Re: build remaining Flex files standalone

On Wed, Aug 17, 2022 at 8:14 AM Andres Freund <andres(at)anarazel(dot)de> wrote:
>
> Hi,
>
> On 2022-08-16 17:41:43 +0700, John Naylor wrote:
> > For v3, I addressed some comments and added .h files to the
> > headerscheck exceptions.
>
> Thanks!
>
>
> > /*
> > * NB: include bootparse.h only AFTER including bootstrap.h, because bootstrap.h
> > * includes node definitions needed for YYSTYPE.
> > */
> >
> > Future cleanup: I see this in headerscheck:
> >
> > # We can't make these Bison output files compilable standalone
> > # without using "%code require", which old Bison versions lack.
> > # parser/gram.h will be included by parser/gramparse.h anyway.
> >
> > That directive has been supported in Bison since 2.4.2.
>
> 2.4.2 is from 2010. So I think we could just start relying on it?
>
>
> > > > +/* functions shared between guc.c and guc-file.l */
> > > > [...]
> > > I think I prefer your suggestion of a guc_internal.h upthread.
> >
> > Started in 0002, but left open the headerscheck failure.
> >
> > Also, if such a thing is meant to be #include'd only by two generated
> > files, maybe it should just live in the directory where they live, and
> > not in the src/include dir?
>
> It's not something we've done for the backend afaics, but I don't see a reason
> not to start at some point.
>
>
> > > > From 7d4ecfcb3e91f3b45e94b9e64c7c40f1bbd22aa8 Mon Sep 17 00:00:00 2001
> > > > From: John Naylor <john(dot)naylor(at)postgresql(dot)org>
> > > > Date: Fri, 12 Aug 2022 15:45:24 +0700
> > > > Subject: [PATCH v201 2/9] Build booscanner.c standalone
> > >
> > > > -# bootscanner is compiled as part of bootparse
> > > > -bootparse.o: bootscanner.c
> > > > +# See notes in src/backend/parser/Makefile about the following two rules
> > > > +bootparse.h: bootparse.c
> > > > + touch $@
> > > > +
> > > > +bootparse.c: BISONFLAGS += -d
> > > > +
> > > > +# Force these dependencies to be known even without dependency info built:
> > > > +bootparse.o bootscan.o: bootparse.h
> > >
> > > Wonder if we could / should wrap this is something common. It's somewhat
> > > annoying to repeat this stuff everywhere.
> >
> > I haven't looked at the Meson effort recently, but if the build rule
> > is less annoying there, I'm inclined to leave this as a wart until
> > autotools are retired.
>
> The only complicating thing in the rules there is the dependencies from one .c
> file to another .c file.
>
>
> > > > diff --git a/contrib/cube/cubedata.h b/contrib/cube/cubedata.h
> > > > index dbe7d4f742..0b373048b5 100644
> > > > --- a/contrib/cube/cubedata.h
> > > > +++ b/contrib/cube/cubedata.h
> > > > @@ -67,3 +67,7 @@ extern void cube_scanner_finish(void);
> > > >
> > > > /* in cubeparse.y */
> > > > extern int cube_yyparse(NDBOX **result);
> > > > +
> > > > +/* All grammar constructs return strings */
> > > > +#define YYSTYPE char *
> > >
> > > Why does this need to be defined in a semi-public header? If we do this in
> > > multiple files we'll end up with the danger of macro redefinition warnings.

For v4, I #defined YYSTYPE

--
John Naylor
EDB: http://www.enterprisedb.com