This reverts commit e2b3c21b.

Normally each module is tested in aq database named contrib_regression,
which is dropped and recreated at the beginhning of each pg_regress run.
This mode, enabled by adding USE_MODULE_DB=1 to the make command line,
runs most modules in a database with the module name embedded in it.

This will make testing pg_upgrade on clusters with the contrib modules
a lot easier.

Still to be done: adapt to the MSVC build system.

Backpatch to 9.0, which is the earliest version it is reasonably possible
to test upgrading from.

Several hacks in certain modes already thought this was a bad idea, so
just disable it globally.

The introduction of the .y -> .c pattern rule causes some .c files such
as bootparse.c to be considered intermediate files in the .y -> .c -> .o
rule chain, which make would automatically delete.  But in coverage
mode, the processing tools such as genhtml need those files, so mark
them as "precious" so that make preserves them.

Numerous flex and bison make rules have appeared in the source tree
over time, and they are all virtually identical, so we can replace
them by pattern rules with some variables for customization.

Users of pgxs will also be able to benefit from this.

Get rid of the fundamentally indefensible assumption that "long long int"
exists and is exactly 64 bits wide on every platform Postgres runs on.
Instead let the configure script select the type to use for "pg_int64".

This is a bit of a pain in the rear since we do not want to pollute client
namespace with all the random symbols that pg_config.h defines; instead
we have to create a separate generated header file, "pg_config_ext.h".
But now that the infrastructure is there, we might have the ability to
add some other stuff that's long been wanting in this area.

port.  The last use was QNX, per Peter Eisentraut.

This is for convenience, now that adding recursive targets is much
easier than it used to be when the NLS stuff was initially added.

The $(or) make function was introduced in GNU make 3.81, so the
previous coding didn't work in 3.80.  Write it differently, and
improve the variable naming to make more sense in the new coding.

configure handles INSTALL as a substitution variable specially, and
apparently it gets confused when it's set to empty.  Use INSTALL_
instead as a workaround to avoid the issue.

In a3176dac we switched to using
install-sh unconditionally, because the configure check
AC_PROG_INSTALL would pick up any random program named install, which
has caused failure reports
(http://archives.postgresql.org/pgsql-hackers/2001-03/msg00312.php).
Now the configure check is much improved and should avoid false
positives.  It has also been shown that using a system install program
can significantly reduce "make install" times, so it's worth trying.

According to the Autoconf documentation, there should be a make rule

pg_config.h: stamp-h

so that with the right setup around this, a change in pg_config.h.in
will trigger a rebuild of everything that depends on pg_config.h.  But
this doesn't always work, sometimes you need to run make twice to get
everything up to date after a change of pg_config.h.in.

The fix is to write the rule as

pg_config.h: stamp-h ;

instead (with an empty command instead of no command).  This is what
Automake-generated makefiles effectively do, so it seems safe to be on
this side.

It's not actually clear why this is (apparently) more correct.  It's
been posted to
<http://lists.gnu.org/archive/html/help-make/2012-04/msg00058.html>
without response so far.

Josh Kupershmidt

Further improve on commit c75e1436.
Instead of building both .o files and binaries in the same make rule,
just rely on the normal .c -> .o rule.  This will ensure that
dependency tracking is used when enabled.  To do this, disable the
implicit direct .c -> binary rule globally, which will also prevent
the original problem (*.dSYM junk) from reappearing elsewhere.

Certain subdirectories do not get built if corresponding options are not
selected at configure time.  However, "make distprep" should visit such
directories anyway, so that constructing derived files to be included in
the tarball happens without requiring all configure options to be given
in the tarball build script.  Likewise, it's better if cleanup actions
unconditionally visit all directories (for example, this ensures proper
cleanup if someone has done a manual make in such a subdirectory).

To handle this, set up a convention that subdirectories that are
conditionally included in SUBDIRS should be added to ALWAYS_SUBDIRS
instead when they are excluded.

Back-patch to 9.1, so that plpython's spiexceptions.h will get provided
in 9.1 tarballs.  There don't appear to be any instances where distprep
actions got missed in previous releases, and anyway this fix requires
gmake 3.80 so we don't want to apply it before 9.1.

Per recommendation from Peter.  Neither choice is bulletproof, but this
is the existing style and it does help prevent unexpected environment
variable substitution.

Apparently there is no buildfarm critter exercising this case after all,
because it fails in several places.  With this patch, build, install,
check-world, and installcheck-world pass for me on OS X.

Also refactor things a little bit so that the same methods for setting
test locale and encoding can be used everywhere.

