rtaneja1 commented on a change in pull request #1081: [NETBEANS-1675]Java Hint to fix error :different case kinds used in the switch in switch expressions URL: https://github.com/apache/incubator-netbeans/pull/1081#discussion_r246718181
########## File path: java/java.hints/src/org/netbeans/modules/java/hints/errors/ConvertToRuleSwitch.java ########## @@ -0,0 +1,336 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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.netbeans.modules.java.hints.errors; + +import com.sun.source.tree.AssignmentTree; +import com.sun.source.tree.BlockTree; +import com.sun.source.tree.BreakTree; +import com.sun.source.tree.CaseTree; +import com.sun.source.tree.ClassTree; +import com.sun.source.tree.ContinueTree; +import com.sun.source.tree.ExpressionStatementTree; +import com.sun.source.tree.ExpressionTree; +import com.sun.source.tree.IdentifierTree; +import com.sun.source.tree.IfTree; +import com.sun.source.tree.LambdaExpressionTree; +import com.sun.source.tree.ReturnTree; +import com.sun.source.tree.StatementTree; +import com.sun.source.tree.SwitchTree; +import com.sun.source.tree.ThrowTree; +import com.sun.source.tree.Tree; +import com.sun.source.util.TreePath; +import com.sun.source.util.TreePathScanner; +import com.sun.tools.javac.tree.JCTree.JCCase; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collections; +import java.util.EnumSet; +import java.util.HashSet; +import java.util.Iterator; +import java.util.List; +import java.util.Set; +import javax.lang.model.element.Element; +import javax.lang.model.element.Modifier; +import javax.lang.model.element.VariableElement; +import javax.tools.Diagnostic; +import org.netbeans.api.java.queries.CompilerOptionsQuery; +import org.netbeans.api.java.source.CompilationInfo; +import org.netbeans.api.java.source.TreeMaker; +import org.netbeans.api.java.source.WorkingCopy; +import org.netbeans.modules.java.hints.TreeShims; +import org.netbeans.modules.java.hints.spi.ErrorRule; +import org.netbeans.spi.editor.hints.Fix; +import org.netbeans.spi.java.hints.JavaFix; +import org.netbeans.spi.java.hints.JavaFix.TransformationContext; +import org.openide.util.NbBundle; + +/** + * Handle error rule "compiler.err.switch.mixing.case.types" and provide the + * fix. + * + * @author vkprabha + */ +public class ConvertToRuleSwitch implements ErrorRule<Void> { + + private static final Set<String> ERROR_CODES = new HashSet<String>(Arrays.asList( + "compiler.err.switch.mixing.case.types")); // NOI18N + + @Override + public Set<String> getCodes() { + return Collections.unmodifiableSet(ERROR_CODES); + } + + @Override + public List<Fix> run(CompilationInfo info, String diagnosticKey, int offset, TreePath treePath, Data<Void> data) { + if (!CompilerOptionsQuery.getOptions(info.getFileObject()).getArguments().contains("--enable-preview")) { + return null; + } + SwitchTree st = (SwitchTree) treePath.getParentPath().getLeaf(); + boolean completesNormally = false; + boolean wasDefault = false; + boolean wasEmpty = false; + for (CaseTree ct : st.getCases()) { + if (ct.getStatements() == null && !(ct instanceof JCCase && ((JCCase) ct).stats != null)) { //TODO: test + return null; + } else if (ct.getStatements() != null) { + if (completesNormally) { + if (!wasEmpty) {//fall-through from a non-empty case + return null; + } + if (wasDefault) {//fall-through from default to a case + return null; + } + if (!wasDefault && ct.getExpression() == null) {//fall-through from a case to default + return null; + } + } + completesNormally = completesNormally(info, new TreePath(treePath.getParentPath(), ct)); + wasDefault = ct.getExpression() == null; + wasEmpty = ct.getStatements().isEmpty(); + } + } + + return Collections.<Fix>singletonList(new ConvertToRuleSwitch.FixImpl(info, treePath).toEditorFix()); + } + + private static boolean completesNormally(CompilationInfo info, TreePath tp) { + class Scanner extends TreePathScanner<Void, Void> { + + private boolean completesNormally = true; + private Set<Tree> seenTrees = new HashSet<>(); + + @Override + public Void visitReturn(ReturnTree node, Void p) { + completesNormally = false; + return null; + } + + @Override + public Void visitBreak(BreakTree node, Void p) { + completesNormally &= seenTrees.contains(info.getTreeUtilities().getBreakContinueTarget(getCurrentPath())); + return null; + } + + @Override + public Void visitContinue(ContinueTree node, Void p) { + completesNormally &= seenTrees.contains(info.getTreeUtilities().getBreakContinueTarget(getCurrentPath())); + return null; + } + + @Override + public Void visitThrow(ThrowTree node, Void p) { + completesNormally = false; + return null; + } + + @Override + public Void visitIf(IfTree node, Void p) { + boolean origCompletesNormally = completesNormally; + scan(node.getThenStatement(), p); + boolean afterThen = completesNormally; + completesNormally = origCompletesNormally; + scan(node.getElseStatement(), p); + completesNormally |= afterThen; + return null; + } + + @Override + public Void visitSwitch(SwitchTree node, Void p) { + //exhaustiveness: (TODO) + boolean hasDefault = node.getCases().stream().anyMatch(c -> c.getExpression() == null); + if (node.getCases().size() > 0) { + scan(node.getCases().get(node.getCases().size() - 1), p); + } + completesNormally |= !hasDefault; + return null; + } + + //TODO: loops + @Override + public Void scan(Tree tree, Void p) { + seenTrees.add(tree); + return super.scan(tree, p); + } + + @Override + public Void visitLambdaExpression(LambdaExpressionTree node, Void p) { + return null; + } + + @Override + public Void visitClass(ClassTree node, Void p) { + return null; + } + } + + Scanner scanner = new Scanner(); + + scanner.scan(tp, null); + return scanner.completesNormally; + } + + @Override + public String getId() { + return ConvertToRuleSwitch.class.getName(); + } + + @Override + public String getDisplayName() { + return NbBundle.getMessage(ConvertToRuleSwitch.class, "FIX_SWITCH_MIX_CASE"); // NOI18N + } + + public String getDescription() { + return NbBundle.getMessage(ConvertToRuleSwitch.class, "FIX_SWITCH_MIX_CASE"); // NOI18N + } + + @Override + public void cancel() { + } + + private static final class FixImpl extends JavaFix { + + CompilationInfo info; + TreePath path; + + public FixImpl(CompilationInfo info, TreePath path) { + super(info, path); + this.info = info; + this.path = path; + } + + @Override + protected String getText() { + return NbBundle.getMessage(ConvertToRuleSwitch.class, "FIX_SWITCH_MIX_CASE"); // NOI18N + } + + public String toDebugString() { + return NbBundle.getMessage(ConvertToRuleSwitch.class, "FIX_SWITCH_MIX_CASE"); // NOI18N + } + + @Override + protected void performRewrite(TransformationContext ctx) { + TreePath tp = ctx.getPath(); + Tree switchBlock = tp.getParentPath().getLeaf(); + if (switchBlock instanceof SwitchTree) { + SwitchTree st = (SwitchTree) switchBlock; + handleSwitchTree(ctx, tp, st); + }//else if Handle SwitchExpressionTree using reflexon Review comment: Is this comment required? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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