On Tuesday, 8 December 2020 at 01:47:51 UTC, Andrew Edwards wrote:
Thanks Jacob. The extern(C) is temporary. I'm doing a direct
port of the code to D using -betterC. Wanted to keep it as
close to the original as possible until everything compiles.
Yes, that's always a good idea. Do the initial port as close as
possible to the original code. Then refactor and start adding D
specific features.
I noticed that static this() does not work if either it or
main() (or both) is marked extern(C).
Yes, that's expected. If you have a regular D main function, the
compiler will recognize that and output an undefined symbol to
the C main function. The C main function is implemented in the D
runtime. The C runtime will call the C main function in the D
runtime. The C main function is responsible for initializing the
D runtime. This includes (not a complete list):
* Converting the arguments passed to the C main function to
`string[]`
* Initializing the garbage collector
* Calling `shared static this()` in all modules
* Calling `static this()` in all modules
* Running the any unit tests
* Finally calling the D main function
When you define a C main function the compiler will recognize
that and not output an undefined symbol. That means the C main
function in the D runtime will never be called. That means the D
runtime is never initialized. This is to allow you to use D
without its runtime or get more control of the startup phase.
So either either you define a D main function and everything
works as expected or you define a C main function and then you
need to manually initialize and deinitialize the D runtime, if
you want to use it. This can be done with [1] and [2].
[1] https://dlang.org/phobos/core_runtime.html#.rt_init
[2] https://dlang.org/phobos/core_runtime.html#.rt_term
--
/Jacob Carlborg
