Re: [PATCH] BaseTools/tools_def: Disable overzealous unused variable warning on Clang

["Rebecca Cran" <rebecca@bsdio.com>]

Reviewed-by: Rebecca Cran <rebecca@bsdio.com>


This should go in for the edk2-stable202305 release.


-- 
Rebecca Cran


On 5/10/23 08:50, Ard Biesheuvel wrote:
> The warnings Clang emits when enabling -Wunneeded-internal-declaration
> (which is part of -Wall) are generating false positives for variables
> whose size gets taken but are not referenced beyond that.
>
> This may happen legitimately in debug code, so let's disable this
> warning for Clang, rather than tiptoe around it in the code base.
>
> This fixes the RELEASE build for OVMF, which triggers this issue in the
> newly added VirtioSerialDxe driver.
>
> Cc: Rebecca Cran <rebecca@bsdio.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> ---
> Reproducer: https://godbolt.org/z/zx6qqjKrK
>
>   BaseTools/Conf/tools_def.template | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
> index b3c822f0bc20046d..65dde57631fb6c95 100755
> --- a/BaseTools/Conf/tools_def.template
> +++ b/BaseTools/Conf/tools_def.template
> @@ -1858,7 +1858,7 @@ DEFINE CLANGDWARF_X64_DLINK2_FLAGS        = -Wl,--defsym=PECOFF_HEADER_SIZE=0x22
>   DEFINE CLANGDWARF_IA32_TARGET             = -target i686-pc-linux-gnu
>
>   DEFINE CLANGDWARF_X64_TARGET              = -target x86_64-pc-linux-gnu
>
>   
>
> -DEFINE CLANGDWARF_WARNING_OVERRIDES    = -Wno-parentheses-equality -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -Wno-empty-body -Wno-unused-const-variable -Wno-varargs -Wno-unknown-warning-option -Wno-unused-but-set-variable -Wno-unused-const-variable -Wno-unaligned-access
>
> +DEFINE CLANGDWARF_WARNING_OVERRIDES    = -Wno-parentheses-equality -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -Wno-empty-body -Wno-unused-const-variable -Wno-varargs -Wno-unknown-warning-option -Wno-unused-but-set-variable -Wno-unused-const-variable -Wno-unaligned-access -Wno-unneeded-internal-declaration
>
>   DEFINE CLANGDWARF_ALL_CC_FLAGS         = DEF(GCC48_ALL_CC_FLAGS) DEF(CLANGDWARF_WARNING_OVERRIDES) -fno-stack-protector -mms-bitfields -Wno-address -Wno-shift-negative-value -Wno-unknown-pragmas -Wno-incompatible-library-redeclaration -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -msoft-float -mno-implicit-float  -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang -funsigned-char -fno-ms-extensions -Wno-null-dereference
>
>   
>
>   ###########################
>