Re: LLVM and Ada

[Brian Drummond <brian@shapes.demon.co.uk>]

On Wed, 21 Mar 2018 06:08:44 -0700, carlojpisani wrote:

> hi guys I need to port ghdl to PPC, MIPS, HPPA on PPC there are old
> bootstrapper (e.g. 4.1.1)
> but I haven't seen them for MIPS and HPPA
> 
> vhdl seems able to be compiled by llvm, but ... llvm seems do have no
> support for MIPS and HPPA
> 
> no dice
> 
> also, I'd like to port vhdl to SGI/MIPS under IRIX in this case, there
> are commercial Ada compilers (e.g. with the MIPS/PRO toolchain)
> 
> let me know

The place for this would be 
https://github.com/ghdl/ghdl

If you run into trouble, open an issue there, Tristan (the main author of 
ghdl) is very helpful.

You need to *compile* ghdl using gcc (including gnat) so the easiest way 
would be if you have native (and fairly recent, >= gcc4.7) installations 
on your desired platforms.

Otherwise, gcc can obviously be used to build cross-compilers, though 
that gets a bit trickier, and while building ghdl sa a crosscompiler 
ought to work, there may be some snags along the way.

GHDL cannot be *compiled* with LLVM because there is no adequate Ada 
compiler in the LLVM toolchain. However, ghdl can be built to target 3 
different code generation backends - gcc, llvm and its own JIT compiler 
(mcode)

(To make ghdl/llvm work, Tristan had to solve LLVM's lack of support for 
nested procedures (and their scope rules) which I believe was the problem 
that stopped the Dragonegg Ada/LLVM compiler in its tracks. So an Ada/
LLVM compiler should be possible...)

So I *think* you want to build ghdl for the gcc backend (to support your 
target CPUs). Whether you can do that natively or you need to cross-
compile depends on having a modern enough gcc compiler on your system.

-- Brian