net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/Statement.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v0.5
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v05.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  ******************************************************************************/
  11 package net.sourceforge.phpdt.internal.compiler.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.codegen.CodeStream;
  14 import net.sourceforge.phpdt.internal.compiler.codegen.Label;
  15 import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
  16 import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
  17 import net.sourceforge.phpdt.internal.compiler.impl.Constant;
  18 import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
  19 import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
  20 import net.sourceforge.phpdt.internal.compiler.problem.ShouldNotImplement;
  21 import net.sourceforge.phpdt.internal.compiler.util.Util;
  22
  23 public abstract class Statement extends AstNode {
  24
  25         /**
  26          * Statement constructor comment.
  27          */
  28         public Statement() {
  29                 super();
  30         }
  31
  32         public FlowInfo analyseCode(
  33                 BlockScope currentScope,
  34                 FlowContext flowContext,
  35                 FlowInfo flowInfo) {
  36                 return flowInfo;
  37         }
  38
  39         public void generateCode(BlockScope currentScope, CodeStream codeStream) {
  40                 throw new ShouldNotImplement(Util.bind("ast.missingStatement")); //$NON-NLS-1$
  41         }
  42
  43         public boolean isEmptyBlock() {
  44                 return false;
  45         }
  46
  47         public boolean isValidJavaStatement() {
  48                 //the use of this method should be avoid in most cases
  49                 //and is here mostly for documentation purpose.....
  50                 //while the parser is responsable for creating
  51                 //welled formed expression statement, which results
  52                 //in the fact that java-non-semantic-expression-used-as-statement
  53                 //should not be parsable...thus not being built.
  54                 //It sounds like the java grammar as help the compiler job in removing
  55                 //-by construction- some statement that would have no effect....
  56                 //(for example all expression that may do side-effects are valid statement
  57                 // -this is an appromative idea.....-)
  58
  59                 return true;
  60         }
  61
  62         public void resolve(BlockScope scope) {
  63         }
  64
  65         public Constant resolveCase(
  66                 BlockScope scope,
  67                 TypeBinding testType,
  68                 SwitchStatement switchStatement) {
  69                 // statement within a switch that are not case are treated as normal statement....
  70
  71                 resolve(scope);
  72                 return null;
  73         }
  74
  75         public void resetStateForCodeGeneration() {
  76         }
  77
  78         /**
  79          * INTERNAL USE ONLY.
  80          * Do nothing by default. This is used to redirect inter-statements jumps.
  81          */
  82         public void branchChainTo(Label label) {
  83         }
  84 }