Add UST_DEBUG env. var. support

[lttng-ust.git] / include / usterr.h

diff --git a/include/usterr.h b/include/usterr.h
index f0cdeb02f7d0922b3041e6c76c9028f02a3935f8..cab65407dca9c0c5740e038008b884d9480ac3d3 100644 (file)
--- a/include/usterr.h
+++ b/include/usterr.h
@@ -1,9 +1,14 @@
-/* Copyright (C) 2009  Pierre-Marc Fournier
+#ifndef _USTERR_H
+#define _USTERR_H
+
+/*
+ * Copyright (C) 2009  Pierre-Marc Fournier
+ * Copyright (C) 2011  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
+ * License as published by the Free Software Foundation; version 2.1 of
+ * the License.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -15,9 +20,6 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
-#ifndef USTERR_H
-#define USTERR_H
-
 #include <string.h>
 #include <sys/types.h>
 #include <sys/syscall.h>
@@ -29,8 +31,21 @@
 
 #include "share.h"
 
+enum ust_loglevel {
+       UST_LOGLEVEL_UNKNOWN = 0,
+       UST_LOGLEVEL_NORMAL,
+       UST_LOGLEVEL_DEBUG,
+};
+
+extern volatile enum ust_loglevel ust_loglevel;
+void init_usterr(void);
+
+static inline int ust_debug(void)
+{
+       return ust_loglevel == UST_LOGLEVEL_DEBUG;
+}
+
 #ifndef UST_COMPONENT
-//#error UST_COMPONENT is undefined
 #define UST_COMPONENT libust
 #endif
 
@@ -38,44 +53,37 @@
 #define XSTR(d) STR(d)
 #define STR(s) #s
 
-/* We sometimes print in the tracing path, and tracing can occur in
- * signal handlers, so we must use a print method which is signal safe.
- */
-
-extern int ust_safe_snprintf(char *str, size_t n, const char *fmt, ...);
-
-#define sigsafe_print_err(fmt, args...) \
-{ \
-       /* Can't use dynamic allocation. Limit ourselves to 250 chars. */ \
-       char ____buf[250]; \
-       int ____saved_errno; \
-\
-       /* Save the errno. */ \
-       ____saved_errno = errno; \
-\
-       ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
-\
-       /* Add end of string in case of buffer overflow. */ \
-       ____buf[sizeof(____buf)-1] = 0; \
-\
-       patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
-       /* Can't print errors because we are in the error printing code path. */ \
-\
-       /* Restore errno, in order to be async-signal safe. */ \
-       errno = ____saved_errno; \
-}
-
 #define UST_STR_COMPONENT XSTR(UST_COMPONENT)
 
-#define ERRMSG(fmt, args...) do { sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" XSTR(__LINE__) ")\n", (long) getpid(), (long) syscall(SYS_gettid), ## args, __func__); fflush(stderr); } while(0)
+#define ERRMSG(fmt, args...)                                   \
+       do {                                                    \
+               fprintf(stderr, UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" XSTR(__LINE__) ")\n",                          \
+                       (long) getpid(),                        \
+                       (long) syscall(SYS_gettid),             \
+                       ## args,                                \
+                       __func__);                              \
+       } while(0)
 
 #ifdef UST_DEBUG
-# define DBG(fmt, args...) ERRMSG(fmt, ## args)
-# define DBG_raw(fmt, args...) do { sigsafe_print_err(fmt, ## args); fflush(stderr); } while(0)
+# define DBG(fmt, args...)             ERRMSG(fmt, ## args)
+# define DBG_raw(fmt, args...)                                 \
+       do {                                                    \
+                fprintf(stderr, fmt, ## args);                 \
+       } while(0)
 #else
-# define DBG(fmt, args...) do {} while(0)
-# define DBG_raw(fmt, args...) do {} while(0)
+# define DBG(fmt, args...)                                     \
+       do {                                                    \
+               if (ust_debug())                                \
+                       ERRMSG(fmt, ## args);                   \
+       } while (0)
+# define DBG_raw(fmt, args...)                                 \
+       do {                                                    \
+               if (ust_debug()) {                              \
+                       fprintf(stderr, fmt, ## args);          \
+               }                                               \
+       } while(0)
 #endif
+
 #define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
 #define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
 #define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
@@ -97,8 +105,16 @@ extern int ust_safe_snprintf(char *str, size_t n, const char *fmt, ...);
        } while(0);
 #endif
 
-#define BUG_ON(condition) do { if (unlikely(condition)) ERR("condition not respected (BUG)"); } while(0)
-#define WARN_ON(condition) do { if (unlikely(condition)) WARN("condition not respected on line %s:%d", __FILE__, __LINE__); } while(0)
+#define BUG_ON(condition)                                      \
+       do {                                                    \
+               if (unlikely(condition))                        \
+                       ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
+       } while(0)
+#define WARN_ON(condition)                                     \
+       do {                                                    \
+               if (unlikely(condition))                        \
+                       WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
+       } while(0)
 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 
-#endif /* USTERR_H */
+#endif /* _USTERR_H */