2 * Copyright (C) 2014 Ondrej Oprala <ooprala@redhat.com>
3 * Copyright (C) 2014 Karel Zak <kzak@redhat.com>
5 * This file may be distributed under the terms of the
6 * GNU Lesser General Public License.
8 #ifndef UTIL_LINUX_DEBUG_H
9 #define UTIL_LINUX_DEBUG_H
13 * util-linux debug macros
15 * The debug stuff is based on <name>_debug_mask that controls what outputs is
16 * expected. The mask is usually initialized by <NAME>_DEBUG= env.variable
18 * After successful initialization the flag <PREFIX>_DEBUG_INIT is always set
19 * to the mask (this flag is required). The <PREFIX> is usually library API
20 * prefix (e.g. MNT_) or program name (e.g. CFDISK_)
22 * In the code is possible to use
24 * DBG(FOO, ul_debug("this is output for foo"));
26 * where for the FOO has to be defined <PREFIX>_DEBUG_FOO.
28 * It's possible to initialize the mask by comma delimited strings with
29 * subsystem names (e.g. "LIBMOUNT_DEBUG=options,tab"). In this case is
30 * necessary to define mask names array. This functionality is optional.
32 * It's strongly recommended to use UL_* macros to define/declare/use
35 * See disk-utils/cfdisk.c: cfdisk_init_debug() for programs debug
36 * or libmount/src/init.c: mnt_init_debug() for library debug
43 struct ul_debug_maskname
{
48 #define UL_DEBUG_EMPTY_MASKNAMES {{ NULL, 0, NULL }}
49 #define UL_DEBUG_DEFINE_MASKNAMES(m) static const struct ul_debug_maskname m ## _masknames[]
50 #define UL_DEBUG_MASKNAMES(m) m ## _masknames
52 #define UL_DEBUG_MASK(m) m ## _debug_mask
53 #define UL_DEBUG_DEFINE_MASK(m) int UL_DEBUG_MASK(m)
54 #define UL_DEBUG_DECLARE_MASK(m) extern UL_DEBUG_DEFINE_MASK(m)
57 * Internal mask flags (above 0xffffff)
59 #define __UL_DEBUG_FL_NOADDR (1 << 24) /* Don't print object address */
62 /* l - library name, p - flag prefix, m - flag postfix, x - function */
63 #define __UL_DBG(l, p, m, x) \
65 if ((p ## m) & l ## _debug_mask) { \
66 fprintf(stderr, "%d: %s: %8s: ", getpid(), # l, # m); \
71 #define __UL_DBG_CALL(l, p, m, x) \
73 if ((p ## m) & l ## _debug_mask) { \
78 #define __UL_DBG_FLUSH(l, p) \
80 if (l ## _debug_mask && \
81 l ## _debug_mask != p ## INIT) { \
86 #define __UL_INIT_DEBUG_FROM_STRING(lib, pref, mask, str) \
88 if (lib ## _debug_mask & pref ## INIT) \
90 else if (!mask && str) { \
91 lib ## _debug_mask = ul_debug_parse_mask(lib ## _masknames, str); \
93 lib ## _debug_mask = mask; \
94 if (lib ## _debug_mask) { \
95 if (getuid() != geteuid() || getgid() != getegid()) { \
96 lib ## _debug_mask |= __UL_DEBUG_FL_NOADDR; \
97 fprintf(stderr, "%d: %s: don't print memory addresses (SUID executable).\n", getpid(), # lib); \
100 lib ## _debug_mask |= pref ## INIT; \
104 #define __UL_INIT_DEBUG_FROM_ENV(lib, pref, mask, env) \
106 const char *envstr = mask ? NULL : getenv(# env); \
107 __UL_INIT_DEBUG_FROM_STRING(lib, pref, mask, envstr); \
112 static inline void __attribute__ ((__format__ (__printf__
, 1, 2)))
113 ul_debug(const char *mesg
, ...)
117 vfprintf(stderr
, mesg
, ap
);
122 static inline int ul_debug_parse_mask(
123 const struct ul_debug_maskname flagnames
[],
129 /* let's check for a numeric mask first */
130 res
= strtoul(mask
, &ptr
, 0);
132 /* perhaps it's a comma-separated string? */
133 if (ptr
&& *ptr
&& flagnames
&& flagnames
[0].name
) {
134 char *msbuf
, *ms
, *name
;
137 ms
= msbuf
= strdup(mask
);
141 while ((name
= strtok_r(ms
, ",", &ptr
))) {
142 const struct ul_debug_maskname
*d
;
145 for (d
= flagnames
; d
&& d
->name
; d
++) {
146 if (strcmp(name
, d
->name
) == 0) {
151 /* nothing else we can do by OR-ing the mask */
156 } else if (ptr
&& strcmp(ptr
, "all") == 0)
162 static inline void ul_debug_print_masks(
164 const struct ul_debug_maskname flagnames
[])
166 const struct ul_debug_maskname
*d
;
171 fprintf(stderr
, "Available \"%s=<name>[,...]|<mask>\" debug masks:\n",
173 for (d
= flagnames
; d
&& d
->name
; d
++) {
176 fprintf(stderr
, " %-8s [0x%04x] : %s\n",
177 d
->name
, d
->mask
, d
->help
);
181 #endif /* UTIL_LINUX_DEBUG_H */