It emerges that libreadline doesn't notice terminal window size change
events unless they occur while collecting input. This is easy to stumble
over if you resize the window while using a pager to look at query output,
but it can be demonstrated without any pager involvement. The symptom is
that queries exceeding one line are misdisplayed during subsequent input
cycles, because libreadline has the wrong idea of the screen dimensions.
The safest, simplest way to fix this is to call rl_reset_screen_size()
just before calling readline(). That causes an extra ioctl(TIOCGWINSZ)
for every command; but since it only happens when reading from a tty, the
performance impact should be negligible. A more valid objection is that
this still leaves a tiny window during entry to readline() wherein delivery
of SIGWINCH will be missed; but the practical consequences of that are
probably negligible. In any case, there doesn't seem to be any good way to
avoid the race, since readline exposes no functions that seem safe to call
from a generic signal handler --- rl_reset_screen_size() certainly isn't.
It turns out that we also need an explicit rl_initialize() call, else
rl_reset_screen_size() dumps core when called before the first readline()
call.
rl_reset_screen_size() is not present in old versions of libreadline,
so we need a configure test for that. (rl_initialize() is present at
least back to readline 4.0, so we won't bother with a test for it.)
We would need a configure test anyway since libedit's emulation of
libreadline doesn't currently include such a function. Fortunately,
libedit seems not to have any corresponding bug.
Merlin Moncure, adjusted a bit by me
xlc provides "long long" unconditionally at C99-compatible language
levels, and this option provokes a warning. The warning interferes with
"configure" tests that fail in response to any warning. Notably, before
commit 85a2a8903f, it interfered with the
test for -qnoansialias. Back-patch to 9.0 (all supported versions).
Expose PG_VERSION_NUM (e.g., "90600") as a Make variable; but for
consistency with the other Make variables holding similar info,
call the variable just VERSION_NUM not PG_VERSION_NUM.
There was some discussion of making this value available as a pg_config
value as well. However, that would entail substantially more work than
this two-line patch. Given that there was not exactly universal consensus
that we need this at all, let's just do a minimal amount of work for now.
Back-patch of commit a5d489ccb7, so that this
variable is actually useful for its intended purpose sometime before 2020.
Michael Paquier, reviewed by Pavel Stehule
Considering the number of cases in which "unused" command line arguments
are silently ignored by compilers, it's fairly astonishing that anybody
thought this warning was useful; it's certainly nothing but an annoyance
when building Postgres. One such case is that neither gcc nor clang
complain about unrecognized -Wno-foo switches, making it more difficult
to figure out whether the switch does anything than one could wish.
Back-patch to 9.3, which is as far back as the patch applies conveniently
(we'd have to back-patch PGAC_PROG_CC_VAR_OPT to go further, and it doesn't
seem worth that).
Darwin --enable-nls builds use a substitute setlocale() that may start a
thread. Buildfarm member orangutan experienced BackendList corruption
on account of different postmaster threads executing signal handlers
simultaneously. Furthermore, a multithreaded postmaster risks undefined
behavior from sigprocmask() and fork(). Emit LOG messages about the
problem and its workaround. Back-patch to 9.0 (all supported versions).
With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, PostgreSQL
backends can crash at exit. Raise a warning during "configure" based on
the compile-time OpenLDAP version number, and test the crash scenario in
the dblink test suite. Back-patch to 9.0 (all supported versions).
This function is pervasive on free software operating systems; import
NetBSD's implementation. Back-patch to 8.4, like the commit that will
harness it.
The configure script's test for <sys/ucred.h> did not work on OpenBSD,
because on that platform <sys/param.h> has to be included first.
As a result, socket peer authentication was disabled on that platform.
Problem introduced in commit be4585b1c2.
Andres Freund, slightly simplified by me.
The main change here is to call security_compute_create_name_raw()
rather than security_compute_create_raw(). This ups the minimum
requirement for libselinux from 2.0.99 to 2.1.10, but it looks
like most distributions will have picked that up before 9.3 is out.
KaiGai Kohei
In commit 71450d7fd6, we added code to inform
suitably-intelligent compilers that ereport() doesn't return if the elevel
is ERROR or higher. This patch extends that to elog(), and also fixes a
double-evaluation hazard that the previous commit created in ereport(),
as well as reducing the emitted code size.
The elog() improvement requires the compiler to support __VA_ARGS__, which
should be available in just about anything nowadays since it's required by
C99. But our minimum language baseline is still C89, so add a configure
test for that.
The previous commit assumed that ereport's elevel could be evaluated twice,
which isn't terribly safe --- there are already counterexamples in xlog.c.
