Enable declaration of default %printer/%destructor. Make the parser

[bison.git] / src / symtab.c

diff --git a/src/symtab.c b/src/symtab.c
index 1f2c17ee81ed7fc1a7dd4797568a6746cc523ecb..821ad56ccd8b13b366b2037d8b2c0ffd94172b56 100644 (file)
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -41,6 +41,15 @@ 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.  |
 `---------------------------------*/
@@ -108,7 +117,7 @@ static void
 redeclaration (symbol* s, const char *what, location first, location second)
 {
   complain_at (second, _("%s redeclaration for %s"), what, s->tag);
-  complain_at (first, _("first declaration"));
+  complain_at (first, _("previous declaration"));
 }
 
 
@@ -147,6 +156,33 @@ symbol_destructor_set (symbol *sym, const char *destructor, location loc)
     }
 }
 
+/*---------------------------------------.
+| Get the computed %destructor for SYM.  |
+`---------------------------------------*/
+
+const char *
+symbol_destructor_get (symbol *sym)
+{
+  /* Token 0 cannot have a %destructor unless the user renames it.  */
+  if (UNIQSTR_EQ (sym->tag, uniqstr_new ("$end")))
+    return NULL;
+
+  if (sym->destructor != NULL)
+    return sym->destructor;
+  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;
+  return default_destructor_location;
+}
 
 /*---------------------------------------------------------------.
 | Set the PRINTER associated with SYM.  Do nothing if passed 0.  |
@@ -158,12 +194,40 @@ symbol_printer_set (symbol *sym, const char *printer, location loc)
   if (printer)
     {
       if (sym->printer)
-       redeclaration (sym, "%printer", sym->destructor_location, loc);
+       redeclaration (sym, "%printer", sym->printer_location, loc);
       sym->printer = printer;
       sym->printer_location = loc;
     }
 }
 
+/*------------------------------------.
+| Get the computed %printer for SYM.  |
+`------------------------------------*/
+
+const char *
+symbol_printer_get (symbol *sym)
+{
+  /* Token 0 cannot have a %printer unless the user renames it.  */
+  if (UNIQSTR_EQ (sym->tag, uniqstr_new ("$end")))
+    return NULL;
+
+  if (sym->printer != NULL)
+    return sym->printer;
+  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;
+  return default_printer_location;
+}
+
 
 /*-----------------------------------------------------------------.
 | Set the PRECEDENCE associated with SYM.  Does nothing if invoked |
@@ -223,8 +287,7 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
 void
 symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
 {
-  if (sym->class != token_sym)
-    abort ();
+  assert (sym->class == token_sym);
 
   if (sym->user_token_number != USER_NUMBER_UNDEFINED
       && sym->user_token_number != user_token_number)
@@ -295,8 +358,7 @@ symbol_make_alias (symbol *sym, symbol *symval, location loc)
       /* sym and symval combined are only one symbol.  */
       nsyms--;
       ntokens--;
-      if (ntokens != sym->number && ntokens != symval->number)
-       abort ();
+      assert (ntokens == sym->number || ntokens == symval->number);
       sym->number = symval->number =
        (symval->number < sym->number) ? symval->number : sym->number;
       symbol_type_set (symval, sym->type_name, loc);
@@ -389,8 +451,7 @@ symbol_pack (symbol *this)
            this->number = this->alias->number = 0;
          else
            {
-             if (this->alias->number == NUMBER_UNDEFINED)
-               abort ();
+             assert (this->alias->number != NUMBER_UNDEFINED);
              this->number = this->alias->number;
            }
        }
@@ -399,10 +460,7 @@ symbol_pack (symbol *this)
        return true;
     }
   else /* this->class == token_sym */
-    {
-      if (this->number == NUMBER_UNDEFINED)
-       abort ();
-    }
+    assert (this->number != NUMBER_UNDEFINED);
 
   symbols[this->number] = this;
   return true;
@@ -505,12 +563,11 @@ symbols_new (void)
 `----------------------------------------------------------------*/
 
 symbol *
-symbol_get (const char *key, location loc)
+symbol_from_uniqstr (const uniqstr key, location loc)
 {
   symbol probe;
   symbol *entry;
 
-  key = uniqstr_new (key);
   probe.tag = key;
   entry = hash_lookup (symbol_table, &probe);
 
@@ -524,6 +581,18 @@ symbol_get (const char *key, location loc)
 }
 
 
+/*----------------------------------------------------------------.
+| 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);
+}
+
+
 /*------------------------------------------------------------------.
 | Generate a dummy nonterminal, whose name cannot conflict with the |
 | user's names.                                                     |
@@ -661,3 +730,32 @@ symbols_pack (void)
              _("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;
+}