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.
RFC: https://wiki.php.net/rfc/null_coalesce_equal_operator
$a ??= $b is $a ?? ($a = $b), with the difference that $a is only
evaluated once, to the degree that this is possible. In particular
in $a[foo()] ?? $b function foo() is only ever called once.
However, the variable access themselves will be reevaluated.
RFC: https://wiki.php.net/rfc/typed_properties_v2
This is a squash of PR #3734, which is a squash of PR #3313.
Co-authored-by: Bob Weinand <bobwei9@hotmail.com>
Co-authored-by: Joe Watkins <krakjoe@php.net>
Co-authored-by: Dmitry Stogov <dmitry@zend.com>
Don't store the live range of the freed variable for FREE_ON_RETURN
frees, instead look it up at runtime. As this is an extremely
unlikely codepath (in particular, it requires a loop variable with
a throwing destructor), saving the runtime lookup of the live range
is not worth the extra complexity this adds everywhere else.
This slightly improves calls to regular function and method calls in cost of a bit slower generator initialization.
Separate call frame for generators, allocated on heap, now created by ZEND_GENERATOR_CREATE instruction.
- SPEC(NO_CONST_CONST) may prevent codegeneration for handlers like ADD_SPEC_CONST_CONST. Compiler and optimizaer should care about constants folding.
- SPEC(COMMUTATIVE) generate only single handler instead of two eqivalents like ADD_SPEC_CONST_CV and ADD_SPEC_CV_CONST. Compiler and optimizer should care avout operands swapping.
This opcodes inserts a local CV into the closure static variable
table. This replaces the previous mechanism of having static
variables marked as LEXICAL, which perform a symtable lookup
during copying.
This means a) functions which contain closures no longer have to
rebuild their symtable (better performance) and b) we can now track
used variables in SSA.
The DECLARE_(ANON_)INHERITED_CLASS(_DELAYED) opcodes were
referencing the parent ce VAR through extended_value. This is
hacky and we can't track the def-use chain in SSA.
To avoid this, the layout of declaration opcodes is changed
as follows: op1 points to the lcname and rtd_key literals, in
that order. (For anon/lambda declarations only one of lcname or
rtd_key is present.) This frees up op2, which is now used to
reference the parent ce VAR in inheriting declarations. The
jmp offset for anon class declarations is moved frop op2 to
extended_value.
The changes were applied both to class and function declarations
to keep everything symmetric.
