;; reftype :: anyref | funcref | exnref | nullref

;; t <: anyref for all reftypes t
;; nullref <: anyref, nullref <: funcref and nullref <: exnref

(module
  (type $sig_anyref (func (param anyref)))
  (type $sig_funcref (func (param funcref)))
  (type $sig_exnref (func (param exnref)))
  (type $sig_nullref (func (param nullref)))

  (func $take_anyref (param anyref))
  (func $take_funcref (param funcref))
  (func $take_exnref (param exnref))
  (func $take_nullref (param nullref))
  (func $foo)

  (table funcref (elem $take_anyref $take_funcref $take_exnref $take_nullref))

  (import "env" "import_func" (func $import_func (param anyref) (result funcref)))
  (import "env" "import_global" (global $import_global anyref))
  (export "export_func" (func $import_func (param anyref) (result funcref)))
  (export "export_global" (global $import_global))

  ;; Test subtype relationship in global initializer expressions
  (global $global_anyref (mut anyref) (ref.null))
  (global $global_funcref (mut funcref) (ref.null))
  (global $global_exnref (mut exnref) (ref.null))
  (global $global_nullref (mut nullref) (ref.null))
  (global $global_anyref2 (mut anyref) (ref.func $foo))
  (global $global_funcref2 (mut funcref) (ref.func $foo))

  (func $test (local $local_anyref anyref) (local $local_funcref funcref)
        (local $local_exnref exnref) (local $local_nullref nullref)
    ;; Test subtype relationship for local.set & Test types for local.get
    (local.set $local_anyref (local.get $local_anyref))
    (local.set $local_anyref (local.get $local_funcref))
    (local.set $local_anyref (local.get $local_exnref))
    (local.set $local_anyref (local.get $local_nullref))
    (local.set $local_anyref (ref.null))
    (local.set $local_anyref (ref.func $foo))
    (local.set $local_funcref (local.get $local_funcref))
    (local.set $local_funcref (ref.null))
    (local.set $local_funcref (ref.func $foo))
    (local.set $local_exnref (local.get $local_exnref))
    (local.set $local_exnref (ref.null))
    (local.set $local_nullref (local.get $local_nullref))
    (local.set $local_nullref (ref.null))

    ;; Test subtype relationship for global.set & Test types for global.get
    (global.set $global_anyref (global.get $global_anyref))
    (global.set $global_anyref (global.get $global_funcref))
    (global.set $global_anyref (global.get $global_exnref))
    (global.set $global_anyref (global.get $global_nullref))
    (global.set $global_anyref (ref.null))
    (global.set $global_anyref (ref.func $foo))
    (global.set $global_funcref (global.get $global_funcref))
    (global.set $global_funcref (ref.null))
    (global.set $global_funcref (ref.func $foo))
    (global.set $global_exnref (global.get $global_exnref))
    (global.set $global_exnref (ref.null))
    (global.set $global_nullref (global.get $global_nullref))
    (global.set $global_nullref (ref.null))

    ;; Test subtype relationship for function call / call_indirect params
    (call $take_anyref (local.get $local_anyref))
    (call $take_anyref (local.get $local_funcref))
    (call $take_anyref (local.get $local_exnref))
    (call $take_anyref (ref.null))
    (call_indirect (type $sig_anyref) (local.get $local_anyref) (i32.const 0))
    (call_indirect (type $sig_anyref) (local.get $local_funcref) (i32.const 0))
    (call_indirect (type $sig_anyref) (local.get $local_exnref) (i32.const 0))
    (call_indirect (type $sig_anyref) (ref.null) (i32.const 0))
    (call_indirect (type $sig_funcref) (local.get $local_funcref) (i32.const 1))
    (call_indirect (type $sig_funcref) (ref.null) (i32.const 1))
    (call_indirect (type $sig_exnref) (local.get $local_exnref) (i32.const 2))
    (call_indirect (type $sig_exnref) (ref.null) (i32.const 2))
    (call_indirect (type $sig_nullref) (local.get $local_nullref) (i32.const 3))
    (call_indirect (type $sig_nullref) (ref.null) (i32.const 3))

    ;; Test subtype relationship for block return type
    (drop
      (block (result anyref)
        (br_if 0 (local.get $local_anyref) (i32.const 1))
      )
    )
    (drop
      (block (result anyref)
        (br_if 0 (local.get $local_funcref) (i32.const 1))
      )
    )
    (drop
      (block (result anyref)
        (br_if 0 (local.get $local_exnref) (i32.const 1))
      )
    )
    (drop
      (block (result anyref)
        (br_if 0 (ref.null) (i32.const 1))
      )
    )
    (drop
      (block (result funcref)
        (br_if 0 (ref.null) (i32.const 1))
      )
    )
    (drop
      (block (result exnref)
        (br_if 0 (ref.null) (i32.const 1))
      )
    )
    (drop
      (block (result nullref)
        (br_if 0 (ref.null) (i32.const 1))
      )
    )

