| /******************************************************************************* |
| * Copyright (c) 2020 Fabrice TIERCELIN and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * Fabrice TIERCELIN - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.ui.fix; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.eclipse.core.runtime.CoreException; |
| |
| import org.eclipse.text.edits.TextEditGroup; |
| |
| import org.eclipse.jdt.core.ICompilationUnit; |
| import org.eclipse.jdt.core.dom.AST; |
| import org.eclipse.jdt.core.dom.ASTNode; |
| import org.eclipse.jdt.core.dom.ASTVisitor; |
| import org.eclipse.jdt.core.dom.Assignment; |
| import org.eclipse.jdt.core.dom.Block; |
| import org.eclipse.jdt.core.dom.ClassInstanceCreation; |
| import org.eclipse.jdt.core.dom.CompilationUnit; |
| import org.eclipse.jdt.core.dom.EnhancedForStatement; |
| import org.eclipse.jdt.core.dom.Expression; |
| import org.eclipse.jdt.core.dom.ForStatement; |
| import org.eclipse.jdt.core.dom.IfStatement; |
| import org.eclipse.jdt.core.dom.InfixExpression; |
| import org.eclipse.jdt.core.dom.MethodInvocation; |
| import org.eclipse.jdt.core.dom.PostfixExpression; |
| import org.eclipse.jdt.core.dom.PrefixExpression; |
| import org.eclipse.jdt.core.dom.SimpleName; |
| import org.eclipse.jdt.core.dom.Statement; |
| import org.eclipse.jdt.core.dom.SuperMethodInvocation; |
| import org.eclipse.jdt.core.dom.ThrowStatement; |
| import org.eclipse.jdt.core.dom.VariableDeclarationFragment; |
| import org.eclipse.jdt.core.dom.VariableDeclarationStatement; |
| import org.eclipse.jdt.core.dom.rewrite.ASTRewrite; |
| import org.eclipse.jdt.core.dom.rewrite.ListRewrite; |
| |
| import org.eclipse.jdt.internal.corext.dom.ASTNodes; |
| import org.eclipse.jdt.internal.corext.dom.InterruptibleVisitor; |
| import org.eclipse.jdt.internal.corext.dom.VarOccurrenceVisitor; |
| import org.eclipse.jdt.internal.corext.fix.CleanUpConstants; |
| import org.eclipse.jdt.internal.corext.fix.CompilationUnitRewriteOperationsFix; |
| import org.eclipse.jdt.internal.corext.fix.CompilationUnitRewriteOperationsFix.CompilationUnitRewriteOperation; |
| import org.eclipse.jdt.internal.corext.fix.LinkedProposalModel; |
| import org.eclipse.jdt.internal.corext.refactoring.structure.CompilationUnitRewrite; |
| |
| import org.eclipse.jdt.ui.cleanup.CleanUpRequirements; |
| import org.eclipse.jdt.ui.cleanup.ICleanUpFix; |
| import org.eclipse.jdt.ui.text.java.IProblemLocation; |
| |
| /** |
| * A fix that adds a break to avoid passive for loop iterations. |
| * |
| * The conditions of triggering are: |
| * <ul> |
| * <li>The structure of the code (for loop, including an if, including assignments)</li> |
| * <li>Two cases of reject: |
| * <ul> |
| * <li>The inner assignments should not do other different assignments in the future (assign other values or assign into other variables),</li> |
| * <li>No side effects after the first assignments.</li> |
| * </ul> |
| * </li> |
| * </ul> |
| */ |
| public class BreakLoopCleanUp extends AbstractMultiFix { |
| public BreakLoopCleanUp() { |
| this(Collections.emptyMap()); |
| } |
| |
| public BreakLoopCleanUp(Map<String, String> options) { |
| super(options); |
| } |
| |
| @Override |
| public CleanUpRequirements getRequirements() { |
| boolean requireAST= isEnabled(CleanUpConstants.BREAK_LOOP); |
| return new CleanUpRequirements(requireAST, false, false, null); |
| } |
| |
| @Override |
| public String[] getStepDescriptions() { |
| if (isEnabled(CleanUpConstants.BREAK_LOOP)) { |
| return new String[] { MultiFixMessages.BreakLoopCleanUp_description }; |
| } |
| |
| return new String[0]; |
| } |
| |
| @Override |
| public String getPreview() { |
| StringBuilder bld= new StringBuilder(); |
| bld.append("boolean isFound = false;\n"); //$NON-NLS-1$ |
| bld.append("for (int i = 0; i < number; i++) {\n"); //$NON-NLS-1$ |
| bld.append(" if (i == 42) {\n"); //$NON-NLS-1$ |
| bld.append(" isFound = true;\n"); //$NON-NLS-1$ |
| |
| if (isEnabled(CleanUpConstants.BREAK_LOOP)) { |
| bld.append(" break;\n"); //$NON-NLS-1$ |
| } |
| |
| bld.append(" }\n"); //$NON-NLS-1$ |
| bld.append("}\n"); //$NON-NLS-1$ |
| |
| if (!isEnabled(CleanUpConstants.BREAK_LOOP)) { |
| bld.append("\n"); //$NON-NLS-1$ |
| } |
| |
| return bld.toString(); |
| } |
| |
| @Override |
| protected ICleanUpFix createFix(CompilationUnit unit) throws CoreException { |