This can do various source code checks that are not appropriate for
either the build or the regression tests.  Currently: duplicate_oids,
SGML syntax and tabs check, NLS syntax check.

Also add make check-world target, and refactor pg_regress invocation
code in makefiles a bit.

This is still pretty rough - among other things, the documentation
needs work, and the messages need a visit from the style police -
but this gets the basic framework in place.

KaiGai Kohei

... based on further tracing through that code.

3.80 breaks if the expansion of $(eval) is long enough to require expansion
of its internal variable_buffer.  For the purposes of $(recurse) that means
it'll work so long as no single evaluation of _create_recursive_target
produces more than 195 bytes.  We can manage that by looping over
subdirectories outside the call instead of complicating the generated rule.
This coding is simpler and more readable anyway.

Or at least, this works for me.  We'll see if the buildfarm likes it.

Replace for loops in makefiles with proper dependencies.  Parallel
make can now span across directories.  Also, make -k and make -q work
properly.

GNU make 3.80 or newer is now required.

files automatically.  Otherwise, the following could happen: When
starting from a clean source tree, the first build would delete the
intermediate file, but also create the dependency file, which
mentions the intermediate file, thus making it non-intermediate.
The second build will then need to rebuild the now non-intermediate
missing file.  So the second build will do work even though nothing
had changed.  One place where this happens is the .c -> .o -> .so
chain for some contrib modules.

flag for src/port/ in front of any -L flags placed in LDFLAGS by configure.
This undoes an L-flag-ordering change that I had thought would be safe,
but seems to be making at least one buildfarm member fail --- the only
theory for orca's failure that I can think of is that it's got an old
copy of libpgport.a in /usr/lib.  Also allow for LDFLAGS_SL to be set by
contrib makefiles before they invoke Makefile.global.

linking both executables and shared libraries, and we add on LDFLAGS_EX when
linking executables or LDFLAGS_SL when linking shared libraries.  This
provides a significantly cleaner way of dealing with link-time switches than
the former behavior.  Also, make sure that the various platform-specific
%.so: %.o rules incorporate LDFLAGS and LDFLAGS_SL; most of them missed that
before.  (I did not add these variables for the platforms that invoke $(LD)
directly, however.  It's not clear if we can do that safely, since for the
most part we assume these variables use CC command-line syntax.)

Per gripe from Aaron Swenson and subsequent investigation.

Mark  "installcheck-parallel", "world", "install-world" and "installcheck-world" make targets as PHONY. Fujii Masao.

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

Update install-sh to that from Autoconf 2.63, plus our Darwin-specific
changes (which I simplified a bit).  install-sh is now able to install
multiple files in one run, so we could simplify our makefiles sometime.

install-sh also now has a -d option to create directories, so we don't need
mkinstalldirs anymore.

Use AC_PROG_MKDIR_P in configure.in, so we can use mkdir -p when available
instead of install-sh -d.  For consistency with the rest of the world,
the corresponding make variable has been renamed from $(mkinstalldirs) to
$(MKDIR_P).

Documentation files in HTML and man formats are now prepared for
distribution using the distprep make target, like everything else.  They
are placed in doc/src/sgml/html and manX and installed from there by
make install, if present.  The business with the tarballs in the tarball
is gone.

Test coverage support now covers the entire source tree, including
contrib, instead of just src/backend.  In a related but independent
development, the commands make coverage and make coverage-html can be run
in any directory.

This turned out to be much easier than feared.  Besides a few ad hoc fixes
to pass the make target down the tree, change all affected makefiles to
list their directories in the SUBDIRS variable, changed from variants like
DIRS and WANTED_DIRS.  MSVC build fix was attempted as well.

This switches the man page building process to use the DocBook XSL stylesheet
toolchain.  The previous targets for Docbook2X are removed. configure has been
updated to look for the new tools.  The Documentation appendix contains the
new build instructions.  There are also a few isolated tweaks in the
documentation to improve places that came out strangely in the man pages.

used to work as intended, but got broken some time ago (a quoted empty string
is not an empty string), and got broken some more by the changes to generate
ecpg's preproc.y automatically.  Given all the unprotected uses of $(PERL)
elsewhere, it seems best to make use of the $(missing) script rather than
trying to ensure each such use is protected individually.  Also fix various
bits of documentation that omitted to mention Perl as a requirement for
building from a CVS pull.  Per a complaint from Robert Haas.

I occasionally use this for debugging, and it seems wasteful to have to
reinvent this all the time.