On compilers that have __builtin_constant_p, we can use that to protect the
second test, since there's no possible optimization gain if the compiler
doesn't know the value of elevel. Otherwise, use a local variable inside
the macros to prevent double evaluation. The local-variable solution is
inferior because (a) it leads to useless code being emitted when elevel
isn't constant, and (b) it increases the optimization level needed for the
compiler to recognize that subsequent code is unreachable. But it seems
better than not teaching non-gcc compilers about unreachability at all.
Lastly, if the compiler has __builtin_unreachable(), we can use that
instead of abort(), resulting in a noticeable code savings since no
function call is actually emitted. However, it seems wise to do this only
in non-assert builds. In an assert build, continue to use abort(), so that
the behavior will be predictable and debuggable if the "impossible"
happens.
These changes involve making the ereport and elog macros emit do-while
statement blocks not just expressions, which forces small changes in
a few call sites.
Andres Freund, Tom Lane, Heikki Linnakangas
I notice that plperl's makefile adds the -I for $perl_archlibexp/CORE
at the end of CPPFLAGS not the beginning. It seems somewhat unlikely
that the include search order has anything to do with why buildfarm
member okapi is failing, but I'm about out of other ideas.
It appears that perl_embed_ldflags should already mention all the libraries
that are required by libperl.so itself. So let's try the test link with
just those and not the other LIBS we've found up to now. This should
more nearly reproduce what will happen when plperl is linked, and perhaps
will fix buildfarm member okapi's problem.
Although most platforms seem to package Perl in such a way that these files
are present even in basic Perl installations, Debian does not. Hence, make
an effort to fail during configure rather than build if --with-perl was
given and these files are lacking. Per gripe from Josh Berkus.
Some versions of libedit expose bogus definitions of setproctitle(),
optreset, and perhaps other symbols that we don't want configure to pick up
on. There was a previous report of similar problems with strlcpy(), which
we addressed in commit 59cf88da91, but the
problem has evidently grown in scope since then. In hopes of not having to
deal with it again in future, rearrange configure's tests for supplied
functions so that we ignore libedit/libreadline except when probing
specifically for functions we expect them to provide.
Per report from Christoph Berg, though this is slightly more aggressive
than his proposed patch.
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.
Currently, the macros only work with fairly recent gcc versions, but there
is room to expand them to other compilers that have comparable features.
Heavily revised and autoconfiscated version of a patch by Andres Freund.
We previously supposed that any given platform would supply both or neither
of these functions, so that one configure test would be sufficient. It now
appears that at least on AIX this is not the case ... which is likely an
AIX bug, but nonetheless we need to cope with it. So use separate tests.
Per bug #6758; thanks to Andrew Hastie for doing the followup testing
needed to confirm what was happening.
Backpatch to 9.1, where we began using these functions.
We had put a test for libxml2's xmlStructuredErrorContext variable in
configure, but of course that doesn't work on Windows builds. The next
best alternative seems to be to test the LIBXML_VERSION symbol provided
by xmlversion.h.
Per report from Talha Bin Rizwan, though this fixes it in a different way
than his proposed patch.
Historically we have not worried about fsync'ing anything during initdb
(in fact, initdb intentionally passes -F to each backend launch to prevent
it from fsync'ing). But with filesystems getting more aggressive about
caching data, that's not such a good plan anymore. Make initdb do a pass
over the finished data directory tree to fsync everything. For testing
purposes, the -N/--nosync flag can be used to restore the old behavior.
Also, testing shows that on Linux, sync_file_range() is much faster than
posix_fadvise() for hinting to the kernel that an fsync is coming,
apparently because the latter blocks on a rather small request queue while
the former doesn't. So use this function if available in initdb, and also
in the backend's pg_flush_data() (where it currently will affect only the
speed of CREATE DATABASE's cloning step).
We will later make pg_regress invoke initdb with the --nosync flag
to avoid slowing down cases such as "make check" in contrib. But
let's not do so until we've shaken out any portability issues in this
patch.
Jeff Davis, reviewed by Andres Freund
All Unix-oid platforms that we currently support should have waitpid(),
since it's in V2 of the Single Unix Spec. Our git history shows that
the wait3 code was added to support NextStep, which we officially dropped
support for as of 9.2. So get rid of the configure test, and simplify the
macro spaghetti in reaper(). Per suggestion from Fujii Masao.
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 a3176dac22 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.
ENABLE_DTRACE unused as of a7b7b07af3
HAVE_ERR_SET_MARK unused as of 4ed4b6c54e
HAVE_FCVT unused as of 4553e1d80f
HAVE_STRUCT_SOCKADDR_UN unused as of b4cea00a1f
HAVE_SYSCONF unused as of f83356c7f5
TM_IN_SYS_TIME never used, obsolescent per Autoconf documentation
These were apparently never used. The AC_SUBST was probably just
added in a copy-and-paste manner. (The shell variables continue to be
used inside configure. The change is just that we don't need them
outside of configure.)
