Re: (dynamic-link "libm") doesn't work on guile

[ludo@gnu.org (Ludovic Courtès)]

Alex Vong <alexvong1995@gmail.com> skribis:

> ludo@gnu.org (Ludovic Courtès) writes:

[...]

>> I think that’s because libm.so and libc.so are linker scripts, whereas
>> libm-2.22.so and libc-2.22.so are the actual ELF files:
>>
>> $ cat ~/.guix-profile/lib/libm.so
>> /* GNU ld script
>> */
>> OUTPUT_FORMAT(elf64-x86-64)
>> GROUP ( /gnu/store/qv7bk62c22ms9i11dhfl71hnivyc82k2-glibc-2.22/lib/libm.so.6  AS_NEEDED ( /gnu/store/qv7bk62c22ms9i11dhfl71hnivyc82k2-glibc-2.22/lib/libmvec.so.1 ) )
>> $ cat ~/.guix-profile/lib/libc.so
>> /* GNU ld script
>>    Use the shared library, but some functions are only in
>>    the static library, so try that secondarily.  */
>> OUTPUT_FORMAT(elf64-x86-64)
>> GROUP ( /gnu/store/qv7bk62c22ms9i11dhfl71hnivyc82k2-glibc-2.22/lib/libc.so.6 /gnu/store/qv7bk62c22ms9i11dhfl71hnivyc82k2-glibc-2.22/lib/libc_nonshared.a  AS_NEEDED ( /gnu/store/qv7bk62c22ms9i11dhfl71hnivyc82k2-glibc-2.22/lib/ld-linux-x86-64.so.2 ) )
>>
> I think you are right, libm.so is a binary file in Debian,

That’s because Debian uses libc < 2.22 (libc 2.22 introduced libmvec,
hence the linker script.)

> Is there way to specify an ABI version (I suppose 6 is the ABI version
> since we have libm.so.6) when dlopening a shared library to avoid this
> glitch?

Unfortunately no, that’s a long-standing libltdl bug:

  https://lists.gnu.org/archive/html/guile-devel/2011-03/msg00021.html
  https://lists.gnu.org/archive/html/bug-libtool/2011-03/msg00029.html

You’d make a lot of people happy by fixing libltdl.  ;-)

Thanks,
Ludo’.