[PATCH] perf jevents: Sort list of input files

["Bernhard M. Wiedemann" <bwiedemann@suse.de>]

Without this, pmu-events.c would be generated with variations in ordering
depending on non-deterministic filesystem readdir order.

I tested that pmu-events.c still has the same number of lines
and that perf list output works.

This patch was done while working on reproducible builds for openSUSE,
but also solves issues in Debian [1] and other distributions.

[1] https://tests.reproducible-builds.org/debian/rb-pkg/unstable/i386/linux.html

Signed-off-by: Bernhard M. Wiedemann <bwiedemann@suse.de>
CC: Ian Rogers <irogers@google.com>
---
 tools/perf/pmu-events/jevents.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index 2bcd07ce609f..f06e1abac7c7 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -381,10 +381,13 @@ def read_json_events(path: str, topic: str) -> Sequence[JsonEvent]:
 
   return events
 
+def sorted_scandir(path: str) -> list[os.DirEntry]:
+  return sorted(os.scandir(path), key=lambda e: e.name)
+
 def preprocess_arch_std_files(archpath: str) -> None:
   """Read in all architecture standard events."""
   global _arch_std_events
-  for item in os.scandir(archpath):
+  for item in sorted_scandir(archpath):
     if item.is_file() and item.name.endswith('.json'):
       for event in read_json_events(item.path, topic=''):
         if event.name:
@@ -497,7 +500,7 @@ def preprocess_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
 def process_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
   """Process a JSON file during the main walk."""
   def is_leaf_dir(path: str) -> bool:
-    for item in os.scandir(path):
+    for item in sorted_scandir(path):
       if item.is_dir():
         return False
     return True
@@ -889,7 +892,7 @@ def main() -> None:
   def ftw(path: str, parents: Sequence[str],
           action: Callable[[Sequence[str], os.DirEntry], None]) -> None:
     """Replicate the directory/file walking behavior of C's file tree walk."""
-    for item in os.scandir(path):
+    for item in sorted_scandir(path):
       if _args.model != 'all' and item.is_dir():
         # Check if the model matches one in _args.model.
         if len(parents) == _args.model.split(',')[0].count('/'):
@@ -930,7 +933,7 @@ struct compact_pmu_event {
 
 """)
   archs = []
-  for item in os.scandir(_args.starting_dir):
+  for item in sorted_scandir(_args.starting_dir):
     if not item.is_dir():
       continue
     if item.name == _args.arch or _args.arch == 'all' or item.name == 'test':
-- 
2.35.3