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1   /*
2    * Copyright (c) 2011, 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 com.sun.tools.javac.util;
27  
28  
29  /**
30   * Simple facility for unconditional assertions.
31   * The methods in this class are described in terms of equivalent assert
32   * statements, assuming that assertions have been enabled.
33   *
34   *  <p><b>This is NOT part of any supported API.
35   *  If you write code that depends on this, you do so at your own risk.
36   *  This code and its internal interfaces are subject to change or
37   *  deletion without notice.</b>
38   */
39  public class Assert {
40      /** Equivalent to
41       *   assert cond;
42       */
43      public static void check(boolean cond) {
44          if (!cond)
45              error();
46      }
47  
48      /** Equivalent to
49       *   assert (o == null);
50       */
51      public static void checkNull(Object o) {
52          if (o != null)
53              error();
54      }
55  
56      /** Equivalent to
57       *   assert (t != null); return t;
58       */
59      public static <T> T checkNonNull(T t) {
60          if (t == null)
61              error();
62          return t;
63      }
64  
65      /** Equivalent to
66       *   assert cond : value;
67       */
68      public static void check(boolean cond, int value) {
69          if (!cond)
70              error(String.valueOf(value));
71      }
72  
73      /** Equivalent to
74       *   assert cond : value;
75       */
76      public static void check(boolean cond, long value) {
77          if (!cond)
78              error(String.valueOf(value));
79      }
80  
81      /** Equivalent to
82       *   assert cond : value;
83       */
84      public static void check(boolean cond, Object value) {
85          if (!cond)
86              error(String.valueOf(value));
87      }
88  
89      /** Equivalent to
90       *   assert cond : value;
91       */
92      public static void check(boolean cond, String msg) {
93          if (!cond)
94              error(msg);
95      }
96  
97      /** Equivalent to
98       *   assert (o == null) : value;
99       */
100     public static void checkNull(Object o, Object value) {
101         if (o != null)
102             error(String.valueOf(value));
103     }
104 
105     /** Equivalent to
106      *   assert (o == null) : value;
107      */
108     public static void checkNull(Object o, String msg) {
109         if (o != null)
110             error(msg);
111     }
112 
113     /** Equivalent to
114      *   assert (o != null) : value;
115      */
116     public static <T> T checkNonNull(T t, String msg) {
117         if (t == null)
118             error(msg);
119         return t;
120     }
121 
122     /** Equivalent to
123      *   assert false;
124      */
125     public static void error() {
126         throw new AssertionError();
127     }
128 
129     /** Equivalent to
130      *   assert false : msg;
131      */
132     public static void error(String msg) {
133         throw new AssertionError(msg);
134     }
135 
136     /** Prevent instantiation. */
137     private Assert() { }
138 }