1 /* 2 * Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.tools.tree; 27 28 import sun.tools.java.*; 29 import sun.tools.asm.Assembler; 30 import sun.tools.asm.Label; 31 import java.util.Hashtable; 32 33 /** 34 * WARNING: The contents of this source file are not part of any 35 * supported API. Code that depends on them does so at its own risk: 36 * they are subject to change or removal without notice. 37 */ 38 public 39 class AndExpression extends BinaryLogicalExpression { 40 /** 41 * constructor 42 */ AndExpression(long where, Expression left, Expression right)43 public AndExpression(long where, Expression left, Expression right) { 44 super(AND, where, left, right); 45 } 46 47 /* 48 * Check an "and" expression. 49 * 50 * cvars is modified so that 51 * cvar.vsTrue indicates variables with a known value if 52 * both the left and right hand side are true 53 * cvars.vsFalse indicates variables with a known value 54 * either the left or right hand side is false 55 */ checkCondition(Environment env, Context ctx, Vset vset, Hashtable<Object, Object> exp, ConditionVars cvars)56 public void checkCondition(Environment env, Context ctx, Vset vset, 57 Hashtable<Object, Object> exp, ConditionVars cvars) { 58 // Find out when the left side is true/false 59 left.checkCondition(env, ctx, vset, exp, cvars); 60 left = convert(env, ctx, Type.tBoolean, left); 61 Vset vsTrue = cvars.vsTrue.copy(); 62 Vset vsFalse = cvars.vsFalse.copy(); 63 64 // Only look at the right side if the left side is true 65 right.checkCondition(env, ctx, vsTrue, exp, cvars); 66 right = convert(env, ctx, Type.tBoolean, right); 67 68 // cvars.vsTrue already reports when both returned true 69 // cvars.vsFalse must be set to either the left or right side 70 // returning false 71 cvars.vsFalse = cvars.vsFalse.join(vsFalse); 72 } 73 74 /** 75 * Evaluate 76 */ eval(boolean a, boolean b)77 Expression eval(boolean a, boolean b) { 78 return new BooleanExpression(where, a && b); 79 } 80 81 /** 82 * Simplify 83 */ simplify()84 Expression simplify() { 85 if (left.equals(true)) { 86 return right; 87 } 88 if (right.equals(false)) { 89 // Preserve effects of left argument. 90 return new CommaExpression(where, left, right).simplify(); 91 } 92 if (right.equals(true)) { 93 return left; 94 } 95 if (left.equals(false)) { 96 return left; 97 } 98 return this; 99 } 100 101 /** 102 * Code 103 */ codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue)104 void codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue) { 105 if (whenTrue) { 106 Label lbl2 = new Label(); 107 left.codeBranch(env, ctx, asm, lbl2, false); 108 right.codeBranch(env, ctx, asm, lbl, true); 109 asm.add(lbl2); 110 } else { 111 left.codeBranch(env, ctx, asm, lbl, false); 112 right.codeBranch(env, ctx, asm, lbl, false); 113 } 114 } 115 } 116