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_LOGTAG_HPP
  25 #define SHARE_VM_LOGGING_LOGTAG_HPP
  26 
  27 #include "memory/allocation.hpp"
  28 #include "utilities/globalDefinitions.hpp"
  29 
  30 // List of available logging tags. New tags should be added here.
  31 // (The tags 'all', 'disable' and 'help' are special tags that can
  32 // not be used in log calls, and should not be listed below.)
  33 #define LOG_TAG_LIST \
  34   LOG_TAG(logging)
  35 
  36 #define PREFIX_LOG_TAG(T) (LogTag::T)
  37 
  38 // Expand a set of log tags to their prefixed names.
  39 // For error detection purposes, the macro passes one more tag than what is supported.
  40 // If too many tags are given, a static assert in the log class will fail.
  41 #define LOG_TAGS_EXPANDED(T0, T1, T2, T3, T4, T5, ...)  PREFIX_LOG_TAG(T0), PREFIX_LOG_TAG(T1), PREFIX_LOG_TAG(T2), \
  42                                                         PREFIX_LOG_TAG(T3), PREFIX_LOG_TAG(T4), PREFIX_LOG_TAG(T5)
  43 // The EXPAND_VARARGS macro is required for MSVC, or it will resolve the LOG_TAGS_EXPANDED macro incorrectly.
  44 #define EXPAND_VARARGS(x) x
  45 #define LOG_TAGS(...) EXPAND_VARARGS(LOG_TAGS_EXPANDED(__VA_ARGS__, __NO_TAG, __NO_TAG, __NO_TAG, __NO_TAG, __NO_TAG, __NO_TAG))
  46 
  47 // Log tags are used to classify log messages.
  48 // Each log message can be assigned between 1 to LogTag::MaxTags number of tags.
  49 // Specifying multiple tags for a log message means that only outputs configured
  50 // for those exact tags, or a subset of the tags with a wildcard, will see the logging.
  51 // Multiple tags should be comma separated, e.g. log_error(tag1, tag2)("msg").
  52 class LogTag : public AllStatic {
  53  public:
  54   // The maximum number of tags that a single log message can have.
  55   // E.g. there might be hundreds of different tags available,
  56   // but a specific log message can only be tagged with up to MaxTags of those.
  57   static const size_t MaxTags = 5;
  58 
  59   enum type {
  60     __NO_TAG,
  61 #define LOG_TAG(name) name,
  62     LOG_TAG_LIST
  63 #undef LOG_TAG
  64     Count
  65   };
  66 
  67   static const char* name(LogTag::type tag) {
  68     return _name[tag];
  69   }
  70 
  71   static LogTag::type from_string(const char *str);
  72 
  73  private:
  74   static const char* _name[];
  75 };
  76 
  77 typedef LogTag::type LogTagType;
  78 
  79 #endif // SHARE_VM_LOGGING_LOGTAG_HPP