[PATCH 6.12 059/277] perf python: split Clang options when invoking Popen

Greg Kroah-Hartman
2025-10-17T15:16:35Z

6.12-stable review patch. If anyone has any objections, please let me know.

------------------

From: Leo Yan <leo.yan@arm.com>

[ Upstream commit c6a43bc3e8f6102a47da0d2e53428d08f00172fb ]

When passing a list to subprocess.Popen, each element maps to one argv
token. Current code bundles multiple Clang flags into a single element,
something like:

cmd = ['clang',
'--target=x86_64-linux-gnu -fintegrated-as -Wno-cast-function-type-mismatch',
'test-hello.c']

So Clang only sees one long, invalid option instead of separate flags,
as a result, the script cannot capture any log via PIPE.

Fix this by using shlex.split() to separate the string so each option
becomes its own argv element. The fixed list will be:

cmd = ['clang',
'--target=x86_64-linux-gnu',
'-fintegrated-as',
'-Wno-cast-function-type-mismatch',
'test-hello.c']

Fixes: 09e6f9f98370 ("perf python: Fix splitting CC into compiler and options")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-2-4305590795b2@arm.com
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/setup.py | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index 649550e9b7aa8..abb567de3e8a9 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -1,6 +1,7 @@
from os import getenv, path
from subprocess import Popen, PIPE
from re import sub
+import shlex

cc = getenv("CC")

@@ -16,7 +17,9 @@ cc_is_clang = b"clang version" in Popen([cc, "-v"], stderr=PIPE).stderr.readline
src_feature_tests = getenv('srctree') + '/tools/build/feature'

def clang_has_option(option):
- cc_output = Popen([cc, cc_options + option, path.join(src_feature_tests, "test-hello.c") ], stderr=PIPE).stderr.readlines()
+ cmd = shlex.split(f"{cc} {cc_options} {option}")
+ cmd.append(path.join(src_feature_tests, "test-hello.c"))
+ cc_output = Popen(cmd, stderr=PIPE).stderr.readlines()
return [o for o in cc_output if ((b"unknown argument" in o) or (b"is not supported" in o) or (b"unknown warning option" in o))] == [ ]

if cc_is_clang:
--
2.51.0