On Sat, 17 Feb 2018, Masahiro Yamada wrote:
> Now, we got a basic ability to test compiler capability in Kconfig.
>
> config CC_HAS_STACKPROTECTOR
> bool
> default $(shell $CC -Werror -fstack-protector -c -x c /dev/null -o
> /dev/null)
>
> This works, but it is ugly to repeat this long boilerplate.
>
> We want to describe like this:
>
> config CC_HAS_STACKPROTECTOR
> bool
> default $(cc-option -fstack-protector)
>
> It is straight-forward to implement a new function, but I do not like
> to hard-code specialized functions like this. Hence, here is another
> feature to add functions from Kconfig files.
>
> A user-defined function can be defined as a string type symbol with
> a special keyword 'macro'. It can be referenced in the same way as
> built-in functions. This feature was also inspired by Makefile where
> user-defined functions are referenced by $(call func-name, args...),
> but I omitted the 'call' to makes it shorter.
>
> The macro definition can contain $(1), $(2), ... which will be replaced
> with arguments from the caller.
>
> Example code:
>
> config cc-option
> string
> macro $(shell $CC -Werror $(1) -c -x c /dev/null -o /dev/null)
I think this syntax for defining a macro shouldn't start with the
"config" keyword, unless you want it to be part of the config symbol
space and land it in .config. And typing it as a "string" while it
actually returns y/n (hence a bool) is also strange.
What about this instead:
macro cc-option
bool $(shell $CC -Werror $(1) -c -x c /dev/null -o /dev/null)
This makes it easier to extend as well if need be.
Nicolas
