+++ /dev/null
-/*******************************************************************************
- * Copyright (c) 2000, 2004 IBM Corporation and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Common Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/cpl-v10.html
- *
- * Contributors:
- * IBM Corporation - initial API and implementation
- *******************************************************************************/
-package org.eclipse.jdt.internal.compiler.ast;
-
-import org.eclipse.jdt.internal.compiler.ASTVisitor;
-import org.eclipse.jdt.internal.compiler.codegen.*;
-import org.eclipse.jdt.internal.compiler.flow.*;
-import org.eclipse.jdt.internal.compiler.lookup.*;
-
-public class ReturnStatement extends Statement {
-
- public Expression expression;
- public TypeBinding expressionType;
- public boolean isSynchronized;
- public SubRoutineStatement[] subroutines;
- public boolean isAnySubRoutineEscaping = false;
- public LocalVariableBinding saveValueVariable;
-
- public ReturnStatement(Expression expr, int s, int e ) {
- sourceStart = s;
- sourceEnd = e;
- expression = expr ;
- }
- public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) { // here requires to generate a sequence of finally blocks invocations depending corresponding
- // to each of the traversed try statements, so that execution will terminate properly.
-
- // lookup the label, this should answer the returnContext
-
- if (expression != null) {
- flowInfo = expression.analyseCode(currentScope, flowContext, flowInfo);
- }
- // compute the return sequence (running the finally blocks)
- FlowContext traversedContext = flowContext;
- int subIndex = 0, maxSub = 5;
- boolean saveValueNeeded = false;
- boolean hasValueToSave = expression != null && expression.constant == NotAConstant;
- do {
- SubRoutineStatement sub;
- if ((sub = traversedContext.subRoutine()) != null) {
- if (this.subroutines == null){
- this.subroutines = new SubRoutineStatement[maxSub];
- }
- if (subIndex == maxSub) {
- System.arraycopy(this.subroutines, 0, (this.subroutines = new SubRoutineStatement[maxSub *= 2]), 0, subIndex); // grow
- }
- this.subroutines[subIndex++] = sub;
- if (sub.isSubRoutineEscaping()) {
- saveValueNeeded = false;
- isAnySubRoutineEscaping = true;
- break;
- }
- }
- traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
-
- ASTNode node;
- if ((node = traversedContext.associatedNode) instanceof SynchronizedStatement) {
- isSynchronized = true;
-
- } else if (node instanceof TryStatement) {
- TryStatement tryStatement = (TryStatement) node;
- flowInfo.addInitializationsFrom(tryStatement.subRoutineInits); // collect inits
- if (hasValueToSave) {
- if (this.saveValueVariable == null){ // closest subroutine secret variable is used
- prepareSaveValueLocation(tryStatement);
- }
- saveValueNeeded = true;
- }
-
- } else if (traversedContext instanceof InitializationFlowContext) {
- currentScope.problemReporter().cannotReturnInInitializer(this);
- return FlowInfo.DEAD_END;
- }
- } while ((traversedContext = traversedContext.parent) != null);
-
- // resize subroutines
- if ((subroutines != null) && (subIndex != maxSub)) {
- System.arraycopy(subroutines, 0, (subroutines = new SubRoutineStatement[subIndex]), 0, subIndex);
- }
-
- // secret local variable for return value (note that this can only occur in a real method)
- if (saveValueNeeded) {
- if (this.saveValueVariable != null) {
- this.saveValueVariable.useFlag = LocalVariableBinding.USED;
- }
- } else {
- this.saveValueVariable = null;
- if ((!isSynchronized) && (expressionType == BooleanBinding)) {
- this.expression.bits |= ValueForReturnMASK;
- }
- }
- return FlowInfo.DEAD_END;
- }
-
- /**
- * Retrun statement code generation
- *
- * generate the finallyInvocationSequence.
