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 */
102