perf python: Disable -Wno-cast-function-type-mismatch if present on clang

commit 00dc514612fe98cfa117193b9df28f15e7c9db9c upstream.

The -Wcast-function-type-mismatch option was introduced in clang 19 and
its enabled by default, since we use -Werror, and python bindings do
casts that are valid but trips this warning, disable it if present.

Closes: https://lore.kernel.org/all/CA+icZUXoJ6BS3GMhJHV3aZWyb5Cz2haFneX0C5pUMUUhG-UVKQ@mail.gmail.com
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org # To allow building with the upcoming clang 19
Link: https://lore.kernel.org/lkml/CA+icZUVtHn8X1Tb_Y__c-WswsO0K8U9uy3r2MzKXwTA5THtL7w@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/perf/util/setup.py

@@ -63,6 +63,8 @@ cflags = getenv('CFLAGS', '').split()
 cflags += ['-fno-strict-aliasing', '-Wno-write-strings', '-Wno-unused-parameter', '-Wno-redundant-decls', '-DPYTHON_PERF' ]
 if cc_is_clang:
     cflags += ["-Wno-unused-command-line-argument" ]
+    if clang_has_option("-Wno-cast-function-type-mismatch"):
+        cflags += ["-Wno-cast-function-type-mismatch" ]
 else:
     cflags += ['-Wno-cast-function-type' ]