undefined `__dso_handle` when linking executable with `atexit()` call with glibc

[fuhsnn]

This snippet:

#include <stdlib.h>

static void fn(void) {}

int main(void) {
    atexit(fn);
}

Failed with:

ld: /usr/lib/x86_64-linux-gnu/libc_nonshared.a(atexit.oS): in function `atexit':
(.text+0x3): undefined reference to `__dso_handle'
ld: a.out: hidden symbol `__dso_handle' isn't defined
ld: final link failed: bad value
error: ld terminated with status 1

I think it's in the driver or pcc-libs, since this also happens with .o produced by gcc.

[ragge0]

Which host, target and flags are you using?

[fuhsnn]

In Debian 12 container, configured with ./configure --prefx=.

[fuhsnn]

Found the cause, glibc's atexit() uses this handle:

0000000000001180 <atexit>:
    1180:       48 8b 15 91 2e 00 00    mov    0x2e91(%rip),%rdx        # 4018 <__dso_handle>
    1187:       31 f6                   xor    %esi,%esi
    1189:       e9 b2 fe ff ff          jmp    1040 <__cxa_atexit@plt>

Which is defined in glibc's own ctrbegin.o

user@debian:~$ readelf -s /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o | grep dso
    16: 0000000000000000     0 OBJECT  GLOBAL HIDDEN     3 __dso_handle

But the default config of pcc uses ctrbegin.o from pcc-libs

user@debian:~$ ~/pccinstl/bin/pcc q.o -###
Portable C Compiler 1.2.0.DEVEL 20231021 for x86_64-pc-linux-gnu
Calling ld -v -d -dynamic-linker /lib64/ld-linux-x86-64.so.2 -e _start /usr/lib/x86_64-linux-gnu/crt1.o /usr/lib/x86_64-linux-gnu/crti.o /home/user/pccinstl/lib/pcc/x86_64-pc-linux-gnu/1.2.0.DEVEL/lib/crtbegin.o q.o -L/home/user/pccinstl/lib/pcc/x86_64-pc-linux-gnu/1.2.0.DEVEL/lib/ -L/usr/lib64/ -L/usr/lib/x86_64-linux-gnu/ -lpcc -lc -lpcc /home/user/pccinstl/lib/pcc/x86_64-pc-linux-gnu/1.2.0.DEVEL/lib/crtend.o /usr/lib/x86_64-linux-gnu/crtn.o

So this should be solved by teaching pcc's driver to link with glibc's crtbegin, or add something like:
__attribute__((visibility("hidden"))) int __dso_handle;
in pcc-libs's ctrbegin.o if targeting glibc.