src/org/eclipse/jdt/internal/compiler/ast/Statement.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2004 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.jdt.internal.compiler.ast;
  12
  13 import org.eclipse.jdt.internal.compiler.impl.*;
  14 import org.eclipse.jdt.internal.compiler.codegen.*;
  15 import org.eclipse.jdt.internal.compiler.flow.*;
  16 import org.eclipse.jdt.internal.compiler.lookup.*;
  17
  18 public abstract class Statement extends ASTNode {
  19
  20         public abstract FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo);
  21
  22         /**
  23          * INTERNAL USE ONLY.
  24          * This is used to redirect inter-statements jumps.
  25          */
  26         public void branchChainTo(Label label) {
  27                 // do nothing by default
  28         }
  29
  30         // Report an error if necessary
  31         public boolean complainIfUnreachable(FlowInfo flowInfo, BlockScope scope, boolean didAlreadyComplain) {
  32
  33                 if ((flowInfo.reachMode() & FlowInfo.UNREACHABLE) != 0) {
  34                         this.bits &= ~ASTNode.IsReachableMASK;
  35                         boolean reported = flowInfo == FlowInfo.DEAD_END;
  36                         if (!didAlreadyComplain && reported) {
  37                                 scope.problemReporter().unreachableCode(this);
  38                         }
  39                         return reported; // keep going for fake reachable
  40                 }
  41                 return false;
  42         }
  43
  44         public abstract void generateCode(BlockScope currentScope, CodeStream codeStream);
  45
  46         public boolean isEmptyBlock() {
  47                 return false;
  48         }
  49
  50         public boolean isValidJavaStatement() {
  51                 //the use of this method should be avoid in most cases
  52                 //and is here mostly for documentation purpose.....
  53                 //while the parser is responsable for creating
  54                 //welled formed expression statement, which results
  55                 //in the fact that java-non-semantic-expression-used-as-statement
  56                 //should not be parsable...thus not being built.
  57                 //It sounds like the java grammar as help the compiler job in removing
  58                 //-by construction- some statement that would have no effect....
  59                 //(for example all expression that may do side-effects are valid statement
  60                 // -this is an appromative idea.....-)
  61
  62                 return true;
  63         }
  64
  65         public StringBuffer print(int indent, StringBuffer output) {
  66                 return printStatement(indent, output);
  67         }
  68         public abstract StringBuffer printStatement(int indent, StringBuffer output);
  69
  70         public abstract void resolve(BlockScope scope);
  71
  72         public Constant resolveCase(BlockScope scope, TypeBinding testType, SwitchStatement switchStatement) {
  73                 // statement within a switch that are not case are treated as normal statement....
  74
  75                 resolve(scope);
  76                 return null;
  77         }
  78
  79 }