Re: x86_64-gnu port -- help needed

[Andreas Schwab]

On Mär 09 2023, Sergey Bugaev wrote:

> x86_64-gnu-gcc -nostdlib -nostartfiles -r -o elf/librtld.map.o
> elf/librtld.mapT.o '-Wl,-(' elf/dl-allobjs.os libc_pic.a
> mach/libmachuser_pic.a hurd/libhurduser_pic.a -lgcc '-Wl,-)'
> -Wl,-Map,elf/librtld.mapT
> x86_64-gnu/bin/ld: libc_pic.a(_exit.os): in function `__GI__exit':
> posix/../sysdeps/mach/hurd/_exit.c:50: multiple definition of `__GI__exit';
> elf/dl-allobjs.os:elf/../sysdeps/mach/hurd/dl-sysdep.c:728: first defined
> here

The only symbol provided by _exit.os that is not defined by
../sysdeps/mach/hurd/dl-sysdep.c is _Exit.  Does anything call this
function?

> x86_64-gnu/bin/ld: libc_pic.a(strtoul.os): in function
> `__GI___strtoul_internal':
> stdlib/../sysdeps/wordsize-64/strtoul.c:108: multiple definition of
> `__GI___strtoul_internal';
> elf/dl-allobjs.os:elf/../sysdeps/mach/hurd/dl-sysdep.c:713: first defined
> here

Similarily, something is pulling in strtoul.os because it references a
symbol from there not defined by ../sysdeps/mach/hurd/dl-sysdep.c.

elf/librtld.mapT should tell you where the references come from.

> 1. What is this about, what's it even trying to do? If this is linking the
> dynamic linker (ld.so / rtld — these are the same thing, right?), then why
> does it need the dl-sysdep version if the real version is available?

The comments in ../sysdeps/mach/hurd/dl-sysdep.c indicate that the
dynamic linker wants to use some stripped down implementation of these
functions.

> 3. How come this works on i686-gnu, the duplicated symbols are clearly
> present there too!

Pure luck, perhaps.

-- 
Andreas Schwab, schwab@linux-m68k.org
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