Re: Unused header file inclusion

On 2019-Jul-31, vignesh C wrote:

> I noticed that there are many header files being
> included which need not be included.

Yeah, we have tooling for this already in src/tools/pginclude. It's
been used before, and it has wreaked considerable havoc; see "git log
--grep pgrminclude".

I think doing this sort of cleanup is useful to a point -- as Andres
mentions, some includes are somewhat more "important" than others, so
judgement is needed in each case.

I think removing unnecessary include lines from header files is much
more useful than from .c files. However, nowadays even I am not very
convinced that that is a very fruitful use of time, since many/most
developers use ccache which will reduce the compile times anyway in many
cases; and development machines are typically much faster than ten years
ago.

Also, I think addition of new include lines to existing .c files should
be a point worth specific attention in patch review, to avoid breaking
reasonable modularity boundaries unnecessarily.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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