1 /*
2 * Copyright (c) 2015, 2016, 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 #ifndef SHARE_VM_LOGGING_LOG_HPP
25 #define SHARE_VM_LOGGING_LOG_HPP
26
27 #include "logging/logLevel.hpp"
28 #include "logging/logPrefix.hpp"
29 #include "logging/logTagSet.hpp"
30 #include "logging/logTag.hpp"
31 #include "memory/allocation.hpp"
32 #include "runtime/os.hpp"
33 #include "utilities/debug.hpp"
34 #include "utilities/ostream.hpp"
35
36 //
37 // Logging macros
38 //
39 // Usage:
40 // log_<level>(<comma separated log tags>)(<printf-style log arguments>);
41 // e.g.
42 // log_debug(logging)("message %d", i);
43 //
44 // Note that these macros will not evaluate the arguments unless the logging is enabled.
45 //
46 #define log_error(...) (!log_is_enabled(Error, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Error>
47 #define log_warning(...) (!log_is_enabled(Warning, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Warning>
48 #define log_info(...) (!log_is_enabled(Info, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Info>
49 #define log_debug(...) (!log_is_enabled(Debug, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Debug>
50 #define log_trace(...) (!log_is_enabled(Trace, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Trace>
51
52 // Macros for logging that should be excluded in product builds.
53 // Available for levels Info, Debug and Trace. Includes test macro that
54 // evaluates to false in product builds.
55 #ifndef PRODUCT
56 #define log_develop_info(...) (!log_is_enabled(Info, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Info>
57 #define log_develop_debug(...) (!log_is_enabled(Debug, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Debug>
58 #define log_develop_trace(...) (!log_is_enabled(Trace, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Trace>
59 #define log_develop_is_enabled(level, ...) log_is_enabled(level, __VA_ARGS__)
60 #else
61 #define DUMMY_ARGUMENT_CONSUMER(...)
62 #define log_develop_info(...) DUMMY_ARGUMENT_CONSUMER
63 #define log_develop_debug(...) DUMMY_ARGUMENT_CONSUMER
64 #define log_develop_trace(...) DUMMY_ARGUMENT_CONSUMER
65 #define log_develop_is_enabled(...) false
66 #endif
67
68 // Convenience macro to test if the logging is enabled on the specified level for given tags.
69 #define log_is_enabled(level, ...) (Log<LOG_TAGS(__VA_ARGS__)>::is_level(LogLevel::level))
70
71 //
72 // Log class for more advanced logging scenarios.
73 // Has printf-style member functions for each log level (trace(), debug(), etc).
74 //
75 // Also has outputStream compatible API for the different log-levels.
76 // The streams are resource allocated when requested and are accessed through
77 // calls to <level>_stream() functions (trace_stream(), debug_stream(), etc).
78 //
79 // Example usage:
80 // LogHandle(logging) log;
81 // if (log.is_debug()) {
82 // ...
83 // log.debug("result = %d", result).trace(" tracing info");
84 // obj->print_on(log.debug_stream());
85 // }
86 //
87 #define LogHandle(...) Log<LOG_TAGS(__VA_ARGS__)>
88
89 template <LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
90 class Log;
91
92 // Non-template helper class for implementing write-slowpath in cpp
93 class LogWriteHelper : AllStatic {
94 private:
95
96 template <LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
97 friend class Log;
98
99 ATTRIBUTE_PRINTF(6, 0)
100 static void write_large(LogTagSet& lts,
101 LogLevelType level,
102 const char* prefix,
103 size_t prefix_len,
104 size_t msg_len,
105 const char* fmt,
106 va_list args);
107 };
108
109 template <LogTagType T0, LogTagType T1 = LogTag::__NO_TAG, LogTagType T2 = LogTag::__NO_TAG, LogTagType T3 = LogTag::__NO_TAG,
110 LogTagType T4 = LogTag::__NO_TAG, LogTagType GuardTag = LogTag::__NO_TAG>
111 class Log VALUE_OBJ_CLASS_SPEC {
112 private:
113 static const size_t LogBufferSize = 512;
114 public:
115 // Make sure no more than the maximum number of tags have been given.
116 // The GuardTag allows this to be detected if/when it happens. If the GuardTag
117 // is not __NO_TAG, the number of tags given exceeds the maximum allowed.
118 STATIC_ASSERT(GuardTag == LogTag::__NO_TAG); // Number of logging tags exceeds maximum supported!
119
120 // Empty constructor to avoid warnings on MSVC about unused variables
121 // when the log instance is only used for static functions.
122 Log() {
123 }
124
125 static bool is_level(LogLevelType level) {
126 return LogTagSetMapping<T0, T1, T2, T3, T4>::tagset().is_level(level);
127 }
128
129 ATTRIBUTE_PRINTF(2, 3)
130 static void write(LogLevelType level, const char* fmt, ...) {
131 va_list args;
132 va_start(args, fmt);
133 vwrite(level, fmt, args);
134 va_end(args);
135 };
136
137 template <LogLevelType Level>
138 ATTRIBUTE_PRINTF(1, 2)
139 static void write(const char* fmt, ...) {
140 va_list args;
141 va_start(args, fmt);
142 vwrite(Level, fmt, args);
143 va_end(args);
144 };
145
146 ATTRIBUTE_PRINTF(2, 0)
147 static void vwrite(LogLevelType level, const char* fmt, va_list args) {
148 char buf[LogBufferSize];
149 va_list saved_args; // For re-format on buf overflow.
150 va_copy(saved_args, args);
151 size_t prefix_len = LogPrefix<T0, T1, T2, T3, T4>::prefix(buf, sizeof(buf));
152 // Check that string fits in buffer; resize buffer if necessary
153 int ret = os::log_vsnprintf(buf + prefix_len, sizeof(buf) - prefix_len, fmt, args);
154 assert(ret >= 0, "Log message buffer issue");
155 size_t msg_len = ret;
156 LogTagSet& lts = LogTagSetMapping<T0, T1, T2, T3, T4>::tagset();
157 if (msg_len >= sizeof(buf)) {
158 LogWriteHelper::write_large(lts, level, buf, prefix_len, msg_len, fmt, saved_args);
159 } else {
160 lts.log(level, buf);
161 }
162 va_end(saved_args);
163 }
164
165 #define LOG_LEVEL(level, name) ATTRIBUTE_PRINTF(2, 0) \
166 Log& v##name(const char* fmt, va_list args) { \
167 vwrite(LogLevel::level, fmt, args); \
168 return *this; \
169 } \
170 Log& name(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3) { \
171 va_list args; \
172 va_start(args, fmt); \
173 vwrite(LogLevel::level, fmt, args); \
174 va_end(args); \
175 return *this; \
176 } \
177 static bool is_##name() { \
178 return is_level(LogLevel::level); \
179 } \
180 static outputStream* name##_stream() { \
181 return new logStream(write<LogLevel::level>); \
182 }
183 LOG_LEVEL_LIST
184 #undef LOG_LEVEL
185 };
186
187 #endif // SHARE_VM_LOGGING_LOG_HPP