NullPointerException https://github.com/antlr/antlr3/issues/162

console

error(100): jconfig/src/main/antlr3/com/initvoid/jconfig/zconf/ZConfHelpLexer.g:17:1: syntax error: antlr: org.antlr.runtime.EarlyExitException
context [anonymous] 1:10 attribute rules isn't defined
error(100): jconfig/src/main/antlr3/com/initvoid/jconfig/zconf/ZConfHelpLexer.g:0:1: syntax error: assign.types: org.antlr.runtime.EarlyExitException
org/antlr/grammar/v3/DefineGrammarItemsWalker.g: node from line 109:4 required (...)+ loop did not match anything at input ';'
error(10):  internal error: jconfig/src/main/antlr3/com/initvoid/jconfig/zconf/ZConfHelpLexer.g : java.lang.NullPointerException
org.antlr.grammar.v3.CodeGenTreeWalker.rules(CodeGenTreeWalker.java:901)
org.antlr.grammar.v3.CodeGenTreeWalker.grammarSpec(CodeGenTreeWalker.java:877)
org.antlr.grammar.v3.CodeGenTreeWalker.grammar_(CodeGenTreeWalker.java:479)
org.antlr.codegen.CodeGenerator.genRecognizer(CodeGenerator.java:415)
org.antlr.Tool.generateRecognizer(Tool.java:674)
org.antlr.Tool.process(Tool.java:487)
org.antlr.Tool.main(Tool.java:98)

ZConfHelpLexer.g

lexer grammar ZConfHelpLexer;

options {
    language=Java;
}

@lexer::header {package com.initvoid.jconfig.zconf;}

//input  	 : lines            EOF	      ;

//lines    : line+  content?            ;

//line  	 :        content?  HELP_EOL  ;

//content  : HELP_LEADING_WS HELP_TEXT  ;

tokens {
    T_MAINMENU            ;
    T_MENU                ;
    T_ENDMENU             ;
    T_SOURCE              ;
    T_CHOICE              ;
    T_ENDCHOICE           ;
    T_COMMENT             ;
    T_CONFIG              ;
    T_MENUCONFIG          ;
    T_HELP                ;
    T_IF                  ;
    T_ENDIF               ;
    T_DEPENDS             ;
    T_OPTIONAL            ;
    T_DEFAULT             ;
    T_PROMPT              ;
    T_TYPE_TRISTATE       ;
    T_DEFAULT_TRISTATE    ;
    T_TYPE_BOOL           ;
    T_TYPE_BOOLEAN        ;
    T_DEFAULT_BOOL        ;
    T_TYPE_INT            ;
    T_TYPE_HEX            ;
    T_TYPE_STRING         ;
    T_SELECT              ;
    T_RANGE               ;
    T_VISIBLE             ;
    T_OPTION              ;
    T_ON                  ;
    T_OPT_MODULES         ;
    T_OPT_DEFCONFIG_LIST  ;
    T_OPT_ENV             ;
    T_OPT_ALLNOCONFIG_Y   ;

    T_AND          ;
    T_OR           ;
    T_OPEN_PAREN   ;
    T_CLOSE_PAREN  ;
    T_NOT          ;
    T_EQUAL        ;
    T_UNEQUAL      ;

    T_DQUOT   ;
    T_SQUOT   ;

    T_FOLD;
    T_EOL;
    T_WORD;
    T_WORD_QUOTE;
}

HELP_LEADING_WS
                                          @init {
                                                    int spaces = 0;
                                                    StringBuilder sb = new StringBuilder();
                                                }
                                         @after {
                                                    while (spaces > 0)
                                                    {
                                                        if (spaces > 8)
                                                        {   sb.append("        "); spaces -= 8; }
                                                        else
                                                        {   sb.append(" "); spaces--; }
                                                    }
                                                    emit(new ClassicToken(HELP_LEADING_WS, sb.toString()));
                                                }
    :                                           { getCharPositionInLine() == 0 }?=>
        (   ' '                                 { spaces++; }
        |   '\t'                                { spaces += 8; spaces -= (spaces \% 8); }
        )+
    ;

HELP_TEXT
    :   (                               options { greedy = false; }:
            ~(  ' '
            |   '\t'
            |   '\r\n'
            |   '\n'
            )
        )
        (                               options { greedy = true; }:
            ~(  '\r\n'
            |   '\n'
            )
        )*
    ;

HELP_EOL
    :   (  '\r\n'
        |   '\n'
        )                                       { input.mark(); }
    ;