/*
* Copyright 2011-2014 Gregory Shrago
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.intellij.grammar.inspection;
import com.intellij.codeInspection.*;
import com.intellij.psi.PsiFile;
import org.intellij.grammar.analysis.BnfFirstNextAnalyzer;
import org.intellij.grammar.generator.ExpressionGeneratorHelper;
import org.intellij.grammar.generator.ExpressionHelper;
import org.intellij.grammar.psi.BnfFile;
import org.intellij.grammar.psi.BnfRule;
import org.jetbrains.annotations.Nls;
import org.jetbrains.annotations.NotNull;
import java.util.ArrayList;
/**
* @author gregsh
*/
public class BnfLeftRecursionInspection extends LocalInspectionTool {
@Nls
@NotNull
@Override
public String getGroupDisplayName() {
return "Grammar/BNF";
}
@Nls
@NotNull
@Override
public String getDisplayName() {
return "Left recursion";
}
@NotNull
@Override
public String getShortName() {
return "BnfLeftRecursionInspection";
}
public boolean isEnabledByDefault() {
return true;
}
public ProblemDescriptor[] checkFile(@NotNull PsiFile file, @NotNull InspectionManager manager, boolean isOnTheFly) {
if (file instanceof BnfFile) {
BnfFile bnfFile = (BnfFile)file;
ExpressionHelper expressionHelper = ExpressionHelper.getCached(bnfFile);
BnfFirstNextAnalyzer analyzer = new BnfFirstNextAnalyzer();
ArrayList<ProblemDescriptor> list = new ArrayList<ProblemDescriptor>();
for (BnfRule rule : bnfFile.getRules()) {
String ruleName = rule.getName();
boolean exprParsing = ExpressionGeneratorHelper.getInfoForExpressionParsing(expressionHelper, rule) != null;
if (!exprParsing && analyzer.asStrings(analyzer.calcFirst(rule)).contains(ruleName)) {
list.add(manager.createProblemDescriptor(rule.getId(), "'" + ruleName + "' employs left-recursion unsupported by generator",
isOnTheFly, LocalQuickFix.EMPTY_ARRAY, ProblemHighlightType.GENERIC_ERROR_OR_WARNING));
}
}
if (!list.isEmpty()) return list.toArray(new ProblemDescriptor[list.size()]);
}
return ProblemDescriptor.EMPTY_ARRAY;
}
}