Re: SPI-header-files safe for C++-compiler

Stefan Kaltenbrunner <stefan@kaltenbrunner.cc> writes:
> wild idea - we could add a bit of configure magic and a special makefile
> target and add a buildfarm stage for that and have it automatically
> check for these things ?

I had been idly toying with the idea of making a tool to check for C++
problems, when it occurred to me that we already have almost the right
thing: src/tools/pginclude/pgcompinclude is a script that checks that
each .h file in the system can be compiled without any other preceding
inclusions except postgres.h.  If run with a C++ compiler instead of C,
seems it would accomplish the task we want.

As it stands, pgcompinclude seems to lack a number of things but they're
all fixable:
    * hard-wired compiler name and flags
    * hard-wired paths
    * should use postgres_fe.h not postgres.h for frontend-usable
      include files (would need a clearer policy for which those are)
    * possible use of unportable idioms (not sure, needs checked)

Given a cleaned-up version of pgcompinclude, we could add a buildfarm
option to invoke it using a specified compiler and options.  I don't
think we need every buildfarm member doing that but getting a
representative sample doing so would be a Good Thing.  Even without
considering the C++ angle, this is an area that's easy to break
and having quicker feedback would be good.  The current practice of
manually running pgcompinclude once in awhile lacks a lot, notably
coverage of different sets of compile options (see notes at the bottom
of src/tools/pginclude/README).

Anybody feel like working on that?

            regards, tom lane