We were being careless in some places about the order of -L switches in
link command lines, such that -L switches referring to external directories
could come before those referring to directories within the build tree.
This made it possible to accidentally link a system-supplied library, for
example /usr/lib/libpq.so, in place of the one built in the build tree.
Hilarity ensued, the more so the older the system-supplied library is.
To fix, break LDFLAGS into two parts, a sub-variable LDFLAGS_INTERNAL
and the main LDFLAGS variable, both of which are "recursively expanded"
so that they can be incrementally adjusted by different makefiles.
Establish a policy that -L switches for directories in the build tree
must always be added to LDFLAGS_INTERNAL, while -L switches for external
directories must always be added to LDFLAGS. This is sufficient to
ensure a safe search order. For simplicity, we typically also put -l
switches for the respective libraries into those same variables.
(Traditional make usage would have us put -l switches into LIBS, but
cleaning that up is a project for another day, as there's no clear
need for it.)
This turns out to also require separating SHLIB_LINK into two variables,
SHLIB_LINK and SHLIB_LINK_INTERNAL, with a similar rule about which
switches go into which variable. And likewise for PG_LIBS.
Although this change might appear to affect external users of pgxs.mk,
I think it doesn't; they shouldn't have any need to touch the _INTERNAL
variables.
In passing, tweak src/common/Makefile so that the value of CPPFLAGS
recorded in pg_config lacks "-DFRONTEND" and the recorded value of
LDFLAGS lacks "-L../../../src/common". Both of those things are
mistakes, apparently introduced during prior code rearrangements,
as old versions of pg_config don't print them. In general we don't
want anything that's specific to the src/common subdirectory to
appear in those outputs.
This is certainly a bug fix, but in view of the lack of field
complaints, I'm unsure whether it's worth the risk of back-patching.
In any case it seems wise to see what the buildfarm makes of it first.
Discussion: https://postgr.es/m/25214.1522604295@sss.pgh.pa.us
The Perl documentation is very clear that stuff calling libperl should
be built with the compiler switches shown by Perl's $Config{ccflags}.
We'd been ignoring that up to now, and mostly getting away with it,
but recent Perl versions contain ABI compatibility cross-checks that
fail on some builds because of this omission. In particular the
sizeof(PerlInterpreter) can come out different due to some fields being
added or removed; which means we have a live ABI hazard that we'd better
fix rather than continuing to sweep it under the rug.
However, it still seems like a bad idea to just absorb $Config{ccflags}
verbatim. In some environments Perl was built with a different compiler
that doesn't even use the same switch syntax. -D switch syntax is pretty
universal though, and absorbing Perl's -D switches really ought to be
enough to fix the problem.
Furthermore, Perl likes to inject stuff like -D_LARGEFILE_SOURCE and
-D_FILE_OFFSET_BITS=64 into $Config{ccflags}, which affect libc ABIs on
platforms where they're relevant. Adopting those seems dangerous too.
It's unclear whether a build wherein Perl and Postgres have different ideas
of sizeof(off_t) etc would work, or whether anyone would care about making
it work. But it's dead certain that having different stdio ABIs in
core Postgres and PL/Perl will not work; we've seen that movie before.
Therefore, let's also ignore -D switches for symbols beginning with
underscore. The symbols that we actually need to import should be the ones
mentioned in perl.h's PL_bincompat_options stanza, and none of those start
with underscore, so this seems likely to work. (If it turns out not to
work everywhere, we could consider intersecting the symbols mentioned in
PL_bincompat_options with the -D switches. But that will be much more
complicated, so let's try this way first.)
This will need to be back-patched, but first let's see what the
buildfarm makes of it.
Ashutosh Sharma, some adjustments by me
Discussion: https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com
Remove $(pkglibdir) from $(rpathdir), since commits
d51924be886c2a05e691fa05b16cb6b30ab8370f and
eda04886c1e048d695728206504ab4198462168e removed direct linkage to
objects stored there. Users are unlikely to notice the difference.
Accompany every $(python_libspec) with $(python_additional_libs); this
doesn't fix a demonstrated bug, but it might do so on rare Python
configurations. With these changes, AIX ceases to be a special case.
Just turning the crank on the project started in commit d51924be8.
These cases turn out to be exact subsets of the boilerplate needed
for hstore_plpython.
Discussion: <2652.1475512158@sss.pgh.pa.us>
The order of inclusion of .o files makes a difference in linker output;
not a functional difference, but still a bitwise difference, which annoys
some packagers who would like reproducible builds.
Report and patch by Christoph Berg
The result closely resembles linking of these modules for the "win32"
port. Augment the $(exports_file) header so the file is also usable as
an import file. Unfortunately, relocating an AIX installation will now
require adding $(pkglibdir) to LD_LIBRARY_PATH. Back-patch to 9.5,
where the modules were introduced.
These modules were all missing essential Windows scaffolding, including
resources files and descriptions, and links to the relevant library
import files. This latter item means that the modules can't be built
with pgxs on Windows, as we don't install the import files. If we ever
decide to install them this restriction could probably be removed.
Also, as with plperl we need to make sure that perl's CORE directory is
last on the include list, as on Windows it appears to contain some
headers with names that clash with names of some headers we include.
Combine the two places that set CPPFLAGS into one. Also, some settings
should be restricted to Windows only. More precisely, -Wno-comment is
a GCC-only option, but Windows in a makefile implies GCC at the moment.
Also, since -Wno-comment is more properly a preprocessor option, move it
to CPPFLAGS to simplify things a bit.
This involves moving perl's CORE library to the end of the include list,
and adding other compilation settings that plperl uses. This won't
completely fix the breakage currently being seen by gcc builds on
Windows, but it will let the build get further, and should be wholly
benign, if not beneficial, on *nix.
This provides a mechanism for specifying conversions between SQL data
types and procedural languages. As examples, there are transforms
for hstore and ltree for PL/Perl and PL/Python.
reviews by Pavel Stěhule and Andres Freund
