Make only libust and libustconsumer use a signal safe usterr.h

[ust.git] / include / usterr_signal_safe.h

diff --git a/include/usterr_signal_safe.h b/include/usterr_signal_safe.h
new file mode 100644 (file)
index 0000000..f12c317
--- /dev/null
+++ b/include/usterr_signal_safe.h
@@ -0,0 +1,110 @@
+/* Copyright (C) 2009  Pierre-Marc Fournier
+ *
+ * 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.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#ifndef _USTERR_SIGNAL_SAFE_H
+#define _USTERR_SIGNAL_SAFE_H
+
+#include <string.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include <ust/core.h>
+
+#include "share.h"
+
+#ifndef UST_COMPONENT
+//#error UST_COMPONENT is undefined
+#define UST_COMPONENT libust
+#endif
+
+/* To stringify the expansion of a define */
+#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, ...)
+       __attribute__ ((format (printf, 3, 4)));
+
+static inline void __attribute__ ((format (printf, 1, 2)))
+       __check_ust_safe_fmt(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)
+
+#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)
+#else
+# define DBG(fmt, args...) __check_ust_safe_fmt(fmt, ## args)
+# define DBG_raw(fmt, args...) __check_ust_safe_fmt(fmt, ## args)
+#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)
+
+#if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
+#define PERROR(call, args...)\
+       do { \
+               char buf[200] = "Error in strerror_r()"; \
+               strerror_r(errno, buf, sizeof(buf)); \
+               ERRMSG("Error: " call ": %s", ## args, buf); \
+       } while(0);
+#else
+#define PERROR(call, args...)\
+       do { \
+               char *buf; \
+               char tmp[200]; \
+               buf = strerror_r(errno, tmp, sizeof(tmp)); \
+               ERRMSG("Error: " call ": %s", ## args, buf); \
+       } 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 WARN_ON_ONCE(condition) WARN_ON(condition)
+
+#endif /* _USTERR_SIGNAL_SAFE_H */