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         public Statement[] statements;         // The array of statements found with this block
  21
  22         public int explicitDeclarations;
  23
  24         public BlockScope scope;               // The number of explicit declaration , used to create scope
  25
  26         public static final Block None = new Block(0);
  27
  28         public Block(int explicitDeclarations) {
  29                 this.explicitDeclarations = explicitDeclarations;
  30         }
  31
  32         public FlowInfo analyseCode(BlockScope currentScope,
  33                         FlowContext flowContext, FlowInfo flowInfo) {
  34
  35                 // empty block
  36                 if (statements == null)
  37                         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,
  42                                         didAlreadyComplain)) {
  43                                 flowInfo = stat.analyseCode(scope, flowContext, flowInfo);
  44                         } else {
  45                                 didAlreadyComplain = true;
  46                         }
  47                 }
  48                 return flowInfo;
  49         }
  50
  51         public static final Block EmptyWith(int sourceStart, int sourceEnd) {
  52
  53                 // return an empty block which position is s and e
  54                 Block bk = new Block(0);
  55                 bk.sourceStart = sourceStart;
  56                 bk.sourceEnd = sourceEnd;
  57                 return bk;
  58         }
  59
  60         /**
  61          * Code generation for a block
  62          */
  63         // public void generateCode(BlockScope currentScope, CodeStream codeStream)
  64         // {
  65         //
  66         // if ((bits & IsReachableMASK) == 0) {
  67         // return;
  68         // }
  69         // int pc = codeStream.position;
  70         // if (statements != null) {
  71         // for (int i = 0, max = statements.length; i < max; i++) {
  72         // statements[i].generateCode(scope, codeStream);
  73         // }
  74         // } // for local variable debug attributes
  75         // if (scope != currentScope) { // was really associated with its own scope
  76         // codeStream.exitUserScope(scope);
  77         // }
  78         // codeStream.recordPositionsFrom(pc, this.sourceStart);
  79         // }
  80         public boolean isEmptyBlock() {
  81
  82                 return statements == null;
  83         }
  84
  85         public StringBuffer printBody(int indent, StringBuffer output) {
  86
  87                 if (this.statements == null)
  88                         return output;
  89                 for (int i = 0; i < statements.length; i++) {
  90                         statements[i].printStatement(indent + 1, output);
  91                         output.append('\n');
  92                 }
  93                 return output;
  94         }
  95
  96         public StringBuffer printStatement(int indent, StringBuffer output) {
  97
  98                 printIndent(indent, output);
  99                 output.append("{\n"); //$NON-NLS-1$
 100                 printBody(indent, output);
 101                 return printIndent(indent, output).append('}');
 102         }
 103
 104         public void resolve(BlockScope upperScope) {
 105
 106                 if (statements != null) {
 107                         scope = explicitDeclarations == 0 ? upperScope : new BlockScope(
 108                                         upperScope, explicitDeclarations);
 109                         int i = 0, length = statements.length;
 110                         while (i < length)
 111                                 statements[i++].resolve(scope);
 112                 }
 113         }
 114
 115         public void resolveUsing(BlockScope givenScope) {
 116
 117                 // this optimized resolve(...) is sent only on none empty blocks
 118                 scope = givenScope;
 119                 if (statements != null) {
 120                         int i = 0, length = statements.length;
 121                         while (i < length)
 122                                 statements[i++].resolve(scope);
 123                 }
 124         }
 125
 126         public String toString(int tab) {
 127
 128                 String s = tabString(tab);
 129                 if (this.statements == null) {
 130                         s += "{\n"; //$NON-NLS-1$
 131                         s += tabString(tab);
 132                         s += "}"; //$NON-NLS-1$
 133                         return s;
 134                 }
 135                 s += "{\n"; //$NON-NLS-1$
 136                 s += this.toStringStatements(tab);
 137                 s += tabString(tab);
 138                 s += "}"; //$NON-NLS-1$
 139                 return s;
 140         }
 141
 142         public String toStringStatements(int tab) {
 143
 144                 if (this.statements == null)
 145                         return ""; //$NON-NLS-1$
 146                 StringBuffer buffer = new StringBuffer();
 147                 for (int i = 0; i < statements.length; i++) {
 148                         buffer.append(statements[i].toString(tab + 1));
 149                         if (statements[i] instanceof Block) {
 150                                 buffer.append("\n"); //$NON-NLS-1$
 151                         } else {
 152                                 buffer.append(";\n"); //$NON-NLS-1$
 153                         }
 154                 }
 155                 ;
 156                 return buffer.toString();
 157         }
 158
 159         public void traverse(ASTVisitor visitor, BlockScope blockScope) {
 160
 161                 if (visitor.visit(this, blockScope)) {
 162                         if (statements != null) {
 163                                 int statementLength = statements.length;
 164                                 for (int i = 0; i < statementLength; i++)
 165                                         statements[i].traverse(visitor, scope);
 166                         }
 167                 }
 168                 visitor.endVisit(this, blockScope);
 169         }
 170
 171         /**
 172          * Dispatch the call on its last statement.
 173          */
 174         public void branchChainTo(Label label) {
 175                 if (this.statements != null) {
 176                         this.statements[statements.length - 1].branchChainTo(label);
 177                 }
 178         }
 179
 180 }