1/* ******************************************************************
2 * debug
3 * Part of FSE library
4 * Copyright (c) Meta Platforms, Inc. and affiliates.
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)
36extern "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/* recommended values for DEBUGLEVEL :
55 * 0 : release mode, no debug, all run-time checks disabled
56 * 1 : enables assert() only, no display
57 * 2 : reserved, for currently active debug path
58 * 3 : events once per object lifetime (CCtx, CDict, etc.)
59 * 4 : events once per frame
60 * 5 : events once per block
61 * 6 : events once per sequence (verbose)
62 * 7+: events at every position (*very* verbose)
63 *
64 * It's generally inconvenient to output traces > 5.
65 * In which case, it's possible to selectively trigger high verbosity levels
66 * by modifying g_debug_level.
67 */
68
69#if (DEBUGLEVEL>=1)
70# define ZSTD_DEPS_NEED_ASSERT
71# include "zstd_deps.h"
72#else
73# ifndef assert /* assert may be already defined, due to prior #include <assert.h> */
74# define assert(condition) ((void)0) /* disable assert (default) */
75# endif
76#endif
77
78#if (DEBUGLEVEL>=2)
79# define ZSTD_DEPS_NEED_IO
80# include "zstd_deps.h"
81extern int g_debuglevel; /* the variable is only declared,
82 it actually lives in debug.c,
83 and is shared by the whole process.
84 It's not thread-safe.
85 It's useful when enabling very verbose levels
86 on selective conditions (such as position in src) */
87
88# define RAWLOG(l, ...) { \
89 if (l<=g_debuglevel) { \
90 ZSTD_DEBUG_PRINT(__VA_ARGS__); \
91 } }
92# define DEBUGLOG(l, ...) { \
93 if (l<=g_debuglevel) { \
94 ZSTD_DEBUG_PRINT(__FILE__ ": " __VA_ARGS__); \
95 ZSTD_DEBUG_PRINT(" \n"); \
96 } }
97#else
98# define RAWLOG(l, ...) {} /* disabled */
99# define DEBUGLOG(l, ...) {} /* disabled */
100#endif
101
102
103#if defined (__cplusplus)
104}
105#endif
106
107#endif /* DEBUG_H_12987983217 */
108