Question about macro _GLIBCXX_RES_LIMITS in libstdc++ testsuite

[Hans-Peter Nilsson]

On Thu, 23 Apr 2015, Bin.Cheng wrote:
> Hi,
> In libstdc++ testsuite, I noticed that macro _GLIBCXX_RES_LIMITS is
> checked/set by GLIBCXX_CHECK_SETRLIMIT, which is further guarded by
> GLIBCXX_IS_NATIVE as below:
>
> AC_DEFUN([GLIBCXX_CONFIGURE_TESTSUITE], [
>   if $GLIBCXX_IS_NATIVE ; then
>     # Do checks for resource limit functions.
>     GLIBCXX_CHECK_SETRLIMIT
>
>     # Look for setenv, so that extended locale tests can be performed.
>     GLIBCXX_CHECK_STDLIB_DECL_AND_LINKAGE_3(setenv)
>   fi
>
> For cross toolchain like arm-linux, _GLIBCXX_RES_LIMITS isn't set.  As
> a result, function __gnu_test::set_file_limit is actually nullified
> and causing case 27_io/fpos/14775.cc failed.
>
> My question is why we want to guard the check with GLIBCXX_IS_NATIVE?
> Could we check it directly, if it's not supported, it's going to fail
> and undef the macro anyway?
>
>
> Thanks,
> bin
>

Good question.  I'm CC:ing the libstdc++ list, maybe that'll
bring an answer before another 1.5 months.

brgds, H-P