/* * Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.tools.tree; import sun.tools.java.*;import sun.tools.asm.Assembler;import java.io.PrintStream;import java.util.Hashtable; /** * WARNING: The contents of this source file are not part of any * supported API.  Code that depends on them does so at its own risk: * they are subject to change or removal without notice. */publicclass AssignExpression extends BinaryAssignExpression {     private FieldUpdater updater = null;     /**     * Constructor     */    public AssignExpression(long where, Expression left, Expression right) {        super(ASSIGN, where, left, right);    }     /**     * Check an assignment expression     */    public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable exp) {        if (left instanceof IdentifierExpression) {            // we don't want to mark an identifier as having a value            // until having evaluated the right-hand side            vset = right.checkValue(env, ctx, vset, exp);            vset = left.checkLHS(env, ctx, vset, exp);        } else {            // normally left to right evaluation.            vset = left.checkLHS(env, ctx, vset, exp);            vset = right.checkValue(env, ctx, vset, exp);        }        type = left.type;        right = convert(env, ctx, type, right);         // Get field updater (access method) if needed, else null.        updater = left.getAssigner(env, ctx);         return vset;    }     /**     * Inline     */    public Expression inlineValue(Environment env, Context ctx) {        if (implementation != null)            return implementation.inlineValue(env, ctx);        // Must be 'inlineLHS' here.  But compare with similar case in        // 'AssignOpExpression' and 'IncDecExpression', which needs 'inlineValue'.        left = left.inlineLHS(env, ctx);        right = right.inlineValue(env, ctx);        if (updater != null) {            updater = updater.inline(env, ctx);        }        return this;    }     /**     * Create a copy of the expression for method inlining     */    public Expression copyInline(Context ctx) {        if (implementation != null)            return implementation.copyInline(ctx);        AssignExpression e = (AssignExpression)clone();        e.left = left.copyInline(ctx);        e.right = right.copyInline(ctx);        if (updater != null) {            e.updater = updater.copyInline(ctx);        }        return e;    }     /**     * The cost of inlining this expression     */    public int costInline(int thresh, Environment env, Context ctx) {        /*----------*        return 2 + super.costInline(thresh, env, ctx);        *----------*/        return (updater != null)            // Cost of rhs expression + cost of access method call.            // Access method call cost includes lhs cost.            ? right.costInline(thresh, env, ctx) +                  updater.costInline(thresh, env, ctx, false)            // Cost of rhs expression + cost of lhs expression +            // cost of store instruction.            : right.costInline(thresh, env, ctx) +                  left.costInline(thresh, env, ctx) + 2;    }     /**     * Code     */    public void codeValue(Environment env, Context ctx, Assembler asm) {        if (updater == null) {            // Field is directly accessible.            int depth = left.codeLValue(env, ctx, asm);            right.codeValue(env, ctx, asm);            codeDup(env, ctx, asm, right.type.stackSize(), depth);            left.codeStore(env, ctx, asm);        } else {            // Must use access method.            // Left operand is always a 'FieldExpression', or            // is rewritten as one via 'implementation'.            updater.startAssign(env, ctx, asm);            right.codeValue(env, ctx, asm);            updater.finishAssign(env, ctx, asm, true);        }    }     public void code(Environment env, Context ctx, Assembler asm) {        if (updater == null) {            // Field is directly accessible.            left.codeLValue(env, ctx, asm);            right.codeValue(env, ctx, asm);            left.codeStore(env, ctx, asm);        } else {            // Must use access method.            // Left operand is always a 'FieldExpression', or            // is rewritten as one via 'implementation'.            updater.startAssign(env, ctx, asm);            right.codeValue(env, ctx, asm);            updater.finishAssign(env, ctx, asm, false);        }    }}