bigbiff | 7b4c7a6 | 2015-01-01 19:44:14 -0500 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2014 Ondrej Oprala <ooprala@redhat.com> |
| 3 | * Copyright (C) 2014 Karel Zak <kzak@redhat.com> |
| 4 | * |
| 5 | * This file may be distributed under the terms of the |
| 6 | * GNU Lesser General Public License. |
| 7 | */ |
| 8 | #ifndef UTIL_LINUX_DEBUG_H |
| 9 | #define UTIL_LINUX_DEBUG_H |
| 10 | |
| 11 | |
| 12 | /* |
| 13 | * util-linux debug macros |
| 14 | * |
| 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 |
| 17 | * |
| 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_) |
| 21 | * |
| 22 | * In the code is possible to use |
| 23 | * |
| 24 | * DBG(FOO, ul_debug("this is output for foo")); |
| 25 | * |
| 26 | * where for the FOO has to be defined <PREFIX>_DEBUG_FOO. |
| 27 | * |
| 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. |
| 31 | * |
| 32 | * It's stringly recommended to use UL_* macros to define/declare/use |
| 33 | * the debug stuff. |
| 34 | * |
| 35 | * See disk-utils/cfdisk.c: cfdisk_init_debug() for programs debug |
| 36 | * or libmount/src/init.c: mnt_init_debug() for library debug |
| 37 | * |
| 38 | */ |
| 39 | |
| 40 | #include <stdarg.h> |
| 41 | #include <string.h> |
| 42 | |
| 43 | struct ul_debug_maskname { |
| 44 | const char *name; |
| 45 | int mask; |
| 46 | const char *help; |
| 47 | }; |
| 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 |
| 51 | |
| 52 | #define UL_DEBUG_DEFINE_MASK(m) int m ## _debug_mask |
| 53 | #define UL_DEBUG_DECLARE_MASK(m) extern UL_DEBUG_DEFINE_MASK(m) |
| 54 | |
| 55 | /* p - flag prefix, m - flag postfix */ |
| 56 | #define UL_DEBUG_DEFINE_FLAG(p, m) p ## m |
| 57 | |
| 58 | /* l - library name, p - flag prefix, m - flag postfix, x - function */ |
| 59 | #define __UL_DBG(l, p, m, x) \ |
| 60 | do { \ |
| 61 | if ((p ## m) & l ## _debug_mask) { \ |
| 62 | fprintf(stderr, "%d: %s: %8s: ", getpid(), # l, # m); \ |
| 63 | x; \ |
| 64 | } \ |
| 65 | } while (0) |
| 66 | |
| 67 | #define __UL_DBG_CALL(l, p, m, x) \ |
| 68 | do { \ |
| 69 | if ((p ## m) & l ## _debug_mask) { \ |
| 70 | x; \ |
| 71 | } \ |
| 72 | } while (0) |
| 73 | |
| 74 | #define __UL_DBG_FLUSH(l, p) \ |
| 75 | do { \ |
| 76 | if (l ## _debug_mask && \ |
| 77 | l ## _debug_mask != p ## INIT) { \ |
| 78 | fflush(stderr); \ |
| 79 | } \ |
| 80 | } while (0) |
| 81 | |
| 82 | |
| 83 | #define __UL_INIT_DEBUG(lib, pref, mask, env) \ |
| 84 | do { \ |
| 85 | if (lib ## _debug_mask & pref ## INIT) \ |
| 86 | ; \ |
| 87 | else if (!mask) { \ |
| 88 | char *str = getenv(# env); \ |
| 89 | if (str) \ |
| 90 | lib ## _debug_mask = ul_debug_parse_envmask(lib ## _masknames, str); \ |
| 91 | } else \ |
| 92 | lib ## _debug_mask = mask; \ |
| 93 | lib ## _debug_mask |= pref ## INIT; \ |
| 94 | } while (0) |
| 95 | |
| 96 | |
| 97 | static inline void __attribute__ ((__format__ (__printf__, 1, 2))) |
| 98 | ul_debug(const char *mesg, ...) |
| 99 | { |
| 100 | va_list ap; |
| 101 | va_start(ap, mesg); |
| 102 | vfprintf(stderr, mesg, ap); |
| 103 | va_end(ap); |
| 104 | fputc('\n', stderr); |
| 105 | } |
| 106 | |
| 107 | static inline void __attribute__ ((__format__ (__printf__, 2, 3))) |
| 108 | ul_debugobj(void *handler, const char *mesg, ...) |
| 109 | { |
| 110 | va_list ap; |
| 111 | |
| 112 | if (handler) |
| 113 | fprintf(stderr, "[%p]: ", handler); |
| 114 | va_start(ap, mesg); |
| 115 | vfprintf(stderr, mesg, ap); |
| 116 | va_end(ap); |
| 117 | fputc('\n', stderr); |
| 118 | } |
| 119 | |
| 120 | static inline int ul_debug_parse_envmask( |
| 121 | const struct ul_debug_maskname flagnames[], |
| 122 | const char *mask) |
| 123 | { |
| 124 | int res; |
| 125 | char *ptr; |
| 126 | |
| 127 | /* let's check for a numeric mask first */ |
| 128 | res = strtoul(mask, &ptr, 0); |
| 129 | |
| 130 | /* perhaps it's a comma-separated string? */ |
| 131 | if (ptr && *ptr && flagnames && flagnames[0].name) { |
| 132 | char *msbuf, *ms, *name; |
| 133 | res = 0; |
| 134 | |
| 135 | ms = msbuf = strdup(mask); |
| 136 | if (!ms) |
| 137 | return res; |
| 138 | |
| 139 | while ((name = strtok_r(ms, ",", &ptr))) { |
| 140 | const struct ul_debug_maskname *d; |
| 141 | ms = ptr; |
| 142 | |
| 143 | for (d = flagnames; d && d->name; d++) { |
| 144 | if (strcmp(name, d->name) == 0) { |
| 145 | res |= d->mask; |
| 146 | break; |
| 147 | } |
| 148 | } |
| 149 | /* nothing else we can do by OR-ing the mask */ |
| 150 | if (res == 0xffff) |
| 151 | break; |
| 152 | } |
| 153 | free(msbuf); |
| 154 | } else if (ptr && strcmp(ptr, "all") == 0) |
| 155 | res = 0xffff; |
| 156 | |
| 157 | return res; |
| 158 | } |
| 159 | |
| 160 | static inline void ul_debug_print_masks( |
| 161 | const char *env, |
| 162 | const struct ul_debug_maskname flagnames[]) |
| 163 | { |
| 164 | const struct ul_debug_maskname *d; |
| 165 | |
| 166 | if (!flagnames) |
| 167 | return; |
| 168 | |
| 169 | fprintf(stderr, "Available \"%s=<name>[,...]|<mask>\" debug masks:\n", |
| 170 | env); |
| 171 | for (d = flagnames; d && d->name; d++) { |
| 172 | if (!d->help) |
| 173 | continue; |
| 174 | fprintf(stderr, " %-8s [0x%04x] : %s\n", |
| 175 | d->name, d->mask, d->help); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | #endif /* UTIL_LINUX_DEBUG_H */ |