Miscellaneous code readability improvements.

[bison.git] / src / parse-gram.y

diff --git a/src/parse-gram.y b/src/parse-gram.y
index faf573ee17cfc583aaaf20156673bd3e12851fd7..6f9ac83b399040695070e9ecf09dc16de0cc0a15 100644 (file)
--- a/src/parse-gram.y
+++ b/src/parse-gram.y
@@ -1,12 +1,13 @@
 %{/* Bison Grammar Parser                             -*- C -*-
 
 %{/* Bison Grammar Parser                             -*- C -*-
 

-   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software
+   Foundation, Inc.

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

-   This program 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
    it under the terms of the GNU General Public License as published by

-   the Free Software Foundation; either version 2 of the License, or
+   the Free Software Foundation, either version 3 of the License, or

    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,


@@ -15,10 +16,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License

-   along with this program; 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/>.  */

 
 #include <config.h>
 #include "system.h"
 
 #include <config.h>
 #include "system.h"


@@ -28,13 +26,13 @@
 #include "files.h"
 #include "getargs.h"
 #include "gram.h"
 #include "files.h"
 #include "getargs.h"
 #include "gram.h"

-#include "muscle_tab.h"
+#include "muscle-tab.h"
+#include "named-ref.h"

 #include "quotearg.h"
 #include "reader.h"
 #include "symlist.h"
 #include "scan-gram.h"
 #include "scan-code.h"
 #include "quotearg.h"
 #include "reader.h"
 #include "symlist.h"
 #include "scan-gram.h"
 #include "scan-code.h"

-#include "strverscmp.h"

 
 #define YYLLOC_DEFAULT(Current, Rhs, N)  (Current) = lloc_default (Rhs, N)
 static YYLTYPE lloc_default (YYLTYPE const *, int);
 
 #define YYLLOC_DEFAULT(Current, Rhs, N)  (Current) = lloc_default (Rhs, N)
 static YYLTYPE lloc_default (YYLTYPE const *, int);


@@ -53,26 +51,26 @@ static void gram_error (location const *, char const *);
 
 static char const *char_name (char);
 
 
 static char const *char_name (char);
 

-static void add_param (char const *, char *, location);
+/** Add a lex-param or a parse-param.
+ *
+ * \param type  \a lex_param or \a parse_param
+ * \param decl  the formal argument
+ * \param loc   the location in the source.
+ */
+static void add_param (char const *type, char *decl, location loc);
+

 
 static symbol_class current_class = unknown_sym;
 
 static symbol_class current_class = unknown_sym;

-static uniqstr current_type = 0;
+static uniqstr current_type = NULL;

 static symbol *current_lhs;
 static location current_lhs_location;
 static symbol *current_lhs;
 static location current_lhs_location;

+static named_ref *current_lhs_named_ref;

 static int current_prec = 0;
 
 static int current_prec = 0;
 

-#ifdef UINT_FAST8_MAX
-# define YYTYPE_UINT8 uint_fast8_t
-#endif
-#ifdef INT_FAST8_MAX
-# define YYTYPE_INT8 int_fast8_t
-#endif
-#ifdef UINT_FAST16_MAX
-# define YYTYPE_UINT16 uint_fast16_t
-#endif
-#ifdef INT_FAST16_MAX
-# define YYTYPE_INT16 int_fast16_t
-#endif
+#define YYTYPE_INT16 int_fast16_t
+#define YYTYPE_INT8 int_fast8_t
+#define YYTYPE_UINT16 uint_fast16_t
+#define YYTYPE_UINT8 uint_fast8_t

 %}
 
 %debug
 %}
 
 %debug


@@ -80,9 +78,9 @@ static int current_prec = 0;
 %defines
 %locations
 %pure-parser
 %defines
 %locations
 %pure-parser

-%error-verbose
-%defines
+%define parse.error "verbose"

 %name-prefix="gram_"
 %name-prefix="gram_"

+%expect 0

 
 %initial-action
 {
 
 %initial-action
 {


@@ -92,16 +90,17 @@ static int current_prec = 0;
   boundary_set (&@$.end, current_file, 1, 1);
 }
 
   boundary_set (&@$.end, current_file, 1, 1);
 }
 

-/* Only NUMBERS have a value.  */

 %union
 {
   symbol *symbol;
   symbol_list *list;
   int integer;
 %union
 {
   symbol *symbol;
   symbol_list *list;
   int integer;

