x86: long-double stub functions are not built-in to libgcc

[cfriedt]

It looks as though qemu_x86 is having some problems with SDK version 0.15.2 and c++

/home/cfriedt/zephyr-sdk-0.15.2/x86_64-zephyr-elf/bin/../lib/gcc/x86_64-zephyr-elf/12.1.0/../../../../x86_64-zephyr-elf/bin/ld.bfd: /home/cfriedt/zephyr-sdk-0.15.2/x86_64-zephyr-elf/x86_64-zephyr-elf/lib/32/soft-float/libstdc++.a(c++locale.o): in function `void std::__convert_to_v<long double>(char const*, long double&, std::_Ios_Iostate&, int* const&)':
c++locale.cc:(.text._ZSt14__convert_to_vIeEvPKcRT_RSt12_Ios_IostateRKPi+0x77): undefined reference to `__unordxf2'
/home/cfriedt/zephyr-sdk-0.15.2/x86_64-zephyr-elf/bin/../lib/gcc/x86_64-zephyr-elf/12.1.0/../../../../x86_64-zephyr-elf/bin/ld.bfd: c++locale.cc:(.text._ZSt14__convert_to_vIeEvPKcRT_RSt12_Ios_IostateRKPi+0x97): undefined reference to `__gexf2'
/home/cfriedt/zephyr-sdk-0.15.2/x86_64-zephyr-elf/bin/../lib/gcc/x86_64-zephyr-elf/12.1.0/../../../../x86_64-zephyr-elf/bin/ld.bfd: c++locale.cc:(.text._ZSt14__convert_to_vIeEvPKcRT_RSt12_Ios_IostateRKPi+0xb7): undefined reference to `__unordxf2'
/home/cfriedt/zephyr-sdk-0.15.2/x86_64-zephyr-elf/bin/../lib/gcc/x86_64-zephyr-elf/12.1.0/../../../../x86_64-zephyr-elf/bin/ld.bfd: c++locale.cc:(.text._ZSt14__convert_to_vIeEvPKcRT_RSt12_Ios_IostateRKPi+0xd7): undefined reference to `__lexf2'
/home/cfriedt/zephyr-sdk-0.15.2/x86_64-zephyr-elf/bin/../lib/gcc/x86_64-zephyr-elf/12.1.0/../../../../x86_64-zephyr-elf/bin/ld.bfd: c++locale.cc:(.text._ZSt14__convert_to_vIeEvPKcRT_RSt12_Ios_IostateRKPi+0xf4): undefined reference to `__gtxf2'

This works fine with mps2_an385, qemu_cortex_a53, qemu_riscv32, qemu_riscv64, and qemu_x86_64, so it looks as though it's localized to 32-bit x86 support. qemu_x86_64 also fails on the tls test permutation at runtime, but it's unrelated.

To reproduce with the fewest steps:

cat << EOF > submanifests/99-thrift.yaml
manifest:
  defaults:
    remote: upstream

  remotes:
    - name: upstream
      url-base: https://github.com/zephyrproject-rtos

  projects:
    - name: gsoc-2022-thrift
      path: modules/lib/thrift
      revision: main
      submodules: true
EOF
west update
twister -i -p qemu_x86 -T ../modules/lib/thrift/tests/lib/thrift/ThriftTest

^^ requires thrift to be available

brew install -y thrift
apt install -y thrift-compiler
dnf install -y thrift

[stephanosio]

cc @dcpleung

[dcpleung]

Do you have a working version of Thrift module that builds with the 0.15.2 SDK? I tried to build it and it complained about struct stat being redefined:

In file included from zephyr/include/zephyr/posix/unistd.h:10,
                 from modules/lib/thrift/.upstream/lib/cpp/src/thrift/transport/TServerSocket.cpp:58:
zephyr/include/zephyr/posix/sys/stat.h:92:8: error: redefinition of 'struct stat'
   92 | struct stat {
      |        ^~~~
In file included from zephyr-sdk-0.15.2/x86_64-zephyr-elf/x86_64-zephyr-elf/sys-include/sys/_default_fcntl.h:211,
                 from zephyr-sdk-0.15.2/x86_64-zephyr-elf/x86_64-zephyr-elf/sys-include/sys/fcntl.h:3,
                 from zephyr-sdk-0.15.2/x86_64-zephyr-elf/x86_64-zephyr-elf/sys-include/fcntl.h:1,
                 from modules/lib/thrift/.upstream/lib/cpp/src/thrift/transport/TServerSocket.cpp:55:
zephyr-sdk-0.15.2/x86_64-zephyr-elf/x86_64-zephyr-elf/sys-include/sys/stat.h:27:9: note: previous definition of 'struct stat'
   27 | struct  stat
      |         ^~~~

[cfriedt]

Do you have a working version of Thrift module that builds with the 0.15.2 SDK? I tried to build it and it complained about struct stat being redefined:

@dcpleung
I've noticed the same thing. You should probably be ok if you check out a zephyr commit from last week.

[cfriedt]

Still hitting this on qemu_x86.

zephyrproject-rtos/gsoc-2022-thrift#158 can be modified to not exclude qemu_x86 to demonstrate the issue. I suspect it will be excluded in thrift until we get a new SDK version.

[keith-packard]

this is a bigger job than it seems -- as near as I can tell, 80-bit soft float support is simply absent from glibc (and, hence, libgcc).