Re: Convert 3.2 sources to ISO C90

[dewar at gnat dot com (Robert Dewar)]

<This, for me, is an alarming trend. I can understand needing a gnat
compiler to bootstrap ada (though unpleasant that might be). I'm worried
about needing gcc 3.1 to bootstrap gcc 3.2 properly. As long as it only
affects sublanguages, that's mostly fine (though making full support for
ada on new platforms might be painful), but deliberately removing bootstrap
>

All it takes is one person somehwere to do the cross-port, and we have found
in practice for GNAT that the need to do cross-ports has not significantly
impeded the spread of GNAT to various architectures such as the Amiga, MS/DOS,
Nextstep (all ports done by volunteers). 

Now to be fair, there is a difference. To port GNAT, you have to port the
runtime in general, and the tasking in particular, not to mention the tools
(e.g. get task switching to work properly in gdb). In practice the raw step
of getting basic non-tasking GNAT working is pretty trivial compared to the
effort of a full port anyway, and is certainly not the painful part, so the
gain of avoiding this in the case of GNAT would be negligible.

Now for C, this issue of the runtime is much less the case, although there
is still likely to be work in the toolset (gcov, gdb, the binutils in general
etc, and if the target has an idiosyncratic debugging info format, then of
course that effort may be much larger).

I understand historically the value of ensuring that gcc bootstraps with
any old C compiler around, but I do think that the cost (which is to
generate a very odd style in the sources, and to have to write in an
ill-defined subset of C) is significant.