yysyntax_error: adjust prior fixes for branch-2.5's lalr1.cc.

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index 33ab08eeddbfc8051720e96917d3956b0b6eae49..8c91fb6876c807a22cd5ab79233dc1c6f858e860 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -692,6 +692,17 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
        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.  In the case of YYABORT or YYACCEPT, an incorrect
+       destructor might then be invoked immediately.  In the case of
+       YYERROR, 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);
 
     yypop_ (yylen);
@@ -715,6 +726,10 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
   | 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_)
       {
@@ -826,7 +841,13 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
 
   yyreturn:
     if (yychar != yyempty_)
-      yydestruct_ ("Cleanup: discarding lookahead", yytoken, &yylval, &yylloc);
+      {
+        /* 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,
+                     &yylloc);
+      }
 
     /* Do not reclaim the symbols of the rule which action triggered
        this YYABORT or YYACCEPT.  */