Undefined Reference to Internal::Generic_1_kHz_Generator::setup() when compiling for Arduino Zero (Atmel ATSAMD21G18)

[Anderl94]

When attempting to compile a project for the Arduino Zero with a DCF77 module, I encountered the following error:

.pio/build/nanoatmega328new/libdcf77_xtal.a(dcf77.cpp.o): In function `DCF77_Clock::set_input_provider(unsigned char (*)())':
dcf77.cpp:(.text._ZN11DCF77_Clock18set_input_providerEPFhvE+0x2): undefined reference to `Internal::Generic_1_kHz_Generator::setup(unsigned char (*)())'

[udoklein]

In the 1 kHz Generator (line

dcf77/dcf77.cpp

Line 1664 in c9b5c54

namespace Generic_1_kHz_Generator {

and below) it fails to properly account for the zero. Obviously this is because my code was developed before the zero entered the market. Feel free to add the missing statements and test it. If it works I can merge it into the code base.

[jho59]

In version 3.3.7 of dcf77.cpp I can see from line 1663 to 1667

namespace Internal {
    namespace Generic_1_kHz_Generator {
        uint8_t zero_provider() {
            return 0;
        }

but on a ArduinoZero or the whole MKR-line it stills throws that error.

Selecting an Adafruit SAMD21/SAMD51 gives a different error:

In file included from D:\EigeneDateien\Dokumente\Arduino\_SAMD21-M0-Mini-Wemos\DCF77a\DCF77a.ino:29:
d:\EigeneDateien\Dokumente\Arduino\libraries\dcf77_xtal/dcf77.h: In member function 'bool Internal::DCF77_Demodulator<Clock_Controller>::dummy_stage::data_ready() const':
d:\EigeneDateien\Dokumente\Arduino\libraries\dcf77_xtal/dcf77.h:1138:63: error: no return statement in function returning non-void [-Werror=return-type]
 1138 |             bool    data_ready()                       const {}
      |                                                               ^
d:\EigeneDateien\Dokumente\Arduino\libraries\dcf77_xtal/dcf77.h: In member function 'uint8_t Internal::DCF77_Demodulator<Clock_Controller>::dummy_stage::avg() const':
d:\EigeneDateien\Dokumente\Arduino\libraries\dcf77_xtal/dcf77.h:1139:63: error: no return statement in function returning non-void [-Werror=return-type]
 1139 |             uint8_t avg()                              const {}
      |                                                               ^
cc1plus.exe: some warnings being treated as errors

I can compile Simple_Clock.ino (ArduinoIDE 2.3.6) only on an ArduinoUNO, Mega or Nano. So that "library dcf77_xtal claims to run on avr, sam architecture(s)..." seems not to be correct