Multiple definitions in libmetal.a

[Mel-Chen]

I'm trying GCC 10 now. When I use GCC 10 toolchain to build libmetal, there are a lot of ld fail.

/work/melc/riscv64-unknown-elf-gcc-10.0.0-20200203/bin/../lib/gcc/riscv64-unknown-elf/10.0.1/../../../../riscv64-unknown-elf/bin/ld: /scratch/melc/workspace/build/product-coreip-sifive/e76mc/freedom-e-sdk/bsp/e76mc/install/lib/release//libmetal.a(libriscv__mmachine__e76mc_a-tty.o):(.bss.__metal_dt_cpu_3_interrupt_controller+0x0): multiple definition of `__metal_dt_cpu_3_interrupt_controller'; /scratch/melc/workspace/build/product-coreip-sifive/e76mc/freedom-e-sdk/bsp/e76mc/install/lib/release//libmetal.a(libriscv__mmachine__e76mc_a-timer.o):(.bss.__metal_dt_cpu_3_interrupt_controller+0x0): first defined here

After GCC 10, -fno-common is default enable, so that the definitions in metal.h will be placed at .bss. .bss not allow multiple definition.
You can use toolchain /work/melc/riscv64-unknown-elf-gcc-10.0.0-20200203, or GCC 8.3 toolchain with -fno-common option, to reproduce this issue.

[issuehsu]

Hi @bsousi5 does this issue be resolved?

[keith-packard]

I've submitted a PR to freedom-devicetree-tools that fixes the machine.h header problem. That's got my test build working.

[issuehsu]

OK, thanks Keith.

[issuehsu]

I am integrating gcc-10 with freedom-e-sdk, and it seems the PR is still not merged, so I cherry-pick this patch for local test. And I still see multiple definition errors.

Following is the build command:
make PROGRAM=minimal-boot TARGET=qemu-sifive-e31 CONFIGURATION=release RISCV_LIBC=nano clean software

One of the error message:
/freedom-e-sdk/bsp/freedom-e310-arty/install/lib/release//libmetal.a(tty.o):(.bss.__metal_dt_spi_10014000+0x0): multiple definition of `__metal_dt_spi_10014000'; /freedom-e-sdk/bsp/freedom-e310-arty/install/lib/release//libmetal.a(synchronize_harts.o):(.bss.__metal_dt_spi_10014000+0x0): first defined here

Thanks!