fix building with GCC 14

[stefantalpalaru]

Implicit function declarations are now an error, so we need to include all those missing headers: https://gcc.gnu.org/gcc-14/porting_to.html

[arch1t3cht]

Thanks! Not that this is a problem, but out of interest: I have gcc 14.2.1, but none of these missing headers are errors for me. Do you know why this is? Am I missing some compiler flag? Or are these implicit declarations only errors on C, not C++?

Also, if you have the time, could you ensure the added headers are alphabetically sorted within their group? i.e. with <algorithm> coming before <limits>. If not I can do this myself before merging.

[stefantalpalaru]

I have gcc 14.2.1, but none of these missing headers are errors for me. Do you know why this is?

Do you have "-fpermissive" in your CXXFLAGS?

could you ensure the added headers are alphabetically sorted within their group?

Done.

[arch1t3cht]

Thanks! But now that I look at this more closely, there's something fishy here. Most of the added headers are part of agi_pre.h (or agi_pre_c.h), i.e. the precompiled headers added to all main Aegisub source files. (And I'm guessing the others may be imported recursively from those) That's also why these files compile fine for me, if I remove the PCH includes, they do indeed break.

So, it seems that the real issue here is that those precompiled headers (or the headers themselves - on my machine meson compiles them into PCHs for Clang, but includes them as normal headers for gcc) aren't being properly included for you. So this could be some issue with our meson build system, or with meson itself.

[stefantalpalaru]

Yes, that's it!

I'm packaging it for my Gentoo overlay and Gentoo's "meson.eclass" disables PCH.