@NotNull
public ATNState newState(@Nullable GrammarAST node) {
ATNState n = new BasicState();
n.setRuleIndex(currentRule.index);
atn.addState(n);
return n;
}
@NotNull
public Handle _ruleRef(@NotNull GrammarAST node) {
Rule r = g.getRule(node.getText());
if (r == null) {
g.tool.errMgr.toolError(ErrorType.INTERNAL_ERROR, "Rule " + node.getText() + " undefined");
return null;
}
RuleStartState start = atn.ruleToStartState[r.index];
ATNState left = newState(node);
ATNState right = newState(node);
int precedence = 0;
if (((GrammarASTWithOptions) node)
.getOptionString(LeftRecursiveRuleTransformer.PRECEDENCE_OPTION_NAME)
!= null) {
precedence =
Integer.parseInt(
((GrammarASTWithOptions) node)
.getOptionString(LeftRecursiveRuleTransformer.PRECEDENCE_OPTION_NAME));
}
RuleTransition call = new RuleTransition(start, r.index, precedence, right);
left.addTransition(call);
node.atnState = left;
return new Handle(left, right);
}
/**
* Checks whether or not {@code symbol} can follow the current state in the ATN. The behavior of
* this method is equivalent to the following, but is implemented such that the complete
* context-sensitive follow set does not need to be explicitly constructed.
*
* <pre>
* return getExpectedTokens().contains(symbol);
* </pre>
*
* @param symbol the symbol type to check
* @return {@code true} if {@code symbol} can follow the current state in the ATN, otherwise
* {@code false}.
*/
public boolean isExpectedToken(int symbol) {
// return getInterpreter().atn.nextTokens(_ctx);
ATN atn = getInterpreter().atn;
ParserRuleContext ctx = _ctx;
ATNState s = atn.states.get(getState());
IntervalSet following = atn.nextTokens(s);
if (following.contains(symbol)) {
return true;
}
// System.out.println("following "+s+"="+following);
if (!following.contains(Token.EPSILON)) return false;
while (ctx != null && ctx.invokingState >= 0 && following.contains(Token.EPSILON)) {
ATNState invokingState = atn.states.get(ctx.invokingState);
RuleTransition rt = (RuleTransition) invokingState.transition(0);
following = atn.nextTokens(rt.followState);
if (following.contains(symbol)) {
return true;
}
ctx = (ParserRuleContext) ctx.parent;
}
if (following.contains(Token.EPSILON) && symbol == Token.EOF) {
return true;
}
return false;
}
/** Build an atom with all possible values in its label */
@NotNull
public Handle wildcard(GrammarAST node) {
ATNState left = newState(node);
ATNState right = newState(node);
left.addTransition(new WildcardTransition(right));
node.atnState = left;
return new Handle(left, right);
}
/** From label A build Graph o-A->o */
public Handle tokenRef(TerminalAST node) {
ATNState left = newState(node);
ATNState right = newState(node);
int ttype = g.getTokenType(node.getText());
left.addTransition(new AtomTransition(right, ttype));
node.atnState = left;
return new Handle(left, right);
}
/** [Aa\t \u1234a-z\]\-] char sets */
@Override
public Handle charSetLiteral(GrammarAST charSetAST) {
ATNState left = newState(charSetAST);
ATNState right = newState(charSetAST);
IntervalSet set = getSetFromCharSetLiteral(charSetAST);
left.addTransition(new SetTransition(right, set));
charSetAST.atnState = left;
return new Handle(left, right);
}
/**
* Build what amounts to an epsilon transition with an action. The action goes into ATN though it
* is ignored during prediction if actionIndex < 0. Only forced are executed during prediction.
*/
public Handle action(ActionAST action) {
// System.out.println("action: "+action);
ATNState left = newState(action);
ATNState right = newState(action);
ActionTransition a = new ActionTransition(right, currentRule.index);
left.addTransition(a);
action.atnState = left;
return new Handle(left, right);
}
public void addRuleFollowLinks() {
for (ATNState p : atn.states) {
if (p != null
&& p.getStateType() == ATNState.BASIC
&& p.getNumberOfTransitions() == 1
&& p.transition(0) instanceof RuleTransition) {
RuleTransition rt = (RuleTransition) p.transition(0);
addFollowLink(rt.ruleIndex, rt.followState);
}
}
}
/**
* Build what amounts to an epsilon transition with a semantic predicate action. The pred is a
* pointer into the AST of the SEMPRED token.
