gcc/jit/jit-logging.h

   1 /* Internals of libgccjit: logging
   2    Copyright (C) 2014-2016 Free Software Foundation, Inc.
   3    Contributed by David Malcolm <dmalcolm@redhat.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it
   8 under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef JIT_LOGGING_H
  22 #define JIT_LOGGING_H
  23
  24 #include "jit-common.h"
  25
  26 namespace gcc {
  27
  28 namespace jit {
  29
  30 /* A gcc::jit::logger encapsulates a logging stream: a way to send
  31    lines of pertinent information to a FILE *.  */
  32
  33 class logger
  34 {
  35  public:
  36   logger (FILE *f_out, int flags, int verbosity);
  37   ~logger ();
  38
  39   void incref (const char *reason);
  40   void decref (const char *reason);
  41
  42   void log (const char *fmt, ...)
  43     GNU_PRINTF(2, 3);
  44   void log_va (const char *fmt, va_list ap)
  45     GNU_PRINTF(2, 0);
  46
  47   void enter_scope (const char *scope_name);
  48   void exit_scope (const char *scope_name);
  49
  50 private:
  51   int m_refcount;
  52   FILE *m_f_out;
  53   int m_indent_level;
  54   bool m_log_refcount_changes;
  55 };
  56
  57 /* The class gcc::jit::log_scope is an RAII-style class intended to make
  58    it easy to notify a logger about entering and exiting the body of a
  59    given function.  */
  60
  61 class log_scope
  62 {
  63 public:
  64   log_scope (logger *logger, const char *name);
  65   ~log_scope ();
  66
  67  private:
  68   logger *m_logger;
  69   const char *m_name;
  70 };
  71
  72 /* The constructor for gcc::jit::log_scope.
  73
  74    The normal case is that the logger is NULL, in which case this should
  75    be largely a no-op.
  76
  77    If we do have a logger, notify it that we're entering the given scope.
  78    We also need to hold a reference on it, to avoid a use-after-free
  79    when logging the cleanup of the owner of the logger.  */
  80
  81 inline
  82 log_scope::log_scope (logger *logger, const char *name) :
  83  m_logger (logger),
  84  m_name (name)
  85 {
  86   if (m_logger)
  87     {
  88       m_logger->incref ("log_scope ctor");
  89       m_logger->enter_scope (m_name);
  90     }
  91 }
  92
  93 /* The destructor for gcc::jit::log_scope; essentially the opposite of
  94    the constructor.  */
  95
  96 inline
  97 log_scope::~log_scope ()
  98 {
  99   if (m_logger)
 100     {
 101       m_logger->exit_scope (m_name);
 102       m_logger->decref ("log_scope dtor");
 103     }
 104 }
 105
 106 /* A gcc::jit::log_user is something that potentially uses a
 107    gcc::jit::logger (which could be NULL).
 108
 109    It is the base class for each of:
 110
 111       - class gcc::jit::recording::context
 112
 113       - class gcc::jit::playback::context
 114
 115       - class gcc::jit::tempdir
 116
 117       - class gcc::jit::result
 118
 119    The log_user class keeps the reference-count of a logger up-to-date.  */
 120
 121 class log_user
 122 {
 123  public:
 124   log_user (logger *logger);
 125   ~log_user ();
 126
 127   logger * get_logger () const { return m_logger; }
 128   void set_logger (logger * logger);
 129
 130   void log (const char *fmt, ...) const
 131     GNU_PRINTF(2, 3);
 132
 133   void enter_scope (const char *scope_name);
 134   void exit_scope (const char *scope_name);
 135
 136  private:
 137   logger *m_logger;
 138 };
 139
 140 /* A shortcut for calling log from a context/result, handling the common
 141    case where the underlying logger is NULL via a no-op.  */
 142
 143 inline void
 144 log_user::log (const char *fmt, ...) const
 145 {
 146   if (m_logger)
 147     {
 148       va_list ap;
 149       va_start (ap, fmt);
 150       m_logger->log_va (fmt, ap);
 151       va_end (ap);
 152     }
 153 }
 154
 155 /* A shortcut for recording entry into a scope from a context/result,
 156    handling the common case where the underlying logger is NULL via
 157    a no-op.  */
 158
 159 inline void
 160 log_user::enter_scope (const char *scope_name)
 161 {
 162   if (m_logger)
 163     m_logger->enter_scope (scope_name);
 164 }
 165
 166 /* A shortcut for recording exit from a scope from a context/result,
 167    handling the common case where the underlying logger is NULL via
 168    a no-op.  */
 169
 170 inline void
 171 log_user::exit_scope (const char *scope_name)
 172 {
 173   if (m_logger)
 174     m_logger->exit_scope (scope_name);
 175 }
 176
 177 } // namespace gcc::jit
 178
 179 } // namespace gcc
 180
 181 /* If the given logger is non-NULL, log entry/exit of this scope to
 182    it, identifying it using __PRETTY_FUNCTION__.  */
 183
 184 #define JIT_LOG_SCOPE(LOGGER) \
 185   gcc::jit::log_scope s (LOGGER, __PRETTY_FUNCTION__)
 186
 187 /* If the given logger is non-NULL, log entry/exit of this scope to
 188    it, identifying it using __func__.  */
 189
 190 #define JIT_LOG_FUNC(LOGGER) \
 191   gcc::jit::log_scope s (LOGGER, __func__)
 192
 193 #endif /* JIT_LOGGING_H */