lib/zstd/common/debug.h

   1 /* ******************************************************************
   2  * debug
   3  * Part of FSE library
   4  * Copyright (c) Yann Collet, Facebook, Inc.
   5  *
   6  * You can contact the author at :
   7  * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
   8  *
   9  * This source code is licensed under both the BSD-style license (found in the
  10  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  11  * in the COPYING file in the root directory of this source tree).
  12  * You may select, at your option, one of the above-listed licenses.
  13 ****************************************************************** */
  14
  15
  16 /*
  17  * The purpose of this header is to enable debug functions.
  18  * They regroup assert(), DEBUGLOG() and RAWLOG() for run-time,
  19  * and DEBUG_STATIC_ASSERT() for compile-time.
  20  *
  21  * By default, DEBUGLEVEL==0, which means run-time debug is disabled.
  22  *
  23  * Level 1 enables assert() only.
  24  * Starting level 2, traces can be generated and pushed to stderr.
  25  * The higher the level, the more verbose the traces.
  26  *
  27  * It's possible to dynamically adjust level using variable g_debug_level,
  28  * which is only declared if DEBUGLEVEL>=2,
  29  * and is a global variable, not multi-thread protected (use with care)
  30  */
  31
  32 #ifndef DEBUG_H_12987983217
  33 #define DEBUG_H_12987983217
  34
  35
  36
  37 /* static assert is triggered at compile time, leaving no runtime artefact.
  38  * static assert only works with compile-time constants.
  39  * Also, this variant can only be used inside a function. */
  40 #define DEBUG_STATIC_ASSERT(c) (void)sizeof(char[(c) ? 1 : -1])
  41
  42
  43 /* DEBUGLEVEL is expected to be defined externally,
  44  * typically through compiler command line.
  45  * Value must be a number. */
  46 #ifndef DEBUGLEVEL
  47 #  define DEBUGLEVEL 0
  48 #endif
  49
  50
  51 /* recommended values for DEBUGLEVEL :
  52  * 0 : release mode, no debug, all run-time checks disabled
  53  * 1 : enables assert() only, no display
  54  * 2 : reserved, for currently active debug path
  55  * 3 : events once per object lifetime (CCtx, CDict, etc.)
  56  * 4 : events once per frame
  57  * 5 : events once per block
  58  * 6 : events once per sequence (verbose)
  59  * 7+: events at every position (*very* verbose)
  60  *
  61  * It's generally inconvenient to output traces > 5.
  62  * In which case, it's possible to selectively trigger high verbosity levels
  63  * by modifying g_debug_level.
  64  */
  65
  66 #if (DEBUGLEVEL>=1)
  67 #  define ZSTD_DEPS_NEED_ASSERT
  68 #  include "zstd_deps.h"
  69 #else
  70 #  ifndef assert   /* assert may be already defined, due to prior #include <assert.h> */
  71 #    define assert(condition) ((void)0)   /* disable assert (default) */
  72 #  endif
  73 #endif
  74
  75 #if (DEBUGLEVEL>=2)
  76 #  define ZSTD_DEPS_NEED_IO
  77 #  include "zstd_deps.h"
  78 extern int g_debuglevel; /* the variable is only declared,
  79                             it actually lives in debug.c,
  80                             and is shared by the whole process.
  81                             It's not thread-safe.
  82                             It's useful when enabling very verbose levels
  83                             on selective conditions (such as position in src) */
  84
  85 #  define RAWLOG(l, ...) {                                       \
  86                 if (l<=g_debuglevel) {                           \
  87                     ZSTD_DEBUG_PRINT(__VA_ARGS__);               \
  88             }   }
  89 #  define DEBUGLOG(l, ...) {                                     \
  90                 if (l<=g_debuglevel) {                           \
  91                     ZSTD_DEBUG_PRINT(__FILE__ ": " __VA_ARGS__); \
  92                     ZSTD_DEBUG_PRINT(" \n");                     \
  93             }   }
  94 #else
  95 #  define RAWLOG(l, ...)      {}    /* disabled */
  96 #  define DEBUGLOG(l, ...)    {}    /* disabled */
  97 #endif
  98
  99
 100
 101 #endif /* DEBUG_H_12987983217 */