*/
public Handle sempred(PredAST pred) {
// System.out.println("sempred: "+ pred);
ATNState left = newState(pred);
ATNState right = newState(pred);
boolean isCtxDependent = UseDefAnalyzer.actionIsContextDependent(pred);
PredicateTransition p =
new PredicateTransition(right, currentRule.index, g.sempreds.get(pred), isCtxDependent);
left.addTransition(p);
pred.atnState = left;
return new Handle(left, right);
}
@Override
public Handle tokenRef(TerminalAST node) {
// Ref to EOF in lexer yields char transition on -1
if (node.getText().equals("EOF")) {
ATNState left = newState(node);
ATNState right = newState(node);
left.addTransition(new AtomTransition(right, IntStream.EOF));
return new Handle(left, right);
}
return _ruleRef(node);
}
@Override
public Handle range(GrammarAST a, GrammarAST b) {
ATNState left = newState(a);
ATNState right = newState(b);
int t1 = CharSupport.getCharValueFromGrammarCharLiteral(a.getText());
int t2 = CharSupport.getCharValueFromGrammarCharLiteral(b.getText());
left.addTransition(new RangeTransition(right, t1, t2));
a.atnState = left;
b.atnState = left;
return new Handle(left, right);
}
/**
* Add an EOF transition to any rule end ATNState that points to nothing (i.e., for all those
* rules not invoked by another rule). These are start symbols then.
*
* <p>Return the number of grammar entry points; i.e., how many rules are not invoked by another
* rule (they can only be invoked from outside). These are the start rules.
*/
public int addEOFTransitionToStartRules() {
int n = 0;
ATNState eofTarget = newState(null); // one unique EOF target for all rules
for (Rule r : g.rules.values()) {
ATNState stop = atn.ruleToStopState[r.index];
if (stop.getNumberOfTransitions() > 0) continue;
n++;
Transition t = new AtomTransition(eofTarget, Token.EOF);
stop.addTransition(t);
}
return n;
}
protected Handle action(GrammarAST node, LexerAction lexerAction) {
ATNState left = newState(node);
ATNState right = newState(node);
boolean isCtxDependent = false;
int lexerActionIndex = getLexerActionIndex(lexerAction);
ActionTransition a =
new ActionTransition(right, currentRule.index, lexerActionIndex, isCtxDependent);
left.addTransition(a);
node.atnState = left;
Handle h = new Handle(left, right);
return h;
}
public Handle _ruleRef(GrammarAST node) {
Rule r = g.getRule(node.getText());
if (r == null) {
g.tool.errMgr.toolError(ErrorType.INTERNAL_ERROR, "Rule " + node.getText() + " undefined");
return null;
}
RuleStartState start = atn.ruleToStartState[r.index];
ATNState left = newState(node);
ATNState right = newState(node);
RuleTransition call = new RuleTransition(start, r.index, right);
left.addTransition(call);
node.atnState = left;
return new Handle(left, right);
}
/**
* For a lexer, a string is a sequence of char to match. That is, "fog" is treated as 'f' 'o' 'g'
* not as a single transition in the DFA. Machine== o-'f'->o-'o'->o-'g'->o and has n+1
* states for n characters.
*/
@Override
public Handle stringLiteral(TerminalAST stringLiteralAST) {
String chars = stringLiteralAST.getText();
chars = CharSupport.getStringFromGrammarStringLiteral(chars);
int n = chars.length();
ATNState left = newState(stringLiteralAST);
ATNState prev = left;
ATNState right = null;
for (int i = 0; i < n; i++) {
right = newState(stringLiteralAST);
prev.addTransition(new AtomTransition(right, chars.charAt(i)));
prev = right;
}
stringLiteralAST.atnState = left;
return new Handle(left, right);
}
/**
* From set build single edge graph o->o-set->o. To conform to what an alt block looks like, must
* have extra state on left. This handles ~A also, converted to ~{A} set.
*/
public Handle set(GrammarAST associatedAST, List<GrammarAST> terminals, boolean invert) {
ATNState left = newState(associatedAST);
ATNState right = newState(associatedAST);
IntervalSet set = new IntervalSet();
for (GrammarAST t : terminals) {
int ttype = g.getTokenType(t.getText());
set.add(ttype);
}
if (invert) {
IntervalSet notSet = set.complement(Token.MIN_TOKEN_TYPE, g.getMaxTokenType());
left.addTransition(new NotSetTransition(right, set, notSet));
} else {
left.addTransition(new SetTransition(right, set));
}
associatedAST.atnState = left;
return new Handle(left, right);
}
/**
* From set build single edge graph {@code o->o-set->o}. To conform to what an alt block looks
* like, must have extra state on left. This also handles {@code ~A}, converted to {@code ~{A}}
* set.