-  char *chars;
+  char const *chars;
+  char *code;

   assoc assoc;
   uniqstr uniqstr;
   unsigned char character;
   assoc assoc;
   uniqstr uniqstr;
   unsigned char character;

+  named_ref *named_ref;

 };
 
 /* Define the tokens together with their human representation.  */
 };
 
 /* Define the tokens together with their human representation.  */


@@ -119,6 +118,7 @@ static int current_prec = 0;
 %token PERCENT_LEFT        "%left"
 %token PERCENT_RIGHT       "%right"
 %token PERCENT_NONASSOC    "%nonassoc"
 %token PERCENT_LEFT        "%left"
 %token PERCENT_RIGHT       "%right"
 %token PERCENT_NONASSOC    "%nonassoc"

+%token PERCENT_PRECEDENCE  "%precedence"

 
 %token PERCENT_PREC          "%prec"
 %token PERCENT_DPREC         "%dprec"
 
 %token PERCENT_PREC          "%prec"
 %token PERCENT_DPREC         "%dprec"


@@ -130,21 +130,19 @@ static int current_prec = 0;
 `----------------------*/
 
 %token
 `----------------------*/
 
 %token

-  PERCENT_AFTER_HEADER    "%after-header"
-  PERCENT_BEFORE_HEADER   "%before-header"
-  PERCENT_DEBUG           "%debug"
+  PERCENT_CODE            "%code"

   PERCENT_DEFAULT_PREC    "%default-prec"
   PERCENT_DEFINE          "%define"
   PERCENT_DEFINES         "%defines"
   PERCENT_DEFAULT_PREC    "%default-prec"
   PERCENT_DEFINE          "%define"
   PERCENT_DEFINES         "%defines"

-  PERCENT_END_HEADER      "%end-header"

   PERCENT_ERROR_VERBOSE   "%error-verbose"
   PERCENT_EXPECT          "%expect"
   PERCENT_EXPECT_RR      "%expect-rr"
   PERCENT_ERROR_VERBOSE   "%error-verbose"
   PERCENT_EXPECT          "%expect"
   PERCENT_EXPECT_RR      "%expect-rr"

+  PERCENT_FLAG            "%<flag>"

   PERCENT_FILE_PREFIX     "%file-prefix"
   PERCENT_GLR_PARSER      "%glr-parser"
   PERCENT_INITIAL_ACTION  "%initial-action"
   PERCENT_FILE_PREFIX     "%file-prefix"
   PERCENT_GLR_PARSER      "%glr-parser"
   PERCENT_INITIAL_ACTION  "%initial-action"

+  PERCENT_LANGUAGE        "%language"

   PERCENT_LEX_PARAM       "%lex-param"
   PERCENT_LEX_PARAM       "%lex-param"

-  PERCENT_LOCATIONS       "%locations"

   PERCENT_NAME_PREFIX     "%name-prefix"
   PERCENT_NO_DEFAULT_PREC "%no-default-prec"
   PERCENT_NO_LINES        "%no-lines"
   PERCENT_NAME_PREFIX     "%name-prefix"
   PERCENT_NO_DEFAULT_PREC "%no-default-prec"
   PERCENT_NO_LINES        "%no-lines"


@@ -152,11 +150,9 @@ static int current_prec = 0;
                          "%nondeterministic-parser"
   PERCENT_OUTPUT          "%output"
   PERCENT_PARSE_PARAM     "%parse-param"
                          "%nondeterministic-parser"
   PERCENT_OUTPUT          "%output"
   PERCENT_PARSE_PARAM     "%parse-param"

-  PERCENT_PURE_PARSER     "%pure-parser"

   PERCENT_REQUIRE        "%require"
   PERCENT_SKELETON        "%skeleton"
   PERCENT_START           "%start"
   PERCENT_REQUIRE        "%require"
   PERCENT_SKELETON        "%skeleton"
   PERCENT_START           "%start"

-  PERCENT_START_HEADER    "%start-header"

   PERCENT_TOKEN_TABLE     "%token-table"
   PERCENT_VERBOSE         "%verbose"
   PERCENT_YACC            "%yacc"
   PERCENT_TOKEN_TABLE     "%token-table"
   PERCENT_VERBOSE         "%verbose"
   PERCENT_YACC            "%yacc"


