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.
It seems that recent gcc versions can optimize away calls to these functions
even when the functions do not exist on the platform, resulting in a bogus
positive result. Avoid this by using a non-constant argument and ensuring
that the function result is not simply discarded. Per report from
François Laupretre.
its presence. This amounts to desupporting Kerberos 5 releases 1.0.*,
which is small loss, and simplifies use of our Kerberos code on platforms
with Red-Hat-style include file layouts. Per gripe from John Gray and
followup discussion.
reliably (ie, regardless of which libraries they depend on). Also
make sure that we don't select headers that obviously belong to the
wrong one of the two libraries. This was discussed back around 4-Sep
but seems to have slipped through the cracks. The header selection
could be checked more closely, perhaps, but let's see if this is good
enough.
actual executable location. This allows people to continue to use
setups where, eg, postmaster is symlinked from a convenient place.
Per gripe from Josh Berkus.
compiler emits any warnings, the test program had better be 100%
correct, not only 90% correct. The recent addition of -Wold-style-definition
broke thread-safety detection on every platform that has that switch,
because the test program used an old-style definition.
-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.
-L spec rather than assuming libpython is in the standard search path
(this returns to the way 7.4 did it). But check the distutils output
to see if it looks like Python has built a shared library, and if so
link with that instead of the probably-not-shared library found in
configdir.
