Message ID | Y9OZibQSy8DYxwbd@tucnak |
---|---|
State | New |
Headers | show |
Series | libstdc++: Fix up FAIL in 17_intro/names.cc on glibc < 2.19 [PR108568] | expand |
On Fri, 27 Jan 2023 at 09:29, Jakub Jelinek <jakub@redhat.com> wrote: > > Hi! > > On gcc112 which has glibc 2.17 I've noticed > FAIL: 17_intro/names.cc (test for excess errors) > FAIL: experimental/names.cc (test for excess errors) > These are because glibc < 2.19 used __unused as field member of various structs, > including mcontext_t in sys/ucontext.h on ppc64le. > This was changed in glibc with > https://gcc.gnu.org/pipermail/libc-alpha/2013-November/045766.html > names.cc even has > #ifdef __GLIBC_PREREQ > #if ! __GLIBC_PREREQ(2, 19) > // Glibc defines this prior to 2.19 > #undef __unused > #endif > #endif > for it, but it doesn't work. The reason is that __GLIBC_PREREQ is defined in > <features.h> but nothing included that header before this spot (it is included later > from bits/stdc++.h). > > The following patch on Linux/Hurd conditionally includes features.h to get > the needed macros before deciding if __unused should be undefined or not. > If needed, I could use __GLIBC_PREREQ then but would need to check if it is > defined and between 1996 and 1999 it wasn't. > > Tested on powerpc64le-linux with glibc 2.17 (where it fixes the > regressions), on x86_64-linux with glibc 2.35 (where it still PASSes), > plus on the latter with -E -dD on the test to verify __unused is just > defined and not undefined later on, ok for trunk? OK, thanks.
--- libstdc++-v3/testsuite/17_intro/names.cc.jj 2023-01-16 23:19:06.292716661 +0100 +++ libstdc++-v3/testsuite/17_intro/names.cc 2023-01-27 10:20:20.787645823 +0100 @@ -252,12 +252,15 @@ #undef y #endif -#ifdef __GLIBC_PREREQ -#if ! __GLIBC_PREREQ(2, 19) +#if defined (__linux__) || defined (__gnu_hurd__) +#if __has_include(<features.h>) +#include <features.h> +#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 19 // Glibc defines this prior to 2.19 #undef __unused #endif #endif +#endif #if __has_include(<newlib.h>) // newlib's <sys/cdefs.h> defines these as macros.