* A semantic predicate failed during validation. Validation of predicates * occurs when normally parsing the alternative just like matching a token. * Disambiguating predicate evaluation occurs when we hoist a predicate into * a prediction decision. *
Inheritance: RecognitionException
Esempio n. 1
0
        public virtual string GetErrorMessage(RecognitionException e, string[] tokenNames)
        {
            string str1 = e.Message;

            if (e is UnwantedTokenException)
            {
                UnwantedTokenException unwantedTokenException = (UnwantedTokenException)e;
                string str2 = unwantedTokenException.Expecting != -1 ? tokenNames[unwantedTokenException.Expecting] : "EndOfFile";
                str1 = "extraneous input " + this.GetTokenErrorDisplay(unwantedTokenException.UnexpectedToken) + " expecting " + str2;
            }
            else if (e is MissingTokenException)
            {
                MissingTokenException missingTokenException = (MissingTokenException)e;
                str1 = "missing " + (missingTokenException.Expecting != -1 ? tokenNames[missingTokenException.Expecting] : "EndOfFile") + " at " + this.GetTokenErrorDisplay(e.Token);
            }
            else if (e is MismatchedTokenException)
            {
                MismatchedTokenException mismatchedTokenException = (MismatchedTokenException)e;
                string str2 = mismatchedTokenException.Expecting != -1 ? tokenNames[mismatchedTokenException.Expecting] : "EndOfFile";
                str1 = "mismatched input " + this.GetTokenErrorDisplay(e.Token) + " expecting " + str2;
            }
            else if (e is MismatchedTreeNodeException)
            {
                MismatchedTreeNodeException treeNodeException = (MismatchedTreeNodeException)e;
                string str2 = treeNodeException.Expecting != -1 ? tokenNames[treeNodeException.Expecting] : "EndOfFile";
                str1 = "mismatched tree node: " + (treeNodeException.Node != null ? treeNodeException.Node.ToString() ?? string.Empty : string.Empty) + " expecting " + str2;
            }
            else if (e is NoViableAltException)
            {
                str1 = "no viable alternative at input " + this.GetTokenErrorDisplay(e.Token);
            }
            else if (e is EarlyExitException)
            {
                str1 = "required (...)+ loop did not match anything at input " + this.GetTokenErrorDisplay(e.Token);
            }
            else if (e is MismatchedSetException)
            {
                MismatchedSetException mismatchedSetException = (MismatchedSetException)e;
                str1 = "mismatched input " + this.GetTokenErrorDisplay(e.Token) + " expecting set " + (object)mismatchedSetException.Expecting;
            }
            else if (e is MismatchedNotSetException)
            {
                MismatchedNotSetException mismatchedNotSetException = (MismatchedNotSetException)e;
                str1 = "mismatched input " + this.GetTokenErrorDisplay(e.Token) + " expecting set " + (object)mismatchedNotSetException.Expecting;
            }
            else if (e is FailedPredicateException)
            {
                FailedPredicateException predicateException = (FailedPredicateException)e;
                str1 = "rule " + predicateException.RuleName + " failed predicate: {" + predicateException.PredicateText + "}?";
            }
            return(str1);
        }
        /** <summary>What error message should be generated for the various exception types?</summary>
         *
         *  <remarks>
         *  Not very object-oriented code, but I like having all error message
         *  generation within one method rather than spread among all of the
         *  exception classes. This also makes it much easier for the exception
         *  handling because the exception classes do not have to have pointers back
         *  to this object to access utility routines and so on. Also, changing
         *  the message for an exception type would be difficult because you
         *  would have to subclassing exception, but then somehow get ANTLR
         *  to make those kinds of exception objects instead of the default.
         *  This looks weird, but trust me--it makes the most sense in terms
         *  of flexibility.
         *
         *  For grammar debugging, you will want to override this to add
         *  more information such as the stack frame with
         *  getRuleInvocationStack(e, this.getClass().getName()) and,
         *  for no viable alts, the decision description and state etc...
         *
         *  Override this to change the message generated for one or more
         *  exception types.
         *  </remarks>
         */
        public virtual string GetErrorMessage(RecognitionException e, string[] tokenNames)
        {
            string msg = e.Message;

