Re: [PATCH v2] hw/acpi: fix breakage due to missing aml stub definitions when acpi is off

[Philippe Mathieu-Daudé]

On 7/11/22 16:27, Ani Sinha wrote:
> Some HW architectures do not support acpi and CONFIG_ACPI is off for them. For
> those architectures, dummy stub function definitions help to resolve symbols.
> This change adds couple of dummy stub definitions so that symbols for those can
> be resolved and failures such as the following can be fixed for or1k targets.
>
> Configuration:
> qemu/build $ ../configure --enable-werror --disable-docs --disable-nettle \
>               --enable-gcrypt --enable-fdt=system --enable-modules \
>               --enable-trace-backends=dtrace --enable-docs \
>              --enable-vfio-user-server \
>               --target-list="ppc64-softmmu or1k-softmmu s390x-softmmu 
> x86_64-softmmu
>   rx-softmmu sh4-softmmu nios2-softmmu"
>
> actual failure:
>
> qemu/build $ QTEST_QEMU_BINARY=./qemu-system-or1k  ./tests/qtest/qos-test
>
> failed to open module:
> /build/qemu/qemu/build/qemu-bundle/usr/local/lib64/qemu/hw-display-virtio-vga.so:
> undefined symbol: aml_return
> qemu-system-or1k: ../util/error.c:59: error_setv: Assertion `*errp ==
> NULL' failed.
> Broken pipe
> ../tests/qtest/libqtest.c:188: kill_qemu() detected QEMU death from
> signal 6 (Aborted) (core dumped)
> Aborted (core dumped)
>
> CC: Bernhard Beschow <shentey@gmail.com>
> Signed-off-by: Ani Sinha <ani@anisinha.ca>
> ---
>   hw/acpi/aml-build-stub.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> changelog:
> v2: cosmetic commit description format update.
>
> diff --git a/hw/acpi/aml-build-stub.c b/hw/acpi/aml-build-stub.c
> index 8d8ad1a314..89a8fec4af 100644
> --- a/hw/acpi/aml-build-stub.c
> +++ b/hw/acpi/aml-build-stub.c
> @@ -26,6 +26,16 @@ void aml_append(Aml *parent_ctx, Aml *child)
>   {
>   }
>   
> +Aml *aml_return(Aml *val)
> +{
> +    return NULL;

Can't return NULL, otherwise aml_append() will crash.

We just want the symbol to be defined, so instead:

      g_assert_not_reached();

> +}