1 /*
   2  * Copyright (c) 2015, 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 "utilities/debug.hpp"
  33 #include "utilities/ostream.hpp"
  34 
  35 //
  36 // Logging macros
  37 //
  38 // Usage:
  39 //   log_<level>(<comma separated log tags>)(<printf-style log arguments>);
  40 // e.g.
  41 //   log_debug(logging)("message %d", i);
  42 //
  43 // Note that these macros will not evaluate the arguments unless the logging is enabled.
  44 //
  45 #define log_error(...)   (!log_is_enabled(Error, __VA_ARGS__))   ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Error>
  46 #define log_warning(...) (!log_is_enabled(Warning, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Warning>
  47 #define log_info(...)    (!log_is_enabled(Info, __VA_ARGS__))    ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Info>
  48 #define log_debug(...)   (!log_is_enabled(Debug, __VA_ARGS__))   ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Debug>
  49 #define log_trace(...)   (!log_is_enabled(Trace, __VA_ARGS__))   ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Trace>
  50 #ifndef PRODUCT
  51 #define log_develop(...) (!log_is_enabled(Develop, __VA_ARGS__)) ? (void)0 : Log<LOG_TAGS(__VA_ARGS__)>::write<LogLevel::Develop>
  52 #else
  53 #define DUMMY_ARGUMENT_CONSUMER(...)
  54 #define log_develop(...) DUMMY_ARGUMENT_CONSUMER
  55 #endif
  56 
  57 // Convenience macro to test if the logging is enabled on the specified level for given tags.
  58 #define log_is_enabled(level, ...) (Log<LOG_TAGS(__VA_ARGS__)>::is_level(LogLevel::level))
  59 
  60 //
  61 // Log class for more advanced logging scenarios.
  62 // Has printf-style member functions for each log level (trace(), debug(), etc).
  63 //
  64 // Also has outputStream compatible API for the different log-levels.
  65 // The streams are resource allocated when requested and are accessed through
  66 // calls to <level>_stream() functions (trace_stream(), debug_stream(), etc).
  67 //
  68 // Example usage:
  69 //   LogHandle(logging) log;
  70 //   if (log.is_debug()) {
  71 //     ...
  72 //     log.debug("result = %d", result).trace(" tracing info");
  73 //     obj->print_on(log.debug_stream());
  74 //   }
  75 //
  76 #define LogHandle(...)  Log<LOG_TAGS(__VA_ARGS__)>
  77 
  78 template <LogTagType T0, LogTagType T1 = LogTag::__NO_TAG, LogTagType T2 = LogTag::__NO_TAG, LogTagType T3 = LogTag::__NO_TAG,
  79           LogTagType T4 = LogTag::__NO_TAG, LogTagType GuardTag = LogTag::__NO_TAG>
  80 class Log VALUE_OBJ_CLASS_SPEC {
  81  private:
  82   static const size_t LogBufferSize = 512;
  83  public:
  84   // Make sure no more than the maximum number of tags have been given.
  85   // The GuardTag allows this to be detected if/when it happens. If the GuardTag
  86   // is not __NO_TAG, the number of tags given exceeds the maximum allowed.
  87   STATIC_ASSERT(GuardTag == LogTag::__NO_TAG); // Number of logging tags exceeds maximum supported!
  88 
  89   static bool is_level(LogLevelType level) {
  90     return LogTagSetMapping<T0, T1, T2, T3, T4>::tagset().is_level(level);
  91   }
  92 
  93   template <LogLevelType Level>
  94   ATTRIBUTE_PRINTF(1, 2)
  95   static void write(const char* fmt, ...) {
  96     va_list args;
  97     va_start(args, fmt);
  98     vwrite<Level>(fmt, args);
  99     va_end(args);
 100   };
 101 
 102   template <LogLevelType Level>
 103   ATTRIBUTE_PRINTF(1, 0)
 104   static void vwrite(const char* fmt, va_list args) {
 105     char buf[LogBufferSize];
 106     size_t prefix_len = LogPrefix<T0, T1, T2, T3, T4>::prefix(buf, sizeof(buf));
 107     int ret = vsnprintf(buf + prefix_len, sizeof(buf) - prefix_len, fmt, args);
 108     assert(ret >= 0 && (size_t)ret < sizeof(buf), "Log message too long");
 109     puts<Level>(buf);
 110   }
 111 
 112   template <LogLevelType Level>
 113   static void puts(const char* string) {
 114     LogTagSetMapping<T0, T1, T2, T3, T4>::tagset().log(Level, string);
 115   }
 116 
 117 #define LOG_LEVEL(level, name) ATTRIBUTE_PRINTF(2, 0) \
 118   Log& v##name(const char* fmt, va_list args) { \
 119     vwrite<LogLevel::level>(fmt, args); \
 120     return *this; \
 121   } \
 122   Log& name(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3) { \
 123     va_list args; \
 124     va_start(args, fmt); \
 125     vwrite<LogLevel::level>(fmt, args); \
 126     va_end(args); \
 127     return *this; \
 128   } \
 129   static bool is_##name() { \
 130     return is_level(LogLevel::level); \
 131   } \
 132   static outputStream* name##_stream() { \
 133     return new logStream(write<LogLevel::level>); \
 134   }
 135   LOG_LEVEL_LIST
 136 #undef LOG_LEVEL
 137 };
 138 
 139 #endif // SHARE_VM_LOGGING_LOG_HPP