[PATCH 1/3] powerpc64: make clang cross-build friendly

[Hari Bathini]

Thanks for the review, Naveen.

On 24/11/25 11:19 am, Naveen N Rao wrote:
> On Sun, Nov 09, 2025 at 02:34:03AM +0530, Hari Bathini wrote:
>> ARCH_USING_PATCHABLE_FUNCTION_ENTRY depends on toolchain support for
>> -fpatchable-function-entry option. The current script that checks
>> for this support only handles GCC. Rename the script and extend it
>> to detect support for -fpatchable-function-entry with Clang as well,
>> allowing clean cross-compilation with Clang toolchains.
>>
>> Signed-off-by: Hari Bathini <hbathini at linux.ibm.com>
>> ---
>>   arch/powerpc/Kconfig                                         | 5 +++--
>>   ...-function-entry.sh => check-fpatchable-function-entry.sh} | 0
>>   2 files changed, 3 insertions(+), 2 deletions(-)
>>   rename arch/powerpc/tools/{gcc-check-fpatchable-function-entry.sh => check-fpatchable-function-entry.sh} (100%)
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 325c1171894d..dfb62e211c92 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -568,8 +568,9 @@ config ARCH_USING_PATCHABLE_FUNCTION_ENTRY
>>   	depends on FUNCTION_TRACER && (PPC32 || PPC64_ELF_ABI_V2)
>>   	depends on $(cc-option,-fpatchable-function-entry=2)
>>   	def_bool y if PPC32
>> -	def_bool $(success,$(srctree)/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh $(CC) -mlittle-endian) if PPC64 && CPU_LITTLE_ENDIAN
>> -	def_bool $(success,$(srctree)/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh $(CC) -mbig-endian) if PPC64 && CPU_BIG_ENDIAN
>> +	def_bool $(success,$(srctree)/arch/powerpc/tools/check-fpatchable-function-entry.sh $(CC) -mlittle-endian) if PPC64 && CPU_LITTLE_ENDIAN && CC_IS_GCC
>> +	def_bool $(success,$(srctree)/arch/powerpc/tools/check-fpatchable-function-entry.sh $(CC) -target ppc64le -mlittle-endian) if PPC64 && CPU_LITTLE_ENDIAN && CC_IS_CLANG
> 
> Can you instead pass $(CLANG_FLAGS) to retain the same command across
> gcc/clang?

Should work, I guess.
But do I need to test for any additional clang flags that
may interfere with what we are trying to check here?

- Hari