Build example project using C++11 with SEGGER_IDE failed

RE: Build example project using C++11 with SEGGER_IDE failed

mjt110 — Fri, 10 May 2019 05:50:01 GMT

Only renamed "main.c"。I checked the code in ”nrf_pwr_mgmt.h“ ( ”nrf_pwr_mgmt_init“ and ”nrf_pwr_mgmt_run“ defined in this header), and I found that there's no "ifdef _cplusplus_ extern "C"" preprocessor at the begining of the head file, after I append these code to this file, the entire project can be built seccessfully.

RE: Build example project using C++11 with SEGGER_IDE failed

awneil — Thu, 09 May 2019 08:20:27 GMT

You said you've renamed "main.c" to "main.cpp" - but have you also renamed all the other *.c source files to *.cpp?

Without that, they will still be built as 'C' - not C++ - and, therefore, linker errors are to be expected ...

RE: Build example project using C++11 with SEGGER_IDE failed

mjt110 — Thu, 09 May 2019 06:18:00 GMT

Thanks for reply! I modify the code like Jakub Rzeszutko said, it works and the "app_util.h" has no error now. But,like awneil said, there are many other areas which also need modifications—— The linker can not find ”nrf_pwr_mgmt_init“ and ”nrf_pwr_mgmt_run“：

When I temporarily comment out these two lines of code，the project build successfully and I can use lambda in main function.

Why the linker can not find ”nrf_pwr_mgmt_init“ and ”nrf_pwr_mgmt_run“?

RE: Build example project using C++11 with SEGGER_IDE failed

awneil — Wed, 08 May 2019 12:30:25 GMT

[quote userid="18697" url="~/f/nordic-q-a/47043/build-example-project-using-c-11-with-segger_ide-failed/185878"]I am aware of these discussions[/quote]

Yes, I'm sure you are - I was addressing mjt110

sorry for confusion.

RE: Build example project using C++11 with SEGGER_IDE failed

Jakub Rzeszutko — Wed, 08 May 2019 09:11:17 GMT

I am aware of these discussions. Designated Initialisers will be supported in C++ 20 🙂 I had major problem with this to change it to constructors. This adds a lot of extra code with ifdefs to our current macros.

What makes me more worry about C++ is a big warning I saw in Keil that MicroLIB is not C++ compatible.

RE: Build example project using C++11 with SEGGER_IDE failed

awneil — Wed, 08 May 2019 09:09:08 GMT

[quote userid="18697" url="~/f/nordic-q-a/47043/build-example-project-using-c-11-with-segger_ide-failed/185871"]It is not so easy as one may think to support C99 and various of C++ standards for all compilers[/quote]

Yes, I appreciate that!

Not sure that mjt110 does, though?

[quote userid="18697" url="~/f/nordic-q-a/47043/build-example-project-using-c-11-with-segger_ide-failed/185871"]So far Nordic is officially supporting C[/quote]

Indeed - there is no claim that it's C++

RE: Build example project using C++11 with SEGGER_IDE failed

awneil — Wed, 08 May 2019 09:03:19 GMT

But you will find many other areas which also need modifications.

In particular, the extensive use of Designated Initialisers - often via complex macros.

Again, there have been posts on this before - and some contributors have shared their C++ compatible re-workings...

https://devzone.nordicsemi.com/search?q=C%2B%2B

EDIT

See Jakub Rzeszutko's reply above - which explains some of the issues, and the scale of the task.

RE: Build example project using C++11 with SEGGER_IDE failed

Jakub Rzeszutko — Wed, 08 May 2019 08:59:43 GMT

Hi awneil,

It is not so easy as one may think to support C99 and various of C++ standards for all compilers: Keil, GCC, SES, IAR.

Currently I am porting one library to be C++ compatible and I am facing C++ standard issues. What compiles in older C++ standards won't compile beginning from C++ 11 but it will compile in C++ 20. And the build result is diffrent depending on used compiler (in terms of building/not building).
So far Nordic is officially supporting C but we have recently started making C++ friendly code as much as possible. However migrating all available libraries to C++ is rather not feasable.

RE: Build example project using C++11 with SEGGER_IDE failed

Jakub Rzeszutko — Wed, 08 May 2019 08:49:02 GMT

Hi,

You can modify code a bit:

#ifdef __GNUC__
#ifdef __cplusplus
#define STATIC_ASSERT_SIMPLE(EXPR)      extern char (*_do_assert(void)) [sizeof(char[1 - 2*!(EXPR)])]
#define STATIC_ASSERT_MSG(EXPR, MSG)    extern char (*_do_assert(void)) [sizeof(char[1 - 2*!(EXPR)])]
#else
#define STATIC_ASSERT_SIMPLE(EXPR)      _Static_assert(EXPR, "unspecified message")
#define STATIC_ASSERT_MSG(EXPR, MSG)    _Static_assert(EXPR, MSG)
#endif
#endif

This will compile just fine.

RE: Build example project using C++11 with SEGGER_IDE failed

awneil — Wed, 08 May 2019 07:37:03 GMT

Yes, it is well known that the standard Nordic code will not build as C++

There has been a number of threads on it ...