perf jevents: Clean up pytype warnings

Improve type hints to clean up pytype warnings.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/20220804221816.1802790-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/pmu-events/jevents.py

@@ -6,8 +6,7 @@ import csv
 import json
 import os
 import sys
-from typing import Callable
-from typing import Sequence
+from typing import (Callable, Optional, Sequence)
 
 # Global command line arguments.
 _args = None
@@ -57,7 +56,7 @@ class JsonEvent:
                                        '. '), '.').replace('\n', '\\n').replace(
                                            '\"', '\\"').replace('\r', '\\r')
 
-    def convert_aggr_mode(aggr_mode: str) -> str:
+    def convert_aggr_mode(aggr_mode: str) -> Optional[str]:
       """Returns the aggr_mode_class enum value associated with the JSON string."""
       if not aggr_mode:
         return None
@@ -67,7 +66,7 @@ class JsonEvent:
       }
       return aggr_mode_to_enum[aggr_mode]
 
-    def lookup_msr(num: str) -> str:
+    def lookup_msr(num: str) -> Optional[str]:
       """Converts the msr number, or first in a list to the appropriate event field."""
       if not num:
         return None
@@ -79,7 +78,7 @@ class JsonEvent:
       }
       return msrmap[int(num.split(',', 1)[0], 0)]
 
-    def real_event(name: str, event: str) -> str:
+    def real_event(name: str, event: str) -> Optional[str]:
       """Convert well known event names to an event string otherwise use the event argument."""
       fixed = {
           'inst_retired.any': 'event=0xc0,period=2000003',
@@ -95,7 +94,7 @@ class JsonEvent:
         return fixed[name.lower()]
       return event
 
-    def unit_to_pmu(unit: str) -> str:
+    def unit_to_pmu(unit: str) -> Optional[str]:
       """Convert a JSON Unit to Linux PMU name."""
       if not unit:
         return None
@@ -154,7 +153,7 @@ class JsonEvent:
     if self.metric_expr:
       self.metric_expr = self.metric_expr.replace('\\', '\\\\')
     arch_std = jd.get('ArchStdEvent')
-    if precise and self.desc and not '(Precise Event)' in self.desc:
+    if precise and self.desc and '(Precise Event)' not in self.desc:
       extra_desc += ' (Must be precise)' if precise == '2' else (' (Precise '
                                                                  'event)')
     event = f'config={llx(configcode)}' if configcode is not None else f'event={llx(eventcode)}'