The variable discardUndefined has an implicit negation in its name,
which makes it hard to understand. Plus, most of the time it is true.
It's better to have a flag that is false most of the time and has a
positive name.
On the first attempt of inverting that variable, I stumbled upon
MainParseArgs, which initially leaves discardUndefined == FALSE, and
after handling the dashed options, sets it to TRUE. This would make a
difference when more command line arguments would be added later via the
.MAKEFLAGS special target.
Upon further inspection, the only place where discardUndefined is used
is in VarAssign_EvalSubst in parse.c, and that place is not reachable
from any of the dashed options. Therefore, discardUndefined could
already be set at the very beginning of MainParseArgs or even when
initializing the global variable itself, without any observable
difference.
Not even the ::= variable modifier could do anything about this since it
is not reachable from the dashed command line options as well, and in
addition, it expands its right-hand side in any case, always discarding
undefined variables. Oh, these little inconsistencies everywhere.
Whenever varUndefined is returned from another function, that is only
done if eflags does not contain VARE_UNDEFERR. Therefore, testing for
that flag is unnecessary.
Special-casing this variable only made the code more complicated.
Furthermore, it is not related to error handling in any way and
therefore distracted the reader from this topic.
then rather than do more try-locks and eventually sleep for a tick,
take a hold on the current owner's lock, drop the page interlock,
and acquire the lock that we took the hold on in a blocking fashion.
After we get the lock, check if the lock that we acquired is still
the lock for the owner of the page that we're interested in.
If the owner hasn't changed then can proceed with this page,
otherwise we will skip this page and move on to a different page.
This dramatically reduces the amount of time that the pagedaemon
sleeps trying to get locks, since even 1 tick is an eternity to sleep
in this context and it was easy to trigger that case in practice,
and with this new method the pagedaemon only very rarely actually blocks
to acquire the lock that it wants since the object locks are adaptive,
and when the pagedaemon does block then the amount of time it spends
sleeping will be generally be much less than 1 tick.
macro indicating the current ARM instruction set. Let's use it.
PR/55778: evbarm64 GENERIC64 kernel fails to build with clang
XXX Handle the fact that for an ARM architecture ARMvX.Y then,
XXX __ARM_ARCH= X * 100 + Y. E.g. for ARMv8.1 __ARM_ARCH = 801.
Even though the pointer was out-of-bounds, a crash was unlikely in
practice, since typical C compilers don't check the pointers for invalid
values after each modification. The memory it pointed to was not
accessed though.
This change doesn't change any of the unit tests since the error
handling code is not yet complete, see the many "handle errors" in the
code. Nevertheless, the "out_FALSE_res = VPR_PARSE_MSG" was wrong since
the error message was only printed in lint mode, not in default mode.