@@ -172,34 +168,43 @@ static int current_prec = 0;
 %token PIPE            "|"
 %token PROLOGUE        "%{...%}"
 %token SEMICOLON       ";"
 %token PIPE            "|"
 %token PROLOGUE        "%{...%}"
 %token SEMICOLON       ";"

-%token TYPE            "type"
+%token TAG             "<tag>"
+%token TAG_ANY         "<*>"
+%token TAG_NONE        "<>"
+%token BRACKETED_ID    "[identifier]"

 
 %type <character> CHAR
 %printer { fputs (char_name ($$), stderr); } CHAR
 
 
 %type <character> CHAR
 %printer { fputs (char_name ($$), stderr); } CHAR
 

-%type <chars> STRING string_content "{...}" PROLOGUE EPILOGUE
+/* braceless is not to be used for rule or symbol actions, as it
+   calls code_props_plain_init.  */
+%type <chars> STRING "%{...%}" EPILOGUE braceless content.opt
+%type <code> "{...}"

 %printer { fputs (quotearg_style (c_quoting_style, $$), stderr); }
 %printer { fputs (quotearg_style (c_quoting_style, $$), stderr); }

-         STRING string_content
-%printer { fprintf (stderr, "{\n%s\n}", $$); } "{...}" PROLOGUE EPILOGUE
+        STRING
+%printer { fprintf (stderr, "{\n%s\n}", $$); }
+        braceless content.opt "{...}" "%{...%}" EPILOGUE

 
 

-%type <uniqstr> TYPE ID ID_COLON
-%printer { fprintf (stderr, "<%s>", $$); } TYPE
-%printer { fputs ($$, stderr); } ID
+%type <uniqstr> TAG ID ID_COLON BRACKETED_ID PERCENT_FLAG variable
+%type <named_ref> named_ref.opt
+%printer { fputs ($$, stderr); } ID variable

 %printer { fprintf (stderr, "%s:", $$); } ID_COLON
 %printer { fprintf (stderr, "%s:", $$); } ID_COLON

+%printer { fprintf (stderr, "%%%s", $$); } PERCENT_FLAG
+%printer { fprintf (stderr, "<%s>", $$); } TAG

 
 %type <integer> INT
 %printer { fprintf (stderr, "%d", $$); } INT
 
 
 %type <integer> INT
 %printer { fprintf (stderr, "%d", $$); } INT
 

-%type <symbol> id id_colon symbol string_as_id
+%type <symbol> id id_colon symbol symbol.prec string_as_id

 %printer { fprintf (stderr, "%s", $$->tag); } id symbol string_as_id
 %printer { fprintf (stderr, "%s:", $$->tag); } id_colon
 
 %type <assoc> precedence_declarator
 %printer { fprintf (stderr, "%s", $$->tag); } id symbol string_as_id
 %printer { fprintf (stderr, "%s:", $$->tag); } id_colon
 
 %type <assoc> precedence_declarator

-%type <list>  symbols.1
+%type <list>  symbols.1 symbols.prec generic_symlist generic_symlist_item

 %%
 
 input:
 %%
 
 input:

-  declarations "%%" grammar epilogue.opt
+  prologue_declarations "%%" grammar epilogue.opt

 ;
 
 
 ;
 
 


@@ -207,47 +212,47 @@ input:
        | Declarations: before the first %%.  |
        `------------------------------------*/
 
        | Declarations: before the first %%.  |
        `------------------------------------*/
 

-declarations:
+prologue_declarations:

   /* Nothing */
   /* Nothing */

-| declarations declaration
+| prologue_declarations prologue_declaration

 ;
 
 ;
 

-declaration:
+prologue_declaration:

   grammar_declaration
   grammar_declaration

-| PROLOGUE
+| "%{...%}"

     {
     {

-      prologue_augment (translate_code ($1, @1), @1, typed);
+      code_props plain_code;
+      code_props_plain_init (&plain_code, $1, @1);
+      code_props_translate_code (&plain_code);
+      gram_scanner_last_string_free ();
+      muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue",
+                        plain_code.code, @1);
+      code_scanner_last_string_free ();

     }
     }

-| "%after-header" "{...}"
+| "%<flag>"

