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The ANTLR 4 grammar compiler.
/*
* [The "BSD license"]
* Copyright (c) 2012 Terence Parr
* Copyright (c) 2012 Sam Harwell
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.antlr.v4.automata;
import org.antlr.runtime.CommonToken;
import org.antlr.v4.codegen.CodeGenerator;
import org.antlr.v4.misc.CharSupport;
import org.antlr.v4.parse.ANTLRParser;
import org.antlr.v4.runtime.IntStream;
import org.antlr.v4.runtime.atn.ATN;
import org.antlr.v4.runtime.atn.ATNState;
import org.antlr.v4.runtime.atn.ActionTransition;
import org.antlr.v4.runtime.atn.AtomTransition;
import org.antlr.v4.runtime.atn.NotSetTransition;
import org.antlr.v4.runtime.atn.RangeTransition;
import org.antlr.v4.runtime.atn.RuleStartState;
import org.antlr.v4.runtime.atn.SetTransition;
import org.antlr.v4.runtime.atn.TokensStartState;
import org.antlr.v4.runtime.atn.Transition;
import org.antlr.v4.runtime.misc.Interval;
import org.antlr.v4.runtime.misc.IntervalSet;
import org.antlr.v4.tool.ErrorType;
import org.antlr.v4.tool.LexerGrammar;
import org.antlr.v4.tool.Rule;
import org.antlr.v4.tool.ast.ActionAST;
import org.antlr.v4.tool.ast.GrammarAST;
import org.antlr.v4.tool.ast.TerminalAST;
import org.stringtemplate.v4.ST;
import org.stringtemplate.v4.STGroup;
import java.util.List;
import java.util.Set;
public class LexerATNFactory extends ParserATNFactory {
public STGroup codegenTemplates;
public LexerATNFactory(LexerGrammar g) {
super(g);
// use codegen to get correct language templates for lexer commands
String language = g.getOptionString("language");
CodeGenerator gen = new CodeGenerator(g.tool, null, language);
codegenTemplates = gen.templates;
}
@Override
public ATN createATN() {
// BUILD ALL START STATES (ONE PER MODE)
Set modes = ((LexerGrammar) g).modes.keySet();
for (String modeName : modes) {
// create s0, start state; implied Tokens rule node
TokensStartState startState = newState(TokensStartState.class, null);
atn.defineMode(modeName, startState);
}
// INIT ACTION, RULE->TOKEN_TYPE MAP
atn.ruleToTokenType = new int[g.rules.size()];
atn.ruleToActionIndex = new int[g.rules.size()];
for (Rule r : g.rules.values()) {
atn.ruleToTokenType[r.index] = g.getTokenType(r.name);
atn.ruleToActionIndex[r.index] = r.actionIndex;
}
// CREATE ATN FOR EACH RULE
_createATN(g.rules.values());
// LINK MODE START STATE TO EACH TOKEN RULE
for (String modeName : modes) {
List rules = ((LexerGrammar)g).modes.get(modeName);
TokensStartState startState = atn.modeNameToStartState.get(modeName);
for (Rule r : rules) {
if ( !r.isFragment() ) {
RuleStartState s = atn.ruleToStartState[r.index];
epsilon(startState, s);
}
}
}
ATNOptimizer.optimize(g, atn);
return atn;
}
@Override
public Handle action(ActionAST action) {
ATNState left = newState(action);
ATNState right = newState(action);
boolean isCtxDependent = false;
int actionIndex = g.lexerActions.get(action);
ActionTransition a =
new ActionTransition(right, currentRule.index, actionIndex, isCtxDependent);
left.addTransition(a);
action.atnState = left;
Handle h = new Handle(left, right);
return h;
}
@Override
public Handle action(String action) {
// define action AST for this rule as if we had found in grammar
ActionAST ast = new ActionAST(new CommonToken(ANTLRParser.ACTION, action));
currentRule.defineActionInAlt(currentOuterAlt, ast);
return action(ast);
}
@Override
public Handle lexerAltCommands(Handle alt, Handle cmds) {
Handle h = new Handle(alt.left, cmds.right);
epsilon(alt.right, cmds.left);
return h;
}
@Override
public String lexerCallCommand(GrammarAST ID, GrammarAST arg) {
ST cmdST = codegenTemplates.getInstanceOf("Lexer" +
CharSupport.capitalize(ID.getText())+
"Command");
cmdST.add("arg", arg.getText());
return cmdST.render();
}
@Override
public String lexerCommand(GrammarAST ID) {
ST cmdST = codegenTemplates.getInstanceOf("Lexer" +
CharSupport.capitalize(ID.getText())+
"Command");
return cmdST.render();
}
@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);
}
@Override
public Handle set(GrammarAST associatedAST, List 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);
}
/** 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