build: look for Perl in configure.

[bison.git] / src / symtab.h

diff --git a/src/symtab.h b/src/symtab.h
index 7a25b360a747890e3418d2c276cefff8a9e46471..7d8cf982650f36ff71f829976388eaa23a7563dd 100644 (file)
--- a/src/symtab.h
+++ b/src/symtab.h
@@ -1,24 +1,22 @@
 /* Definitions for symtab.c and callers, part of Bison.
 
-   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2004, 2005, 2006, 2007
-   Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989, 1992, 2000-2002, 2004-2007, 2009-2012 Free
+   Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
-   Bison is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
 
-   Bison is distributed in the hope that it will be useful,
+   This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    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., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /**
  * \file symtab.h
@@ -62,23 +60,30 @@ struct symbol
   /** The location of its first occurrence.  */
   location location;
 
-  /** Its \c \%type.  */
+  /** Its \c \%type.
+
+      Beware that this is the type_name as was entered by the user,
+      including silly things such as "]" if she entered "%token <]> t".
+      Therefore, when outputting type_name to M4, be sure to escape it
+      into "@}".  See quoted_output for instance.  */
   uniqstr type_name;
+
   /** Its \c \%type's location.  */
   location type_location;
 
   /** Any \c \%destructor declared specifically for this symbol.
 
-     Access this field only through <tt>symbol</tt>'s interface functions.  For
-     example, if <tt>symbol::destructor = NULL</tt>, a default \c \%destructor
-     or a per-type \c \%destructor might be appropriate, and
-     \c symbol_destructor_get will compute the correct one.  */
+      Access this field only through <tt>symbol</tt>'s interface
+      functions.  For example, if <tt>symbol::destructor = NULL</tt>, a
+      default \c \%destructor or a per-type \c \%destructor might be
+      appropriate, and \c symbol_destructor_get will compute the
+      correct one.  */
   code_props destructor;
 
   /** Any \c \%printer declared specifically for this symbol.
 
-     Access this field only through <tt>symbol</tt>'s interface functions.
-     \sa symbol::destructor  */
+      Access this field only through <tt>symbol</tt>'s interface functions.
+      \sa symbol::destructor  */
   code_props printer;
 
   symbol_number number;
@@ -87,9 +92,9 @@ struct symbol
   assoc assoc;
   int user_token_number;
 
-  /* Points to the other in the identifier-symbol pair for an alias.
-     Special value USER_NUMBER_ALIAS in the identifier half of the
-     identifier-symbol pair for an alias.  */
+  /* Points to the other in the symbol-string pair for an alias.
+     Special value USER_NUMBER_HAS_STRING_ALIAS in the symbol half of the
+     symbol-string pair for an alias.  */
   symbol *alias;
   symbol_class class;
   bool declared;
@@ -98,11 +103,11 @@ struct symbol
 /** Undefined user number.  */
 #define USER_NUMBER_UNDEFINED -1
 
-/* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
-   *has* (not is) a string literal alias.  For instance, `%token foo
+/* `symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
+   this symbol has a literal string alias.  For instance, `%token foo
    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
-   USER_NUMBER_ALIAS.  */
-#define USER_NUMBER_ALIAS -9991
+   USER_NUMBER_HAS_STRING_ALIAS.  */
+#define USER_NUMBER_HAS_STRING_ALIAS -9991
 
 /* Undefined internal token number.  */
 #define NUMBER_UNDEFINED (-1)
@@ -124,8 +129,11 @@ symbol *dummy_symbol_get (location loc);
 /** Is this a dummy nonterminal?  */
 bool symbol_is_dummy (const symbol *sym);
 
-/** Declare the new symbol \c sym.  Make it an alias of \c symval.  */
-void symbol_make_alias (symbol *sym, symbol *symval, location loc);
+/**
+ * Make \c str the literal string alias of \c sym.  Copy token number,
+ * symbol number, and type from \c sym to \c str.
+ */
+void symbol_make_alias (symbol *sym, symbol *str, location loc);
 
 /** Set the \c type_name associated with \c sym.