[Info-vax] LLVM, was: Re: And another one bites the dust....

[Arne Vajhøj]

On 2/23/2022 2:06 PM, Simon Clubley wrote:
> On 2022-02-22, Arne Vajhøj <arne at vajhoej.dk> wrote:
>>
>> I don't think the request was to be able to build with a
>> compiler supporting a subset of C++ XX - I think the request
>> was for being able to build with a compiler fully
>> supporting C++ XX but where XX is not latest and greatest.
>>
> 
> Yes, that's exactly what I mean.
> 
>> That makes bootstrapping a bit tricky.
>>
> 
> Why ? It's just another set of source files to be compiled as far
> as the existing compiler is concerned. What the source code implements
> does not need to match the language or language variant it is written in.

Thumbs on keyboard - the other way around.

Requiring latest C++ version makes bootstrapping difficult,
because existing compilers may be older C++ version.

> Until gcc 4.8, you could build gcc using just a C compiler,

That is even nicer than working with any C++ version.

But I can understand the desire to go from C to C++. Some code
can become a lot cleaner.

But I am not so sure that requiring latest C++ really gain so
much.

>                                                          unless
> you wanted Ada included, in which case you had to use an existing
> gcc that also had Ada support built in (because the Ada frontend was
> written in Ada).

Give how rare Ada compilers are and that C/C++ has pretty good compiler
support (lex/yacc, flex/bison etc.) then that choices does not make
sense to me.

Arne