| if (!isEnabled(CleanUpConstants.BREAK_LOOP)) { |
| return null; |
| } |
| |
| final List<CompilationUnitRewriteOperation> rewriteOperations= new ArrayList<>(); |
| |
| unit.accept(new ASTVisitor() { |
| final class SideEffectVisitor extends InterruptibleVisitor { |
| private final Set<SimpleName> localVariableNames; |
| private boolean hasSideEffect; |
| |
| private SideEffectVisitor(final Set<SimpleName> localVariableNames) { |
| this.localVariableNames= localVariableNames; |
| } |
| |
| private boolean hasSideEffect() { |
| return hasSideEffect; |
| } |
| |
| @Override |
| public boolean visit(final Assignment node) { |
| if (!ASTNodes.hasOperator(node, Assignment.Operator.ASSIGN)) { |
| hasSideEffect= true; |
| return interruptVisit(); |
| } |
| |
| return visitVar(node.getLeftHandSide()); |
| } |
| |
| private boolean visitVar(final Expression modifiedVar) { |
| if (!(modifiedVar instanceof SimpleName)) { |
| hasSideEffect= true; |
| return interruptVisit(); |
| } |
| |
| boolean isFound= false; |
| |
| for (SimpleName localVariableName : localVariableNames) { |
| if (ASTNodes.isSameVariable(localVariableName, modifiedVar)) { |
| isFound= true; |
| break; |
| } |
| } |
| |
| if (!isFound) { |
| hasSideEffect= true; |
| return interruptVisit(); |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public boolean visit(final PrefixExpression node) { |
| if (ASTNodes.hasOperator(node, PrefixExpression.Operator.INCREMENT, PrefixExpression.Operator.DECREMENT)) { |
| return visitVar(node.getOperand()); |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public boolean visit(final PostfixExpression node) { |
| return visitVar(node.getOperand()); |
| } |
| |
| @Override |
| public boolean visit(final InfixExpression node) { |
| if (ASTNodes.hasOperator(node, InfixExpression.Operator.PLUS) && ASTNodes.hasType(node, String.class.getCanonicalName()) |
| && (mayCallImplicitToString(node.getLeftOperand()) |
| || mayCallImplicitToString(node.getRightOperand()) |
| || mayCallImplicitToString(node.extendedOperands()))) { |
| hasSideEffect= true; |
| return interruptVisit(); |
| } |
| |
| return true; |
| } |
| |
| private boolean mayCallImplicitToString(final List<Expression> extendedOperands) { |
| if (extendedOperands != null) { |
| for (Expression expression : extendedOperands) { |
| if (mayCallImplicitToString(expression)) { |
| return true; |
| } |
| } |
| } |
| |
| return false; |
| } |
| |
| private boolean mayCallImplicitToString(final Expression expression) { |
| return !ASTNodes.hasType(expression, String.class.getCanonicalName(), boolean.class.getSimpleName(), short.class.getSimpleName(), int.class.getSimpleName(), long.class.getSimpleName(), float.class.getSimpleName(), double.class.getSimpleName(), |
| Short.class.getCanonicalName(), Boolean.class.getCanonicalName(), Integer.class.getCanonicalName(), Long.class.getCanonicalName(), Float.class.getCanonicalName(), |
| Double.class.getCanonicalName()) && !(expression instanceof PrefixExpression) && !(expression instanceof InfixExpression) |
| && !(expression instanceof PostfixExpression); |
| } |
| |
| @Override |
| public boolean visit(final SuperMethodInvocation node) { |
| hasSideEffect= true; |
| return interruptVisit(); |
| } |
| |
| @Override |
| public boolean visit(final MethodInvocation node) { |
| hasSideEffect= true; |
| return interruptVisit(); |
| } |
| |
| @Override |
| public boolean visit(final ClassInstanceCreation node) { |
| hasSideEffect= true; |
| return interruptVisit(); |
| } |
| |
| @Override |
| public boolean visit(final ThrowStatement node) { |
| hasSideEffect= true; |
| return interruptVisit(); |
| } |
| } |
| |
| @Override |
| public boolean visit(final ForStatement node) { |
| Set<SimpleName> vars= new HashSet<>(); |
| |
| for (Expression initializer : (List<Expression>) node.initializers()) { |
| vars.addAll(ASTNodes.getLocalVariableIdentifiers(initializer, true)); |
| } |
| |
| if (node.getExpression() == null |
| || hasSideEffect(node.getExpression(), vars) |
| || node.updaters().isEmpty()) { |
| return true; |
| } |
| |
| for (Expression updater : (List<Expression>) node.updaters()) { |
| if (hasSideEffect(updater, vars)) { |
| return true; |
| } |
| } |
| |
| return visitLoopBody(node.getBody(), vars); |
| } |
| |
| private boolean hasSideEffect(final ASTNode node, final Set<SimpleName> allowedVars) { |
