+++ /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
- * Genady Beriozkin - added support for reporting assignment with no effect
- *******************************************************************************/
-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 Assignment extends Expression {
-
- public Expression lhs;
- public Expression expression;
-
- 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 = lhs;
- lhs.bits |= IsStrictlyAssignedMASK; // tag lhs as assigned
-
- this.expression = expression;
-
- this.sourceStart = lhs.sourceStart;
- this.sourceEnd = sourceEnd;
- }
-
- public FlowInfo analyseCode(
- BlockScope currentScope,
- FlowContext flowContext,
- FlowInfo flowInfo) {
- // record setting a variable: 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.
-
- return ((Reference) lhs)
- .analyseAssignment(currentScope, flowContext, flowInfo, this, false)
- .unconditionalInits();
- }
-
- 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
- }
- }
-
- 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) {
-
- //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;
- if (!(this.lhs instanceof Reference) || this.lhs.isThis()) {
- scope.problemReporter().expressionShouldBeAVariable(this.lhs);
- return null;
- }
- 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(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,
- rhsType,
- this.resolvedType);
- return this.resolvedType;
- }
- /* (non-Javadoc)
- * @see org.eclipse.jdt.internal.compiler.ast.Expression#resolveTypeExpecting(org.eclipse.jdt.internal.compiler.lookup.BlockScope, org.eclipse.jdt.internal.compiler.lookup.TypeBinding)
- */
- public TypeBinding resolveTypeExpecting(
- BlockScope scope,
- TypeBinding expectedType) {
-
- TypeBinding type = super.resolveTypeExpecting(scope, expectedType);
- // signal possible accidental boolean assignment (instead of using '==' operator)
- if (expectedType == BooleanBinding
- && this.lhs.resolvedType == BooleanBinding
- && (this.lhs.bits & IsStrictlyAssignedMASK) != 0) {
- scope.problemReporter().possibleAccidentalBooleanAssignment(this);
- }
-
- return type;
- }
-
- public void traverse(ASTVisitor visitor, BlockScope scope) {
-
- if (visitor.visit(this, scope)) {
- lhs.traverse(visitor, scope);
- expression.traverse(visitor, scope);
- }
- visitor.endVisit(this, scope);
- }
-}
\ No newline at end of file
projects / org.ibex.tool.git / blobdiff