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Fix handling of alts with some configs predicated and some configs unpredicated (should be treated as always true)

This commit is contained in:
sharwell 2012-02-09 01:11:09 -06:00
parent 9c554a002b
commit 46d5458617
3 changed files with 43 additions and 31 deletions
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63
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
View File

@ -565,21 +565,28 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
int nalts = decState.getNumberOfTransitions();
List<DFAState.PredPrediction> predPredictions =
predicateDFAState(D, D.configset, outerContext, nalts);
IntervalSet conflictingAlts = getConflictingAltsFromConfigSet(D.configset);
if ( D.predicates.size() < conflictingAlts.size() ) {
reportInsufficientPredicates(dfa, startIndex, input.index(),
conflictingAlts,
decState,
getPredsForAmbigAlts(conflictingAlts, D.configset, nalts),
D.configset,
false);
if ( predPredictions!=null ) {
IntervalSet conflictingAlts = getConflictingAltsFromConfigSet(D.configset);
if ( D.predicates.size() < conflictingAlts.size() ) {
reportInsufficientPredicates(dfa, startIndex, input.index(),
conflictingAlts,
decState,
getPredsForAmbigAlts(conflictingAlts, D.configset, nalts),
D.configset,
false);
}
input.seek(startIndex);
predictedAlt = evalSemanticContext(predPredictions, outerContext);
if ( predictedAlt!=ATN.INVALID_ALT_NUMBER ) {
return predictedAlt;
}
if (D.prediction == ATN.INVALID_ALT_NUMBER) {
throw noViableAlt(input, outerContext, D.configset, startIndex);
}
predictedAlt = D.prediction;
}
input.seek(startIndex);
predictedAlt = evalSemanticContext(predPredictions, outerContext);
if ( predictedAlt!=ATN.INVALID_ALT_NUMBER ) {
return predictedAlt;
}
throw noViableAlt(input, outerContext, D.configset, startIndex);
}
if ( D.isAcceptState ) return predictedAlt;
@ -736,14 +743,9 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
// we have a validating predicate; test it
// Update DFA so reach becomes accept state with predicate
predPredictions = getPredicatePredictions(conflictingAlts, altToPred);
if ( D.isCtxSensitive ) {
// D.ctxToPredicates.put(outerContext, predPredictions);
}
else {
D.predicates = predPredictions;
}
D.predicates = predPredictions;
D.prediction = ATN.INVALID_ALT_NUMBER; // make sure we use preds
}
D.prediction = ATN.INVALID_ALT_NUMBER; // make sure we use preds
return predPredictions;
}
@ -754,11 +756,18 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
// REACH=[1|1|[]|0:0, 1|2|[]|0:1]
SemanticContext[] altToPred = new SemanticContext[nalts +1];
int n = altToPred.length;
for (int i = 0; i < n; i++) altToPred[i] = SemanticContext.NONE;
int nPredAlts = 0;
for (ATNConfig c : configs) {
if ( c.semanticContext!=SemanticContext.NONE && ambigAlts.contains(c.alt) ) {
if ( ambigAlts.contains(c.alt) ) {
altToPred[c.alt] = SemanticContext.or(altToPred[c.alt], c.semanticContext);
}
}
int nPredAlts = 0;
for (int i = 0; i < n; i++) {
if (altToPred[i] == null) {
altToPred[i] = SemanticContext.NONE;
}
else if (altToPred[i] != SemanticContext.NONE) {
nPredAlts++;
}
}
@ -817,10 +826,12 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
predictedAlt = pair.alt; // default prediction
break;
}
boolean evaluatedResult = pair.pred.eval(parser, outerContext);
if ( debug || dfa_debug ) {
System.out.println("eval pred "+pair+"="+pair.pred.eval(parser, outerContext));
System.out.println("eval pred "+pair+"="+evaluatedResult);
}
if ( pair.pred.eval(parser, outerContext) ) {
if ( evaluatedResult ) {
if ( debug || dfa_debug ) System.out.println("PREDICT "+pair.alt);
predictedAlt = pair.alt;
break;

9
runtime/Java/src/org/antlr/v4/runtime/atn/SemanticContext.java
View File

@ -189,14 +189,15 @@ public abstract class SemanticContext {
}
public static SemanticContext and(SemanticContext a, SemanticContext b) {
if ( a == NONE ) return b;
if ( b == NONE ) return a;
if ( a == null || a == NONE ) return b;
if ( b == null || b == NONE ) return a;
return new AND(a, b);
}
public static SemanticContext or(SemanticContext a, SemanticContext b) {
if ( a == NONE ) return b;
if ( b == NONE ) return a;
if ( a == null ) return b;
if ( b == null ) return a;
if ( a == NONE || b == NONE ) return NONE;
return new OR(a, b);
}
}

2
tool/test/org/antlr/v4/test/TestSemPredEvalParser.java
View File

@ -274,7 +274,7 @@ public class TestSemPredEvalParser extends BaseTest {
"alt 1\n";
assertEquals(expecting, found);
expecting = "";
expecting = null;
assertEquals(expecting, stderrDuringParse);
}