From: Jens Remus <jremus@linux.ibm.com>
Date: Wed, 10 Jun 2026 11:23:43 +0000 (+0200)
Subject: perf build: Do not duplicate CFLAGS in Python extension builds
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=bcd2cc4405bdb9ac77210d0df5990d46c311be66;p=thirdparty%2Fkernel%2Flinux.git

perf build: Do not duplicate CFLAGS in Python extension builds

setuptools already uses CFLAGS.  Passing CFLAGS with additional flags as
extra compile arguments causes CFLAGS to effectively get passed twice:

$ make -C tools/perf V=1 JOBS=1
...
building 'perf' extension
gcc [CFLAGS] -fPIC -Iutil/include -I/usr/include/python3.14 \
  -c /root/linux/tools/perf/util/python.c \
  -o python_ext_build/tmp/root/linux/tools/perf/util/python.o \
  [CFLAGS] \
  -fno-strict-aliasing -Wno-write-strings -Wno-unused-parameter \
  -Wno-redundant-decls -Wno-cast-function-type \
  -Wno-declaration-after-statement

Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Polensky <japo@linux.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index b65b1792ca056..a0ce76624a230 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -74,18 +74,17 @@ class install_lib(_install_lib):
         self.build_dir = build_lib
 
 
-cflags = getenv('CFLAGS', '').split()
 # switch off several checks (need to be at the end of cflags list)
-cflags += ['-fno-strict-aliasing', '-Wno-write-strings', '-Wno-unused-parameter', '-Wno-redundant-decls' ]
+extra_cflags = ['-fno-strict-aliasing', '-Wno-write-strings', '-Wno-unused-parameter', '-Wno-redundant-decls' ]
 if cc_is_clang:
-    cflags += ["-Wno-unused-command-line-argument" ]
+    extra_cflags += ["-Wno-unused-command-line-argument" ]
     if clang_has_option("-Wno-cast-function-type-mismatch"):
-        cflags += ["-Wno-cast-function-type-mismatch" ]
+        extra_cflags += ["-Wno-cast-function-type-mismatch" ]
 else:
-    cflags += ['-Wno-cast-function-type' ]
+    extra_cflags += ['-Wno-cast-function-type' ]
 
 # The python headers have mixed code with declarations (decls after asserts, for instance)
-cflags += [ "-Wno-declaration-after-statement" ]
+extra_cflags += [ "-Wno-declaration-after-statement" ]
 
 src_perf  = f'{srctree}/tools/perf'
 build_lib = getenv('PYTHON_EXTBUILD_LIB')
@@ -94,7 +93,7 @@ build_tmp = getenv('PYTHON_EXTBUILD_TMP')
 perf = Extension('perf',
                  sources = [ src_perf + '/util/python.c' ],
 		         include_dirs = ['util/include'],
-		         extra_compile_args = cflags,
+		         extra_compile_args = extra_cflags,
                  )
 
 setup(name='perf',