[PATCH 13/13] perf python: Use -Wno-redundant-decls to build with PYTHON=python3

From: Arnaldo Carvalho de Melo
Date: Wed Sep 19 2018 - 10:26:35 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

When building in ClearLinux using 'make PYTHON=python3' with gcc 8.2.1
it fails with:

GEN /tmp/build/perf/python/perf.so
In file included from /usr/include/python3.7m/Python.h:126,
from /git/linux/tools/perf/util/python.c:2:
/usr/include/python3.7m/import.h:58:24: error: redundant redeclaration of â_PyImport_AddModuleObjectâ [-Werror=redundant-decls]
PyAPI_FUNC(PyObject *) _PyImport_AddModuleObject(PyObject *, PyObject *);
^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/python3.7m/import.h:47:24: note: previous declaration of â_PyImport_AddModuleObjectâ was here
PyAPI_FUNC(PyObject *) _PyImport_AddModuleObject(PyObject *name,
^~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
error: command 'gcc' failed with exit status 1

And indeed there is a redundant declaration in that Python.h file, one
with parameter names and the other without, so just add
-Wno-error=redundant-decls to the python setup instructions.

Now perf builds with gcc in ClearLinux with the following Dockerfile:

# docker.io/acmel/linux-perf-tools-build-clearlinux:latest
FROM docker.io/clearlinux:latest
MAINTAINER Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
RUN swupd update && \
swupd bundle-add sysadmin-basic-dev
RUN mkdir -m 777 -p /git /tmp/build/perf /tmp/build/objtool /tmp/build/linux && \
groupadd -r perfbuilder && \
useradd -m -r -g perfbuilder perfbuilder && \
chown -R perfbuilder.perfbuilder /tmp/build/ /git/
USER perfbuilder
COPY rx_and_build.sh /
ENV EXTRA_MAKE_ARGS=PYTHON=python3
ENTRYPOINT ["/rx_and_build.sh"]

Now to figure out why the build fails with clang, that is present in the
above container as detected by the rx_and_build.sh script:

clang version 6.0.1 (tags/RELEASE_601/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/sbin
make: Entering directory '/git/linux/tools/perf'
BUILD: Doing 'make -j4' 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: [ OFF ]
... dwarf_getlocations: [ OFF ]
... glibc: [ OFF ]
... gtk2: [ OFF ]
... libaudit: [ OFF ]
... libbfd: [ OFF ]
... libelf: [ OFF ]
... libnuma: [ OFF ]
... numa_num_possible_cpus: [ OFF ]
... libperl: [ OFF ]
... libpython: [ OFF ]
... libslang: [ OFF ]
... libcrypto: [ OFF ]
... libunwind: [ OFF ]
... libdw-dwarf-unwind: [ OFF ]
... zlib: [ OFF ]
... lzma: [ OFF ]
... get_cpuid: [ OFF ]
... bpf: [ OFF ]

Makefile.config:331: *** No gnu/libc-version.h found, please install glibc-dev[el]. Stop.
make[1]: *** [Makefile.perf:206: sub-make] Error 2
make: *** [Makefile:70: all] Error 2
make: Leaving directory '/git/linux/tools/perf'

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Thiago Macieira <thiago.macieira@xxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-c3khb9ac86s00qxzjrueomme@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/setup.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index 97efbcad076e..1942f6dd24f6 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -35,7 +35,7 @@ class install_lib(_install_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' ]
+cflags += ['-fno-strict-aliasing', '-Wno-write-strings', '-Wno-unused-parameter', '-Wno-redundant-decls' ]
if cc != "clang":
cflags += ['-Wno-cast-function-type' ]

--
2.14.4