* src/symtab.h, src/symtab.c (symbol_t): printer and

printer_location are new members.
(symbol_printer_set): New.
* src/parse-gram.y (PERCENT_PRINTER): New token.
Handle its associated rule.
* src/scan-gram.l: Adjust.
(handle_destructor_at, handle_destructor_dollar): Rename as...
(handle_symbol_code_at, handle_symbol_code_dollar): these.
* src/output.c (symbol_printers_output): New.
(output_skeleton): Call it.
* data/bison.simple (yysymprint): New.  Cannot be named yyprint
since there are already many grammar files with a user `yyprint'.
Replace the calls to YYPRINT to calls to yysymprint.
* tests/calc.at: Adjust.
* tests/torture.at (AT_DATA_STACK_TORTURE): Remove YYPRINT: it was
taking advantage of parser very internal details (stack size!).

src/output.c

@@ -639,6 +639,39 @@ symbol_destructors_output (FILE *out)
 }
 
 
+/*-------------------------------------.
+| Output the symbol printers to OOUT.  |
+`-------------------------------------*/
+
+static void
+symbol_printers_output (FILE *out)
+{
+  int i;
+  int first = 1;
+
+  fputs ("m4_define([b4_symbol_printers], \n[", out);
+  for (i = 0; i < nsyms; ++i)
+    if (symbols[i]->destructor)
+      {
+	symbol_t *symbol = symbols[i];
+
+	/* Filename, lineno,
+	   Symbol-name, Symbol-number,
+	   destructor, typename. */
+	fprintf (out, "%s[[[%s]], [[%d]], [[%s]], [[%d]], [[%s]], [[%s]]]",
+		 first ? "" : ",\n",
+		 infile, symbol->printer_location.first_line,
+		 symbol_tag_get (symbol),
+		 symbol->number,
+		 symbol->printer,
+		 symbol->type_name);
+
+	first = 0;
+      }
+  fputs ("])\n\n", out);
+}
+
+
 static void
 save_column (int symbol, int default_state)
 {
@@ -1053,6 +1086,7 @@ output_skeleton (void)
   actions_output (out);
   token_definitions_output (out);
   symbol_destructors_output (out);
+  symbol_printers_output (out);
 
   muscles_m4_output (out);
 