            if (e is UnwantedTokenException)
            {
                UnwantedTokenException ute = (UnwantedTokenException)e;
                string tokenName           = "<unknown>";
                if (ute.Expecting == TokenTypes.EndOfFile)
                {
                    tokenName = "EndOfFile";
                }
                else
                {
                    tokenName = tokenNames[ute.Expecting];
                }
                msg = "extraneous input " + GetTokenErrorDisplay(ute.UnexpectedToken) +
                      " expecting " + tokenName;
            }
            else if (e is MissingTokenException)
            {
                MissingTokenException mte = (MissingTokenException)e;
                string tokenName          = "<unknown>";
                if (mte.Expecting == TokenTypes.EndOfFile)
                {
                    tokenName = "EndOfFile";
                }
                else
                {
                    tokenName = tokenNames[mte.Expecting];
                }
                msg = "missing " + tokenName + " at " + GetTokenErrorDisplay(e.Token);
            }
            else if (e is MismatchedTokenException)
            {
                MismatchedTokenException mte = (MismatchedTokenException)e;
                string tokenName             = "<unknown>";
                if (mte.Expecting == TokenTypes.EndOfFile)
                {
                    tokenName = "EndOfFile";
                }
                else
                {
                    tokenName = tokenNames[mte.Expecting];
                }
                msg = "mismatched input " + GetTokenErrorDisplay(e.Token) +
                      " expecting " + tokenName;
            }
            else if (e is MismatchedTreeNodeException)
            {
                MismatchedTreeNodeException mtne = (MismatchedTreeNodeException)e;
                string tokenName = "<unknown>";
                if (mtne.Expecting == TokenTypes.EndOfFile)
                {
                    tokenName = "EndOfFile";
                }
                else
                {
                    tokenName = tokenNames[mtne.Expecting];
                }
                // workaround for a .NET framework bug (NullReferenceException)
                string nodeText = (mtne.Node != null) ? mtne.Node.ToString() ?? string.Empty : string.Empty;
                msg = "mismatched tree node: " + nodeText + " expecting " + tokenName;
            }
            else if (e is NoViableAltException)
            {
                //NoViableAltException nvae = (NoViableAltException)e;
                // for development, can add "decision=<<"+nvae.grammarDecisionDescription+">>"
                // and "(decision="+nvae.decisionNumber+") and
                // "state "+nvae.stateNumber
                msg = "no viable alternative at input " + GetTokenErrorDisplay(e.Token);
            }
            else if (e is EarlyExitException)
            {
                //EarlyExitException eee = (EarlyExitException)e;
                // for development, can add "(decision="+eee.decisionNumber+")"
                msg = "required (...)+ loop did not match anything at input " +
                      GetTokenErrorDisplay(e.Token);
            }
            else if (e is MismatchedSetException)
            {
                MismatchedSetException mse = (MismatchedSetException)e;
                msg = "mismatched input " + GetTokenErrorDisplay(e.Token) +
                      " expecting set " + mse.Expecting;
            }
            else if (e is MismatchedNotSetException)
            {
                MismatchedNotSetException mse = (MismatchedNotSetException)e;
                msg = "mismatched input " + GetTokenErrorDisplay(e.Token) +
                      " expecting set " + mse.Expecting;
            }
            else if (e is FailedPredicateException)
            {
                FailedPredicateException fpe = (FailedPredicateException)e;
                msg = "rule " + fpe.RuleName + " failed predicate: {" +
                      fpe.PredicateText + "}?";
            }
            return(msg);
        }
Esempio n. 3
0
        /// <summary>
        /// What error message should be generated for the various exception types?
        ///
        /// Not very object-oriented code, but I like having all error message generation
        /// within one method rather than spread among all of the exception classes. This
        /// also makes it much easier for the exception handling because the exception
        /// classes do not have to have pointers back to this object to access utility
        /// routines and so on. Also, changing the message for an exception type would be
        /// difficult because you would have to subclassing exception, but then somehow get
        /// ANTLR to make those kinds of exception objects instead of the default.
        ///
        /// This looks weird, but trust me--it makes the most sense in terms of flexibility.
        ///
        /// For grammar debugging, you will want to override this to add more information
        /// such as the stack frame with GetRuleInvocationStack(e, this.GetType().Fullname)
        /// and, for no viable alts, the decision description and state etc...
        ///
        /// Override this to change the message generated for one or more exception types.
        /// </summary>
        public virtual string GetErrorMessage(RecognitionException e, string[] tokenNames)
        {
            string msg = e.Message;

