[pacman-dev] LTO and PGO build options

[Que Quotion]

>Adding -flto to CFLAGS and forgetting also is fine.  Remove it when the
software is broken with LTO.

The only way this makes logical sense is if you mean for *packagers*
to do so, but I have never known any to do so. I don't think it's any
more appropriate to distribute PKGBUILDs with optimizations enabled by
default. Much better to leave that to users; much too troublesome to
ask them to edit each PKGBUILD they want to optimize. Doing this in
makepkg works better than a wrapper script, and involves less work for
both users and packagers--who would also have the opportunity to
specify packages that must not use LTO.

>Add -flto to CFLAGS, report broken software upstream.  I am not adding
this to makepkg.

That's dissapointing. There's practically no downside to having LTO
available in makepkg.>I was talking about the patch you provided being
untested.  You appear
to have understood that as you have fixed it....

Yeah, and you were right--but you came to that conclusion on a whim.

>upx is dropped. optipng is dropped.

Oh, I see. Sorry to hear about that. makepkg's automated (opt-in)
optimization of packages is one of the features I considered vastly
superior to other package creation tools.

>I am not adding an option to makepkg that does non-deterministic
optimisation.

It always would have been an option for users to choose, not a policy,
ie "enable at your own (negligible) risk".

I don't think I have the constitution to maintain a makepkg fork for
extra optimization features, but its sounding like a good idea.