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Merge branch 'new-conflicting-alts' of github.com:parrt/antlr4 into new-conflicting-alts

This commit is contained in:
Terence Parr 2012-10-13 10:48:43 -07:00
parent 4fe0517431 d6d3f6f506
commit a9ccda48ab
2 changed files with 10 additions and 55 deletions
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59
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
View File

@ -255,17 +255,11 @@ import java.util.Set;
*/
public class ParserATNSimulator extends ATNSimulator {
public static boolean debug = true;
public static boolean debug = false;
public static boolean debug_list_atn_decisions = false;
public static boolean dfa_debug = false;
public static boolean retry_debug = false;
/** Should we simulate tail recursion for loops in SLL mode? Costs
* about 10% in time to turn on so let's leave off. Full LL turns
* it on for sure.
*/
public static final boolean SLL_loopsSimulateTailRecursion = false;
public static int ATN_failover = 0;
public static int predict_calls = 0;
public static int retry_with_context = 0;
@ -407,12 +401,10 @@ public class ParserATNSimulator extends ATNSimulator {
", outerContext="+outerContext.toString(parser));
}
DecisionState decState = atn.getDecisionState(dfa.decision);
boolean loopsSimulateTailRecursion = SLL_loopsSimulateTailRecursion;
boolean fullCtx = false;
ATNConfigSet s0_closure =
computeStartState(dfa.atnStartState,
ParserRuleContext.EMPTY,
loopsSimulateTailRecursion,
fullCtx);
dfa.s0 = addDFAState(dfa, new DFAState(s0_closure));
@ -457,11 +449,9 @@ public class ParserATNSimulator extends ATNSimulator {
if ( dfa_debug ) System.out.println("DFA state "+s.stateNumber+" LA(1)=="+getLookaheadName(input));
if ( s.requiresFullContext && !SLL ) {
if ( dfa_debug ) System.out.println("ctx sensitive state "+outerContext+" in "+s);
boolean loopsSimulateTailRecursion = true;
boolean fullCtx = true;
ATNConfigSet s0_closure =
computeStartState(dfa.atnStartState, outerContext,
loopsSimulateTailRecursion,
fullCtx);
retry_with_context_from_dfa++;
int alt = execATNWithFullContext(dfa, s, s0_closure,
@ -620,10 +610,8 @@ public class ParserATNSimulator extends ATNSimulator {
DecisionState decState = atn.getDecisionState(dfa.decision);
while (true) { // while more work
boolean loopsSimulateTailRecursion = SLL_loopsSimulateTailRecursion;
// System.out.println("REACH "+getLookaheadName(input));
ATNConfigSet reach = computeReachSet(previous, t,
loopsSimulateTailRecursion,
false);
if ( reach==null ) {
// if any configs in previous dipped into outer context, that
@ -710,11 +698,9 @@ public class ParserATNSimulator extends ATNSimulator {
// code complexity.)
if ( debug ) System.out.println("RETRY with outerContext="+outerContext);
// don't look up context in cache now since we're just creating state D
loopsSimulateTailRecursion = true;
ATNConfigSet s0_closure =
computeStartState(dfa.atnStartState,
outerContext,
loopsSimulateTailRecursion,
true);
predictedAlt = execATNWithFullContext(dfa, D, s0_closure,
input, startIndex,
@ -805,7 +791,7 @@ public class ParserATNSimulator extends ATNSimulator {
// System.out.println("LL REACH "+getLookaheadName(input)+
// " from configs.size="+previous.size()+
// " line "+input.LT(1).getLine()+":"+input.LT(1).getCharPositionInLine());
reach = computeReachSet(previous, t, true, fullCtx);
reach = computeReachSet(previous, t, fullCtx);
if ( reach==null ) {
// if any configs in previous dipped into outer context, that
// means that input up to t actually finished entry rule
@ -873,14 +859,13 @@ public class ParserATNSimulator extends ATNSimulator {
// looking further.
if ( /* TODO: len(all subsets)>1 or input consistent with a subset with len=1 */ true ) {
reportAmbiguity(dfa, D, startIndex, input.index(), reach.conflictingAlts, reach);
reportAmbiguity(dfa, D, startIndex, input.index(), getConflictingAlts(reach), reach);
}
return getConflictingAlts(reach).nextSetBit(0);
}
protected ATNConfigSet computeReachSet(ATNConfigSet closure, int t,
boolean loopsSimulateTailRecursion,
boolean fullCtx)
{
if ( debug ) System.out.println("in computeReachSet, starting closure: " + closure);
@ -915,8 +900,7 @@ public class ParserATNSimulator extends ATNSimulator {