            if (e is UnwantedTokenException)
            {
                UnwantedTokenException ute = (UnwantedTokenException)e;
                string tokenName           = "<unknown>";
                if (ute.Expecting == Token.EOF)
                {
                    tokenName = "EOF";
                }
                else
                {
                    tokenName = tokenNames[ute.Expecting];
                }
                msg = "extraneous input " + GetTokenErrorDisplay(ute.UnexpectedToken) +
                      " expecting " + tokenName;
            }
            else if (e is MissingTokenException)
            {
                MissingTokenException mte = (MissingTokenException)e;
                string tokenName          = "<unknown>";
                if (mte.Expecting == Token.EOF)
                {
                    tokenName = "EOF";
                }
                else
                {
                    tokenName = tokenNames[mte.Expecting];
                }
                msg = "missing " + tokenName + " at " + GetTokenErrorDisplay(e.Token);
            }
            else if (e is MismatchedTokenException)
            {
                MismatchedTokenException mte = (MismatchedTokenException)e;
                string tokenName             = "<unknown>";
                if (mte.Expecting == Token.EOF)
                {
                    tokenName = "EOF";
                }
                else
                {
                    tokenName = tokenNames[mte.Expecting];
                }
                msg = "mismatched input " + GetTokenErrorDisplay(e.Token) + " expecting " + tokenName;
            }
            //else if (e is MismatchedTreeNodeException)
            //{
            //  MismatchedTreeNodeException mtne = (MismatchedTreeNodeException)e;
            //  string tokenName = "<unknown>";
            //  if (mtne.expecting == Token.EOF)
            //  {
            //    tokenName = "EOF";
            //  }
            //  else
            //  {
            //    tokenName = tokenNames[mtne.expecting];
            //  }
            //  // The ternary operator is only necessary because of a bug in the .NET framework
            //  msg = "mismatched tree node: " + ((mtne.Node!=null && mtne.Node.ToString()!=null) ?
            //    mtne.Node : string.Empty) + " expecting " + tokenName;
            //}
            else if (e is NoViableAltException)
            {
                //NoViableAltException nvae = (NoViableAltException)e;
                // for development, can add "decision=<<"+nvae.grammarDecisionDescription+">>"
                // and "(decision="+nvae.decisionNumber+") and
                // "state "+nvae.stateNumber
                msg = "no viable alternative at input " + GetTokenErrorDisplay(e.Token);
            }
            else if (e is EarlyExitException)
            {
                //EarlyExitException eee = (EarlyExitException)e;
                // for development, can add "(decision="+eee.decisionNumber+")"
                msg = "required (...)+ loop did not match anything at input " + GetTokenErrorDisplay(e.Token);
            }
            else if (e is MismatchedSetException)
            {
                MismatchedSetException mse = (MismatchedSetException)e;
                msg = "mismatched input " + GetTokenErrorDisplay(e.Token) + " expecting set " + mse.expecting;
            }
            else if (e is MismatchedNotSetException)
            {
                MismatchedNotSetException mse = (MismatchedNotSetException)e;
                msg = "mismatched input " + GetTokenErrorDisplay(e.Token) + " expecting set " + mse.expecting;
            }
            else if (e is FailedPredicateException)
            {
                FailedPredicateException fpe = (FailedPredicateException)e;
                msg = "rule " + fpe.ruleName + " failed predicate: {" + fpe.predicateText + "}?";
            }
            return(msg);
        }
Esempio n. 4
0
        /** Fill a list of all NFA states visited during the parse */
        protected virtual void ParseEngine( String startRule,
                                   NFAState start,
                                   NFAState stop,
                                   IIntStream input,
                                   Stack<object> ruleInvocationStack,
                                   IDebugEventListener actions,
                                   IList visitedStates )
        {
            NFAState s = start;
            if ( actions != null )
            {
                actions.EnterRule( s.nfa.grammar.FileName, start.enclosingRule.Name );
            }
            int t = input.LA( 1 );
            while ( s != stop )
            {
                if ( visitedStates != null )
                {
                    visitedStates.Add( s );
                }
                //Console.Out.WriteLine( "parse state " + s.stateNumber + " input=" + s.nfa.grammar.getTokenDisplayName( t ) );
                // CASE 1: decision state
                if ( s.DecisionNumber > 0 && s.nfa.grammar.GetNumberOfAltsForDecisionNFA( s ) > 1 )
                {
                    // decision point, must predict and jump to alt
                    DFA dfa = s.nfa.grammar.GetLookaheadDFA( s.DecisionNumber );
                    //if ( s.nfa.grammar.type != GrammarType.Lexer )
                    //{
                    //    Console.Out.WriteLine( "decision: " +
                    //                   dfa.getNFADecisionStartState().Description +
                    //                   " input=" + s.nfa.grammar.getTokenDisplayName( t ) );
                    //}
                    int m = input.Mark();
                    int predictedAlt = Predict( dfa );
                    if ( predictedAlt == NFA.INVALID_ALT_NUMBER )
                    {
                        String description = dfa.NFADecisionStartState.Description;
                        NoViableAltException nvae =
                            new NoViableAltException( description,
                                                          dfa.DecisionNumber,
                                                          s.stateNumber,
                                                          input );
                        if ( actions != null )
                        {
                            actions.RecognitionException( nvae );
                        }
                        input.Consume(); // recover
                        throw nvae;
                    }
                    input.Rewind( m );
                    int parseAlt =
                        s.TranslateDisplayAltToWalkAlt( predictedAlt );
                    //if ( s.nfa.grammar.type != GrammarType.Lexer )
                    //{
                    //    Console.Out.WriteLine( "predicted alt " + predictedAlt + ", parseAlt " + parseAlt );
                    //}
                    NFAState alt;
                    if ( parseAlt > s.nfa.grammar.GetNumberOfAltsForDecisionNFA( s ) )
                    {
                        // implied branch of loop etc...
                        alt = s.nfa.grammar.nfa.GetState( s.endOfBlockStateNumber );
                    }
                    else
                    {
                        alt = s.nfa.grammar.GetNFAStateForAltOfDecision( s, parseAlt );
                    }
                    s = (NFAState)alt.transition[0].target;
                    continue;
                }

