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.
Instead of checking for this during DO_FCALL, already detect this
case during get_method()/get_static_method(), similar to visibility
checks.
This causes a minor difference in behavior, in that arguments will
no longer be evaluated. I think this is correct though (and consistent
with visibility errors).
* PHP-7.4:
Remove HOT attribute from some VM handlers. Comparisons almost always followed by JMPZ/JMPNZ; JMPZNZ is rare used.
Remove --with-zlib-dir option from mysqlnd config
The exception mechanism assumes that exceptions from DO_FCALL are
already happening after the function call. This means that we are
currently leaking the passed arguments, and I think we can also
corrupt the VM stack due to incorrect frame linking in some cases
(there are assertion failures if the VM stack page size is reduced).
Instead handle the stack frame freeing manually for this special
case.
The normal function already throws TypeError through the usual zpp
mechanism, but the VM implementation handles this manually and has
not been updated.
Argument unpacking may need to create references inside the array
that is being unpacked. However, it currently can only do this
if a plain variable is unpacked, not for any nested accesses,
because the value is fetched for read. Resolve this by fetching
the operands for RW.
Make sure we deref the OBJ_IS result, because we store it in a TMP
var, which is not allowed to contain references and will cause
assertion failures in the unspecialized VM.
This also partially reverts fd463a9a60,
which merged the TMP and VAR specializations of COALESCE to work
around this bug.
An alternative would be to change the result type of OBJ_IS back
to VAR.
By avoiding unused variable opline warnings. Also clean up the
replacement of ZEND_VM_SPEC -- we were sometimes treating it as
an always-defined constant with a value (what it actually is) and
sometimes as a conditionally defined constant (which it isn't, but
which still worked thanks to the specializer). Switch to only
treating it as a constant with a value.
