module/zstd/lib/common/debug.h

   1 /* ******************************************************************
   2  * debug
   3  * Part of FSE library
   4  * Copyright (c) 2013-2020, 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 #if defined (__cplusplus)
  36 extern "C" {
  37 #endif
  38
  39
  40 /* static assert is triggered at compile time, leaving no runtime artefact.
  41  * static assert only works with compile-time constants.
  42  * Also, this variant can only be used inside a function. */
  43 #define DEBUG_STATIC_ASSERT(c) (void)sizeof(char[(c) ? 1 : -1])
  44
  45
  46 /* DEBUGLEVEL is expected to be defined externally,
  47  * typically through compiler command line.
  48  * Value must be a number. */
  49 #ifndef DEBUGLEVEL
  50 #  define DEBUGLEVEL 0
  51 #endif
  52
  53
  54 /* DEBUGFILE can be defined externally,
  55  * typically through compiler command line.
  56  * note : currently useless.
  57  * Value must be stderr or stdout */
  58 #ifndef DEBUGFILE
  59 #  define DEBUGFILE stderr
  60 #endif
  61
  62
  63 /* recommended values for DEBUGLEVEL :
  64  * 0 : release mode, no debug, all run-time checks disabled
  65  * 1 : enables assert() only, no display
  66  * 2 : reserved, for currently active debug path
  67  * 3 : events once per object lifetime (CCtx, CDict, etc.)
  68  * 4 : events once per frame
  69  * 5 : events once per block
  70  * 6 : events once per sequence (verbose)
  71  * 7+: events at every position (*very* verbose)
  72  *
  73  * It's generally inconvenient to output traces > 5.
  74  * In which case, it's possible to selectively trigger high verbosity levels
  75  * by modifying g_debug_level.
  76  */
  77
  78 #if (DEBUGLEVEL>=1)
  79 #  include <assert.h>
  80 #else
  81 #  ifndef assert   /* assert may be already defined, due to prior #include <assert.h> */
  82 #    define assert(condition) ((void)0)   /* disable assert (default) */
  83 #  endif
  84 #endif
  85
  86 #if (DEBUGLEVEL>=2)
  87 #  include <stdio.h>
  88 extern int g_debuglevel; /* the variable is only declared,
  89                             it actually lives in debug.c,
  90                             and is shared by the whole process.
  91                             It's not thread-safe.
  92                             It's useful when enabling very verbose levels
  93                             on selective conditions (such as position in src) */
  94
  95 #  define RAWLOG(l, ...) {                                      \
  96                 if (l<=g_debuglevel) {                          \
  97                     fprintf(stderr, __VA_ARGS__);               \
  98             }   }
  99 #  define DEBUGLOG(l, ...) {                                    \
 100                 if (l<=g_debuglevel) {                          \
 101                     fprintf(stderr, __FILE__ ": " __VA_ARGS__); \
 102                     fprintf(stderr, " \n");                     \
 103             }   }
 104 #else
 105 #  define RAWLOG(l, ...)      {}    /* disabled */
 106 #  define DEBUGLOG(l, ...)    {}    /* disabled */
 107 #endif
 108
 109
 110 #if defined (__cplusplus)
 111 }
 112 #endif
 113
 114 #endif /* DEBUG_H_12987983217 */