-/*******************************************************************************
- * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Common Public License v0.5
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/cpl-v05.html
- *
- * Contributors:
- * IBM Corporation - initial API and implementation
- ******************************************************************************/
package net.sourceforge.phpdt.internal.compiler.ast;
-import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
-import net.sourceforge.phpdt.internal.compiler.codegen.CodeStream;
-import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
-import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
-import net.sourceforge.phpdt.internal.compiler.flow.InitializationFlowContext;
-import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
-import net.sourceforge.phpdt.internal.compiler.lookup.LocalVariableBinding;
-import net.sourceforge.phpdt.internal.compiler.lookup.MethodBinding;
-import net.sourceforge.phpdt.internal.compiler.lookup.MethodScope;
-import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
+import java.util.List;
-public class ReturnStatement extends Statement {
- public Expression expression;
-
- public TypeBinding expressionType;
- public boolean isSynchronized;
- public AstNode[] subroutines;
- 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;
- while (true) {
- AstNode sub;
- if ((sub = traversedContext.subRoutine()) != null) {
- if (this.subroutines == null){
- this.subroutines = new AstNode[maxSub];
- }
- if (subIndex == maxSub) {
- System.arraycopy(this.subroutines, 0, (this.subroutines = new AstNode[maxSub *= 2]), 0, subIndex); // grow
- }
- this.subroutines[subIndex++] = sub;
- if (sub.cannotReturn()) {
- saveValueNeeded = false;
- break;
- }
- }
- AstNode node;
-
- if ((node = traversedContext.associatedNode) instanceof SynchronizedStatement) {
- isSynchronized = true;
-
- } else if (node instanceof TryStatement && hasValueToSave) {
- if (this.saveValueVariable == null){ // closest subroutine secret variable is used
- prepareSaveValueLocation((TryStatement)node);
- }
- saveValueNeeded = true;
-
- } else if (traversedContext instanceof InitializationFlowContext) {
- currentScope.problemReporter().cannotReturnInInitializer(this);
- return FlowInfo.DeadEnd;
- }
-
- // remember the initialization at this
- // point for dealing with blank final variables.
- traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
-
- FlowContext parentContext;
- if ((parentContext = traversedContext.parent) == null) { // top-context
- break;
- } else {
- traversedContext = parentContext;
- }
- }
- // resize subroutines
- if ((subroutines != null) && (subIndex != maxSub)) {
- System.arraycopy(subroutines, 0, (subroutines = new AstNode[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.used = true;
- }
- } else {
- this.saveValueVariable = null;
- if ((!isSynchronized) && (expressionType == BooleanBinding)) {
- this.expression.bits |= ValueForReturnMASK;
- }
- }
- return FlowInfo.DeadEnd;
-}
-
/**
- * 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
+ * A return statement.
+ * @author Matthieu Casanova
*/
-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(currentScope, 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++) {
- AstNode sub;
- if ((sub = subroutines[i]) instanceof SynchronizedStatement) {
- codeStream.load(((SynchronizedStatement) sub).synchroVariable);
- codeStream.monitorexit();
- } else {
- TryStatement trySub = (TryStatement) sub;
- if (trySub.subRoutineCannotReturn) {
- codeStream.goto_(trySub.subRoutineStartLabel);
- codeStream.recordPositionsFrom(pc, this.sourceStart);
- return;
- } else {
- codeStream.jsr(trySub.subRoutineStartLabel);
- }
- }
- }
- }
- if (saveValueVariable != null) codeStream.load(saveValueVariable);
-
- if ((expression != null) && (expression.constant != NotAConstant)) {
- codeStream.generateConstant(expression.constant, expression.implicitConversion);
- generateStoreSaveValueIfNecessary(currentScope, codeStream);
- }
- // output the suitable return bytecode or wrap the value inside a descriptor for doits
- this.generateReturnBytecode(currentScope, codeStream);
-
- codeStream.recordPositionsFrom(pc, this.sourceStart);
-}
-/**
- * Dump the suitable return bytecode for a return statement
- *
- */
-public void generateReturnBytecode(BlockScope currentScope, 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(BlockScope currentScope, 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 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 && BlockScope.areTypesCompatible(expressionType, methodType)) {
- expression.implicitWidening(methodType, expressionType);
- return;
- }
- if (methodType != null){
- scope.problemReporter().typeMismatchErrorActualTypeExpectedType(expression, expressionType, methodType);
- }
-}
-public String toString(int tab){
+public class ReturnStatement extends Statement {
- String s = tabString(tab) ;
- s = s + "return "; //$NON-NLS-1$
- if (expression != null )
- s = s + expression.toStringExpression() ;
- return s;
-}
-public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope scope) {
- if (visitor.visit(this, scope)) {
- if (expression != null)
- expression.traverse(visitor, scope);
- }
- visitor.endVisit(this, scope);
-}
+ public Expression expression;
+
+ public ReturnStatement(final Expression expression, final int sourceStart, final int sourceEnd) {
+ super(sourceStart, sourceEnd);
+ this.expression = expression;
+ }
+
+ public String toString(final int tab) {
+ final String s = tabString(tab);
+ if (expression == null) {
+ return s + "return";//$NON-NLS-1$
+ }
+ return s + "return " + expression.toStringExpression();//$NON-NLS-1$
+ }
+
+ /**
+ * Get the variables from outside (parameters, globals ...)
+ */
+ public void getOutsideVariable(final List list) {
+ }
+
+ /**
+ * get the modified variables.
+ */
+ public void getModifiedVariable(final List list) {
+ if (expression != null) {
+ expression.getModifiedVariable(list);
+ }
+ }
+
+ /**
+ * Get the variables used.
+ */
+ public void getUsedVariable(final List list) {
+ if (expression != null) {
+ expression.getUsedVariable(list);
+ }
+ }
}
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