[PATCH 5.10 093/132] tools build: Remove needless libpython-version feature check that breaks test-all fast path

Greg Kroah-Hartman
2021-12-13T10:17:50Z

From: Arnaldo Carvalho de Melo <acme@redhat.com>

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@arm.com>
Fixes: 66dfdff03d196e51 ("perf tools: Add Python 3 support")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jaroslav Škarvada <jskarvad@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/YaYmeeC6CS2b8OSz@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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
@@ -49,7 +49,6 @@ 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
@@ -31,7 +31,6 @@ 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 \
@@ -220,9 +219,6 @@ $(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
@@ -181,7 +177,6 @@
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
@@ -259,8 +259,6 @@ 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