Re: [PATCH] libstdc++: Ensure __gthread_self doesn't call undefined weak symbol [PR 95989]

[Jonathan Wakely via Gcc-patches]

On 11/11/20 19:08 +0100, Jakub Jelinek via Libstdc++ wrote:

On Wed, Nov 11, 2020 at 05:24:42PM +0000, Jonathan Wakely wrote:

--- a/libgcc/gthr-posix.h
+++ b/libgcc/gthr-posix.h
@@ -684,7 +684,14 @@ __gthread_equal (__gthread_t __t1, __gthread_t __t2)
 static inline __gthread_t
 __gthread_self (void)
 {
+#if __GLIBC_PREREQ(2, 27)

What if it is a non-glibc system where __GLIBC_PREREQ macro isn't defined?

Ah yes, I forgot non-glibc systems exist :-)

Thanks, I'll fix it tomorrow, and test on some more targets.

I think you'd get then
error: missing binary operator before token "("
So I think you want
#if defined __GLIBC__ && defined __GLIBC_PREREQ
#if __GLIBC_PREREQ(2, 27)
 return pthread_self ();
#else
 return __gthrw_(pthread_self) ();
#else
 return __gthrw_(pthread_self) ();
#endif
or similar.

        Jakub