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Diffstat (limited to 'libblkid/src/debug.h')
| -rw-r--r-- | libblkid/src/debug.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/libblkid/src/debug.h b/libblkid/src/debug.h new file mode 100644 index 000000000..0229ab329 --- /dev/null +++ b/libblkid/src/debug.h @@ -0,0 +1,179 @@ +/* + * Copyright (C) 2014 Ondrej Oprala <ooprala@redhat.com> + * Copyright (C) 2014 Karel Zak <kzak@redhat.com> + * + * This file may be distributed under the terms of the + * GNU Lesser General Public License. + */ +#ifndef UTIL_LINUX_DEBUG_H +#define UTIL_LINUX_DEBUG_H + + +/* + * util-linux debug macros + * + * The debug stuff is based on <name>_debug_mask that controls what outputs is + * expected. The mask is usually initialized by <NAME>_DEBUG= env.variable + * + * After successful initialization the flag <PREFIX>_DEBUG_INIT is always set + * to the mask (this flag is required). The <PREFIX> is usually library API + * prefix (e.g. MNT_) or program name (e.g. CFDISK_) + * + * In the code is possible to use + * + * DBG(FOO, ul_debug("this is output for foo")); + * + * where for the FOO has to be defined <PREFIX>_DEBUG_FOO. + * + * It's possible to initialize the mask by comma delimited strings with + * subsystem names (e.g. "LIBMOUNT_DEBUG=options,tab"). In this case is + * necessary to define mask names array. This functionality is optional. + * + * It's stringly recommended to use UL_* macros to define/declare/use + * the debug stuff. + * + * See disk-utils/cfdisk.c: cfdisk_init_debug() for programs debug + * or libmount/src/init.c: mnt_init_debug() for library debug + * + */ + +#include <stdarg.h> +#include <string.h> + +struct ul_debug_maskname { + const char *name; + int mask; + const char *help; +}; +#define UL_DEBUG_EMPTY_MASKNAMES {{ NULL, 0, NULL }} +#define UL_DEBUG_DEFINE_MASKNAMES(m) static const struct ul_debug_maskname m ## _masknames[] +#define UL_DEBUG_MASKNAMES(m) m ## _masknames + +#define UL_DEBUG_DEFINE_MASK(m) int m ## _debug_mask +#define UL_DEBUG_DECLARE_MASK(m) extern UL_DEBUG_DEFINE_MASK(m) + +/* p - flag prefix, m - flag postfix */ +#define UL_DEBUG_DEFINE_FLAG(p, m) p ## m + +/* l - library name, p - flag prefix, m - flag postfix, x - function */ +#define __UL_DBG(l, p, m, x) \ + do { \ + if ((p ## m) & l ## _debug_mask) { \ + fprintf(stderr, "%d: %s: %8s: ", getpid(), # l, # m); \ + x; \ + } \ + } while (0) + +#define __UL_DBG_CALL(l, p, m, x) \ + do { \ + if ((p ## m) & l ## _debug_mask) { \ + x; \ + } \ + } while (0) + +#define __UL_DBG_FLUSH(l, p) \ + do { \ + if (l ## _debug_mask && \ + l ## _debug_mask != p ## INIT) { \ + fflush(stderr); \ + } \ + } while (0) + + +#define __UL_INIT_DEBUG(lib, pref, mask, env) \ + do { \ + if (lib ## _debug_mask & pref ## INIT) \ + ; \ + else if (!mask) { \ + char *str = getenv(# env); \ + if (str) \ + lib ## _debug_mask = ul_debug_parse_envmask(lib ## _masknames, str); \ + } else \ + lib ## _debug_mask = mask; \ + lib ## _debug_mask |= pref ## INIT; \ + } while (0) + + +static inline void __attribute__ ((__format__ (__printf__, 1, 2))) +ul_debug(const char *mesg, ...) +{ + va_list ap; + va_start(ap, mesg); + vfprintf(stderr, mesg, ap); + va_end(ap); + fputc('\n', stderr); +} + +static inline void __attribute__ ((__format__ (__printf__, 2, 3))) +ul_debugobj(void *handler, const char *mesg, ...) +{ + va_list ap; + + if (handler) + fprintf(stderr, "[%p]: ", handler); + va_start(ap, mesg); + vfprintf(stderr, mesg, ap); + va_end(ap); + fputc('\n', stderr); +} + +static inline int ul_debug_parse_envmask( + const struct ul_debug_maskname flagnames[], + const char *mask) +{ + int res; + char *ptr; + + /* let's check for a numeric mask first */ + res = strtoul(mask, &ptr, 0); + + /* perhaps it's a comma-separated string? */ + if (ptr && *ptr && flagnames && flagnames[0].name) { + char *msbuf, *ms, *name; + res = 0; + + ms = msbuf = strdup(mask); + if (!ms) + return res; + + while ((name = strtok_r(ms, ",", &ptr))) { + const struct ul_debug_maskname *d; + ms = ptr; + + for (d = flagnames; d && d->name; d++) { + if (strcmp(name, d->name) == 0) { + res |= d->mask; + break; + } + } + /* nothing else we can do by OR-ing the mask */ + if (res == 0xffff) + break; + } + free(msbuf); + } else if (ptr && strcmp(ptr, "all") == 0) + res = 0xffff; + + return res; +} + +static inline void ul_debug_print_masks( + const char *env, + const struct ul_debug_maskname flagnames[]) +{ + const struct ul_debug_maskname *d; + + if (!flagnames) + return; + + fprintf(stderr, "Available \"%s=<name>[,...]|<mask>\" debug masks:\n", + env); + for (d = flagnames; d && d->name; d++) { + if (!d->help) + continue; + fprintf(stderr, " %-8s [0x%04x] : %s\n", + d->name, d->mask, d->help); + } +} + +#endif /* UTIL_LINUX_DEBUG_H */ |