native_posix fails to compile on macOS

[ochipara]

Hi,

I am trying to compile hello_world for native_posix on an os x (high sierra). I am able to use cmake to generate the build files, but it fails during compilation. I am getting the following error

FAILED: zephyr/CMakeFiles/offsets.dir/arch/posix/core/offsets/offsets.c.obj
/usr/bin/gcc -DBUILD_VERSION=zephyr-v1.13.0-1408-g7700eb2a15 -DKERNEL -D_FORTIFY_SOURCE=2 -D_POSIX_C_SOURCE=200809 -D_XOPEN_SOURCE=600 -D_XOPEN_SOURCE_EXTENDED -D__ZEPHYR__=1 -I../../../kernel/include -I../../../arch/posix/include -I../../../soc/posix/inf_clock -I../../../soc/posix/inf_clock/include -I../../../soc/posix/include -I../../../boards/posix/native_posix -I../../../include -I../../../include/drivers -Izephyr/include/generated -m32 -Os -g -Wall -Wformat -Wformat-security -Wno-format-zero-length -imacros /Users/ochipara/Working/embedded/r_and_r/zephyr/samples/hello_world/build/zephyr/include/generated/autoconf.h -ffreestanding -Wno-main -fno-asynchronous-unwind-tables -fno-pie -fno-pic -fno-strict-overflow -Wno-pointer-sign -Werror=implicit-int -Wpointer-arith -ffunction-sections -fdata-sections -fno-freestanding -m32 -MMD -MP -include /Users/ochipara/Working/embedded/r_and_r/zephyr/arch/posix/include/posix_cheats.h -std=c11 -MD -MT zephyr/CMakeFiles/offsets.dir/arch/posix/core/offsets/offsets.c.obj -MF zephyr/CMakeFiles/offsets.dir/arch/posix/core/offsets/offsets.c.obj.d -o zephyr/CMakeFiles/offsets.dir/arch/posix/core/offsets/offsets.c.obj -c /Users/ochipara/Working/embedded/r_and_r/zephyr/arch/posix/core/offsets/offsets.c
clang: error: unknown argument: '-fno-freestanding'

I remove the '-fno-freestanding' flag from ninja.build, then I am running into additional errors due to not finding the macros GEN_OFFSET_SYM and GEN_ABSOLUTE_SYM. Any help in getting the sample to compile for native_posix would be appreciated.

Thanks,
-- Octav

[aescolar]

Hi @ochipara , we have not tried to get native_posix working on mac OS and do know from a couple of people who tried that it does not work.

[Emil-Gydesen-Bose]

@ochipara I see that the error is clang: error: unknown argument: '-fno-freestanding'

Have you tried compiling with GCC instead of clang? I don't own a mac myself, but I've heard that gcc symlinks to the clang (llvm) compiler by default on macs, so that you think you have GCC, but you don't.

There's a couple of guides on how to download, build and install GCC on macs on the web, if you haven't already tried compiling with GCC.

[marc-hb]

@ochipara I see that the error is clang: error: unknown argument: '-fno-freestanding'

I suspect this particular error is gone with a more recent XCode. On Mojave now:

$ clang --version
Apple LLVM version 10.0.1 (clang-1001.0.46.4)
$ clang --help | grep standing
  -ffreestanding          Assert that the compilation takes place in a freestanding environment

I don't own a mac myself, but I've heard that gcc symlinks to the clang (llvm) compiler by default on macs, so that you think you have GCC, but you don't.

This is correct. Don't invoke gcc on a Mac, it's deceptive (unless you installed it yourself). Use clang.

There's a couple of guides on how to download, build and install GCC on macs on the web, if you haven't already tried compiling with GCC.

The most likely easiest: https://formulae.brew.sh/formula/gcc

[raveslave]

I suspect this particular error is gone with a more recent XCode.

I'm on latest os + xcode Apple clang version 11.0.0 (clang-1100.0.33.16, not getting the fno- error, but instead a bunch of ../kernel/include/kernel_offsets.h:27:1: error: unknown directive

[raveslave]

any plans to support LLVM/Xcode on macOS or should we use gcc for the native_posix use case (on mac)?

[aescolar]

@raveslave No plans wrt macOS and native_posix

[eanderlind]

Building zephyr/samples/hello_world with gcc (10.2 installed via homebrew, with a manual link ln -s /usr/local/bin/gcc-10 /usr/local/bin/gcc) on macOS 10.15.7 (ie only 64-bit supported) with
west build -b native_posix_64 -d build_posix64
selects correct gcc toolchain, however stumbles when compiling ``zephyr/arch/posix/core/offsets/offsets.c`with errors

../../../kernel/include/kernel_offsets.h:28:2: error: unknown directive
        .type   ___cpu_t_current_OFFSET,@object
        ^
../../../kernel/include/kernel_offsets.h:29:2: error: unknown directive
        .type   ___cpu_t_nested_OFFSET,@object
        ^
../../../kernel/include/kernel_offsets.h:30:2: error: unknown directive
        .type   ___cpu_t_irq_stack_OFFSET,@object
        ^    (truncated the rest..)

It looks like the struct member .type isn't defined for macOS. Any suggestions which include directive could be wrong and which .cmake file to modify?
(-m64 flag was set, but zephyr/.config didn't have any flags containing X86)

Note: With same setup, west build -b qemu_x86_64 -d build_qemu64 also fails - it incorrectly selects the
gccarmemb toolchain even when creating a new build dir (and complains it doesn't understand `m64 flag).
Logic for selecting target seems incorrect for this case.

Building west build -b qemu_cortex_m3 is successful.

[zephyrbot]

Hi @aescolar,

This issue, marked as an Enhancement, was opened a while ago and did not get any traction. It was just assigned to you based on the labels. If you don't consider yourself the right person to address this issue, please re-assing it to the right person.

Please take a moment to review if the issue is still relevant to the project. If it is, please provide feedback and direction on how to move forward. If it is not, has already been addressed, is a duplicate, or is no longer relevant, please close it with a short comment explaining the reason.

@ochipara you are also encouraged to help moving this issue forward by providing additional information and confirming this request/issue is still relevant to you.

Thanks!