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tools lib traceevent: Report better error message on bad function args

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When Jiri Olsa was writing a function callback for
scsi_trace_parse_cdb(), he thought that the traceevent library had a
bug in it because he was getting this error:

  Error: expected ')' but read ','
  Error: expected ')' but read ','
  Error: expected ')' but read ','
  Error: expected ')' but read ','

But in truth, he didn't have the write number of arguments for the
function callback, and the error was the library detecting the
discrepancy. A better error message would have prevented the confusion:

  Error: function 'scsi_trace_parse_cdb()' only expects 2 arguments but event scsi_dispatch_cmd_timeout has more
  Error: function 'scsi_trace_parse_cdb()' only expects 2 arguments but event scsi_dispatch_cmd_start has more
  Error: function 'scsi_trace_parse_cdb()' only expects 2 arguments but event scsi_dispatch_cmd_error has more
  Error: function 'scsi_trace_parse_cdb()' only expects 2 arguments but event scsi_dispatch_cmd_done has more

Or

  Error: function 'scsi_trace_parse_cdb()' expects 4 arguments but event scsi_dispatch_cmd_timeout only uses 3
  Error: function 'scsi_trace_parse_cdb()' expects 4 arguments but event scsi_dispatch_cmd_start only uses 3
  Error: function 'scsi_trace_parse_cdb()' expects 4 arguments but event scsi_dispatch_cmd_error only uses 3
  Error: function 'scsi_trace_parse_cdb()' expects 4 arguments but event scsi_dispatch_cmd_done only uses 3

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-a4c34w62vl0diitvxb7bt3er@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Steven Rostedt 2013-11-18 21:38:20 -05:00 committed by Arnaldo Carvalho de Melo
parent 3160565f0e
commit 3a3ffa2e82
1 changed files with 18 additions and 10 deletions
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28
tools/lib/traceevent/event-parse.c
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@ -2710,7 +2710,6 @@ process_func_handler(struct event_format *event, struct pevent_function_handler
struct print_arg *farg;
enum event_type type;
char *token;
const char *test;
int i;
arg->type = PRINT_FUNC;
@ -2727,15 +2726,19 @@ process_func_handler(struct event_format *event, struct pevent_function_handler
}
type = process_arg(event, farg, &token);
if (i < (func->nr_args - 1))
test = ",";
else
test = ")";
if (test_type_token(type, token, EVENT_DELIM, test)) {
free_arg(farg);
free_token(token);
return EVENT_ERROR;
if (i < (func->nr_args - 1)) {
if (type != EVENT_DELIM || strcmp(token, ",") != 0) {
warning("Error: function '%s()' expects %d arguments but event %s only uses %d",
func->name, func->nr_args,
event->name, i + 1);
goto err;
}
} else {
if (type != EVENT_DELIM || strcmp(token, ")") != 0) {
warning("Error: function '%s()' only expects %d arguments but event %s has more",
func->name, func->nr_args, event->name);
goto err;
}
}
*next_arg = farg;
@ -2747,6 +2750,11 @@ process_func_handler(struct event_format *event, struct pevent_function_handler
*tok = token;
return type;
err:
free_arg(farg);
free_token(token);
return EVENT_ERROR;
}
static enum event_type