maint: update for changes to gnulib's announce-gen.

[bison.git] / data / yacc.c

diff --git a/data/yacc.c b/data/yacc.c
index 5e7b55fc31e4af09232d323ca1e658db24c3d5ef..5780a29594b7ed0f04ca801aa8ce8bb770797bef 100644 (file)
--- a/data/yacc.c
+++ b/data/yacc.c
@@ -1,12 +1,11 @@
                                                              -*- C -*-
 # Yacc compatible skeleton for Bison
 
-# Copyright (C) 1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
-# 2007, 2008, 2009 Free Software Foundation, Inc.
+# Copyright (C) 1984, 1989-1990, 2000-2010 Free Software Foundation,
+# Inc.
 
 m4_pushdef([b4_copyright_years],
-           [1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
-            2007, 2008, 2009])
+           [1984, 1989-1990, 2000-2010])
 
 # 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
@@ -630,7 +629,6 @@ do                                                          \
     {                                                          \
       yychar = (Token);                                                \
       yylval = (Value);                                                \
-      yytoken = YYTRANSLATE (yychar);                          \
       YYPOPSTACK (1);                                          \
       goto yybackup;                                           \
     }                                                          \
@@ -1429,6 +1427,17 @@ yyreduce:
       ]b4_user_actions[
       default: break;
     }
+  /* User semantic actions sometimes alter yychar, and that requires
+     that yytoken be updated with the new translation.  We take the
+     approach of translating immediately before every use of yytoken.
+     One alternative is translating here after every semantic action,
+     but that translation would be missed if the semantic action invokes
+     YYABORT, YYACCEPT, or YYERROR immediately after altering yychar or
+     if it invokes YYBACKUP.  In the case of YYABORT or YYACCEPT, an
+     incorrect destructor might then be invoked immediately.  In the
+     case of YYERROR or YYBACKUP, subsequent parser actions might lead
+     to an incorrect destructor call or verbose syntax error message
+     before the lookahead is translated.  */
   YY_SYMBOL_PRINT ("-> $$ =", yyr1[yyn], &yyval, &yyloc);
 
   YYPOPSTACK (yylen);
@@ -1457,6 +1466,10 @@ yyreduce:
 | yyerrlab -- here on detecting error |
 `------------------------------------*/
 yyerrlab:
+  /* Make sure we have latest lookahead translation.  See comments at
+     user semantic actions for why this is necessary.  */
+  yytoken = YYTRANSLATE (yychar);
+
   /* If not already recovering from an error, report this error.  */
   if (!yyerrstatus)
     {
@@ -1609,8 +1622,13 @@ yyexhaustedlab:
 
 yyreturn:
   if (yychar != YYEMPTY)
-     yydestruct ("Cleanup: discarding lookahead",
-                yytoken, &yylval]b4_locations_if([, &yylloc])[]b4_user_args[);
+    {
+      /* Make sure we have latest lookahead translation.  See comments at
+         user semantic actions for why this is necessary.  */
+      yytoken = YYTRANSLATE (yychar);
+      yydestruct ("Cleanup: discarding lookahead",
+                  yytoken, &yylval]b4_locations_if([, &yylloc])[]b4_user_args[);
+    }
   /* Do not reclaim the symbols of the rule which action triggered
      this YYABORT or YYACCEPT.  */
   YYPOPSTACK (yylen);