tools lib traceevent: Introduce pevent_strerror
The pevent_strerror() sets @buf to a string that describes the
(libtraceevent-specific) error condition that is passed via @errnum.
This is similar to strerror_r() and does same thing if @errnum has a
standard errno value.
To sync error string with its code, define PEVENT_ERRORS with _PE()
macro and use it as suggested by Steven.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1345618831-9148-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/event-parse.c b/event-parse.c
index a46cae7..1373e4c 100644
--- a/event-parse.c
+++ b/event-parse.c
@@ -4795,6 +4795,49 @@
return ret;
}
+#undef _PE
+#define _PE(code, str) str
+static const char * const pevent_error_str[] = {
+ PEVENT_ERRORS
+};
+#undef _PE
+
+int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
+ char *buf, size_t buflen)
+{
+ int idx;
+ const char *msg;
+
+ if (errnum >= 0) {
+ strerror_r(errnum, buf, buflen);
+ return 0;
+ }
+
+ if (errnum <= __PEVENT_ERRNO__START ||
+ errnum >= __PEVENT_ERRNO__END)
+ return -1;
+
+ idx = errnum - __PEVENT_ERRNO__START;
+ msg = pevent_error_str[idx];
+
+ switch (errnum) {
+ case PEVENT_ERRNO__MEM_ALLOC_FAILED:
+ case PEVENT_ERRNO__PARSE_EVENT_FAILED:
+ case PEVENT_ERRNO__READ_ID_FAILED:
+ case PEVENT_ERRNO__READ_FORMAT_FAILED:
+ case PEVENT_ERRNO__READ_PRINT_FAILED:
+ case PEVENT_ERRNO__OLD_FTRACE_ARG_FAILED:
+ snprintf(buf, buflen, "%s", msg);
+ break;
+
+ default:
+ /* cannot reach here */
+ break;
+ }
+
+ return 0;
+}
+
int get_field_val(struct trace_seq *s, struct format_field *field,
const char *name, struct pevent_record *record,
unsigned long long *val, int err)
diff --git a/event-parse.h b/event-parse.h
index 3c48229..527df03 100644
--- a/event-parse.h
+++ b/event-parse.h
@@ -345,6 +345,16 @@
PEVENT_NSEC_OUTPUT = 1, /* output in NSECS */
};
+#define PEVENT_ERRORS \
+ _PE(MEM_ALLOC_FAILED, "failed to allocate memory"), \
+ _PE(PARSE_EVENT_FAILED, "failed to parse event"), \
+ _PE(READ_ID_FAILED, "failed to read event id"), \
+ _PE(READ_FORMAT_FAILED, "failed to read event format"), \
+ _PE(READ_PRINT_FAILED, "failed to read event print fmt"), \
+ _PE(OLD_FTRACE_ARG_FAILED,"failed to allocate field name for ftrace")
+
+#undef _PE
+#define _PE(__code, __str) PEVENT_ERRNO__ ## __code
enum pevent_errno {
PEVENT_ERRNO__SUCCESS = 0,
@@ -357,15 +367,11 @@
*/
__PEVENT_ERRNO__START = -100000,
- PEVENT_ERRNO__MEM_ALLOC_FAILED = __PEVENT_ERRNO__START,
- PEVENT_ERRNO__PARSE_EVENT_FAILED,
- PEVENT_ERRNO__READ_ID_FAILED,
- PEVENT_ERRNO__READ_FORMAT_FAILED,
- PEVENT_ERRNO__READ_PRINT_FAILED,
- PEVENT_ERRNO__OLD_FTRACE_ARG_FAILED,
+ PEVENT_ERRORS,
__PEVENT_ERRNO__END,
};
+#undef _PE
struct cmdline;
struct cmdline_list;
@@ -583,6 +589,8 @@
const char *pevent_data_comm_from_pid(struct pevent *pevent, int pid);
void pevent_event_info(struct trace_seq *s, struct event_format *event,
struct pevent_record *record);
+int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
+ char *buf, size_t buflen);
struct event_format **pevent_list_events(struct pevent *pevent, enum event_sort_type);
struct format_field **pevent_event_common_fields(struct event_format *event);