    ;; Test subtype relationship for loop return type
    (drop
      (loop (result anyref)
        (local.get $local_anyref)
      )
    )
    (drop
      (loop (result anyref)
        (local.get $local_funcref)
      )
    )
    (drop
      (loop (result anyref)
        (local.get $local_exnref)
      )
    )
    (drop
      (loop (result anyref)
        (ref.null)
      )
    )
    (drop
      (loop (result funcref)
        (local.get $local_funcref)
      )
    )
    (drop
      (loop (result funcref)
        (ref.null)
      )
    )
    (drop
      (loop (result exnref)
        (local.get $local_exnref)
      )
    )
    (drop
      (loop (result exnref)
        (ref.null)
      )
    )
    (drop
      (loop (result nullref)
        (ref.null)
      )
    )

    ;; Test subtype relationship for if return type
    (drop
      (if (result anyref)
        (i32.const 1)
        (local.get $local_anyref)
        (local.get $local_exnref)
      )
    )
    (drop
      (if (result anyref)
        (i32.const 1)
        (ref.func $foo)
        (ref.null)
      )
    )
    (drop
      (if (result funcref)
        (i32.const 1)
        (ref.func $foo)
        (ref.null)
      )
    )
    (drop
      (if (result exnref)
        (i32.const 1)
        (local.get $local_exnref)
        (ref.null)
      )
    )
    (drop
      (if (result nullref)
        (i32.const 1)
        (local.get $local_nullref)
        (ref.null)
      )
    )

    ;; Test subtype relationship for try return type
    (drop
      (try (result anyref)
        (local.get $local_anyref)
        (catch
          (exnref.pop)
        )
      )
    )
    (drop
      (try (result anyref)
        (ref.func $foo)
        (catch
          (drop (exnref.pop))
          (ref.null)
        )
      )
    )
    (drop
      (try (result funcref)
        (ref.func $foo)
        (catch
          (drop (exnref.pop))
          (ref.null)
        )
      )
    )
    (drop
      (try (result exnref)
        (ref.null)
        (catch
          (exnref.pop)
        )
      )
    )
    (drop
      (try (result nullref)
        (ref.null)
        (catch
          (drop (exnref.pop))
          (ref.null)
        )
      )
    )

    ;; Test subtype relationship for typed select
    (drop
      (select (result anyref)
        (local.get $local_anyref)
        (ref.func $foo)
        (i32.const 1)
      )
    )
    (drop
      (select (result anyref)
        (local.get $local_exnref)
        (local.get $local_anyref)
        (i32.const 1)
      )
    )
    (drop
      (select (result anyref)
        (local.get $local_anyref)
        (ref.null)
        (i32.const 1)
      )
    )
    (drop
      (select (result anyref)
        (ref.null)
        (ref.func $foo)
        (i32.const 1)
      )
    )
    (drop
      (select (result funcref)
        (ref.func $foo)
        (ref.null)
        (i32.const 1)
      )
    )
    (drop
      (select (result exnref)
        (ref.null)
        (local.get $local_exnref)
        (i32.const 1)
      )
    )
    (drop
      (select (result nullref)
        (ref.null)
        (ref.null)
        (i32.const 1)
      )
    )
    (drop
      (select (result i32)
        (i32.const 0)
        (i32.const 2)
        (i32.const 1)
      )
    )

    ;; ref.is_null takes any reference types
    (drop (ref.is_null (local.get $local_anyref)))
    (drop (ref.is_null (local.get $local_exnref)))
    (drop (ref.is_null (ref.func $foo)))
    (drop (ref.is_null (ref.null)))
  )

  ;; Test subtype relationship in function return type
  (func $return_anyref (result anyref) (local $local_anyref anyref)
    (local.get $local_anyref)
  )
  (func $return_anyref2 (result anyref)
    (ref.func $foo)
  )
  (func $return_anyref3 (result anyref) (local $local_exnref exnref)
    (local.get $local_exnref)
  )
  (func $return_anyref4 (result anyref)
    (ref.null)
  )
  (func $return_funcref (result funcref)
    (ref.func $foo)
  )
  (func $return_funcref2 (result funcref)
    (ref.null)
  )
  (func $return_exnref (result exnref) (local $local_exnref exnref)
    (local.get $local_exnref)
  )
  (func $return_exnref2 (result exnref)
    (ref.null)
  )
  (func $return_nullref (result nullref) (local $local_nullref nullref)
    (local.get $local_nullref)
  )

  ;; Test subtype relationship in returns
  (func $return_anyref_returns (result anyref) (local $local_anyref anyref)
        (local $local_exnref exnref)
    (return (local.get $local_anyref))
    (return (local.get $local_exnref))
    (return (ref.func $foo))
    (return (ref.null))
  )
  (func $return_funcref_returns (result funcref)
    (return (ref.func $foo))
    (return (ref.null))
  )
  (func $return_exnref_returns (result exnref) (local $local_exnref exnref)
    (return (local.get $local_exnref))
    (return (ref.null))
  )
  (func $return_nullref_returns (result nullref) (local $local_nullref nullref)
    (return (local.get $local_nullref))
    (return (ref.null))
  )
)