checkdate() — internals

checkdate() — internals

Where it lives

• Signature: src/builtins/system/checkdate.rs
• Lowering: src/codegen/lower_inst/builtins/system.rs:163 (lower_checkdate)
• Function symbol: lower_checkdate()

Lowering notes

• Lowers checkdate(month, day, year) through the shared Gregorian-validation runtime helper.
• Marshals the three integers into the leading ABI argument registers (unboxing any boxed
• Mixed/Union argument), then calls __rt_checkdate, which returns PHP true/false in the
• integer result register for a valid/invalid date.

Runtime helpers

The following runtime helpers are referenced:

• __rt_checkdate
• __rt_getdate

Signature summary

function checkdate(int $month, int $day, int $year): bool

What the type checker enforces

• Arity: takes exactly 3 arguments.

Cross-references

• User reference for checkdate()