Re: [PATCH v2 04/14] meson: Introduce CONFIG_TCG_TARGET

[Thomas Huth <thuth@redhat.com>]

On 03/02/2025 04.18, Richard Henderson wrote:
> Use CONFIG_TCG as a project-wide flag to indicate that TCG is enabled
> for *some* target.  Use CONFIG_TCG_TARGET to indicate that TCG is
> enabled for a specific target.
> 
> Within a specific compilation unit, we can remap CONFIG_TCG based on
> CONFIG_TCG_TARGET.  This allows us to avoid changes to the bulk of
> the code base.
> 
> Within meson.build, while CONFIG_TCG may be set in config_host_data,
> it may not be set within config_target.  Thus all references to
> CONFIG_TCG in source_set 'when:' need not be updated.
> 
> For the moment, CONFIG_TCG and CONFIG_TCG_TARGET are identical.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   include/qemu/osdep.h |  7 +++++++
>   meson.build          | 11 +++++++----
>   2 files changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index 112ebdff21..1f6f73a148 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -34,9 +34,16 @@
>   #include "config-host.h"
>   #ifdef COMPILING_PER_TARGET
>   #include CONFIG_TARGET
> +# ifdef CONFIG_TCG_TARGET
> +#  undef CONFIG_TCG_TARGET
> +# else
> +#  undef CONFIG_TCG
> +# endif
>   #else
>   #include "exec/poison.h"
>   #endif
> +#pragma GCC poison CONFIG_TCG_TARGET

Shouldn't that rather go before the "#endif" instead?

Also, would it be possible to rather adjust scripts/make-config-poison.sh 
instead of poisoning this switch manually?

  Thomas

>   
>   /*
>    * HOST_WORDS_BIGENDIAN was replaced with HOST_BIG_ENDIAN. Prevent it from
> diff --git a/meson.build b/meson.build
> index b72114819b..5ca3cc3f34 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -3270,11 +3270,14 @@ foreach target : target_dirs
>   
>     target_kconfig = []
>     foreach sym: accelerators
> -    if sym == 'CONFIG_TCG' or target in accelerator_targets.get(sym, [])
> -      config_target += { sym: 'y' }
> -      config_all_accel += { sym: 'y' }
> -      target_kconfig += [ sym + '=y' ]
> +    if sym == 'CONFIG_TCG'
> +      config_target += { 'CONFIG_TCG_TARGET': 'y' }
> +    elif target not in accelerator_targets.get(sym, [])
> +      continue
>       endif
> +    config_target += { sym: 'y' }
> +    config_all_accel += { sym: 'y' }
> +    target_kconfig += [ sym + '=y' ]
>     endforeach
>     if target_kconfig.length() == 0
>       if default_targets