src/parse-gram.h

@@ -15,37 +15,38 @@
      PERCENT_NTERM = 262,
      PERCENT_TYPE = 263,
      PERCENT_DESTRUCTOR = 264,
-     PERCENT_UNION = 265,
-     PERCENT_LEFT = 266,
-     PERCENT_RIGHT = 267,
-     PERCENT_NONASSOC = 268,
-     PERCENT_EXPECT = 269,
-     PERCENT_START = 270,
-     PERCENT_PREC = 271,
-     PERCENT_VERBOSE = 272,
-     PERCENT_ERROR_VERBOSE = 273,
-     PERCENT_OUTPUT = 274,
-     PERCENT_FILE_PREFIX = 275,
-     PERCENT_NAME_PREFIX = 276,
-     PERCENT_DEFINE = 277,
-     PERCENT_PURE_PARSER = 278,
-     PERCENT_DEFINES = 279,
-     PERCENT_YACC = 280,
-     PERCENT_DEBUG = 281,
-     PERCENT_LOCATIONS = 282,
-     PERCENT_NO_LINES = 283,
-     PERCENT_SKELETON = 284,
-     PERCENT_TOKEN_TABLE = 285,
-     TYPE = 286,
-     EQUAL = 287,
-     SEMICOLON = 288,
-     COLON = 289,
-     PIPE = 290,
-     ID = 291,
-     PERCENT_PERCENT = 292,
-     PROLOGUE = 293,
-     EPILOGUE = 294,
-     BRACED_CODE = 295
+     PERCENT_PRINTER = 265,
+     PERCENT_UNION = 266,
+     PERCENT_LEFT = 267,
+     PERCENT_RIGHT = 268,
+     PERCENT_NONASSOC = 269,
+     PERCENT_EXPECT = 270,
+     PERCENT_START = 271,
+     PERCENT_PREC = 272,
+     PERCENT_VERBOSE = 273,
+     PERCENT_ERROR_VERBOSE = 274,
+     PERCENT_OUTPUT = 275,
+     PERCENT_FILE_PREFIX = 276,
+     PERCENT_NAME_PREFIX = 277,
+     PERCENT_DEFINE = 278,
+     PERCENT_PURE_PARSER = 279,
+     PERCENT_DEFINES = 280,
+     PERCENT_YACC = 281,
+     PERCENT_DEBUG = 282,
+     PERCENT_LOCATIONS = 283,
+     PERCENT_NO_LINES = 284,
+     PERCENT_SKELETON = 285,
+     PERCENT_TOKEN_TABLE = 286,
+     TYPE = 287,
+     EQUAL = 288,
+     SEMICOLON = 289,
+     COLON = 290,
+     PIPE = 291,
+     ID = 292,
+     PERCENT_PERCENT = 293,
+     PROLOGUE = 294,
+     EPILOGUE = 295,
+     BRACED_CODE = 296
    };
 # endif
   /* POSIX requires `int' for tokens in interfaces.  */
@@ -59,37 +60,38 @@
 #define PERCENT_NTERM 262
 #define PERCENT_TYPE 263
 #define PERCENT_DESTRUCTOR 264
-#define PERCENT_UNION 265
-#define PERCENT_LEFT 266
-#define PERCENT_RIGHT 267
-#define PERCENT_NONASSOC 268
-#define PERCENT_EXPECT 269
-#define PERCENT_START 270
-#define PERCENT_PREC 271
-#define PERCENT_VERBOSE 272
-#define PERCENT_ERROR_VERBOSE 273
-#define PERCENT_OUTPUT 274
-#define PERCENT_FILE_PREFIX 275
-#define PERCENT_NAME_PREFIX 276
-#define PERCENT_DEFINE 277
-#define PERCENT_PURE_PARSER 278
-#define PERCENT_DEFINES 279
-#define PERCENT_YACC 280
-#define PERCENT_DEBUG 281
-#define PERCENT_LOCATIONS 282
-#define PERCENT_NO_LINES 283
-#define PERCENT_SKELETON 284
-#define PERCENT_TOKEN_TABLE 285
-#define TYPE 286
-#define EQUAL 287
-#define SEMICOLON 288
-#define COLON 289
-#define PIPE 290
-#define ID 291
-#define PERCENT_PERCENT 292
-#define PROLOGUE 293
-#define EPILOGUE 294
-#define BRACED_CODE 295
+#define PERCENT_PRINTER 265
+#define PERCENT_UNION 266
+#define PERCENT_LEFT 267
+#define PERCENT_RIGHT 268
+#define PERCENT_NONASSOC 269
+#define PERCENT_EXPECT 270
+#define PERCENT_START 271
+#define PERCENT_PREC 272
+#define PERCENT_VERBOSE 273
+#define PERCENT_ERROR_VERBOSE 274
+#define PERCENT_OUTPUT 275
+#define PERCENT_FILE_PREFIX 276
+#define PERCENT_NAME_PREFIX 277
+#define PERCENT_DEFINE 278
+#define PERCENT_PURE_PARSER 279
+#define PERCENT_DEFINES 280
+#define PERCENT_YACC 281
+#define PERCENT_DEBUG 282
+#define PERCENT_LOCATIONS 283
+#define PERCENT_NO_LINES 284
+#define PERCENT_SKELETON 285
+#define PERCENT_TOKEN_TABLE 286
+#define TYPE 287
+#define EQUAL 288
+#define SEMICOLON 289
+#define COLON 290
+#define PIPE 291
+#define ID 292
+#define PERCENT_PERCENT 293
+#define PROLOGUE 294
+#define EPILOGUE 295
+#define BRACED_CODE 296
 
 
 
@@ -103,8 +105,8 @@ typedef union {
   char *string;
   associativity assoc;
 } yystype;
-/* Line 1271 of /usr/local/share/bison/bison.simple.  */
-#line 108 "y.tab.h"
+/* Line 1313 of /usr/local/share/bison/bison.simple.  */
+#line 110 "y.tab.h"
 # define YYSTYPE yystype
 #endif
 

src/parse-gram.y

@@ -103,9 +103,13 @@ braced_code_t current_braced_code = action_braced_code;
 