                // CASE 2: finished matching a rule
                if ( s.IsAcceptState )
                { // end of rule node
                    if ( actions != null )
                    {
                        actions.ExitRule( s.nfa.grammar.FileName, s.enclosingRule.Name );
                    }
                    if ( ruleInvocationStack.Count == 0 )
                    {
                        // done parsing.  Hit the start state.
                        //Console.Out.WriteLine( "stack empty in stop state for " + s.enclosingRule );
                        break;
                    }
                    // pop invoking state off the stack to know where to return to
                    NFAState invokingState = (NFAState)ruleInvocationStack.Pop();
                    RuleClosureTransition invokingTransition =
                            (RuleClosureTransition)invokingState.transition[0];
                    // move to node after state that invoked this rule
                    s = invokingTransition.followState;
                    continue;
                }

                Transition trans = s.transition[0];
                Label label = trans.label;
                if ( label.IsSemanticPredicate )
                {
                    FailedPredicateException fpe =
                        new FailedPredicateException( input,
                                                     s.enclosingRule.Name,
                                                     "can't deal with predicates yet" );
                    if ( actions != null )
                    {
                        actions.RecognitionException( fpe );
                    }
                }

                // CASE 3: epsilon transition
                if ( label.IsEpsilon )
                {
                    // CASE 3a: rule invocation state
                    if ( trans is RuleClosureTransition )
                    {
                        ruleInvocationStack.Push( s );
                        s = (NFAState)trans.target;
                        //Console.Out.WriteLine( "call " + s.enclosingRule.name + " from " + s.nfa.grammar.getFileName() );
                        if ( actions != null )
                        {
                            actions.EnterRule( s.nfa.grammar.FileName, s.enclosingRule.Name );
                        }
                        // could be jumping to new grammar, make sure DFA created
                        if ( !s.nfa.grammar.AllDecisionDFAHaveBeenCreated )
                        {
                            s.nfa.grammar.CreateLookaheadDFAs();
                        }
                    }
                    // CASE 3b: plain old epsilon transition, just move
                    else
                    {
                        s = (NFAState)trans.target;
                    }
                }

                // CASE 4: match label on transition
                else if ( label.Matches( t ) )
                {
                    if ( actions != null )
                    {
                        if ( s.nfa.grammar.type == GrammarType.Parser ||
                             s.nfa.grammar.type == GrammarType.Combined )
                        {
                            actions.ConsumeToken( ( (ITokenStream)input ).LT( 1 ) );
                        }
                    }
                    s = (NFAState)s.transition[0].target;
                    input.Consume();
                    t = input.LA( 1 );
                }

                // CASE 5: error condition; label is inconsistent with input
                else
                {
                    if ( label.IsAtom )
                    {
                        MismatchedTokenException mte =
                            new MismatchedTokenException( label.Atom, input );
                        if ( actions != null )
                        {
                            actions.RecognitionException( mte );
                        }
                        input.Consume(); // recover
                        throw mte;
                    }
                    else if ( label.IsSet )
                    {
                        MismatchedSetException mse =
                            new MismatchedSetException( ( (IntervalSet)label.Set ).ToRuntimeBitSet(),
                                                       input );
                        if ( actions != null )
                        {
                            actions.RecognitionException( mse );
                        }
                        input.Consume(); // recover
                        throw mse;
                    }
                    else if ( label.IsSemanticPredicate )
                    {
                        FailedPredicateException fpe =
                            new FailedPredicateException( input,
                                                         s.enclosingRule.Name,
                                                         label.SemanticContext.ToString() );
                        if ( actions != null )
                        {
                            actions.RecognitionException( fpe );
                        }
                        input.Consume(); // recover
                        throw fpe;
                    }
                    else
                    {
                        throw new RecognitionException( input ); // unknown error
                    }
                }
            }
            //Console.Out.WriteLine( "hit stop state for " + stop.enclosingRule );
            if ( actions != null )
            {
                actions.ExitRule( s.nfa.grammar.FileName, stop.enclosingRule.Name );
            }
        }