first scanner /parser copied from the jdt java version

[phpeclipse.git] / net.sourceforge.phpeclipse / src / net / sourceforge / phpdt / internal / compiler / ast / Assignment.java

diff --git a/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/Assignment.java b/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/Assignment.java
new file mode 100644 (file)
index 0000000..5f7c560
--- /dev/null
+++ b/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/Assignment.java
@@ -0,0 +1,117 @@
+/*******************************************************************************
+ * 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.*;
+import net.sourceforge.phpdt.internal.compiler.flow.*;
+import net.sourceforge.phpdt.internal.compiler.lookup.*;
+
+public class Assignment extends Expression {
+
+       public Reference 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.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 lhs
+                       .analyseAssignment(currentScope, flowContext, flowInfo, this, false)
+                       .unconditionalInits();
+       }
+
+       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;
+               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);
+       }
+
+       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)
+                       return null;
+
+               // 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)))
+                       || (scope.areTypesCompatible(expressionTb, this.lhsType))) {
+                       expression.implicitWidening(this.lhsType, expressionTb);
+                       return this.lhsType;
+               }
+               scope.problemReporter().typeMismatchErrorActualTypeExpectedType(
+                       expression,
+                       expressionTb,
+                       this.lhsType);
+               return null;
+       }
+
+       public String toString(int tab) {
+
+               //no () when used as a statement 
+               return tabString(tab) + toStringExpressionNoParenthesis();
+       }
+
+       public String toStringExpression() {
+
+               //subclass redefine toStringExpressionNoParenthesis()
+               return "(" + toStringExpressionNoParenthesis() + ")"; //$NON-NLS-2$ //$NON-NLS-1$
+       } 
+       
+       public String toStringExpressionNoParenthesis() {
+
+               return lhs.toStringExpression() + " " //$NON-NLS-1$
+                       + "=" //$NON-NLS-1$
+                       + ((expression.constant != null) && (expression.constant != NotAConstant)
+                               ? " /*cst:" + expression.constant.toString() + "*/ " //$NON-NLS-1$ //$NON-NLS-2$
+                               : " ")  //$NON-NLS-1$
+                       + expression.toStringExpression();
+       }
+       public void traverse(IAbstractSyntaxTreeVisitor 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