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Posted to notifications@netbeans.apache.org by GitBox <gi...@apache.org> on 2019/01/10 11:06:21 UTC
[GitHub] 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
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_r246709273
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File path: java/java.hints/src/org/netbeans/modules/java/hints/errors/ConvertToRuleSwitch.java
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@@ -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
+
+ }
+
+ }
+
+ private static void handleSwitchTree(TransformationContext ctx, TreePath tp, SwitchTree st) {
+ WorkingCopy wc = ctx.getWorkingCopy();
+ TreeMaker make = wc.getTreeMaker();
+ List<CaseTree> newCases = new ArrayList<>();
+ List<ExpressionTree> patterns = new ArrayList<>();
+ Set<VariableElement> variablesDeclaredInOtherCases = new HashSet<>();
+
+ for (Iterator<? extends CaseTree> it = st.getCases().iterator(); it.hasNext();) {
+ CaseTree ct = it.next();
+ TreePath casePath = new TreePath(tp, ct);
+ patterns.addAll(TreeShims.getExpressions(ct));
+ List<? extends StatementTree> statements = null;
+ if (ct.getStatements() == null) {
+ statements = ((JCCase) ct).stats;
+ } else {
+ statements = new ArrayList<>(ct.getStatements());
+ }
+ if (statements.isEmpty()) {
+ if (it.hasNext()) {
+ continue;
+ }
+ //last case, no break
+ } else if (statements.get(statements.size() - 1).getKind() == Tree.Kind.BREAK
+ && ctx.getWorkingCopy().getTreeUtilities().getBreakContinueTarget(new TreePath(new TreePath(tp, ct), statements.get(statements.size() - 1))) == st) {
+ statements.remove(statements.size() - 1);
+ } else {
+ new TreePathScanner<Void, Void>() {
+ @Override
+ public Void visitBlock(BlockTree node, Void p) {
+ if (!node.getStatements().isEmpty()
+ && node.getStatements().get(node.getStatements().size() - 1).getKind() == Tree.Kind.BREAK
+ && ctx.getWorkingCopy().getTreeUtilities().getBreakContinueTarget(new TreePath(getCurrentPath(), node.getStatements().get(node.getStatements().size() - 1))) == st) {
+ wc.rewrite(node, make.removeBlockStatement(node, node.getStatements().get(node.getStatements().size() - 1)));
+ //TODO: optimize ifs?
+ }
+ return super.visitBlock(node, p);
+ }
+ }.scan(new TreePath(new TreePath(tp, ct), statements.get(statements.size() - 1)), null);
+ }
+ Set<Element> seenVariables = new HashSet<>();
+ int idx = 0;
+ for (StatementTree statement : new ArrayList<>(statements)) {
+ TreePath statementPath = new TreePath(casePath, statement);
+ if (statement.getKind() == Tree.Kind.EXPRESSION_STATEMENT) {
+ ExpressionTree expr = ((ExpressionStatementTree) statement).getExpression();
+ if (expr.getKind() == Tree.Kind.ASSIGNMENT) {
+ AssignmentTree at = (AssignmentTree) expr;
+ Element var = wc.getTrees().getElement(new TreePath(new TreePath(statementPath, at), at.getVariable()));
+ if (variablesDeclaredInOtherCases.contains(var)) {
+ seenVariables.add(var);
+ //XXX: take type from the original variable
+ wc.rewrite(statement,
+ make.Variable(make.Modifiers(EnumSet.noneOf(Modifier.class)), var.getSimpleName(), make.Type(var.asType()), at.getExpression()));
+ }
+ }
+ }
+ Set<Element> thisStatementSeenVariables = new HashSet<>();
+ new TreePathScanner<Void, Void>() {
+ @Override
+ public Void visitIdentifier(IdentifierTree node, Void p) {
+ Element el = wc.getTrees().getElement(getCurrentPath());
+ if (variablesDeclaredInOtherCases.contains(el) && seenVariables.add(el)) {
+ thisStatementSeenVariables.add(el);
+ }
+ return super.visitIdentifier(node, p);
+ }
+ }.scan(statementPath, null);
+
+// Todo : Need to check the use case
+// if (!thisStatementSeenVariables.isEmpty()) {
+// for (Element el : thisStatementSeenVariables) {
+// VariableElement var = (VariableElement) el;
+// statements.add(idx++, make.Variable(make.Modifiers(EnumSet.noneOf(Modifier.class)), var.getSimpleName(), make.Type(var.asType()), null));
+// }
+// }
+ idx++;
+ }
+ Tree body = make.Block(statements, false);
+ if (statements.size() == 1) {
+ if (statements.get(0).getKind() == Tree.Kind.EXPRESSION_STATEMENT
+ || statements.get(0).getKind() == Tree.Kind.THROW
+ || statements.get(0).getKind() == Tree.Kind.BLOCK) {
+ body = statements.get(0);
+ }
+ }
+ newCases.add(make.Case(patterns, body));
+ patterns = new ArrayList<>();
+ for (StatementTree statement : ct.getStatements()) {
Review comment:
check formatting
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