Re: Unused header file inclusion

Hi,

On 2019-08-19 13:07:50 -0700, Andres Freund wrote:
> On 2019-08-18 14:37:34 -0400, Tom Lane wrote:
> > That's with a script I use that's like cpluspluscheck except it tests
> > with plain gcc not g++. I attached it for the archives' sake.
> >
> > Oddly, cpluspluscheck does not complain about those cases, but it
> > does complain about
>
> Hm. I don't understand why it's not complaining. Wonder if it's a
> question of the flags or such.

I'ts caused by -fsyntax-only

# These switches are g++ specific, you may override if necessary.
CXXFLAGS=${CXXFLAGS:- -fsyntax-only -Wall}

which also explains why your headercheck doesn't have that problem, it
doesn't use -fsyntax-only.

> > (My headerscheck script is missing that header; I need to update it to
> > match the latest version of cpluspluscheck.)
>
> I wonder if we should just add a #ifndef HEADERCHECK or such to the
> headers that we don't want to process as standalone headers (or #ifndef
> NOT_STANDALONE or whatever). That way multiple tools can rely on these markers,
> rather than copying knowledge about that kind of information into
> multiple places.
>
> I wish we could move the whole logic of those scripts into makefiles, so
> we could employ parallelism.

Hm. Perhaps the way to do that would be to use gcc's -include to include
postgres.h, and use -Wc++-compat to detect c++ issues, rather than using
g++. Without tempfiles it ought to be a lot easier to just do all of the
relevant work in make, without a separate shell script. The
python/perl/ecpg logic would b e abit annoying, but probably not too
bad? Think we could just always add all of them?

Greetings,

Andres Freund