Re: accept4 and SOCK_NONBLOCK

[Florian Weimer]

* Richard W. M. Jones:

> On Tue, Aug 20, 2019 at 05:37:58PM +0200, Florian Weimer wrote:
>> * Richard W. M. Jones:
>> 
>> > As for why accept4 is being replaced at all, the only reference to it
>> > in config.log is:
>> >
>> >   configure:25630: checking whether accept4 is declared
>> >   configure:25630: gcc -c -O2 -g -pipe -Wall -Werror=format-security 
>> > -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions 
>> > -fstack-protector-strong -grecord-gcc-switches 
>> > -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 
>> > -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic 
>> > -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection  
>> > conftest.c >&5
>> >   configure:25630: $? = 0
>> >   configure:25630: result: yes
>> 
>> What does the test program look like?  Does it include <config.h>?
>> accept4 requires _GNU_SOURCE.
>
> I'm not sure how to find out.  However m4/accept.m4 (supplied
> by gnulib itself) does contain:
>
>   dnl Persuade glibc <sys/socket.h> to declare accept4().
>   AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
>
> so I guess the test *ought* to be using _GNU_SOURCE.

And the configure test acctually succeeded, which I missed.  So it has
to be something else.  You'll have to investigate the generated files to
see what's going wrong there.

Thanks,
Florian