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
The former name was too likely to conflict with symbols from external
headers; and, as seen in recent buildfarm failures in member spoonbill,
it has now happened at least in plpython.
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.
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.
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
vintage Linux is even more broken than we realized: a link to libreadline
will succeed, and fail only at runtime. It seems that an AC_TRY_RUN test
is the only reliable way to check whether this is really safe. Per report
from Tatsuo.
shared libraries. We've tried this before and had problems with libreadline
not linking properly on some platforms, but that seems to be a libreadline
bug that may have been fixed by now. In any case, it's early enough in the
8.4 devel cycle that we can afford to have some transient breakage while
we work out any portability problems.
On Darwin, we try -Wl,-dead_strip_dylibs, which seems to be the equivalent
incantation there.
uses of the long-deprecated float32 in contrib/seg; the definitions themselves
are still there, but no longer used. fmgr/README updated to match.
I added a CREATE FUNCTION to account for existing seg_center() code in seg.c
too, and some tests for it and the neighbor functions. At the same time,
remove checks for NULL which are not needed (because the functions are declared
STRICT).
I had to do some adjustments to contrib's btree_gist too. The choices for
representation there are not ideal for changing the underlying types :-(
Original patch by Zoltan Boszormenyi, with some adjustments by me.
- Change configure.in to use Autoconf 2.61 and update generated files.
- Update build system and documentation to support now directory variables
offered by Autoconf 2.61.
- Replace usages of PGAC_CHECK_ALIGNOF by AC_CHECK_ALIGNOF, now available
in Autoconf 2.61.
- Drop our patched version of AC_C_INLINE, as Autoconf now has the change.
-O2 -Wall -Wmissing-prototypes -Wpointer-arith
Check whether the version of GCC we are using supports any of:
-Wdeclaration-after-statement
-Wendif-labels
-Wold-style-definition
And add the supported flags to CFLAGS.
When --enable-debug is used, then the default CFLAGS for non-GCC is just
-g without -O.
Backpatch enhancement of Autoconf inline test that detects problems with
the HP C compiler.
rewritten and the protocol is changed, but most elog calls are still
elog calls. Also, we need to contemplate mechanisms for controlling
all this functionality --- eg, how much stuff should appear in the
postmaster log? And what API should libpq expose for it?
separate macro. Also add support for %I64d which is the way on Windows.
The code that checks for the 64-bit int type now gives more reasonable
results when cross-compiling: In that case we just take the compiler's
information and trust that the arithmetic works. Disabling int64 is too
pessimistic.
Interfaced a lot of the custom tests to the config.cache, in the process
made them separate macros and grouped them out into files. Made naming
adjustments.
Removed a couple of useless/unused configure tests.
Disabled C++ by default. C++ is no more special than Perl, Python, and Tcl.
And it breaks equally often. :(
