[PATCH v4] glibcextract.py: Add compile_c_snippet

[Florian Weimer]

* Adhemerval Zanella:

> It might be used on tests to check if a snippet build with the provided
> compiler and flags.
> ---
>  scripts/glibcextract.py | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
>
> diff --git a/scripts/glibcextract.py b/scripts/glibcextract.py
> index 43ab58ffe2..33463087da 100644
> --- a/scripts/glibcextract.py
> +++ b/scripts/glibcextract.py
> @@ -17,6 +17,7 @@
>  # License along with the GNU C Library; if not, see
>  # <https://www.gnu.org/licenses/>.
>  
> +import collections
>  import os.path
>  import re
>  import subprocess
> @@ -173,3 +174,20 @@ def compare_macro_consts(source_1, source_2, cc, macro_re, exclude_re=None,
>              if not allow_extra_2:
>                  ret = 1
>      return ret
> +
> +CompileResult = collections.namedtuple("CompileResult", "returncode output")
> +
> +def compile_c_snippet(snippet, cc, extra_cc_args=''):
> +    """Compile and return whether the SNIPPET can be build with CC along
> +       EXTRA_CC_ARGS compiler flags.  Return a CompileResult with RETURNCODE
> +       being 0 for success, or the failure value and the compiler output.
> +    """
> +    with tempfile.TemporaryDirectory() as temp_dir:
> +        c_file_name = os.path.join(temp_dir, 'test.c')
> +        obj_file_name = os.path.join(temp_dir, 'test.o')
> +        with open(c_file_name, 'w') as c_file:
> +            c_file.write(snippet + '\n')
> +        cmd = cc.split() + extra_cc_args.split() + ['-c', '-o', obj_file_name,
> +                c_file_name]
> +        r = subprocess.run(cmd, capture_output=True)
> +        return CompileResult(r.returncode, r.stderr)

Meh.

Traceback (most recent call last):
  File "../sysdeps/unix/sysv/linux/tst-mount-compile.py", line 66, in <module>
    main()
  File "../sysdeps/unix/sysv/linux/tst-mount-compile.py", line 38, in main
    args.cc).returncode != 0:
  File "/home/bmg/src/glibc/scripts/glibcextract.py", line 192, in compile_c_snippet
    r = subprocess.run(cmd, capture_output=True)
  File "/usr/lib64/python3.6/subprocess.py", line 423, in run
    with Popen(*popenargs, **kwargs) as process:
TypeError: __init__() got an unexpected keyword argument 'capture_output'

That's with Python 3.6.

Thanks,
Florian