Building LDC runtime for a microcontroller

[IGotD-]

On Monday, 7 September 2020 at 19:12:59 UTC, aberba wrote:
>
> How about an alternative runtime + standard library for 
> embedded systems...with a least bare minimum. I've seen a 
> number of efforts to get D to run in those environments but 
> almost none of them is packaged for others to consume.

Adam D. Ruppe's book "D cookbook" describes another way by 
augmenting object.d in order to get "full D" to compile. I guess 
this was written before betterC existed. It will be similar to 
betterC, a very naked system without druntime. To be honest I 
like this approach better as it opens up for gradually adding 
functionality.

A small runtime + standard library is about the only possibility 
in order to fit in those microconroller systems. Alternatively it 
might be better just start from scratch and implement often 
limited functionality they requires. The problem as I mentioned 
before was that OS dependent stuff is mixed with OS independent. 
I think that OS independent should be broken out so that it can 
more easily be used for embedded programming.

Memory management can be a problem too. OS independent library 
code might expect full GC support and there seems to be no 
documentation which functions that does and which doesn't. I was 
thinking GC might not be that much of a problem for medium sized 
microcontroller systems. In practice you can have a fixed pool 
that is initialized from the beginning, non expandable. Still 
there is a GC memory overhead penalty.


In the C/C++ world generic standard C libraries for embedded 
systems are rare, often unfinished, limited, GPL soiled so there 
are difficulties there as well. Often there are tons of POSIX 
filth in them as they are assumed to run on some kind Linux 
system.