Re: meson: Add support for building with precompiled headers

Hi,

On 2022-10-05 16:21:55 -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > On 2022-10-05 16:09:14 -0400, Tom Lane wrote:
> >> Color me confused, but how does it work to #define that from the command
> >> line if it can't be overridden from within the program?
> 
> > If specified on the commandline it's also used when generating the precompiled
> > header - of course that's not possible when it's just #define'd in some .c
> > file.
> 
> Ah, so there's a separate cache of precompiled headers for each set of
> compiler command-line arguments?  Got it.

Worse, it builds the precompiled header for each "target" (static/shared lib,
executable), right now. Hence I've only added them for targets that have
multiple .c files. I've been planning to submit an improvement to meson that
does what you propose, it'd not be hard, but before it's actually usable, it
didn't seem worth investing time in that.

Greetings,

Andres Freund