}
else {
for (ATNConfig c : intermediate) {
closure(c, reach, closureBusy, false,
loopsSimulateTailRecursion, fullCtx);
closure(c, reach, closureBusy, false, fullCtx);
}
}
@ -927,7 +911,6 @@ public class ParserATNSimulator extends ATNSimulator {
@NotNull
public ATNConfigSet computeStartState(@NotNull ATNState p,
@Nullable RuleContext ctx,
boolean loopsSimulateTailRecursion,
boolean fullCtx)
{
// always at least the implicit call to start rule
@ -938,8 +921,7 @@ public class ParserATNSimulator extends ATNSimulator {
ATNState target = p.transition(i).target;
ATNConfig c = new ATNConfig(target, i+1, initialContext);
Set<ATNConfig> closureBusy = new HashSet<ATNConfig>();
closure(c, configs, closureBusy, true,
loopsSimulateTailRecursion, fullCtx);
closure(c, configs, closureBusy, true, fullCtx);
}
return configs;
@ -1110,17 +1092,14 @@ public class ParserATNSimulator extends ATNSimulator {
ambig detection thought :(
*/
// TODO: loopsSimulateTailRecursion might not be necessary. seems slow without it. see what that is 12/29/11
protected void closure(@NotNull ATNConfig config,
@NotNull ATNConfigSet configs,
@NotNull Set<ATNConfig> closureBusy,
boolean collectPredicates,
boolean loopsSimulateTailRecursion,
boolean fullCtx)
{
final int initialDepth = 0;
closureCheckingStopStateAndLoopRecursion(config, configs, closureBusy, collectPredicates,
loopsSimulateTailRecursion,
fullCtx,
initialDepth);
}
@ -1129,7 +1108,6 @@ public class ParserATNSimulator extends ATNSimulator {
@NotNull ATNConfigSet configs,
@NotNull Set<ATNConfig> closureBusy,
boolean collectPredicates,
boolean loopsSimulateTailRecursion,
boolean fullCtx,
int depth)
{
@ -1147,7 +1125,7 @@ public class ParserATNSimulator extends ATNSimulator {
if ( debug ) System.out.println("FALLING off rule "+
getRuleName(config.state.ruleIndex));
closure_(config, configs, closureBusy, collectPredicates,
loopsSimulateTailRecursion, fullCtx, depth);
fullCtx, depth);
continue;
}
ATNState invokingState = atn.states.get(ctx.invokingState);
@ -1162,7 +1140,6 @@ public class ParserATNSimulator extends ATNSimulator {
c.reachesIntoOuterContext = config.reachesIntoOuterContext;
assert depth > Integer.MIN_VALUE;
closureCheckingStopStateAndLoopRecursion(c, configs, closureBusy, collectPredicates,
loopsSimulateTailRecursion,
fullCtx, depth - 1);
}
return;
@ -1173,29 +1150,9 @@ public class ParserATNSimulator extends ATNSimulator {
getRuleName(config.state.ruleIndex));
}
}
else if ( loopsSimulateTailRecursion ) {
if ( config.state.getClass()==StarLoopbackState.class ||
config.state.getClass()==PlusLoopbackState.class )
{
config.context =
SingletonPredictionContext.create(config.context, config.state.stateNumber);
// alter config; it's ok, since all calls to closure pass in a fresh config for us to chase
if ( debug ) System.out.println("Loop back; push "+config.state.stateNumber+", stack="+config.context);
}
else if ( config.state.getClass()==LoopEndState.class ) {
if ( debug ) System.out.print("Loop end; pop, stack=" + config.context);
LoopEndState end = (LoopEndState)config.state;
// pop all the way back until we don't see the loopback state anymore
int loopBackStateNumber = end.loopBackState.stateNumber;
config.context = config.context.popAll(loopBackStateNumber,
configs.fullCtx,
mergeCache);
if ( debug ) System.out.println(" becomes "+config.context);
}
}
closure_(config, configs, closureBusy, collectPredicates,
loopsSimulateTailRecursion, fullCtx, depth);
fullCtx, depth);
}
/** Do the actual work of walking epsilon edges */
@ -1203,7 +1160,6 @@ public class ParserATNSimulator extends ATNSimulator {
@NotNull ATNConfigSet configs,
@NotNull Set<ATNConfig> closureBusy,
boolean collectPredicates,
boolean loopsSimulateTailRecursion,
boolean fullCtx,
int depth)
{
@ -1248,7 +1204,6 @@ public class ParserATNSimulator extends ATNSimulator {
}
closureCheckingStopStateAndLoopRecursion(c, configs, closureBusy, continueCollecting,
loopsSimulateTailRecursion,
fullCtx, newDepth);
}
}

6
tool/playground/T.g
View File

@ -3,9 +3,9 @@ s : expr[0] ;
expr[int _p]
: ID
( {5 >= $_p}? '*' expr[6]
| {4 >= $_p}? '+' expr[5]
)*
( {5 >= $_p}? '*' expr[6]
| {4 >= $_p}? '+' expr[5]
)*
;
ID : [a-zA-Z]+ ; // match identifiers