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Fix ATN optimizer leaving loop back state numbers in an inconsistent state

This commit is contained in:
Sam Harwell 2012-08-04 22:22:28 -05:00
parent 1e88980db5
commit 2947fe6a2a
5 changed files with 15 additions and 6 deletions
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10
runtime/Java/src/org/antlr/v4/runtime/atn/ATNSimulator.java
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@ -32,6 +32,7 @@ package org.antlr.v4.runtime.atn;
import org.antlr.v4.runtime.dfa.DFAState;
import org.antlr.v4.runtime.misc.IntervalSet;
import org.antlr.v4.runtime.misc.NotNull;
import org.antlr.v4.runtime.misc.Pair;
import java.util.ArrayList;
import java.util.List;
@ -64,6 +65,7 @@ public abstract class ATNSimulator {
//
// STATES
//
List<Pair<LoopEndState, Integer>> loopBackStateNumbers = new ArrayList<Pair<LoopEndState, Integer>>();
int nstates = toInt(data[p++]);
for (int i=1; i<=nstates; i++) {
int stype = toInt(data[p++]);
@ -75,11 +77,17 @@ public abstract class ATNSimulator {
ATNState s = stateFactory(stype, i);
s.ruleIndex = toInt(data[p++]);
if ( stype == ATNState.LOOP_END ) { // special case
((LoopEndState)s).loopBackStateNumber = toInt(data[p++]);
int loopBackStateNumber = toInt(data[p++]);
loopBackStateNumbers.add(new Pair<LoopEndState, Integer>((LoopEndState)s, loopBackStateNumber));
}
atn.addState(s);
}
// delay the assignment of loop back states until we know all the state instances have been initialized
for (Pair<LoopEndState, Integer> pair : loopBackStateNumbers) {
pair.a.loopBackState = atn.states.get(pair.b);
}
//
// RULES
//

2
runtime/Java/src/org/antlr/v4/runtime/atn/LoopEndState.java
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@ -31,5 +31,5 @@ package org.antlr.v4.runtime.atn;
/** Mark the end of a * or + loop */
public class LoopEndState extends ATNState {
public int loopBackStateNumber;
public ATNState loopBackState;
}

3
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
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@ -987,7 +987,8 @@ public class ParserATNSimulator<Symbol extends Token> extends ATNSimulator {
if ( debug ) System.out.println("Loop end; pop, stack=" + config.context);
RuleContext p = config.context;
LoopEndState end = (LoopEndState) config.state;
while ( !p.isEmpty() && p.invokingState == end.loopBackStateNumber ) {
int loopBackStateNumber = end.loopBackState.stateNumber;
while ( !p.isEmpty() && p.invokingState == loopBackStateNumber ) {
p = config.context = config.context.parent; // "pop"
}
}

2
tool/src/org/antlr/v4/automata/ATNSerializer.java
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@ -89,7 +89,7 @@ public class ATNSerializer {
}
data.add(s.getStateType());
data.add(s.ruleIndex);
if ( s.getStateType() == ATNState.LOOP_END ) data.add(((LoopEndState)s).loopBackStateNumber);
if ( s.getStateType() == ATNState.LOOP_END ) data.add(((LoopEndState)s).loopBackState.stateNumber);
nedges += s.getNumberOfTransitions();
for (int i=0; i<s.getNumberOfTransitions(); i++) {
Transition t = s.transition(i);

4
tool/src/org/antlr/v4/automata/ParserATNFactory.java
View File

@ -425,7 +425,7 @@ public class ParserATNFactory implements ATNFactory {
atn.defineDecisionState(loop);
LoopEndState end = newState(LoopEndState.class, plusAST);
blkStart.loopBackState = loop;
end.loopBackStateNumber = loop.stateNumber;
end.loopBackState = loop;
plusAST.atnState = blkStart;
epsilon(blkEnd, loop); // blk can see loop back
@ -468,7 +468,7 @@ public class ParserATNFactory implements ATNFactory {
LoopEndState end = newState(LoopEndState.class, starAST);
StarLoopbackState loop = newState(StarLoopbackState.class, starAST);
entry.loopBackState = loop;
end.loopBackStateNumber = loop.stateNumber;
end.loopBackState = loop;
BlockAST blkAST = (BlockAST)starAST.getChild(0);
entry.isGreedy = isGreedy(blkAST);