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.
* Change a number of "resource used as offset" notices to warnings,
which were previously missed.
* Throw the "resource used as offset" warning for isset() as well.
* Make array_key_exists() behavior with regard to different key
types consistent with isset() and normal array accesses. All key
types now use the usual coercions and array/object keys throw
TypeError.
Closes GH-4887.
We are now guaranteed that $this always exists inside methods, as
well as insides closures (if they use $this at all).
This removes checks for $this existence from the individual object
opcodes. Instead ZEND_FETCH_THIS is used in the cases where $this
is not guaranteed to exist, which is mainly the pseudo-main scope.
Closes GH-3822.
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.
instanceof_function() requires linked classes. I'm not reusing
unlinked_instanceof() here, because it performs class loading,
which wouldn't be right here, I think.
Split out the simple equality check into an inline function --
this is one of the common cases.
Replace instanceof_function_ex with zend_class_implements_interface.
There are a few more places where it may be used.
Nikita Popov