[tip:perf/urgent] perf python: Filter out -specs=/a/b/c from the python binding cc options

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  4be92cf018c391c4ecc5fd091fae8c152de3692f
Gitweb:     http://git.kernel.org/tip/4be92cf018c391c4ecc5fd091fae8c152de3692f
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Wed, 15 Feb 2017 21:36:48 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 17 Feb 2017 10:31:13 -0300

perf python: Filter out -specs=/a/b/c from the python binding cc options

The -spec=/path/to/file can be used to change what gcc puts in the cc,
ld, etc command lines, but this is not present in clang, filter it out
at the setup.py file by changing python2's internal variable where it
keeps its initial CFLAGS value.

With this all of perf can be built in at least Fedora 25, fixing this
problem:

    GEN      /tmp/build/perf/python/perf.so
    CC       /tmp/build/perf/builtin-buildid-list.o
  clang-4.0: error: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1' [-Werror,-Wunused-command-line-argument]
  clang-4.0: error: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1' [-Werror,-Wunused-command-line-argument]
  error: command 'clang' failed with exit status 1

Now I need to change all the containers where I have clang to build
perf with it, so that we can check that in other distros (opensuse, debian,
ubuntu, etc) this also works.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-g9lhgr162ao8ao29vvf0hgm1@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/setup.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index c868098..af415fe 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -1,8 +1,15 @@
 #!/usr/bin/python2
 
-from distutils.core import setup, Extension
 from os import getenv
 
+cc = getenv("CC")
+if cc == "clang":
+    from _sysconfigdata import build_time_vars
+    from re import sub
+    build_time_vars["CFLAGS"] = sub("-specs=[^ ]+", "", build_time_vars["CFLAGS"])
+
+from distutils.core import setup, Extension
+
 from distutils.command.build_ext   import build_ext   as _build_ext
 from distutils.command.install_lib import install_lib as _install_lib