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-rw-r--r--include/debug.h181
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diff --git a/include/debug.h b/include/debug.h
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+++ b/include/debug.h
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+/*
+ * 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 strongly 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_MASK(m) m ## _debug_mask
+#define UL_DEBUG_DEFINE_MASK(m) int UL_DEBUG_MASK(m)
+#define UL_DEBUG_DECLARE_MASK(m) extern UL_DEBUG_DEFINE_MASK(m)
+
+/*
+ * Internal mask flags (above 0xffffff)
+ */
+#define __UL_DEBUG_FL_NOADDR (1 << 24) /* Don't print object address */
+
+
+/* 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_FROM_STRING(lib, pref, mask, str) \
+ do { \
+ if (lib ## _debug_mask & pref ## INIT) \
+ ; \
+ else if (!mask && str) { \
+ lib ## _debug_mask = ul_debug_parse_mask(lib ## _masknames, str); \
+ } else \
+ lib ## _debug_mask = mask; \
+ if (lib ## _debug_mask) { \
+ if (getuid() != geteuid() || getgid() != getegid()) { \
+ lib ## _debug_mask |= __UL_DEBUG_FL_NOADDR; \
+ fprintf(stderr, "%d: %s: don't print memory addresses (SUID executable).\n", getpid(), # lib); \
+ } \
+ } \
+ lib ## _debug_mask |= pref ## INIT; \
+ } while (0)
+
+
+#define __UL_INIT_DEBUG_FROM_ENV(lib, pref, mask, env) \
+ do { \
+ const char *envstr = mask ? NULL : getenv(# env); \
+ __UL_INIT_DEBUG_FROM_STRING(lib, pref, mask, envstr); \
+ } 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 int ul_debug_parse_mask(
+ 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 */