Instead of having a completely independent encoding for type list
entries. This is going to use more memory, but I'm not particularly
concerned about that, as type unions that contain multiple classes
should be uncommon. On the other hand, this allows us to treat
top-level types and types inside lists mostly the same.
A new ZEND_TYPE_FOREACH macros allows to transparently treat list
and non-list types the same way. I'm not using it everywhere it could be
used for now, just the places that seemed most obvious.
Of course, this will make any future type system changes much simpler,
as it will not be necessary to duplicate all logic two times.
According to RFC: https://wiki.php.net/rfc/union_types_v2
The type representation now makes use of both the pointer payload
and the type mask at the same time. Additionall, zend_type_list is
introduced as a new kind of pointer payload, which is used to store
multiple class types. Each of the class types is a tagged pointer,
which may be either a class name or class entry. The latter is only
used for typed properties, while arguments/returns will instead use
cache slots. A type list can contain a mix of both names and CEs at
the same time, as not all classes may be resolvable.
One thing this is missing is support for union types in arginfo
and stubs, which I want to handle separately.
I've also dropped the special object code from the JIT implementation
for now -- I plan to add this back in a different form at a later time.
For now I did not want to include non-trivial JIT changes together
with large functional changes.
Another possible piece of follow-up work is to implement "iterable"
as an internal alias for "array|Traversable". I believe this will
eliminate quite a few special-cases that had to be implemented.
Closes GH-4838.
We now store the pointer payload and the type mask separately. This
is in preparation for union types, where we will be using both at
the same time.
To avoid increasing the size of arginfo structures, the
pass_by_reference and is_variadic fields are now stored as part of
the type_mask (8-bit are reserved for custom use).
Different types of pointer payloads are distinguished based on bits
in the type_mask.
Assigning to an uninitialized typed property will no longer trigger
a call to __set(). However, calls to __set() are still triggered if
the property is explicitly unset().
This gives us both the behavior people generally expect, and still
allows ORMs to do lazy initialization by unsetting properties.
For PHP 8, we should fine a way to forbid unsetting of declared
properties entirely, and provide a different way to achieve lazy
initialization.
Parent interfaces are copied into the interface list during
inheritance, so there's no need to perform a recursive check.
Only exception are instanceof checks performed during inheritance
itself. However, we already have unlinked_instanceof for this
purpose, it just needs to be taught to handle this case.
Closes GH-4857.
Property types are invariant, but may still have to load classes in
order to check for class aliases. This class loading should follow
the same rules as all other variance checks, rather than just
loading unconditionally.
This change integrates property type invariance checks into the
variance system as a new obligation type, and prevent early binding
if the type check cannot be performed.
Not NULLing the static_variables pointer for shadow methods during
static var shutdown would be a way to avoid this leak, but unless
there's evidence that inherited private methods with static vars are
actually a common use-case, I don't think we should keep this kind
of fragile edge-case optimization.
Fixes OSS-Fuzz #17875.
This switches zend_type from storing a single IS_* type code to
storing a MAY_BE_* type mask. Right now most code still assumes
that there is only a single type in the mask (or two together
with MAY_BE_NULL). But this will make it a lot simpler to introduce
union types.
An additional advantage (and why I'm doing this separately), is
that a number of special cases no longer need to be handled
separately: We can do a single mask & (1 << type) check to handle
all simple types, booleans (true|false) and null.
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.
The requirements for parent/interface are difference than for the
variance checks in type declarations. The latter can work on fully
unlinked classes, but the former need inheritance to be essentially
finished, only variance checks may still be outstanding.
Adding a new flag for this because we have lots of space, but we
could also represent these "inheritance states" more compactly in
the future.
While we don't need to give this method separate static vars, we
do still need to perform an addref, as there will be a corresponding
delref in the dtor.