     {
     {

-      /* Remove the '{', and replace the '}' with '\n'.  */
-      $2[strlen ($2) - 1] = '\n';
-      prologue_augment (translate_code ($2+1, @2), @2, true);
+      muscle_percent_define_ensure ($1, @1, true);

     }
     }

-| "%before-header" "{...}"
+| "%define" variable content.opt

     {
     {

-      /* Remove the '{', and replace the '}' with '\n'.  */
-      $2[strlen ($2) - 1] = '\n';
-      prologue_augment (translate_code ($2+1, @2), @2, false);
+      muscle_percent_define_insert ($2, @2, $3,
+                                    MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);

     }
     }

-| "%debug"                                 { debug_flag = true; }
-| "%define" string_content
+| "%defines"                       { defines_flag = true; }
+| "%defines" STRING

     {
     {

-      static char one[] = "1";
-      muscle_insert ($2, one);
+      defines_flag = true;
+      spec_defines_file = xstrdup ($2);

     }
     }

-| "%define" string_content string_content  { muscle_insert ($2, $3); }
-| "%defines"                               { defines_flag = true; }
-| "%end-header" "{...}"
+| "%error-verbose"

     {
     {

-      /* Remove the '{', and replace the '}' with '\n'.  */
-      $2[strlen ($2) - 1] = '\n';
-      muscle_code_grow ("end_header", translate_code ($2+1, @2), @2);
+      muscle_percent_define_insert ("parse.error", @1, "verbose",
+                                    MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);

     }
     }

-| "%error-verbose"                         { error_verbose = true; }
-| "%expect" INT                            { expected_sr_conflicts = $2; }
-| "%expect-rr" INT                        { expected_rr_conflicts = $2; }
-| "%file-prefix" "=" string_content        { spec_file_prefix = $3; }
+| "%expect" INT                    { expected_sr_conflicts = $2; }
+| "%expect-rr" INT                { expected_rr_conflicts = $2; }
+| "%file-prefix" STRING            { spec_file_prefix = $2; }
+| "%file-prefix" "=" STRING        { spec_file_prefix = $3; } /* deprecated */

 | "%glr-parser"
     {
       nondeterministic_parser = true;
 | "%glr-parser"
     {
       nondeterministic_parser = true;


@@ -255,27 +260,50 @@ declaration:
     }
 | "%initial-action" "{...}"
     {
     }
 | "%initial-action" "{...}"
     {

-      muscle_code_grow ("initial_action", translate_symbol_action ($2, @2), @2);
+      code_props action;
+      code_props_symbol_action_init (&action, $2, @2);
+      code_props_translate_code (&action);
+      gram_scanner_last_string_free ();
+      muscle_code_grow ("initial_action", action.code, @2);
+      code_scanner_last_string_free ();

     }
     }

-| "%lex-param" "{...}"                    { add_param ("lex_param", $2, @2); }
-| "%locations"                             { locations_flag = true; }
-| "%name-prefix" "=" string_content        { spec_name_prefix = $3; }
-| "%no-lines"                              { no_lines_flag = true; }
-| "%nondeterministic-parser"              { nondeterministic_parser = true; }
-| "%output" "=" string_content             { spec_outfile = $3; }
-| "%parse-param" "{...}"                  { add_param ("parse_param", $2, @2); }
-| "%pure-parser"                           { pure_parser = true; }
-| "%require" string_content                { version_check (&@2, $2); }
-| "%skeleton" string_content               { skeleton = $2; }
-| "%start-header" "{...}"
+| "%language" STRING           { language_argmatch ($2, grammar_prio, @1); }
+| "%lex-param" "{...}"         { add_param ("lex_param", $2, @2); }
+| "%name-prefix" STRING         { spec_name_prefix = $2; }
+| "%name-prefix" "=" STRING     { spec_name_prefix = $3; } /* deprecated */
+| "%no-lines"                   { no_lines_flag = true; }
+| "%nondeterministic-parser"   { nondeterministic_parser = true; }
+| "%output" STRING              { spec_outfile = $2; }
+| "%output" "=" STRING          { spec_outfile = $3; }  /* deprecated */
+| "%parse-param" "{...}"       { add_param ("parse_param", $2, @2); }
+| "%require" STRING             { version_check (&@2, $2); }
+| "%skeleton" STRING

