Ejemplo n.º 1
0
        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);
        }
Ejemplo n.º 2
0
        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);
        }