Minimum GCC version

[Robin Haberkorn]

Dear fellow Scintilla developers,

what's the current minimum supported GCC and Clang version?
After upgrading to v5.5.7 (or rather HEAD), I noticed that charconv is
used, which appears to require at least GCC 8.1 [1], although I can't
really confirm that.

At v5.5.4 I was assuming that the minimum version is GCC 5.0. But the
oldest I was building with was probably GCC 7.x. That was on NetBSD 10,
for which you will soon receive another patch. Actually I upgraded
Scintilla, so I can provide you with a patch that cleanly applies to HEAD.
It would be tragic if that broke my NetBSD port again. Although I could
just require a newer GCC from pkgsrc, I suppose.
I had v5.5.4 building on Ubuntu 14.04 via PPA even. Can't find which gcc
this had.
The upgrade also broke openSUSE 15.5-15.6. But again, perhaps I can pull
in a newer non-default GCC as a build dependency.

Best regards,
Robin

[1] https://stackoverflow.com/a/64104715

[Robin Haberkorn]

Ah, I see that in the release mail for 5.5.7, Neil actually states GCC
9 or Clang 9.

[Neil Hodgson]

Robin Haberkorn:
> ... I noticed that charconv is used ...

> At v5.5.4 I was assuming that the minimum version is GCC 5.0. But the
> oldest I was building with was probably GCC 7.x. That was on NetBSD 10,
> for which you will soon receive another patch. Actually I upgraded
> Scintilla, so I can provide you with a patch that cleanly applies to HEAD.

Recent Scintilla uses std::from_chars for selection serialization.
std::from_chars is defined by <charconv>.

std::from_chars is part of C++17. Scintilla has required C++17 for 7
years now and code changes should be able to depend on this.

Supporting older compiler versions adds extra work to new features and
maintenance so it's unlikely I'll accept work-arounds. Indeed, it may
be time to consider incrementing the language baseline to C++20, a
standard from 5 years ago.

Neil

[Robin Haberkorn]

On Sat Sep 27, 2025 at 04:07:12 GMT +03, Neil Hodgson wrote:
> Supporting older compiler versions adds extra work to new features and
> maintenance so it's unlikely I'll accept work-arounds. Indeed, it may
> be time to consider incrementing the language baseline to C++20, a
> standard from 5 years ago.

I would argue against it. 5 years ago the standard was released,
but when did all the major compilers fully support it? How long did
it take to become available in all relevant operating systems and
Linux distributions?

Also, compatibility with slightly outdated systems is nice to have.
But that's my philosophy personally.
I bump versions only if I have a very good reason.

Best regards,
Robin