perf tools: Add missing newline when parsing empty BPF proggie

This is not specific to BPF but was found when parsing a .c BPF proggie
that while valid, had no events attached to tracepoints, kprobes, etc:

Very minimal file that perf's BPF code can compile:

  # cat empty.c
  char _license[] __attribute__((section("license"), used)) = "GPL";
  int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE;
  #

Before this patch:

  # perf trace -e empty.c
  WARNING: event parser found nothinginvalid or unsupported event: 'empty.c'
  Run 'perf list' for a list of valid events

   Usage: perf trace [<options>] [<command>]
      or: perf trace [<options>] -- <command> [<options>]
      or: perf trace record [<options>] [<command>]
      or: perf trace record [<options>] -- <command> [<options>]

      -e, --event <event>   event/syscall selector. use 'perf list' to list available events
    #

After:

  # perf trace -e empty.c
  WARNING: event parser found nothing
  invalid or unsupported event: 'empty.c'
  Run 'perf list' for a list of valid events

   Usage: perf trace [<options>] [<command>]
      or: perf trace [<options>] -- <command> [<options>]
      or: perf trace record [<options>] [<command>]
      or: perf trace record [<options>] -- <command> [<options>]

      -e, --event <event>   event/syscall selector. use 'perf list' to list available events
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-8ysughiz00h6mjpcot04qyjj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2018-05-03 15:59:58 -03:00
parent 3a0887997d
commit c23080a6e4
1 changed files with 1 additions and 1 deletions

View File

@ -1715,7 +1715,7 @@ int parse_events(struct perf_evlist *evlist, const char *str,
struct perf_evsel *last;
if (list_empty(&parse_state.list)) {
WARN_ONCE(true, "WARNING: event parser found nothing");
WARN_ONCE(true, "WARNING: event parser found nothing\n");
return -1;
}