[PATCH v5 3/4] rust: add a Kconfig function to test for support of bindgen options

[Asuna Yang]

On 12/4/25 5:06 PM, Vivian Wang wrote:

>> +
>> +# $(bindgen-backend-option,<flag>)
>> +# Return y if bindgen backend supports <flag>, n otherwise
>> +# For now, the backend refers only to libclang, so more specifically, this function tests whether the given flag is recognized by the libclang used by bindgen.
>> +bindgen-backend-option = $(success,trap "rm -f .tmp_$$.h" EXIT; touch .tmp_$$.h; $(BINDGEN) .tmp_$$.h -- --target=$(BINDGEN_TARGET) $(1))
>>
> Can probably be simplified down to:
> 
> $(BINDGEN) /dev/null -- -x c --target=$(BINDGEN_TARGET) $(1)
> 

bindgen is sensitive to file extensions. If the file is not .h or .hpp, 
it complains:

panicked at bindgen/ir/context.rs:562:15:
libclang error; possible causes include:
- Invalid flag syntax
- Unrecognized flags
- Invalid flag arguments
- File I/O errors
- Host vs. target architecture mismatch