- *
- * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
- * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
- */
- public void generateCode(BlockScope currentScope, CodeStream codeStream) {
- if ((bits & IsReachableMASK) == 0) {
- return;
- }
- int pc = codeStream.position;
- // generate the expression
- if ((expression != null) && (expression.constant == NotAConstant)) {
- expression.generateCode(currentScope, codeStream, needValue()); // no value needed if non-returning subroutine
- generateStoreSaveValueIfNecessary(codeStream);
- }
-
- // generation of code responsible for invoking the finally blocks in sequence
- if (subroutines != null) {
- for (int i = 0, max = subroutines.length; i < max; i++) {
- SubRoutineStatement sub = subroutines[i];
- sub.generateSubRoutineInvocation(currentScope, codeStream);
- if (sub.isSubRoutineEscaping()) {
- codeStream.recordPositionsFrom(pc, this.sourceStart);
- SubRoutineStatement.reenterExceptionHandlers(subroutines, i, codeStream);
- return;
- }
- sub.exitAnyExceptionHandler();
- }
- }
- if (saveValueVariable != null) codeStream.load(saveValueVariable);
-
- if ((expression != null) && (expression.constant != NotAConstant)) {
- codeStream.generateConstant(expression.constant, expression.implicitConversion);
- generateStoreSaveValueIfNecessary(codeStream);
- }
- // output the suitable return bytecode or wrap the value inside a descriptor for doits
- this.generateReturnBytecode(codeStream);
- codeStream.recordPositionsFrom(pc, this.sourceStart);
- SubRoutineStatement.reenterExceptionHandlers(subroutines, -1, codeStream);
- }
- /**
- * Dump the suitable return bytecode for a return statement
- *
- */
- public void generateReturnBytecode(CodeStream codeStream) {
-
- if (expression == null) {
- codeStream.return_();
- } else {
- switch (expression.implicitConversion >> 4) {
- case T_boolean :
- case T_int :
- codeStream.ireturn();
- break;
- case T_float :
- codeStream.freturn();
- break;
- case T_long :
- codeStream.lreturn();
- break;
- case T_double :
- codeStream.dreturn();
- break;
- default :
- codeStream.areturn();
- }
- }
- }
- public void generateStoreSaveValueIfNecessary(CodeStream codeStream){
- if (saveValueVariable != null) codeStream.store(saveValueVariable, false);
- }
- public boolean needValue(){
- return (subroutines == null) || (saveValueVariable != null) || isSynchronized;
- }
- public void prepareSaveValueLocation(TryStatement targetTryStatement){
-
- this.saveValueVariable = targetTryStatement.secretReturnValue;
- }
- public StringBuffer printStatement(int tab, StringBuffer output){
-
- printIndent(tab, output).append("return "); //$NON-NLS-1$
- if (expression != null )
- expression.printExpression(0, output) ;
- return output.append(';');
- }
- public void resolve(BlockScope scope) {
- MethodScope methodScope = scope.methodScope();
- MethodBinding methodBinding;
- TypeBinding methodType =
- (methodScope.referenceContext instanceof AbstractMethodDeclaration)
- ? ((methodBinding = ((AbstractMethodDeclaration) methodScope.referenceContext).binding) == null
- ? null
- : methodBinding.returnType)
- : VoidBinding;
- if (methodType == VoidBinding) {
- // the expression should be null
- if (expression == null)
- return;
- if ((expressionType = expression.resolveType(scope)) != null)
- scope.problemReporter().attemptToReturnNonVoidExpression(this, expressionType);
- return;
- }
- if (expression == null) {
- if (methodType != null) scope.problemReporter().shouldReturn(methodType, this);
- return;
- }
- if ((expressionType = expression.resolveType(scope)) == null)
- return;
-
- if (methodType != null && expression.isConstantValueOfTypeAssignableToType(expressionType, methodType)) {
- // dealing with constant
- expression.implicitWidening(methodType, expressionType);
- return;
- }
- if (expressionType == VoidBinding) {
- scope.problemReporter().attemptToReturnVoidValue(this);
- return;
- }
- if (methodType != null && expressionType.isCompatibleWith(methodType)) {
- expression.implicitWidening(methodType, expressionType);
- return;
- }
- if (methodType != null){
- scope.problemReporter().typeMismatchErrorActualTypeExpectedType(expression, expressionType, methodType);
- }
- }
- public void traverse(ASTVisitor visitor, BlockScope scope) {
- if (visitor.visit(this, scope)) {
- if (expression != null)
- expression.traverse(visitor, scope);
- }
- visitor.endVisit(this, scope);
- }
-}
projects / org.ibex.tool.git / blobdiff