Require default %destructor/%printer to be declared using

%symbol-default instead of an empty symbol list, and start working on
new per-type %destructor/%printer.  Discussed at
<http://lists.gnu.org/archive/html/bison-patches/2006-09/msg00007.html>.
* NEWS (2.3+): Add %symbol-default to example.
* bison.texinfo (Freeing Discarded Symbols): Likewise.
(Bison Symbols): Add entry for %symbol-default.
* src/parse-gram.y (PERCENT_SYMBOL_DEFAULT): New token.
(generic_symlist, generic_symlist_item): New nonterminals for creating
a list in which each item is a symbol, semantic type, or
%symbol-default.
(grammar_declaration): Use generic_symlist in %destructor and %printer
declarations instead of symbols.1 or an empty list.
(symbol_declaration, precedence_declaration, symbols.1): Update actions
for changes to symbol_list.
* src/reader.c: Update for changes to symbol_list.
* src/scan-code.l: Likewise.
* src/scan-gram.l: Scan new PERCENT_SYMBOL_DEFAULT token.
* src/symlist.c, src/symlist.h: Extend such that a list node may
represent a semantic type or a %symbol-default in addition to just an
ordinary symbol.  Add switched functions for setting %destructor's and
%printer's.
* tests/actions.at, tests/input.at: Add %symbol-default to all default
%destructor/%printer declarations.