 %token PERCENT_TOKEN       "%token"
 %token PERCENT_NTERM       "%nterm"
+
 %token PERCENT_TYPE        "%type"
 %token PERCENT_DESTRUCTOR  "%destructor"
+%token PERCENT_PRINTER     "%printer"
+
 %token PERCENT_UNION       "%union"
+
 %token PERCENT_LEFT        "%left"
 %token PERCENT_RIGHT       "%right"
 %token PERCENT_NONASSOC    "%nonassoc"
@@ -212,6 +216,16 @@ grammar_declaration:
       symbol_list_free ($4);
       current_braced_code = action_braced_code;
     }
+| "%printer"
+    { current_braced_code = printer_braced_code; }
+  BRACED_CODE symbols.1
+    {
+      symbol_list_t *list;
+      for (list = $4; list; list = list->next)
+	symbol_printer_set (list->sym, $3, list->location);
+      symbol_list_free ($4);
+      current_braced_code = action_braced_code;
+    }
 ;
 
 symbol_declaration:

src/reader.h

@@ -52,7 +52,8 @@ int gram_parse (void *control);
 typedef enum braced_code_e
   {
     action_braced_code,
-    destructor_braced_code
+    destructor_braced_code,
+    printer_braced_code
   } braced_code_t;
 /* FIXME: This is really a dirty hack which demonstrates that we
    should probably not try to parse the actions now.  */

src/scan-gram.l

@@ -136,6 +136,7 @@ blanks   [ \t\f]+
   "%nterm"                return PERCENT_NTERM;
   "%output"               return PERCENT_OUTPUT;
   "%prec"                 return PERCENT_PREC;
+  "%printer"              return PERCENT_PRINTER;
   "%pure"[-_]"parser"     return PERCENT_PURE_PARSER;
   "%right"                return PERCENT_RIGHT;
   "%skeleton"             return PERCENT_SKELETON;
@@ -524,7 +525,7 @@ blanks   [ \t\f]+
 %%
 
 /*------------------------------------------------------------------.
-| CP is pointing to a wannabee semantic value (i.e., a `$').        |
+| TEXT is pointing to a wannabee semantic value (i.e., a `$').      |
 |                                                                   |
 | Possible inputs: $[<TYPENAME>]($|integer)                         |
 |                                                                   |
@@ -532,11 +533,10 @@ blanks   [ \t\f]+
 `------------------------------------------------------------------*/
 
 static inline void
-handle_action_dollar (char *cp, location_t location)
+handle_action_dollar (char *text, location_t location)
 {
   const char *type_name = NULL;
-
-  ++cp;
+  char *cp = text + 1;
 
   /* Get the type name if explicit. */
   if (*cp == '<')
@@ -588,31 +588,24 @@ handle_action_dollar (char *cp, location_t location)
     }
   else
     {
-      char buf[] = "$c";
-      buf[1] = *cp;
-      complain_at (location, _("%s is invalid"), quote (buf));
+      complain_at (location, _("%s is invalid"), quote (text));
     }
 }
 
 
-/*---------------------------------------.
-| CP is pointing to $$ in a destructor.  |
-`---------------------------------------*/
+/*---------------------------------------------------------------.
+| TEXT is expexted tp be $$ in some code associated to a symbol: |
+| destructor or printer.                                         |
+`---------------------------------------------------------------*/
 
 static inline void
-handle_destructor_dollar (char *cp, location_t location)
+handle_symbol_code_dollar (char *text, location_t location)
 {
-  ++cp;
+  char *cp = text + 1;
   if (*cp == '$')
-    {
-      obstack_sgrow (&string_obstack, "]b4_dollar_dollar[");
-    }
+    obstack_sgrow (&string_obstack, "]b4_dollar_dollar[");
   else
-    {
-      char buf[] = "$c";
-      buf[1] = *cp;
-      complain_at (location, _("%s is invalid"), quote (buf));
-    }
+    complain_at (location, _("%s is invalid"), quote (text));
 }
 
 
@@ -632,7 +625,8 @@ handle_dollar (braced_code_t braced_code_kind,
       break;
 
     case destructor_braced_code:
-      handle_destructor_dollar (text, location);
+    case printer_braced_code:
+      handle_symbol_code_dollar (text, location);
       break;
     }
 }
@@ -646,21 +640,21 @@ handle_dollar (braced_code_t braced_code_kind,
 static inline void
 handle_action_at (char *text, location_t location)
 {
+  char *cp = text + 1;
   locations_flag = 1;
-  ++text;
 
-  if (*text == '$')
+  if (*cp == '$')
     {
       obstack_sgrow (&string_obstack, "]b4_lhs_location[");
     }
-  else if (isdigit (*text) || *text == '-')
+  else if (isdigit (*cp) || *cp == '-')
     {
       /* RULE_LENGTH is the number of values in the current rule so
 	 far, which says where to find `$0' with respect to the top of
 	 the stack.  It is not the same as the rule->length in the
 	 case of mid rule actions.  */
       int rule_length = symbol_list_length (current_rule->next);
-      int n = strtol (text, &text, 10);
+      int n = strtol (cp, &cp, 10);
 
       if (n > rule_length)
 	complain_at (location, _("invalid value: %s%d"), "@", n);
@@ -670,31 +664,24 @@ handle_action_at (char *text, location_t location)
     }
   else
     {
-      char buf[] = "@c";
-      buf[1] = *text;
-      complain_at (location, _("%s is invalid"), quote (buf));
+      complain_at (location, _("%s is invalid"), quote (text));
     }
 }
 
