1 /* 2 * Copyright (c) 2011, 2018, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 25 package org.graalvm.compiler.java; 26 27 public class JsrScope { 28 29 public static final JsrScope EMPTY_SCOPE = new JsrScope(); 30 31 private final long scope; 32 33 private JsrScope(long scope) { 34 this.scope = scope; 35 } 36 37 public JsrScope() { 38 this.scope = 0; 39 } 40 41 public int nextReturnAddress() { 42 return (int) (scope & 0xffff); 43 } 44 45 public JsrScope push(int jsrReturnBci) { 46 if ((scope & 0xffff000000000000L) != 0) { 47 throw new JsrNotSupportedBailout("only four jsr nesting levels are supported"); 48 } 49 return new JsrScope((scope << 16) | jsrReturnBci); 50 } 51 52 public boolean isEmpty() { 53 return scope == 0; 54 } 55 56 public boolean isPrefixOf(JsrScope other) { 57 return (scope & other.scope) == scope; 58 } 59 60 public JsrScope pop() { 61 return new JsrScope(scope >>> 16); 62 } 63 64 @Override 65 public int hashCode() { 66 return (int) (scope ^ (scope >>> 32)); 67 } 68 69 @Override 70 public boolean equals(Object obj) { 71 if (this == obj) { 72 return true; 73 } 74 return obj != null && getClass() == obj.getClass() && scope == ((JsrScope) obj).scope; 75 } 76 77 @Override 78 public String toString() { 79 StringBuilder sb = new StringBuilder(); 80 long tmp = scope; 81 sb.append(" ["); 82 while (tmp != 0) { 83 sb.append(", ").append(tmp & 0xffff); 84 tmp = tmp >>> 16; 85 } 86 sb.append(']'); 87 return sb.toString(); 88 } 89 }