upgrading cpp/c mixed project from 3.2 to 3.4 fail to build

[eyalsol]

we are trying to upgrade the project, we work on, from ZephyrOS 3.2 to 3.4 the prj.conf in version 3.2 was:

```

enable c++ support CONFIG_CPLUSPLUS=y CONFIG_LIB_CPLUSPLUS=y CONFIG_STD_CPP20=y CONFIG_NEWLIB_LIBC=y

the prj.conf in version 3.4:

CONFIG_CPP=y CONFIG_REQUIRES_FULL_LIBCPP=y CONFIG_REQUIRES_FULL_LIBC=y CONFIG_STD_CPP20=y

The Error we get: in file included from ~/zephyr_workspace/zephyr/include/zephyr/types.h:11, from ~/zephyr_workspace/zephyr/include/zephyr/kernel_includes.h:17, from ~/zephyr_workspace/zephyr/include/zephyr/kernel.h:17, from ~/zephyr_workspace/zephyr/arch/riscv/core/offsets/offsets.c:16: ~/tools/syntacore/sc-dt-2023.11/riscv-gcc/lib/gcc/riscv64-unknown-elf/12.2.1/include/stdint.h:9:16: fatal error: stdint.h: No such file or directory 9 | # include_next | ^~~~~~ compilation terminated. ninja: build stopped: subcommand failed.

we have tried other config parameters but it was still failing with other errors. Any assistance will be appreciated

[github-actions[bot]]

Hi @eyalsol! We appreciate you submitting your first issue for our open-source project. 🌟

Even though I'm a bot, I can assure you that the whole community is genuinely grateful for your time and effort. 🤖💙

[ndrs-pst]

@eyalsol I've been working on a mixed C/C++ project since Zephyr 3.2 and am currently using version 3.5. My configuration for the ARM platform (arm-zephyr-eabi) is as follows:

CONFIG_CPP=y
CONFIG_STD_CPP20=y
CONFIG_GLIBCXX_LIBCPP=y
CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_NANO=y

Additionally, I was able to compile successfully using your prj.conf in Zephyr 3.5. Hope this helps!

[eyalsol]

@ndrs-pst
thanks for tying to build it.

1. I am using syntacore riscv toolchain
2. i wonder if you can set <functional> in cpp file and <stdint.h> in a c file and test if that work for you

Thanks

[eyalsol]

I am trying with your configuration and get

~/demo/main.cpp:18:10: fatal error: functional: No such file or directory
   18 | #include <functional>

[eyalsol]

Issue resolved.

the toolchain in use is syntacore: sc-dt-2023.11, riscv-gcc, riscv64-unknown-elf.

I had to explicitly set this in CMakeLists.txt:

set(TOOLCHAIN_HAS_NEWLIB ON CACHE BOOL "True if toolchain supports newlib") the prj.conf is set to:

CONFIG_CPP=y
CONFIG_REQUIRES_FULL_LIBCPP=y
CONFIG_NEWLIB_LIBC=y
CONFIG_STD_CPP20=y

closing the issue