[PATCH 1/1] perf python: Fix clang detection to strip out options passed in $CC

[Arnaldo Carvalho de Melo]

The clang check in the python setup.py file expected $CC to be just the
name of the compiler, not the compiler + options, i.e. all options were
expected to be passed in $CFLAGS, this ends up making it fail in systems
where CC is set to, e.g.:

 "aarch64-linaro-linux-gcc --sysroot=/oe/build/tmp/work/juno-linaro-linux/perf/1.0-r9/recipe-sysroot"

Like this:

  $ python3
  >>> from subprocess import Popen
  >>> a = Popen(["aarch64-linux-gnu-gcc --sysroot=/oe/build/tmp/work/juno-linaro-linux/perf/1.0-r9/recipe-sysroot", "-v"])
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    File "/usr/lib/python3.6/subprocess.py", line 729, in __init__
      restore_signals, start_new_session)
    File "/usr/lib/python3.6/subprocess.py", line 1364, in _execute_child
      raise child_exception_type(errno_num, err_msg, err_filename)
  FileNotFoundError: [Errno 2] No such file or directory: 'aarch64-linux-gnu-gcc --sysroot=/oe/build/tmp/work/juno-linaro-linux/perf/1.0-r9/recipe-sysroot': 'aarch64-linux-gnu-gcc --sysroot=/oe/build/tmp/work/juno-linaro-linux/perf/1.0-r9/recipe-sysroot'
  >>>

Make it more robust, covering this case, by passing cc.split()[0] as the
first arg to popen().

Reported-by: Daniel Dí <daniel.diaz@xxxxxxxxxx>
Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>,
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
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 8a065a6f9713..347b2c0789e4 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -3,7 +3,7 @@ from subprocess import Popen, PIPE
 from re import sub
 
 cc = getenv("CC")
-cc_is_clang = b"clang version" in Popen([cc, "-v"], stderr=PIPE).stderr.readline()
+cc_is_clang = b"clang version" in Popen([cc.split()[0], "-v"], stderr=PIPE).stderr.readline()
 
 def clang_has_option(option):
     return [o for o in Popen([cc, option], stderr=PIPE).stderr.readlines() if b"unknown argument" in o] == [ ]
-- 
2.21.1