With this optimization flag enabled, recent versions of gcc can generate
incorrect code that assumes variable-length arrays (such as oidvector)
are actually fixed-length because they're embedded in some larger struct.
The known instance of this problem was fixed in 9.2 and up by commit
8137f2c323 and followon work, which hides
actually-variable-length catalog fields from the compiler altogether.
And we plan to gradually convert variable-length fields to official
"flexible array member" notation over time, which should prevent this type
of bug from reappearing as gcc gets smarter. We're not going to try to
back-port those changes into older branches, though, so apply this
band-aid instead.
Andres Freund
This is a backpatch of commit 649839dd9 to unsupported branches
REL8_2_STABLE and REL8_3_STABLE, so that they work with newer toolsets.
Suggested solution from Tom Lane. Problem discovered, probably not
for the first time, while testing the mingw-w64 32 bit compiler.
Backpatched to all live branches.
The mingw people don't appear to care about compatibility with non-GNU
versions of getopt, so force use of our own copy of getopt on Windows.
Also, ensure that we make use of optreset when using our own copy.
Per report from Andrew Dunstan. Back-patch to all versions supported
on Windows.
This prevents compiler optimizations that assume overflow won't occur, which
breaks numerous overflow tests that we need to have working. It is known
that gcc 4.3 causes problems and possible that 4.1 does. Per my proposal
of some time ago and a recent report from Kris Jurka.
Backpatch as far as 8.0, which is as far as the patch conveniently goes.
7.x was pretty short of overflow tests anyway, so it may not matter there,
even assuming that anyone cares whether 7.x builds on recent gcc.
unportable backslashes in awk script (per Patrick Welche), and add
brackets to prevent autoconf from mangling sed's regexp (the sed call
here never did what was expected).
include it if it links properly. It seems too risky to assume that
standard functions like pow() are not special-cased by the compiler.
Per report from Andreas Lange that build fails on Solaris cc compiler
with -fast. Even though we don't consider that a supported option,
I'm worried that similar issues will arise with other compilers.
code relies on the checking macro actually being called at the end, or the
automatic undiversion will produce garbage. These sort of implicit
side-effects undermine the modularity of the macros and happen to break the
ODBC driver which makes use of them.
Also put the warnings at the very end of configure, so there is an even
better chance of seeing them.
max_stack_depth is not set to an unsafe value.
This commit also provides configure-time checking for <sys/resource.h>,
and cleans up some perhaps-unportable code associated with use of that
include file and getrlimit().
Buildfarm results from 'gazelle' show that there are indeed libedit
versions for which history.h is a needed header, even though it's
apparently been dropped entirely in other versions. Grumble.
Per Bob Friesenhahn's report, this file is not supplied by some versions
of libedit, and even when it is supplied it seems to be just a link to
readline.h, so we don't need to include it anyway.
Also, ensure that we won't try to use a too-old version of Bison.
The previous coding would bleat but then use it anyway; better to invoke
the 'missing' script if any grammar files need to be rebuilt.
repeatedly. Now that we don't have to worry about memory leaks from
glibc's qsort, we can safely put CHECK_FOR_INTERRUPTS into the tuplesort
comparators, as was requested a couple months ago. Also, get rid of
non-reentrancy and an extra level of function call in tuplesort.c by
providing a variant qsort_arg() API that passes an extra void * argument
through to the comparison routine. (We might want to use that in other
places too, I didn't look yet.)