undefined reference to `nrf_libuarte_async_tx'

[Mecadev]

Hello, I'm trying to compile the LIBUARTE example from SDK 16 but im getting undefined reference errors, this is what I've done so far:

1. in sdk_config.h defined

   NRF_LIBUARTE_DRV_UARTE0

   , (I've also copied the config file provided in the example folder).
2. Included in the main.cpp file 

   "nrf_libuarte_async.h"

3. Included to the project the corresponding source files and include directories from "SDK_ROOT/components/libraries/libuarte"

This is the console output:

c:/progra~2/gnutoo~1/92019-~1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: CMakeFiles/example.dir/main.cpp.obj: in function `libuarte_rtc_handler(nrfx_rtc_int_type_t)':
C:\Nordic\Uart_test2\src/main.cpp:28: undefined reference to `nrf_libuarte_async_timeout_handler(nrf_libuarte_async_t const*)'
c:/progra~2/gnutoo~1/92019-~1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: CMakeFiles/example.dir/main.cpp.obj: in function `uart_event_handler(void*, nrf_libuarte_async_evt_t*)':
C:\Nordic\Uart_test2\src/main.cpp:52: undefined reference to `nrf_libuarte_async_tx(nrf_libuarte_async_t const*, unsigned char*, unsigned int)'
c:/progra~2/gnutoo~1/92019-~1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Nordic\Uart_test2\src/main.cpp:73: undefined reference to `nrf_libuarte_async_rx_free(nrf_libuarte_async_t const*, unsigned char*, unsigned int)'
c:/progra~2/gnutoo~1/92019-~1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Nordic\Uart_test2\src/main.cpp:79: undefined reference to `nrf_libuarte_async_tx(nrf_libuarte_async_t const*, unsigned char*, unsigned int)'
c:/progra~2/gnutoo~1/92019-~1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: CMakeFiles/example.dir/main.cpp.obj: in function `main':
C:\Nordic\Uart_test2\src/main.cpp:121: undefined reference to `nrf_libuarte_async_init(nrf_libuarte_async_t const*, nrf_libuarte_async_config_t const*, void (*)(void*, nrf_libuarte_async_evt_t*), void*)'
c:/progra~2/gnutoo~1/92019-~1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Nordic\Uart_test2\src/main.cpp:125: undefined reference to `nrf_libuarte_async_enable(nrf_libuarte_async_t const*)'
c:/progra~2/gnutoo~1/92019-~1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Nordic\Uart_test2\src/main.cpp:127: undefined reference to `nrf_libuarte_async_tx(nrf_libuarte_async_t const*, unsigned char*, unsigned int)'
c:/progra~2/gnutoo~1/92019-~1/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Nordic\Uart_test2\src/main.cpp:132: undefined reference to `nrf_libuarte_async_tx(nrf_libuarte_async_t const*, unsigned char*, unsigned int)'
collect2.exe: error: ld returned 1 exit status
mingw32-make.exe[3]: *** [src\CMakeFiles\example.dir\build.make:815: src/example.elf] Error 1
mingw32-make.exe[2]: *** [CMakeFiles\Makefile2:350: src/CMakeFiles/example.dir/all] Error 2
mingw32-make.exe[2]: *** Waiting for unfinished jobs....

What am I missing? any thoughts?

[Mecadev]

Ok I've figure it out, I though the libuarte library header file had the extern "C" brackets like all the sdk libraries, seems like they forgot to add it, hope they add it in newer SDK releases!.

[Amanda Hsieh]

Hi,

Good to know you figure out the issue. However, the SDK 16 LIBUARTE example has already done what you did, and I don't see any error while compiling the unmodified example. 

-Amanda H.

[Mecadev]

Yes, that's because you're compiling with C (I'm compiling for C++ arm-none-eabi), with c++ there are some mods that has to be done, like adding extern C (and macros c++ compatibility) , sdk 16.0 on that specific library doesn't have them.