Whether the default %destructor/%printer applies to a particular symbol

[bison.git] / src / symtab.c

diff --git a/src/symtab.c b/src/symtab.c
index ef59c6eef70e1d7a95e40979970fca38ba47f2a5..e3c450f4e44b8c126f6e756e4cdac44c4abc53d7 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 +156,34 @@ symbol_destructor_set (symbol *sym, const char *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;
+
+  /* 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;
+  return default_destructor_location;
+}
 
 /*---------------------------------------------------------------.
 | Set the PRINTER associated with SYM.  Do nothing if passed 0.  |
@@ -158,12 +195,41 @@ 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)
+{
+  /* Per-symbol %printer.  */
+  if (sym->printer != NULL)
+    return sym->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;
+  return default_printer_location;
+}
+
 
 /*-----------------------------------------------------------------.
 | Set the PRECEDENCE associated with SYM.  Does nothing if invoked |
@@ -223,13 +289,19 @@ 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)
 {
+  int *user_token_numberp;
+
   assert (sym->class == token_sym);
 
-  if (sym->user_token_number != USER_NUMBER_UNDEFINED
-      && sym->user_token_number != user_token_number)
+  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);
 
-  sym->user_token_number = user_token_number;
+  *user_token_numberp = user_token_number;
   /* User defined $end token? */
   if (user_token_number == 0)
     {
@@ -291,12 +363,7 @@ symbol_make_alias (symbol *sym, symbol *symval, location loc)
       sym->user_token_number = USER_NUMBER_ALIAS;
       symval->alias = sym;
       sym->alias = symval;
-      /* sym and symval combined are only one symbol.  */
-      nsyms--;
-      ntokens--;
-      assert (ntokens == sym->number || ntokens == symval->number);
-      sym->number = symval->number =
-       (symval->number < sym->number) ? symval->number : sym->number;
+      symval->number = sym->number;
       symbol_type_set (symval, sym->type_name, loc);
     }
 }
@@ -499,12 +566,11 @@ 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);
 
@@ -518,6 +584,18 @@ 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.                                                     |
@@ -539,6 +617,11 @@ dummy_symbol_get (location loc)
   return sym;
 }
 
+bool
+symbol_is_dummy (const symbol *sym)
+{
+  return sym->tag[0] == '@';
+}
 
 /*-------------------.
 | Free the symbols.  |
@@ -639,11 +722,35 @@ symbols_token_translations_init (void)
 void
 symbols_pack (void)
 {
-  symbols = xcalloc (nsyms, sizeof *symbols);
-
   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 ();
 
   if (startsymbol->class == unknown_sym)
@@ -655,3 +762,32 @@ 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;
+}