xref: /freebsd/sys/contrib/zstd/lib/common/debug.h (revision c697fb7f)
1 /* ******************************************************************
2    debug
3    Part of FSE library
4    Copyright (C) 2013-present, Yann Collet.
5 
6    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
7 
8    Redistribution and use in source and binary forms, with or without
9    modification, are permitted provided that the following conditions are
10    met:
11 
12        * Redistributions of source code must retain the above copyright
13    notice, this list of conditions and the following disclaimer.
14        * Redistributions in binary form must reproduce the above
15    copyright notice, this list of conditions and the following disclaimer
16    in the documentation and/or other materials provided with the
17    distribution.
18 
19    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31    You can contact the author at :
32    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
33 ****************************************************************** */
34 
35 
36 /*
37  * The purpose of this header is to enable debug functions.
38  * They regroup assert(), DEBUGLOG() and RAWLOG() for run-time,
39  * and DEBUG_STATIC_ASSERT() for compile-time.
40  *
41  * By default, DEBUGLEVEL==0, which means run-time debug is disabled.
42  *
43  * Level 1 enables assert() only.
44  * Starting level 2, traces can be generated and pushed to stderr.
45  * The higher the level, the more verbose the traces.
46  *
47  * It's possible to dynamically adjust level using variable g_debug_level,
48  * which is only declared if DEBUGLEVEL>=2,
49  * and is a global variable, not multi-thread protected (use with care)
50  */
51 
52 #ifndef DEBUG_H_12987983217
53 #define DEBUG_H_12987983217
54 
55 #if defined (__cplusplus)
56 extern "C" {
57 #endif
58 
59 
60 /* static assert is triggered at compile time, leaving no runtime artefact.
61  * static assert only works with compile-time constants.
62  * Also, this variant can only be used inside a function. */
63 #define DEBUG_STATIC_ASSERT(c) (void)sizeof(char[(c) ? 1 : -1])
64 
65 
66 /* DEBUGLEVEL is expected to be defined externally,
67  * typically through compiler command line.
68  * Value must be a number. */
69 #ifndef DEBUGLEVEL
70 #  define DEBUGLEVEL 0
71 #endif
72 
73 
74 /* DEBUGFILE can be defined externally,
75  * typically through compiler command line.
76  * note : currently useless.
77  * Value must be stderr or stdout */
78 #ifndef DEBUGFILE
79 #  define DEBUGFILE stderr
80 #endif
81 
82 
83 /* recommended values for DEBUGLEVEL :
84  * 0 : release mode, no debug, all run-time checks disabled
85  * 1 : enables assert() only, no display
86  * 2 : reserved, for currently active debug path
87  * 3 : events once per object lifetime (CCtx, CDict, etc.)
88  * 4 : events once per frame
89  * 5 : events once per block
90  * 6 : events once per sequence (verbose)
91  * 7+: events at every position (*very* verbose)
92  *
93  * It's generally inconvenient to output traces > 5.
94  * In which case, it's possible to selectively trigger high verbosity levels
95  * by modifying g_debug_level.
96  */
97 
98 #if (DEBUGLEVEL>=1)
99 #  include <assert.h>
100 #else
101 #  ifndef assert   /* assert may be already defined, due to prior #include <assert.h> */
102 #    define assert(condition) ((void)0)   /* disable assert (default) */
103 #  endif
104 #endif
105 
106 #if (DEBUGLEVEL>=2)
107 #  include <stdio.h>
108 extern int g_debuglevel; /* the variable is only declared,
109                             it actually lives in debug.c,
110                             and is shared by the whole process.
111                             It's not thread-safe.
112                             It's useful when enabling very verbose levels
113                             on selective conditions (such as position in src) */
114 
115 #  define RAWLOG(l, ...) {                                      \
116                 if (l<=g_debuglevel) {                          \
117                     fprintf(stderr, __VA_ARGS__);               \
118             }   }
119 #  define DEBUGLOG(l, ...) {                                    \
120                 if (l<=g_debuglevel) {                          \
121                     fprintf(stderr, __FILE__ ": " __VA_ARGS__); \
122                     fprintf(stderr, " \n");                     \
123             }   }
124 #else
125 #  define RAWLOG(l, ...)      {}    /* disabled */
126 #  define DEBUGLOG(l, ...)    {}    /* disabled */
127 #endif
128 
129 
130 #if defined (__cplusplus)
131 }
132 #endif
133 
134 #endif /* DEBUG_H_12987983217 */
135