public virtual ATN CreateATN()
{
_CreateATN(g.rules.Values);
Debug.Assert(atn.maxTokenType == g.GetMaxTokenType());
AddRuleFollowLinks();
AddEOFTransitionToStartRules();
ATNOptimizer.Optimize(g, atn);
foreach (System.Tuple <Rule, ATNState, ATNState> pair in preventEpsilonClosureBlocks)
{
LL1Analyzer analyzer = new LL1Analyzer(atn);
ATNState blkStart = pair.Item2;
ATNState blkStop = pair.Item3;
IntervalSet lookahead = analyzer.Look(blkStart, blkStop, PredictionContext.EmptyLocal);
if (lookahead.Contains(Antlr4.Runtime.TokenConstants.Epsilon))
{
ErrorType errorType = pair.Item1 is LeftRecursiveRule ? ErrorType.EPSILON_LR_FOLLOW : ErrorType.EPSILON_CLOSURE;
g.tool.errMgr.GrammarError(errorType, g.fileName, ((GrammarAST)pair.Item1.ast.GetChild(0)).Token, pair.Item1.name);
}
}
foreach (System.Tuple <Rule, ATNState, ATNState> pair in preventEpsilonOptionalBlocks)
{
int bypassCount = 0;
for (int i = 0; i < pair.Item2.NumberOfTransitions; i++)
{
ATNState startState = pair.Item2.Transition(i).target;
if (startState == pair.Item3)
{
bypassCount++;
continue;
}
LL1Analyzer analyzer = new LL1Analyzer(atn);
if (analyzer.Look(startState, pair.Item3, PredictionContext.EmptyLocal).Contains(Antlr4.Runtime.TokenConstants.Epsilon))
{
g.tool.errMgr.GrammarError(ErrorType.EPSILON_OPTIONAL, g.fileName, ((GrammarAST)pair.Item1.ast.GetChild(0)).Token, pair.Item1.name);
goto continueOptionalCheck;
}
}
if (bypassCount != 1)
{
throw new InvalidOperationException("Expected optional block with exactly 1 bypass alternative.");
}
continueOptionalCheck:
;
}
return(atn);
}
public override ATN CreateATN()
{
// BUILD ALL START STATES (ONE PER MODE)
ICollection <string> modes = ((LexerGrammar)g).modes.Keys;
foreach (string modeName in modes)
{
// create s0, start state; implied Tokens rule node
TokensStartState startState = NewState <TokensStartState>(null);
atn.DefineMode(modeName, startState);
}
// INIT ACTION, RULE->TOKEN_TYPE MAP
atn.ruleToTokenType = new int[g.rules.Count];
foreach (Rule r in g.rules.Values)
{
atn.ruleToTokenType[r.index] = g.GetTokenType(r.name);
}
// CREATE ATN FOR EACH RULE
_CreateATN(g.rules.Values);
atn.lexerActions = new ILexerAction[indexToActionMap.Count];
foreach (KeyValuePair <int, ILexerAction> entry in indexToActionMap)
{
atn.lexerActions[entry.Key] = entry.Value;
}
// LINK MODE START STATE TO EACH TOKEN RULE
foreach (string modeName in modes)
{
IList <Rule> rules = ((LexerGrammar)g).modes[modeName];
TokensStartState startState = atn.modeNameToStartState[modeName];
foreach (Rule r in rules)
{
if (!r.IsFragment())
{
RuleStartState s = atn.ruleToStartState[r.index];
Epsilon(startState, s);
}
}
}
ATNOptimizer.Optimize(g, atn);
return(atn);
}
