From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> commit 3d1d57debee2d342a47615707588b96658fabb85 upstream. Since 66dfdff03d196e51 ("perf tools: Add Python 3 support") we don't use the tools/build/feature/test-libpython-version.c version in any Makefile feature check: $ find tools/ -type f | xargs grep feature-libpython-version $ The only place where this was used was removed in 66dfdff03d196e51: - ifneq ($(feature-libpython-version), 1) - $(warning Python 3 is not yet supported; please set) - $(warning PYTHON and/or PYTHON_CONFIG appropriately.) - $(warning If you also have Python 2 installed, then) - $(warning try something like:) - $(warning $(and ,)) - $(warning $(and ,) make PYTHON=python2) - $(warning $(and ,)) - $(warning Otherwise, disable Python support entirely:) - $(warning $(and ,)) - $(warning $(and ,) make NO_LIBPYTHON=1) - $(warning $(and ,)) - $(error $(and ,)) - else - LDFLAGS += $(PYTHON_EMBED_LDFLAGS) - EXTLIBS += $(PYTHON_EMBED_LIBADD) - LANG_BINDINGS += $(obj-perf)python/perf.so - $(call detected,CONFIG_LIBPYTHON) - endif And nowadays we either build with PYTHON=python3 or just install the python3 devel packages and perf will build against it. But the leftover feature-libpython-version check made the fast path feature detection to break in all cases except when python2 devel files were installed: $ rpm -qa | grep python.*devel python3-devel-3.9.7-1.fc34.x86_64 $ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ; $ make -C tools/perf O=/tmp/build/perf install-bin make: Entering directory '/var/home/acme/git/perf/tools/perf' BUILD: Doing 'make -j32' parallel build HOSTCC /tmp/build/perf/fixdep.o <SNIP> $ cat /tmp/build/perf/feature/test-all.make.output In file included from test-all.c:18: test-libpython-version.c:5:10: error: #error 5 | #error | ^~~~~ $ ldd ~/bin/perf | grep python libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007fda6dbcf000) $ As python3 is the norm these days, fix this by just removing the unused feature-libpython-version feature check, making the test-all fast path to work with the common case. With this: $ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ; $ make -C tools/perf O=/tmp/build/perf install-bin |& head make: Entering directory '/var/home/acme/git/perf/tools/perf' BUILD: Doing 'make -j32' parallel build HOSTCC /tmp/build/perf/fixdep.o HOSTLD /tmp/build/perf/fixdep-in.o LINK /tmp/build/perf/fixdep Auto-detecting system features: ... dwarf: [ on ] ... dwarf_getlocations: [ on ] ... glibc: [ on ] $ ldd ~/bin/perf | grep python libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007f58800b0000) $ cat /tmp/build/perf/feature/test-all.make.output $ Reviewed-by: James Clark <james.clark@xxxxxxx> Fixes: 66dfdff03d196e51 ("perf tools: Add Python 3 support") Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx> Cc: Ian Rogers <irogers@xxxxxxxxxx> Cc: Jaroslav Škarvada <jskarvad@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Link: https://lore.kernel.org/lkml/YaYmeeC6CS2b8OSz@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/build/Makefile.feature | 1 - tools/build/feature/Makefile | 4 ---- tools/build/feature/test-all.c | 5 ----- tools/build/feature/test-libpython-version.c | 11 ----------- tools/perf/Makefile.config | 2 -- 5 files changed, 23 deletions(-) delete mode 100644 tools/build/feature/test-libpython-version.c --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -52,7 +52,6 @@ FEATURE_TESTS_BASIC := numa_num_possible_cpus \ libperl \ libpython \ - libpython-version \ libslang \ libslang-include-subdir \ libcrypto \ --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -30,7 +30,6 @@ FILES= test-numa_num_possible_cpus.bin \ test-libperl.bin \ test-libpython.bin \ - test-libpython-version.bin \ test-libslang.bin \ test-libslang-include-subdir.bin \ test-libcrypto.bin \ @@ -214,9 +213,6 @@ $(OUTPUT)test-libperl.bin: $(OUTPUT)test-libpython.bin: $(BUILD) $(FLAGS_PYTHON_EMBED) -$(OUTPUT)test-libpython-version.bin: - $(BUILD) - $(OUTPUT)test-libbfd.bin: $(BUILD) -DPACKAGE='"perf"' -lbfd -ldl --- a/tools/build/feature/test-all.c +++ b/tools/build/feature/test-all.c @@ -14,10 +14,6 @@ # include "test-libpython.c" #undef main -#define main main_test_libpython_version -# include "test-libpython-version.c" -#undef main - #define main main_test_libperl # include "test-libperl.c" #undef main @@ -193,7 +189,6 @@ int main(int argc, char *argv[]) { main_test_libpython(); - main_test_libpython_version(); main_test_libperl(); main_test_hello(); main_test_libelf(); --- a/tools/build/feature/test-libpython-version.c +++ /dev/null @@ -1,11 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -#include <Python.h> - -#if PY_VERSION_HEX >= 0x03000000 - #error -#endif - -int main(void) -{ - return 0; -} --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -247,8 +247,6 @@ endif FEATURE_CHECK_CFLAGS-libpython := $(PYTHON_EMBED_CCOPTS) FEATURE_CHECK_LDFLAGS-libpython := $(PYTHON_EMBED_LDOPTS) -FEATURE_CHECK_CFLAGS-libpython-version := $(PYTHON_EMBED_CCOPTS) -FEATURE_CHECK_LDFLAGS-libpython-version := $(PYTHON_EMBED_LDOPTS) FEATURE_CHECK_LDFLAGS-libaio = -lrt