lib: add internal BT_LIB_LOG*_APPEND_CAUSE() macros

[babeltrace.git] / src / lib / lib-logging.c

diff --git a/src/lib/lib-logging.c b/src/lib/lib-logging.c
index 1c5338c55ecb9ea953f195d0ccf4ed578b9d9f89..66bfe9d31a91f229c48de2a047e7013ddaf45ddf 100644 (file)
--- a/src/lib/lib-logging.c
+++ b/src/lib/lib-logging.c
@@ -20,11 +20,8 @@
  * SOFTWARE.
  */
 
-/*
- * This is just to satisfy the preprocessor check in "lib/logging.h":
- * this file does not log anything.
- */
-#define BT_LOG_TAG ""
+#define BT_LOG_TAG "LIB/LIB-LOGGING"
+#include "lib/logging.h"
 
 #include <stdarg.h>
 #include <stdio.h>
@@ -38,6 +35,7 @@
 #include <babeltrace2/trace-ir/event-const.h>
 #include <babeltrace2/trace-ir/packet-const.h>
 #include <babeltrace2/trace-ir/stream-const.h>
+#include <babeltrace2/current-thread.h>
 
 #include "logging.h"
 #include "assert-pre.h"
@@ -1488,3 +1486,41 @@ void bt_lib_log(const char *func, const char *file, unsigned line,
        va_end(args);
        _bt_log_write_d(func, file, line, lvl, tag, "%s", lib_logging_buf);
 }
+
+void bt_lib_maybe_log_and_append_cause(const char *func, const char *file,
+               unsigned line, int lvl, const char *tag,
+               const char *fmt, ...)
+{
+       va_list args;
+       bt_current_thread_error_append_cause_status status;
+
+       BT_ASSERT(fmt);
+       va_start(args, fmt);
+       bt_common_custom_vsnprintf(lib_logging_buf, LIB_LOGGING_BUF_SIZE, '!',
+               handle_conversion_specifier_bt, NULL, fmt, &args);
+       va_end(args);
+
+       /* Log conditionally, but always append the error cause */
+       if (BT_LOG_ON(lvl)) {
+               _bt_log_write_d(func, file, line, lvl, tag, "%s",
+                       lib_logging_buf);
+       }
+
+       status = bt_current_thread_error_append_cause_from_unknown(
+               "Babeltrace library", file, line, "%s", lib_logging_buf);
+       if (status) {
+               /*
+                * Worst case: this error cause is not appended to the
+                * current thread's error.
+                *
+                * We can accept this as it's an almost impossible
+                * scenario and returning an error here would mean you
+                * need to check the return value of each
+                * BT_LIB_LOG*_APPEND_CAUSE() macro and that would be
+                * cumbersome.
+                */
+               BT_LOGE("Cannot append error cause to current thread's "
+                       "error object: status=%s",
+                       bt_common_func_status_string(status));
+       }
+}