net.sourceforge.phpeclipse/src/net/sourceforge/phpeclipse/internal/compiler/ast/Block.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 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 net.sourceforge.phpeclipse.internal.compiler.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
  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.lookup.BlockScope;
  18
  19 public class Block extends Statement {
  20
  21         public Statement[] statements;
  22         public int explicitDeclarations;
  23         // the number of explicit declaration , used to create scope
  24         public BlockScope scope;
  25         public static final Block None = new Block(0);
  26
  27         public Block(int explicitDeclarations) {
  28                 this.explicitDeclarations = explicitDeclarations;
  29         }
  30
  31         public FlowInfo analyseCode(
  32                 BlockScope currentScope,
  33                 FlowContext flowContext,
  34                 FlowInfo flowInfo) {
  35
  36                 // empty block
  37                 if (statements == null) return flowInfo;
  38                 boolean didAlreadyComplain = false;
  39                 for (int i = 0, max = statements.length; i < max; i++) {
  40                         Statement stat;
  41                         if (!flowInfo.complainIfUnreachable(stat = statements[i], scope, didAlreadyComplain)) {
  42                                 flowInfo = stat.analyseCode(scope, flowContext, flowInfo);
  43                         } else {
  44                                 didAlreadyComplain = true;
  45                         }
  46                 }
  47                 return flowInfo;
  48         }
  49
  50         public static final Block EmptyWith(int sourceStart, int sourceEnd) {
  51
  52                 //return an empty block which position is s and e
  53                 Block bk = new Block(0);
  54                 bk.sourceStart = sourceStart;
  55                 bk.sourceEnd = sourceEnd;
  56                 return bk;
  57         }
  58
  59         /**
  60          * Code generation for a block
  61          */
  62 //      public void generateCode(BlockScope currentScope, CodeStream codeStream) {
  63 //
  64 //              if ((bits & IsReachableMASK) == 0) {
  65 //                      return;
  66 //              }
  67 //              int pc = codeStream.position;
  68 //              if (statements != null) {
  69 //                      for (int i = 0, max = statements.length; i < max; i++) {
  70 //                              statements[i].generateCode(scope, codeStream);
  71 //                      }
  72 //              } // for local variable debug attributes
  73 //              if (scope != currentScope) { // was really associated with its own scope
  74 //                      codeStream.exitUserScope(scope);
  75 //              }
  76 //              codeStream.recordPositionsFrom(pc, this.sourceStart);
  77 //      }
  78
  79         public boolean isEmptyBlock() {
  80
  81                 return statements == null;
  82         }
  83
  84         public void resolve(BlockScope upperScope) {
  85
  86                 if (statements != null) {
  87                         scope =
  88                                 explicitDeclarations == 0
  89                                         ? upperScope
  90                                         : new BlockScope(upperScope, explicitDeclarations);
  91                         int i = 0, length = statements.length;
  92                         while (i < length)
  93                                 statements[i++].resolve(scope);
  94                 }
  95         }
  96
  97         public void resolveUsing(BlockScope givenScope) {
  98
  99                 // this optimized resolve(...) is sent only on none empty blocks
 100                 scope = givenScope;
 101                 if (statements != null) {
 102                         int i = 0, length = statements.length;
 103                         while (i < length)
 104                                 statements[i++].resolve(scope);
 105                 }
 106         }
 107
 108         public String toString(int tab) {
 109
 110                 String s = tabString(tab);
 111                 if (this.statements == null) {
 112                         s += "{\n"; //$NON-NLS-1$
 113                         s += tabString(tab);
 114                         s += "}"; //$NON-NLS-1$
 115                         return s;
 116                 }
 117                 s += "{\n"; //$NON-NLS-1$
 118                 s += this.toStringStatements(tab);
 119                 s += tabString(tab);
 120                 s += "}"; //$NON-NLS-1$
 121                 return s;
 122         }
 123
 124         public String toStringStatements(int tab) {
 125
 126                 if (this.statements == null)
 127                         return ""; //$NON-NLS-1$
 128                 StringBuffer buffer = new StringBuffer();
 129                 for (int i = 0; i < statements.length; i++) {
 130                         buffer.append(statements[i].toString(tab + 1));
 131                         if (statements[i] instanceof Block) {
 132                                 buffer.append("\n"); //$NON-NLS-1$
 133                         } else {
 134                                 buffer.append(";\n"); //$NON-NLS-1$
 135                         }
 136                 };
 137                 return buffer.toString();
 138         }
 139
 140         public void traverse(
 141                 IAbstractSyntaxTreeVisitor visitor,
 142                 BlockScope blockScope) {
 143
 144                 if (visitor.visit(this, blockScope)) {
 145                         if (statements != null) {
 146                                 int statementLength = statements.length;
 147                                 for (int i = 0; i < statementLength; i++)
 148                                         statements[i].traverse(visitor, scope);
 149                         }
 150                 }
 151                 visitor.endVisit(this, blockScope);
 152         }
 153
 154         /**
 155          * Dispatch the call on its last statement.
 156          */
 157         public void branchChainTo(Label label) {
 158                  if (this.statements != null) {
 159                         this.statements[statements.length - 1].branchChainTo(label);
 160                  }
 161         }
 162
 163 }