+/***********************************************************************************************************************************
+ * 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 java.util.List;
-
-/**
- * A return statement.
- * @author Matthieu Casanova
- */
-public final class ReturnStatement extends Statement {
-
- private final 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 ...)
- *
- * @param list the list where we will put variables
- */
- public void getOutsideVariable(final List list) {}
-
- /**
- * get the modified variables.
- *
- * @param list the list where we will put variables
- */
- public void getModifiedVariable(final List list) {
- if (expression != null) {
- expression.getModifiedVariable(list);
- }
- }
-
- /**
- * Get the variables used.
- *
- * @param list the list where we will put variables
- */
- public void getUsedVariable(final List list) {
- if (expression != null) {
- expression.getUsedVariable(list);
- }
- }
-}
+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);
+ }
+}
\ No newline at end of file
git://git.phpeclipse.com / phpeclipse.git / blobdiff