| SideEffectVisitor variableUseVisitor= new SideEffectVisitor(allowedVars); |
| variableUseVisitor.traverseNodeInterruptibly(node); |
| return variableUseVisitor.hasSideEffect(); |
| } |
| |
| @Override |
| public boolean visit(final EnhancedForStatement node) { |
| if (ASTNodes.isArray(node.getExpression())) { |
| Set<SimpleName> vars= new HashSet<>(); |
| vars.add(node.getParameter().getName()); |
| return visitLoopBody(node.getBody(), vars); |
| } |
| |
| return true; |
| } |
| |
| private boolean visitLoopBody(final Statement body, final Set<SimpleName> allowedVars) { |
| List<Statement> statements= ASTNodes.asList(body); |
| |
| if (statements == null || statements.isEmpty()) { |
| return true; |
| } |
| |
| for (int i= 0; i < statements.size() - 1; i++) { |
| Statement statement= statements.get(i); |
| allowedVars.addAll(ASTNodes.getLocalVariableIdentifiers(statement, true)); |
| |
| if (hasSideEffect(statement, allowedVars)) { |
| return true; |
| } |
| } |
| |
| IfStatement ifStatement= ASTNodes.as(statements.get(statements.size() - 1), IfStatement.class); |
| |
| if (ifStatement != null && ifStatement.getElseStatement() == null && !hasSideEffect(ifStatement.getExpression(), allowedVars)) { |
| List<Statement> assignments= ASTNodes.asList(ifStatement.getThenStatement()); |
| |
| if (areAssignmentsValid(allowedVars, assignments)) { |
| rewriteOperations.add(new BreakLoopOperation(ifStatement)); |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| private boolean areAssignmentsValid(final Set<SimpleName> allowedVars, final List<Statement> assignments) { |
| if (assignments.isEmpty()) { |
| return false; |
| } |
| |
| for (Statement statement : assignments) { |
| VariableDeclarationStatement variableDeclaration= ASTNodes.as(statement, VariableDeclarationStatement.class); |
| Assignment assignment= ASTNodes.asExpression(statement, Assignment.class); |
| |
| if (variableDeclaration != null) { |
| for (Object obj : variableDeclaration.fragments()) { |
| VariableDeclarationFragment fragment= (VariableDeclarationFragment) obj; |
| |
| if (!ASTNodes.isHardCoded(fragment.getInitializer())) { |
| return false; |
| } |
| } |
| } else if (assignment != null |
| && ASTNodes.hasOperator(assignment, Assignment.Operator.ASSIGN) |
| && ASTNodes.isHardCoded(assignment.getRightHandSide()) |
| && ASTNodes.isPassive(assignment.getLeftHandSide())) { |
| VarOccurrenceVisitor varOccurrenceVisitor= new VarOccurrenceVisitor(allowedVars, true); |
| varOccurrenceVisitor.traverseNodeInterruptibly(assignment.getLeftHandSide()); |
| |
| if (varOccurrenceVisitor.isVarUsed()) { |
| return false; |
| } |
| } else { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| }); |
| |
| if (rewriteOperations.isEmpty()) { |
| return null; |
| } |
| |
| return new CompilationUnitRewriteOperationsFix(MultiFixMessages.BreakLoopCleanUp_description, unit, |
| rewriteOperations.toArray(new CompilationUnitRewriteOperation[0])); |
| } |
| |
| @Override |
| public boolean canFix(final ICompilationUnit compilationUnit, final IProblemLocation problem) { |
| return false; |
| } |
| |
| @Override |
| protected ICleanUpFix createFix(final CompilationUnit unit, final IProblemLocation[] problems) throws CoreException { |
| return null; |
| } |
| |
| private static class BreakLoopOperation extends CompilationUnitRewriteOperation { |
| private final IfStatement ifStatement; |
| |
| public BreakLoopOperation(final IfStatement ifStatement) { |
| this.ifStatement= ifStatement; |
| } |
| |
| @Override |
| public void rewriteAST(final CompilationUnitRewrite cuRewrite, final LinkedProposalModel linkedModel) throws CoreException { |
| ASTRewrite rewrite= cuRewrite.getASTRewrite(); |
| AST ast= cuRewrite.getRoot().getAST(); |
| TextEditGroup group= createTextEditGroup(MultiFixMessages.BreakLoopCleanUp_description, cuRewrite); |
| |
| if (ifStatement.getThenStatement() instanceof Block) { |
| ListRewrite listRewrite= rewrite.getListRewrite(ifStatement.getThenStatement(), Block.STATEMENTS_PROPERTY); |
| listRewrite.insertLast(ast.newBreakStatement(), group); |
| } else { |
| Block newBlock= ast.newBlock(); |
| newBlock.statements().add(ASTNodes.createMoveTarget(rewrite, ifStatement.getThenStatement())); |
| newBlock.statements().add(ast.newBreakStatement()); |
| ASTNodes.replaceButKeepComment(rewrite, ifStatement.getThenStatement(), newBlock, group); |
| } |
| } |
| } |
| } |