As both C and C++ standards require applications running under an OS to
return 'int', adapt that for Zephyr to align with those standard. This also
eliminates errors when building with clang when not using -ffreestanding,
and reduces the need for compiler flags to silence warnings for both clang
and gcc
Signed-off-by: Keith Packard <keithp@keithp.com>
The C++ standard requires the main() function to have the return type
of 'int' and does not allow the main() to be defined with the 'void'
return type. Moreover, GCC goes as far as to emit a hard error when the
'::main()' has the return type of `void`.
This commit introduces an option to instruct the Zephyr kernel to call
the 'int main(void)' instead of the 'void main(void)' in case a Zephyr
application defines main() in a C++ source file.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
To support arm-ds / armlink it is required that the weak main is located
in an object externally to the object using the weak symbol.
If the weak symbol is inside the object referring to it, then the weak
symbol will be used and this will result in
```
Error: L6200E: Symbol __ARM_use_no_argv multiply defined
(by init.o and main.o).
```
as both the weak and strong symbols are used.
Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>
