Move internal headers to 'src/' dir

[lttng-ust.git] / src / common / logging.h

diff --git a/src/common/logging.h b/src/common/logging.h
new file mode 100644 (file)
index 0000000..4001c88
--- /dev/null
+++ b/src/common/logging.h
@@ -0,0 +1,139 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2009 Pierre-Marc Fournier
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _USTERR_SIGNAL_SAFE_H
+#define _USTERR_SIGNAL_SAFE_H
+
+#include <string.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include "common/patient.h"
+#include "common/compat/tid.h"
+#include "common/safe-snprintf.h"
+
+enum ust_err_loglevel {
+       UST_ERR_LOGLEVEL_UNKNOWN = 0,
+       UST_ERR_LOGLEVEL_NORMAL,
+       UST_ERR_LOGLEVEL_DEBUG,
+};
+
+extern volatile enum ust_err_loglevel ust_err_loglevel
+       __attribute__((visibility("hidden")));
+
+void ust_err_init(void)
+       __attribute__((visibility("hidden")));
+
+#ifdef LTTNG_UST_DEBUG
+static inline bool ust_err_debug_enabled(void)
+{
+       return true;
+}
+#else /* #ifdef LTTNG_UST_DEBUG */
+static inline bool ust_err_debug_enabled(void)
+{
+       return ust_err_loglevel == UST_ERR_LOGLEVEL_DEBUG;
+}
+#endif /* #else #ifdef LTTNG_UST_DEBUG */
+
+/*
+ * The default component for error messages.
+ */
+#ifndef UST_COMPONENT
+#define UST_COMPONENT libust
+#endif
+
+/* To stringify the expansion of a define */
+#define UST_XSTR(d) UST_STR(d)
+#define UST_STR(s) #s
+
+#define UST_ERR_MAX_LEN        512
+
+/*
+ * 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.
+ */
+/* Can't use dynamic allocation. Limit ourselves to UST_ERR_MAX_LEN chars. */
+/* Add end of string in case of buffer overflow. */
+#define sigsafe_print_err(fmt, args...)                                        \
+do {                                                                   \
+       if (ust_err_debug_enabled()) {                                  \
+               char ____buf[UST_ERR_MAX_LEN];                          \
+               int ____saved_errno;                                    \
+                                                                       \
+               ____saved_errno = errno;        /* signal-safety */     \
+               ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
+               ____buf[sizeof(____buf) - 1] = 0;                       \
+               ust_patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
+               errno = ____saved_errno;        /* signal-safety */     \
+               fflush(stderr);                                         \
+       }                                                               \
+} while (0)
+
+#define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)
+
+#define ERRMSG(fmt, args...)                   \
+       do {                                    \
+               sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n", \
+               (long) getpid(),                \
+               (long) lttng_gettid(),          \
+               ## args, __func__);             \
+       } while(0)
+
+
+#define DBG(fmt, args...)      ERRMSG(fmt, ## args)
+#define DBG_raw(fmt, args...)  sigsafe_print_err(fmt, ## args)
+#define WARN(fmt, args...)     ERRMSG("Warning: " fmt, ## args)
+#define ERR(fmt, args...)      ERRMSG("Error: " fmt, ## args)
+#define BUG(fmt, args...)      ERRMSG("BUG: " fmt, ## args)
+
+#if !defined(__GLIBC__) || ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
+/*
+ * Version using XSI strerror_r.
+ */
+#define PERROR(call, args...)                                          \
+       do {                                                            \
+               if (ust_err_debug_enabled()) {                          \
+                       char perror_buf[200] = "Error in strerror_r()"; \
+                       strerror_r(errno, perror_buf,                   \
+                                       sizeof(perror_buf));            \
+                       ERRMSG("Error: " call ": %s", ## args,          \
+                                       perror_buf);                    \
+               }                                                       \
+       } while(0)
+#else
+/*
+ * Version using GNU strerror_r, for linux with appropriate defines.
+ */
+#define PERROR(call, args...)                                          \
+       do {                                                            \
+               if (ust_err_debug_enabled()) {                          \
+                       char *perror_buf;                               \
+                       char perror_tmp[200];                           \
+                       perror_buf = strerror_r(errno, perror_tmp,      \
+                                       sizeof(perror_tmp));            \
+                       ERRMSG("Error: " call ": %s", ## args,          \
+                                       perror_buf);                    \
+               }                                                       \
+       } while(0)
+#endif
+
+#define BUG_ON(condition)                                      \
+       do {                                                    \
+               if (caa_unlikely(condition))                    \
+                       ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
+       } while(0)
+#define WARN_ON(condition)                                     \
+       do {                                                    \
+               if (caa_unlikely(condition))                    \
+                       WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
+       } while(0)
+#define WARN_ON_ONCE(condition) WARN_ON(condition)
+
+#endif /* _USTERR_SIGNAL_SAFE_H */