+
+void
+default_destructor_set (const char *destructor, location loc)
+{
+  if (default_destructor != NULL)
+    {
+      complain_at (loc, _("redeclaration for default %%destructor"));
+      complain_at (default_destructor_location, _("previous declaration"));
+    }
+  default_destructor = destructor;
+  default_destructor_location = loc;
+}
+
+void
+default_printer_set (const char *printer, location loc)
+{
+  if (default_printer != NULL)
+    {
+      complain_at (loc, _("redeclaration for default %%printer"));
+      complain_at (default_printer_location, _("previous declaration"));
+    }
+  default_printer = printer;
+  default_printer_location = loc;
+}