Horton

Re: pl/perl extension fails on Windows

Tom Lane <tgl@sss.pgh.pa.us>

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Christoph Berg <myon@debian.org>
Cc: Sandeep Thakkar <sandeep.thakkar@enterprisedb.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-08-14T17:16:29Z
Lists: pgsql-hackers 
Christoph Berg <myon@debian.org> writes:
> HEAD as of 5a5c2feca still has the same problem on kfreebsd. Is there
> anything I could dump so we understand the problem better?

Yeah, I did not expect that 5a5c2feca would change anything on
non-Windows.

What we need to do is verify that PL/Perl's idea of
sizeof(PerlInterpreter) is different from Perl's own idea, and then
find out why --- ie, just which fields have different size/alignment
in the two compiles.

You mentioned upthread that configure shows this:

> checking for CFLAGS recommended by Perl... -D_REENTRANT -D_GNU_SOURCE
> -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include
> -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
> checking for CFLAGS to compile embedded Perl... -DDEBIAN

If the source of the problem is the same mechanism as it was for the
other platforms, then presumably the issue is that we need one or more
of
	-D_REENTRANT
	-D_GNU_SOURCE
	-D_LARGEFILE_SOURCE
	-D_FILE_OFFSET_BITS=64
to be defined while building PL/Perl.  Now, it couldn't be -D_GNU_SOURCE
that's at issue, because we turn that on in src/template/linux:

# Force _GNU_SOURCE on; plperl is broken with Perl 5.8.0 otherwise
CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"

(That ancient comment is pretty interesting in this connection, isn't it.)

And I'd have thought that _LARGEFILE_SOURCE=1 and _FILE_OFFSET_BITS=64
were the default behavior on any modern platform anyway, but maybe
kfreebsd is weird about that.  Anyway, you could try sticking combinations
of these symbols into perl_embed_ccflags in src/Makefile.global and
rebuilding PL/Perl to see if the problem goes away; if that works it would
give us a leg up on where the problem is.

			regards, tom lane

Commits

  1. MSVC: Test whether 32-bit Perl needs -D_USE_32BIT_TIME_T.

  2. Further tweaks to compiler flags for PL/Perl on Windows.

  3. Absorb -D_USE_32BIT_TIME_T switch from Perl, if relevant.

  4. PL/Perl portability fix: absorb relevant -D switches from Perl.

  5. PL/Perl portability fix: avoid including XSUB.h in plperl.c.