libperf: Get rid of attr.id field

Now there's no in-tree user of the field.  To remove the possible bug
later, let's get rid of the 'id' field and add a comment for that.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230825152552.112913-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index e563dd8c3628f0830767e3cdee626c84336288a9..ae64090184d328f3089832139d8d385f4bd934af 100644 (file)
--- a/tools/lib/perf/include/perf/event.h
+++ b/tools/lib/perf/include/perf/event.h
@@ -148,7 +148,13 @@ struct perf_record_switch {
 struct perf_record_header_attr {
        struct perf_event_header header;
        struct perf_event_attr   attr;
-       __u64                    id[];
+       /*
+        * Array of u64 id follows here but we cannot use a flexible array
+        * because size of attr in the data can be different then current
+        * version.  Please use perf_record_header_attr_id() below.
+        *
+        * __u64                 id[];  // do not use this
+        */
 };
 
 /* Returns the pointer to id array based on the actual attr size. */