1 /*
2 * Copyright (c) 2015, 2017, 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 jdk.internal.jshell.debug;
27
28 import java.io.PrintStream;
29 import java.util.HashMap;
30 import java.util.Map;
31 import jdk.jshell.JShell;
32
33 /**
34 * This class is used to externally control output messages for debugging the
35 * implementation of the JShell API.
36 * <p>
37 * This is not part of the SPI nor API.
38 */
39 public class InternalDebugControl {
40
41 /**
42 * This is a static only class; The constructor should never be called.
43 */
44 private InternalDebugControl() {
45 }
46
47 /**
48 * General debugging.
49 */
50 public static final int DBG_GEN = 0b0000001;
51
52 /**
53 * File manager debuging.
54 */
55 public static final int DBG_FMGR = 0b0000010;
56
57 /**
58 * Completion analysis debugging.
59 */
60 public static final int DBG_COMPA = 0b0000100;
61
62 /**
63 * Dependency debugging.
64 */
65 public static final int DBG_DEP = 0b0001000;
66
67 /**
68 * Event debugging.
69 */
70 public static final int DBG_EVNT = 0b0010000;
71
72 /**
73 * Event debugging.
74 */
75 public static final int DBG_WRAP = 0b0100000;
76
77 private static Map<JShell, Integer> debugMap = null;
78
79 /**
80 * Sets which debug flags are enabled for a given JShell instance. The flags
81 * are or'ed bits as defined in {@code DBG_*}.
82 *
83 * @param state the JShell instance
84 * @param flags the or'ed debug bits
85 */
86 public static void setDebugFlags(JShell state, int flags) {
87 if (debugMap == null) {
88 debugMap = new HashMap<>();
89 }
90 debugMap.put(state, flags);
91 }
92
93 /**
94 * Release a JShell instance.
95 *
96 * @param state the JShell instance
97 */
98 public static void release(JShell state) {
99 if (debugMap != null) {
100 debugMap.remove(state);
101 }
102 }
103
104 /**
105 * Tests if any of the specified debug flags are enabled.
106 *
107 * @param state the JShell instance
108 * @param flag the {@code DBG_*} bits to check
109 * @return true if any of the flags are enabled
110 */
111 public static boolean isDebugEnabled(JShell state, int flag) {
112 if (debugMap == null) {
113 return false;
114 }
115 Integer flags = debugMap.get(state);
116 if (flags == null) {
117 return false;
118 }
119 return (flags & flag) != 0;
120 }
121
122 /**
123 * Displays debug info if the specified debug flags are enabled.
124 *
125 * @param state the current JShell instance
126 * @param err the {@code PrintStream} to report on
127 * @param flags {@code DBG_*} flag bits to check
128 * @param format format string for the output
129 * @param args args for the format string
130 */
131 public static void debug(JShell state, PrintStream err, int flags, String format, Object... args) {
132 if (isDebugEnabled(state, flags)) {
133 err.printf(format, args);
134 }
135 }
136
137 /**
138 * Displays a fatal exception as debug info.
139 *
140 * @param state the current JShell instance
141 * @param err the {@code PrintStream} to report on
142 * @param ex the fatal Exception
143 * @param where additional context
144 */
145 public static void debug(JShell state, PrintStream err, Throwable ex, String where) {
146 if (isDebugEnabled(state, 0xFFFFFFFF)) {
147 err.printf("Fatal error: %s: %s\n", where, ex.getMessage());
148 ex.printStackTrace(err);
149 }
150 }
151 }