     {
     {

-      /* Remove the '{', and replace the '}' with '\n'.  */
-      $2[strlen ($2) - 1] = '\n';
-      muscle_code_grow ("start_header", translate_code ($2+1, @2), @2);
+      char const *skeleton_user = $2;
+      if (strchr (skeleton_user, '/'))
+        {
+          size_t dir_length = strlen (current_file);
+          char *skeleton_build;
+          while (dir_length && current_file[dir_length - 1] != '/')
+            --dir_length;
+          while (dir_length && current_file[dir_length - 1] == '/')
+            --dir_length;
+          skeleton_build =
+            xmalloc (dir_length + 1 + strlen (skeleton_user) + 1);
+          if (dir_length > 0)
+            {
+              strncpy (skeleton_build, current_file, dir_length);
+              skeleton_build[dir_length++] = '/';
+            }
+          strcpy (skeleton_build + dir_length, skeleton_user);
+          skeleton_user = uniqstr_new (skeleton_build);
+          free (skeleton_build);
+        }
+      skeleton_arg (skeleton_user, grammar_prio, @1);

     }
     }

-| "%token-table"                           { token_table_flag = true; }
-| "%verbose"                               { report_flag = report_states; }
-| "%yacc"                                  { yacc_flag = true; }
+| "%token-table"                { token_table_flag = true; }
+| "%verbose"                    { report_flag |= report_states; }
+| "%yacc"                       { yacc_flag = true; }

 | /*FIXME: Err?  What is this horror doing here? */ ";"
 ;
 
 | /*FIXME: Err?  What is this horror doing here? */ ";"
 ;
 


@@ -286,20 +314,18 @@ grammar_declaration:
     {
       grammar_start_symbol_set ($2, @2);
     }
     {
       grammar_start_symbol_set ($2, @2);
     }

-| "%destructor" "{...}" symbols.1
+| "%destructor" "{...}" generic_symlist

     {
       symbol_list *list;
     {
       symbol_list *list;

-      const char *action = translate_symbol_action ($2, @2);

       for (list = $3; list; list = list->next)
       for (list = $3; list; list = list->next)

-       symbol_destructor_set (list->sym, action, @2);
+       symbol_list_destructor_set (list, $2, @2);

       symbol_list_free ($3);
     }
       symbol_list_free ($3);
     }

-| "%printer" "{...}" symbols.1
+| "%printer" "{...}" generic_symlist

     {
       symbol_list *list;
     {
       symbol_list *list;

-      const char *action = translate_symbol_action ($2, @2);

       for (list = $3; list; list = list->next)
       for (list = $3; list; list = list->next)

-       symbol_printer_set (list->sym, action, @2);
+       symbol_list_printer_set (list, $2, @2);

       symbol_list_free ($3);
     }
 | "%default-prec"
       symbol_list_free ($3);
     }
 | "%default-prec"


@@ -310,12 +336,24 @@ grammar_declaration:
     {
       default_prec = false;
     }
     {
       default_prec = false;
     }

+| "%code" braceless
+    {
+      /* Do not invoke muscle_percent_code_grow here since it invokes
+         muscle_user_name_list_grow.  */
+      muscle_code_grow ("percent_code()", $2, @2);
+      code_scanner_last_string_free ();
+    }
+| "%code" ID braceless
+    {
+      muscle_percent_code_grow ($2, @2, $3, @3);
+      code_scanner_last_string_free ();
+    }

 ;
 
 
 ;
 
 

-/*----------*
- | %union.  |
- *----------*/
+/*---------.
+| %union.  |
+`---------*/

 
 %token PERCENT_UNION "%union";
 
 
 %token PERCENT_UNION "%union";
 


@@ -325,21 +363,11 @@ union_name:
 ;
 
 grammar_declaration:
 ;
 
 grammar_declaration:

-  "%union" union_name "{...}"
+  "%union" union_name braceless

     {
     {

-      char const *body = $3;
-
-      if (typed)
-       {
-         /* Concatenate the union bodies, turning the first one's
-            trailing '}' into '\n', and omitting the second one's '{'.  */
-         char *code = muscle_find ("stype");
-         code[strlen (code) - 1] = '\n';
-         body++;
-       }
-
-      typed = true;
-      muscle_code_grow ("stype", body, @3);
+      union_seen = true;
+      muscle_code_grow ("stype", $3, @3);
+      code_scanner_last_string_free ();

