src/org/eclipse/jdt/internal/compiler/ast/Clinit.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.ASTVisitor;
  14 import org.eclipse.jdt.internal.compiler.*;
  15 import org.eclipse.jdt.internal.compiler.codegen.*;
  16 import org.eclipse.jdt.internal.compiler.flow.*;
  17 import org.eclipse.jdt.internal.compiler.lookup.*;
  18 import org.eclipse.jdt.internal.compiler.parser.*;
  19 import org.eclipse.jdt.internal.compiler.problem.*;
  20
  21 public class Clinit extends AbstractMethodDeclaration {
  22
  23         public final static char[] ConstantPoolName = "<clinit>".toCharArray(); //$NON-NLS-1$
  24
  25         private FieldBinding assertionSyntheticFieldBinding = null;
  26         private FieldBinding classLiteralSyntheticField = null;
  27
  28         public Clinit(CompilationResult compilationResult) {
  29                 super(compilationResult);
  30                 modifiers = 0;
  31                 selector = ConstantPoolName;
  32         }
  33
  34         public void analyseCode(
  35                 ClassScope classScope,
  36                 InitializationFlowContext staticInitializerFlowContext,
  37                 FlowInfo flowInfo) {
  38
  39                 if (ignoreFurtherInvestigation)
  40                         return;
  41                 try {
  42                         ExceptionHandlingFlowContext clinitContext =
  43                                 new ExceptionHandlingFlowContext(
  44                                         staticInitializerFlowContext.parent,
  45                                         this,
  46                                         NoExceptions,
  47                                         scope,
  48                                         FlowInfo.DEAD_END);
  49
  50                         // check for missing returning path
  51                         this.needFreeReturn = flowInfo.isReachable();
  52
  53                         // check missing blank final field initializations
  54                         flowInfo = flowInfo.mergedWith(staticInitializerFlowContext.initsOnReturn);
  55                         FieldBinding[] fields = scope.enclosingSourceType().fields();
  56                         for (int i = 0, count = fields.length; i < count; i++) {
  57                                 FieldBinding field;
  58                                 if ((field = fields[i]).isStatic()
  59                                         && field.isFinal()
  60                                         && (!flowInfo.isDefinitelyAssigned(fields[i]))) {
  61                                         scope.problemReporter().uninitializedBlankFinalField(
  62                                                 field,
  63                                                 scope.referenceType().declarationOf(field));
  64                                         // can complain against the field decl, since only one <clinit>
  65                                 }
  66                         }
  67                         // check static initializers thrown exceptions
  68                         staticInitializerFlowContext.checkInitializerExceptions(
  69                                 scope,
  70                                 clinitContext,
  71                                 flowInfo);
  72                 } catch (AbortMethod e) {
  73                         this.ignoreFurtherInvestigation = true;
  74                 }
  75         }
  76
  77         /**
  78          * Bytecode generation for a <clinit> method
  79          *
  80          * @param classScope org.eclipse.jdt.internal.compiler.lookup.ClassScope
  81          * @param classFile org.eclipse.jdt.internal.compiler.codegen.ClassFile
  82          */
  83         public void generateCode(ClassScope classScope, ClassFile classFile) {
  84
  85                 int clinitOffset = 0;
  86                 if (ignoreFurtherInvestigation) {
  87                         // should never have to add any <clinit> problem method
  88                         return;
  89                 }
  90                 try {
  91                         clinitOffset = classFile.contentsOffset;
  92                         this.generateCode(classScope, classFile, clinitOffset);
  93                 } catch (AbortMethod e) {
  94                         // should never occur
  95                         // the clinit referenceContext is the type declaration
  96                         // All clinit problems will be reported against the type: AbortType instead of AbortMethod
  97                         // reset the contentsOffset to the value before generating the clinit code
  98                         // decrement the number of method info as well.
  99                         // This is done in the addProblemMethod and addProblemConstructor for other
 100                         // cases.
 101                         if (e.compilationResult == CodeStream.RESTART_IN_WIDE_MODE) {
 102                                 // a branch target required a goto_w, restart code gen in wide mode.
