[llvm-dev] unable to compile llvm with gcc 4.7.4

[Renato Golin via llvm-dev]

On 12 October 2016 at 18:37,  <sylvain.bertrand at gmail.com> wrote:
> Suggestion is not clear answer. How such a decision taken? Is there a board of
> people which have to vote to valid the choice of minimal gcc (and clang) version
> effective?

We don't have such process, unfortunately. :)


> If gcc 4.7 (last 1-step C boostrap-able c++-ish compiler) is phased out, then,
> to bootstrap llvm from a C compiler/runtime, gcc(4.7.4) + gcc(version>=4.8)
> will have to be setup first.

I want to understand your constraints, as I think this is a unique
case that I wasn't considering.

I normally worry about what's available on systems, so that users can
"just compile" using the system compiler and libraries. That's why I
only worry about 4.8+, because that's what's available on most old,
stable systems.

But you seem to need a C compiler and bootstrap GCC 4.7. Is this a
full bootstrap? Including glibc and binutils? If so, how do you
control their versions?

More importantly, why can't you just use the GCC that comes with
distros, or why can't you just compile your toolchain once and use
everywhere?

After all, GCC has moved on from plain C because it wasn't that
important to most of them either.

So, this trend is not LLVM-specific, but it's aggravated in LLVM
because we like more shiny toys than the GCC devs. :)

cheers,
--renato