Re: Cross compiling 6.2.0 aarch64-softmmu for aarch64 host with musl, struct redefiniton errors

[Peter Maydell]

On Sun, 23 Jan 2022 at 08:58, Adam Baxter <voltagex@voltagex.org> wrote:
> I'm trying to compile qemu 6.2.0 using musl-cross.
>
> I am getting the following errors on make:
>
> /output/aarch64-linux-musl/include/asm/sigcontext.h:83:8: error: redefinition 
> of 'struct esr_context'
> /output/aarch64-linux-musl/include/asm/sigcontext.h:116:8: error: 
> redefinition of 'struct extra_context'
> /output/aarch64-linux-musl/include/asm/sigcontext.h:125:8: error: 
> redefinition of 'struct sve_context'

I think this must be a musl problem. Quoting the full error
message:

In file included from /output/aarch64-linux-musl/include/asm/ptrace.h:26,
                 from linux-headers/asm/kvm.h:37,
                 from /src/qemu/linux-headers/linux/kvm.h:15,
                 from /src/qemu/include/sysemu/kvm.h:25,
                 from ../hw/arm/boot.c:18:
/output/aarch64-linux-musl/include/asm/sigcontext.h:28:8: error:
redefinition of 'struct sigcontext'
   28 | struct sigcontext {
      |        ^~~~~~~~~~
In file included from /output/aarch64-linux-musl/include/signal.h:48,
                 from /src/qemu/include/qemu/osdep.h:105,
                 from ../hw/arm/boot.c:10:
/output/aarch64-linux-musl/include/bits/signal.h:18:16: note:
originally defined here
   18 | typedef struct sigcontext {
      |                ^~~~~~~~~~
In file included from /output/aarch64-linux-musl/include/asm/ptrace.h:26,
                 from linux-headers/asm/kvm.h:37,
                 from /src/qemu/linux-headers/linux/kvm.h:15,
                 from /src/qemu/include/sysemu/kvm.h:25,
                 from ../hw/arm/boot.c:18:
/output/aarch64-linux-musl/include/asm/sigcontext.h:66:8: error:
redefinition of 'struct _aarch64_ctx'
   66 | struct _aarch64_ctx {
      |        ^~~~~~~~~~~~
In file included from /output/aarch64-linux-musl/include/signal.h:48,
                 from /src/qemu/include/qemu/osdep.h:105,
                 from ../hw/arm/boot.c:10:
/output/aarch64-linux-musl/include/bits/signal.h:29:8: note:
originally defined here
   29 | struct _aarch64_ctx {
      |        ^~~~~~~~~~~~


The compiler is complaining because the system headers (provided by
musl) are defining these structs both in asm/sigcontext.h and
in signal.h, which means those headers can't both be included
at once. This isn't QEMU related: musl's headers just seem to
be broken here. glibc doesn't have this bug.

-- PMM