 103                                 try {
 104                                         classFile.contentsOffset = clinitOffset;
 105                                         classFile.methodCount--;
 106                                         classFile.codeStream.wideMode = true; // request wide mode
 107                                         this.generateCode(classScope, classFile, clinitOffset);
 108                                         // restart method generation
 109                                 } catch (AbortMethod e2) {
 110                                         classFile.contentsOffset = clinitOffset;
 111                                         classFile.methodCount--;
 112                                 }
 113                         } else {
 114                                 // produce a problem method accounting for this fatal error
 115                                 classFile.contentsOffset = clinitOffset;
 116                                 classFile.methodCount--;
 117                         }
 118                 }
 119         }
 120
 121         /**
 122          * Bytecode generation for a <clinit> method
 123          *
 124          * @param classScope org.eclipse.jdt.internal.compiler.lookup.ClassScope
 125          * @param classFile org.eclipse.jdt.internal.compiler.codegen.ClassFile
 126          */
 127         private void generateCode(
 128                 ClassScope classScope,
 129                 ClassFile classFile,
 130                 int clinitOffset) {
 131
 132                 ConstantPool constantPool = classFile.constantPool;
 133                 int constantPoolOffset = constantPool.currentOffset;
 134                 int constantPoolIndex = constantPool.currentIndex;
 135                 classFile.generateMethodInfoHeaderForClinit();
 136                 int codeAttributeOffset = classFile.contentsOffset;
 137                 classFile.generateCodeAttributeHeader();
 138                 CodeStream codeStream = classFile.codeStream;
 139                 this.resolve(classScope);
 140
 141                 codeStream.reset(this, classFile);
 142                 TypeDeclaration declaringType = classScope.referenceContext;
 143
 144                 // initialize local positions - including initializer scope.
 145                 MethodScope staticInitializerScope = declaringType.staticInitializerScope;
 146                 staticInitializerScope.computeLocalVariablePositions(0, codeStream);
 147
 148                 // 1.4 feature
 149                 // This has to be done before any other initialization
 150                 if (this.assertionSyntheticFieldBinding != null) {
 151                         // generate code related to the activation of assertion for this class
 152                         codeStream.generateClassLiteralAccessForType(
 153                                 classScope.enclosingSourceType(),
 154                                 classLiteralSyntheticField);
 155                         codeStream.invokeJavaLangClassDesiredAssertionStatus();
 156                         Label falseLabel = new Label(codeStream);
 157                         codeStream.ifne(falseLabel);
 158                         codeStream.iconst_1();
 159                         Label jumpLabel = new Label(codeStream);
 160                         codeStream.goto_(jumpLabel);
 161                         falseLabel.place();
 162                         codeStream.iconst_0();
 163                         jumpLabel.place();
 164                         codeStream.putstatic(this.assertionSyntheticFieldBinding);
 165                 }
 166                 // generate initializers
 167                 if (declaringType.fields != null) {
 168                         for (int i = 0, max = declaringType.fields.length; i < max; i++) {
 169                                 FieldDeclaration fieldDecl;
 170                                 if ((fieldDecl = declaringType.fields[i]).isStatic()) {
 171                                         fieldDecl.generateCode(staticInitializerScope, codeStream);
 172                                 }
 173                         }
 174                 }
 175                 if (codeStream.position == 0) {
 176                         // do not need to output a Clinit if no bytecodes
 177                         // so we reset the offset inside the byte array contents.
 178                         classFile.contentsOffset = clinitOffset;
 179                         // like we don't addd a method we need to undo the increment on the method count
 180                         classFile.methodCount--;
 181                         // reset the constant pool to its state before the clinit
 182                         constantPool.resetForClinit(constantPoolIndex, constantPoolOffset);
 183                 } else {
 184                         if (this.needFreeReturn) {
 185                                 int oldPosition = codeStream.position;
 186                                 codeStream.return_();
 187                                 codeStream.updateLocalVariablesAttribute(oldPosition);
 188                         }
 189                         // Record the end of the clinit: point to the declaration of the class
 190                         codeStream.recordPositionsFrom(0, declaringType.sourceStart);
 191                         classFile.completeCodeAttributeForClinit(codeAttributeOffset);
 192                 }
 193         }
 194
 195         public boolean isClinit() {
 196
 197                 return true;
 198         }
 199
 200         public boolean isInitializationMethod() {
 201
 202                 return true;
 203         }
 204
 205         public boolean isStatic() {
 206
 207                 return true;
 208         }
 209
 210         public void parseStatements(Parser parser, CompilationUnitDeclaration unit) {
 211                 //the clinit is filled by hand ....
 212         }
 213
 214         public StringBuffer print(int tab, StringBuffer output) {
 215
 216                 printIndent(tab, output).append("<clinit>()"); //$NON-NLS-1$
 217                 printBody(tab + 1, output);
 218                 return output;
 219         }
 220
 221         public void resolve(ClassScope classScope) {
 222
 223                 this.scope = new MethodScope(classScope, classScope.referenceContext, true);
 224         }
 225
 226         public void traverse(
 227                 ASTVisitor visitor,
 228                 ClassScope classScope) {
 229
 230                 visitor.visit(this, classScope);
 231                 visitor.endVisit(this, classScope);
 232         }
 233
 234         // 1.4 feature
 235         public void setAssertionSupport(FieldBinding assertionSyntheticFieldBinding) {
 236
 237                 this.assertionSyntheticFieldBinding = assertionSyntheticFieldBinding;
 238
 239                 // we need to add the field right now, because the field infos are generated before the methods
 240                 SourceTypeBinding sourceType =
 241                         this.scope.outerMostMethodScope().enclosingSourceType();
 242                 this.classLiteralSyntheticField =
 243                         sourceType.addSyntheticField(sourceType, scope);
 244         }
 245
 246 }