Thanks for your explanation. I did not realise that __USE_GNU is evil. :-/ FWIW, there is a sound explanation of the difference between _GNU_SOURCE and __USE_GNU here: https://stackoverflow.com/questions/7296963/gnu-source-and-use-gnu Thanks, Mirsad On Mon, May 13, 2024 at 1:02 AM Jarkko Sakkinen <jarkko@xxxxxxxxxx> wrote: > > On Sat May 11, 2024 at 12:02 AM EEST, Mirsad Todorovac wrote: > > On 5/10/24 22:52, John Hubbard wrote: > > > On 5/10/24 1:37 PM, Mirsad Todorovac wrote: > > > ... > > >> The fix defines __USE_GNU before including <stdio.h> in case it isn't already > > >> defined. After this intervention the module compiles OK. > > > > > > Instead of interventions, I believe the standard way to do this is to simply > > > define _GNU_SOURCE before including the header file(s). For example, the > > > following also fixes the compilation failure on Ubuntu: > > > > > > diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c > > > index 9820b3809c69..bb6e795d06e2 100644 > > > --- a/tools/testing/selftests/sgx/main.c > > > +++ b/tools/testing/selftests/sgx/main.c > > > @@ -1,6 +1,7 @@ > > > // SPDX-License-Identifier: GPL-2.0 > > > /* Copyright(c) 2016-20 Intel Corporation. */ > > > > > > +#define _GNU_SOURCE > > > #include <cpuid.h> > > > #include <elf.h> > > > #include <errno.h> > > > > > > > > > However, that's not required, because Edward Liaw is already on v4 of > > > a patchset[1] that fixes up the _GNU_SOURCE problem for all selftests. > > > > > > [1] https://lore.kernel.org/all/20240510000842.410729-2-edliaw@xxxxxxxxxx/ > > > > > > thanks, > > > > Hi, > > > > Yes, I actually like Ed's solution more, because it solves the asprintf() prototype > > problem with TEST_HARNESS_MAIN macro for all of the tests. > > > > Sorry for the noise and the time wasted reviewing. 8-| > > > > Best regards, > > Mirsad Todorovac > > Yeah, well, it does not cause any harm and I was not sure when the patch > set is in mainline so thus gave the pointers. Anyway, never ever touch > __USE_GNU and always look at the man page from man7.org next time and > should cause less friction... > > BR, Jarkko
