Relying on setting ERROR if an exception happened during the
property address fetch is both a bit fragile and may pessimize
other codepaths that will check for exceptions in the VM. Adding
an extra exception check instead, which should also allow us to
drop the use of ERROR in this area in master.
This removes object auto-vivification support.
This also means that we can remove the corresponding special
handling for typed properites: We no longer need to check that a
property is convertible to stdClass if such a conversion might
take place indirectly due to a nested property write.
Additionally OBJ_W style operations now no longer modify the
object operand, and as such we no longer need to treat op1 as a
def in SSA form.
The next step would be to actually compile the whole LHS of OBJ_W
operations in R rather than W mode, but that causes issues with
SimpleXML, whose object handlers depend on the current compilation
structure.
Part of https://wiki.php.net/rfc/engine_warnings.
This is a fix for symfony/symfony#32995.
The behavior is:
* Throwing exception when loading parent/interface is allowed
(and we will also throw one if the class is simply not found).
* If this happens, the bucket key for the class is reset, so
it's possibly to try registering the same class again.
* However, if the class has already been used due to a variance
obligation, the exception is upgraded to a fatal error, as we
cannot safely unregister the class stub anymore.
No notice is thrown for list() accesses, because we did not come
to an agreement regarding patterns like
while ([$key, $value] = yield $it->next()) { ... }
where silent null access may be desirable.
No effort is made to suppress multiple notices in access chains
likes $x[0][0][0], because the technical complexity this causes
does not seem worthwhile.
RFC: https://wiki.php.net/rfc/notice-for-non-valid-array-container
Another stab in the dark to fix the intermittent failures of timeout
tests on macos CI: We're using ITIMER_PROF, which means that the
timer counts against user+system time. The "busy" wait loop counts
against real time. Currently it calls microtime() on every iteration.
If that call is implemented as a syscall rather than going through
vDSO or commpage we might be seeing many context switches here which
drive up the real time, but not user or system time.
See if making the loop busier and calling microtime() less helps the
situation.
RFC: https://wiki.php.net/rfc/tostring_exceptions
And convert some object to string conversion related recoverable
fatal errors into Error exceptions.
Improve exception safety of internal code performing string
conversions.
Ensure that the "creating default object from empty value" warning is
always thrown. Previously some cases were missing the warning, in
particular those going through FETCH_OBJ_W rather than a dedicated
opcode (like ASSIGN_OBJ).
One slightly unfortunate side-effect of this change is that something
like $a->b->c = 'd' will now generate two warnings rather than one
when $a is null (one for property b, one for property c).
