yysyntax_error: improve invocation readability.

[bison.git] / data / lalr1.java

diff --git a/data/lalr1.java b/data/lalr1.java
index ea9565488e4486cc3e00656520a79ae1bbd4d1d4..c6bd4038494cd41b1376f3d022eb12ccfaf5e202 100644 (file)
--- a/data/lalr1.java
+++ b/data/lalr1.java
@@ -1,6 +1,6 @@
 # Java skeleton for Bison -*- autoconf -*-
 
-# Copyright (C) 2007, 2008 Free Software Foundation, Inc.
+# Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
 
 # 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
@@ -17,15 +17,23 @@
 
 m4_include(b4_pkgdatadir/[java.m4])
 
-b4_defines_if([b4_fatal([%s: %%defines does not make sense in Java], [b4_skeleton])])
-m4_ifval(m4_defn([b4_symbol_destructors]),
-        [b4_fatal([%s: %%destructor does not make sense in Java], [b4_skeleton])],
-        [])
+b4_defines_if([b4_fatal([%s: %%defines does not make sense in Java],
+              [b4_skeleton])])
+
+# We don't depend on %debug in Java, but pacify warnings about non-used flags.
+b4_parse_trace_if([0], [0])
+
+m4_define([b4_symbol_no_destructor_assert],
+[b4_symbol_if([$1], [has_destructor],
+              [b4_fatal([%s: %s: %%destructor does not make sense in Java],
+                        [b4_skeleton],
+                        [b4_symbol_action_location([$1], [destructor])])])])
+b4_symbol_foreach([b4_symbol_no_destructor_assert])
 
 m4_divert_push(0)dnl
 @output(b4_parser_file_name@)@
 b4_copyright([Skeleton implementation for Bison LALR(1) parsers in Java],
-  [2007, 2008])
+             [2007, 2008, 2009, 2010])
 
 b4_percent_define_ifdef([package], [package b4_percent_define_get([package]);
 ])[/* First part of user declarations.  */
@@ -342,11 +350,9 @@ b4_lexer_if([[
    * printing an error message.  */
   public static final int YYERROR = 2;
 
-  /**
-   * Returned by a Bison action in order to print an error message and start
-   * error recovery.  */
-  public static final int YYFAIL = 3;
-
+  // Internal return codes that are not supported for user semantic
+  // actions.
+  private static final int YYERRLAB = 3;
   private static final int YYNEWSTATE = 4;
   private static final int YYDEFAULT = 5;
   private static final int YYREDUCE = 6;
@@ -525,7 +531,7 @@ m4_popdef([b4_at_dollar])])dnl
 
         /* Take a decision.  First try without lookahead.  */
         yyn = yypact_[yystate];
-        if (yyn == yypact_ninf_)
+        if (yy_pact_value_is_default_ (yyn))
           {
             label = YYDEFAULT;
             break;
@@ -564,8 +570,8 @@ m4_popdef([b4_at_dollar])])dnl
         /* <= 0 means reduce or error.  */
         else if ((yyn = yytable_[yyn]) <= 0)
           {
-            if (yyn == 0 || yyn == yytable_ninf_)
-              label = YYFAIL;
+            if (yy_table_value_is_error_ (yyn))
+              label = YYERRLAB;
             else
               {
                 yyn = -yyn;
@@ -599,7 +605,7 @@ m4_popdef([b4_at_dollar])])dnl
       case YYDEFAULT:
         yyn = yydefact_[yystate];
         if (yyn == 0)
-          label = YYFAIL;
+          label = YYERRLAB;
         else
           label = YYREDUCE;
         break;
@@ -616,7 +622,7 @@ m4_popdef([b4_at_dollar])])dnl
       /*------------------------------------.
       | yyerrlab -- here on detecting error |
       `------------------------------------*/
-      case YYFAIL:
+      case YYERRLAB:
         /* If not already recovering from an error, report this error.  */
         if (yyerrstatus_ == 0)
           {
@@ -668,7 +674,7 @@ m4_popdef([b4_at_dollar])])dnl
         for (;;)
           {
             yyn = yypact_[yystate];
-            if (yyn != yypact_ninf_)
+            if (!yy_pact_value_is_default_ (yyn))
               {
                 yyn += yyterror_;
                 if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
@@ -727,7 +733,8 @@ m4_popdef([b4_at_dollar])])dnl
             StringBuffer res;
 
             /* Start YYX at -YYN if negative to avoid negative indexes in
-               YYCHECK.  */
+               YYCHECK.  In other words, skip the first -YYN actions for this
+               state because they are default actions.  */
             int yyxbegin = yyn < 0 ? -yyn : 0;
 
             /* Stay within bounds of both yycheck and yytname.  */
@@ -735,7 +742,8 @@ m4_popdef([b4_at_dollar])])dnl
             int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
             int count = 0;
             for (int x = yyxbegin; x < yyxend; ++x)
-              if (yycheck_[x + yyn] == x && x != yyterror_)
+              if (yycheck_[x + yyn] == x && x != yyterror_
+                  && !yy_table_value_is_error_ (yytable_[x + yyn]))
                 ++count;
 
             // FIXME: This method of building the message is not compatible
@@ -746,19 +754,38 @@ m4_popdef([b4_at_dollar])])dnl
               {
                 count = 0;
                 for (int x = yyxbegin; x < yyxend; ++x)
-                  if (yycheck_[x + yyn] == x && x != yyterror_)
+                  if (yycheck_[x + yyn] == x && x != yyterror_
+                      && !yy_table_value_is_error_ (yytable_[x + yyn]))
                     {
                       res.append (count++ == 0 ? ", expecting " : " or ");
                       res.append (yytnamerr_ (yytname_[x]));
                     }
               }
-        return res.toString ();
+            return res.toString ();
           }
       }
 ]])[
     return "syntax error";
   }
 
+  /**
+   * Whether the given <code>yypact_</code> value indicates a defaulted state.
+   * @@param yyvalue   the value to check
+   */
+  private static boolean yy_pact_value_is_default_ (int yyvalue)
+  {
+    return yyvalue == yypact_ninf_;
+  }
+
+  /**
+   * Whether the given <code>yytable_</code> value indicates a syntax error.
+   * @@param yyvalue   the value to check
+   */
+  private static boolean yy_table_value_is_error_ (int yyvalue)
+  {
+    return yyvalue == yytable_ninf_;
+  }
+
   private static final ]b4_int_type_for([b4_pact])[ yypact_ninf_ = ]b4_pact_ninf[;
   private static final ]b4_int_type_for([b4_table])[ yytable_ninf_ = ]b4_table_ninf[;
 
@@ -821,5 +848,5 @@ b4_percent_code_get[]dnl
 
 }
 
-b4_epilogue
+b4_epilogue[]dnl
 m4_divert_pop(0)dnl