Previously, we included <xlocale.h> only if necessary to get the definition
of type locale_t.  According to notes in PGAC_TYPE_LOCALE_T, this is
important because on some versions of glibc that file supplies an
incompatible declaration of locale_t.  (This info may be obsolete, because
on my RHEL6 box that seems to be the *only* definition of locale_t; but
there may still be glibc's in the wild for which it's a live concern.)

It turns out though that on FreeBSD and maybe other BSDen, you can get
locale_t from stdlib.h or locale.h but mbstowcs_l() and friends only from
<xlocale.h>.  This was leaving us compiling calls to mbstowcs_l() and
friends with no visible prototype, which causes a warning and could
possibly cause actual trouble, since it's not declared to return int.

Hence, adjust the configure checks so that we'll include <xlocale.h>
either if it's necessary to get type locale_t or if it's necessary to
get a declaration of mbstowcs_l().

Report and patch by Aleksander Alekseev, somewhat whacked around by me.
Back-patch to all supported branches, since we have been using
mbstowcs_l() since 9.1.

This allows sane behavior in a PGXS build done on a machine where build
tools such as bison are missing.

Jim Nasby

Per buildfarm member anchovy, 2.6.0 exists in the wild now.
Hopefully it works with Postgres; if not, we'll have to do something
about that, but in any case claiming it's "too old" is pretty silly.

Per a suggestion from Tom Lane.  Back-patch to 9.0 (all supported
versions).  While only 9.4 and up have code known to elicit this
compiler bug, we were disabling inlining by accident until commit
43d89a23.

According to recent tests, this case now works fine, so there's no reason
to reject it anymore.  (Even if there are still some OpenBSD platforms
in the wild where it doesn't work, removing the check won't break any case
that worked before.)

We can actually remove the entire test that discovers whether libpython
is threaded, since without the OpenBSD case there's no need to know that
at all.

Per report from Davin Potts.  Back-patch to all active branches.

Usually the search would find plain "tclsh" without any trouble,
but some installations might only have the version-numbered flavor
of that program.

No compatibility problems have been reported with 8.6, so we might
as well back-patch this to all active branches.

Christoph Berg

This test used to just define an unused static inline function and check
whether that causes a warning.  But newer clang versions warn about
unused static inline functions when defined inside a .c file, but not
when defined in an included header, which is the case we care about.
Change the test to cope.

Andres Freund

The BSD-ish members of the buildfarm all seem to think removing this
was a bad idea.  It looks to me like it resulted in omitting the system
header inclusion necessary to detect the fields of struct tm correctly.

ENABLE_DTRACE            unused as of a7b7b07a
HAVE_ERR_SET_MARK        unused as of 4ed4b6c5
HAVE_FCVT                unused as of 4553e1d8
HAVE_STRUCT_SOCKADDR_UN  unused as of b4cea00a
HAVE_SYSCONF             unused as of f83356c7
TM_IN_SYS_TIME           never used, obsolescent per Autoconf documentation

PGAC_PATH_COLLATEINDEX supposed that it could use AC_PATH_PROGS to search
for collateindex.pl, but that macro will only accept files that are marked
executable, and at least some DocBook installations don't mark the script
executable (a case the docs Makefile was already prepared for).  Accept the
script if it's present and readable in $DOCBOOKSTYLE/bin, and otherwise
search the PATH as before.

Having fixed that up, we don't need the fallback case that was in the docs
Makefile, and instead can throw an understandable error if configure didn't
find the script.  Per recent trouble report from John Lumby.

According to Chris Rees, this has worked for awhile, and the current
FreeBSD port is removing the test anyway.

Original patch by Lars Kanis, reviewed by Nishiyama Tomoaki and tweaked some by me.

This compiler, or at least the latest version of it, is currently broken, and
only passes the regression tests if built with -O0.

They have been unneeded since the use of the string module has been
removed in a65ed83f.

Because of ABI tagging, the library version number might no longer be
exactly the Python version number, so do extra lookups.  This affects
installations without a shared library, such as ActiveState's
installer.

Also update the way to detect the location of the 'config' directory,
which can also be versioned.

Ashesh Vashi

This is reported to be necessary on some versions of that OS.  In service
of this, cause PGAC_PROG_CC_CFLAGS_OPT to reject switches that result in
compiler warnings, since on yet other versions of that OS, the switch does
nothing except provoke a warning.

Report and patch by Ibrar Ahmed, further tweaking by me.

When testing the stderr produced by various thread-support flags, also
run a compilation in addition to a link, because clang warns on
certain flags when compiling but not when linking.

This adds collation support for columns and domains, a COLLATE clause
to override it per expression, and B-tree index support.

Peter Eisentraut
reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch

This can be used to build 64 bit Windows binaries, not only on 64 bit
Windows but on supported cross-compiling hosts including 32 bit Windows,
Cygwin, Darwin and Linux.

Per previous failure of buildfarm member koi (which is no longer
failing, alas).

them after the fact.  This is a more elegant fix for bug #5595.

These are just cosmetic and don't seem worth back-patching far.
I put them into 9.0 just because it was trivial to do so.

build tree.  If we actually build the docs in the VPATH tree, those dirs
will get created then; but if they're present and empty, they capture the
vpathsearch searches in "make install", preventing installation of prebuilt
docs that might exist in the source tree.  Per bug #5595 from Dmtiriy Igrishin.
Fix based on idea from Peter Eisentraut.

at end of files.

Added a configure test for "long long" datatypes. So far this is only used in ecpg and replaces the old test that was kind of hackish.

This variable is apparently only for Python internally.  In newer releases
of Python this variable pulls in more and more libraries that users are
less likely to have, leading to potential build failures.

output.  Per bug #5339, Perl 5.11 has changed the format of that output
enough to break the previous coding.

Alex Hunsaker

configure warnings.

compilers, by applying a configure check to see if the compiler will accept
an unreferenced "static inline foo ..." function without warnings.  It is
believed that such warnings are the only reason not to declare inlined
functions in headers, if the compiler understands "inline" at all.

Kurt Harriman

versions < 5.8.  Also, if there's no Perl, emit a warning informing the
user that he won't be able to build from a CVS pull.  This is exactly the
same treatment we give Bison and Perl, and for the same reasons.

Behaves more or less unchanged compared to Python 2, but the new language
variant is called plpython3u.  Documentation describing the naming scheme
is included.

shell construct to hide away the stderr output.  Python 3.1 actually core
dumps on the current invocation (http://bugs.python.org/issue7111), but the
new version also has the more general advantage of saving the error message
in config.log for analysis.

perl_embed_ldflags setting.  On OS X it seems that ExtUtils::Embed is
trying to force a universal binary to be built, but you need to specify
that a lot further upstream if you want Postgres built that way; the only
result of including -arch in perl_embed_ldflags is some warnings at the
plperl.so link step.  Per my complaint and Jan Otto's suggestion.