(YYSTACK_ALLOC_MAXIMUM): New macro.

(YYSIZE_T): Define to unsigned long int when using an older compiler.
(yyparse): Revamp code to generate long syntax error message, to
make it easier to translate, and to avoid problems with arithmetic
overflow.  Change "virtual memory" to "memory" in diagnostic, since
we don't know whether the memory is virtual.

data/yacc.c

@@ -238,13 +238,21 @@ b4_syncline([@oline@], [@ofile@])[
 # ifdef YYSTACK_ALLOC
    /* Pacify GCC's `empty if-body' warning. */
 #  define YYSTACK_FREE(Ptr) do { /* empty */; } while (0)
+#  ifndef YYSTACK_ALLOC_MAXIMUM
+#   define YYSTACK_ALLOC_MAXIMUM 4032 /* reasonable circa 2005 */
+#  endif
 # else
 #  if defined (__STDC__) || defined (__cplusplus)
 #   include <stdlib.h> /* INFRINGES ON USER NAME SPACE */
 #   define YYSIZE_T size_t
+#  else
+#   define YYSIZE_T unsigned long int
 #  endif
 #  define YYSTACK_ALLOC YYMALLOC
 #  define YYSTACK_FREE YYFREE
+#  ifndef YYSTACK_ALLOC_MAXIMUM
+#   define YYSTACK_ALLOC_MAXIMUM ((YYSIZE_T) -1)
+#  endif
 # endif
 #endif /* ! defined (yyoverflow) || YYERROR_VERBOSE */
 
@@ -647,7 +655,7 @@ int yydebug;
    if the built-in stack extension method is used).
 
    Do not make this value too large; the results are undefined if
-   SIZE_MAX < YYSTACK_BYTES (YYMAXDEPTH)
+   YYSTACK_ALLOC_MAXIMUM < YYSTACK_BYTES (YYMAXDEPTH)
    evaluated with infinite-precision integer arithmetic.  */
 
 #ifndef YYMAXDEPTH
@@ -1081,12 +1089,36 @@ yyerrlab:
 
       if (YYPACT_NINF < yyn && yyn < YYLAST)
 	{
-	  YYSIZE_T yysize = 0;
 	  int yytype = YYTRANSLATE (yychar);
-	  const char* yyprefix;
-	  char *yymsg;
+	  YYSIZE_T yysize0 = yystrlen (yytname[yytype]);
+	  YYSIZE_T yysize = yysize0;
+	  YYSIZE_T yysize1;
+	  int yysize_overflow = 0;
+	  char *yymsg = 0;
+#	  define YYERROR_VERBOSE_ARGS_MAXIMUM 5
+	  char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
 	  int yyx;
 
+#if 0
+	  /* This is so xgettext sees the translatable formats that are
+	     constructed on the fly.  */
+	  _("syntax error, unexpected %s");
+	  _("syntax error, unexpected %s, expecting %s");
+	  _("syntax error, unexpected %s, expecting %s or %s");
+	  _("syntax error, unexpected %s, expecting %s or %s or %s");
+	  _("syntax error, unexpected %s, expecting %s or %s or %s or %s");
+#endif
+	  char *yyfmt;
+	  char const *yyf;
+	  static char const yyunexpected[] = "syntax error, unexpected %s";
+	  static char const yyexpecting[] = ", expecting %s";
+	  static char const yyor[] = " or %s";
+	  char yyformat[sizeof yyunexpected
+			+ sizeof yyexpecting - 1
+			+ ((YYERROR_VERBOSE_ARGS_MAXIMUM - 2)
+			   * (sizeof yyor - 1))];
+	  char const *yyprefix = yyexpecting;
+
 	  /* Start YYX at -YYN if negative to avoid negative indexes in
 	     YYCHECK.  */
 	  int yyxbegin = yyn < 0 ? -yyn : 0;
@@ -1094,44 +1126,61 @@ yyerrlab:
 	  /* Stay within bounds of both yycheck and yytname.  */
 	  int yychecklim = YYLAST - yyn;
 	  int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
-	  int yycount = 0;
+	  int yycount = 1;
+
+	  yyarg[0] = yytname[yytype];
+	  yyfmt = yystpcpy (yyformat, yyunexpected);
 
-	  yyprefix = _(", expecting ");
 	  for (yyx = yyxbegin; yyx < yyxend; ++yyx)
 	    if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR)
 	      {
-		yysize += yystrlen (yyprefix) + yystrlen (yytname [yyx]);
-		yycount += 1;
-		if (yycount == 5)
+		if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM)
 		  {
-		    yysize = 0;
+		    yycount = 1;
+		    yysize = yysize0;
+		    yyformat[sizeof yyunexpected - 1] = '\0';
 		    break;
 		  }
+		yyarg[yycount++] = yytname[yyx];
+		yysize1 = yysize + yystrlen (yytname[yyx]);
+		yysize_overflow |= yysize1 < yysize;
+		yysize = yysize1;
+		yyfmt = yystpcpy (yyfmt, yyprefix);
+		yyprefix = yyor;
 	      }
-	  yysize += (strlen (_("syntax error, unexpected "))
-		     + yystrlen (yytname[yytype]) + 1);
-	  yymsg = (char *) YYSTACK_ALLOC (yysize);
-	  if (yymsg != 0)
-	    {
-	      char *yyp = yystpcpy (yymsg, _("syntax error, unexpected "));
-	      yyp = yystpcpy (yyp, yytname[yytype]);
 
-	      if (yycount < 5)
+	  yyf = _(yyformat);
+	  yysize1 = yysize + strlen (yyf);
+	  yysize_overflow |= yysize1 < yysize;
+	  yysize = yysize1;
+
+	  if (!yysize_overflow && yysize <= YYSTACK_ALLOC_MAXIMUM)
+	    yymsg = (char *) YYSTACK_ALLOC (yysize);
+	  if (yymsg)
+	    {
+	      /* Avoid sprintf, as that infringes on the user's name space.
+		 Don't have undefined behavior even if the translation
+		 produced a string with the wrong number of "%s"s.  */
+	      char *yyp = yymsg;
+	      int yyi = 0;
+	      while ((*yyp = *yyf))
 		{
-		  yyprefix = _(", expecting ");
-		  for (yyx = yyxbegin; yyx < yyxend; ++yyx)
-		    if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR)
-		      {
-			yyp = yystpcpy (yyp, yyprefix);
-			yyp = yystpcpy (yyp, yytname[yyx]);
-			yyprefix = _(" or ");
-		      }
+		  if (*yyp == '%' && yyf[1] == 's' && yyi < yycount)
+		    {
+		      yyp = yystpcpy (yyp, yyarg[yyi++]);
+		      yyf += 2;
+		    }
+		  else
+		    {
+		      yyp++;
+		      yyf++;
+		    }
 		}
 	      yyerror (]b4_yyerror_args[yymsg);
 	      YYSTACK_FREE (yymsg);
 	    }
 	  else
-	    yyerror (]b4_yyerror_args[_("syntax error; also virtual memory exhausted"));
+	    yyerror (]b4_yyerror_args[_("syntax error; also memory exhausted"));
 	}
       else
 #endif /* YYERROR_VERBOSE */