zval_pack() — internals

zval_pack() — internals

Where it lives

• Signature: src/builtins/pointers/zval_pack.rs
• Lowering: src/codegen/lower_inst/builtins/pointers.rs:533 (lower_zval_pack)
• Function symbol: lower_zval_pack()

Lowering notes

• Lowers zval_pack(value) by boxing the operand as a Mixed cell and invoking
• __rt_zval_pack, which returns a pointer to a freshly allocated 16-byte zval.
• __rt_zval_pack only reads the (tag, lo, hi) triple out of the boxed Mixed
• cell; it never retains or frees that cell. When the operand was not already
• Mixed/Union, emit_box_current_value_as_mixed allocated a fresh owned box
• (persisting strings, increfing array/object/mixed children), so that box is a
• throwaway temporary that must be deep-released after the pack call or it leaks
• one Mixed cell per call. When the operand is already Mixed/Union no box was
• created, so the operand’s own live cell must not be freed here.

Runtime helpers

The following runtime helpers are referenced:

• __rt_mixed_free_deep
• __rt_zval_pack

Signature summary

function zval_pack(mixed $value): pointer

What the type checker enforces

• Arity: takes exactly 1 argument.

Eval interpreter (magician)

Not callable from eval’d code — the magician interpreter has no entry for this builtin.

Cross-references

• User reference for zval_pack()