Running out of ce_flags and fn_flags options

[DanielEScherzer]

zend_compile.h defines a bunch of ZEND_ACC_* flags for use in the following fields

• ce_flags: zend_class_entry
• fn_flags: zend_op_array / zend_internal_function
• flags: zend_property_info
• value.u2.constant_flags (bottom 16 bits): zend_constant

Function flags already use 31 of 32 possible values (not using 1 << 30) and some values are used twice (one flag for internal classes and another for userland classes with the same values)

Class flags already use 31 of 32 possible values (not using 1 << 31)

This task is for tracking ideas and progress for being able to add more flags without issues

[DanielEScherzer]

Some existing ideas:

• switch from a 32 bit flags to 64 bit flags
• use 2 bits instead of 4 for marking classes as class/interface/trait/enum since they can only ever be one of these

[iluuu1994]

switch from a 32 bit flags to 64 bit flags

One problem was ReflectionClass::getModifiers() and friends on 32-bit. On these platforms, PHP's int type will not be sufficient to represent all flags. We might deprecate these in favor of something array-based. Or just offer no alternative, and encourage the use of the isFlag() methods.

[DanielEScherzer]

One problem was ReflectionClass::getModifiers() and friends on 32-bit. On these platforms, PHP's int type will not be sufficient to represent all flags. We might deprecate these in favor of something array-based. Or just offer no alternative, and encourage the use of the isFlag() methods.

Is there any reason that we need getModifiers() to return the same values as the ZEND_ACC_* flags? I think properties have the biggest set of modifiers reported: ZEND_ACC_PPP_MASK | ZEND_ACC_PPP_SET_MASK | ZEND_ACC_STATIC | ZEND_ACC_READONLY | ZEND_ACC_ABSTRACT | ZEND_ACC_VIRTUAL | ZEND_ACC_FINAL

and we could just map public=>1, protected=>2, private=>4, etc. regardless of the real values on the C side

Alternatively, we could document that only flags that Reflection does not care about should be in the higher 32 bits

[iluuu1994]

Is there any reason that we need getModifiers() to return the same values as the ZEND_ACC_* flags?

Probably not, no. Remapping might work. It's a BC break because the value changes, but hopefully that shouldn't matter. We should however make sure that the same flags have the same value across getModifiers() methods.

[iluuu1994]

FYI, I'm going to propose this patch again for master in the coming days. Having thought about it, we may not need a solution for reflection on 32-bit at all. If some flag needs to be exposed, we can simply make space in the lower bit range by moving a non-exposed constant to the higher range.

[iluuu1994]

After Niels, Dmitry has also noted that he'd prefer new fields rather than extending the current one. I've merged this solution now here: php/php-src#19991 This part remains:

If some flag needs to be exposed, we can simply make space in the lower bit range by moving a non-exposed constant to the higher range.