Subject: Re: bug#19935: Checking whether C compiler handles -Wenum-compare does not work

From: Jim Meyering <[email-masked]>
Date: Sat, 19 Sep 2015 18:16:40 -0700

On Tue, Feb 24, 2015 at 3:02 AM, Lukasz Dorau
<[email-masked]> wrote:
> Checking whether C compiler handles -Wenum-compare does not work:
>
> configure:34007: checking whether C compiler handles -Wenum-compare
> configure:34026: gcc -std=gnu99 -o conftest -g -O2  -Wenum-compare
> conftest.c  >&5
> cc1: warning: command line option "-Wenum-compare" is valid for C++/ObjC++
> but not for C
> configure:34026: $? = 0
> configure:34037: result: yes
>
> Whole config.log is attached.
>
> As a result make fails:
> $ make
> make  all-recursive
> make[1]: Entering directory `/mnt/files/repos/grep'
> Making all in po
> make[2]: Entering directory `/mnt/files/repos/grep/po'
> make[2]: Nothing to be done for `all'.
> make[2]: Leaving directory `/mnt/files/repos/grep/po'
> Making all in lib
> make[2]: Entering directory `/mnt/files/repos/grep/lib'
> make  all-am
> make[3]: Entering directory `/mnt/files/repos/grep/lib'
>   CC       binary-io.o
> cc1: warning: command line option "-Wenum-compare" is valid for C++/ObjC++
> but not for C

Thanks for the report and sorry about the delay.
I'm guessing that is due to your use of an older version of gcc.
Can you still reproduce that problem using grep-2.21? If so, can you
try a newer version of gcc?

Which version of gcc are you using?