va_start & va_end are not defined

[Adminius]

i'm missing this two functions:

• va_start
• va_end

i had success with this workaround:

`if defined(ARDUINO_ARCH_STM32)
#include <stdarg.h>
#define va_start(v,l) __builtin_va_start(v,l)
#define va_end(v) __builtin_va_end(v)
#endif

in which file i can make PR? :)

[fpistm]

I think you could simply include stdio.h here:

Arduino_Core_STM32/cores/arduino/wiring.h

Line 23 in bad5b56

#include <stdint.h>

Edit: seems not enough. Anyway, i think solution should be to include properly stdarg.h.

[fpistm]

I've made some test/search
Adding this in Wiring.h is sufficient:

#include <stdio.h>
#include <stdarg.h>

But it seems not directly include in other core, it is present in wring_private.h.
Only included in source file requiring this.
https://github.com/arduino/Arduino/blob/a5aea72cc6cf5161eedeb1f08692adb26fbb9305/hardware/arduino/avr/cores/arduino/wiring_private.h#L28
https://github.com/PaulStoffregen/cores/blob/27cdeb1cb9d2a26a44fa9cf7169c97944cf39a19/teensy3/wiring_private.h#L26

So I think, I should not add it directly in wiring.h while not understand why other use wiring_private.h

[Adminius]

if add my implementaion in wiring_privat.h it doesn't work.
But it works in wiring.h...

P.S. im on vacation in paris until weekend, so i'm not available...

[fpistm]

Hi @Adminius ,
could you share with me your use case to understand why it's not working with wiring_private.h

[Adminius]

we use in our KONNEKTING Library a Debug Class, that uses this to functions.

You can complie a DemoSketch with KDEBUG enabled to test it

[fpistm]

@Adminius
I've tested and build is now ok.
Let me know if it is ok then I will merge #253