/*******************************************************************************
- * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
+ * 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 v0.5
+ * 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-v05.html
+ * http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
- ******************************************************************************/
+ * Genady Beriozkin - added support for reporting assignment with no effect
+ *******************************************************************************/
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.ASTVisitor;
import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
import net.sourceforge.phpdt.internal.compiler.lookup.BaseTypeBinding;
+import net.sourceforge.phpdt.internal.compiler.lookup.Binding;
import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
public class Assignment extends Expression {
- public Reference lhs;
+ public Expression lhs;
public Expression expression;
- public TypeBinding lhsType;
-
+
public Assignment(Expression lhs, Expression expression, int sourceEnd) {
//lhs is always a reference by construction ,
//but is build as an expression ==> the checkcast cannot fail
- this.lhs = (Reference) lhs;
+ this.lhs = lhs;
+ lhs.bits |= IsStrictlyAssignedMASK; // tag lhs as assigned
+
this.expression = expression;
this.sourceStart = lhs.sourceStart;
// a field reference, a blank final field reference, a field of an enclosing instance or
// just a local variable.
- return lhs
+ return ((Reference) lhs)
.analyseAssignment(currentScope, flowContext, flowInfo, this, false)
.unconditionalInits();
}
- public void generateCode(
- BlockScope currentScope,
- CodeStream codeStream,
- boolean valueRequired) {
+ void checkAssignmentEffect(BlockScope scope) {
+
+ Binding left = getDirectBinding(this.lhs);
+ if (left != null && left == getDirectBinding(this.expression)) {
+ scope.problemReporter().assignmentHasNoEffect(this, left.shortReadableName());
+ this.bits |= IsAssignmentWithNoEffectMASK; // record assignment has no effect
+ }
+ }
- // various scenarii are possible, setting an array reference,
- // a field reference, a blank final field reference, a field of an enclosing instance or
- // just a local variable.
+// public void generateCode(
+// BlockScope currentScope,
+// CodeStream codeStream,
+// boolean valueRequired) {
+//
+// // various scenarii are possible, setting an array reference,
+// // a field reference, a blank final field reference, a field of an enclosing instance or
+// // just a local variable.
+//
+// int pc = codeStream.position;
+// if ((this.bits & IsAssignmentWithNoEffectMASK) != 0) {
+// if (valueRequired) {
+// this.expression.generateCode(currentScope, codeStream, true);
+// }
+// } else {
+// ((Reference) lhs).generateAssignment(currentScope, codeStream, this, valueRequired);
+// // variable may have been optimized out
+// // the lhs is responsible to perform the implicitConversion generation for the assignment since optimized for unused local assignment.
+// }
+// codeStream.recordPositionsFrom(pc, this.sourceStart);
+// }
+
+ Binding getDirectBinding(Expression someExpression) {
+ if (someExpression instanceof SingleNameReference) {
+ return ((SingleNameReference)someExpression).binding;
+ } else if (someExpression instanceof FieldReference) {
+ FieldReference fieldRef = (FieldReference)someExpression;
+ if (fieldRef.receiver.isThis() && !(fieldRef.receiver instanceof QualifiedThisReference)) {
+ return fieldRef.binding;
+ }
+ }
+ return null;
+ }
+ public StringBuffer print(int indent, StringBuffer output) {
- int pc = codeStream.position;
- lhs.generateAssignment(currentScope, codeStream, this, valueRequired);
- // variable may have been optimized out
- // the lhs is responsible to perform the implicitConversion generation for the assignment since optimized for unused local assignment.
- codeStream.recordPositionsFrom(pc, this.sourceStart);
+ //no () when used as a statement
+ printIndent(indent, output);
+ return printExpressionNoParenthesis(indent, output);
}
+ public StringBuffer printExpression(int indent, StringBuffer output) {
+ //subclass redefine printExpressionNoParenthesis()
+ output.append('(');
+ return printExpressionNoParenthesis(0, output).append(')');
+ }
+
+ public StringBuffer printExpressionNoParenthesis(int indent, StringBuffer output) {
+
+ lhs.printExpression(indent, output).append(" = "); //$NON-NLS-1$
+ return expression.printExpression(0, output);
+ }
+
+ public StringBuffer printStatement(int indent, StringBuffer output) {
+
+ //no () when used as a statement
+ return print(indent, output).append(';');
+ }
public TypeBinding resolveType(BlockScope scope) {
// due to syntax lhs may be only a NameReference, a FieldReference or an ArrayReference
constant = NotAConstant;
- this.lhsType = lhs.resolveType(scope);
- TypeBinding expressionTb = expression.resolveType(scope);
- if (this.lhsType == null || expressionTb == null)
+ if (!(this.lhs instanceof Reference)) {
+ scope.problemReporter().expressionShouldBeAVariable(this.lhs);
+ }
+ this.resolvedType = lhs.resolveType(scope); // expressionType contains the assignment type (lhs Type)
+ TypeBinding rhsType = expression.resolveType(scope);
+ if (this.resolvedType == null || rhsType == null) {
return null;
-
+ }
+ checkAssignmentEffect(scope);
+
// Compile-time conversion of base-types : implicit narrowing integer into byte/short/character
// may require to widen the rhs expression at runtime
- if ((expression.isConstantValueOfTypeAssignableToType(expressionTb, this.lhsType)
- || (this.lhsType.isBaseType() && BaseTypeBinding.isWidening(this.lhsType.id, expressionTb.id)))
- || (BlockScope.areTypesCompatible(expressionTb, this.lhsType))) {
- expression.implicitWidening(this.lhsType, expressionTb);
- return this.lhsType;
+ if ((expression.isConstantValueOfTypeAssignableToType(rhsType, this.resolvedType)
+ || (this.resolvedType.isBaseType() && BaseTypeBinding.isWidening(this.resolvedType.id, rhsType.id)))
+ || rhsType.isCompatibleWith(this.resolvedType)) {
+ expression.implicitWidening(this.resolvedType, rhsType);
+ return this.resolvedType;
}
scope.problemReporter().typeMismatchErrorActualTypeExpectedType(
expression,
- expressionTb,
- this.lhsType);
- return null;
+ rhsType,
+ this.resolvedType);
+ return this.resolvedType;
}
public String toString(int tab) {
: " ") //$NON-NLS-1$
+ expression.toStringExpression();
}
- public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope scope) {
+ public void traverse(ASTVisitor visitor, BlockScope scope) {
if (visitor.visit(this, scope)) {
lhs.traverse(visitor, scope);
git://git.phpeclipse.com / phpeclipse.git / blobdiff