ARM (Raspberry PI) build

I'm trying to build this project for ARM but I'm having an issue. Please bear with me as I'm very rusty when it comes to C/C++ builds.

During the cmake --build . process I get the following error:

[ 50%] Linking C executable hdr_histogram_test
/usr/bin/ld: ../src/libhdr_histogram_static.a(hdr_histogram.c.o): in function `counts_inc_normalised_atomic':
hdr_histogram.c:(.text+0x204): undefined reference to `__atomic_fetch_add_8'
/usr/bin/ld: hdr_histogram.c:(.text+0x220): undefined reference to `__atomic_fetch_add_8'
/usr/bin/ld: ../src/libhdr_histogram_static.a(hdr_histogram.c.o): in function `update_min_max_atomic':
hdr_histogram.c:(.text+0x2dc): undefined reference to `__atomic_load_8'
/usr/bin/ld: hdr_histogram.c:(.text+0x32c): undefined reference to `__atomic_compare_exchange_8'
/usr/bin/ld: hdr_histogram.c:(.text+0x354): undefined reference to `__atomic_load_8'
/usr/bin/ld: hdr_histogram.c:(.text+0x398): undefined reference to `__atomic_compare_exchange_8'
/usr/bin/ld: ../src/libhdr_histogram_static.a(hdr_writer_reader_phaser.c.o): in function `_hdr_phaser_get_epoch':
hdr_writer_reader_phaser.c:(.text+0x18): undefined reference to `__atomic_load_8'
/usr/bin/ld: ../src/libhdr_histogram_static.a(hdr_writer_reader_phaser.c.o): in function `_hdr_phaser_set_epoch':
hdr_writer_reader_phaser.c:(.text+0x58): undefined reference to `__atomic_store_8'
/usr/bin/ld: ../src/libhdr_histogram_static.a(hdr_writer_reader_phaser.c.o): in function `_hdr_phaser_reset_epoch':
hdr_writer_reader_phaser.c:(.text+0x8c): undefined reference to `__atomic_exchange_8'
/usr/bin/ld: ../src/libhdr_histogram_static.a(hdr_writer_reader_phaser.c.o): in function `hdr_phaser_writer_enter':
hdr_writer_reader_phaser.c:(.text+0x1c0): undefined reference to `__atomic_fetch_add_8'
/usr/bin/ld: ../src/libhdr_histogram_static.a(hdr_writer_reader_phaser.c.o): in function `hdr_phaser_writer_exit':
hdr_writer_reader_phaser.c:(.text+0x238): undefined reference to `__atomic_fetch_add_8'
collect2: error: ld returned 1 exit status
gmake[2]: *** [test/CMakeFiles/hdr_histogram_test.dir/build.make:120: test/hdr_histogram_test] Error 1
gmake[1]: *** [CMakeFiles/Makefile2:1007: test/CMakeFiles/hdr_histogram_test.dir/all] Error 2
gmake: *** [Makefile:182: all] Error 2

Now I went ahead, deleted my "build" folder and re-did it all like so:

LDFLAGS="-latomic" cmake ../HdrHistogram_c/
LDFLAGS="-latomic" cmake --build . -v

Got same error, but this time I can see this (thanks to "-v" argument):

/usr/bin/cc -latomic CMakeFiles/hdr_histogram_test.dir/hdr_histogram_test.c.o CMakeFiles/hdr_histogram_test.dir/minunit.c.o -o hdr_histogram_test  ../src/libhdr_histogram_static.a /usr/lib/arm-linux-gnueabihf/libz.so -lpthread -lm -lrt 

Now that won't work because -latomic is like first argument here.
But this works just fine, with -latomic at the end:

/usr/bin/cc CMakeFiles/hdr_histogram_test.dir/hdr_histogram_test.c.o CMakeFiles/hdr_histogram_test.dir/minunit.c.o -o hdr_histogram_test  ../src/libhdr_histogram_static.a /usr/lib/arm-linux-gnueabihf/libz.so -lpthread -lm -lrt  -latomic

What am I doing wrong? Anyone managed to build this project for ARM (Raspberry PI)?

Thanks!

Start by reproducing the ARM Raspberry Pi build with the CMake commands and verbose output shown, then inspect how the hdr_histogram_test target links ../src/libhdr_histogram_static.a. Done means the linker receives -latomic after the static library and cmake --build . completes successfully on ARM.