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    1   /*
    2    $Id: VariableScopeCodeVisitor.java,v 1.10 2004/04/01 06:21:53 cpoirier Exp $
    3
    4    Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
    5
    6    Redistribution and use of this software and associated documentation
    7    ("Software"), with or without modification, are permitted provided
    8    that the following conditions are met:
    9
    10   1. Redistributions of source code must retain copyright
    11      statements and notices.  Redistributions must also contain a
    12      copy of this document.
    13
    14   2. Redistributions in binary form must reproduce the
    15      above copyright notice, this list of conditions and the
    16      following disclaimer in the documentation and/or other
    17      materials provided with the distribution.
    18
    19   3. The name "groovy" must not be used to endorse or promote
    20      products derived from this Software without prior written
    21      permission of The Codehaus.  For written permission,
    22      please contact info@codehaus.org.
    23
    24   4. Products derived from this Software may not be called "groovy"
    25      nor may "groovy" appear in their names without prior written
    26      permission of The Codehaus. "groovy" is a registered
    27      trademark of The Codehaus.
    28
    29   5. Due credit should be given to The Codehaus -
    30      http://groovy.codehaus.org/
    31
    32   THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
    33   ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
    34   NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
    35   FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
    36   THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
    37   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    38   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    39   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    40   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    41   STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    42   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
    43   OF THE POSSIBILITY OF SUCH DAMAGE.
    44
    45   */
    46  package org.codehaus.groovy.classgen;
    47
    48  import java.util.Set;
    49
    50  import org.codehaus.groovy.ast.CodeVisitorSupport;
    51  import org.codehaus.groovy.ast.Parameter;
    52  import org.codehaus.groovy.ast.VariableScope;
    53  import org.codehaus.groovy.ast.expr.BinaryExpression;
    54  import org.codehaus.groovy.ast.expr.ClosureExpression;
    55  import org.codehaus.groovy.ast.expr.Expression;
    56  import org.codehaus.groovy.ast.expr.MethodCallExpression;
    57  import org.codehaus.groovy.ast.expr.PostfixExpression;
    58  import org.codehaus.groovy.ast.expr.PrefixExpression;
    59  import org.codehaus.groovy.ast.expr.VariableExpression;
    60  import org.codehaus.groovy.ast.stmt.ForStatement;
    61
    62  import org.codehaus.groovy.syntax.Types;
    63
    64  /***
    65   * A visitor which figures out which variables are in scope
    66   *
    67   * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
    68   * @version $Revision: 1.10 $
    69   */
    70  public class VariableScopeCodeVisitor extends CodeVisitorSupport {
    71
    72      private VariableScope scope;
    73
    74      public VariableScopeCodeVisitor(VariableScope scope) {
    75          this.scope = scope;
    76      }
    77
    78      public Set getReferencedVariables() {
    79          return scope.getReferencedVariables();
    80      }
    81
    82      public Set getDeclaredVariables() {
    83          return scope.getDeclaredVariables();
    84      }
    85
    86
    87
    88      public void visitBinaryExpression(BinaryExpression expression) {
    89          Expression leftExpression = expression.getLeftExpression();
    90          if (expression.getOperation().isA(Types.ASSIGNMENT_OPERATOR) && leftExpression instanceof VariableExpression) {
    91              declareVariable((VariableExpression) leftExpression);
    92          }
    93          else {
    94              leftExpression.visit(this);
    95          }
    96          expression.getRightExpression().visit(this);
    97      }
    98
    99      public void visitForLoop(ForStatement forLoop) {
    100         declareVariable(forLoop.getVariable());
    101
    102         super.visitForLoop(forLoop);
    103     }
    104
    105     public void visitClosureExpression(ClosureExpression expression) {
    106         VariableScopeCodeVisitor visitor = createClosureVisitor(expression);
    107         expression.getCode().visit(visitor);
    108     }
    109
    110     public void visitVariableExpression(VariableExpression expression) {
    111         // check for undeclared variables?
    112         String variable = expression.getVariable();
    113         /*
    114         if (!parameterSet.contains(variable)) {
    115             referencedVariables.add(variable);
    116         }
    117         */
    118         getReferencedVariables().add(variable);
    119     }
    120
    121
    122     public void visitPostfixExpression(PostfixExpression expression) {
    123         Expression exp = expression.getExpression();
    124         if (exp instanceof VariableExpression) {
    125             declareVariable((VariableExpression) exp);
    126         }
    127         else {
    128             exp.visit(this);
    129         }
    130     }
    131
    132     public void visitPrefixExpression(PrefixExpression expression) {
    133         Expression exp = expression.getExpression();
    134         if (exp instanceof VariableExpression) {
    135             declareVariable((VariableExpression) exp);
    136         }
    137         else {
    138             exp.visit(this);
    139         }
    140     }
    141
    142     public void visitMethodCallExpression(MethodCallExpression call) {
    143         if (call.isImplicitThis()) {
    144             getReferencedVariables().add(call.getMethod());
    145         }
    146         super.visitMethodCallExpression(call);
    147     }
    148
    149     protected void setParameters(Parameter[] parameters) {
    150         /*
    151         parameterSet.clear();
    152         for (int i = 0; i < parameters.length; i++) {
    153             parameterSet.add(parameters[i].getName());
    154         }
    155         */
    156
    157         for (int i = 0; i < parameters.length; i++) {
    158             declareVariable(parameters[i].getName());
    159         }
    160     }
    161
    162     protected void declareVariable(VariableExpression varExp) {
    163         String variable = varExp.getVariable();
    164         declareVariable(variable);
    165     }
    166
    167     protected void declareVariable(String variable) {
    168         /*
    169         if (!parameterSet.contains(variable)) {
    170             declaredVariables.add(variable);
    171             getReferencedVariables().add(variable);
    172         }
    173         */
    174         getDeclaredVariables().add(variable);
    175         getReferencedVariables().add(variable);
    176     }
    177
    178     protected VariableScopeCodeVisitor createClosureVisitor(ClosureExpression expression) {
    179         VariableScope closureScope = new VariableScope(scope);
    180         expression.setVariableScope(closureScope);
    181         VariableScopeCodeVisitor answer = new VariableScopeCodeVisitor(closureScope);
    182         answer.setParameters(expression.getParameters());
    183         return answer;
    184     }
    185 }