LibJS: Make Value() default-construct the undefined value

The special empty value (that we use for array holes, Optional<Value>
when empty and a few other other placeholder/sentinel tasks) still
exists, but you now create one via JS::js_special_empty_value() and
check for it with Value::is_special_empty_value().

The main idea here is to make it very unlikely to accidentally create an
unexpected special empty value.
This commit is contained in:
Andreas Kling 2025-04-04 23:16:34 +02:00 committed by Andreas Kling
commit 3cf50539ec
Notes: github-actions[bot] 2025-04-05 09:21:31 +00:00
43 changed files with 165 additions and 122 deletions

View file

@ -298,7 +298,7 @@ public:
emit<Bytecode::Op::PrepareYield>(Operand(Register::saved_return_value()), value);
else
emit<Bytecode::Op::Mov>(Operand(Register::saved_return_value()), value);
emit<Bytecode::Op::Mov>(Operand(Register::exception()), add_constant(Value {}));
emit<Bytecode::Op::Mov>(Operand(Register::exception()), add_constant(js_special_empty_value()));
emit<Bytecode::Op::Jump>(Label { *m_current_basic_block->finalizer() });
return;
}