net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/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.phpdt.internal.compiler.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.ASTVisitor;
  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         public StringBuffer printBody(int indent, StringBuffer output) {
  84
  85                 if (this.statements == null) return output;
  86                 for (int i = 0; i < statements.length; i++) {
  87                         statements[i].printStatement(indent + 1, output);
  88                         output.append('\n');
  89                 }
  90                 return output;
  91         }
  92
  93         public StringBuffer printStatement(int indent, StringBuffer output) {
  94
  95                 printIndent(indent, output);
  96                 output.append("{\n"); //$NON-NLS-1$
  97                 printBody(indent, output);
  98                 return printIndent(indent, output).append('}');
  99         }
 100         public void resolve(BlockScope upperScope) {
 101
 102                 if (statements != null) {
 103                         scope =
 104                                 explicitDeclarations == 0
 105                                         ? upperScope
 106                                         : new BlockScope(upperScope, explicitDeclarations);
 107                         int i = 0, length = statements.length;
 108                         while (i < length)
 109                                 statements[i++].resolve(scope);
 110                 }
 111         }
 112
 113         public void resolveUsing(BlockScope givenScope) {
 114
 115                 // this optimized resolve(...) is sent only on none empty blocks
 116                 scope = givenScope;
 117                 if (statements != null) {
 118                         int i = 0, length = statements.length;
 119                         while (i < length)
 120                                 statements[i++].resolve(scope);
 121                 }
 122         }
 123
 124         public String toString(int tab) {
 125
 126                 String s = tabString(tab);
 127                 if (this.statements == null) {
 128                         s += "{\n"; //$NON-NLS-1$
 129                         s += tabString(tab);
 130                         s += "}"; //$NON-NLS-1$
 131                         return s;
 132                 }
 133                 s += "{\n"; //$NON-NLS-1$
 134                 s += this.toStringStatements(tab);
 135                 s += tabString(tab);
 136                 s += "}"; //$NON-NLS-1$
 137                 return s;
 138         }
 139
 140         public String toStringStatements(int tab) {
 141
 142                 if (this.statements == null)
 143                         return ""; //$NON-NLS-1$
 144                 StringBuffer buffer = new StringBuffer();
 145                 for (int i = 0; i < statements.length; i++) {
 146                         buffer.append(statements[i].toString(tab + 1));
 147                         if (statements[i] instanceof Block) {
 148                                 buffer.append("\n"); //$NON-NLS-1$
 149                         } else {
 150                                 buffer.append(";\n"); //$NON-NLS-1$
 151                         }
 152                 };
 153                 return buffer.toString();
 154         }
 155
 156         public void traverse(
 157             ASTVisitor visitor,
 158                 BlockScope blockScope) {
 159
 160                 if (visitor.visit(this, blockScope)) {
 161                         if (statements != null) {
 162                                 int statementLength = statements.length;
 163                                 for (int i = 0; i < statementLength; i++)
 164                                         statements[i].traverse(visitor, scope);
 165                         }
 166                 }
 167                 visitor.endVisit(this, blockScope);
 168         }
 169
 170         /**
 171          * Dispatch the call on its last statement.
 172          */
 173         public void branchChainTo(Label label) {
 174                  if (this.statements != null) {
 175                         this.statements[statements.length - 1].branchChainTo(label);
 176                  }
 177         }
 178
 179 }