 
-/*--------------------------------------------.
-| TEXT is expexted tp be @$ in a destructor.  |
-`--------------------------------------------*/
+/*---------------------------------------------------------------.
+| TEXT is expexted tp be @$ in some code associated to a symbol: |
+| destructor or printer.                                         |
+`---------------------------------------------------------------*/
 
 static inline void
-handle_destructor_at (char *text, location_t location)
+handle_symbol_code_at (char *text, location_t location)
 {
-  ++text;
-  if (*text == '$')
-    {
-      obstack_sgrow (&string_obstack, "]b4_at_dollar[");
-    }
+  char *cp = text + 1;
+  if (*cp == '$')
+    obstack_sgrow (&string_obstack, "]b4_at_dollar[");
   else
-    {
-      char buf[] = "$c";
-      buf[1] = *text;
-      complain_at (location, _("%s is invalid"), quote (buf));
-    }
+    complain_at (location, _("%s is invalid"), quote (text));
 }
 
 
@@ -714,7 +701,8 @@ handle_at (braced_code_t braced_code_kind,
       break;
 
     case destructor_braced_code:
-      handle_destructor_at (text, location);
+    case printer_braced_code:
+      handle_symbol_code_at (text, location);
       break;
     }
 }

src/symtab.c

@@ -118,8 +118,7 @@ symbol_type_set (symbol_t *symbol, location_t location, char *type_name)
 
 
 /*-------------------------------------------------------------------.
-| Set the DESTRUCTOR associated to SYMBOL.  Does nothing if passed 0 |
-| as DESTRUCTOR.                                                      |
+| Set the DESTRUCTOR associated to SYMBOL.  Do nothing if passed 0.  |
 `-------------------------------------------------------------------*/
 
 void
@@ -129,14 +128,33 @@ symbol_destructor_set (symbol_t *symbol, location_t location, char *destructor)
     {
       if (symbol->destructor)
 	complain_at (location,
-		     _("destructor redeclaration for %s"),
-		     symbol_tag_get (symbol));
+		     _("%s redeclaration for %s"),
+		     "%destructor", symbol_tag_get (symbol));
       symbol->destructor = destructor;
       symbol->destructor_location = location;
     }
 }
 
 
+/*----------------------------------------------------------------.
+| Set the PRITNER associated to SYMBOL.  Do nothing if passed 0.  |
+`----------------------------------------------------------------*/
+
+void
+symbol_printer_set (symbol_t *symbol, char *printer, location_t location)
+{
+  if (printer)
+    {
+      if (symbol->printer)
+	complain_at (location,
+		     _("%s redeclaration for %s"),
+		     "%printer", symbol_tag_get (symbol));
+      symbol->printer = printer;
+      symbol->printer_location = location;
+    }
+}
+
+
 /*------------------------------------------------------------------.
 | Set the PRECEDENCE associated to SYMBOL.  Does nothing if invoked |
 | with UNDEF_ASSOC as ASSOC.                                        |

src/symtab.h

@@ -59,11 +59,12 @@ struct symbol_s
   /* The location of its first occurence.  */
   location_t location;
 
-  /* Its %type and associated destructor.  */
+  /* Its %type and associated printer and destructor.  */
   char *type_name;
   char *destructor;
   location_t destructor_location;
-
+  char *printer;
+  location_t printer_location;
 
   symbol_number_t number;
   short prec;
@@ -116,6 +117,10 @@ void symbol_type_set PARAMS ((symbol_t *symbol, location_t location,
 void symbol_destructor_set PARAMS ((symbol_t *symbol, location_t location,
 				    char *destructor));
 
+/* Set the PRINTER associated to SYMBOL.  */
+void symbol_printer_set PARAMS ((symbol_t *symbol,
+				 char *printer, location_t location));
+
 /* Set the PRECEDENCE associated to SYMBOL.  Ensures that SYMBOL is a
    terminal.  Does nothing if invoked with UNDEF_ASSOC as ASSOC.  */
 void symbol_precedence_set PARAMS ((symbol_t *symbol, location_t location,