The following code poses a problem in the JIT:
```php
class A {
public $prop = 1;
}
class B extends A {
public $prop = 1 {
get => parent::$prop::get() * 2;
}
}
function test(A $a) {
var_dump($a->prop);
}
test(new B);
```
The JIT would assume A::$prop in test() could be accessed directly
through OBJ_PROP_NUM(). However, since child classes can add new hooks
to existing properties, this assumption no longer holds.
To avoid introducing more JIT checks, a hooked property that overrides a
unhooked property now results in a separate zval slot that is used
instead of the parent slot. This causes the JIT to pick the slow path
due to an IS_UNDEF value in the parent slot.
zend_class_entry.properties_info_table poses a problem in that
zend_get_property_info_for_slot() and friends will be called using the
child slot, which does not store its property info, since the parent
slot already does. In this case, zend_get_property_info_for_slot() now
provides a fallback that will iterate all property infos to find the
correct one.
This also uncovered a bug (see Zend/tests/property_hooks/dump.phpt)
where the default value of a parent property would accidentally be
inherited by the child property.
Fixes GH-17376
Closes GH-17870
Instead of always saying that a name is reserved or deprecated and
cannot/should not be used as a class name, take the usage into account and say
the name cannot be used as an enum name, trait name, etc. In the process, for
class names add a missing "a".
This flag is longer set since the merge of property hooks in
780a8280d2. This patch removes it completely,
because the corresponding error messages are unreachable.
Alignment is not necessary while calculating slots reserved for
zend_execute_data and _zend_vm_stack.
ZEND_STATIC_ASSERT ensures the correct alignment while code
compilation. Credit is to Ilija Tovilo.
PR: https://github.com/php/php-src/pull/10988
Signed-off-by: Tony Su <tao.su@intel.com>
Reviewed-by : Ilija Tovilo
Reviewed-by : Dmitry Stogov
Reviewed-by : Niels Dossche
Struct members require some alignment based on their type. This means
that if a struct member is not aligned, there will be a hole created by
the compiler in the struct, which is wasted space. This patch reorders
some of the most commonly used structs, but in such a way that the
fields which were in the same cache line still belong together.
The only exception to this is exception_ignore_args, which was
temporally not close to nearby members, and as such I placed
it further up to close a hole.
On 64-bit Linux this gives us the following shrinks:
* zend_op_array: 248 -> 240
* zend_ssa_var: 56 -> 48
* zend_ssa_var_info: 48 -> 40
* php_core_globals: 672 -> 608
* zend_executor_globals: 1824 -> 1792
On 32-bit, the sizes will either remain the same or will result in
smaller shrinks.
Prefer to see clean code.
In MAKE_NOP macro, op.num is first set to 0, but immediately set to
-1 by SET_UNUSED macro, which invalidates previous set-to-zero code.
So clean the code to make it look nice and neat.
Signed-off-by: Tony Su <tao.su@intel.com>
`zend_uchar` suggests that the value is an ASCII character, but here,
it's about very small integers. This is misleading, so let's use a
C99 integer instead.
On all architectures currently supported by PHP, `zend_uchar` and
`uint8_t` are identical. This change is only about code readability.
This fixes the oversight that an anonymous class should be able to be
readonly. Other identifiers such as final and abstract do not make
sense. As we still want nice errors for when users try to use these
modifiers, or use multiple modifiers, we introduce a new function
zend_add_anonymous_class_modifier that will perform verification for
anonymous class modifiers, just like zend_add_class_modifier does for
non-anonymous classes.
Closes GH-10381
Use a shared non-terminal for all class modifiers. This avoids conflicts when
adding modifiers that are only valid for certain targets. This change is
necessary for asymmetric visibility but might be useful for other future
additions.
Closes GH-9926
The ast node flag constants ZEND_DIM_ALTERNATIVE_SYNTAX and
ZEND_ENCAPS_VAR_DOLLAR_CURLY_VAR_VAR node have identical values (1<<1),
causing a deprecation notice to be incorrectly emitted before the fatal error
for unsupported syntax.
Fixes GH-9263
Explicitly check for AST_VAR/AST_DIM kind for future compatibility
`AST_PROP`/`AST_METHOD_CALL` and nullsafe variants can also be found in
encapsulated strings - currently they have no flags but they may have flags in
the future. This also clarifies that this deprecation warning can only happen
for AST_VAR/AST_DIM nodes for certain `attr` values.
This avoids a possible significant performance penalty, when some leaf function was observed, deep in the stack.
As a side effect, we are not iterating over prev_execute_data anymore and thus, non-observed fake frames, possibly on stack, cannot have any impact on the observer anymore (especially within zend_observer_fcall_end_all).
Saving the previous observer happens now directly on the VM stack. If there is any observer, function frames are allocated an extra zval (the last temporary), which will, on observed frames, contain the previous observed frame address.
There are two main motivations to this:
a) The logic for handling internal and userland observation can be unified.
b) Unwinding of observed functions on a bailout does notably not include observers. Even if users of observers were to ensure such handling themselves, it would be impossible to retain the relative ordering - either the user has to unwind all internal observed frames before the automatic unwinding (zend_observer_fcall_end_all) or afterwards, but not properly interleaved.
Signed-off-by: Bob Weinand <bobwei9@hotmail.com>
https://wiki.php.net/rfc/strtolower-ascii means that these functions no longer
depend on the current locale in php 8.2. Before that, this was unsafe to
evaluate at compile time.
Followup to GH-7506
Add strcmp/strcasecmp/strtolower/strtoupper functions
Add bin2hex/hex2bin and related functions
Update test of garbage collection using strtolower to use something else to create a refcounted string
For FETCH_DIM_W etc encode the context it is being used in
(dim, obj, ref or incdec) so we can throw an appropriate error
message for invalid string offset use, in a way that does not
require inspecting neighboring opcodes. The implementation is
similar to the flags used for FETCH_OBJ.
This means that we do not have to be careful about preserving
following opcodes during optimization.
Closes GH-7599.
Add additional zend_compile_position argument, which can be either
AT_SHEBANG, AT_OPEN_TAG or AFTER_OPEN_TAG. The previous behavior
corresponds to AFTER_OPEN_TAG.
Closes GH-7462.
It's possible for delayed early binding opcodes to get optimized
away if they are "unreachable". However, we still need to attempt
early binding for them. (In some cases we also corrupt the early
binding list outright during optimization, which is how I got here.)
Fix this by storing information about delayed early binding
independently of DECLARE_CLASS_DELAYED opcodes, so early binding is
performed even after the opcode has been dropped.
Same as with the IteratorAggregate case, allow reusing get_iterator
if none of the Iterator methods are overridden. Drop the
REUSE_GET_ITERATOR flag that previously allowed ArrayIterator to
opt-in to unconditional get_iterator reuse, and drop the override
handling it did, in favor of the automated approach.
