Re: Unused header file inclusion

Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> On 2019-Jul-31, Andres Freund wrote:
>> * I think a lot of the interlinking stems from the bad idea to use
>> typedef's everywhere. In contrast to structs they cannot be forward
>> declared portably in our version of C. We should use a lot more struct
>> forward declarations, and just not use the typedef.

> I don't know about that ... I think the problem is that we both declare
> the typedef *and* define the struct in the same place.  If we were to
> split those things to separate files, the required rebuilds would be
> much less, I think, because changing a struct would no longer require
> recompiles of files that merely pass those structs around (that's very
> common for Node-derived structs).  Forward-declaring structs in
> unrelated header files just because they need them, feels a bit like
> cheating to me.

Yeah.  I seem to recall a proposal that nodes.h should contain

    typedef struct Foo Foo;

for every node type Foo, and then the other headers would just
fill in the structs, and we could get rid of a lot of ad-hoc
forward struct declarations and other hackery.

            regards, tom lane