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 --- 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 dd289d15acfd62ff058bbaed7e565bb958e3a3c8..9cae2c472f4ad4d9579e8528b8bb0152df6fe20e 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") assert cc, "Environment variable CC not set" @@ -22,7 +23,9 @@ assert srctree, "Environment variable srctree, for the Linux sources, not set" src_feature_tests = f'{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: -- 2.34.1