perf jevents.py: Ensure event names aren't duplicated

Duplicate event names break invariants in 'perf list'. Assert that an
event name isn't duplicated so that broken JSON won't build.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Atish Patra <atishp@rivosinc.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Charles Ci-Jyun Wu <dminus@andestech.com>
Cc: Eric Lin <eric.lin@sifive.com>
Cc: Greentime Hu <greentime.hu@sifive.com>
Cc: Guilherme Amadio <amadio@gentoo.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Inochi Amaoto <inochiama@outlook.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Locus Wei-Han Chen <locus84@andestech.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Vincent Chen <vincent.chen@sifive.com>
Cc: Will Deacon <will@kernel.org>
Cc: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240805194424.597244-5-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/pmu-events/jevents.py

@@ -503,8 +503,11 @@ def print_pending_events() -> None:
 
   first = True
   last_pmu = None
+  last_name = None
   pmus = set()
   for event in sorted(_pending_events, key=event_cmp_key):
+    if last_pmu and last_pmu == event.pmu:
+      assert event.name != last_name, f"Duplicate event: {last_pmu}/{last_name}/ in {_pending_events_tblname}"
     if event.pmu != last_pmu:
       if not first:
         _args.output_file.write('};\n')
@@ -516,6 +519,7 @@ def print_pending_events() -> None:
       pmus.add((event.pmu, pmu_name))
 
     _args.output_file.write(event.to_c_string(metric=False))
+    last_name = event.name
   _pending_events = []
 
   _args.output_file.write(f"""