src/parse-gram.h

@@ -48,53 +48,54 @@
      PERCENT_TYPE = 262,
      PERCENT_DESTRUCTOR = 263,
      PERCENT_PRINTER = 264,
-     PERCENT_LEFT = 265,
-     PERCENT_RIGHT = 266,
-     PERCENT_NONASSOC = 267,
-     PERCENT_PREC = 268,
-     PERCENT_DPREC = 269,
-     PERCENT_MERGE = 270,
-     PERCENT_AFTER_HEADER = 271,
-     PERCENT_BEFORE_HEADER = 272,
-     PERCENT_DEBUG = 273,
-     PERCENT_DEFAULT_PREC = 274,
-     PERCENT_DEFINE = 275,
-     PERCENT_DEFINES = 276,
-     PERCENT_END_HEADER = 277,
-     PERCENT_ERROR_VERBOSE = 278,
-     PERCENT_EXPECT = 279,
-     PERCENT_EXPECT_RR = 280,
-     PERCENT_FILE_PREFIX = 281,
-     PERCENT_GLR_PARSER = 282,
-     PERCENT_INITIAL_ACTION = 283,
-     PERCENT_LEX_PARAM = 284,
-     PERCENT_LOCATIONS = 285,
-     PERCENT_NAME_PREFIX = 286,
-     PERCENT_NO_DEFAULT_PREC = 287,
-     PERCENT_NO_LINES = 288,
-     PERCENT_NONDETERMINISTIC_PARSER = 289,
-     PERCENT_OUTPUT = 290,
-     PERCENT_PARSE_PARAM = 291,
-     PERCENT_PURE_PARSER = 292,
-     PERCENT_REQUIRE = 293,
-     PERCENT_SKELETON = 294,
-     PERCENT_START = 295,
-     PERCENT_START_HEADER = 296,
-     PERCENT_TOKEN_TABLE = 297,
-     PERCENT_VERBOSE = 298,
-     PERCENT_YACC = 299,
-     BRACED_CODE = 300,
-     CHAR = 301,
-     EPILOGUE = 302,
-     EQUAL = 303,
-     ID = 304,
-     ID_COLON = 305,
-     PERCENT_PERCENT = 306,
-     PIPE = 307,
-     PROLOGUE = 308,
-     SEMICOLON = 309,
-     TYPE = 310,
-     PERCENT_UNION = 311
+     PERCENT_SYMBOL_DEFAULT = 265,
+     PERCENT_LEFT = 266,
+     PERCENT_RIGHT = 267,
+     PERCENT_NONASSOC = 268,
+     PERCENT_PREC = 269,
+     PERCENT_DPREC = 270,
+     PERCENT_MERGE = 271,
+     PERCENT_AFTER_HEADER = 272,
+     PERCENT_BEFORE_HEADER = 273,
+     PERCENT_DEBUG = 274,
+     PERCENT_DEFAULT_PREC = 275,
+     PERCENT_DEFINE = 276,
+     PERCENT_DEFINES = 277,
+     PERCENT_END_HEADER = 278,
+     PERCENT_ERROR_VERBOSE = 279,
+     PERCENT_EXPECT = 280,
+     PERCENT_EXPECT_RR = 281,
+     PERCENT_FILE_PREFIX = 282,
+     PERCENT_GLR_PARSER = 283,
+     PERCENT_INITIAL_ACTION = 284,
+     PERCENT_LEX_PARAM = 285,
+     PERCENT_LOCATIONS = 286,
+     PERCENT_NAME_PREFIX = 287,
+     PERCENT_NO_DEFAULT_PREC = 288,
+     PERCENT_NO_LINES = 289,
+     PERCENT_NONDETERMINISTIC_PARSER = 290,
+     PERCENT_OUTPUT = 291,
+     PERCENT_PARSE_PARAM = 292,
+     PERCENT_PURE_PARSER = 293,
+     PERCENT_REQUIRE = 294,
+     PERCENT_SKELETON = 295,
+     PERCENT_START = 296,
+     PERCENT_START_HEADER = 297,
+     PERCENT_TOKEN_TABLE = 298,
+     PERCENT_VERBOSE = 299,
+     PERCENT_YACC = 300,
+     BRACED_CODE = 301,
+     CHAR = 302,
+     EPILOGUE = 303,
+     EQUAL = 304,
+     ID = 305,
+     ID_COLON = 306,
+     PERCENT_PERCENT = 307,
+     PIPE = 308,
+     PROLOGUE = 309,
+     SEMICOLON = 310,
+     TYPE = 311,
+     PERCENT_UNION = 312
    };
 #endif
 /* Tokens.  */
@@ -106,53 +107,54 @@
 #define PERCENT_TYPE 262
 #define PERCENT_DESTRUCTOR 263
 #define PERCENT_PRINTER 264
-#define PERCENT_LEFT 265
-#define PERCENT_RIGHT 266
-#define PERCENT_NONASSOC 267
-#define PERCENT_PREC 268
-#define PERCENT_DPREC 269
-#define PERCENT_MERGE 270
-#define PERCENT_AFTER_HEADER 271
-#define PERCENT_BEFORE_HEADER 272
-#define PERCENT_DEBUG 273
-#define PERCENT_DEFAULT_PREC 274
-#define PERCENT_DEFINE 275
-#define PERCENT_DEFINES 276
-#define PERCENT_END_HEADER 277
-#define PERCENT_ERROR_VERBOSE 278
-#define PERCENT_EXPECT 279
-#define PERCENT_EXPECT_RR 280
-#define PERCENT_FILE_PREFIX 281
-#define PERCENT_GLR_PARSER 282
-#define PERCENT_INITIAL_ACTION 283
-#define PERCENT_LEX_PARAM 284
-#define PERCENT_LOCATIONS 285
-#define PERCENT_NAME_PREFIX 286
-#define PERCENT_NO_DEFAULT_PREC 287
-#define PERCENT_NO_LINES 288
-#define PERCENT_NONDETERMINISTIC_PARSER 289
-#define PERCENT_OUTPUT 290
-#define PERCENT_PARSE_PARAM 291
-#define PERCENT_PURE_PARSER 292
-#define PERCENT_REQUIRE 293
-#define PERCENT_SKELETON 294
-#define PERCENT_START 295
-#define PERCENT_START_HEADER 296
-#define PERCENT_TOKEN_TABLE 297
-#define PERCENT_VERBOSE 298
-#define PERCENT_YACC 299
-#define BRACED_CODE 300
-#define CHAR 301
-#define EPILOGUE 302
-#define EQUAL 303
-#define ID 304
-#define ID_COLON 305
-#define PERCENT_PERCENT 306
-#define PIPE 307
-#define PROLOGUE 308
-#define SEMICOLON 309
-#define TYPE 310
-#define PERCENT_UNION 311
+#define PERCENT_SYMBOL_DEFAULT 265
+#define PERCENT_LEFT 266
+#define PERCENT_RIGHT 267
+#define PERCENT_NONASSOC 268
+#define PERCENT_PREC 269
+#define PERCENT_DPREC 270
+#define PERCENT_MERGE 271
+#define PERCENT_AFTER_HEADER 272
+#define PERCENT_BEFORE_HEADER 273
+#define PERCENT_DEBUG 274
+#define PERCENT_DEFAULT_PREC 275
+#define PERCENT_DEFINE 276
+#define PERCENT_DEFINES 277
+#define PERCENT_END_HEADER 278
+#define PERCENT_ERROR_VERBOSE 279
+#define PERCENT_EXPECT 280
+#define PERCENT_EXPECT_RR 281
+#define PERCENT_FILE_PREFIX 282
+#define PERCENT_GLR_PARSER 283
+#define PERCENT_INITIAL_ACTION 284
+#define PERCENT_LEX_PARAM 285
+#define PERCENT_LOCATIONS 286
+#define PERCENT_NAME_PREFIX 287
+#define PERCENT_NO_DEFAULT_PREC 288
+#define PERCENT_NO_LINES 289
+#define PERCENT_NONDETERMINISTIC_PARSER 290
+#define PERCENT_OUTPUT 291
+#define PERCENT_PARSE_PARAM 292
+#define PERCENT_PURE_PARSER 293
+#define PERCENT_REQUIRE 294
+#define PERCENT_SKELETON 295
+#define PERCENT_START 296
+#define PERCENT_START_HEADER 297
+#define PERCENT_TOKEN_TABLE 298
+#define PERCENT_VERBOSE 299
+#define PERCENT_YACC 300
+#define BRACED_CODE 301
+#define CHAR 302
+#define EPILOGUE 303
+#define EQUAL 304
+#define ID 305
+#define ID_COLON 306
+#define PERCENT_PERCENT 307
+#define PIPE 308
+#define PROLOGUE 309
+#define SEMICOLON 310
+#define TYPE 311
+#define PERCENT_UNION 312
 
 
 
@@ -171,7 +173,7 @@ typedef union YYSTYPE
   unsigned char character;
 }
 /* Line 1535 of yacc.c.  */
-#line 175 "parse-gram.h"
+#line 177 "parse-gram.h"
 	YYSTYPE;
 # define YYSTYPE_IS_TRIVIAL 1
 # define yystype YYSTYPE /* obsolescent; will be withdrawn */