     }
 ;
 
     }
 ;
 


@@ -357,24 +385,25 @@ symbol_declaration:
       current_class = unknown_sym;
       current_type = NULL;
     }
       current_class = unknown_sym;
       current_type = NULL;
     }

-| "%type" TYPE symbols.1
+| "%type" TAG symbols.1

     {
       symbol_list *list;
     {
       symbol_list *list;

+      tag_seen = true;

       for (list = $3; list; list = list->next)
       for (list = $3; list; list = list->next)

-       symbol_type_set (list->sym, $2, @2);
+       symbol_type_set (list->content.sym, $2, @2);

       symbol_list_free ($3);
     }
 ;
 
 precedence_declaration:
       symbol_list_free ($3);
     }
 ;
 
 precedence_declaration:

-  precedence_declarator type.opt symbols.1
+  precedence_declarator tag.opt symbols.prec

     {
       symbol_list *list;
       ++current_prec;
       for (list = $3; list; list = list->next)
        {
     {
       symbol_list *list;
       ++current_prec;
       for (list = $3; list; list = list->next)
        {

-         symbol_type_set (list->sym, current_type, @2);
-         symbol_precedence_set (list->sym, current_prec, $1, @1);
+         symbol_type_set (list->content.sym, current_type, @2);
+         symbol_precedence_set (list->content.sym, current_prec, $1, @1);

        }
       symbol_list_free ($3);
       current_type = NULL;
        }
       symbol_list_free ($3);
       current_type = NULL;


@@ -382,27 +411,56 @@ precedence_declaration:
 ;
 
 precedence_declarator:
 ;
 
 precedence_declarator:

-  "%left"     { $$ = left_assoc; }
-| "%right"    { $$ = right_assoc; }
-| "%nonassoc" { $$ = non_assoc; }
+  "%left"       { $$ = left_assoc; }
+| "%right"      { $$ = right_assoc; }
+| "%nonassoc"   { $$ = non_assoc; }
+| "%precedence" { $$ = precedence_assoc; }

 ;
 
 ;
 

-type.opt:
+tag.opt:

   /* Nothing. */ { current_type = NULL; }
   /* Nothing. */ { current_type = NULL; }

-| TYPE           { current_type = $1; }
+| TAG            { current_type = $1; tag_seen = true; }

 ;
 
 ;
 

-/* One or more nonterminals to be %typed. */
+/* Just like symbols.1 but accept INT for the sake of POSIX.  */
+symbols.prec:
+  symbol.prec
+    { $$ = symbol_list_sym_new ($1, @1); }
+| symbols.prec symbol.prec
+    { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
+;
+
+symbol.prec:
+    symbol { $$ = $1; }
+  | symbol INT { $$ = $1; symbol_user_token_number_set ($1, $2, @2); }
+  ;
+
+/* One or more symbols to be %typed. */

 symbols.1:
 symbols.1:

-  symbol            { $$ = symbol_list_new ($1, @1); }
-| symbols.1 symbol  { $$ = symbol_list_prepend ($1, $2, @2); }
+  symbol
+    { $$ = symbol_list_sym_new ($1, @1); }
+| symbols.1 symbol
+    { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
+;
+
+generic_symlist:
+  generic_symlist_item { $$ = $1; }
+| generic_symlist generic_symlist_item { $$ = symbol_list_prepend ($1, $2); }
+;
+
+generic_symlist_item:
+  symbol    { $$ = symbol_list_sym_new ($1, @1); }
+| TAG       { $$ = symbol_list_type_new ($1, @1); }
+| "<*>"     { $$ = symbol_list_default_tagged_new (@1); }
+| "<>"      { $$ = symbol_list_default_tagless_new (@1); }

 ;
 
 /* One token definition.  */
 symbol_def:
 ;
 
 /* One token definition.  */
 symbol_def:

-  TYPE
+  TAG

      {
        current_type = $1;
      {
        current_type = $1;

+       tag_seen = true;

      }
 | id
      {
      }
 | id
      {


@@ -458,7 +516,8 @@ rules_or_grammar_declaration:
 ;
 
 rules:
 ;
 
 rules:

-  id_colon { current_lhs = $1; current_lhs_location = @1; } rhses.1
+  id_colon named_ref.opt { current_lhs = $1; current_lhs_location = @1;
+    current_lhs_named_ref = $2; } rhses.1

 ;
 
 rhses.1:
 ;
 
 rhses.1:


@@ -469,23 +528,65 @@ rhses.1:
 
 rhs:
   /* Nothing.  */
 
 rhs:
   /* Nothing.  */

-    { grammar_current_rule_begin (current_lhs, current_lhs_location); }
-| rhs symbol
-    { grammar_current_rule_symbol_append ($2, @2); }
-| rhs "{...}"
-    { grammar_current_rule_action_append ($2, @2); }
+    { grammar_current_rule_begin (current_lhs, current_lhs_location,
+                                 current_lhs_named_ref); }
+| rhs symbol named_ref.opt
+    { grammar_current_rule_symbol_append ($2, @2, $3); }
+| rhs "{...}" named_ref.opt
+    { grammar_current_rule_action_append ($2, @2, $3); }

 | rhs "%prec" symbol
     { grammar_current_rule_prec_set ($3, @3); }
 | rhs "%dprec" INT
     { grammar_current_rule_dprec_set ($3, @3); }
 | rhs "%prec" symbol
     { grammar_current_rule_prec_set ($3, @3); }
 | rhs "%dprec" INT
     { grammar_current_rule_dprec_set ($3, @3); }

-| rhs "%merge" TYPE
+| rhs "%merge" TAG

     { grammar_current_rule_merge_set ($3, @3); }
 ;
 
     { grammar_current_rule_merge_set ($3, @3); }
 ;
 

+named_ref.opt:
+  /* Nothing. */ { $$ = 0; }
+|
+  BRACKETED_ID   { $$ = named_ref_new($1, @1); }
+;
+
+
+/*---------------------------.
+| variable and content.opt.  |
+`---------------------------*/
+
+/* The STRING form of variable is deprecated and is not M4-friendly.
+   For example, M4 fails for `%define "[" "value"'.  */
+variable:
+  ID
+| STRING { $$ = uniqstr_new ($1); }
+;
+
+/* Some content or empty by default. */
+content.opt:
+  /* Nothing. */   { $$ = ""; }
+| STRING
+;
+
+
+/*------------.
+| braceless.  |
+`------------*/
+
+braceless:
+  "{...}"
+    {
+      code_props plain_code;
+      $1[strlen ($1) - 1] = '\n';
+      code_props_plain_init (&plain_code, $1+1, @1);
+      code_props_translate_code (&plain_code);
+      gram_scanner_last_string_free ();
+      $$ = plain_code.code;
+    }
+;
+

 
 

-/*---------------*
- | Identifiers.  |
- *---------------*/
+/*--------------.
+| Identifiers.  |
+`--------------*/

 
 /* Identifiers are returned as uniqstr values by the scanner.
    Depending on their use, we may need to make them genuine symbols.  */
 
 /* Identifiers are returned as uniqstr values by the scanner.
    Depending on their use, we may need to make them genuine symbols.  */


@@ -520,19 +621,16 @@ string_as_id:
     }
 ;
 
     }
 ;
 

-/* A string used for its contents.  Don't quote it.  */
-string_content:
-  STRING
-    { $$ = $1; }
-;
-
-

 epilogue.opt:
   /* Nothing.  */
 | "%%" EPILOGUE
     {
 epilogue.opt:
   /* Nothing.  */
 | "%%" EPILOGUE
     {

-      muscle_code_grow ("epilogue", translate_code ($2, @2), @2);
+      code_props plain_code;
+      code_props_plain_init (&plain_code, $2, @2);
+      code_props_translate_code (&plain_code);

       gram_scanner_last_string_free ();
       gram_scanner_last_string_free ();

+      muscle_code_grow ("epilogue", plain_code.code, @2);
+      code_scanner_last_string_free ();

     }
 ;
 
     }
 ;
 


@@ -620,6 +718,7 @@ add_param (char const *type, char *decl, location loc)
   gram_scanner_last_string_free ();
 }
 
   gram_scanner_last_string_free ();
 }
 

+

 static void
 version_check (location const *loc, char const *version)
 {
 static void
 version_check (location const *loc, char const *version)
 {