*/
@NotNull
@Override
public Handle set(
@NotNull GrammarAST associatedAST, @NotNull List<GrammarAST> terminals, boolean invert) {
ATNState left = newState(associatedAST);
ATNState right = newState(associatedAST);
IntervalSet set = new IntervalSet();
for (GrammarAST t : terminals) {
int ttype = g.getTokenType(t.getText());
set.add(ttype);
}
if (invert) {
left.addTransition(new NotSetTransition(right, set));
} else {
left.addTransition(new SetTransition(right, set));
}
associatedAST.atnState = left;
return new Handle(left, right);
}
List<ANTLRMessage> checkRuleDFA(String gtext, String ruleName, String expecting)
throws Exception {
ErrorQueue equeue = new ErrorQueue();
Grammar g = new Grammar(gtext, equeue);
ATN atn = createATN(g);
ATNState s = atn.ruleToStartState[g.getRule(ruleName).index];
if (s == null) {
System.err.println("no such rule: " + ruleName);
return null;
}
ATNState t = s.transition(0).target;
if (!(t instanceof DecisionState)) {
System.out.println(ruleName + " has no decision");
return null;
}
DecisionState blk = (DecisionState) t;
checkRuleDFA(g, blk, expecting);
return equeue.all;
}
@Override
public Handle set(GrammarAST associatedAST, List<GrammarAST> alts, boolean invert) {
ATNState left = newState(associatedAST);
ATNState right = newState(associatedAST);
IntervalSet set = new IntervalSet();
for (GrammarAST t : alts) {
if (t.getType() == ANTLRParser.RANGE) {
int a = CharSupport.getCharValueFromGrammarCharLiteral(t.getChild(0).getText());
int b = CharSupport.getCharValueFromGrammarCharLiteral(t.getChild(1).getText());
set.add(a, b);
} else if (t.getType() == ANTLRParser.LEXER_CHAR_SET) {
set.addAll(getSetFromCharSetLiteral(t));
} else if (t.getType() == ANTLRParser.STRING_LITERAL) {
int c = CharSupport.getCharValueFromGrammarCharLiteral(t.getText());
if (c != -1) {
set.add(c);
} else {
g.tool.errMgr.grammarError(
ErrorType.INVALID_LITERAL_IN_LEXER_SET, g.fileName, t.getToken(), t.getText());
}
} else if (t.getType() == ANTLRParser.TOKEN_REF) {
g.tool.errMgr.grammarError(
ErrorType.UNSUPPORTED_REFERENCE_IN_LEXER_SET, g.fileName, t.getToken(), t.getText());
}
}
if (invert) {
left.addTransition(new NotSetTransition(right, set));
} else {
Transition transition;
if (set.getIntervals().size() == 1) {
Interval interval = set.getIntervals().get(0);
transition = new RangeTransition(right, interval.a, interval.b);
} else {
transition = new SetTransition(right, set);
}
left.addTransition(transition);
}
associatedAST.atnState = left;
return new Handle(left, right);
}
/**
* Build what amounts to an epsilon transition with a semantic predicate action. The {@code pred}
* is a pointer into the AST of the {@link ANTLRParser#SEMPRED} token.
*/
@Override
public Handle sempred(PredAST pred) {
// System.out.println("sempred: "+ pred);
ATNState left = newState(pred);
ATNState right = newState(pred);
AbstractPredicateTransition p;
if (pred.getOptionString(LeftRecursiveRuleTransformer.PRECEDENCE_OPTION_NAME) != null) {
int precedence =
Integer.parseInt(
pred.getOptionString(LeftRecursiveRuleTransformer.PRECEDENCE_OPTION_NAME));
p = new PrecedencePredicateTransition(right, precedence);
} else {
boolean isCtxDependent = UseDefAnalyzer.actionIsContextDependent(pred);
p = new PredicateTransition(right, currentRule.index, g.sempreds.get(pred), isCtxDependent);
}
left.addTransition(p);
pred.atnState = left;
return new Handle(left, right);
}
@Override
public void visitState(ATNState p) {
if (p.getClass() == ATNState.class && p.getNumberOfTransitions() == 1) {
ATNState q = p.transition(0).target;
if (p.transition(0) instanceof RuleTransition) {
q = ((RuleTransition) p.transition(0)).followState;
}
if (q.getClass() == ATNState.class) {
// we have p-x->q for x in {rule, action, pred, token, ...}
// if edge out of q is single epsilon to block end
// we can strip epsilon p-x->q-eps->r
Transition trans = q.transition(0);
if (q.getNumberOfTransitions() == 1
&& trans.isEpsilon()
&& !(trans instanceof ActionTransition)) {
ATNState r = trans.target;
if (r instanceof BlockEndState
|| r instanceof PlusLoopbackState
|| r instanceof StarLoopbackState) {
// skip over q
if (p.transition(0) instanceof RuleTransition) {
((RuleTransition) p.transition(0)).followState = r;
} else {
p.transition(0).target = r;
}
atn.removeState(q);
}
}
}
}
}
void epsilon(ATNState a, @NotNull ATNState b) {
if (a != null) a.addTransition(new EpsilonTransition(b));
}
protected void epsilon(ATNState a, @NotNull ATNState b, boolean prepend) {
if (a != null) {
int index = prepend ? 0 : a.getNumberOfTransitions();
a.addTransition(index, new EpsilonTransition(b));
}
}