RISC-V port

[Luís Marques]

On Thursday, 24 May 2018 at 14:01:48 UTC, Luís Marques wrote:
> When an expection is thrown the function _d_throw_exception is 
> called. In turn, it calls _Unwind_RaiseException. But that 
> function fails, returning a high numeric value that isn't part 
> of the expected return type enum (_Unwind_Reason_Code) values. 
> So the D exception personality is never called, and the catch 
> block is never executed. The only thing that is currently 
> missing in the assembly is the CFI stack adjustment directives. 
> But I don't think that's what's causing the problem, because 1) 
> when those are missing in the C++ code basic exception handling 
> still works, and 2) I've tried to manually add those to the 
> assembly file and it makes no difference.

Clue: when I call __cxa_throw in D code instead of throwing 
normally (i.e., calling _d_throw_exception), the D personality 
handler *is* called. Which indicates that, indeed, the problem is 
*not* in the generated assembly file. So I guess it's something 
that _d_throw_exception does which isn't quite right, although I 
can't see what.