I lost some time trying to know how to find the returned type.
It's not that obvious it is stored in the _argument_ information array.
For the sake of Internet, here is the full code checking that a function _has_ a returned type:
```c
zend_function *function = /* e.g. fci_cache->function_handler */;
if (!(function->op_array.fn_flags & ZEND_ACC_HAS_RETURN_TYPE)) {
php_printf("no return type\n");
} else {
php_printf("has a return type\n");
php_printf("return type = %s\n", zend_get_type_by_const(ZEND_TYPE_CODE(function->common.arg_info[-1].type)));
}
```
* PHP-7.4:
Free two bits in fn_flags by merging ZEND_ACC_HEAP_RT_CACHE/ZEND_ACC_USER_ARG_INFO and ZEND_ACC_DONE_PASS_TWO/ZEND_ACC_ARENA_ALLOCATED that may be used only for user/internal functions
Only deprecate unbinding of $this from a closure if $this is
syntactically used within the closure.
This is desired to support Laravel's macro system, see laravel/framework#29482.
This should still allow us to implement the performance improvements
we're interested in for PHP 8, without breaking existing use-cases.
Keep track of delayed variance obligations and check them after
linking a class is otherwise finished. Obligations may either be
unresolved method compatibility (because the necessecary classes
aren't available yet) or open parent/interface dependencies. The
latter occur because we allow the use of not fully linked classes
as parents/interfaces now.
An important aspect of the implementation is we do not require
classes involved in variance checks to be fully linked in order for
the class to be fully linked. Because the involved types do have to
exist in the class table (as partially linked classes) and we do
check these for correct variance, we have the guarantee that either
those classes will successfully link lateron or generate an error,
but there is no way to actually use them until that point and as
such no possibility of violating the variance contract. This is
important because it ensures that a class declaration always either
errors or will produce an immediately usable class afterwards --
there are no cases where the finalization of the class declaration
has to be delayed until a later time, as earlier variants of this
patch did.
Because variance checks deal with classes in various stages of
linking, we need to use a special instanceof implementation that
supports this, and also introduce finer-grained flags that tell us
which parts have been linked already and which haven't.
Class autoloading for variance checks is delayed into a separate
stage after the class is otherwise linked and before delayed
variance obligations are processed. This separation is needed to
handle cases like A extends B extends C, where B is the autoload
root, but C is required to check variance. This could end up
loading C while the class structure of B is in an inconsistent
state.
