ReturnStatement.java
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net.sourceforge.phpdt.internal.compiler.ast |
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PHPeclipse |
View: Reasons, Metrics, Source Code
These are the metrics that contribute to the Enerjy Score for this file, ranked by impact. So the metrics listed at the top influence the score to a greater extent that the metrics listed at the bottom.
/***********************************************************************************************************************************
* Copyright (c) 2000, 2003 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 net.sourceforge.phpdt.internal.compiler.ast;
import net.sourceforge.phpdt.internal.compiler.ASTVisitor;
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;
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;
do {
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;
}
}
traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
ASTNode node = traversedContext.associatedNode;
// 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 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.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
* net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
* @param codeStream
* net.sourceforge.phpdt.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++) {
// 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(codeStream);
// }
// // output the suitable return bytecode or wrap the value inside a
// descriptor for doits
// this.generateReturnBytecode(codeStream);
//
// codeStream.recordPositionsFrom(pc, this.sourceStart);
// }
/**
* 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 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 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 String toString(int tab) {
String s = tabString(tab);
s = s + "return "; //$NON-NLS-1$
if (expression != null)
s = s + expression.toStringExpression();
return s;
}
public void traverse(ASTVisitor visitor, BlockScope scope) {
if (visitor.visit(this, scope)) {
if (expression != null)
expression.traverse(visitor, scope);
}
visitor.endVisit(this, scope);
}
}
The table below shows all metrics for ReturnStatement.java.




